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Sample records for bed biomass gasifier

  1. Artificial neural network models for biomass gasification in fluidized bed gasifiers

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Hernández, J. Alfredo; Bruno, Joan Carles;

    2013-01-01

    Artificial neural networks (ANNs) have been applied for modeling biomass gasification process in fluidized bed reactors. Two architectures of ANNs models are presented; one for circulating fluidized bed gasifiers (CFB) and the other for bubbling fluidized bed gasifiers (BFB). Both models determin...... experimental data used R2 > 0.98. Furthermore a sensitivity analysis has been applied in each ANN model showing that all studied input variables are important....

  2. Hydrodynamic study on gasification of biomass in a fluidized bed gasifier

    OpenAIRE

    S.BASKARA SETHUPATHY; Natarajan, E.

    2012-01-01

    Current scenario of energy insecurity urges us to realize the importance of alternate energy sources. In country with variety of vegetation like India, Biomass finds its place of which fluidized bed gasification of biomass could be more effective. This paper emphasizes the importance of a fluidized bed gasifier for energy conversion of agro-residues for useful purposes. Coconut Shell and Ground nut shell of gross calorific value 19.43MJ/kg and 14.91 MJ/kg respectively are taken for the study....

  3. Performance of entrained flow and fluidised bed biomass gasifiers on different scales

    International Nuclear Information System (INIS)

    Highlights: ► Gasification of biomass in fluidised bed and entrained flow reactors is modelled. ► The systems are evaluated for a thermal input from 10 MW to 500 MW. ► Special attention is given to the preconditioning methods for biomass. ► Fluidised bed and entrained flow gasifiers are compared in terms of efficiency and costs. - Abstract: This biomass gasification process study compares the energetic and economic efficiencies of a dual fluidised bed and an oxygen-blown entrained flow gasifier from 10 MWth to 500 MWth. While fluidised bed gasification became the most applied technology for biomass in small and medium scale facilities, entrained flow gasification technology is still used exclusively for industrial scale coal gasification. Therefore, it is analysed whether and for which capacity the entrained flow technology is an energetically and economically efficient option for the thermo-chemical conversion of biomass. Special attention is given to the pre-conditioning methods for biomass to enable the application in an entrained flow gasifier. Process chains are selected for the two gasifier types and subsequently transformed to simulation models. The simulation results show that the performance of both gasifier types is similar for the production of a pressurised product gas (2.5 MPa). The cold gas efficiency of the fluidised bed is 76–79% and about 0.5–2 percentage points higher than for the entrained flow reactor. The net efficiencies of both technologies are similar and between 64% and 71% depending on scale. The auxiliary power consumption of the entrained flow reactor is caused mainly by the air separation unit, the oxygen compression, and the fuel pulverisation, whereas the fluidised bed requires additional power mainly for gas compression. The costs for the product gas are determined as between €4.2 cent/kWh (500 MWth) and €7.4 cent/kWh (10 MWth) in the economic analysis of both technologies. The study indicates that the entrained flow

  4. Three-dimensional full-loop simulation of a dual fluidized-bed biomass gasifier

    OpenAIRE

    Liu, H; Cattolica, RJ; Seiser, R.; Liao, CH

    2015-01-01

    © 2015. A three-dimensional CFD model was developed to simulate the full-loop of a dual fluidized-bed biomass gasification system consisting of a gasifier, a combustor, a cyclone separator, and a loop-seal. This full-loop simulation includes the chemical kinetic modeling of biomass drying and pyrolysis, heterogeneous char reactions, and homogeneous gas-phase reactions. In the model, the gas phase is described using Large Eddy Simulation (LES) and the particle phase is described with the Multi...

  5. Performance Analysis of an Integrated Fixed Bed Gasifier Model for Different Biomass Feedstocks

    Directory of Open Access Journals (Sweden)

    Sharmina Begum

    2013-12-01

    Full Text Available Energy recovery from biomass by gasification technology has attracted significant interest because it satisfies a key requirement of environmental sustainability by producing near zero emissions. Though it is not a new technology, studies on its integrated process simulation and analysis are limited, in particular for municipal solid waste (MSW gasification. This paper develops an integrated fixed bed gasifier model of biomass gasification using the Advanced System for Process ENngineering (Aspen Plus software for its performance analysis. A computational model was developed on the basis of Gibbs free energy minimization. The model is validated with experimental data of MSW and food waste gasification available in the literature. A reasonable agreement between measured and predicted syngas composition was found. Using the validated model, the effects of operating conditions, namely air-fuel ratio and gasifier temperature, on syngas production are studied. Performance analyses have been done for four different feedstocks, namely wood, coffee bean husks, green wastes and MSWs. The ultimate and proximate analysis data for each feedstock was used for model development. It was found that operating parameters have a significant influence on syngas composition. An air-fuel ratio of 0.3 and gasifier temperature of 700 °C provides optimum performance for a fixed bed gasifier for MSWs, wood wastes, green wastes and coffee bean husks. The developed model can be useful for gasification of other biomasses (e.g., food wastes, rice husks, poultry wastes and sugarcane bagasse to predict the syngas composition. Therefore, the study provides an integrated gasification model which can be used for different biomass feedstocks.

  6. Theoretical and experimental investigation of biomass gasification process in a fixed bed gasifier

    International Nuclear Information System (INIS)

    This investigation concerns the process of air biomass gasification in a fixed bed gasifier. Theoretical equilibrium calculations and experimental investigation of the composition of syngas were carried out and compared with findings of other researchers. The influence of excess air ratio (λ) and parameters of biomass on the composition of syngas were investigated. A theoretical model is proposed, based on the equilibrium and thermodynamic balance of the gasification zone. The experimental investigation was carried out at a setup that consists of a gasifier connected by a pipe with a water boiler fired with coal (50 kWth). Syngas obtained in the gasifier is supplied into the coal firing zone of the boiler, and co-combusted with coal. The moisture content in biomass and excess air ratio of the gasification process are crucial parameters, determining the composition of syngas. Another important parameter is the kind of applied biomass. Despite similar compositions and dimensions of the two investigated feedstocks (wood pellets and oats husk pellets), compositions of syngas obtained in the case of these fuels were different. On the basis of tests it may be stated that oats husk pellets are not a suitable fuel for the purpose of gasification.

  7. Gasification of biomass and coal in a pressurised fluidised bed gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Andries, J.; Jong, W. de; Hein, K.R.G. [Technische Univ. Delft (Netherlands)

    1998-09-01

    During a 3 year (1996-1998) multinational JOULE project, partly funded by the EU, experimental and theoretical research is being done on co-gasification of biomass (pelletised straw and Miscanthus) and coal in a pressurised fluidised bed reactor. The influence of feedstock and operating conditions on gasification characteristics has been studied using a 1.5 MW{sub th} gasifier, which has been operated at a pressure of 5 bar and temperatures up to 900 C. The project and the test rig are described and results obtained in the first part of the project are presented and analysed. (orig.)

  8. Hydrodynamic study on gasification of biomass in a fluidized bed gasifier

    Directory of Open Access Journals (Sweden)

    S.BASKARA SETHUPATHY

    2012-01-01

    Full Text Available Current scenario of energy insecurity urges us to realize the importance of alternate energy sources. In country with variety of vegetation like India, Biomass finds its place of which fluidized bed gasification of biomass could be more effective. This paper emphasizes the importance of a fluidized bed gasifier for energy conversion of agro-residues for useful purposes. Coconut Shell and Ground nut shell of gross calorific value 19.43MJ/kg and 14.91 MJ/kg respectively are taken for the study. The particle size is restricted not to exceed 3mm. Various empirical correlations involved in fluidization are studied and their interdependence is detailed. From various published data, importance of inert materials and their relative proportions with biomass fuels are studied and optimum biomass to sand ratio is fixed as 10 to 15% by mass. Equations for predicting the minimum fluidization velocities of these mixtures are also discussed. Variations of Fluidization parameters such asminimum fluidization velocity, bubble rise velocity, expanded bed height with respect to temperature, equivalence ratio, particle size is studied and their quantification is analyzed. A 108 mm internal diameter and 1400 mm high FBG is used for the study. Fuel is fed through screw feeder and air is supplied through blower. In the down stream side cyclone separator is placed after which the sampling and burner lines are connected. A regression model is developed and the feasibility of gasifying coconut shell and groundnut shell are discussed. Earlier and present work of coconut shell gasification proves fluidized bed gasification is more appropriate for agro residues.

  9. Artificial neural network modelling approach for a biomass gasification process in fixed bed gasifiers

    International Nuclear Information System (INIS)

    Highlights: • 2 Different equilibrium models are developed and their performance is analysed. • Neural network prediction models for 2 different fixed bed gasifier types are developed. • The influence of different input parameters on neural network model performance is analysed. • Methodology for neural network model development for different gasifier types is described. • Neural network models are verified for various operating conditions based on measured data. - Abstract: The number of the small and middle-scale biomass gasification combined heat and power plants as well as syngas production plants has been significantly increased in the last decade mostly due to extensive incentives. However, existing issues regarding syngas quality, process efficiency, emissions and environmental standards are preventing biomass gasification technology to become more economically viable. To encounter these issues, special attention is given to the development of mathematical models which can be used for a process analysis or plant control purposes. The presented paper analyses possibilities of neural networks to predict process parameters with high speed and accuracy. After a related literature review and measurement data analysis, different modelling approaches for the process parameter prediction that can be used for an on-line process control were developed and their performance were analysed. Neural network models showed good capability to predict biomass gasification process parameters with reasonable accuracy and speed. Measurement data for the model development, verification and performance analysis were derived from biomass gasification plant operated by Technical University Dresden

  10. Improving the performance of fluidized bed biomass/waste gasifiers for distributed electricity: A new three-stage gasification system

    International Nuclear Information System (INIS)

    Methods to increase the conversion of char and tar in fluidized bed gasifiers (FBG) are discussed, with the focus on small to medium-size biomass/waste gasifiers for power production (from 0.5 to 10 MWe). Optimization of such systems aims at (i) maximizing energy utilization of the fuel (maximizing char conversion), (ii) minimizing secondary treatment of the gas (by avoiding complex tar cleaning), and (iii) application in small biomass-to-electricity gasification plants. The efficiency of various measures to increase tar and char conversion within a gasification reactor (primary methods) is discussed. The optimization of FBG by using in-bed catalysts, by addition of steam and enriched air as gasification agent, and by secondary-air injection, although improving the process, is shown to be insufficient to attain the gas purity required for burning the gas in an engine to produce electricity. Staged gasification is identified as the only method capable of reaching the targets mentioned above with reasonable simplicity and cost, so it is ideal for power production. A promising new stage gasification process is presented. It is based on three stages: FB devolatilization, non-catalytic air/steam reforming of the gas coming from the devolatilizer, and chemical filtering of the gas and gasification of the char in a moving bed supplied with the char generated in the devolatilizer. Design considerations and comparison with one-stage FBG are discussed. - Highlights: ► Optimization of fluidized bed biomass gasifiers is reviewed. ► The effectiveness of primary measures for tar and char conversion for small/medium scale units are discussed. ► Feasible measures for adjusting operation of fluidized bed gasifiers are assessed. ► A new three-staged-fluidized-bed gasification system for biomasses and wastes is proposed.

  11. DEVELOPMENT AND EVALUATION OF A LOW-DENSITY BIOMASS FEEDING SYSTEM FOR FLUIDIZED BED GASIFIERS

    OpenAIRE

    A. E. Ghaly; A. Ergudenler; S. Alsuhaibani; V. V. Ramakrishnan

    2013-01-01

    For efficient operation of a biomass gasifier, the biomass material must be fed continuously to the system. A feeding system for chopped straw and rice husk was designed, constructed and evaluated. It consisted of: a frame, a hopper, an auger, two agitators, a drive system and a power unit. Initial testing showed that wheat straw and rice husk, being highly cohesive materials, created tunnel flow and piping conditions. This occurs when the pressure above an impending dome of material is too s...

  12. Testing of downstream catalysts for tar destruction with a guard bed in a fluidised bed biomass gasifier at pilot plant scale

    Energy Technology Data Exchange (ETDEWEB)

    Aznar, M.P.; Frances, E.; Campos, I.J.; Martin, J.A.; Gil, J. [Saragossa Univ. (Spain). Dept. of Chemistry and Environment Engineering; Corella, J. [Complutense Univ. of Madrid (Spain). Dept. of Chemical Engineering

    1996-12-31

    A new pilot plant for advanced gasification of biomass in a fast fluidised bed is now fully operative at University of Saragossa, Spain. It is a `3rd generation` pilot plant. It has been built up after having used two previous pilot plants for biomass gasification. The main characteristic of this pilot plant is that it has two catalytic reactors connected in series, downstream the biomass gasifier. Such reactors, of 4 cm i.d., are placed in a slip stream in a by-pass from the main gasifier exit gas. The gasification is made at atmospheric pressure, with flow rates of 3-50 kg/in, using steam + O{sub 2} mixtures as the gasifying agent. Several commercial Ni steam-reforming catalyst are being tested under a realistic raw gas composition. Tar eliminations or destructions higher than 99 % are easily achieved. (orig.) 2 refs.

  13. DEVELOPMENT AND EVALUATION OF A LOW-DENSITY BIOMASS FEEDING SYSTEM FOR FLUIDIZED BED GASIFIERS

    Directory of Open Access Journals (Sweden)

    A. E. Ghaly

    2013-01-01

    Full Text Available For efficient operation of a biomass gasifier, the biomass material must be fed continuously to the system. A feeding system for chopped straw and rice husk was designed, constructed and evaluated. It consisted of: a frame, a hopper, an auger, two agitators, a drive system and a power unit. Initial testing showed that wheat straw and rice husk, being highly cohesive materials, created tunnel flow and piping conditions. This occurs when the pressure above an impending dome of material is too small resulting in the creation of a stable dome and blockage of the discharge. In order to achieve good flow conditions, it was concluded that the hopper must operate under "mass outflow" and the material should not be allowed to build up along the flow channels. These objectives were achieved by the proper redesign of the hopper configuration, the installation of agitators in the hopper and use of an auger in the outlet duct leading into the gasifier. However, as the augur was used to move the biomass material from hopper to the gasifier, it was observed that hot gases leaked from the gasifier into the hopper and heat was also transmitted from the gasifier to the hopper though the augur shaft by conduction resulting in burning of biomass material in the hopper. Therefore, the augur shaft was fitted with copper tubing to serve as a water cooling system and the tapered section of the augur was fitted with a stainless steel section with water inlet and outlet to serve as a secondary cooling system. After, the system has been successfully modified for feeding wheat straw and rice husk, it was tested to determine the optimum operating conditions. Mass flow tests were performed with four sprocket combinations and four auger speeds. Increasing the auger speed and/or the lower agitator speed increased the straw output of the feeding system. However, increases in the upper agitator speed resulted in reduced mass flow of the material due to the mixing effect created

  14. Analysis of Operation Parameters in a Dual Fluidized Bed Biomass Gasifier Integrated with a Biomass Rotary Dryer: Development and Application of a System Model

    Directory of Open Access Journals (Sweden)

    Nargess Puadian

    2014-07-01

    Full Text Available An integrated system model was developed in UniSim Design for a dual fluidized bed (DFB biomass gasifier and a rotary biomass dryer using a combination of user-defined and built-in unit operations. A quasi-equilibrium model was used for modelling biomass steam gasification in the DFB gasifier. The biomass drying was simulated with consideration of mass and energy balances, heat transfer, and dryer’s configuration. After validation using experimental data, the developed system model was applied to investigate: (1 the effects of gasification temperature and steam to biomass (S/B ratio on the gasification performance; (2 the effect of air supplied to the fast fluidized bed (FFB reactor and feed biomass moisture content on the integrated system performance, energy and exergy efficiencies. It was found that gasification temperature and S/B ratio have positive effects on the gasification yields; a H2/CO ratio of 1.9 can be achieved at the gasification temperature of 850 °C with a S/B ratio of 1.2. Consumption of excessive fuel in the system at higher biomass feed moisture content can be compensated by the heat recovery such as steam generation while it has adverse impact on exergy efficiency of the system.

  15. Co-gasification of biomass and coal in a pressurised fluidised bed gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Andries, L.; Hein, K.R.G. [Lab. for Thermal Power Engineering, Dept. of Mechanical Engineering and Marine Technology, Delft Univ. of Technology (Netherlands)

    1996-12-31

    The Laboratory for Thermal Power Engineering of the Delft University of Technology is participating in an EU funded, international, R + D project which is designed to aid European industry in addressing issues regarding co-utilisation of biomass and/or waste in advanced coal conversion processes. The project comprises three main programmes, each of which includes a number of smaller subprogrammes. The three main programmes are: Coal-biomass systems component development and design; Coal-biomass environmental studies; Techno-economic assessment studies. (orig)

  16. Biomass gasification: the understanding of sulfur, tar, and char reaction in fluidized bed gasifiers

    OpenAIRE

    Meng, X.

    2012-01-01

    As one of the currently available thermo-chemical conversion technologies, biomass gasification has received considerable interest since it increases options for combining with various power generation systems. The product gas or syngas produced from biomass gasification is environmental friendly alternatives to conventional petrochemical fuels for the production of electricity, hydrogen, synthetic transportation biofuels and other chemicals. The product gas normally contains the major compon...

  17. Biomass Gasifier for Computer Simulation; Biomassa foergasare foer Computer Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hansson, Jens; Leveau, Andreas; Hulteberg, Christian [Nordlight AB, Limhamn (Sweden)

    2011-08-15

    This report is an effort to summarize the existing data on biomass gasifiers as the authors have taken part in various projects aiming at computer simulations of systems that include biomass gasification. Reliable input data is paramount for any computer simulation, but so far there is no easy-accessible biomass gasifier database available for this purpose. This study aims at benchmarking current and past gasifier systems in order to create a comprehensive database for computer simulation purposes. The result of the investigation is presented in a Microsoft Excel sheet, so that the user easily can implement the data in their specific model. In addition to provide simulation data, the technology is described briefly for every studied gasifier system. The primary pieces of information that are sought for are temperatures, pressures, stream compositions and energy consumption. At present the resulting database contains 17 gasifiers, with one or more gasifier within the different gasification technology types normally discussed in this context: 1. Fixed bed 2. Fluidised bed 3. Entrained flow. It also contains gasifiers in the range from 100 kW to 120 MW, with several gasifiers in between these two values. Finally, there are gasifiers representing both direct and indirect heating. This allows for a more qualified and better available choice of starting data sets for simulations. In addition to this, with multiple data sets available for several of the operating modes, sensitivity analysis of various inputs will improve simulations performed. However, there have been fewer answers to the survey than expected/hoped for, which could have improved the database further. However, the use of online sources and other public information has to some extent counterbalanced the low response frequency of the survey. In addition to that, the database is preferred to be a living document, continuously updated with new gasifiers and improved information on existing gasifiers.

  18. Particle Distribution in a Fixed Bed Down Draft Wood Gasifier

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    2005-01-01

    Char particle samples were collected from six distances above the grate in a fixed bed of a down draft biomass gasifier. Each sample was separated into twelve size fractions by screening through standard sieves in order to determine the local particle size distribution. The ash contents of each...... particle fraction was determined. The measured ash content in the larger particles was nearly constant throughout the bed, while ash accumulated in particle sizes around 1 mm near the bottom....

  19. Simulation of the biomass updraft gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Teislev, B.

    2006-07-15

    A consistent (steady state, one-dimensional) mathematical model for a biomass updraft gasifier has been developed based on mass- and energy balances and assuming ideal mixtures of gases and solids. The gases considered are 0{sub 2}, N{sub 2}, H{sub 2}O, CO{sub 2}, H{sub 2}, CO, CH{sub 4} and TAR and the solids are Ash, Carbon, dry Wood and HzO moisture and described by their partial densities in the gasifier bed, together with their axial velocities and temperature. The processes considered are Carbon Oxidation, H{sub 2}0 and CO{sub 2} reduction, the Water Gas Shift process, dry Wood Pyrolysis and Moist Biomass Drying and are described by their temperature and concentration dependant reaction rates. The same mathematical formulation is used throughout the reactor and the methodology used is to solve the resulting 16 partial and algebraic equations (with 16 variables, 8 gaseous partial densities, 4 solids partial densities, 2 velocities and 2 temperatures) in a Newton-Raphson approach using variable length of the integration step. The transition through oxidation and reduction and the passage through the drying zone has been preliminary verified to be in accordance with experimental evidence, but the software developed has not yet been able to describe the transition to pyrolysis and drying and therefore, the final product gas composition from the updraft gasifier has not been verified (apart from verification using a zero-dimensional model). For use in further work an Addendum describing the approach in the form of a 'pseudo code' (including several comments for readers not conversant with the programming language used in the present work - Visual Basic) is included. (au)

  20. Simulation of the biomass updraft gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Teislev, B.

    2006-07-15

    A consistent (steady state, one-dimensional) mathematical model for a biomass updraft gasifier has been developed based on mass- and energy balances and assuming ideal mixtures of gases and solids. The gases considered are 0{sub 2}, N{sub 2}, H{sub 2}0, CO{sub 2}, H{sub 2}, CO, CH{sub 4} and TAR and the solids are Ash, Carbon, dry Wood and H{sub 2}O moisture and described by their partial densities in the gasifier bed - together with their axial velocities and temperature. The processes considered are Carbon Oxidation, H{sub 2}0 and CO{sub 2} reduction, the Water Gas Shift process, dry Wood Pyrolysis and Moist Biomass Drying and are described by their temperature and concentration dependant reaction rates. The same mathematical formulation is used throughout the reactor and the methodology used is to solve the resulting 16 partial and algebraic equations (with 16 variables - 8 gaseous partial densities, 4 solids partial densities, 2 velocities and 2 temperatures) in a Newton-Raphson approach using variable length of the integration step. The transition through oxidation and reduction and the passage through the drying zone has been preliminary verified to be in accordance with experimental evidence, but the software developed has not yet been able to describe the transition to pyrolysis and drying and therefore, the final product gas composition from the updraft gasifier has not been verified (apart from verification using a zero-dimensional model). For use in further work an Addendum describing the approach in the form of a 'pseudo code' (including several comments for readers not conversant with the programming language used in the present work - Visual Basic) is included. (au)

  1. Handbook of biomass downdraft gasifier engine systems

    Energy Technology Data Exchange (ETDEWEB)

    Reed, T B; Das, A

    1988-03-01

    This handbook has been prepared by the Solar Energy Research Institute under the US Department of Energy /bold Solar Technical Information Program/. It is intended as a guide to the design, testing, operation, and manufacture of small-scale (less than 200 kW (270 hp)) gasifiers. A great deal of the information will be useful for all levels of biomass gasification. The handbook is meant to be a practical guide to gasifier systems, and a minimum amount of space is devoted to questions of more theoretical interest.

  2. Biomass-Derived Hydrogen from a Thermally Ballasted Gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Robert C

    2007-04-06

    The goal of this project is to develop an indirectly heated gasification system that converts switchgrass into hydrogen-rich gas suitable for powering fuel cells. The project includes investigations of the indirectly-heated gasifier, development of particulate removal equipment, evaluation of catalytic methods for upgrading producer gas, development of contaminant measurement and control techniques, modeling of the thermal performance of the ballasted gasifier, and estimation of the cost of hydrogen from the proposed gasification system. Specific technologies investigated include a thermally ballasted gasifier, a moving bed granular filter, and catalytic reactors for steam reforming and water-gas shift reaction. The approach to this project was to employ a pilot-scale (5 ton per day) gasifier to evaluate the thermally ballasted gasifier as a means for producing hydrogen from switchgrass. A slipstream from the gasifier was used to evaluate gas cleaning and upgrading options. Other tests were conducted with laboratory-scale equipment using simulated producer gas. The ballasted gasifier operated in conjunction with a steam reformer and two-stage water-gas shift reactor produced gas streams containing 54.5 vol-% H2. If purge gas to the feeder system could be substantially eliminated, hydrogen concentration would reach 61 vol-%, which closely approaches the theoretical maximum of 66 vol-%. Tests with a combined catalyst/sorbent system demonstrated that steam reforming and water-gas shift reaction could be substantially performed in a single reactor and achieve hydrogen concentrations exceeding 90 vol-%. Cold flow trials with a laboratory-scale moving bed granular filter achieved particle removal efficiencies exceeding 99%. Two metal-based sorbents were tested for their ability to remove H2S from biomass-derived producer gas. The ZnO sorbent, tested at 450° C, was effective in reducing H2S from 200 ppm to less than 2 ppm (>99% reduction) while tests with the MnO sorbent

  3. Potentials of Selected Malaysian Biomasses as Co-Gasification Fuels with Oil Palm Fronds in a Fixed-Bed Downdraft Gasifier

    Directory of Open Access Journals (Sweden)

    Moni Mohamad Nazmi Zaidi

    2014-07-01

    Full Text Available Oil palm frond (OPF has been successfully gasified to produce syngas and has since deemed as a potential source of biomass fuel in Malaysia. However, if OPF is to be utilized as a main fuel for industrial-scale firing/gasification plant, interruption in fuel supply may occur due to numerous reasons, for instance inefficient fuel processing and ineffective transportation. A secondary supporting solid fuel is therefore necessary as a partial component to the main fuel in such cases, where the secondary fuel is combusted with the main fuel to adhere to main fuel shortage. Gasification of two fuels together, known as co-gasification, is practiced worldwide, some in industrial scale. However, current practice utilizes biomass fuel as the secondary fuel to coal in co-gasification. This investigation explores into the feasibility of co-gasifying two biomass fuels together to produce syngas. OPF was chosen as the primary fuel and a selection of Malaysian biomasses were studied to discover their compatibility with OPF in co-gasification. Biomass selection was made using score-and-rank method and their selection criteria are concisely discussed.

  4. The Effect of Air Preheating in a Biomass CFB Gasifier using ASPEN Plus Simulation

    OpenAIRE

    Doherty, Wayne; Reynolds, Anthony; Kennedy, David

    2009-01-01

    In the context of climate change, increasing efficiency and energy security, biomass gasification is likely to play an important role in energy production. Atmospheric circulating fluidised bed (CFB) technology was selected for the current study. The primary objective of this research is to develop a computer simulation model of a CFB biomass gasifier that can accurately predict gasifier performance under various operating conditions. An original model was developed using ASPEN Plus (Advan...

  5. A downdraft high temperature steam-only solar gasifier of biomass char: A modelling study

    International Nuclear Information System (INIS)

    A numerical model of a solar downdraft gasifier of biomass char (biochar) with steam based on the systems kinetics is developed. The model calculates the dynamic and steady state profiles, predicting the temperature and concentration profiles of gas and solid phases, based on the mass and heat balances. The Rosseland equation is used to calculate the radiative transfer within the bed. The char reactivity factor (CFR) is taken into account with an exponential variation. The bed heating dynamics as well as the steam velocity effects are tested. The model results are compared with different experimental results from a solar packed bed gasifier, and the temperature profile is compared to an experimental downdraft gasifier. Hydrogen is the principal product followed by carbon monoxide, the carbon dioxide production is small and the methane production is negligible, indicating a high quality syngas production. By applying the temperature gradient theory in the steam-only gasification process for a solar gasifier design, a solar downdraft gasifier improves the energy conversion efficiency by over 20% when compared to a solar packed bed gasifier. The model predictions are in good agreement with the experimental results found in the literature. -- Highlights: → The solar downdraft gasifier set-up improve the solar updraft gasifier performance. → The temperature gradient theory is introduced. → A high quality syngas produced, the hydrogen is the principal component. → An exponential CFR variation is adjusted to the heat transfer in the bed.

  6. Fixed bed gasification of solid biomass fuels

    Energy Technology Data Exchange (ETDEWEB)

    Haavisto, I. [Condens Oy, Haemeenlinna (Finland)

    1996-12-31

    Fixed bed biomass gasifiers are feasible in the effect range of 100 kW -10 MW. Co-current gasification is available only up to 1 MW for technical reasons. Counter-current gasifiers have been used in Finland and Sweden for 10 years in gasification heating plants, which are a combination of a gasifier and an oil boiler. The plants have proved to have a wide control range, flexible and uncomplicated unmanned operation and an excellent reliability. Counter-current gasifiers can be applied for new heating plants or for converting existing oil and natural gas boilers into using solid fuels. There is a new process development underway, aiming at motor use of the producer gas. The development work involves a new, more flexible cocurrent gasifier and a cleaning step for the counter-current producer gas. (orig.)

  7. Biomass Power Generation through Direct Integration of Updraft Gasifier and Stirling Engine Combustion System

    OpenAIRE

    Jai-Houng Leu

    2010-01-01

    Biomass is the largest renewable energy source in the world. Its importance grows gradually in the future energy market. Since most biomass sources are low in energy density and are widespread in space, small-scale biomass conversion system is therefore more competitive than a large stand-alone conversion plant. The current study proposes a small-scale solid biomass power system to explore the viability of direct coupling of an updraft fixed bed gasifier with a Stirling engine. The modified u...

  8. Bubbling fluidised bed gasification of wheat straw-gasifier performance using mullite as bed material

    OpenAIRE

    Mac an Bhaird, Seán T.; Hemmingway, Phil; Walsh, Eilín; McDonnell, Kevin; et al.

    2015-01-01

    The adoption of wheat straw as a fuel for gasification processes has been hindered due to a lack of experience and its propensity to cause bed agglomeration in fluidised bed gasifiers. In this study wheat straw was gasified in a small scale, air blown bubbling fluidised bed using mullite as bed material. The gasifier was successfully operated and isothermal bed conditions maintained at temperatures up to 750 ◦C. Below this temperature, the gasifier was operated at equivalence ratios from 0.1 ...

  9. Energetic, ecologic and fluid-dynamic analysis of a fluidized bed gasifier operating with sugar cane bagasse

    International Nuclear Information System (INIS)

    This work aims to study the thermodynamic, ecological and fluid-dynamic aspects of a circulating fluidized bed gasifier using sugar cane bagasse as biomass, in order to estimate a model of its normal operation. In the initial stage was analysed the composition of biomass selected (sugar cane bagasse) and its lower heating value (LHV) was calculated. The energy balance of the gasifier was done, being the volumetric flow of air, synthesis gas and biomass estimated. Also the power produced by this gasifier was theoretically estimated. Then the circulating fluidized bed gasifier was designed for operation with approximately 100 kg/h of processed biomass. Cross-sectional area of the reactor, feeder size, diameter of the exit zone of the gases and minimum height of the expanded bed were selected. Some bed gasifier hydrodynamic factors were also studied. The minimum fluidization velocity, fluidization terminal velocity, and average fluidizing velocity were calculated, in order to understand the fluid-dynamic behaviour of gasification of this fuel. It was obtained a theoretical model that can support a possible prototype of circulating fluidized bed gasifier biomass. Finally, there were studied the ecological aspects of the gasifier, through an overall methodology. Ecological efficiencies were estimated for two scenarios: first considering the carbon cycle and thereafter disregarding the carbon cycle. In both cases, it can be proved the ecological viability of the project. -- Highlights: • we develop a methodology to size a fluidized bed gasifier. • we validate this methodology comparing to a fixed bed gasifier values. • we aggregate ecological efficiency to this methodology

  10. CFD modelling of an open core downdraft moving bed biomass gasifier; Modelado de un gasificador estratificado de lecho movil de biomasa, utilizando CFD

    Energy Technology Data Exchange (ETDEWEB)

    Rogel-Ramirez, A [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: ARogelR@iingen.unam.mx

    2008-10-15

    This paper contains the description of a bidimensional Computational Fluid Dynamics (CFD), model Developer to simulate the flow and reaction in a stratified downdraft biomass gasifier, whereby Eulerian conservation equations are solved for particle and gas phase components, velocities and specific enthalpies. The model is based on the PHOENICS package and represents a tool which can be used in gasifier analysis and design. Contributions of chemical kinetics and the mixing rate using the EBU approach are considered in the gas phase global homogeneous reactions. The harmonic blending of chemical kinetics and mass transfer effects, determine the global heterogeneous reactions between char and O{sub 2}, CO{sub 2} and H{sub 2}O. The turbulence effect in the gas phase is accounted by the standard {kappa}-{epsilon} approach. The model provides information of the producer gas composition, velocities and temperature at the outlet, and allows different operating parameters and feed properties to be changed. Finally, a comparison with experimental data available in literature was done, which showed satisfactory agreement from a qualitative point of view, though further validation is required. [Spanish] Este estudio describe un modelo numerico bidimensional, basado en Dinamica de Fluidos Computacional (CFD), desarrollado para simular el flujo y las reacciones que ocurren en un gasificador estratificado de flujos paralelos, en el que se resuelven ecuaciones de conservacion Eulerianas para los componentes de la fase gaseosa, la fase solida, velocidades y entalpias especificas. El modelo esta basado en el codigo PHOENICS y representa una herramienta que puede ser utilizada en el analisis y diseno de gasificadores. En las reacciones globales homogeneas se consideran las contribuciones de la cinetica quimica y la rapidez de mezclado, usando el modelo Eddy Brake-UP (EBU). La medida harmonica de la cinetica quimica y la transferencia de masa, determinan las velocidades globales de

  11. Improved Gasifier Availability with Bed Material and Additives

    Energy Technology Data Exchange (ETDEWEB)

    Grootjes, A.J.; Van der Meijden, C.M.; Visser, H.J.M.; Van der Drift, A. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2013-07-15

    In order to valorize several feedstock, gasification is one of the technologies developed over the past decades. ECN developed the MILENA gasifier. In order for MILENA to become a commercial success, the gasifier needs to be feedstock flexible, robust and economically sound, operating with high availability. One of the characteristics of MILENA is high efficiency but with a higher tar content, compared to some other Dual Fluidized Bed (DFB) gasifiers. In order to reduce the issues that are associated with high tar levels in the product gas, the effect of a number of primary measures was studied. This paper presents results obtained in the last two years, focused on improving the gasifier availability by conducting experiments in a 25 kWth lab scale MILENA gasifier. Amongst others, gas composition, tar content and calorific value of the product gas were compared. Scanning Electron Microscope analysis was used to investigate bed material changes. Results show that Austrian olivine can be activated by Fuel B as well as by Additive A and B. The water-gas shift reaction is enhanced and the tar content is reduced significantly, especially the heavy tars that dominate the tar dew point. Activated olivine has a calcium-rich layer. The results show that with MILENA, we are able to lower and control the tar dew point, which will possibly increase the availability of a MILENA gasifier.

  12. Scaling up biomass gasifier use: an application-specific approach

    International Nuclear Information System (INIS)

    Biomass energy accounts for about 11% of the global primary energy supply, and it is estimated that about 2 billion people worldwide depend on biomass for their energy needs. Yet, most of the use of biomass is in a primitive and inefficient manner, primarily in developing countries, leading to a host of adverse implications on human health, environment, workplace conditions, and social well being. Therefore, the utilization of biomass in a clean and efficient manner to deliver modern energy services to the world's poor remains an imperative for the development community. One possible approach to do this is through the use of biomass gasifiers. Although significant efforts have been directed towards developing and deploying biomass gasifiers in many countries, scaling up their dissemination remains an elusive goal. Based on an examination of biomass gasifier development, demonstration, and deployment efforts in India-a country with more than two decades of experiences in biomass gasifier development and dissemination, this article identifies a number of barriers that have hindered widespread deployment of biomass gasifier-based energy systems. It also suggests a possible approach for moving forward, which involves a focus on specific application areas that satisfy a set of criteria that are critical to deployment of biomass gasifiers, and then tailoring the scaling up strategy to the characteristics of the user groups for that application. Our technical, financial, economic and institutional analysis suggests an initial focus on four categories of applications-small and medium enterprises, the informal sector, biomass-processing industries, and some rural areas-may be particularly feasible and fruitful

  13. Down-flow moving-bed gasifier with catalyst recycle

    Science.gov (United States)

    Halow, John S.

    1999-01-01

    The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction.

  14. Engineering analysis of biomass gasifier product gas cleaning technology

    Energy Technology Data Exchange (ETDEWEB)

    Baker, E.G.; Brown, M.D.; Moore, R.H.; Mudge, L.K.; Elliott, D.C.

    1986-08-01

    For biomass gasification to make a significant contribution to the energy picture in the next decade, emphasis must be placed on the generation of clean, pollutant-free gas products. This reports attempts to quantify levels of particulated, tars, oils, and various other pollutants generated by biomass gasifiers of all types. End uses for biomass gases and appropriate gas cleaning technologies are examined. Complete systems analysis is used to predit the performance of various gasifier/gas cleanup/end use combinations. Further research needs are identified. 128 refs., 20 figs., 19 tabs.

  15. Air Gasification of Agricultural Waste in a Fluidized Bed Gasifier: Hydrogen Production Performance

    OpenAIRE

    A. B. Alias; Reza Alipour Moghadam; M. A. Mohd Salleh; W. A. Wan Ab Karim Ghani

    2009-01-01

    Recently, hydrogen production from biomass has become an attractive technology for power generation. The main objective pursued in this work is to investigate the hydrogen production potential from agricultural wastes (coconut coir and palm kernel shell) by applying the air gasification technique. An experimental study was conducted using a bench-scale fluidized bed gasifier with 60 mm diameter and 425 mm height. During the experiments, the fuel properties and the effects of operating paramet...

  16. Mathematical model of processes of reactor with gasified fluidized bed

    International Nuclear Information System (INIS)

    An original scheme of steam generator with gasifying fluidized bed has been presented as a possible solution for reconstruction of furnace with pulverized burning of coal. The method is effective when applied in combination with desulfurization for the purpose of reducing the CO2 emissions level. A mathematical model has been developed, which determines the correlation primary (fluidizing) and (burning out) secondary air with sufficient for the practice accuracy

  17. Comparison of mass and energy balances for air blown and thermally ballasted fluidized bed gasifiers

    International Nuclear Information System (INIS)

    The objective of this study was to compare the mass and energy balances for a conventional air blown fluidized bed gasifier and a ballasted fluidized bed gasifier developed at Iowa State University. The ballasted gasifier is an indirectly heated gasifier that uses a single reactor for both combustion and pyrolysis. Heat accumulated in high-temperature phase change material during the combustion phase is released during the pyrolysis phase to generate producer gas. Gas composition, tar and char contents, cold gas efficiency, carbon conversion, and hydrogen yield per unit biomass input were determined as part of these evaluation. During the pyrolysis phase of ballasted gasification, higher volumetric concentrations of hydrogen and methane were obtained than during air blown gasification. Hydrogen yield for ballasted gasification was 14 g kg−1 of biomass, which was about 20% higher than that obtained during air blown gasification. The higher heating value of the producer gas also reached higher levels during the ballasted pyrolysis phase than that of air blown gasification. Heating value for air blown gasification was 5.2 MJ m−3 whereas the heating value for the ballasted pyrolysis phase averaged 5.5 MJ m−3, reaching a maximum of 8.0 MJ m−3. The ballasted gasifier was expected to yield producer gas with average heating value as high as 15 MJ m−3 but excessive use of nitrogen to purge and cool the fuel feeder system greatly diluted the producer gas. Relatively simple redesign of the feeder system would greatly reduce the use of purge gas and may increase the heating values to about 17.5 MJ m−3. Higher char production per kilogram of biomass was associated with the ballasted system, producing 140 g kg−1 of biomass compared to only 53 g kg−1 of biomass during air blown gasification. On the other hand, tar concentrations in the producer gas were 6.0 g m−3 for ballasted gasification compared to 11.7 g m−3 for air blown gasification. On balance, carbon

  18. Characterization of Inorganic Elements in Woody Biomass Bottom Ash from a Fixed-bed Combustion System, a Downdraft Gasifier and a Wood Pellet Burner by Fractionation

    OpenAIRE

    Adrian K. James; Steve S. Helle; Thring, Ronald W.; Gurkaran S. Sarohia; P. Michael Rutherford

    2014-01-01

    The direct combustion of biomass residues produces large quantities of bottom ash. Environmental sustainable management requires that ash recycling should be carried out whenever possible. Suitable applications of bottom ash are based predominantly on its chemical properties. The presence of major ash forming and trace elements along with other intrinsic properties unique to bottom ash, suggest its potential as a soil additive. But, ash quality must be of a high standard to prevent environmen...

  19. Comparison of pulp-mill-integrated hydrogen production from gasified black liquor with stand-alone production from gasified biomass

    International Nuclear Information System (INIS)

    When gasified black liquor is used for hydrogen production, significant amounts of biomass must be imported. This paper compares two alternative options for producing hydrogen from biomass: (A) pulp-mill-integrated hydrogen production from gasified back liquor; and (B) stand-alone production of hydrogen from gasified biomass. The comparison assumes that the same amount of biomass that is imported in Alternative A is supplied to a stand-alone hydrogen production plant and that the gasified black liquor in Alternative B is used in a black liquor gasification combined cycle (BLGCC) CHP unit. The comparison is based upon equal amounts of black liquor fed to the gasifier, and identical steam and power requirements for the pulp mill. The two systems are compared on the basis of total CO2 emission consequences, based upon different assumptions for the reference energy system that reflect different societal CO2 emissions reduction target levels. Ambitions targets are expected to lead to a more CO2-lean reference energy system, in which case hydrogen production from gasified black liquor (Alternative A) is best from a CO2 emissions' perspective, whereas with high CO2 emissions associated with electricity production, hydrogen from gasified biomass and electricity from gasified black liquor (Alternative B) is preferable. (author)

  20. Modeling biomass gasification in circulating fluidized beds

    Science.gov (United States)

    Miao, Qi

    In this thesis, the modeling of biomass gasification in circulating fluidized beds was studied. The hydrodynamics of a circulating fluidized bed operating on biomass particles were first investigated, both experimentally and numerically. Then a comprehensive mathematical model was presented to predict the overall performance of a 1.2 MWe biomass gasification and power generation plant. A sensitivity analysis was conducted to test its response to several gasifier operating conditions. The model was validated using the experimental results obtained from the plant and two other circulating fluidized bed biomass gasifiers (CFBBGs). Finally, an ASPEN PLUS simulation model of biomass gasification was presented based on minimization of the Gibbs free energy of the reaction system at chemical equilibrium. Hydrodynamics plays a crucial role in defining the performance of gas-solid circulating fluidized beds (CFBs). A 2-dimensional mathematical model was developed considering the hydrodynamic behavior of CFB gasifiers. In the modeling, the CFB riser was divided into two regions: a dense region at the bottom and a dilute region at the top of the riser. Kunii and Levenspiel (1991)'s model was adopted to express the vertical solids distribution with some other assumptions. Radial distributions of bed voidage were taken into account in the upper zone by using Zhang et al. (1991)'s correlation. For model validation purposes, a cold model CFB was employed, in which sawdust was transported with air as the fluidizing agent. A comprehensive mathematical model was developed to predict the overall performance of a 1.2 MWe biomass gasification and power generation demonstration plant in China. Hydrodynamics as well as chemical reaction kinetics were considered. The fluidized bed riser was divided into two distinct sections: (a) a dense region at the bottom of the bed where biomass undergoes mainly heterogeneous reactions and (b) a dilute region at the top where most of homogeneous

  1. Alkali retention/separation during bagasse gasification: a comparison between a fluidised bed and a cyclone gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Gabra, M. [Lulea University of Technology (Sweden). Div. of Energy Engineering; Energy Technology Centre, Pitea (Sweden); Nordin, A. [Umea University (Sweden). Dept. of Inorganic Chemistry; Ohman, M. [Energy Technology Centre, Pitea (Sweden); Umea University (Sweden). Dept. of Inorganic Chemistry; Kjellstrom, B. [Lulea University of Technology (Sweden). Div. of Energy Engineering

    2001-12-01

    Biomass fuelled integrated gasification/gas turbines (BIG/GTS) have been found to be one of the most promising technologies to maximise electricity output in the sugar industry. However, biomass fuels contain alkali metals (Na and K) which may be released during the gasification processes and cause deleterious effects on the downstream hardware (e.g. the blades of gas turbines). Much research has therefore been focused on different kinds of gas cleaning. Most of these projects are using a fluidised bed gasifier and includes extensive gas cleaning which leads to a high capital investment. Increasing alkali retention/separation during the gasification may lead to improved producer gas quality and reduced costs for gas cleaning. However, very little quantitative information is available about the actual potential of this effect. In the present work, comparative bench-scale tests of bagasse gasification were therefore run in an isothermal fluidised bed gasifier and in a cyclone gasifier to evaluate which gasification process is most attractive as regards alkali retention/separation, and to try to elucidate the mechanisms responsible for the retention. The alkali retention in the fluidised bed gasifier was found to be in the range of 12-4% whereas in the cyclone gasifier the alkali separation was found to be about 70%. No significant coating of the fluidised bed's bed material particles could be observed. The SEM/EDS and the elemental maps of the bed material show that a non-sticky ash matrix consisting of mainly Si, AI and K were distributed in a solid form separated from the particles of bed material. This indicates the formation of a high temperature melting potassium containing silicate phase, which is continuously scavenged and lost from the bed through elutriation. (author)

  2. Study tour to biomass gasifiers in Germany

    International Nuclear Information System (INIS)

    A study trip to a biomass gasification plant in Germany took place from 13-15 November 2000. The goal of the trip was to obtain information on German developments, experience, and possibilities in the field of biomass gasification. The participants were representatives of Dutch parties in the energy sector: waste sector, manufacturers, producers, policy makers and consultants. The most important feature was the visit to plants that were in operation. Due in particular to the new EEG (Emeuerbare-Energien-Gesetz/Renewable Energy) legislation, German policy makers have created an initial market for sustainable energy with a degree of success. The key feature is that EEG makes projects 'bankable' by guaranteeing a return delivery compensation. An EEG-type scheme designed to accelerate the development of sustainable energy could be an interesting instrument also for the Netherlands. The plan was to visit four plants and have a number of presentations in a period of three days. Preference was for relatively new plants with differing concepts. The following plants were visited and/or presented: 200-kWe CHP wood gasification plant, based on AHT technology, located at Domsland in Eckenfoerde; a 10,000 tonnes/year wood gasification plant, based on 'cupola furnace' technology of blast furnaces, located at Holzhausen near Leipzig; a 1-MWe wood gasification plant, based on Carbo-V technology, located at Freiberg; and finally a 23-MWe CBP wood gasification plant, also based on Juch technology, located at Siebenlehn. In clearly appears that Germany is ahead of the Netherlands in the realisation of gasification plants. Still, there are certain problems with the reliability of operation. The plants selected were relatively new (with the possible exception of Espenhain) and they are having too many teething problems. Sound insight has been obtained into the various concepts of decentralised energy generation from biomass and how this can be fitted into the existing infrastructure

  3. The study of solid circulation rate in a compartmented fluidized bed gasifier (CFBG)

    Science.gov (United States)

    Wee, S. K.; Pok, Y. W.; Law, M. C.; Lee, V. C. C.

    2016-06-01

    Biomass waste has been abundantly available in Malaysia since the booming of palm oil industry. In order to tackle this issue, gasification is seen a promising technology to convert waste into energy. In view of the heat requirement for endothermic gasification reaction as well as the complex design and operation of multiple fluidized beds, compartmented fluidized bed gasifier (CFBG) with the combustor and the gasifier as separate compartments is proposed. As such, solid circulation rate (SCR) is one of the essential parameters for steady gasification and combustion to be realized in their respective compartments. Experimental and numerical studies (CFD) on the effect of static bed height, main bed aeration, riser aeration and v-valve aeration on SCR have been conducted in a cold- flow CFBG model with only river sand as the fluidizing medium. At lower operating range, the numerical simulations under-predict the SCR as compared to that of the experimental results. Also, it predicts slightly different trends over the range. On the other hand, at higher operating range, the numerical simulations are able to capture those trends as observed in the experimental results at the lower operating range. Overall, the numerical results compare reasonably well with that of the experimental works.

  4. Modeling particle population balances in fluidized-bed wood gasifiers

    International Nuclear Information System (INIS)

    An unsteady model is developed for the particle size distribution in fluidized-bed reactors including fragmentation, abrasion, elutriation and the chemical reactions of wood gasification. Based on the assumption of constant conditions (gas composition, temperature, velocity) of the surrounding atmosphere, an analytical solution is developed for the distribution of sizes belonging to the classes of mother and fine particles. It is found that for the typical feed sizes (minimum above 3 × 10−2 mm) and the usual maximum size of fine particles (2.4 × 10−3 mm), the behavior of fine particles is quasi-steady with respect to mother particles. The numerical solution of the quasi-steady formulation of particle population balances is also coupled with a two-phase (bubble and emulsion), three-zone (bed, splash zone and freeboard) model for a bubbling fluidized-bed reactor, giving predictions of the producer gas composition in agreement with measurements for air gasification of wood. - Highlights: • Particle size distribution in fluidized-bed gasifiers is modeled. • Fragmentation, abrasion, elutriation and the chemical reactions of wood gasification are described. • A quasi-steady behavior of the fine particles with respect to mother particles is found. • The particle size distribution model is coupled with a transport model for a bubbling fluidized bed. • Good agreement is obtained between measurements and predictions for highly variable operating conditions

  5. Characterization and treatment of tars and biomass gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Baker, E.G.; Brown, M.D.; Elliott, D.C.; Mudge, L.K.

    1988-08-01

    Biomass gasification and pyrolysis have the potential to make a significant impact on energy supplies in the United States and have demonstrated their commercial potential in many projects around the country. The environmental aspects of biomass gasification need to be defined to assure that the technology makes its maximum impact on energy supplies. One area that needs further development is characterization and treatment of the tar byproduct from gasifiers and pyrolyzers. This paper examines the effect of the type of gasifier/pyrolyzer and the processing conditions on the yield and properties of tars and condensates. End use limitations for tars are discussed. Wet scrubbing is the most common method of tar removal from gases. The scrub liquor will require treatment to remove organics before it can be disposed. Pacific Northwest Laboratory (PNL) is developing a catalytic tar destruction process that will treat the hot, raw gas from the gasifier and convert the tars to gas. The process increases the gas yield and cold gas efficiency of the gasification process, produces a clean gas that can be used for many applications, and produces a clean condensate that can be disposed with minimal treatment. 10 refs., 2 figs., 1 tab.

  6. Method for online measurement of the CHON composition of raw gas from biomass gasifier

    International Nuclear Information System (INIS)

    Highlights: • Measuring the CHON composition of a raw gas by current methods is challenging. • An alternative method is to burn the raw gas before measuring the CHON composition. • The CHON contents of the raw gas can be accurately measured by the alternative method. • Measuring the CHON contents of the raw gas is now performed in a “one-step” analysis. • The new method is used to evaluate the operation of a dual fluidised bed gasifier. - Abstract: For unattended biomass gasification processes, rapid methods for monitoring the elemental composition (CHON) of the raw gas leaving the gasifier are needed. Conventional methods rely on time-consuming and costly laboratory procedures for analysing the condensable part of the raw gas. An alternative method, presented in this work, assesses the CHON composition of raw gas in a “one step” analysis without the need to previously characterise its chemical species composition. Our method is based on the quantitative conversion of a raw gas of complex chemical composition into CO2, H2O, and N2 in a small combustor. The levels of these simple species can be measured with high accuracy and good time resolution, and the CHON composition of the raw gas can be determined from the mass balance across the combustor. To evaluate this method, an online combustion facility was built and used to analyse the raw gas from the Chalmers 2-MWth dual fluidised bed steam gasifier. Test runs of the developed facility demonstrated complete combustion of the raw gas and the measurements were both fast and reliable. The new method used in combination with zero-dimensional reactor modelling provides valuable data for the operational monitoring of gasification processes, such as the degree of fuel conversion, composition of the char exiting the gasifier, oxygen transport by catalytic bed material, and amount of condensables in raw gas

  7. Sampling of contaminants from product gases of biomass gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Staahlberg, P.; Lappi, M.; Kurkela, E.; Simell, P.; Oesch, P.; Nieminen, M. [VTT Energy, Espoo (Finland). New Energy Technologies

    1998-12-01

    Reliable sampling and analysis of products from biomass gasification are essential for the successful process development and economical operation of commercial gasifiers. One of the most important and most difficult analytical tasks is to characterise the emissions from the gasifiers. This report presents a review of the sampling and analytical systems employed and developed when doing research on coal and biomass gasification. In addition to the sampling systems published in the literature, experiences obtained in various biomass gasification R and D projects of VTT in 1985-1995 are described. The present sampling methods used for different gas contaminants at VTT are also briefly presented. This report focuses mainly on the measurement of tars, nitrogen compounds and sulphur gases. Isokinetic and non-isokinetic sampling train systems are described and, in addition, special sampling apparatus based on liquid-quenched probe and gas dilution is briefly outlined. Sampling of tars with impinger systems and sampling of heavy tars with filter techniques are described in detail. Separate sampling of particulates is briefly discussed. From inorganic compounds the sampling systems used for H{sub 2}S and other sulphur gases, NH{sub 3} and HCN and HCl are presented. Proper storage of the samples is also included in the report. (orig.) 90 refs.

  8. Advanced biomass power generation: The biomass-integrated gasifier/gas turbine and beyond

    International Nuclear Information System (INIS)

    The most promising initial strategy for modernizing bioenergy is the production of electricity or the cogeneration of electricity and heat using advanced gas turbines fired by gasified biomass. The major advances that have been made in coal gasification technology, to marry the gas turbine to coal, are readily adaptable to biomass applications. integrating biomass gasifiers with aeroderivative gas turbines in particular makes it possible to achieve high efficiencies and low unit capital costs at the modest scales required with bioenergy systems. Beyond the turn of the century fuel cells operated on gasified biomass offer the promise of even higher performance levels. For the near term, electricity produced with biomass-integrated gasifier/gas turbine (BIG/GT) power systems not only offers major environmental benefits but also would be competitive with electricity produced from fossil fuels and nuclear energy in a wide range of circumstances. It is reasonable to expect that biomass could be providing 25-35% of total global power generation in the second quarter of the next century, helping make it possible to substantially reduce CO2 emissions from the power sector relative to present levels in that time frame

  9. Modeling and simulation of a downdraft biomass gasifier 1. Model development and validation

    International Nuclear Information System (INIS)

    An 'EQB' computer program for a downdraft gasifier has been developed to predict steady state performance. Moving porous bed of suction gasifier is modeled as one-dimensional (1-D) with finite control volumes (CVs), where conservation of mass, momentum and energy is represented by fluid flow, heat transfer analysis, drying, pyrolysis, oxidation and reduction reaction modules; which have solved in integral form using tri-diagonal matrix algorithm (TDMA) for reaction temperatures, pressure drop, energetics and product composition. Fluid flow module relates the flow rate with pressure drop, while biomass drying is described by mass transfer 1-D diffusion equation coupled with vapour-liquid-equilibrium relation. When chemical equilibrium is used in oxidation zone, the empirically predicted pyrolysis products (volatiles and char) and kinetic modeling approach for reduction zone constitutes an efficient algorithm allowing rapid convergence with adequate fidelity. Predictions for pressure drop and power output (gasifier) are found to be very sensitive, while gas composition or calorific value, temperature profile and gasification efficiency are less sensitive within the encountered range of gas flow rate.

  10. Experimental Gasification of Biomass in an Updraft Gasifier with External Recirculation of Pyrolysis Gases

    OpenAIRE

    Adi Surjosatyo; Fajri Vidian; Yulianto Sulistyo Nugroho

    2014-01-01

    The updraft gasifier is a simple type of reactor for the gasification of biomass that is easy to operate and has high conversion efficiency, although it produces high levels of tar. This study attempts to observe the performance of a modified updraft gasifier. A modified updraft gasifier that recirculates the pyrolysis gases from drying zone back to the combustion zone and gas outlet at reduction zone was used. In this study, the level of pyrolysis gases that returned to the combustion zone w...

  11. Perovskite sensing materials for syngas composition monitoring and biomass gasifier numerical model validation: A preliminary approach

    Science.gov (United States)

    Pallozzi, V.; Di Carlo, A.; Zaza, F.; Villarini, M.; Carlini, M.; Bocci, E.

    2016-06-01

    Biomass gasification represents a suitable choice for global environmental impact reduction, but more efforts on the process efficiency need to be conducted in order to enhance the use of this technology. Studies on inputs and outputs of the process, as well as measurements and controls of syngas composition and correlated organic and inorganic impurities, are crucial points for the optimization of the entire process: models of the system and sensing devices are, thus, very attractive for this purpose. In particular, perovskite based chemoresistive sensors could represent a promising technology, since their simplicity in function, relatively low cost and direct high temperature operation. The aim of this work is to develop a steam fluidized bed biomass gasifier model, for the prediction of the process gas composition, and new perovskite compounds, LaFeO3 based, as sensing material of chemoresistive sensors for syngas composition and impurities measurements. Chemometric analysis on the combustion synthesis via citrate-nitrate technique of LaFeO3 was also performed, in order to evaluate the relationship between synthesis conditions and perovskite materials and, thus, sensor properties. Performance of different sensors will be tested, in next works, with the support of the developed gasifier model.

  12. BIOMASS-FUELED, SMALL-SCALE, INTEGRATED-GASIFIER, GAS-TURBINE POWER PLANT: PROGRESS REPORT ON THE PHASE 2 DEVELOPMENT

    Science.gov (United States)

    The paper reports the latest efforts to complete development of Phase 2 of a three-phase effort to develop a family of small-scale (1 to 20 MWe) biomass-fueled power plants. The concept envisioned is an air-blown pressurized fluidized-bed gasifier followed by a dry hot gas clean...

  13. Pyrolysis Model of Single Biomass Pellet in Downdraft Gasifier

    Institute of Scientific and Technical Information of China (English)

    薛爱军; 潘继红; 田茂诚; 伊晓璐

    2016-01-01

    By coupling the heat transfer equation with semi-global chemical reaction kinetic equations, a one-dimensional, unsteady mathematical model is developed to describe the pyrolysis of single biomass pellet in the pyrolysis zone of downdraft gasifier. The simulation results in inert atmosphere and pyrolysis zone agree well with the published experimental results. The pyrolysis of biomass pellets in pyrolysis zone is investigated, and the results show that the estimated convective heat transfer coefficient and emissivity coefficient are suitable. The mean pyro-lysis time is 15.22%, shorter than that in inert atmosphere, and the pellet pyrolysis process in pyrolysis zone belongs to fast pyrolysis. Among the pyrolysis products, tar yield is the most, gas the second, and char the least. During pyrolysis, the temperature change near the center is contrary to that near the surface. Pyrolysis gradually moves inwards layer by layer. With the increase of pyrolysis temperature and pellet diameter, the total pyrolysis time, tar yield, char yield and gas yield change in different ways. The height of pyrolysis zone is calculated to be 1.51—3.51 times of the characteristic pellet diameter.

  14. REFINEMENT OF PRODUCER GAS GENERATED FROM BIOMASS GASIFIER

    Directory of Open Access Journals (Sweden)

    L. KUMARARAJA

    2016-01-01

    Full Text Available Producer gas (PG generated from biomass by thermo-chemical gasification process has been proved to be a reliable and renewable substitute for petroleum fuels to drive internal combustion engines. The gasification technology has been developed well and also commercialised. However, more technological advancements must happen in the refining of PG. Generally, the refinement is confined to the removal of tar and particulates from PG before supplying it to the engines. This paper proposes to remove additionally carbon dioxide and water vapour from PG so that its heating value can be increased and faster combustion can be attained in the engine cylinder. In this direction, the various CO2 removal technologies which are currently employed for combustion flue gas, natural gas and biogas have been first studied in detail. They are: physical absorption in solvents, chemical absorption by reagents, adsorption, membrane separation and refrigeration. In the present research, a batch of experiments has been conducted by washing PG with water to absorb CO2 physically and in a separate batch of experiments PG has been treated with aqueous ammonia to absorb CO2 chemically. For both experiments, the PG was generated by a downdraft biomass gasifier fed with wood pieces. The CO2 reduction obtained was 10.9% in physical absorption by water and 95% in chemical absorption by aqueous ammonia. Along with the reduction of CO2 and H2O from PG, the tar and particulates content of PG could also be reduced by absorption method.

  15. Apparatus, components and operating methods for circulating fluidized bed transport gasifiers and reactors

    Energy Technology Data Exchange (ETDEWEB)

    Vimalchand, Pannalal; Liu, Guohai; Peng, Wan Wang

    2015-02-24

    The improvements proposed in this invention provide a reliable apparatus and method to gasify low rank coals in a class of pressurized circulating fluidized bed reactors termed "transport gasifier." The embodiments overcome a number of operability and reliability problems with existing gasifiers. The systems and methods address issues related to distribution of gasification agent without the use of internals, management of heat release to avoid any agglomeration and clinker formation, specific design of bends to withstand the highly erosive environment due to high solid particles circulation rates, design of a standpipe cyclone to withstand high temperature gasification environment, compact design of seal-leg that can handle high mass solids flux, design of nozzles that eliminate plugging, uniform aeration of large diameter Standpipe, oxidant injection at the cyclone exits to effectively modulate gasifier exit temperature and reduction in overall height of the gasifier with a modified non-mechanical valve.

  16. Pressure-drop predictions in a fixed-bed coal gasifier

    OpenAIRE

    Bunt, John Reginald; Luckos, Adam

    2011-01-01

    In the Sasol Synfuels plant in Secunda, Sasol-Lurgi fixed-bed dry-bottom gasifiers are used for the conversion of low-grade bituminous coals to synthesis gas (syngas). The gasifiers are fed with lump coal having a particle size in the range from 5 to 100 mm. Operating experience shows that the average particle size and particle-size distribution (PSD) of feed coal, char and ash influence the pressure drop across the bed and the gas-flow distribution within the bed. These hydrodynamic phenomen...

  17. Application of Exergoeconomic and Exergoenvironmental Analysis to an SOFC System with an Allothermal Biomass Gasifier

    Directory of Open Access Journals (Sweden)

    George Tsatsaronis

    2009-12-01

    Full Text Available

    In the future, energy conversion systems will be needed that reduce the environmental impact and costs of energy supply when fossil fuels are employed. An alternative is using biomass as a renewable energy resource to achieve both effects. For this reason, interest in biomass gasification processes resurged considerably in the past years. In particular, combination of allothermal biomass gasification with a high-temperature solid oxide fuel cell (SOFC has met with great interest as an attractive option for electricity generation. To objectively evaluate this new biomass conversion process, the newly developed exergoenvironmental analysis and the established exergoeconomic analysis are applied. The basic idea of both methods is that in energy conversion systems, exergy represents the only rational basis for assigning environmental impacts and costs to the energy carriers and to the inefficiencies within the system. The present article identifies the most relevant system components from the environmental and economic points of view and provides information about possibilities of design improvements. Comparison of the results of both methods reveals that the most relevant process components are the SOFC, the heat exchanger for preheating the air, and the allothermal fluidized-bed gasifier. A special focus will be placed on differences between both analysis methods.

    •  This paper is an updated version of a paper published in the ECOS'08 proceedings.

  18. Pressure-drop predictions in a fixed-bed coal gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Adam Luckos; John R. Bunt [Sasol Technology, Sasolburg (South Africa). R& amp; D Division

    2011-03-15

    In the Sasol Synfuels plant in Secunda, Sasol-Lurgi fixed-bed dry-bottom gasifiers are used for the conversion of low-grade bituminous coals to synthesis gas (syngas). The gasifiers are fed with lump coal having a particle size in the range from 5 to 100 mm. Operating experience shows that the average particle size and particle-size distribution (PSD) of feed coal, char and ash influence the pressure drop across the bed and the gas-flow distribution within the bed. These hydrodynamic phenomena are responsible for stable gasifier operation and for the quality and production rate of the syngas. The counter-current operation produces four characteristic zones in the gasifier, namely, drying, de-volatilization, reduction and combustion. The physical properties of the solids (i.e. average particle size, PSD, sphericity and density) are different in each of these zones. Similarly, the chemical composition of the syngas, its properties (temperature, density and viscosity) and superficial velocity vary along the height of the bed. The most popular equation used to estimate the pressure drop in packed beds is that proposed by Ergun. The Ergun equation gives good predictions for non-reacting, isothermal packed beds made of uniformly sized, spherical or nearly spherical particles. In the case of fixed-bed gasifiers, predictions by the Ergun equation based on the average or inlet values of bed and gas flow parameters are unsatisfactory because the bed structure and gas flow vary significantly in the different reaction zones. In this study, the Ergun equation is applied to each reaction zone separately. The total pressure drop across the bed is then calculated as the sum of pressure drops in all zones. It is shown that the total pressure drop obtained this way agrees better with the measured result. 44 refs., 2 tabs.

  19. The effect of air preheating in a biomass CFB gasifier using ASPEN Plus simulation

    Energy Technology Data Exchange (ETDEWEB)

    Doherty, Wayne; Reynolds, Anthony; Kennedy, David [Department of Mechanical Engineering, Dublin Institute of Technology, Bolton Street, Dublin 1 (Ireland)

    2009-09-15

    In the context of climate change, efficiency and energy security, biomass gasification is likely to play an important role. Circulating fluidised bed (CFB) technology was selected for the current study. The objective of this research is to develop a computer model of a CFB biomass gasifier that can predict gasifier performance under various operating conditions. An original model was developed using ASPEN Plus. The model is based on Gibbs free energy minimisation. The restricted equilibrium method was used to calibrate it against experimental data. This was achieved by specifying the temperature approach for the gasification reactions. The model predicts syn-gas composition, conversion efficiency and heating values in good agreement with experimental data. Operating parameters were varied over a wide range. Parameters such as equivalence ratio (ER), temperature, air preheating, biomass moisture and steam injection were found to influence syn-gas composition, heating value, and conversion efficiency. The results indicate an ER and temperature range over which hydrogen (H{sub 2}) and carbon monoxide (CO) are maximised, which in turn ensures a high heating value and cold gas efficiency (CGE). Gas heating value was found to decrease with ER. Air preheating increases H{sub 2} and CO production, which increases gas heating value and CGE. Air preheating is more effective at low ERs. A critical air temperature exists after which additional preheating has little influence. Steam has better reactivity than fuel bound moisture. Increasing moisture degrades performance therefore the input fuel should be pre-dried. Steam injection should be employed if a H{sub 2} rich syn-gas is desired. (author)

  20. The effect of air preheating in a biomass CFB gasifier using ASPEN Plus simulation

    International Nuclear Information System (INIS)

    In the context of climate change, efficiency and energy security, biomass gasification is likely to play an important role. Circulating fluidised bed (CFB) technology was selected for the current study. The objective of this research is to develop a computer model of a CFB biomass gasifier that can predict gasifier performance under various operating conditions. An original model was developed using ASPEN Plus. The model is based on Gibbs free energy minimisation. The restricted equilibrium method was used to calibrate it against experimental data. This was achieved by specifying the temperature approach for the gasification reactions. The model predicts syn-gas composition, conversion efficiency and heating values in good agreement with experimental data. Operating parameters were varied over a wide range. Parameters such as equivalence ratio (ER), temperature, air preheating, biomass moisture and steam injection were found to influence syn-gas composition, heating value, and conversion efficiency. The results indicate an ER and temperature range over which hydrogen (H2) and carbon monoxide (CO) are maximised, which in turn ensures a high heating value and cold gas efficiency (CGE). Gas heating value was found to decrease with ER. Air preheating increases H2 and CO production, which increases gas heating value and CGE. Air preheating is more effective at low ERs. A critical air temperature exists after which additional preheating has little influence. Steam has better reactivity than fuel bound moisture. Increasing moisture degrades performance therefore the input fuel should be pre-dried. Steam injection should be employed if a H2 rich syn-gas is desired. (author)

  1. Air Gasification of Agricultural Waste in a Fluidized Bed Gasifier: Hydrogen Production Performance

    Directory of Open Access Journals (Sweden)

    A. B. Alias

    2009-05-01

    Full Text Available Recently, hydrogen production from biomass has become an attractive technology for power generation. The main objective pursued in this work is to investigate the hydrogen production potential from agricultural wastes (coconut coir and palm kernel shell by applying the air gasification technique. An experimental study was conducted using a bench-scale fluidized bed gasifier with 60 mm diameter and 425 mm height. During the experiments, the fuel properties and the effects of operating parameters such as gasification temperatures (700 to 900°C, fluidization ratio (2 to 3.33 m/s, static bed height (10 to 30 mm and equivalence ratio (0.16 to 0.46 were studied. It was concluded that substantial amounts of hydrogen gas (up to 67 mol% could be produced utilizing agricultural residues such as coconut and palm kernel shell by applying this fluidization technique. For both samples, the rise of temperature till 900°C favored further hydrocarbon reactions and allowed an increase of almost 67 mol% in the release of hydrogen. However, other parameters such as fluidizing velocity and feed load showed only minor effects on hydrogen yield. In conclusion, agricultural waste can be assumed as an alternative renewable energy source to the fossil fuels, and the environmental pollution originating from the disposal of agricultural residues can be partially reduced.

  2. Residence time distribution measurements in an Advanced Pressurized Fluidized Bed Gasifier (APFBG) using radiotracer technique

    International Nuclear Information System (INIS)

    Residence time distributions (RTDs) of coal were measured at different operating conditions in a pressurized fluidized bed gasifier using radiotracer technique. Two different tracers i.e. coal labeled with gold-198 and lanthanum-140 were used as tracers. The comparison of the results obtained with the two tracers indicated that lanthanum-140 was suitable tracer for tracing coal phase in the gasifier. From the measured RTD curves, mean residence times were determined and measured data was simulated using tanks-in-series model. The simulation of data indicated that the gasifier behaved as a well-mixed reactor with minor bypassing. The results of the study were used to modify/optimize the design of the gasifier. (author)

  3. Effectiveness factors for a commercial steam reforming (Ni) catalyst and for a calcined dolomite used downstream biomass gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Corella, J.; Narvaez, I.; Orio, A. [Madrid Univ. (Spain). Dept. of Chem. Eng.

    1996-12-31

    A commercial steam reforming catalyst from BASF, the G1-25 S one, and a calcined dolomite, Norte-1, from Cantabria-Spain, have been used, once crushed and sieved to different particle fractions between 1.0 and 4.0 mm. The materials have been tested downstream small pilot biomass gasifiers, bubbling fluidized bed type, gasifying with air and with steam. The Thiele modulus and the effectiveness factor have been calculated at temperatures of 750-850 deg C. It is experimentally shown that diffusion control plays an important part when particle size is larger than ca. 0.5 mm. This has to be taken into account when comparing the quality of the solids for tar elimination. (author) (5 refs.)

