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Sample records for fluidised bed gasifier

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

    International Nuclear Information System (INIS)

    Tremel, Alexander; Becherer, Dominik; Fendt, Sebastian; Gaderer, Matthias; Spliethoff, Hartmut

    2013-01-01

    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 MW th to 500 MW th . 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 MW th ) and €7.4 cent/kWh (10 MW th ) in the economic analysis of both technologies. The study indicates that the

  2. 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.)

  3. Potential of synthesis gas production from rubber wood chip gasification in a bubbling fluidised bed gasifier

    International Nuclear Information System (INIS)

    Kaewluan, Sommas; Pipatmanomai, Suneerat

    2011-01-01

    Experiments of rubber wood chip gasification were carried out in a 100-kW th bubbling fluidised bed gasifier to investigate the effect of air to fuel ratio (represented as equivalence ratio - ER) on the yield and properties of synthesis gas. For all experiments, the flow rate of ambient air was fixed, while the feed rate of rubber wood chip was adjusted to vary ER in the range of 0.32-0.43. Increasing ER continuously raised the bed temperature, which resulted in higher synthesis gas yield and lower yield of ash and tar. However, higher ER generally gave synthesis gas of lower heating value, partly due to the dilution of N 2 . Considering the energy efficiency of the process, the optimum operation was achieved at ER = 0.38, which yielded 2.33 Nm 3 of synthesis gas per kg of dry biomass at the heating value of 4.94 MJ/Nm 3 . The calculated carbon conversion efficiency and gasification efficiency were 97.3% and 80.2%, respectively. The mass and energy balance of the gasification process showed that the mass and energy distribution was significantly affected by ER and that the energy losses accounted for ∼25% of the total output energy. The economical assessment of synthesis gas utilisation for heat and electricity production based on a 1-MW th bubbling fluidised bed gasifier and the operational data resulting from the rubber wood chip gasification experiments in this study clearly demonstrated the attractiveness of replacing heavy fuel oil and natural gas by the synthesis gas for heat applications in terms of 70% and 50% annual saving of fuel cost, respectively. However, the case of electricity production does not seem a preferable option due to its current technical and non-technical barriers.

  4. Microwave-assisted synthesis of geopolymers from fluidised bed gasifier bottom ash

    CSIR Research Space (South Africa)

    Oboirien, BO

    2013-09-01

    Full Text Available Fluidised bed gasification (FBG) is a clean coal technology suitable for power and fuel generation from low grade coals. However, the resulting bottom ash presents some disposal challenges to the power plants and the environment. The production...

  5. Making the most of South Africa’s low-quality coal: Converting high-ash coal to fuel gas using bubbling fluidised bed gasifiers

    CSIR Research Space (South Africa)

    Engelbrecht, AD

    2010-08-31

    Full Text Available for process heating or for power generation using the IGCC (Integrated Gasification Combined Cycle) process. A high-ash coal from the Waterberg coalfield was tested in a bubbling fluidised bed gasifier using various gasification agents and operating conditions...

  6. 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.

  7. 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

    1997-12-31

    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.

  8. 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)

  9. Fluidised bed heat exchangers

    International Nuclear Information System (INIS)

    Elliott, D.E.; Healey, E.M.; Roberts, A.G.

    1974-01-01

    Problems that have arisen during the initial stages of development of fluidised bed boilers in which heat transfer surfaces are immersed in fluidised solids are discussed. The very high heat transfer coefficients that are obtained under these conditions can be exploited to reduce the total heat transfer surface to a fraction of that in normal boilers. However, with the high heat flux levels involved, tube stressing becomes more important and it is advantageous to use smaller diameter tubes. One of the initial problems was that the pumping power absorbed by the fluidised bed appeared to be high. The relative influence of the fluidising velocity (and the corresponding bed area), tube diameter, tube spacing, heat transfer coefficient and bed temperature on pumping power and overall cost was determined. This showed the importance of close tube packing and research was undertaken to see if this would adversely affect the heat transfer coefficient. Pressure operation also reduces the pumping power. Fouling and corrosion tests in beds burning coal suggest that higher temperatures could be reached reliably and cost studies show that, provided the better refractory metals are used, the cost of achieving higher temperatures is not unduly high. It now remains to demonstrate at large scale that the proposed systems are viable and that the methods incorporated to overcome start up and part lead running problems are satisfactory. The promising role of these heat transfer techniques in other applications is briefly discussed

  10. Fluidised bed cereal cooking

    International Nuclear Information System (INIS)

    Jenkins, Simon Anthony

    2002-01-01

    Man has been cooking food for thousands of years for a number of reasons: to improve flavour and palatability, sterilise, increase digestibility, improve texture and colour. Increasingly more advanced techniques are employed today in food production plants to engineer foods with many different properties. With this in mind manufacturers are constantly seeking to improve processing techniques and apply new or different technologies (such as microwaves, RF and extrusion) to develop foods with new properties (like puffed texture starches) and to increase process efficiencies (energy efficiency, water reduction). This thesis reports on work undertaken to demonstrate the potential to achieve high temperature starch conversion of whole wheat grains in a fluidised bed, thereby reducing the amount of water required and processing time. Specifically, wheat from the farm at 14% water content is cooked in a fluidised bed. The fluidised bed heats the wheat quickly by convective heating. In addition, energy can be delivered directly to the grain by microwave heating during fluidisation. Degree of starch conversion is determined by measuring the reduction in size of endotherm of reaction as observed by Differential Scanning Calorimetry. The fluidising gas, processing temperature and starting moisture content were varied in order to investigate their effect on the cooking process. A mathematical model based on energy and species concentration equations was developed to help understand the internal grain processes. The model coupled the thermal energy equation with water diffusion. The effect of water evaporation was represented as a thermal sink in the energy equation. Popular kinetic models from literature were adapted to predict the degree of starch conversion. The model gives solutions consistent with experimental data and physical intuition. A commercial computational fluid dynamics package was used to study simple airflow and particle tracks in the fluidisation column. A

  11. Fluidised bed gasification of low grade South African coals

    CSIR Research Space (South Africa)

    North, BC

    2006-09-01

    Full Text Available gasifiers. Fluidised bed Entrained flow Coal particle size 0.5 mm – 5 mm 0 – 0.5 mm Coal moisture Dry Dry/slurry Coal type Non-caking coals Any coal Ash in coal < 60% < 30% Gasification agents Air/steam/oxygen Steam/oxygen Gasification... properties important for fluidised bed gasification are: square4 Coal reactivity in atmospheres of CO2 and H2O square4 Caking index and free swelling index (FSI) square4 Ash fusion temperature (AFT) 5.1 Coal reactivity The gasifcation reactions (1...

  12. Fluidised bed combustion system

    International Nuclear Information System (INIS)

    McKenzie, E.C.

    1976-01-01

    Fluidized bed combustion systems that facilitates the maintenance of the depth of the bed are described. A discharge pipe projects upwardly into the bed so that bed material can flow into its upper end and escape downwardly. The end of the pipe is surrounded by an enclosure and air is discharged into the enclosure so that material will enter the pipe from within the enclosure and have been cooled in the enclosure by the air discharged into it. The walls of the enclosure may themselves be cooled

  13. Solid phase transport in series fluidised bed reactors

    International Nuclear Information System (INIS)

    Hayes, M.R.

    1980-01-01

    In a multistage counter-current fluidised bed column, fluidised bed material is recycled within each stage and a fraction is continuously withdrawn to the next lower stage at a rate dependent only on the rate of removal of the fluidised bed material from the base of the column. It has a particular application to the ion exchange treatment of liquids containing suspended solids, for example leach solutions from uranium ores. (author)

  14. Fungi solubilisation of low rank coal: performances of stirred tank, fluidised bed and packed bed reactors

    CSIR Research Space (South Africa)

    Oboirien, BO

    2013-02-01

    Full Text Available Coal biosolubilisation was investigated in stirred tank reactor, fluidised bed and fixed bed bioreactors with a view to highlight the advantages and shortcomings of each of these reactor configurations. The stirred aerated bioreactor and fluidised...

  15. Fluidised bed gasification of high-ash South African coals: An experimental and modelling study

    CSIR Research Space (South Africa)

    Engelbrecht, AS

    2011-11-01

    Full Text Available model (CeSFaMB). The predictive capability of the model was analysed in terms of the degree of variation between experimental and simulated results for each test. The calibrated model was used to design a 15 MW fluidised bed coal gasifier...-scale BFBG are given in Figure 1 and Table 1. Process description Coal, air, oxygen and steam are the input streams to the process which produce the output streams: gas and char (ash). Coal is fed to the gasifier by means of a screw conveyor at a...

  16. 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.)

  17. Biofluid process: fluidised-bed gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

    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.)

  18. Modeling and Simulation of a lab-scale Fluidised Bed

    Directory of Open Access Journals (Sweden)

    Britt Halvorsen

    2002-04-01

    Full Text Available The flow behaviour of a lab-scale fluidised bed with a central jet has been simulated. The study has been performed with an in-house computational fluid dynamics (CFD model named FLOTRACS-MP-3D. The CFD model is based on a multi-fluid Eulerian description of the phases, where the kinetic theory for granular flow forms the basis for turbulence modelling of the solid phases. A two-dimensional Cartesian co-ordinate system is used to describe the geometry. This paper discusses whether bubble formation and bed height are influenced by coefficient of restitution, drag model and number of solid phases. Measurements of the same fluidised bed with a digital video camera are performed. Computational results are compared with the experimental results, and the discrepancies are discussed.

  19. Coal-char combustion in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mehrotra, S.P.; Pande, M. [Indian Institute of Technolgy, Kanpur (India)

    2001-12-01

    Combustion of bituminous coal chars ranging from 0.8 mm to 1.8 mm has been studied in a fluidised bed reactor at temperatures ranging from 500 to 850{sup o}C. The fluidised bed consists of inert sand particles of average size of 0.5 mm and reactive coal char particles. A heat balance has been worked out to calculate the rate of combustion of char from measured incremental changes in the bed temperature during combustion. Investigations on partially burnt particles suggest that the ash layer which builds up around the burning core of char particles is non-flaking and the particles burn in a shrinking core manner. Analysis of rate data indicates that the rate of combustion is controlled by chemical reaction kinetics, though diffusion of oxygen through the bundary layer begins to influence the overall reaction kinetics at higher temperatures. The burnt out time varies linearly with particle size. Activation energy for the chemical reaction control regime is found to be around 68 kJ/mole.

  20. Pressurised fluidised-bed gasification experiments with biomass, peat and coal at VTT in 1991-1994. Gasification of Danish wheat, straw and coal

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E; Laatikainen-Luntama, J; Staahlberg, P; Moilanen, A [VTT Energy, Espoo (Finland). Energy Production Technologies

    1997-12-31

    Fluidised-bed air gasification of three different Danish straw feedstocks and Colombian bituminous coal was studied in the PDU-scale test facilities of VTT. The test programme was divided into two different modes of operation. First, the usability of straw as the only feedstock was investigated by operating the gasifier at relatively low temperature normally used in biomass gasifiers. In this operation mode the main aim was to find out the limits for gasification temperatures, set by the sintering behaviour of the straw. Secondly, the use of straw as an additional feedstock in a fluidised-bed coal gasifier was examined by operating the gasifier at about 1 000 deg C with different ratings of straw and coal feeding. The gasifier was operated at 5 bar pressure and at 80 990 deg C. The product gas was cleaned by ceramic candle filters operated at 465-540 deg C. Concentrations of tars, nitrogen com- pounds, sulphur gases, vapour-phase alkali metals as well as chlorine were determined in different operating conditions. (12 refs.)

  1. a novel interconnected fluidised bed for the combined flash pyrolysis of biomass and combustion of char

    NARCIS (Netherlands)

    Janse, A.M.C.; Janse, Arthur M.C.; Biesheuvel, P.M.; Biesheuvel, Pieter Maarten; Prins, W.; van Swaaij, Willibrordus Petrus Maria

    1999-01-01

    A novel system of two adjacent fluidised beds operating in different gas atmospheres and exchanging solids was developed for the combined flash pyrolysis of biomass and combustion of the produced char. Fluidised sand particles (200 μm < dp < 400 μm) are transported from the pyrolysis reactor to the

  2. A novel interconnected fluidised bed for the combined flash pyrolysis of biomass and combustion of char.

    NARCIS (Netherlands)

    Janse, Arthur M.C.; Janse, A.M.C.; Biesheuvel, P.M.; Biesheuvel, Pieter Maarten; Prins, W.; van Swaaij, Willibrordus Petrus Maria

    2000-01-01

    A novel system of two adjacent fluidised beds operating in different gas atmospheres and exchanging solids was developed for the combined flash pyrolysis of biomass and combustion of the produced char. Fluidised sand particles (200 μm < dp < 400 μm) are transported from the pyrolysis reactor to the

  3. Combustion of poultry litter in a fluidised bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    P. Abelha; I. Gulyurtlu; D. Boavida; J. Seabra Barros; I. Cabrita; J. Leahy; B. Kelleher; M. Leahy [DEECA-INETI, Lisbon (Portugal)

    2003-04-01

    Combustion studies of poultry litter alone or mixed with peat by 50% on weight basis were undertaken in an atmospheric bubbling fluidised bed. Because of high moisture content of poultry litter, there was some uncertainty whether the combustion could be sustained on 100% poultry litter and as peat is very available in Ireland, its presence was considered to help to improve the combustion. However, the results showed that, as long as the moisture content of poultry litter was kept below 25%, the combustion did not need the addition of peat. The main parameters that were investigated are (i) moisture content, (ii) air staging, and (iii) variations in excess air levels along the freeboard. The main conclusions of the results are (i) combustion was influenced very much by the conditions of the fuel supply, (ii) the steady fuel supply was strongly dependent on the moisture content of the poultry litter, (iii) temperature appeared to be still very influential in reducing the levels of unburned carbon and hydrocarbons released from residues, (iv) the air staging in the freeboard improved combustion efficiency by enhancing the combustion of volatiles released from residues in the riser and (vi) NOx emissions were influenced by air staging in the freeboard. Particles collected from the bed and the two cyclones were analysed to determine the levels of heavy metals and the leachability tests were carried out with ashes collected to verify whether or not they could safely be used in agricultural lands. 8 refs., 1 fig., 8 tabs.

  4. 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.

  5. 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.

  6. The combustion of coal blends in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Boavida, Dulce; Abelha, Pedro; Gulyurtlu, Ibrahim; Cabrita, Isabel

    1999-07-01

    Combustion studies of five coals of different origin were carried out in a laboratory scale fluidised bed combustor. Five blends prepared by mixing two coals based on their petrological characterisation, in varying amounts, were selected to study the possibility of reduction NO{sub x}, N{sub 2}O and SO{sub 2} emissions. The results showed that some blends had the opposite behaviour concerning the release of NO{sub x} and SO{sub 2} in relation to parent coals, and the emissions were higher than expected. The N{sub 2}O amounts observed were, however, in almost all blends tested, lower than predicted values. With some blends, the mixing levels intended to reduce SO{sub 2} were not always found to correspond to those for simultaneous decrease of Nox. Most of the blends studied showed some evidence of interaction between them. Varying the proportion of the blend components was observed to alter the temperatures at which interactions were stronger.

  7. 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...

  8. Experimental measurement of variation of heat transfer coefficient and temperature gradients in 16'' deep fluidised beds

    International Nuclear Information System (INIS)

    Blacker, P.T.; McLain, D.R.

    1962-04-01

    The object of the experiments was to choose suitable particulate materials for a fluidised bed cooler, to test a deep fluidised bed for uniformity of heat transfer coefficient, and to explore the temperature distribution in a centrally heated annular fluidised bed. This memorandum records the techniques used and some of the practical aspects involved, together with the performance results obtained, for the assistance of other experimenters who may wish to use fluidised beds as a laboratory technique. Mathematical correlation of the results has not been attempted since some of the properties of the bed material were not known and to determine them was beyond the scope of the work programme. Rather, we have compared our results with those of other experimenters. Graphite tubes, for use in steady state thermal stress experiments, are to be heated by a graphite radiant heater situated in the bore and cooled on the outer surface. The tubes are 2 cm. bore, 8 cm. outside diameter and 48 cm. long. The outside temperature of the tubes is to be between 500 deg. C. and 1500 deg. C. It is estimated that the heat transfer rate required for fracture at the outer surface is 30 watts/cm 2 . This could readily be achieved by cooling with liquid metals, water or high velocity gas. However, serious problems of either materials compatibility or mechanical complexity make these undesirable. A water-cooled fluidised bed of compatible solids fluidised with nitrogen gas can overcome most of these problems and give heat transfer coefficients close to that required, vis. about 0.1 w/cm C . A coolant bed about 20'' long would be required and an annulus of about 2'' radial width round the specimen was considered to be practicable

  9. Experimental measurement of variation of heat transfer coefficient and temperature gradients in 16'' deep fluidised beds

    Energy Technology Data Exchange (ETDEWEB)

    Blacker, P T; McLain, D R [Reactor Development Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1962-04-15

    The object of the experiments was to choose suitable particulate materials for a fluidised bed cooler, to test a deep fluidised bed for uniformity of heat transfer coefficient, and to explore the temperature distribution in a centrally heated annular fluidised bed. This memorandum records the techniques used and some of the practical aspects involved, together with the performance results obtained, for the assistance of other experimenters who may wish to use fluidised beds as a laboratory technique. Mathematical correlation of the results has not been attempted since some of the properties of the bed material were not known and to determine them was beyond the scope of the work programme. Rather, we have compared our results with those of other experimenters. Graphite tubes, for use in steady state thermal stress experiments, are to be heated by a graphite radiant heater situated in the bore and cooled on the outer surface. The tubes are 2 cm. bore, 8 cm. outside diameter and 48 cm. long. The outside temperature of the tubes is to be between 500 deg. C. and 1500 deg. C. It is estimated that the heat transfer rate required for fracture at the outer surface is 30 watts/cm{sup 2}. This could readily be achieved by cooling with liquid metals, water or high velocity gas. However, serious problems of either materials compatibility or mechanical complexity make these undesirable. A water-cooled fluidised bed of compatible solids fluidised with nitrogen gas can overcome most of these problems and give heat transfer coefficients close to that required, vis. about 0.1 w/cm C . A coolant bed about 20'' long would be required and an annulus of about 2'' radial width round the specimen was considered to be practicable.

  10. Method for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    Science.gov (United States)

    Grindley, Thomas

    1989-01-01

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600.degree. to 1800.degree. F. and are partially quenched with water to 1000.degree. to 1200.degree. F. before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime/limestone.

  11. Gaseous emissions in pressurised fluidised-bed combustion. Analysis and summary of the pilot experiments

    International Nuclear Information System (INIS)

    Korpela, T.; Hippinen, I.; Konkola, M.

    1996-01-01

    The influence of operating conditions on gaseous emissions in pressurised fluidised-bed combustion have been studied. The research objectives have been behaviour of sulphur absorbents and reduction of sulphur dioxide emissions, reduction of nitrogen oxide emissions, release of vapour-phase alkalimetals and carbon monoxide emissions. The sulphur capture capacities of calcium-based sorbents under PFBC conditions have been studied at a pressurised fluidised-bed reactor and at a pressurised thermogravimetric apparatus. The project has also connected results of the experimental PFBC at HUT/EVO. (author)

  12. Gas distributor for fluidized bed coal gasifier

    Science.gov (United States)

    Worley, Arthur C.; Zboray, James A.

    1980-01-01

    A gas distributor for distributing high temperature reaction gases to a fluidized bed of coal particles in a coal gasification process. The distributor includes a pipe with a refractory reinforced lining and a plurality of openings in the lining through which gas is fed into the bed. These feed openings have an expanding tapered shape in the downstream or exhaust direction which aids in reducing the velocity of the gas jets as they enter the bed.

  13. Experience gained in bench scale and pilot scale fluidised bed processing

    CSIR Research Space (South Africa)

    Hadley, TD

    2005-01-01

    Full Text Available of titanium dioxide. Expertise in the design and commissioning of industrial-scale plants has led to the supply (through licensees) of a biomass sludge incinerator/boiler generating 26t/h steam, a 20 MW high-sulphur pitch incinerator and a 12 MW fluidised bed...

  14. Granular dynamics simulation of segregation phenomena in bubbling gas-fluidised beds

    NARCIS (Netherlands)

    Hoomans, B.P.B.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria

    2000-01-01

    A hard-sphere discrete particle model of a gas-fluidised bed was used in order to simulate segregation phenomena in systems consisting of particles of different sizes. In the model, the gas-phase hydrodynamics is described by the spatially averaged Navier¿Stokes equations for two-phase flow. For

  15. Heat transfer in a membrane assisted fluidised bed with immersed horizontal tubes

    NARCIS (Netherlands)

    Deshmukh, S.A.R.K.; Volkers, S.; van Sint Annaland, M.; Kuipers, J.A.M.

    2004-01-01

    The effect of gas permeation through horizontally immersed membrane tubes on the heat transfer characteristics in a membrane assisted fluidised bed was investigated experimentally. Local time-averaged heat transfer coefficients from copper tubes arranged in a staggered formation with the membrane

  16. Optimum diameter of a circulating fluidised bed combustor with negative wall heat flux

    CSIR Research Space (South Africa)

    Baloyi, J

    2015-07-01

    Full Text Available on irreversibilities in a 7 m circulating fluidised bed combustor with a negative wall heat flux, firing a mixture of air and solid pitch pine wood, was investigated. An analytical expression was derived that predicts the entropy generation rate, thereby...

  17. Air gasification of agricultural waste in a fluidized bed gasifier: hydrogen production performance

    Energy Technology Data Exchange (ETDEWEB)

    Wan Ab Karim Ghani, W. A.; Moghadam, R. A.; Mohd Salleh, M. A. [Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Alias, A. B. [Chemical Engineering, Universiti Teknologi MARA Malaysia, 54500 Shah Alam, Selangor (Malaysia)

    2009-07-01

    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 parameters such as gasification temperatures (700 to 900 {sup o}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 {sup o}C favored further hydrocarbon reactions and allowed an increase of almost 67 mol% in the release of hydrogen. However, other parameters such as fluidising 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. (author)

  18. Bed-To-Wall Heat Transfer in a Supercritical Circulating Fluidised Bed Boiler

    Directory of Open Access Journals (Sweden)

    Błaszczuk Artur

    2014-06-01

    Full Text Available The purpose of this work is to find a correlation for heat transfer to walls in a 1296 t/h supercritical circulating fluidised bed (CFB boiler. The effect of bed-to-wall heat transfer coefficient in a long active heat transfer surface was discussed, excluding the radiation component. Experiments for four different unit loads (i.e. 100% MCR, 80% MCR, 60% MCR and 40% MCR were conducted at a constant excess air ratio and high level of bed pressure (ca. 6 kPa in each test run. The empirical correlation of the heat transfer coefficient in a large-scale CFB boiler was mainly determined by two key operating parameters, suspension density and bed temperature. Furthermore, data processing was used in order to develop empirical correlation ranges between 3.05 to 5.35 m·s-1 for gas superficial velocity, 0.25 to 0.51 for the ratio of the secondary to the primary air, 1028 to 1137K for bed temperature inside the furnace chamber of a commercial CFB boiler, and 1.20 to 553 kg·m-3 for suspension density. The suspension density was specified on the base of pressure measurements inside the boiler’s combustion chamber using pressure sensors. Pressure measurements were collected at the measuring ports situated on the front wall of the combustion chamber. The obtained correlation of the heat transfer coefficient is in agreement with the data obtained from typical industrial CFB boilers.

  19. 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 determine...

  20. Kinetic evaluation of an anaerobic fluidised-bed reactor treating slaughterhouse wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Borja, R. [Consejo Superior de Investigaciones Cientificas, Seville (Spain). Inst. de la Grasa; Banks, C.J.; Zhengjian Wang [Manchester Univ. (United Kingdom). Inst. of Science and Technology

    1995-09-01

    An anaerobic fluidised-bed reactor for purification of slaughterhouse wastewater was modelled as a continuous-flow, completely-mixed homogeneous microbial system, with the feed COD as the limiting-substrate concentration. The average microbial residence time in the reactor was defined in terms of conventional sludge-retention-time. The experimental data obtained indicated that the Michaelis-Menten expression was applicable to a description of substrate utilisation (i.e. COD removal) in the anaerobic fluidised-bed system. The maximum substrate utilisation rate, k, and the Michaelis constant, K{sub s}, were determined to be 1.2/day and 0.039 g/l. The observed biomass yield in the reactor decreased with increasing sludge-retention-time. The specific methane production rate observed was a linear function of the specific substrate-utilisation rate. (Author)

  1. Gasification of Biomass with CO2 and H2O Mixtures in a Catalytic Fluidised Bed.

    Czech Academy of Sciences Publication Activity Database

    Jeremiáš, Michal; Pohořelý, Michael; Svoboda, Karel; Manovic, V.; Anthony, E.J.; Skoblia, S.; Beňo, Z.; Šyc, Michal

    2017-01-01

    Roč. 210, DEC 15 (2017), s. 605-610 ISSN 0016-2361 R&D Projects: GA ČR GC14-09692J Grant - others:NSC(TW) 103-2923-E-042A-001-MY3 Institutional support: RVO:67985858 Keywords : fluidised bed * gasification * catalyst Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use OBOR OECD: Energy and fuels Impact factor: 4.601, year: 2016

  2. Coal. Fluidized bed, a world record; Charbon. Lit fluidise: record mondial

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    In April 1996, the `Societe Provencale du Lit Fluidise`, a subsidiary of Electricite de France (EDF) has put into service in Gardanne, the most powerful circulating fluidized bed boiler in the world, producing 600 MWt; it was constructed by GEC Alsthom Stein Industrie, and will strongly reduce the SO{sub 2} emissions from the coal power plant of Gardanne, which use a highly sulfurous coal. New regulations concerning the French coal industry are also introduced

  3. Advanced circulating fluidised bed technology (CFB) for large-scale solid biomass fuel firing power plants

    Energy Technology Data Exchange (ETDEWEB)

    Jaentti, Timo; Zabetta, Edgardo Coda; Nuortimo, Kalle [Foster Wheeler Energia Oy, Varkaus (Finland)

    2013-04-01

    Worldwide the nations are taking initiatives to counteract global warming by reducing their greenhouse gas emissions. Efforts to increase boiler efficiency and the use of biomass and other solid renewable fuels are well in line with these objectives. Circulating fluidised bed boilers (CFB) are ideal for efficient power generation, capable to fire a broad variety of solid biomass fuels from small CHP plants to large utility power plants. Relevant boiler references in commercial operation are made for Finland and Poland.

  4. Coal. Fluidized bed, a world record; Charbon. Lit fluidise: record mondial

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    In April 1996, the `Societe Provencale du Lit Fluidise`, a subsidiary of Electricite de France (EDF) has put into service in Gardanne, the most powerful circulating fluidized bed boiler in the world, producing 600 MWt; it was constructed by GEC Alsthom Stein Industrie, and will strongly reduce the SO{sub 2} emissions from the coal power plant of Gardanne, which use a highly sulfurous coal. New regulations concerning the French coal industry are also introduced

  5. Co-combustion of waste with coal in a circulating fluidised bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, I.; Boavida, D.; Abelha, P.; Lopes, H.; Cabrita, I. [DEECA-INETI, Lisboa (Portugal)

    2002-07-01

    The results of a study of cocombustion of waste with coal is described. Various wastes (biomass, sludge, and refuse derived fuel) were burned with coal in a circulating fluidised bed combustor. Conditions that prevent segregated combustion, reduce production of nitrogen oxides, and attain high combustion efficiency were studied. The effects of variations in air staging in the riser, mixing of air with volatiles, coal/biomass ratio, methods of feeding biomass, and temperature are described. 5 refs., 3 figs., 5 tabs.

  6. Fluidisation and dispersion behaviour of small high density pellicular expanded bed adsorbents

    DEFF Research Database (Denmark)

    Theodossiou, Irini; Elsner, H.D.; Thomas, Owen R. T.

    2002-01-01

    correlation for characterisation of expanded bed systems is questioned. Residence time distribution studies using acetone tracers, demonstrated that in comparison to existing commercial supports, the small pellicular prototype materials generally possessed far superior hydrodynamic properties, which augurs......, fluidisation behaviour was poorly predicted from the Richardson-Zaki correlation, with experimentally determined values of the expansion index being considerably higher than the theoretical values. The reasons for these discrepancies are discussed in detail and the validity of applying this widely used...

  7. Gasification of Biomass with CO2 and H2O Mixtures in a Catalytic Fluidised Bed.

    Czech Academy of Sciences Publication Activity Database

    Jeremiáš, Michal; Pohořelý, Michael; Svoboda, Karel; Manovic, V.; Anthony, E.J.; Skoblia, S.; Beňo, Z.; Šyc, Michal

    2017-01-01

    Roč. 210, DEC 15 (2017), s. 605-610 ISSN 0016-2361 R&D Projects: GA ČR GC14-09692J Grant - others:NSC(TW) 103-2923-E-042A-001-MY3 Institutional support: RVO:67985858 Keywords : fluidised bed * gasification * catalyst Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use OBOR OECD: Energy and fuel s Impact factor: 4.601, year: 2016

  8. Model of fragmentation of limestone particles during thermal shock and calcination in fluidised beds

    Energy Technology Data Exchange (ETDEWEB)

    Saastamoinen, J.; Pikkarainen, T.; Tourunen, A.; Rasanen, M.; Jantti, T. [VTT Technical Research Center, Jyvaskyla (Finland)

    2008-11-15

    Fragmentation of limestone due to thermal shock and calcination in a fluidised bed was studied through experiments and modelling. The time for heating was estimated by model calculations and the time for calcination by measurements. Fragmentation due to thermal shock was carried out by experiments in a CO{sub 2} atmosphere in order to prevent the effect of calcination. It was found to be much less than fragmentation due to calcination. Average particle sizes before and after fragmentation are presented for several types of limestone. The effects of particle size and gas composition on the primary fragmentation were studied through experiments. Increasing the fluidisation velocity increased the tendency to fragment. The evolution of the particle size distribution (PSD) of limestone particles due to thermal shock and during calcination (or simultaneous calcination and sulphation) were calculated using a population balance model. Fragmentation due to thermal shock is treated as an instantaneous process. The fragmentation frequency during calcination is presented as exponentially decaying over time. In addition to the final PSD, this model also predicts the PSD during the calcination process. The fragmentation was practically found to end after 10 min. Furthermore. a population balance method to calculate the particle size distribution and amount of limestone in fluidised beds in dynamic and steady state, when feeding history is known, is presented.

  9. Local total and radiative heat-transfer coefficients during the heat treatment of a workpiece in a fluidised bed

    International Nuclear Information System (INIS)

    Gao, W.M.; Kong, L.X.; Hodgson, P.D.

    2006-01-01

    The heat-transfer coefficients around a workpiece immersed in an electrically heated heat treatment fluidised bed were studied. A suspension probe designed to simulate a workpiece of complex geometry was developed to measure local total and radiative heat-transfer coefficients at a high bed temperature. The probe consisted of an energy-storage region separated by insulation from the fluidised bed, except for the measuring surface, and a multi-thermocouple measurement system. Experiments in the fluidised bed were performed for a fluidising medium of 120-mesh alumina, a wide temperature range of 110-1050 deg. C and a fluidising number range of 1.18-4.24. It was found that the workpiece surface temperature has a more significant effect on heat transfer than the bed temperature. The total heat-transfer coefficient at the upper surface of the workpiece sharply decreased at the start of heating, and then steadily increased as heating progressed, while a sharp decrease became a rapid increase and then a slow increase for the radiative heat-transfer coefficient. A great difference in the heat-transfer coefficients around the workpiece was observed

  10. Method and apparatus for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    Science.gov (United States)

    Grindley, T.

    1988-04-05

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier is described. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600 to 1800 F and are partially quenched with water to 1000 to 1200 F before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime /limestone. 1 fig.

  11. Dynamical and technological consequences of multiple isolas of steady states in a catalytic fluidised-bed reactor

    Directory of Open Access Journals (Sweden)

    Bizon Katarzyna

    2017-09-01

    Full Text Available Steady-state characteristics of a catalytic fluidised bed reactor and its dynamical consequences are analyzed. The occurrence of an untypical steady-state structure manifesting in a form of multiple isolas is described. A two-phase bubbling bed model is used for a quantitative description of the bed of catalyst. The influence of heat exchange intensity and a fluidisation ratio onto the generation of isolated solution branches is presented for two kinetic schemes. Dynamical consequences of the coexistence of such untypical branches of steady states are presented. The impact of linear growth of the fluidisation ratio and step change of the cooling medium temperature onto the desired product yield is analyzed. The results presented in this study confirm that the identification of a region of the occurrence of multiple isolas is important due to their strong impact both on the process start-up and its control.

  12. A moving-bed gasifier with internal recycle of pyrolysis gas

    NARCIS (Netherlands)

    Susanto, H.; Beenackers, A.A C M

    A co-current moving bed gasifier with internal recycle and separate combustion of pyrolysis gas has been developed with the aim of producing a design suitable for scaling-up downdraft gasifiers while maintaining a low tar content in the producer gas. Using wood chips with a moisture content of 7-9

  13. Validation of the flux number as scaling parameter for top-spray fluidised bed systems

    DEFF Research Database (Denmark)

    Hede, Peter Dybdahl; Bach, P.; Jensen, Anker Degn

    2008-01-01

    2SO4 using Dextrin as binder in three top-spray fluidised bed scales, i.e. a small-scale (type: GEA Aeromatic-Fielder Strea-1), medium-scale (type: Niro MP-1) and large-scale (type: GEA MP-2/3). Following the parameter guidelines adapted from the original patent description, the flux number....... Coating conditions with flux number values of 4.5 and 4.7 were however successful in terms of agglomeration tendency and match of particle size fractions, but indicated in addition a strong influence of nozzle pressure. The present paper suggests even narrower boundaries for the flux number compared...

  14. A multi-biofuel, fluidised-bed district heating plant in Sweden

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    At the end of 1984, the city of Haessleholm in Sweden started up a 65 MW district heating plant which included a 14 MW solid fuel plant. The plant included a specially-designed fluidised-bed boiler, capable of burning all grades of solid fuel, including organic fuel of such low grade that no other boilers around Haessleholm could use it. By 1992, the district heating system served some 250 detached houses and 6,000 flats as well as several schools and industrial premises. The biofuel boiler provides almost 60% of the energy required. (UK)

  15. Gas-particle interactions in dense gas-fluidised beds

    NARCIS (Netherlands)

    Li, J.; Kuipers, J.A.M.

    2003-01-01

    The occurrence of heterogeneous flow structures in gas-particle flows seriously affects gas¿solid contacting and transport processes in dense gas-fluidized beds. A computational study, using a discrete particle method based on Molecular Dynamics techniques, has been carried out to explore the

  16. Energy recovery from sewage sludge by means of fluidised bed gasification

    International Nuclear Information System (INIS)

    Gross, Bodo; Eder, Christian; Grziwa, Peter; Horst, Juri; Kimmerle, Klaus

    2008-01-01

    Because of its potential harmful impact on the environment, disposal of sewage sludge is becoming a major problem all over the world. Today the available disposal measures are at the crossroads. One alternative would be to continue its usage as fertiliser or to abandon it. Due to the discussions about soil contamination caused by sewage sludge, some countries have already prohibited its application in agriculture. In these countries, thermal treatment is now presenting the most common alternative. This report describes two suitable methods to directly convert sewage sludge into useful energy on-site at the wastewater treatment plant. Both processes consist mainly of four devices: dewatering and drying of the sewage sludge, gasification by means of fluidised bed technology (followed by a gas cleaning step) and production of useful energy via CHP units as the final step. The process described first (ETVS-Process) is using a high pressure technique for the initial dewatering and a fluidised bed technology utilising waste heat from the overall process for drying. In the second process (NTVS-Process) in addition to the waste heat, solar radiation is utilised. The subsequent measures - gasification, gas cleaning and electric and thermal power generation - are identical in both processes. The ETVS-Process and the NTVS-Process are self-sustaining in terms of energy use; actually a surplus of heat and electricity is generated in both processes

  17. A technical pilot plant assessment of flue gas desulfurisation in a circulating fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, F.J.; Ollero, P. [Universidad de Sevilla (Spain). Dept. de Ingenieria Quimica y Ambiental; Cabanillas, A.; Otero, J. [Centro de Investigaciones Energeticas y Medioambientales, (CIEMAT), Madrid (Spain)

    2002-11-01

    Flue gas desulfurisation in a circulating fluidised bed absorber (CFBA) is quite a novel dry desulfurisation technology [6th International Conference on Circulating Fluidised Beds (1999) 601] that shows significant advantages in comparison with other dry technologies and that could also be competitive with the widely-used wet FGD technology. This experimental study analyses the performance of a flue gas treatment plant comprising a CFBA and an electrostatic precipitator (ESP). The most significant aspects considered in this study are: the effect of precollecting the fly ash, the effect of the SO{sub 2} inlet concentration, the effect of power plant load changes, the contribution of the final particulate control equipment to the overall SO{sub 2} removal efficiency and the impact of the desulfurisation unit on the ESP behaviour and its final dust emissions. In addition, the behaviour of the integrated CFBA-ESP system with respect to the main operating parameters was studied by means of a fractional factorial design of experiments. All this experimental work was carried out in a 3-MWe equivalent pilot plant that processes real gases withdrawn from the Los Barrios Power Plant. Processing a flue gas with up to 2000 ppm SO{sub 2} concentration, a sulfur removal of 95-97% with a lime utilisation of 75% was achieved. A simple regression model to evaluate the efficiency of the whole system is also proposed.(author)

  18. Recommendations for conversions of grate fired boilers to fluidising beds; Anvisningar foer konvertering av rosterpannor till fluidiserad baeddteknik

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Lars; Ingman, Rolf [AaF Energikonsult AB, Stockholm (Sweden)

    2001-03-01

    This report gives advice and recommendations for retrofitting of grate fired boilers to fluidising beds. Nine plants have been visited and experiences from these conversion projects have been gathered and analysed. Among the important points planning, fuel specification, heat balance calculations and clarifying of delivery limits can be mentioned. It is also important not to underestimate the need for education of the operational staff.

  19. SO3 Formation and the Effect of Fly Ash in a Bubbling Fluidised Bed under Oxy-Fuel Combustion Conditions.

    Czech Academy of Sciences Publication Activity Database

    Sarbassov, Y.; Duan, L.; Jeremiáš, Michal; Manovic, V.; Anthony, E.J.

    2017-01-01

    Roč. 167, DEC 1 (2017), s. 314-321 ISSN 0378-3820 Institutional support: RVO:67985858 Keywords : SO3 formation * oxy-fuel combustion * fluidised bed Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use OBOR OECD: Energy and fuels Impact factor: 3.752, year: 2016

  20. SO3 Formation and the Effect of Fly Ash in a Bubbling Fluidised Bed under Oxy-Fuel Combustion Conditions.

    Czech Academy of Sciences Publication Activity Database

    Sarbassov, Y.; Duan, L.; Jeremiáš, Michal; Manovic, V.; Anthony, E.J.

    2017-01-01

    Roč. 167, DEC 1 (2017), s. 314-321 ISSN 0378-3820 Institutional support: RVO:67985858 Keywords : SO3 formation * oxy- fuel combustion * fluidised bed Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use OBOR OECD: Energy and fuel s Impact factor: 3.752, year: 2016

  1. On suitability of novel fluidised bed technique for separation of metallic powders during commercial powder metallurgical processing

    NARCIS (Netherlands)

    Ritherdon, J; Dechsiri, C; Jones, AR; Hoffmann, AC; Wright, IG

    Experiments have been performed to test the efficiency with which a novel fluidised bed technique could separate different metallic powders in terms of size and density. The overall aim was to assess the potential of this technique for the commercial separation of defective powder fractions from

  2. Application of process tomography in gas-solid fluidised beds in different scales and structures

    Science.gov (United States)

    Wang, H. G.; Che, H. Q.; Ye, J. M.; Tu, Q. Y.; Wu, Z. P.; Yang, W. Q.; Ocone, R.

    2018-04-01

    Gas-solid fluidised beds are commonly used in particle-related processes, e.g. for coal combustion and gasification in the power industry, and the coating and granulation process in the pharmaceutical industry. Because the operation efficiency depends on the gas-solid flow characteristics, it is necessary to investigate the flow behaviour. This paper is about the application of process tomography, including electrical capacitance tomography (ECT) and microwave tomography (MWT), in multi-scale gas-solid fluidisation processes in the pharmaceutical and power industries. This is the first time that both ECT and MWT have been applied for this purpose in multi-scale and complex structure. To evaluate the sensor design and image reconstruction and to investigate the effects of sensor structure and dimension on the image quality, a normalised sensitivity coefficient is introduced. In the meantime, computational fluid dynamic (CFD) analysis based on a computational particle fluid dynamic (CPFD) model and a two-phase fluid model (TFM) is used. Part of the CPFD-TFM simulation results are compared and validated by experimental results from ECT and/or MWT. By both simulation and experiment, the complex flow hydrodynamic behaviour in different scales is analysed. Time-series capacitance data are analysed both in time and frequency domains to reveal the flow characteristics.

  3. The Low temperature CFB gasifier

    DEFF Research Database (Denmark)

    Stoholm, P.; Nielsen, Rasmus Glar; Fock, Martin W.

    2003-01-01

    %) particle separation by the hot secondary cyclone. The next LT-CFB experiment, currently under preparation, is expected to be on either municipal/industrial waste or animal manure. Eventually a 500 kW LT-CFB test plant scheduled for commission during summer 2003, and the anticipated primary LT......The Low Temperature Circulating Fluidised Bed (LT-CFB) gasification process aims at avoiding problems due to ash deposition and agglomeration when using difficult fuels such as agricultural biomass and many waste materials. This, as well as very simple gas cleaning, is achieved by pyrolysing...... the fuel at around 650?C in a CFB reaction chamber and subsequently gasifying the char at around 730oC in a slowly fluidised bubbling bed chamber located in the CFB particle recirculation path. In this paper the novel LT-CFB concept is further described together with the latest test results from the 50 k...

  4. Temperature and pressure distributions in a 400 kW{sub t} fluidized bed straw gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Erguedenler, A.; Ghaly, A.E.; Hamdullahpur, F. [Technical Univ. of Nova Scotia, Halifax (Canada)

    1993-12-31

    The temperature and pressure distribution characteristics of a 400 kW (thermal) dual-distributor type fluidized bed straw gasifier were investigated. The effects of the bed height, equivalence ratio (actual air-fuel ratio:stoichiometric air-fuel ratio) and fluidization velocity on the temperature and pressure variations in the gasifier were studied. Generally, the bed temperature reached the steady state condition within 15--20 minutes. The average temperature of the dense bed ranged from 649{degrees}C to 875{degrees}C depending on the levels of operating parameters used. The bed temperature increased linearly with increases in the equivalence ratio, higher bed temperatures were observed with lower bed height and no clear trend for the bed temperature with respect to variations in fluidization velocity was observed. The bed height, equivalence ratio and fluidization velocity affected the pressure drop in the fluidized bed gasifier. Increasing the fluidization velocity and/or decreasing the equivalence ratio resulted in higher pressure drops in the dense bed and the freeboard regions whereas increasing the bed height increased the pressure drop only in the dense bed.

  5. A new process control strategy for aqueous film coating of pellets in fluidised bed

    DEFF Research Database (Denmark)

    Larsen, C.C.; Sonnergaard, Jørn; Bertelsen, Pernille Scholdan

    2003-01-01

    The parameters with effect on maximum spray rate and maximum relative outlet air humidity when coating pellets in a fluidised bed were investigated. The tested variables include type of water based modified release film coating (Eudragit® NE 30D, Eudragit® RS 30D, Aquacoat ECD®) coating principle...... (top spray, bottom spray), inlet air humidity and type of pellets (sugar spheres, microcrystalline cellulose pellets). The maximum spray rate was not influenced by the coating principles. The highest spray rate was obtained for the film polymer with the lowest tackiness which is assumed...... to be the controlling factor. The type of pellets affected the maximum spray rate. A thermodynamic model for the coating process is employed throughout the process and not just during steady state. The thermodynamic model is incorporated into a new process control strategy. The process control strategy is based on in...

  6. Reactivity of coal chars prepared in a fluidised bed reactor at different burn-off degrees

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, A.H.; Arenillas, A.; Rubiera, F.; Fuente, E.; Pis, J.J. [Inst. Nacional del Carbon, Oviedo (Spain)

    1997-12-31

    The main goal of this work has been to study the effect of the textural properties of coal chars, obtained from partially burned coal, on their reactivity to oxygen. A low volatile bituminous coal was used to prepare chars, with different levels of burn-off, in a bench-scale fluidised bed reactor. Textural characterisation of the samples was accomplished by measuring true (helium) and apparent (mercury) densities, and mercury porosimetry. An increase in the burn-off degree gave rise to a densification of the chars. Porosity development greatly changed during progressive burning of the samples. DTG burning profiles and isothermal gasification were utilised to estimate the reactivities of the precursor coal and its partially burned chars. Reactivity reached a maximum value at an intermediate burn-off and strongly decreased at higher burn-off degrees. (orig.)

  7. Comparative simulation of a fluidised bed reformer using industrial process simulators

    Science.gov (United States)

    Bashiri, Hamed; Sotudeh-Gharebagh, Rahmat; Sarvar-Amini, Amin; Haghtalab, Ali; Mostoufi, Navid

    2016-08-01

    A simulation model is developed by commercial simulators in order to predict the performance of a fluidised bed reformer. As many physical and chemical phenomena take place in the reformer, two sub-models (hydrodynamic and reaction sub-models) are needed. The hydrodynamic sub-model is based on the dynamic two-phase model and the reaction sub-model is derived from the literature. In the overall model, the bed is divided into several sections. In each section, the flow of the gas is considered as plug flow through the bubble phase and perfectly mixed through the emulsion phase. Experimental data from the literature were used to validate the model. Close agreement was found between the model of both ASPEN Plus (ASPEN PLUS 2004 ©) and HYSYS (ASPEN HYSYS 2004 ©) and the experimental data using various sectioning of the reactor ranged from one to four. The experimental conversion lies between one and four sections as expected. The model proposed in this work can be used as a framework in developing the complicated models for non-ideal reactors inside of the process simulators.

  8. Occurrence of bromine in fluidised bed combustion of solid recovered fuel

    Energy Technology Data Exchange (ETDEWEB)

    Vainikka, P.

    2011-12-15

    Corrosive ash species are the single most important factor limiting the electric efficiency of steam boiler plants fired with waste or biomass. Chlorine has been found to have a central role in the chemistry involved as it reduces the melting temperature of ash, forms corrosive vapour and gas species in the furnace and halogenated deposits on boiler heat transfer surfaces. In this context chlorine has been extensively researched. At the time of writing this thesis there was hardly any published data available on the occurrence of bromine (Br) in the aforementioned context. The objective of this work was to review the occurrence of bromine in solid fuels and characterise the behaviour of bromine in full-scale fluidised bed combustion. The review on the occurrence of bromine in solid fuels revealed that in anthropogenic wastes bromine is mainly found in connection to flame retarded substances. Several weight percentages of bromine can be found in plastics treated with brominated flame retardants (BFRs). Bromine is typically found some 100-200 mg kg-1 in mixed municipal solid wastes (MSW). Bromine may be enriched in fuels with high share of plastics, such as solid recovered fuel (SRF) or refuse derived fuel (RDF). Up to 2000 mg kg-1 was found as a monthly average in SRF, typical levels being 20-200 mg kg-1. Wastewater sludge from paper mills may contain bromine 20-100 mg kg-1 due the use of bromine based biocides. In other fuels bromine may be found in significant amounts in marine influenced coal deposits and peat as well as in biomass treated with brominated pesticides. In the experimental part SRF, spruce bark and wastewater sludge from a paper mill were co-fired in a full- scale bubbling fluidised bed (BFB) boiler, and the collected fuels, aerosols and waterwall deposits were analysed with the focus on the fate of bromine. Bromine was mainly found to form water soluble high vapour pressure alkali metal halides in the furnace - in the form of KBr(g) and NaBr(g) as

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

    NARCIS (Netherlands)

    Groeneveld, M.J.; van Swaaij, Willibrordus Petrus Maria

    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

  10. Measurements of dioxin emissions during co-firing in a fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    I. Gulyurtlu; A.T. Crujeira; P. Abelha; I. Cabrita [INETI, Lisbon (Portugal). Departamento de Engenharia Energetica e Controle Ambiental

    2007-09-15

    The emissions of dioxins could be considerable when fuels with high chlorine content are used, particularly in fluidised beds due to constraints to use temperatures in the range 800-900{sup o}C for other considerations. However, mixing of fuels with different characteristics may lead to a reduction in dioxin emissions. Studies are currently being undertaken at the above-mentioned department in mixing fuels of varying chlorine and sulphur contents to monitor the emissions of dioxins both in the gas and solid phases. Furthermore, the influence of certain elements like Cu in the ash in the emissions of dioxins is also studied to verify the catalytic effect. The INETI pilot-scale test facility is used for the combustion work. Two different coals, namely Colombian and Polish, are used as the base fuel. The supplementary fuels for co-firing include MBM and straw pellets. The combustion temperature is maintained at about 800-830{sup o}C range without any limestone addition. The residence time of over 2 s is respected. Results obtained by far suggest that the presence of sulphur in both fuels have a very strong effect on the eventual emissions of dioxins and the synergy regarding to reduce the dioxins below the levels permitted is possible by mixing fuels based on their characteristics. The paper reports the results obtained and evaluates the effect of fuel nature and operating conditions on the emissions of dioxins. 34 refs., 8 figs., 12 tabs.

  11. Nutrients removal in hybrid fluidised bed bioreactors operated with aeration cycles.

    Science.gov (United States)

    Martin, Martin; Enríquez, L López; Fernández-Polanco, M; Villaverde, S; Garcia-Encina, P A

    2007-01-01

    Abstract Two hybrid fluidised bed reactors filled with sepiolite and granular activated carbon (GAC) were operated with short cycled aeration for removing organic matter, total nitrogen and phosphorous, respectively. Both reactors were continuously operated with synthetic and/or industrial wastewater containing 350-500 mg COD/L, 110-130 mg NKT/L, 90-100 mg NH3-N/L and 12-15 mg P/L for 8 months. The reactor filled with sepiolite, treating only synthetic wastewater, removed COD, ammonia, total nitrogen and phosphorous up to 88, 91, 55 and 80% with a hydraulic retention time (HRT) of 10 h, respectively. These efficiencies correspond to removal rates of 0.95 kgCODm(-3)d(-1) and 0.16 kg total N m(-3)d(-1). The reactor filled with GAC was operated for 4 months with synthetic wastewater and 4 months with industrial wastewater, removing 98% of COD, 96% of ammonia, and 66% of total nitrogen, with an HRT of 13.6 h. No significant phosphorous removing activity was observed in this reactor. Microbial communities growing with both reactors were followed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The microbial fingerprints, i.e. DGGE profiles, indicated that biological communities in both reactors were stable along the operational period even when the operating conditions were changed.

  12. 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)

  13. 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)

    1997-12-31

    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)

  14. Ash behavior and de-fluidization in low temperature circulating fluidized bed biomass gasifier

    DEFF Research Database (Denmark)

    Narayan, Vikas

    ensures that high-alkali biomass fuels can be used without risks of bed de-fluidization. This thesis aims to understand the behavior of alkali metals and ash in the LTCFB system. The thesis work involved measurements made on bed material and product gas dust samples on a 100kW LTCFB gasifier placed......Biomass is increasingly used as a fuel for power generation. Herbaceous fuels however, contain high amounts of alkali metals which get volatilized at high temperatures and forms salts with low melting points and thus condense on pipelines, reactor surfaces and may cause de-fluidization. A Low......-Temperature Circulating Fluidized Bed System (LTCFB) gasifier allows pyrolysis and gasification of biomass to occur at low temperatures thereby improving the retention of alkali and other ash species within the system and minimizing the amount of ash species in the product gas. In addition, the low reactor temperature...

  15. Sulphation of calcium-based sorbents in circulating fluidised beds under oxy-fuel combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Francisco Garcia-Labiano; Luis F. de Diego; Alberto Abad; Pilar Gayan; Margarita de las Obras-Loscertales; Aranzazu Rufas; Juan Adanez [Instituto de Carboquimica (CSIC), Zaragoza (Spain). Dept. Energy and Environment

    2009-07-01

    Sulphur Retention (SR) by calcium-based sorbents is a process highly dependent on the temperature and CO{sub 2} concentration. In circulating fluidised beds combustors (CFBC's) operating under oxy-fuel conditions, the sulphation process takes place in atmospheres enriched in CO{sub 2} with bed concentrations that can vary from 40 to 95%. Under so high CO{sub 2} concentrations, very different from that in conventional coal combustion atmosphere with air, the calcination and sulphation behaviour of the sorbent must be defined to optimise the SR process in the combustor. The objective of this work was to determine the SO{sub 2} retention capacity of a Spanish limestone at typical oxy-fuel conditions in CFBC's. Long term duration tests of sulphation (up to 24 h), to simulate the residence time of sorbents in CFBC's, were carried out by thermogravimetric analysis (TGA). Clear behaviour differences were found under calcining and non-calcining conditions. Especially relevant was the result obtained at calcining conditions but close to the thermodynamic temperature given for sorbent calcination. This situation must be avoided in CFBC's because the CO{sub 2} produced inside the particle during calcination can destroy the particles if a non-porous sulphate product layer has been formed around the particle. The effect of the main variables on the sorbent sulphation such as SO{sub 2} concentration, temperature, and particle size were analysed in the long term TGA tests. These data were also used to determine the kinetic parameters for the sulphation under oxy-fuel combustion conditions, which were able to adequately predict the sulphation conversion values in a wide range of operating conditions. 20 refs., 5 figs., 2 tabs.

  16. Co-gasification of meat and bone meal with coal in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    E. Cascarosa; L. Gasco; G. Gea; J.L. Sanchez; J. Arauzo [Universidad de Zaragoza (Spain). Thermochemical Processes Group

    2011-08-15

    After the Bovine Spongiform Encephalopathy illness appeared, the meat and bone meat (MBM) produced from animal residues became an important waste. In spite of being a possible fuel due to its heating value (around 21.4 MJ/kg), an important fraction of the meat and bone meal is being sent to landfills. The aim of this work is to evaluate the co-gasification of low percentages of meat and bone meal with coal in a fluidised bed reactor as a potential waste management alternative. The effect of the bed temperature (800-900{sup o}C), the equivalence ratio (0.25-0.35) and the percentage of MBM in the solid fed (0-1 wt.%) on the co-gasification product yields and properties is evaluated. The results show the addition of 1 wt.% of MBM in a coal gasification process increases the gas and the liquid yield and decreases the solid yield at 900{sup o}C and 0.35 of temperature and equivalence ratio operational conditions. At operational conditions of 900{sup o}C and equivalence ratio of 0.35, the specific yield to gas (y{sub gas}) increases from 3.18 m{sup 3}(STP)/kg to 4.47 m{sup 3}(STP)/kg. The gas energy yield decreased 24.1% and the lower heating value of the gas decreases from 3.36 MJ/m{sup 3}(STP) to 2.16 MJ/m{sup 3}(STP). The concentration of the main gas components (H{sub 2}, CO and CO{sub 2}) hardly varies with the addition of MBM, however the light hydrocarbon concentrations decrease and the H{sub 2}S concentration increases at the higher temperature (900{sup o}C). 32 refs., 9 figs., 7 tabs.

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

    International Nuclear Information System (INIS)

    Diniz Filho, Paulo Tasso; Silveira, Jose Luz; Tuna, Celso Eduardo; Lamas, Wendell de Queiroz

    2013-01-01

    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

  18. 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.)

  19. Thermal disposal of sewage sludges by fluidised bed combustion with low emissions of pollutants. Thermische Entsorgung kommunaler Klaerschlaemme durch schadstoffarme Verbrennung in der Wirbelschicht

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, B. (Technische Univ. Magdeburg (Germany). Inst. fuer Thermische Apparate- und Umwelttechnik, Abt. Umwelttechnik); Lindau, S. (Technische Univ. Magdeburg (Germany). Inst. fuer Thermische Apparate- und Umwelttechnik, Abt. Umwelttechnik); Busse, U. (Technische Univ. Magdeburg (Germany). Inst. fuer Thermische Apparate- und Umwelttechnik, Abt. Umwelttechnik)

    1992-04-01

    The volume of sludge from the sewage treatment represents the largest problem in the waste management in Germany recently. The thermal treatment is inevitable for the solution of the problem. The fluidised bed combustion is suitable for a very good usability of sewage sludge. Experimental investigations carried out in a stationary fluidised bed in laboratory scale. The emissions of gaseous air pollutants are influenced by the properties of the sludge and the parameters of the process. The dependence of the formation and the reactions of the pollutants from various parameters are analysed and judged. (orig.)

  20. 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.)

  1. Gaseous emissions in pressurised fluidised-bed combustion. Analysis and summary of the pilot experiments; Kaasumaiset paeaestoet paineistetussa leijukerrospoltossa. Koetulosten kaesittely ja yhteenveto

    Energy Technology Data Exchange (ETDEWEB)

    Korpela, T.; Hippinen, I.; Konkola, M. [Helsinki Univ. of Technology, Espoo (Finland)

    1996-12-01

    The influence of operating conditions on gaseous emissions in pressurised fluidised-bed combustion have been studied. The research objectives have been behaviour of sulphur absorbents and reduction of sulphur dioxide emissions, reduction of nitrogen oxide emissions, release of vapour-phase alkalimetals and carbon monoxide emissions. The sulphur capture capacities of calcium-based sorbents under PFBC conditions have been studied at a pressurised fluidised-bed reactor and at a pressurised thermogravimetric apparatus. The project has also connected results of the experimental PFBC at HUT/EVO. (author)

  2. Hybrid Molten Bed Gasifier for High Hydrogen Syngas Production

    Energy Technology Data Exchange (ETDEWEB)

    Rue, David [Gas Technology Institute, Des Plaines, IL (United States)

    2017-05-23

    The techno-economic analyses of the hybrid molten bed gasification technology and laboratory testing of the HMB process were carried out in this project by the Gas Technology Institute and partner Nexant, Inc. under contract with the US Department of Energy’s National Energy Technology Laboratory. This report includes the results of two complete IGCC and Fischer-Tropsch TEA analyses comparing HMB gasification with the Shell slagging gasification process as a base case. Also included are the results of the laboratory simulation tests of the HMB process using Illinois #6 coal fed along with natural gas, two different syngases, and steam. Work in this 18-month project was carried out in three main Tasks. Task 2 was completed first and involved modeling, mass and energy balances, and gasification process design. The results of this work were provided to Nexant as input to the TEA IGCC and FT configurations studied in detail in Task 3. The results of Task 2 were also used to guide the design of the laboratory-scale testing of the HMB concept in the submerged combustion melting test facility in GTI’s industrial combustion laboratory. All project work was completed on time and budget. A project close-out meeting reviewing project results was conducted on April 1, 2015 at GTI in Des Plaines, IL. The hybrid molten bed gasification process techno-economic analyses found that the HMB process is both technically and economically attractive compared with the Shell entrained flow gasification process. In IGCC configuration, HMB gasification provides both efficiency and cost benefits. In Fischer-Tropsch configuration, HMB shows small benefits, primarily because even at current low natural gas prices, natural gas is more expensive than coal on an energy cost basis. HMB gasification was found in the TEA to improve the overall IGCC economics as compared to the coal only Shell gasification process. Operationally, the HMB process proved to be robust and easy to operate. The burner

  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

    samples,agglomeration could be attributed to viscous silicate melts formed from reaction of inorganic alkalineand alkali earth species with silica from the bed particles. A mathematical model that addresses the defluidization behavior of alkali-rich samples was developed based on the experiments performed...... and calcium, which may form viscous melts that adhere on the surface of the colliding bed particles and bind them to form agglomerates. In this paper, studies were made to understand the behavior of inorganic elements (mainly K, Si and Ca) on agglomeration and de-fluidization of alkali rich bed...... in the bench-scale fluidized bed reactor as well as on results from literature. The model was then used topredict the de-fluidization behavior of alkali-rich bed material in a large-scale LTCFB gasifier....

  4. Gas generation by co-gasification of biomass and coal in an autothermal fluidized bed gasifier

    International Nuclear Information System (INIS)

    Wang, Li-Qun; Chen, Zhao-Sheng

    2013-01-01

    In this study, thermochemical biomass and coal co-gasification were performed on an autothermal fluidized bed gasifier, with air and steam as oxidizing and gasifying media. The experiments were completed at reaction temperatures of 875 °C–975 °C, steam-to-biomass ratio of 1.2, and biomass-to-coal ratio of 4. This research aims to determine the effects of reaction temperature on gas composition, lower heating value (LHV), as well as energy and exergy efficiencies, of the product gas. Over the ranges of the test conditions used, the product gas LHV varies between 12 and 13.8 MJ/Nm 3 , and the exergy and energy efficiencies of the product gas are in the ranges of 50.7%–60.8% and 60.3%–85.1%, respectively. The results show that high reaction temperature leads to higher H 2 and CO contents, as well as higher exergy and energy efficiencies of the product gas. In addition, gas LHV decreases with temperature. The molar ratio of H 2 /CO is larger than 1 at temperatures above 925 °C. Our experimental analysis shows that co-gasification of biomass and coal in an autothermal fluidized bed gasifier for gas production is feasible and promising. -- Highlights: • An innovative steam co-gasification process for gas production was proposed. • Co-gasification of biomass and coal in an autothermal fluidized bed gasifier was tested. • High temperature favors H 2 production. • H 2 and CO contents increase, whereas CO 2 and CH 4 levels decrease with increase in T. • Exergy and energy efficiencies of gases increase with increase in T

  5. Effect of organic loading rate on anaerobic treatment of slaughterhouse wastewater in a fluidised-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Borja, R. [Consejo Superior de Investigaciones Cientificas, Seville (Spain). Inst. de la Grasa; Banks, C.J.; Zhengjian Wang [Manchester Univ. (United Kingdom). Inst. of Science and Technology

    1995-09-01

    COD removal efficiencies in the range 75.0-98.9% were achieved in an aerobic fluidised-bed reactor treating slaughterhouse wastewater, when evaluated at organic loading rates (OLR) of between 2.9 and 54.0 g COD/l.d, hydraulic retention times (HRT) of between 0.5 and 8 h and feed COD concentrations of between 250 and 4500 mg/l. More than 94% of feed COD could be removed up to OLR of about 27 g COD/l.d. Up to 0.320 litres of methane were produced per gram of COD removed and this methane production rate was independent of the OLR applied in this investigation. Volatile fatty acid (VFA) concentration in the reactor increased sharply at an OLR of about 30 g COD/l.d and, therefore, sufficient alkalinity should be provided to prevent pH from dropping to an undesirable level. The anaerobic fluidised-bed system can be operated at a significantly higher liquid throughput than other previously reported systems while maintaining its excellent efficiency. (Author)

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

    International Nuclear Information System (INIS)

    Lysenko, Steve; Sadaka, Samy; Brown, Robert C.

    2012-01-01

    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

  7. Mathematical modelling of sewage sludge incineration in a bubbling fluidised bed with special consideration for thermally-thick fuel particles.

    Science.gov (United States)

    Yang, Yao Bin; Sharifi, Vida; Swithenbank, Jim

    2008-11-01

    Fluidised bed combustor (FBC) is one of the key technologies for sewage sludge incineration. In this paper, a mathematical model is developed for the simulation of a large-scale sewage sludge incineration plant. The model assumes the bed consisting of a fast-gas phase, an emulsion phase and a fuel particle phase with specific consideration for thermally-thick fuel particles. The model further improves over previous works by taking into account throughflow inside the bubbles as well as the floating and random movement of the fuel particles inside the bed. Validation against both previous lab-scale experiments and operational data of a large-scale industrial plant was made. Calculation results indicate that combustion split between the bed and the freeboard can range from 60/40 to 90/10 depending on the fuel particle distribution across the bed height under the specific conditions. The bed performance is heavily affected by the variation in sludge moisture level. The response time to variation in feeding rate is different for different parameters, from 6 min for outlet H2O, 10 min for O2, to 34 min for bed temperature.

  8. Discrete particle simulation of bubble and slug formation in a two-dimensional gas-fluidised bed: A hard-sphere approach.

    NARCIS (Netherlands)

    Hoomans, B.P.B.; Kuipers, J.A.M.; Briels, Willem J.; van Swaaij, Willibrordus Petrus Maria

    1996-01-01

    A discrete particle model of a gas-fluidised bed has been developed and in this the two-dimensional motion of the individual, spherical particles was directly calculated from the forces acting on them, accounting for the interaction between the particles and the interstitial gas phase. Our collision

  9. Co-combustion of coal and non-recyclable paper & plastic waste in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Boavida, D.; Abelha, P.; Gulyurtlu, I.; Cabrita, I. [DEECA-INETI, Lisbon (Portugal)

    2002-07-01

    Co-combustion of waste with coal was carried out using a fluidised bed combustor with the aim of achieving a fuel mixture with little variations in its heating value and simultaneously reducing the accumulation of non-toxic waste material by upgrading them for energy purposes. Results obtained indicate that the feeding of waste materials could present serious problems which could render conditions for a stable combustion difficult to achieve. The waste was fed mixed with coal and there was some difference observed in results regarding the combustion efficiency and emissions. Part of the combustion of waste material, contrary to that of coal, was observed to take place in the freeboard where the temperature was as much as 150{degree}C above that of the bed. 6 refs., 8 figs., 8 tabs.

  10. Co-combustion of coal and non-recyclable paper and plastic waste in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    D. Boavida; P. Abelha; I. Gulyurtlu; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

    2003-10-01

    Co-combustion of waste with coal was carried out using a fluidised bed combustor with the aim of achieving a fuel mixture with little variations in its heating value and simultaneously reducing the accumulation of non-toxic waste material by upgrading them for energy purposes. Results obtained indicate that the feeding of waste materials plays an important role to achieve conditions for a stable combustion. The form in which the fuel is fed to the combustor makes a significant contribution to achieve desirable combustion performance and differences were observed in results regarding the combustion efficiency and emissions when waste was fed densified or in a fluffy state when it was burned mixed with coal. Part of the combustion of waste material, contrary to that of coal, was observed to take place in the freeboard where the temperature was as much as 150{sup o}C above that of the bed. 15 refs., 8 figs., 8 tabs.

  11. Performance of a pilot-scale, steam-blown, pressurized fluidized bed biomass gasifier

    Science.gov (United States)

    Sweeney, Daniel Joseph

    With the discovery of vast fossil resources, and the subsequent development of the fossil fuel and petrochemical industry, the role of biomass-based products has declined. However, concerns about the finite and decreasing amount of fossil and mineral resources, in addition to health and climate impacts of fossil resource use, have elevated interest in innovative methods for converting renewable biomass resources into products that fit our modern lifestyle. Thermal conversion through gasification is an appealing method for utilizing biomass due to its operability using a wide variety of feedstocks at a wide range of scales, the product has a variety of uses (e.g., transportation fuel production, electricity production, chemicals synthesis), and in many cases, results in significantly lower greenhouse gas emissions. In spite of the advantages of gasification, several technical hurdles have hindered its commercial development. A number of studies have focused on laboratory-scale and atmospheric biomass gasification. However, few studies have reported on pilot-scale, woody biomass gasification under pressurized conditions. The purpose of this research is an assessment of the performance of a pilot-scale, steam-blown, pressurized fluidized bed biomass gasifier. The 200 kWth fluidized bed gasifier is capable of operation using solid feedstocks at feedrates up to 65 lb/hr, bed temperatures up to 1600°F, and pressures up to 8 atm. Gasifier performance was assessed under various temperatures, pressure, and feedstock (untreated woody biomass, dark and medium torrefied biomass) conditions by measuring product gas yield and composition, residue (e.g., tar and char) production, and mass and energy conversion efficiencies. Elevated temperature and pressure, and feedstock pretreatment were shown to have a significant influence on gasifier operability, tar production, carbon conversion, and process efficiency. High-pressure and temperature gasification of dark torrefied biomass

  12. 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.

  13. 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.

  14. Stabilization of ash from combustion of MSW in a fluidised bed boiler

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Wilewska, Magda [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Environmental Inorganic Chemistry

    2004-06-01

    Due to restrictions against the land filling of combustible waste and directives from authorities that favour energy recovery from the waste, combustion of household waste is becoming more common. Even though combustion of MSW reduces the volume of waste to be handled by approximately 90%, it produces ash residues containing most of the metals present in the original fuel and a number of other species carried through the boiler or formed during combustion. The residues can be divided into three categories: 1. Stable, inert ash that can be utilised in, for example, construction applications 2. Ash that is stable enough to be land filled as nonhazardous waste 3. Ash that contains large amounts of soluble components and potentially toxic metal species. The regulations considering leaching of ash components set limits for the release of soluble salts and toxic metals. Some fly ashes show low leachability for metals but gives a salt release that is too close to the limit for total dissolved solids. Since fly ash from FBC boilers represent the largest volume of ash from these boilers there is a need for a simple and cheap treatment method that reduces the amount of soluble salts, i.e. NaCl, KCl etc, in the ash. After stabilisation, the ash is supposed to go into a more stable category. The aim of this project has been to investigate the applicability of a method to wash such an ash with water. The work included laboratory studies of the ash properties, the water washing process, filtration properties of the ash slurry and also tests of the method in pilot scale at a full scale boiler. This work has been concentrated towards the investigation of cyclone ash from a bubbling fluidised bed boiler in Lidkoeping fired with 100% household waste. Elemental composition of ash samples before and after washing/filtration was determined by AAS or ICP after a suitable dissolution of the sample. The mineralogy of ash samples was analysed using X-ray powder diffractometry. This method

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

    International Nuclear Information System (INIS)

    Martínez-Lera, S.; Torrico, J.; Pallarés, J.; Gil, A.

    2013-01-01

    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/m 3 and cold gas efficiencies up to 60%

  16. Gasification of torrefied Miscanthus × giganteus in an air-blown bubbling fluidized bed gasifier.

    Science.gov (United States)

    Xue, G; Kwapinska, M; Horvat, A; Kwapinski, W; Rabou, L P L M; Dooley, S; Czajka, K M; Leahy, J J

    2014-05-01

    Torrefaction is suggested to be an effective method to improve the fuel properties of biomass and gasification of torrefied biomass should provide a higher quality product gas than that from unprocessed biomass. In this study, both raw and torrefied Miscanthus × giganteus (M×G) were gasified in an air-blown bubbling fluidized bed (BFB) gasifier using olivine as the bed material. The effects of equivalence ratio (ER) (0.18-0.32) and bed temperature (660-850°C) on the gasification performance were investigated. The results obtained suggest the optimum gasification conditions for the torrefied M × G are ER 0.21 and 800°C. The product gas from these process conditions had a higher heating value (HHV) of 6.70 MJ/m(3), gas yield 2m(3)/kg biomass (H2 8.6%, CO 16.4% and CH4 4.4%) and cold gas efficiency 62.7%. The comparison between raw and torrefied M × G indicates that the torrefied M × G is more suitable BFB gasification. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. 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.

  18. Nano particle fluidisation in model 2-D and 3-D beds using high speed X-ray imaging and microtomography

    International Nuclear Information System (INIS)

    Gundogdu, O.; Jenneson, P. M.; Tuzun, U.

    2007-01-01

    Nanoparticles and nanocomposites have become a major focus of interest in science and technology due to exceptional properties they provide. However, handling and processing of ultra-fine powders is very challenging because they are extremely cohesive. Fluidization is one of techniques available to process powders. It has become increasingly important to understand how these nanoparticles can be handled and processed to benefit from their favourable properties. A high spatial (down to 400 nm) and temporal resolution (down to 1 ms) X-ray imaging apparatus has been designed to study nanoparticles in fluidized beds under different gas flow velocities. The mean volume distribution of the nanoparticle agglomerates was determined with X-ray microtomography. The X-ray microtomography technique provides valuable in situ, non-destructive structural information on the morphological changes that take place during fluidisation of powder samples

  19. Nano particle fluidisation in model 2-D and 3-D beds using high speed X-ray imaging and microtomography

    Energy Technology Data Exchange (ETDEWEB)

    Gundogdu, O. [University of Surrey, Chemical and Process Engineering, School of Engineering (United Kingdom)], E-mail: o.gundogdu@surrey.ac.uk; Jenneson, P. M. [University of Surrey, Department of Physics, School of Electronics and Physical Sciences (United Kingdom); Tuzun, U. [University of Surrey, Chemical and Process Engineering, School of Engineering (United Kingdom)

    2007-04-15

    Nanoparticles and nanocomposites have become a major focus of interest in science and technology due to exceptional properties they provide. However, handling and processing of ultra-fine powders is very challenging because they are extremely cohesive. Fluidization is one of techniques available to process powders. It has become increasingly important to understand how these nanoparticles can be handled and processed to benefit from their favourable properties. A high spatial (down to 400 nm) and temporal resolution (down to 1 ms) X-ray imaging apparatus has been designed to study nanoparticles in fluidized beds under different gas flow velocities. The mean volume distribution of the nanoparticle agglomerates was determined with X-ray microtomography. The X-ray microtomography technique provides valuable in situ, non-destructive structural information on the morphological changes that take place during fluidisation of powder samples.

  20. Development of a modified equilibrium model for biomass pilot-scale fluidized bed gasifier performance predictions

    International Nuclear Information System (INIS)

    Rodriguez-Alejandro, David A.; Nam, Hyungseok; Maglinao, Amado L.; Capareda, Sergio C.; Aguilera-Alvarado, Alberto F.

    2016-01-01

    The objective of this work is to develop a thermodynamic model considering non-stoichiometric restrictions. The model validation was done from experimental works using a bench-scale fluidized bed gasifier with wood chips, dairy manure, and sorghum. The model was used for a further parametric study to predict the performance of a pilot-scale fluidized biomass gasifier. The Gibbs free energy minimization was applied to the modified equilibrium model considering a heat loss to the surroundings, carbon efficiency, and two non-equilibrium factors based on empirical correlations of ER and gasification temperature. The model was in a good agreement with RMS <4 for the produced gas. The parametric study ranges were 0.01 < ER < 0.99 and 500 °C < T < 900 °C to predict syngas concentrations and its LHV (lower heating value) for the optimization. Higher aromatics in tar were contained in WC gasification compared to manure gasification. A wood gasification tar simulation was produced to predict the amount of tars at specific conditions. The operating conditions for the highest quality syngas were reconciled experimentally with three biomass wastes using a fluidized bed gasifier. The thermodynamic model was used to predict the gasification performance at conditions beyond the actual operation. - Highlights: • Syngas from experimental gasification was used to create a non-equilibrium model. • Different types of biomass (HTS, DM, and WC) were used for gasification modelling. • Different tar compositions were identified with a simulation of tar yields. • The optimum operating conditions were found through the developed model.

  1. Application of Scaling-Law and CFD Modeling to Hydrodynamics of Circulating Biomass Fluidized Bed Gasifier

    Directory of Open Access Journals (Sweden)

    Mazda Biglari

    2016-06-01

    Full Text Available Two modeling approaches, the scaling-law and CFD (Computational Fluid Dynamics approaches, are presented in this paper. To save on experimental cost of the pilot plant, the scaling-law approach as a low-computational-cost method was adopted and a small scale column operating under ambient temperature and pressure was built. A series of laboratory tests and computer simulations were carried out to evaluate the hydrodynamic characteristics of a pilot fluidized-bed biomass gasifier. In the small scale column solids were fluidized. The pressure and other hydrodynamic properties were monitored for the validation of the scaling-law application. In addition to the scaling-law modeling method, the CFD approach was presented to simulate the gas-particle system in the small column. 2D CFD models were developed to simulate the hydrodynamic regime. The simulation results were validated with the experimental data from the small column. It was proved that the CFD model was able to accurately predict the hydrodynamics of the small column. The outcomes of this research present both the scaling law with the lower computational cost and the CFD modeling as a more robust method to suit various needs for the design of fluidized-bed gasifiers.

  2. Axial concentration profiles and N{sub 2}O flue gas in a pilot scale bubbling fluidised bed coal combustor

    Energy Technology Data Exchange (ETDEWEB)

    Tarelho, L.A.C.; Matos, M.A.A.; Pereira, F.J.M.A. [Environment and Planning Department, University of Aveiro, 3810-193 Aveiro (Portugal)

    2005-05-15

    Atmospheric Bubbling Fluidised Bed Coal Combustion (ABFBCC) of a bituminous coal and anthracite with particle diameters in the range 500-4000 {mu}m was investigated in a pilot-plant facility (circular section with 0.25 m internal diameter and 3 m height). The experiments were conducted at steady-state conditions using three excess air levels (10%, 25% and 50%) and bed temperatures in the 750-900 {sup o}C range. Combustion air was staged, with primary air accounting for 100%, 80% and 60% of total combustion air. For both types of coal, virtually no N{sub 2}O was found in significant amounts inside the bed. However, just above the bed-freeboard interface, the N{sub 2}O concentration increased monotonically along the freeboard and towards the exit flue. The N{sub 2}O concentrations in the reactor ranged between 0-90 ppm during bituminous coal combustion and 0-30 ppm for anthracite. For both coals, the lowest values occurred at the higher bed temperature (900 {sup o}C) with low excess air (10%) and high air staging (60% primary air), whereas the highest occurred at the lower bed temperature (750 {sup o}C for bituminous, 825 {sup o}C for anthracite) with high excess air (50%) and single stage combustion. Most of the observed results could be qualitatively interpreted in terms of a set of homogeneous and heterogeneous reactions, where catalytic surfaces (such as char, sand and coal ash) can play an important role in the formation and destruction of N{sub 2}O and its precursors (such as HCN, NH{sub 3} and HCNO) by free radicals (O, H, OH) and reducing species (H{sub 2}, CO, HCs)

  3. A new model for coal gasification on pressurized bubbling fluidized bed gasifiers

    International Nuclear Information System (INIS)

    Sánchez, Cristian; Arenas, Erika; Chejne, Farid; Londoño, Carlos A.; Cisneros, Sebastian; Quintana, Juan C.

    2016-01-01

    Highlights: • A new model was proposed for the simulation of fluidized bed reactors. • The model was validated against experimental data found in the literature. • The model was compared and found to be superior to other models reported in the literature. • Effects of pressure, temperature, steam/coal and air/coal ratios over gas composition were studied. - Abstract: Many industries have taken interest in the use of coal gasification for the production of chemicals and fuels. This gasification can be carried out inside a fluidized bed reactor. This non-ideal reactor is difficult to predict due to the complex physical phenomena and the different chemical changes that the feedstock undergoes. The lack of a good model to simulate the reactor’s behavior produces less efficient processes and plant designs. Various approaches to the proper simulation of such reactor have been proposed. In this paper, a new model is developed for the simulation of a pressurized bubbling fluidized bed (PBFB) gasifier that rigorously models the physical phenomena and the chemical changes of the feedstock inside the reactor. In the model, the reactor is divided into three sections; devolatilization, volatile reactions and combustion-gasification. The simulation is validated against experimental data reported in the literature and compared with other models proposed by different authors; once the model is validated, the dependence of the syngas composition on operational pressure, temperature, steam/coal and air/coal ratios are studied. The results of this article show how this model satisfactorily predicts the performance of PBFB gasifiers.