  4. Research into Biomass and Waste Gasification in Atmospheric Fluidized Bed

    Energy Technology Data Exchange (ETDEWEB)

    Skala, Zdenek; Ochrana, Ladislav; Lisy, Martin; Balas, Marek; Kohout, Premysl; Skoblja, Sergej

    2007-07-01

    Considerable attention is paid in the Czech Republic to renewable energy sources. The largest potential, out of them all, have biomass and waste. The aim therefore is to use them in CHP in smaller units (up to 5MWel). These are the subject of the research summarized in our article. The paper presents results of experimental research into gasification in a 100 kW AFB gasifier situated in Energy Institute, Faculty of Mechanical Engineering, Brno University of Technology, and fitted with gas cleaning equipment. Within the research, study was carried out into gas cleaning taking primary measures in the fluidized bed and using hot filter, metal-based catalytic filter, and wet scrubber. Descriptions and diagrams are given of the gasifier and new ways of cleaning. Results include: Impact of various fuels (farming and forest wastes and fast-growing woods and culm plants) on fuel gas quality. Individual kinds of biomass have very different thermal and physical properties; Efficiency of a variety of cleaning methods on content of dust and tars and comparison of these methods; and, Impact of gasifier process parameters on resultant gas quality. (auth)

  5. Gasification of solid waste — potential and application of co-current moving bed gasifiers

    NARCIS (Netherlands)

    Groeneveld, M.J.; Swaaij, van W.P.M.

    1979-01-01

    A review is given of gasification processes for solid fuels with special emphasis on waste gasification. Although the co-current moving bed gasifier has not been under consideration for a long time, it offers interesting possibilities for waste gasification. Some operational data are given. Two pote

  6. Identification of reaction zones in a commercial Sasol-Lurgi fixed bed dry bottom gasifier operating on North Dakota lignite

    Energy Technology Data Exchange (ETDEWEB)

    S.J. Mangena; J.R. Bunt; F.B. Waanders; G. Baker [Sasol Technology (Pty) Ltd., Sasolburg (South Africa)

    2011-01-15

    The objective of this study was to determine the reaction zones occurring in the Sasol-Lurgi fixed bed dry bottom (S-L FBDB) gasifier operating on North Dakota lignite. A Turn-Out sampling method and subsequent chemical analyses of the gasifier fuel bed samples was used to determine the reaction zones occurring in the commercial MK IV, S-L FBDB gasifier operating on North Dakota lignite. The reaction zones were further compared with the same reactor operating on bituminous coal. Based on the results obtained from this study it was found that about two thirds of the gasifier volume was used for drying and de-volatilising the lignite thus leaving only about a third of the reactor volume for gasification and combustion. Nonetheless, due to the high reactivity of the lignite, the char was consumed within a third of the remaining gasifier volume. Clear overlaps between the reaction zones were observed in the gasifiers thus confirming the gradual transition from one reaction zone to another as reported in literature. Due to the high moisture content in the lignite, the pyrolysis zone in the gasifiers operating on North Dakota lignite occurred lower/deeper in the gasifier fuel bed as compared to the same gasifier operating on South African bituminous coal from the Highveld coalfield. All the other reaction zones in the gasifier operating on bituminous coal were also higher in the bed compared to the lignite operation. This can therefore explain the higher gas outlet temperatures for the S-L FBDB gasifiers operating on higher rank coals when compared to the gasifiers operating on lignite. The fact that the entire reactor volume was utilized for drying, de-volatilisation, gasification and combustion with carbon conversion of {gt} 98% makes the S-L FBDB gasifier very suitable for lignite gasification. 8 refs., 8 figs., 1 tab.

  7. Air-steam gasification of different types of coals using fluidised bed gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Othman, N.F. [TNB Research Sdn. Bhd., Kawasan Inst. Penyelidikan, Selangor Darul Ehsan (Malaysia); Bosrooh, M.H.; Majid, K.A. [Tenaga National Univ., Selangor (Malaysia)

    2008-07-01

    Coal gasification has been touted as being the cleanest technology for producing energy from coal. The coal reserve in Malaysia is 1712 million tonnes of coal ranging from lignite to anthracite. Lignite and sub-bituminous coals have shown potential to be easily gasified and suitable for Integrated Gasification Combined Cycle (IGCC) power generation. This laboratory study investigated the gasification of Adaro, DEJ, Hunter Valley, Merit Pila and Mukah Balingian coals. The study made use of an atmospheric fluidized bed gasifier using air and air-steam as the fluidizing media. Gas chromatography was used to determination the producer gas compositions. The gasification experiments were conducted at a bed temperature of 600 degrees C. The influence of air and steam as the gasifying agents in the gasification process was studied, and the producer gas compositions were compared according to the type of gasifying agent. Air-steam gasification revealed a significant increase in carbon monoxide, carbon dioxide, methane and hydrogen content in the producer gas compared with the air gasification. The study also showed that hydrogen, carbon monoxide and methane were significantly higher in the sub-bituminous coal than in the bituminous coal. The quality of the producer gas improved, as steam was introduced as the gasifying agent. 10 refs., 4 tabs., 2 figs.

  8. PERFORMANCE STUDIES ON DOWNDRAFT GASIFIER WITH BIOMASS ENERGY SOURCES AVAILABLE IN REMOTE VILLAGES

    Directory of Open Access Journals (Sweden)

    V. ChristusJeya Singh

    2014-01-01

    Full Text Available Increasing global concern over the environmental issues and depletion of fossil fuels, significant interest has been shown by the researchers to develop alternate energy technologies like biomass, biogas, solar to meet the future energy demand. The prediction of the performance of different biomass energy sources in gasifiers is needed for the implementation of this technology to fulfil the need of decentralized heat and power applications, relevant to remote villages. This study presents the theoretical and experimental studies conducted on a 50 kW downdraft biomass gasifier with various biomass materials such as wood, coconut shell, rubber seed kernel and coir pith which are generally available in villages. Two-zone kinetic equilibrium model approach is used to predict the composition and temperature of the producer gas. The influence of equivalence ratio on the reaction temperature, quality of producer gas and gasifier conversion efficiency are discussed. The experimental and theoretical studies show that the rubber seed kernel can be effectively used as a feedstock of the biomass gasifier to meet the rural energy demand.

  9. Process modeling and thermodynamic analysis of Lurgi fixed-bed coal gasifier in an SNG plant

    International Nuclear Information System (INIS)

    Highlights: • A comprehensive model is proposed for the Lurgi fixed-bed gasifier. • A strategy is proposed to accelerate the convergence of the model solutions. • Satisfactory agreement between model predictions and industrial data is obtained. • An exergy analysis is applied to both the Lurgi gasifier and the gasification system. - Abstract: This paper presents a comprehensive steady state kinetic model of a commercial-scale pressurized Lurgi fixed-bed dry bottom coal gasifier. The model is developed using the simulator Aspen Plus. Five sequential modules: drying zone, pyrolysis zone, gasification zone, combustion zone and overall heat recovery unit, are considered in the main process model. A non-linear programming (NLP) model is employed to estimate the pyrolysis products, which include char, coal gas and high-weight hydrocarbons/distillable liquids (tar, phenol, naphtha and oil). To accelerate solution convergence, an external FORTRAN subroutine is used to simulate the kinetics of the combustion and gasification processes which are formulated in terms of a series of continuous stirred-tank reactors. The model is validated with industrial data. The effects of two key operating parameters, namely oxygen/coal mass ratio and steam/coal mass ratio, on the thermodynamic efficiencies of the Lurgi gasifier and the gasification system as a whole are investigated via extensive simulation studies

  10. Physical property behaviour of North Dakota lignite in an oxygen/steam blown moving bed gasifier

    OpenAIRE

    Mangena, S.J.; Bunt, J.R.; Waanders, F.B.

    2013-01-01

    In this study lignite originating from North Dakota (USA) was thermally treated in an oxygen/steam blown commercial-scale moving bed gasifier operating on lump coal at the Dakota Gasification Company (DGC) in order to identify the physical property changes that occur during heating. After reaction, the solid particulate remnants were extracted from the reactor and characterised using standard techniques. Thermal fragmentation was found to be severe with the coal tested, i.e. the l...

  11. Experience with Operation of Two-Stages Fixed Bed Gasifiers

    Czech Academy of Sciences Publication Activity Database

    Skoblia, S.; Beňo, Z.; Brynda, Jiří; Pohořelý, Michael; Picek, I.

    Prague : CTU publishing house, 2015 - (Winter, F.; Hrdlička, J.), s. 42 ISBN 978-80-01-05736-0. [International Conference for Young Researchers and PhD Students /9./. Monínec (CZ), 04.05.2015-06.05.2015] R&D Projects: GA TA ČR(CZ) TA04020853 Institutional support: RVO:67985858 Keywords : two-stage biomass gasification * woog chips * gas composition Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  12. Thermo-economic optimization of a Solid Oxide Fuel Cell – Gas turbine system fuelled with gasified lignocellulosic biomass

    International Nuclear Information System (INIS)

    Highlights: • Biomass gasification combined with SOFC–GT hybrid system was studied. • Syngas hot cleaning unit is used in order to improve the efficiency of the system. • Energy integration in order to recover the maximum heat available inside the process. • Multi-objective optimization maximizing the efficiency and minimizing the capital investment costs. - Abstract: Within the context of sustainable energy supply and CO2 emissions reduction a Solid Oxide Fuel Cell (SOFC) – gas turbine hybrid system, fuelled with gasified woody biomass is studied in detail for small and medium scale applications (100 kWth,BM and 8 MWth,BM of dry biomass input). The system consists of an air dryer unit, a gasifier, a hot cleaning section made of a particulate removal unit (cyclone and candle filter) and a two-stage tar removal unit, a SOFC and a gas turbine with optional CO2 capture. This modern technology has the advantage of using a renewable and CO2-neutral source and to be economically competitive at medium scales. The competitiveness of different process options is systematically compared by applying a coherent approach combining flowsheeting, energy integration and economic evaluation in a multi-objective optimization framework. This analysis reveals the importance of process integration maximizing the heat recovery and valorizing the waste heat, by cogeneration for example. The studied process options include direct and indirect circulating fluidized bed gasifier (using respectively oxygen or steam as gasification agent) and Viking gasifier, atmospheric or pressurized systems and optional pre-reforming in the hot gas cleaning. To close the thermal energy balance, a fraction of the produced syngas can be burnt. The energy integration results reveal that the steam production for the gasification and reforming are key parameters (S/B and S/C ratio) defining the process performance. A multi-objective optimization maximizing the efficiency and minimizing the capital

  13. Waste heat recovery using a thermoelectric power generation system in a biomass gasifier

    International Nuclear Information System (INIS)

    The aim of this study is to investigate the use of waste heat that is recovered from a biomass gasifier. In the gasification process, the low heating value of biomass can be transferred to a high heating value for combustible gaseous fuel, a form that is widely used in industry and power plants. Conventionally, some of cleaning processes need to be conducted under higher operating temperatures that the low temperatures typically used to burn biomass. Therefore, the catalytic reactor was designed before installation the scrubber in the downdraft gasifier system to make effective use of the waste heat. The experimental result shows that the temperature of the gasifier outlet is about 623–773 K; dolomite is used for tar removal in the catalytic reactor. To further improve the use of waste heat, a thermoelectric generator is added to provide for the recovery of waste heat. The thermoelectric generator system is manufactured using a Bi2Te3 based material and is composed of eight thermoelectric modules on the surface of catalytic reactor. The measured surface temperature of the catalytic reactor is 473–633 K that is the correct temperature for Bi2Te3 as thermoelectric generator. The result shows that the maximum power output of the thermoelectric generator system is 6.1 W and thermoelectric generator power density is approximately 193.1 W/m2. - Highlights: • Set up the thermoelectric power generation system to recover waste heat from biomass gasifier. • Bi2Te3 based material is suitable for choosing as a thermoelectric generator in the waste heat recovery temperature range of 473–633 K form gasifier. • The maximum power density can reach 193.1 W/m2 for waste heat recovery

  14. Co-Gasification of Coal and Biomass in an IGCC Power Plant: Gasifier Modeling

    Directory of Open Access Journals (Sweden)

    Luis Correas

    2004-12-01

    Full Text Available Co-gasification of coal and biomass in an existing coal-fired IGCC power plant is proposed as an efficient, flexible and environmentally friendly way to increase the biomass contribution to electricity generation. A model of an entrained flow gasifier is described and validated with nearly 3,000 actual steady-state operational data points (4,800 hours. The model is then used to study co-gasification of coal, petroleum coke and up to 10 percent of several types of biomass. As a result, the influence of fuel variations on gasifier performance and modifications in operation that should be made in co-gasification are obtained. A conclusion of our study is that co-gasification is possible provided that operation is properly adapted. A validated model can be very useful for predicting operating points for new fuel mixtures.

  15. Numerical Study on Combustion Features of Gasified Biomass Gas

    OpenAIRE

    Zhang, Xiaoxiang

    2015-01-01

    There is a great interest to develop biomass combustion systems for industrial and utility applications. Improved biomass energy conversion systems are designed to provide better combustion efficiencies and environmental friendly conditions, as well as the fuel flexibility options in various applications. The gas derived from the gasification process of biomass is considered as one of the potential candidates to substitute traditional fuels in a combustion process. However, the gascomposition...

  16. A simple process modelling for a dry-feeding entrained bed coal gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.; Choi, S.; Paek, M. [Korean Advanced Institute of Science & Technology, Taejon (Republic of Korea). Dept. of Mechanical Engineering

    2011-07-01

    A dry-feeding entrained bed coal gasifier was numerically modelled by simultaneously solving the rate equations for chemical reactions of the solid and gas phases. This model describes simplified physical and chemical processes in the entrained bed coal gasifier. Chemical reaction processes for coal gasification and combustion are considered along with the simplified gas flow passage in the reactor, so that progress of reactions at the designated spatial location is represented. Gasification phenomena of coal particles were separated into devolatilization, gas-phase, and solid-phase reactions. Coal gasifier geometry was simplified to a pseudo-two-dimensional (pseudo-2D) reactor model based on the 1D plug flow concept. The dimension in the pseudo-2D model was conceptually divided by considering the recirculation effect. As a result, carbon conversion, cold gas efficiency, and temperature distribution were obtained at variable oxygen to coal mass ratio, steam to coal mass ratio, and operating pressure. Operating conditions could be appropriately controlled by knowing the degree of reaction in the reactor.

  17. 140 g H{sub 2}/kg biomass d.a.f. by a CO-shift reactor downstream from a FB biomass gasifier and a catalytic steam reformer

    Energy Technology Data Exchange (ETDEWEB)

    Corella, Jose; Molina, Gregorio; Toledo, Jose M. [Department of Chemical Engineering, University ' ' Complutense' ' of Madrid, 28040 Madrid (Spain); Aznar, Maria P.; Caballero, Miguel A. [Chemical and Environmental Engineering Department, CPS, 3 Maria de Luna st., University of Saragossa, 50018 Saragossa (Spain)

    2008-04-15

    The effect of adding a CO-shift reactor downstream from a fluidized bed biomass gasifier and a steam reforming catalytic reactor is studied in this paper. The upstream gasifier was of small pilot plant scale, 10 kg biomass/h. Therefore, the downstream catalytic reactors, steam reformer and CO-shift, operated under a real gasification gas. The gasifying agent used was H{sub 2}O-O{sub 2} mixtures. The CO-shift catalytic reactor used had one high (HT) and one low temperature (LT) adiabatic beds. Two commercial catalysts were used throughout the process. CO-conversions (eliminations) were higher than 90% and a H{sub 2}-content as high as 73 vol%, dry basis, were obtained by the CO-shift system. This H{sub 2} content is equivalent to a yield of 140gH{sub 2}/kg biomass d.a.f. The CO conversion and the increase (up to 14 vol%) of the H{sub 2} content, correlate well with the molar steam/CO ratio in the gasification gas at the inlet of the HT bed. (author)

  18. Performance modelling and validation of biomass gasifiers for trigeneration plants

    OpenAIRE

    Puig Arnavat, Maria

    2011-01-01

    This thesis develops a simple but rigorous model for simulation, design and preliminary evaluation of trigeneration plants based on biomass gasification. It includes a review and study of various models proposed for the biomass gasification process and different plant configurations. A modified thermodynamic equilibrium model is developed for application to real processes that do not reach equilibrium. In addition, two artificial neural network models, based on experimental published data, ar...

  19. Decomposition of matters and biomass gasifying in plasma generated in plasmatron stabilised by water

    International Nuclear Information System (INIS)

    In this paper experimental results of Decomposition of matters and biomass gasifying in plasma generated in plasmatron stabilised by water are presented. Used plasmatron is described. Process is characterised by high efficiency. Synthetic gas produced with this technology has high quality and is suitable for next technological treatment, it has high content of hydrogen and carbon monooxide, a little content of carbon dioxide and other gases

  20. Thermal valorization of post-consumer film waste in a bubbling bed gasifier

    International Nuclear Information System (INIS)

    Highlights: • Film waste from packaging is a common waste, a fraction of which is not recyclable. • Gasification can make use of the high energy value of the non-recyclable fraction. • This waste and two reference polymers were gasified in a bubbling bed reactor. • This experimental research proves technical feasibility of the process. • It also analyzes impact of composition and ER on the performance of the plant. - Abstract: The use of plastic bags and film packaging is very frequent in manifold sectors and film waste is usually present in different sources of municipal and industrial wastes. A significant part of it is not suitable for mechanical recycling but could be safely transformed into a valuable gas by means of thermal valorization. In this research, the gasification of film wastes has been experimentally investigated through experiments in a fluidized bed reactor of two reference polymers, polyethylene and polypropylene, and actual post-consumer film waste. After a complete experimental characterization of the three materials, several gasification experiments have been performed to analyze the influence of the fuel and of equivalence ratio on gas production and composition, on tar generation and on efficiency. The experiments prove that film waste and analogue polymer derived wastes can be successfully gasified in a fluidized bed reactor, yielding a gas with a higher heating value in a range from 3.6 to 5.6 MJ/m3 and cold gas efficiencies up to 60%

  1. Fixed-bed gasifier and cleanup system engineering summary report through Test Run No. 100

    Energy Technology Data Exchange (ETDEWEB)

    Pater, K. Jr.; Headley, L.; Kovach, J.; Stopek, D.

    1984-06-01

    The state-of-the-art of high-pressure, fixed-bed gasification has been advanced by the many refinements developed over the last 5 years. A novel full-flow gas cleanup system has been installed and tested to clean coal-derived gases. This report summarizes the results of tests conducted on the gasifier and cleanup system from its inception through 1982. Selected process summary data are presented along with results from complementary programs in the areas of environmental research, process simulation, analytical methods development, and component testing. 20 references, 32 figures, 42 tables.

  2. Simulation of coal gasification in a pressurized spout-fluid bed gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Li, Q.J.; Zhang, M.Y.; Zhong, W.Q.; Wang, X.F.; Xiao, R.; Jin, B.S. [Nanjing Institute of Chemical Technology, Nanjing (China). Dept. of Environmental Engineering

    2009-04-15

    Based on an Eulerian-Eulerian method, a three-dimensional kinetic model involving mass transfer, momentum transfer, heat transfer, and chemical reaction is developed to simulate the process of coal gasification in a 2 MWth, pressurized spout-fluid bed of 450 mm in diameter with bed pressure up to 0.5 MPa. The effects of operating pressure and bed temperature on coal gasification are investigated. The high operating pressure is beneficial to coal gasification due to the fact that the fluidization in the reactor becomes better. On one hand, a higher bed temperature can accelerate the rate of reaction. On the other hand, more air will be taken in the gasifier to keep the higher bed temperature which will consume part of combustible gases produced by coal pyrolysis or gasification. Experimental verification was carried out in a 2 MWth, thermal input pressurized spout-fluid bed under the same operating condition. The comparison of calculation results with experimental results shows that most of the calculation errors are within the range of 15%.

  3. Defluidization in fluidized bed gasifiers using high-alkali content fuels

    DEFF Research Database (Denmark)

    Narayan, Vikas; Jensen, Peter Arendt; Henriksen, Ulrik Birk;

    2016-01-01

    major concern in thermal conversion of biomass encountered in fluidized beds is bed agglomeration, which may result in de-fluidization, leading to unscheduled downtime and additional costs. Biomass fuels, especially herbaceous plants, often contain significant amounts of silicon, potassium and...... using strawas a fuel. It was seen that in sand þ KCl agglomerates, the sand particles were bound by KCl melts. Onlyvery limited chemical reaction was observed between KCl and the sand particles and no presence of silicate melts in the agglomerates. For sand þ K2CO3 mixtures and for LTCFB bed material...

  4. Identification of reaction zones in a commercial Sasol-Lurgi fixed bed dry bottom gasifier operating on North Dakota lignite

    OpenAIRE

    Baker, G; Bunt, John Reginald; Waanders, Frans Boudewijn; Mangena, S.J.

    2011-01-01

    The Sasol-Lurgi fixed bed dry bottom gasification technology has the biggest market share in the world with 101 gasifiers in operation. To be able to further improve the technology and also to optimise the operating plants, it is important that the fundamentals of the process are understood. The main objective of this study was to determine the reaction zones occurring in the Sasol-Lurgi fixed bed dry bottom (S-L FBDB) gasifier operating on North Dakota lignite. A Turn-Out sampling method and...

  5. Punctuated continuity: The technological trajectory of advanced biomass gasifiers

    International Nuclear Information System (INIS)

    Recent interest in biofuels and bio-refineries has been building upon the technology of biomass gasification. This technology developed since the 1980s in three periods, but failed to break through. We try to explain this by studying the technological development from a quasi-evolutionary perspective, drawing upon the concepts of technological paradigms and technological trajectories. We show that the socio-economic context was most important, as it both offered windows of opportunity as well as provided direction to developments. Changes in this context resulted in paradigm shifts, characterized by a change in considered end-products and technologies, as well as a change in companies involved. Other influences on the technological trajectory were firm specific differences, like the focus on a specific feedstock, scale and more recently biofuels to be produced. These were strengthened by the national focus of supporting policies, as well as specific attention for multiple technologies in policies of the USA and European Commission. Over each period we see strong variation that likely benefitted the long term development of the technology. Despite policy efforts that included variation and institutionalization, our case shows that the large changes in socio-economic context and the technological challenges were hard to overcome. - Highlights: • Advanced biomass gasification, as important enabling technology for biofuels and the bio-based economy, has been lacking success despite decades of research and development. • We try to explain this by reconstructing its technological trajectory. • We focus on processes of variation and selection, and interaction between local demonstration projects and the upcoming technological field. • The development of the technology over each period shows strong variation. • Long RD and D times in combination with major changes in the socio-economic context have resulted in discontinuities that even affected premium

  6. Cogeneration based on gasified biomass - a comparison of concepts

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Fredrik

    1999-01-01

    In this report, integration of drying and gasification of biomass into cogeneration power plants, comprising gas turbines, is investigated. The thermodynamic cycles considered are the combined cycle and the humid air turbine cycle. These are combined with either pressurised or near atmospheric gasification, and steam or exhaust gas dryer, in a number of combinations. An effort is made to facilitate a comparison of the different concepts by using, and presenting, similar assumptions and input data for all studied systems. The resulting systems are modelled using the software package ASPEN PLUS{sup TM}, and for each system both the electrical efficiency and the fuel utilisation are calculated. The investigation of integrated gasification combined cycles (IGCC), reveals that systems with pressurised gasification have a potential for electrical efficiencies approaching 45% (LHV). That is 4 - 5 percentage points higher than the corresponding systems with near atmospheric gasification. The type of dryer in the system mainly influences the fuel utilisation, with an advantage of approximately 8 percentage points (LHV) for the steam dryer. The resulting values of fuel utilisation for the IGCC systems are in the range of 78 - 94% (LHV). The results for the integrated gasification humid air turbine systems (IGHAT) indicate that electrical efficiencies close to the IGCC are achievable, provided combustion of the fuel gas in highly humidified air is feasible. Reaching a high fuel utilisation is more difficult for this concept, unless the temperature levels in the district heating network are low. For comparison a conventional cogeneration plant, based on a CFB boiler and a steam turbine (Rankine cycle), is also modelled in ASPEN PLUS{sup TM}. The IGCC and IGHAT show electrical efficiencies in the range of 37 - 45% (LHV), compared with a calculated value of 31% (LHV) for the Rankine cycle cogeneration plant. Apart from the electrical efficiency, also a high value of fuel

  7. Exergetic assessment of an integrated gasifier/boiler system for hydrogen production with different biomass types

    Energy Technology Data Exchange (ETDEWEB)

    Kalinci, Y. [Dokuz Eylul Univ., Izmir (Turkey). Izmir Vocational School; Hepbasli, A. [Ege Univ., Izmir (Turkey). Dept. of Mechanical Engineering; Dincer, I. [Univ. of Ontario Inst. of Technology, Oshawa, ON (Canada). Faculty of Engineering and Applied Science

    2009-07-01

    Biomass comprises all living matter present on earth and is derived from growing plants including algae, trees and crops or animal manure. It usually consists of carbon, hydrogen, oxygen and nitrogen. Sulfur is also present in small quantities, while some biomass consists of significant amounts of inorganic species. Biomass has the potential to accelerate the realization of hydrogen as a major fuel of the future. Since biomass is renewable and consumes atmospheric carbon dioxide (CO{sub 2}) during growth, it can have a small net CO{sub 2} impact compared to fossil fuels. However, hydrogen from biomass has major challenges as there are no completed technology demonstrations. In addition, the yield of hydrogen is low from biomass to biomass since the hydrogen content in biomass is low to begin with and the energy content is low due to the 40 percent oxygen content of biomass. This paper highlighted the importance of biomass-based syntactical gas and hydrogen production and reviewed the characteristics of six different biomass fuels used in various gasification systems and their energetic aspects and technical details. These fuels included almond shells; walnut prunings; rice straw; whole tree wood chips; sludge; and non-recyclable waste paper for hydrogen production from an integrated gasifier-boiler power system. The paper also presented a case study on biomass-based hydrogen production and assessed its thermodynamic performance through exergy. The results of the study were discussed through exergetic, irreversibility and improvement potential. It was concluded that the highest exergy rate was found for walnut pruning and almond shell. 15 refs., 6 tabs., 6 figs.

  8. A comparative analysis of two solid mixing models suitable for coal fluidized bed combustors and gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Abanades, J.C.; Atares, S.; Grasa, G.

    1999-07-01

    Rapid solid mixing is important to avoid undesirable temperature profiles in fluidized beds combustors and gasifiers. In this work, two alternative mathematical models for solid axial mixing are compared and their suitability for coal based fluidized beds is discussed. The two models: the Dispersion Model (May (1959)) and the Countercurrent Backmixing Model (van Deemter (1967)) were postulated early in the development of fluidized beds and both have been applied successfully despite their fundamental differences in conception. A numerical analysis investigating the convergence in the predictions of both models under practical conditions has been carried out. There is a wide area of practical interest in which both models are close (relative to typical experimental errors). Reasonable values for the bubble/slug parameters in the CCBM model are able to fit data where the dispersion model has been previously successful. This result has been confirmed with both their experimental data and other published works. The conclusion from this analysis is that the CCBM model is more reliable idealization in describing and scaling up solid mixing in coal based fluidized beds.

  9. Experimental Gasification of Biomass in an Updraft Gasifier with External Recirculation of Pyrolysis Gases

    Directory of Open Access Journals (Sweden)

    Adi Surjosatyo

    2014-01-01

    Full Text Available The updraft gasifier is a simple type of reactor for the gasification of biomass that is easy to operate and has high conversion efficiency, although it produces high levels of tar. This study attempts to observe the performance of a modified updraft gasifier. A modified updraft gasifier that recirculates the pyrolysis gases from drying zone back to the combustion zone and gas outlet at reduction zone was used. In this study, the level of pyrolysis gases that returned to the combustion zone was varied, and as well as measurements of gas composition, lower heating value and tar content. The results showed that an increase in the amount of pyrolysis gases that returned to the combustion zone resulted in a decrease in the amount of tar produced. An increase in the amount of recirculated gases tended to increase the concentrations of H2 and CH4 and reduce the concentration of CO with the primary (gasification air flow held constant. Increasing the primary air flow tended to increase the amount of CO and decrease the amount of H2. The maximum of lower heating value was 4.9 MJ/m3.

  10. Test of different biomass into the IISc open-top co-current gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Giordano, P. [Xylowatt SA, Chatel-St-Denis (Switzerland); Hasler, P. [Verenum SA, Zuerich (Switzerland); Dasappa, S. [Indian Institute of Science, Combustion Gasification and Propulsion Laboratory, Bangalore (India)

    2001-07-01

    This report made for the Swiss Federal Office of Energy (SFOE) describes the efforts made to demonstrate the technical feasibility of combined heat and power generation using wood gasification. The report describes a project involving a small open-top gasifier based on a design realised by the Indian Institute of Science (IISc). The tests made with various wood fuels such as clean wood chips, waste-wood chips, pecan nut shells, crushed oak briquettes, wood pellets, coffee hull pellets and chicken litter pellets are described and the results of measurements made concerning particulate matter, tar and certain organic compounds are presented. The discussion of the results shows that certain types of biomass can easily be used as a fuel for the small gasifier whereas others, such as coffee hull pellets, are less suitable. The report suggests that other possible fuels, such as olive and apricot stones, sludge from waste water treatment plant or plastic residue from refuse treatment should be tested in the gasifier. These tests could also provide the opportunity of testing appropriate gas treatment equipment at the same time.

  11. Sustainable model for financial viability of decentralized biomass gasifier based power projects

    International Nuclear Information System (INIS)

    This paper made a modest attempt for designing a sustainable model for financial viability of biomass gasifier power projects for enhancing electricity access in India and other developing countries. For long term sustainability of distributed generation projects in remote rural areas, viability from both project implementing agency (PIA) and the end-users need to be ensured. The minimum required prices of electricity from both PIA and end-user perspective have been estimated. While for PIA the cost recovery is the key for viability, the affordability to pay the electricity cost is crucial for the end users. Analysis carried out in this paper on the basis of data obtained from operational projects implemented in India reveal that it is essential to operate the system at a higher capacity utilization factor. While this can be achieved though creating convergence with locally relevant economic activity, it is also observed that micro-enterprises cannot pay beyond a certain price of electricity to keep it sustainable. This paper sets forth a case for developing a regulatory mechanism to extend the tariff fixation for the projects and providing cross-subsidies to ensure long term sustainability of off-grid project. - Highlights: → We design sustainable financial model for viability of biomass gasifier projects. → Analysis based on field data obtained from operational projects in India. Estimated electricity pricing from both implementing agency and end-users perspective. → A regulatory mechanism for tariff fixation and cross subsidization is recommended.

  12. Sustainable model for financial viability of decentralized biomass gasifier based power projects

    Energy Technology Data Exchange (ETDEWEB)

    Palit, Debajit, E-mail: debajitp@teri.res.in [Energy and Resources Institute, IHC Complex, Lodhi Road, New Delhi 110003 (India); Malhotra, Ramit, E-mail: ramit.malhotra@teri.res.in [Energy and Resources Institute, IHC Complex, Lodhi Road, New Delhi 110003 (India); Kumar, Atul, E-mail: atulk@teri.res.in [Energy and Resources Institute, IHC Complex, Lodhi Road, New Delhi 110003 (India); Copernicus Institute of Sustainable Development, Faculty of Geosciences, Utrecht University, P.O. Box 80115, 3508 TC Utrecht (Netherlands)

    2011-09-15

    This paper made a modest attempt for designing a sustainable model for financial viability of biomass gasifier power projects for enhancing electricity access in India and other developing countries. For long term sustainability of distributed generation projects in remote rural areas, viability from both project implementing agency (PIA) and the end-users need to be ensured. The minimum required prices of electricity from both PIA and end-user perspective have been estimated. While for PIA the cost recovery is the key for viability, the affordability to pay the electricity cost is crucial for the end users. Analysis carried out in this paper on the basis of data obtained from operational projects implemented in India reveal that it is essential to operate the system at a higher capacity utilization factor. While this can be achieved though creating convergence with locally relevant economic activity, it is also observed that micro-enterprises cannot pay beyond a certain price of electricity to keep it sustainable. This paper sets forth a case for developing a regulatory mechanism to extend the tariff fixation for the projects and providing cross-subsidies to ensure long term sustainability of off-grid project. - Highlights: > We design sustainable financial model for viability of biomass gasifier projects. > Analysis based on field data obtained from operational projects in India. Estimated electricity pricing from both implementing agency and end-users perspective. > A regulatory mechanism for tariff fixation and cross subsidization is recommended.

  13. Biomass-gasifier steam-injected gas turbine cogeneration for the cane sugar industry

    International Nuclear Information System (INIS)

    Steam injection for power and efficiency augmentation in aeroderivative gas turbines has been commercially established for natural gas-fired cogeneration since 1980. Steam-injected gas turbines fired with coal and biomass are being developed. A performance and economic assessment of biomass integrated-gasifier steam-injected gas turbine (BIG/STIG) cogeneration systems is carried out here. A detailed economic case study is presented for the second largest sugar factory in Jamaica, with cane residues as the fuel. BIG/STIG cogeneration units would be attractive investments for sugar producers, who could sell large quantities of excess electricity to the utility, or for the utility, as a low-cost generating option. Worldwide, the cane sugar industry could support some 50,000 MW of BIG/STIG electric generation capacity. The relatively modest development effort required to commercialize the BIG/STIG technology is discussed in a companion paper prepared for this conference

  14. Effect of operating parameters on performance of an integrated biomass gasifier, solid oxide fuel cells and micro gas turbine system

    International Nuclear Information System (INIS)

    An integrated power system of biomass gasification with solid oxide fuel cells (SOFC) and micro gas turbine has been investigated by thermodynamic model. A zero-dimensional electrochemical model of SOFC and one-dimensional chemical kinetics model of downdraft biomass gasifier have been developed to analyze overall performance of the power system. Effects of various parameters such as moisture content in biomass, equivalence ratio and mass flow rate of dry biomass on the overall performance of system have been studied by energy analysis. It is found that char in the biomass tends to be converted with decreasing of moisture content and increasing of equivalence ratio due to higher temperature in reduction zone of gasifier. Electric and combined heat and power efficiencies of the power system increase with decreasing of moisture content and increasing of equivalence ratio, the electrical efficiency of this system could reach a level of approximately 56%.Regarding entire conversion of char in gasifier and acceptable electrical efficiency above 45%, operating condition in this study is suggested to be in the range of moisture content less than 0.2, equivalence ratio more than 0.46 and mass flow rate of biomass less than 20  kg h−1. - Highlights: • One-dimension chemical kinetics model of biomass gasifier has been developed. • Un-reacted char have been predicted along the height of the reduction zone of gasifier. • Effects of process parameters on char flow rate and efficiencies of BG, SOFC and GT system have been examined. • Regarding entire char conversion and acceptable system efficiency, the operating condition has been proposed

  15. Mathematical Modelling of Gradient Chain Biomass Gasifier%梯度链条式生物质气化炉数值模拟

    Institute of Scientific and Technical Information of China (English)

    蔡建军; 王清成; 王全

    2015-01-01

    According to the biomass gasification discipline, biomass gasification process is divided into four stages in gra-dient chain biomass gasifier.Thus can control gasification conditions in different gasification stage.Mathematical modeling methods have been employed to simulate a gradient chain biomass gasifier, not only the temperature, concentra-tion distributing of the top of bed in different conditions, but also gasification character of gasifier chamber were calcula ted, by varying the ratio of actual air fuel ratio and stoichiometric air fuel ratio( ER) .The results showed that the tem-perature, concentration distributing( CO, CH4 , C2 H4 , Cn Hm , H2 ) , carbon conversion efficiency, HLV of the gas fuel, gasification efficiency vary in the range of 622.24℃,CO 13.81%,CH4 3.26%,C2 H4 0.601%,C2 H6 0.002%,Cn Hm 10.936%, H2 3.82%, 75.1%, 5501 kJ/Nm3 , 57.56%, and this effect of gasification better than downdraft fixed bed gasifier, a fixed-bed gasifier and bubbling bed gasifier.%梯度链条式生物质气化炉按照气化规律从空间上将生物质气化过程分为4个阶段,可实现对各气化阶段气化条件进行控制。为此,对梯度链条式生物质气化炉进行数值模拟,通过改变ER ,计算出不同 ER 下床层顶部各组分的温度和浓度分布及炉膛气相的气化特性。模拟结果显示:气化合成气出口温度622.24℃;气化合成气中CO为13.81%、CH4为3.26%、C2H4为0.601%、C2H6为0.002%、CnHm为10.936%、H2为3.82%;碳转化效率为75.1%,低位热值为5501 kJ/Nm3,气化效率为57.56%。该气化效果比下吸式固定床气化炉、固定床气化炉及鼓泡床气化炉空气气化效果好。

  16. Gasification of rice straw in a fluidized-bed gasifier for syngas application in close-coupled boiler-gasifier systems.

    Science.gov (United States)

    Calvo, L F; Gil, M V; Otero, M; Morán, A; García, A I

    2012-04-01

    The feasibility and operation performance of the gasification of rice straw in an atmospheric fluidized-bed gasifier was studied. The gasification was carried out between 700 and 850 °C. The stoichiometric air-fuel ratio (A/F) for rice straw was 4.28 and air supplied was 7-25% of that necessary for stoichiometric combustion. Mass and power balances, tar concentration, produced gas composition, gas phase ammonia, chloride and potassium concentrations, agglomeration tendencies and gas efficiencies were assessed. Agglomeration was avoided by replacing the normal alumina-silicate bed by a mixture of alumina-silicate sand and MgO. It was shown that it is possible to produce high quality syngas from the gasification of rice straw. Under the experimental conditions used, the higher heating value (HHV) of the produced gas reached 5.1 MJ Nm(-3), the hot gas efficiency 61% and the cold gas efficiency 52%. The obtained results prove that rice straw may be used as fuel for close-coupled boiler-gasifier systems. PMID:22297044

  17. Crystallization of synthetic coal-petcoke slag mixtures simulating those encountered in entrained bed slagging gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Jinichiro Nakano; Seetharaman Sridhar; Tyler Moss; James Bennett; Kyei-Sing Kwong [National Energy Technology Laboratory, Pittsburgh, PA (United States)

    2009-09-15

    Commercial entrained bed slagging gasifiers use a carbon feedstock of coal, petcoke, or combinations of them to produce CO and H{sub 2}. These carbon sources contain mineral impurities that liquefy during gasification and flow down the gasification sidewall, interacting with the refractory linear and solidifying in the cooler zones of the gasifier. Proper slag flow is critical to good gasifier operation. A hot-stage confocal scanning laser microscope (CSLM) was used to analyze the kinetic behavior of slag crystallization for a range of synthetic coal-petcoke mixtures. On the basis of the observed precipitation during cool down studies in the 1200-1700{sup o}C temperature range, a time-temperature-transformation (TTT) diagram was created. The crystallization studies were conducted with a CO/CO{sub 2} (=1.8) corresponding to a gasification PO{sub 2} of approximately 10-8 atm at 1500{sup o}C. Ash chemistries were chosen such that they correspond to coal-petcoke feedstock mixtures with coal ash amounts of 0, 10, 30, 50, 70, and 100% (by weight), with the balance being petcoke ash. The TTT diagram exhibited two crystallization areas, one above and one below 1350{sup o}C. At the nose of the higher temperature curves, karelianite (V{sub 2}O{sub 3}) crystallization occurred and was fastest for a 30% coal-petcoke ash mixture. The second nose was located below 1350{sup o}C and had spinel-type phases that formed at 1200{sup o}C, in which preferred atomic occupation at the octahedral and tetrahedral sites varied depending upon the ash composition. At 1200{sup o}C, an Al-rich spinel formed for 100% coal slag and a Fe-rich spinel formed in petcoke-enriched slags. The addition of petcoke ash to coal ash promoted crystallization in the slag, with additional crystalline phases, such as V-rich spinel, forming at the lower temperatures. These phases were not predicted using commercially available databases. 30 refs., 18 figs.

  18. Design improvements and performance testing of a biomass gasifier based electric power generation system

    International Nuclear Information System (INIS)

    The objective of the research work, reported in this paper is, to design and develop a down draft gasifier based power generation system of 75 KWe. A heat exchanger was designed and installed which recycles the waste heat of the hot gas, to improve the efficiency of the system. An improved ash removal system was introduced to minimize the charcoal removal rate from the reactor, to increase the gas production efficiency. A detailed analysis of the mass, energy and elemental balance is presented in the paper. The cold gas efficiency of the system is increased from 75.0% to 88.4%, due to the improvements made in the ash removal method. The Specific Fuel Consumption (SFC) rate of the system is 1.18 kg kWh−1. The energy conversion efficiency of the system, from fuel wood to electric power was found to be 18%. Significant increase in calorific value of the producer gas was achieved by supplying hot air for gasification. -- Highlights: •Design improvement of the system resulted 21.4% increase in cold gas efficiency (88.4%). •Mass, energy and elemental balance of a biomass gasifier system for power generation is analysed. •A heat exchanger is introduced in the system to recalculate the waste heat from the hot gas. •An innovative vibrating grate mechanism is designed and integrated with the gasifier system. •Specific Fuel Consumption is worked out to be 1.2 kg/kWh, which accounts for reduction of SFC to 20%

  19. Behavior of Alkali Metals and Ash in a Low-Temperature Circulating Fluidized Bed (LTCFB) Gasifier

    DEFF Research Database (Denmark)

    Narayan, Vikas; Jensen, Peter Arendt; Henriksen, Ulrik Birk;

    2016-01-01

    W and a 6 MW LTCFBgasifier. Of the total fuel ash entering the system, the largest fraction (40−50%) was retained in the secondary cyclone bottoms,while a lower amount (8−10%) was released as dust in the exit gas. Most of the alkali and alkaline earth metals were retained inthe solid ash, along with Si......, the low reactor temperature ensures that high-alkali biomass fuels canbe used without risk of bed defluidization. This paper presents the first investigation of the fate of alkali metals and ash in lowtemperaturegasifiers. Measurements on bed material and product gas dust samples were made on a 100 k...

  20. Analysis and control of the METC fluid bed gasifier. Final report (includes technical progress report for October 1994--January 1995), September 1994--September 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This document presents a modeling and control study of the Fluid Bed Gasification (FBG) unit at the Morgantown Energy Technology Center (METC). The work is performed under contract no. DE-FG21-94MC31384. The purpose of this study is to generate a simple FBG model from process data, and then use the model to suggest an improved control scheme which will improve operation of the gasifier. The work first developes a simple linear model of the gasifier, then suggests an improved gasifier pressure and MGCR control configuration, and finally suggests the use of a multivariable control strategy for the gasifier.

  1. Experimental Analysis of a Producer Gas Generated by a Chir Pine Needle (Leaf in a Downdraft Biomass Gasifier

    Directory of Open Access Journals (Sweden)

    Mr. Akhilesh Kumar

    2014-10-01

    Full Text Available Today’s Indian scenario is facing an unprecedented energy crisis as the conventional energy resources of India are consistently deteriorating with the limited stock of these natural minerals posing a staggering threat to the Indian economy. Among all the available resources biomass proves to be a satisfactory substitute for compensating the energy void due to these natural resources. Biomass is a renewable resource with almost zero net CO2 emission which is processed with the help of biomass gasifier which is concurrently used with a chir pine needle. The performance of the biomass gasifier system is evaluated in terms of equivalence ratio, producer gas composition, calorific value of the producer gas, gas production rate and cold gas efficiency. The experimental results are compared with those reported in the literature.

  2. Operation of a steam hydro-gasifier in a fluidized bed reactor

    OpenAIRE

    Park, Chan Seung; Norbeck, Joseph N.

    2008-01-01

    Carbonaceous material, which can comprise municipal waste, biomass, wood, coal, or a natural or synthetic polymer, is converted to a stream of methane and carbon monoxide rich gas by heating the carbonaceous material in a fluidized bed reactor using hydrogen, as fluidizing medium, and using steam, under reducing conditions at a temperature and pressure sufficient to generate a stream of methane and carbon monoxide rich gas but at a temperature low enough and/or at a pressure high enough to en...

  3. Analysis of bed agglomeration during gasification of wheat straw in a bubbling fluidised bed gasifier using mullite as bed material

    OpenAIRE

    Mac an Bhaird, Seán T.; Walsh, Eilín; Hemmingway, Phil; McDonnell, Kevin; et al.

    2014-01-01

    The quantity and composition of the ash content of straw poses technical challenges to its thermal conversion and have been widely reported to cause severe ash sintering and bed agglomeration during fluidised bed gasification. Literature indicates that a combination of reactor design and bed material measures is required to avoid defluidisation at temperatures above 800 °C. Using scanning electron microscopy and energy dispersive X-ray spectroscopy this study investigated the initial agglomer...

  4. Exergetic assessment of an integrated gasifier/boiler system for hydrogen production with different biomass types

    International Nuclear Information System (INIS)

    In this study, we utilize some experimental data taken from the literature, especially on the air blown gasification characteristics of six different biomass fuels, namely almond shell (ASF), walnut pruning (WPF), rice straw (RSF), whole tree wood chips (WWF), sludge (SLF) and non-recyclable waste paper (NPF) for hydrogen production from an integrated gasifier-boiler power system. Then, we undertake an exergy analysis of this integrated system and assess its performance through energy and exergy efficiencies. The exergy content values calculated for the biomass fuels range from 15.89 to 22.07 MJ/kg. The stack gas is examined at cyclone out, and the hydrogen concentrations determined change between 7 and 18 (%v/v) for NPF and ASF. Furthermore, the system considered is studied in terms of irreversibility and improvement potential rates. These rate values change from 6.82 to 43.11 kW for irreversibility and 6.01 to 41.24 kW for improvement potential, respectively. The exergy efficiencies of the system are calculated as 4.33 to 11.89%. Finally, we consider N and NH3 contents of the six biomass fuels and their stack gas compositions. (author)

  5. Performance of fluidized bed steam gasification of biomass - Modeling and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Loha, Chanchal; Chatterjee, Pradip K. [Thermal Engineering Group, Central Mechanical Engineering Research Institute, CSIR, Durgapur 713 209 (India); Chattopadhyay, Himadri [Dept. of Mechanical Engineering, Jadavpur University, Kolkata 700 032 (India)

    2011-03-15

    This paper presents the investigation of the performance from different biomasses in a fluidized bed gasifier where steam has been used as gasifying as well as fluidizing agent. An experimental setup is fabricated to study the gasification performance of rice husk, which is of special relevance to rice-producing countries like China and India. An equilibrium modeling approach is deployed to predict the gas composition which has been compared with the experimental results. Calibration of the model with appropriate modeling coefficients was necessary to achieve close resemblance with the experimental values. Further, the model is used to predict the gas compositions from other biomass and benchmarked with the performance of coal. In this study, the gasification temperature is varied from 650 C to 800 C, whereas the steam-to-biomass ratio (S/B) is varied from 0.75 to 2.00. As the gasification temperature increases, the production of H{sub 2} and CO increases but the generation of CH{sub 4} and CO{sub 2} reduces. The steam-to-biomass ratio was again found to influence the production rates. With increasing steam input, H{sub 2}, CO{sub 2} and CH{sub 4} were found to increase while CO reduces. (author)

  6. Thermodynamic Model of a Very High Efficiency Power Plant based on a Biomass Gasifier, SOFCs, and a Gas Turbine

    Directory of Open Access Journals (Sweden)

    P V Aravind

    2012-07-01

    Full Text Available Thermodynamic calculations with a power plant based on a biomass gasifier, SOFCs and a gas turbine are presented. The SOFC anode off-gas which mainly consists of steam and carbon dioxides used as a gasifying agent leading to an allothermal gasification process for which heat is required. Implementation of heat pipes between the SOFC and the gasifier using two SOFC stacks and intercooling the fuel and the cathode streams in between them has shown to be a solution on one hand to drive the allothermal gasification process and on the other hand to cool down the SOFC. It is seen that this helps to reduce the exergy losses in the system significantly. With such a system, electrical efficiency around 73% is shown as achievable.

  7. Formation and removal of biomass-derived contaminants in fluidized-bed gasification processes

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1996-12-31

    The objectives of this thesis were to examine the effects of the feedstock and the operating conditions of a fluidized-bed gasifier on the formation of tars and nitrogen-containing compounds and to study the effectiveness of the hot gas cleaning methods developed for the removal of particulates, alkali metals, tars and nitrogen-containing compounds. The most essential part of the work was carried out in the pressurized fluidized-bed gasification test facilities composed of an air-blown bubbling fluidized-bed gasifier and subsequent hot gas filter unit. The operation pressure of the test rig could be varied in the range 0.3 - 1.0 MPa and the maximum allowable gasification temperature was 1 050 deg C. The maximum capacity with biomass fuels was 80 kg/h. A wide range of feedstocks from hard coals, lignite and peat to different wood derived fuels and straw were used in the gasification tests. Two different types of ceramic filters were tested in the filter unit connected to the pressurized fluidized-bed gasifier. The filter unit was operated in a temperature range of 400 - 740 deg C. The particulate removal requirements set by the gas turbines were met by both types of filters and with product gases derived from all the feedstocks tested. In addition to the gasification and gas filtration tests, catalytic tar and ammonia decomposition was studied using both laboratory and bench-scale test facilities. Inexpensive calcium-based bulk materials, dolomites and limestones, were efficient tar decomposition catalysts in atmospheric-pressure tests

  8. Energy study of the energy supply systems for isolated communities in Cuba from the use of biomass gasifiers downdraft

    International Nuclear Information System (INIS)

    At work a comprehensive energy analysis of plants generating electricity from the gasification of various biomass that currently conceived by the management of the Electric Union for the electrification of isolated communities in the fields of Cuba is made. For this, based on the properties of the main biomass available, the calculations needed are performed to evaluate the efficiency of the gasifier and other components of energy transformation system. The power generation are taken into consideration and an assessment of the needs of biomass in each case is made. (full text)

  9. Steam gasification of various feedstocks at a dual fluidised bed gasifier: Impacts of operation conditions and bed materials

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Christoph; Koppatz, Stefan; Hofbauer, Hermann [Vienna University of Technology, Institute of Chemical Engineering, Vienna (Austria)

    2011-03-15

    Gasification of biomass is an attractive technology for combined heat and power production as well as for synthesis processes such as production of liquid and gaseous biofuels. Dual fluidised bed (DFB) technology offers the advantage of a nearly nitrogen-free product gas mainly consisting of H{sub 2}, CO, CO{sub 2} and CH{sub 4}. The DFB steam gasification process has been developed at Vienna University of Technology over the last 15 years using cold flow models, laboratory units, mathematical modelling and simulation. The main findings of the experimental work at a 100-kW pilot scale unit are presented. Different fuels (wood pellets, wood chips, lignite, coal, etc.) and different bed materials (natural minerals such as olivine, limestones, calcites, etc. as well as modified olivines) have been tested and the influence on tar content as well as gas composition was measured and compared among the different components. Moreover, the influence of operating parameters such as fuel moisture content, steam/fuel ratio and gasification temperature on the product gas has been investigated. DFB steam gasification of solid biomass coupled with CO{sub 2} capture, the so-called absorption enhanced reforming (AER) process, is highlighted. The experiments in pilot scale led to commercial realisation of this technology in demonstration scale. Summarising, the DFB system offers excellent fuel flexibility to be used in advanced power cycles as well as in polygeneration applications. (orig.)

  10. Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems. Volume 2, Appendix A: Fixed bed gasifier and sulfur sorbent regeneration subsystem computer model development: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Blough, E.; Russell, W.; Leach, J.W.

    1990-08-01

    Computer models have been developed for evaluating conceptual designs of integrated coal gasification combined cycle power plants. An overall system model was developed for performing thermodynamic cycle analyses, and detailed models were developed for predicting performance characteristics of fixed bed coal gasifiers and hot gas clean up subsystem components. The overall system model performs mass and energy balances and does chemical equilibrium analyses to determine the effects of changes in operating conditions, or to evaluate proposed design changes. An existing plug flow model for fixed bed gasifiers known as the Wen II model was revised and updated. Also, a spread sheet model of zinc ferrite sulfur sorbent regeneration subsystem was developed. Parametric analyses were performed to determine how performance depends on variables in the system design. The work was done to support CRS Sirrine Incorporated in their study of standardized air blown coal gasifier gas turbine concepts.

  11. Dual fluidized bed design for the fast pyrolysis of biomass

    Science.gov (United States)

    A mechanism for the transport of solids between fluidised beds in dual fluidised bed systems for the fast pyrolysis of biomass process was selected. This mechanism makes use of an overflow standpipe to transport solids from the fluidised bed used for the combustion reactions to a second fluidised be...

  12. Equilibrium modeling of gasification: Gibbs free energy minimization approach and its application to spouted bed and spout-fluid bed gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Jarungthammachote, S.; Dutta, A. [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology, P.O. Box 4, Klongluang, Pathumthani 12120 (Thailand)

    2008-06-15

    Spouted beds have been found in many applications, one of which is gasification. In this paper, the gasification processes of conventional and modified spouted bed gasifiers were considered. The conventional spouted bed is a central jet spouted bed, while the modified spouted beds are circular split spouted bed and spout-fluid bed. The Gibbs free energy minimization method was used to predict the composition of the producer gas. The major six components, CO, CO{sub 2}, CH{sub 4}, H{sub 2}O, H{sub 2} and N{sub 2}, were determined in the mixture of the producer gas. The results showed that the carbon conversion in the gasification process plays an important role in the model. A modified model was developed by considering the carbon conversion in the constraint equations and in the energy balance calculation. The results from the modified model showed improvements. The higher heating values (HHV) were also calculated and compared with the ones from experiments. The agreements of the calculated and experimental values of HHV, especially in the case of the circular split spouted bed and the spout-fluid bed were observed. (author)

  13. Gasification of biomass wastes in an entrained flow gasifier: Effect of the particle size and the residence time

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Juan J.; Aranda-Almansa, Guadalupe [Universidad de Castilla-La Mancha, Departamento de Mecanica Aplicada e Ingenieria de Proyectos, Escuela Tecnica Superior de Ingenieros Industriales (Edificio Politecnico), Avenida Camilo Jose Cela s/n, 13071 Ciudad Real (Spain); Bula, Antonio [Universidad del Norte, Departamento de Ingenieria Mecanica, Km.5 Antigua Via Puerto Colombia, Barranquilla (Colombia)

    2010-06-15

    Experimental tests in an entrained flow gasifier have been carried out in order to evaluate the effect of the biomass particle size and the space residence time on the gasifier performance and the producer gas quality. Three types of biomass fuels (grapevine pruning and sawdust wastes, and marc of grape) and a fossil fuel (a coal-coke blend) have been tested. The results obtained show that a reduction in the fuel particle size leads to a significant improvement in the gasification parameters. The thermochemical characterisation of the resulting char-ash residue shows a sharp increase in the fuel conversion for particles below 1 mm diameter, which could be adequate to be used in conventional entrained flow gasifiers. Significant differences in the thermochemical behaviour of the biomass fuels and the coal-coke blend have been found, especially in the evolution of the H{sub 2}/CO ratio with the space time, mainly due to the catalytic effect of the coal-coke ash. The reaction temperature and the space time have a significant effect on the H{sub 2}/CO ratio (the relative importance of each of these parameters depending on the temperature), this value being independent of the fuel particle size. (author)

  14. Biomass gasifier projects for decentralized power supply in India: A financial evaluation

    International Nuclear Information System (INIS)

    Results of a techno-economic evaluation of biomass gasifier based projects for decentralized power supply for remote locations in India are presented. Contributions of different components of diesel engine generator (DG) sets, dual fuel (DF) engine generator sets and 100% producer gas (HPG) engine generator sets to their capital costs as well as to the levelized unit cost of electricity (LUCE) delivered by the same have been analyzed. LUCE delivered to the consumers has been estimated to be varying in the range of Rs. 13.14-24.49/kWh (US$ 0.30-0.55/kWh) for DF BGPP. LUCE increases significantly if BGPP is operated at part loads. Presently available 40kW capacity HPG systems in India are expected to be financially competitive with a DG set of equivalent capacity beyond a break-even diesel price of Rs. 34.70/l. It is expected to be financially more attractive than an equivalent capacity DF BGPP for diesel prices of more than Rs. 44.29/l. In certain specific conditions operating two smaller capacity systems has been found to be attractive as against a single larger capacity system

  15. Scaling Up Biomass Gasifier Use in India; BarriersInterventions & Remedies: A Review

    OpenAIRE

    Mr. Ritesh U.Nrupekar; Prof. Rajesh B.Choksi

    2014-01-01

    In India, work on gasifiers for energy applications started in the early 1980s. These efforts received a boost with the Department of Non-conventional Energy Sources‟ (DNES, latter MNES, now a ministry, MNRE) dissemination program that was initiated in 1987. While this subsidy-based program was successful in placing about 1200 gasifier systems for irrigation pumping in the field, most of these units were non-operational soon after for lots of reasons. Despite all this, large-scale gasifier de...

  16. Scaling Up Biomass Gasifier Use in India; BarriersInterventions & Remedies: A Review

    Directory of Open Access Journals (Sweden)

    Mr. Ritesh U.Nrupekar

    2014-06-01

    Full Text Available In India, work on gasifiers for energy applications started in the early 1980s. These efforts received a boost with the Department of Non-conventional Energy Sources‟ (DNES, latter MNES, now a ministry, MNRE dissemination program that was initiated in 1987. While this subsidy-based program was successful in placing about 1200 gasifier systems for irrigation pumping in the field, most of these units were non-operational soon after for lots of reasons. Despite all this, large-scale gasifier deployment has still not taken off in India. The fact that scale -up did not take place automatically even in cases where gasifiers are economically clearly feasible indicates that there are a number of issues to be considered and barriers to be overcome for successful large-scale deployment. To facilitate gasifier deployment among poorer and nonskilled users (i.e., unorganized, small-scale firms, rural areas; and lack of systematic programs targeted towards scale-up. Especially important is the fact that the particulars of implementing gasifier-based energy systems depend on the kind of application and context; therefore the approach has to be tailored to the specific application – this impedes the potential success of any single approach to scale-up.

  17. Modeling of reaction kinetics in bubbling fluidized bed biomass gasification reactor

    Energy Technology Data Exchange (ETDEWEB)

    Thapa, R.K.; Halvorsen, B.M. [Telemark University College, Kjolnes ring 56, P.O. Box 203, 3901 Porsgrunn (Norway); Pfeifer, C. [University of Natural Resources and Life Sciences, Vienna (Austria)

    2013-07-01

    Bubbling fluidized beds are widely used as biomass gasification reactors as at the biomass gasification plant in Gussing, Austria. The reactor in the plant is a dual circulating bubbling fluidized bed gasification reactor. The plant produces 2MW electricity and 4.5MW heat from the gasification of biomass. Wood chips as biomass and olivine particles as hot bed materials are fluidized with high temperature steam in the reactor. As a result, biomass undergoes endothermic chemical reaction to produce a mixture of combustible gases in addition to some carbon-dioxide (CO2). The combustible gases are mainly hydrogen (H2), carbon monoxide (CO) and methane (CH4). The gas is used to produce electricity and heat via utilization in a gas engine. Alternatively, the gas is further processed for gaseous or liquid fuels, but still on the process of development level. Composition and quality of the gas determine the efficiency of the reactor. A computational model has been developed for the study of reaction kinetics in the gasification rector. The simulation is performed using commercial software Barracuda virtual reactor, VR15. Eulerian-Lagrangian approach in coupling of gas-solid flow has been implemented. Fluid phase is treated with an Eulerian formulation. Discrete phase is treated with a Lagrangian formulation. Particle-particle and particle-wall interactions and inter-phase heat and mass transfer have been taken into account. Series of simulations have been performed to study model prediction of the gas composition. The composition is compared with data from the gasifier at the CHP plant in Güssing, Austria. The model prediction of the composition of gases has good agreements with the result of the operating plant.

  18. Experimental and predicted approaches for biomass gasification with enriched air-steam in a fluidised bed.

    Science.gov (United States)

    Fu, Qirang; Huang, Yaji; Niu, Miaomiao; Yang, Gaoqiang; Shao, Zhiwei

    2014-10-01

    Thermo-chemical gasification of sawdust refuse-derived fuel was performed on a bench-scale fluidised bed gasifier with enriched air and steam as fluidising and oxidising agents. Dolomite as a natural mineral catalyst was used as bed material to reform tars and hydrocarbons. A series of experiments were carried out under typical operating conditions for gasification, as reported in the article. A modified equilibrium model, based on equilibrium constants, was developed to predict the gasification process. The sensitivity analysis of operating parameters, such as the fluidisation velocity, oxygen percentage of the enriched air and steam to biomass ratios on the produced gas composition, lower heating value, carbon conversion and cold gas efficiency was investigated. The results showed that the predicted syngas composition was in better agreement with the experimental data compared with the original equilibrium model. The higher fluidisation velocity enhanced gas-solid mixing, heat and mass transfers, and carbon fines elutriation, simultaneously. With the increase of oxygen percentage from 21% to 45%, the lower heating value of syngas increased from 5.52 MJ m(-3) to 7.75 MJ m(-3) and cold gas efficiency from 49.09% to 61.39%. The introduction of steam improved gas quality, but a higher steam to biomass ratio could decrease carbon conversion and gasification efficiency owing to a low steam temperature. The optimal value of steam to biomass ratio in this work was 1.0. PMID:25265865

  19. Multifluid modeling of the desulfurization process within a bubbling fluidized bed coal gasifier

    OpenAIRE

    Armstrong, L-M.; Gu, Sai; Luo, K. H.; P Mahanta

    2013-01-01

    The desulfurization process to a two-dimensional (2-D) and three-dimensional (3-D) Eulerian-Eulerian computational fluid dynamic (CFD) model of a coal bubbling fluidized gasifier is introduced. The desulfurization process is important for the reduction of harmful SOx emissions; therefore, the development of a CFD model capable of predicting chemical reactions involving desulfurization is key to the optimization of reactor designs and operating conditions. To model the process, one gaseous pha...

  20. Gasification of Ligno-Cellulosic Biomass in a Fluidized Bed of Sand and a Mixture of Sand with Dolomitic Limestone

    Czech Academy of Sciences Publication Activity Database

    Pohořelý, Michael; Jeremiáš, Michal; Kameníková, Petra; Svoboda, Karel; Skoblia, S.; Beňo, Z.; Durda, Tomáš; Barger, A.; Šyc, Michal; Hartman, Miloslav; Punčochář, Miroslav

    Vienna : Technische Universität Wien, 2013 - (Hofbauer, H.; Fuchs, M.), s. 1-15 ISBN 978-3-9502754-8-3. [International Conference on Polygeneration Strategies 13. Vienna (AT), 03.09.2013-05.09.2013] R&D Projects: GA TA ČR TA01020366 Grant ostatní: RFCS(XE) RFCR-CT-2010-00009 Institutional support: RVO:67985858 Keywords : dolomitic limestone * fluidized-bed gasifier * biomass Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides

  1. Agglomeration and reaction characteristics of various coal chars in fluidized-bed coal gasifier; Ryudoso sekitan gas ka ronai deno sekitan no gyoshu tokusei to hanno tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Uemiya, S.; Aoki, K.; Mori, S.; Kojima, T. [Seikei University, Tokyo (Japan). Faculty of Engineering

    1996-10-28

    With relation to the coals delivered as common samples in the coal fundamental technology development project, an experimental study was conducted on agglomeration characteristics and reaction characteristics in the fluidized-bed coal gasifier. For the experiment, used was a fluidized bed gasifier inserted with a cone-shape dispersion plate with a nozzle in the center. After raising the temperature of the gasifier up to 773K, gasification was conducted sending to the gasifier air from the nozzle and steam from the dispersion plate. The mean particle diameter and gas concentration of chars were measured till the temperature reaches 1373K. As a result of the experiment, it was confirmed that the carbon conversion ratio increases with a decrease in coalification degree of the coal. Moreover, influence of the coal kind was markedly observed at the grid zone of the lower part of the bed, and it was clarified that the lower carbon content ratio the coal kind has, the faster the speed of CO formation and water gasification get. The agglomeration temperature of charcoal which is a product of the condensate is lower by as many as several hundred K than the point of softening, and it was considered to be necessary to study the relation with the temperature distribution in the bed. 3 refs., 3 figs., 1 tab.

  2. Modeling and simulation of combined pyrolysis and reduction zone for a downdraft biomass gasifier

    International Nuclear Information System (INIS)

    This paper simulates the behavior of a global fixed bed biomass gasification reactor. The pyrolysis zone and reduction zone models are combined to simulate the global process of biomass gasification. The volatiles and gases released from the pyrolysis zone were assumed to crack into equivalent amounts of CO, CH4 and H2O. It is considered that the volatiles and gases leave the pyrolysis zone instantaneously and enter the reduction zone as initial gas concentrations. The numerical method applied is a Runge-Kutta fourth order method for solution of the pyrolysis zone model and finite differences for the reduction zone model to solve numerically the coupled ordinary differential equations. Simulations are performed for the varying pyrolysis temperature with a heating rate of 25 K/min and constant temperature of 1400 K as the initial reduction zone temperature at the same time. The simulation results for the temperature and concentrations of the gaseous species are in good agreement with published experimental data

  3. An investigation of the reactivity of chars formed in fluidized-bed gasifiers: equipment development and initial tests

    Energy Technology Data Exchange (ETDEWEB)

    A. Cousins; N. Paterson; D.R. Dugwell; R. Kandiyoti [Imperial College London, London (United Kingdom). Department of Chemical Engineering

    2006-03-15

    Chars formed during air and oxygen blown gasification processes have a low reactivity. This is due to changes that occur in the structure and morphology of the original coal during heating. In part, the changes depend on conditions prevailing during the pyrolysis stage and partly on the length of time spent at peak temperature. Previous work in this laboratory has highlighted that the gasification reactivity of a char depends on the conditions of its formation. This means that chars must be prepared under realistic conditions when conducting laboratory scale reactivity studies that are intended to support a larger scale development. This is not easy to do and requires the development of dedicated methods for preparing the char. In this paper, the development of a laboratory-scale test, based on a laboratory-scale spouted bed gasifier, is described that is able to prepare chars under conditions that represent those in an air-blown gasifier. The reactivity of the prepared chars is then examined to identify how the reactivity of the char varies within the envisaged operating window of the process. A feature of this apparatus is that the char formation time is known accurately, which has required the development of novel feeding and draining mechanisms. These enable the coal particles to be injected quickly into the reactor and the sand/char bed drained and quenched rapidly after a known residence time. The extent of char deactivation can be measured with residence times between 2 and 3600 s. In this paper, the validation of the experiment is described and some preliminary results are reported. 7 refs., 10 figs., 2 tabs.

  4. Performance evaluation of atmospheric biomass integrated gasifier combined cycle systems under different strategies for the use of low calorific gases

    International Nuclear Information System (INIS)

    This work aims at a performance evaluation of atmospheric BIGCC (biomass integrated gasifier combined cycle) systems operating under different strategies for the use of low calorific fuel in gas turbines. The fuel is a synthetic gas derived from gasification of sugar cane residues. Two analysed strategies for surge control on gas turbines originally designed for operation on natural gas are de-rating and air extraction from the compressor. Another strategy for use of biomass derived gas is the retrofit of a gas turbine through modification of the expander geometry. Three generic gas turbines, whose main parameters have been taken from off the shelf machines, are proposed as representative of certain classes of gas turbines. Results are compared to the hypothetical situation in which it is possible to accept any increase in gas turbine pressure ratio. According to the results, de-rating is the worst surge control strategy, both from the point of view of power production and thermal efficiency. Conversely, results showed considerable gains that can be obtained on cycle power production when the gas turbine expander is modified. Additionally, an overview of issues concerning the suitability of sugar cane residues (bagasse and trash) for the production of gasified gas and its use in BIGCC plants is presented

  5. Hot-gas desulfurization. II. Use of gasifier ash in a fluidized-bed process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schrodt, J.T.

    1981-02-01

    Three gasifier coal ashes were used as reactant/sorbents in batch fluidized-beds to remove hydrogen sulfide from hot, made-up fuel gases. It is predominantly the iron oxide in the ash that reacts with and removes the hydrogen sulfide; the sulfur reappears in ferrous sulfide. Sulfided ashes were regenerated by hot, fluidizing streams of oxygen in air; the sulfur is recovered as sulfur dioxide, exclusively. Ash sorption efficiency and sulfur capacity increase and stabilize after several cycles of use. These two parameters vary directly with the iron oxide content of the ash and process temperature, but are independent of particle size in the range 0.01 - 0.02 cm. A western Kentucky No. 9 ash containing 22 weight percent iron as iron oxide sorbed 4.3 weight percent sulfur at 1200/sup 0/F with an ash sorption efficiency of 0.83 at ten percent breakthrough. A global, fluidized-bed, reaction rate model was fitted to the data and it was concluded that chemical kinetics is the controlling mechanism with a predicted activation energy of 19,600 Btu/lb mol. Iron oxide reduction and the water-gas-shift reaction were two side reactions that occurred during desulfurization. The regeneration reaction occurred very rapidly in the fluid-bed regime, and it is suspected that mass transfer is the controlling phenomenon.

  6. Ground tests of 120 kW(heat) biomass fired gasifier diesel installation

    Energy Technology Data Exchange (ETDEWEB)

    Zyssin, L.V.; Maronet, I.J.; Morshin, V.N. [Energotechnology Ltd., St. Petersburg (Russian Federation)

    1996-12-31

    For the 1 MW and less power range diesel gasifier power plants could be considered as one of the main energy sources. The brief information about works carried out in Russia according to this direction is presented. Data of preliminary tests for gas diesel installations are presented. (orig.)

  7. Validation of Continuous CHP Operation of a Two-Stage Biomass Gasifier

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Jensen, Torben Kvist;

    2006-01-01

    The Viking gasification plant at the Technical University of Denmark was built to demonstrate a continuous combined heat and power operation of a two-stage gasifier fueled with wood chips. The nominal input of the gasifier is 75 kW thermal. To validate the continuous operation of the plant, a 9-day...... measurement campaign was performed. The campaign verified a stable operation of the plant, and the energy balance resulted in an overall fuel to gas efficiency of 93% and a wood to electricity efficiency of 25%. Very low tar content in the producer gas was observed: only 0.1 mg/Nm3 naphthalene could be...... measured in raw gas. A stable engine operation on the producer gas was observed, and very low emissions of aldehydes, N2O, and polycyclic aromatic hydrocarbons were measured....