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

    International Nuclear Information System (INIS)

    Mikulandrić, Robert; Lončar, Dražen; Böhning, Dorith; Böhme, Rene; Beckmann, Michael

    2014-01-01

    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

  5. 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)

    McIlveen-Wright, D.R.; Huang, Y.; McMullan, J.T.; Pinto, F.; Franco, C.; Gulyurtlu, I.; Armesto, L.; Cabanillas, A.; Caballero, M.A.; Aznar, M.P.

    2006-01-01

    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)

  6. Characteristics of ash and particle emissions during bubbling fluidised bed combustion of three types of residual forest biomass.

    Science.gov (United States)

    Ribeiro, João Peres; Vicente, Estela Domingos; Alves, Célia; Querol, Xavier; Amato, Fulvio; Tarelho, Luís A C

    2017-04-01

    Combustion of residual forest biomass (RFB) derived from eucalypt (Eucalyptus globulus), pine (Pinus pinaster) and golden wattle (Acacia longifolia) was evaluated in a pilot-scale bubbling fluidised bed reactor (BFBR). During the combustion experiments, monitoring of temperature, pressure and exhaust gas composition has been made. Ash samples were collected at several locations along the furnace and flue gas treatment devices (cyclone and bag filter) after each combustion experiment and were analysed for their unburnt carbon content and chemical composition. Total suspended particles (TSP) in the combustion flue gas were evaluated at the inlet and outlet of cyclone and baghouse filter and further analysed for organic and elemental carbon, carbonates and 57 chemical elements. High particulate matter collection efficiencies in the range of 94-99% were observed for the baghouse, while removal rates of only 1.4-17% were registered for the cyclone. Due to the sand bed, Si was the major element in bottom ashes. Fly ashes, in particular those from eucalypt combustion, were especially rich in CaO, followed by relevant amounts of SiO 2 , MgO and K 2 O. Ash characteristics varied among experiments, showing that their inorganic composition strongly depends on both the biomass composition and combustion conditions. Inorganic constituents accounted for TSP mass fractions up to 40 wt%. Elemental carbon, organic matter and carbonates contributed to TSP mass fractions in the ranges 0.58-44%, 0.79-78% and 0.01-1.7%, respectively.

  7. Enhanced model for integrated simulation of an entrained bed gasifier implemented as Aspen Hysys extension

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M; Bojarski, A; Ferrer-Nadal, S; Kopanos, G; Mitta, N; Pinilla, C A; Nougues, J M; Velo, E; Puigjaner, L [Universitat Politecnica de Catalunya, Barcelona (Spain). Dept. of Chemical Engineering-CEPIMA

    2007-07-01

    In this work an enhanced mathematical model of an entrained bed gasifier has been developed for improved synthesis gas production. The gasification model considers five stages: pyrolysis, volatiles combustion, char combustion, gasification and a final gas equilibrium zone. Mathematical simulations are carried out to help finding out feasible operating conditions of the process to achieve improved process performance. Visual Basic (VB) is tested as tool for modelling, by using the Aspen Hysys Extension (AHE) interface standards. This standard provides a suitable environment for this purpose, since it allows the creation of completely custom modules which are easy to plug and use thus facilitating the handling of complex models ready to interact with commercial simulation platforms. In this work, integration of different models is accomplished in Aspen Hysys (AH), which provides the basic connectivity within models components, and the thermodynamic framework needed. The integrated modules simulation environment platform uses data from ELCOGAS for validation purposes with excellent preliminary results. 9 refs., 2 figs.

  8. 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor.

    Science.gov (United States)

    Lapa, N; Barbosa, R; Lopes, M H; Mendes, B; Abelha, P; Boavida, D; Gulyurtlu, I; Oliveira, J Santos

    2007-08-17

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub-products of such type

  10. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lapa, N. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)]. E-mail: ncsn@fct.unl.pt; Barbosa, R. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Lopes, M.H. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Mendes, B. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal); Abelha, P. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Gulyurtlu, I. [National Institute of Engineering, Technology and Innovation (INETI), Department of Energetic Engineering and Environmental Control (DEECA). Edificio J, Estrada do Paco do Lumiar, 22, 1649-038 Lisbon (Portugal); Santos Oliveira, J. [Environmental Biotechnology Researching Unit (UBiA), Faculty of Science and Technology (FCT), New University of Lisbon - UNL, Ed. Departamental, piso 3, gabinete 377, Quinta da Torre, 2829-516 Caparica (Portugal)

    2007-08-17

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

  11. Chemical and ecotoxicological characterization of ashes obtained from sewage sludge combustion in a fluidised-bed reactor

    International Nuclear Information System (INIS)

    Lapa, N.; Barbosa, R.; Lopes, M.H.; Mendes, B.; Abelha, P.; Gulyurtlu, I.; Santos Oliveira, J.

    2007-01-01

    In 1999, the DEECA/INETI and the UBiA/FCT/UNL started a researching project on the partition of heavy metals during the combustion of stabilised sewage sludge (Biogran[reg]), in a fluidised-bed reactor, and on the quality of the bottom ashes and fly ashes produced. This project was entitled Bimetal and was funded by the Portuguese Foundation for Science and Technology. In this paper only the results on the combustion of Biogran[reg]) are reported. The combustion process was performed in two different trials, in which different amounts of sewage sludge and time of combustion were applied. Several ash samples were collected from the bed (bottom ashes) and from two cyclones (first cyclone and second cyclone ashes). Sewage sludge, bed material (sand) and ash samples were submitted to the leaching process defined in the European leaching standard EN 12457-2. The eluates were characterized for a set of inorganic chemical species. The ecotoxicological levels of the eluates were determined for two biological indicators (Vibrio fischeri and Daphnia magna). The results were compared with the limit values of the CEMWE French Regulation. The samples were also ranked according to an index based on the chemical characterization of the eluates. It was observed an increase of the concentration of metals along the combustion system. The ashes trapped in the second cyclone, for both combustion trials, showed the highest concentration of metals in the eluates. Chemically, the ashes of the second cyclone were the most different ones. In the ecotoxicological point of view, the ecotoxicity levels of the eluates of the ashes, for both combustion cycles, did not follow the same pattern as observed for the chemical characterization. The ashes of the first cyclone showed the highest ecotoxicity levels for V. fischeri and D. magna. This difference on chemical and ecotoxicological results proves the need for performing both chemical and ecotoxicological characterizations of the sub

  12. Comparison of coal/solid recovered fuel (SRF) with coal/refuse derived fuel (RDF) in a fluidised bed reactor

    International Nuclear Information System (INIS)

    Wagland, S.T.; Kilgallon, P.; Coveney, R.; Garg, A.; Smith, R.; Longhurst, P.J.; Pollard, S.J.T.; Simms, N.

    2011-01-01

    An experimental study was undertaken to compare the differences between municipal solid waste (MSW) derived solid recovered fuel (SRF) (complying with CEN standards) and refuse derived fuel (RDF). Both fuels were co-combusted with coal in a 50 kW fluidised bed combustor and the metal emissions were compared. Synthetic SRF was prepared in the laboratory by grinding major constituents of MSW such as paper, plastic, textile and wood. RDF was obtained from a local mechanical treatment plant. Heavy metal emissions in flue gas and ash samples from the (coal + 10% SRF) fuel mixture were found to be within the acceptable range and were generally lower than that obtained for coal + 10% RDF fuel mixture. The relative distribution of heavy metals in ash components and the flue gas stream shows the presence of a large fraction (up to 98%) of most of the metals in the ash (except Hg and As). Thermo-gravimetric (TG) analysis of SRF constituents was performed to understand the behaviour of fuel mixtures in the absence and presence of air. The results obtained from the experimental study will enhance the confidence of fuel users towards using MSW-derived SRF as an alternative fuel.

  13. Effects of droplet size and type of binder on the agglomerate growth mechanisms by melt agglomeration in a fluidised bed.

    Science.gov (United States)

    Seo, Anette; Holm, Per; Schaefer, Torben

    2002-08-01

    This study was performed in order to evaluate the effects of binder droplet size and type of binder on the agglomerate growth mechanisms by melt agglomeration in a fluidised bed granulator. Lactose monohydrate was agglomerated with melted polyethylene glycol (PEG) 3000 or Gelucire 50/13 (esters of polyethylene glycol and glycerol), which was atomised at different nozzle air flow rates giving rise to median droplet sizes of 40, 60, and 80 microm. Different product temperatures were investigated, below the melting range, in the middle of the melting range, and above the melting range for each binder. The agglomerates were found to be formed by initial nucleation of lactose particles immersed in the melted binder droplets. Agglomerate growth occurred by coalescence between nuclei followed by coalescence between agglomerates. Complex effects of binder droplet size and type of binder were seen at low product temperatures. Low product temperatures resulted in smaller agglomerate sizes, because the agglomerate growth was counteracted by very high binder viscosity or solidification of the binder. At higher product temperatures, neither the binder droplet size nor the type of binder had a clear effect on the final agglomerate size.

  14. 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.

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

    Science.gov (United States)

    Martínez-Lera, S; Torrico, J; Pallarés, J; Gil, A

    2013-07-01

    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%. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Fluidised bed combustion: a new route to power and heat from coal

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, H D [Bergbau-Forschung G.m.b.H., Essen (Germany, F.R.)

    1978-02-01

    The functioning of fluidized-bed firings and their advantages with regard to SO/sub 2/ emissions are described. The principle of design of a fluidized-bed boiler and a gas/steam turbine power plant with fluidized-bed firing under pressure is outlined. The application and their economics in heat and power generation and marketing potential of fluidized-bed firings and their economics in heat and power generation is pointed out. The construction of waste-fired incinerators has already become possible, but there is still a lot of development work to be done until fluidized-bed firings can be used in central heatings, combined-cycle power plants, and large power plants.

  17. Wear oxidation of evaporator coils in fluidised bed captive power plants

    International Nuclear Information System (INIS)

    Ghosal, S.K.; De, P.K.

    2000-01-01

    Combustion of pulverised coal or gas to form steam in thermal power plants is a common practice. Corrosion of water-wall, superheater and reheater tubes is the typical problem faced in these power plants. Modification of process conditions, redesigning of equipment and selection of more corrosion resistant materials are few methods which have been tried to combat corrosion to a certain extent. Restricted heat transfer efficiency is another problem associated with these power plants. In order to bring upon improvements, fluidized bed combustors are being used in some advanced thermal power plants at present because of excellent combustion and heat transfer efficiencies. Even with low grade coals, higher combustion efficiency could be achieved in these combustors due to excellent gas/solid chemical reactivity at relatively low reaction temperatures. Further improvements in in-bed heat transfer and bed temperature uniformity have been possible with the use of sand in bed. However, erosion, corrosion and combined erosion/corrosion are some of the major modes of material degradation associated with these fluidized bed combustors using sand. Recently in a captive power unit using bubbling fluidized bed combustors containing sand, evaporator coils made of carbon steel were seen to be severely affected by erosion corrosion. The directional nature of metal removal from the studs, tube OD and ultimately the rupture of the thinned tube wall confirmed the above observation. Microstructural examinations showed loss of carbon at certain places including those near the leaked/punctured regions at the prevailing bed temperature of 850 deg C. This paper describes the detailed investigations carried out on wear oxidation phenomenon occurred in a captive thermal power plant using advanced bubbling fluidized bed combustors. (author)

  18. Particulate and PCDD/F emissions from coal co-firing with solid biofuels in a bubbling fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    H. Lopes; I. Gulyurtlu; P. Abelha; T. Crujeira; D. Salema; M. Freire; R. Pereira; I. Cabrita [INETI, Lisbon (Portugal). DEECA

    2009-12-15

    In the scope of the COPOWER project SES6-CT-2004 to investigate potential synergies of co-combustion of different biofuels with coal, a study of emissions of particulate matter and PCDD/F was carried out. The biofuels tested were meat and bone meal (MBM), sewage sludge biopellets (BP), straw pellets (SP), olive bagasse (OB) and wood pellets (WP). The tests performed include co-firing of 5%, 15% and 25% by weight of biofuels with coals of different origin. Both monocombustion and co-firing were carried out. Combustion tests were performed on a pilot fluidised bed, equipped with cyclones and air staging was used in order to achieve almost complete combustion of fuels with high volatile contents and to control gaseous emissions. Particulate matter emissions were isokinetically sampled in the stack and their particle size analysis was performed with a cascade impactor (Mark III). The results showed that most particles emitted were below 10 {mu}m (PM10) for all the tests, however, with the increasing share of biofuels and also during combustion of pure biofuels, especially olive bagasse, straw and MBM, very fine particles, below about 1 {mu}m were present. With the exception of sewage sludge, greater amounts of biofuels appeared to give rise to the decrease in particulate mean diameters and increase in PM percentages below 1 {mu}m. The formation of very fine particles could be related with the presence of aerosol forming elements such as K, Na (in the case of MBM) and Cl in biofuels, which even resulted in higher PM emissions when the ash content of fuels decreased. A correlation wasverified between the increase of PCDD/F with the decrease of PM mean diameter. This may be due to higher specific surface area and greater Cu concentration in the fly ashes. 33 refs., 11 figs., 4 tabs.

  19. Characterising boiler ash from a circulating fluidised bed municipal solid waste incinerator and distribution of PCDD/F and PCB.

    Science.gov (United States)

    Zhang, Mengmei; Buekens, Alfons; Li, Xiaodong

    2018-05-31

    In this study, ash samples were collected from five locations situated in the boiler of a circulating fluidised bed municipal solid waste incinerator (high- and low-temperature superheater, evaporator tubes and upper and lower economiser). These samples represent a huge range of flue gas temperatures and were characterised for their particle size distribution, surface characteristics, elemental composition, chemical forms of carbon and chlorine and distribution of polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and biphenyls (PCB). Enrichment of chlorine, one of the main elements of organochlorinated pollutants, and copper, zinc and lead, major catalytic metals for dioxin-like compounds, was observed in lower-temperature ash deposits. The speciation of carbon and chlorine on ash surfaces was established, showing a positive correlation between organic chlorine and oxygen-containing carbon functional groups. The load of PCDD/F and PCB (especially dioxin-like PCB) tends to rise rapidly with falling temperature of flue gas, reaching their highest value in economiser ashes. The formation of PCDD/F congeners through the chlorophenol precursor route apparently was enhanced downstream the boiler. Principal component analysis (PCA) was applied to study the links between the ash characteristics and distribution of chloro-aromatics. The primary purpose of this study is improving the understanding of any links between the characteristics of ash from waste heat systems and its potential to form PCDD/F and PCB. The question is raised whether further characterisation of fly ash may assist to establish a diagnosis of poor plant operation, inclusive the generation, destruction and eventual emission of persistent organic pollutants (POPs).

  20. Cofiring of difficult fuels: The effect of Ca-based sorbents on the gas chemistry in fluidised bed combustion; Kalsiumpohjaisten lisaeaineiden vaikutus leijukerrospolton kaasukemiaan vaikeiden polttoaineiden sekapoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Aeijaelae, M.; Partanen, J.; Fabritius, M.; Elo, T.; Virta, A.K. [Imatran Voima Oy, Vantaa (Finland)

    1997-10-01

    The objective of this project is to establish the effects of Ca-based sorbents on sulphur, halogen and alkaline chemistry in fluidised bed combustion of difficult fuels, and to find out any restrictions on the use of these sorbents. The aim is to acquire sufficient knowledge to ensure the operational reliability of power plants and to minimise the emissions and costs of flue gas cleaning. The results enable the owner to anticipate necessary changes associated with slagging, fouling and emission control in the existing power plants, when there are plans to increase the range of fuels used. (orig.)

  1. Fluidised bed technology – Applications and R&D in Southern Africa

    CSIR Research Space (South Africa)

    North, BC

    2007-06-28

    Full Text Available Bed area : 25 m2 Plant purpose : A 10 MW plant for the combustion of duff coal at greater than 98 % burnout to provide hot gases for drying slag. Subsequently also used for organic waste incineration. Project duration : 1988 to 1989 Current...

  2. Experience gained in pilot-scale and bench-scale fluidised beds processing

    CSIR Research Space (South Africa)

    Hadley, TD

    2006-02-01

    Full Text Available for clean coal technology thrust COMMISSIONED PLANTS Slagment Hot Gas Generator Client : Slagment Bed area : 25 m2 Plant purpose : A 10 MW plant for the combustion of duff coal at greater than 98% burnout to provide hot gases for the drying...

  3. CO-COMBUSTION OF REFUSE DERIVED FUEL WITH COAL IN A FLUIDISED BED COMBUSTOR

    Directory of Open Access Journals (Sweden)

    W. A. WAN AB KARIM GHANI

    2009-03-01

    Full Text Available Power generation from biomass is an attractive technology which utilizes municipal solid waste-based refused derived fuel. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from refuse derived fuel was co-fired with coal in a 0.15 m diameter and 2.3 m high fluidized bed combustor. The combustion efficiency and carbon monoxide emissions were studied and compared with those from pure coal combustion. This study proved that the blending effect had increased the carbon combustion efficiency up to 12% as compared to single MSW-based RDF. Carbon monoxide levels fluctuated between 200-1600 ppm were observed when coal is added. It is evident from this research that efficient co-firing of biomass with coal can be achieved with minimum modification of existing coal-fired boilers.

  4. Carbonation of Mg(OH){sub 2} in a pressurised fluidised bed for CO{sub 2} sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Fagerlund, J.

    2012-07-01

    To date, a number of methods to accelerate natural weathering or in other words increase the CO{sub 2} uptake rate of various minerals have been suggested; commonly this is known as mineral carbonation or CO{sub 2} mineralisation. A brief literature review of recently published articles in this field is presented, showing that the interest in mineral carbonation is increasing. However, it should be noted that mineral carbonation is only one option in a larger portfolio of various carbon dioxide capture and storage (CCS) alternatives. Unlike many other options, the CO{sub 2} mineralisation option considered in this thesis is largely founded on the possibility to utilise the exothermic nature of magnesium carbonation and based on this notion, it has been divided into three steps. The first two steps are energy demanding, while the third step is energy 'negative', and in theory, the source of the energy required in the first two steps. Unfortunately, however, the energy demanded by the first two steps, Mg extraction and Mg(OH){sub 2} production, is (currently) much higher than what could be generated by the subsequent Mg(OH){sub 2} carbonation step. Nevertheless, opportunities to reduce the energy intensity of the process in question are still being investigated, and while an energy-neutral carbonation process might be difficult to achieve, energy requirements can still be rendered industrially acceptable (and comparable to or even better than for other CCS methods). The main focus of this thesis lies with the third step, Mg(OH){sub 2} carbonation, which is performed using a pressurised fluidised bed (PFB). The elevated CO{sub 2} pressure conditions (typically approx 20 bar) allow for the carbonation reaction to take place at higher temperatures (typically approx 500 deg C) than otherwise due to thermodynamic constraints on carbonate stability. The increase in reaction rate as a function of temperature follows the Arrhenius equation of exponential increase

  5. Feasibility study - Lowered bed temperature in Fluidised Bed boilers for waste; Foerstudie - Saenkt baeddtemperatur i FB-pannor foer avfallsfoerbraenning

    Energy Technology Data Exchange (ETDEWEB)

    Niklasson, Fredrik

    2009-01-15

    Waste incineration generally serves two purposes; 1) dispose of waste and 2) generation of heat and power. In the process of power production from waste fuels, the steam temperatures in super heaters are generally limited by the severe fouling and corrosion that occurs at elevated material temperatures, caused by high concentrations of alkali metals and chloride in the flue gas and fly ash. The overall aim of a continuation of present project is to determine if a reduced temperature of the bed zone in a fluidized bed waste incinerator reduces the amount of alkali chlorides in the flue gas. If so, a reduced bed temperature might enable increased steam temperature in super heaters, or, at unchanged steam temperature, improve the lifespan of the super heaters. The results from the project are of interest for plant owners wishing to improve performance of existing plants. The results may also be used to modify the design of future plants by boiler manufacturers. The aim of present pre-study was to determine how far the bed temperature can be reduced in a waste fired fluidized bed boiler in Boraas while maintaining a stable operation with sufficient combustion temperature in the freeboard to fulfil the directives of waste incineration. A continuation of the project will be based on the results from present study. The work is based on experiments at the test boiler. During the present study, no other measurements were performed apart from some sampling of bed material and ashes at different modes of operation. The experiments show that it is possible to alter the air and recycled flue gas in such a manner that the bed temperature is reduced from about 870 deg C to 700 deg C at 100% load and normal fuel mixture, while fulfilling the directive of 850 deg C at 2 seconds. Within normal variations of the fuel properties, however, the bed temperature increases to somewhat above 700 deg C if the fuel turns dry, while it falls below 650 deg C when the fuel turns wet. With

  6. Dry formulations of the biocontrol agent Candida sake CPA-1 using fluidised bed drying to control the main postharvest diseases on fruits.

    Science.gov (United States)

    Carbó, Anna; Torres, Rosario; Usall, Josep; Fons, Estanislau; Teixidó, Neus

    2017-08-01

    The biocontrol agent Candida sake CPA-1 is effective against several diseases. Consequently, the optimisation of a dry formulation of C. sake to improve its shelf life and manipulability is essential for increasing its potential with respect to future commercial applications. The present study aimed to optimise the conditions for making a dry formulation of C. sake using a fluidised bed drying system and then to determine the shelf life of the optimised formulation and its efficacy against Penicillium expansum on apples. The optimal conditions for the drying process were found to be 40 °C for 45 min and the use of potato starch as the carrier significantly enhanced the viability. However, none of the protective compounds tested increased the viability of the dried cells. A temperature of 25 °C for 10 min in phosphate buffer was considered as the optimum condition to recover the dried formulations. The dried formulations should be stored at 4 °C and air-packaged; moreover, shelf life assays indicated good results after 12 months of storage. The formulated products maintained their biocontrol efficacy. A fluidised bed drying system is a suitable process for dehydrating C. sake cells; moreover, the C. sake formulation is easy to pack, store and transport, and is a cost-effective process. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  7. Hydrodynamic study of the turbulent fluidized beds; Etude hydrodynamique des lits fluidises turbulents

    Energy Technology Data Exchange (ETDEWEB)

    Taxil, I.

    1996-12-20

    Gas-solid turbulent fluidization has already been widely studied in the literature. However, its definition and specificities remain controversial and confused. Most of the studies focussed on the turbulent transition velocities are based on wall pressure drop fluctuations studies. In this work, we first characterize the turbulent regime with the classical study of pressure drop signals with standard deviation analysis, completed with a more specific frequency analysis and also by a stochastic analysis. Then, we evaluate bubble flow properties. Experimental results have been obtained in a 0.2 m I.D. fluidized bed expanding to 0.4 m I.D. in the freeboard in order to limit entrainment at high fluidization velocities. The so lid used was FCC catalyst. It was fluidized by air at ambient conditions. The superficial fluidization velocity ranged 0.2 to 2 m/s. Fast response transducers recorded pressure drop at the wall and bubble flow properties (bubble size, bubble velocity and bubble frequency) could be deduced from a light reflected signal at various bed locations with optical fibers. It has been shown the turbulent regime is delimited by two velocities: Uc (onset of turbulent regime) and Utr (onset of transport regime), which can be determined based on standard deviations, dominant frequencies and width of wave land of pressure signals. The stochastic analysis confirms that the signal enriches in frequencies in the turbulent regime. Bubble size and bubble velocity could be correlated to the main superficial gas velocity. The main change in bubble flow in the turbulent regime was shown to be the stagnation of the bubble frequency at its maximum value. It was also shown that the bubble flow properties in the turbulent regime imply a strong aeration of the emulsion phase. (authors) 76 refs.

  8. 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

  9. Leaching Behavior of Circulating Fluidised Bed MSWI Air Pollution Control Residue in Washing Process

    Directory of Open Access Journals (Sweden)

    Zhiliang Chen

    2016-09-01

    Full Text Available In this study, air pollution control (APC residue is conducted with water washing process to reduce its chloride content. A novel electrical conductivily (EC measurement method is proposed to monitor the dynamic change of chloride concentrations in leachate as well as the chloride content of the residue. The method equally applies to various washing processes with different washing time, liquid/solid ratio and washing frequency. The results show that washing effectively extracts chloride salts from APC residues, including those from circulating fluidized bed (CFB municipal solid waste incineration (MSWI. The most appropriate liquid/solid ratio and washing time in the first washing are found to be around 4 L water per kg of APC residue and 30 min, respectively, and washing twice is required to obtain maximum dissolution. The pH value is the major controlling factor of the heavy metals speciation in leachate, while chloride concentration also affects the speciation of Cd. Water washing causes no perceptible transfer of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs from the APC residue to leachate. The chloride concentration is strongly related with electrical conductivity (EC, as well as with the concentrations of calcium, sodium and potassium of washing water. Their regression analyses specify that soluble chloride salts and EC could act as an indirect indicator to monitor the change of chloride concentration and remaining chloride content, thus, contributing to the selection of the optimal washing conditions.

  10. Investigation of flow behaviour of coal particles in a pilot-scale fluidized bed gasifier (FBG) using radiotracer technique.

    Science.gov (United States)

    Pant, H J; Sharma, V K; Kamudu, M Vidya; Prakash, S G; Krishanamoorthy, S; Anandam, G; Rao, P Seshubabu; Ramani, N V S; Singh, Gursharan; Sonde, R R

    2009-09-01

    Knowledge of residence time distribution (RTD), mean residence time (MRT) and degree of axial mixing of solid phase is required for efficient operation of coal gasification process. Radiotracer technique was used to measure the RTD of coal particles in a pilot-scale fluidized bed gasifier (FBG). Two different radiotracers i.e. lanthanum-140 and gold-198 labeled coal particles (100 gm) were independently used as radiotracers. The radiotracer was instantaneously injected into the coal feed line and monitored at the ash extraction line at the bottom and gas outlet at the top 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 tanks-in-series model. The simulation of RTD data indicated good degree of mixing with small fraction of the feed material bypassing/short-circuiting from the bottom of the gasifier. The results of the investigation were found useful for optimizing the design and operation of the FBG, and scale-up of the gasification process.

  11. 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.

  12. Design, scale-up, Six Sigma in processing different feedstocks in a fixed bed downdraft biomass gasifier

    Science.gov (United States)

    Boravelli, Sai Chandra Teja

    This thesis mainly focuses on design and process development of a downdraft biomass gasification processes. The objective is to develop a gasifier and process of gasification for a continuous steady state process. A lab scale downdraft gasifier was designed to develop the process and obtain optimum operating procedure. Sustainable and dependable sources such as biomass are potential sources of renewable energy and have a reasonable motivation to be used in developing a small scale energy production plant for countries such as Canada where wood stocks are more reliable sources than fossil fuels. This thesis addresses the process of thermal conversion of biomass gasification process in a downdraft reactor. Downdraft biomass gasifiers are relatively cheap and easy to operate because of their design. We constructed a simple biomass gasifier to study the steady state process for different sizes of the reactor. The experimental part of this investigation look at how operating conditions such as feed rate, air flow, the length of the bed, the vibration of the reactor, height and density of syngas flame in combustion flare changes for different sizes of the reactor. These experimental results also compare the trends of tar, char and syngas production for wood pellets in a steady state process. This study also includes biomass gasification process for different wood feedstocks. It compares how shape, size and moisture content of different feedstocks makes a difference in operating conditions for the gasification process. For this, Six Sigma DMAIC techniques were used to analyze and understand how each feedstock makes a significant impact on the process.

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

    International Nuclear Information System (INIS)

    Jarungthammachote, S.; Dutta, A.

    2008-01-01

    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 2 , CH 4 , H 2 O, H 2 and N 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

  14. Techno-economic analysis of lignite fuelled IGCC with CO{sub 2} capture. Comparing fluidized bed and entrained flow gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guangjian; Wu, Zhen; Zhang, Haiying [North China Electric Power Univ., Beijing (China). School of Energy and Power Engineering

    2013-07-01

    Integrated coal gasification combined cycle (IGCC) plants with pre-combustion capture of CO{sub 2} represent one of the most promising options for generating low-cost decarbonized power using bituminous coals. This work systematically quantify the effect of coal rank on the efficiency and economics of IGCC systems with CO2 capture and storage (CCS), with a special focus on comparison of systems using fluidized-bed gasifier (U-GAS) and entrained flow gasifier (Shell). It was found that the Shell IGCCs are little affect by low rank coal after pre-drying in terms of thermal efficiency and the levelized cost of electricity (LCOE) is only increase by 2-6% for lignite cases with and without CCS compared with bituminous coal cases. The specific CO{sub 2} emissions of U-GAS gasifier based lignite fuelled IGCC with CCS is 198 g/kWhe, almost two times of shell gasifier cases, mainly due to lower carbon conversion in the gasifier and the higher methane in the raw gas of gasifier. However, the total capital cost and COE of U-Gas IGCCs are 15-20% less than that of Shell IGCCs because of lower capital cost of gasifier, coal drying units and air separate units per kWe.

  15. Experience in a 6.2 MW{sub e} pressurized fluidized bed gasifier with high ash Indian coals

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, G.; Rajasekaran, A.; Periyakaruppan, V.; Krishnamoorthy, S. [Bharat Heavy Electricals Ltd., Tiruchirappalli (India)

    2006-07-01

    Bharat Heavy Electrical Limited has installed a 165 tons/day air-blown pressurized fluidized bed gasifier (PFBG) as an add-on to their 6.2 MW IGCC demonstration plant and has operated it for more than 4000 hours. Improvements in the gasifier refractory lining, ash extraction and cooling devices, air distribution and temperature measuring devices were incorporated to improve the reliability and performance. Coal with 30-42% ash and high calorific value in the range of 15-20 MJ/kg was used during these operations with crushed coal of 1-4 mm as well as -6 mm coal with fines. Tests were conducted at gasifier pressure of 0.3-1.0 MPa, fluidized bed temperature of 980-1050{sup o}C and at various fluidized velocities and air to steam ratios. Once through carbon conversion efficiency of 90%, cold gas efficiency of 69% and dry gas calorific value of 4.4-4.6 MJ/Nm{sup 3} were obtained. About 15% char in fly ash (with 40% ash coal) was established by TGA. Seal pot system was added for recyling fly ash from the first cyclone to enhance carbon conversion, other parameters and to reduce the char in fly ash to acceptable level. Trends and correlations were established for constituents of gas, carbon conversion efficiency, cold gas efficiency, calorific value of gas and gas yield. BHEL is currently working with a partner to install a 125 MW IGCC plant. The paper elaborates the schematic and constructional details of the PFBG, operating experience and performance. 3 refs., 9 figs.

  16. 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.

  17. Incineration as a treatment option for shredder light fractions (SLF) by a stationary fluidised bed combustion; Untersuchungen zur Verbrennung von Shredderleichtfraktionen in einer stationaeren Wirbelschicht

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Gaston

    2011-07-15

    In this paper the suitability of the stationary fluidised bed combustion as a treatment option for shredder light fractions (SLF) is discussed. This SLF, SLF coarse grain and SLF generated in a further mechanical treatment were burned. The results show a strong change in grain size distribution of the bed material during the combustion the SLF and SLF-coarse fractions. The formation of agglomerates significantly impaired the fluidization. The main reason for this effect is the high content of alkali and alkaline earth metals in the SLF. During the incineration of SLF generated by further mechanical treatment the change in grain size distribution declines much more slowly. This results from the separation of hard plastics with higher calcium contents during further mechanical processing. The tests also showed a complete burnout and a significant enrichment of metals in the solid combustion residues (fabric filter ash bed ash, cyclone ash). These residues represent a recycling concentrate, which needs to be open in the future. (orig.)

  18. Multi-gene genetic programming based predictive models for municipal solid waste gasification in a fluidized bed gasifier.

    Science.gov (United States)

    Pandey, Daya Shankar; Pan, Indranil; Das, Saptarshi; Leahy, James J; Kwapinski, Witold

    2015-03-01

    A multi-gene genetic programming technique is proposed as a new method to predict syngas yield production and the lower heating value for municipal solid waste gasification in a fluidized bed gasifier. The study shows that the predicted outputs of the municipal solid waste gasification process are in good agreement with the experimental dataset and also generalise well to validation (untrained) data. Published experimental datasets are used for model training and validation purposes. The results show the effectiveness of the genetic programming technique for solving complex nonlinear regression problems. The multi-gene genetic programming are also compared with a single-gene genetic programming model to show the relative merits and demerits of the technique. This study demonstrates that the genetic programming based data-driven modelling strategy can be a good candidate for developing models for other types of fuels as well. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Neves, Daniel; Thunman, Henrik; Tarelho, Luís; Larsson, Anton; Seemann, Martin; Matos, Arlindo

    2014-01-01

    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 CO 2 , H 2 O, and N 2 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-MW th 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

  20. Fuel conversion efficiency and energy balance of a 400 kW{sub t} fluidized bed straw gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Erguedenler, A.; Ghaly, A.E.; Hamdullahpur, F. [Technical Univ. of Nova Scotia, Halifax (Canada)

    1993-12-31

    A 400 kW (thermal) dual-distributor type fluidized bed gasifier developed for the energy recovery from cereal straw was used to investigate the effects of equivalence ratio (actual air-fuel ratio: stoichiometric air-fuel ratio), fluidization velocity and bed height on the fuel conversion efficiency from wheat straw. The energy balance was also performed on the system under those operating conditions. The results indicated that the equivalence ratio was the most significant parameter affecting the fuel conversion efficiency and the energy recovered from the straw in the form of gas. Both the fuel conversion efficiency and the energy recovery increased with increases in the equivalence ratio. The fluidization velocity and bed height had minimal effects on these parameters. A fuel conversion efficiency as high as 98% was obtained at the equivalence ratio of 0.35. The energy recovered in the form of gas and the sensible heat of the produced gas were in the ranges of 40--70% and 9--17%, respectively. Unaccounted losses showed a dramatic increase at lower equivalence ratios and were in the range of 6--53% depending on the operating condition.

  1. Climate effect of an integrated wheat production and bioenergy system with Low Temperature Circulating Fluidized Bed gasifier

    International Nuclear Information System (INIS)

    Sigurjonsson, Hafthor Ægir; Elmegaard, Brian; Clausen, Lasse Røngaard; Ahrenfeldt, Jesper

    2015-01-01

    Highlights: • Wheat straw removal from agricultural system has considerable GWP effect. • Changing the carbon conv. in the gasifier to 0.8–0.86 mitigates those effects. • Considerable difference is between sequestration potential of straw and biochar. • Lowering the carbon conversion improves GWP, but depends on subst. technology. - Abstract: When removing biomass residues from the agriculture for bioenergy utilization, the nutrients and carbon stored within these “residual resources” are removed as-well. To mitigate these issues the energy industry must try to conserve and not destroy the nutrients. The paper analyses a novel integration between the agricultural system and the energy system through the Low Temperature Circulating Fluidized Bed (LT-CFB) gasifier from the perspective of wheat grain production and electricity generation using wheat straw, where the effects of removing the straw from the agricultural system are assessed along with the effects of recycling the nutrients and carbon back to the agricultural system. The methods used to assess the integration was Life Cycle Assessment (LCA) with IPCC’s 2013 100 year global warming potential (GWP) as impact assessment method. The boundary was set from cradle to gate with two different functional units, kg grain and kW h electricity produced in Zealand, Denmark. Two cases were used in the analysis: 1. nutrient balances are regulated by mineral fertilization and 2. the nutrient balances are regulated by yield. The analysis compare three scenarios of gasifier operation based on carbon conversion to two references, no straw removal and straw combustion. The results show that the climate effect of removing the straws are mitigated by the carbon soil sequestration with biochar, and electricity and district heat substitution. Maximum biochar production outperforms maximum heat and power generation for most substituted electricity and district heating scenarios. Irrespective of the substituted

  2. Uncertainty Quantification Analysis of Both Experimental and CFD Simulation Data of a Bench-scale Fluidized Bed Gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Shahnam, Mehrdad [National Energy Technology Lab. (NETL), Morgantown, WV (United States). Research and Innovation Center, Energy Conversion Engineering Directorate; Gel, Aytekin [ALPEMI Consulting, LLC, Phoeniz, AZ (United States); Subramaniyan, Arun K. [GE Global Research Center, Niskayuna, NY (United States); Musser, Jordan [National Energy Technology Lab. (NETL), Morgantown, WV (United States). Research and Innovation Center, Energy Conversion Engineering Directorate; Dietiker, Jean-Francois [West Virginia Univ. Research Corporation, Morgantown, WV (United States)

    2017-10-02

    Adequate assessment of the uncertainties in modeling and simulation is becoming an integral part of the simulation based engineering design. The goal of this study is to demonstrate the application of non-intrusive Bayesian uncertainty quantification (UQ) methodology in multiphase (gas-solid) flows with experimental and simulation data, as part of our research efforts to determine the most suited approach for UQ of a bench scale fluidized bed gasifier. UQ analysis was first performed on the available experimental data. Global sensitivity analysis performed as part of the UQ analysis shows that among the three operating factors, steam to oxygen ratio has the most influence on syngas composition in the bench-scale gasifier experiments. An analysis for forward propagation of uncertainties was performed and results show that an increase in steam to oxygen ratio leads to an increase in H2 mole fraction and a decrease in CO mole fraction. These findings are in agreement with the ANOVA analysis performed in the reference experimental study. Another contribution in addition to the UQ analysis is the optimization-based approach to guide to identify next best set of additional experimental samples, should the possibility arise for additional experiments. Hence, the surrogate models constructed as part of the UQ analysis is employed to improve the information gain and make incremental recommendation, should the possibility to add more experiments arise. In the second step, series of simulations were carried out with the open-source computational fluid dynamics software MFiX to reproduce the experimental conditions, where three operating factors, i.e., coal flow rate, coal particle diameter, and steam-to-oxygen ratio, were systematically varied to understand their effect on the syngas composition. Bayesian UQ analysis was performed on the numerical results. As part of Bayesian UQ analysis, a global sensitivity analysis was performed based on the simulation results, which shows

  3. Ruedersdorf cement works substitutes raw material and fuel by means of a circulating fluidised bed; Roh- und Brennstoffsubstitution mit einer Zirkulierenden Wirbelschicht im Zementwerk Ruedersdorf

    Energy Technology Data Exchange (ETDEWEB)

    Scur, P. [Ruedersdorfer Zement GmbH, Ruedersdorf (Germany)

    1998-09-01

    The purpose of the present paper is to point out the great potential the cement industry holds for the utilisation of waste materials. There are meanwhile sufficient studies and measuring results to demonstrate the environmental acceptability of the processes and products involved. The solution found for Ruedersdorf cement kiln of using a circulating a fluidised bed for waste utilisation is a good example of the potential still available for conserving natural resources and landfill area. Efficient industrial applications of this kind should become a future mainstay of the waste industry. [Deutsch] In dem vorliegenden Beitrag sollte gezeigt werden, dass die Zementindustrie ueber ein hohes Potential zur thermischen und stofflichen Verwertung von Abfallstoffen verfuegt. Es liegen ausreichende Untersuchungen und konkrete Messergebnisse vor, mit denen die Umweltvertraeglichkeit von Prozess und Produkt nachgewiesen werden kann. Die Loesung zur Abfallverwertung an der Ruedersdorfer Zementofenanlage mit Hilfe einer Zirkulierenden Wirbelschicht ist ein Beispiel fuer die Reserven zur Schonung natuerlicher Ressourcen und zur Einsparung von Deponieraeumen. Derartige sinnvolle industrielle Einsatzmoeglichkeiten sollten ein wichtiges Standbein fuer die zukuenftige Abfallwirtschaft sein. (orig.)

  4. Allothermal steam gasification of biomass in cyclic multi-compartment bubbling fluidized-bed gasifier/combustor - new reactor concept.

    Science.gov (United States)

    Iliuta, Ion; Leclerc, Arnaud; Larachi, Faïçal

    2010-05-01

    A new reactor concept of allothermal cyclic multi-compartment fluidized bed steam biomass gasification is proposed and analyzed numerically. The concept combines space and time delocalization to approach an ideal allothermal gasifier. Thermochemical conversion of biomass in periodic time and space sequences of steam biomass gasification and char/biomass combustion is simulated in which the exothermic combustion compartments provide heat into an array of interspersed endothermic steam gasification compartments. This should enhance unit heat integration and thermal efficiency and procure N(2)-free biosyngas with recourse neither to oxygen addition in steam gasification nor contact between flue and syngas. The dynamic, one-dimensional, multi-component, non-isothermal model developed for this concept accounts for detailed solid and gas flow dynamics whereupon gasification/combustion reaction kinetics, thermal effects and freeboard-zone reactions were tied. Simulations suggest that allothermal operation could be achieved with switch periods in the range of a minute supporting practical feasibility for portable small-scale gasification units. Copyright 2009 Elsevier Ltd. All rights reserved.

  5. 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...

  6. Numerical Simulation of Fluidized Bed Gasifier for Integrated Gasification Combined Cycle

    Directory of Open Access Journals (Sweden)

    CHEN Ju-hui

    2017-06-01

    Full Text Available The overall thermal efficiency of the integrated gasification combined cycle ( IGCC has not been sufficiently improved. In order to achieve higher power generation efficiency,the advanced technology of IGCC has been developed which is on the basis of the concept of exergy recovery. IGCC systems and devices from the overall structure of opinion,this technology will generate electricity for the integration of advanced technology together,the current utilization of power generation technology and by endothermic reaction of steam in the gasifier,a gas turbine exhaust heat recovery or the solid oxide fuel cell. It is estimated that such the use of exergy recycling has the advantage of being easy to use,separating,collecting fixed CO2,making it very attractive,and can increase the overall efficiency by 10% or more. The characteristics of fluidized bed gasifier,one of the core equipment of the IGCC system,and its effect on the whole system were studied.

  7. Thermodynamic optimisation and computational analysis of irreversibilities in a small-scale wood-fired circulating fluidised bed adiabatic combustor

    CSIR Research Space (South Africa)

    Baloyi, J

    2014-06-01

    Full Text Available parameters on energy and exergy characteristics and exergy losses. International Journal of Energy Research 2006; 30: 203-219. [24] Ziebik A, stanek W. Energy and exergy system analysis of thermal improvements of blast-furnace plants. International... in the riser column of a pressurized circulating fluidized bed. International Journal of Energy Research 2006; 30: 149-162. [27] Cihan A, Hacihafizoglu O, Kahveci K. Energy-exergy analysis and modenization suggestions for a combined-cycle power plant...

  8. A Three-Dimensional Numerical Study of Gas-Particle Flow and Chemical Reactions in Circulating Fluidised Bed Reactors

    DEFF Research Database (Denmark)

    Hansen, Kim Granly

    Three-dimensional Computational Fluid Dynamics (CFD) simulations of Circulating Fluidized Beds (CFB's) have been performed. The computations are performed using a 3D multiphase computational fluid dynamics code with an Eulerian description of both gas and particle phases. The turbulent motion...... implemented in the CFD code FLOTRACS-MP-3D. The decomposition reaction is studied in a 3D representation of a 0.254 m i.d. riser, which has been studied experimentally by Ouyang et al. (1993). Comparison between measured and simulated time-averaged ozone concentration at different elevations in the riser...

  9. Investigation of coalescence kinetics of microcristalline cellulose in fluidised bed spray agglomeration: experimental studies and modelling approach

    Directory of Open Access Journals (Sweden)

    M. Peglow

    2005-06-01

    Full Text Available In this paper a model for fluidized bed spray agglomeration is presented. To describe the processes of heat and mass transfer, a physical based model is derived. The model takes evaporation process from the wetted particles as well as the effects of transfer phenomena between suspension gas and bypass gas into account. The change of particle size distribution during agglomeration, modeled by population balances, is linked to the heat and mass transfer model. A new technique is derived to extract agglomeration and nucleation rates from experimental data. Comparisons of experiments and simulations are presented.

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

    International Nuclear Information System (INIS)

    Pant, H.J.; Sharma, V.K.; Gursharan Singh; Vidhya Kamadu, M.; Prakash, S.G.; Krishanamoorthy, S.; Ramani, N.V.S.; Sonde, R.R.

    2004-01-01

    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)

  11. Investigation on catalytic gasification of high-ash coal with mixing-gas in a small-scale fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    Chen, X.; Zhang, J.; Lin, J. [Fuzhou University, Fuzhou (China)

    2005-10-15

    The experimental study on the Yangquan high-ash coal catalytic gasification with mixing gas by using solid alkali or waste liquid of viscose fiber as the catalyst in a small-scale fluidized bed with 28 mm i.d. was carried out. The loading saturation levels of two catalysts in Yangquan high-ash coal are about 6%. Under the gasification temperature ranging from 830 to 900{sup o}C and from 900 to 920{sup o}C, the apparent reaction order of Yangquan high-ash coal with respect to the unreacted carbon fraction approximates to 2.3 and 1/3 for the non-catalyst case, respectively. Also, the different values of apparent reaction order in the two temperature ranges are presented for the case with 3% solid alkali catalyst loaded. At the low temperature ranging from 830 to 860{sup o}C, the apparent reaction order of catalytic gasification is 1 since enough active carbon sites on the coal surface are formed during the catalytic gasification by solid alkali. But at the high temperature ranging from 860 to 920{sup o}C, the sodium carbonate produced by the reaction of solid alkali with carbon dioxide can be easily fused, transferred and re-distributed, which affects the gasification reaction rate, and the apparent reaction order of catalytic gasification is reduced to 1.3. 10 refs., 9 figs., 4 tab s.

  12. Producer gas production of Indonesian biomass in fixed-bed downdraft gasifier as an alternative fuels for internal combustion engines

    Science.gov (United States)

    Simanjuntak, J. P.; Lisyanto; Daryanto, E.; Tambunan, B. H.

    2018-03-01

    downdraft biomass gasification reactors, coupled with reciprocating internal combustion engines (ICE) are a viable technology for small scale heat and power generation. The direct use of producer gas as fuel subtitution in an ICE could be of great interest since Indonesia has significant land area in different forest types that could be used to produce bioenergy and convert forest materials to bioenergy for use in energy production and the versatility of this engine. This paper will look into the aspect of biomass energie as a contributor to energy mix in Indonesia. This work also contains information gathered from numerous previews study on the downdraft gasifier based on experimental or simulation study on the ability of producer gas as fuels for internal combustion engines aplication. All data will be used to complement the preliminary work on biomass gasification using downdraft to produce producer gas and its application to engines.

  13. Mathematical modeling of a fluidized bed gasifier for steam gasification of coal using high-temperature nuclear reactor heat

    International Nuclear Information System (INIS)

    Kubiak, H.; vanHeek, K.-H.; Juntgen, H.

    1986-01-01

    Coal gasification is a well-known technique and has already been developed and used since a long time. In the last few years, forced by the energy situation, new efforts have been made to improve known processes and to start new developments. Conventional gasification processes use coal not only as feedstock to be gasified but also for supply of energy for reaction heat, steam production, and other purposes. With a nuclear high temperature reactor (HTR) as a source for process heat, it is possible to transform the whole of the feed coal into gas. This concept offers advantages over existing gasification processes: saving of coal, as more gas can be produced from coal; less emission of pollutants, as the HTR is used for the production of steam and electricity instead of a coal-fired boiler; and lower production costs for the gas

  14. On a clean power generation system with the co-gasification of biomass and coal in a quadruple fluidized bed gasifier.

    Science.gov (United States)

    Yan, Linbo; He, Boshu

    2017-07-01

    A clean power generation system was built based on the steam co-gasification of biomass and coal in a quadruple fluidized bed gasifier. The chemical looping with oxygen uncoupling technology was used to supply oxygen for the calciner. The solid oxide fuel cell and the steam turbine were combined to generate power. The calcium looping and mineral carbonation were used for CO 2 capture and sequestration. The aim of this work was to study the characteristics of this system. The effects of key operation parameters on the system total energy efficiency (ŋ ten ), total exergy efficiency (ŋ tex ) and carbon sequestration rate (R cs ) were detected. The energy and exergy balance calculations were implemented and the corresponding Sankey and Grassmann diagrams were drawn. It was found that the maximum energy and exergy losses occurred in the steam turbine. The system ŋ ten and ŋ tex could be ∼50% and ∼47%, and R cs could be over unit. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. 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.

  16. VOC emission control by circulating fluidized bed adsorption; Controle de l'emission de composes organiques volatils par adsorption en lit fluidise circulant

    Energy Technology Data Exchange (ETDEWEB)

    Song, W.

    2003-12-15

    This work deals with the circulating fluidized bed technology, applied to the elimination by adsorption of volatile organic compounds (VOCs), like toluene, in a gas flow. In the process, the adsorbent (millimetric spherical grains of micro-porous carbon) is moved by a strong flow rate of gas inside a vertical tube without lining. Mass and heat transfers are very important and important volumes of compounds can be processed. This work presents the determination of the adsorption equilibrium, the description of the experimental facility and of the results of experiments, the development of an original model of the process which combines a flow model and a mass transfer model, a parametric study of this model, and finally, some extensions of the process principle to staged operations with pressure variation or temperature variation cycles. (J.S.)

  17. Second stage gasifier in staged gasification and integrated process

    Science.gov (United States)

    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.

  18. 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.

  19. Technical review of coal gasifiers for production of synthetic natural gas

    International Nuclear Information System (INIS)

    Lee, Geun Woo; Shin, Yong Seung

    2012-01-01

    Because of the increasing cost of oil and natural gas, energy production technologies using coal, including synthetic natural gas (SNG) and integrated gasification combined cycle (IGCC), have attracted attention because of the relatively low cost of coal. During the early stage of a project, the developer or project owner has many options with regard to the selection of a gasifier. In particular, from the viewpoint of feasibility, the gasifier is a key factor in the economic evaluation. This study compares the technical aspects of gasifiers for a real SNG production project in an early stage. A fixed bed slagging gasifier, wet type entrained gasifier, and dry type entrained gasifier, all of which have specific advantages, can be used for the SNG production project. Base on a comparison of the process descriptions and performances of each gasifier, this study presents a selection guideline for a gasifier for an SNG production project that will be beneficial to project developers and EPC (Engineering, Procurement, Construction) contractors

  20. 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

  1. 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)

  2. 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...

  3. Mathematic modulation of a simulation program for a coal and wood counter-current moving bed gasifier, which includes pyrolysis and drying processes and processes alternatives; Modelagem matematica e simulacao em computador de gaseificador de leito fixo contra-corrente para carvoes e biomassa com inclusao de processos de pirolise, secagem e alternativas do processo

    Energy Technology Data Exchange (ETDEWEB)

    Souza Santos, M.L. de [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    1985-12-31

    A new version of a simulation program for coal and wood counter-current fixed bed gasifier has been completed and provides: all the principal information variables of the process throughout the bed as mass flow and composition for 13 gases and 6 solids, temperature of the gas and solid phases, reaction rates of combustion, gasification, pyrolysis and drying processes; composition, mass flow, temperature, combustion enthalpy and other produced gases physical and chemical properties; possibility of process alternatives analysis as volatiles recycling in order to eliminate tar, double withdrawn of gases and combinations. Comparisons between simulation and experimental results are presented. (author). 26 refs., 1 tab

  4. Tar formation in a steam-O2 blown CFB gasifier and a steam blown PBFB gasifier (BabyHPR) : Comparison between different on-line measurement techniques and the off-line SPA sampling and analysis method

    NARCIS (Netherlands)

    Meng, X.; Mitsakis, P.; Mayerhofen, M.; De Jong, W.; Gaderer, M.; Verkooijen, A.H.M.; Spliethoff, H.

    2012-01-01

    Two on-line tar measurement campaigns were carried out using an atmospheric pressure 100 “”kWth steam-O2 blown circulating fluidized bed (CFB) gasifier at the Delft University of Technology (TUD) and a 30–40kWth steam blown pressurized bubbling fluidized bed (PBFB) gasifier BabyHPR (Heatpipe

  5. Sampling/classification of gasifier particulates

    International Nuclear Information System (INIS)

    Wegrzyn, J.

    1984-01-01

    A high temperature and pressure real time extractive sampling probe for particulate monitoring was built at Brookhaven National Laboratory and tested on Morgantown Energy Technology Center's 42 inch fixed bed gasifier. The probe was specifically designed for the conditions of highly loaded particulate and condensable streams, that exist at the outlet of a fixed bed gasifier. Some of the salient features of the probe are: porous tube gas injection, aerodynamic particle classification in the presence of condensable vapors, β gauge particle detection, and micro processor control. Three of the key design problems were the separation of the particles from the vapor without promoting condensation, the prevention of plugging, and real time monitoring. Some plugging did occur over the seven day sampling period, but by over pressurizing and back purging the clog was blown back into the process stream. The tests validate the proof of concept of the sampling probe and indicated that the particulate output from the bed came in the form of bursts (several minutes in duration) rather than in the form of a steady stream

  6. 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)

  7. OUT Success Stories: Biomass Gasifiers

    International Nuclear Information System (INIS)

    Jones, J.

    2000-01-01

    The world's first demonstration of an efficient, low-pressure biomass gasifier capable of producing a high-quality fuel is now operating in Vermont. The gasifier converts 200 tons of solid biomass per day into a clean-burning gas with a high energy content for electricity generation

  8. 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...

  9. Effect of operating conditions on performance of silica gel-water air-fluidised desiccant cooler

    Directory of Open Access Journals (Sweden)

    Rogala Zbigniew

    2017-01-01

    Full Text Available Fluidised desiccant cooling is reported in the literature as an efficient way to provide cooling for air-conditioning purposes. The performance of this technology can be described by electric and thermal Coefficients of Performance (COP and Specific Cooling Power (SCP. In this paper comprehensive theoretical study was carried out in order to assess the effect of operating conditions such as: superficial air velocity, desiccant particle diameter, bed switching time and desiccant filling height on the performance of fluidised desiccant cooler (FDC. It was concluded that FDC should be filled with as small as possible desiccant particles featuring diameters and should not be operated with shorter switching times than optimum. Moreover in order to efficiently run such systems superficial air velocities during adsorption and desorption should be similar. At last substantial effect of desiccant filling height on performance of FDC was presented.

  10. Modelling transient 3D multi-phase criticality in fluidised granular materials - the FETCH code

    International Nuclear Information System (INIS)

    Pain, C.C.; Gomes, J.L.M.A.; Eaton, M.D.; Ziver, A.K.; Umpleby, A.P.; Oliveira, C.R.E. de; Goddard, A.J.H.

    2003-01-01

    The development and application of a generic model for modelling criticality in fluidised granular materials is described within the Finite Element Transient Criticality (FETCH) code - which models criticality transients in spatial and temporal detail from fundamental principles, as far as is currently possible. The neutronics model in FETCH solves the neutron transport in full phase space with a spherical harmonics angle of travel representation, multi-group in neutron energy, Crank Nicholson based in time stepping, and finite elements in space. The fluids representation coupled with the neutronics model is a two-fluid-granular-temperature model, also finite element fased. A separate fluid is used to represent the liquid/vapour gas and the solid fuel particle phases, respectively. Particle-particle, particle-wall interactions are modelled using a kinetic theory approach on an analogy between the motion of gas molecules subject to binary collisions and granular flows. This model has been extensively validated by comparison with fluidised bed experimental results. Gas-fluidised beds involve particles that are often extremely agitated (measured by granular temperature) and can thus be viewed as a particularly demanding application of the two-fluid model. Liquid fluidised systems are of criticality interest, but these can become demanding with the production of gases (e.g. radiolytic and water vapour) and large fluid/particle velocities in energetic transients. We present results from a test transient model in which fissile material ( 239 Pu) is presented as spherical granules subsiding in water, located in a tank initially at constant temperature and at two alternative over-pressures in order to verify the theoretical model implemented in FETCH. (author)

  11. 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)

  12. Experimental study of the mechanisms of CO{sub 2} capture by calcium cycle under circulating fluidized bed conditions; Etude experimentale des mecanismes de capture du CO{sub 2} par cycle calcium en lit fluidise circulant

    Energy Technology Data Exchange (ETDEWEB)

    Hoteit, A

    2006-06-15

    The work undertaken in this Thesis in partnership with department R and D of ALSTOM Power Boilers, CEMEX and the ADEME, relates to the experimental study of various phenomena associated to CO{sub 2} capture under circulating fluidized bed conditions. The size of particles, temperature and the CO{sub 2} concentration have an influence on the limestone calcination reaction. The reaction of carbonation of lime is not total. During successive cycles of calcination/carbonation, the rate of carbonation obtained with hydrated lime is increasingly higher than that obtained with the lime. Under continuously reducing conditions, the decomposition of sulphates present in the bed ashes is not total. This decomposition is total under reduction/oxidation cycles. A modeling of calcination allowed to determine the intrinsic kinetic constants of calcination and carbonation. (author)

  13. Validation of a two-fluid model used for the simulation of dense fluidized beds; Validation d`un modele a deux fluides applique a la simulation des lits fluidises denses

    Energy Technology Data Exchange (ETDEWEB)

    Boelle, A.

    1997-02-17

    A two-fluid model applied to the simulation of gas-solid dense fluidized beds is validated on micro scale and on macro scale. Phase coupling is carried out in the momentum and energy transport equation of both phases. The modeling is built on the kinetic theory of granular media in which the gas action has been taken into account in order to get correct expressions of transport coefficients. A description of hydrodynamic interactions between particles in high Stokes number flow is also incorporated in the model. The micro scale validation uses Lagrangian numerical simulations viewed as numerical experiments. The first validation case refers to a gas particle simple shear flow. It allows to validate the competition between two dissipation mechanisms: drag and particle collisions. The second validation case is concerted with sedimenting particles in high Stokes number flow. It allows to validate our approach of hydrodynamic interactions. This last case had led us to develop an original Lagrangian simulation with a two-way coupling between the fluid and the particles. The macro scale validation uses the results of Eulerian simulations of dense fluidized bed. Bed height, particles circulation and spontaneous created bubbles characteristics are studied and compared to experimental measurement, both looking at physical and numerical parameters. (author) 159 refs.

  14. CFD-DEM Simulation of Minimum Fluidisation Velocity in Two Phase Medium

    Directory of Open Access Journals (Sweden)

    H Khawaja

    2016-09-01

    Full Text Available In this work, CFD-DEM (computational fluid dynamics - discrete element method has been used to model the 2 phase flow composed of solid particle and gas in the fluidised bed. This technique uses the Eulerian and the Langrangian methods to solve fluid and particles respectively. Each particle is treated as a discrete entity whose motion is governed by Newton's laws of motion. The particle-particle and particle-wall interaction is modelled using the classical contact mechanics. The particles motion is coupled with the volume averaged equations of the fluid dynamics using drag law. In fluidised bed, particles start experiencing drag once the fluid is passing through. The solid particles response to it once drag experienced is just equal to the weight of the particles. At this moment pressure drop across the bed is just equal to the weight of particles divide by the cross-section area. This is the first regime of fluidization, also referred as ‘the regime of minimum fluidization’. In this study, phenomenon of minimum fluidization is studied using CFD-DEM simulation with 4 different sizes of particles 0.15 mm, 0.3 mm, 0.6 mm, and 1.2 mm diameters. The results are presented in the form of pressure drop across the bed with the fluid superficial velocity. The achieved results are found in good agreement with the experimental and theoretical data available in literature.

  15. Thermodynamic modeling of small scale biomass gasifiers: Development and assessment of the ''Multi-Box'' approach.

    Science.gov (United States)

    Vakalis, Stergios; Patuzzi, Francesco; Baratieri, Marco

    2016-04-01

    Modeling can be a powerful tool for designing and optimizing gasification systems. Modeling applications for small scale/fixed bed biomass gasifiers have been interesting due to their increased commercial practices. Fixed bed gasifiers are characterized by a wide range of operational conditions and are multi-zoned processes. The reactants are distributed in different phases and the products from each zone influence the following process steps and thus the composition of the final products. The present study aims to improve the conventional 'Black-Box' thermodynamic modeling by means of developing multiple intermediate 'boxes' that calculate two phase (solid-vapor) equilibriums in small scale gasifiers. Therefore the model is named ''Multi-Box''. Experimental data from a small scale gasifier have been used for the validation of the model. The returned results are significantly closer with the actual case study measurements in comparison to single-stage thermodynamic modeling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. 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)

  17. 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)

  18. Simulations of a Circulating Fluidized Bed Chemical Looping Combustion System Utilizing Gaseous Fuel; Simulation de la combustion en boucle chimique d'une charge gazeuse dans un lit fluidise circulant

    Energy Technology Data Exchange (ETDEWEB)

    Mahalatkar, K.; Kuhlman, J. [West Virginia University, Dept. of Mechanical and Aerospace Engineering, Morgantown, WV, 26506 (United States); Mahalatkar, K. [ANSYS Inc., 3647 Collins Ferry Road Suite A, Morgantown, WV, 26505 (United States); Kuhlman, J.; Huckaby, E.D.; O' Brien, T. [National Energy Technology Laboratory, 3610 Collins Ferry Road, Morgantown, WV, 26507 (United States)

    2011-03-15

    Numerical studies using Computational Fluid Dynamics (CFD) have been carried out for a complete circulating fluidized bed chemical looping combustor described in the literature (Abad et al., 2006 Fuel 85, 1174-1185). There have been extensive experimental studies in Chemical Looping Combustion (CLC), however CFD simulations of this concept are quite limited. The CLC experiments that were simulated used methane as fuel. A 2-D continuum model was used to describe both the gas and solid phases. Detailed sub-models to account for fluid-particle and particle-particle interaction forces were included. Global models of fuel and carrier chemistry were utilized. The results obtained from CFD were compared with experimental outlet species concentrations, solid circulation rates, solid mass distribution in the reactors, and leakage and dilution rates. The transient CFD simulations provided a reasonable match with the reported experimental data. (authors)

  19. Numerical modelling 2 D and 3 D of circulating fluidized bed: application to the realization of regime diagrams; Modelisation numerique 2D et 3D de lit fluidise circulant: application a la realisation du diagramme des regimes

    Energy Technology Data Exchange (ETDEWEB)

    Begis, J.; Balzer, G.

    1997-02-01

    The numerical modelling of internal CFB boilers flows faced with complex phenomenons due to the flows un-stationariness, the heterogeneousness of the particle size distribution, and interactions between the two phases and the walls. Our study consisted in applying numerical models to the experimental configuration of cold circulating fluidized bed studied at the Cerchar. Special attention was given to the analysis of particles - wall interactions models, stemming from Jenkins (1992) and Louge`s (1994) theories, as well as the influence of the particles on fluid turbulence. In order to realize numerical simulations, we have used Eulerian two-phases flow codes developed at NHL medolif(2D), ESTET-ASTRID(3D). From different tests we have deducted that the most appropriate model for the realization of CFB`s prediction is the model taking in account the influence of particles on fluid turbulence. Then, to evaluate the validity limits of this model, we have built the regime diagram, and we have compared it with the experimental diagram. We have concluded that the simulation allows to describe the different CFB`s working regimes, and especially transitions. We have also noticed the importance of the choice of the mean diameter of the simulated particles. In this way, making a correction of the simulated particles` diameter in comparison with Sauter mean particle diameter, we obtained numerical results in good agreement with experimental data. (authors) 13 refs.

  20. Study of the behaviour of gaseous pollutants during the incineration of municipal solid waste in a circulating fluidized bed; Etude du devenir des polluants gazeux lors de l`incineration d`ordures menageres en lit fluidise circulant

    Energy Technology Data Exchange (ETDEWEB)

    Desroches-Ducarne, E

    1997-09-30

    The Circulating Fluidized Bed (CFB) combustor seems to be a promising tool, being able to burn a variety of fuels whilst maintaining low emissions levels. The present work describes an experimental and theoretical investigation into the formation and destruction of acid gases (HCl and SO{sub 2}) and nitrogen oxides (NO and N{sub 2}O) during Municipal Solid Waste incineration. Experiments were conducted on six different fuels (namely MSW, mixtures of wood, paper, plastics, polyethylene...). The effect of five parameters (temperature, excess air, air staging, calcium addition and moisture) on the emissions levels was investigated. A statistical study on the experimental data allowed us to quantify the impact of the operating conditions and the influence of the fuel characteristics. A mathematical model has been developed which includes the main physical and chemical steps of combustion in CFB and which predicts the pollutant emissions under various operating conditions. A parametric study of the influence of operating conditions on emissions showed that in most cases the trends predicted by the model are in agreement with the experimental observations. (author) 175 refs.

  1. 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

  2. Formation and destruction mechanisms of nitrogen oxides during coal combustion in circulating fluidized beds; Mecanismes de formation et de destruction des oxydes d`azote lors de la combustion du charbon en lit fluidise circulant

    Energy Technology Data Exchange (ETDEWEB)

    Borrel, G.; Lecuyer, I. [Universite du Haut-Rhin, 68 - Mulhouse (France)

    1997-01-01

    Formation and reduction of nitrogen oxides (NO and N{sub 2}O) during coal combustion in a circulating fluidized bed (CFBC) are very complicated and yet badly known. The aim of the present study was to better characterize these phenomena on a small-sized experimental unit (reactor diameter: 5 cm), with the possibility to re-inject the solids in the bottom of the furnace, as in a real industrial unit. This should allow then to develop a numerical set of chemical reactions involving the nitrogen oxides. The experimental results showed that coal ash plays a great role in reducing nitrogen oxides, the determining parameter being the quantity of unburnt carbon remaining in the ash. The study then detailed the interaction between nitrogen oxides and de-volatilized (char) according to the temperature, NO{sub x} concentration and the mass of solid. In the absence of oxygen small quantities of char can very significantly reduce NO as well as N{sub 2}O. It was possible to establish destruction kinetics on these particles, and orders of reaction could be determined versus the NO{sub x} concentration and the char particle mass (heterogeneous phase chemical reactions). Then, the coal pyrolysis study enabled to identify the products released during coal devolatilization and thermogravimetric analyses displayed several successive weight losses due CO, CO{sub 2} and CH{sub 4} releases, during a linear temperature increase. Lastly coal combustion was studied in the small pilot with variable experimental conditions. Using the previous experimental was studied in the small pilot with variable experimental conditions. Using the previous experimental results, a model was developed to calculate NO{sub x} concentrations during the coal combustion and validated. The NO and N{sub 2}O contents calculated are thoroughly correlated with the experimental data whatever the injection carbon/oxygen ratio is. (author) 96 refs.

  3. Bottom ash from fluidising bed boilers as filler material in district heating pipe culverts. Chemical and geotechnical characterisation; Pannsand som kringfyllnadsmaterial foer fjaerrvaermeroergravar. Kemisk och geoteknisk karaktaerisering av fluidbaeddsand

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, Roger; Rogbeck, Jan; Suer, Pascal

    2004-01-01

    Bottom ashes from fluid bed boilers have been characterised, both geotechnically and chemically, in order to investigate the possibility to use them as filler material in district heating pipe culverts. Bottom ashes from both biofuel boilers and waste boilers are represented in this project. The companies which ashes have been characterised are Sundsvall Energi AB, Sydkraft OestVaerme AB, Sydkraft MaelarVaerme AB, Eskilstuna Miljoe och Energi, Stora Enso Fors, Soederenergi and Fortum Vaerme. A total of ten ashes have been analysed where three ashes originates from Sundsvall Energi AB, two from Sydkraft OestVaerme AB and one from the each of the remaining companies. The chemical analyses have been performed both on fresh ashes and on ashes aged for three months. The geotechnical analyses performed are grain size distribution, packing abilities and permeability. Chemical analyses performed are total content, available content, leaching tests (leaching both by shaking method and column procedure) and organic analyses (PAH, EOX, TOC, dioxin and fenol). The geotechnical analyses show that the ashes fulfils the demands that are put on the filler material used in district heating pipe culverts. When using the ashes in applications, light compaction should be performed due to the risk of crushing the material which may cause an increased amount of fine material. The leachability of fine material is larger than for coarse material. The ashes are relatively insensitive to precipitation. Bio fuel based bottom ashes have a lower content of environmental affecting substances than waste fuel based ashes. This is also shown in the leaching analyses. The leaching water from fresh ashes contains a higher concentration of leachable components than aged ashes. When aged the pH in the ashes decreases due to carbon uptake and hydration and this makes metals as Pb, Cu, Cr and Zn less mobile. On the other hand, an increase in leachability of Sb, Mo and SO{sub 4} is shown when the ashes

  4. Fluid-bed methane proposed

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    The first full scale plant for the production of methane from organic waste could be built in the next few years believes M.J. Nyns of the University of Louvain, Belgium, utilizing either expanded bed or fluidised bed systems, with more than one stage, in a continuous flow arrangement. Up to 8.0 m cubed gas/m cubed digester/day could be produced with residence times reduced to 34 hours.

  5. A Philippines gasifier case study

    International Nuclear Information System (INIS)

    Bernardo, F.P.; Kilayko, G.U.

    1991-01-01

    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

  6. 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

  7. 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

  8. REFRACTORY FOR BLACK LIQUOR GASIFIERS

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr.; Alireza Rezaie

    2003-12-01

    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 (LFHT) 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

  9. Refractory for Black Liquor Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    William L. Headrick Jr; Alireza Rezaie

    2003-12-01

    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 (LFHT) 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. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. High Performance Gasification with the Two-Stage Gasifier

    DEFF Research Database (Denmark)

    Gøbel, Benny; Hindsgaul, Claus; Henriksen, Ulrik Birk

    2002-01-01

    , air preheating and pyrolysis, hereby very high energy efficiencies can be achieved. Encouraging results are obtained at a 100 kWth laboratory facility. The tar content in the raw gas is measured to be below 25 mg/Nm3 and around 5 mg/Nm3 after gas cleaning with traditional baghouse filter. Furthermore...... a cold gas efficiency exceeding 90% is obtained. In the original design of the two-stage gasification process, the pyrolysis unit consists of a screw conveyor with external heating, and the char unit is a fixed bed gasifier. This design is well proven during more than 1000 hours of testing with various...... fuels, and is a suitable design for medium size gasifiers....

  20. Chemical Processes Related to Combustion in Fluidised Bed

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Lindqvist, Oliver [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Environmental Inorganic Chemistry

    2002-12-01

    This report covers work that has been carried out in the combustion chemistry group at the Dept. of Environmental Inorganic Chemistry, Chalmers, within the STEM project 12859-1, during the period 2000-07-01 to 2002-06-30. The work was comprised of the following parts: Sulphur chemistry under pressurised and atmospheric conditions; Gas/solid reactions related to sintering and fouling; Chemistry of volatile metals in combustion; Ash leaching properties; Theoretical modelling of the interactions between ions in a solution and mineral surfaces; Some related issues and co-operations with other departments. The work on sulphur chemistry has been a central issue in our group and it has now been finalised with a PhD thesis discussing some aspects of the sulphation of limestone under pressurised conditions. The influence of a number of parameters on the sulphation efficiency was investigated and compared with similar studies under atmospheric conditions. In a special study it was shown that the influence of alternating calcining - non-calcining conditions on the conversion was substantial. In addition, the oxidation of CaS and sulphided limestone was studied and a regeneration method for the sulphide sorbent was proposed. In the project part concerning gas - solid reactions that are relevant to sintering and fouling, the application of an on-line measurement technique for the study of alkali metal capture by kaolin or other sorbents is described. A new reactor set-up has been constructed and the initial results from this set up are promising. The chemistry of cadmium in combustion of MSW and biomass is the object of a PhD project. This work has been concentrated on the task of identifying Cd-compounds in fly ash samples. It has now come to a point where enough data has been collected to make it possible to give an indication about the Cd speciation in some ash types. In MSW ash particles, cadmium seem to occur mainly as chloride, oxide and sulphate. The work will continue with evaluation of other biomass ash particles and, as an extension, the speciation of Cu and Zn will be studied as well. Ash fractions from combustion of MSW in a BFB boiler have been investigated regarding composition and leaching properties, i.e. environmental impact risks. The release of salts from the cyclone ash fraction can be minimised by the application of a simple washing process, thus securing that the leaching of soluble substances stays within the regulative limits. The MSW ash - water systems contain some interesting chemical issues, such as the interactions between Cr(VI) and reducing substances like Al-metal. The understanding of such chemical processes is important since it gives a possibility to predict effects of a change in ash composition. An even more detailed understanding of interactions between a solution containing ions and particle surfaces can be gained by theoretical modelling. In this project (and with additional unding from Aangpannefoereningens Forskningsstiftelse) a theoretical description of ion-ion interactions and the solid-liquid-interface has been developed. Some related issues are also included in this report. The publication of a paper on the reactions of ammonia in the presence of a calcining limestone surface is one of them. A review paper on the influence of combustion conditions on the properties of fly ash and its applicability as a cement replacement in concrete is another. The licentiate thesis describing the sampling and measurement of Cd in flue gas is also included since it was finalised during the present period. A co-operation project involving the Geology Dept. at Goeteborg Univ. and our group is briefly discussed. This project concerns the utilisation of granules produced from wood ash and dolomite as nutrient source for forest soil. Finally, the plans for our flue gas simulator facility are discussed.

  1. Reactive Gas Solids Flow in Circulating Fluidised Beds

    DEFF Research Database (Denmark)

    Hjertager, Bjørn Helge; Solberg, Tron; Hansen, Kim Granly

    2005-01-01

    Progress in modelling and simulation of flow processes in gas/particle systems carried out at the authors? research group are presented. Emphasis is given to computational fluid dynamics (CFD) models that use the multi-dimensional multi fluid techniques. Turbulence modelling strategies for gas...

  2. Characterisation of coal and chars in fluidised bed gasification

    CSIR Research Space (South Africa)

    Oboirien, BO

    2009-03-01

    Full Text Available impact on the physical structure of the residual char. 4 In summary, the distinct burnout characteristics of coals could be attributed to the differences in the macerals and microlithotypes compositions, and mineral matter distribution....0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 REFLECTANCE % RE LA TIV E FR EQ UE NC Y % Increasing reflectance, decreasing volatiles, expected Increase in ignition temperature and time for burn-out Figure...

  3. Sustainable nitrification in fluidised bed reactor with immobilised ...

    African Journals Online (AJOL)

    2012-02-01

    Feb 1, 2012 ... polyacrylamide, polystyrene, polyurethane and polyethylene glycol, have been .... and photographed under ultraviolet light. The representative ..... ited NOB population in immobilised pellets, the degradation of NH4. +-N by ...

  4. Sustainable nitrification in fluidised bed reactor with immobilised ...

    African Journals Online (AJOL)

    TOC concentration above 800 mg·ℓ-1 was not able to cause the inhibition of the heterotrophs over the nitrifiers. PCR-DGGE results indicated the presence of Nitrosomonas (ammonia-oxidising bacteria) and Nitrobacter (nitrite-oxidising bacteria) in the immobilised pellets. Keywords: bioimmobilisation, ammonium, partial ...

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

    Directory of Open Access Journals (Sweden)

    Jai-Houng Leu

    2010-01-01

    Full Text Available 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 updraft fixed bed gasifier employs an embedded combustor inside the gasifier to fully combust the synthetic gas generated by the gasifier. The flue gas produced by the synthetic gas combustion inside the combustion tube is piped directly to the heater head of the Stirling engine. The engine will then extract and convert the heat contained in the flue gas into electricity automatically. Output depends on heat input. And, the heat input is proportional to the flow rate and temperature of the flue gas. The preliminary study of the proposed direct coupling of an updraft gasifier with a 25 kW Stirling engine demonstrates that full power output could be produced by the current system. It could be found from the current investigation that no auxiliary fuel is required to operate the current system smoothly. The proposed technology and units could be considered as a viable solid biomass power system.

  6. Experimental and computational studies on a gasifier based stove

    International Nuclear Information System (INIS)

    Varunkumar, S.; Rajan, N.K.S.; Mukunda, H.S.

    2012-01-01

    Highlights: ► A simple method to calculate the fraction of HHC was devised. ► η g for stove is same as that of a downdraft gasifier. ► Gas from stove contains 5.5% of CH 4 equivalent of HHC. ► Effect of vessel size on utilization efficiency brought out clearly. ► Contribution of radiative heat transfer from char bed to efficiency is 6%. - Abstract: The work reported here is concerned with a detailed thermochemical evaluation of the flaming mode behaviour of a gasifier based stove. Determination of the gas composition over the fuel bed, surface and gas temperatures in the gasification process constitute principal experimental features. A simple atomic balance for the gasification reaction combined with the gas composition from the experiments is used to determine the CH 4 equivalent of higher hydrocarbons and the gasification efficiency (η g ). The components of utilization efficiency, namely, gasification–combustion and heat transfer are explored. Reactive flow computational studies using the measured gas composition over the fuel bed are used to simulate the thermochemical flow field and heat transfer to the vessel; hither-to-ignored vessel size effects in the extraction of heat from the stove are established clearly. The overall flaming mode efficiency of the stove is 50–54%; the convective and radiative components of heat transfer are established to be 45–47 and 5–7% respectively. The efficiency estimates from reacting computational fluid dynamics (RCFD) compare well with experiments.

  7. Process for gasifying fuels with the recovery of rich gases

    Energy Technology Data Exchange (ETDEWEB)

    Jahns, F

    1921-04-10

    A process for gasifying fuels with recovery of water-free, rich-in-tar gases in a ring-gas-producer characterized by hot-gas-stream arising from the gasification bed of a fresh chamber in the known way is divided. One part is conducted through an old chamber, the other part is led first during the drying through the fresh fuel and with the received water-vapor also through the old chamber and then during the carbonization with the carbonization products is led to the carbonization-gas conduit.

  8. Fluidized bed gasification of selected South African coals

    CSIR Research Space (South Africa)

    Engelbrecht, AD

    2010-05-01

    Full Text Available that due to the good heat and mass transfer properties of fluidised beds, coal with ash contents up to 70% can be utilised. The CSIR’s research and development work resulted in the installation of five bubbling fluidised bed combustors (BFBCs) between... 1989 and 1999. Other companies, such as Babcock and Scientific Design, also installed a number of BFBC plants during this time. It was realised during the development of BFBC technology that due to the low lateral dispersion coefficient of coal...