  8. Aerosol sampling of an experimental stirred-bed Lurgi coal gasifier

    International Nuclear Information System (INIS)

    An aerosol sampling system has been designed, constructed and used to sample process streams of a low Btu coal gasifier. The system withdrew a sample of the gas from the process stream of the gasifier, cooled and diluted the gas immediately with nitrogen and transported the resulting aerosol to a sampling chamber. A number of aerosol sampling instruments were employed to sample the aerosol. Excess sample was pulled through a chamber, subjected to cleanup and exhausted from the system. The overall system configuration was designed to provide samples of respirable-sized particles (approximately equal to 10 μm). Non-size-selective samples for determination of bulk aerosol properties were collected using filters. Cascade impactors were used to obtain size-selected samples for determination of aerosol properties as a function of aerodynamic size. The Lovelace Aerosol Particle Separator was used to obtain size-differentiated samples for electron microscopy as well as to obtain aerodynamically sized particles for determination of effective particle densities. Sampling point-to-plane electrostatic precipitators were used to deposit aerosol material directly onto scanning electron microscope stubs and transmission electron grids. Finally, Tenax-GC was used to obtain vapor-phase samples of hydrocarbons in the aerosol. In a collaborative program with the Morgantown Energy Research Center, two locations in the process stream of a low Btu coal gasification unit have been sampled with this system. The aerosol produced from clean gas was found to be smaller in diameter than that produced from the raw gas. Examination of individual particles by scanning and transmission microscopy revealed differences in particle morphology between the two aerosols

  9. Trace element behaviour in the Sasol-Lurgi fixed-bed dry-bottom gasifier. Part 3 - The non-volatile elements: Ba, Co, Cr, Mn, and V

    Energy Technology Data Exchange (ETDEWEB)

    J.R. Bunt; F.B. Waanders [Sasol Technology (Pty) Ltd., Sasolburg (South Africa)

    2010-03-15

    The paper discusses environmentally-focussed research developments by Sasol where trace element simulation and validation of model predictions have been undertaken for the gasification process operating on low-rank bituminous Highveld coal. A Sasol-Lurgi fixed-bed dry-bottom (FBDB) gasifier was mined via turn-out sampling to determine the trace element changes through the gasifier, results being used for comparison with Fact-Sage modelled data for the non-volatile trace elements Ba, Co, Cr, Mn and V. Good agreement between measured results and model predictions in terms of ash phase partitioning behaviour was obtained for Ba, Co, Mn and V but rather poor agreement between model predicted and measured results were obtained for Cr partitioning to the solid ash fraction, which yielded a large overbalance (outside of experimental error) in the case of the measured results. This anomaly was found to not be caused by erosion of the gasifier internals, but rather possibly be ascribed to accumulation and contamination caused by likely condensation and vaporisation of this species during the gasifier sampling campaign, as well as by the particle size reduction processes utilized prior to elemental analyses. When considering the predicted speciation behaviour of the elements studied, the model output in some cases needs to be treated with some caution when validating findings with standard text book data for the elements studied, but was found to correctly model the elemental ash phase partitioning behaviour during fixed-bed gasification. Leaching tests have been conducted on the bottom ash collected from the gasifier and results have shown that the trace elements studied are firmly bound into the ash matrix and therefore would not be released during later disposal. The relative enrichment in trace element content observed for Cr within the gasifier should be further investigated. 29 refs., 11 figs., 3 tabs.

  10. Biofluid process: fluidised-bed gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, A. [ATEKO a.s., Hradec Kralove (Czech Republic)

    1996-12-31

    Fluidised-bed gasification of biomass was developed by ATEKO by using long-term experience from coal gasification. An experimental unit was built and a number of tests, first with sawdust gasification, were carried out. A gas combustion engine combined with a power generator was installed and operated in power production. (orig.)

  11. Microbial biomass and productivity in seagrass beds

    Science.gov (United States)

    Moriarty, D. J.; Boon, P. I.; Hansen, J. A.; Hunt, W. G.; Poiner, I. R.; Pollard, P. C.; Skyring, G. W.; White, D. C.

    1985-01-01

    Different methods for measuring the rates of processes mediated by bacteria in sediments and the rates of bacterial cell production have been compared. In addition, net production of the seagrass Zostera capricorni and bacterial production have been compared and some interrelationships with the nitrogen cycle discussed. Seagrass productivity was estimated by measuring the plastochrone interval using a leaf stapling technique. The average productivity over four seasons was 1.28 +/- 0.28 g C m-2 day-1 (mean +/- standard deviation, n = 4). Bacterial productivity was measured five times throughout a year using the rate of tritiated thymidine incorporated into DNA. Average values were 33 +/- 12 mg C m-2 day-1 for sediment and 23 +/- 4 for water column (n = 5). Spatial variability between samples was greater than seasonal variation for both seagrass productivity and bacterial productivity. On one occasion, bacterial productivity was measured using the rate of 32P incorporated into phospholipid. The values were comparable to those obtained with tritiated thymidine. The rate of sulfate reduction was 10 mmol SO4(-2) m-2 day-1. The rate of methanogenesis was low, being 5.6 mg CH4 produced m-2 day-1. A comparison of C flux measured using rates of sulfate reduction and DNA synthesis indicated that anaerobic processes were predominant in these sediments. An analysis of microbial biomass and community structure, using techniques of phospholipid analysis, showed that bacteria were predominant members of the microbial biomass and that of these, strictly anaerobic bacteria were the main components. Ammonia concentration in interstitial water varied from 23 to 71 micromoles. Estimates of the amount of ammonia required by seagrass showed that the ammonia would turn over about once per day. Rapid recycling of nitrogen by bacteria and bacterial grazers is probably important.

  12. Biomass gasification in fixed bed type down draft: theoretical and experimental aspects; Gasificacao de biomassa em leito fixo tipo concorrente: aspectos teoricos e experimentais

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Juan Daniel; Andrade, Rubenildo Vieira; Lora, Electo Eduardo Silva [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Inst. de Engenharia Mecanica. Nucleo de Excelencia em Geracao Termeletrica e Distribuida

    2008-07-01

    Actually are recognizing the advantages of biomass in reducing dependence on fossil fuels and significant reduction in emissions of greenhouse effect gases such as Co2. Also are known the different conversion of biomass routes for their use or exploitation, such as thermochemical process (gasification, pyrolysis and combustion), the biological process (fermentation and transesterification) and the physical process (densification, reducing grain and mechanical pressing). In this sense, the gasification is regarded as the most promising mechanism to obtain a homogeneous gaseous fuel with sufficient quality in the small scale distributed generation. This work presents some aspects of biomass gasification in fixed bed, as well as some preliminary results in the evaluation and operation of fixed bed down draft gasifier with double stage air supply of the NEST, identifying the adequate air supply quantity (equivalence ratio in the range of 0,35 to 0,45) for obtaining a fuel gas with lower heating value around 4 MJ/N m3. (author)

  13. CO-FIRING COAL, FEEDLOT, AND LITTER BIOMASS (CFB AND LFB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

    Energy Technology Data Exchange (ETDEWEB)

    Kalyan Annamalai; John Sweeten; Saqib Mukhtar; Ben Thien; Gengsheng Wei; Soyuz Priyadarsan

    2002-01-15

    result as the levels of N are higher in the biomass fuel than in coal. Further experiments showed that biomass is twice or more effective than coal when used in a reburning process to reduce NO{sub x} emissions. Since crushing costs of biomass fuels may be prohibitive, stoker firing may be cost effective; in order simulate such a firing, future work will investigate the performance of a gasifier when fired with larger sized coal and biomass. It will be a fixed bed gasifier, and will evaluate blends, coal, and biomass. Computer simulations were performed using the PCGC-2 code supplied by BYU and modified by A&M with three mixture fractions for handling animal based biomass fuels in order to include an improved moisture model for handling wet fuels and phosphorus oxidation. Finally the results of the economic analysis show that considerable savings can be achieved with the use of biomass. In the case of higher ash and moisture biomass, the fuel cost savings will be reduced, due to increased transportation costs. A spreadsheet program was created to analyze the fuel savings for a variety of different moisture levels, ash levels, and power plant operating parameters.

  14. CO-FIRING COAL, FEEDLOT, AND LITTER BIOMASS (CFB AND LFB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

    International Nuclear Information System (INIS)

    result as the levels of N are higher in the biomass fuel than in coal. Further experiments showed that biomass is twice or more effective than coal when used in a reburning process to reduce NO(sub x) emissions. Since crushing costs of biomass fuels may be prohibitive, stoker firing may be cost effective; in order simulate such a firing, future work will investigate the performance of a gasifier when fired with larger sized coal and biomass. It will be a fixed bed gasifier, and will evaluate blends, coal, and biomass. Computer simulations were performed using the PCGC-2 code supplied by BYU and modified by A and M with three mixture fractions for handling animal based biomass fuels in order to include an improved moisture model for handling wet fuels and phosphorus oxidation. Finally the results of the economic analysis show that considerable savings can be achieved with the use of biomass. In the case of higher ash and moisture biomass, the fuel cost savings will be reduced, due to increased transportation costs. A spreadsheet program was created to analyze the fuel savings for a variety of different moisture levels, ash levels, and power plant operating parameters

  15. Technical and economic assessment of producing hydrogen by reforming syngas from the Battelle indirectly heated biomass gasifier

    International Nuclear Information System (INIS)

    The technical and economic feasibility of producing hydrogen from biomass by means of indirectly heated gasification and steam reforming was studied. A detailed process model was developed in ASPEN Plus trademark to perform material and energy balances. The results of this simulation were used to size and cost major pieces of equipment from which the determination of the necessary selling price of hydrogen was made. A sensitivity analysis was conducted on the process to study hydrogen price as a function of biomass feedstock cost and hydrogen production efficiency. The gasification system used for this study was the Battelle Columbus Laboratory (BCL) indirectly heated gasifier. The heat necessary for the endothermic gasification reactions is supplied by circulating sand from a char combustor to the gasification vessel. Hydrogen production was accomplished by steam reforming the product synthesis gas (syngas) in a process based on that used for natural gas reforming. Three process configurations were studied. Scheme 1 is the full reforming process, with a primary reformer similar to a process furnace, followed by a high temperature shift reactor and a low temperature shift reactor. Scheme 2 uses only the primary reformer, and Scheme 3 uses the primary reformer and the high temperature shift reactor. A pressure swing adsorption (PSA) system is used in all three schemes to produce a hydrogen product pure enough to be used in fuel cells. Steam is produced through detailed heat integration and is intended to be sold as a by-product

  16. Defluidisation of fluidised beds during gasification of biomass

    International Nuclear Information System (INIS)

    Defluidisation and agglomeration during fluidised bed gasification of biomass is analysed and discussed. It is argued that the agglomeration and defluidisation processes, in principle, closely resemble those that determine the behaviour of glass during glass processing. Crucial properties for working with glass melts are the viscosity, stickiness, surface tension, etc. It is, however, (very) difficult to theoretically quantify these properties through thermodynamics or other theoretical means. Hence it will be problematic to theoretically predict agglomeration and defluidisation. Models for predicting defluidisation must therefore probably be of an empirical nature. As a consequence of this, a number of fluidised bed gasification tests were empirically analysed with respect to defluidisation. In total 145 tests were evaluated; of these 51 defluidised or exhibited some kind of bed disturbance. A number of fuels and bed materials were included in the analysis using a multivariate statistical approach. Based on the analysis an empirical regression equation for predicting the defluidisation temperature during fluidised bed gasification is suggested. -- Highlights: → An empirical regression equation for predicting the defluidisation temperature is suggested. → Alkali and pressure lowers the defluidisation temperatures, whilst Ca and Mg has the opposite effect. → Magnesite as bed material relative to quartz or olivine sand increase defluidisation temperatures with more than 100 oC.

  17. Biomass gasification as the first hot step in clean syngas production process - gas quality optimization and primary tar reduction measures in a 100 kW thermal input steam-oxygen blown CFB gasifier

    International Nuclear Information System (INIS)

    Syngas production based on biomass gasification is an attractive, feasible alternative to fossil fuel feedstock for the production of transportation fuels. However, the product gas from biomass gasification must be cleaned and tailored to comply with strict syngas quality requirements, as it consists of a wide variety of major and minor components and impurities. The characterization of such species is important to determine downstream gas treatment steps, and to assess the efficiency of the gasification process. This paper gives an overview of the results obtained during experiments on steam-oxygen gasification of biomass using 100 kW maximal thermal input circulating fluidized bed gasifier (CFBG) that have been performed at Delft University of Technology during the CHRISGAS project. The unit is also equipped with a high-temperature ceramic gas filter and downstream reactors for upgrading of the gas. In the experiments biomass types of both woody and agricultural origin have been used. They were represented by clean wood, demolition wood, an energy crop species (miscanthus) and a true residue (Dutch straw), respectively. Moreover, different bed materials have been applied, namely quartz sand, treated and untreated olivine and magnesite. During the experiments extensive measurements of gas composition have been carried out throughout the integrated test rig. The gas characterization included major gas components as well as certain minor species and tar. The results show that with the use of magnesite as bed material, remarkable increases of hydrogen yield were attained, as compared to sand or olivine; up to a volume fraction of almost 40% (dry, nitrogen-free basis). Also the H2:CO ratio increased from values near or lower than 1 to 2.3-2.6. This is near the values needed, for e.g., Fischer-Tropsch diesel production, indicating a potential for simplification of the gas upgrading. Furthermore, by using magnesite tar content of the raw gas was reduced to values near 2

  18. Study of biomass combustion characteristics for the development of a catalytic combustor/gasifier

    OpenAIRE

    Dody, Joseph W.

    1985-01-01

    The research reported here explored, a "new" approach to biomass energy conversion for small-scale process heat-applications. The conversion process uses close-coupled catalytic. combustion to burn combustibles in effluent generated by primary combustion or gasification of biomass fuels. Computer control of primary and secondary air flow rates allow control of the devices output power while maintaining fuel-lean or stoichiometric conditions in the effluent entering the catalytic combustion...

  19. Economic scales for first-generation biomass-gasifier/gas turbine combined cycles fueled from energy plantations

    International Nuclear Information System (INIS)

    This paper assesses the scales at which commercial, first-generation biomass integrated-gasifier/gas turbine combined cycle (BIG/GTCC) technology is likely to be most economic when fueled by plantation-derived biomass. First-generation BIG/GTCC systems are likely to be commercially offered by vendors beginning around 2000 and will be based on either pressurized or atmospheric-pressure gasification. Both plant configurations are considered here, with estimates of capital and operating costs drawn from published and other sources. Prospective costs of a farm-grown energy crop (switchgrass) delivered to a power plant are developed with the aid of a geographic information system (GIS) for agricultural regions in the North Central and Southeast US in the year 2000 and 2020. A simplified approach is applied to estimate the cost of delivering chipped eucalyptus from an existing plantation in Northeast Brazil. The optimum capacity (MWopt), defined as that which yields the minimum calculated cost of electricity (COEm), varies by geographic region due to differences in delivered biomass costs. With pressurized BIG/GTCC plants, MWopt is in the range of 230--320 MWe for the sites considered, assuming most of the land around the power plant is farmed for energy crop production. For atmospheric-pressure BIG/GTCC plants, MWopt ranges from 110 to 142 MWe. When a lower fraction of the land around a plant is used for energy farming, values for MWopt are smaller than these. In all cases, the cost of electricity is relatively insensitive to plant capacity over a wide range around MWopt

  20. Potential approaches to improve gasification of high water content biomass rich in cellulose in dual fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Li; Xu, Guangwen [State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, Beijing (China); Suda, Toshiyuki [Research Laboratory, IHI Corporation, Ltd., Yokohama (Japan); Murakami, Takahiro [National Institute of Advanced Science and Technology, Tsukuba (Japan)

    2010-08-15

    Biomass containing water of 30-65 wt.% and rich in cellulose, such as various grounds of drinking materials and the lees of spirit and vinegar, is not suitable for biological digestion, and the thermal conversion approach has to be applied to its conversion into bioenergy. The authors have recently worked on converting such biomass into middle heating-value gas via dual fluidized bed gasification (DFBG) integrated with various process intensification technologies. This article is devoted to highlighting those technical ways, including the choice of the superior technical deployment for a DFBG system, the impregnation of Ca onto fuel in fuel drying, the integration of gas cleaning with fuel gasification via two-stage DFBG (T-DFBG), and the decoupling of fuel drying/pyrolysis and char gasification via the decoupled DFBG (D-DFBG). The attained results demonstrated that the superior deployment of bed combination for the DFBG should be a bubbling/turbulent fluidized bed gasifier integrated with a pneumatic riser combustor. In terms of improving efficiency of fuel conversion into combustible gas and suppressing tar generation during gasification, the impregnation of Ca onto fuel exhibited distinctively high upgrading effect, while both the T-DFBG and D-DFBG were also demonstrated to be effective to a certain degree. (author)

  1. Concepts of Emission Reduction in Fluidized Bed Combustion of Biomass

    Directory of Open Access Journals (Sweden)

    Amon Purgar

    2012-01-01

    Full Text Available A status report on fluidized bed technology in Austria is under preparation, in response to the Fluidized Bed Conversion multi-lateral technology initiative of the International Energy Agency. This status report focuses on the current operation of fluidized bed combustors. Combustors have been installed in the following industrial sectors: pulp and paper, biomass heat and power plants, waste-to-energy plants, and communal sewage sludge treatment plants. There are also some small demonstration plants. These plants all have in common that they treat renewable fuel types. In many cases, only bio-fuels are treated. Besides the ability to burn a wide range of low-grade and difficult fuels, fluidized bed combustors have the advantages of low NOX emissions and the possibility of in-process capture of SO2. Various emission reduction concepts for fluidized bed combustors that are typical for their industrial sector are discussed. The discussion of these concepts focuses on NOX, SO2 and dust.

  2. Process performance improvement in a co-current, fixed bed biomass gasification facility by control system modifications

    International Nuclear Information System (INIS)

    Highlights: • Software algorithms for biomass gasification process improvement have been developed. • Advanced control solution has been proposed for on-line process control. • Different process variables have been controlled simultaneously. • Different process improvement cases have been analysed. • Data for system development has been extracted from co-current, fixed bed gasifier. - Abstract: Advanced control solutions are a developing technology which represent a promising approach to tackle problems related to efficiency and environmental aspects of biomass gasification process in a cost effective way. In this paper the potential of advanced control concept to improve gasification process efficiency and to reduce negative environmental effects of the process has been analysed. Advanced control solution, based on feedforward–feedback control approach has been developed using collected operation data and the effects of control concept on gasification process have been analysed using developed artificial neural network based prediction model. Measurement data for the controller and simulation model development has been extracted from a 75 MWth co-current, fixed bed biomass gasification plant operated by Technical University Dresden. The effects of 6 different process improvement goals for controller algorithms development have been analysed during 20 h of plant operation. The analysis has shown that with introduction of advanced control solutions process efficiency could be improved up to 20%, together with reduction of negative environmental aspects of the process

  3. Heavy metal characterization of circulating fluidized bed derived biomass ash.

    Science.gov (United States)

    Li, Lianming; Yu, Chunjiang; Bai, Jisong; Wang, Qinhui; Luo, Zhongyang

    2012-09-30

    Although the direct combustion of biomass for energy that applies circulating fluidized bed (CFB) technology is steadily expanding worldwide, only few studies have conducted an environmental assessment of biomass ash thus far. Therefore, this study aims to integrate information on the environmental effects of biomass ash. We investigated the concentration of heavy metal in biomass ash samples (bottom ash, cyclone ash, and filter ash) derived from a CFB boiler that combusted agricultural and forest residues at a biomass power plant (2×12 MW) in China. Ash samples were gathered for the digestion and leaching test. The heavy metal content in the solution and the leachate was studied via an inductively coupled plasma-mass spectrometer and a Malvern Mastersizer 2000 mercury analyzer. Measurements for the chemical composition, particle size distribution, and the surface morphology were carried out. Most of the metals in cyclone ash particles were enriched, whereas Ti and Hg were enriched in filter ash. Residence time contributed most to heavy metal enrichment. Under HJ/T 300 conditions, the heavy metals showed serious leaching characteristics. Under EN 12457-2 conditions, leaching behavior was hardly detected. PMID:22840499

  4. Modeling work of a small scale gasifier/SOFC CHP system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, M.; Aravind, P.V.; Qu, Z.; Woudstra, N.; Verkooijen, A.H.M. [Delft University of Technology (Netherlands). Dept. of Mechanical Engineering], Emails: ming.liu@tudelft.nl, p.v.aravind@tudelft.nl, z.qu@tudelft.nl, n.woudstra@tudelft.nl, a. h. m. verkooijen@tudelft.nl; Cobas, V.R.M. [Federal University of Itajuba (UNIFEI), Pinheirinhos, MG (Brazil). Dept. of Mechanical Engineering], E-mail: vlad@unifei.edu.br

    2009-07-01

    For a highly efficient biomass gasification/Solid Oxide Fuel Cell (SOFC) Combined Heat and Power (CHP) generation system, the gasifier, the accompanying gas cleaning technologies and the CHP unit must be carefully designed as an integrated unit. This paper describes such a system involving a two-stage fixed-bed down draft gasifier, a SOFC CHP unit and a gas cleaning system. A gas cleaning system with both low temperature and high temperature sections is proposed for coupling the gasifier and the SOFC. Thermodynamic modeling was carried out for the gasifier/SOFC system with the proposed gas cleaning system. The net AC electrical efficiency of this system is around 30% and the overall system efficiency is around 60%. This paper also describes various exergy losses in the system and the future plans for integrated gasifier-GCU-SOFC experiments from which the results will be used to validate the modeling results of this system. (author)

  5. Study tour to biomass gasifiers in Germany; Studiereis naar biomassavergassingsinstallaties in Duitsland

    Energy Technology Data Exchange (ETDEWEB)

    Knoef, H.A.M. [BTG Biomass Technology Group, Enschede (Netherlands)

    2000-12-01

    A study trip to a biomass gasification plant in Germany took place from 13-15 November 2000. The goal of the trip was to obtain information on German developments, experience, and possibilities in the field of biomass gasification. The participants were representatives of Dutch parties in the energy sector: waste sector, manufacturers, producers, policy makers and consultants. The most important feature was the visit to plants that were in operation. Due in particular to the new EEG (Emeuerbare-Energien-Gesetz/Renewable Energy) legislation, German policy makers have created an initial market for sustainable energy with a degree of success. The key feature is that EEG makes projects 'bankable' by guaranteeing a return delivery compensation. An EEG-type scheme designed to accelerate the development of sustainable energy could be an interesting instrument also for the Netherlands. The plan was to visit four plants and have a number of presentations in a period of three days. Preference was for relatively new plants with differing concepts. The following plants were visited and/or presented: 200-kWe CHP wood gasification plant, based on AHT technology, located at Domsland in Eckenfoerde; a 10,000 tonnes/year wood gasification plant, based on 'cupola furnace' technology of blast furnaces, located at Holzhausen near Leipzig; a 1-MWe wood gasification plant, based on Carbo-V technology, located at Freiberg; and finally a 23-MWe CBP wood gasification plant, also based on Juch technology, located at Siebenlehn. In clearly appears that Germany is ahead of the Netherlands in the realisation of gasification plants. Still, there are certain problems with the reliability of operation. The plants selected were relatively new (with the possible exception of Espenhain) and they are having too many teething problems. Sound insight has been obtained into the various concepts of decentralised energy generation from biomass and how this can be fitted into the

  6. Chaos Transfer in Fluidized Beds Accompanied with Biomass Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    唐松涛; 李定凯; 吕子安; 沈幼庭

    2003-01-01

    Experiments of biomass pyrolysis were carried out in a fiuidized bed, and dynamic signals of pressure and temperature were recorded. Correlation dimension was employed to characterize the chaotic behavior of pressure and temperature signals. Both pressure and temperature signals exhibit chaotic behavior, and the chaotic behavior of temperature signals is always weaker than that of pressure signals. Chaos transfer theory was advanced to explain the above phenomena. The discussion on the algorithm of the correlation dimension shows that the distance definition based on rhombic neighborhood is a better choice than the traditional one based on spherical neighborhood. The former provides a satisfactory result in a much shorter time.

  7. Emission characterization for a down draft gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Charles Denys da Luz; Nogueira, Manoel Fernandes Martins [Federal University of Para (UFPA), Belem, PA (Brazil). Lab. de Engenharia Mecanica], E-mail: mfmn@ufpa.br

    2010-07-01

    Gasification is the thermal-chemical conversion of biomass into combustible gas, which can be used as combustion fuel in internal combustion motors or syngas with applications across the chemical industry. To check the performance of a gasifier one needs to quantify the contained energy in the produced gas as well as the quantity of produced carbon for the calculation of mean energy efficiency and the carbon conversion factor of the gas using experimentally obtained data. Energy efficiency is quantified value that describes the relationship between the respective quantities of energy contained in the biomass used and the gas produced, in the same sense, the carbon conversion is a quantity of carbonaceous compounds present in used biomass and the amount of carbon in the produced gas. The present document evaluates the energy efficiency and the carbon conversion factor of a prototype model of a downdraft gasifier from India that was modified by a local company. The nominal parameters of the gasifier's function are as follows: gas production capacity running on 45 kW, biomass consumption (acai seeds) of 15 kg/h. The gasifier dimensions are as follows: diameter of 150 mm and height of 2000 mm. The energy efficiency and the carbon conversion rate are quantified, the pressure loss due to the bed reactor and the temperature of the gases are also measured at the reactor exit; the tar, particle composite and non-condensable gas (CO, CO{sub 2}, CH{sub 4}, SO{sub 2}, N{sub 2} e NO{sub x}) concentrations were measured in the produced gas at the cleaning process. (author)

  8. Investigation of flow behaviour of coat/ash particles in an advanced pressurised fluidized bed gasifier (APFBG) using radiotracer technique

    International Nuclear Information System (INIS)

    Knowledge of Residence Time Distribution (RTD), Mean Residence Time (MRT) and degree of backmixing of solid phase is important for efficient operation of the coal gasifier. Radiotracer technique was used for measure RTD of coal/ash particles in a pilot-scale gasifier and obtain the values of MRT and backmixing. Lanthanum 140 labeled coal (100 g) was used as a tracer. The tracer was instantaneously injected into the coal feed line and monitored at ash and gas outlets of the gasifier using collimated scintillation detectors. The measured RTD data were treated and MRTs of coal/ash particles were determined. The treated data were simulated using tank-in-series model. The simulation RTD data indicated good degree of mixing with minor bypassing/short-circulating of coal particles. The results of the investigation were found useful for scale-up of the gasification process. (author)

  9. Biomass Gasifier Energy Cyber-Physical System Design with Coupling of the Wind and Solar Energy

    Directory of Open Access Journals (Sweden)

    Zhihuan Zhang

    2013-07-01

    Full Text Available The air pollution in China has been quite serious, and biomass is extremely rich in large agricultural country. In the view of current situation, highly efficient solar collectors, wind energy and solar energy coupled heating straw gasification system is studied. The stability of continuous gas production is analyzed in various weather conditions including windy, calm, sunny and cloudy. Highly efficient solar panels, wind energy and solar energy coupled heating straw gasification control system is raised. This system overcomes the time variability of the weather conditions to ensure the stability of the continuous gas production under a variety of weather conditions. It has high quality of gas production, strong anti-interference ability and robustness.

  10. Morgantown low-Btu gasifier simulation program

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    This project's overall purpose is to develop a Morgantown low-Btu gasifier system simulation program. The gasifier system consists of a moving bed gasifier and a gas clean-up system, and the present report concerns steady-state simulation of the gasifier. Since the gasifier output controls the performance of the gas clean-up system, it is necessary to investigate the effects of steam/coal and oxygen/coal ratios and of feed temperature on the gasifier output. Simulation of the gasifier performance, therefore, was undertaken to gain quantitative understanding of these effects. This gasifier simulation program will be coupled with a gas clean-up system simulation program now under development. Simulation of the entire gasifier system will serve as a guideline in planning experiments to enable its optimum overall operation.

  11. Process integration and optimization of a solid oxide fuel cell – Gas turbine hybrid cycle fueled with hydrothermally gasified waste biomass

    International Nuclear Information System (INIS)

    Due to its suitability for using wet biomass, hydrothermal gasification is a promising process for the valorization of otherwise unused waste biomass to synthesis gas and biofuels. Solid oxide fuel cell (SOFC) based hybrid cycles are considered as the best candidate for a more efficient and clean conversion of (bio) fuels. A significant potential for the integration of the two technologies is expected since hydrothermal gasification requires heat at 673–773 K, whereas SOFC is characterized by heat excess at high temperature due to the limited electrochemical fuel conversion. This work presents a systematic process integration and optimization of a SOFC-gas turbine (GT) hybrid cycle fueled with hydrothermally gasified waste biomass. Several design options are systematically developed and compared through a thermodynamic optimization approach based on First Law and exergy analysis. The work demonstrates the considerable potential of the system that allows for converting wet waste biomass into electricity at a First Law efficiency of up to 63%, while simultaneously enabling the separation of biogenic carbon dioxide for further use or sequestration. -- Highlights: ► Hydrothermal gasification is a promising process for the valorization of waste wet biomass. ► Solid Oxide Fuel Cell – Gas Turbine hybrid cycle emerges as the best candidates for conversion of biofuels. ► A systematic process integration and optimization of a SOFC-GT hybrid cycle fuelled with hydrothermally gasified biomass is presented. ► The system may convert wet waste biomass to electricity at a First Law efficiency of 63% while separating the biogenic carbon dioxide. ► The process integration enables to improve the First Law efficiency of around 4% with respect to a non-integrated system.

  12. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS (CFB AND CLB) FUELS IN PULVERIZED FUEL AND FIXED BED BURNERS

    Energy Technology Data Exchange (ETDEWEB)

    Kalyan Annamalai; John Sweeten; Saqib Mukhtar; Ben Thein; Gengsheng Wei; Soyuz Priyadarsan; Senthil Arumugam; Kevin Heflin

    2003-08-28

    Intensive animal feeding operations create large amounts of animal waste that must be safely disposed of in order to avoid environmental degradation. Cattle feedlots and chicken houses are two examples. In feedlots, cattle are confined to small pens and fed a high calorie grain-diet diet in preparation for slaughter. In chicken houses, thousands of chickens are kept in close proximity. In both of these operations, millions of tons of manure are produced every year. The manure could be used as a fuel by mixing it with coal in a 90:10 blend and firing it in an existing coal suspension fired combustion systems. This technique is known as co-firing, and the high temperatures produced by the coal will allow the biomass to be completely combusted. Reburn is a process where a small percentage of fuel called reburn fuel is injected above the NO{sub x} producing, conventional coal fired burners in order to reduce NO{sub x}. The manure could also be used as reburn fuel for reducing NO{sub x} in coal fired plants. An alternate approach of using animal waste is to adopt the gasification process using a fixed bed gasifier and then use the gases for firing in gas turbine combustors. In this report, the cattle manure is referred to as feedlot biomass (FB) and chicken manure as litter biomass (LB). The report generates data on FB and LB fuel characteristics. Co-firing, reburn, and gasification tests of coal, FB, LB, coal: FB blends, and coal: LB blends and modeling on cofiring, reburn systems and economics of use of FB and LB have also been conducted. The biomass fuels are higher in ash, lower in heat content, higher in moisture, and higher in nitrogen and sulfur (which can cause air pollution) compared to coal. Small-scale cofiring experiments revealed that the biomass blends can be successfully fired, and NO{sub x} emissions will be similar to or lower than pollutant emissions when firing coal. Further experiments showed that biomass is twice or more effective than coal when

  13. Biomass gasification in a circulating fluidized bed; Vergasung von Biomasse in der zirkulierenden Wirbelschicht

    Energy Technology Data Exchange (ETDEWEB)

    Ising, M.; Hoelder, D.; Backhaus, C.; Althaus, W. [Fraunhofer Inst. fuer Umwelt-, Sicherheits- und Energietechnik UMSICHT, Oberhausen (Germany)

    1998-09-01

    Biomass gasification in a circulating fluidized bed, in combination with a gas engine or gas burner, is a promising option for energetic use of biomass. Economic efficiency analyses on the basis of the UMSICHT plant show that this technology for combined heat and power generation from biomass is promising also for the range below 10 MW. The economic situation of any plant must be considered for the specific boundary conditions imposed by the power supply industry. The feasibility of the process was tested in a demonstration plant at Oberhausen. The plant was optimized further in extensive test series, and a number of tar reduction processes were investigated and improved on. The authors now intend to prove that gasification in a circulating fluidized bed combined with a gas engine cogeneration plant is feasible in continuous operation. (orig./SR) [Deutsch] Die Vergasung von Biomasse in der zirkulierenden Wirbelschicht ist in Kombination mit einem Gasmotor oder einem Gasbrenner eine vielversprechende Option fuer die energetische Biomassenutzung. Wirtschaftlichkeitsbetrachtungen auf Basis der UMSICHT-Anlage zeigen, dass diese Technologie fuer die gekoppelte Strom- und Waermeerzeugung aus Biomasse auch im Leistungsbereich unter 10 MW grosse Chancen verspricht. Dabei ist die oekonomische Situation einer Anlage im Einzelfall unter Beachtung der energiewirtschaftlichen Randbedingungen zu beurteilen. Durch den Betrieb einer Demonstrationsanlage in Oberhausen konnte die Funktion des Verfahrens nachgewiesen werden. In weiteren umfangreichen Versuchsreihen werden die Anlage weiter optimiert und verschiedene Konzepte zur Teerminderung untersucht und weiterentwickelt. Angestrebt ist der Nachweis des Dauerbetriebs von ZWS-Vergasung zusammen mit dem Gasmotoren-BHKW. (orig./SR)

  14. Preliminary tests with a birch wood pellets up-draft air gasifier

    OpenAIRE

    Grimm, Alejandro; Suarez, José; Björnbom, Emilia; Zanzi Vigouroux, Rolando

    2004-01-01

    In Sweden and Cuba a variety of biomass have being investigated for energyconversion through termochemical processes into solid, liquids and gaseous products. Biomass gasification in fixed bed seem to be attractive option for the conversion ofagricultural and forest residues into gases suitable for use as alternative fuel in gasengines in rural areas, heat or electricity production. This paper discusses the performance characteristics of a up - draft gasifier withBirch wood pellets. The bench...

  15. Two-stage dual fluidized bed gasification: Its conception and application to biomass

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Guangwen [Research Laboratory, IHI Corporation, Ltd., Isogo-Ku, Yokohama 235-8501 (Japan); Institute of Process Engineering, Chinese Academy of Sciences, Haidian, Beijing 100080 (China); Murakami, Takahiro [Research Laboratory, IHI Corporation, Ltd., Isogo-Ku, Yokohama 235-8501 (Japan); Clean Gas Group, National Institute of Advanced Science and Technology, Tsukuba, Ibaraki 305-8569 (Japan); Suda, Toshiyuki; Matsuzaw, Yoshiaki; Tani, Hidehisa [Research Laboratory, IHI Corporation, Ltd., Isogo-Ku, Yokohama 235-8501 (Japan)

    2009-01-15

    The quoted two-stage dual fluidized bed gasification (T-DFBG) devises the use of a two-stage fluidized bed (TFB) to replace the single-stage bubbling fluidized bed gasifier involved in the normally encountered dual fluidized bed gasification (N-DFBG) systems. By feeding fuel into the lower stage of the TFB, this lower stage functions as a fuel gasifier similar to that in the N-DFBG so that the upper stage of the TFB works to upgrade the produced gas in the lower stage and meanwhile to suppress the possible elutriation of fuel particles fed into the freeboard of the lower-stage bed. The heat carrier particles (HCPs) circulated from the char combustor enter first the upper stage of the TFB to facilitate the gas upgrading reactions occurring therein, and the particles are in turn forwarded into the lower stage to provide endothermic heat for fuel pyrolysis and gasification reactions. Consequently, with T-DFBG it is hopeful to increase gasification efficiency and decrease tar content in the produced gas. This anticipation was corroborated through gasifying dry coffee grounds in two 5.0kg/h experimental setups configured according to the principles of T-DFBG and N-DFBG, respectively. In comparison with the N-DFBG case, the test according to T-DFBG increased, the fuel C conversion and cold gas efficiency by about 7% and decreased tar content in the produced gas by up to 25% under similar reaction conditions. Test results demonstrated also that all these upgrading effects via adopting T-DFBG were more pronounced when a Ca-based additive was blended into the fuel. (author)

  16. Benefits of Allothermal Biomass Gasification for Co-Firing

    Energy Technology Data Exchange (ETDEWEB)

    Van der Meijden, C.M.; Van der Drift, A.; Vreugdenhil, B.J. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2012-04-15

    Many countries have set obligations to reduce the CO2 emissions from coal fired boilers. Co-firing of biomass in existing coal fired power plants is an attractive solution to reduce CO2 emissions. Co-firing can be done by direct mixing of biomass with coal (direct co-firing) or by converting the biomass into a gas or liquid which is fired in a separate burner (indirect co-firing). Direct co-firing is a rather simple solution, but requires a high quality and expensive biomass fuel (e.g. wood pellets). Indirect co-firing requires an additional installation that converts the solid biomass into a gas or liquid, but has the advantage that it can handle a wide range of cheap biomass fuels (e.g. demolition wood) and most of the biomass ash components are separated from the gas before it enters the boiler. Separation of biomass ash can prevent fouling issues in the boiler. Indirect co-firing, using biomass gasification technology, is already common practice. In Geertruidenberg (the Netherlands) a 80 MWth Lurgi CFB gasifier produces gas from demolition wood which is co-fired in the Amer PC boiler. In Ruien (Belgium) a 50 MWth Foster Wheeler fluidized bed gasifier is in operation. The Energy research Centre of the Netherlands (ECN) developed a 'second generation' allothermal gasifier called the MILENA gasifier. This gasifier has some major advantages over conventional fluidized bed gasifiers. The heating value of the produced gas is approximately 2.5 times higher than of gas produced by conventional bubbling / circulating fluidized bed gasifiers. This results in smaller adaptations to the membrane wall of the boiler for the gas injection, thus lower costs. A major disadvantage of most fluidized bed gasifiers is the incomplete conversion of the fuel. Typical fuel conversions vary between 90 and 95%. The remaining combustible material, also containing most of the biomass ash components, is blown out of the gasifier and removed from the gas stream by a cyclone to

  17. Production of renewable energy from biomass and waste materials using fluidized bed technologies

    International Nuclear Information System (INIS)

    Malaysian industries generate substantial amount of biomass and waste materials such as wastes from agricultural and wood based industries, sludge waste from waste-water treatment plants and solid waste from municipals. Incinerating these waste materials not only produces renewable energy, but also solving their disposal problems. Fluidized bed combustors are widely used for incinerating these biomass materials. The significant advantages of fluidized bed incineration include simple design, efficient, and ability to reduce air pollution emissions. This paper discusses the opportunities and challenges of producing the green energy from biomass materials using the fluidized bed technologies. (Author)

  18. A CFD model for biomass combustion in a packed bed furnace

    Science.gov (United States)

    Karim, Md. Rezwanul; Ovi, Ifat Rabbil Qudrat; Naser, Jamal

    2016-07-01

    Climate change has now become an important issue which is affecting environment and people around the world. Global warming is the main reason of climate change which is increasing day by day due to the growing demand of energy in developed countries. Use of renewable energy is now an established technique to decrease the adverse effect of global warming. Biomass is a widely accessible renewable energy source which reduces CO2 emissions for producing thermal energy or electricity. But the combustion of biomass is complex due its large variations and physical structures. Packed bed or fixed bed combustion is the most common method for the energy conversion of biomass. Experimental investigation of packed bed biomass combustion is difficult as the data collection inside the bed is challenging. CFD simulation of these combustion systems can be helpful to investigate different operational conditions and to evaluate the local values inside the investigation area. Available CFD codes can model the gas phase combustion but it can't model the solid phase of biomass conversion. In this work, a complete three-dimensional CFD model is presented for numerical investigation of packed bed biomass combustion. The model describes the solid phase along with the interface between solid and gas phase. It also includes the bed shrinkage due to the continuous movement of the bed during solid fuel combustion. Several variables are employed to represent different parameters of solid mass. Packed bed is considered as a porous bed and User Defined Functions (UDFs) platform is used to introduce solid phase user defined variables in the CFD. Modified standard discrete transfer radiation method (DTRM) is applied to model the radiation heat transfer. Preliminary results of gas phase velocity and pressure drop over packed bed have been shown. The model can be useful for investigation of movement of the packed bed during solid fuel combustion.

  19. Heat Transfer in a Fixed Biomass Char Bed

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Henriksen, Ulrik Birk; Glarborg, P.; Jensen, A.; Arendt, P.

    2002-01-01

    A thermal conductivity model based on the Yagi and Kunii model together with a bed model was developed to describe the thermal conductivity of a straw char bed. The bed model describes the relationship between the distance between particles and the external porosity. To verify the model, thermal ...

  20. On the gasification of biomass in a steam-oxygen blown CFB gasifier with the focus on gas quality upgrading: technology background, experiments and mathematical modeling

    NARCIS (Netherlands)

    Siedlecki, M.

    2011-01-01

    This work presents and discusses the results of the research on the gasification of biomass in an atmospheric circulating fluidized bed, with a mixture of steam and oxygen as fluidization / gasification medium. The main objectives of this research were to investigate and improve the gasification pro

  1. Biomass ash-bed material interactions leading to agglomeration in FBC

    DEFF Research Database (Denmark)

    Visser, H.J.M.; van Lith, Simone Cornelia; Kiel, J.H.A.

    2008-01-01

    In (bubbling) fluidized-bed combustion and gasification of biomass, several potential problems are associated with the inorganic components of the fuel. A major problem area is defluidization due to bed agglomeration. The most common found process leading to defluidization in commercial-scale ins...

  2. The influence of fine char particles burnout on bed agglomeration during the fluidized bed combustion of a biomass fuel

    Energy Technology Data Exchange (ETDEWEB)

    Scala, Fabrizio; Chirone, Riccardo [Istituto di Ricerche sulla Combustione, CNR, P.le V. Tecchio, 80-80125 Naples (Italy); Salatino, Piero [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, P.le V. Tecchio, 80-80125 Naples (Italy)

    2003-11-15

    The combustion of biomass char in a bubbling fluidized bed is hereby addressed, with specific reference to the influence that the combustion of fine char particles may exert on ash deposition and bed agglomeration phenomena. Experiments of steady fluidized bed combustion (FBC) of powdered biomass were carried out with the aim of mimicking the postcombustion of attrited char fines generated in the fluidized bed combustion of coarse char. Experimental results showed that the char elutriation rate is much smaller than expected on the basis of the average size of the biomass powder and of the carbon loading in the combustor. Samples of bed material collected after prolonged operation of the combustor were characterized by scanning electron microscopy (SEM)-EDX analysis and revealed the formation of relatively coarse sand-ash-carbon aggregates. The phenomenology is consistent with the establishment of a char phase attached to the bed material as a consequence of adhesion of char fines onto the sand particles. Combustion under sound-assisted fluidization conditions was also tested. As expected, enhancement of fines adhesion on bed material and further reduction of the elutriation rate were observed. Experimental results are interpreted in the light of a simple model which accounts for elutriation of free fines, adhesion of free fines onto bed material and detachment of attached fines by attrition of char-sand aggregates. Combustion of both free and attached char fines is considered. The parameters of the model are assessed on the basis of the measured carbon loadings and elutriation rates. Model computations are directed to estimate the effective size and the peak temperature of char-sand aggregates. The theoretical estimates of the effective aggregate size match fairly well those observed in the experiments.

  3. Condensate from a two-stage gasifier

    DEFF Research Database (Denmark)

    Bentzen, Jens Dall; Henriksen, Ulrik Birk; Hindsgaul, Claus

    2000-01-01

    Condensate, produced when gas from downdraft biomass gasifier is cooled, contains organic compounds that inhibit nitrifiers. Treatment with activated carbon removes most of the organics and makes the condensate far less inhibitory. The condensate from an optimised two-stage gasifier is so clean...... compounds and the level of inhibition are so low that condensate from the optimised two-stage gasifier can be led to the public sewer....

  4. Energy recovery by gasification of agricultural and forestry wastes in fluidized bed reactors and in moving bed reactors with internal recycle of pyrolysis gas; process development and reactor modelling. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Aarsen, F.G. van den; Susanto, H.; Beenackers, A.A.C.M.; Swaaij, W.P.M. van

    1986-01-01

    A modified co-current moving gasifier bed has been developed which substantially reduces product gas tar content compared to conventional down draft gasifiers and allows for a better scale-up of the reactor. These improvements have been realized by installing an ejector in the air inlet which sucks the pyrolysis gases into the gasifying air stream and allows for subsequent combustion of the pyrolysis products in a separate combustor. In relation to the modelling of a fluidized bed biomass gasifier, we studied the fast pyrolysis of beech wood particles and the char-carbondioxide gasification kinetics in a bench scale fluidized bed reactor. A 30 cm diameter fluidized bed biomass gasifier has been constructed and the reactor performance on wood and rice husks has been studied. Those experiments (at 50 kg biomass/hr) revealed that a good gas quality is produced if the reactor is operated above 800/sup 0/ C, in the co-current mode (bottomfeed). Ongoing research is on mass transfer and flow behaviour in the fluidized bed reactor; a mathematical model of the fluidized bed gasifier is under development.

  5. Biomass Conversion into Solid Composite Fuel for Bed-Combustion

    Directory of Open Access Journals (Sweden)

    Tabakaev Roman B.

    2015-01-01

    Full Text Available The purpose of this research is the conversion of different types of biomass into solid composite fuel. The subject of research is the heat conversion of biomass into solid composite fuel. The research object is the biomass of the Tomsk region (Russia: peat, waste wood, lake sapropel. Physical experiment of biomass conversion is used as method of research. The new experimental unit for thermal conversion of biomass into carbon residue, fuel gas and pyrolysis condensate is described. As a result of research such parameters are obtained: thermotechnical biomass characteristics, material balances and product characteristics of the heat-technology conversion. Different methods of obtaining solid composite fuel from the products of thermal technologies are considered. As a result, it is established: heat-technology provides efficient conversion of the wood chips and peat; conversion of the lake sapropel is inefficient since the solid composite fuel has the high ash content and net calorific value.

  6. Biomass CFB gasifier connected to a 350 MW{sub t}h steam boiler fired with coal and natural gas - THERMIE demonstration project in Lahti in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Palonen, J. [Foster Wheeler Energia Oy, Varkaus (Finland). Varkaus Global New Products

    1997-12-31

    The successful experience in developing the advanced Foster Wheeler Energi Oy`s (former Ahlstroem Pyropower) Circulating Fluidized Bed combustion system subsequently led to the development of the CFB gasification technology in the early 1980s. The driving force for the developing work was the dramatic increase in oil price during the oil crises. The primary advantage of CFB gasification technology is that the it enables the substitution of expensive fuels e.g. oil or gas with cheap solid fuels. These cheap fuels are typically different types of waste woods, bark or other biofuels. In the CFB gasifier these solid fuels are converted to gaseous fuel which can be used instead of other expensive fuels. In some cases this also solves a waste disposal problem, providing a secondary economic and environmental benefit. Foster Wheeler Energia Oy has supplied four commercial scale atmospheric CFB gasifiers in the mid 80s to the pulp and paper industry with capacities from 17 to 35 MW based on fuel input. These applications utilize waste wood as feedstock and the units are still successfully operation today. Lahden Laempoevoima Oy is a Finnish power company producing power and district heat for the city of Lahti. The company is 50 % owned by the city of Lahti and 50 % by Imatran Voima Oy, which is the largest utility power company in Finland. Lahden Laempoevoima Oy operates the Kymijaervi power plant locating nearby the city of Lahti in Southern Finland. To keep the energy prices as low as possible, Lahden Laempoevoima is continuously looking for the most economical fuel sources, and simultaneously, trying to improve the environmental acceptability of the energy production. At the moment, about 300 GWh/a different type of biofuels and refuse fuels are available in the Lahti area. On an annual basis, the available amount of biofuels and refuse fuels is enough to substitute for about 15 % of the fuels burned in the main boiler equalling max 30 % of coal. The aim in this Lahden

  7. Energetic use of wood and biomass by circulating fluidized bed gasification. Final report

    International Nuclear Information System (INIS)

    The project's objective was the development and utilization of a biomass gasification process based on CFB-gasification with dry hot gas upgrading for IC-engine operation. Construction and operation of a test plant at pilot scale with 400 kW fuel input capacity. Development of a mathematical model for CFB-gasification. Reliable operation of CFB-gasifier, good results at partial load and good behaviour at changing the load. Air blown gasification of wood chips yielded lower heating values (LHV) up to 5500 kJ/m3 (s.T.p., dry) for the gas. Main attention to measures for tar removal. Target value was 3 (s.T.p.) for napthalene + PAH. Average amount of tar after CBF-gasifier at 3000-5000 mg/m3 (s.T.p.). Primary measures aiming at a decreased tar production were not suitable for achieving the target value. Several secondary measures were tested. Tars could almost completely be cracked or reformed by special catalysts. In continuous test runs of more than 100 h duration tar contents less than 50 mg/m3 were achieved. A scale up for a catalytic gas cleaning system based on the results is planned. Estimations of economics show the process concept to be advantegous for plants up to 30 MW fuel input capacity. Profitable costs for combined heat and power production from biomass can be expected. (orig.)

  8. Experimental numerical study utilizing CFD in a stratified gasifier operating with biomass; Estudio numerico experimental de un gasificador estratificado que opera con biomasa, utilizando CFD

    Energy Technology Data Exchange (ETDEWEB)

    Rogel Ramirez, Alejandro

    2007-07-01

    The central idea behind this work is the developing of a numeric-experimental model, useful to optimize the biomass stratified gasifier design. Firstly, model validation will be carried up by comparison with reference experimental data available. This study describes a 1-D + 2-D numerical model used to simulate the gasification of pine wood pellets in a stratified downdraft gasifier whereby Eulerian conservation equations are solved for particle and gas phase components, velocities and specific enthalpies. The model takes into account the biomass particle process such as heating up, drying, primary pyrolysis of biomass, secondary pyrolysis of tar, homogeneous reactions and heterogeneous combustion/gasification reactions, and particle size change. This CFD model can be used to predict temperature profiles, gas composition, producer gas lower heating value, and carbon conversion efficiency, and the reactor performance when operating parameters and feed properties are changed. The standard {kappa}-{epsilon} and RNG {kappa}-{epsilon} models were used to simulate the turbulent flow conditions. [Spanish] La idea central del presente trabajo es el desarrollo de un modelo numerico- experimental, para optimizar el diseno de gasificadores estratificados de biomasa. Primeramente, el modelo sera validado utilizando datos experimentales disponibles en la literatura. Este estudio describe un modelo numerico 1-D+2-D, utilizado para simular la gasificacion de 'pelets' de madera de pino en un gasificador estratificado de flujos paralelos, en el que se resuelven ecuaciones de conservacion Eulerianas para los componentes de la fase gaseosa, la fase solida, velocidades y entalpias especificas. El modelo considera procesos como: calentamiento, secado de la biomasa, pirolisis primaria de la madera, pirolisis secundaria de los alquitranes, reacciones homogeneas, reacciones heterogeneas de combustion/gasificacion y cambio en el tamano de la particula. Este modelo CFD puede ser

  9. Forest biomass waste combustion in a pilot-scale bubbling fluidised bed combustor

    International Nuclear Information System (INIS)

    Combustion experiments of forest biomass waste in a pilot-scale bubbling fluidised bed combustor were performed under the following conditions: i) bed temperature in the range 750-800 oC, ii) excess air in the range 10-100%, and iii) air staging (80% primary air and 20% secondary air). Longitudinal pressure, temperature and gas composition profiles along the reactor were obtained. The combustion progress along the reactor, here defined as the biomass carbon conversion to CO2, was calculated based on the measured CO2 concentration at several locations. It was found that 75-80% of the biomass carbon was converted to CO2 in the region located below the freeboard first centimetres, that is, the region that includes the bed and the splash zone. Based on the CO2 and NO concentrations in the exit flue gas, it was found that the overall biomass carbon conversion to CO2 was in the range 97.2-99.3%, indicating high combustion efficiency, whereas the biomass nitrogen conversion to NO was lower than 8%. Concerning the Portuguese regulation about gaseous emissions from industrial biomass combustion, namely, the accomplishment of CO, NO and volatile organic compounds (VOC) (expressed as carbon) emission limits, the set of adequate operating conditions includes bed temperatures in the range 750oC-800 oC, excess air levels in the range 20%-60%, and air staging with secondary air accounting for 20% of total combustion air.

  10. Possible ways of suppression of agglomeration of particles in fluidized bed combustion of selected waste biomass fuels

    International Nuclear Information System (INIS)

    Fluidized bed combustion (FBC) of biomass is often complicated by agglomeration of particles within the bed. The alkali compounds from biomass ash have tendency to accumulate esp. in a bed with sand particles. For typical cases of FBC of straw, wood and sewage sludge from a paper mill the experimental results on fluidized bed particle agglomeration are presented and possible ways for agglomeration abatement are critically assessed (author)

  11. Production of synthesis gas by co-gasifying coke and natural gas in a fixed bed reactor

    International Nuclear Information System (INIS)

    The production of synthesis gas has gained increasing importance because of its use as raw material for various industrial syntheses. In this paper synthesis gas generation during the reaction of a coal/methane with steam and oxygen, which is called the co-gasification of coal and natural gas, was investigated using a laboratory scale fixed bed reactor. It is found that about 95% methane conversion and 80% steam decomposition have been achieved when the space velocity of input gas (oxygen and methane) is less than 200 h-1 and reaction temperature about 1000 oC. The product gas contains about 95% carbon monoxide and hydrogen. The reaction system is near the equilibrium when leaving the reactor

  12. Fuel bed evaluations and coal properties transformation in a Sasol-Lurgi fixed bed dry bottom gasifier operating on North Dakota lignite / Setobane Jonas Mangena

    OpenAIRE

    Mangena, Setobane Jonas

    2008-01-01

    The growth in coal consumption worldwide as well as the high oil prices in the recent past has led to the current increased interest in the application of coal gasification technologies. The Sasoi-Lurgi Fixed Bed Dry Bottom (S-L FBDB) gasification technology is one such technology that has the biggest market share in the world and maintains its competitive edge particularly with regard to gasification of low grade and low rank coal. To ensure sustained competitive advantage through tech...

  13. FLASH PYROLYSIS OF BIOMASS PARTICLES IN FLUIDIZED BED FOR BIO-OIL PRODUCTION

    Institute of Scientific and Technical Information of China (English)

    Shurong; Wang; Mengxiang; Fang; Chunjiang; Yu; Zhongyang; Luo; Kefa; Cen

    2005-01-01

    Biomass utilization could relieve the pressure caused by conventional energy shortage and environmental pollution. Advantage should be taken of the abundant biomass in China as clean energy source to substitute for traditional fossil fuels. At present, flash pyrolysis appears to be an efficient method to produce high yields of liquids that could either be directly used as fuel or converted to other valuable chemicals. Experiments were carried out of pyrolyzing biomass particles in a hot dense fluidized bed of sand to obtain high-quality bio-oil. Among four kinds of biomass species adopted in our experiment, Padauk Wood had the best characteristics in producing bio-oil. GC-MS analysis showed bio-oil to be a complex mixture consisting of many compounds. Furthermore, an integrated model was proposed to reveal how temperature influences biomass pyrolysis. Computation indicated that biomass particles underwent rapid heating before pyrolysis.

  14. Hot and Dry Cleaning of Biomass-Gasified Gas Using Activated Carbons with Simultaneous Removal of Tar, Particles, and Sulfur Compounds

    Directory of Open Access Journals (Sweden)

    Kinya Sakanishi

    2012-05-01

    Full Text Available This study proposes a gas-cleaning process for the simultaneous removal of sulfur compounds, tar, and particles from biomass-gasified gas using Fe-supported activated carbon and a water-gas shift reaction. On a laboratory scale, the simultaneous removal of H2S and COS was performed under a mixture of gases (H2/CO/CO2/CH4/C2H4/N2/H2S/COS/steam. The reactions such as COS + H2 → H2S + CO and COS + H2O → H2S + CO2 and the water-gas shift reaction were promoted on the Fe-supported activated carbon. The adsorption capacity with steam was higher than that without steam. On a bench scale, the removal of impurities from a gas derived from biomass gasification was investigated using two activated filters packed with Fe-supported activated carbon. H2S and COS, three- and four-ring polycyclic aromatic hydrocarbons (PAHs, and particles were removed and a water-gas shift reaction was promoted through the first filter at 320–350 °C. The concentrations of H2S and COS decreased to less than 0.1 ppmv. Particles and the one- and two-ring PAHs, except for benzene, were then removed through the second filter at 60–170 °C. The concentration of tar and particles decreased from 2428 to 102 mg Nm−3 and from 2244 to 181 mg Nm−3, respectively.

  15. Modeling of a biomass high temperature steam gasifier integrated with assisted solar energy and a micro gas turbine

    International Nuclear Information System (INIS)

    Highlights: • A parametric study determines optimal system requirements for different feedstock. • The effect that biomass and moisture levels have on syngas composition is analyzed. • The novel system proposed optimizes heat recovery and water consumption. • Competitive solar efficiency is obtained at low steam to biomass ratios. • Overall CHP utilization factors range between 30% and 43%. - Abstract: A mathematical model that describes a trailer scale biomass steam gasification system coupled with a solar collector heat source and a micro gas turbine is reported in this paper. This combined heat and power system is set to a prescribed output of 20 kWe and several system conditions have been optimized in a parametric study to minimize resource consumption rates. Biomass feeding rates under optimal conditions were found to range between 23 and 63 kg/h depending on the types of feedstock and other parameters. Water consumption is reduced through a condensation and recirculation process that is part of a heat recovery unit. Also, solar energy requirements have been reduced by means of a recuperator that extracts heat out of the combustion products. The overall system performance has been evaluated by a utilization factor which was found to range between 30% and 43%. The system has been compared to a baseline case of an air breathing gasification system of a similar scale. It was found that steam gasification produces the syngas with heating values over twice as high as those obtained by air gasification. Steam gasification also led to a 25% and 50% reduction in emission rates of contaminants like CO2 and nitrogen oxides respectively relative to the baseline case

  16. Purchase of power by State Electricity Boards from biomass gasifier systems: formulating a long term national policy

    International Nuclear Information System (INIS)

    Current policy for purchase of power from renewable sources of energy by State Electricity Boards in India is examined and certain changes in that policy are suggested. State Electricity Boards are reluctant to buy power from renewables as such a purchase is seen by the Boards as being of against their economic interests. But if socio-environmental and climatological costs of power of thermal plants are taken into consideration, it becomes imperative that a long term policy for power purchase from renewables by electricity boards will have to be followed. Such a policy is outlined. After giving formulae for unit cost of generation from thermal power plants, diesel generation (DG) sets and biomass gasification, it is recommended that basis for the purchase price for power generated through biomass gas should be the cost of generation through DG sets or cost of generation through biomass gasification whichever is lower. A clause for automatic price escalation should also be a part of such policy. Some measures to compensate electricity boards for purchase of power from renewables are suggested. They include levying of a special surcharge by boards on their electricity sales and funding by the Central Government. (M.G.B.)

  17. Biomass energy conversion: conventional and advanced technologies

    International Nuclear Information System (INIS)

    Increasing interest in biomass energy conversion in recent years has focused attention on enhancing the efficiency of technologies converting biomass fuels into heat and power, their capital and operating costs and their environmental emissions. Conventional combustion systems, such as fixed-bed or grate units and entrainment units, deliver lower efficiencies (<25%) than modem coal-fired combustors (30-35%). The gasification of biomass will improve energy conversion efficiency and yield products useful for heat and power generation and chemical synthesis. Advanced biomass gasification technologies using pressurized fluidized-bed systems, including those incorporating hot-gas clean-up for feeding gas turbines or fuel cells, are being demonstrated. However, many biomass gasification processes are derivatives of coal gasification technologies and do not exploit the unique properties of biomass. This paper examines some existing and upcoming technologies for converting biomass into electric power or heat. Small-scale 1-30 MWe units are emphasized, but brief reference is made to larger and smaller systems, including those that bum coal-biomass mixtures and gasifiers that feed pilot-fuelled diesel engines. Promising advanced systems, such as a biomass integrated gasifier/gas turbine (BIG/GT) with combined-cycle operation and a biomass gasifier coupled to a fuel cell, giving cycle efficiencies approaching 50% are also described. These advanced gasifiers, typically fluid-bed designs, may be pressurized and can use a wide variety of biomass materials to generate electricity, process steam and chemical products such as methanol. Low-cost, disposable catalysts are becoming available for hot-gas clean-up (enhanced gas composition) for turbine and fuel cell systems. The advantages, limitations and relative costs of various biomass gasifier systems are briefly discussed. The paper identifies the best known biomass power projects and includes some information on proposed and

  18. Modeling and simulation of biomass air-steam gasification in a fluidized bed

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    By considering the features of fluidized-bed reactors and the kinetic mechanism of biomass gasification,a steady-state,isothermal,one-dimensional and twophase mathematical model of biomass gasification kinetics in bubbling fluidized beds was developed.The model assumes the existence of two phases - a bubble and an emulsion phase - with chemical reactions occurring in both phases.The axial gas dispersion in the two phases is accounted for and the pyrolysis of biomass is taken to be instantaneous.The char and gas species CO,CO2,H2,H2O,CH4 and 8 chemical reactions are included in the model.The mathematical model belongs to a typical boundary value problem of ordinary differential equations and its solution is obtained by a Matlab program.Utilizing wood powder as the feedstock,the calculated data show satisfactory agreement with experimental results and proves the effectiveness and reliability of the model.

  19. An SEM/EDX study of bed agglomerates formed during fluidized bed combustion of three biomass fuels

    International Nuclear Information System (INIS)

    The agglomeration behaviour of three biomass fuels (exhausted and virgin olive husk and pine seed shells) during fluidized bed combustion in a lab-scale reactor was studied by means of SEM/EDX analysis of bed agglomerate samples. The effect of the fuel ash composition, bed temperature and sand particle size on agglomeration was investigated. The study was focused on the main fuel ash components and on their interaction with the bed sand particles. Agglomeration was favoured by high temperature, small sand size, a high fraction of K and Na and a low fraction of Ca and Mg in the fuel ash. An initial fuel ash composition close to the low-melting point eutectic composition appears to enhance agglomeration. The agglomerates examined by SEM showed a hollow structure, with an internal region enriched in K and Na where extensive melting is evident and an external one where sand particles are only attached by a limited number of fused necks. Non-molten or partially molten ash structures deposited on the sand surface and enriched in Ca and Mg were also observed. These results support an ash deposition-melting mechanism: the ash released by burning char particles inside the agglomerates is quantitatively deposited on the sand surface and then gradually embedded in the melt. The low-melting point compounds in the ash migrate towards the sand surface enriching the outermost layer, while the ash structure is progressively depleted of these compounds

  20. Production Of Bio fuel Starter From Biomass Waste Using Rocking Kiln Fluidized Bed System

    International Nuclear Information System (INIS)

    The biggest biomass source in Malaysia comes from oil palm industry. According to the statistic in 2010, Malaysia produced 40 million tones per year of biomass of which 30 million tones of biomass originated from the oil palm industries. The biomass waste such as palm kernel shell can be used to produce activated carbon and bio fuel starter. A new type of rotary kiln, called Rocking Kiln Fluidized Bed (RKFB) was developed in Nuclear Malaysia to utilize the large amount of the biomass to produce high value added products. This system is capable to process biomass with complete combustion to produce bio fuel starter. With this system, the produced charcoal has calorific value, 33MJ/ kg that is better than bituminous coal with calorific value, 25-30 MJ/ kg. In this research, the charcoals produced were further used to produce the bio fuel starter. This paper will elaborate the experimental set-up of the Rocking Kiln Fluidized Bed (RKFB) for bio fuel starter production and the quality of the produced bio fuel starter. (author)

  1. Characterization of hydrodynamics and solids mixing in fluidized beds involving biomass

    Science.gov (United States)

    Fotovat, Farzam

    This thesis focuses on the characterization of hydrodynamics and mixing phenomena in fluidized beds containing mixtures of sand and irregular biomass particles. The first objective of this study is understanding the effect of the large biomass particles on the bubbling characteristics and gas distribution pattern of sand fluidized beds. The second objective is the characterization of mixing/segregation of biomass and sand particles under fluidization conditions. A variety of experimental techniques are employed to study the behavior of two constituting phases of a fluidized bed, i.e., dilute (bubble) and dense (emulsion) phases. Exploring the characteristic fluidization velocities of sand-biomass mixtures unveils that the onset of bubbling in these systems occurs at a higher gas velocity compared to that of the initial fluidization velocity (Uif). The initial bubbling velocity (Uib), the final fluidization velocity ( Uff), and the transition gas velocity from bubbling to turbulent regime (Uc) rise by increasing the fraction of biomass in the mixture. Statistical analysis of the pressure signal at top of the bed reveals that increasing the biomass load hinders the evolution of bubbles at a low gas velocity (Useparation of the main components of the shredded bulky waste. A step-wise process has been developed based on the elutriation and density segregation techniques. After removal of the light and interwoven species of the shredded waste by elutriation, the nonelutriated materials are further separated into two successive fluidization columns. Polypropylene and glass beads are introduced as the fluidization media in these columns in order to make density segregation of the target and not-target components possible. Hence, undesirable combustible matters and hard plastic are separated as the overflow of the first and second fluidization steps. A second elutriation column is also devised to separate and recover fiber and soft plastic. To determine optimal operating

  2. Attached biomass growth and substrate utilization rate in a moving bed biofilm reactor

    OpenAIRE

    J. J. Marques; Souza, R. R.; C. S. Souza; I. C. C. Rocha

    2008-01-01

    A moving bed bioreactor containing cubes of polyether foam immersed in a synthetic wastewater (an aqueous mixture of meat extract, yeast extract, dextrose, meat peptone, ammonium chloride, potassium chloride, sodium chloride, sodium bicarbonate, potassium mono-hydrogen-phosphate and magnesium sulphate) was used to evaluate bacterial growth and biomass yield parameters based on Monod's equation. The wastewater was supplied in the bottom of the equipment flowing ascending in parallel with a dif...

  3. Fluidized Bed Gasification of Biomass: the Yield of Hydrogen under Different Operating Conditions

    Czech Academy of Sciences Publication Activity Database

    Jeremiáš, Michal; Pohořelý, Michael; Svoboda, Karel; Skoblia, S.; Beňo, Z.; Kameníková, Petra; Durda, Tomáš

    Praha : KANAG - TISK, 2014 - (Bouzek, K.; Doucek, A.), s. 38 ISBN 978-80-7080-878-8. [5International Conference on Hydrogen Technologies /5./. Prague (CZ), 02.04.2014-04.04.2014] R&D Projects: GA MŠk(CZ) 7C11009 Grant ostatní: RFCS(XE) RFCR-CT-2010-0009 Institutional support: RVO:67985858 Keywords : biomass * gasification * dolomite * limestone * fluidized bed Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  4. CFD Modelling of Heat Supply in Fluidized Bed Fast Pyrolysis of Biomass

    OpenAIRE

    Mellin, Pelle; Wu, Yueshi; Kantarelis, Efthymios; Yang, Weihong

    2014-01-01

    This paper investigates the heat supply to the fast pyrolysis process, by addition of oxygen in the fluidizing gas. Since the technology will be further developed, a solution for the heat supply in a large-scale reactor must be conceived, which is one option to achieve the primary target: to operate with as little extra heat as possible. Corrections for the granular bed material and the biomass particles are implemented in the simulation. User Defined Functions (UDF) is extensively used to de...

  5. A phenomenological energy model of biomass pyrolysis under autothermal fluidized bed conditions

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, J.; Beaton, P. [University of the Orient, Santiago de Cuba (Cuba). Faculty of Mechanical Engineering; Zanzi, R. [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2006-06-15

    In Cuba a variety of types of biomass is being investigated for energy conversion through thermochemical processes into solid, liquid, and gas products. A continuous bench fluidized bed pyrolysis has been designed and is currently under testing. In this article, a transport model has been developed to simulate the axial temperature fields in a bench. The model and experimental results indicated that (1) two zones exist inside of the fluidization column, the dense bed where the exothermic and endothermic reactions are active, and the freeboard zone where the temperature of the pyrolysis product decreases continuously; (2) the bed temperature increases with an increase in the air factor. The predicted temperature is in quantitative agreement with experimental measurements. (Author)

  6. Process simulation of biomass gasification in a bubbling fluidized bed reactor

    International Nuclear Information System (INIS)

    Highlights: • Bubbling fluidized bed gasification of biomass is studied by computer simulation. • The effect of some critical parameters on gasification performance is studied. • The performance of air–steam gasification of wood chips is analyzed. • Model predictions are compared against available data from the literature. • The optimum operating conditions for the gasification are found. - Abstract: A detailed process model was developed to simulate the air–steam gasification of biomass in a bubbling fluidized bed for hydrogen and syngas production by coupling Aspen Plus simulator and dedicated FORTRAN subroutines. Effects of critical parameters, including gasification temperature, steam/biomass ratio (SBR), equivalence ratio (ER), and biomass particle size (BPS) on the composition of fuel gas were discussed. The results indicate that the high temperature is more favorable for production of useful syngas (H2 and CO) and hydrogen yield (HY). The simulation results also demonstrate that ER is the most important factor in the process; higher ER contributed to higher carbon conversion, tar reforming, and gas yield, however, it lowered gas caloric value and cold gas efficiency. However, steam injection recognized as a key factor to produce more hydrogen rich gas in the SBR range studied, but had a major effect on CO2 formation. The model is validated by experimental data and found relatively to be in good agreement

  7. Attached biomass growth and substrate utilization rate in a moving bed biofilm reactor

    Directory of Open Access Journals (Sweden)

    J. J. Marques

    2008-12-01

    Full Text Available A moving bed bioreactor containing cubes of polyether foam immersed in a synthetic wastewater (an aqueous mixture of meat extract, yeast extract, dextrose, meat peptone, ammonium chloride, potassium chloride, sodium chloride, sodium bicarbonate, potassium mono-hydrogen-phosphate and magnesium sulphate was used to evaluate bacterial growth and biomass yield parameters based on Monod's equation. The wastewater was supplied in the bottom of the equipment flowing ascending in parallel with a diffused air current that provided the mixing of the reactor content. Suspended and attached biomass concentration was measured through gravimetric methods. Good agreement was found between experimental kinetic parameters values and those obtained by other researchers. The only significant difference was the high global biomass content about 2 times the values obtained in conventional processes, providing high performance with volumetric loading rates up to 5.5 kg COD/m³/d.