  9. The R.D.F. gasifier of Florentine area

    Energy Technology Data Exchange (ETDEWEB)

    Barducci, G. [Studio Tecnico di Ingegneria Ambientale, Firenze (Italy)

    1993-12-31

    L.E.G. (Low Energy Gas) from large biomass gasification plants, to be used as a fuel for electricity production, is a suitable means for adding value -- from an energetic point of view -- to the R.D.F. (Refuse Derived Fuel) and to the agricultural and forestry residues. R.D.F. can be converted to a clean gas turbine fuel by gasification that consists in a partial combustion with oxygen or air and steam. In that sense it seems worthwhile to analyze the capacity of a gasifier such as the Greve in Chianti`s recirculating fluidized bed gasifier. The world`s first full-scale R.D.F. gasification plant has been designed in Florence; it is now realized in Greve in Chianti and, at the moment, is starting the industrial management. The plant is designed to gasify 200 t/d of pelletized R.D.F. producing about 17.000/19.000 Nmc/h of low energy gas (LEG) with a net calorific value (NCV) of about 5 MJ/Nmc and a total energy content (at the outlet of the gasifiers) of about 7.5 MJ/Nmc. The produced LEG will be partly burned on site for power production while partly will be cooled, dedusted and transported to the kiln of the adjacent cement factory. The design idea of R.D.F. gasification starts from field of waste treatment and recycling and develops new, advanced technical and economical sinergy with the field of industrial production and electric power generation. The gasification of fuels derived from selected wastes (and/or industrial refuse) and the exploitation of the lean gas produced is the most advanced point in the development of heat conversion processes.

  10. 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.

  11. High temperature corrosion in gasifiers

    Directory of Open Access Journals (Sweden)

    Bakker Wate

    2004-01-01

    Full Text Available Several commercial scale coal gasification combined cycle power plants have been built and successfully operated during the last 5-10 years. Supporting research on materials of construction has been carried out for the last 20 years by EPRI and others. Emphasis was on metallic alloys for heat exchangers and other components in contact with hot corrosive gases at high temperatures. In this paper major high temperature corrosion mechanisms, materials performance in presently operating gasifiers and future research needs will be discussed.

  12. 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.

  13. Simulation of petcoke gasification in slagging moving bed reactors

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, Soumitro; Sarkar, T.K.; Sen, P.K. [Research and Development Center, Engineers India Limited, Gurgaon 122001 (India)

    2005-03-25

    A mathematical model for simulation of moving bed petcoke gasifiers was developed. The model introduces a new feed characterization method, gas-phase resistance and volatilization models. The model is validated using reported data for a slagging gasifier. Effect of feed oxygen-to-coke and steam-to-coke ratios and feed coke rates on gasification performance was examined. Slagging zone moving bed gasifier operation with very high petcoke fluxes of over 4000 kg/m{sup 2}/h was possible with high petcoke conversion. Peak gas temperatures exceeded 1500 {sup o}C. Fluxes higher than 5000 kg/m{sup 2}/h are limited by an approach to fluidization of small particles in the combustion zone. The moving bed gasifier performance was found superior to performance of an entrained flow gasifier (EFG) with respect to energy efficiency and oxygen consumption.

  14. Fixed bed gasification of solid biomass fuels

    Energy Technology Data Exchange (ETDEWEB)

    Haavisto, I [Condens Oy, Haemeenlinna (Finland)

    1997-12-31

    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.)

  15. 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.)

  16. Mathematic modelling of a fixed-bed gasifier as component of a plant for decentral biomass utilisation; Mathematische Modellierung eines Festbettvergasers als Bestandteil einer Anlage zur dezentralen Nutzung von Biomasse

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

    This paper presents a two-dimensional nonstationary model that describes processes taking place during gasification in a fixed bed. For didactic purposes the process is split up into and described in terms of the partial models ''chemical reaction'', ''drying'', ''heat transfer'' and ''mass flow''. [German] Es wird ein zweidimensionales, instationaeres Modell zur Beschreibung der Vorgaenge bei der Vergasung im Festbett vorgestellt. Dabei werden zylinderfoermige Reaktoren betrachtet. Zur Beschreibung wird der Gesamtvorgang in die Teilmodelle 'chemische Reaktion', 'Trocknung', 'Waermeuebertragung' und 'Massefluss' unterteilt. Die einzelnen Teilmodelle werden vorgestellt. (orig.)

  17. Thermochemical equilibrium modelling of a gasifying process

    International Nuclear Information System (INIS)

    Melgar, Andres; Perez, Juan F.; Laget, Hannes; Horillo, Alfonso

    2007-01-01

    This article discusses a mathematical model for the thermochemical processes in a downdraft biomass gasifier. The model combines the chemical equilibrium and the thermodynamic equilibrium of the global reaction, predicting the final composition of the producer gas as well as its reaction temperature. Once the composition of the producer gas is obtained, a range of parameters can be derived, such as the cold gas efficiency of the gasifier, the amount of dissociated water in the process and the heating value and engine fuel quality of the gas. The model has been validated experimentally. This work includes a parametric study of the influence of the gasifying relative fuel/air ratio and the moisture content of the biomass on the characteristics of the process and the producer gas composition. The model helps to predict the behaviour of different biomass types and is a useful tool for optimizing the design and operation of downdraft biomass gasifiers

  18. 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

  19. Contribution to the knowledge of spouted beds, including in particular an experimental study on the void fraction of the dense phase

    International Nuclear Information System (INIS)

    Eljas, Yves.

    1975-10-01

    The spouted bed is a gas-solid contact technique used to replace fluidisation when the solid particles are too large and too dense. Part one gives a bibliographical study on the aerodynamic aspect of spouted beds. Part two describes an experimental study of the void fraction distribution in a two-dimensional bed [fr

  20. 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...... that the organic compounds and the inhibition effect are very low even before treatment with activated carbon. The moderate inhibition effect relates to a high content of ammonia in the condensate. The nitrifiers become tolerant to the condensate after a few weeks of exposure. The level of organic compounds...... and the level of inhibition are so low that condensate from the optimised two-stage gasifier can be led to the public sewer....

  1. Results with a bench scale downdraft biomass gasifier for agricultural and forestry residues

    Energy Technology Data Exchange (ETDEWEB)

    Olgun, Hayati [TUBITAK Marmara Research Center, Energy Institute, P.O. Box 21, 41470 Gebze, Kocaeli (Turkey); Ozdogan, Sibel; Yinesor, Guzide [Marmara University-Goztepe Campus, Faculty of Engineering - Department of Mechanical Engineering, 34722 Kuyubasi Kadikoy Istanbul (Turkey)

    2011-01-15

    A small scale fixed bed downdraft gasifier system to be fed with agricultural and forestry residues has been designed and constructed. The downdraft gasifier has four consecutive reaction zones from the top to the bottom, namely drying, pyrolysis, oxidation and reduction zones. Both the biomass fuel and the gases move in the same direction. A throat has been incorporated into the design to achieve gasification with lower tar production. The experimental system consists of the downdraft gasifier and the gas cleaning unit made up by a cyclone, a scrubber and a filter box. A pilot burner is utilized for initial ignition of the biomass fuel. The product gases are combusted in the flare built up as part of the gasification system. The gasification medium is air. The air to fuel ratio is adjusted to produce a gas with acceptably high heating value and low pollutants. Within this frame, different types of biomass, namely wood chips, barks, olive pomace and hazelnut shells are to be processed. The developed downdraft gasifier appears to handle the investigated biomass sources in a technically and environmentally feasible manner. This paper summarizes selected design related issues along with the results obtained with wood chips and hazelnut shells. (author)

  2. 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.

  3. Design and techno economic evaluation of biomass gasifier for ...

    African Journals Online (AJOL)

    This paper addresses the design, performance and economic evaluation of biomass based open core downdraft gasifier for industrial process heat application. The gasifier is having feed rate as 90 kg h-1 and producing about 850 MJ h-1 of heat. The gasifier has been installed in M/S Phosphate India Pvt. Limited, Udaipur ...

  4. Improvement of Combustion Characteristics in Fluidized Bed

    International Nuclear Information System (INIS)

    Mohamed, H.S.; El Sourougy, M.R.; Faik, M.

    2009-01-01

    The present investigation is directed towards the experimental study of the effect of a new design of the bed temperature on the overall thermal efficiency and heat transfer by conduction, convection and radiation in gaseous fuel-fluidized bed combustion system. The experiments are performed on a water-cooled fluidized bed model furnace with cylindrical cross-section of 0.25 m diameter and its height is 0.60 m. the fluidising medium used is sand particles with average diameter 1.5 mm. The bed temperature is varied between 700 degree C and 1100 degree C. Measurements f carbon dioxide, carbon monoxide and oxygen concentrations are carried out by using water-cooled sampling probe, and infrared and paramagnetic analyzers. The results obtained show that the bed temperature, the total heat transfer to the wall and the bed combustion efficiency increase with the decrease of the air-fuel ratio. It is also found that 91% of the total heat transfer is in the fluidising part of the bed and most of this heat is transferred by convection from hot sand particles to the wall. Two empirical formulae for the calculation of the wall heat transfer coefficient and the particle convective heat transfer coefficient are proposed. A verification of the proposed empirical formulae is made by comparing the calculated values with the experimental results.

  5. Gas fluidized bed reactor

    International Nuclear Information System (INIS)

    Bernardelli, H. da C.

    1976-03-01

    The equations of motion for both gas and particles in a gas fluidised system are stablished through general assumptions which are generally accepted on physical grounds. The resulting model is used to study the velocity fields of each phase in the case of an isolated bubble rising close to the flat distributor plate. A well posed problem results for the solution of Laplace's equation of the potential flow of the particles when consideration is given to the presence of the distributor as a boundary condition. The corresponding stream functions are also obtained which enable the drawing of the motion patterns using numerical techniques. The following two dimensional cases are analysed: S/b=1; S/b=1,5; S/b=2,5; S/b=5 and the limiting case S/b→αinfinite. The results for the interphase exchange between bubbles and particulate phases are applied to a gas fluidised bed reactor and its effect on the chemical conversion is studied for the simplest cases of piston flow and perfect mixing in the particulate phase [pt

  6. 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.

  7. Gasifier selection, design and gasification of oil palm fronds with preheated and unheated gasifying air.

    Science.gov (United States)

    Guangul, Fiseha M; Sulaiman, Shaharin A; Ramli, Anita

    2012-12-01

    Oil palm frond biomass is abundantly available in Malaysia, but underutilized. In this study, gasifiers were evaluated based on the available literature data and downdraft gasifiers were found to be the best option for the study of oil palm fronds gasification. A downdraft gasifier was constructed with a novel height adjustment mechanism for changing the position of gasifying air and steam inlet. The oil palm fronds gasification results showed that preheating the gasifying air improved the volumetric percentage of H(2) from 8.47% to 10.53%, CO from 22.87% to 24.94%, CH(4) from 2.02% to 2.03%, and higher heating value from 4.66 to 5.31 MJ/Nm(3) of the syngas. In general, the results of the current study demonstrated that oil palm fronds can be used as an alternative energy source in the energy diversification plan of Malaysia through gasification, along with, the resulting syngas quality can be improved by preheating the gasifying air. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. A rice husk gasifier for paddy drying

    International Nuclear Information System (INIS)

    Mirani, A.A.; Kalwar, S.A.; Ahmad, M.

    2013-01-01

    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)

  9. Predictive Model to determine the composition of the gas generated in a downdraft gasifier

    International Nuclear Information System (INIS)

    D'Espaux Shelton, Elbis; Copa Rey, José Ramón; Brito Sauvanel, Angel Luis

    2017-01-01

    There is currently a trend of using gasification modeling to describe the process without the need to develop experiments, which can be costly. This work presented the necessary tools to analyze the development of a mathematical model with the objective of predicting the chemical composition of the gas generated in a fixed bed downdraft gasifier, with parallel flows and air as a gasification agent as a function of kind of biomass used and the operating parameters of the equipment. This model allows the calculation of thermochemical processes that occur inside a downdraft gasifier and also the determination of temperature profiles. The model developed was based on the energy balance and species equations approach and the control volumes method was used. (author)

  10. State of the art and the future fuel portfolio of fluidized bed combustion systems; Status und kuenftiges Brennstoffportfolio bei Wirbelschichtfeuerungen

    Energy Technology Data Exchange (ETDEWEB)

    Szentannai, Pal; Friebert, Arpad; Winter, Franz [Technische Univ. Wien (Austria). Inst. fuer Verfahrens-, Umwelttechnik und technische Biowissenschaften

    2008-07-01

    Coal, biomass and substitute fuels energetically can be used efficiently and with low pollution in fluidized bed plants. In comparison to biomass there are significant differences between the circulating and stationary fluidized bed technology. The stationary fluidised bed is fed predominantly with biomasses and residual substances. Coal usually is the basis fuel in the circulating fluidised bed. Biomass and residual substances frequently are course-fired. The state of the art is the employment of a broad fuel mixture in small and large fluidized-bed combustion systems. Future developments present an increased use of sewage sludge, fluidized bed combustion systems with wood as a basis fuel, utilization of household waste and the gas production.

  11. Development and Testing of Prototype Commercial Gasifier Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zelepouga, Serguei [Gas Technology Inst., Des Plaines, IL (United States); Moery, Nathan [Gas Technology Inst., Des Plaines, IL (United States); Wu, Mengbai [Gas Technology Inst., Des Plaines, IL (United States); Saveliev, Alexei [Gas Technology Inst., Des Plaines, IL (United States)

    2015-01-31

    This report presents the results of the sensor development and testing at the Wabash River gasifier. The project work was initiated with modification of the sensor software (Task 2) to enable real time temperature data acquisition, and to process and provide the obtained gasifier temperature information to the gasifier operators. The software modifications were conducted by the North Carolina State University (NCSU) researchers. The modified software was tested at the Gas Technology Institute (GTI) combustion laboratory to assess the temperature recognition algorithm accuracy and repeatability. Task 3 was focused on the sensor hardware modifications needed to improve reliability of the sensor system. NCSU conducted numerical modeling of the sensor probe’s purging flow. Based on the modeling results the probe purging system was redesigned to prevent carbon particulates deposition on the probe’s sapphire window. The modified design was evaluated and approved by the Wabash representative. The modified gasifier sensor was built and installed at the Wabash River gasifier on May 1 2014. (Task 4) The sensor was tested from the startup of the gasifier on May 5, 2015 until the planned autumn gasifier outage starting in the beginning of October, 2015. (Task 5) The project team successfully demonstrated the Gasifier Sensor system’s ability to monitor gasifier temperature while maintaining unobstructed optical access for six months without any maintenance. The sensor examination upon completion of the trial revealed that the system did not sustain any damage.

  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. Cost and operational acceptability improvements to gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Connor, A.

    2003-07-01

    This work reports on the operation of two gasifiers by Biomass Engineering Ltd. in Northern Ireland, and the simplification of their gas conditioning system. Details are given of the high tar destruction levels achieved, the locally available wood waste and pallet wood, and the use of a back-pulsable dry ceramic filtration system for removing trace organics and particulates from the resulting gas prior to gas cooling, final filtration and use in a gas engine. The results of a techno-economic assessment of the original scrubbing system and the new ceramic filtration system indicating cost savings are presented. Further work to optimise the parameters of the filters is planned.

  14. Design and techno economic evaluation of biomass gasifier for ...

    African Journals Online (AJOL)

    user

    2Department of Renewable Energy Sources, College of Technology and Engineering, Maharana Pratap University of. Agriculture ... downdraft gasifier for industrial process heat application. The gasifier is ... generation and biofuels production, and it may be pro- ... Nomenclature: ηg, The hot gas efficiency of the gasification.

  15. Fluid Dynamics of Pressurized, Entrained Coal Gasifiers

    International Nuclear Information System (INIS)

    1997-01-01

    Pressurized, entrained gasification is a promising new technology for the clean and efficient combustion of coal. Its principle is to operate a coal gasifier at a high inlet gas velocity to increase the inflow of reactants, and at an elevated pressure to raise the overall efficiency of the process. Unfortunately, because of the extraordinary difficulties involved in performing measurements in hot, pressurized, high-velocity pilot plants, its fluid dynamics are largely unknown. Thus the designer cannot predict with certainty crucial phenomena like erosion, heat transfer and solid capture. In this context, we are conducting a study of the fluid dynamics of Pressurized Entrained Coal Gasifiers (PECGs). The idea is to simulate the flows in generic industrial PECGs using dimensional similitude. To this end, we employ a unique entrained gas-solid flow facility with the flexibility to recycle--rather than discard--gases other than air. By matching five dimensionless parameters, suspensions in mixtures of helium, carbon dioxide and sulfur hexafluoride simulate the effects of pressure and scale-upon the fluid dynamics of PECGs. Because it operates under cold, atmospheric conditions, the laboratory facility is ideal for detailed measurements

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

    International Nuclear Information System (INIS)

    Andersson, E.; Harvey, S.

    2007-01-01

    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 CO 2 emission consequences, based upon different assumptions for the reference energy system that reflect different societal CO 2 emissions reduction target levels. Ambitions targets are expected to lead to a more CO 2 -lean reference energy system, in which case hydrogen production from gasified black liquor (Alternative A) is best from a CO 2 emissions' perspective, whereas with high CO 2 emissions associated with electricity production, hydrogen from gasified biomass and electricity from gasified black liquor (Alternative B) is preferable. (author)

  17. Production of 800 kW of electrical power using medium calorific gas from a biomass gasifier integrated in a combined cycle

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, I.; Cabrita, I. [Instituto Nacional de Engenharia e Tecnologia Industrial, Lisboa (Portugal)

    1993-12-31

    An allothermal fluidized bed biomass gasifier is under construction to operate at a pressure slightly above atmospheric to produce a gaseous fuel of medium heating value. The output of the gasifier is 2.5 {times} 10{sup 6} kcal/h and will be attached to a gas turbine that is specifically modified to burn the gas produced. The amount of electricity to be generated will be 800 kW. The gasifying medium used is superheated steam at 2.5 bars and 400{degrees}C and the amount needed will be 280 kg/h. The gasifier will have a cross sectional area of 2.1 m{sup 2} with dimensions of 1 500 mm {times} 1 400 mm. There is a heat exchanger to provide the heat needed for the gasification reactions. The gasifier will operate at about 850{degrees}C and the biomass throughput will be about 950 kg/h. The amount of gas that is to be produced will be about 1 300 kg/h or 1 900 Nm{sup 3}/h. Part of the gas obtained will be burned in an external combustor to provide the heat for the gasifier. The gas turbine to be employed is a single shaft turbine designed to drive 750 kVA electrical generator. The turbine combustion chamber is somewhat modified to allow for the lower heating value of the gas. However, there is no loss of efficiency in the turbine output due to lower calorific value of the fuel. The turbine inlet temperature is 900/{degrees}C and that of the exhaust will be 500{degrees}C. The amount of gas to be used is about 745 Nm{sup 3}/h. The paper reports the experimental results obtained from a pilot-scale gasifier operating under similar conditions. The results of test runs carried out with a gas turbine are also presented.

  18. 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...

  19. 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.

    1997-12-31

    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.)

  20. 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.)

  1. Performance evaluation of open core gasifier on multi-fuels

    Energy Technology Data Exchange (ETDEWEB)

    Bhoi, P.R.; Singh, R.N.; Sharma, A.M.; Patel, S.R. [Thermo Chemical Conversion Division, Sardar Patel Renewable Energy Research Institute (SPRERI), Vallabh Vidyanagar 388 120, Gujarat (India)

    2006-06-15

    Sardar Patel renewable energy research institute (SPRERI) has designed and developed open core, throat-less, down draft gasifier and installed it at the institute. The gasifier was designed for loose agricultural residues like groundnut shells. The purpose of the study is to evaluate the gasifier on multi-fuels such as babul wood (Prosopis juliflora), groundnut shell briquettes, groundnut shell, mixture of wood (Prosopis juliflora) and groundnut shell in the ratio of 1:1 and cashew nut shell. The gasifier performance was evaluated in terms of fuel consumption rate, calorific value of producer gas and gasification efficiency. Gasification efficiency of babul wood (Prosopis juliflora), groundnut shell briquettes, groundnut shell, mixture of Prosopis juliflora and groundnut shell in the ratio of 1:1 and cashew nut shell were 72%, 66%, 70%, 64%, 70%, respectively. Study revealed that babul wood (Prosopis juliflora), groundnut shell briquettes, groundnut shell, mixture of wood (Prosopis juliflora) and groundnut shell in the ratio of 1:1 and cashew nut shell were satisfactorily gasified in open core down draft gasifier. The study also showed that there was flow problem with groundnut shell. (author)

  2. 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

  3. Particulate Emissions from Fluidised Bed Combustion of Ligite with Mineral Sorbents

    Czech Academy of Sciences Publication Activity Database

    Smolík, Jiří; Schwarz, Jaroslav; Ondráčková, Lucie; Veselý, Václav; Sýkorová, Ivana; Kučera, Jan; Havránek, Vladimír

    2000-01-01

    Roč. 31, Suppl. 1 (2000), s. S670-S671 ISSN 0021-8502. [European Aerosol Conference 2000. Dublin, 03.09.2000-08.09.2000] R&D Projects: GA ČR GA104/00/1297; GA AV ČR IAA2046904 Institutional research plan: CEZ:AV0Z4072921; CEZ:AV0Z3046908 Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.071, year: 2000

  4. Utilization of post-reclamation dusts by combustion and oxidising in a pulsating, fluidised bed

    Directory of Open Access Journals (Sweden)

    J. Dańko

    2008-03-01

    Full Text Available Invcaigations of thc urilization process of durn. originated from thc mcchanical scclamatbn of uscd moulding sands with Furfury1 alcohol.werc pcrformcd. Colnbustion and oxidat ion processes of pulvcriscd and scparatetl in cycloncs binding agcnts and othcr organiccomponents wcrc carricd out in thc thcrmal mlairncr wherc a grain hcd ~mdcnvent pulsating fluidisat ion cithcs by thc atmnsphcric air orhy oxypcn cnriched air. Factors dclcrmining an effective pcrlormancc of dusls utilization by oxidising in rhc oxygcn cncichcd air wcreindicated and thc plan for thc Furthcr rcscwch was outlined.

  5. Mathematical Determination of Thermal Load for Fluidised Bed Furnaces Using Sawdust

    Directory of Open Access Journals (Sweden)

    Antonescu Nicolae

    2014-06-01

    Full Text Available For technical applications, a physical model capable of predicting the particle evolution in the burning process along its trajectory through the furnace is very useful. There are two major demands: all the thermo-dynamic processes that describe the particle burning process must be accounted and the model must be written in such equation terms to allow the intervention for parameter settings and particle definition. The computations were performed for the following parameters: furnace average temperature between 700 and 1200 °C, size of the sawdust particle from 4 to 6 mm and fix carbon ignition between 500 and 900 °C. The values obtained for the characteristic parameters of the burning process ranged from 30 to 60 [kg/(h·m3] for the gravimetrical burning speed WGh and from 150 to 280 [kW/m3] for the volumetric thermal load of the furnace QV. The main conclusion was that the calculus results are in good agreement with the experimental data from the pilot installations and the real-case measurements in the sawdust working boiler furnaces or pre-burning chambers. Another very important conclusion is that the process speed variation, when the furnace temperature changes, confirms the thermo-kinetic predictions, namely that the burning process speed decreases when the furnace temperature increases.

  6. Wall heat flux influence on the thermodynamic optimisation of irreversibilities of a circulating fluidised bed combustor

    CSIR Research Space (South Africa)

    Baloyi, J

    2016-07-01

    Full Text Available . The irreversibilities generated were arrived at by computing the entropy generation rates due to the combustion and frictional pressure drop processes. For the combustor where the wall condition was changed from adiabatic to negative heat flux (that is heat leaving...

  7. Fluidised bed gasification of South African coals – experimental results and process integration

    CSIR Research Space (South Africa)

    Engelbrecht, A

    2011-06-01

    Full Text Available % to 51.6%. The new design however requires a significantly larger heat exchange area to exchange the extra energy that was not exchanged in the preliminary design. It is therefore recommended that a cost analysis should be done to determine whether...

  8. Co-firing coal and biomass in a fluidised bed boiler

    CSIR Research Space (South Africa)

    North, BC

    2005-11-01

    Full Text Available ) Nozzle performance trials iv) Large scale combustion trials (including further pumping trials). These phases are covered in greater detail below. Theoretical Studies The first step was to draw up a composite fuel table, where the relative feed.... An example is given in Table 2C. Deviations from theoretical behaviour were investigated, reasons postulated and solutions proposed. Nozzle Performance Trials Trials were carried out at the client’s premises and at the CSIR in order to determine...

  9. 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

  10. Slagging gasifier refractories. A new pathway to longer refractory life

    Energy Technology Data Exchange (ETDEWEB)

    Schnake, Mark [Harbinson-Walker Refractories Company, Mexico, MO (United States)

    2013-07-01

    Solid fuel slagging gasification to convert coal or petroleum coke feedstocks into syngas has rapidly evolved over the last 25 years. The gasifier is a high temperature, high pressure reaction chamber. Operating temperatures are between 1250 and 1575 C. Pressures will be between 20.4 and 68 atm. Syngas has been typically used for chemical feedstocks, fuel for power plants, or for steam and hydrogen generation in other industrial applications. Ash which comes from the solid fuel during gasification has many impurities. It melts during the gasifier reactor operation forming a liquid that penetrates the refractory lining. Given time, the refractory will wear away from thermal spalling, structural spalling, or overheating of the refractory. In some cases, all three wear mechanisms are seen in the same gasifier lining. Industry users have identified refractory life as one major limiting factor in worldwide use of this technology. Users have stated if the refractory liner can increase on-line availability of the gasifier operation, more industry acceptance of this technology is possible. Harbison-Walker Refractories Company will review destructive factors affecting lining life and discuss new refractory materials that have dramatically increased gasifier lining life and reliability. New refractory materials will be presented and supported by field trial results and post mortem analysis.

  11. Low-Chrome/Chrome Free Refractories for Slagging Gasifiers

    International Nuclear Information System (INIS)

    Bennett, J.P.; Kwong, K.-S.; Powell, C.P.; Thomas, H.; Petty, A.V. Jr.

    2007-01-01

    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

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

    International Nuclear Information System (INIS)

    Ghosh, Debyani; Sagar, Ambuj D.; Kishore, V.V.N.

    2006-01-01

    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. Reactions homogenes en phase gazeuse dans les lits fluidises

    Science.gov (United States)

    Laviolette, Jean-Philippe

    This thesis presents a study on homogeneous gas-phase reactions in fluidized beds. The main objective is to develop new tools to model and characterize homogeneous gas-phase reactions in this type of reactor. In the first part of this work, the non-premixed combustion of C 1 to C4 n-alkanes with air was investigated inside a bubbling fluidized bed of inert sand particles at intermediate temperatures: 923 K ≤ TB ≤ 1123 K. For ethane, propane and n-butane, combustion occurred mainly in the freeboard region at bed temperatures below T1 = 923 K. On the other hand, complete conversion occurred within 0.2 m of the injector at: T2 = 1073 K. For methane, the measured values of T1 and T2 were significantly higher at 1023 K and above 1123 K, respectively. The fluidized bed combustion was accurately modeled with first-order global kinetics and two one-phase PFR models in series: one PFR to model the region close to the injector and another to represent the main fluidized bed body. The measured global reaction rates for C2 to C4 n-alkanes were characterized by a uniform Arrhenius expression, while the global reaction rate for methane was significantly slower. Reactions in the injector region either led to significant conversion in that zone or an autoignition delay inside the main fluidized bed body. The conversion in the injector region increased with rising fluidized bed temperature and decreased with increasing jet velocity. To account for the promoting and inhibiting effects, an analogy was made with the concept of induction time: the PFR length (bi) of the injector region was correlated to the fluidized bed temperature and jet velocity using an Arrhenius expression. In the second part of this work, propane combustion experiments were conducted in the freeboard of a fluidized bed of sand particles at temperatures between 818 K and 923 K and at superficial gas velocity twice the minimum fluidization velocity. The freeboard region was characterized by simultaneous

  14. Straw Gasification in a Two-Stage Gasifier

    DEFF Research Database (Denmark)

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

    2002-01-01

    - and 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, and the ash...

  15. Lignite chemical conversion in an indirect heat rotary kiln gasifier

    Directory of Open Access Journals (Sweden)

    Hatzilyberis Kostas S.

    2006-01-01

    Full Text Available The results on the gasification of Greek lignite using two indirect heat (allothermal pilot rotary kiln gasifiers are reported in the present work. The development of this new reactor-gasifier concept intended for solid fuels chemical conversion exploits data and experience gained from the following two pilot plants. The first unit A (about 100 kg/h raw lignite demonstrated the production of a medium heating value gas (12-13 MJ/Nm3 with quite high DAF (dry ash free coal conversions, in an indirect heat rotary gasifier under mild temperature and pressure conditions. The second unit B is a small pilot size unit (about 10 kg/h raw lignite comprises an electrically heated rotary kiln, is an operation flexible and exhibits effective phase mixing and enhanced heat transfer characteristics. Greek lignite pyrolysis and gasification data were produced from experiments performed with pilot plant B and the results are compared with those of a theoretical model. The model assumes a scheme of three consecutive-partly parallel processes (i. e. drying, pyrolysis, and gasification and predicts DAF lignite conversion and gas composition in relatively good agreement with the pertinent experimental data typical of the rotary kiln gasifier performance. Pilot plant B is currently being employed in lime-enhanced gasification studies aiming at the production of hydrogen enriched synthesis gas. Presented herein are two typical gas compositions obtain from lignite gasification runs in the presence or not of lime. .

  16. 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)

  17. Development of advanced air-blown entrained-flow two-stage bituminous coal IGCC gasifier

    Directory of Open Access Journals (Sweden)

    Abaimov Nikolay A.

    2017-01-01

    Full Text Available Integrated gasification combined cycle (IGCC technology has two main advantages: high efficiency, and low levels of harmful emissions. Key element of IGCC is gasifier, which converts solid fuel into a combustible synthesis gas. One of the most promising gasifiers is air-blown entrained-flow two-stage bituminous coal gasifier developed by Mitsubishi Heavy Industries (MHI. The most obvious way to develop advanced gasifier is improvement of commercial-scale 1700 t/d MHI gasifier using the computational fluid dynamics (CFD method. Modernization of commercial-scale 1700 t/d MHI gasifier is made by changing the regime parameters in order to improve its cold gas efficiency (CGE and environmental performance, namely H2/CO ratio. The first change is supply of high temperature (900°C steam in gasifier second stage. And the second change is additional heating of blast air to 900°C.

  18. Bed Bugs

    Science.gov (United States)

    Prevent, identify, and treat bed bug infestations using EPA’s step-by-step guides, based on IPM principles. Find pesticides approved for bed bug control, check out the information clearinghouse, and dispel bed bug myths.

  19. Sulfate reduction in an entrained-flow black liquor gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Kymaelaeinen, M.; Janka, K. [Tampella Power, Tampere (Finland); Frederick, W.J.; Littau, M.; Sricharoenchaikul, V.; Jivakanun, N.; Waag, K. [Oregon State Univ., Corvallis, OR (United States). Dept. of Chemical Engineering

    1995-12-31

    Sulfate reduction and carbon conversion during pyrolysis and gasification of black liquor particles were experimentally studied in a laminar entrained-flow reactor. A model was also developed to simulate an entrained-flow black liquor gasifier. Experimental results were then compared to model calculations. Results indicated that carbon must be present to get a high degree of sulfate reduction during gasification. It is therefore important to balance the rates of carbon conversion and sulfate reduction. High local temperatures in the reactor should be avoided so that carbon does not convert too rapidly, but temperatures of nearly 1000 degrees C are required to achieve good sulfate reduction. It was suggested that a new equation was needed to adequately predict sulfate reduction in an entrained-flow black liquor gasifier. 12 refs., 8 figs., 5 tabs.

  20. Study of ammonia removal from coal-gasified fuel

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Takeharu; Sato, Mikio [Central Research Inst. of Electric Power Industry, Yokosuka, Kanagawa (Japan)

    1998-07-01

    In integrated coal gasification combined-cycle power-generation (IGCC) systems, ammonia in gasified fuel is passed through a hot/dry type gas clean-up facility into a gas turbine. The ammonia is converted to nitrogen oxides in the gas turbine combustion process. Therefore, ammonia removal from coal-gasified fuel effectively reduces NO{sub x} emissions in IGCC systems. The authors clarified the optimum NO/NH{sub 3} ratio, the optimum concentration of added O{sub 2}, and the influence of CO, H{sub 2}, and CH{sub 4} in the coal-gasified fuel on NH{sub 3} decomposition and NO reduction through experiments using a tubular flow reactor and numerical analysis based on reaction kinetics. The main results were as follows: (1) The optimum NO/NH{sub 3} ratio for maximizing NH{sub 3} decomposition and NO reduction was about 1. (2) The NH{sub 3} decomposition ratio depended only on H{sub 2}, and decreased rapidly with increasing H{sub 2} concentration. (3) The NO reduction ratio decreased with an increasing H{sub 2} concentration. (4) The remaining CH{sub 4}, which was not decomposed by pyrolysis, increased with an increasing CH{sub 4} concentration and caused the reaction temperature to rise, as opposed to cases of CO and H{sub 2}. (5) The method was effective in decreasing total fixed nitrogen (TFN) by up to 40% and minimizing the total concentration of remaining NH{sub 3} and NO in air-blown, coal-gasified fuel.

  1. Modelling of a downdraft gasifier fed by agricultural residues

    International Nuclear Information System (INIS)

    Antonopoulos, I.-S.; Karagiannidis, A.; Gkouletsos, A.; Perkoulidis, G.

    2012-01-01

    Highlights: ► Development of software for downdraft gasification simulation. ► Prediction of the syngas concentration. ► Prediction of the syngas heating value. ► Investigation of the temperature effect in reduction zone in syngas concentration. - Abstract: A non-stoichiometric model for a downdraft gasifier was developed in order to simulate the overall gasification process. Mass and energy balances of the gasifier were calculated and the composition of produced syngas was predicted. The capacity of the modeled gasifier was assumed to be 0.5 MW, with an Equivalence Ratio (EQ) of 0.45. The model incorporates the chemical reactions and species involved, while it starts by selecting all species containing C, H, and O, or any other dominant elements. Olive wood, miscanthus and cardoon were tested in the formulated model for a temperature range of 800–1200 °C, in order to examine the syngas composition and the moisture impact on the supplied fuel. Model results were then used in order to design an olive wood gasification reactor.

  2. Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    1990-07-01

    CRS Sirrine (CRSS) is evaluating a novel IGCC process in which gases exiting the gasifier are burned in a gas turbine combustion system. The turbine exhaust gas is used to generate additional power in a conventional steam generator. This results in a significant increase in efficiency. However, the IGCC process requires development of novel approaches to control SO{sub 2} and NO{sub x} emissions and alkali vapors which can damage downstream turbine components. Ammonia is produced from the reaction of coal-bound nitrogen with steam in the reducing zone of any fixed bed coal gasifier. This ammonia can be partially oxidized to NO{sub x} when the product gas is oxidized in a gas turbine combustor. Alkali metals vaporize in the high-temperature combustion zone of the gasifier and laser condense on the surface of small char or ash particles or on cooled metal surfaces. It these alkali-coated materials reach the gas turbine combustor, the alkali will revaporize condense on turbine blades and cause rapid high temperature corrosion. Efficiency reduction will result. PSI Technology Company (PSIT) was contracted by CRSS to evaluate and recommend solutions for NO{sub x} emissions and for alkali metals deposition. Various methods for NO{sub x} emission control and the potential process and economic impacts were evaluated. This included estimates of process performance, heat and mass balances around the combustion and heat transfer units and a preliminary economic evaluation. The potential for alkali metal vaporization and condensation at various points in the system was also estimated. Several control processes and evaluated, including an order of magnitude cost for the control process.

  3. Ash related bed agglomeration during fluidized bed combustion, further development of the classification method based on CCSEM; CCSEM-luokitusmenetelmaen jatkokehittaeminen tuhkan aiheuttaman agglomeroitumisen tutkimisessa leiju- ja kiertopetipoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, R; Patrikainen, T; Heikkinen, R; Tiainen, M; Virtanen, M [Oulu Univ. (Finland). Inst. of Chemistry

    1997-10-01

    The scope of this project is to use the information and experience gained from the development of classification method to predict ash related problems like bed agglomeration during fluidised combustion. If boilers have to be shut down due to slagging or agglomeration of the bed material may cause significant economic losses for the entire energy production chain. Mineral classification methods based on the scanning electron microscopy are commonly used for coal ash investigation. In this work different biomass, peat, and peat-wood ash, fluidised-bed materials, and bed agglomerates were analysed with SEM-EDS combined with automatic image analysis software. The properties of ash particles are different depending on the fuel type. If biomass like wood or bark are added to peat the resulting ash has different properties. Due to the low mineral content in the original peat and to the fact that the majority of inorganic material is bound to the organic matrix, the classification has turned out to be less informative than was hoped. However, good results are obtained the by use of quasiternary diagrams. With these diagrams the distribution of particle composition is easily illustrated and thus meaningful prediction can be made of the slagging and agglomerating properties of ash. The content of ten different elements are determined for each particle by SEM-EDS combined with Link AIA software. The composition of the diagram corners can be varied Freely within these ten elements. (orig.)

  4. Test of pyrolysis gasifier stoves in two institutional kitchens in Uganda

    DEFF Research Database (Denmark)

    Wendelbo, Pall; Nielsen, Per Sieverts

    1998-01-01

    : The main purpose of the paper is to evaluate tests of institutional kitchens carried out at schools in Uganda 1997. The results of the tests for the institutional kitchen with pyrolysis gasifier stoves are compared with the fuel use in traditional kitchens with three-stone stoves. The project......, respectively. The cooking place was build up with a rotating plate on which tree gasifier units were placed. In this way it was possible to change on of the gasifier units when necessary. The pot was then mounted on a tripod app. 10 cm above the gasifier units. The results of the tests show that the improved...

  5. Textural properties of chars as determined by petrographic analysis: comparison between air-blown, oxygen-blown and oxygen-enriched gasification

    CSIR Research Space (South Africa)

    Oboirien, BO

    2012-11-01

    Full Text Available In this study, the textural properties of chars generated from a vitrinite, high ash coal in a fluidised bed gasifier under air-blown, oxygen-blown and oxygen-enriched conditions were determined by detailed petrographic analysis. The char samples...

  6. Pyrolysis of Pinus pinaster in a two-stage gasifier: Influence of processing parameters and thermal cracking of tar

    Energy Technology Data Exchange (ETDEWEB)

    Fassinou, Wanignon Ferdinand; Toure, Siaka [Laboratoire d' Energie Solaire-UFR-S.S.M.T. Universite de Cocody, 22BP582 Abidjan 22 (Ivory Coast); Van de Steene, Laurent; Volle, Ghislaine; Girard, Philippe [CIRAD-Foret, TA 10/16, 73, avenue J.-F. Breton, 34398 Montpellier, Cedex 5 (France)

    2009-01-15

    A new two-stage gasifier with fixed-bed has recently been installed on CIRAD facilities in Montpellier. The pyrolysis and the gasifier units are removable. In order to characterise the pyrolysis products before their gasification, experiments were carried out, for the first time only with the pyrolysis unit and this paper deals with the results obtained. The biomass used is Pinus pinaster. The parameters investigated are: temperature, residence time and biomass flow rate. It has been found that increasing temperature and residence time improve the cracking of tars, gas production and char quality (fixed carbon rate more than 90%, volatile matter rate less than 4%). The increase of biomass flow rate leads to a bad char quality. The efficiency of tar cracking, the quality and the heating value of the charcoal and the gases, indicate that: temperature between 650 C and 750 C, residence time of 30 min, biomass flow rate between 10 and 15 kg/h should be the most convenient experimental conditions to get better results from the experimental device and from the biomass pyrolysis process. The kinetic study of charcoal generation shows that the pyrolysis process, in experimental conditions, is a first-order reaction. The kinetic parameters calculated are comparable with those found by other researchers. (author)

  7. An investigation into heat recovery from the surface of a cyclone dust collector attached to a downdraft biomass gasifier

    International Nuclear Information System (INIS)

    Nwokolo, Nwabunwanne; Mamphweli, Sampson; Makaka, Golden

    2016-01-01

    Highlights: • At a temperature of 450 °C–500 °C, hot syngas is regarded as a good heat carrier. • A significant quantity of energy (665893.07 kcal) is lost via the surface of the cyclone. • The surface temperature 150 °C–220 °C was within the low waste heat recovery temperature. - Abstract: The gas leaving the reactor of a downdraft biomass gasifier contains large quantities of heat energy; this is due to the fact that the gas passes through a hot bed of charcoal before leaving the reactor. This heat is normally wasted in the gas scrubber/cooler that cools it from between 400 °C–500 °C to ambient temperature (around 25 °C). The waste heat stream under consideration is the raw syngas that emanates from a gasification process in a downdraft gasifier situated at Melani Village, Eastern Cape. This loss of heat is undesirable as it impacts on the thermal efficiency of the system. This study investigates the feasibility of heat recovery from the surface of the cyclone dust collector prior to entering the gas scrubber. It was shown that there was a downward decrease in temperature along the length of the cyclone. It is found that the total quantity of heat contained in the gas was 665893.07 kcal, which could indicate the viability of recovering heat from the cyclone.

  8. 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.

  9. Aggregation capability of a fluidised layer of granular material during treatment of water with high DOC and low alkalinity

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Martin; Pivokonská, Lenka; Tomášková, Hana

    2008-01-01

    Roč. 8, č. 1 (2008), s. 9-17 ISSN 1606-9749 R&D Projects: GA ČR GA103/07/1016 Institutional research plan: CEZ:AV0Z20600510 Keywords : water treatment * aggregation * fluidised layer * agitation Subject RIV: BK - Fluid Dynamics

  10. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. CFD-DEM Simulation of Propagation of Sound Waves in Fluid Particles Fluidised Medium

    Directory of Open Access Journals (Sweden)

    H Khawaja

    2016-09-01

    Full Text Available In this work, speed of sound in 2 phase mixture has been explored using CFD-DEM (Computational Fluid Dynamcis - Discrete Element Modelling. In this method volume averaged Navier Stokes, continuity and energy equations are solved for fluid. Particles are simulated as individual entities; their behaviour is captured by Newton's laws of motion and classical contact mechanics. Particle-fluid interaction is captured using drag laws given in literature. The speed of sound in a medium depends on physical properties. It has been found experimentally that speed of sound drops significantly in 2 phase mixture of fluidised particles because of its increased density relative to gas while maintaining its compressibility. Due to the high rate of heat transfer within 2 phase medium as given in Roy et al. (1990, it has been assumed that the fluidised gas-particle medium is isothermal. The similar phenomenon has been tried to be captured using CFD-DEM numerical simulation. The disturbance is introduced and fundamental frequency in the medium is noted to measure the speed of sound for e.g. organ pipe. It has been found that speed of sound is in agreement with the relationship given in Roy et al. (1990. Their assumption that the system is isothermal also appears to be valid.

  12. Catalytic combustion of gasified waste - Experimental part. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jaeraas, Sven; Kusar, Henrik [Royal Institute of Technology, Stockholm (Sweden). Chemical Engineering and Technology

    2003-08-01

    This final report covers the work that has been performed within the project P 10547-2, 'Catalytic combustion of gasified waste - system analysis ORWARE'. This project is part of the research programme 'Energy from Waste' financed by the Swedish National Energy Administration. The project has been carried out at the division of Industrial Ecology and at the division of Chemical Technology at Royal Inst. of Technology. The aim of the project has been to study the potentials for catalytic combustion of gasified waste. The supposed end user of the technique is a smaller community in Sweden with 15,000-20,000 inhabitants. The project contains of two sub projects: an experimental part carried out at Chemical Technology and a system analysis carried out at Industrial Ecology. This report covers the experimental part of the project carried out at Chemical Technology. The aim for the experimental part has been to develop and test catalysts with long life-time and a high performance, to reduce the thermal-NO{sub x} below 5 ppm and to significantly reduce NO{sub x} formed from fuel-bound nitrogen. Different experimental studies have been carried out within the project: a set-up of catalytic materials have been tested over a synthetic mixture of the gasified waste, the influence of sulfur present in the gas stream, NO{sub x} formation from fuel bound nitrogen, kinetic studies of CO and H{sub 2} with and without the presence of water and the effects of adding a co-metal to palladium catalysts Furthermore a novel annular reactor design has been used to carry out experiments for kinetic measurements. Real gasification tests of waste pellets directly coupled to catalytic combustion have successfully been performed. The results obtained from the experiments, both the catalytic combustion and from the gasification, have been possible to use in the system analysis. The aim of the system analysis of catalytic combustion of gasified waste takes into consideration

  13. Efficiency tests on the pyrolysis gasifier stove Peko Pe

    DEFF Research Database (Denmark)

    Nielsen, Per Sieverts

    1996-01-01

    This paper presents results from water boiling tests on the pyrolysis gasifier stove Peko Pe, which has been developed by the Norwegian Paal Wendelbo. The stove efficiency determined vary between 21 and 29% when burning dry Danish woodchips (10% moisture) with an estimated caloric value of 16 MJ...... the water content in the grass. In Adjumani refugee camp it was furthermore found that the stove was able to provide sufficient energy from solid combustion, after the pyrolysis was stopped, to boil water for additional 25-30 minutes with lid. This effect was not seen in the tests on woodchips in Denmark...

  14. The research and development of pressurized ash agglomerating fluidized bed coal gasification

    Energy Technology Data Exchange (ETDEWEB)

    Fang Yitian; Wu Jinhu; Chen Hanshi [Chinese Academy of Sciences, Taiyuan (China). Institute of Coal Chemistry

    1999-11-01

    Coal gasification tests in a pressurized ash agglomeration fluidized bed coal gasifier were carried out. The effects of pressure and temperature on the gasification capacity, carbon conversion, carbon content in discharged ash and gas composition were investigated. Gasification capacity was shown to be in direct proportion to operation pressure. Tests of hot gas dedusting using a moving granular bed were also carried out. 3 refs., 6 figs., 2 tabs.

  15. Comparison of Shell, Texaco, BGL and KRW gasifiers as part of IGCC plant computer simulations

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Furimsky, E. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

    2005-07-01

    The performances of four IGCC plants employing Shell, Texaco, BGL and KRW gasifiers were simulated using ASPEN Plus software for three different feeds. Performance analyses and comparisons of all four IGCC plants were performed based on the established data bank from the simulation. Discussions were focused on gas compositions, gasifier selection and overall performance.

  16. Combustion of cork waste in a circulating fluidized bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, I.; Boavida, D.; Miranda, M.; Cabrita, I. [Dept. de Tecnologias de Combustao, ITE-INETI, Lisboa (Portugal); Abelha, P. [Coaltec e Ambiente, Lisboa (Portugal)

    1999-07-01

    There is currently an ongoing joint project between Portugal and Spain, which is being funded by the FAIR programme. The principal objective of the FAIR project is to investigate the application of the fluidised bed combustion (FBC) technology to burn cork wastes with the aim of overcoming the difficulties currently experienced in the cork processing industries. The combustion studies at INETI were carried out using the 300 kW{sub th} circulating fluidised bed facility. The combustor is square in cross section with each side being 0.3 m long. The combustor height is 5 m. The temperatures in the bed, the riser and that of the flue gases leaving the reactor were continuously monitored. The combustion gases leaving the reactor passed through the recycling cyclone first to capture most of particulates elutriated out of the combustor. The solid particles were intermittently collected for analysis to determine the amount of carbon present, which helped the combustion efficiency to be calculated. Instantaneous measurements of O{sub 2}, CO, CO{sub 2}, NO{sub x}, N{sub 2}O and SO{sub 2} present levels in the flue gases were also carried out. The combustion tests were done with both the cork waste dust and granular virgin cork. The difference is that cork dust gets contaminated during the process due to the use of various additives. Most of the combustion took place in the riser where the temperature was at times up to 523 K above that of the bed. The unburned carbon level was low ranging from about 1.5 to 2.% suggesting that most of the particles burned to completion in the riser. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Seggiani, Maurizia, E-mail: m.seggiani@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy); Puccini, Monica, E-mail: m.puccini@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy); Raggio, Giovanni, E-mail: g.raggio@tiscali.it [Italprogetti Engineering SPA, Lungarno Pacinotti, 59/A, 56020 San Romano (Pisa) (Italy); Vitolo, Sandra, E-mail: s.vitolo@diccism.unipi.it [Department of Chemical Engineering, Industrial Chemistry and Material Science, University of Pisa, Largo Lucio Lazzarino 1, 56126 Pisa (Italy)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Cogasification of sewage sludge with wood pellets in updraft gasifier was analysed. Black-Right-Pointing-Pointer The effects of sewage sludge content on the gasification process were examined. Black-Right-Pointing-Pointer Sewage sludge addition up to 30 wt.% reduces moderately the process performance. Black-Right-Pointing-Pointer At high sewage sludge content slagging and clinker formation occurred. Black-Right-Pointing-Pointer 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. NH{sub 3}, HCl and HF contents were very low because most of these compounds were retained in the wet scrubber systems. On the other hand, high H{sub 2}S 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

  18. Computer simulation of a downdraft wood gasifier for tea drying

    Energy Technology Data Exchange (ETDEWEB)

    Jayah, T.H.; Lu Aye; Fuller, R.J.; Stewart, D.F. [University of Melbourne, Victoria (Australia). International Technologies Centre, Department of Civil and Environmental Engineering

    2003-10-01

    A gasifier has been fabricated on Sri Lanka for the tea industry, but there is a lack of knowledge of the effect of certain key operating parameters and design features on its performance. Experimental testing of the design under various conditions has produced data that has been used to calibrate a computer program, developed to investigate the impact of those parameters and features on conversion efficiency. The program consists of two sub-models of the pyrolysis and gasification zones, respectively. The pyrolysis sub-model has been used to determine the maximum temperature and the composition of the gas entering the gasification zone. The gasification zone sub-model has been calibrated using data gathered from the experiments. It was found that a wood chip size of 3-5 cm with a moisture content below 15% (d.b.) should be used in this gasifier. Feed material with a fixed carbon content of higher than 30% and heat losses of more than 15% should be avoided. For the above parameters, the gasification zone should be 33 cm long to achieve an acceptable conversion efficiency. (author)

  19. 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.

  20. Design, development and testing of small downdraft gasifiers for domestic cookstoves

    International Nuclear Information System (INIS)

    Sutar, Kailasnath B.; Kohli, Sangeeta; Ravi, M.R.

    2017-01-01

    The design methodology available in the literature for downdraft gasifiers of large capacity (∼40–600 kW_t_h) is not directly applicable to very small sized gasifiers. In the present work, design and development of small downdraft gasifiers of 4 kW_t_h and 2.5 kW_t_h nominal capacities, for domestic cookstove application, have been carried out by non-linear extrapolation of data in literature for large gasifiers. The prototypes thus developed were found to give maximum gasification efficiency close to 80%. Extensive experimentation was conducted in the laboratory to study the effect of two operating parameters, viz., gasification air flow rate and the fuel particle size, on the performance of these gasifiers. The performance parameters studied included calorific value of the gas, gasification efficiency, air-biomass ratio and the hearth load. Through detailed analysis of the results, it has been shown that the two operating parameters affect the gasifier performance primarily through their impact on reactor temperature and the total particle surface area available for the reactions. This explains the observation of an optimal gasification air flow rate for best gasification efficiency. It is also shown that the producer gas flow rate varies linearly with gasification air flow rate for a wide range of operating conditions on different sizes of gasifiers. It is also seen that different sizes of the gasifiers can have a different hearth load corresponding to best efficiency. - Highlights: • Developed a design methodology for small downdraft gasifiers by adapting guidelines meant for larger gasifiers. • Developed two prototypes of gasifiers: 4 kW_t_h and 2.5 kW_t_h with gasification efficiency ∼80%. • Reactor temperature and total particle surface area available for reactions affect the gasifier performance. • The optimal gasification air flow rate and particle size for best gasification efficiency are explained using the above. • Producer gas versus

  1. Batch top-spray fluid bed coating: Scale-up insight using dynamic heat- and mass-transfer modelling

    DEFF Research Database (Denmark)

    Hede, Peter Dybdahl; Bach, P.; Jensen, Anker Degn

    2009-01-01

    A mathematical model was developed for batch top-spray fluid bed coating processes based on Ronsse et al. [2007a.b. Combined population balance and thermodynamic modelling of the batch top-spray fluidised bed coating process. Part I-model development and validation. journal of Food Engineering 78......, 296-307; Combined population balance and thermodynamic modelling of the batch top-spray fluidised bed coating process. Part II-model and process analysis. journal of Food Engineering 78, 308-322]. The model is based on one-dimensional discretisation of the fluid bed into a number of well-mixed control......-up principles by comparing simulation results with experimental temperature and humidity data obtained from inorganic salt coating of placebo cores in three pilot fluid bed scales being a 0.5kg small-scale (GEA Aeromatic-Fielder Strea-1), 4kg medium-scale (GEA Niro MP-1) and 24kg large-scale (GEA MP-2...

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

    NARCIS (Netherlands)

    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

  3. 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...... by the particle size and the cut size ofthe primary and secondary cyclones. A model accounting for the ash collection by the plant cyclones was shown to predict theproduct gas ash particle release reasonably well....

  4. Numerical investigation of slag formation in an entrained-flow gasifier

    Science.gov (United States)

    Zageris, G.; Geza, V.; Jakovics, A.

    2018-05-01

    A CFD mathematical model for an entrained-flow gasifier is constructed – the model of an actual gasifier is rendered in 3D and appropriately meshed. Then, the turbulent gas flow in the gasifier is modeled with the realizable k-ε approach, taking devolatilization, combustion and coal gasification in account. Various such simulations are conducted, obtaining results for different air inlet positions and by tracking particles of varying sizes undergoing devolatilization and gasification. The model identifies potential problematic zones where most particles collide with the gasifier walls, indicating risk regions where ash deposits could most likely form. In conclusion, effects on the formation of an ash layer of air inlet positioning and particle size allowed in the main gasifier tank are discussed, and viable solutions such as radial inlet positioning for decreasing the amount of undesirable deposits are proposed. We also conclude that the particular chemical reactions that take place inside the gasifier play a significant role in determining how slagging occurs inside a gasifier.

  5. Slag Behavior in Gasifiers. Part I: Influence of Coal Properties and Gasification Conditions

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2013-02-01

    Full Text Available In the entrained-flow gasifiers used in integrated gasification combined cycle (IGCC plants, the majority of mineral matter transforms to liquid slag on the wall of the gasifier and flows out the bottom. However, a small fraction of the mineral matter is entrained (as fly ash with the raw syngas out of the gasifier to downstream processing. This molten/sticky fly ash could cause fouling of the syngas cooler. To improve gasification availability through better design and operation of the gasification process, a better understanding of slag behavior and the characteristics of the slagging process is needed. Char/ash properties, gas compositions in the gasifier, the gasifier wall structure, fluid dynamics, and plant operating conditions (mainly temperature and oxygen/carbon ratio all affect slagging behavior. Because coal has varying ash content and composition, different operating conditions are required to maintain the slag flow and limit problems downstream. In Part I, we review the main types and the operating conditions of entrained-flow gasifiers and coal properties used in IGCC plants; we identify and discuss the key coal ash properties and the operating conditions impacting slag behavior; finally, we summarize the coal quality criteria and the operating conditions in entrained-flow gasifiers. In Part II, we discuss the constitutive modeling related to the rheological studies of slag flow.

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

    OpenAIRE

    Kuhe, Aondoyila; Aliyu, Samuel Jacob

    2015-01-01

    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 ...

  8. Hydrodynamics of a hybrid circulating fluidized bed reactor with a partitioned loop seal system

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Dal-Hee; Moon, Jong-Ho; Jin, Gyoung Tae; Shun, Dowon [Korea Institute of Energy Research, Daejeon (Korea, Republic of); Yun, Minyoung; Park, Chan Seung; Norbeck, Joseph M. [University of California, Riverside (United States)

    2015-07-15

    A circulating fluidized bed (CFB) with a hybrid design has been developed and optimized for steam hydrogasification. The hybrid CFB is composed of a bubbling fluidized bed (BFB) type combustor and a fast fluidized bed (FB) type gasifier. Char is burnt in the combustor and the generated heat is supplied to the gasifier along with the bed materials. Two different types of fluidized beds are connected to each other with a newly developed partitioned loop seal to avoid direct contact between two separate gas streams flowing in each fluidized bed. Gas mixing tests were carried out with Air and Argon in a cold model hybrid CFB to test the loop seal efficiency. Increase in solid inventory in the loop seal can improve the gas separation efficiency. It can be realized at higher gas velocity in fast bed and with higher solid inventory in the loop seal system. In addition, bed hydrodynamics was investigated with varying gas flow conditions and particle sizes in order to obtain a full understanding of changes of solid holdup in the FB. The solid holdup in the FB increased with increasing gas velocity in the BFB. Conversely, increase in gas velocity in the FB contributed to reducing the solid holdup in the FB. It was observed that changing the particle size of bed material does not have a big impact on hydrodynamic parameters.

  9. A comparative study of charcoal gasification in two types of spouted bed reactors

    International Nuclear Information System (INIS)

    Abdul Salam, P.; Bhattacharya, S.C.

    2006-01-01

    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

  10. Hydrodynamics of a hybrid circulating fluidized bed reactor with a partitioned loop seal system

    International Nuclear Information System (INIS)

    Bae, Dal-Hee; Moon, Jong-Ho; Jin, Gyoung Tae; Shun, Dowon; Yun, Minyoung; Park, Chan Seung; Norbeck, Joseph M.

    2015-01-01

    A circulating fluidized bed (CFB) with a hybrid design has been developed and optimized for steam hydrogasification. The hybrid CFB is composed of a bubbling fluidized bed (BFB) type combustor and a fast fluidized bed (FB) type gasifier. Char is burnt in the combustor and the generated heat is supplied to the gasifier along with the bed materials. Two different types of fluidized beds are connected to each other with a newly developed partitioned loop seal to avoid direct contact between two separate gas streams flowing in each fluidized bed. Gas mixing tests were carried out with Air and Argon in a cold model hybrid CFB to test the loop seal efficiency. Increase in solid inventory in the loop seal can improve the gas separation efficiency. It can be realized at higher gas velocity in fast bed and with higher solid inventory in the loop seal system. In addition, bed hydrodynamics was investigated with varying gas flow conditions and particle sizes in order to obtain a full understanding of changes of solid holdup in the FB. The solid holdup in the FB increased with increasing gas velocity in the BFB. Conversely, increase in gas velocity in the FB contributed to reducing the solid holdup in the FB. It was observed that changing the particle size of bed material does not have a big impact on hydrodynamic parameters

  11. Effect of fluidization number on the combustion of simulated municipal solid waste in a fluidized bed

    International Nuclear Information System (INIS)

    Anwar Johari; Mutahharah, M.M.; Abdul, A.; Salema, A.; Kalantarifard, A.; Rozainee, M.

    2010-01-01

    The effect of fluidization number on the combustion of simulated municipal solid was in a fluidized bed was investigated. Simulated municipal solid waste was used a sample and it was formulated from major waste composition found in Malaysia which comprised of food waste, paper, plastic and vegetable waste. Proximate and ultimate analyses of the simulated were conducted and results showed its composition was similar to the actual Malaysian municipal solid waste composition. Combustion study was carried out in a rectangular fluidized bed with sand of mean particle size of 0.34 mm as a fluidising medium. The range of fluidization numbers investigated was 3 to 11 U mf . The combustion was carried out at stoichiometric condition (Air Factor = 1). Results showed that the best fluidization number was in the range of 5 to 7 U mf with 5 U mf being the most optimum in which the bed temperature was sustained in a much longer period. (author)

  12. Study on the structure and gasification characteristics of selected South African bituminous coals in fluidised bed gasification

    CSIR Research Space (South Africa)

    Oboirien, BO

    2011-04-01

    Full Text Available . The microstructural characteristics of the parent coals and their resultant chars were determined using XRD, FT-IR, Raman and petrographic analysis. The microstructural changes that occurred in the organic (maceral) and the inorganic (mineral) fractions...

  13. Fluidised bed membrane reactor for ultrapure hydrogen production via methane steam reforming: Experimental demonstration and model validation

    NARCIS (Netherlands)

    Patil, C.S.; van Sint Annaland, M.; Kuipers, J.A.M.

    2007-01-01

    Hydrogen is emerging as a future alternative for mobile and stationary energy carriers in addition to its use in chemical and petrochemical applications. A novel multifunctional reactor concept has been developed for the production of ultrapure hydrogen View the MathML source from light hydrocarbons

  14. Fluidised bed membrane reactor for ultrapure hydrogen production via methane steam reforming: Experimental demonstration and model validation

    NARCIS (Netherlands)

    Patil, C.S.; Sint Annaland, van M.; Kuipers, J.A.M.

    2007-01-01

    Hydrogen is emerging as a future alternative for mobile and stationary energy carriers in addition to its use in chemical and petrochemical applications. A novel multifunctional reactor concept has been developed for the production of ultrapure hydrogen (<10 ppm CO) from light hydrocarbons such as

  15. Study on the structure and gasification characteristics of selected South African bituminous coal in fluidised bed gasification

    CSIR Research Space (South Africa)

    Oboirien, BO

    2009-10-01

    Full Text Available that contributed to the higher aromaticity and high burnout level, while for Matla and Duhva with 0.64% and 0.76% Rov values, both the rank and inertinite content playing a role in the carbon conversion with the rank reducing the level of burnout. Table 3...

  16. The behaviour of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, M.H.; Abelha, P.; Lapa, N.; Oliveira, J.S.; Cabrita, I.; Gulyurtlu, I. [INETI, Lisbon (Portugal)

    2003-07-01

    Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FBC with the aim of characterizating the ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out and the amount of unburned carbon leaving the combustor but captured in cyclone was large enough to ensure substantial retention of mercury at low temperatures, hence could contribute to an improvement of the mercury release which still remains an issue of great concern to resolve during combustion of waste materials.

  17. The behavior of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Helena M.; Abelha, P.; Cabrita, I. [INETI-DEECA, Lisboa (Portugal); Lapa, N.; Oliveira, J.S. [UNL-Ubia, Monte de Caparica (Portugal)

    2003-07-01

    Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FRC aiming at the characterization of ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges, suggesting that there could be opportunities for their reactor further use. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out, and the amount of unburned carbon leaving the combustor but captured in the cyclone was large enough to ensure substantial retention of mercury at low temperatures, and, hence, could contribute to an improvement of the mercury release, which still remains an issue of great concern to resolve during combustion of waste materials.

  18. The behaviour of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed.

    Science.gov (United States)

    Helena Lopes, M; Abelha, P; Lapa, N; Oliveira, J S; Cabrita, I; Gulyurtlu, I

    2003-01-01

    Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FBC aiming at the characterization of ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges, suggesting that there could be opportunities for their further use. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out and the amount of unburned carbon leaving the combustor but captured in cyclone was large enough to ensure substantial retention of mercury at low temperatures, hence could contribute to an improvement of the mercury release which still remains an issue of great concern to resolve during combustion of waste materials.

  19. The behaviour of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed

    International Nuclear Information System (INIS)

    Helena Lopes, M.; Abelha, P.; Lapa, N.; Oliveira, J.S.; Cabrita, I.; Gulyurtlu, I.

    2003-01-01

    Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FBC aiming at the characterization of ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges, suggesting that there could be opportunities for their further use. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out and the amount of unburned carbon leaving the combustor but captured in cyclone was large enough to ensure substantial retention of mercury at low temperatures, hence could contribute to an improvement of the mercury release which still remains an issue of great concern to resolve during combustion of waste materials

  20. An update on field test results for an engineered refractory for slagging gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Dogan, O.N.; Alman, D.E.; Jablonski, P.D.; Hawk, J.A.

    2006-05-01

    The widespread commercial adaptation of slagging gasifier technology to produce power, fuel, and/or chemicals from coal will depend in large measure on the technology’s ability to prove itself both economic and reliable. Improvements in gasifier reliability, availability, and maintainability will in part depend on the development of improved performance structural materials with longer service life in this application. Current generation refractory materials used to line the air-cooled, slagging gasifier vessel, and contain the gasification reaction, often last no more than three to 18 months in commercial applications. The downtime required for tear-out and replacement of these critical materials contributes to gasifier on-line availabilities that fall short of targeted goals. In this talk we will discuss the development of an improved refractory material engineered by the NETL for longer service life in this application, and provide an update on recent field test results.

  1. Prediction of the working parameters of a wood waste gasifier through an equilibrium model

    Energy Technology Data Exchange (ETDEWEB)

    Altafini, Carlos R.; Baretto, Ronaldo M. [Caxias do Sul Univ., Dept. of Mechanical Engineering, Caxias do Sul, RS (Brazil); Wander, Paulo R. [Caxias do Sul Univ., Dept. of Mechanical Engineering, Caxias do Sul, RS (Brazil); Federal Univ. of Rio Grande do Sul State (UFRGS), Mechanical Engineering Postgraduation Program (PROMEC), RS (Brazil)

    2003-10-01

    This paper deals with the computational simulation of a wood waste (sawdust) gasifier using an equilibrium model based on minimization of the Gibbs free energy. The gasifier has been tested with Pinus Elliotis sawdust, an exotic specie largely cultivated in the South of Brazil. The biomass used in the tests presented a moisture of nearly 10% (wt% on wet basis), and the average composition results of the gas produced (without tar) are compared with the equilibrium models used. Sensitivity studies to verify the influence of the moisture sawdust content on the fuel gas composition and on its heating value were made. More complex models to reproduce with better accuracy the gasifier studied were elaborated. Although the equilibrium models do not represent the reactions that occur at relatively high temperatures ( {approx_equal} 800 deg C) very well, these models can be useful to show some tendencies on the working parameter variations of a gasifier. (Author)

  2. Fluidized bed reactor for processing particles coated with carbon

    International Nuclear Information System (INIS)

    Marschollek, M.; Simon, W.; Walter, C.

    1978-01-01

    The carbon coating of production returns of these particles first has to be removed before the heavy metal core released can be reprocessed. For reasons of criticality, removal of burnt-up particles downwards must be possible in the fluidized bed reactor even if the reactor diameter is greater than 800 mm, and the material temperatures must not exceed 650 0 C. It consists of an upper cylindrical and a lower conical part, where, according to the invention, the gas distributor heads in the conical part are situated in several planes above one another for the fluidisation and combustion gas and where they are evently distributed over the reactor crossection, so that an even flow profile is achieved over the reactor cross section. (HP) [de

  3. Multi-stage circulating fluidized bed syngas cooling

    Science.gov (United States)

    Liu, Guohai; Vimalchand, Pannalal; Guan, Xiaofeng; Peng, WanWang

    2016-10-11

    A method and apparatus for cooling hot gas streams in the temperature range 800.degree. C. to 1600.degree. C. using multi-stage circulating fluid bed (CFB) coolers is disclosed. The invention relates to cooling the hot syngas from coal gasifiers in which the hot syngas entrains substances that foul, erode and corrode heat transfer surfaces upon contact in conventional coolers. The hot syngas is cooled by extracting and indirectly transferring heat to heat transfer surfaces with circulating inert solid particles in CFB syngas coolers. The CFB syngas coolers are staged to facilitate generation of steam at multiple conditions and hot boiler feed water that are necessary for power generation in an IGCC process. The multi-stage syngas cooler can include internally circulating fluid bed coolers, externally circulating fluid bed coolers and hybrid coolers that incorporate features of both internally and externally circulating fluid bed coolers. Higher process efficiencies can be realized as the invention can handle hot syngas from various types of gasifiers without the need for a less efficient precooling step.

  4. Performance and emission reduction potential of micro-gasifier improved through better design

    Directory of Open Access Journals (Sweden)

    Kamil Dino Adem

    2017-01-01

    Full Text Available Biomass gasification is getting popular for household cooking application in most developing countries including Ethiopia. The preference for biomass gasification is due to the generation of less CO (Carbon Monoxide and PM (Particulate Matter in comparison with other biomass cookstoves. Our study showed the improvement in thermal efficiency and emission reduction potential of micro-gasifier. A prototype micro-gasifier was built and tested using the water boiling test protocol. The test results gave a thermal efficiency of 39.6% and a specific fuel consumption of 57 g of fuel/ liter of water. With regard to indoor air pollution, the maximum CO & PM registered were 12.5 ppm and 1.85 mg/m3, respectively. Using clean development mechanism (CDM methodology, the estimated emission reduction potential of the micro-gasifier is 1.30 tCO2 per micro-gasifier per year. Generally, the micro-gasifier has better performance compared to the previous designs proposed by other researchers. Thus, disseminating our micro-gasifier at a larger scale in developing countries such as Ethiopia will be beneficial in reducing deforestation and emission that will be brought about by using open-fire stoves and thus, helps to obtain carbon credit.

  5. Performance and Characteristics of a Cyclone Gasifier for Gasification of Sawdust

    Science.gov (United States)

    Azman Miskam, Muhamad; Zainal, Z. A.; Idroas, M. Y.

    The performance and characteristics of a cyclone gasifier for gasification of sawdust has been studied and evaluated. The system applied a technique to gasify sawdust through the concept of cyclonic motion driven by air injected at atmospheric pressure. This study covers the results obtained for gasification of ground sawdust from local furniture industries with size distribution ranging from 0.25 to 1 mm. It was found that the typical wall temperature for initiating stable gasification process was about 400°C. The heating value of producer gas was about 3.9 MJ m-3 that is sufficient for stable combustion in a dual-fuel engine generator. The highest thermal output from the cyclone gasifier was 57.35 kWT. The highest value of mass conversion efficiency and enthalpy balance were 60 and 98.7%, respectively. The highest efficiency of the cyclone gasifier obtained was 73.4% and this compares well with other researchers. The study has identified the optimum operational condition for gasifying sawdust in a cyclone gasifier and made conclusions as to how the steady gasification process can be achieved.

  6. FY 1996 report on the results of the development of an entrained bed coal gasification power plant. Part 2. Investigational study of verification plant; 1995 nendo seika hokokusho. Funryusho sekitan gaska hatsuden plant kaihatsu - Sono 2. Jissho plant ni kansuru chosa kenkyu hen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    For the purpose of developing the technology of the integrated coal gasification combined cycle power generation, an investigational study of verification plant was made, and the FY 1996 results were summarized. In this fiscal year, the conceptual design was made of the Nakoso method based on the method of Nakoso pilot plant, the fixed bed method in which fixed bed gas refining facilities tested in Nakoso pilot plant were adopted, and the packed bed method. In the Nakoso method, 5 cases were studied using the air blown two-stage entrained bed for gasifier, dry two-stage fluidized bed for desulfurization and dry granular bed packed bed for dust removal. In the fixed bed method, 2 cases were studied using the air blown two-stage entrained bed for gasifier and dry fixed bed for gas refining. In the packed bed method, 2 cases were studied using the air blown two-stage entrained bed for gasifier and dry packed bed for gas refining. As to gas turbine facilities, 5 cases were studied in which GT output is 115MW - 215MW (output of combined cycle power generation: 220MW - 420MW). (NEDO)

  7. Numerical Investigation for the Plasma Coal Gasifier of 150kW and 1400kW

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyeong Yeong; Suh, Jae Seung [Hannam University, Daejeon (Korea, Republic of); Lho, Tai Hyeop [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2016-05-15

    This study has verification of simulation for the gasifier of 150kWe and focuses on prediction of performance for the gasifier of 1.4MWe with a computational fluid dynamics (CFD) method. It is possible to predict flow patterns, tracks of particles, combustion characteristics, temperature distributions and chemical distributions using the commercial CFD solver ANSYS/FLUENT. Integrated coal gasification combined cycle (IGCC) has gained a lot of interest because they can produce cleaner gaseous fuels such as hydrogen, carbon monoxide and methane. Therefore, the National Fusion Research Institute (NFRI) plant has been investigating the application of their plasma technology to gasify coal. It is a fusion plasma technology for better efficiency of low-carbon fuels. They recently completed experiment for the gasifier of 150kwe, and are currently trying experiment for the gasifier of 1.4MWe. They have tried to design the gasifier that has cold gases of a higher efficiency. However it is considerably complicated and expensive that performance of gasifier is experimentally studied, because it is difficult to measure or control gases of very high temperature. This study has numerical investigation for the phenomena of coal gasification for coal gasifier of 150kWe and 1.4MWe at experiment operating conditions. This study has verification of simulation for the gasifier of 150kWe, and predicts performance for the gasifier of 1.4MWe. The gasifier of 1.4MWe will have a cold gas of higher efficiency than gasifier of 150kWe because can generate many hydrogen gas. So this gasification has the potential to become cornerstone technology in many hydrogen industries.

  8. Detailed model for practical pulverized coal furnaces and gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.J.; Smoot, L.D.

    1989-08-01

    This study has been supported by a consortium of nine industrial and governmental sponsors. Work was initiated on May 1, 1985 and completed August 31, 1989. The central objective of this work was to develop, evaluate and apply a practical combustion model for utility boilers, industrial furnaces and gasifiers. Key accomplishments have included: Development of an advanced first-generation, computer model for combustion in three dimensional furnaces; development of a new first generation fouling and slagging submodel; detailed evaluation of an existing NO{sub x} submodel; development and evaluation of an improved radiation submodel; preparation and distribution of a three-volume final report: (a) Volume 1: General Technical Report; (b) Volume 2: PCGC-3 User's Manual; (c) Volume 3: Data Book for Evaluation of Three-Dimensional Combustion Models; and organization of a user's workshop on the three-dimensional code. The furnace computer model developed under this study requires further development before it can be applied generally to all applications; however, it can be used now by specialists for many specific applications, including non-combusting systems and combusting geseous systems. A new combustion center was organized and work was initiated to continue the important research effort initiated by this study. 212 refs., 72 figs., 38 tabs.

  9. Effect of small-scale biomass gasification at the state of refractory lining the fixed bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Janša, Jan, E-mail: jan.jansa@vsb.cz; Peer, Vaclav, E-mail: vaclav.peer@vsb.cz; Pavloková, Petra, E-mail: petra.pavlokova@vsb.cz [VŠB – Technical University of Ostrava, Energy Research Center, 708 33 Ostrava (Czech Republic)

    2016-06-30

    The article deals with the influence of biomass gasification on the condition of the refractory lining of a fixed bed reactor. The refractory lining of the gasifier is one part of the device, which significantly affects the operational reliability and durability. After removing the refractory lining of the gasifier from the experimental reactor, there was done an assessment how gasification of different kinds of biomass reflected on its condition in terms of the main factors affecting its life. Gasification of biomass is reflected on the lining, especially through sticking at the bottom of the reactor. Measures for prolonging the life of lining consist in the reduction of temperature in the reactor, in this case, in order to avoid ash fusion biomass which it is difficult for this type of gasifier.

  10. Gasification of Rice Husk in a Downdraft Gasifier: The Effect of Equivalence Ratio on the Gasification Performance, Properties, and Utilization Analysis of Byproducts of Char and Tar

    Directory of Open Access Journals (Sweden)

    Zhongqing Ma

    2015-03-01

    Full Text Available Rice husks (RH are a potential biomass source for bio-energy production in China, such as bio-gas production by gasification technology. In this paper, a bench-scale downdraft fixed bed gasifier (DFBG and a tar sampling system were designed. The effect of equivalence ratio (ER on gasification performance in terms of the temperature in the gasifier, the composition distribution of the producer gas, and the tar content in the producer gas was studied. The maximum lower heating value of 4.44 MJ/Nm3, minimum tar content of 1.34 g/Nm3, and maximum cold gas efficiency of 50.85% were obtained at ER of 0.211. In addition, the characteristics of gasification byproducts, namely bio-char and bio-tar, were analyzed. The proximate and ultimate analysis (especially of the alkali metal, the surface morphology, the surface area, and the pore size distribution of the rice husk char (RHC were obtained by the use of X-ray fluorescence (XRF and scanning electron microscopy (SEM, as well as by using the Brunauer-Emmett-Teller (BET method. The components of light tar and heavy tar were obtained by using gas chromatography-mass spectrometry (GC-MS.

  11. 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)

  12. Possibility study of gasifier with axial circulating flue gas for reducing Tar

    Science.gov (United States)

    Poowadin, T.; Polsongkram, M.; Khantikomol, P.

    2018-01-01

    This present research article aims to study the possibility of gasification by axial core flue gas circulating kiln and find the efficiency of syngas production. An axial core flue gas circulating tube was installed in the center of the updraft gasifier in purposing of tar reducing. In the present study, the eucalyptus wood chip 4, 8, and 10 kg with the moisture content 16% were examined. Several type-K thermocouples were employed to measure the temperatures at preheat, combustion, reduction, pyrolysis, drying, and gas outlet zone. The results showed that the temperatures in the combustion and the reduction zone of the kiln with the axial core flue gas recirculating were lower than the kiln without the core owing to installing the core would reduce the combustion zone area in biomass burning. Obviously, the temperature in the pyrolysis and drying zone were nearly the same as both with and without the core. In consideration of syngas components, it was found that CO production from the gasifier with the core was higher than the gasifier without the core about 25%. Other gases, however, were almost same. The syngas production efficiency obtained from the gasifier with the core decreased with increasing the mass of biomass. It showed that the highest efficiency was 30% at 4 kg supplying biomass. In comparison, the efficiencies of both the kilns with and without the core were not different. For liquid product, the amount of liquid decreased about 47.23% comparing with the gasifier without the core.

  13. Steam gasification of coal using a pressurized circulating fluidized bed

    International Nuclear Information System (INIS)

    Werner, K.F.J.

    1989-09-01

    Subject of this investigation is the process engineering of a coal gasification using nuclear heat. A special aspect is the efficiency. To this purpose a new method for calculating the kinetics of hard coal steam gasification in a fluidized bed is presented. It is used for evaluations of gasification kinetics in a large-scale process on the basis of laboratory-scale experiments. The method is verified by experimental data from a large-scale gasifier. The investment costs and the operating costs of the designed process are estimated. (orig.) [de

  14. Performance Evaluation of Throatless Gasifier Using Pine Needles as a Feedstock for Power Generation

    Directory of Open Access Journals (Sweden)

    Dhaundiyal Alok

    2016-03-01

    Full Text Available This paper deals with the performance evaluation of a throatless gasifier TG-SI-10E. Evaluation of the throatless gasifier was done in three streams, which were the thermal, design and economic aspects. It was tested with pine needles, derived from the Himalayan chir pine (Pinus roxburghii. A non-isokinetic sampling technique was used for measuring the tar and dust contents. The carbon dioxide and carbon monoxide emission at the exhaust of engine was in the range of 12.8% and 0.1-0.5% respectively. The maximum temperature of producer gas measured at the outlet of the gasifier was 505 °C. The specific biomass consumption rate of pine needles was calculated to be 1.595 kg/kWh (electrical. Specific gasification rate for the given design was found to be 107 kg/m2h. Economic evaluation was based on direct tax incidence.