  8. Plastic waste elimination by co-gasification with coal and biomass in fluidized bed with air in pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Aznar, Maria P.; Caballero, Miguel A.; Sancho, Jesus A.; Frances, E. [Chemical and Environmental Engineering Department, Centro Politecnico Superior, Maria de Luna 3, University of Zaragoza, 50018 Zaragoza (Spain)

    2006-05-15

    Treatment of plastic waste by gasification in fluidized bed with air using dolomite as tar cracking catalyst has been studied. The gasifier has a 1 m high bed zone (diameter of 9.2 cm) followed by a 1 m high freeboard (diameter of 15.4 cm). The feedstock is composed of blends of plastic waste with pine wood sawdust and coal at flow rates of 1-4 kg/h. Operating variables studied were gasifier bed temperature (750-880 {sup o}C), equivalence ratio (0.30-0.46), feedstock composition and the influence of secondary air insertion in freeboard. Product distribution includes gas and char yields, gas composition (H{sub 2}, CO, CO{sub 2}, CH{sub 4}, light hydrocarbons), heating value and tar content in the flue gas. As a result, a gas with a medium hydrogen content (up to 15% dry basis) and low tar content (less than 0.5 g/m{sub n}{sup 3}) is obtained. (author)

  9. Tar Production from Biomass Pyrolysis in a Fluidized Bed Reactor: A Novel Turbulent Multiphase Flow Formulation

    Science.gov (United States)

    Bellan, J.; Lathouwers, D.

    2000-01-01

    A novel multiphase flow model is presented for describing the pyrolysis of biomass in a 'bubbling' fluidized bed reactor. The mixture of biomass and sand in a gaseous flow is conceptualized as a particulate phase composed of two classes interacting with the carrier gaseous flow. The solid biomass is composed of three initial species: cellulose, hemicellulose and lignin. From each of these initial species, two new solid species originate during pyrolysis: an 'active' species and a char, thus totaling seven solid-biomass species. The gas phase is composed of the original carrier gas (steam), tar and gas; the last two species originate from the volumetric pyrolysis reaction. The conservation equations are derived from the Boltzmann equations through ensemble averaging. Stresses in the gaseous phase are the sum of the Newtonian and Reynolds (turbulent) contributions. The particulate phase stresses are the sum of collisional and Reynolds contributions. Heat transfer between phases, and heat transfer between classes in the particulate phase is modeled, the last resulting from collisions between sand and biomass. Closure of the equations must be performed by modeling the Reynolds stresses for both phases. The results of a simplified version (first step) of the model are presented.

  10. Biomass Torrefaction Process Review and Moving Bed Torrefaction System Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Shakar Tumuluru; Shahab Sokhansanj; Christopher T. Wright; Richard D. Boardman

    2010-08-01

    Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300 C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200-230 C and 270-280 C. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, producing a final product that will have a lower mass but a higher heating value. An important aspect of research is to establish a degree of torrefaction where gains in heating value offset the loss of mass. There is a lack of literature on torrefaction reactor designs and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes (a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and (b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed for different capacities, designing the heat loads and gas flow rates, and developing an interactive excel sheet where the user can define design specifications. In this report, 25-1000 kg/hr are used in equations for the design of the torrefier, examples of calculations, and specifications for the torrefier.

  11. Biomass Torrefaction Process Review and Moving Bed Torrefaction System Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Shakar Tumuluru; Shahab Sokhansanj; Christopher T. Wright

    2010-08-01

    Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300°C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200–230ºC and 270–280ºC. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, producing a final product that will have a lower mass but a higher heating value. An important aspect of research is to establish a degree of torrefaction where gains in heating value offset the loss of mass. There is a lack of literature on torrefaction reactor designs and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed for different capacities, designing the heat loads and gas flow rates, and developing an interactive excel sheet where the user can define design specifications. In this report, 25–1000 kg/hr are used in equations for the design of the torrefier, examples of calculations, and specifications for the torrefier.

  12. Fixed (slow moving) bed updraft gasification of agricultural residues

    Energy Technology Data Exchange (ETDEWEB)

    Vigouroux, Rolando Zanzi [Royal Institute of Technology (KTH), Stockholm (Sweden). Dept. of Chemical Engineering and Technology], E-mail: rolando@ket.kth.se; Escalona, Ronoldy Faxas [University of Oriente, Santiago de Cuba (Cuba). Fac. of Mechanical Engineering], E-mail: faxas@fim.uo.edu.cu

    2009-07-01

    Birch, in form of pellets has been gasified in updraft fixed-bed gasifier using air as oxidation agent. The main objectives were to study the effect of the treatment conditions on the distribution of the products and the composition of product gas. The influence of the air flow rates on the composition of the producer gas has been studied. The amount of the biomass used in the experiments was varied between 1 and 4 kg and the flow rate of the air was varied from 1.1 to 2.6 m3/h. Increased airflow rates favored higher temperatures. Excessively high airflow rates resulted in fast consumption of the biomass and it also favored combustion over gasification and thus formation of lower amounts of combustible products. High airflow rates caused also higher yields of tars, due to the shorter residence time of the tar-rich gas in the gasifier and thus unfavorable conditions for tar cracking. (author)

  13. Commercial gasifier for IGCC applications study report

    Energy Technology Data Exchange (ETDEWEB)

    Notestein, J.E.

    1990-06-01

    This was a scoping-level study to identify and characterize the design features of fixed-bed gasifiers appearing most important for a gasifier that was to be (1) potentially commercially attractive, and (2) specifically intended for us in integrated coal gasification/combined-cycle (IGCC) applications. It also performed comparative analyses on the impact or value of these design features and on performance characteristics options of the whole IGCC system since cost, efficiency, environmental traits, and operability -- on a system basis -- are what is really important. The study also reviewed and evaluated existing gasifier designs, produced a conceptual-level gasifier design, and generated a moderately advanced system configuration that was utilized as the reference framework for the comparative analyses. In addition, technical issues and knowledge gaps were defined. 70 figs., 31 tabs.

  14. Computational simulation of the biomass gasification process in a fluidized bed reactor

    International Nuclear Information System (INIS)

    In an agro-industrial country as Cuba many residues of cultivation like the rice and the cane of sugar take place, besides the forest residues in wooded extensions. Is an interesting application for all this biomass, the gasification technology, by its high efficiency and its positive environmental impact. The computer simulation appears like a useful tool in the researches of parameters of operation of a gas- emitting, because it reduces the number of experiments to realise and the cost of the researches. In the work the importance of the application of the computer simulation is emphasized to anticipate the hydrodynamic behavior of fluidized bed and of the process of combustion of the biomass for different residues and different conditions of operation. A model using CFD for the simulation of the process of combustion in a gas- emitting of biomass sets out of fluidized bed, the hydrodynamic parameters of the multiphasic flow from the elaboration of a computer simulator that allows to form and to vary the geometry of the reactor, as well as the influence of the variation of magnitudes are characterized such as: speed, diameter of the sand and equivalent reason. Experimental results in cylindrical channels appear, to complete the study of the computer simulation realised in 2D. (author)

  15. The production of cellulase in a spouted bed fermentor using cells immobilized in biomass support particles.

    Science.gov (United States)

    Webb, C; Fukuda, H; Atkinson, B

    1986-01-01

    Continuous cellulase production by Trichoderma viride QM 9123, immobilized in 6 mm diameter, spherical, stainless steel biomass support particles, has been achieved using a medium containing glucose as the main carbon source. Experiments were carried out in a 10-L spouted bed fermentor. In this type of reactor-recycled broth is used to create a jet at the base of a bed of particles, causing the particles to spout and circulate. During the circulation, particles pass through a region of high shear near the jet inlet. This effectively prevents a buildup of excess biomass and thus enables steady-state conditions to be achieved during continuous operation. Continuous production of cellulase was achieved at significantly higher yield and productivity than in conventional systems. At a dilution rate of 0.15 h(-1) (nominal washout rate for freely suspended cells is 0.012 h(-1)), the yield of cellulase on glucose was 31% higher than that measured during batch operation, while the volumetric productivity (31.5 FPA U/L. h) was 53% greater than in the batch system. The specific cellulase productivity of the immobilized cells was more than 3 times that of freely suspended cells, showing that diffusional limitations can be beneficial. This offers significant opportunity for the further development of biomass support particles and associated bioreactors. PMID:18553840

  16. Simulation of emission performance and combustion efficiency in biomass fired circulating fluidized bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Gungor, Afsin [Nigde University, Faculty of Engineering and Architecture, Department of Mechanical Engineering, 51100 Nigde (Turkey)

    2010-04-15

    In this study, the combustion efficiency and the emission performance of biomass fired CFBs are tested via a previously published 2D model [Gungor A. Two-dimensional biomass combustion modeling of CFB. Fuel 2008; 87: 1453-1468.] against two published comprehensive data sets. The model efficiently simulates the outcome with respect to the excess air values, which is the main parameter that is verified. The combustion efficiency of OC changes between 82.25 and 98.66% as the excess air increases from 10 to 116% with the maximum error of about 8.59%. The rice husk combustion efficiency changes between 98.05 and 97.56% as the bed operational velocity increases from 1.2 to 1.5 m s{sup -1} with the maximum error of about 7.60%. CO and NO{sub x} emissions increase with increasing bed operational velocity. Increasing excess air results in slightly higher levels of NO{sub x} emission. A significant amount of combustion occurs in the upper zone due to the high volatile content of the biomass fuels. (author)

  17. Biomass Thermochemical Conversion Program. 1984 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

    1985-01-01

    The objective of the program is to generate scientific data and conversion process information that will lead to establishment of cost-effective process for converting biomass resources into clean fuels. The goal of the program is to develop the data base for biomass thermal conversion by investigating the fundamental aspects of conversion technologies and by exploring those parameters that are critical to the conversion processes. The research activities can be divided into: (1) gasification technology; (2) liquid fuels technology; (3) direct combustion technology; and (4) program support activities. These activities are described in detail in this report. Outstanding accomplishments during fiscal year 1984 include: (1) successful operation of 3-MW combustor/gas turbine system; (2) successful extended term operation of an indirectly heated, dual bed gasifier for producing medium-Btu gas; (3) determination that oxygen requirements for medium-Btu gasification of biomass in a pressurized, fluidized bed gasifier are low; (4) established interdependence of temperature and residence times on biomass pyrolysis oil yields; and (5) determination of preliminary technical feasibility of thermally gasifying high moisture biomass feedstocks. A bibliography of 1984 publications is included. 26 figs., 1 tab.

  18. Biomass fueled fluidized bed combustion: atmospheric emissions, emission control devices and environmental regulations

    International Nuclear Information System (INIS)

    Fluidized bed combustors have become the technological choice for power generation from biomass fuels in California. Atmospheric emission data obtained during compliance tests are compared for five operating 18 to 32 MW fluidized bed combustion power plants. The discussion focuses on the impact of fuel properties and boiler design criteria on the emission of pollutants, the efficiency of pollution control devices, and regulations affecting atmospheric emissions. Stack NOx emission factors are shown not to vary substantially among the five plants which burn fuels with nitrogen concentrations between 0.3 and 1.1% dry weight. All facilities use at least one particular control device, but not all use limestone injection or other control techniques for sulfur and chlorine. The lack of control for chlorine suggests the potential for emission of toxic species due to favorable temperature conditions existing in the particulate control devices, particularly when burning fuels containing high concentrations of chlorine. (Author)

  19. Control methods for mitigating biomass ash-related problems in fluidized beds.

    Science.gov (United States)

    Vamvuka, D; Zografos, D; Alevizos, G

    2008-06-01

    Embodiment of biomass combustion technologies in the Cretan energy system will play an important role and will contribute to the local development. The main biomass fuels of Crete are the agricultural residues olive kernel and olive tree wood. Future applications of these biofuels may create, among others, operational problems related to ash effects. In this regard, the thermal behavior of the ashes during lab-scale fluidized bed combustion tests was examined, in terms of slagging/fouling and agglomeration of bed material. Control methodologies for mitigating ash problems were applied, such as leaching the raw fuels with water and using different mineral additives during combustion. The ashes and the bed material were characterized in terms of mineralogical, chemical and morphological analyses and the slagging/fouling and agglomeration propensities were determined. The results showed that fly ashes were rich in Ca, Si and Fe minerals and contained substantial amounts of alkali, falling within the range of "certain or probable slagging/fouling". Leaching of the raw fuels with water resulted in a significant reduction of the problematic elements K, Na, Cl and S in the fly ashes. The use of fuel additives decreased the concentrations of alkali and iron minerals in the fly ashes. With clay additives calcium compounds were enriched in the bottom ash, while with carbonate additives they were enriched in the fly ash. Fuel additives or water leaching reduced the slagging/fouling potential due to alkali. Under the conditions of the combustion tests, no signs of ash deposition or bed agglomeration were noticed. PMID:17826986

  20. Co-gasification of Colombian coal and biomass in fluidized bed: An experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Jhon F. Velez; Farid Chejne; Carlos F. Valdes; Eder J. Emery; Carlos A. Londono [Universidad Nacional de Colombia, Antioquia (Colombia). Grupo de Termodinamica Aplicada y Energias Alternativas

    2009-03-15

    The main results of an experimental work on co-gasification of Colombian biomass/coal blends in a fluidized bed working at atmospheric pressure are reported in this paper. Several samples of blends were prepared by mixing 6-15wt% biomass (sawdust, rice or coffee husk) with coal. Experimental assays were carried out by using mixtures of different steams/blends (Rvc) and air/blend (Rac) ratios showing the feasibility to implement co-gasification as energetic alternative to produce fuel gas to heat and to generate electricity and the possibility of converting clean and efficiently the refuse coal to a low-heating value gas. 29 refs., 5 figs., 4 tabs.

  1. The environmental and economical advantages of fluidized bed combustion for biomass and wastes

    International Nuclear Information System (INIS)

    Government and individuals in the United Kingdom are both working towards improvements in the environment. This article examines the economic and environmental advantages which might accrue from fluidized bed combustion of biomass and various waste products. Not only are waste products reused and recycled but electric power is generated without the harmful emissions of CO2 and SO2 which accompany thermal power plant use. Energy generation technologies are now being developed which are acceptable to the community and use renewable energy sources. (UK)

  2. Circulating fluidized-bed technologies for the conversion of biomass into energy

    International Nuclear Information System (INIS)

    The paper introduces circulating fluidized-bed (CFB) combustion and CFB gasification. CFB combustion units are state-of-the-art and have proven their ability to convert biomass into power and/or steam. The existing units and projects in developing countries are discussed as examples of conventional technology. To illustrate advanced technologies, CFB gasification is discussed. Important process parameters of plants already in operation or under construction in developed countries are shown, Criteria for the selection of CFB combustion or gasification based on available feedstocks and products required are discussed. Finally, a procedure for implementing Lurgi's CFB technology in developing countries is proposed. (author)

  3. Processes for washing a spent ion exchange bed and for treating biomass-derived pyrolysis oil, and apparatuses for treating biomass-derived pyrolysis oil

    Science.gov (United States)

    Baird, Lance Awender; Brandvold, Timothy A.

    2015-11-24

    Processes and apparatuses for washing a spent ion exchange bed and for treating biomass-derived pyrolysis oil are provided herein. An exemplary process for washing a spent ion exchange bed employed in purification of biomass-derived pyrolysis oil includes the step of providing a ion-depleted pyrolysis oil stream having an original oxygen content. The ion-depleted pyrolysis oil stream is partially hydrotreated to reduce the oxygen content thereof, thereby producing a partially hydrotreated pyrolysis oil stream having a residual oxygen content that is less than the original oxygen content. At least a portion of the partially hydrotreated pyrolysis oil stream is passed through the spent ion exchange bed. Water is passed through the spent ion exchange bed after passing at least the portion of the partially hydrotreated pyrolysis oil stream therethrough.

  4. Liquid transportation fuels via large-scale fluidised-bed gasification of lignocellulosic biomass

    Energy Technology Data Exchange (ETDEWEB)

    Hannula, I.; Kurkela, E.

    2013-04-15

    With the objective of gaining a better understanding of the system design trade-offs and economics that pertain to biomass-to-liquids processes, 20 individual BTL plant designs were evaluated based on their technical and economic performance. The investigation was focused on gasification-based processes that enable the conversion of biomass to methanol, dimethyl ether, Fischer-Tropsch liquids or synthetic gasoline at a large (300 MWth of biomass) scale. The biomass conversion technology was based on pressurised steam/O2-blown fluidised-bed gasification, followed by hot-gas filtration and catalytic conversion of hydrocarbons and tars. This technology has seen extensive development and demonstration activities in Finland during the recent years and newly generated experimental data has also been used in our simulation models. Our study included conceptual design issues, process descriptions, mass and energy balances and production cost estimates. Several studies exist that discuss the overall efficiency and economics of biomass conversion to transportation liquids, but very few studies have presented a detailed comparison between various syntheses using consistent process designs and uniform cost database. In addition, no studies exist that examine and compare BTL plant designs using the same front-end configuration as described in this work. Our analysis shows that it is possible to produce sustainable low-carbon fuels from lignocellulosic biomass with first-law efficiency in the range of 49.6-66.7% depending on the end-product and process conditions. Production cost estimates were calculated assuming Nth plant economics and without public investment support, CO2 credits or tax assumptions. They are 58-65 euro/MWh for methanol, 58-66 euro/MWh for DME, 64-75 euro/MWh for Fischer-Tropsch liquids and 68-78 euro/MWh for synthetic gasoline. (orig.)

  5. The formation of impurities in fluidized-bed gasification of biomass, peat and coal; Epaepuhtauksien muodostuminen leijukerroskaasutuksessa

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Laatikainen-Luntama, J.; Kurkela, M.; Leppaelahti, J.; Koljonen, T.; Oesch, P. [VTT Energy, Espoo (Finland); Alen, R. [Jyvaeskylae Univ. (Finland)

    1996-12-01

    The objective of this three-year-long project was to study the effects of different process parameters and bed materials on the formation of impurities in pressurized fluidized-bed gasification. The main emphasis of the project was focused on the formation of tars and nitrogen compounds in wood, peat and coal gasification. The aims of the research were to find out such operating conditions, where the formation of problematic high-molecular-weight tars can be minimised and to create a better understanding on the fate of fuel nitrogen in fluidized-bed gasifiers. Main part of the research was carried out in a bench-scale pressurised fluidized-bed reactor (ID 30 mm), where the effects of pressure, temperature, gas atmosphere and bed material were studied with different feedstocks. Most of the test series were carried out using the same feedstocks as earlier used in the PDU-scale fluidized-bed gasification tests of VTT (pine wood, pine bark, wheat straw, two peats, Rhenish brown coal, Polish and Illinois No.6 bituminous coals). The effects of operating parameters on the product yields (gas components, tars, char) were first studied under inert nitrogen atmosphere. The conversion of fuel nitrogen into ammonia and HCN were also determined for the different feedstocks over the different operating conditions. These studies showed that ammonia is the main fixed nitrogen compound of fluidized-bed pyrolysis with all the feedstocks studied. The conversions of fuel nitrogen into ammonia and HCN was highest with the high volatile fuels and lowest with the two hard coals. Gas atmosphere had a dramatic effect on the conversion of fuel nitrogen; much higher ammonia yields were determined in real gasification gas atmosphere than in inert pyrolysis carried out in N{sub 2} or Argon atmosphere. In addition to the pressurised fluidized-bed pyrolysis tests, laboratory scale pyrolysis research was carried out in order to compare the pyrolysis behaviour of the different feedstocks

  6. Pyrolysis kinetics of biomass (herb residue) under isothermal condition in a micro fluidized bed

    International Nuclear Information System (INIS)

    Highlights: • Herb residual pyrolysis kinetics was studied under isothermal condition. • A micro fluidized bed was used as the reactor. • Pyrolysis reaction in the fluidized bed can be finished in around 10 s. • The values of activation energy for generating H2, CO, CO2 and CH4 were achieved. - Abstract: Herb residue is one of the most important industrial biomass in China in terms of availability and potential for use as a bioenergy resource. The kinetics of the thermal decomposition of this fuel in an inert atmosphere was evaluated using a micro fluidized bed. The isothermal differential analysis was applied for determination of kinetic parameters for the major gas components formation including reaction order, activation energy and pre-exponential factor. The temperature inside the micro fluidized bed was steady and the pyrolysis reaction of herb residue finished in around 10 s at 600–800 °C. The reaction time for complete releasing of individual gas components was shorter at higher temperature. Experimental results showed that under the conditions studied, the values of activation energy for generating H2, CO, CO2 and CH4 were 18.90, 12.05, 10.48 and 11.31 kJ/mol respectively, corresponding to the values of pre-exponential factor in the range of 0.88–1.38 s−1. The results indicated that H2 was the most difficult to form due to the highest activation energy, while generating CO was the easiest corresponding to the lowest activation energy. Compared with TGA and other analysis approaches, the kinetic parameters obtain by the micro fluidized bed were significantly lower benefiting from its quick reaction features

  7. The Development of Ni/Dolomite Catalyst in Simultaneous Biomass Gasification and Reforming in Fluidized Bed

    Directory of Open Access Journals (Sweden)

    Anawat Ketcong

    2009-01-01

    Full Text Available Simultaneous gasification and steam reforming of the biomass on Ni/dolomite catalyst in fluidized bed reactor were studied in the gaseous production in the one stage reactor. Problem statement: The parameters such as temperature, steam flow rate, biomass feed rate, gas flow rate for fluidization, oxygen flow rate and catalyst types were studied to produce the high gaseous products including tar elimination. Approach: The temperature at 780°C, steam flow rate of 222 mmoL h-1, gas flow rate for fluidization 450 mL min-1 and oxygen input 50 mL min-1 were found to be the suitable conditions. The Ni/Dolomite and the developed Ni/Dolomite were studied about their performance. Results: It was confirmed that Ni/Dolomite and newly developed Ni-WO3/Dolomite show high performance in biomass gasification. Conclusion/Recommendations: It was claimed that Ni/Dolomite catalyst was the effective and give best performance for tar cracking. Newly developed Ni-WO3/Dolomite catalyst was investigated to resist sulfur nd coking. Three types of catalyst were used in the biomass gasification, which are Ni/Dolomite, Ni/Dolomite+Silica binder and Ni-WO3/Dolomite. From the XRD analysis, structures of type 1 (Ni/dolomite and type 2 (Ni/Dolomite+Silica binder were similar which were in CaCO3, MgNiO2, NiO and MgO forms. Type 3 (Ni-WO3/Dolomite was CaWO4, MgNiO2, NiO and MgO forms. When the catalytic gasification was operated, newly Ni- WO3/Dolomite catalyst was the best catalyst for bamboo and palm shell biomasses, which could produce the high carbon monoxide and hydrogen but low methane and carbon dioxide were found. Carbon deposition on catalyst was around 0.37 mg according to the TG analysis.

  8. Fixed and entrained flow gasifiers - examples

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2009-03-15

    Gasification is a flexible, reliable, and clean energy technology that can turn a variety of low-value feedstocks into high-value products, help reduce our dependence on foreign oil and natural gas, and can provide a clean alternative source of baseload electricity, fertilizers, fuels, and chemicals. According to the Gasification Technologies Council (www.gasification.org) today there are more than 420 gasifiers currently in use in some 140 facilities worldwide. By 2015, worldwide gasification capacity is projected to grow 70%, with 80% of the growth occurring in Asia. The prime movers behind this expected growth are the chemical, fertilizer, and coal-to-liquids industries in China, oil sands in Canada, polygeneration (hydrogen and power or chemicals) and substitute natural gas in the United States, and refining in Europe. Looking far into the future gasification can be a link technology to a hydrogen economy as it produces the hydrogen that will be needed for fuel cells. The heart of a gasification plant is the gasifier. There are several basic designs, distinguished by the use of wet or dry feed, the use of air or oxygen, the reactor's flow direction (up-flow, downflow, or circulating), and the gas cooling process. Hereunder, in addition to Abraham who gives examples of a fluidized and an entrained flow gasifier, the Lurgi fixed bed gasifier as well as the two entrained flow gasifiers from Shell and GE as examples for worldwide utilized gasifiers are shortly described. (orig.)

  9. Second stage gasifier in staged gasification and integrated process

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohai; Vimalchand, Pannalal; Peng, Wan Wang

    2015-10-06

    A second stage gasification unit in a staged gasification integrated process flow scheme and operating methods are disclosed to gasify a wide range of low reactivity fuels. The inclusion of second stage gasification unit operating at high temperatures closer to ash fusion temperatures in the bed provides sufficient flexibility in unit configurations, operating conditions and methods to achieve an overall carbon conversion of over 95% for low reactivity materials such as bituminous and anthracite coals, petroleum residues and coke. The second stage gasification unit includes a stationary fluidized bed gasifier operating with a sufficiently turbulent bed of predefined inert bed material with lean char carbon content. The second stage gasifier fluidized bed is operated at relatively high temperatures up to 1400.degree. C. Steam and oxidant mixture can be injected to further increase the freeboard region operating temperature in the range of approximately from 50 to 100.degree. C. above the bed temperature.

  10. Co-firing of biomass and other wastes in fluidised bed systems

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, I.; Lopes, H.; Boavida, D.; Abelha, P. [INETI/DEECA, Lisboa (Portugal); Werther, J.; Hartge, E.-U.; Wischnewski, R. [TU Hamburg-Harburg (Georgia); Leckner, B.; Amand, L.-E.; Davidsson, K. [Chalmers Univ. of Technology (Sweden); Salatino, P.; Chirone, R.; Scala, F.; Urciuolo, M. [Dipartimento di Ingegneria Chimica, Universita di Napoli Frederico II and Istituto di Ricerche sulla Combustione (Italy); Oliveira, J.F.; Lapa, N.

    2006-07-01

    A project on co-firing in large-scale power plants burning coal is currently funded by the European Commission. It is called COPOWER. The project involves 10 organisations from 6 countries. The project involves combustion studies over the full spectrum of equipment size, ranging from small laboratory-scale reactors and pilot plants, to investigate fundamentals and operating parameters, to proving trials on a commercial power plant in Duisburg. The power plant uses a circulating fluidized bed boiler. The results to be obtained are to be compared as function of scale-up. There are two different coals, 3 types of biomass and 2 kinds of waste materials are to be used for blending with coal for co-firing tests. The baseline values are obtained during a campaign of one month at the power station and the results are used for comparison with those to be obtained in other units of various sizes. Future tests will be implemented with the objective to achieve improvement on baseline values. The fuels to be used are already characterized. There are ongoing studies to determine reactivities of fuels and chars produced from the fuels. Reactivities are determined not only for individual fuels but also for blends to be used. Presently pilot-scale combustion tests are also undertaken to study the effect of blending coal with different types of biomass and waste materials. The potential for synergy to improve combustion is investigated. Simultaneously, studies to verify the availability of biomass and waste materials in Portugal, Turkey and Italy have been undertaken. Techno-economic barriers for the future use of biomass and other waste materials are identified. The potential of using these materials in coal fired power stations has been assessed. The conclusions will also be reported.

  11. Comparison of waste water treatment between completely mixed and fluidised bed reactor; development and structure of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Toman, M.; Mejac, B.

    1988-08-01

    The aerobic biological treatment of waste water from production of semisynthetic antibiotics in a completely mixed reactor and in a fluidised bed reactor was studied. The formation and development of new biomass on the sand of a fluidised bed was observed, so that differences in the structure of organisms of the concomitant biocenosis could be detected. In a fluidised bed reactor the same quality of treatednwater was gained on account of a 4-5 times higher volumetric and hydraulic loading as it was the case with a conventional activated sludge plant. The biocenosis of the fluidised bed was abundant in individua and species. The biofilm of the sand depended on substrate degradation rate as well as on rubbing among the sand particles. An optimal biofilm developed on the sand of a fluidised bed reactor 10 to 15 days after the experiment had began, and that condition remained unchanged as the experiment continued.

  12. LT-CFB. Applications and follow-up. CP Kelco. Appendix 1. [Low Temperature Circulating Fluid Bed gasifier]; LT-CFB. Anvendelsesmuligheder og opfoelgning. CP Kelco. Bilag 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-04-15

    This appendix describes how LT-CFB advantageously can gasify residual products at the company CP Kelco's factory. CP Kelco produces the gelation, thickeners and stabilizers carrageenan and pectin from seaweed and citrus peel. Residues from the production consist of a fiber-containing biological material, which has a calorific value of dry matter about 15 to 20 MJ / kg. In addition, there are waste products from the wastewater treatment plant, which are also proposed re-used in the project. The report describes the economic analyses, the overall data and system design for two scenarios, whereas the description of the plant capacities, sizes and detailed data etc. are described only for one scenario. In addition to savings in the purchase of natural gas the gas production also results in a significant reduction in CO{sub 2} emissions, the product gas being characterized as CO{sub 2} neutral. Since CP Kelco is subject to the CO{sub 2} quota system the saved amount of CO{sub 2} emissions represents a significant value. In the economic analyses, the value of 1 ton of CO{sub 2} is set at DKK 100. (LN)

  13. Simulated moving bed separation of agarose-hydrolyzate components for biofuel production from marine biomass.

    Science.gov (United States)

    Kim, Pung-Ho; Nam, Hee-Geun; Park, Chanhun; Wang, Nien-Hwa Linda; Chang, Yong Keun; Mun, Sungyong

    2015-08-01

    The economically-efficient separation of galactose, levulinic acid (LA), and 5-hydroxymethylfurfural (5-HMF) in acid hydrolyzate of agarose has been a key issue in the area of biofuel production from marine biomass. To address this issue, an optimal simulated moving bed (SMB) process for continuous separation of the three agarose-hydrolyzate components with high purities, high yields, and high throughput was developed in this study. As a first step for this task, the adsorption isotherm and mass-transfer parameters of each component on the qualified adsorbent were determined through a series of multiple frontal experiments. The determined parameters were then used in optimizing the SMB process for the considered separation. Finally, the optimized SMB process was tested experimentally using a self-assembled SMB unit with four zones. The SMB experimental results and the relevant computer simulations verified that the developed process in this study was quite successful in the economically-efficient separation of galactose, LA, and 5-HMF in a continuous mode with high purities and high yields. It is thus expected that the developed SMB process in this study will be able to serve as one of the trustworthy ways of improving the economic feasibility of biofuel production from marine biomass. PMID:26141276

  14. Co-combustion of biomass and gaseous fuel in a novel configuration of fluidized bed: Thermal characteristics

    International Nuclear Information System (INIS)

    Highlights: • Jetting-fountain fluidized bed enables smooth co-firing of biomass and gaseous fuel. • Applying jetting-fountain configuration dampens greatly freeboard overheating. • Heat gain by bed greatly increases with jetting-fountain configuration. • Increasing gaseous fuel ratio causes more reduction in freeboard overheating. • Heat gain by bed considerably increases with increasing gaseous fuel ratio. - Abstract: Experimental study on co-combustion of rice straw and natural gas has been performed in a fluidized bed. The used combustor allows the novel, jetting-fountain configuration and the conventional operation as well. In the jetting-fountain configuration, natural gas premixed with the air sufficient for combustion proceeds through the jet pipe to create a jetting-fountain zone. Whereas only the air required for rice straw combustion passes through the gas distributor. The experiments show that smooth combustion of natural gas with rice straw can be performed in the jetting-fountain fluidized bed avoiding acoustic effects and explosions of burning bubbles that occurs in conventional operation. The jetting-fountain fluidized bed is shown to dampen greatly the freeboard overheating at particularly lower bed temperatures. This is because the fountain-particles absorb a great part of heat released in the freeboard and recover it back to the bed. It is confirmed by measuring the in-bed cooling load that was found to increase considerably at lower bed temperatures. The natural gas contribution is found to play a major role when applying the jetting-fountain configuration. Increasing the natural gas contribution enlarges the fountain zone that causes greater reduction in the freeboard overheating and recovers more heat back to the bed. Measuring the in-bed cooling also approves the later conclusion

  15. An Experimental Investigation of Hydrogen Production from Biomass

    Institute of Scientific and Technical Information of China (English)

    吕鹏梅; 常杰; 付严; 王铁军; 陈勇; 祝京旭

    2003-01-01

    In gaseous products of biomass steam gasification, there exist a lot of CO, CH4 and other hydrocarbons that can be converted to hydrogen through steam reforming reactions. There exists potential hydrogen production from the raw gas of biomass steam gasification. In the present work, the characteristics of hydrogen production from biomass steam gasification were investigated in a small-scale fluidized bed. In these experiments, the gasifying agent (air) was supplied into the reactor from the bottom of the reactor and the steam was added into the reactor above biomass feeding location. The effects of reaction temperature, steam to biomass ratio, equivalence ratio (ER) and biomass particle size on hydrogen yield and hydrogen yield potential were investigated. The experimental results showed that higher reactor temperature, proper ER, proper steam to biomass ratio and smaller biomass particle size will contribute to more hydrogen and potential hydrogen yield.

  16. ALTENER - Biomass event in Finland

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The publication contains the lectures held in the Biomass event in Finland. The event was divided into two sessions: Fuel production and handling, and Co-combustion and gasification sessions. Both sessions consisted of lectures and the business forum during which the companies involved in the research presented themselves and their research and their equipment. The fuel production and handling session consisted of following lectures and business presentations: AFB-NETT - business opportunities for European biomass industry; Wood waste in Europe; Wood fuel production technologies in EU- countries; new drying method for wood waste; Pellet - the best package for biofuel - a view from the Swedish pelletmarket; First biomass plant in Portugal with forest residue fuel; and the business forum of presentations: Swedish experiences of willow growing; Biomass handling technology; Chipset 536 C Harvester; KIC International. The Co-combustion and gasification session consisted of following lectures and presentations: Gasification technology - overview; Overview of co-combustion technology in Europe; Modern biomass combustion technology; Wood waste, peat and sludge combustion in Enso Kemi mills and UPM-Kymmene Rauma paper mill; Enhanced CFB combustion of wood chips, wood waste and straw in Vaexjoe in Sweden and Grenaa CHP plant in Denmark; Co-combustion of wood waste; Biomass gasification projects in India and Finland; Biomass CFB gasifier connected to a 350 MW{sub t}h steam boiler fired with coal and natural gas - THERMIE demonstration project in Lahti (FI); Biomass gasification for energy production, Noord Holland plant in Netherlands and Arbre Energy (UK); Gasification of biomass in fixed bed gasifiers, Wet cleaning and condensing heat recovery of flue gases; Combustion of wet biomass by underfeed grate boiler; Research on biomass and waste for energy; Engineering and consulting on energy (saving) projects; and Research and development on combustion of solid fuels

  17. Industrial demonstration plant for the gasification of herb residue by fluidized bed two-stage process.

    Science.gov (United States)

    Zeng, Xi; Shao, Ruyi; Wang, Fang; Dong, Pengwei; Yu, Jian; Xu, Guangwen

    2016-04-01

    A fluidized bed two-stage gasification process, consisting of a fluidized-bed (FB) pyrolyzer and a transport fluidized bed (TFB) gasifier, has been proposed to gasify biomass for fuel gas production with low tar content. On the basis of our previous fundamental study, an autothermal two-stage gasifier has been designed and built for gasify a kind of Chinese herb residue with a treating capacity of 600 kg/h. The testing data in the operational stable stage of the industrial demonstration plant showed that when keeping the reaction temperatures of pyrolyzer and gasifier respectively at about 700 °C and 850 °C, the heating value of fuel gas can reach 1200 kcal/Nm(3), and the tar content in the produced fuel gas was about 0.4 g/Nm(3). The results from this pilot industrial demonstration plant fully verified the feasibility and technical features of the proposed FB two-stage gasification process. PMID:26849201

  18. A rice husk gasifier for paddy drying

    International Nuclear Information System (INIS)

    Due to energy crisis and constant increase in the price of fossil fuels, the world's trend changes to renewable sources of energy like solar, wind and biomass gasification. Substantial biomass potential is available in Pakistan in the form of agriculture or forest residue (rice straw, rice husk, cotton stalks, corn cobs, wood chips, wood saw, etc.). These can be best utilised for the production of producer gas or synthetic gas that can be used for drying of agricultural crops. The drying process is an important activity of post harvest processing for long-term storage. Rice husk is nowadays commonly used for biomass gasification and its heat content value is about 15MJ/kg. It constitutes about 30 percent of rice production. A rice husk gasifier was developed and evaluated on paddy drying at Japan International Cooperation Agency (JICA), Tsukuba International Center (TBIC), Japan. Rice husk gasifier has following major components; husk feeding system, ash chamber, burner, centrifugal fan, drying chamber, gasifier reactor, air duct and an electric motor of 0.37kW. The average drying plenum air temperature was recorded as 45 degree C during the drying process. The paddy 'IR 28' from initial moisture content of 24% was dried up to 14% moisture content for about 3.33h consuming 3kg/h of rice husk. The efficiency was found to be 58%. The rice husk gasifier can also be used for drying the fruits and vegetables, provided that heat exchanger should be attached with it. The overall performance of rice husk gasifier was satisfactory and will be beneficial for small scale farmers, food processors and millers as well. (author)

  19. EFFECTS OF NUTRIENT ENRICHMENT ON PRIMARY PRODUCTION AND BIOMASS OF SEDIMENT MICROALGAE IN A SUBTROPICAL SEAGRASS BED(1).

    Science.gov (United States)

    Bucolo, Philip; Sullivan, Michael J; Zimba, Paul V

    2008-08-01

    Eutrophication of coastal waters often leads to excessive growth of microalgal epiphytes attached to seagrass leaves; however, the effect of increased nutrient levels on sediment microalgae has not been studied within seagrass communities. A slow-release NPK Osmocote fertilizer was added to sediments within and outside beds of the shoal grass Halodule wrightii, in Big Lagoon, Perdido Key, Florida. Gross primary production (GPP) and biomass (HPLC photopigments) of sediment microalgae within and adjacent to fertilized and control H. wrightii beds were measured following two 4-week enrichment periods during June and July 2004. There was no effect of position on sediment microalgal GPP or biomass in control and enriched plots. However, nutrient enrichment significantly increased GPP in both June and July. These results suggest that sediment microalgae could fill some of the void in primary production where seagrass beds disappear due to excessive nutrient enrichment. Sedimentary chl a (proxy of total microalgal biomass) significantly increased only during the June enrichment period, whereas fucoxanthin (proxy of total diatom biomass) was not increased by nutrient enrichment even though its concentration doubled in the enriched plots in June. PMID:27041604

  20. Study of a 30 MW bubbling fluidized bed combustor based on co-firing biomass and coal

    Indian Academy of Sciences (India)

    Hemant Kumar; S K Mohapatra; Ravi Inder Singh

    2015-06-01

    Today’s power generation sources are largely dependent on fossil fuels due to which the future sustainable development has become a challenge. A significant amount of the pollutant emissions such as carbon dioxide, carbon monoxide and nitrogen oxide from the power sector is related to the use of fossil fuels for power generation. As the demand for electricity is growing rapidly, emissions of carbon dioxide and other pollutants from this sector can be expected to increase unless other alternatives are made available. Among the energy sources that can substitute fossil fuels, biomass fuels appear as one of the options with a high worldwide potential. In the Punjab region of India, Fluidized-bed combustion technology is being used for converting biomass into thermal energy and power generation in various small scale units. The investigation of biomass-based plant through experimental activities and numerical simulation is the scope of this study. The investigations were done at Captive Power Plant (CPP), Ambuja Cement Limited, a project of Holcim, District Ropar, India. During experimental investigations, the study of bed temperatures and steam temperatures at different zones has been done for coal fired and biomass fired combustors with 30% share. No clear effects of co-firing on boiler performance are observed. However, the operational behavior of the boiler in terms of bed temperature and stack emissions shows a different trend. During simulation, the contours of temperature have been obtained for both the boilers and the trends are found in agreement with real process.

  1. High Temperature Air/Steam Gasification (HTAG) Of Biomass – Influence of Air/Steam flow rate in a Continuous Updraft Gasifier

    OpenAIRE

    Arif, Muhammad Jalil

    2013-01-01

    Biomass is an important source of energy and the most important fuel worldwide after coal, oil and natural gas. Biomass does not add carbon dioxide to the atmosphere as it absorbs the same amount of carbon in growing as it releases when consumed as a fuel. Its advantage is that it can be used to generate electricity with the same equipment or power plants that are now burning fossil fuels. However, the low energy density of the biomass requires developments and advances in conversion technolo...

  2. Clean Hydrogen Production via Novel Steam-Air Gasification of Biomass

    International Nuclear Information System (INIS)

    Gasification converts biomass into H2 and CO rich product gas by using air, oxygen and/or steam as reaction agent. An experimental and modelling study of hydrogen production was conducted using a laboratory scale counter-current fixed bed gasifier with preheated air and steam as the gasifying agents. Commercial charcoal was used as the fuel and the reactor bed was maintained at temperatures of 750-960 C by external heaters. H2 (17-28 vol%), CO (5-11 vol%) and CO2 (18-21 vol%) forms a large portion of the synthesis gas produced depending on the ratio of the gasifying agent. The experimental work was coupled with both equilibrium and kinetic modelling to predict the equilibrium composition, conversion rates and temperature profile. (authors)

  3. Combustion of palm kernel shell in a fluidized bed: Optimization of biomass particle size and operating conditions

    International Nuclear Information System (INIS)

    Highlights: • Safe burning of palm kernel shell is achievable in a FBC using alumina as the bed material. • Thermogravimetric analysis of the shell with different particle sizes is performed. • Optimal values of the shell particle size and excess air lead to the minimum emission costs. • Combustion efficiency of 99.4–99.7% is achievable when operated under optimal conditions. • CO and NO emissions of the FBC are at levels substantially below national emission limits. - Abstract: This work presents a study on the combustion of palm kernel shell (PKS) in a conical fluidized-bed combustor (FBC) using alumina sand as the bed material to prevent bed agglomeration. Prior to combustion experiments, a thermogravimetric analysis was performed in nitrogen and dry air to investigate the effects of biomass particle size on thermal and combustion reactivity of PKS. During the combustion tests, the biomass with different mean particle sizes (1.5 mm, 4.5 mm, 7.5 mm, and 10.5 mm) was burned at a 45 kg/h feed rate, while excess air was varied from 20% to 80%. Temperature and gas concentrations (O2, CO, CxHy as CH4, and NO) were recorded along the axial direction in the reactor as well as at stack. The experimental results indicated that the biomass particle size and excess air had substantial effects on the behavior of gaseous pollutants (CO, CxHy, and NO) in different regions inside the reactor, as well as on combustion efficiency and emissions of the conical FBC. The CO and CxHy emissions can be effectively controlled by decreasing the feedstock particle size and/or increasing excess air, whereas the NO emission can be mitigated using coarser biomass particles and/or lower excess air. A cost-based approach was applied to determine the optimal values of biomass particle size and excess air, ensuring minimum emission costs of burning the biomass in the proposed combustor. From the optimization analysis, the best combustion and emission performance of the conical FBC is

  4. Process Integration and Optimization of a Solid Oxide Fuel Cell – Gas Turbine Hybrid Cycle fuelled with Hydrothermally Gasified Waste Biomass

    OpenAIRE

    Facchinetti, Emanuele; Gassner, Martin; D'Amelio, Matilde; Maréchal, François; Favrat, Daniel

    2012-01-01

    Due to its suitability for using wet biomass, hydrothermal gasification is a promising process for the valorization of otherwise unused waste biomass to synthesis gas and biofuels. Solid oxide fuel cell (SOFC) based hybrid cycles are considered as the best candidate for a more efficient and clean conversion of (bio)fuels. A significant potential for the integration of the two technologies is expected since hydrothermal gasification requires heat at 673-773 K, whereas SOFC is characterized by ...

  5. Review on Biomass Torrefaction Process and Product Properties and Design of Moving Bed Torrefaction System Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Shankar Tumuluru; Christopher T. Wright; Shahab Sokhansanj

    2011-08-01

    A Review on Torrefaction Process and Design of Moving Bed Torrefaction System for Biomass Processing Jaya Shankar Tumuluru1, Shahab Sokhansanj2 and Christopher T. Wright1 Idaho National Laboratory Biofuels and Renewable Energy Technologies Department Idaho Falls, Idaho 83415 Oak Ridge National Laboratory Bioenergy Resource and Engineering Systems Group Oak Ridge, TN 37831 Abstract Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300 C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200-230 C and 270-280 C. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, which produces a final product that will have a lower mass but a higher heating value. There is a lack of literature on the design aspects of torrefaction reactor and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes (a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and (b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed torrefier for different capacities ranging from 25-1000 kg/hr, designing the heat loads and gas flow rates, and

  6. Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalystes to Poisons form High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Burton Davis; Gary Jacobs; Wenping Ma; Khalid Azzam; Janet ChakkamadathilMohandas; Wilson Shafer

    2009-09-30

    There has been a recent shift in interest in converting not only natural gas and coal derived syngas to Fischer-Tropsch synthesis products, but also converting biomass-derived syngas, as well as syngas derived from coal and biomass mixtures. As such, conventional catalysts based on iron and cobalt may not be suitable without proper development. This is because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using entrained-flow oxygen-blown gasifier gasification gasification) than solely from coal, other compounds may actually be increased. Of particular concern are compounds containing alkali chemicals like the chlorides of sodium and potassium. In the first year, University of Kentucky Center for Applied Energy Research (UK-CAER) researchers completed a number of tasks aimed at evaluating the sensitivity of cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts and a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to alkali halides. This included the preparation of large batches of 0.5%Pt-25%Co/Al{sub 2}O{sub 3} and 100Fe: 5.1Si: 3.0K: 2.0Cu (high alpha) catalysts that were split up among the four different entities participating in the overall project; the testing of the catalysts under clean FT and WGS conditions; the testing of the Fe-Cr WGS catalyst under conditions of co-feeding NaCl and KCl; and the construction and start-up of the continuously stirred tank reactors (CSTRs) for poisoning investigations.

  7. Ammonia Yield from Gasification of Biomass and Coal in Fluidized Bed Reactor

    Czech Academy of Sciences Publication Activity Database

    Jeremiáš, Michal; Pohořelý, Michael; Bode, P.; Skoblia, S.; Beňo, Z.; Svoboda, Karel

    2014-01-01

    Roč. 117, Part B (2014), s. 917-925. ISSN 0016-2361 R&D Projects: GA MŠk(CZ) 7C11009 Grant ostatní: RFCS(XE) RFCR-CT-2010-0009 Institutional support: RVO:67985858 Keywords : limestone * NH3 * dolomite * NOx * gasifying agent Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.520, year: 2014

  8. Co-gasification of different rank coals with biomass and petroleum coke in a high-pressure reactor for H{sub 2}-rich gas production

    Energy Technology Data Exchange (ETDEWEB)

    Fermoso, J.; Arias, B.; Gil, M.V.; Plaza, M.G.; Pevida, C.; Pis, J.J.; Rubiera, F. [CSIC, Oviedo (Spain)

    2010-05-15

    Four coals of different rank were gasified, using a steam/oxygen mixture as gasifying agent, at atmospheric and elevated pressure in a fixed bed reactor fitted with a solids feeding system in continuous mode. Independently of coal rank, an increase in gasification pressure led to a decrease in H{sub 2} + CO production and carbon conversion. Gasification of the different rank Coals revealed that the higher the carbon content and reactivity, the greater the hydrogen production, co-gasification experiments of binary (coal-biomass) and ternary blends (coal-petcoke-biomass) were conducted at high pressure to study possible synergetic effects. Interactions between the blend components were found to modify the gas production. An improvement in hydrogen production and cold gas efficiency was achieved when the coal was gasified with biomass.

  9. Sintering behavior of flying slag particles in entrained-bed coal gasifiers. 3rd Report. Effect of soot on sintering behavior of flying slag particles; Kiryuso sekitan gas ka ro ni okeru hisan slag fun no shoketsu tokusei. 3. Char chu tansobun no slag shoketsu yokusei sayo

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, A.; Kida, E. [Babcock Hitachi K.K., Tokyo (Japan)

    1997-05-25

    The effect of char addition on sintering behavior of flying slag particles in an entrained-bed coal gasifier was examined using four kinds of amorphous water-quenched slag obtained at the pilot plant of HYCOL. This plant was designed to gasify 50 tons of coal per day. The sintering temperatures of the four slags without char were all approximately 800{degree}C. However, Taiheiyo coal slag did not sinter at 900{degree}C when the char added. It was considered that the char collected by the cyclon was a mixture of soot and unburned coal particles and the soot prevented the slag from sintering. Therefore, the effect of soot on sintering behavior was clarified using carbon black as soot. SEM and EDX analyses showed that very small soot particles acted as a dispersant in the slag. 12 refs., 13 figs., 2 tabs.

  10. 灰熔聚流化床气化炉内气固两相流的数值模拟%NUMERICAL SIMULATION OF GAS-SOLID FLOW IN THEASH-AGGLOMERATING FLUIDIZED BED GASIFIER

    Institute of Scientific and Technical Information of China (English)

    范江; 武小芳; 马素霞

    2011-01-01

    Eulerian-Eulerian two-fluid model was used to simulate the gas-solid flow behaviors in certain chemical fertilizer company' s running ash-agglomerating fluidized bed gasifier . The range and proper matching relations between fluidized and spouting gas velocity were showed from the simulating results. It shows fluidized gas velocity can neither be too small, which may lead to dead districts around the gas distributor, nor too big because the designing and operating characteristics of ICC will be lost. With the increasing of spouting gas velocity, the mixing churning is enhanced under a certain fluidizing gas velocity. However, spouting gas velocity which exceeds some value results in the flow structure of slugging and is not conducive to the operating of ICC efficiently and safely.%应用欧拉双流体模型模拟了某化肥厂现运行的灰熔聚流化床煤气化炉(用ICC表示)内的气固两相流动行为,得出了所模拟ICC的合理流化气速与喷动气速的速度范围及匹配关系:流化气速不能太小,否则布风板区域会出现死区;流化气速也不能太大,否则将失去ICC的设计运行特点.当流化气速一定时,随喷动气速的增加,搅动混合增强,但过大的喷动气速会使床内的流动结构出现腾涌,不利于ICC的高效安全运行.

  11. Energetic evaluation of low potential biomass gasifier coupled with a burner of the produced gas for generation of heat; Avaliacao energetica de um gaseificador de biomassa de baixa potencia, associado a um combustor do gas produzido, para geracao de calor

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Samuel [Universidade de Brasilia (FAV/UNB), DF (Brazil). Fac. de Agronomia e Medicina Veterinaria], email: samuelmartin@unb.nr; Silva, Jadir Nogueira [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola; Machado, Cassio Silva; Zanatta, Fabio Luis; Galvarro, Svetlana F.S. [Universidade Federal de Vicosa (UFV), MG (Brazil)

    2011-07-01

    In the search of alternatives for sustainable socio-economic development, this study had the objective of evaluating the energetic performance of a concurrent flow biomass gasifier associated with a burner for the gas produced which was of low potential for air heating using a renewable energy source (substituting non-renewable). In this system 4 tests were performed using eucalyptus chips (tests 1 and 2) and logs (tests 3 and 4) as fuel, for the two fan motor frequencies of 60 and 50 hertz. Temperature in the combustion chamber was monitored, along with fuel consumption and other variables. In the tests, the average exhaust air temperature was maintained between 92.7 and 100.4 deg C, and the reduction in the motor frequency from 60 to 50 Hz caused an increase in the duration of the tests. The system presented the best energetic performance when utilizing a frequency of 60 Hz for both fuel types. However, the results of energy efficiency varied very little when comparing tests performed at the same fan frequency. Thus, the gasification process was little affected by variation in the physical characteristics of the tested fuels, and it was recommended that the equipment operate with a frequency of 60 Hz. (author)

  12. Research and evaluation of biomass resources/conversion/utilization systems (market/experimental analysis for development of a data base for a fuels from biomass model). Quarterly technical progress report, November 1, 1979-January 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Y.K.; Chen, Y.C.; Chen, H.T.; Helm, R.W.; Nelson, E.T.; Shields, K.J.; Stringer, R.P.; Bailie, R.C.

    1980-01-01

    The biomass allocation model has been developed and is undergoing testing. Data bases for biomass feedstock and thermochemical products are complete. Simulated data on process efficiency and product costs are being used while more accurate data are being developed. Market analyses data are stored for the biomass allocation model. The modeling activity will assist in providing process efficiency information required for the allocation model. Process models for entrained bed and fixed bed gasifiers based on coal have been adapted to biomass. Fuel product manufacturing costs will be used as inputs for the data banks of the biomass allocations model. Conceptual economics have been generated for seven of the fourteen process configurations via a biomass economic computer program. The PDU studies are designed to demonstrate steady state thermochemical conversions of biomass to fuels in fluidized, moving and entrained bed reactor configurations. Pulse tests in a fluidized bed to determine the effect of particle size on reaction rates and product gas composition have been completed. Two hour shakedown tests using peanut hulls and wood as the biomass feedstock and the fluidized bed reactor mode have been carried out. A comparison was made of the gas composition using air and steam - O/sub 2/. Biomass thermal profiles and biomass composition information shall be provided. To date approximately 70 biomass types have been collected. Chemical characterization of this material has begun. Thermal gravimetric, pyrogaschromatographic and effluent gas analysis has begun on pelletized samples of these biomass species.

  13. Production of biocrudes from biomass in a fixed-bed tubular reactor: product yields and compositions

    Energy Technology Data Exchange (ETDEWEB)

    Putun, A.E.; Ozcan, A.; Gercel, H.F.; Putun, E. [Anadolu University, Eskisehir (Turkey). Dept. of Chemical Engineering, Faculty of Engineering and Architecture

    2001-08-10

    Fixed-bed pyrolysis in a tubular reactor was conducted on three biomass samples. Euphorbia rigida, sunflower (Helianthus annus L.) pressed bagasse and hazelnut (Corylus avellana) shells, to determine the possibility of each being a potential source of renewable fuels and chemical feedstocks. The effects of pyrolysis temperature and sweep gas (N{sub 2}) flow rate on the pyrolysis yields and chemical compositions of the biocrudes obtained were investigated. The maximum biocrude yield of 45.7 wt% was obtained from sunflower pressed bagasse in N{sub 2} atmosphere at a pyrolysis temperature of 823 K and fixed heating rate of 7 K min{sup -1}. However, this biocrude yield can be compared with the biocrude of Euphorbia rigida (31.5 wt%) at optimum conditions. The biocrude yield of sunflower pressed bagasse increased by 26.4% as the final temperature was increased from 673 to 823 K whereas the biocrude yield of Euphorbia rigida increased by 30.8% more than sunflower pressed bagasse when the final temperature was increased from 673 to 823 K. The pyrolysis products were characterized by elemental analysis, high performance size exclusion chromatography (HPSEC) and {sup 1}H NMR spectroscopy, and also compared with the currently utilized transport fuels by simulated distillation. The pentane subfractions of biocrudes were analyzed for the quantification of hydrocarbons by gas chromatography. The chemical characterizations have shown that the biocrudes obtained from Euphorbia rigida, sunflower pressed bagasse and hazelnut shells were quite similar to crude oil and shale oil. 30 refs., 4 figs., 6 tabs.

  14. A new dissection methodology and investigation into coal property transformational behaviour impacting on a commercial-scale Sasol-Lurgi MK IV fixed-bed gasifier / John Reginald Bunt

    OpenAIRE

    Bunt, John Reginald

    2006-01-01

    Gasification behaviour is particle dependent, whilst gasifier (reactor) behaviour is an averaging process of individual responses of each particle [Glover, 1991]. It was hypothesized in the case of the present study that if it were possible to extract and analyse particles from different reaction zones within a gasifier, it may be likely to enhance the understanding as to the contribution that these particles make towards gasification. This better understanding of the particle-type compositio...

  15. Methodology for sizing, energy analysis and selection of equipment for a biomass gasifier to drive an internal combustion engine; Metodologia de dimensionamento, analise energetica e selecao de equipamentos de um gaseificador de biomassa para o acionamento de um motor de combustao interna

    Energy Technology Data Exchange (ETDEWEB)

    Coronado, Christian Rodriguez; Silveira, Jose Luz [Universidade Estadual Paulista (FEG/UNESP), Guaratingueta, SP (Brazil). Fac. de Engenharia], e-mails: christian@feg.unesp.br, joseluz@feg.unesp.br; Arauzo, Jesus Perez [University of Zaragoza (UNIZAR), Zaragoza (Spain). Centro Politecnico Superior. Chemical and Environmental Engineering Dept.], e-mail: qtarauzo@unizar.es

    2006-07-01

    Alter both oil crisis, of 1973 and 1979, a bad effect of the elevated costs and continuously increment of the oil prices was noted, for this reason, the interest for renewable energies sources widely available in developing countries was increased. All over the world, governments have formulated main objectives for energies savings and search for friendly technologies, taking into account the effects related with the environment. The imminent scarcity of fossil fuels has made humanity the rational use of primary energies, as a result of these; new plants with improved technology have been conceived taking into account energy savings and efficiency improvement. In this context, biomass gasification technologies are important, since they consist in techniques of parallel production of electricity and heat from just one fuel. This work consists in the development of a gasifier down draft of 100 kW for an internal combustion engine, which includes its sizing process and its energy analysis. The sizing includes design facts and the parameters of the conditioning systems for the exhaust gas. This part is mainly based in the experience of a work group of the Zaragoza State University - Spain, UNIZAR, specialists in the construction of small down draft gasifiers, for every case, air will be used as a gasifier agent and as biomass forestall. The availability of biomass resources and the application of the national energetic view system are relevant. The gasifier will have a 100 kg/h of feeding, the energetic analysis includes the matter and energy balance and the respective efficient such cold as hot efficient of the exhaust gas. Moreover it will be tried the equipment recommended for the cleaning and conditioning of this gas fuel for this equipment in particular. (author)

  16. Evaluation of biomass gasification in a ternary diagram

    International Nuclear Information System (INIS)

    The present paper addresses the development of an alternative approach to illustrate biomass gasification in a ternary diagram which is constructed using data from thermodynamic equilibrium modeling of air-blown atmospheric wood gasification. It allows the location of operation domains of slagging entrained-flow, fluidized-bed/dry-ash entrained-flow and fixed/moving-bed gasification systems depending on technical limitations mainly due to ash melting behavior. Performance parameters, e.g. cold gas efficiency or specific syngas production, and process parameters such as temperature and carbon conversion are displayed in the diagram depending on the three independent mass flows representing (1) the gasifying agent, (2) the dry biomass and (3) the moisture content of the biomass. The graphical approach indicates the existence of maxima for cold gas efficiency (84.9%), syngas yield (1.35 m3 (H2 + CO STP)/kg (waf)) and conversion of carbon to CO (81.1%) under dry air-blown conditions. The fluidized-bed/dry-ash entrained-flow processes have the potential to reach these global maxima since they can operate in the identified temperature range from 700 to 950 °C. Although using air as a gasifying agent, the same temperature range posses a potential of H2/CO ratios up to 2.0 at specific syngas productions of 1.15 m3 (H2 + CO STP)/kg (waf). Fixed/moving-bed and fluidized-bed systems can approach a dry product gas LHV from 3.0 to 5.5 MJ/m3 (dry STP). The ternary diagram was also used to study the increase of gasifying agent oxygen fraction from 21 to 99 vol.%. While the dry gas LHV can be increased significantly, the maxima of cold gas efficiency (+6.5%) and syngas yield (+7.4%) are elevated only slightly. - Highlights: • Novel graphical approach for comprehensive assessment of biomass gasification. • Parameters fields for temperature, conversion, cold gas efficiency, syngas yield etc. • Identification of operation ranges for entrained, fluid and moving-bed

  17. Packed-bed column biosorption of chromium(VI) and nickel(II) onto Fenton modified Hydrilla verticillata dried biomass.

    Science.gov (United States)

    Mishra, Ashutosh; Tripathi, Brahma Dutt; Rai, Ashwani Kumar

    2016-10-01

    The present study represents the first attempt to investigate the biosorption potential of Fenton modified Hydrilla verticillata dried biomass (FMB) in removing chromium(VI) and nickel(II) ions from wastewater using up-flow packed-bed column reactor. Effects of different packed-bed column parameters such as bed height, flow rate, influent metal ion concentration and particle size were examined. The outcome of the column experiments illustrated that highest bed height (25cm); lowest flow rate (10mLmin(-1)), lowest influent metal concentration (5mgL(-1)) and smallest particle size range (0.25-0.50mm) are favourable for biosorption. The maximum biosorption capacity of FMB for chromium(VI) and nickel(II) removal were estimated to be 89.32 and 87.18mgg(-1) respectively. The breakthrough curves were analyzed using Bed Depth Service Time (BDST) and Thomas models. The experimental results obtained agree to both the models. Column regeneration experiments were also carried out using 0.1M HNO3. Results revealed good reusability of FMB during ten cycles of sorption and desorption. Performance of FMB-packed column in treating secondary effluent was also tested under identical experimental conditions. Results demonstrated significant reduction in chromium(VI) and nickel(II) ions concentration after the biosorption process. PMID:27400422

  18. Technoeconomic assessment of biomass to energy

    International Nuclear Information System (INIS)

    A spreadsheet-based decision support system has been developed that allows easy evaluation of integrated biomass to electricity and biomass to ethanol systems. The Bioenergy Assessment Model (BEAM) has been developed to allow the techno-economic assessment of biomass to electricity and biomass to ethanol schemes, including investigation of the interfacing issues. Technical and economic parameters can be assessed for a variety of feedstocks, conversion technologies and generating cycles. Production modules are currently available for biomass supply from short rotation coppice and conventional forestry relevant to conditions and practices in NW Europe. The biomass conversion modules include pre-treatment (reception, storage, handling, comminution, screening and drying); atmospheric gasification (generic gasifier, wet gas scrubbing, dual fuel engine); pressure gasification (generic gasifier, hot gas filtration, gas turbine combined cycle); fast pyrolysis for liquid bio-fuel-oil (pyrolyser, oil storage, pilot-injected diesel engine); combustion (fluid bed combuster steam turbine), conventional acid hydrolysis fermentation and the NREL SSF process to ethanol. In addition there is a further module which can be used to examine the collection, mass burn and generation of electricity from MSW. BEAM has been used, and the results presented in this paper, to determine the costs of generating bio-electricity from short rotation coppice and conventional forestry over a range of power outputs and for each conversion technology. Alternative feedstock supply strategies have been examined and relations drawn between delivered feedstock cost and cost of electricity. (author)

  19. The Influence of H2O and CO2 Addition to the Gasification Media during Oxyfuel Fluidized Bed Gasification of Biomass

    Czech Academy of Sciences Publication Activity Database

    Jeremiáš, Michal; Pohořelý, Michael; Kameníková, Petra; Skoblia, S.; Svoboda, Karel; Punčochář, Miroslav

    2010, VP2.1.12. ISBN N. [European Biomass Conference & Exhibition /18./. Lyon (FR), 03.05.2010-07.05.2010] R&D Projects: GA MŠk 2B08048 Grant ostatní: RFCR(XE) CT/2007/00005 Institutional research plan: CEZ:AV0Z40720504 Keywords : fluidized bed * gasification * biomass Subject RIV: CI - Industrial Chemistry, Chemical Engineering http://www.conference-biomass.com/

  20. Matched Design and Application of Circular Type Cyclone Deduster in Pulverized Coal Gasifier with Ash Melting Collection Fluidized Bed%环流式旋风除尘器在灰融聚流化床粉煤气化炉中的配套设计及应用

    Institute of Scientific and Technical Information of China (English)

    毕可军

    2014-01-01

    In allusion to problem required to make the matched dsign in case of firstly using circular type cyclone deduster in pulverized coal gasifier with ash melting collection fluidized bed; author has introduced the technical features, process flow of pulverized coal gasification technology with ash melting collection fluidized bed;has discussed the working princilpe, process parameters, arrange type, wearable lining for circular type cyclone deduster-completed with pulverized coal gasifier with ash melting collection fluidized bed;has summarized the applicative effect of the circular type cyclone deduster after using the matched design.%针对环流式旋风除尘器在灰融聚流化床粉煤气化炉中首次应用时需进行配套设计的问题,介绍了灰融聚流化床粉煤气化技术特点、工艺流程;论述了环流式旋风除尘器配套灰融聚流化床粉煤气化炉的工作原理、工艺参数、配置方式、耐磨衬里;总结了采用配套设计后环流式旋风除尘器的应用效果。

  1. Development of fluidized bed combustion of biomass; Leijupolttoprosessin kehittaeminen vaikeille biopolttoaineille soveltuvaksi

    Energy Technology Data Exchange (ETDEWEB)

    Hiltunen, M.; Vaehaenen-Koivuluoma, T. [Foster Wheeler Energia Oy, Karhula (Finland)

    1997-10-01

    Some commercial BFB boilers burning biofuels, or biofuels and industrial wood wastes have suffered serious problems in bed material sintering. In worst cases the cumulation of reactive alkali compounds has caused total sintering of bed material even during a few days` operation. This presentation reports the results obtained from three separate cases, where sintering problems occurred. Boiler A burned biofuel with quartz sand and limestone addition. Boiler B burned softwood bark and industrial wood waste with sand addition. Boiler C burned softwood bark and sludge with sand addition. Due to the fuel used, bed sintering occurred in all boilers. Obviously, sintering was also influenced by some technical problems. Bed material samples have been analyzed with XRF and SEM-EDS techniques. According to these analyses, the main reason for sintering in boiler A is the cumulation of reactive potassium in bed material. In boiler B, the main reason is the fuel change from a mixture of softwood bark and industrial wood waste to pure industrial wood waste. The extra load of reactive sodium exceeded the critical concentration of alkali compounds in bed material. Also in boiler C, the fuel change from a mixture of softwood bark and sludge to pure softwood bark seems to be one of the reasons for bed sintering. After the fuel change the bed saturated with reactive potassium and the bed sintered. (orig.)

  2. Fast Pyrolysis of Biomass in a Spout-fluidized Bed Reactor--Analysis of Composition and Combustion Characteristics of Liquid Product from Biomass

    Institute of Scientific and Technical Information of China (English)

    陈明强; 王君; 王新运; 张学才; 张素平; 任铮伟; 颜涌捷

    2006-01-01

    In order to gain insight into the fast pyrolysis mechanism of biomass and the relationship between bio-oil composition and pyrolysis reaction conditions, to assess the possibility for the raw bio-oil to be used as fuel, and to evaluate the concept of spout-fluidized bed reactor as the reactor for fast pyrolysis of biomass to prepare fuel oil, the composition and combustion characteristics of bio-oil prepared in a spout-fluidized bed reactor with a designed maximum capacity 5 kg/h of sawdust as feeding material, were investigated by GC-MS and thermogravimetry. 14 aromatic series chemicals were identified. The thermogravimetric analysis indicated that the bio-oil was liable to combustion, the combustion temperature increased with the heating rate, and only minute ash was generated when it burned. The kinetics of the combustion reaction was studied and the kinetic parameters were calculated by both Ozawa-Flynn-Wall and Popsecu methods. The results agree well with each other. The most probable combustion mechanism functions determined by Popescu method are f(α)=k(1-α)2(400~406 ℃), f(α)=1/2k(1-α)3 (406~416 ℃) and f( α)=2k(1-α)3/2 (416~430 ℃) respectively.

  3. Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalysts to Poisons from High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Burton Davis; Gary Jacobs; Wenping Ma; Dennis Sparks; Khalid Azzam; Janet Chakkamadathil Mohandas; Wilson Shafer; Venkat Ramana Rao Pendyala

    2011-09-30

    There has been a recent shift in interest in converting not only natural gas and coal derived syngas to Fischer-Tropsch synthesis products, but also converting biomass-derived syngas, as well as syngas derived from coal and biomass mixtures. As such, conventional catalysts based on iron and cobalt may not be suitable without proper development. This is because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using entrained-flow oxygen-blown gasifier gasification gasification) than solely from coal, other compounds may actually be increased. Of particular concern are compounds containing alkali chemicals like the chlorides of sodium and potassium. In the first year, University of Kentucky Center for Applied Energy Research (UK-CAER) researchers completed a number of tasks aimed at evaluating the sensitivity of cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts and a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to alkali halides. This included the preparation of large batches of 0.5%Pt-25%Co/Al{sub 2}O{sub 3} and 100Fe: 5.1Si: 3.0K: 2.0Cu (high alpha) catalysts that were split up among the four different entities participating in the overall project; the testing of the catalysts under clean FT and WGS conditions; the testing of the Fe-Cr WGS catalyst under conditions of co-feeding NaCl and KCl; and the construction and start-up of the continuously stirred tank reactors (CSTRs) for poisoning investigations. In the second and third years, researchers from the University of Kentucky Center for Applied Energy Research (UK-CAER) continued the project by evaluating the sensitivity of a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to a number of different compounds, including KHCO{sub 3}, NaHCO{sub 3}, HCl, HBr, HF, H{sub 2}S, NH{sub 3}, and a combination of H

  4. A combined system comprising a biomass gasifier and a Stirling engine. Design and optimisation for continuous operation; Eine Anlagenkombination aus Biomassevergaser und Stirlingmotor. Anlagendesign und Auslegung fuer den Dauerbetrieb

    Energy Technology Data Exchange (ETDEWEB)

    Huelscher, Manfred [Qalovis Farmer Automatic Energy GmbH, Laer (Germany)

    2010-07-01

    Conventional wood gasifiers consist of a gasifier, gas filter, and internal combustion engine. The contribution presents a novel system comprising a gasifier, burner, and Stirling engine. To enhance the electric efficiency, the burner is operated with air preheated via reculperation. The Stirling characteristic is known, and the gasification/combustion system can be calculated and designed on the basis of the Stirling data. The dust problem of the Stirling heat exchanger is solved by an automatic filter system, so that low-maintenance long-term operation becomes possible.

  5. Using fuzzy logic to control the power of a biomass gasifier ventilation system motor to ensure suitable oxidation temperature for tar cracking; Uso da logica fuzzy para controle da potencia do motor do sistema de ventilacao de um gaseificador de biomassa que assegure temperatura de oxidacao adequada para craqueamento do alcatrao

    Energy Technology Data Exchange (ETDEWEB)

    Rezende, Oscar L.T.; Kulitz, Hans H. [Instituto Federal de Educacao, Ciencia e Tecnologia do Espirito Santo (IFES), Vitoria, ES (Brazil)], email: oscar@ifes.edu.br; Silva, Jadir N.; Galvarro, Svetlana F.S. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola; Martin, Samuel [Universidade de Brasilia (FAV/UNB), DF (Brazil). Fac. de Agronomia e Medicina Veterinaria

    2011-07-01

    There are several models of biomass gasifier. The one used in this study was the concurrent model, in which fuel is fed through the top and air feed occurs in descending flow through combustion and reduction zones, producing low-tar gas. Nevertheless, total tar burning must be ensured in order to produce a gas, suitable for several applications. This study aimed at developing a fuzzy-based algorithm to control the active power applied to a gasifier ventilation system motor, which can ensure adequate oxidation temperature for cracking tar that may be present in the gas produced. The input variables of the fuzzy controller were oxidation zone temperature and the variation rate of this temperature. The output variable was active power. The rule base was created using experimental data. The tests performed with this algorithm allowed observing that the oxidation temperature can be set to a value desired, which does not occur in gasification processes without ventilation system control. (author)

  6. Heterotrophic, nitrifying and denitrifying activity of biomass from fluidized bed reactor operated with aeration cycles

    International Nuclear Information System (INIS)

    Biomass activity can be defined as the mass of substrate metabolised per unit of biomass and time. This parameter have a great importance to know the metabolic conditions of the microorganisms in a biological process, and can be use for an adequate operation and control of a wastewater treatment system. There are different methods to determine biomass activity, but the more useful are those based on the determination of the rate of substrate consumption or products generation. (Author)

  7. Biomass Gasification in Internal Circulating Fluidized Beds: a Thermodynamic Predictive Tool

    Czech Academy of Sciences Publication Activity Database

    Miccio, F.; Svoboda, Karel; Schosger, J.-P.; Baxter, D.

    2008-01-01

    Roč. 25, č. 4 (2008), s. 721-726. ISSN 0256-1115 Institutional research plan: CEZ:AV0Z40720504 Keywords : fluidized bed * gasification * fluidized bed Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.830, year: 2008

  8. Combustion of gases released from peat or biomass in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Raiko, R. [Tampere Univ. of Technology (Finland). Energy and Process Engineering

    1996-12-01

    Temperature and gas concentration experiments have been conducted to determine at what temperature carbon monoxide, methane and propane begin to react within the particulate phase of a bubbling fluidized bed. The fluidized bed reactor used in these experiments was a stainless-steel tube with an internal diameter of 50 mm surrounded by an electric heater. Two different natural quartz sands were used (d{sub p} =0.35 mm and 0.6 mm). The bed height used varied between 100 and 260 mm (in unfluidized state). A porous plate distributor, made of kaowool, was used to avoid jets appearing at the distributor. The bed was operated at incipient fluidization (u = 5.9-9 cm/s). The bed temperatures used ranged from 600 deg C to 850 deg C. It was found that carbon monoxide, methane and propane react inside a fluidized bed, but often other conditions than temperature have a considerable effect on the rate of the reaction. The critical temperature was found to be 650 deg C for propane and carbon monoxide and 700 deg C for methane. With under-stoichiometric mixture of carbon monoxide and air the heat release can be over 2.5 MW/m{sup 3} when bed temperature is 650 deg C. According to these experiments it is obvious that the reaction mechanism for carbon monoxide oxidation inside a fluidized bed differs greatly from that of gas phase only. The results of our more than 1300 test runs show clearly the varying effects of the different bed materials. Even with the same bed material totally different results can be obtained. In order to elucidate the possible changes of particle surface, microscopic and porosimetric studies was conducted with both fresh bed particles and used bed particles. Also the effect of commonly used ingredients, like limestone and dolomite, was tested. A global model for carbon monoxide oxidation inside a fluidized bed was introduced. The model was tested against measured data from the laboratory-scale fluidized bed test rig. (Abstract Truncated)

  9. Development of Methane and Nitrous Oxide Emission Factors for the Biomass Fired Circulating Fluidized Bed Combustion Power Plant

    OpenAIRE

    Chang-Sang Cho; Jae-Hwan Sa; Ki-Kyo Lim; Tae-Mi Youk; Seung-Jin Kim; Seul-Ki Lee; Eui-Chan Jeon

    2012-01-01

    This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH4), Nitrous oxide (N2O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH4 and N2O were me...

  10. Catalytic destruction of tar in biomass derived producer gas

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate catalytic destruction of tar formed during gasification of biomass, with the goal of improving the quality of the producer gas. This work focuses on nickel based catalysts treated with alkali in an effort to promote steam gasification of the coke that deposits on catalyst surfaces. A tar conversion system consisting of a guard bed and catalytic reactor was designed to treat the producer gas from an air blown, fluidized bed biomass gasifier. The guard bed used dolomite to crack the heavy tars. The catalytic reactor was used to evaluate three commercial steam reforming catalysts. These were the ICI46-1 catalyst from Imperial Chemical Industry and Z409 and RZ409 catalysts from Qilu Petrochemical Corp. in China. A 0.5-3 l/min slipstream from a 5 tpd biomass gasifier was used to test the tar conversion system. Gas and tar were sampled before and after the tar conversion system to evaluate the effectiveness of the system. Changes in gas composition as functions of catalytic bed temperature, space velocity and steam/TOC (total organic carbon) ratio are presented. Structural changes in the catalysts during the tests are also described

  11. Simulation of co-firing coal and biomass in circulating fluidized beds

    International Nuclear Information System (INIS)

    Highlights: ► The effect of the biomass share on CO, NOx and SO2 emissions are investigated. ► New model shows similar emissions trends for co-firing to industrial data. ► Biomass share has a positive effect on lowering the emissions in co-firing. - Abstract: In this study, the effect of the biomass share on CO, NOx and SO2 emissions are investigated to reveal the benefits of co-firing biomass and coal in CFBs by using a developed model. The results are compared with two published comprehensive data sets. The results show that CO, NOx and SO2 emissions decrease as the biomass share increases for industrial scale CFB combustors.

  12. Bed agglomeration in biomass fueled CFB-boilers; Sintring av baeddmaterial vid biobraensleeldning i CFB

    Energy Technology Data Exchange (ETDEWEB)

    Zintl, F. [TPS Termiska Processer AB, Nykoeping (Sweden)

    1997-02-01

    In fluidized-bed boilers fired with solid fuels operational problems caused by spontaneous defluidization are sometimes observed. This bed agglomeration can be caused by sintering phenomena where fuel components and/or bed material may be involved. In serious cases the problems can lead to expensive operation breaks. The objective in this project was to show whether this type of operational problems can be minimized by choice of other than conventional bed materials. The study was carried out as model experiments in a larger laboratory scale. In a fluidized bed fired with propane a number of both well known and more unusual bed materials were tried out. The choice of bed materials included some common sands (silver and quartz sand) and, as possible alternatives, olivine sand, zirconium sand, calcined dolomite and the synthetic materials sintered magnesite (MgO) and mullite (alumina silicate). The model experiments were started at about 700 deg C and the temperature then raised until an irreversible bed agglomeration was observed, or to a maximum of 1100 deg C. The most promising results were obtained with calcined dolomite, being an active bed material. With this material no irreversible agglomerations were observed at all. The expensive synthetic materials sintered magnesite and mullite and the zirconium sand turned out as the next best. Olivine sand, on the other hand, showed a clear sensitivity to physical agglomeration and some sensitivity also towards sintering. The common sand types based on silicon oxide clearly showed the worst results. 12 refs, 5 figs, 1 tab 12 refs, 5 figs, 1 tab

  13. Modeling of flow conditions in down draft gasifiers using tin film models

    DEFF Research Database (Denmark)

    Jensen, Torben Kvist; Gøbel, Benny; Henriksen, Ulrik Birk

    2003-01-01

    In order to examine how an inhomogeneous char bed affects the gas flow through the bed, a dynamic model have been developed to describe the flow distribution in a down draft gasifier. The gas flow distribution through the bed was determined using a thin film model approach. The temperatures in the...

  14. Techno-Economic Study of Adsorption Processes for Pre-Combustion Carbon Capture at a Biomass CHP Plant

    OpenAIRE

    Oreggioni, Gabriel David; Friedrich, Daniel; Brandani, Stefano; Ahn, Hyungwoong

    2014-01-01

    An exemplary 10 MWth biomass CHP plant with a FICFB (Fast Internally Circulating Fluidised Bed) gasifier and Jenbacher type 6 gas engine was simulated to estimate the power and thermal outputs. The biomass-fuelled CHP plant was modified for carbon capture using either adsorption or amine process. It was found that a two-stage, two-bed PVSA (Pressure Vacuum Swing Adsorption) unit applied to syngas stream for pre-combustion capture spent less specific energy per captured CO2 than a conventional...

  15. Gasification of hazelnut shells in a downdraft gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Dogru, M.; Howarth, C.R.; Akay, G.; Keskinler, B. [University of Newcastle (United Kingdom). Dept. of Chemical and Process Engineering; Malik, A.A. [Waste to Energy Ltd., Sudbury (United Kingdom)

    2002-05-01

    The potential offered by biomass to reduce greenhouse gas production is now being more widely recognised. The energy in biomass may be realised either by direct combustion use, or by upgrading into more valuable and usable products such as gas, fuel oil and higher value products for utilisation in the chemical industry or for clean power generation. Up till now, gasification work has concentrated on woody biomass but recently sources of other biomass with large energy production potential have been identified, namely hazelnut shells. Therefore, a pilot scale downdraft gasifier is used to investigate gasification potential of hazelnut shells. A full mass balance is reported including the tar production rate as well as the composition of the produced gas as a function of feed rate. Additionally, the effect of feed rate on the CV/composition of the product gas and the associated variations of gasifier zone temperatures are determined with temperatures recorded throughout the main zones of the gasifier and also at the gasifier outlet and gas cleaning zones. Pressure drops are also measured across the gasifier and gas cleaning system because the produced gas may be used in conjunction with a power production engine when it is important to have low pressure drop in the system. The quality of the product gas is found to be dependent on the smooth flow of the fuel and the uniformity of the pyrolysis, and so the difficulties, encountered during the experiments are detailed. The optimum operation of the gasifier is found to be between 1.44 and 1.47 N m{sup 3}/kg of air fuel ratios at the values of 4.06 and 4.48 kg/h of wet feed rate which produces the producer gas with a good GCV of about 5 MJ/m{sup 3} at a volumetric flow of 8-9 N m{sup 3}/h product gas. It was concluded that hazelnut shells could be easily gasified in a downdraft gasifier to produce good quality gas with minimum polluting by-products. It is suggested that, in view of ease of operation, small

  16. 含硫生物质气化气催化燃烧性能研究%Catalytic Combustion of Sulphur-Bearing Gasified Biomass

    Institute of Scientific and Technical Information of China (English)

    彭丹; 孙路石; 王志远; 向军; 胡松; 苏胜; 王鹏恒

    2012-01-01

    Precious metal based catalyst Pd/LaAl11O19 and Pt/LaA111019 were prepared and characterized by means of XRD and BET. Then washcoated on cordierite monoliths and tested in a bench scale reactor with a synthetic low-heating value fuel that resembles the gas from gasification of biomass, besides 0.005% hydrogen sulphide were added to the fuel to investigate the influence of sulphur on the catalytic combustion. Combined the characterization results of XPS, SEM and FTIR after the activity tests, a preliminary analysis of the mechanism for the sulfur poisoning of the catalysts were deduced. The results show excellent catalytic activity for the catalysts which significantly reducing the ignition temperature of combustible ingredients, the low temperature activity for Pd was superior to Pt. Besides all samples were deactivated to some extent by addition of sulphur, although poisoning effect varied depending on the active phase. The poisoning processes mainly through the formation of sulfate which deposition on the surface composition, then covered the active site resulting a decrease in catalytic activity.%制备了Pt和Pd负载LaAl11O19整体式催化剂,借助XRD和BET对其进行了表征,同时考察了催化剂作用下模拟生物质气化气的燃烧特性及气化气中加入H2S对可燃成分催化燃烧的影响。结合失活样的XPS、SEM和FTIR表征结果,初步分析催化剂硫中毒的机理。结果表明,制得催化剂活性优良,明显降低了可燃成分的起燃温度,低温下Pd的活性优于Pt,Pd和Pt在抗硫中毒性上是不同的,催化剂失活是通过生成的表面硫酸盐覆盖活性位,失活后有一定的再生性。

  17. Effect of temperature and dolomite on tar formation during gasification of torrefied biomass in a pressurized fluidized bed

    International Nuclear Information System (INIS)

    This work investigates the effect of temperature and bed material on the yields and composition of gas and tar produced from gasification of two types of biomass feedstock previously torrefied at 275 °C. Special attention was devoted to the evolution of tar composition under the different experimental conditions. Experiments were conducted in a fluidized bed reactor using two different types of bed material (sand and dolomite) under a constant pressure of 0.5 MPa and at two temperature levels (750 and 850 °C). Tar destruction reactions promoted by the catalyst (dolomite) enhanced the production of some of the gas components (H2, CO2, CO and CH4) whereas C2 hydrocarbons decreased, this effect being slightly more relevant at 850 °C. Comparable trends were observed with increasing temperature, which had a positive effect on cracking reactions and tar destruction. For both feedstocks, the increase in temperature resulted in (i) higher gas yields, and (ii) enhanced char gasification rate. On the other hand the evolution of tar yield and composition revealed a possible competition between two tar reaction pathways during gasification, (i) tar polymerization, and (ii) de-alkylation, dehydration and cracking of tars, depending on the experimental conditions and feedstock used. - Highlights: • An experimental study of pressurized gasification of torrefied biomass is presented. • Special attention was devoted to the evolution of tar composition. • Increasing temperature and dolomite presence led to higher gas and lower tar yields. • Tar evolution revealed a possible competition between two tar reaction pathways

  18. Bio-syngas production from biomass catalytic gasification

    International Nuclear Information System (INIS)

    A promising application for biomass is liquid fuel synthesis, such as methanol or dimethyl ether (DME). Previous studies have studied syngas production from biomass-derived char, oil and gas. This study intends to explore the technology of syngas production from direct biomass gasification, which may be more economically viable. The ratio of H2/CO is an important factor that affects the performance of this process. In this study, the characteristics of biomass gasification gas, such as H2/CO and tar yield, as well as its potential for liquid fuel synthesis is explored. A fluidized bed gasifier and a downstream fixed bed are employed as the reactors. Two kinds of catalysts: dolomite and nickel based catalyst are applied, and they are used in the fluidized bed and fixed bed, respectively. The gasifying agent used is an air-steam mixture. The main variables studied are temperature and weight hourly space velocity in the fixed bed reactor. Over the ranges of operating conditions examined, the maximum H2 content reaches 52.47 vol%, while the ratio of H2/CO varies between 1.87 and 4.45. The results indicate that an appropriate temperature (750 oC for the current study) and more catalyst are favorable for getting a higher H2/CO ratio. Using a simple first order kinetic model for the overall tar removal reaction, the apparent activation energies and pre-exponential factors are obtained for nickel based catalysts. The results indicate that biomass gasification gas has great potential for liquid fuel synthesis after further processing

  19. Comparative Kinetic Studies and Performance Evaluation of Biofilm and Biomass Characteristics of Pseudomonas fluorescens in Degrading Synthetic Phenolic Effluent in Inverse Fluidized Bed Biofilm Reactor.

    Science.gov (United States)

    Begum, S Sabarunisha; Radha, K V

    2016-05-01

    The bioremediation potential of Pseudomonas fluorescens was studied in an Inverse Fluidized Bed Biofilm Reactor under batch recirculation conditions using synthetic phenolic effluent of various concentrations (400, 600, 800, 1000 and 1200 mg/l). The performance of the reactor was investigated and the characteristics of biomass and biofilm were determined by evaluating biofilm dry density and thickness, bioparticle density, suspended and attached biomass concentration, chemical oxygen demand and phenol removal efficiency. Biodegradation kinetics had been studied for suspended biomass culture and biofilm systems with respect to its specific growth and substrate consumption rates. Suspended biomass followed substrate inhibition kinetics and the experimental data fitted well with the Haldane model. The degradation kinetic behavior of biofilm revealed that a well adapted biofilm system with effective control of biofilm thickness in an inverse fluidized bed biofilm reactor overcomes substrate inhibition effects by tolerating higher phenol concentration and fitted well to the Monod model. PMID:27131305

  20. Effect of Temperature in Fluidized Bed Fast Pyrolysis of Biomass: Oil Quality Assessment in Test Units

    NARCIS (Netherlands)

    Westerhof, R.J.M.; Brilman, D.W.F.; Swaaij, van W.P.M.; Kersten, S.R.A.

    2010-01-01

    Pine wood was pyrolyzed in a 1 kg/h fluidized bed fast pyrolysis reactor that allows a residence time of pine wood particles up to 25 min. The reactor temperature was varied between 330 and 580 °C to study the effect on product yields and oil composition. Apart from the physical−chemical analysis, a

  1. 生物质气化火灾爆炸事故复合型风险评价%Integrated Risk Assessment of Biomass Gasified Fire and Explosion Accidents

    Institute of Scientific and Technical Information of China (English)

    闫放; 许开立; 姚锡文; 王犇

    2015-01-01

    为降低生物质气化火灾爆炸事故发生的概率,提出了一种将贝叶斯网络与 boW-tie 法相结合的风险评价方法。通过建立火灾爆炸事故的故障树并转化成贝叶斯网络,然后计算各基本事件的重要度,进而找出系统中导致事故发生的薄弱环节。采用 boW-tie 对薄弱环节进行分析,提出相应的预防措施与控制措施,并计算了薄弱环节采取控制措施后事故发生概率降低的幅度。该方法可精确找出导致事故发生的最主要原因及有效预防控制措施,达到有效降低生物质气化火灾爆炸事故发生概率的目的。%In order to reduce the occurrence of fire and explosion accidents ,a risk assessment approach integrating Bayesian netWork and boW-tie analysis Was proposed.Firstly,the fault tree is established and transformed into Bayesian netWork.Then the Weak points Which might lead to accidents can be pinpointed by calculating the importance of each basic event.The boW-tie analysis is given on the Weak points to Work out the precautions and control measures,and the reduction of accident frequency is calculated after taking control measures for the Weak points. The reasons for such accidents can be found accurately by this approach,Which helps to take appropriate precautions and control measures so as to effectively reduce the occurrence of biomass gasified fire and explosion accidents.

  2. Feeding activity of mussels Mytilus edulis related to near-bed currents and phytoplankton biomass

    DEFF Research Database (Denmark)

    Dolmer, Per

    The feeding activity of blue mussels Mytilus edulis was investigated in the field and related to near-bottom current velocities and the phytoplankton biomass in the near-bottom water layers for four days. The body content of Chl-a in mussels and their shell gap size were used as indices of...

  3. Nitrogen compounds in pressurised fluidised bed gasification of biomass and fossil fuels

    NARCIS (Netherlands)

    De Jong, W.

    2005-01-01

    Fossil fuels still dominate the energy supply in modern societies. The resources, however, are depleting. Therefore, other energy sources are to be exploited further within this century. Biomass is one of the practically CO2 neutral, renewable contributors to the future energy production. Nowadays m

  4. Pressurized gasification of biomass - complete power plant technology; Biomassan paineistettu kaasutus valmis voimalaitostekniikaksi

    Energy Technology Data Exchange (ETDEWEB)

    Virkkunen, L. [Enviropower Oy, Tampere (Finland)

    1994-12-31

    Enviropower Oy, which is an affiliate of Tampella Power Oy, has just finished a large gasification test program at the 20 MW test power plant situated at Tampere. Total amount of 3 000 m{sup 3} of finnish mixed wood chips were gasified during the tests in 1993. Enviropower has been the first which has gasified biomass using large-scale pressurized system. The technology can be applied both for biomass and coal. This so called multi-fuel boiler increases the possibilities to use biomass as fuels, and also improves the competitivity of it because it makes the merely utilization of biomass possible also in the coal fired power plants. Gasification technique, based on wood, waste wood and peat, will be commercialized fast in the plants which partially utilizes also other fuels than coal. The most economical way to increase the utilization of biomass is to gasify it with other fuels using the new technology. The gasification combined cycle power plant, based on pressurized fluidized bed gasification can coarsely be compared with common natural gas combined cycle power plants. Gas, produced by gasification from solid fuels, is used as fuel instead of natural gas. The process is very simple. Coal, waste wood, peat and other solid fuels are heated in a fluidized bed type pressurized reactor at the temperature of about one thousand degrees celsius, under the conditions in which the fuels are gasified. The sulfur, the dust and the other harmful compounds are removed from the product gas, and the clean gas is combusted in a gas turbine and the heat produced in the process is converted into electric power using heat recovery boiler and steam turbine

  5. Measurement and prediction of the emission of pollutants from the combustion of coal and biomass in a fixed bed furnace

    Energy Technology Data Exchange (ETDEWEB)

    Ross, A.B.; Jones, J.M.; Chaiklangmuang, S.; Pourkashanian, M.; Williams, A.; Kubica, K.; Andersson, J.T.; Kerst, M.; Danihelka, P.; Bartle, K.D. [University of Leeds, Leeds (United Kingdom). Dept. of Fuel and Energy

    2002-03-01

    The effect of co-combustion of coal and biomass has been studied for a fixed bed appliance originally designed for coal and in widespread use in many parts of the world especially Eastern Europe. Organic, inorganic and gaseous emissions have been measured. Organic compounds have been determined for a range of fuel combinations. These include polycyclic aromatic hydrocarbons PAH, alkyl PAH, a range of oxygenated compounds (including phenols, aldehydes, and ketones, oxygenated polycyclic aromatic compounds (O-PAC) and dioxins), polycyclic aromatic sulphur hydrocarbons (PASH), nitrogenated polycyclic aromatic compounds (N-PAC) and common volatile organic compounds (VOC). Inorganic species include trace heavy metals, as well as the gases, CO, CO{sub 2}, SO{sub x} and NOx. The concentration of the trace metals in the ash and fly ash have been compared to equilibrium calculations of the emission profiles during co-combustion. 18 refs., 8 figs., 8 tabs.

  6. Biomass fast pyrolysis in fluidized bed : product cleaning by in-situ filtration

    OpenAIRE

    Wang, Xiaoquan

    2006-01-01

    This thesis is dedicated to the subject of fast pyrolysis in a fluid bed reactor. A large part of the work is related to reactor design aspects of fast pyrolysis, a subject that has not been considered sufficiently. Past research efforts were focussed mainly on the kinetics of wood pyrolysis and the testing of different reactor types by measuring the bio-oil yield as a function of the reactor temperature.

  7. Production of methanol/DME from biomass

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Münster-Swendsen, Janus;

    In this project the production of DME/methanol from biomass has been investigated. Production of DME/methanol from biomass requires the use of a gasifier to transform the solid fuel to a synthesis gas (syngas) - this syngas can then be catalytically converted to DME/methanol. Two different gasifi...

  8. Substitute natural gas from biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Tunaa, Per (Lund Inst. of Technology, Lund (SE))

    2008-03-15

    Biomass is by many considered as the only alternative to phase-out the usage of fossil fuels such as natural gas and oil especially for the transportation sector where alternative solutions, such as hydrogen fuel cells and batteries, are not yet fully developed. Thermal gasification or other methods such as pyrolysis of the biomass must be applied in order to produce an intermediate product suitable for further upgrading to either gaseous or liquid products. This thesis will evaluate the possibilities of producing, substitute natural gas, (SNG) from biomass gasification by using computer simulation. Three different gasification techniques were evaluated; entrained-flow, fluidized-bed and indirect gasification coupled with two different desulphurisation systems and two methanation processes. The desulphurisation systems were a zinc oxide bed and a Rectisol wash system. Methanation were performed by a series of adiabatic reactors with gas recycling and by an isothermal reactor. The impact on SNG efficiency from system pressure, isothermal methanation temperature and PSA methane recovery were evaluated as well. The results show that the fluidized-bed and the indirect gasifier have the highest SNG efficiency. Furthermore there are little to no difference between the methanation processes and small differences for the gas cleanup systems. SNG efficiencies in excess of 50 % were possible for all gasifiers. SNG efficiency is defined as the energy in the SNG product divided by the total input to the system from biomass, drying and oxygen. Increasing system pressure has a negative impact on SNG efficiency as well as increasing operating costs due to increased power for compression. Isothermal methanation temperature has no significant impact on SNG efficiency. Recovering as much methane as possible in the PSA is the most important parameter. Recovering methane that has been dissolved in condensed process water increases the SNG efficiency by 2-10% depending on system.

  9. Gasification of fuel blends from biomass and wastes

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Arne [Lund Univ. (Sweden). Dept. of Chemical Engineering II

    2000-04-01

    Pressurized air-blown fluidized-bed gasification of biomass and biomass-based fuel blends were carried out at LTH. The operation was stable and smooth. The fluidized-bed functioned well in keeping a stable gasification and homogeneous conditions along the reactor. Parameters, such as the equivalent ratio, the bed temperature and the freeboard temperature were studied. It was found that the equivalent ratio was the dominant factor when the carbon conversion was complete. The energy content of the fuel gas, the fuel gas production, and the amount of tar and LHCs increased with decreasing equivalent ratio. Low freeboard and bed temperatures can lead to low carbon conversion and low gasification efficiency. Below 100% carbon conversion, the fuel-N conversion to ammonia increased with increasing reactor temperature. The tendency was similar for the carbon conversion to gas, but it was more pronounced. A high reactor temperature helped to reduce the amount of LHCs and tar in the fuel gas. Fuel blends with plastic or carton waste in biomass were successfully gasified. A waste fraction of 20% was found practical. Higher ratio may cause blocking in the feeding system for carton and demand special care to control the equivalent ratio for plastics. No melting problem was observed for plastics. The product gas quality was not much affected by adding the wastes. No clear increase of the chlorine content in the fuel gas was observed. However mixing of plastics greatly increased the amounts of LHCs and tar in the fuel gas. In general, introducing a small amount of plastic and carton wastes into biomass gasification will not require much change in the gasification system. This gives rise to the possibility of co-gasifying wastes in an ordinary biomass gasifier. From lab-scale experiments, a model for ammonia decomposition was proposed. A Ni-based catalyst was chosen to be applied for the fuel gas from the gasifier. At 800-900 deg C, and 3-sec space-time, 65-95% ammonia removal and

  10. Trace elements partitioning during co-firing biomass with lignite in a pilot-scale fluidized bed combustor

    International Nuclear Information System (INIS)

    This study describes the partitioning of 18 trace elements (As, Ba, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, P, Pb, Sb, Se, Sn, Tl, V, Zn) and 9 major and minor elements (Al, Ca, Fe, K, Mg, Na, S, Si, Ti) during co-firing of olive residue, hazelnut shell and cotton residue with high sulfur and ash content lignite in 0.3 MWt Middle East Technical University (METU) Atmospheric Bubbling Fluidized Bed Combustor (ABFBC) test rig with limestone addition. Concentrations of trace elements in coal, biomass, limestone, bottom ash, cyclone ash and filter ash were determined by inductively coupled plasma optical emission and mass spectroscopy (ICP-OES and ICP-MS). Partitioning of major and minor elements are influenced by the ash split between the bottom ash and fly ash and that the major proportion of most of the trace elements (As, Ba, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Tl, V and Zn) are recovered in fly ash when firing lignite only. Co-firing lignite with biomass enhances partitioning of these elements to fly ash. Co-firing also shifts the partitioning of Cd, P, Sb and Sn from bottom to fly ash

  11. Trace elements partitioning during co-firing biomass with lignite in a pilot-scale fluidized bed combustor.

    Science.gov (United States)

    Gogebakan, Zuhal; Selçuk, Nevin

    2009-03-15

    This study describes the partitioning of 18 trace elements (As, Ba, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, P, Pb, Sb, Se, Sn, Tl, V, Zn) and 9 major and minor elements (Al, Ca, Fe, K, Mg, Na, S, Si, Ti) during co-firing of olive residue, hazelnut shell and cotton residue with high sulfur and ash content lignite in 0.3 MW(t) Middle East Technical University (METU) Atmospheric Bubbling Fluidized Bed Combustor (ABFBC) test rig with limestone addition. Concentrations of trace elements in coal, biomass, limestone, bottom ash, cyclone ash and filter ash were determined by inductively coupled plasma optical emission and mass spectroscopy (ICP-OES and ICP-MS). Partitioning of major and minor elements are influenced by the ash split between the bottom ash and fly ash and that the major proportion of most of the trace elements (As, Ba, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Tl, V and Zn) are recovered in fly ash when firing lignite only. Co-firing lignite with biomass enhances partitioning of these elements to fly ash. Co-firing also shifts the partitioning of Cd, P, Sb and Sn from bottom to fly ash. PMID:18621479

  12. Development of methane and nitrous oxide emission factors for the biomass fired circulating fluidized bed combustion power plant.

    Science.gov (United States)

    Cho, Chang-Sang; Sa, Jae-Hwan; Lim, Ki-Kyo; Youk, Tae-Mi; Kim, Seung-Jin; Lee, Seul-Ki; Jeon, Eui-Chan

    2012-01-01

    This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH(4)), Nitrous oxide (N(2)O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH(4) and N(2)O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH(4) and N(2)O exhausted from the CFB boiler. As a result, the emission factors of CH(4) and N(2)O are 1.4 kg/TJ (0.9-1.9 kg/TJ) and 4.0 kg/TJ (2.9-5.3 kg/TJ) within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N(2)O emission, compared to the emission factor of the CFB boiler using fossil fuel. PMID:23365540

  13. Development of Methane and Nitrous Oxide Emission Factors for the Biomass Fired Circulating Fluidized Bed Combustion Power Plant

    Directory of Open Access Journals (Sweden)

    Chang-Sang Cho

    2012-01-01

    Full Text Available This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH4, Nitrous oxide (N2O. The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF, RDF and Refused Plastic Fuel (RPF of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH4 and N2O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH4 and N2O exhausted from the CFB boiler. As a result, the emission factors of CH4 and N2O are 1.4 kg/TJ (0.9–1.9 kg/TJ and 4.0 kg/TJ (2.9–5.3 kg/TJ within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N2O emission, compared to the emission factor of the CFB boiler using fossil fuel.

  14. Modified Thermodynamic Equilibrium Model for Biomass Gasification: A Study of the Influence of Operating Conditions

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Bruno, Juan Carlos; Coronas, Alberto

    2012-01-01

    This paper presents a mathematical model for biomass gasification processes developed in the equation solver program Engineering Equation Solver (EES) with an implemented user-friendly interface. It is based on thermodynamic equilibrium calculations and includes some modifications to be adapted...... data from different authors for downdraft, fluidized-bed gasifiers and different biomasses, showing good agreement between reported data and modeled values. In addition, it has been used to evaluate the influence of different operating parameters [equivalence ratio (ER), air preheating, steam injection...

  15. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2002-03-31

    Proposed activities for quarter 7 (12/15/01-3/14/2002): (1) Incorporation of moisture model into PCGC2 code. Parametric study of moisture effects on flame structure and pollutants emissions in cofiring of coal and Liter Biomass (LB) (Task 4); (2) Use the ash tracer method to determine the combustion efficiency and comparison it to results from gas analysis (Task 2); (3) Effect of swirl on combustion performance (Task 2); (4) Completion of the proposed modifications to the gasifier setup (Task 3); (5) Calibration of the Gas Chromatograph (GC) used for measuring the product gas species (Task 3); and (6) To obtain temperature profiles for different fuels under different operating conditions in the fixed bed gasifier (Task 3).

  16. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    International Nuclear Information System (INIS)

    Proposed activities for quarter 7 (12/15/01-3/14/2002): (1) Incorporation of moisture model into PCGC2 code. Parametric study of moisture effects on flame structure and pollutants emissions in cofiring of coal and Liter Biomass (LB) (Task 4); (2) Use the ash tracer method to determine the combustion efficiency and comparison it to results from gas analysis (Task 2); (3) Effect of swirl on combustion performance (Task 2); (4) Completion of the proposed modifications to the gasifier setup (Task 3); (5) Calibration of the Gas Chromatograph (GC) used for measuring the product gas species (Task 3); and (6) To obtain temperature profiles for different fuels under different operating conditions in the fixed bed gasifier (Task 3)

  17. Fundamental studies of synthesis-gas production based on fluidised-bed gasification of biomass (UCGFunda)

    Energy Technology Data Exchange (ETDEWEB)

    Reinikainen, M.; Moilanen, A.; Simell, P.; Hannula, I.; Nasrullah, M.; Kurkela, E. (VTT Technical Research Centre of Finland, Espoo (Finland))

    2009-10-15

    The research is directed towards methods of producing transportation bio-fuels via the synthesis-gas route, with emphasis on the synthesis-gas production and gas cleaning steps. The subtopics of the research project are (1) fuel characterisation and ash behaviour in the gasification step, (2) reaction mechanisms related to gas cleaning, (3) evaluations of alternative process configurations and applications and (4) international co-operation. VTT itself finances also two additional subtopics: (5) new analysis techniques and (6) hydrogen from biomass via gasification. A lot of data on the reactivity and ash sintering properties of various kinds of biomasses has been obtained in the project and the information will now be formulated into a mathematical model. In addition to catalysis also thermal reactions play an important role in gas cleaning. Both experimental and modelling work on both of the reaction types is being carried out. Three techno-economic evaluations on alternative and competing technologies will be completed in the coming year. International development in syngas technology has been closely monitored in all subtopics as well as by participating in relevant IEA-tasks. New analysis techniques developed in the project have proven very useful and for instance a fast on-line tar analysis method is now well established. (orig.)

  18. Fluidized bed gasification of sugar cane bagasse. Influence on gas composition

    Energy Technology Data Exchange (ETDEWEB)

    Esperanza, E.; Aleman, Y. [Univ. of las Villas, Santa Clara (Cuba). Biomass Thermoconversion group/CETA; Arauzo, J.; Gea, G. [Univ. of Zaragoza (Spain). Chemical and Environmental Engineering Dept.

    1999-07-01

    Air and steam gasification of biomass has been studied at different temperatures. The experiments have been carried out in a bench scale plant. It consists of an atmospheric bubbling fluidized bed gasifier heated by an electric furnace. The gasification process have been carried out at high heating rates and low residence time of the gases. The biomass used has been Cuban sugar cane bagasse. Three operating parameters have been evaluated to improve the gas composition: Equivalence Ratio (E.R.) in the range of 0.15 to 0.55; the bed temperature from 780 to 920 deg C; and steam/biomass ratio (S/B) from 0.1 g/g to 0.5 g/g. The results obtained show the effect of these operating parameters in gas composition and the conditions to obtain higher yield to gas and else the maximum energy.

  19. An experimental study on hydrogen-rich gas production via steam gasification of biomass in a research-scale fluidized bed

    International Nuclear Information System (INIS)

    Highlights: • Steam gasification via fluidized-bed is an interesting technology for hydrogen rich gas production. • The increase of steam/biomass ratio plays a major role on the hydrogen yield. • Hydrogen yield slightly increases as the biomass particle size decreases. • Tar yield strongly depends on reaction temperature. - Abstract: A research scale fluidized-bed reactor has been built and used to study the effect of steam/biomass ratio, time duration of experiments, reactor temperature, and biomass particle size on hydrogen yield and tar content in produced syngas during steam gasification of biomass. Batch experiments were performed with wood residue crushed into three different sizes of 0.5–1 mm (small), 1–2.5 mm (medium), and 2.5–5 mm (large), at reactor temperatures of 700, 800, and 900 °C. As the steam/biomass ratio increases, a decrease in formation of CO, accompanied by an increase in the hydrogen concentration, is observed. As expected, an increase in reactor temperature leads to a significant increase of H2 output and tar reforming. The obtained results show that hydrogen yield increases as time duration of the experiment is increased. It is also found that a reduction in particle diameter leads to a significant improvement in hydrogen yield

  20. Feeding activity of mussels Mytilus edulis related to near-bed currents and phytoplankton biomass

    DEFF Research Database (Denmark)

    Dolmer, Per

    . During day 3 and day 4 the near-bed current velocities increased to 6.5 and 3.9 cm s(-1). respectively, and the Chl-a was homogeneously distributed in the water column. Now only 17 and 25% of the mussels had closed valves and they accumulated a larger amount of Chl-a. The actual population filtration...... rates were estimated from the density of active mussels times the estimated filtration rates (based on the gap size of the mussels and literature values for corresponding filtration rates). Actual population filtration rates ranged from 6.4 to 22.8 m(3) m(-2) d(-1) on days 1 and 3, respectively......, corresponding to 27 and 98% of the estimated population filtration capacity. (C) 2000 Elsevier Science B.V. All rights reserved....

  1. Fundamental studies of synthesis-gas production based on fluidised-bed gasification of biomass - UCGFUNDA

    Energy Technology Data Exchange (ETDEWEB)

    Reinikainen, M. [VTT Technical Research Centre of Finland, Espoo (Finland)], email: matti.reinikainen@vtt.fi

    2012-07-01

    The project was directed towards improved methods of producing transportation bio-fuels via the synthesis-gas route. The aim of the project was to broaden and deepen the knowledge base and, in particular, generate new fundamental information about the most critical process steps from the point of view of the realisation of the technology. The subtopics of the research project were: (1) Fuel characterisation and ash behaviour in the gasification step (2) Reaction mechanisms related to gas cleaning, in particular the reactions of hydrocarbons at gasification temperatures, during hot-gas filtration and on catalytic surfaces (3) Evaluations of alternative process configurations and applications (4) Monitoring of developments elsewhere in the world (5) New analysis techniques (6) Hydrogen from biomass via gasification.

  2. Fundamental studies of synthesis-gas production based on fluidised-bed gasification of biomass - UCGFunda

    Energy Technology Data Exchange (ETDEWEB)

    Reinikainen, M.; Moilanen, A.; Simell, P.; Hannula, I.; Kurkela, E. (VTT Technical Research Centre of Finland, Espoo (Finland)), Email: matti.reinikainen@vtt.fi; Suominen, T.P. (Aabo Akademi, Turku (Finland). Lab. of Industrial Chemistry and Reaction Engineering); Linnekoski, J.; Roenkkoenen, E. (Aalto University, School of Science and Technology, Espoo (Finland). Lab. of Industrial Chemistry.)

    2010-10-15

    The research is directed towards methods of producing transportation bio-fuels via the synthesis-gas route, with emphasis on the synthesis-gas production and gas cleaning steps. The subtopics of the research project are (1) fuel characterisation and ash behaviour in the gasification step, (2) reaction mechanisms related to gas cleaning, (3) evaluations of alternative process configurations and applications and (4) international cooperation. VTT itself finances also two additional subtopics: (5) new analysis techniques and (6) hydrogen from biomass via gasification. The project comprises experimental work, modelling, techno-economic evaluations as well as studies based on literature. The project is steered by a wide industrial consortium and the research work is carried out by VTT, Aalto University and Aabo Akademi. International development in syngas technology has been closely monitored in all subtopics as well as by participating in relevant IEA-tasks. (orig.)

  3. Method and apparatus for automated, modular, biomass power generation

    Science.gov (United States)

    Diebold, James P.; Lilley, Arthur; Browne, Kingsbury III; Walt, Robb Ray; Duncan, Dustin; Walker, Michael; Steele, John; Fields, Michael; Smith, Trevor

    2011-03-22

    Method and apparatus for generating a low tar, renewable fuel gas from biomass and using it in other energy conversion devices, many of which were designed for use with gaseous and liquid fossil fuels. An automated, downdraft gasifier incorporates extensive air injection into the char bed to maintain the conditions that promote the destruction of residual tars. The resulting fuel gas and entrained char and ash are cooled in a special heat exchanger, and then continuously cleaned in a filter prior to usage in standalone as well as networked power systems.

  4. Morphological study of biomass during the start-up period of a fixed-bed anaerobic reactor treating domestic sewage

    Directory of Open Access Journals (Sweden)

    Cláudio Antonio Andrade Lima

    2005-09-01

    Full Text Available This work focused on a morphological study of the microorganisms attached to polyurethane foam matrices in a horizontal-flow anaerobic immobilized biomass (HAIB reactor treating domestic sewage. The experiments consisted of monitoring the biomass colonization process of foam matrices in terms of the amount of retained biomass and the morphological characteristics of the cells attached to the support during the start-up period. Non-fluorescent rods and cocci were found to predominate in the process of attachment to the polyurethane foam surface. From the 10th week of operation onwards, an increase was observed in the morphological diversity, mainly due to rods, cocci, and Methanosaeta-like archaeal cells. Hydrodynamic problems, such as bed clogging and channeling occurred in the fixed-bed reactor, mainly due to the production of extracellular polymeric substances and their accumulation in the interstices of the bed causing a gradual deterioration of its performance, which eventually led to the system's collapse. These results demonstrated the importance and usefulness of monitoring the dynamics of the formation of biofilm during the start-up period of HAIB reactors, since it allowed the identification of operational problems.Este trabalho apresenta um estudo morfológico de microrganismos aderidos à espuma de poliuretano em reator anaeróbio horizontal de leito fixo (RAHLF, aplicado ao tratamento de esgoto sanitário. O processo de colonização do suporte pela biomassa anaeróbia e as características morfológicas das células aderidas foram monitorados durante o período de partida do reator. Bacilos e cocos não fluorescentes foram predominantes no processo de aderência direta à espuma de poliuretano. Aumento na diversidade biológica foi observado a partir da 10ª semana de operação do reator, com predominância de bacilos, cocos e arqueas metanogênicas semelhantes a Methanosaeta. Problemas hidrodinâmicos, tais como formação de

  5. PNNL Coal Gasifier Transportation Logistics

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Douglas J.; Guzman, Anthony D.

    2011-04-13

    This report provides Pacific Northwest National laboratory (PNNL) craftspeople with the necessary information and suggested configurations to transport PNNL’s coal gasifier from its current location at the InEnTec facility in Richland, Washington, to PNNL’s Laboratory Support Warehouse (LSW) for short-term storage. A method of securing the gasifier equipment is provided that complies with the tie-down requirements of the Federal Motor Carrier Safety Administration’s Cargo Securement Rules.

  6. Gasification of ‘Loose’ Groundnut Shells in a Throathless Downdraft Gasifier

    Directory of Open Access Journals (Sweden)

    Aondoyila Kuhe

    2015-07-01

    Full Text Available In this paper, gasification potential of biomass residue was investigated using a laboratory scale throatless downdraft gasifier. Experimental results of groundnut shell was gasified in the throatless downdraft gasifier to produce a clean gas with a calorific value of around 5.92 MJ/Nm3 and a combustible fraction of 45% v/v. Low moisture (8.6% and ash content (3.19% are the main advantages of groundnut shells for gasification. It is suggested that gasification of shell waste products is a clean energy alternative to fossil fuels. The product gas can be used efficiently for heating and possible usage in internal combustion engines.

  7. A comparison of circulating fluidised bed combustion and gasification power plant technologies for processing mixtures of coal, biomass and plastic waste

    Energy Technology Data Exchange (ETDEWEB)

    McIlveen-Wright, D.R.; Huang, Y.; McMullan, J.T. [NICERT, University of Ulster at Jordanstown, Newtownabbey BT37 0QB, Northern Ireland (United Kingdom); Pinto, F.; Franco, C.; Gulyurtlu, I. [INETI-DEECA, Estrada do Paco do Lumiar, 22, 1649-038 Lisboa (Portugal); Armesto, L.; Cabanillas, A. [CIEMAT, Avda Complutense, 22, 28040 Madrid (Spain); Caballero, M.A.; Aznar, M.P. [Chemical and Environmental Engineering Department, Centro Politecnico Superior, Maria de Luna, University of Saragossa, 50018 Saragossa (Spain)

    2006-09-15

    Environmental regulations concerning emission limitations from the use of fossil fuels in large combustion plants have stimulated interest in biomass for electricity generation. The main objective of the present study was to examine the technical and economic viability of using combustion and gasification of coal mixed with biomass and plastic wastes, with the aim of developing an environmentally acceptable process to decrease their amounts in the waste stream through energy recovery. Mixtures of a high ash coal with biomass and/or plastic using fluidised bed technologies (combustion and gasification) were considered. Experiments were carried out in laboratory and pilot plant fluidised bed systems on the combustion and air/catalyst and air/steam gasification of these feedstocks and the data obtained were used in the techno-economic analyses. The experimental results were used in simulations of medium to large-scale circulating fluidised bed (CFB) power generation plants. Techno-economic analysis of the modelled CFB combustion systems showed efficiencies of around 40.5% (and around 46.5% for the modelled CFB gasification systems) when fuelled solely by coal, which were only minimally affected by co-firing with up to 20% biomass and/or wastes. Specific investments were found to be around $2150/kWe to $2400/kWe ($1350/kWe to $1450/kWe) and break-even electricity selling prices to be around $68/MWh to $78/MWh ($49/MWh to $54/MWh). Their emissions were found to be within the emission limit values of the large combustion plant directive. Fluidised bed technologies were found to be very suitable for co-firing coal and biomass and/or plastic waste and to offer good options for the replacement of obsolete or polluting power plants. (author)

  8. A comparison of circulating fluidised bed combustion and gasification power plant technologies for processing mixtures of coal, biomass and plastic waste

    International Nuclear Information System (INIS)

    Environmental regulations concerning emission limitations from the use of fossil fuels in large combustion plants have stimulated interest in biomass for electricity generation. The main objective of the present study was to examine the technical and economic viability of using combustion and gasification of coal mixed with biomass and plastic wastes, with the aim of developing an environmentally acceptable process to decrease their amounts in the waste stream through energy recovery. Mixtures of a high ash coal with biomass and/or plastic using fluidised bed technologies (combustion and gasification) were considered. Experiments were carried out in laboratory and pilot plant fluidised bed systems on the combustion and air/catalyst and air/steam gasification of these feedstocks and the data obtained were used in the techno-economic analyses. The experimental results were used in simulations of medium to large-scale circulating fluidised bed (CFB) power generation plants. Techno-economic analysis of the modelled CFB combustion systems showed efficiencies of around 40.5% (and around 46.5% for the modelled CFB gasification systems) when fuelled solely by coal, which were only minimally affected by co-firing with up to 20% biomass and/or wastes. Specific investments were found to be around $2150/kWe to $2400/kWe ($1350/kWe to $1450/kWe) and break-even electricity selling prices to be around $68/MWh to $78/MWh ($49/MWh to $54/MWh). Their emissions were found to be within the emission limit values of the large combustion plant directive. Fluidised bed technologies were found to be very suitable for co-firing coal and biomass and/or plastic waste and to offer good options for the replacement of obsolete or polluting power plants. (author)

  9. Biomass granular screw feeding: An experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Jianjun; Grace, John R. [Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC, V6 T 1Z3 (Canada)

    2011-02-15

    Successful feeding is critical to biomass utilization processes, but difficult due to the heterogeneity, physical properties and moisture content of the particles. The objectives of the present study were to find the mechanisms of blockage in screw feeding and to determine the effects of particle mean size (0.5-15 mm), size distribution, shape, moisture content (10-60%), density and compressibility on biomass particle feeding at room temperature. Wood pellets, sawdust, hog fuel and wood shavings were tested in a screw feeder/lock hopper system previously employed to feed sawdust into a pilot-scale circulating fluidized-bed gasifier. Experimental results showed that large particles, wide size distributions, large bulk densities and high moisture contents generally led to larger torque requirements for screw feeding. The ''choke section'' and seal plug play important roles in determining the torque requirements. (author)

  10. Results concerning a clean co-combustion technology of waste biomass with fossil fuel, in a pilot fluidised bed combustion facility

    Energy Technology Data Exchange (ETDEWEB)

    Ionel, Ioana; Trif-Tordai, Gavril; Ungureanu, Corneliu; Popescu, Francisc; Lontis, Nicolae [Politehnica Univ. Timisoara (Romania). Faculty for Mechanical Engineering

    2008-07-01

    The research focuses on a facility, the experimental results, interpretation and future plans concerning a new developed technology of using waste renewable energy by applying the cocombustion of waste biomass with coal, in a fluidised bed system. The experimental facility is working entirely in accordance to the allowed limits for the exhaust flue gas concentration, with special concern for typical pollutants. The experiments conclude that the technology is cleaner, has as main advantage the possibility to reduce both the SO{sub 2} and CO{sub 2} exhaust in comparison to standard fossil fuel combustion, under comparable circumstances. The combustion is occurring in a stable fluidised bed. (orig.)

  11. Aviary heating: control of air temperature heated by a set biomass gasifier-combustor in a co-current flow, using a frequency inverter; Aquecimento de aviarios: controle da temperatura do ar aquecido por um conjunto gaseificador-combustor de biomassa de fluxo concorrente, utilizando um inversor de frequencia

    Energy Technology Data Exchange (ETDEWEB)

    Santos, William Rosario dos [Universidade Presidente Antonio Carlos (UNIPAC), Ponte Nova, MG (Brazil); Silva, Jadir Nogueira; Oliveira Filho, Delly; Martins, Marcio Aredes; Oliveira, Jofran Luiz de [Universidade Federal de Vicosa (UFV), MG (Brazil)], Emails: jadir@ufv.br, delly@ufv.br, aredes@ufv.br, jofran.oliveira@ufv.br

    2009-07-01

    One of the problems with using the gasifier for heating purposes in poultry facilities is the waste of energy during the day, once the equipment does not have control of the thermal and power generated. During this period, the difference in temperature between the air and the standard for the birds inside the building is lower than when compared with the nocturnal period. During the day, the temperature inside the poultry house is controlled by curtains, which occurs without diminishing the biomass burning. Another way to control the temperature is the shutdown of the system, which requires the constant attention of the operator. In this way, there is a potential for energy savings if the thermal power could be controlled according to the demand, which can be represented by the temperature gradient. The purpose of this study was to control the temperature of exhaustion air from a set combustor-gasifier (down draft), based on the model developed by Martin et al. (2006), through the control of speed of the fan engine and also controlling the flow contributions of primary and secondary air in the combustor. The experiment was carried out in the Energy and Pre-processing of Agricultural Products areas, at the Department of Agricultural Engineering - Federal University of Vicosa. (author)

  12. In-situ catalytic upgrading of biomass pyrolysis vapor: Co-feeding with methanol in a multi-zone fixed bed reactor

    International Nuclear Information System (INIS)

    Highlights: • Aromatics yield improved with increasing H/Ceff ratio of the feed. • HZSM-5 catalyst was an effective catalyst for in-situ bio-oil upgrading. • Biomass/methanol co-feeding attenuated the coke formation. • Methanol co-feeding enhanced the bio-oil quality. - Abstract: The in-situ catalytic upgrading of the biomass pyrolysis vapor and its mixture with methanol were conducted in a fixed bed multi-zone reactor. The steps were comprised; thermally converting the biomass in the pyrolysis reactor, passing its vapor in contact with the HZSM-5 zeolite catalyst in the presence of methanol vapor, and transformation of the resulting upgraded pyrolysis vapor into the liquid product. The biomass pyrolysis and catalytic pyrolysis vapor upgrading were performed at 500 °C. The highly valuable chemicals production was a function of the hydrogen to carbon effective ratio (H/Ceff) of the feed. This ratio was regulated by changing the relative amount of biomass and methanol. More aromatic hydrocarbons (50.02 wt.%) and less coke deposition on the catalyst (1.3 wt.%) were yielded from the biomass, when methanol was co-fed to the catalytic pyrolysis process (H/Ceff = 1.35). In this contribution, the deposited coke on the catalyst was profoundly investigated. The coke, with high contents of oxo-aromatics and aromatic compounds, was generated by polymerization of biomass lignin derived components activated by catalyst acid sites

  13. Investigation of ash deposition in a pilot-scale fluidized bed combustor co-firing biomass with lignite.

    Science.gov (United States)

    Gogebakan, Zuhal; Gogebakan, Yusuf; Selçuk, Nevin; Selçuk, Ekrem

    2009-01-01

    This study presents the results from investigation of ash deposition characteristics of a high ash and sulfur content lignite co-fired with three types of biomass (olive residue, 49 wt%; hazelnut shell, 42 wt%; and cotton residue, 41 wt%) in 0.3 MW(t) Middle East Technical University (METU) Atmospheric Bubbling Fluidized Bed Combustion (ABFBC) Test Rig. Deposit samples were collected on an air-cooled probe at a temperature of 500 degrees C. Samples were analyzed by SEM/EDX and XRD methods. The results reveal that co-firing lignite with olive residue, hazelnut shell and cotton residue show low deposition rates. High concentrations of silicon, calcium, sulfur, iron, and aluminum were found in deposit samples. No chlorine was detected in deposits. Calcium sulfate and potassium sulfate were detected as major and minor components of the deposits, respectively. High sulfur and alumina-silicate content of lignite resulted in formation of alkali sulfates instead of alkali chlorides. Therefore, fuel blends under consideration can be denoted to have low-fouling propensity. PMID:18762413

  14. Photoconversion of gasified organic materials into biologically-degradable plastics

    Science.gov (United States)

    Weaver, Paul F.; Maness, Pin-Ching

    1993-01-01

    A process is described for converting organic materials (such as biomass wastes) into a bioplastic suitable for use as a biodegradable plastic. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide and hydrogen, followed by photosynthetic bacterial assimilation of the gases into cell material. The process is ideally suited for waste recycling and for production of useful biodegradable plastic polymer.

  15. Demonstration of a 1 MWe biomass power plant at USMC Base Camp Lejeune. Report for July 1994-May 1997

    Energy Technology Data Exchange (ETDEWEB)

    Cleland, J.; Purvis, C.R.

    1998-06-01

    The paper discusses a biomass energy conversion project being sponsored by EPA to demonstrate an enviromentally and economically sound electrical power option for government installations, industrial sites, rural cooperatives, small municipalities, and developing countries. Wood gasification combined with internal combustion engines was chosen because of (1) recent improvements in gas cleaning, (2) simple economical operation for units < 10 MW, and (3) the option of a clean cheap fuel for the many existing facilities generating expensive electricity from petroleum fuels with reciprocating engines. The plant incorporates a downdraft, moving-bed gasifier utilizing hogged waste wood from the Marine Corps Base at Camp Lejeune, NC. A moving-bed bulk wood dryer and both spark ignition and diesel engines are included. Unique process design features are described briefly, relative to the gasifier, wood drying, tar separation, and process control. A test plan for process optimization and demonstration of reliability, economics, and environmental impact is outlined.

  16. Pilot-scale experience with biological nutrient removal and biomass yield reduction in a liquid-solid circulating fluidized bed bioreactor.

    Science.gov (United States)

    Chowdhury, Nabin; Nakhla, George; Zhu, Jesse; Islam, Mohammad

    2010-01-01

    A pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor was developed at the Adelaide Pollution Control Plant, London, Ontario, Canada, to study its commercial viability for biological nutrient removal. Lava rock particles of 600 microm were used as a biomass carrier media. The LSCFB removed approximately 90% organic, 80% nitrogen, and 70% phosphorus at loading rates of 4.12 kg COD/m3 x d, 0.26 kg N/m3 x d, and 0.052 kg P/m3 x d, and an empty bed contact time of 1.5 hours. Effluent characterized by clarifier removed suspended solids removal without chemicals. A significant reduction (approximately 75%) in biomass yield to 0.12 to 0.16 g VSS/g chemical oxygen demand (COD) was observed, primarily because of long biological solids retention time (SRT) of 20 to 39 days and a combination of anoxic and aerobic COD consumption. PMID:20942332

  17. Removal of furan and phenolic compounds from simulated biomass hydrolysates by batch adsorption and continuous fixed-bed column adsorption methods.

    Science.gov (United States)

    Lee, Sang Cheol; Park, Sunkyu

    2016-09-01

    It has been proposed to remove all potential inhibitors and sulfuric acid in biomass hydrolysates generated from dilute-acid pretreatment of biomass, based on three steps of sugar purification process. This study focused on its first step in which furan and phenolic compounds were selectively removed from the simulated hydrolysates using activated charcoal. Batch adsorption experiments demonstrated that the affinity of activated charcoal for each component was highest in the order of vanillic acid, 4-hydroxybenzoic acid, furfural, acetic acid, sulfuric acid, and xylose. The affinity of activated charcoal for furan and phenolic compounds proved to be significantly higher than that of the other three components. Four separation strategies were conducted with a combination of batch adsorption and continuous fixed-bed column adsorption methods. It was observed that xylose loss was negligible with near complete removal of furan and phenolic compounds, when at least one fixed-bed column adsorption was implemented in the strategy. PMID:27289057

  18. An overview of CFD modelling of small-scale fixed-bed biomass pellet boilers with preliminary results from a simplified approach

    International Nuclear Information System (INIS)

    Highlights: ► Overview of the overall approach of modelling fixed-bed biomass boilers in CFD. ► Bed sub-models of moisture evaporation, devolatisation and char combustion reviewed. ► A method of embedding a combustion model in discrete fuel zones within the CFD is suggested. ► Includes sample of preliminary results for a 50 kW pellet boiler. ► Clear physical trends predicted. - Abstract: The increasing global energy demand and mounting pressures for CO2 mitigation call for increased efficient utilization of biomass, particularly for heating domestic and commercial buildings. The authors of the present paper are investigating the optimization of the combustion performance and NOx emissions of a 50 kW biomass pellet boiler fabricated by a UK manufacturer. The boiler has a number of adjustable parameters including the ratio of air flow split between the primary and secondary supplies, the orientation, height, direction and number of the secondary inlets. The optimization of these parameters provides opportunities to improve both the combustion efficiency and NOx emissions. When used carefully in conjunction with experiments, Computational Fluid Dynamics (CFD) modelling is a useful tool for rapidly and at minimum cost examining the combustion performance and emissions from a boiler with multiple variable parameters. However, modelling combustion and emissions of a small-scale biomass pellet boiler is not trivial and appropriate fixed-bed models that can be coupled with the CFD code are required. This paper reviews previous approaches specifically relevant to simulating fixed-bed biomass boilers. In the first part it considers approaches to modelling the heterogeneous solid phase and coupling this with the gas phase. The essential components of the sub-models are then overviewed. Importantly, for the optimization process a model is required that has a good balance between accuracy in predicting physical trends, with low computational run time. Finally, a

  19. Refractory for Black Liquor Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Musa Karakus; Xiaoting Laing

    2005-10-01

    The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

  20. CHP from Updraft Gasifier and Stirling Engine

    DEFF Research Database (Denmark)

    Jensen, N.; Werling, J.; Carlsen, Henrik;

    2002-01-01

    The combination of thermal gasification with a Stirling engine is an interesting concept for use in small combined heat and power plants based on biomass. By combining the two technologies a synergism can potentially be achieved. Technical problems, e.g. gas cleaning and fouling of the Stirling...... engine heat exchanger, can be eliminated and the overall electric efficiency of the system can be improved. At the Technical University of Denmark a Stirling engine fueled by gasification gas has been developed. In this engine the combustion system and the geometry of the hot heat exchanger...... of the Stirling engine has been adapted to the use of a gas with a low specific energy content and a high content of tar and particles. In the spring of 2001 a demonstration plant has been built in the western part of Denmark where this Stirling engine is combined with an updraft gasifier. A mathematical...

  1. Gasification of biomass for energy production. State of technology in Finland and global market perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Wilen, C.; Kurkela, E. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1997-12-31

    This report reviews the development of the biomass gasification technology in Finland over the last two decades. Information on Finnish biomass resources and use, energy economy and national research policy is provided as background. Global biomass resources and potential energy from biomass markets are also assessed based on available literature, to put the development of the gasification technology into a wider perspective of global biomass utilization for energy production. The increasing use of biomass and other indigenous forms of energy has been part and parcel of the Finnish energy policy for some twenty years. Biomass and peat account for almost 20% of the production of primary energy in Finland. As the consumption of biofuels is significantly lower than the annual growth or renewal, the use of bioenergy is considered to be an important measure of reducing carbon dioxide emissions. Research and development on thermal gasification of solid fuels was initiated in the late 1970s in Finland. The principal aim was to decrease the dependence of Finnish energy economy on imported oil by increasing the utilization potential of indigenous fuels. Development in the early 1980s focused on simple atmospheric-pressure fuel gas applications including a gasification heating plant. Eight Bioneer updraft gasifiers (abt 5 MW{sub th}) were constructed in 1982-1986, and a new Bioneer gasifier was commissioned in eastern Finland in 1996. A Pyroflow circulating fluidised-bed gasifies was also commercialized in the mid-1980s; four gasifiers (15-35 MW{sub th}) were commissioned. In the late 1980s the interest in integrated gasification combined-cycle (IGCC) power plants, based on pressurised air gasification of biomass and hot gas cleanup, increased in Finland and in many other countries. The utilization potential for indigenous fuels is mainly in medium-scale combined heat and electricity production (20-150 MW,). Foster Wheeler Energia Oy, Carbona Inc. and Imatran Voima Oy are

  2. Gasification of biomass for energy production. State of technology in Finland and global market perspectives

    International Nuclear Information System (INIS)

    This report reviews the development of the biomass gasification technology in Finland over the last two decades. Information on Finnish biomass resources and use, energy economy and national research policy is provided as background. Global biomass resources and potential energy from biomass markets are also assessed based on available literature, to put the development of the gasification technology into a wider perspective of global biomass utilization for energy production. The increasing use of biomass and other indigenous forms of energy has been part and parcel of the Finnish energy policy for some twenty years. Biomass and peat account for almost 20% of the production of primary energy in Finland. As the consumption of biofuels is significantly lower than the annual growth or renewal, the use of bioenergy is considered to be an important measure of reducing carbon dioxide emissions. Research and development on thermal gasification of solid fuels was initiated in the late 1970s in Finland. The principal aim was to decrease the dependence of Finnish energy economy on imported oil by increasing the utilization potential of indigenous fuels. Development in the early 1980s focused on simple atmospheric-pressure fuel gas applications including a gasification heating plant. Eight Bioneer updraft gasifiers (abt 5 MWth) were constructed in 1982-1986, and a new Bioneer gasifier was commissioned in eastern Finland in 1996. A Pyroflow circulating fluidised-bed gasifies was also commercialized in the mid-1980s; four gasifiers (15-35 MWth) were commissioned. In the late 1980s the interest in integrated gasification combined-cycle (IGCC) power plants, based on pressurised air gasification of biomass and hot gas cleanup, increased in Finland and in many other countries. The utilization potential for indigenous fuels is mainly in medium-scale combined heat and electricity production (20-150 MW,). Foster Wheeler Energia Oy, Carbona Inc. and Imatran Voima Oy are the main

  3. Influence of Partial Combustion on Rapid Pyrolysis of Wood Biomass

    Science.gov (United States)

    Yasuda, Hajime; Yamada, Osamu; Kaiho, Mamoru; Shinagawa, Takuya; Matsui, Satoshi; Iwasaki, Toshihiko; Shimada, Sohei

    A batch reactor was made and used in this work. In an actual rapid pyrolyzer/gasifier, each biomass is thrown into high temperature zone in the reactor. In order to simulate the reaction occurred in a fluidized bed rapid pyrolyzer/gasifier, the reactor was designed to inject samples into reaction zone directly and to control the reaction time optionally. Rapid pyrolysis of wood biomasses, such as Konara, bagasse, and EFB (Empty Fruit Bunch), was carried out at 1073K in nitrogen with the reaction time range of 2-20s. Difference in product distribution with varying reaction time was observed apparently among Konara, bagasse, and EFB. The difference in the reactivity among sorts of biomass should be considered even when their elemental composition and/or components ratio are similar. Rapid pyrolysis of wood biomass (Japanese cedar) with small amount of oxygen as gasification agent was also carried out. The amount of product gas was decreased through 1s to 2s and the decreasing rate was higher with increase in the amount of oxygen.

  4. Comparative evaluation of kinetic, equilibrium and semi-equilibrium models for biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Buragohain, Buljit [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Chakma, Sankar; Kumar, Peeush [Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Mahanta, Pinakeswar [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Moholkar, Vijayanand S. [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India)

    2013-07-01

    Modeling of biomass gasification has been an active area of research for past two decades. In the published literature, three approaches have been adopted for the modeling of this process, viz. thermodynamic equilibrium, semi-equilibrium and kinetic. In this paper, we have attempted to present a comparative assessment of these three types of models for predicting outcome of the gasification process in a circulating fluidized bed gasifier. Two model biomass, viz. rice husk and wood particles, have been chosen for analysis, with gasification medium being air. Although the trends in molar composition, net yield and LHV of the producer gas predicted by three models are in concurrence, significant quantitative difference is seen in the results. Due to rather slow kinetics of char gasification and tar oxidation, carbon conversion achieved in single pass of biomass through the gasifier, calculated using kinetic model, is quite low, which adversely affects the yield and LHV of the producer gas. Although equilibrium and semi-equilibrium models reveal relative insensitivity of producer gas characteristics towards temperature, the kinetic model shows significant effect of temperature on LHV of the gas at low air ratios. Kinetic models also reveal volume of the gasifier to be an insignificant parameter, as the net yield and LHV of the gas resulting from 6 m and 10 m riser is same. On a whole, the analysis presented in this paper indicates that thermodynamic models are useful tools for quantitative assessment of the gasification process, while kinetic models provide physically more realistic picture.

  5. Promoting effect of various biomass ashes on the steam gasification of low-rank coal

    International Nuclear Information System (INIS)

    Highlights: • Biomass ash was utilized to promote gasification of low rank coal. • Promoting effect of biomass ash highly depended on AAEM content in the ash. • Stability of the ash could be improved by maintaining AAEM amount in the ash. • Different biomass ash could have completely different catalytic activity. - Abstract: Application of biomass ash as a catalyst to improve gasification rate is a promising way for the effective utilization of waste ash as well as for the reduction of cost. Investigation on the catalytic activity of biomass ash to the gasification of low rank coal was performed in details in the present study. Ashes from 3 kinds of biomass, i.e. brown seaweed/BS, eel grass/EG, and rice straw/RS, were separately mixed with coal sample and gasified in a fixed bed downdraft reactor using steam as the gasifying agent. BS and EG ashes enhanced the gas production rate greater than RS ash. Higher catalytic activity of BS or EG ash was mainly attributed to the higher content of alkali and alkaline earth metal (AAEM) and lower content of silica in it. Higher content of silica in the RS ash was identified to have inhibiting effect for the steam gasification of coal. Stable catalytic activity was remained when the amount of AAEM in the regenerated ash was maintained as that of the original one

  6. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Kalyan Annamalai; Dr. John Sweeten; Dr. Sayeed Mukhtar

    2000-10-24

    The following are proposed activities for quarter 1 (6/15/00-9/14/00): (1) Finalize the allocation of funds within TAMU to co-principal investigators and the final task lists; (2) Acquire 3 D computer code for coal combustion and modify for cofiring Coal:Feedlot biomass and Coal:Litter biomass fuels; (3) Develop a simple one dimensional model for fixed bed gasifier cofired with coal:biomass fuels; and (4) Prepare the boiler burner for reburn tests with feedlot biomass fuels. The following were achieved During Quarter 5 (6/15/00-9/14/00): (1) Funds are being allocated to co-principal investigators; task list from Prof. Mukhtar has been received (Appendix A); (2) Order has been placed to acquire Pulverized Coal gasification and Combustion 3 D (PCGC-3) computer code for coal combustion and modify for cofiring Coal: Feedlot biomass and Coal: Litter biomass fuels. Reason for selecting this code is the availability of source code for modification to include biomass fuels; (3) A simplified one-dimensional model has been developed; however convergence had not yet been achieved; and (4) The length of the boiler burner has been increased to increase the residence time. A premixed propane burner has been installed to simulate coal combustion gases. First coal, as a reburn fuel will be used to generate base line data followed by methane, feedlot and litter biomass fuels.

  7. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    International Nuclear Information System (INIS)

    The following are proposed activities for quarter 1 (6/15/00-9/14/00): (1) Finalize the allocation of funds within TAMU to co-principal investigators and the final task lists; (2) Acquire 3 D computer code for coal combustion and modify for cofiring Coal:Feedlot biomass and Coal:Litter biomass fuels; (3) Develop a simple one dimensional model for fixed bed gasifier cofired with coal:biomass fuels; and (4) Prepare the boiler burner for reburn tests with feedlot biomass fuels. The following were achieved During Quarter 5 (6/15/00-9/14/00): (1) Funds are being allocated to co-principal investigators; task list from Prof. Mukhtar has been received (Appendix A); (2) Order has been placed to acquire Pulverized Coal gasification and Combustion 3 D (PCGC-3) computer code for coal combustion and modify for cofiring Coal: Feedlot biomass and Coal: Litter biomass fuels. Reason for selecting this code is the availability of source code for modification to include biomass fuels; (3) A simplified one-dimensional model has been developed; however convergence had not yet been achieved; and (4) The length of the boiler burner has been increased to increase the residence time. A premixed propane burner has been installed to simulate coal combustion gases. First coal, as a reburn fuel will be used to generate base line data followed by methane, feedlot and litter biomass fuels

  8. A Philippines gasifier case study

    International Nuclear Information System (INIS)

    The gasifier programme failed to achieve its objective of significantly reducing farmers' dependence on diesel fuel and in improving their financial positions both on Panay Island and elsewhere in the Philippines. The causes appear to be institutional and managerial rather than any inherent weakness in the technology itself. 2 tabs

  9. REFRACTORY FOR BLACK LIQUOR GASIFIERS

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Musa Karakus; Jun Wei

    2005-03-01

    The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

  10. Bolivia: A Gasified Democracy

    Directory of Open Access Journals (Sweden)

    Willem Assies

    2004-04-01

    Full Text Available In October 2003 a wave of popular protest  brought down the Sánchez de Lozada government  in Bolivia. The intention to export natural gas to  the United States and Mexico triggered the protests, but actually stood for widespread discontent  with the Sánchez de Lozada government, the  preceding governments and the economic policies  pursued since 1985. The events belie the opinion  of various students of the Latin American democratic transitions who held that Bolivian democracy  was on its way towards consolidation and suggest that the recent inquiries into the quality of Latin  American democracies may point a way ahead in  rethinking democracy in the region. Taking such  assessments as a reference, this article reviews the  ‘gas war’ and looks at the Bolivian political regime as it has functioned over the past decades. It  will be argued that the ‘pacted democracy’, that  until now sustained institutionality, and the economic model adopted in 1985 have excluded an  important part of the population, both in political terms and where poverty alleviation and equity is  concerned. Increasing popular protest has been  met with increasing repression, which gradually  turned Bolivia into a ‘democradura’, or a ‘gasified  democracy’ that relies on teargas and bullets to  uphold itself. At present the country finds itself at  a crossroads. It either may reinvent democracy or  become an institutionalized ‘democradura’. Resumen: Bolivia: una democracia gasificadaEn octubre de 2003 una ola de protesta popular  llevó a la caída del gobierno de Sánchez de Lozada en Bolivia. La intención de exportar gas natural a los Estados Unidos y México gatilló dichas  protestas, aunque en realidad reflejaron un descontento general con el gobierno Sánchez de  Lozada, los gobiernos anteriores y las políticas  económicas implementadas desde 1985. Los  sucesos desmienten la opinión de varios analistas  de las

  11. Experiences with RDF pellets in a gasifier

    International Nuclear Information System (INIS)

    Decreasing dependence upon landfills means MSW recycling and organic diversion programs grow but there is still waste remaining. A community near Toronto is turn the residuals into pellets augmented with high calorific value industry wastes. The pellet fuel has reduced ash, trace metal, and halogen concentrations when compared to MSW. Some of these pellets are being used to heat a greenhouse in southwestern Ontario using a chain grate gasifier and boiler system. This paper discusses some of the results of the initial operation and testing of a pair of these units. The gasifier has evolved and is currently rated at 20.2 GJ/h, consuming up to 940 kg/h of RDF pellets or the thermal equivalent in wood pellets. Twounits, with hot water storage tanks, are sufficient to satisfy the greenhouses 50 GJ/hr heating needs. The units boiler exhausts are treated with powdered lime before passing through separate fabric filter systems. One fabric filter was equipped with REMEDIA bags for PCDD/F removal, the other had a typical fibreglass filter. A combination of recirculated flue gas and fresh combustion air is blown up through the grate and fuel bed, into three independently controlled combustion zones. Under fire air oxygen levels are used to control temperatures within the gasification chamber. A smaller unit, 3.78 GJ/h capacity, was tested twice in 2008 and the current version was tested in early 2009. More tests are planned for the spring of 2010. While the tests have generally shown excellent emission performance, mercury, chlorine, and PCDD/F have been higher than anticipated. The finding of elevated levels of Cl2 in the exhaust gasses has been suggested as the main reason for the unusually high PCDD/F emissions. The findings related to chlorine and PCDD/F in this process is the main thrust of the paper. (author)

  12. Secondary reactions of tar during thermochemical biomass conversion[Dissertation 14341

    Energy Technology Data Exchange (ETDEWEB)

    Morf, P.O.