  15. Thermodynamic Model for Updraft Gasifier with External Recirculation of Pyrolysis Gas

    Directory of Open Access Journals (Sweden)

    Fajri Vidian

    2016-01-01

    Full Text Available Most of the thermodynamic modeling of gasification for updraft gasifier uses one process of decomposition (decomposition of fuel. In the present study, a thermodynamic model which uses two processes of decomposition (decomposition of fuel and char is used. The model is implemented in modification of updraft gasifier with external recirculation of pyrolysis gas to the combustion zone and the gas flowing out from the side stream (reduction zone in the updraft gasifier. The goal of the model obtains the influences of amount of recirculation pyrolysis gas fraction to combustion zone on combustible gas and tar. The significant results of modification updraft are that the increases amount of recirculation of pyrolysis gas will increase the composition of H2 and reduce the composition of tar; then the composition of CO and CH4 is dependent on equivalence ratio. The results of the model for combustible gas composition are compared with previous study.

  16. Comparison of Refractory Performance in Black Liquor Gasifiers and a Smelt Test System

    International Nuclear Information System (INIS)

    Peascoe, RA

    2001-01-01

    Prior laboratory corrosion studies along with experience at the black liquor gasifier in New Bern, North Carolina, clearly demonstrate that serious material problems exist with the gasifier's refractory lining. Mullite-based and alumina-based refractories used at the New Bern facility suffered significant degradation even though they reportedly performed adequately in smaller scale systems. Oak Ridge National Laboratory's involvement in the failure analysis, and the initial exploration of suitable replacement materials, led to the realization that a simple and reliable, complementary method for refractory screening was needed. The development of a laboratory test system and its suitability for simulating the environment of black liquor gasifiers was undertaken. Identification and characterization of corrosion products were used to evaluate the test system as a rapid screening tool for refractory performance and as a predictor of refractory lifetime. Results from the test systems and pl ants were qualitatively similar

  17. Advanced One-Dimensional Entrained-Flow Gasifier Model Considering Melting Phenomenon of Ash

    Directory of Open Access Journals (Sweden)

    Jinsu Kim

    2018-04-01

    Full Text Available A one-dimensional model is developed to represent the ash-melting phenomenon, which was not considered in the previous one-dimensional (1-D entrained-flow gasifier model. We include sensible heat of slag and the fusion heat of ash in the heat balance equation. To consider the melting of ash, we propose an algorithm that calculates the energy balance for three scenarios based on temperature. We also use the composition and the thermal properties of anorthite mineral to express ash. gPROMS for differential equations is used to solve this algorithm in a simulation; the results include coal conversion, gas composition, and temperature profile. Based on the Texaco pilot plant gasifier, we validate our model. Our results show good agreement with previous experimental data. We conclude that the sensible heat of slag and the fusion heat of ash must be included in the entrained flow gasifier model.

  18. Simulation of the gasification of animal wastes in a dual gasifier using Aspen Plus®

    International Nuclear Information System (INIS)

    Fernandez-Lopez, M.; Pedroche, J.; Valverde, J.L.; Sanchez-Silva, L.

    2017-01-01

    Highlights: • The gasification of manure was evaluated using the software Aspen Plus®. • Composition and LHV of the obtained syngas depends on the operating conditions. • CO 2 net emissions for the steam and CO 2 gasification processes were calculated. • Manure steam gasification can be used as feedstock for Fischer-Tropsch. • Manure CO 2 gasification lead to a syngas suitable for energy production. - Abstract: The gasification of an animal waste biomass (manure) in a dual gasifier was studied using the software Aspen Plus®. For this purpose, a model based on a Gibbs free energy reactor was considered. Effects of the gasification temperature, the gasifying/biomass ratio and the use of steam and CO 2 as the gasifying agents on the composition and the low heating value (LHV) of the produced syngas were evaluated. In this sense, the H 2 /CO ratio and the LHV were the parameters calculated to stablish the best operating conditions for the production of either hydrocarbons via Fischer-Tropsch or energy. Furthermore, the CO 2 net emissions generated by the gasification process were also important in the selection of the best operating conditions from an environmental point of view. The obtained results showed that for both gasifying agents the H 2 and CO production was favoured at high temperatures whereas the production of CH 4 and CO 2 was favoured at low ones. On the other hand, the H 2 production was higher when steam was used as the gasifying agent and the formation of CO was enhanced when CO 2 was considered as gasification agent. An increase of the gasifying agent/biomass ratio had a negatively influence on the production of CH 4 , leading to a decrease of the LHV. Therefore, steam as the gasifying agent and high temperatures favoured the obtaining of a syngas suitable for the Fischer-Tropsch process whereas CO 2 and low gasification temperatures enhanced a syngas with a high LHV which could be used for energy production. Finally, the net CO 2

  19. The Design, Construction and Operation of a 75 kW Two-Stage Gasifier

    DEFF Research Database (Denmark)

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

    2003-01-01

    The Two-Stage Gasifier was operated for several weeks (465 hours) and of these 190 hours continuously. The gasifier is operated automatically unattended day and night, and only small adjustments of the feeding rate were necessary once or twice a day. The operation was successful, and the output...... as expected. The engine operated well on the produced gas, and no deposits were observed in the engine afterwards. The bag house filter was an excellent and well operating gas cleaning system. Small amounts of deposits consisting of salts and carbonates were observed in the hot gas heat exchangers. The top...

  20. Biomass downdraft gasifier with internal cyclonic combustion chamber: design, construction, and experimental results.

    Science.gov (United States)

    Patil, Krushna; Bhoi, Prakash; Huhnke, Raymond; Bellmer, Danielle

    2011-05-01

    An exploratory downdraft gasifier design with unique biomass pyrolysis and tar cracking mechanism is evolved at Oklahoma State University. This design has an internal separate combustion section where turbulent, swirling high-temperature combustion flows are generated. A series of research trials were conducted using wood shavings as the gasifier feedstock. Maximum tar cracking temperatures were above 1100°C. Average volumetric concentration levels of major combustible components in the product gas were 22% CO and 11% H(2). Hot and cold gas efficiencies were 72% and 66%, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Low-Cost Syngas Shifting for Remote Gasifiers: Combination of CO2 Adsorption and Catalyst Addition in a Novel and Simplified Packed Structure

    Directory of Open Access Journals (Sweden)

    Ricardo A. Narváez C.

    2018-02-01

    Full Text Available This paper presents the technical validation of a novel, low-complexity alternative based on the inclusion of a patented (IEPI-MU-2016-185 packed bed for improving the performance of remote, small-scale gasification facilities. This study was carried out in an updraft, atmospheric-pressure gasifier, outfitted with a syngas reflux line, air and oxygen feed, and an upper packed-bed coupled to the gasification unit to improve the syngas quality by catalytic treatment and CO2 adsorption. The experimental facility is located in the rural community San Pedro del Laurel, Ecuador. Gasification experiments, with and without packed material in the upper chamber, were performed to assess its effect on the syngas quality. The assessment revealed that the packed material increases the carbon monoxide (CO content in the syngas outlet stream while carbon dioxide (CO2 was reduced. This option appears to be a suitable and low-complexity alternative for enhancing the content of energy vectors of syngas in gasification at atmospheric pressure since CO/CO2 ratios of 5.18 and 3.27 were achieved against reported values of 2.46 and 0.94 for operations which did not include the addition of packed material. It is concluded that the upper packed-bed is an active element able to modify syngas characteristics since CO2 content was reduced.

  2. Gasified rice hull biochar affects nutrition and growth of five horticulture crops in container culture

    Science.gov (United States)

    Phosphate fertilizers used in the production of greenhouse crops can be problematic if released into the environment. Furthermore, the price of phosphate is increasing as demand increases and world supplies decrease. The objective of this research was to determine if gasified rice hull biochar (GR...

  3. 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.)

  4. 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)

    1997-12-31

    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.)

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

    NARCIS (Netherlands)

    Palit, D.; Malhotra, R.; Kumar, Atul

    2011-01-01

    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

  6. A financial evaluation of biomass-gasifier-based power generation in India

    International Nuclear Information System (INIS)

    Tripathi, A.K.; Iyer, P.V.R.; Kandpal, T.C.

    1997-01-01

    A preliminary financial evaluation of biomass-gasifier-based power generation in India was undertaken. Simple cost functions were developed and used for this purpose. The unit cost of electricity has been estimated for a variety of scenarios taking into account some of the uncertainties associated with this emerging technology in India. (author)

  7. Advanced gasifier and water gas shift technologies for low cost coal conversion to high hydrogen syngas

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Andrew Kramer [Gas Technology Inst., Des Plaines, IL (United States)

    2016-09-30

    The Gas Technology Institute (GTI) and team members RTI International (RTI), Coanda Research and Development, and Nexant, are developing and maturing a portfolio of technologies to meet the United States Department of Energy (DOE) goals for lowering the cost of producing high hydrogen syngas from coal for use in carbon capture power and coal-to-liquids/chemicals. This project matured an advanced pilot-scale gasifier, with scalable and commercially traceable components, to readiness for use in a first-of-a-kind commercially-relevant demonstration plant on the scale of 500-1,000 tons per day (TPD). This was accomplished through cold flow simulation of the gasifier quench zone transition region at Coanda and through an extensive hotfire gasifier test program on highly reactive coal and high ash/high ash fusion temperature coals at GTI. RTI matured an advanced water gas shift process and catalyst to readiness for testing at pilot plant scale through catalyst development and testing, and development of a preliminary design basis for a pilot scale reactor demonstrating the catalyst. A techno-economic analysis was performed by Nexant to assess the potential benefits of the gasifier and catalyst technologies in the context of power production and methanol production. This analysis showed an 18%reduction in cost of power and a 19%reduction in cost of methanol relative to DOE reference baseline cases.

  8. Dynamic modeling of Shell entrained flow gasifier in an integrated gasification combined cycle process

    International Nuclear Information System (INIS)

    Lee, Hyeon-Hui; Lee, Jae-Chul; Joo, Yong-Jin; Oh, Min; Lee, Chang-Ha

    2014-01-01

    Highlights: • Detailed dynamic model for the Shell entrained flow gasifier was developed. • The model included sub-models of reactor, membrane wall, gas quench and slag flow. • The dynamics of each zone including membrane wall in the gasifier were analyzed. • Cold gas efficiency (81.82%), gas fraction and temperature agreed with Shell data. • The model could be used as part of the overall IGCC simulation. - Abstract: The Shell coal gasification system is a single-stage, up-flow, oxygen-blown gasifier which utilizes dry pulverized coal with an entrained flow mechanism. Moreover, it has a membrane wall structure and operates in the slagging mode. This work provides a detailed dynamic model of the 300 MW Shell gasifier developed for use as part of an overall IGCC (integrated gasification combined cycle) process simulation. The model consists of several sub-models, such as a volatilization zone, reaction zone, quench zone, slag zone, and membrane wall zone, including heat transfers between the wall layers and steam generation. The dynamic results were illustrated and the validation of the gasifier model was confirmed by comparing the results in the steady state with the reference data. The product gases (H 2 and CO) began to come out from the exit of the reaction zone within 0.5 s, and nucleate boiling heat transfer was dominant in the water zone of the membrane wall due to high heat fluxes. The steady state of the process was reached at nearly t = 500 s, and our simulation data for the steady state, such as the temperature and composition of the syngas, the cold gas efficiency (81.82%), and carbon conversion (near 1.0) were in good agreement with the reference data

  9. Date palm waste gasification in downdraft gasifier and simulation using ASPEN HYSYS

    International Nuclear Information System (INIS)

    Bassyouni, M.; Waheed ul Hasan, Syed; Abdel-Aziz, M.H.; Abdel-hamid, S.M.-S.; Naveed, Shahid; Hussain, Ahmed; Ani, Farid Nasir

    2014-01-01

    Highlights: • Simulation of date palm waste gasification using ASPEN HYSYS was studied. • A steady state simulation of downdraft gasifier has been developed. • The results were used to predict synthesis gas composition. • Simulation results and experimental results are in good agreement. - Abstract: The present research aims to study the simulation of date palm waste gasification using ASPEN HYSYS. A steady state simulation of downdraft gasifier firing date palm leaves has been developed. The model is able to predict syngas composition with sound accuracy and can be used to find optimal operating conditions of the gasifier. Biomass is defined as an unconventional hypothetical solid component in HYSYS. A set of six reactor models simulates various reaction zones of the downdraft gasifier in accordance with its hydrodynamics. Biomass decomposition into constituents in the pyrolysis zone is modeled with a conversion reactor. The combustion of char and volatiles in the combustion zone are modeled with equilibrium and Gibbs reactor models respectively. The gasification zone is modeled with a Gibbs and equilibrium reactor. The results of simulation are validated against experimental results of a parametric variability study on a lab scale gasifier. The proportion of synthesis gas increase as temperature increases (concentration, molar fraction, and partial pressure). CO 2 and CH 4 in the product gases were also found to decrease with increasing temperature. At 800 °C, the exit gas reaches a stable molar composition (H 2 = 56.27%, CO = 21.71%, CO 2 = 18.24%, CH 4 = 3.78%). Increasing steam to biomass ratio increases CO 2 and H 2 at the expense of CO, governed by shift reaction. Steam induction increases the methane contents, thereby improves the heating value of the product gas

  10. Date palm waste gasification in downdraft gasifier and simulation using ASPEN HYSYS

    Energy Technology Data Exchange (ETDEWEB)

    Bassyouni, M. [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Department of Chemical Engineering, Higher Technological Institute, Tenth of Ramdan City (Egypt); Waheed ul Hasan, Syed [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Abdel-Aziz, M.H., E-mail: helmy2002@gmail.com [Department of Chemical and Materials Engineering, King Abdulaziz University, Rabigh 21911 (Saudi Arabia); Chemical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria (Egypt); Abdel-hamid, S. M.-S. [Department of Chemical Engineering, Higher Technological Institute, Tenth of Ramdan City (Egypt); Naveed, Shahid [Punjab Institute of Contemporary Sciences, 5.5 KM Raiwind Road, Lahore (Pakistan); Hussain, Ahmed [Department of Nuclear Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Ani, Farid Nasir [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, UTM 81310 Johor Bahru (Malaysia)

    2014-12-15

    Highlights: • Simulation of date palm waste gasification using ASPEN HYSYS was studied. • A steady state simulation of downdraft gasifier has been developed. • The results were used to predict synthesis gas composition. • Simulation results and experimental results are in good agreement. - Abstract: The present research aims to study the simulation of date palm waste gasification using ASPEN HYSYS. A steady state simulation of downdraft gasifier firing date palm leaves has been developed. The model is able to predict syngas composition with sound accuracy and can be used to find optimal operating conditions of the gasifier. Biomass is defined as an unconventional hypothetical solid component in HYSYS. A set of six reactor models simulates various reaction zones of the downdraft gasifier in accordance with its hydrodynamics. Biomass decomposition into constituents in the pyrolysis zone is modeled with a conversion reactor. The combustion of char and volatiles in the combustion zone are modeled with equilibrium and Gibbs reactor models respectively. The gasification zone is modeled with a Gibbs and equilibrium reactor. The results of simulation are validated against experimental results of a parametric variability study on a lab scale gasifier. The proportion of synthesis gas increase as temperature increases (concentration, molar fraction, and partial pressure). CO{sub 2} and CH{sub 4} in the product gases were also found to decrease with increasing temperature. At 800 °C, the exit gas reaches a stable molar composition (H{sub 2} = 56.27%, CO = 21.71%, CO{sub 2} = 18.24%, CH{sub 4} = 3.78%). Increasing steam to biomass ratio increases CO{sub 2} and H{sub 2} at the expense of CO, governed by shift reaction. Steam induction increases the methane contents, thereby improves the heating value of the product gas.

  11. Liquid CO2/Coal Slurry for Feeding Low Rank Coal to Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Marasigan, Jose [Electric Power Research Institute, Inc., Palo Alto, CA (United States); Goldstein, Harvey [Electric Power Research Institute, Inc., Palo Alto, CA (United States); Dooher, John [Electric Power Research Institute, Inc., Palo Alto, CA (United States)

    2013-09-30

    This study investigates the practicality of using a liquid CO2/coal slurry preparation and feed system for the E-Gas™ gasifier in an integrated gasification combined cycle (IGCC) electric power generation plant configuration. Liquid CO2 has several property differences from water that make it attractive for the coal slurries used in coal gasification-based power plants. First, the viscosity of liquid CO2 is much lower than water. This means it should take less energy to pump liquid CO2 through a pipe compared to water. This also means that a higher solids concentration can be fed to the gasifier, which should decrease the heat requirement needed to vaporize the slurry. Second, the heat of vaporization of liquid CO2 is about 80% lower than water. This means that less heat from the gasification reactions is needed to vaporize the slurry. This should result in less oxygen needed to achieve a given gasifier temperature. And third, the surface tension of liquid CO2 is about 2 orders of magnitude lower than water, which should result in finer atomization of the liquid CO2 slurry, faster reaction times between the oxygen and coal particles, and better carbon conversion at the same gasifier temperature. EPRI and others have recognized the potential that liquid CO2 has in improving the performance of an IGCC plant and have previously conducted systemslevel analyses to evaluate this concept. These past studies have shown that a significant increase in IGCC performance can be achieved with liquid CO2 over water with certain gasifiers. Although these previous analyses had produced some positive results, they were still based on various assumptions for liquid CO2/coal slurry properties.

  12. The UNDP/World Bank monitoring program on small scale biomass gasifiers (BTG's experience on tar measurements)

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

    By the time that small-scale biomass gasifiers were 'rediscovered' and promoted for use in developing countries (1970s), UNDP and the World Bank were well aware of the pitfalls of previous attempts to diffuse decentralized energy technologies. Therefore they decided to initiate a technology assessment programme before endorsing and/or stimulating a widespread gasifier introduction programme in developing countries. On July 1, 1983, the UNDP/WB worldwide Small-scale biomass gasifier monitoring was initiated, which was to {sup c}ollect uniform data on the actual field performance, economics, safety and public acceptability of biomass gasifiers currently operating in developing countries{sup .} For the UNDP/WB program BTG developed a tar measuring protocol which was used at twenty gasifiers worldwide (Indonesia, Philippines, Brazil, Mali, Seychelles, Vanuatu and Burundi). Other parameters monitored include pressure and temperatures at various spots, gasflow, fuel consumption, lubrication oil analyses, gas-composition analyses, emission measurements. The seven year programme showed that most of donor funded projects failed, mainly because there was not sufficient commitment from involved parties. National programs on the utilization of loca available biomass resources mostly failed because the fuel did not suit the requirements of gasifier reactor. In case of proper project design/set-up most of the small scale biomass gasifiers operated without major problems. Examples of such projects are the ones in Balong and Majalengka (Indonesia) Onesua (Vanuatu), Espara Feliz (Brazil) and Dogofiry (Mali). A motivated team of technicians, operators, managers is one the most important items within this respect. Most of the heat gasifiers are installed commercially and are much more successful compared to the subsidized power gasifiers. Local manufactured gasifiers are generally constructed of low quality materials causing frequent technical problems. However, locally

  13. A numerical model for chemical reaction on slag layer surface and slag layer behavior in entrained-flow gasifier

    Directory of Open Access Journals (Sweden)

    Liu Sheng

    2013-01-01

    Full Text Available The paper concerns with slag layer accumulation, chemical reaction on slag layer surface, and slag layer flow, heat and mass transfer on the wall of entrained-flow coal gasifier. A slag layer model is developed to simulate slag layer behaviors in the coal gasifier. This 3-D model can predict temperature, slag particle disposition rate, disposition particle composition, and syngas distribution in the gasifier hearth. The model is used to evaluate the effects of O2/coal ratio on slag layer behaviors.

  14. 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

  15. 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

    1998-12-31

    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

  16. Toxicological and chemical characterization of the process stream materials and gas combustion products of an experimental low-btu coal gasifier.

    Science.gov (United States)

    Benson, J M; Hanson, R L; Royer, R E; Clark, C R; Henderson, R F

    1984-04-01

    The process gas stream of an experimental pressurized McDowell-Wellman stirred-bed low-Btu coal gasifier, and combustion products of the clean gas were characterized as to their mutagenic properties and chemical composition. Samples of aerosol droplets condensed from the gas were obtained at selected positions along the process stream using a condenser train. Mutagenicity was assessed using the Ames Salmonella mammalian microsome mutagenicity assay (TA98, with and without rat liver S9). All materials required metabolic activation to be mutagenic. Droplets condensed from gas had a specific mutagenicity of 6.7 revertants/microgram (50,000 revertants/liter of raw gas). Methylnaphthalene, phenanthrene, chrysene, and nitrogen-containing compounds were positively identified in a highly mutagenic fraction of raw gas condensate. While gas cleanup by the humidifier-tar trap system and Venturi scrubber led to only a small reduction in specific mutagenicity of the cooled process stream material (4.1 revertants/microgram), a significant overall reduction in mutagenicity was achieved (to 2200 revertants/liter) due to a substantial reduction in the concentration of material in the gas. By the end of gas cleanup, gas condensates had no detectable mutagenic activity. Condensates of combustion product gas, which contained several polycyclic aromatic compounds, had a specific mutagenicity of 1.1 revertants/microgram (4.0 revertants/liter). Results indicate that the process stream material is potentially toxic and that care should be taken to limit exposure of workers to the condensed tars during gasifier maintenance and repair and to the aerosolized tars emitted in fugitive emissions. Health risks to the general population resulting from exposure to gas combustion products are expected to be minimal.

  17. Experimental and computational study and development of the bituminous coal entrained-flow air-blown gasifier for IGCC

    International Nuclear Information System (INIS)

    Abaimov, N A; Osipov, P V; Ryzhkov, A F

    2016-01-01

    In the paper the development of the advanced bituminous coal entrained-flow air- blown gasifier for the high power integrated gasification combined cycle is considered. The computational fluid dynamics technique is used as the basic development tool. The experiment on the pressurized entrained-flow gasifier was performed by “NPO CKTI” JSC for the thermochemical processes submodel verification. The kinetic constants for Kuznetsk bituminous coal (flame coal), obtained by thermal gravimetric analysis method, are used in the model. The calculation results obtained by the CFD model are in satisfactory agreements with experimental data. On the basis of the verified model the advanced gasifier structure was suggested which permits to increase the hydrogen content in the synthesis gas and consequently to improve the gas turbine efficiency. In order to meet the specified requirements vapor is added on the second stage of MHI type gasifier and heat necessary for air gasification is compensated by supplemental heating of the blasting air. (paper)

  18. Investigation of combustion of coal briquettes in a fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Boavida, Dulce; Abelha, Pedro; Gulyurtlu, Ibrahim; Cabrita, Isabel

    1999-07-01

    This paper discusses the results obtained from an experimental combustion work undertaken to investigate the behaviour of multicomponent briquettes, prepared by mixing two different particle sizes of coal and two different types of binder species. single briquettes were burned over a wide range of temperatures in a laboratory scale fluidised bed combustor facility. Nitrogen (NO{sub x}, and N{sub 2}O) and Sulphur (SO{sub 2}) oxides emissions resulting from the combustion of these briquettes were constantly monitored during the time of burning. The levels of O{sub 2}, CO{sub 2} and CO were also recorded during the same period. Experimental results showed that coal particle size influenced burn-out times and emissions levels of some of gaseous species. The hinder type was also found to have a major influence on the emissions of different pollutants.The temperature was observed to significantly influence the extent of the effects of the other operating parameters studied.

  19. 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

    1997-12-31

    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

  20. 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

  1. 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...

  2. 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.

  3. Carbon formation and metal dusting in hot-gas cleanup systems of coal gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, R.R.; Tortorelli, P.F.; Judkins, R.R.; DeVan, J.H.; Wright, I.G. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1995-11-01

    The product gas resulting from the partial oxidation of Carboniferous materials in a gasifier is typically characterized by high carbon and sulfur, but low oxygen, activities and, consequently, severe degradation of the structural and functional materials can occur. The objective of this task was to establish the potential risks of carbon deposition and metal dusting in advanced coal gasification processes by examining the current state of knowledge regarding these phenomena, making appropriate thermochemical calculations for representative coal gasifiers, and addressing possible mitigation methods. The paper discusses carbon activities, iron-based phase stabilities, steam injection, conditions that influence kinetics of carbon deposition, and influence of system operating parameters on carbon deposition and metal dusting.

  4. 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....

  5. Enriched-air fluidized bed gasification using bench and pilot scale reactors of dairy manure with sand bedding based on response surface methods

    International Nuclear Information System (INIS)

    Nam, Hyungseok; Maglinao, Amado L.; Capareda, Sergio C.; Rodriguez-Alejandro, David Aaron

    2016-01-01

    Enriched-air gasification was performed in fluidized bed reactors using the processed dairy manure which was mixed with sand bedding. The effects of temperature, modified equivalence ratio (ER_m), and oxygen concentration on the gas products were investigated based on the statistical models using a bench-scale reactor in order to obtain empirical correlations. Then, the empirical equations were applied to compare the produced gases from a pilot-scale fluidized bed gasifier. The empirical and actual H_2 and CH_4 compositions were within a 10% error, while the sum of produced CO and CO_2 gases showed similar composition within 3% error. The most influential factors for the syngas heating value were temperature followed by the oxygen concentration and ER (equivalence ratio). The composition of H_2 (2.1–11.5%) and CO (5.9–20.3%) rose with an increase in temperature and oxygen concentration. The variation of CO_2 (16.8–31.6%) was mainly affected by the degree of oxygen concentration in the gasifying agent. The ranges of the LHV (lower heating value), carbon conversion efficiency and cold gas efficiency were discussed. An economic review showed favorable indications for on-site dairy manure gasification process for electric power based on the depreciable payback period and the power production costs. - Highlights: • Sand mixed dairy manure obtained directly from a dairy farm was processed and used. • Response surface methodology was used to investigate the enriched-air gasification. • Syngas results from bench and pilot scale gasifiers were compared and reviewed. • A highest LVH of 8 MJ/Nm"3 was obtained from the enriched-air gasification. • The power production costs were determined to be $0.053/kWh

  6. 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.

  7. 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.

  8. Investigation of sewage sludge gasification with use of flue gas as a gasifying agent

    Directory of Open Access Journals (Sweden)

    Maj Izabella

    2017-01-01

    Full Text Available The paper presents results of investigation of low-temperature sewage sludge gasification with use of flue gas as a gasifying agent. Tests were conducted in a laboratory stand, equipped with a gasification reactor designed and constructed specifically for this purpose. During presented tests, gas mixture with a composition of typical flue gases was used as a gasifying agent. The measuring system ensures online measurements of syngas composition: CO, CO2, H2, CH4. As a result of gasification process a syngas with combustible components has been obtained. The aim of the research was to determine the usability of sewage sludge for indirect cofiring in power boilers with the use of flue gas from the boiler as a gasifying agent and recirculating the syngas to the boiler’s combustion chamber. Results of presented investigation will be used as a knowledge base for industrial-scale sewage sludge gasification process. Furthermore, toxicity of solid products of the process has been determined by the use of Microtox bioassay. Before tests, solid post-gasification residues have been ground to two particle size fractions and extracted into Milli-Q water. The response of test organisms (bioluminescent Aliivibrio fischeri bacteria in reference to a control sample (bacteria exposed to 2% NaCl solution was measured after 5 and 15 minutes of exposure. The obtained toxicity results proved that thermal treatment of sewage sludge by their gasification reduces their toxicity relative to water organisms.

  9. 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.

  10. Decomposition of tar in gas from updraft gasifier by thermal cracking

    DEFF Research Database (Denmark)

    Brandt, Peder; Henriksen, Ulrik Birk

    2000-01-01

    Continuing earlier work with tar reduction by partial oxidation of pyrolysis gas [1] thermal cracking has been evaluated as a gas cleaning process. The work has been focusing on cleaning gas from updraft gasifiers, and the long term purpose is to develop a tar cleaning unit based on thermal...... cracking. An experimental set-up has been built, in which a flow of contaminated gas can be heated up to 1290°C in a reactor made of pure Al2O3. Four measurements were made. Three with gas from a pyrolysis unit simulating updraft gasifier, and one with gas from an updraft gasifier. Cracking temperatures...... was 1200, 1250 and 1290°C, and the residence time at this temperature was 0.5 second. The measurements show that at the selected residence time of 0.5 second, the gas flow in a thermal tar cracking unit has to be heated to at least 1250°C to achieve sufficient tar cleaning. At 1290°C, a tar content as low...

  11. Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems. Volume 3, Appendix B: NO{sub x} and alkali vapor control strategies: Final report

    Energy Technology Data Exchange (ETDEWEB)

    1990-07-01

    CRS Sirrine (CRSS) is evaluating a novel IGCC process in which gases exiting the gasifier are burned in a gas turbine combustion system. The turbine exhaust gas is used to generate additional power in a conventional steam generator. This results in a significant increase in efficiency. However, the IGCC process requires development of novel approaches to control SO{sub 2} and NO{sub x} emissions and alkali vapors which can damage downstream turbine components. Ammonia is produced from the reaction of coal-bound nitrogen with steam in the reducing zone of any fixed bed coal gasifier. This ammonia can be partially oxidized to NO{sub x} when the product gas is oxidized in a gas turbine combustor. Alkali metals vaporize in the high-temperature combustion zone of the gasifier and laser condense on the surface of small char or ash particles or on cooled metal surfaces. It these alkali-coated materials reach the gas turbine combustor, the alkali will revaporize condense on turbine blades and cause rapid high temperature corrosion. Efficiency reduction will result. PSI Technology Company (PSIT) was contracted by CRSS to evaluate and recommend solutions for NO{sub x} emissions and for alkali metals deposition. Various methods for NO{sub x} emission control and the potential process and economic impacts were evaluated. This included estimates of process performance, heat and mass balances around the combustion and heat transfer units and a preliminary economic evaluation. The potential for alkali metal vaporization and condensation at various points in the system was also estimated. Several control processes and evaluated, including an order of magnitude cost for the control process.

  12. Letter to the Editor. Three-dimensional Modeling of a Circulating Fluidized-Bed Gasifier for Sewage Sludge

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav

    2006-01-01

    Roč. 61, č. 12 (2006), s. 4132-4133 ISSN 0009-2509 Institutional research plan: CEZ:AV0Z40720504 Keywords : fluidization * terminal velocity * drag coeffficient Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.629, year: 2006

  13. FY 1991 report on the results of the development of an entrained bed coal gasification power plant. Part 4. Operation of pilot plant; 1991 nendo seika hokokusho. Funryusho sekitan gaska hatsuden plant kaihatsu - Sono 4. Pilot plant unten sosa hen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-01-01

    A record was summarized of the operation of the 200 t/d entrained bed coal gasification pilot plant that was constructed with the aim of establishing technology of the integrated coal gasification combined cycle power generation. As to the actual results of operation hours, the paper summarized the records of gasifier facilities, gas refining facilities, gas turbine facilities and safety environment facilities which were collected from April 1991 to January 1993. Relating to the actual results of start-up/stop, the paper summarized the records of gasifier facilities, gas refining facilities (desulfurization), gas refining facilities (dedusting), gas turbine facilities and safety environment facilities. Further, operation manuals were made for the schedule of plant start-up/stop, generalization, gasifier facilities, gas refining facilities (desulfurization), gas refining facilities (dedusting), gas turbine facilities, actual pressure/actual size combustor testing facilities and safety environment facilities. (NEDO)

  14. Bioenergy originating from biomass combustion in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Crujeira, T.; Gulyurtlu, I.; Lopes, H.; Abelha, P.; Cabrita, I. [INETI/DEECA, Lisboa (Portugal)

    2008-07-01

    Bioenergy could significantly contribute to reducing and controlling greenhouse emissions (GHG) and to replace fossil fuels in large power plants. Although the use of biomass, originating from forests, could be beneficial, particularly in preventing fires, there are obstacles to achieve a sustainable supply chain of biomass in most European countries. In addition, there are also technical barriers as requirements of biomass combustion may differ from those of coal, which could mean significant retrofitting of existing installations. The combustion behaviour of different biomass materials were studied on a pilot fluidised bed combustor, equipped with two cyclones for particulate matter removal. The gaseous pollutants leaving the stack were sampled under isokinetic conditions for particulate matter, chlorine compounds, heavy metals and dioxins and furans (PCDD/F). The results obtained indicated that the combustion of these materials did not present any operational problem, although for temperatures above 800{sup o}C, bed agglomeration could be observed for all biomass materials studied. Most of the combustion of biomass, contrary to what is observed for coal, takes place in the riser where the temperature was as much as 150{sup o}C above that of the bed. Stable combustion conditions were achieved as well as high combustion efficiency. When compared with the emissions of bituminous coal, the most used fossil fuel, the emissions of CO and SO2 were found to be lower and NOx emissions were similar to those of coal. HCl and PCDD/F could be considerable with biomasses containing high chlorine levels, as in the case of straw. It was observed that the nature of ash could give rise serious operating problems.

  15. Tests of Bed Agglomeration Tendency Using a Rotating Furnace; Roterugn foer bedoemning av sintringsbenaegenhet

    Energy Technology Data Exchange (ETDEWEB)

    Larfeldt, Jenny; Zintl, Frank [TPS Termiska Processer AB, Nykoeping (Sweden)

    2003-08-01

    Bed sintering is a well known problem in fluidised bed boilers. In order to avoid bed sintering the bed material turn over ratio is high which leads a high consumption of bed material. This work aims at developing and evaluating a method for testing the bed agglomeration tendency of a FB bed material by using a rotating furnace. A rotating furnace has been designed and tests have shown that three temperatures describing the increasing agglomeration tendency can be evaluated; TA when several particles stick to each other and to the crucible wall, TB when half of the material sticks to the wall and TC when almost all the material forms a ball in the crucible. Comparison with bed agglomeration tests has shown that TA is between 80 deg C to 130 deg C lower than the bed agglomeration temperature from fluid bed tests. It is shown that TB is closer to the bed agglomeration temperature and finally that the temperature TC is higher than the bed agglomeration temperature. It is concluded that in the rotating furnace sticking of particles is visualised early, and that this sticking will not cause defluidisation of the bed until more than half of the material in the crucible is sticky. Repeated tests has been performed at a heating rate of 5 deg/minute and a rotating speed of 12 rpm and a furnace inclination of 20 deg was found to give distinct results in the evaluation. The evaluation has shown to be reproducible at lower temperatures. At higher temperatures, around 1,000 deg C, the evaluation was complicated by a poor picture quality which probably can be improved by proper cooling of the camera. It has also been shown that sticking of material in the rotating furnace could be detected at relatively low temperatures of 750 deg C that disappeared at higher temperatures. This is likely to be explained by melting salts that evaporates as temperature increase. At even higher temperatures the sticking reappeared until a ball was formed in the crucible. The latter sticking is

  16. Tests with blast furnace slag as bed material in a 12 MW waste fired BFB boiler; Fullskalefoersoek med Hyttsand som baeddmaterial i 12 MW avfallseldad BFB-panna

    Energy Technology Data Exchange (ETDEWEB)

    Eklund, Anders; Oehman, Marcus

    2004-11-01

    A full-scale trial has been performed at Saeverstaverket twin 12 MWth BFB boilers in Bollnaes using Hyttsand (a proprietary blast furnace slag) as bed material. The purpose has been to investigate if Hyttsand can be used as bed material in FB boilers for difficult types of fuels. Used fuel has been municipal waste, recovered wood fuel and different types of bio fuels. The test period was 19 days and nearly 100 tons of Hyttsand was used. The most important conclusions are: Good fluidisation can be achieved with Hyttsand as bed material. Hyttsand can fluidise without any changes in boiler settings. Hyttsand can also be mixed with Baskarpsand (a natural sand with over 90% SiO{sub 2}) and used as bed material without any negative changes to the boiler performance. Bed material make-up rate is reduced with up to 30 % when using Hyttsand compared to using Baskarpsand. Other conclusions are: Bed temperature increased slightly and bed temperature deviation decreased. Emissions was in general not affected, however emissions of SO{sub 2} increased slightly. More deposit containing more sulphur was formed on superheater surfaces when using Hyttsand. The increased amount of sulphur when using Hyttsand could be an effect of higher content of sulphur in the fuel or, which is more likely, that sulphur is released from Hyttsand and forms gaseous sulphurous gases. No significant change in produced amounts of fly-, cyclone- or bottom ash. Hyttsand and Baskarpsand had both similar coatings on their particles and similar agglomeration tendencies. There have been some start-up problems during the trials, including two more severe boiler disturbances, but most of these disturbances can be explained and avoided in the future. Previous investigations in laboratory scale using Hyttsand as bed material when firing different bio fuels have shown the advantage of Hyttsand with its higher resistance against a chemical reaction with alkali in the fuel ash compared to conventional bed materials

  17. Techno-economic assessment of a solar PV, fuel cell, and biomass gasifier hybrid energy system

    Directory of Open Access Journals (Sweden)

    Anand Singh

    2016-11-01

    Full Text Available The interest of power is expanding step by step all through the world. Because of constrained measure of fossil fuel, it is vital to outline some new non-renewable energy frameworks that can diminish the reliance on ordinary energy asset. A hybrid off-grid renewable energy framework might be utilized to reduction reliance on the traditional energy assets. Advancement of crossover framework is a procedure to choose the best mix of part and there cost that can give shabby, solid and successful option energy resource. In this paper sun oriented photovoltaic, fuel cell, biomass gasifier generator set, battery backup and power conditioning unit have been simulated and optimized for educational institute, energy centre, Maulana Azad National Institute of Technology, Bhopal in the Indian state of Madhya Pradesh. The area of the study range on the guide situated of 23°12′N latitude and 77°24′E longitude. In this framework, the essential wellspring of power is sun based solar photovoltaic system and biomass gasifier generator set while fuel cell and batteries are utilized as reinforcement supply. HOMER simulator has been utilized to recreate off the grid and it checks the specialized and financial criteria of this hybrid energy system. The execution of every segment of this framework is dissected lastly delicate examination has been performing to enhance the mixture framework at various conditions. In view of the recreation result, it is found that the cost of energy (COE of a biomass gasifier generator set, solar PV and fuel cell crossover energy system has been found to be 15.064 Rs/kWh and complete net present cost Rs.51,89003. The abundance power in the proposed framework is observed to be 36 kWh/year with zero rates unmet electrical burden.

  18. Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Anbo [Center for Photonics Technology, Blacksburgh, VA (United States); Yu, Zhihao [Center for Photonics Technology, Blacksburgh, VA (United States)

    2015-11-30

    This report summarizes technical progress on the program “Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health,” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The scope of work entails analyses of traveling grating generation technologies in an optical fiber, as well as the interrogation of the gratings to infer a distributed temperature along the fiber, for the purpose of developing a real-time refractory health condition monitoring technology for coal gasifiers. During the project period, which is from 2011-2015, three different sensing principles were studied, including four-wave mixing (FWM), coherent optical time-domain reflectometer (C-OTDR) and Brillouin optical time-domain analysis (BOTDA). By comparing the three methods, the BOTDA was selected for further development into a complete bench-top sensing system for the proposed high-temperature sensing application. Based on the input from Eastman Chemical, the industrial collaborator on this project, a cylindrical furnace was designed and constructed to simulate typical gasifier refractory temperature conditions in the laboratory, and verify the sensor’s capability to fully monitor refractory conditions on the back-side at temperatures up to 1000°C. In the later stages of the project, the sensing system was tested in the simulated environment for its sensing performance and high-temperature survivability. Through theoretical analyses and experimental research on the different factors affecting the sensor performance, a sensor field deployment strategy was proposed for possible future sensor field implementations.