    2001-07-01

    This dissertation submitted to the Swiss Federal Institute of Technology in Zurich presents and discusses the results obtained during the examination of the processes involved in the formation and conversion of tar in biomass gasification plant. Details are given on the laboratory reactor system used to provide separated tar production and conversion for the purposes of the experiments carried out. The results of analyses made of the tar and the gaseous products obtained after its conversion at various temperatures are presented. The development of kinetic models using the results of the experiments that were carried out is described. The results of the experiments and modelling are compared with the corresponding results obtained using a full-scale down-draft, fixed-bed gasifier. The author is of the opinion that the reaction conditions found in full-scale gasifiers can be well simulated using heterogeneous tar conversion experiments using the lab reactor system.

  13. Diesel power plants based on biomass gasification; Biomassan ja turpeen kaasutukseen perustuvien dieselvoimalaitosten toteutettavuustutkimus

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Staahlberg, P.; Solantausta, Y.; Wilen, C.

    1995-12-31

    Different power production systems have been developed for biomass feedstocks. However, only few of these systems can meet the following three requirements: (a) suitability to small scale electricity production (< 5-10 MWe), (b) reliable operation with realistically available biomass feedstocks, and (c) potential for economical competitiveness. The fluidized-bed boilers have been successfully operated with wood waste and peat down to outputs of the order of 5 MWe and the investment costs have been successfully lowered to a reasonable level. However, this concept is most suitable for combined heat and electricity production and smaller plant sizes are not considered feasible. One of the most promising alternative for this commercially proven technology is the diesel power plant based on gasification. This concept has a potential for higher power to heat ratios in cogeneration or higher efficiency in separate electricity production. The objectives of this project were (a) to evaluate the technical and economical feasibility of diesel power plants based on biomass gasification and (b) to study the effects of operating conditions (temperature, bed material and air staging) on the performance of a circulating fluidized-bed gasifier. The experimental part of the project was carried out on a new PDU-scale Circulating Fluidized-Bed Gasification test facility of VTT. Wood residues were used as the feedstocks and the experiments were mainly focused on tar formation and gasifier performance. The results will be compared to earlier VTT data obtained for bubbling-bed reactors. The techno-economic feasibility studies are carried out using existing process modelling tools of VTT and the gasification based diesel plants will be compared to conventional fluidized-bed boilers

  14. Diesel power plants based on biomass gasification; Biomassan ja turpeen kaasutukseen perustuen dieselvoimalaitosten toteutettavuustutkimus

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Staahlberg, P.; Solantausta, Y. [VTT Energy, Espoo (Finland)

    1996-12-01

    Different power production systems have been developed for biomass feedstocks. However, only few of these systems can meet the following three requirements: (1) suitability to small scale electricity production (<5-10 MWe), (2) reliable operation with realistically available biomass feedstocks, and (3) potential for economical competitiveness. The fluidized-bed boilers have been successfully operated with wood waste and peat down to outputs of the order of 5 MWe and the investment costs have been successfully lowered to a reasonable level. However, this concept is most suitable for combined heat and electricity production and smaller plant sizes are not considered feasible. One of the most promising alternative for this commercially proven technology is the diesel power plant based on gasification. This concept has a potential for higher power to heat ratios in cogeneration or higher efficiency in separate electricity production. The objectives of this project were (1) to evaluate the technical and economical feasibility of diesel power plants based on biomass gasification and (2) to study the effects of operating conditions (temperature, bed material and air staging) on the performance of a circulating fluidized-bed gasifier. The experimental part of the project was carried out on a new PDU-scale Circulating Fluidized-Bed Gasification test facility of VTT. Wood residues were used as the feedstocks and the experiments were mainly focused on tar formation and gasifier performance. The results will be compared to earlier VTT data obtained for bubbling-bed reactors. The techno-economic feasibility studies are carried out using existing process modelling tools of VTT and the gasification based diesel plants will be compared to conventional fluidized-bed boilers. The studies are scheduled to be completed in March 1996. (author)

  15. Strategies to reduce gaseous KCl and chlorine in deposits during combustion of biomass in fluidised bed boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kassman, Haakan

    2012-11-01

    Combustion of a biomass with an enhanced content of alkali and chlorine (Cl) can result in operational problems including deposit formation and superheater corrosion. The strategies applied to reduce such problems include co-combustion and the use of additives. In this work, measures were investigated in order to decrease the risk of superheater corrosion by reducing gaseous KCl and the content of chlorine in deposits. The strategies applied were sulphation of KCl by sulphur/sulphate containing additives (i.e. elemental sulphur (S) and ammonium sulphate (AS)) and co-combustion with peat. Both sulphation of KCl and capture of potassium (K) in ash components can be of importance when peat is used. The experiments were mainly performed in a 12 MW circulation fluidised bed (CFB) boiler equipped for research purposes but also in a full-scale CFB boiler. The results were evaluated by means of IACM (on-line measurements of gaseous KCl), conventional gas analysis, deposit and corrosion probe measurements and ash analysis. Ammonium sulphate performed significantly better than elemental sulphur. Thus the presence of SO{sub 3} (i.e. AS) is of greater importance than that of SO{sub 2} (i.e. S) for sulphation of gaseous KCl and reduction of chlorine in deposits. Only a minor reduction of gaseous KCl was obtained during co-combustion with peat although chlorine in the deposits was greatly reduced. This reduction was supposedly due to capture of K by reactive components from the peat ash in parallel to sulphation of KCl. These compounds remained unidentified. The effect of volatile combustibles on the sulphation of gaseous KCl was investigated. The poorest sulphation was attained during injection of ammonium sulphate in the upper part of the combustion chamber during the lowest air excess ratio. The explanation for this is that SO{sub 3} was partly consumed by side reactions due to the presence of combustibles. These experimental results were supported by modelling, although the

  16. Characterization of Rice Husk for Cyclone Gasifier

    Science.gov (United States)

    Mohamad Yusof, I.; Farid, N. A.; Zainal, Z. A.; Azman, M.

    The characterization of rice husk from local rice mills has been studied and evaluated to determine its potential utilization as a biomass fuel for a cyclone gasifier. The raw rice husk was pre-treated throughout a grinding process into smaller sizes of particles which is within a range of 0.4 to 1 mm and the sample of ground rice husk was analyzed for its fuel characteristics. The result of proximate analysis shows that the ground rice husk with size distribution within 0.4 to 1 mm contains 13.4% of fixed carbon, 62.95% of volatile matter and 18.5% of ash on dry basis. The moisture content of the sample was measured and determined as 10.4% (wet basis) and the calorific value was found to be approximately 14.8 MJ kg-1 with bulk density of 91.46 kg m-3. The result of ultimate analysis validates both ash and moisture content which are found to be 18.15 and 10.4%, respectively. Other elemental compositions determined by the ultimate analysis are carbon (37.9%), hydrogen (5.2%), nitrogen (0.14%), sulfur (0.61%) and oxygen (27.7% by difference). The study has identified that the fuel characteristics of the ground rice husk is comparable with other types of biomass and thus, making it another potential source of fuel for the cyclone gasification system.

  17. REFRACTORY FOR BLACK LIQUOR GASIFIERS

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr.; Alireza Rezaie

    2004-04-01

    The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

  18. Refractory for Black Liquor Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Alireza Rezaie; Xiaoting Liang; Musa Karakus; Jun Wei

    2005-12-01

    The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials were selected or developed that reacted with the gasifier environment to form protective surfaces in

  19. REFRACTORY FOR BLACK LIQUOR GASIFIERS

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Alireza Rezaie

    2004-07-01

    The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

  20. REFRACTORY FOR BLACK LIQUOR GASIFIERS

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Musa Karakus; Xiaoting Liang

    2005-07-01

    The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

  1. Refractory for Black Liquor Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Musa Karakus; Xiaoting Liang

    2005-10-01

    The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials were selected/developed that either react with the gasifier environment to form protective surfaces in

  2. REFRACTORY FOR BLACK LIQUOR GASIFIERS

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Jun Wei

    2005-01-01

    The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

  3. REFRACTORY FOR BLACK LIQUOR GASIFIERS

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Alireza Rezaie

    2004-10-01

    The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

  4. REFRACTORY FOR BLACK LIQUOR GASIFIERS

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Jun Wei

    2005-04-01

    The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

  5. Refractory for Black Liquor Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick; Musa Karakus; Alireza Rezaie

    2004-03-30

    The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

  6. Three-zonal engineering method of heat calculation for fluidized bed furnaces based on data on commercial investigations of heat generation distribution during biomass combustion

    Science.gov (United States)

    Litun, D. S.; Ryabov, G. A.

    2016-02-01

    A three-zonal method of heat calculation of furnaces for combustion of biomass and low-caloric fuel in the fluidized bed is described. The method is based on equations of thermal and material balances that account for heat generation by fuel in the zone, heat-and-mass transfer heat exchange between the furnace media and surfaces that bound the zone, and heat-and-mass transfer between furnace zones. The calculation procedure for heat generation by fuel in the fluidized bed (FB) using the heat generation portion by the fuel is proposed. Based on commercial investigations, the main factors that affect the average temperature in the FB and the portion of fuel heat that is released in the FB are determined. Results of commercial investigations showed that the airflow coefficient in the FB should be recognized as the main operation parameter that affects the average temperature in the FB and, consequently, heat generation in the FB. The gas flow rate in the FB can be marked out as the second factor that affects the consumption degree of oxidizer supplied in the FB. Commercial investigations revealed that mixing is affected by the gas flow rate in the FB and the bed material particle size, which may be changed during the boiler operation because of the agglomeration of particles of sand and ash. The calculation processing of commercial investigations on a KM-75-40M boiler of a CHP-3 of an Arkhangelsk Pulp and Paper Mill (APPM), which was carried out using the inverse problem procedure by means of a developed computer program, determined the range of the fuel heat release share in the FB, which was 0.26-0.45 at an excess air factor of 0.59-0.93 in the bed, and the heat release share in the maximum temperature zone in the total heat release in the superbed space. The heat release share in the bed is determined as an approximating function of the excess air factor in the bed and the fluidization number. The research results can be used during designing boilers with the

  7. Kinetics of gasification and combustion of residues, biomass and coal in a bubbling fluidized bed; Die Kinetik der Vergasung und Verbrennung unterschiedlicher Abfaelle, Biomassen und Kohlen in der blasenbildenden Wirbelschicht

    Energy Technology Data Exchange (ETDEWEB)

    Hamel, S.; Krumm, W. [Siegen Univ. (Gesamthochschule) (Germany). Lehrstuhl fuer Energie- und Umweltverfahrenstechnik

    1998-09-01

    The combustion and gasification characteristics of Rhenish brown coal, domestic waste, waste plastics, wood and sewage sludge were investigated in a bubbling atmospheric fluidized bed in the laboratory scale. The materials were pyrolyzed in the fluidized bed in a nitrogen atmosphere. The residual coke was combuted in the presence of oxygen with varying operating parameters or else gasified in the presence of carbon dioxide. The different materials were characterized by global combustion rates, and kinetic parameters were determined for residual coke combustion. (orig.) [Deutsch] Das Verbrennungs- und Vergasungsverhalten von Rheinischer Braunkohle, Hausmuell, Restkunststoff, Holz und Klaerschlamm wurde in einer blasenbildenden, atmosphaerischen Laborwirbelschicht untersucht. Die Einsatzstoffe wurden in der mit Stickstoff fluidisierten Wirbelschicht pyrolysiert. Der verbleibende Restkoks wurde anschliessend unter Variation der Betriebsparameter mit Sauerstoff verbrannt oder mit Kohlendioxid vergast. Die unterschiedlichen Einsatzstoffe wurden durch globale Vebrennungsraten charakterisiert. Fuer die Restkoksverbrennung wurden kinetische Parameter ermittelt. (orig.)

  8. Formation of naphthalene at gasification of biomass and hot gas cleanup with dolomite

    International Nuclear Information System (INIS)

    Tar generated at gasification of biomass and municipal wastes is an unwanted byproduct. With dolomite as catalyst the tar content is reduced to such a level as to allow final cleaning of the fuel gas with water. It is still desirable to further reduce the naphthalene level in the fuel gas. The aim of the project is to determine the influence of process variables on cracking of naphthalene with dolomite in a small fluidized bed gasifier, and to determine the influence on the content of BTX in the gas from the same variables. 10 refs, 21 figs, 1 tab

  9. Emissions of SO2, NO and N2O in a circulating fluidized bed combustor during co-firing coal and biomass.

    Science.gov (United States)

    Xie, Jian-jun; Yang, Xue-min; Zhang, Lei; Ding, Tong-li; Song, Wen-li; Lin, Wei-gang

    2007-01-01

    This paper presents the experimental investigations of the emissions of SO2, NO and N20 in a bench scale circulating fluidized bed combustor for coal combustion and co-firing coal and biomass. The thermal capacity of the combustor is 30 kW. The setup is electrically heated during startup. The influence of the excess air, the degree of the air staging, the biomass share and the feeding position of the fuels on the emissions of SO2, NO and N2O were studied. The results showed that an increase in the biomass shares resulted in an increase of the CO concentration in the flue gas, probably due to the high volatile content of the biomass. In co-firing, the emission of SO2 increased with increasing biomass share slightly, however, non-linear increase relationship between SO2 emission and fuel sulfur content was observed. Air staging significantly decreased the NO emission without raising the SO2 level. Although the change of the fuel feeding position from riser to downer resulted in a decrease in the NO emission level, no obvious change was observed for the SO2 level. Taking the coal feeding position R as a reference, the relative NO emission could significantly decrease during co-firing coal and biomass when feeding fuel at position D and keeping the first stage stoichiometry greater than 0.95. The possible mechanisms of the sulfur and nitrogen chemistry at these conditions were discussed and the ways of simultaneous reduction of SO2, NO and N20 were proposed. PMID:17913163

  10. Techno Economic Analysis of Hydrogen Production by gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Francis Lau

    2002-12-01

    general term, and includes heating as well as the injection of other ''ingredients'' such as oxygen and water. Pyrolysis alone is a useful first step in creating vapors from coal or biomass that can then be processed in subsequent steps to make liquid fuels. Such products are not the objective of this project. Therefore pyrolysis was not included in the process design or in the economic analysis. High-pressure, fluidized bed gasification is best known to GTI through 30 years of experience. Entrained flow, in contrast to fluidized bed, is a gasification technology applied at much larger unit sizes than employed here. Coal gasification and residual oil gasifiers in refineries are the places where such designs have found application, at sizes on the order of 5 to 10 times larger than what has been determined for this study. Atmospheric pressure gasification is also not discussed. Atmospheric gasification has been the choice of all power system pilot plants built for biomass to date, except for the Varnamo plant in Sweden, which used the Ahlstrom (now Foster Wheeler) pressurized gasifier. However, for fuel production, the disadvantage of the large volumetric flows at low pressure leads to the pressurized gasifier being more economical.

  11. Dynamic Testing of Gasifier Refractory

    Energy Technology Data Exchange (ETDEWEB)

    Michael D. Mann; Wayne S. Seames; Devdutt Shukla; Xi Hong; John P. Hurley

    2005-12-01

    The University of North Dakota (UND) Chemical Engineering Department in conjunction with the UND Energy & Environmental Research Center (EERC) have initiated a program to examine the combined chemical (reaction and phase change) and physical (erosion) effects experienced by refractory materials under slagging coal gasification conditions. The goal of this work is to devise a mechanism of refractory loss under these conditions. The controlled-atmospheric dynamic corrodent application furnace (CADCAF) was utilized to simulate refractory/slag interactions under dynamic conditions that more realistically simulate the environment in a slagging coal gasifier than any of the static tests used previously by refractory manufacturers and researchers. High-alumina and high-chromia refractory bricks were tested using slags obtained from two solid fuel gasifiers. Testing was performed at 1475 C in a reducing atmosphere (2% H{sub 2} in N{sub 2}) The CADCAF tests show that high-chrome refractories have greater corrosion resistance than high-aluminum refractories; coal slag readily diffuses into the refractory through its grain boundaries; the refractory grains are more stable than the matrix in the tests, and the grains are the first line of defense against corrosion; calcium and alkali in the slag are more corrosive than iron; and silicon and calcium penetrate the deepest into the refractory. The results obtained from this study are preliminary and should be combined with result from other research programs. In particular, the refractory corrosion results from this study should be compared with refractories removed from commercial gasifiers.

  12. Fixed bed column study for Cu (II) removal from aqueous solution using water hyacinth (Eichornia crassipes) biomass.

    Science.gov (United States)

    Gandhimathi, R; Ramesh, S T; Yadu, Anubhav; Bharathi, K S

    2013-07-01

    This paper reports the results of the study on the performance of low-cost biosorbent water hyacinth (WH) in removing Cu (II) from aqueous solution. The adsorbent material adopted was found to be an efficient media for the removal of Cu (II) in continuous mode using fixed bed column. The column studies were conducted with 10 mg/L metal solution with a flow rate of 10 mL/min with different bed depths such as 10, 20 and 30 cm. The column design parameters like adsorption rate constant, adsorption capacity and minimum bed depth were calculated. It was found that, the adsorption capacity of copper ions by water hyacinth increased by increasing the bed depth and the contact time. PMID:25509946

  13. Advanced Gasifier Pilot Plant Concept Definition

    Energy Technology Data Exchange (ETDEWEB)

    Steve Fusselman; Alan Darby; Fred Widman

    2005-08-31

    This report presents results from definition of a preferred commercial-scale advanced gasifier configuration and concept definition for a gasification pilot plant incorporating those preferred technologies. The preferred commercial gasifier configuration was established based on Cost Of Electricity estimates for an IGCC. Based on the gasifier configuration trade study results, a compact plug flow gasifier, with a dry solids pump, rapid-mix injector, CMC liner insert and partial quench system was selected as the preferred configuration. Preliminary systems analysis results indicate that this configuration could provide cost of product savings for electricity and hydrogen ranging from 15%-20% relative to existing gasifier technologies. This cost of product improvement draws upon the efficiency of the dry feed, rapid mix injector technology, low capital cost compact gasifier, and >99% gasifier availability due to long life injector and gasifier liner, with short replacement time. A pilot plant concept incorporating the technologies associated with the preferred configuration was defined, along with cost and schedule estimates for design, installation, and test operations. It was estimated that a 16,300 kg/day (18 TPD) pilot plant gasifier incorporating the advanced gasification technology and demonstrating 1,000 hours of hot-fire operation could be accomplished over a period of 33 months with a budget of $25.6 M.

  14. Release of K, Cl, and S during combustion and co-combustion with wood of high-chlorine biomass in bench and pilot scale fuel beds

    DEFF Research Database (Denmark)

    Johansen, Joakim Myung; Aho, Martti; Paakkinen, Kari;

    2013-01-01

    Studies of the release of critical ash-forming elements from combustion of biomass are typically conducted with small sample masses under well controlled conditions. In biomass combustion on a grate, secondary recapture and release reactions in the fuel-bed may affect the overall release and...... release profile was observed for Cl, from 65% to nearly 100%. Complete release of S was achieved at 1234°C with a linear increase from 70% at 906°C. Co-combustion of corn stover with low-Cl wood chips served to increase the bed temperature, resulting in complete and close to complete release of Cl and S......, respectively. An increase in the relative K-release was observed when increasing the wood chip fraction from 40% to 100% (energy basis). Pilot scale flue gas results indicate that the share of Cl released as HCl decreases towards 0% as the share of wood chips is increased towards 100%. Hence, co-combustion of...

  15. Thermal decomposition and gasification of biomass pyrolysis gases using a hot bed of waste derived pyrolysis char.

    Science.gov (United States)

    Al-Rahbi, Amal S; Onwudili, Jude A; Williams, Paul T

    2016-03-01

    Chars produced from the pyrolysis of different waste materials have been investigated in terms of their use as a catalyst for the catalytic cracking of biomass pyrolysis gases during the two-stage pyrolysis-gasification of biomass. The chars were produced from the pyrolysis of waste tyres, refused derived fuel and biomass in the form of date stones. The results showed that the hydrocarbon tar yields decreased significantly with all the char materials used in comparison to the non-char catalytic experiments. For example, at a cracking temperature of 800°C, the total product hydrocarbon tar yield decreased by 70% with tyre char, 50% with RDF char and 9% with biomass date stones char compared to that without char. There was a consequent increase in total gas yield. Analysis of the tar composition showed that the content of phenolic compounds decreased and polycyclic aromatic hydrocarbons increased in the product tar at higher char temperatures. PMID:26773946

  16. Effect of sewage sludge content on gas quality and solid residues produced by cogasification in an updraft gasifier

    International Nuclear Information System (INIS)

    Highlights: ► Cogasification of sewage sludge with wood pellets in updraft gasifier was analysed. ► The effects of sewage sludge content on the gasification process were examined. ► Sewage sludge addition up to 30 wt.% reduces moderately the process performance. ► At high sewage sludge content slagging and clinker formation occurred. ► Solid residues produced resulted acceptable at landfills for non-hazardous waste. - Abstract: In the present work, the gasification with air of dehydrated sewage sludge (SS) with 20 wt.% moisture mixed with conventional woody biomass was investigated using a pilot fixed-bed updraft gasifier. Attention was focused on the effect of the SS content on the gasification performance and on the environmental impact of the process. The results showed that it is possible to co-gasify SS with wood pellets (WPs) in updraft fixed-bed gasification installations. However, at high content of sewage sludge the gasification process can become instable because of the very high ash content and low ash fusion temperatures of SS. At an equivalent ratio of 0.25, compared with wood pellets gasification, the addition of sewage sludge led to a reduction of gas yield in favor of an increase of condensate production with consequent cold gas efficiency decrease. Low concentrations of dioxins/furans and PAHs were measured in the gas produced by SS gasification, well below the limiting values for the exhaust gaseous emissions. NH3, HCl and HF contents were very low because most of these compounds were retained in the wet scrubber systems. On the other hand, high H2S levels were measured due to high sulfur content of SS. Heavy metals supplied with the feedstocks were mostly retained in gasification solid residues. The leachability tests performed according to European regulations showed that metals leachability was within the limits for landfilling inert residues. On the other hand, sulfate and chloride releases were found to comply with the limits for

  17. BIOMASS GASIFICATION AND POWER GENERATION USING ADVANCED GAS TURBINE SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    David Liscinsky

    2002-10-20

    A multidisciplined team led by the United Technologies Research Center (UTRC) and consisting of Pratt & Whitney Power Systems (PWPS), the University of North Dakota Energy & Environmental Research Center (EERC), KraftWork Systems, Inc. (kWS), and the Connecticut Resource Recovery Authority (CRRA) has evaluated a variety of gasified biomass fuels, integrated into advanced gas turbine-based power systems. The team has concluded that a biomass integrated gasification combined-cycle (BIGCC) plant with an overall integrated system efficiency of 45% (HHV) at emission levels of less than half of New Source Performance Standards (NSPS) is technically and economically feasible. The higher process efficiency in itself reduces consumption of premium fuels currently used for power generation including those from foreign sources. In addition, the advanced gasification process can be used to generate fuels and chemicals, such as low-cost hydrogen and syngas for chemical synthesis, as well as baseload power. The conceptual design of the plant consists of an air-blown circulating fluidized-bed Advanced Transport Gasifier and a PWPS FT8 TwinPac{trademark} aeroderivative gas turbine operated in combined cycle to produce {approx}80 MWe. This system uses advanced technology commercial products in combination with components in advanced development or demonstration stages, thereby maximizing the opportunity for early implementation. The biofueled power system was found to have a levelized cost of electricity competitive with other new power system alternatives including larger scale natural gas combined cycles. The key elements are: (1) An Advanced Transport Gasifier (ATG) circulating fluid-bed gasifier having wide fuel flexibility and high gasification efficiency; (2) An FT8 TwinPac{trademark}-based combined cycle of approximately 80 MWe; (3) Sustainable biomass primary fuel source at low cost and potentially widespread availability-refuse-derived fuel (RDF); (4) An overall integrated

  18. Comparison of ORC Turbine and Stirling Engine to Produce Electricity from Gasified Poultry Waste

    OpenAIRE

    Franco Cotana; Antonio Messineo; Alessandro Petrozzi; Valentina Coccia; Gianluca Cavalaglio; Andrea Aquino

    2014-01-01

    The Biomass Research Centre, section of CIRIAF, has recently developed a biomass boiler (300 kW thermal powered), fed by the poultry manure collected in a nearby livestock. All the thermal requirements of the livestock will be covered by the heat produced by gas combustion in the gasifier boiler. Within the activities carried out by the research project ENERPOLL (Energy Valorization of Poultry Manure in a Thermal Power Plant), funded by the Italian Ministry of Agriculture and Forestry, this p...

  19. Modeling of biomass gasification

    International Nuclear Information System (INIS)

    Full text: Optimal conversion of chemical energy of the biomass or other solid fuel into the desired gas depends on proper configuration, sizing, and choice of gasifier operating conditions. Optimum operating conditions are often derived through trials on the unit or by experiments on pilot plants. Simulation, or mathematical modeling, allows the designer or plant engineer to reasonably optimize the operation or the design of the plant. The good mathematical model can: find optimum operating conditions or a design for the gasifier, provide information on extreme operating conditions (high temperature, high pressure) where experiments are difficult to perform, provide information over a much wider range of conditions than one can obtain experimentally, better interpret experimental results and analyze abnormal behavior of a gasifier, if that occurs, assist scale-up of the gasifier from one successfully operating size to another, and from one feedstock to another. The equilibrium model is independent of the gasifier design which can make them more suitable for a system study of the most important process parameters. The use of an equilibrium model assumes that the residence time of the reactants in the gasifier is high enough to reach chemical equilibrium. For established biomass ultimate analysis, temperature of gasification air and temperature of produced gas, combining the mass balance equations with the equations for the equilibrium constants and equation of energy balance, the equivalence ratio (ER) and composition of produced gas can be obtained. A mathematical model for investigation of the influence of temperature of the produced gas and temperature of gasification air on the process parameters was developed. It can be used for estimation and design of gasification equipment. key words: biomass gasification, mathematical modeling, equilibrium model

  20. Biomass Wet Firewood Experimental Study of the Direct-Fired Gasifier Performance%生物质湿柴直燃气化炉性能的试验研究

    Institute of Scientific and Technical Information of China (English)

    张巍; 王维新; 马飞

    2013-01-01

    为了研究生物质湿柴直燃气化炉在燃烧时秸秆的各个参数对其加热效率的影响规律,以热效率为评价指标,对棉花秸秆长度,棉花秸秆数量以及棉花秸秆含水率等试验因素进行中心组合试验,对结果进行了方差分析,研究各因素对湿柴炉加热效率影响的主次关系,确定较优参数组合.结果表明,棉花秸秆长度38.20 em、棉花秸秆数量67根、含水率15.40%时为较优参数组合.其热效率可达30.20%以上.%In order to graduate substance wet firewood direct-fired gasifier burning straw various parameters investigated its heating efficiency, thermal efficiency evaluation index, orthogonal experiment experimental factors of length of cotton stalks, cotton stalks, cotton stalks moistureand. Analysis of variance results, the study of various factors on the relationship between the primary and secondary the wet wood stove heating efficiency impact, determine the optimum parameters combination. The results show that: length 38.20cm, 15.40% of the cotton stalks the number of 67, the moisture content of cotton stalks as a combination of the optimum parameters, the thermal efficiency of up to 30.20%.

  1. Mercury emissions during cofiring of sub-bituminous coal and biomass (chicken waste, wood, coffee residue, and tobacco stalk) in a laboratory-scale fluidized bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Yan Cao; Hongcang Zhou; Junjie Fan; Houyin Zhao; Tuo Zhou; Pauline Hack; Chia-Chun Chan; Jian-Chang Liou; Wei-ping Pan [Western Kentucky University (WKU), Bowling Green, KY (USA). Institute for Combustion Science and Environmental Technology (ICSET)

    2008-12-15

    Four types of biomass (chicken waste, wood pellets, coffee residue, and tobacco stalks) were cofired at 30 wt % with a U.S. sub-bituminous coal (Powder River Basin Coal) in a laboratory-scale fluidized bed combustor. A cyclone, followed by a quartz filter, was used for fly ash removal during tests. The temperatures of the cyclone and filter were controlled at 250 and 150{sup o}C, respectively. Mercury speciation and emissions during cofiring were investigated using a semicontinuous mercury monitor, which was certified using ASTM standard Ontario Hydra Method. Test results indicated mercury emissions were strongly correlative to the gaseous chlorine concentrations, but not necessarily correlative to the chlorine contents in cofiring fuels. Mercury emissions could be reduced by 35% during firing of sub-bituminous coal using only a quartz filter. Cofiring high-chlorine fuel, such as chicken waste (Cl = 22340 wppm), could largely reduce mercury emissions by over 80%. When low-chlorine biomass, such as wood pellets (Cl = 132 wppm) and coffee residue (Cl = 134 wppm), is cofired, mercury emissions could only be reduced by about 50%. Cofiring tobacco stalks with higher chlorine content (Cl = 4237 wppm) did not significantly reduce mercury emissions. Gaseous speciated mercury in flue gas after a quartz filter indicated the occurrence of about 50% of total gaseous mercury to be the elemental mercury for cofiring chicken waste, but occurrence of above 90% of the elemental mercury for all other cases. Both the higher content of alkali metal oxides or alkali earth metal oxides in tested biomass and the occurrence of temperatures lower than 650{sup o}C in the upper part of the fluidized bed combustor seemed to be responsible for the reduction of gaseous chlorine and, consequently, limited mercury emissions reduction during cofiring. 36 refs., 3 figs. 1 tab.

  2. Production of methanol/DME from biomass

    Energy Technology Data Exchange (ETDEWEB)

    Ahrenfeldt, J.; Birk Henriksen, U.; Muenster-Swendsen, J.; Fink, A.; Roengaard Clausen, L.; Munkholt Christensen, J.; Qin, K.; Lin, W.; Arendt Jensen, P.; Degn Jensen, A.

    2011-07-01

    In this project the production of DME/methanol from biomass has been investigated. Production of DME/methanol from biomass requires the use of a gasifier to transform the solid fuel to a synthesis gas (syngas) - this syngas can then be catalytically converted to DME/methanol. Two different gasifier types have been investigated in this project: 1) The Two-Stage Gasifier (Viking Gasifier), designed to produce a very clean gas to be used in a gas engine, has been connected to a lab-scale methanol plant, to prove that the gas from the gasifier could be used for methanol production with a minimum of gas cleaning. This was proved by experiments. Thermodynamic computer models of DME and methanol plants based on using the Two-Stage Gasification concept were created to show the potential of such plants. The models showed that the potential biomass to DME/methanol + net electricity energy efficiency was 51-58% (LHV). By using waste heat from the plants for district heating, the total energy efficiencies could reach 87-88% (LHV). 2) A lab-scale electrically heated entrained flow gasifier has been used to gasify wood and straw. Entrained flow gasifiers are today the preferred gasifier type for commercial coal gasification, but little information exists on using these types of gasifiers for biomass gasification. The experiments performed provided quantitative data on product and gas composition as a function of operation conditions. Biomass can be gasified with less oxygen consumption compared to coal. The organic fraction of the biomass that is not converted to gas appears as soot. Thermodynamic computer models of DME and methanol plants based on using entrained flow gasification were created to show the potential of such plants. These models showed that the potential torrefied biomass to DME/methanol + net electricity energy efficiency was 65-71% (LHV). Different routes to produce liquid transport fuels from biomass are possible. They include production of RME (rapeseed oil

  3. Research and evaluation of biomass resources/conversion/utilization systems (market/experimental analysis for development of a data base for a fuels from biomass model). Quarterly technical progress report, August 1, 1979-October 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Y.K.; Chen, Y.C.; Chen, H.C.; Nelson, E.T.; Stringer, R.P.

    1979-01-01

    Market analyses information now stored in the biomass feedstock data base includes for each species: feedstock amount by region and season in tons/year; heating values in Btu/lb for those feedstock for which published data are available, and; feedstock cost in $/mm Btu. Information now stored in the product data base includes for each product: product amount by region in mm Btu/year and product cost in $/mm Btu. Biomass characterization procedures have now been developed and these will be used to characterize approximately 100 biomass species. TGA analyses will be supplemented with a pyrogram and a pyrochromatogram to further characterize each biomass. Tests were run on the PDU in the fluidized bed mode to determine the effects of particle size on reaction time. Thirteen tests were run during this quarter to verify the results from previous testing. The PDU is being modified to accommodate future sustained runs. Allocation modeling program is now functional and being tested as data is provided to the feedstock and product data banks. A mathematical model has been developed by modifying the Texaco Entrained Bed Pilot Plant Gasifier Model to simulate biomass gasification in an Entrained Bed. Results are being evaluated. Models for other reaction modes are being evaluated. A biomass economic program has been developed to provide average product fuel costs using 15 thermochemical processes.

  4. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  5. INVESTIGATION OF FUEL CHEMISTRY AND BED PERFORMANCE IN A FLUIDIZED BED BLACK LIQUOR STEAM REFORMER

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Whitty

    2003-12-01

    The University of Utah project ''Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer'' (DOE award number DE-FC26-02NT41490) was developed in response to a solicitation for projects to provide technical support for black liquor and biomass gasification. The primary focus of the project is to provide support for a DOE-sponsored demonstration of MTCI's black liquor steam reforming technology at Georgia-Pacific's paper mill in Big Island, Virginia. A more overarching goal is to improve the understanding of phenomena that take place during low temperature black liquor gasification. This is achieved through five complementary technical tasks: (1) construction of a fluidized bed black liquor gasification test system, (2) investigation of bed performance, (3) evaluation of product gas quality, (4) black liquor conversion analysis and modeling and (5) computational modeling of the Big Island gasifier. Four experimental devices have been constructed under this project. The largest facility, which is the heart of the experimental effort, is a pressurized fluidized bed gasification test system. The system is designed to be able to reproduce conditions near the black liquor injectors in the Big Island steam reformer, so the behavior of black liquor pyrolysis and char gasification can be quantified in a representative environment. The gasification test system comprises five subsystems: steam generation and superheating, black liquor feed, fluidized bed reactor, afterburner for syngas combustion and a flue gas cooler/condenser. The three-story system is located at University of Utah's Industrial Combustion and Gasification Research Facility, and all resources there are available to support the research.

  6. Gasification of a Coal, Biomass, and a Coal-Biomass Mixture in a Fluidized Bed of Dolomite Particles by a Gas Containing Oxygen-CO2 Mixtures

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Karel; Pohořelý, Michael; Kameníková, Petra; Jeremiáš, Michal; Skoblia, S.; Šyc, Michal; Punčochář, Miroslav

    Gliwice : Institute of Thermal Technology, 2011 - (Ksiadz, A.; Werle, S.), s. 114-115 ISBN 978-83-61506-06-5. [International Conference on Carbon Reduction Technologies CaReTECH 2011. Polish Jurassic Highland (Orle Gniazdo) (PL), 19.09.2011-22.09.2011] R&D Projects: GA MŠk 2B08048 Grant ostatní: RFCS(XE) CT-2010-00009 Institutional research plan: CEZ:AV0Z40720504 Keywords : fluidized bed * gasification * CO2 Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use

  7. Biomass Thermochemical Conversion Program. 1983 Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Schiefelbein, G.F.; Stevens, D.J.; Gerber, M.A.

    1984-08-01

    Highlights of progress achieved in the program of thermochemical conversion of biomass into clean fuels during 1983 are summarized. Gasification research projects include: production of a medium-Btu gas without using purified oxygen at Battelle-Columbus Laboratories; high pressure (up to 500 psia) steam-oxygen gasification of biomass in a fluidized bed reactor at IGT; producing synthesis gas via catalytic gasification at PNL; indirect reactor heating methods at the Univ. of Missouri-Rolla and Texas Tech Univ.; improving the reliability, performance, and acceptability of small air-blown gasifiers at Univ. of Florida-Gainesville, Rocky Creek Farm Gasogens, and Cal Recovery Systems. Liquefaction projects include: determination of individual sequential pyrolysis mechanisms at SERI; research at SERI on a unique entrained, ablative fast pyrolysis reactor for supplying the heat fluxes required for fast pyrolysis; work at BNL on rapid pyrolysis of biomass in an atmosphere of methane to increase the yields of olefin and BTX products; research at the Georgia Inst. of Tech. on an entrained rapid pyrolysis reactor to produce higher yields of pyrolysis oil; research on an advanced concept to liquefy very concentrated biomass slurries in an integrated extruder/static mixer reactor at the Univ. of Arizona; and research at PNL on the characterization and upgrading of direct liquefaction oils including research to lower oxygen content and viscosity of the product. Combustion projects include: research on a directly fired wood combustor/gas turbine system at Aerospace Research Corp.; adaptation of Stirling engine external combustion systems to biomass fuels at United Stirling, Inc.; and theoretical modeling and experimental verification of biomass combustion behavior at JPL to increase biomass combustion efficiency and examine the effects of additives on combustion rates. 26 figures, 1 table.

  8. CANMET Gasifier Liner Coupon Material Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Mark Fitzsimmons; Dave Grimmett; Bryan McEnerney

    2007-01-31

    This report provides detailed test results consisting of test data and post-test inspections from Task 1 ''Cooled Liner Coupon Development and Test'' of the project titled ''Development of Technologies and Capabilities for Coal Energy Resources--Advanced Gasification Systems Development (AGSD)''. The primary objective of this development and test program is to verify that ceramic matrix composite (CMC) liner materials planned for use in an advanced gasifier pilot plant will successfully withstand the environments in a commercial gasifier. Pratt & Whitney Rocketdyne (PWR) designed and fabricated the cooled liner test assembly article that was tested in a slagging gasifier at CANMET Energy Technology Center (CETC-O) in Ottawa, Ontario, Canada. The test program conducted in 2006 met the objective of operating the cooled liner test article at slagging conditions in a small scale coal gasifier at CETC-O for over the planned 100 hours. The test hardware was exposed to at least 30 high temperature excursions (including start-up and shut-down cycles) during the test program. The results of the testing has provided valuable information on gasifier startup and required cooling controls in steady state operation of future advanced gasifiers using similar liners. The test program also provided a significant amount of information in the areas of CMC materials and processing for improved capability in a gasifier environment and insight into CMC liner fabrication that will be essential for near-term advanced gasifier projects.

  9. Biomass gasification for energy production

    Energy Technology Data Exchange (ETDEWEB)

    Lundberg, H.; Morris, M.; Rensfelt, E. [TPS Termiska Prosesser Ab, Nykoeping (Sweden)

    1997-12-31

    Biomass and waste are becoming increasingly interesting as fuels for efficient and environmentally sound power generation. Circulating fluidized bed (CFB) gasification for biomass and waste has been developed and applied to kilns both in the pulp and paper industry and the cement industry. A demonstration plant in Greve-in- Chianti, Italy includes two 15 MW{sub t}h RDF-fuelled CFB gasifiers of TPS design, the product gas from which is used in a cement kiln or in steam boiler for power generation. For CFB gasification of biomass and waste to reach a wider market, the product gas has to be cleaned effectively so that higher fuel to power efficiencies can be achieved by utilizing power cycles based on engines or gas turbines. TPS has developed both CFB gasification technology and effective secondary stage tar cracking technology. The integrated gasification - gas-cleaning technology is demonstrated today at pilot plant scale. To commercialise the technology, the TPS`s strategy is to first demonstrate the process for relatively clean fuels such as woody biomass and then extend the application to residues from waste recycling. Several demonstration projects are underway to commercialise TPS`s gasification and gas cleaning technology. In UK the ARBRE project developed by ARBRE Energy will construct a gasification plant at Eggborough, North Yorkshire, which will provide gas to a gas turbine and steam turbine generation system, producing 10 MW and exporting 8 Mw of electricity. It has been included in the 1993 tranche of the UK`s Non Fossil Fuel Obligation (NFFO) and has gained financial support from EC`s THERMIE programme as a targeted BIGCC project. (author)

  10. Gasification of bio-oil: Effects of equivalence ratio and gasifying agents on product distribution and gasification efficiency.

    Science.gov (United States)

    Zheng, Ji-Lu; Zhu, Ming-Qiang; Wen, Jia-Long; Sun, Run-Cang

    2016-07-01

    Bio-oil derived from fast pyrolysis of rice husk was gasified for producing gas. The effectiveness of equivalence ratio and gasifying agents on the gas composition, ratio of H2/CO, tar amount, low heating value, degree of oxidation and cold gas efficiency of the gas were comprehensively investigated. Under different equivalence ratios and gasifying agents, the gases can be used as synthesis gas for Fischer-Tropsch synthesis, fuel gas for gas turbines in a power plant and reducing gas for ore reduction, respectively. The H2 concentration, CO level and cold gas efficiency of the resulted gas derived from gasification of bio-oil were significantly higher, while tar content was remarkably lower than those derived from gasification of solid biomass using the same equivalent ratio value and gasifying agent. In short, bio-oil gasification is economically feasible for large scale production of fuels and chemicals. PMID:27017126

  11. Catalytic fast pyrolysis of straw biomass in an internally interconnected fluidized bed to produce aromatics and olefins: effect of different catalysts.

    Science.gov (United States)

    Zhang, Huiyan; Xiao, Rui; Jin, Baosheng; Shen, Dekui; Chen, Ran; Xiao, Guomin

    2013-06-01

    A novel reactor, named internally interconnected fluidized bed (IIFB), was specially designed for catalytic fast pyrolysis (CFP) of straw biomass. Catalytic characteristics of four types of catalysts (ZSM-5, LOSA-1, Gamma-Al2O3 and spent FCC catalysts) for producing aromatics and olefins were investigated in this reactor. The results show that IIFB reactor can realize CFP process. The maximum carbon yields of aromatics (12.8%) and C2-C4 olefins (10.5%) were obtained with ZSM-5. ZSM-5 shows the highest selectivity of naphthalene (12.1%), whereas spent FCC catalyst presents the highest selectivity of benzene (45.5%). The selectivity of ethylene and propylene are equal in the present of ZSM-5 and LOSA-1. Gamma-Al2O3 and spent FCC catalysts show a higher selectivity of ethylene than that of propylene. This paper provides a new reactor for CFP process and some suggestions for choosing catalyst. PMID:23587812

  12. Demonstration of a 1 MWe biomass power plant at USMC Base Camp Lejeune

    International Nuclear Information System (INIS)

    A biomass energy conversion project is being sponsored by the U.S. Environmental Protection Agency (EPA) to demonstrate an environmentally and economically sound electrical power option for government installations, industrial sites, rural cooperatives, small municipalities, and developing countries. Under a cooperative agreement with EPA, Research Triangle Institute is initiating operation of the Camp Lejeune Energy from Wood (CLEW) biomass plant. Wood gasification combined with internal combustion engines was chosen because of (1) recent improvements in gas cleaning, (2) simple, economical operation for units less than 10 MW, and (3) the option of a clean, cheap fuel for the many existing facilities generating expensive electricity from petroleum fuels with reciprocating engines. The plant incorporates a downdraft, moving bed gasifier utilizing hogged waste wood from the Marine Corps Base at Camp Lejeune, NC. A moving bed bulk wood dryer and both spark ignition and diesel engines are included. Unique process design features are briefly described relative to the gasifier, wood drying, tar separation, and process control. A test plan for process optimization and demonstration of reliability, economics, and environmental impact is outlined. (author)

  13. Diversity, biomass and distribution pattern of Sargassum beds in the South West lagoon of New Caledonia (South Pacific)

    OpenAIRE

    Mattio, L.; Dirberg, G.; Payri, Claude; Andréfouët, Serge

    2008-01-01

    Sargassum (Phaeophyceae, Fucales) is a genus of worldwide distribution recently recognised to proliferate in several regions of the South Pacific. In New Caledonia, species of this genus naturally structure one of the major lagoon habitats but their extent, composition and biomass remain largely unknown. To fill these gaps in our knowledge over large areas, we applied a combination of remote sensing and in situ methods applied to the Neo Caledonian South West Lagoon. Space borne high resoluti...

  14. Co-gasification of biosolids with biomass: Thermogravimetric analysis and pilot scale study in a bubbling fluidized bed reactor.

    Science.gov (United States)

    Yu, Ming Ming; Masnadi, Mohammad S; Grace, John R; Bi, Xiaotao T; Lim, C Jim; Li, Yonghua

    2014-10-17

    This work studied the feasibility of co-gasification of biosolids with biomass as a means of disposal with energy recovery. The kinetics study at 800°C showed that biomass, such as switchgrass, could catalyze the reactions because switchgrass ash contained a high proportion of potassium, an excellent catalyst for gasification. However, biosolids could also inhibit gasification due to interaction between biomass alkali/alkaline earth metals and biosolids clay minerals. In the pilot scale experiments, increasing the proportion of biosolids in the feedstock affected gasification performance negatively. Syngas yield and char conversion decreased from 1.38 to 0.47m(3)/kg and 82-36% respectively as the biosolids proportion in the fuel increased from 0% to 100%. Over the same range, the tar content increased from 10.3 to 200g/m(3), while the ammonia concentration increased from 1660 to 19,200ppmv. No more than 25% biosolids in the fuel feed is recommended to maintain a reasonable gasification. PMID:25459803

  15. Quantitative evaluation of minerals in fly ashes of biomass, coal and biomass-coal mixture derived from circulating fluidised bed combustion technology

    International Nuclear Information System (INIS)

    The chemical and mineralogical composition of fly ash samples collected from laboratory scale circulating fluidised bed (CFB) combustion facility have been investigated. Three fly ashes were collected from the second cyclone in a 50 kW laboratory scale boiler, after the combustion of different solid fuels. Characterisation of the fly ash samples was conducted by means of X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Quantitative analysis of the crystalline (mineral) and amorphous phases in each ash sample was carried out using the Rietveld-based Siroquant system, with an added spike of ZnO to evaluate the amorphous content. SiO2 is the dominant oxide in the fly ashes, with CaO, Al2O3 and Fe2O3 also present in significant proportions. XRD results show that all three fly ashes contain quartz, anhydrite, hematite, illite and amorphous phases. The minerals calcite, feldspar, lime and periclase are present in ashes derived from Polish coal and/or woodchips. Ash from FBC combustion of a Greek lignite contains abundant illite, whereas illite is present only in minor proportions in the other ash samples.

  16. Quantitative evaluation of minerals in fly ashes of biomass, coal and biomass-coal mixture derived from circulating fluidised bed combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    Koukouzas, N.; Ward, C.R.; Papanikolaou, D.; Li, Z.S.; Ketikidis, C. [Institute of Solid Fuels Technology & Applications, Athens (Greece)

    2009-09-15

    The chemical and mineralogical composition of fly ash samples collected from laboratory scale circulating fluidised bed (CFB) combustion facility have been investigated. Three fly ashes were collected from the second cyclone in a 50 kW laboratory scale boiler, after the combustion of different solid fuels. Characterisation of the fly ash samples was conducted by means of X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Quantitative analysis of the crystalline (mineral) and amorphous phases in each ash sample was carried out using the Rietveld-based Siroquant system, with an added spike of ZnO to evaluate the amorphous content. SiO{sub 2} is the dominant oxide in the fly ashes, with CaO, Al{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} also present in significant proportions. XRD results show that all three fly ashes contain quartz, anhydrite, hematite, illite and amorphous phases. The minerals calcite, feldspar, lime and periclase are present in ashes derived from Polish coal and/or woodchips. Ash from FBC combustion of a Greek lignite contains abundant illite, whereas illite is present only in minor proportions in the other ash samples.

  17. Quantitative evaluation of minerals in fly ashes of biomass, coal and biomass-coal mixture derived from circulating fluidised bed combustion technology

    Energy Technology Data Exchange (ETDEWEB)

    Koukouzas, Nikolaos, E-mail: koukouzas@certh.gr [Centre for Research and Technology Hellas, Institute for Solid Fuels Technology and Applications, Mesogeion Ave. 357-359, 15231 Halandri, Athens (Greece); Ward, Colin R. [School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052 (Australia); Papanikolaou, Dimitra [Centre for Research and Technology Hellas, Institute for Solid Fuels Technology and Applications, Mesogeion Ave. 357-359, 15231 Halandri, Athens (Greece); Li, Zhongsheng [School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052 (Australia); Ketikidis, Chrisovalantis [Centre for Research and Technology Hellas, Institute for Solid Fuels Technology and Applications, Mesogeion Ave. 357-359, 15231 Halandri, Athens (Greece)

    2009-09-30

    The chemical and mineralogical composition of fly ash samples collected from laboratory scale circulating fluidised bed (CFB) combustion facility have been investigated. Three fly ashes were collected from the second cyclone in a 50 kW laboratory scale boiler, after the combustion of different solid fuels. Characterisation of the fly ash samples was conducted by means of X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Quantitative analysis of the crystalline (mineral) and amorphous phases in each ash sample was carried out using the Rietveld-based Siroquant system, with an added spike of ZnO to evaluate the amorphous content. SiO{sub 2} is the dominant oxide in the fly ashes, with CaO, Al{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} also present in significant proportions. XRD results show that all three fly ashes contain quartz, anhydrite, hematite, illite and amorphous phases. The minerals calcite, feldspar, lime and periclase are present in ashes derived from Polish coal and/or woodchips. Ash from FBC combustion of a Greek lignite contains abundant illite, whereas illite is present only in minor proportions in the other ash samples.

  18. Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Blough, E.; Russell, W.; Leach, J.W.

    1990-08-01

    Computer models have been developed for evaluating conceptual designs of integrated coal gasification combined cycle power plants. An overall system model was developed for performing thermodynamic cycle analyses, and detailed models were developed for predicting performance characteristics of fixed bed coal gasifiers and hot gas clean up subsystem components. The overall system model performs mass and energy balances and does chemical equilibrium analyses to determine the effects of changes in operating conditions, or to evaluate proposed design changes. An existing plug flow model for fixed bed gasifiers known as the Wen II model was revised and updated. Also, a spread sheet model of zinc ferrite sulfur sorbent regeneration subsystem was developed. Parametric analyses were performed to determine how performance depends on variables in the system design. The work was done to support CRS Sirrine Incorporated in their study of standardized air blown coal gasifier gas turbine concepts.

  19. Mathematical modelling of the gasification of cellulose-containing biomass using a zoning model; Mathematische Modellierung der Vergasung zellulosehaltiger Biomasse mit Hilfe eines Zonenmodells

    Energy Technology Data Exchange (ETDEWEB)

    Jung, K.; Saller, G.; Funk, G.; Krumm, W. [Siegen Univ. (Gesamthochschule) (Germany). Inst. fuer Energietechnik

    1998-09-01

    The composition of the product gas is decisive for the further process stages. In contrast to coal gasification, which has been investigated for more than a century, there is still a lack of theoretical and experimental knowledge on biomass gasification. The contribution presents a mathematical model that is to provide deeper knowledge of the constant-flow fixed-bed gasifier, which is still widely regarded as a `black box`. (orig./SR) [Deutsch] Einen wesentlichen Prozessschritt der thermochemischen Konversion stellt der Vergasungsprozess dar, da die Zusammensetzung des erhaltenen Gases fuer die weiteren Prozessschritte von entscheidender Bedeutung ist. Im Gegensatz zur Vergasung von Kohle, die bereits seit fast 100 Jahren untersucht wird, besteht bei der Vergasung von Biomasse ein starker Nachholbedarf in Bezug auf das theoretische und experimentelle Detailwissen. In diesem Beitrag wird im Rahmen eines mathematischen Modells ein Ansatz vorgestellt, in dem der Gleichstrom-Festbettvergaser, der bisher meist als `blackbox` betrachtet wurde, weiter aufgeschluesselt wird. (orig./SR)

  20. Biomass fast pyrolysis for bio-oil production in a fluidized bed reactor under hot flue atmosphere.

    Science.gov (United States)

    Li, Ning; Wang, Xiang; Bai, Xueyuan; Li, Zhihe; Zhang, Ying

    2015-10-01

    Fast pyrolysis experiments of corn stalk were performed to investigate the optimal pyrolysis conditions of temperature and bed material for maximum bio-oil production under flue gas atmosphere. Under the optimized pyrolysis conditions, furfural residue, xylose residue and kelp seaweed were pyrolyzed to examine their yield distributions of products, and the physical characteristics of bio-oil were studied. The best flow rate of the flue gas at selected temperature is obtained, and the pyrolysis temperature at 500 degrees C and dolomite as bed material could give a maximum bio-oil yield. The highest bio-oil yield of 43.3% (W/W) was achieved from corn stalk under the optimal conditions. Two main fractions were recovered from the stratified bio-oils: light oils and heavy oils. The physical properties of heavy oils from all feedstocks varied little. The calorific values of heavy oils were much higher than that of light oils. The pyrolysis gas could be used as a gaseous fuel due to a relatively high calorific value of 6.5-8.5 MJ/m3. PMID:26964339

  1. Manipulation of gasification coal feed in order to increase the ash fusion temperature of the coal to operate the gasifiers at higher temperatures / Johannes Chrisstoffel van Dyk

    OpenAIRE

    Van Dyk, Johannes Chrisstoffel

    2006-01-01

    Coal is a crucial feedstock for South Africa's unique synfuels and petrochemicals industry and used by Sasol as a feedstock to produce synthesis gas via the Sasol-Lurgi Fixed Bed Dry Bottom (FBDB) gasification process. The ash fusion temperature (AFT) gives detail information on the suitability of a coal source for gasification purposes, and specifically to the extent ash agglomeration or clinkering is likely to occur within the gasifier. Ash clinkering inside the gasifier can cause channel b...

  2. Small-Scale Coal-Biomass to Liquids Production Using Highly Selective Fischer-Tropsch Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Gangwal, Santosh K. [Southern Research Institute, Durham, NC (United States); McCabe, Kevin [Southern Research Institute, Durham, NC (United States)

    2015-04-30

    The research project advanced coal-to-liquids (CTL) and coal-biomass to liquids (CBTL) processes by testing and validating Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to convert gasifier syngas predominantly to gasoline, jet fuel and diesel range hydrocarbon liquids, thereby eliminating expensive wax upgrading operations The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream testing/demonstration. Southern Research designed, installed and commissioned a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport integrated gasifier (TRIGTM). The test-rig was designed to receive up to 5 lb/h raw syngas augmented with bottled syngas to adjust the H2/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of 2 to 4 L/day. It employed a 2-inch diameter boiling water jacketed fixed-bed heat-exchange FT reactor incorporating Chevron’s catalyst in Intramicron’s high thermal conductivity micro-fibrous entrapped catalyst (MFEC) packing to efficiently remove heat produced by the highly exothermic FT reaction.

  3. Fluidized-bed gasification/pyrolysis technology for waste-to-energy

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, T. [Ebara Corp., Tokyo (Japan)

    2008-07-01

    Fluidized-bed gasification of biomass and waste is expected to be a core technology for addressing global energy supply issues, fossil fuel conservation and environmental concerns regarding greenhouse gas emissions. Ebara Corporation has developed a unique fluidized-bed gasification technology known as the internally circulating fluidized-bed gasifier (ICFG), which can convert various forms of biomass and waste into high calorific product gas/oil that can be used as an alternative fuel for power generation as well as in chemical and liquid fuel synthesis. This paper summarized the general features of the ICFG as well as its research and development status. More than 10,900 hours of pyrolysis/gasification demonstration tests of various feedstocks and 120 hours of laboratory tests at 3 test facilities in Japan have revealed various levels of performance and the feasibility of the ICFG as a fluidized-bed gasification/pyrolysis technology for waste-to-energy and waste-to-chemical production. Several feasibility studies have been conducted to determine the commercial viability of this technology in Japan and elsewhere in the near future. 5 refs., 2 tabs., 9 figs.

  4. High temperature electrolyte supported Ni-GDC/YSZ/LSM SOFC operation on two-stage Viking gasifier product gas

    DEFF Research Database (Denmark)

    Hofmann, P.; Schweiger, A.; Fryda, L.;

    2007-01-01

    This paper presents the results from a 150 h test of a commercial high temperature single planar solid oxide fuel cell (SOFC) operating on wood gas from the Viking two-stage fixed-bed downdraft gasifier, which produces an almost tar-free gas, that was further cleaned for particulates, sulphur and...

  5. Production of bio-oil from biomass: slow pyrolysis of rapeseed (Brassica napus L.) in a fixed-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Onay, O. [Anadolu University (Turkey). Faculty of Engineering

    2003-09-01

    Rapeseed (Brassica napus L.) pyrolysis experiments were performed in a fixed-bed reactor. The effects of heating rate, final pyrolysis temperature, particle size, and pyrolysis atmosphere on pyrolysis product yields and chemical compositions have been investigated. The maximum oil yield of 51.7% was obtained at a pyrolysis temperature of 550{sup o}C with particle sizes in the range of +0.6 to 1.8 mm in a sweeping gas atmosphere (100 cm{sup 3} min{sup -1} N{sub 2}) and a heating rate of 30{sup o}C min{sup -1}. The chemical characterization has shown that the oil obtained from rapeseed may be potentially valuable as fuels and chemical feedstocks. (author)

  6. Fast pyrolysis of biomass in fluidized bed reactor UNICAMP, Brazil: problems, causes and solutions; Pirolise rapida de biomassa em reator de leito fluidizado UNICAMP-Brasil: problemas, causas e solucoes

    Energy Technology Data Exchange (ETDEWEB)

    Mesa Perez, Juan Miguel; Marin Mesa, Henry Ramon [Bioware Tecnologia, Campinas, SP (Brazil); Rocha, Jose Dilcio; Olivares Gomez, Edgardo [Universidade Estadual de Campinas (NIPE/UNICAMP), SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico; Cortez, Luis Augusto Barbosa; Shimabukuro, Fabio Rodrigo; Vallin, Marco Jim Gui [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola

    2006-07-01

    The fluidized bed reactor developed by the researchers of the UNICAMP in the installations of the Sugar Cane Technology Center (CTC), in Piracicaba-SP, is the first reactor of biomass fast pyrolysis in Brazil to produce bio-oil. In this work the problems of operation with the reactor in functioning are presented as the emptying of gases produced in the pyrolysis by means of the biomass feeding system, the block of the thread of biomass feeding, the inert material sintering in the bed, etc. The possible causes are described. Thus it, the first ones could be solved, either by the reduction of the height of the inert bed, or by the increase of the wadding percentage of the thread, among others. These results of the exploratory tests make possible the steady work of the plant, greater knowledge of the phenomena that occur during the fast pyrolysis in flutizide bed, as well as the establishment of adjusted levels for the identified independent factors during the remaining experimental works. (author)

  7. Stoichiometric, mass, energy and exergy balance analysis of countercurrent fixed-bed gasification of post-consumer residues

    International Nuclear Information System (INIS)

    Air-blown gasification studies were conducted on a countercurrent fixed-bed gasifier for municipal residue-based Refuse Derived Fuel (RDF) pellets and compared with the mass and energy performance features of gasifier with other biomass and residual fuels. The mass conversion efficiency and cold gas efficiency (CGE) of the gasifier were observed to be 83% and 73%, respectively for RDF pellets. The higher heating value and global energy content of the producer gas generated from gasification of RDF pellets was observed to be 5.58 MJ Nm-3 and 12.2 MJ kg-1, respectively. The tar content in the gas generated from RDF pellets was observed to be about 45% less than the tar content in the gas generated from wood chips (WC). Empirical stoichiometric equations were developed to describe the gasification of different fuels. A complete thermodynamic analysis was performed to determine the magnitudes of various inefficiencies and irreversibilities involved in the process. It was evaluated for RDF pellets that 27% of the exergy or available energy input was dissipated in the system due to various irreversibilities taking place in the gasification process. The second law CGE was observed to be highest for RDF pellets i.e. 56% followed by charred soybean straw pellets and WC. Thermal energy in the form of sensible heat energy accounted for 6-7% of the total energy; the available energy accounted for 2-3% of the total energy output of the process

  8. Comparison of ORC Turbine and Stirling Engine to Produce Electricity from Gasified Poultry Waste

    Directory of Open Access Journals (Sweden)

    Franco Cotana

    2014-08-01

    Full Text Available The Biomass Research Centre, section of CIRIAF, has recently developed a biomass boiler (300 kW thermal powered, fed by the poultry manure collected in a nearby livestock. All the thermal requirements of the livestock will be covered by the heat produced by gas combustion in the gasifier boiler. Within the activities carried out by the research project ENERPOLL (Energy Valorization of Poultry Manure in a Thermal Power Plant, funded by the Italian Ministry of Agriculture and Forestry, this paper aims at studying an upgrade version of the existing thermal plant, investigating and analyzing the possible applications for electricity production recovering the exceeding thermal energy. A comparison of Organic Rankine Cycle turbines and Stirling engines, to produce electricity from gasified poultry waste, is proposed, evaluating technical and economic parameters, considering actual incentives on renewable produced electricity.

  9. Thermodynamic analysis of small-scale dimethyl ether (DME) and methanol plants based on the efficient two-stage gasifier

    DEFF Research Database (Denmark)

    Clausen, Lasse Røngaard; Elmegaard, Brian; Ahrenfeldt, Jesper;

    2011-01-01

    Models of dimethyl ether (DME) and methanol synthesis plants have been designed by combining the features of the simulation tools DNA and Aspen Plus. The plants produce DME or methanol by catalytic conversion of a syngas generated by gasification of woody biomass. Electricity is co-produced in the...... plants by a gas engine utilizing the unconverted syngas. A two-stage gasifier with a cold gas efficiency of 93% is used, but because of the design of this type of gasifier, the plants have to be of small-scale (5 MWth biomass input). The plant models show energy efficiencies from biomass to DME....../methanol + electricity of 51–58% (LHV), which shows to be 6-8%-points lower than efficiencies achievable on large-scale plants based on torrefied biomass pellets. By using waste heat from the plants for district heating, the total energy efficiencies become 87–88%....

  10. Fundamental studies of synthesis-gas production based on fluidised-bed gasification of biomass-UCGFunda

    Energy Technology Data Exchange (ETDEWEB)

    Reinikainen, M.; Moilanen, A.; Simell, P.; Hannula, I.; Kurkela, E. (VTT Technical Research Centre of Finland, Espoo (Finland)), e-mail: matti.reinikainen@vtt.fi; Suominen, T. P. (Aabo Akademi, Turku (Finland), Teknisk Kemi och Reaktionsteknik), e-mail: timo.suominen@abo.fi; Linnekoski, J. (Aalto Univ., School of Science and Technology, Espoo (Finland), Lab. of Industrial Chemistry)

    2011-11-15

    The research was directed towards methods of producing transportation bio-fuels via the synthesis-gas route, with emphasis on the synthesis-gas production and gas cleaning steps. The subtopics of the research project were (1) fuel characterisation and ash behaviour in the gasification step, (2) reaction mechanisms related to gas cleaning, (3) evaluations of alternative process configurations and applications and (4) international cooperation. VTT itself financed also two additional subtopics: (5) new analysis techniques and (6) hydrogen from biomass via gasification. The project comprised experimental work, modelling, techno-economic evaluations as well as studies based on literature. The project was steered by a wide industrial consortium and the research work was carried out by VTT, Aalto University and Aabo Akademi. International development in syngas technology was closely monitored in all subtopics as well as by participating in relevant IEA-tasks. More information on the project can be found on project webpage http://www.vtt.fi/proj/ucgfunda/ (orig.)

  11. TASK 3: PILOT PLANT GASIFIER TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Fusselman, Steve

    2015-11-01

    Aerojet Rocketdyne (AR) has developed an innovative gasifier concept incorporating advanced technologies in ultra-dense phase dry feed system, rapid mix injector, and advanced component cooling to significantly improve gasifier performance, life, and cost compared to commercially available state-of-the-art systems. Design, fabrication and initial testing of the pilot plant compact gasifier was completed in 2011 by a development team led by AR. Findings from this initial test program, as well as subsequent gasifier design and pilot plant testing by AR, identified a number of technical aspects to address prior to advancing into a demonstration-scale gasifier design. Key among these were an evaluation of gasifier ability to handle thermal environments with highly reactive coals; ability to handle high ash content, high ash fusion temperature coals with reliable slag discharge; and to develop an understanding of residual properties pertaining to gasification kinetics as carbon conversion approaches 99%. The gasifier did demonstrate the ability to withstand the thermal environments of highly reactive Powder River Basin coal, while achieving high carbon conversion in < 0.15 seconds residence time. Continuous operation with the high ash fusion temperature Xinyuan coal was demonstrated in long duration testing, validating suitability of outlet design as well as downstream slag discharge systems. Surface area and porosity data were obtained for the Xinyuan and Xinjing coals for carbon conversion ranging from 85% to 97%, and showed a pronounced downward trend in surface area per unit mass carbon as conversion increased. Injector faceplate measurements showed no incremental loss of material over the course of these experiments, validating the commercially traceable design approach and supportive of long injector life goals. Hybrid testing of PRB and natural gas was successfully completed over a wide range of natural gas feed content, providing test data to anchor predictions

  12. Biomass pyrolysis in a fixed-bed reactor: Effects of pyrolysis parameters on product yields and characterization of products

    International Nuclear Information System (INIS)

    Slow pyrolysis of eastern giant fennel (Ferula orientalis L.) stalks has been performed in a fixed-bed tubular reactor with (ZnO, Al2O3) and without catalyst at six different temperatures ranging from 350 °C to 600 °C with heating rates of 15, 30, 50 °C/min. The amounts of bio-char, bio-oil and gas produced, as well as the compositions of the resulting bio-oils were determined by FT-IR and GC–MS. The effects of pyrolysis parameters such as temperature, catalyst and ratio of catalyst, particle size (Dp) and sweeping gas flow rate on product yields were investigated. According to results, temperature and catalyst seem to be the main factors effecting the conversion of F. orientalis L. into solid, liquid and gaseous products. The highest liquid yield (45.22%) including water was obtained with 15% zinc oxide catalyst at 500 °C temperature at a heating rate of 50 °C/min when 0.224 > Dp > 0.150 mm particle size raw material and 100 cm3/min of sweeping gas flow rate were used. - Highlights: • Ferula orientalis L. stalks were converted to solid, liquid and gaseous products. • Effects of various parameters on product yields were investigated. • 500 °C of temperature, heating rate of 50 °C/min and zinc oxide provide the optimum conditions for bio-oil formation. • 81 different compounds were identified by GC–MS in the bio-oils obtained at 500 °C

  13. Effects of lipids and oleic acid on biomass development in anaerobic fixed-bed reactors. Part II: Oleic acid toxicity and biodegradability.

    Science.gov (United States)

    Alves, M M; Vieira, J A; Pereira, R M; Pereira, M A; Mota, M

    2001-01-01

    Oleic acid toxicity and biodegradability were followed during long-term operation of two similar anaerobic fixed-bed units. When treating an oleate based effluent, the sludge from the bioreactor that was acclimated with lipids during the first operation period, showed a higher tolerance to oleic acid toxicity (IC50 = 137 mg/l) compared with the sludge fed with a non-fat substrate (IC50 = 80 mg/l). This sludge showed also the highest biodegradation capacity of oleic acid, achieving maximum methane production rates between 33 and 46 mlCH4(STP)/gVS.day and maximum percentages of methanization between 85 and 98% for the range of concentrations between 500 and 900 mg oleate/l. When oleate was the sole carbon source fed to both digesters, the biomass became encapsulated with organic matter, possibly oleate or an intermediate of its degradation, e.g. stearate that was degraded at a maximum rate of 99 mlCH4(STP)/gVS.day. This suggests the possibility of using adsorption-degradation cycles for the treatment of LCFA based effluents. Both tolerance to toxicity and biodegradability of oleic acid were improved by acclimatization with lipids or oleate below a threshold concentration. PMID:11257881

  14. Diesel power plants based on biomass gasification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Staahlberg, P.; Solantausta, Y.; Wilen, C.

    1996-12-31

    The aim of the project was to assess the competitiveness and market potential of small-scale power plant concepts based on biomass gasification and on diesel/gas engines, and to study the effect of process parameters on the efficiency of the circulating fluidized-bed gasifier and on the formation of tarry impurities. Alternative diesel/gas engine power plant concepts based on gasification in scale 6-50 MW{sub e} were assessed. In the basic version, where the electricity is generated only by the a diesel/gas engine, the efficiency level of 37 % is achieved in power generation. When steam cycle is added to the process the efficiency of power generation increases to 44-48 %. The efficiencies achieved in the process are very high compared with those of biomass power plant processes on a commercial level or under development. The most significant potential of biomass-based power generation is made up by wastes of sugar industries in south and Central America and in Asia. There are also very extensive growth potentials of bioenergy use in the NAFTA countries (USA, Canada and Mexico) and in Europe. In Europe, the bioenergy use is expected to grow most sharply in Italy, Spain, Germany and Poland. Carbon conversion obtained in the gasifier was in the range of 99.0-99.9 % for sawdust and 96-98 % for forest residue chips. The tar content of the product gas 10-15 g/m- m{sup 3}{sub n}, for sawdust in the gasification temperature of 830-930 deg C and with sand as circulating fluid-bed. When dolomite was used as circulating fluid-bed, the tar contents were 2-3 g/m{sup 3}{sub n} at as low temperatures as 880-890 deg C. The tar content of gas can be reduced sharply by phasing of gasification air and by using catalytic circulating fluid-bed material Bioenergy Research Programme; LIEKKI 2 Research Programme. 26 refs., 40 figs.

  15. Porous filtering media comparison through wet and dry sampling of fixed bed gasification products

    International Nuclear Information System (INIS)

    The syngas produced by fixed bed gasifiers contains high quantities of particulate and tars. This issue, together with its high temperature, avoids its direct exploitation without a proper cleaning and cooling process. In fact, when the syngas produced by gasification is used in an Internal Combustion engine (IC), the higher the content of tars and particulate, the higher the risk to damage the engine is. If these compounds are not properly removed, the engine may fail to run. A way to avoid engine fails is to intensify the maintenance schedule, but these stops will reduce the system profitability. From a clean syngas does not only follow higher performance of the generator, but also less pollutants in the atmosphere. When is not possible to work on the gasification reactions, the filter plays the most important role in the engine safeguard process. This work is aimed at developing and comparing different porous filters for biomass gasifiers power plants. A drum filter was developed and tested filling it with different filtering media available on the market. As a starting point, the filter was implemented in a Power Pallet 10 kW gasifier produced by the California-based company ''ALL Power Labs''. The original filter was replaced with different porous biomasses, such as woodchips and corn cobs. Finally, a synthetic zeolites medium was tested and compared with the biological media previously used. The Tar Sampling Protocol (TSP) and a modified ''dry'' method using the Silica Gel material were applied to evaluate the tars, particulate and water amount in the syngas after the filtration process. Advantages and disadvantages of every filtering media chosen were reported and discussed

  16. System studies on Biofuel production via Integrated Biomass Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Jim; Lundgren, Joakim [Luleaa Univ. of Technology Bio4Energy, Luleaa (Sweden); Malek, Laura; Hulteberg, Christian [Lund Univ., Lund (Sweden); Pettersson, Karin [Chalmers Univ. of Technology, Goeteborg (Sweden); Wetterlund, Elisabeth [Linkoeping Univ. Linkoeping (Sweden)

    2013-09-01

    A large number of national and international techno-economic studies on industrially integrated gasifiers for production of biofuels have been published during the recent years. These studies comprise different types of gasifiers (fluidized bed, indirect and entrained flow) integrated in different industries for the production of various types of chemicals and transportation fuels (SNG, FT-products, methanol, DME etc.) The results are often used for techno-economic comparisons between different biorefinery concepts. One relatively common observation is that even if the applied technology and the produced biofuel are the same, the results of the techno-economic studies may differ significantly. The main objective of this project has been to perform a comprehensive review of publications regarding industrially integrated biomass gasifiers for motor fuel production. The purposes have been to identify and highlight the main reasons why similar studies differ considerably and to prepare a basis for fair techno-economic comparisons. Another objective has been to identify possible lack of industrial integration studies that may be of interest to carry out in a second phase of the project. Around 40 national and international reports and articles have been analysed and reviewed. The majority of the studies concern gasifiers installed in chemical pulp and paper mills where black liquor gasification is the dominating technology. District heating systems are also well represented. Only a few studies have been found with mechanical pulp and paper mills, steel industries and the oil refineries as case basis. Other industries have rarely, or not at all, been considered for industrial integration studies. Surprisingly, no studies regarding integration of biomass gasification neither in saw mills nor in wood pellet production industry have been found. In the published economic evaluations, it has been found that there is a large number of studies containing both integration and

  17. Effect of the influent COD concentration on the anaerobic digestion of winery wastewaters from grape-red and tropical fruit (guava) wine production in fluidized bed reactors with chilean natural zeolite for biomass immobilization

    OpenAIRE

    Montalvo, Silvio; Guerrero, Lorna; Borja Padilla, Rafael; Cortés, Isel; Sánchez, Enrique; Colmenarejo Morcillo, Manuel F.

    2010-01-01

    The effect of the influent COD concentration on the performance of anaerobic fluidized bed reactors treating winery wastewaters from grape-red wine (GRWW) and guava wine production (GWW) was studied at laboratory scale. Two reactors were used: one treating GRWW (AFB1) and the other processing GWW (AFB2). The behaviour of these reactors packed with Chilean zeolite as biomass immobilization support was compared at mesophilic temperature (35 °C). Influent COD varied from 1–24 g L...

  18. JV Task 46 - Development and Testing of a Thermally Integrated SOFC-Gasification System for Biomass Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Phillip Hutton; Nikhil Patel; Kyle Martin; Devinder Singh

    2008-02-01

    The Energy & Environmental Research Center has designed a biomass power system using a solid oxide fuel cell (SOFC) thermally integrated with a downdraft gasifier. In this system, the high-temperature effluent from the SOFC enables the operation of a substoichiometric air downdraft gasifier at an elevated temperature (1000 C). At this temperature, moisture in the biomass acts as an essential carbon-gasifying medium, reducing the equivalence ratio at which the gasifier can operate with complete carbon conversion. Calculations show gross conversion efficiencies up to 45% (higher heating value) for biomass moisture levels up to 40% (wt basis). Experimental work on a bench-scale gasifier demonstrated increased tar cracking within the gasifier and increased energy density of the resultant syngas. A series of experiments on wood chips demonstrated tar output in the range of 9.9 and 234 mg/m{sup 3}. Both button cells and a 100-watt stack was tested on syngas from the gasifier. Both achieved steady-state operation with a 22% and 15% drop in performance, respectively, relative to pure hydrogen. In addition, tar tolerance testing on button cells demonstrated an upper limit of tar tolerance of approximately 1%, well above the tar output of the gasifier. The predicted system efficiency was revised down to 33% gross and 27% net system efficiency because of the results of the gasifier and fuel cell experiments. These results demonstrate the feasibility and benefits of thermally integrating a gasifier and a high-temperature fuel cell in small distributed power systems.

  19. Agglomeration of ash during combustion of peat and biomass in fluidized-bed reactors. Development of image analysis technique based on scanning electron microscopy; Tuhkan muuntuminen leijukerroskaasutuksessa ja -poltossa. Haitallisten hivenmetallien vapautuminen ja alkalien kaeyttaeytyminen

    Energy Technology Data Exchange (ETDEWEB)

    Kauppinen, E. [VTT Chemistry, Espoo (Finland); Arpiainen, V.; Jokiniemi, J. [VTT Energy, Espoo (Finland)] [and others

    1996-12-01

    The objective of the project is to study the behaviour of alkali metals (Na and K) and hazardous trace elements (Sb, As, Be, Cd, Cr, Co, Pb, Mn, Ni, Se and Zn) during fluidized bed combustion and gasification of solid fuels. The areas of interest are the release of elements studied from the bed and the behaviour of gaseous and particle-phase species after the release from the bed. During 1995 combustion and gasification experiments of Polish coal in bubbling bed were carried out with a laboratory scale fluidized bed gasifier in atmospheric pressure. Flue gas samples were drawn from the freeboard of the reactor and cooled quickly using a dilution probe. Ash particle size distributions were determined using low pressure impactors and differential mobility analyser. The morphology of the ash particles was studied with a scanning electron microscope (SEM) and will be further studied with transmission electron microscopy (TEM). The ash matrix elements (Si, Al, Fe, Ca and Mg) and the alkali metals (Na and K) were not significantly vaporized during the combustion process. More than 99 % of each of these elements was found in ash particles larger than 0.4 {mu}m. In Polish coal the alkali metals are bound mainly in silicates. The alkali metals were not released from the silicate minerals during the combustion process. A significant fraction of As, Cd and Pb was vaporized, released as gaseous species from the fuel particle and condensed mainly on the fine ash particles. 20 - 34 % of cadmium was present in fly ash particles smaller than 0.6 {mu}m (during combustion in 950 deg C), whereas only 1 % of the total ash was in this size fraction. All of the hazardous trace elements studied (As, Be, Cd, Co, Cr, Mn and Zn) were enriched in ash size fraction 0.6 - 5 {mu}m. The enrichment of Co, Cr, Mn, Ni, Pb and Sb was more significant during combustion in 950 deg C than in lower temperature (850 deg C)

  20. 浅析流化床生物质与煤共气化技术方案%Briefly Analyzing Scheme for Biomass and Coal Co-gasification Technology of Fluidized Bed

    Institute of Scientific and Technical Information of China (English)

    毕可军; 毛少祥; 孔北方; 柏林红

    2012-01-01

    In allusion to problems that the biomass was difficult to gasity independently, author has discussed the co-complemented technical scheme of biomass with coal co-gasification; has introduced the physical property of biomass and its gasification features; has discussed the technical features and process flow for pulverized coal gasification technology with fluidized bed of ash meh collection ; has presented the technical scheme to make co-gasification of biomass with coal on basis of pulverized coal gasification technology with fluidized bed of ash meh collection ; and also has presented the relative solution measures for existing problems.%针对生物质能源难以单独气化的问题,探讨了生物质与煤共气化的互补性技术方案;介绍了生物质的物理性质和气化特性;论述了灰融聚流化床粉煤气化技术的特点和工艺流程;提出了在灰融聚流化床粉煤气化的基础上进行生物质与煤共气化技术方案,对存在的问题提出了相关解决措施。

  1. Experimental study on biomass gasification in a double air stage downdraft reactor

    International Nuclear Information System (INIS)

    This work presents an experimental study of the gasification of a wood biomass in a moving bed downdraft reactor with two-air supply stages. This configuration is considered as primary method to improve the quality of the producer gas, regarding its tar reduction. By varying the air flow fed to the gasifier and the distribution of gasification air between stages (AR), being the controllable and measurable variables for this type of gasifiers, measuring the CO, CH4 and H2 gas concentrations and through a mass and energy balance, the gas yield and its power, the cold efficiency of the process and the equivalence ratio (ER), as well as other performance variables were calculated. The gasifier produces a combustible gas with a CO, CH4 and H2 concentrations of 19.04, 0.89 and 16.78% v respectively, at a total flow of air of 20 Nm3 h-1 and an AR of 80%. For these conditions, the low heating value of the gas was 4539 kJ Nm-3. Results from the calculation model show a useful gas power and cold efficiency around 40 kW and 68%, respectively. The resulting ER under the referred operation condition is around 0.40. The results suggested a considerable effect of the secondary stage over the reduction of the CH4 concentration which is associated with the decreases of the tar content in the produced gas. Under these conditions the biomass devolatilization in the pyrolysis zone gives much lighter compounds which are more easily cracked when the gas stream passes through the combustion zone. -- Highlights: → Obtained results an important for a better phenomenological understanding of processes occurring in two stage gasification reactors. → The air flow is the fundamental parameter in the operation of downdraft gasifiers. → CH4 reduction is associated with a decreases in the tar content. → An enhancement in the thermal cracking of tar is carried out in the two-air downdraft gasifier.

  2. PFB air gasification of biomass. Investigation of product formation and problematic issues related to ammonia, tar and alkali

    Energy Technology Data Exchange (ETDEWEB)

    Padban, Nader

    2000-09-01

    Fluidised bed thermal gasification of biomass is an effective route that results in 100 % conversion of the fuel. In contrast to chemical, enzymatic or anaerobic methods of biomass treatment, the thermal conversion leaves no contaminated residue after the process. The product gas evolved within thermal conversion can be used in several applications such as: fuel for gas turbines, combustion engines and fuel cells, and raw material for production of chemicals and synthetic liquid fuels. This thesis treats a part of the experimental data from two different gasifiers: a 90 kW{sub th} pressurised fluidised bubbling bed gasifier at Lund University and a 18 MW{sub th} circulating fluidised bed gasifier integrated with gas turbine (IGCC) in Vaernamo. A series of parallel and consecutive chemical reactions is involved in thermal gasification, giving origin to formation of a variety of products. These products can be classified within three major groups: gases, tars and oils, and char. The proportion of these categories of species in the final product is a matter of the gasifier design and the process parameters. The thesis addresses the technical and theoretical aspects of the biomass thermochemical conversion and presents a new approach in describing the gasification reactions. There is an evidence of fuel effect on the characteristics of the final products: a mixture of plastic waste (polyethylene) and biomass results in higher concentration of linear hydrocarbons in the gas than gasification of pure biomass. Mixing the biomass with textile waste (containing aromatic structure) results in a high degree of formation of aromatic compounds and light tars. Three topic questions within biomass gasification, namely: tar, NO{sub x} and alkali are discussed in the thesis. The experimental results show that gasification at high ER or high temperature decreases the total amount of the tars and simultaneously reduces the contents of the oxygenated and alkyl-substituted poly

  3. Development of Fischer-Tropsch catalysis for gasified biomass

    OpenAIRE

    Lögdberg, Sara

    2007-01-01

    In order to secure the energy supply to an increasing population and at the same time limit the damage to Earth, i.e. avoiding a fatal climate change as a result of anthropogenic emissions of greenhouse gases (primarily CO2), immediate action is necessary. This includes reducing the energy consumption, increasing the energy conversion efficiency, and using renewable energies. The transport sector is the one most dependent on fossil energy and it stands for a significant part of the energy con...

  4. Optimal Operation of Biomass Gasifier Based Hybrid Energy System

    OpenAIRE

    Balamurugan, P.; Kumaravel, S.; Ashok, S.

    2011-01-01

    The focus of the world on renewable energy sources is growing rapidly due to its availability and environment friendliness. However, the renewable energy influenced by natural conditions is being intermittent, it is difficult to accomplish stable energy supply only by one kind of renewable energy source. In order to achieve reliability, it is necessary to integrate two or more energy sources together in an optimal way as hybrid energy system. Optimal allocation of sources, unpredictable load ...

  5. System overview and characterization of a high-temperature, high-pressure, entrained-flow, laboratory-scale gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, Madison A.; Dreyer, Christopher B.; Parker, Terence E.; Porter, Jason M., E-mail: jporter@mines.edu [Department of Mechanical Engineering, Colorado School of Mines, Golden, Colorado 80401 (United States); Jakulewicz, Micah S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2015-05-15

    The high-temperature, high-pressure, entrained-flow, laboratory-scale gasifier at the Colorado School of Mines, including the primary systems and the supporting subsystems, is presented. The gasifier is capable of operating at temperatures and pressures up to 1650 °C and 40 bar. The heated section of the reactor column has an inner diameter of 50 mm and is 1 m long. Solid organic feedstock (e.g., coal, biomass, and solid waste) is ground into batches with particle sizes ranging from 25 to 90 μm and is delivered to the reactor at feed rates of 2–20 g/min. The maximum useful power output of the syngas is 10 kW, with a nominal power output of 1.2 kW. The initial characterization and demonstration results of the gasifier system with a coal feedstock are also reported.

  6. Adaptive monitoring of emissions in energy boilers using self-organizing maps: An application to a biomass-fired CFB (circulating fluidized bed)

    International Nuclear Information System (INIS)

    Improvement of energy efficiency, reduction of operating costs, and reduction of harmful emissions released into the atmosphere are issues of major concern in modern energy plants. While air emissions have to be restricted due to tightening environmental legislation, at the same time it is ever more important to be able to respond quickly to any changes in the load demand or fuel quality. As unpredictability increases with changing fuel quality and more complex operational strategies, undesired phenomena such as increased emission release rates may become more likely. Therefore, it is crucial that emission monitoring systems are able to adapt to varying conditions, and advanced methodologies are needed for monitoring and decision-support. In this paper a novel approach for advanced monitoring of emissions in CFB (circulating fluidized bed) boilers is described. In this approach a model based on SOM (self-organizing maps) is updated regularly to respond to the prevailing condition of the boiler. After creating each model a new set of measurements is input to the system, and the current state of the process is determined using vector distance calculation. Finally, the system evaluates the current condition and may alert if a preset limit defined for each emission component is exceeded. - Highlights: • An adaptive monitoring approach based on self-organizing maps is presented. • The system can monitor the current state of a combustion process and its emissions. • The system is designed to alert when the preset limits defined for emissions are exceeded. • Due to regular updating routine the system is able to adapt to changing conditions. • The application is demonstrated using data from a biomass-fired energy boiler

  7. Fluidized Bed Gasification as a Mature And Reliable Technology for the Production of Bio-Syngas and Applied in the Production of Liquid Transportation Fuels—A Review

    Directory of Open Access Journals (Sweden)

    Adrian H.M. Verkooijen

    2011-03-01

    Full Text Available Biomass is one of the renewable and potentially sustainable energy sources and has many possible applications varying from heat generation to the production of advanced secondary energy carriers. The latter option would allow mobile services like the transportation sector to reduce its dependency on the fossil fuel supply. This article reviews the state-of-the-art of the fluidization technology applied for the gasification of biomass aimed at the production of gas for subsequent synthesis of the liquid energy carriers via, e.g., the Fischer-Tropsch process. It discusses the advantages of the gasification technology over combustion, considers the size of the conversion plant in view of the local biomass availability, assesses the pros and cons of different gasifier types in view of the application of the product gas. Subsequently the article focuses on the fluidized bed technology to discuss the main process parameters and their influence on the product composition and the operability of the gasifier. Finally a synthesis process (FT is introduced shortly to illustrate the necessary gas cleaning steps in view of the purity requirements for the FT feed gas.

  8. 3-D capacitance density imaging of fluidized bed

    Science.gov (United States)

    Fasching, George E.

    1990-01-01

    A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved.

  9. Effect of Gasifying Medium on the Coal Chemical Looping Gasification with CaSO4 as Oxygen Carrier☆

    Institute of Scientific and Technical Information of China (English)

    Yongzhuo Liu; Weihua Jia; Qingjie Guo; Hojung Ryu

    2014-01-01

    The chemical looping gasification uses an oxygen carrier for solid fuel gasification by supplying insufficient lattice oxygen. The effect of gasifying medium on the coal chemical looping gasification with CaSO4 as oxygen carrier is investigated in this paper. The thermodynamical analysis indicates that the addition of steam and CO2 into the system can reduce the reaction temperature, at which the concentration of syngas reaches its maximum value. Experimental result in thermogravimetric analyzer and a fixed-bed reactor shows that the mixture sample goes through three stages, drying stage, pyrolysis stage and chemical looping gasification stage, with the temper-ature for three different gaseous media. The peak fitting and isoconversional methods are used to determine the reaction mechanism of the complex reactions in the chemical looping gasification process. It demonstrates that the gasifying medium (steam or CO2) boosts the chemical looping process by reducing the activation energy in the overall reaction and gasification reactions of coal char. However, the mechanism using steam as the gasifying medium differs from that using CO2. With steam as the gasifying medium, parallel reactions occur in the begin-ning stage, followed by a limiting stage shifting from a kinetic to a diffusion regime. It is opposite to the reaction mechanism with CO2 as the gasifying medium.

  10. Biomass waste gasification - can be the two stage process suitable for tar reduction and power generation?

    Science.gov (United States)

    Sulc, Jindřich; Stojdl, Jiří; Richter, Miroslav; Popelka, Jan; Svoboda, Karel; Smetana, Jiří; Vacek, Jiří; Skoblja, Siarhei; Buryan, Petr

    2012-04-01

    A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stage gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100-350 kW(th). The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950°C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar compound contents confirmed superiority of the two stage gasification system, drastic decrease of aromatic compounds with two and higher number of benzene rings by 1-2 orders. On the other hand the two stage gasification (with overall ER=0.71) led to substantial reduction of gas heating value (LHV=3.15 MJ/Nm(3)), elevation of gas volume and increase of nitrogen content in fuel gas. The increased temperature (>950°C) at the entrance to the char bed caused also substantial decrease of ammonia content in fuel gas. The char with higher content of ash leaving the

  11. Commissioning an Engineering Scale Coal Gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Reid, Douglas J.; Bearden, Mark D.; Cabe, James E.

    2010-07-01

    This report explains the development, commissioning, and testing of an engineering scale slagging coal gasifier at PNNL. The initial objective of this project was to commission the gasifier with zero safety incidents. The commissioning work was primarily an empirical study that required an engineering design approach. After bringing the gasifier on-line, tests were conducted to assess the impact of various operating parameters on the synthesis gas (syngas) product composition. The long-term intent of this project is to produce syngas product for use by internal Pacific Northwest National Laboratory (PNNL) researchers in catalyst, materials, and instrumentation development. Future work on the project will focus on improving the reliability and performance of the gasifier, with a goal of continuous operation for greater than 4 hours using coal feedstock. In addition, alternate designs that allow for increased flexibility regarding the fuel sources that can be used for syngas production is desired. Continued modifications to the fuel feed system will be pursued to address these goals. Alternative feed mechanisms such as a coal/methanol slurry are being considered.

  12. Biomass IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Salo, K.; Keraenen, H. [Enviropower Inc., Espoo (Finland)

    1996-12-31

    Enviropower Inc. is developing a modern power plant concept based on pressurised fluidized-bed gasification and gas turbine combined cycle (IGCC). The process is capable of maximising the electricity production with a variety of solid fuels - different biomass and coal types - mixed or separately. The development work is conducted on many levels. These and demonstration efforts are highlighted in this article. The feasibility of a pressurised gasification based processes compared to competing technologies in different applications is discussed. The potential of power production from biomass is also reviewed. (orig.) 4 refs.

  13. Results from tests of a Stirling engine and wood chips gasifier plant

    DEFF Research Database (Denmark)

    Carlsen, Henrik; Bovin, Jonas Kabell; Werling, J.;

    2002-01-01

    The combination of thermal gasification and a Stirling engine is an interesting concept for use in small Combined Heat and Power (CHP) plants based on biomass, because the need for gas cleaning is eliminated and problems with fouling of the Stirling engine heater are considerably reduced....... Furthermore, the overall electric efficiency of the system can be improved. At the Technical University of Denmark a small CHP plant based on a Stirling engine and an updraft gasifier has been developed and tested successfully. The advantages of updraft gasifiers are the simplicity and that the amount...... of the Stirling engine reduces the problems with tar to a minor problem in the design of the burner. The Stirling engine, which has an electric power output of 35 kW, is specifically designed for utilisation of fuels with a content of particles. The gas burner for the engine is designed for low specific energy...

  14. System studies on biofuel production via integrated biomass gasification

    OpenAIRE

    Andersson, Jim; Lundgren, Joakim; Malek, Laura; Hultegren, Christian; Pettersson, Karin; Wetterlund, Elisabeth

    2013-01-01

    A large number of national and international techno-economic studies on industrially integrated gasifiers for production of biofuels have been published during the recent years. These studies comprise different types of gasifiers (fluidized bed, indirect and entrained flow) integrated in different industries for the production of various types of chemicals and transportation fuels (SNG, FT-products, methanol, DME etc.) The results are often used for techno-economic comparisons between differe...

  15. The Low Temperature CFB Gasifier

    DEFF Research Database (Denmark)

    Stoholm, P.; Nielsen, Rasmus Glar; Richardt, K.;

    2004-01-01

    straw, animal manure and waste and for co-firing the product gas in existing, e.g. coal fired power plant boilers. The aim is to prevent fouling, agglomeration and high temperature corrosion caused by potassium and chlorine and other fuel components when producing electricity. So far 92 hours......The Low Temperature Circulating Fluidised Bed (LT-CFB) gasification process is described together with the 50 kW and the 500 kW test plants and latest test results. The LT-CFB process is especially developed for medium and large scale (few to >100 MW) gasification of problematic bio-fuels like...... of experiments with the 50 kW test plant with two extremely difficult types of straw has shown low char losses and high retentions of ash including e.g. potassium. Latest 27 hours of experiments with dried, high ash pig- and hen manure has further indicated the concepts high fuel flexibility. The new 500 kW test...

  16. Fluidised-bed combustion of gasification residue

    Energy Technology Data Exchange (ETDEWEB)

    Korpela, T.; Kudjoi, A.; Hippinen, I.; Heinolainen, A.; Suominen, M.; Lu Yong [Helsinki Univ. of Technology (Finland). Lab of Energy Economics and Power Plant Engineering

    1996-12-01

    Partial gasification processes have been presented as possibilities for future power production. In the processes, the solid materials removed from a gasifier (i.e. fly ash and bed material) contain unburnt fuel and the fuel conversion is increased by burning this gasification residue either in an atmospheric or a pressurised fluidised-bed. In this project, which is a part of European JOULE 2 EXTENSION research programme, the main research objectives are the behaviour of calcium and sulphur compounds in solids and the emissions of sulphur dioxide and nitrogen oxides (NO{sub x} and N{sub 2}O) in pressurised fluidised-bed combustion of gasification residues. (author)

  17. Issues Impacting Refractory Service Life in Biomass/Waste Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, J.P.; Kwong, K.-S.; Powell, C.A.

    2007-03-01

    Different carbon sources are used, or are being considered, as feedstock for gasifiers; including natural gas, coal, petroleum coke, and biomass. Biomass has been used with limited success because of issues such as ash impurity interactions with the refractory liner, which will be discussed in this paper.

  18. EVALUATION OF A PROCESS TO CONVERT BIOMASS TO METHANOL FUEL

    Science.gov (United States)

    The report gives results of a review of the design of a reactor capable of gasifying approximately 50 lb/hr of biomass for a pilot-scale facility to develop, demonstrate, and evaluate the Hynol Process, a high-temperature, high-pressure method for converting biomass into methanol...

  19. Survey of biomass gasification. Volume III. Current technology and research

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-04-01

    This survey of biomass gasification was written to aid the Department of Energy and the Solar Energy Research Institute Biological and Chemical Conversion Branch in determining the areas of gasification that are ready for commercialization now and those areas in which further research and development will be most productive. Chapter 8 is a survey of gasifier types. Chapter 9 consists of a directory of current manufacturers of gasifiers and gasifier development programs. Chapter 10 is a sampling of current gasification R and D programs and their unique features. Chapter 11 compares air gasification for the conversion of existing gas/oil boiler systems to biomass feedstocks with the price of installing new biomass combustion equipment. Chapter 12 treats gas conditioning as a necessary adjunct to all but close-coupled gasifiers, in which the product is promptly burned. Chapter 13 evaluates, technically and economically, synthesis-gas processes for conversion to methanol, ammonia, gasoline, or methane. Chapter 14 compiles a number of comments that have been assembled from various members of the gasifier community as to possible roles of the government in accelerating the development of gasifier technology and commercialization. Chapter 15 includes recommendations for future gasification research and development.

  20. High Temperature Air/Steam Gasification of Biomass Wastes - Stage 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Blasiak, Wlodzimierz; Szewczyk, Dariusz; Lucas, Carlos; Rafidi, Nabil; Abeyweera Ruchira; Jansson, Anna; Bjoerkman, Eva [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Materials Science and Engineering

    2003-05-01

    In Jan 2002 the Division of Energy and Furnace Technology started the project High Temperature Air an Steam Gasification (HTAG) of biomass wastes, following the approval made by Swedish Energy Agency. The research proved successful; with the fixed bed updraft gasifier coupled to the highly regenerative preheater equipment able to produce a fuel gas not only from wood pellets but also from wood chips, bark and charcoal with considerably reduced amount of tar. This report provides information on solid biomass conversion into fuel gas as a result of air and steam gasification process performed in a fixed bed updraft gasifier. The first chapter of the report presents the overall objectives and the specific objectives of the work. Chapter 2 summarizes state-of-the-art on the gasification field stating some technical differences between low and high temperature gasification processes. Description and schemes of the experimental test rig are provided in Chapter 3. The equipment used to perform measurements of different sort and that installed in the course of the work is described in Chapter 4. Chapter 5 describes the methodology of experiments conducted whose results were processed and evaluated with help of the scheme of equations presented in Chapter 6, called raw data evaluation. Results of relevant experiments are presented and discussed in Chapter 7. A summary discussion of the tar analysis is presented in Chapter 8. Chapter 9 summarizes the findings of the research work conducted and identifies future efforts to ensure the development of next stage. Final chapter provides a summary of conclusions and recommendations of the work. References are provided at the end of the report. Aimed to assist the understanding of the work done, tables and graphs of experiments conducted, irrespective to their quality, are presented in appendices.

  1. Effectiveness of briquetting bio mass materials with different ratios in 10 kW down draft gasifier

    OpenAIRE

    K.sivakumar; B. Sivaraman; N.Krishna Mohan

    2011-01-01

    This paper discuss about the effectiveness of using Briquetting of rural bio mass material in Down draft gasifier for easy operation and power generation, during winter and rainy season. Sawdust a milling residue is available in huge quantity. Apart from the problems of transportation, storage, and handling, the direct burning of loosesaw dust biomass in conventional grates is associated with very low thermal efficiency and widespread air pollution. The conversion efficiency is as low as 40% ...

  2. 内加热移动床生物质炭化中试设备监控系统开发%Monitoring and control system development for pilot-scale moving bed biomass carbonization equipment with internal heating

    Institute of Scientific and Technical Information of China (English)

    丛宏斌; 赵立欣; 孟海波; 姚宗路

    2015-01-01

    Biochar is a pyrolysis solid product of biological organic material (biomass) in anoxic and anaerobic conditions, It can be widely used in carbon emission reduction, water purification, adsorption of heavy metals and soil improvement, etc., so it can partly provide solutions for the focus issues of global concern, such as climate warming, environmental pollution and soil degradation. The production and application of biochar have aroused wide attention of researchers both at home and abroad. According to the continuity of production process, two types of biomass carbonization techniques have been developed in China, which are respectively fixed bed carbonization technique and moving bed carbonization technique. The fixed bed carbonization techniques can be divided into kiln carbonization technique and retort carbonization. Accordingly, the kiln carbonization technique commonly adopts spontaneous combustion heating method, its corresponding equipments have the features of simple structure and low-cost, so this technique has been used widely in China. The retort carbonization technique adopts external heating method, so its corresponding device has more complicated structure than the kiln carbonization technique, this technique can commonly realize the poly-generation of biochar and other byproducts. The moving bed carbonization technique is upgraded from the fixed bed carbonization technique, and according to flowing the direction of material, this technique can be divided into transverse flow moving bed carbonization technique and vertical flow moving bed carbonization technique. Continuous producing is the remarkable feature of the moving bed biomass carbonization technique, and it has higher automation level and lower labor intensity, compared with the fixed bed carbonization technique. The moving bed carbonization technique represents developing direction of China’s biomass carbonization technique. Aimed at the problems of low productivity, high energy

  3. Tunable Diode Laser Sensors to Monitor Temperature and Gas Composition in High-Temperature Coal Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Ronald [Stanford Univ., CA (United States); Whitty, Kevin [Univ. of Utah, Salt Lake City, UT (United States)

    2014-12-01

    The integrated gasification combined cycle (IGCC) when combined with carbon capture and storage can be one of the cleanest methods of extracting energy from coal. Control of coal and biomass gasification processes to accommodate the changing character of input-fuel streams is required for practical implementation of integrated gasification combined-cycle (IGCC) technologies. Therefore a fast time-response sensor is needed for real-time monitoring of the composition and ideally the heating value of the synthesis gas (here called syngas) as it exits the gasifier. The goal of this project was the design, construction, and demonstration an in situ laserabsorption sensor to monitor multiple species in the syngas output from practical-scale coal gasifiers. This project investigated the hypothesis of using laser absorption sensing in particulateladen syngas. Absorption transitions were selected with design rules to optimize signal strength while minimizing interference from other species. Successful in situ measurements in the dusty, high-pressure syngas flow were enabled by Stanford’s normalized and scanned wavelength modulation strategy. A prototype sensor for CO, CH4, CO2, and H2O was refined with experiments conducted in the laboratory at Stanford University, a pilot-scale at the University of Utah, and an engineering-scale gasifier at DoE’s National Center for Carbon Capture with the demonstration of a prototype sensor with technical readiness level 6 in the 2014 measurement campaign.

  4. Performance of Open Core Gasifier with Briquette of different Crop Residues

    Directory of Open Access Journals (Sweden)

    M.S. Khardiwar*1 ,

    2014-05-01

    Full Text Available The open core gasifier was designed for loose agricultural residues like soybean briquette, pigeon pea briquette and mix briquette of (soybean + pigeon pea. In this experiment using air in gasification as supplementation mode there result found better as air suction mode there was less tar and gas quality. The gasifier performance was evaluated in terms of fuel consumption rate, calorific value of producer gas and gasification efficiency. Optimum value of specific gasification rate for gasification of briquette of mix biomass in open core gasifier reactor is 252 kg/h- m2 . The lower heating value of producer gas under the optimum operating conditions is about 4.10 - 4.57 (MJ/m3 .The pigeon pea briquette has show the maximum temperature in oxidation zone was 1397 ˚C.which as higher the ash fusion temperature increase. The flame Temperature of soybean briquette, pigeon pea briquette, and mix briquette is 624, 634, and 619 ˚C respectively is attained at the burner. Gasification efficiency of soybean briquette, pigeon pea briquette and mix briquette of (soybean + pigeon pea. 56%, 51%, 53%, respectively. The gas produced from the briquette could used to replace the coal and wood.

  5. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    International Nuclear Information System (INIS)

    The following are proposed activities for quarter 3 (12/15/00-3/14/01): (1) Conduct TGA and fuel characterization studies - Task 1; (2) Continue to perform re-burn experiments. - Task 2; (3) Design fixed bed combustor. - Task 3; and (4) Modify the PCGC2 code to include moisture evaporation model - Task 4. The following were achieved During Quarter 3 (12/15/0-3/14/01): (1) Conducted TGA and Fuel Characterization studies (Appendix I). A comparison of -fuel properties, TGA traces etc is given in Appendix I. Litter has 3 and 6 times more N compared to coal on mass and heat basis. The P of litter is almost 2% (Task 1). Both litter biomass (LB) and feedlot biomass (FB) have been pulverized. The size distributions are similar for both litter and FB in that 75% pass through 150(micro)m sieve while for coal 75% pass through 60(micro)m sieve. Rosin Rammler curve parameters are given. The TGA characteristics of FB and LB are similar and pyrolysis starts at 100 C below that of coal; (2) Reburn experiments with litter and with FB have been performed (Appendix II) -Task 2. Litter is almost twice effective (almost 70-90% reduction) compared to coal in reducing the NOx possibly due to presence of N in the form of NH(sub 3); (3) Designed fixed bed gasifier/combustor (Appendix III) - Task 3; and (4) Modified PCGC2 to include moisture evaporation model in coal and biomass particles. (Appendix IV) - Task 4

  6. Pyrolysis gasification of dried sewage sludge in a combined screw and rotary kiln gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Young Nam; Kim, Seong Cheon [BK21 Team for Hydrogen Production, Department of Environmental Engineering, Chosun University, 375 Seosuk-dong, Dong-gu, Gwangju 501-759 (Korea, Republic of); Yoshikawa, Kunio [Frontier Research Center, Tokyo Institute of Technology, G5-8, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan)

    2011-04-15

    A pyrolysis gasifier, with carbonization and activation steps, was developed to convert dried sludge into activated char and gas fuel energy. To determine the optimal driving conditions, parametric investigations were conducted on the amount of steam input, pyrolysis gasifier temperature and moisture content in the dried sludge. The optimal conditions for the dried sludge were found to be a steam input of 10 mL/min, gasifier temperature of 820 C and moisture content of 11% with a holding time in the pyrolysis gasifier of 1 h. The specific area of the activated char was 40.1 m{sup 2}/g, with an average pore diameter and volume of 63.49 Aa and 0.2354 cm{sup 3}/g, respectively. The pyrolysis gases were H{sub 2} (34.1%), CO (18.6%), CH{sub 4} (8.5%) and CO{sub 2} (8%). The higher heating value for the pyrolysis gas was 10,107 kJ/N m{sup 3}. To determine the tar adsorption characteristics, a benzene adsorption test was conducted using a fixed bed adsorption tower (H/D = 2, GHSV = 1175/h). The saturation point of the activated char was found after 45 min, and the amount of adsorption was 140 mg/g. Therefore, the pyrolysis gasification of sewage sludge can produce activated char which can be used to reduce tar, and gasification gas which can be utilized as a high enthalpy gas fuel. (author)

  7. Investigations in gasification of biomass mixtures using thermodynamic equilibrium and semi-equilibrium models

    Energy Technology Data Exchange (ETDEWEB)

    Buragohain, Buljit; Mahanta, Pinakeswar; Moholkar, Vijayanand S. [Center for Energy, Indian Institute of Technology Guwahati, Guwahati - 781 039, Assam (India)

    2011-07-01

    Biomass gasifiers with power generation capacities exceeding 1 MW have large biomass consumption. Availability of a single biomass in such large quantities is rather difficult, and hence, mixtures of biomasses need to be used as feed-stock for these gasifiers. This study has assessed feasibility of biomass mixtures as fuel in biomass gasifiers for decentralized power generation using thermodynamic equilibrium and semi-equilibrium (with limited carbon conversion) model employing Gibbs energy minimization. Binary mixtures of common biomasses found in northeastern states of India such as rice husk, bamboo dust and saw dust have been taken for analysis. The potential for power generation from gasifier has been evaluated on the basis of net yield (in Nm3) and LHV (in MJ/Nm3) of the producer gas obtained from gasification of 100 g of biomass mixture. The results of simulations have revealed interesting trends in performance of gasifiers with operating parameters such as air ratio, temperature of gasification and composition of the biomass mixture. For all biomass mixtures, the optimum air ratio is {approx} 0.3 with gasification temperature of 800oC. Under total equilibrium conditions, and for engine-generator efficiency of 30%, the least possible fuel consumption is found to be 0.8 kg/kW-h. As revealed in the simulations with semi-equilibrium model, this parameter shows an inverse variation with the extent of carbon conversion. For low carbon conversions ({approx} 60% or so), the specific fuel consumption could be as high as 1.5 kg/kW-h. The results of this study have also been compared with previous literature (theoretical as well as experimental) and good agreement has been found. This study, thus, has demonstrated potential of replacement of a single biomass fuel in the gasifier with mixtures of different biomasses.

  8. Tar Management and Recycling in Biomass Gasification and Syngas Purification

    Science.gov (United States)

    McCaffrey, Zach

    Removal of tars is critical to the design and operation of biomass gasification systems as most syngas utilization processing equipment (e.g. internal combustion engines, gas turbines, fuel cells, and liquid fuel synthesis reactors) have a low tolerance for tar. Capturing and disposal of tar is expensive due to equipment costs, high hazardous waste disposal costs where direct uses cannot be found, and system energy losses incurred. Water scrubbing is an existing technique commonly used in gasification plants to remove contaminants and tar; however using water as the absorbent is non-ideal as tar compounds have low or no water solubility. Hydrophobic solvents can improve scrubber performance and this study evaluated tar solubility in selected solvents using slip-streams of untreated syngas from a laboratory fluidized bed reactor operated on almond composite feedstock using both air and steam gasification. Tar solubility was compared with Hansen's solubility theory to examine the extent to which the tar removal can be predicted. As collection of tar without utilization leads to a hazardous waste problem, the study investigated the effects of recycling tars back into the gasifier for destruction. Prior to experiments conducted on tar capture and recycle, characterizations of the air and steam gasification of the almond composite mix were made. This work aims to provide a better understanding of tar collection and solvent selection for wet scrubbers, and to provide information for designing improved tar management systems for biomass gasification.

  9. CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

    International Nuclear Information System (INIS)

    The following are proposed activities for quarter 2 (9/15/00-12/14/00): (1) Conduct TGA and fuel characterization studies-Task 1; (2) Perform re-burn experiments-Task 2; (3) Fabricate fixed bed gasifier/combustor-Task 3; and (4) Modify the 3D combustion modeling code for feedlot and litter fuels-Task 4. The following were achieved During Quarter 2 (9/15/00-12/14/00): (1) The chicken litter has been obtained from Sanderson farms in Denton, after being treated with a cyclonic dryer. The litter was then placed into steel barrels and shipped to California to be pulverized in preparation for firing. Litter samples have also been sent for ultimate/proximate laboratory analyses.-Task 1; (2) Reburn-experiments have been conducted on coal, as a base case for comparison to litter biomass. Results will be reported along with litter biomass as reburn fuel in the next report-Task 2; (3) Student has not yet been hired to perform task 3. Plans are ahead to hire him or her during quarter No. 3; and (4) Conducted a general mixture fraction model for possible incorporation in the code

  10. Thermodynamics analysis of refinery sludge gasification in adiabatic updraft gasifier.

    Science.gov (United States)

    Ahmed, Reem; Sinnathambi, Chandra M; Eldmerdash, Usama; Subbarao, Duvvuri

    2014-01-01

    Limited information is available about the thermodynamic evaluation for biomass gasification process using updraft gasifier. Therefore, to minimize errors, the gasification of dry refinery sludge (DRS) is carried out in adiabatic system at atmospheric pressure under ambient air conditions. The objectives of this paper are to investigate the physical and chemical energy and exergy of product gas at different equivalent ratios (ER). It will also be used to determine whether the cold gas, exergy, and energy efficiencies of gases may be maximized by using secondary air injected to gasification zone under various ratios (0, 0.5, 1, and 1.5) at optimum ER of 0.195. From the results obtained, it is indicated that the chemical energy and exergy of producer gas are magnified by 5 and 10 times higher than their corresponding physical values, respectively. The cold gas, energy, and exergy efficiencies of DRS gasification are in the ranges of 22.9-55.5%, 43.7-72.4%, and 42.5-50.4%, respectively. Initially, all 3 efficiencies increase until they reach a maximum at the optimum ER of 0.195; thereafter, they decline with further increase in ER values. The injection of secondary air to gasification zone is also found to increase the cold gas, energy, and exergy efficiencies. A ratio of secondary air to primary air of 0.5 is found to be the optimum ratio for all 3 efficiencies to reach the maximum values. PMID:24672368

  11. Experimental investigations on a 20 kWe, solid biomass gasification system

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Avdhesh Kr. [Mechanical Engg. Department, D.C.R. University of Science and Technology, Murthal (Sonepat)-131039 (India)

    2011-01-15

    When the objective is to generate motive or electric power via I.C. engine, the overall pressure drop through the suction gasification system in addition to gas quality has become a sensitive issue. This work, therefore, presents an experimental study on a suction gasifier (downdraft) arrangement operating on kiker wood or Acacia nilotica (L). Studies were conducted to investigate the influence of fluid flow rate on pressure drop through the gasifier system for ambient isothermal airflow and ignited mode, pumping power, and air-fuel ratio, gas composition and gasification efficiency. Results of pressure drop, temperature profile, gas composition or calorific value are found to be sensitive with fluid flow rate. Ignited gasifier gives much higher pressure drop when compared against newly charged gasifier bed with isothermal ambient airflow. Higher reaction temperatures in gasifier tends to enhance gasifier performance, while, overall pressure drop and thus pumping power through the system increases. Both ash accumulated gasifier bed and sand bed filters with tar laden quartz particles also show much higher pressure drops. (author)

  12. Process for electrochemically gasifying coal using electromagnetism

    Science.gov (United States)

    Botts, Thomas E.; Powell, James R.

    1987-01-01

    A process for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution.

  13. Coating for gasifiable carbon-graphite fibers

    Science.gov (United States)

    Harper-Tervet, Jan (Inventor); Dowler, Warren L. (Inventor); Yen, Shiao-Ping S. (Inventor); Mueller, William A. (Inventor)

    1982-01-01

    A thin, uniform, firmly adherent coating of metal gasification catalyst is applied to a carbon-graphite fiber by first coating the fiber with a film-forming polymer containing functional moieties capable of reaction with the catalytic metal ions. Multivalent metal cations such as calcium cross-link the polymer such as a polyacrylic acid to insolubilize the film by forming catalytic metal macro-salt links between adjacent polymer chains. The coated fibers are used as reinforcement for resin composites and will gasify upon combustion without evolving conductive airborne fragments.

  14. Bed Agglomeration During the Steam Gasification of a High Lignin Corn Stover Simultaneous Saccharification and Fermentation (SSF) Digester Residue

    Energy Technology Data Exchange (ETDEWEB)

    Howe, Daniel T.; Taasevigen, Danny J.; Gerber, Mark A.; Gray, Michel J.; Fernandez, Carlos A.; Saraf, Laxmikant; Garcia-Perez, Manuel; Wolcott, Michael P.

    2015-11-13

    This research investigates the bed agglomeration phenomena during the steam gasification of a high lignin residue produced from the simultaneous saccharification and fermentation (SSF) of corn stover in a bubbling fluidized bed. The studies were conducted at 895°C using alumina as bed material. Biomass was fed at 1.5 kg/hr, while steam was fed to give a velocity equal to 2.5 times the minimum fluidization velocity, with a steam/carbon ratio of 0.9. The pelletized feedstock was co-fed with a cooling nitrogen stream to mitigate feed line plugging issues. Tar production was high at 50.3 g/Nm3, and the fraction of C10+ compounds was greater than that seen in the gasification of traditional lignocellulosic feedstocks. Carbon closures over 94 % were achieved for all experiments. Bed agglomeration was found to be problematic, indicated by pressure drop increases observed below the bed and upstream of the feed line. Two size categories of solids were recovered from the reactor, +60 mesh and -60 mesh. After a 2.75-hour experiment, 61.7 wt % was recovered as -60 mesh particles and 38.2 wt% of the recovered reactor solids were +60 mesh. A sizeable percentage, 31.8 wt%, was +20 mesh. The -60 mesh particles were mainly formed by the initial bed material (Al2O3). Almost 50 wt. % of the + 20 mesh particles was found to be formed by organics. The unreacted carbon remaining in the reactor resulted in a low conversion rate to product gas. ICP-AES, SEM, SEM-EDS, and XRD confirmed that the large agglomerates (+ 20 mesh) were not encapsulated bed material but rather un-gasified feedstock pellets with sand particles attached to it.

  15. Behaviour of selected major elements during fixed-bed gasification of South African bituminous coal

    OpenAIRE

    Bunt, J.R.; F.B. Waanders; Schobert, H.

    2012-01-01

    The Sasol-Lurgi Fixed Bed Dry Bottom gasifier (S-L FBDB) treats a feed coal containing c.a. 30% ash forming minerals, which means that there are complex mineralogical processes occurring simultaneously with each other, and in the gasification reactions, within the reactor. To obtain an understanding of the mineral transformational behaviour, a quenched commercial-scale S-L FBDB gasifier was sampled and characterized mineralogically. Crystalline phases measured by XRD analyses show the ash exi...

  16. A dual fired downdraft gasifier system to produce cleaner gas for power generation: Design, development and performance analysis

    International Nuclear Information System (INIS)

    The existing biomass gasifier systems have several technical challenges, which need to be addressed. They are reduction of impurities in the gas, increasing the reliability of the system, easy in operation and maintenance. It is also essential to have a simple design of gasifier system for power generation, which can work even in remote locations. A dual fired downdraft gasifier system was designed to produce clean gas from biomass fuel, used for electricity generation. This system is proposed to overcome a number of technical challenges. The system is equipped with dry gas cleaning and indirect gas cooling equipment. The dry gas cleaning system completely eliminates wet scrubbers that require large quantities of water. It also helps to do away with the disposal issues with the polluted water. With the improved gasifier system, the tar level in the raw gas is less than 100 mg Nm−3.Cold gas efficiency has improved to 89% by complete gasification of biomass and recycling of waste heat into the reactor. Several parameters, which are considered in the design and development of the reactors, are presented in detail with their performance indicators. - Highlights: • Hot air injection in dual fired reactor reduces the tar content to less than 100 mg Nm−3. • In clean gas the tar content is 35 mg Nm−3 and the dust content is nil. • The specific gasification rate is 2.8 Nm3 kg−1 of fuel wood and cold gas efficiency is 89.7%. • CV of the gas: 5.3 MJ Nm−3, SFC: 1.1 kg kWh−1 and wood to power efficiency: 21%. • Cold gas efficiency is improved by optimizing the reactor's design and recycling the waste heat from hot gas

  17. Thermodynamics second law efficiency analysis for high temperature biomass gasification

    International Nuclear Information System (INIS)

    The key challenge for biomass-based system is to develop efficient conversion technologies to reduce impact of ecological drawbacks. The development of efficient technologies for biomass gasification requires correct use of thermodynamics. This paper addresses gasifier performance analysis based on the second law of thermodynamics to quantify irreversibilities in biomass gasification process at high temperatures in the range 800K-1400K. The analysis is based on exegetic model that account for the quality of energy by means of irreversibilities. (author)

  18. Exergy analysis of biomass-to-synthetic natural gas (SNG) process via indirect gasification of various biomass feedstock

    International Nuclear Information System (INIS)

    This paper presents an exergy analysis of SNG production via indirect gasification of various biomass feedstock, including virgin (woody) biomass as well as waste biomass (municipal solid waste and sludge). In indirect gasification heat needed for endothermic gasification reactions is produced by burning char in a separate combustion section of the gasifier and subsequently the heat is transferred to the gasification section. The advantages of indirect gasification are no syngas dilution with nitrogen and no external heat source required. The production process involves several process units, including biomass gasification, syngas cooler, cleaning and compression, methanation reactors and SNG conditioning. The process is simulated with a computer model using the flow-sheeting program Aspen Plus. The exergy analysis is performed for various operating conditions such as gasifier pressure, methanation pressure and temperature. The largest internal exergy losses occur in the gasifier followed by methanation and SNG conditioning. It is shown that exergetic efficiency of biomass-to-SNG process for woody biomass is higher than that for waste biomass. The exergetic efficiency for all biomass feedstock increases with gasification pressure, whereas the effects of methanation pressure and temperature are opposite for treated wood and waste biomass.

  19. Use of fuzzy logic to control a gasifier biomass ventilation system and maintenance of the temperature in the oxidation zone; Uso da logica fuzzy para controle do sistema de ventilacao de um gaseificador de biomassa e manutencao da temperatura da zona de oxidacao

    Energy Technology Data Exchange (ETDEWEB)

    Rezende, Oscar L.T.; Kulitz, Hans H. [Instituto Federal de Educacao, Ciencia e Tecnologia do Espirito Santo (IFES), Vitoria, ES (Brazil); Silva, Jadir N.; Galvarro, Svetlana F.S.; Machado, Cassio [Universidade Federal de Vicosa (UFV), MG (Brazil)], E-mail: oscar@ifes.edu.br

    2012-11-01

    This study aims at developing a fuzzy-based algorithm to control the frequency applied to the motor of a gasifier ventilation system in order to ensure adequate temperature in the oxidation zone and produce good quality gas. The input variables of the fuzzy controller were: error, which determines the difference between the desired temperature and the temperature at a given instant; and temperature variation, which will inform if it is increasing or decreasing at a given instant. The response variable was the operation frequency of the ventilation system motor. The rule base was built based on experimental data. The tests with the control algorithm allowed us to see that it is possible to control the oxidation zone temperature - producing gas in a stable way, which does not occur in gasification processes without ventilation system control. (author)

  20. Biomass thermochemical conversion - overview of results; Biomassan jalostus - tutkimusalueen katsaus

    Energy Technology Data Exchange (ETDEWEB)

    Sipilae, K. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1995-12-31

    In this Bioenergy research program the thermochemical conversion activities are mainly concentrated in three fields (1) flash pyrolysis and the use of wood oil in boilers and engines (2) biomass gasification for gas engine power plants and finally (3) conversion of black liquor and extractives in a pulp mill to various liquid fuels. Parallel to activities in Finland also significant work has been done in EU-Joule and Apas projects and in the IEA Bioenergy Agreement. In the area of flash pyrolysis technology, three new laboratory and PDU-units have been installed to VTT in order to produce various qualities of bio oils from wood and straw. The quality of pyrolysis oils have been characterized by physical and chemical methods supported by EU and IEA networks. Several companies are carrying out pyrolysis activities as well: Neste Oy is testing the wood oil in a 200 kW boiler, Waertsilae Diesel Oy is testing Canadian wood oil in a 1.5 MWe diesel power plant engine and Vapo Oy is carrying out investigations to produce pyrolysis oils in Finland. The biomass gasification coupled to a gas engine is an interesting alternative for small scale power production parallel to existing fluid bed boiler technology. VTT has installed a circulating fluid bed gasifier with advanced gas cleaning system to test various technologies in order to feed the gas to an engine. In order to produce liquid fuels at a pulp mill, the laboratory work has continued using crude soap as a raw material for high pressure liquid phase treatment and atmospheric pyrolysis process. The quality of the oil is like light fuel oil or diesel fuel, possibilities to use it as a lubricant will be investigated

  1. Hydrogen production from high-moisture content biomass in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Antal, M.J. Jr.; Matsumura, Y.; Onuma, M.T. [Univ. of Hawaii, Honolulu, HI (United States)] [and others

    1995-09-01

    Wet biomass (water hyacinth, banana trees, cattails, green algae, kelp, etc.) grows rapidly and abundantly around the world. However, wet biomass is not regarded as a promising feedstock for conventional thermochemical conversion processes because the cost of drying the material is too high. Prior work has shown that low concentrations of glucose (a model compound for whole biomass) and various wet biomass species (water hyacinth, algae) can be completely gasified in supercritical water at 600{degrees}C and 34.5 MPa after a 30 s residence time. But higher concentrations of glucose evidenced incomplete conversion. For this reason, flow reactors were fabricated which could accommodate packed beds of catalyst, and studies were initiated of the steam reforming (gasification) reactions in the presence of various candidate heterogeneous catalysts. The goal is to identify active catalysts for steam reforming biomass slurries in supercritical water. Soon after tests began, a suitable class of carbon-based catalysts was discovered. These catalysts effect complete (>99%) conversion of high-concentration glucose (up to 22% by weight) to a hydrogen-rich synthesis gas. High space velocities are realized [>20 (g/hr)/g], and the catalyst is stable over a period of several hours. The carbon catalyst is not expensive, and exists in a wide variety of forms and compositions. After this discovery, work has focused on four interrelated tasks: (1) tests to identify the most active form and composition of the catalyst; (2) tests employing the preferred catalyst to study the effect of feedstock composition on carbon conversion and gas composition; (3) studies of catalyst deactivation and subsequent reactivation, including the in-house synthesis of bifunctional catalysts which incorporate promoters and stabilizers; and (4) the design and fabrication of a larger, new reactor with a slurry feeder intended to handle high-concentration, wet biomass feeds.

  2. The use of woody biomass for large-scale generation of power

    International Nuclear Information System (INIS)

    Growth of wood as an agricultural crop, for use in the large-scale production of electricity, provides a biomass fuel using intensive, but sustainable, agricultural practices. Short-rotation cropping (SRC) schemes, in which trees are grown in large plantations, could be used to produce electricity on a scale sufficient to form a significant part of a national energy supply system. The net CO2 emissions from biomass-based electricity are substantially less than from conventional fossil-fuel fired generation. The objective of the study reported in this paper is to assess the extent to which this approach to power generation could be adopted if climate change considerations lead to the implementation of measures to reduce emissions of CO2 to atmosphere. In the study reported here, 1GWe of electricity is produced from a number of SRC-based power stations, selected so as to minimize cost. The study is based in Spain a country believed to be reasonably well suited to SRC and representative of countries with a temperate climate. The best site produces electricity at 9.2 c/kWh. The other sites are more expensive, the average over 22 sites being 10.1 cents/kWh. These costs are for fluidized-bed combustion with a cumulative installed capacity approaching 1GWe; additional capacity will be more expensive. It is likely that the cost of biomass based SRC would be reduced as new technology, such as biomass gasifiers working in combined cycles, is introduced and the number of installations is increased. SRC biomass could supply about 5% (2.3GWe) of the present Spanish electrical capacity. Conceivably, this could be raised to about 10% if less suitable land is also used and SCR biomass is able to compete with some agricultural crops

  3. Contributions at the DGMK conference ''conversion of biomass''. Conference report; Beitraege zur DGMK-Fachbereichstagung ''Konversion von Biomassen''. Tagungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Within the DGMK conference from 19th to 21st March 2012 in Rotenburg a.d. Fulda (Federal Republic of Germany), the following lectures were held: (1) Biorefineries in the context of the considerations on a future bio economy (K. Wagemann); (2) Characterisation of ethylene glycol - pyrolysis coke slurries, the model fuel of bioliq {sup registered} gasifier (T. Nicoleit); (3) Additional gas generation from fermentation residues amounting to 25 % of the balanced yield of biogas due to the energy content (T. Lehmann); (4) Production of phenols from lignin by means of flash pyrolysis in a circulating fluidised bed - process development and product analytics (M. Franck); (5) Impact of the conditions of torrefication on the temporal decrease in mass of single particles of biomass (A. Becker); (6) Lignins to Aromatic compounds. The Base catalysed degradation in continuous reactors - a tentative review (D. Schmiedl); (7) Thermogravimetric investigations of the pyrolytic degradation of different residues of biomass (G. Pena Chipatecua); (8) Field test campaign for SOFC units with gasification product gas as a preliminary for the SOFC based cogeneration (S. Martini); (9) One-zone-model for pour reactors of industrial size (U. Hellwig); (10) On the actual state of the thermochemical gasification of biomass in Germany at the beginning of 2012 (D. Braekow); (11) Production of green hydrogen based on syngas from biomass gasification (H. Tautz); (12) The BioSyn process - biomass gasification for the generation of syngas free of tar (L. Rochlitz); (13) Efficiency and framework conditions of AER biomass gasification (J. Breilochs); (14) Processing and cleaning of syngas from biomass (S. Vodegel); (15) Processing of product gas from gasification of biomass by means of heat extraction with hot gas cooler with integrated structure pipes and tar extraction with quenching and wet electro filter (C. Hamel); (16) Comparing tests of catalyst for reforming tar and methane in product gases

  4. Review and analysis of biomass gasification models

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Bruno, Joan Carles; Coronas, Alberto

    2010-01-01

    The use of biomass as a source of energy has been further enhanced in recent years and special attention has been paid to biomass gasification. Due to the increasing interest in biomass gasification, several models have been proposed in order to explain and understand this complex process, and the...... design, simulation, optimisation and process analysis of gasifiers have been carried out. This paper presents and analyses several gasification models based on thermodynamic equilibrium, kinetics and artificial neural networks. The thermodynamic models are found to be a useful tool for preliminary...

  5. Experimental study on application of high temperature reactor excess heat in the process of coal and biomass co-gasification to hydrogen-rich gas

    International Nuclear Information System (INIS)

    The paper presents the results of the experimental study on the simulated application of HTR (High Temperature Reactor) excess heat in the process of allothermal co-gasification of coal and biomass. The laboratory scale installation with a fixed bed gasifier and auxiliary gasification agents pre-heating system, simulating the utilization of the HTR excess heat, were applied in the study. Steam and oxygen were the gasification media employed, and the process was focused on hydrogen-rich gas production. The results of the co-gasification of fuel blends of various biomass content at 800 °C and in various system configurations proved that the application of the simulated HTR excess heat in pre-heating of the gasification agents leads to the increase in the gaseous product yield. Furthermore, the HCA (Hierarchical Clustering Analysis) employed in the experimental data analysis revealed that the gasification of fuel blends of 20 and 40%w/w of biomass content results in higher volumes of the total gas, hydrogen, carbon monoxide and carbon dioxide than gasification of fuel blends of higher biomass content. - Highlights: • Simulated utilization of HTR excess heat in co-gasification of coal and biomass. • Assessment of three system configurations in terms of hydrogen production. • Application of the HCA in the experimental data set analysis. • Variation in gas components volume and content with fuel blend composition

  6. Effects of lipids and oleic acid on biomass development in anaerobic fixed-bed reactors. Part II : oleic acid toxicity and biodegradability

    OpenAIRE

    Alves, M.M.; Vieira, J. A. Mota; Pereira, R. M. Álvares; M. A. PEREIRA; Mota, M.

    2001-01-01

    Oleic acid toxicity and biodegradability were followed during long-term operation of two similar anaerobic fixed-bed units. When treating an oleate based effluent, the sludge from the bioreactor that was acclimated with lipids during the first operation period, showed a higher tolerance to oleic acid toxicity (IC50=137 mg/l) compared with the sludge fed with a non-fat substrate (IC50=80 mg/l). This sludge showed also the highest biodegradation capacity of oleic acid, achieving max...

  7. An Experimental and Numerical Investigation of Fluidized Bed Gasification of Solid Waste

    Directory of Open Access Journals (Sweden)

    Sharmina Begum

    2013-12-01

    Full Text Available Gasification is a thermo-chemical process to convert carbon-based products such as biomass and coal into a gas mixture known as synthetic gas or syngas. Various types of gasification methods exist, and fluidized bed gasification is one of them which is considered more efficient than others as fuel is fluidized in oxygen, steam or air. This paper presents an experimental and numerical investigation of fluidized bed gasification of solid waste (SW (wood. The experimental measurement of syngas composition was done using a pilot scale gasifier. A numerical model was developed using Advanced System for Process ENgineering (Aspen Plus software. Several Aspen Plus reactor blocks were used along with user defined FORTRAN and Excel code. The model was validated with experimental results. The study found very similar performance between simulation and experimental results, with a maximum variation of 3%. The validated model was used to study the effect of air-fuel and steam-fuel ratio on syngas composition. The model will be useful to predict the various operating parameters of a pilot scale SW gasification plant, such as temperature, pressure, air-fuel ratio and steam-fuel ratio. Therefore, the model can assist researchers, professionals and industries to identify optimized conditions for SW gasification.

  8. ENHANCEMENT OF STRUCTURAL FOAM MATERIALS BY INCORPORATION OF GASIFIER SLAG

    Energy Technology Data Exchange (ETDEWEB)

    Olin Perry Norton; Ronald A. Palmer; W. Gene Ramsey

    2006-03-15

    As advanced gasification technology is increasingly adopted as an energy source, disposal of the resulting slag will become a problem. We have shown that gasifier slag can be incorporated into foamed glass, which is currently being manufactured as an abrasive and as an insulating material. The slag we add to foamed glass does not simply act as filler, but improves the mechanical properties of the product. Incorporation of gasifier slag can make foamed glass stronger and more abrasion resistant.

  9. Effectiveness of briquetting bio mass materials with different ratios in 10 kW down draft gasifier

    Directory of Open Access Journals (Sweden)

    K.Sivakumar

    2011-11-01

    Full Text Available This paper discuss about the effectiveness of using Briquetting of rural bio mass material in Down draft gasifier for easy operation and power generation, during winter and rainy season. Sawdust a milling residue is available in huge quantity. Apart from the problems of transportation, storage, and handling, the direct burning of loosesaw dust biomass in conventional grates is associated with very low thermal efficiency and widespread air pollution. The conversion efficiency is as low as 40% with particulate emissions in the flue gases in excess of 3000 mg/ Nm. In addition, a large percentage of unburnt carbonaceous ash has to be disposed off. Briquetting ofthe sawdust with cow dung could mitigate these pollution problems while at the same time making use of the important domestic energy resources. The easily available rural bio mass material saw dust and rurally available binder material cum bio mass cow dung is used for briquetting. This experiment was carried out with briquetting of saw dust and binder cow dung at different ratio. It is experimentally investigated at 8000C using gasification technique in a downdraft gasifier. The air flow rate and pressure drop across the gasifier has been measured. The percentage of combustible gases like H2, CO, CH4, CO2, and N2 formed during gasification are found. The calorific value of the producer gas for different ratio of briquetting biomass material has been found out. Experimental results indicate that briquetting at 75:25 ratio of sawdust and cow dung is the best suitable biomass Briquette for gasifier compared to the other two ratios considered. The result shows that the gas composition of methane is comparably high in this ratio (i.e. 75:25 than other two ratios i.e.(50:50 and (25:75. The results also show that pressure drop across the gasifier and producer gas composition increases withincrease in air flow rate. Also found that, thermal efficiency is comparatively high at 75:25 ratio briquettes

  10. Reduced ash related operational problems (slagging, bed agglomeration, corrosion and fouling) by co-combustion biomass with peat; Minskade askrelaterade driftsproblem (belaeggning, slaggning, hoegtemperatur-korrosion, baeddagglomerering) genom inblandning av torv i biobraenslen

    Energy Technology Data Exchange (ETDEWEB)

    Oehman, Marcus; Boman, Christoffer; Erhardsson, Thomas; Gilbe, Ram; Pommer, Linda; Bostroem, Dan; Nordin, Anders; Samuelsson, Robert; Burvall, Jan

    2006-12-15

    Combustion studies were performed in both a fluidized bed (5 kW) and in an under-feed pellets burner (20 kW) to elucidate the responsible mechanisms for the positive effects on ash related operational problems (i.e. slagging, fouling, corrosion and bed agglomeration) during co-combustion of several problematic biomass with peat. Three typical carex-containing Swedish peat samples with differences in e.g. silicon-, calcium- and sulfur contents were co-fired with logging residues, willow and straw in proportions corresponding to 15-40 weight %d.s. Mixing of corresponding 20 wt-% of peat significantly reduced the bed agglomeration tendencies for all fuels. The fuel specific agglomeration temperature were increased by 150-170 deg C when adding peat to the straw fuel and approximately 70-100 deg C when adding peat to the logging residue- and the willow fuel. The increased level of calcium in the inner bed particle layer caused by the added reactive calcium from the peat and/or removing alkali in the gas phase to a less reactive particular form via sorption and/or reaction with reactive peat ash (containing calcium, silica etc.) during which larger particles (>1{mu}m) are formed where collected potassium is present in a less reactive form, is considered to be the dominated reason for the increased agglomeration temperatures during combustion of logging residues and willow. During straw combustion, the ash forming matter were found as individual ash sticky particles in the bed. The iron, sulphur and calcium content of these individual ash particles were significantly increased when adding peat to the fuel mix thereby decreasing the stickiness of these particles i.e. reducing the agglomeration tendencies. Adding peat to the relatively silicon-poor fuels (willow and logging residues) resulted in higher slagging tendencies, especially when the relative silicon rich peat fuel (Brunnskoelen) was used. However, when co-combusting peat with the relatively silicon and potassium

  11. Integrated biomass gasification combined cycle distributed generation plant with reciprocating gas engine and ORC

    OpenAIRE

    Kalina, Jacek

    2011-01-01

    Abstract The paper theoretically investigates the performance of a distributed generation plant made up of gasifier, Internal Combustion Engine (ICE) and Organic Rankine Cycle (ORC) machine as a bottoming unit. The system can be used for maximization of electricity production from biomass in the case where there is no heat demand for cogeneration plant. To analyze the performance of the gasifier a model based on the thermodynamic equilibrium approach is used. Performance of the gas...

  12. EVALUATION OF A PROCESS TO CONVERT BIOMASS TO METHANOL FUEL - PROJECT SUMMARY

    Science.gov (United States)

    The report gives results of a review of the design of a reactor capable of gasifying approximately 50 lb/hr of biomass for a pilot-scale facility to develop, demonstrate, and evaluate the Hynol Process, a high-temperature, high-pressure method for converting biomass into methanol...

  13. Real Time Flame Monitoring of Gasifier and Injectors

    Energy Technology Data Exchange (ETDEWEB)

    Zelepouga, Serguei; Saveliev, Alexei

    2011-12-31

    This project is a multistage effort with the final goal to develop a practical and reliable nonintrusive gasifier injector monitor to assess burner wear and need for replacement. The project team included the National Energy Technology Laboratory (NETL), Gas Technology Institute (GTI), North Carolina State University, and ConocoPhillips. This report presents the results of the sensor development and testing initially at GTI combustion laboratory with natural gas flames, then at the Canada Energy Technology Center (CANMET), Canada in the atmospheric coal combustor as well as in the pilot scale pressurized entrained flow gasifier, and finally the sensor capabilities were demonstrated at the Pratt and Whitney Rocketdyne (PWR) Gasifier and the Wabash River Repowering plant located in West Terre Haute, IN. The initial tests demonstrated that GTI gasifier sensor technology was capable of detecting shape and rich/lean properties of natural gas air/oxygen enriched air flames. The following testing at the Vertical Combustor Research Facility (VCRF) was a logical transition step from the atmospheric natural gas flames to pressurized coal gasification environment. The results of testing with atmospheric coal flames showed that light emitted by excited OH* and CH* radicals in coal/air flames can be detected and quantified. The maximum emission intensities of OH*, CH*, and black body (char combustion) occur at different axial positions along the flame length. Therefore, the excitation rates of CH* and OH* are distinct at different stages of coal combustion and can be utilized to identify and characterize processes which occur during coal combustion such as devolatilization, char heating and burning. To accomplish the goals set for Tasks 4 and 5, GTI utilized the CANMET Pressurized Entrained Flow Gasifier (PEFG). The testing parameters of the PEFG were selected to simulate optimum gasifier operation as well as gasifier conditions normally resulting from improper operation or

  14. Improving methane production efficiency from biomass product gas via pressurized fluidized bed system%适宜增压流化床操作参数提高生物质热气化气合成甲烷效率

    Institute of Scientific and Technical Information of China (English)

    冯飞; 沈来宏; 肖军; 吕潇

    2015-01-01

    Natural gas is one of the clean primary energy sources and high-quality chemical raw materials. Technology of methane production from biomass thermo-chemical gasification (biomass-to-SNG) is one of the most important pathways to produce synthetic natural gas (SNG) to substitute diminishing natural gas. In the biomass-to-SNG process, the biomass is first converted into product gas through biomass gasification. Then, the product gas full of CO and H2is synthesized into methane through the methanation processes after some proper cleaning and conditioning processes. Finally, the crude synthetic natural gas is upgraded with CO2 removal and gas dehydration. In the whole biomass-to-SNG process, the methanation process of product gas is a key step. A pressurized fluidized bed methanation reactor system was designed and constructed, which is mainly composed of a main reactor and auxiliary equipments. An experimental study of methane production from product gas was carried out on this methantion reactor system with the commercial methanation catalyst as bed material. The Energy Dispersive Spectrometer analysis indicates that the methanation catalyst contains high nickel content and was squashed into small particles for the study. Then, the effects of methanation temperature, pressure, space velocity, and ratio of H2 to CO on the performance indexes (i.e. methane formation rate and CO conversion rate) were investigated. The results show that methane is efficiently produced on this pressurized fluidized bed methanation reactor system and the typical methane formation rate is higher than 3.2 mol/(L·h) while the CO conversion rate is more than 80%. Higher methanation temperature is favored to the methanation process and the methane formation rate and CO conversion rate achieve the maximum values at the methanation temperature about 350℃. However, when the methanation temperature is higher than 350℃, the methane formation rate and CO conversion rate decline slowly since the

  15. Experimental study on temperature profile of fixed - bed gasification of oil-palm fronds

    Science.gov (United States)

    Atnaw, Samson M.; Sulaiman, Shaharin A.; Moni, M. Nazmi Z.

    2012-06-01

    Currently the world's second largest palm oil producer Malaysia produces large amount of oil palm biomass each year. The abundance of the biomass introduces a challenge to utilize them as main feedstock for heat and energy generation. Although some oil palm parts and derivatives like empty fruit bunch and fibre have been commercialized as fuel, less attention has been given to oil palm fronds (OPF). Initial feasibility and characterization studies of OPF showed that it is highly feasible as fuel for gasification to produce high value gaseous fuel or syngas. This paper discusses the experimental gasification attempt carried out on OPF using a 50 kW lab scale downdraft gasifier and its results. The conducted study focused on the temperature distributions within the reactor and the characteristics of the dynamic temperature profile for each temperature zones during operation. OPF feedstock of one cubic inch in individual size with 15% average moisture content was utilized. An average pyrolysis zone temperature of 324°Cand an average oxidation zone temperature of 796°Cwere obtained over a total gasification period of 74 minutes. A maximum oxidation zone temperature of 952°Cwas obtained at 486 lpm inlet air flow rate and 10 kg/hr feedstock consumption rate. Stable bluish flare was produced for more than 70% of the total gasification time. The recorded temperature profiles produced closely similar patterns with the temperature profiles recorded from the gasification of woody materials. Similar temperature profile was obtained comparing the results from OPF gasification with that of woody biomass. Furthermore, the successful ignition of the syngas produced from OPF gasification ascertained that OPF indeed has a higher potential as gasification feedstock. Hence, more detailed studies need to be done for better understanding in exploiting the biomass as a high prospect alternative energy solution. In addition, a study of the effect of initial moisture content of OPF

  16. Catalytic steam gasification of biomass in fluidized bed at low temperature: Conversion from livestock manure compost to hydrogen-rich syngas

    International Nuclear Information System (INIS)

    Utilizing large amounts of animal waste as a source of renewable energy has the potential to reduce its disposal problems and associated pollution issues. Gasification characteristics of the manure compost make it possible for low temperature gasification. In this paper, an energy efficient approach to hydrogen-rich syngas from manure compost is represented at relatively low temperature, around 600 oC, in a continuous-feeding fluidized bed reactor. The effects of catalyst performance, reactor temperature, steam, and reaction type on gas yield, gas composition, and carbon conversion efficiency are discussed. The Ni-Al2O3 catalyst simultaneously promotes tar cracking and steam reforming. Higher temperature contributes to higher gas yield and carbon conversion. The steam introduction increases hydrogen yield, by steam reforming and water-gas shift reaction. Two-stage gasification is also tried, showing the advantage of better catalyst utilization and enhancing the catalytic reactions to some extent.

  17. Gasification technologies for heat and power from biomass

    NARCIS (Netherlands)

    Beenackers, AACM; Maniatis, K; Kaltschmitt, M; Bridgwater, AV

    1997-01-01

    A critical review is presented of biomass gasifier systems presently commercially available or under development. Advantages and possible problem areas are discussed in relation to particular applications. Both large and small scale technologies are reviewed. Catalysed by the EC JOULE and AIR progra

  18. Effects of operating conditions and fuel properties on emission performance and combustion efficiency of a swirling fluidized-bed combustor fired with a biomass fuel

    International Nuclear Information System (INIS)

    This work reports an experimental study on firing 80 kg/h rice husk in a swirling fluidized-bed combustor (SFBC) using an annular air distributor as the swirl generator. Two NOx emission control techniques were investigated in this work: (1) air staging of the combustion process, and (2) firing rice husk as moisturized fuel. In the first test series for the air-staged combustion, CO, NO and CxHy emissions and combustion efficiency were determined for burning 'as-received' rice husk at fixed excess air of 40%, while secondary-to-primary air ratio (SA/PA) was ranged from 0.26 to 0.75. The effects of SA/PA on CO and NO emissions from the combustor were found to be quite weak, whereas CxHy emissions exhibited an apparent influence of air staging. In the second test series, rice husks with the fuel-moisture content of 8.4% to 35% were fired at excess air varied from 20% to 80%, while the flow rate of secondary air was fixed. Radial and axial temperature and gas concentration (O2, CO, NO) profiles in the reactor, as well as CO and NO emissions, are discussed for the selected operating conditions. The temperature and gas concentration profiles for variable fuel quality exhibited significant effects of both fuel-moisture and excess air. As revealed by experimental results, the emission of NO from this SFBC can be substantially reduced through moisturizing rice husk, while CO is effectively mitigated by injection of secondary air into the bed splash zone, resulting in a rather low emission of CO and high (over 99%) combustion efficiency of the combustor for the ranges of operating conditions and fuel properties.

  19. 双流化床生物质气化及CO2捕获的模拟%Simulation of biomass gasification in dual fluidized beds with CO2 capture

    Institute of Scientific and Technical Information of China (English)

    夏小宝; 解东来; 叶根银

    2011-01-01

    用Aspen Plus建立了双流化床气化和燃烧模型,对生物质在双流化床中气化及CaO吸收合成气中的CO2过程进行了模拟研究;探讨不同反应条件:气化温度、蒸汽与生物质的质量配比(S/B)以及CaO循环量与生物质的质量配比(Ca/B)对合成气成分的影响,为该类型工业反应器的研发提供了理论依据.模拟分析结果表明:气化温度低于700℃时,CaO能很好地吸收气化过程中产生的CO2并促进平衡反应向产氢方向进行;在温度为650℃及CaO作用下,S/B在0.6~1.7内对合成气成分的影响不大;CaO的加入能够有效地改善合成气的组成,合成气中氢气浓度能达到95%以上,氢气产量达到52 mol/kg.%An Aspen model was built to simulate the gasification and combustion processes in the dual fluidized beds. The processes of biomass gasification and CO2 adsorption by CaO were stud-ied.The effects of gasification temperature, biomass ratio to steam (S/B), CaO to biomass ratio (Ca/B) on the syngas composition were discussed. Simulation results indicated that CaO can effectively capture the CO2 in the syngas and shift the thermodynamics balance to hydrogen production direction when the gasification temperature was below 700 X.. Steam to biomass ratio (0.6-1.7) has very little influences on the syn-gas composition under the gasification temperature of 650 ℃ and with the existence of CaO. The addition and circulation of CaO can effectively improve the syngas composition. The hydrogen concentration in the syngas can reach up to 95% and hydrogen production rate reach 52 mol/kg.

  20. Evaluation of the conversion efficiency of the 180Nm3/h Johansson Biomass Gasifier™

    Directory of Open Access Journals (Sweden)

    Ntshengedzeni S. Mamphweli, Edson L. Meyer

    2010-01-01

    Full Text Available Biomass gasification is the thermochemical conversion of biomass materials into a producer gas, which is a mixture of carbon monoxide, carbon dioxide, methane, hydrogen, nitrogen and water vapour. The 180Nm3/h System Johansson Biomass Gasifier (SJBG at Eskom research and Innovation Centre is used for research and development initiatives, and also for demonstration purposes. The aim of this research was to investigate the efficiency of the gasifier and. This is done through an analysis of the gas profiles at the gasifier using a custom-built gas and temperature measurement system. Non-Dispersive Infrared gas detection technique is applied to monitor the volume and quality of producer gas. Palladium/Nickel gas sensing is applied to monitor the hydrogen content in the gas stream. Temperature in the gasifier is monitored through the use of type K thermocouples. The gas and temperature sensors are connected to the data logger interfaced to a computer. The heating value of the producer gas was determined from the percentage composition of the combustible gases. Evaluation of the efficiency of this gasifier was done before the installation of a 300Nm3/h at a rural village. The gasifier achieved an efficiency of 75% with an average gas heating value of 6MJ/Nm3.

  1. Fuel gas from biomass for power and heat generation. Results of tests at the test gasification plant at Technical University Dresden; Brenngase aus Biomasse fuer die Strom- und Waermeerzeugung. Ergebnisse der Untersuchungen am Vergasungsversuchsstand der TU Dresden

    Energy Technology Data Exchange (ETDEWEB)

    Boehning, D.; Beckmann, M. [Technische Universitaet Dresden (Germany). Institut fuer Energietechnik

    2009-07-01

    The gasification of biomass into smaller decentralized plants with a thermal output up to 500 kW has been a subject of variable intensity in research and development. The current development state of the process is however still insufficient regardless of the process, such that a reliable and economic operation of the plants can be guaranteed. For the use of the produced fuel in the gas-engine, high standards are necessary for its quality. The article focusses on the reduction of tar content in fuel gas via catalytic partial oxidation. It describes the theoretical analysis of fundamentals with results and presents experimental tests at the gasification plant and the obtained results. Tests have been realized at the 75 kW{sub th} fixed bed gasifier at the catalytic partial oxidation (1{sup st} Function unit) and at the cooling of gas (2{sup nd} Function unit). The construction and material of the catalyst are essential parameters as well as the apply amount of oxygen, the position of supplying and mixing. By the use of a gas cooling in a stationary fluidized bed is it possible to decrease the tar content in the fuel gas, via condensation on bed material (charcoal). The gas cooling is installed behind the catalyst. The outcome of the combination of both gas treatment-function-units is a further monovariant for optimization. The second unit can also be considered as a ''safety filter''. (orig.)

  2. Review of Study on Character and Development of Spouted Circulating Fluidized Bed Equipments for Biomass Fast Pyrolysis%喷动循环流化床生物质快速热解设备的特性分析与发展研究综述

    Institute of Scientific and Technical Information of China (English)

    任学勇; 常建民; 王鹏起; 苟进胜; 张立塔; 佟立成

    2009-01-01

    Present situations of domestic and foreign researches on biomass fast pyrolysis devices are summarized.Detailed accounts on spouted bed and circulating fluidized bed are stated and more in-depth analysis on spouted circulating fluidized bed is given.The orientation of research on spouted circulating fluidized bed fast pyrolysis devices is explored.%简要综述了生物质快速热解设备研究的国内外现状,继而详述了喷动床和循环流化床,重点对喷动循环流化床作了较深入的探析,探讨了喷动循环流化床快速热解设备研究的发展方向.

  3. Guideline for safe and eco-friendly biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Vos, J.; Knoef, H. (BTG biomass technology group, Enschede (Netherlands)); Hauth, M. (Graz Univ. of Technology. Institute of Thermal Engineering, Graz (Austria)) (and others)

    2009-11-15

    The objective of the Gasification Guide project is to accelerate the market penetration of small-scale biomass gasification systems (< 5 MW fuel power) by the development of a Guideline and Software Tool to facilitate risk assessment of HSE aspects. The Guideline may also be applied in retrofitting or converting old thermal plants in the Eastern European countries - with rich biomass recourses - to new gasification plants. The objective of this document is to guide key target groups identifying potential hazards and make a proper risk assessment. The software tool is an additional aid in the risk assessment. This guideline is intended to be a training tool and a resource for workers and employers to safely design, fabricate, construct, operate and maintain small-scale biomass gasification facilities. The Guideline is applicable with the following constraints: 1) The maximum scale of the gasification plant was agreed to be about 1 MW{sub e}. The reason is that large companies do have normally their safety rules in place; 2) This means in principle only fixed bed gasifier designs. However, most parts are also valid to other designs and even other thermal conversion processes; 3) The use of contaminated biomass is beyond the scope of this Guideline. The Guideline contains five major chapters; Chapter 2 briefly describes the gasification technology in general. Chapter 3 gives an overview of major legal framework issues on plant permission and operation. The legal frame is changing and the description is based on the situation by the end of 2007. Chapter 4 explains the theory behind the risk assessment method and risk reduction measures. Chapter 5 is the heart of the Guideline and gives practical examples of good design, operation and maintenance principles. The practical examples and feedback have been received throughout the project and the description is based on mid-2009. Chapter 6 describes the best techniques currently available for emission abatement which are

  4. Comparison of Integrated Gasifier-Combined Cycle and AFB-steam turbine systems for industrial cogeneration

    Science.gov (United States)

    Nainiger, J. J.; Abbott, J. M.; Burns, R. K.

    1981-01-01

    In the cogeneration technology alternatives study (CTAS) a number of advanced coal fired systems were examined and systems using a integrated coal gasifier IGCC or a fluid bed combustor AFB were found to yield attractive cogeneration results in industrial cogeneration applications. A range of site requirements and cogeneration sizing strategies using ground rules based on CTAS were used in comparing an IGCC and an AFB. The effect of time variations in site requirements and the sensitivity to fuel and electricity price assumptions are examined. The economic alternatives of industrial or utility ownership are also considered. The results indicate that the IGCC system has potentially higher fuel and emission savings and could be an attractive option for utility ownership. The AFB steam turbine system has a potentially higher return on investment and could be attractive assuming industrial ownership.

  5. Fluidized-bed gasification of biomass: Conversion of fine carabon particles in the freeboard; Biomassevergasung in der Wirbelschicht: Umsatz von feinen Kohlenstoffpartikeln im Freeboard

    Energy Technology Data Exchange (ETDEWEB)

    Miccio, F. [Ist. Ricerche sulla Combustione-CNR, Napoli (Italy); Moersch, O.; Spliethoff, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen

    1998-09-01

    The conversion of carbon particles in gasification processes was investigated in a fluidized-bed reactor of the Institute of Chemical Engineering and Steam Boiler Technology of Stuttgart University. This reactor is heated electrically to process temperature, and freeboard coal particles can be sampled using an isokinetic probe. The fuel used in the experiments consisted of beech wood chips. The temperature and air rating, i.e. the main parameters of the process, were varied in order to investigate their influence on product gas quality and carbon conversion. The conversion rate is influenced to a significant extent by grain disintegration and discharge of carbon particles. In gasification conditions, a further conversion process takes place in the freeboard. (orig.) [Deutsch] In dieser Arbeit wird die Umsetzung von Kohlenstoffpartikeln unter Vergasungsbedingungen untersucht. Die Versuche wurden an einem Wirbelschichtreaktor des Instituts fuer Verfahrenstechnik und Dampfkesselwesen der Universitaet Stuttgart durchgefuehrt. Dieser Reaktor wird elektrisch auf Prozesstemperatur beheizt. Mit Hilfe einer isokinetischen Sonde koennen Proben von Kohlenstoffpartikeln im Freeboard genommen werden. Als Brennstoff wurden zerkleinerte Buchenholz-Hackschnitzel eingesetzt. Variiert wurden als Hauptparameter des Prozesses Temperatur und Luftzahl. Untersucht wurde der Einfluss dieser Parameter auf die Qualitaet des Produktgases und die Umsetzung des Kohlenstoffes. Kornzersetzungs- und Austragsvorgaenge von Kohlenstoffpartikeln spielen eine wichtige Rolle fuer den Kohlenstoffumsatz. Unter Vergasungsbedingungen findet im Freeboard eine weitere Umsetzung der Partikel statt. (orig.)

  6. Hydrogen production from biomass. Optimization of gasification by experimental by experimental statistical design; Produccion de hidrogeno a partir de biomasa. Optimizacion de la gasificacion por aplicacion del diseno estadistico de experimentos

    Energy Technology Data Exchange (ETDEWEB)

    Arteche Calvo, A.

    2008-07-01

    Biomass conversion into a gas with high content in hydrogen is considered as a future alternative to obtain energy and chemicals products for renewable sources. One of the current technologies for this purpose is the gasification using steam as gasification agent. The technical objective of this work is the study of the process of biomass gasification with steam and oxygen as thermochemical process of transformation of biomass to obtain the maximum amount of hydrogen with lowest tar content. Materials and Methods. An experimental statistical strategy with three variables and two levels of operation was planned to optimize the gasification process. the study was conducted without changing the type of biomass-fed, the type of catalyst used and the quantity of bed inside the gasifier. Two mathematical models have been obtained as results. Both of them correlated the experimental factors to the production of hydrogen and tars. The design of experiments methodology has been applied to assess the influence os several experimental factors, such as the introduced amount of steam, the use of catalyst and oxygen, both in the production of hydrogen, as in the minimization of the formation of tars. This statistical technique has enabled the modeling of the selected biomass gasification performing the minimum number of pilot plant tests to identify possible improvements and optimizations both in the yield of produced hydrogen as in the generation of tars. (Author) 10 refs.

  7. Gas Turbine Combustion and Ammonia Removal Technology of Gasified Fuels

    Directory of Open Access Journals (Sweden)

    Takeharu Hasegawa

    2010-03-01

    Full Text Available From the viewpoints of securing a stable supply of energy and protecting our global environment in the future, the integrated gasification combined cycle (IGCC power generation of various gasifying methods has been introduced in the world. Gasified fuels are chiefly characterized by the gasifying agents and the synthetic gas cleanup methods and can be divided into four types. The calorific value of the gasified fuel varies according to the gasifying agents and feedstocks of various resources, and ammonia originating from nitrogenous compounds in the feedstocks depends on the synthetic gas clean-up methods. In particular, air-blown gasified fuels provide low calorific fuel of 4 MJ/m3 and it is necessary to stabilize combustion. In contrast, the flame temperature of oxygen-blown gasified fuel of medium calorie between approximately 9–13 MJ/m3 is much higher, so control of thermal-NOx emissions is necessary. Moreover, to improve the thermal efficiency of IGCC, hot/dry type synthetic gas clean-up is needed. However, ammonia in the fuel is not removed and is supplied into the gas turbine where fuel-NOx is formed in the combustor. For these reasons, suitable combustion technology for each gasified fuel is important. This paper outlines combustion technologies and combustor designs of the high temperature gas turbine for various IGCCs. Additionally, this paper confirms that further decreases in fuel-NOx emissions can be achieved by removing ammonia from gasified fuels through the application of selective, non-catalytic denitration. From these basic considerations, the performance of specifically designed combustors for each IGCC proved the proposed methods to be sufficiently effective. The combustors were able to achieve strong results, decreasing thermal-NOx emissions to 10 ppm (corrected at 16% oxygen or less, and fuel-NOx emissions by 60% or more, under conditions where ammonia concentration per fuel heating value in unit volume was 2.4 × 102 ppm

  8. Chemical-looping gasification of biomass in a 10k Wth interconnected fluidized bed reactor using Fe2 O3/Al2 O3 oxygen carrier

    Institute of Scientific and Technical Information of China (English)

    HUSEYIN Sozen; WEI Guo-qiang; LI Hai-bin; HE Fang; HUANG Zhen

    2014-01-01

    The aim of this research is to design and operate a 10 kW hot chemical-looping gasification ( CLG) unit using Fe2 O3/Al2 O3 as an oxygen carrier and saw dust as a fuel. The effect of the operation temperature on gas composition in the air reactor and the fuel reactor, and the carbon conversion of biomass to CO2 and CO in the fuel reactor have been experimentally studied. A total 60 h run has been obtained with the same batch of oxygen carrier of iron oxide supported with alumina. The results show that CO and H2 concentrations are increased with increasing temperature in the fuel reactor. It is also found that with increasing fuel reactor temperature, both the amount of residual char in the fuel reactor and CO2 concentration of the exit gas from the air reactor are degreased. Carbon conversion rate and gasification efficiency are increased by increasing temperature and H2 production at 870 ℃reaches the highest rate. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET-surface area tests have been used to characterize fresh and reacted oxygen carrier particles. The results display that the oxygen carrier activity is not declined and the specific surface area of the oxygen carrier particles is not decreased significantly.

  9. Gasification of peat and biomass in suspension flow 2; Turpeen ja biomassan suspensiokaasutus 2

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Hepola, J. [VTT Energy, Espoo (Finland); Haukka, P.; Vehmaan-Kreula, M.; Raiko, R. [Tampere Univ. of Technology (Finland)

    1996-12-01

    This project was an extension of the earlier Liekki-project 402 carried out in 1993-1994. The aims of the 1995 project were: (1) to study the formation of problematic tar/soot compounds and nitrogen pounds in the conditions of entrained flow gasification of biomass and peat, (2) study the product yields and kinetics of pyrolysis, and (3) to develop simulation methods for entrained flow pyrolysis and gasification. Pyrolysis and gasification tests were carried out at a new entrained flow reactor of the Gasification Research Group of VTT using mainly peat as the feedstock. The pyrolysis kinetics was studies using three particle size distributions of fuel peat (0.075-0.125 mm, 0.16-0.25 mm and 0.315-0.5 mm). The char yields were determined at two temperatures (900 and 1000 deg C) and the effects fuel to gas ratio (suspension density) as well as the effects of gas atmosphere were determined. Limited amount of tests were also carried out with pine wood and dried de-inking sludge. The formation of tars and nitrogen compounds was studied with peat as the feedstock. Based on the test results of this project and the on earlier fluidized-bed gasification data of VTT, the following conclusions can be made: (1) the char yields in rapid entrained flow pyrolysis of small particles of peat and biomass are considerably lower than derived in fluid-bed pyrolysis of more coarse feedstocks. Consequently, simple entrained flow reactors without any recycling of char could already give rather high carbon conversions. However, high carbon conversions can also be easily achieved in fluidized-bed gasifiers with biomass fuels due to the high gasification reactivity of the char, (2) more tars were formed in entrained flow pyrolysis of peat than in fluidized-bed experiments carried out at the same temperature, (3) the total conversion of peat nitrogen to NH{sub 3}+HCN was as high in the entrained flow pyrolysis as in the fluid-bed pyrolysis experiments. (Abstract Truncated)

  10. Efficient gasification of wet biomass residue to produce middle caloric gas

    Institute of Scientific and Technical Information of China (English)

    Guangwen Xu; Takahiro Murakami; Toshiyuki Suda; Hidehisa Tani; Yutaka Mito

    2008-01-01

    Various process residues represent a kind of biomass resource already concentrated but containing water as much as 60 wt.%.These materials are generally treated as waste or simply combusted directly to generate heat.Recently,we attempted to convert them into middle caloric gas to substitute for natural gas,as a chemical or a high-rank gaseous fuel for advanced combustion utilities.Such conversion is implemented through dual fluidized bed gasification (DFBG).Concerning the high water content of the fuels,DFBG was suggested to accomplish either with high-efficiency fuel drying in advance or direct decoupling of fuel drying/pyrolysis from char gasification and tar/hydrocarbon reforming.Along with fuel drying,calcium-based catalyst can be impregnated into the fuel,without much additional cost,to increase the fuel's gasification reactivity and to reduce tar formation.This article reports the Ca impregnation method and its resulting effects on gasification reactivity and tar suppression ability.Meanwhile,the principle of directly gasifying wet fuel with decoupled dual fluidized bed gasification (D-DFBG) is also highlighted.

  11. Gasifiers optimized for fuel cell applications

    Science.gov (United States)

    Steinfeld, G.; Fruchtman, J.; Hauserman, W. B.; Lee, A.; Meyers, S. J.

    Conventional coal gasification carbonate fuel cell systems are typically configured so that the fuel gas is primarily hydrogen, carbon monoxide, and carbon dioxide, with waste heat recovery for process requirements and to produce additional power in a steam bottoming cycle. These systems make use of present day gasification processes to produce the low to medium Btu fuel gas which in turn is cleaned up and consumed by the fuel cell. These conventional gasification/fuel cell systems have been studied in recent years projecting system efficiencies of 45-53 percent (HHV). Conventional gasification systems currently available evolved as stand-alone systems producing low to medium Btu gas fuel gas. The requirements of the gasification process dictates high temperatures to carry out the steam/carbon reaction and to gasify the tars present in coal. The high gasification temperatures required are achieved by an oxidant which consumes a portion of the feed coal to provide the endothermic heat required for the gasification process. The thermal needs of this process result in fuel gas temperatures that are higher than necessary for most end use applications, as well as for gas cleanup purposes. This results in some efficiency and cost penalties. This effort is designed to study advanced means of power generation by integrating the gasification process with the unique operating characteristics of carbonate fuel cells to achieve a more efficient and cost effective coal based power generating system. This is to be done by altering the gasification process to produce fuel gas compositions which result in more efficient fuel cell operation and by integrating the gasification process with the fuel cell as shown in Figure 2. Low temperature catalytic gasification was chosen as the basis for this effort due to the inherent efficiency advantages and compatibility with fuel cell operating temperatures.

  12. Process simulation of biomass gasification integrated with a solid oxide fuel cell stack

    Science.gov (United States)

    Doherty, Wayne; Reynolds, Anthony; Kennedy, David

    2015-03-01

    Biomass gasification-solid oxide fuel cell (BG-SOFC) combined heat and power (CHP) systems are of major interest in the context of climate change mitigation, energy security and increasing energy efficiency. Aspen Plus is employed to simulate various BG-SOFC CHP systems. The aim of the research work is to investigate the technical feasibility of these systems and to study the influence of important operating parameters and examine integration options. Systems based on dual fluidised bed steam gasification and tubular SOFC technologies are modelled. The cathode recycle and electric heater integration options are not attractive in comparison to the base case anode recycle system. Thermal integration, i.e. using SOFC flue gas as gasifier oxidant, is desirable. Lowering the syngas preheat temperature (prior to SOFC anodes) is highly recommended and is more practical than lowering the cathode air preheat temperature. Results of the parametric study indicate that: steam to carbon ratio and biomass moisture content should be as low as possible; fuel utilisation factor can change the mode of operation of the plant (focus on electricity or heat); high temperature syngas cleaning is very attractive; gasification air preheating is more attractive than gasification steam superheating. High efficiencies are predicted, proving the technical feasibility of BG-SOFC CHP systems.

  13. Semi-continuous feeding and gasification of alfalfa and wheat straw pellets in a lab-scale fluidized bed reactor

    International Nuclear Information System (INIS)

    Highlights: • Alfalfa and wheat straw pellets were gasified in a lab-scale fluid-bed reactor. • ER varied between 0.20 and 0.35 at which several parameters investigated. • ER = 0.35 was found optimum for alfalfa at which process performance improved. • ER = 0.30 revealed optimum for wheat straw at which gasification was effective. - Abstract: Small scale air-blown fluidized bed gasification of alfalfa and wheat straw pellets were conducted for semi-continuous solid feeding and range of operating conditions varied due to the modifications in equivalence ratio (ER) (0.20–0.35) achieved both by varying solid and air input. Alfalfa pellets displayed an improvement in several gasification variables such as gas lower heating value (∼4.1 MJ/Nm3), specific gas yield (1.66 Nm3/kg), cold gas efficiency (∼42%) and carbon conversion efficiency (∼72%) as ER maximized to 0.35 which was found optimum for this feedstock for the present course of experiments. Gasification parameters of wheat straw pellets on the other hand were characterized by a great degree of variation as the ER progressively increased. The optimum performance of this biomass was likely to achieve at ER = 0.30 when gas lower heating value and cold gas efficiency maximized to ∼4 MJ/Nm3 and ∼37% respectively. Moreover, a substantial drop in tar yield (58.7 g/Nm3) at this ER was also indicative to the optimal thermal conversion at this point of operation. Overall, both the feedstocks presented promising alternatives for utilization into the small-scale fluidized bed gasification which is increasingly emerging as a sustainable solution towards processing lignocellulosic biomass

  14. Gasifier-combustor using chips of eucalyptus firewood in drying pulped coffee; Gasificador/combustor a cavacos de lenha na secagem de cafe despolpado

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jadir Nogueira da; Saiki, Emilio Takashi; Vilarinho, Mauricio Coelho; Cardoso Sobrinho, Jose [Vicosa Univ., MG (Brazil). Dept. de Engenharia Agricola

    2000-07-01

    This study aimed to determine the viability of the of a gasifier/combustor using chip of eucalyptus firewood as fuel, in drying pulped coffee. The gasifier used was designed by Silva (1988) with modifications in the gasification chamber, being the area of the grate reduced from 0,21 to 0,06m{sup 2}. An addition of a coating involving the gasifier was done and a damper was placed in the exit of the combustion chamber. The air heated up in the combustor was sent to dryer developed by Campos (1998) that possessed four movable metallic chambers with movement and hoisted by a pulleys system. It was dried coffee with initial moisture of 54,5% w.b. up to 11,1{+-}1,6% w.b. The moisture of the coffee was determined by equipment of the universal type, EDABO and stove. The temperature of the drying air was of 60 deg C, static pressure of the air in the exit of the fan of 9 mm ca with speed of 46,3m{sup 3}.min{sup -1}. It was ended that the gasifier using chips of eucalyptus firewood as fuel consumed among 15,3 and 18,8 kg/hour of the biomass and that the equipment is viable for the drying of pulped coffee, not impregnating it with smoke or other particles, usually generated in the direct fired furnaces. (author)

  15. Low-Chrome/Chrome Free Refractories for Slagging Gasifiers

    International Nuclear Information System (INIS)

    Gasifiers are containment vessels used to react carbon-containing materials with oxygen and water, producing syngas (CO and H2) that is used in chemical and power production. It is also a potential source of H2 in a future hydrogen economy. Air cooled slagging gasifiers are one type of gasifier, operating at temperatures from 1275-1575 C and at pressures of 400 psi or higher. They typically use coal or petroleum coke as the carbon source, materials which contain ash impurities that liquefy at the gasification temperatures, producing liquid slag in quantities of 100 or more tons/day, depending on the carbon fed rate and the percent ash present in the feedstock. The molten slag is corrosive to refractory linings, causing chemical dissolution and spalling. The refractory lining is composed of chrome oxide, alumina, and zirconia; and is replaced every 3-24 months. Gasifier users would like greater on-line availability and reliability of gasifier liners, something that has impacted gasifier acceptance by industry. Research is underway at NETL to improve refractory service life and to develop a no-chrome or low-chrome oxide alternative refractory liner. Over 250 samples of no- or low-chrome oxide compositions have been evaluated for slag interactions by cup testing; with potential candidates for further studies including those with ZrO2, Al2O3, and MgO materials. The development of improved liner materials is necessary if technologies such as IGCC and DOE's Near Zero Emissions Advanced Fossil Fuel Power Plant are to be successful and move forward in the marketplace

  16. Air gasification of rice husk in bubbling fluidized bed reactor with bed heating by conventional charcoal.

    Science.gov (United States)

    Makwana, J P; Joshi, Asim Kumar; Athawale, Gaurav; Singh, Dharminder; Mohanty, Pravakar

    2015-02-01

    An experimental study of air gasification of rice husk was conducted in a bench-scale fluidized bed gasifier (FBG) having 210 mm diameter and 1600 mm height. Heating of sand bed material was performed using conventional charcoal fuel. Different operating conditions like bed temperature, feeding rate and equivalence ratio (ER) varied in the range of 750-850 °C, 25-31.3 kg/h, and 0.3-0.38, respectively. Flow rate of air was kept constant (37 m(3)/h) during FBG experiments. The carbon conversion efficiencies (CCE), cold gas efficiency, and thermal efficiency were evaluated, where maximum CCE was found as 91%. By increasing ER, the carbon conversion efficiency was decreased. Drastic reduction in electric consumption for initial heating of gasifier bed with charcoal compared to ceramic heater was ∼45%. Hence rice husk is found as a potential candidate to use directly (without any processing) in FBG as an alternative renewable energy source from agricultural field. PMID:25446789

  17. CHP from Updraft Gasifier and Stirling Engine

    OpenAIRE

    Jensen, N; Werling, J.; Carlsen, Henrik; Henriksen, Ulrik Birk

    2002-01-01

    The combination of thermal gasification with a Stirling engine is an interesting concept for use in small combined heat and power plants based on biomass. By combining the two technologies a synergism can potentially be achieved. Technical problems, e.g. gas cleaning and fouling of the Stirling engine heat exchanger, can be eliminated and the overall electric efficiency of the system can be improved. At the Technical University of Denmark a Stirling engine fueled by gasification gas has been ...

  18. Gasification of wood in a fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, L.C. de; Marti, T.; Frankenhaeuser, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    A first series of gasification experiments with our fluidized bed gasifier was performed using clean sawdust as fuel. The installation and the analytical systems were tested in a parametric study in which gasification temperature and equivalence ratio were varied. The data acquired will serve to establish the differences between the gasification of clean wood and the gasification of Altholz (scrapwood) and wood/plastics mixtures. (author) 1 fig., 3 tabs., 5 refs.

  19. Power generation in small scale from gasification of biomass; Geracao eletrica em pequena escala a partir da gaseificacao de biomassa

    Energy Technology Data Exchange (ETDEWEB)

    Lora, Electo Eduardo Silva; Andrade, Rubenildo Vieira; Aradas, Maria Eugenia Corria [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Inst. de Engenharia Mecanica. Nucleo de Excelencia em Geracao Termeletrica e Distribuida (NEST)

    2004-07-01

    This paper present a review about biomass gasifier technology and discuss its advantages, disadvantages and applications as well as shows some succeeded experiences in this area. The paper also presents an analysis of the biomass gas use in alternative engines and in new distributed generation technology such as Stirling engines and microturbines. (author)

  20. Environmental risks of biomass ashes application in soils [Resumo

    OpenAIRE

    Freire, M; Lopes, M. Helena; Tarelho, L.

    2014-01-01

    This work presents the potential environmental risks of biomass ashes application in forest soils. The ashes were collected in five industrial biomass thermal plants using different technologies: bubbling fluidized bed combustor and grate furnace.

  1. Numerical simulation of a 200 kW down draft gasifier using acai seed (Euterpe oleracea mart.) as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Itai, Y.; Rocha, H.M.Z. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Faculdade de Engenharia Mecanica]. E-mails: yuuitai@ufpa.br; hendrick@ufpa.br; Brasil, A.M. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Faculdade de Engenharia Sanitaria e Ambiental]. E-mail: ambrasil@ufpa.br; Malico, I. [Universidade de Evora (Portugal)]. E-mail: imbm@uevora.pt

    2008-07-01

    In this work a thermochemical equilibrium model for downdraft gasifiers has been proposed. The model was compared to the model developed in Gordon and McBride (1994). The properties such as efficiency of cold gas, LHV and temperature of an Amazonian biomass Euterpe olearacea Mart. was simulated. The numerical simulations aimed the maximization of H{sub 2} and CH{sub 4} in a gasification process. The model simulated numerically the influence of the gasifying relative fuel/air ratio and the biomass moisture content on the syngas composition. Two values of moisture content 33% and 37.5% were suggested for the gasification of acai seed for the maximization of the H{sub 2} and CH{sub 4} concentrations in a range of the equivalence ratio, {phi}, between 2.3 and 4. The results also showed that to achieve the maximization of CH{sub 4} with {phi} = 4 the reaction temperature drops in average of 35.44%. (author)

  2. Biomass Gas Cleanup Using a Therminator

    Energy Technology Data Exchange (ETDEWEB)

    Dayton, David C; Kataria, Atish; Gupta, Rabhubir

    2012-03-06

    The objective of the project is to develop and demonstrate a novel fluidized-bed process module called a Therminator to simultaneously destroy and/or remove tar, NH3 and H2S from raw syngas produced by a fluidized-bed biomass gasifier. The raw syngas contains as much as 10 g/m3 of tar, 4,000 ppmv of NH3 and 100 ppmv of H2S. The goal of the Therminator module would be to use promising regenerable catalysts developed for removing tar, ammonia, and H2S down to low levels (around 10 ppm). Tars are cracked to a non-condensable gas and coke that would deposit on the acid catalyst. We will deposit coke, much like a fluid catalytic cracker (FCC) in a petroleum refinery. The deposited coke fouls the catalyst, much like FCC, but the coke would be burned off in the regenerator and the regenerated catalyst would be returned to the cracker. The rapid circulation between the cracker and regenerator would ensure the availability of the required amount of regenerated catalyst to accomplish our goal. Also, by removing sulfur down to less than 10 ppmv, NH3 decomposition would also be possible in the cracker at 600-700°C. In the cracker, tar decomposes and lays down coke on the acid sites of the catalyst, NH3 is decomposed using a small amount of metal (e.g., nickel or iron) catalyst incorporated into the catalyst matrix, and H2S is removed by a small amount of a metal oxide (e.g. zinc oxide or zinc titanate) by the H2S-metal oxide reaction to form metal sulfide. After a tolerable decline in activity for these reactions, the catalyst particles (and additives) are transported to the regenerator where they are exposed to air to remove the coke and to regenerate the metal sulfide back to metal oxide. Sulfate formation is avoided by running the regeneration with slightly sub-stoichiometric quantity of oxygen. Following regeneration, the catalyst is transported back to the cracker and the cycling continues. Analogous to an FCC reactor system, rapid cycling will allow the use of very

  3. Producer gas cleaning in a dual fluidized bed reformer - a comparative study of performance with ilmenite and a manganese oxide as catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Berguerand, Nicolas; Lind, Fredrik; Seemann, Martin; Thunman, Henrik [Chalmers University of Technology, Department of Energy and Environment, Goeteborg (Sweden)

    2012-09-15

    Secondary catalytic gas conditioning is one strategy to eliminate tars formed in a producer gas during biomass gasification. However, most catalysts tend to lose their tar reforming activity after a short period of operation due to carbon formation. A novel technique for catalytic gas cleaning based on two interconnected fluidized beds has been investigated; this technique can be applied to all types of gasifiers. The idea is to reform the tar components into useful molecules - even at high tar contents - by means of a circulating catalyst. More precisely, the producer gas is cleaned with catalyst in one of the reactors, referred to as the fuel reactor, while the catalyst is continuously regenerated in another reactor, the air reactor (AR). The system described here is coupled with the Chalmers 2-4 MW{sub th} biomass gasifier while the AR is fed with nitrogen-diluted air. The effect of different catalysts on both the tar content and the gas composition was investigated. Some of the tested materials do not only reform tars, they also influence the H{sub 2}/CO ratio in a beneficial manner; in particular, ratios closer to 3 in the reformed gas are favorable if subsequent methanation is implemented. In this paper, comparative results based on testing with manganese- and iron-based catalysts are presented. The former is a manufactured catalyst while the latter is a natural ore. Results suggest that both show satisfying ability for regeneration from carbon deposits. Higher temperature enhances tar decomposition during the experiment with both catalysts. Moreover, the iron-based catalyst enhances the water-gas shift activity, which in turn impacts the total amount of produced gas. On the other hand, the manganese-based catalyst seems to display a higher propensity for tar conversion. (orig.)

  4. Straw Gasification in a Two-Stage Gasifier

    DEFF Research Database (Denmark)

    Bentzen, Jens Dall; Hindsgaul, Claus; Henriksen, Ulrik Birk;

    2002-01-01

    to maintain a high fuel reactivity, a mixture of phosphorus acid, calcium hydroxide, molasses and water was mixed into the ground pellets. Following the gasifier was running continuously for more than 50 hours as planned. Several tar, gas and particle measurements were carried out during the test...

  5. Spouting of biomass particles: a review.

    Science.gov (United States)

    Cui, Heping; Grace, John R

    2008-07-01

    Recent research on biomass multiphase flow in spouted beds is reviewed, beginning with fundamental work on hydrodynamic parameters, such as minimum spouting velocity, pressure drop and fountain height. We then consider experimental studies on biomass multiphase flow in such processes as pulp drying, liquid spouting of pulp fibres, drying and coating of agricultural biomass, and bioreactors. Finally, we summarize modelling efforts with respect to spouting of biomass particles. PMID:17570657

  6. Influence of operation conditions and additives on the development of producer gas and tar reduction in air gasification of construction woody wastes using a two-stage gasifier.

    Science.gov (United States)

    Mun, Tae-Young; Kim, Jin-O; Kim, Jin-Won; Kim, Joo-Sik

    2011-07-01

    Air gasification was conducted with fractions of construction woody wastes in a two-stage gasifier, consisting of a fluidized bed zone and a tar cracking zone. The aim of this work is to investigate the influence of reaction conditions and additives on the composition of producer gas and tar content in producer gas. A producer gas obtained with activated carbon of 540 g at an ER of 0.26 was mainly composed of H(2) (25 vol.%), CO (22 vol.%) and CH(4) (5 vol.%). Regarding tar removal efficiency, activated carbon was better than olivine. The tar removal rate with virgin activated carbon reached up to 80%. The reuse of spent activated carbon caused an efficiency loss in tar removal to some extent. Overall, it seems that the strong need for intensive downstream tar removal measurements can be removed with the use of a two-stage gasifier and the application of activated carbon. PMID:21565495

  7. Air gasification of mixed plastic wastes using calcined dolomite and activated carbon in a two-stage gasifier to reduce tar

    International Nuclear Information System (INIS)

    In this experiment, air gasification was conducted with a fraction of mixed plastic wastes using a two-stage gasifier. Calcined dolomite as a bed material and activated carbon as a tar-cracking additive were simultaneously used for the production of a producer gas containing low tar and high hydrogen. The effects of the bed material, equivalence ratio (ER), amount of activated carbon, and temperatures in two reaction zones (the upper- and lower-reactor) on the composition of producer gas and amount of tar generated were investigated. When the amount of activated carbon increased from 0 to 900 g using calcined dolomite as the bed material, the concentrations of H2 and CO in the producer gas increased sharply from 14.9 to 26.1 vol% and from 9.4 to 16.8 vol%, respectively. When 900 g of activated carbon was applied, the total tar amount was about 96% less than that obtained with only silica sand as the bed material. The maximum Lower Heating Value (LHV) of the producer gas was about 13.4 MJ/Nm3. - Highlights: ► Stable gasification of mixed plastic wastes was conducted in a two-stage gasifier. ► Strong tar removal was achieved with the combination of activated carbon and dolomite. ► Increasing amount of activated carbon resulted in less tar and high hydrogen production. ► Chlorine in feed material was mainly transferred to char or captured by activated carbon

  8. Biomass co-firing

    DEFF Research Database (Denmark)

    Yin, Chungen

    2013-01-01

    Co-firing biomass with fossil fuels in existing power plants is an attractive option for significantly increasing renewable energy resource utilization and reducing CO2 emissions. This chapter mainly discusses three direct co-firing technologies: pulverized-fuel (PF) boilers, fluidized-bed combus......Co-firing biomass with fossil fuels in existing power plants is an attractive option for significantly increasing renewable energy resource utilization and reducing CO2 emissions. This chapter mainly discusses three direct co-firing technologies: pulverized-fuel (PF) boilers, fluidized...

  9. Effect of Operating Conditions on Catalytic Gasification of Bamboo in a Fluidized Bed

    Directory of Open Access Journals (Sweden)

    Thanasit Wongsiriamnuay

    2013-01-01

    Full Text Available Catalytic gasification of bamboo in a laboratory-scale, fluidized bed reactor was investigated. Experiments were performed to determine the effects of reactor temperature (400, 500, and 600°C, gasifying medium (air and air/steam, and catalyst to biomass ratio (0 : 1, 1 : 1, and 1.5 : 1 on product gas composition, H2/CO ratio, carbon conversion efficiency, heating value, and tar conversion. From the results obtained, it was shown that at 400°C with air/steam gasification, maximum hydrogen content of 16.5% v/v, carbon conversion efficiency of 98.5%, and tar conversion of 80% were obtained. The presence of catalyst was found to promote the tar reforming reaction and resulted in improvement of heating value, carbon conversion efficiency, and gas yield due to increases in H2, CO, and CH4. The presence of steam and dolomite had an effect on the increasing of tar conversion.

  10. Experimental Investigation on Addition of Anticorrosive Agent in a 50-MW Biomass-Fired Circulating Fluidized Bed Boiler%生物质循环流化床锅炉掺烧防腐蚀剂的试验研究

    Institute of Scientific and Technical Information of China (English)

    宋景慧; 谭巍

    2014-01-01

    Experiments on combustion of pure biomass and biomass with anticorrosive agent were carried out in a 50-MW biomass-fired circulating fluidized bed boiler. The anticorrosive agent has a porous structure and mainly contains magnesium oxide (MgO), kaolin, activated alumina (Al2O3) and foamer. Results obtained in experiments show that, boiler thermal efficiency was weakly influenced by the anticorrosive agent, and contents of K and Cl in flue ash decreased as contrast to the increase of K and Cl in furnace slag. When the mass percentage of anticorrosive agent is 3%, in the flue ash, the K values ranged from 7.62%to 5.69%, and Cl values reduced from 3.86%to 2.35%. While in furnace slag, the values K varied from 4.03%to 4.71%, and Cl values increased from 756.58 mg/kg to 1 121.31 mg/kg. Due to the anticorrosive agent, the content of HCl in flue gas decreased from 25 mg/Nm3 to 15 mg/Nm3, as the emission of NO increased from 268 mg/Nm3 to 309 mg/Nm3.%在亚洲最大的50 MW生物质循环流化床直燃锅炉上进行了掺烧防腐蚀剂的燃烧试验,防腐蚀剂采用多孔膜结构,主要成分是MgO、高岭土、活性Al2O3和发泡剂,试验结果表明:掺烧防腐蚀剂不会降低锅炉热效率,且能够有效地降低飞灰中K、Cl元素的含量,将其固留在炉渣中。当防腐蚀剂添加量占总燃料质量的3%时,飞灰中的K元素含量由7.62%下降为5.69%,Cl元素含量由3.86%下降为2.35%;而炉渣中的K元素含量由4.03%上升为4.71%,Cl元素含量由756.58 mg/kg上升为1121.31 mg/kg;同时烟气中的HCl排放量由25 mg/Nm3下降为15 mg/Nm3,NO含量由268 mg/Nm3上升为309 mg/Nm3。

  11. Biofuels and biochemicals production from forest biomass in Western Canada

    International Nuclear Information System (INIS)

    Biomass can be used for the production of fuels, and chemicals with reduced life cycle (greenhouse gas) emissions. Currently, these fuels and chemicals are produced mainly from natural gas and other fossil fuels. In Western Canada, forest residue biomass is gasified for the production of syngas which is further synthesized to produce different fuels and chemicals. Two types of gasifiers: the atmospheric pressure gasifier (commercially known as SilvaGas) and the pressurized gasifier (commercially known as RENUGAS) are considered for syngas production. The production costs of methanol, (dimethyl ether), (Fischer-Tropsch) fuels, and ammonia are $0.29/kg, $0.47/kg, $0.97/kg, and $2.09/kg, respectively, for a SilvaGas-based gasification plant with a capacity of 2000 dry tonnes/day. The cost of producing methanol, DME, F-T fuels, and ammonia in a RENUGAS-based plant are $0.45/kg, $0.69/kg, $1.53/kg, and $2.72/kg, respectively, for a plant capacity of 2000 dry tonnes/day. The minimum cost of producing methanol, DME, F-T fuels, and ammonia are $0.28/kg, $0.44/kg, $0.94/kg, and $2.06/kg at plant capacities of 3000, 3500, 4000, and 3000 dry tonnes/day, respectively, using the SilvaGas-based gasification process. Biomass-based fuels and chemicals are expensive compared to fuels and chemicals derived from fossil fuels, and carbon credits can help them become competitive. -- Highlights: → Forest residue can be used for production of fuels and chemicals in Western Canada. → Methanol, dimethyl ether, Fischer-Tropsch fuel and ammonia are focus of this study. → This study estimates the production cost of these fuels and chemicals from biomass. → Economic optimum sizes of production plants are also estimated through modeling. → Costs of fuels and chemicals from biomass are higher than that from fossil fuels.

  12. A comparative study of charcoal gasification in two types of spouted bed reactors

    Energy Technology Data Exchange (ETDEWEB)

    Abdul Salam, P. [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology, P.O. Box 4, Klongluang, Pathumthani 12120 (Thailand); Bhattacharya, S.C. [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology, P.O. Box 4, Klongluang, Pathumthani 12120 (Thailand)] e-mail: bhatta@ait.ac.th

    2006-03-01

    Gasification is considered to be a favourable method for converting a solid fuel into a more versatile gaseous fuel. Performance of a gasifier depends on the design of the gasifier, type of fuel used and air flow rate, etc. The applications of spouted bed for a variety of processes such as drying, coating, pyrolysis, gasification and combustion have been reported. Gasification of solid fuels in a spouted bed, which has certain potential advantages over other fluid bed configurations, appears to be an under-exploited technique so far. Central jet distributors are the most commonly used in the experimental studies that has been reported in the literature. Circular slit distributor is a new concept. This paper presents results of a comparative experimental study on air gasification of charcoal in central jet and circular slit inert sand spouted beds. The experiments were carried for an equivalence ratio of 0.25. The effect of spouting velocity and type of the distributor on the gasification performance were discussed. The steady state dense bed temperature varied between 979 and 1183 deg C for central jet spouted bed and between 964 and 1235 deg C for circular slit spouted bed. At higher spouting velocities, the gasification efficiency of the circular slit spouted bed was slightly more compared with that of central jet spouted bed.

  13. A comparative study of charcoal gasification in two types of spouted bed reactors

    Energy Technology Data Exchange (ETDEWEB)

    Salam, P.A.; Bhattacharya, S.C. [Asian Institute of Technology, Pathumthani (Thailand). School of Environmental, Resources and Development

    2006-03-01

    Gasification is considered to be a favourable method for converting a solid fuel into a more versatile gaseous fuel. Performance of a gasifier depends on the design of the gasifier, type of fuel used and airflow rate, etc. The applications of spouted bed for a variety of processes such as drying, coating, pyrolysis, gasification and combustion have been reported. Gasification of solid fuels in a spouted bed, which has certain potential advantages over other fluid bed configurations, appears to be an under-exploited technique so far. Central jet distributors are the most commonly used in the experimental studies that has been reported in the literature. Circular slit distributor is a new concept. This paper presents results of a comparative experimental study on air gasification of charcoal in central jet and circular slit inert sand spouted beds. The experiments were carried for an equivalence ratio of 0.25. The effect of spouting velocity and type of the distributor on the gasification performance were discussed. The steady state dense bed temperature varied between 979 and 1183{sup o}C for central jet spouted bed and between 964 and 1235{sup o}C for circular slit spouted bed. At higher spouting velocities, the gasification efficiency of the circular slit spouted bed was slightly more compared with that of central jet spouted bed. (author)

  14. Integrated Biomass Gasification with Catalytic Partial Oxidation for Selective Tar Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lingzhi; Wei, Wei; Manke, Jeff; Vazquez, Arturo; Thompson, Jeff; Thompson, Mark

    2011-05-28

    Biomass gasification is a flexible and efficient way of utilizing widely available domestic renewable resources. Syngas from biomass has the potential for biofuels production, which will enhance energy security and environmental benefits. Additionally, with the successful development of low Btu fuel engines (e.g. GE Jenbacher engines), syngas from biomass can be efficiently used for power/heat co-generation. However, biomass gasification has not been widely commercialized because of a number of technical/economic issues related to gasifier design and syngas cleanup. Biomass gasification, due to its scale limitation, cannot afford to use pure oxygen as the gasification agent that used in coal gasification. Because, it uses air instead of oxygen, the biomass gasification temperature is much lower than well-understood coal gasification. The low temperature leads to a lot of tar formation and the tar can gum up the downstream equipment. Thus, the biomass gasification tar removal is a critical technology challenge for all types of biomass gasifiers. This USDA/DOE funded program (award number: DE-FG36-O8GO18085) aims to develop an advanced catalytic tar conversion system that can economically and efficiently convert tar into useful light gases (such as syngas) for downstream fuel synthesis or power generation. This program has been executed by GE Global Research in Irvine, CA, in collaboration with Professor Lanny Schmidt's group at the University of Minnesota (UoMn). Biomass gasification produces a raw syngas stream containing H2, CO, CO2, H2O, CH4 and other hydrocarbons, tars, char, and ash. Tars are defined as organic compounds that are condensable at room temperature and are assumed to be largely aromatic. Downstream units in biomass gasification such as gas engine, turbine or fuel synthesis reactors require stringent control in syngas quality, especially tar content to avoid plugging (gum) of downstream equipment. Tar- and ash-free syngas streams are a critical

  15. Coal gasifier supplying MHD-steam power plant

    International Nuclear Information System (INIS)

    An atmospheric pressure coal gasifier is combined with an MHD generator and a vapor generator to provide an entirely coal-fueled power generating system. The combustible low btu gas formed in the gasifier is passed through a gas cleaner wherein particulate matter, gaseous sulfur compounds, and char are removed to produce a clean combustible low btu gas. A first portion of the clean combustible low btu gas and the char are passed to the burner of the MHD generator as a source of fuel. A second portion of the clean combustible low btu gas is passed to a direct-fired air heater as a source of fuel for preheating the combustion air supplied to the burner of the mhd generator

  16. Biomass boilers

    OpenAIRE

    Nahodil, Jiří

    2011-01-01

    Bachelor’s thesis deals with the use of biomass for heating houses and apartment houses. The first part is dedicated to biomass. Here are mentioned the possibility of energy recovery, treatment and transformation of biomass into a form suitable for burning, its properties and combustion process itself. The second part is devoted to biomass boilers, their separation and description. The last section compares the specific biomass boiler with a boiler to natural gas, particularly from an economi...

  17. Failure Mechanisms in High Chrome Oxide Gasifier Refractories

    Science.gov (United States)

    Bennett, James P.; Kwong, Kyei-Sing

    2011-04-01

    Gasification is a high-temperature, high-pressure chemical process used to convert a carbon feedstock into CO and H2 (syngas) for use in power generation and the production of chemicals. It is also a leading candidate as a source of hydrogen in a hydrogen economy and is one of several technologies expected to see increased use in advanced fossil fuel power systems in the future. Gasification is being evaluated because of its high efficiency, its ability to capture CO2 for sequestration or reuse in other applications, and its potential for carbon feedstock fuel flexibility. At the heart of the gasification process is a gasifier, a high pressure chemical reaction vessel used to contain the interactions between carbon and water in a shortage of oxygen, producing syngas. The gasifier is lined with high chrome oxide materials to protect the containment vessel. Gasifiers are complex systems, and failure of the refractories used to line them was identified by industry as a limitation to their reliability and availability and to their increased use. NETL researchers have examined spent high-Cr2O3 (over 90 pct Cr2O3) refractories from numerous gasifiers to determine in-service failure mechanisms. This analysis revealed that premature failure of the high chrome oxide refractories was related to ash in the carbon feedstock, which liquefies during gasification and interacts with the refractories, leading to wear by chemical dissolution or spalling (structural and chemical). A discussion of this postmortem wear of spent refractory materials and of thermodynamic modeling used to explain microstructural changes leading to wear are explained in this article. This information will serve the basis to develop improved performance refractory materials.

  18. 内循环串行流化床生物质催化热解试验研究%Experimental Investigation on Biomass Catalytic Pyrolysis in an Internal Interconnected Fluidized Bed

    Institute of Scientific and Technical Information of China (English)

    叶江明; 潘其文; 张会岩; 王邓惠; 何光莹; 肖睿

    2011-01-01

    在处理量为0.2 kg/h的新型内循环串行流化床(IIFB)上进行了生物质催化热解制油的试验研究.以木屑为原料、石英砂为热载体,研究了在没有催化剂条件下反应温度对热解产物分布的影响;以HZSM-5催化剂与石英砂混合物为床料进行了催化热解试验,并对热解产物和反应后的催化剂进行了表征分析.结果表明:反应温度为515℃时,液体产物的收率最高.HZSM-5催化剂的加入促进了气体以及焦炭的生成,使液体产物的收率降低,且催化剂体积分数越大,影响越显著.催化荆表面的积炭经燃烧反应后被除去,催化剂的稳定性得到改善.热解不可冷凝气体的主要成分为CO和CO2,随着热解温度的升高,CO2产量下降,CO和CH4的产量增加.经HZSM-5催化热解后,生物油中的酸、醛和酮类物质含量明显减少,而小分子的烃类与酚类物质含量明显增加,表明催化剂具有明显的脱氧效果.%Experimental study on biomass catalytic pyrolysis for oil production was carried out on a new type internal interconnected fluidized bed (IIFB) with capacity of 0.2 kg/h. Using sawdust as the raw material and quartz sand as the heat carrier, the effect of reaction temperature on distribution of pyrolysis products was studied without catalyst. Catalytic pyrolysis experiments were carried out by using the mixture of HZSM-5 catalyst and quartz sand as the bed material, after which corresponding pyrolysis products and the used catalyst were characterized and analyzed. Results show that the liquid production is the largest at a reaction temperature of 515 ℃. Addition of catalyst HZSM-5 promotes the formation of gas and char, thus reducing the production of liquids. The more volumetric fraction of catalyst is, the more obvious the effect will be. The deposit char on surface of the catalyst is removed by combustion reaction, and the stability of the catalyst is improved. The main compositions of incondensable

  19. 浆态床反应器中生物质合成气合成二甲醚的研究%DME synthesis from biomass-derived syngas in a slurry-bed reactor

    Institute of Scientific and Technical Information of China (English)

    马俊国; 葛庆杰; 马现刚; 徐恒泳

    2012-01-01

    Dimethyl ether (DME) synthesis from biomass-derived syngas in a slurry-bed reactor was investigated over a hybrid catalyst composed of methanol synthesis catalyst and molecular sieve. The results showed that the catalyst containing SAPO-11 exhibits higher DME selectivity and catalytic stability, which is closely related to the weak acidity of SAPO-11 in the hybrid catalysts. 40% CO conversion and 95% DME selectivity in organic products could be kept during 35 h stability test over the hybrid catalyst when the weight ratio of methanol synthesis catalyst to SAPO-11 was 3.%进行了浆态床反应器中,甲醇合成催化剂与分子筛混合制复合催化剂上,生物质制取的合成气(简称生物质合成气)一步法合成二甲醚的研究,重点考察了不同脱水组分和工艺条件对催化剂反应性能的影响,同时,结合NH3 -TPD等手段对催化剂进行了表征.结果表明,含有较弱酸性SAPO-11分子筛的复合催化剂更适合生物质合成气原料气杂质多、氢碳比低的特点,在合成二甲醚反应中具有更高的选择性和稳定性.250℃、5 MPa、500 h-1时,在甲醇催化剂与SAPO-11分子筛比例为3∶1的复合催化剂上,合成气合成二甲醚反应35 h内,CO转化率稳定在40%以上,二甲醚在有机产品中的选择性保持在97%左右.

  20. Study on Microstructure and Slag Corrosion Mechanism of High Chrome Bricks for Gasifier

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Research was focused on slag corrosion mechanism of high chrome bricks used for different types of gasifier by comparing the structure of high chrome bricks for petroleum coke gasifier and water-coal slurry gasifier with slag corroded testing brick and water coal slurry gasifier through Scanning Electron Microscope (SEM) examination and X-ray diffraction. Results show that for high chrome brick used for petroleum coke gasifier, corrosion is mainly caused by Cr2O3 in the brick and V2O5 in molten slag and liquid phase generation at low temperature; for high chrome brick used for water-coal slurry gasifier, corrosion is caused by dissolution of Cr2O3 in molten slag and corrosion of ZrO2. For LIRR-HK95 brick, it performs better petroleum coke corrosion resistance than the others due to the optimal composition and structure.

  1. LaMnAl11O19催化剂上生物质气化气燃烧中NH3-NOx的转化特性%Conversion of NH3-NOx in gasified biomass over LaMnAl11 O19 catalyst

    Institute of Scientific and Technical Information of China (English)

    彭丹; 孙路石; 王志远; 孔继红; 向军; 胡松; 苏胜

    2011-01-01

    采用共沉淀法制备了LaMnAl11O19六铝酸盐催化剂,采用XRD、BET和XPS对样品结构进行了表征,并通过模拟生物质气化气的燃烧实验和NH3单独氧化实验,分别考察了催化燃烧和均相燃烧过程中NH3的转化特性.利用原位漫反射红外光谱(in-situ DRIFT)法在线研究了NH3在催化剂表面的吸附和氧化信息.结果表明,焙烧后催化剂形成磁铅石(MP)结构的六铝酸盐晶体,且具有较大的比表面积,Mn以+2、+3价形式存在晶体中.均相燃烧下模拟气中的NH3在500℃开始反应,随之就有NO生成.催化燃烧工况下NH3氧化曲线和模拟气中NH3的转化曲线相差不大,NH3的起燃温度为310℃,反应后随之就有NO生成,NO在350℃~800℃保持一个较高的浓度.NO2的生成温度较高,并仅在较窄的温度区间内出现,在整个燃烧过程中仅检测到几个10-6的N2O,反应过程中有40%以上的NH3转化成NO.DRIFT结果表明,催化剂作用下NH3的转化遵循-NH反应机理,即催化剂表面吸附的NH3分解产生-NH,-NH与氧原子(O)反应生成HNO,再进一步反应生成N2或N2O,或是-NH直接与氧分子(O2)反应生成NO.%LaMnAl1,O19 catalysts were prepared by co-precipitation method and characterized with XRD, BET and XPS. The conversion of NH3 at the conditions of catalytic combustion and homogeneous combustion were studied by combustion of simulated biomass gasification gas and NH3 oxidation, respectively. Moreover, the NH3 adsorption and oxidation on the surfaces of the catalyst samples were examined by in-situ DRIFT experiments. It was found that calcination of the percursors at 1 200℃ led to the formation of a final monophasic materials with MP structure and high surface area, while the Mn ions were either divalent or trivalent. Under homogeneous combustion condition, NH3 at simulated biomass gasification gas started to react at 500℃, then NO was formed. Under catalytic combustion condition, the curves of NH3 oxidation with

  2. Biomass fuelled trigeneration system in selected buildings

    International Nuclear Information System (INIS)

    Highlights: → We model a commercial building scale biomass fuelled trigeneration plant. → It is economically feasible to use willow chips, miscanthus and rice husk as the fuel to operate the trigeneration system. → The efficiency of TG is much higher than that of PO, but is lower than that of the combined heat and power (CHP) configuration. → The breakeven electricity selling price (BESP) of the TG system is better than that of the PO option with the CHP option producing the cheapest electricity. -- Abstract: Many buildings require simultaneous electricity, heating and cooling. Biomass is one of the renewable energy sources which is not intermittent, location-dependent or very difficult to store. If grown sustainably, biomass can be considered to be CO2 neutral. A trigeneration system consisting of an internal combustion (IC) engine integrated with biomass gasification may offer a combination for delivering heat, electricity and cooling cleanly and economically. The producer gas generated by the gasifier is used to provide electricity for building use via the IC engine. The waste heat is recovered from the engine cooling system and exhaust gases to supply hot water to space heating, excess heat is also used to drive an absorption cooling system. The proposed system is designed to meet the energy requirements for selected commercial buildings and district heating/cooling applications. This work focuses on the modeling and simulation of a commercial building scale trigeneration plant fuelled by a biomass downdraft gasifier. In order to use both energy and financial resources most efficiently, technical and economic analyses were carried out, using the ECLIPSE process simulation package. The study also looks at the impact of different biomass feedstock (willow, rice husk and miscanthus) on the performance of a trigeneration plant.

  3. Biomass fuelled trigeneration system in selected buildings

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y., E-mail: y.huang@ulster.ac.u [Centre for Sustainable Technologies, School of Built Environment, University of Ulster, Newtownabbey, BT37 0QB (United Kingdom); Wang, Y.D. [The Sir Joseph Swan Institute for Energy Research, Newcastle University, Newcastle Upon Tyne, NE1 7RU (United Kingdom); Rezvani, S.; McIlveen-Wright, D.R.; Anderson, M.; Hewitt, N.J. [Centre for Sustainable Technologies, School of Built Environment, University of Ulster, Newtownabbey, BT37 0QB (United Kingdom)

    2011-06-15

    Highlights: {yields} We model a commercial building scale biomass fuelled trigeneration plant. {yields} It is economically feasible to use willow chips, miscanthus and rice husk as the fuel to operate the trigeneration system. {yields} The efficiency of TG is much higher than that of PO, but is lower than that of the combined heat and power (CHP) configuration. {yields} The breakeven electricity selling price (BESP) of the TG system is better than that of the PO option with the CHP option producing the cheapest electricity. -- Abstract: Many buildings require simultaneous electricity, heating and cooling. Biomass is one of the renewable energy sources which is not intermittent, location-dependent or very difficult to store. If grown sustainably, biomass can be considered to be CO{sub 2} neutral. A trigeneration system consisting of an internal combustion (IC) engine integrated with biomass gasification may offer a combination for delivering heat, electricity and cooling cleanly and economically. The producer gas generated by the gasifier is used to provide electricity for building use via the IC engine. The waste heat is recovered from the engine cooling system and exhaust gases to supply hot water to space heating, excess heat is also used to drive an absorption cooling system. The proposed system is designed to meet the energy requirements for selected commercial buildings and district heating/cooling applications. This work focuses on the modeling and simulation of a commercial building scale trigeneration plant fuelled by a biomass downdraft gasifier. In order to use both energy and financial resources most efficiently, technical and economic analyses were carried out, using the ECLIPSE process simulation package. The study also looks at the impact of different biomass feedstock (willow, rice husk and miscanthus) on the performance of a trigeneration plant.

  4. Syngas production by gasification of aquatic biomass with CO2/O2 and simultaneous removal of H2S and COS using char obtained in the gasification

    International Nuclear Information System (INIS)

    Applicability of gulfweed as feedstock for a biomass-to-liquid (BTL) process was studied for both production of gas with high syngas (CO + H2) content via gasification of gulfweed and removal of gaseous impurities using char obtained in the gasification. Gulfweed as aqueous biomass was gasified with He/CO2/O2 using a downdraft fixed-bed gasifier at ambient pressure and 900 °C at equivalence ratios (ER) of 0.1–0.3. The syngas content increased while the conversion to gas on a carbon basis decreased with decreasing ER. At an ER of 0.1 and He/CO2/O2 = 0/85/15%, the syngas content was maximized at 67.6% and conversion to gas on a carbon basis was 94.2%. The behavior of the desulfurization using char obtained during the gasification process at ER = 0.1 and He/CO2/O2 = 0/85/15% was investigated using a downdraft fixed-bed reactor at 250–550 °C under 3 atmospheres (H2S/N2, COS/N2, and a mixture of gases composed of CO, CO2, H2, N2, CH4, H2S, COS, and steam). The char had a higher COS removal capacity at 350 °C than commercial activated carbon because (Ca,Mg)S crystals were formed during desulfurization. The char simultaneously removed H2S and COS from the mixture of gases at 450 °C more efficiently than did activated carbon. These results support this novel BTL process consisting of gasification of gulfweed with CO2/O2 and dry gas cleaning using self-supplied bed material. -- Highlights: • A product gas with high syngas content was produced from the gasification of gulfweed with CO2/O2. • The syngas content increased with decreasing the equivalence ratio. • The syngas content was maximized at 67.6% at an ER of 0.1 and He/CO2/O2 = 0/85/15%. • The char simultaneously removed H2S and COS from a mixture of gases at 450 °C efficiently

  5. Analytical Investigations of Kinetic and Heat Transfer in Slow Pyrolysis of a Biomass Particle

    OpenAIRE

    S.J Ojolo; C.A. Osheku; M.G Sobamowo

    2013-01-01

    The utilization of biomass for heat and power generation has aroused the interest of most researchers especially those of energy .In converting solid fuel to a usable form of energy,pyrolysis plays an integral role. Understanding this very important phenomenon in the thermochemical conversion processes and representing it with appropriate mathematical models is vital in the design of pyrolysis reactors and biomass gasifiers. Therefore, this study presents analytical solutions to the kinetic a...

  6. Biomass pretreatment

    Science.gov (United States)

    Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P

    2013-05-21

    A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.

  7. Effect of bed temperature and bed composition on agglomeration during gasification of high-sodium, high-sulphur lignite in a spouted fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    D.P. McCullough; P.J. Mullinger; P.J. Ashman [University of Adelaide, Adelaide, SA (Australia). Cooperative Research Centre for Clean Power from Lignite, School of Chemical Engineering

    2003-07-01

    Fluidised bed gasification (FBG) is an alternative process for coal utilisation that delivers improved efficiencies and lower temperature operation compared to conventional technology. Agglomeration and defluidisation are phenomena that have the potential to occur within fluidised bed reactors, which can interrupt stable process operation. While extensive work has been carried out investigating fluidised bed combustion of lignite, relatively little work has been carried out for lignite under fluidised bed gasification conditions. Gasification of high sodium, high sulphur content lignite in a spouted bed gasifier (SBG) indicates that agglomeration and defluidisation is only an issue when maximum bed temperature exceeds approximately 850{degree}C and air/fuel ratios of 2.5 outside of these conditions, defluidisation is not detected. It is also demonstrated that defluidisation occurs before agglomeration, rather than as a result of agglomeration as previously thought. The Rosin-Rammler method of describing particle size distribution is found to yield appropriate variables for quantification of the extent of agglomeration taking place in cases where defluidisation is a factor. However, it has been shown by this method that while initial results indicated that agglomeration extent varies directly with maximum bed temperature, further results have shown that other variables, such as superficial velocity, have a significant impact on the extent of agglomeration. Investigations are currently continuing. 9 refs., 8 figs., 9 tabs.

  8. Bed to wall heat transfer in supercritical water fluidized bed: Comparison with the gas–solid fluidized bed

    International Nuclear Information System (INIS)

    Supercritical water (SCW) fluidized bed is a new reactor concept for gasification of wet biomass. In this paper, the Eulerian two-fluid model based on Kinetic Theory of Granular Flow in fluidized bed was established, and the physical model of movement of single bubble up the wall was adopted. The comparison studies of particle distribution, temperature distribution and transient heat transfer characteristics between the SCW and gas–solid fluidized bed were carried out. The results show that the bubble diameter and rise velocity in SCW fluidized bed are smaller than those in gas–solid fluidized bed. With the increasing solid volume fraction near the wall, the bed-to-wall heat transfer coefficient decreases in SCW fluidized bed, while it increases in gas–solid fluidized bed. What is more, the bed-to-wall heat transfer coefficient is sensitive to superficial velocity where the solid volume fraction is low, which is different from that in gas–solid fluidized bed

  9. Economic analysis of a 20 kW gasifier; Analise economica de um gaseificador de 20 kW

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcos Vinicius Miranda da; Rocha, Brigida Ramati Pereira da [Universidade Federal do Para (NEDS/UFPA), Belem, PA (Brazil). Nucleo de Energia para o Desenvolvimento Sustentavel], e-mail: neds@ufpa.br

    2006-07-01

    The gasification of biomass residues has been pointed as an alternative in electricity supplying for small communities of the Amazon region, because it promotes a significant substitution of the diesel oil in the electric power generation. This paper presents an economic analysis of an electricity generation system (gasifier and generator set) of 20 kw that is installed in the community of Jenipauba, in the State of Para. That analysis confirms the economic attractiveness of that energy alternative on the generator sets that operate exclusively with diesel oil. It also shows the impact of the labor law on electricity generation cost, as well as the need of subsidizing the electric power generation, because the community of Jenipauba is very poor. (author)

  10. Environmental assessment of the atlas bio-energy waste wood fluidized bed gasification power plant. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Holzman, M.I.

    1995-08-01

    The Atlas Bio-Energy Corporation is proposing to develop and operate a 3 MW power plant in Brooklyn, New York that will produce electricity by gasification of waste wood and combustion of the produced low-Btu gas in a conventional package steam boiler coupled to a steam-electric generator. The objectives of this project were to assist Atlas in addressing the environmental permit requirements for the proposed power plant and to evaluate the environmental and economic impacts of the project compared to more conventional small power plants. The project`s goal was to help promote the commercialization of biomass gasification as an environmentally acceptable and economically attractive alternative to conventional wood combustion. The specific components of this research included: (1) Development of a permitting strategy plan; (2) Characterization of New York City waste wood; (3) Characterization of fluidized bed gasifier/boiler emissions; (4) Performance of an environmental impact analysis; (5) Preparation of an economic evaluation; and (6) Discussion of operational and maintenance concerns. The project is being performed in two phases. Phase I, which is the subject of this report, involves the environmental permitting and environmental/economic assessment of the project. Pending NYSERDA participation, Phase II will include development and implementation of a demonstration program to evaluate the environmental and economic impacts of the full-scale gasification project.

  11. Optical Fiber Sensor Instrumentation for Slagging Coal Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Anbo Wang; Kristie Cooper

    2008-07-19

    Coal gasifier is one of the most promising solutions for clean fossil energy. Refractory thickness monitoring and online real-time temperature measurement is needed for improved reliability and advanced process control for current and future generation power plants. The objective of this program is to design and implement an optical fiber based sensing system that could potentially be used to monitor refractory wall thickness and temperature inside a coal gasifier. For the thickness monitoring, the system should be able to operate at temperatures up to 1000 C. For this temperature range, silica fiber can still work so it is chosen for the sensor design. The measurement is based on a photon counting optical time domain reflectometer. A narrow light pulse is launched into a silica fiber which could be embedded into the gasifier refractory wal