  19. Environmental performance of gasified willow from different lands including land-use changes

    DEFF Research Database (Denmark)

    Saez de Bikuna Salinas, Koldo; Hauschild, Michael Zwicky; Pilegaard, Kim

    2017-01-01

    A life-cycle assessment (LCA) of a low-input, short rotation coppice (SRC) willow grown on different Danish lands was performed. Woodchips are gasified, producer gas is used for co-generation of heat and power (CHP) and the ash-char output is applied as soil amendment in the field. A hybrid model...... for abandoned farmland, as a relative C stock loss compared to natural regeneration. ILUC results show that area related GHG emissions are dominant (93% of iLUCfood and 80% of iLUCfeed), transformation being more important (82% of iLUCfood) than occupation (11%) impacts. LCA results show that CHP from willow...

  20. Carbon Formation and Metal Dusting in Hot-Gas Cleanup Systems of Coal Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, Peter F.; Judkins, Roddie R.; DeVan, Jackson H.; Wright, Ian G.

    1995-12-31

    There are several possible materials/systems degradation modes that result from gasification environments with appreciable carbon activities. These processes, which are not necessarily mutually exclusive, include carbon deposition, carburization, metal dusting, and CO disintegration of refractories. Carbon formation on solid surfaces occurs by deposition from gases in which the carbon activity (a sub C) exceeds unity. The presence of a carbon layer CO can directly affect gasifier performance by restricting gas flow, particularly in the hot gas filter, creating debris (that may be deposited elsewhere in the system or that may cause erosive damage of downstream components), and/or changing the catalytic activity of surfaces.

  1. Cogeneration applications of biomass gasifier/gas turbine technologies in the cane sugar and alcohol industries

    International Nuclear Information System (INIS)

    Ogden, J.M.; Williams, R.H.; Fulmer, M.E.

    1994-01-01

    Biomass integrated gasifier/gas turbine (BIG/GT) technologies for cogeneration or stand-alone power applications hold forth the promise of being able to produce electricity at lower cost in many instances than most alternatives, including large central-station, coal-fired, steam-electric power plants with fuel gas desulphurization, nuclear power plants, and hydroelectricity power plants. BIG/GT technologies offer environmental benefits as well, including the potential for zero net carbon dioxide emissions, if the biomass feedstock is grown renewably. (author). 77 refs., 9 figs., 16 tabs

  2. Experimental study on the gasification characteristics of coal and orimulsion in 0.5 T/D gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ho Young; Kim, Jong Young; An, Dal Hong; Park, Tae Jun [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

    1995-12-31

    For the construction of commercial plant for IGCC imported from aboard in near future, it is aimed to get gasification data, practice the gasification design capability, and develop a fundamental key technology through the experiments for different kinds of coals (Datong, Roto, Alaska) by 0.5 T/D gasifier. We performed the experiments for physical properties and reactivities on selected coals by means of Drop Tube Reactor, numerical analysis for the reactor. Throughout the characteristic studies of orimulsion gasification, feasibility studies for orimulsion gasification as a fuel for power plant be performed. With the six experiment runs for the coal gasifier, several problems were found to remedy. After remedies, the gasifier could run at good operating conditions maintaining with 200% design feed rate over 1200-1550 degree. The third and fourth gasification runs with Roto were satisfactorily completed, during which gross heating values from produced gas were 7200-8200 Kcal/Nm{sup 3}. (author). 118 refs., 145 figs.

  3. Experimental study on the gasification characteristics of coal and orimulsion in 0.5 T/D gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ho Young; Kim, Jong Young; An, Dal Hong; Park, Tae Jun [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

    1996-12-31

    For the construction of commercial plant for IGCC imported from aboard in near future, it is aimed to get gasification data, practice the gasification design capability, and develop a fundamental key technology through the experiments for different kinds of coals (Datong, Roto, Alaska) by 0.5 T/D gasifier. We performed the experiments for physical properties and reactivities on selected coals by means of Drop Tube Reactor, numerical analysis for the reactor. Throughout the characteristic studies of orimulsion gasification, feasibility studies for orimulsion gasification as a fuel for power plant be performed. With the six experiment runs for the coal gasifier, several problems were found to remedy. After remedies, the gasifier could run at good operating conditions maintaining with 200% design feed rate over 1200-1550 degree. The third and fourth gasification runs with Roto were satisfactorily completed, during which gross heating values from produced gas were 7200-8200 Kcal/Nm{sup 3}. (author). 118 refs., 145 figs.

  4. 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.

  5. Lignite air-steam gasification in the fluidized bed of iron-containing slag catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, B.N.; Shchipko, M.L.; Golovin, Yu. [Inst. of Chemistry of Natural Organic Materials, Academgorodok, Krasnoyarsk (Russian Federation)

    1995-12-01

    The influence of fluidized bed of iron-containing slag particles on air-steam gasification of powdered Kansk-Achinsk lignite in entrained flow was studied in pilot installation with productivity about 60 kg per hour. Slag of Martin process and boiler slag were used as catalytic active materials until their complete mechanical attrition. Two following methods of catalytic gasification of lignite were compared: the partial gasification in stationary fluidized bed of slag particles with degree of fuel conversion 40-70% and complete gasification in circulating bed of slag particles. In the first case only the most reactive part of fuel is gasified with the simultaneously formation of porous carbon residue with good sorption ability. It was found the catalytic fluidized bed improves heat transfer from combustion to reduction zone of gas-generator and increases the rate of fuel conversion at the temperature range 900-1000{degrees}C. At these temperatures the degree of conversion is depended considerably on the duration time of fuel particles in the catalytic fluidized bed. The influence of catalytic fluidized bed height and velocity of reaction mixture on the temperature profiles in the gas-generator was studied. The optimal relationship was found between the fluidized bed height and velocity of flow which makes possible to produce the gas with higher calorific value at maximum degree of fuel conversion.

  6. Numerical simulations for the coal/oxidant distribution effects between two-stages for multi opposite burners (MOB) gasifier

    International Nuclear Information System (INIS)

    Unar, Imran Nazir; Wang, Lijun; Pathan, Abdul Ghani; Mahar, Rasool Bux; Li, Rundong; Uqaili, M. Aslam

    2014-01-01

    Highlights: • We simulated a double stage 3D entrained flow coal gasifier with multi-opposite burners. • The various reaction mechanisms have evaluated with experimental results. • The effects of coal and oxygen distribution between two stages on the performance of gasifier have investigated. • The local coal to oxygen ratio is affecting the overall efficiency of gasifier. - Abstract: A 3D CFD model for two-stage entrained flow dry feed coal gasifier with multi opposite burners (MOB) has been developed in this paper. At each stage two opposite nozzles are impinging whereas the two other opposite nozzles are slightly tangential. Various numerical simulations were carried out in standard CFD software to investigate the impacts of coal and oxidant distributions between the two stages of the gasifier. Chemical process was described by Finite Rate/Eddy Dissipation model. Heterogeneous and homogeneous reactions were defined using the published kinetic data and realizable k–ε turbulent model was used to solve the turbulence equations. Gas–solid interaction was defined by Euler–Lagrangian frame work. Different reaction mechanism were investigated first for the validation of the model from published experimental results. Then further investigations were made through the validated model for important parameters like species concentrations in syngas, char conversion, maximum inside temperature and syngas exit temperature. The analysis of the results from various simulated cases shows that coal/oxidant distribution between the stages has great influence on the overall performance of gasifier. The maximum char conversion was found 99.79% with coal 60% and oxygen 50% of upper level of injection. The minimum char conversion was observed 95.45% at 30% coal with 40% oxygen at same level. In general with oxygen and coal above or equal to 50% of total at upper injection level has shown an optimized performance

  7. Practice Hospital Bed Safety

    Science.gov (United States)

    ... Home For Consumers Consumer Updates Practice Hospital Bed Safety Share Tweet Linkedin Pin it More sharing options ... It depends on the complexity of the bed." Safety Tips CDRH offers the following safety tips for ...

  8. Bed Bugs and Schools

    Science.gov (United States)

    Bed bugs have long been a pest – feeding on blood, causing itchy bites and generally irritating their human hosts. They are successful hitchhikers, and can move from an infested site to furniture, bedding, baggage, boxes, and clothing.

  9. Gasification of algal biomass (Cladophora glomerata L.) with CO2/H2O/O2 in a circulating fluidized bed.

    Science.gov (United States)

    Ebadi, Abdol Ghaffar; Hisoriev, Hikmat

    2017-11-28

    Gasification is one of the most important thermochemical routes to produce both synthesis gas (syngas) and chars. The quality of produced syngas wieldy depends on the operating conditions (temperature, residence time, heating rate, and gasifying agent), hydrodynamic properties of gasifier (particle size, minimum fluidization velocity, and gasifier size), and type of feedstock (coal, biomass, oil, and municipal solid wastes). In the present study, simulation of syngas production via circulating fluidized bed (CFB) gasification of algal biomass (Cladophora glomerata L.) at different gasifying agents and particle sizes was carried out, using Aspen Plus simulator. The model which has been validated by using experimental data of the technical literature was used to evaluate the influence of operating conditions on gas composition and performance parameters. The results show that biomass gasification using pure oxygen as the gasification agent has great potential to improve the caloric value of produced gas and performance indicators. It was also found that the produced gas caloric value, syngas yield, and performance parameters (CCE and CGE) increase with reaction temperature but are inversely proportional to the biomass particle size.

  10. Carbon conversion predictor for fluidized bed gasification of biomass fuels - from TGA measurements to char gasification particle model

    Energy Technology Data Exchange (ETDEWEB)

    Konttinen, J.T. [University of Jyvaeskylae, Department of Chemistry, Renewable Energy Programme, POB 35, Jyvaeskylae (Finland); Moilanen, A. [VTT Technical Research Centre of Finland, POB 1000, Espoo (Finland); Martini, N. de; Hupa, M. [Abo Akademi University, Process Chemistry Centre, Combustion and Materials Chemistry, Turku (Finland)

    2012-09-15

    When a solid fuel particle is injected into a hot fluidized bed, the reactivity of fuel char in gasification reactions (between char carbon and steam and CO{sub 2}) plays a significant role for reaching a good carbon conversion. In this paper, the gasification reactivity data of some solid waste recovered fuels (SRF) obtained from thermogravimetric analysis (TGA) experiments is presented. Gas mixtures (H{sub 2}O, H{sub 2}, CO{sub 2}, CO), were used in the experiments to find the inhibitive effects of CO and H{sub 2}. Average char gasification reactivity values are determined from the TGA results. Kinetic parameters for char carbon gasification reactivity correlations are determined from this data. The Uniform Conversion model is used to account for the change of gasification reaction rate as function of carbon conversion. Some discrepancies, due to complicated ash-carbon interactions, are subjects of further research. In the carbon conversion predictor, laboratory measured reactivity numbers are converted into carbon conversion numbers in a real-scale fluidized bed gasifier. The predictor is a relatively simple and transparent tool for the comparison of the gasification reactivity of different fuels in fluidized bed gasification. The residence times for solid fuels in fluidized bed gasifiers are simulated. Simulations against some pilot-scale results show reasonable agreement. (orig.)

  11. Influence of operating conditions on the air gasification of dry refinery sludge in updraft gasifier

    International Nuclear Information System (INIS)

    Ahmed, R; Sinnathambi, C M

    2013-01-01

    In the present work, details of the equilibrium modeling of dry refinery sludge (DRS) are presented using ASPEN PLUS Simulator in updraft gasifier. Due to lack of available information in the open journal on refinery sludge gasification using updraft gasifier, an evaluate for its optimum conditions on gasification is presented in this paper. For this purpose a Taguchi Orthogonal array design, statistical software is applied to find optimum conditions for DRS gasification. The goal is to identify the most significant process variable in DRS gasification conditions. The process variables include; oxidation zone temperature, equivalent ratio, operating pressure will be simulated and examined. Attention was focused on the effect of optimum operating conditions on the gas composition of H 2 and CO (desirable) and CO 2 (undesirable) in terms of mass fraction. From our results and finding it can be concluded that the syngas (H 2 and CO) yield in term of mass fraction favors high oxidation zone temperature and at atmospheric pressure while CO 2 acid gas favor at a high level of equivalent ratio as well as air flow rate favoring towards complete combustion.

  12. Assessment of the gasification characteristics of some agricultural and forest industry residues using a laboratory gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Williams, R O; Goss, J R

    1979-01-01

    Gasification means here the reaction of solid fuels with air to yield a low calorific value gas, suitable as a fuel. The solid fuels considered are agricultural and forest industry residues. A laboratory-scale downdraft gasifier was used to study the gasification properties of certain biomass fuels. The grate is the most critical part of the gasifier. Two designs were tested: a rotating eccentric grate and a perforated steel basket. The latter was specifically designed for use with granular fuels such as mulled walnut shells. Batch tests were performed with different biomass fuels and at varying fuel consumption rates. The composition of the generated gas and the mass and heat balances were determined. Substantial closure errors are reported. These are considered to be the result of tars in the gas which were not accounted for. Yields varied from 75.5% in the case of walnut shells to 46% for rice hulls. With a biomass fuel consisting of a mixture of two sizes of walnut shells, yields in excess of 80% were recorded at high fuel consumption rates. Some practical aspects concerning the gasification of biomass fuels and problems associated with cotton gin trash, rice hulls, and wood residues are discussed.

  13. Introduction of an energy efficiency tool for small scale biomass gasifiers – A thermodynamic approach

    International Nuclear Information System (INIS)

    Vakalis, S.; Patuzzi, F.; Baratieri, M.

    2017-01-01

    Highlights: • Analysis of plants for electricity, heat and materials production. • Thermodynamic analysis by using exergy, entransy and statistical entropy. • Extrapolation of a single efficiency index by combining the thermodynamic parameters. • Application of methodology for two monitored small scale gasifiers. - Abstract: Modern gasification plants, should be treated as poly-generation facilities because, alongside the production of electricity and heat, valuable or waste materials streams are generated. Thus, integrated methods should be introduced in order to account for the full range and the nature of the products. Application of conventional hybrid indicators that convert the output into monetary units or CO_2 equivalents are a source of bias because of the inconsistency of the conversion factors and unreliability of the available data. Therefore, this study introduces a novel thermodynamic-based method for assessing gasification plants performance by means of exergy, entransy and statistical entropy. A monitoring campaign has been implemented on two small scale gasifiers and the results have been applied on the proposed method. The energy plants are compared in respect to their individual thermodynamic parameters for energy production and materials distribution. In addition, the method returns one single value which is a resultant of all the investigated parameters and is a characteristic value of the overall performance of an energy plant.

  14. Evaluation of energy plantation crops in a high-throughput indirectly heated biomass gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Paisley, M.A.; Litt, R.D. [Battelle, Columbus, OH (United States)

    1993-12-31

    Experiments were run in Battelle`s 10 ton per day Process Research Unit (PRU) gasifier using two high-growth, energy plantation crops -- hybrid poplar -- and an herbaceous biomass crop -- switch grass. The results show that both feedstocks provide gas production rates, product gas compositions, and heating value similar to other biomass feedstocks tested in the Battelle gasification process. The ash compositions of the switch grass and hybrid poplar feedstocks were high in potassium relative to previously tested biomass feedstocks. High growth biomass species tend to concentrate minerals such as potassium in the ash. The higher potassium content in the ash can then cause agglomeration problems in the gasification system. A method for controlling this agglomeration through the addition of small amounts (approximately 2 percent of the wood feed rate) of an additive could adequately control the agglomeration tendency of the ash. During the testing program in the PRU, approximately 50 tons of hybrid poplar and 15 tons of switch grass were gasified to produce a medium Btu product gas.

  15. Combustion performance of cellulosic biomass in a gasifier-based cookstove

    Science.gov (United States)

    Sulaiman, Shaharin A.; Romli, Raffisyazana

    2012-06-01

    Depletion in fossil fuel and increase in the world population may change the trend in future kitchens in households. Cooking with LPG fuel may one day become impossible and households would have to consider alternatives such as electric stoves. One other solution to this problem is through the use of biomass cook stoves. However, traditional cook stoves, predominantly used in the households, are not efficient and its utilizations for domestic cooking have been a major contributor to the ill effects related in respiratory and other health problem. Improved cook stoves programs implemented in the developing world attempt to address these problems. Biomass gasification appears to have significant potential in Asia for domestic cooking applications. Gasifier-based cook stoves are fuel efficient in comparison to traditional cook stove. The objective of this paper is to study the performance of various type of cellulosic biomass in a gasifier-based cook stove. The biomass considered in this study are oil palm fronds, dried leaves, wood sticks, coconut shells, bagasse, charcoal, and saw dust. The samples are analyzed in order to study their chemical properties. The thermochemical properties of the biomass were characterized. The performance of the each of the samples is studied by observing the time taken to boil water. It is found that oil palm fronds are the best type of biomass for the gasifer cook stove. It is also concluded that the higher the carbon content and the calorific value in a biomass, the lesser the time taken to boil the water.

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

    International Nuclear Information System (INIS)

    Palit, Debajit; Malhotra, Ramit; Kumar, Atul

    2011-01-01

    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.

  17. Enhanced Productivity of Chemical Processes Using Dense Fluidized Beds

    Energy Technology Data Exchange (ETDEWEB)

    Sibashis Banerjee; Alvin Chen; Rutton Patel; Dale Snider; Ken Williams; Timothy O' Hern; Paul Tortora

    2008-02-29

    The work detailed in this report addresses Enabling Technologies within Computational Technology by integrating a “breakthrough” particle-fluid computational technology into traditional Process Science and Engineering Technology. The work completed under this DOE project addresses five major development areas 1) gas chemistry in dense fluidized beds 2) thermal cracking of liquid film on solids producing gas products 3) liquid injection in a fluidized bed with particle-to-particle liquid film transport 4) solid-gas chemistry and 5) first level validation of models. Because of the nature of the research using tightly coupled solids and fluid phases with a Lagrangian description of the solids and continuum description of fluid, the work provides ground-breaking advances in reactor prediction capability. This capability has been tested against experimental data where available. The commercial product arising out of this work is called Barracuda and is suitable for a wide (dense-to-dilute) range of industrial scale gas-solid flows with and without reactions. Commercial applications include dense gas-solid beds, gasifiers, riser reactors and cyclones.

  18. Combustion studies in a fluidised bed-The link between temperature, NO{sub x} and N{sub 2}O formation, char morphology and coal type

    Energy Technology Data Exchange (ETDEWEB)

    Valentim, B.; Lemos de Sousa, M.J. [Centro de Geologia da Universidade do Porto, Faculdade de Ciencias, Praca de Gomes Teixeira, 4099-002, Porto (Portugal); Abelha, P.; Boavida, D.; Gulyurtlu, I. [Departamento de Engenharia Energetica e Controlo Ambiental (DEECA), Instituto Nacional de Engenharia, Tecnologia e Inovacao (INETI), Estrada do Paco do Lumiar, 22, Edif. J, 1649-038, Lisboa (Portugal)

    2006-06-06

    Five commercially available high volatile bituminous coals from different origins were studied with the objective of characterizing their petrographic nature with respect to emissions of NO{sub x} and N{sub 2}O. The chars produced [at temperatures ranging from 700 to 1000 {sup o}C] from these coals were also petrographic ally analyzed to assess the contribution of char to NO{sub x} and N{sub 2}O formation during combustion. Vitrinite-rich coals produced higher porous chars (cenospheres and tenuinetworks) than those that are rich in inertinite. The former coals were, however, found to release lower concentrations of NO. Consistent with previous works, N{sub 2}O emissions were observed to decrease significantly with temperature, however, on the whole, the N{sub 2}O emissions from vitrinite-rich high volatile coals were less than those from inertinite-rich coals. Additionally, high porous chars were found to give rise to lower emissions of NO and N{sub 2}O. (author)

  19. Chemical Processes Related to Combustion in Fluidised Bed. Report for the period 2002-07-01 to 2004-06-30

    Energy Technology Data Exchange (ETDEWEB)

    Steenari, Britt-Marie; Lindqvist, Oliver [Chalmers University of Technology, Goeteborg (Sweden). Dep. of Environmental Inorganic Chemistry

    2005-02-01

    One part of the project was an investigation of the mechanism and kinetics of the absorption of potassium and cadmium in kaolin. Addition of kaolin has been suggested as a method to decrease problems like ash sintering, fouling and corrosion. The results showed that kaolin binds potassium effectively, especially if it is present as chloride or hydroxide. Reducing atmosphere and the presence of water vapour favours the absorption. The products are mainly silicates with low solubility. Cadmium is also absorbed by kaolin in a similar way. In the second part of the project, the chemical forms of some metals present in fly ash from combustion of MSW and bio fuels were studied. The most common Cd-compounds found were sulphate, oxide, chloride and silicate. It was also shown that Cd often is incorporated in calcium minerals, such as calcium silicates, CaO and CaC0{sub 3}, due to the fact that the ions Ca{sup 2+} and Cd{sup 2+} are almost similar in size and charge.

  20. Compartment modeling of coal gasification in an entrained flow gasifier: A study on the influence of operating conditions

    International Nuclear Information System (INIS)

    Kong, Xiangdong; Zhong, Weimin; Du, Wenli; Qian, Feng

    2014-01-01

    Highlights: • Gasification of Shenfu coal in an industrial Texaco gasifier for syngas production. • An equivalent compartment model is developed using Aspen Plus. • Effects of operating parameters on gasification performance indices are studied. • Choosing a reasonable ROC to enhance the gasification efficiency can be flexible. - Abstract: Coal gasifiers are core components of coal-based polygeneration systems for power and chemical production. To study the effects of operational parameters on the performance of entrained flow coal gasifiers, this paper presents an equivalent compartment model (CM) using the Aspen Plus process simulator. The CM blocking is established based on gasifier flow field analysis, using a number of compartments. A simple configuration of these compartments involving material recirculation should be able to simulate the main flow and provide the temperature and gas component distributions. The model predictions exhibit good agreement with industrial data in the model validation. The influences of the oxygen-to-carbon ratio (ROC) and the coal slurry concentration on the gasification performance are discussed. Within the calculation range, the increase in the coal slurry concentration enhances the yield of the effective compositions in product gas. For a given slurry concentration of 62%, the efficient gas yield is a maximum for ROC of 1.43 kg/kg, whereas the oxygen consumption is a minimum for ROC of 1.37 kg/kg. According to the intended final use, however, choosing a reasonable ROC to obtain a higher efficient syngas yield and lower oxygen consumption can be flexible

  1. Effect of hydrogen chloride on the corrosion of an FeCrAlY alloy in simulated coal gasifier atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Coley, K.S.; Rhoades-Brown, J.E.; Blick, K.

    1989-03-01

    An iron chromium aluminium yttrium steel was exposed to a simulated coal gasifier atmosphere containing 1000 ppm and 2200 ppm hydrogen chloride at 450/sup 0/C. Increasing hydrogen chloride content was found to accelerate reaction rates, and significantly alter the microstructure and composition of the corrosion product. Tentative explanations for these results, involving vapour phase transport of metal chlorides are proposed.

  2. Simulation of biomass-steam gasification in fluidized bed reactors: Model setup, comparisons and preliminary predictions.

    Science.gov (United States)

    Yan, Linbo; Lim, C Jim; Yue, Guangxi; He, Boshu; Grace, John R

    2016-12-01

    A user-defined solver integrating the solid-gas surface reactions and the multi-phase particle-in-cell (MP-PIC) approach is built based on the OpenFOAM software. The solver is tested against experiments. Then, biomass-steam gasification in a dual fluidized bed (DFB) gasifier is preliminarily predicted. It is found that the predictions agree well with the experimental results. The bed material circulation loop in the DFB can form automatically and the bed height is about 1m. The voidage gradually increases along the height of the bed zone in the bubbling fluidized bed (BFB) of the DFB. The U-bend and cyclone can separate the syngas in the BFB and the flue gas in the circulating fluidized bed. The concentration of the gasification products is relatively higher in the conical transition section, and the dry and nitrogen-free syngas at the BFB outlet is predicted to be composed of 55% H 2 , 20% CO, 20% CO 2 and 5% CH 4 . Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. A new design method for fluidized bed conversion of largely heterogeneous binary fuels

    Directory of Open Access Journals (Sweden)

    Szentannai Pal

    2017-01-01

    Full Text Available Binary fuels of a fluidized bed combustor or gasifier are solids composed of two groups of particles. Their optimal handling in the same bed becomes rather difficult if their hydrodynamic properties differ by two orders of magnitude or more. Both of these fuel classes are directly fed into the reactor in most cases but the rather homogeneous fuel originally fed switches into a binary character inside the reactor in some others. A typical example of the latter case is the thermal utilization of rubber wastes. A novel design is proposed in the present paper by setting up a non-mixing, non-elutriated binary bed. Design criteria and procedure are formulated as well. One of the known calculation methods is proposed to be applied for assuring a segregated bed by means of choosing the bed components, geometry, and gas velocity conveniently. Cold model experiments are proposed to be applied for assuring no elutriation of the fine fuel particles and no sinking of the coarse fuel particles in the same time. A simple experiment is proposed for determining the common minimum fluidization velocity of the binary bed because known calculation methods can not be applied here.

  4. 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.

  5. Properties and effects of remaining carbon from waste plastics gasifying on iron scale reduction.

    Science.gov (United States)

    Zhang, Chongmin; Chen, Shuwen; Miao, Xincheng; Yuan, Hao

    2011-06-01

    The carbonous activities of three kinds of carbon-bearing materials gasified from plastics were tested with coal coke as reference. The results showed that the carbonous activities of these remaining carbon-bearing materials were higher than that of coal-coke. Besides, the fractal analyses showed that the porosities of remaining carbon-bearing materials were higher than that of coal-coke. It revealed that these kinds of remaining carbon-bearing materials are conducive to improve the kinetics conditions of gas-solid phase reaction in iron scale reduction. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

    Larson, E.D.; Williams, R.H.; Ogden, J.M.; Hylton, M.G.

    1991-01-01

    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

  7. Fluid-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, G.; Schoebotham, N.

    1981-02-01

    In Energy Equipment Company's two-stage fluidized bed system, partial combustion in a fluidized bed is followed by burn-off of the generated gases above the bed. The system can be retrofitted to existing boilers, and can burn small, high ash coal efficiently. It has advantages when used as a hot gas generator for process drying. Tests on a boiler at a Cadbury Schweppes plant are reported.

  8. Measurement and modeling the coefficient of restitution of char particles under simulated entrained flow gasifier conditions

    Science.gov (United States)

    Gibson, LaTosha M.

    Inefficiencies in plant operations due to carbon loss in flyash, necessitate control of ash deposition and the handling of the slag disposal. Excessive char/ash deposition in convective coolers causes reduction in the heat transfer, both in the radiative (slagging) section and in the low-temperature convective (fouling) heating section. This can lead to unplanned shutdowns and result in an increased cost of electricity generation. CFD models for entrained flow gasification have used the average bulk coal composition to simulate slagging and ash deposition with a narrow particle size distribution (PSD). However, the variations in mineral (inorganic) and macerals (organic) components in coal have led to particles with a variation in their inorganic and organic composition after grinding as governed by their Particle Size Distribution (PSD) and mineral liberation kinetics. As a result, each particle in a PSD of coal exhibits differences in its conversion, particle trajectory within the gasifier, fragmentation, swelling, and slagging probability depending on the gasifier conditions (such as the temperature, coal to oxygen ratio, and swirling capacity of the coal injector). Given the heterogeneous behavior of char particles within a gasifier, the main objective of this work was to determine boundary conditions of char particle adhering and/or rebounding from the refractory wall or a layer of previously adhered particles. In the past, viscosity models based on the influence of ash composition have been used as the method to characterize sticking. It is well documented that carbon contributes to the non-wettability of particles. Therefore, it has been hypothesized that viscosity models would not be adequate to accurately predict the adhesion behavior of char. Certain particle wall impact models have incorporated surface tension which can account the contributions of the carbon content to the adhesive properties of a char particle. These particle wall impact models also

  9. Fluidized bed incinerator development

    International Nuclear Information System (INIS)

    Ziegler, D.L.; Johnson, A.J.

    1976-01-01

    A fluidized bed incinerator is being developed for burning rad contaminated solid and liquid waste materials. In situ neutralization of acid gases by the bed material, catalytic afterburning, and gas filtration are used to produce a clean flue gas without the use of aqueous scrubbing

  10. Design of gamma radiation equipment for studying a bubbling gas fluidized bed. Determination of a radial void fraction profile and bubble velocities in a 0.40 m column

    Energy Technology Data Exchange (ETDEWEB)

    Hoogeveen, M O [Technische Univ. Delft (Netherlands). Lab. voor Fysische Technologie

    1993-12-01

    In this work the possibility of the use of gamma radiation in investigating bubbles in a large three dimensional gas-fluidised bed was examined. A measuring system was designed based upon the absorption of gamma radiation. As high energy (>100 keV) gamma radiation penetrates deeply into matter, it can be used to scan through a gas-solid fluidised bed. The attenuation of a beam of mono-energetic photons is related to the amount of solid particles in the path of the beam. With the gamma absorption technique two parameters can be determined: The void fraction and the bubble velocity. With one narrow beam of gamma radiation a chordal void fraction can be measured in the homogeneous part of the bed. An optimalisation procedure for the void fraction determination led to the choice of Cs-137 as radiation source. This optimalisation procedure concerned minimizing of the standard deviation in the determined chordal void fraction as a function of the energy of gamma radiation. With two narrow parallel beams placed at a distance of 12 cm above each other a bubble velocity can be obtained. A cross-correlation between the two detector responses gives the time shift between the two responses. The system was designed for velocity measurements in the non-homogeneous part of the column. A simulation of the two beam measurement method for an air fluidized bed, 0.40 m in diameter, of polystyrene particles led to the choice of 100 mCi for the source strength for each of the two Cs-137 sources. For a 100 mCi Cs-137 source a shielding of 8 cm of lead is necessary to comply with safety regulations, concerning the use of radioactive materials. A source holder was designed, containing two encapsulated 100 mCi Cs-137 sources, in accordance with the regulations in the licence of the Delft University of Technology for the use of encapsulated sources. (orig.).

  11. Design of gamma radiation equipment for studying a bubbling gas fluidized bed. Determination of a radial void fraction profile and bubble velocities in a 0.40 m column

    International Nuclear Information System (INIS)

    Hoogeveen, M.O.

    1993-12-01

    In this work the possibility of the use of gamma radiation in investigating bubbles in a large three dimensional gas-fluidised bed was examined. A measuring system was designed based upon the absorption of gamma radiation. As high energy (>100 keV) gamma radiation penetrates deeply into matter, it can be used to scan through a gas-solid fluidised bed. The attenuation of a beam of mono-energetic photons is related to the amount of solid particles in the path of the beam. With the gamma absorption technique two parameters can be determined: The void fraction and the bubble velocity. With one narrow beam of gamma radiation a chordal void fraction can be measured in the homogeneous part of the bed. An optimalisation procedure for the void fraction determination led to the choice of Cs-137 as radiation source. This optimalisation procedure concerned minimizing of the standard deviation in the determined chordal void fraction as a function of the energy of gamma radiation. With two narrow parallel beams placed at a distance of 12 cm above each other a bubble velocity can be obtained. A cross-correlation between the two detector responses gives the time shift between the two responses. The system was designed for velocity measurements in the non-homogeneous part of the column. A simulation of the two beam measurement method for an air fluidized bed, 0.40 m in diameter, of polystyrene particles led to the choice of 100 mCi for the source strength for each of the two Cs-137 sources. For a 100 mCi Cs-137 source a shielding of 8 cm of lead is necessary to comply with safety regulations, concerning the use of radioactive materials. A source holder was designed, containing two encapsulated 100 mCi Cs-137 sources, in accordance with the regulations in the licence of the Delft University of Technology for the use of encapsulated sources. (orig.)

  12. Attempts on cardoon gasification in two different circulating fluidized beds

    Directory of Open Access Journals (Sweden)

    Chr. Christodoulou

    2014-11-01

    Full Text Available Few tests have been carried out in order to evaluate the use of cardoon in gasification and combustion applications most of the researchers dealt with agglomeration problems. The aim of this work is to deal with the agglomeration problem and to present a solution for the utilization of this biofuel at a near industrial application scale. For this reason, two experiments were conducted, one in TU Delft and one in Centre for Research and Technology Hellas (CERTH, using fuel cardoon and 50% w/w cardoon blended with 50% w/w giant reed respectively. Both experimental campaigns were carried out in similar atmospheric circulating fluidized bed gasifiers. Apart from the feedstock, the other differences were the gasification medium and the bed material used in each trial. The oxidizing agent at TUD׳s run was O2/steam, whereas CERTH׳s tests used air. When experiments with the cardoon 50% w/w–giant reed 50% w/w blend were performed no agglomeration problems were presented. Consequently, gasification could be achieved in higher temperature than that of pure cardoon which led to the reduction of tar concentration.

  13. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUIDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    International Nuclear Information System (INIS)

    Unknown

    2001-01-01

    Foster Wheeler Development Corporation is working under DOE contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% while producing near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The unique aspect of the process is that it utilizes a pressurized circulating fluidized bed partial gasifier and does not attempt to consume the coal in a single step. To convert all the coal to syngas in a single step requires extremely high temperatures ((approx)2500 to 2800F) that melt and vaporize the coal and essentially drive all coal ash contaminants into the syngas. Since these contaminants can be corrosive to power generating equipment, the syngas must be cooled to near room temperature to enable a series of chemical processes to clean the syngas. Foster Wheeler's process operates at much lower temperatures that control/minimize the release of contaminants; this eliminates/minimizes the need for the expensive, complicated syngas heat exchangers and chemical cleanup systems typical of high temperature gasification. By performing the gasification in a circulating bed, a significant amount of syngas can still be produced despite the reduced temperature and the circulating bed allows easy scale up to large size plants. Rather than air, it can also operate with oxygen to facilitate

  14. Optimal operation for 3 control parameters of Texaco coal-water slurry gasifier with MO-3LM-CDE algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Cuiwen; Zhang, Yakun; Gu, Xingsheng [Ministry of Education, East China Univ. of Science and Technology, Shanghai (China). Key Lab. of Advanced Control and Optimization for Chemical Processes

    2013-07-01

    Optimizing operation parameters for Texaco coal-water slurry gasifier with the consideration of multiple objectives is a complicated nonlinear constrained problem concerning 3 BP neural networks. In this paper, multi-objective 3-layer mixed cultural differential evolution (MO-3LM-CDE) algorithms which comprise of 4 multi-objective strategies and a 3LM-CDE algorithm are firstly presented. Then they are tested in 6 benchmark functions. Finally, the MO-3LM-CDE algorithms are applied to optimize 3 control parameters of the Texaco coal-water slurry gasifier in methanol production of a real-world chemical plant. The simulation results show that multi-objective optimal results are better than the respective single-objective optimal operations.

  15. A dual fired downdraft gasifier system to produce cleaner gas for power generation: Design, development and performance analysis

    International Nuclear Information System (INIS)

    Raman, P.; Ram, N.K.; Gupta, Ruchi

    2013-01-01

    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 Nm 3 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

  16. TVA coal-gasification commercial demonstration plant project. Volume 5. Plant based on Koppers-Totzek gasifier. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    This volume presents a technical description of a coal gasification plant, based on Koppers-Totzek gasifiers, producing a medium Btu fuel gas product. Foster Wheeler carried out a conceptual design and cost estimate of a nominal 20,000 TPSD plant based on TVA design criteria and information supplied by Krupp-Koppers concerning the Koppers-Totzek coal gasification process. Technical description of the design is given in this volume.

  17. To gasify or not to gasify torrefied wood? : Investigating the effect of torrefaction on oxygen steam blown circulating fluidized bed gasification of wood, focusing on permanent gas and tar composition, and environmental performance

    NARCIS (Netherlands)

    Tsalidis, G.A.

    2018-01-01

    Biomass is a sustainable biofuel as long as it does not compete with food and feed production. Gasification is a versatile technology that produces a gas which can be converted into various high value products. Torrefaction is a technology that converts biomass to a more coal alike product with

  18. Novel intrinsic-based submodel for char particle gasification in entrained-flow gasifiers: Model development, validation and illustration

    International Nuclear Information System (INIS)

    Schulze, S.; Richter, A.; Vascellari, M.; Gupta, A.; Meyer, B.; Nikrityuk, P.A.

    2016-01-01

    Highlights: • Model resolving intra-particle species transport for char conversion was formulated. • TGA experiments of char particle conversion in gas flow were conducted. • The experimental results for char conversion validated the model. • CFD simulations of endothermic reactor with developed model were carried out. - Abstract: The final carbon conversion rate is of critical importance in the efficiency of gasifiers. Therefore, comprehensive modeling of char particle conversion is of primary interest for designing new gasifiers. This work presents a novel intrinsic-based submodel for the gasification of a char particle moving in a hot flue gas environment considering CO 2 and H 2 O as inlet species. The first part of the manuscript describes the model and its derivation. Validations against experiments carried out in this work for German lignite char are reported in the second part. The comparison between submodel predictions and experimental data shows good agreement. The importance of char porosity change during gasification is demonstrated. The third part presents the results of CFD simulations using the new submodel and a surface-based submodel for a generic endothermic gasifier. The focus of CFD simulations is to demonstrate the crucial role of intrinsic based heterogeneous reactions in the adequate prediction of carbon conversion rates.

  19. Modeling the emissions of a dual fuel engine coupled with a biomass gasifier-supplementing the Wiebe function.

    Science.gov (United States)

    Vakalis, Stergios; Caligiuri, Carlo; Moustakas, Konstantinos; Malamis, Dimitris; Renzi, Massimiliano; Baratieri, Marco

    2018-03-12

    There is a growing market demand for small-scale biomass gasifiers that is driven by the economic incentives and the legislative framework. Small-scale gasifiers produce a gaseous fuel, commonly referred to as producer gas, with relatively low heating value. Thus, the most common energy conversion systems that are coupled with small-scale gasifiers are internal combustion engines. In order to increase the electrical efficiency, the operators choose dual fuel engines and mix the producer gas with diesel. The Wiebe function has been a valuable tool for assessing the efficiency of dual fuel internal combustion engines. This study introduces a thermodynamic model that works in parallel with the Wiebe function and calculates the emissions of the engines. This "vis-à-vis" approach takes into consideration the actual conditions inside the cylinders-as they are returned by the Wiebe function-and calculates the final thermodynamic equilibrium of the flue gases mixture. This approach aims to enhance the operation of the dual fuel internal combustion engines by identifying the optimal operating conditions and-at the same time-advance pollution control and minimize the environmental impact.

  20. Thermodynamic modelling of an onsite methanation reactor for upgrading producer gas from commercial small scale biomass gasifiers.

    Science.gov (United States)

    Vakalis, S; Malamis, D; Moustakas, K

    2018-06-15

    Small scale biomass gasifiers have the advantage of having higher electrical efficiency in comparison to other conventional small scale energy systems. Nonetheless, a major drawback of small scale biomass gasifiers is the relatively poor quality of the producer gas. In addition, several EU Member States are seeking ways to store the excess energy that is produced from renewables like wind power and hydropower. A recent development is the storage of energy by electrolysis of water and the production of hydrogen in a process that is commonly known as "power-to-gas". The present manuscript proposes an onsite secondary reactor for upgrading producer gas by mixing it with hydrogen in order to initiate methanation reactions. A thermodynamic model has been developed for assessing the potential of the proposed methanation process. The model utilized input parameters from a representative small scale biomass gasifier and molar ratios of hydrogen from 1:0 to 1:4.1. The Villar-Cruise-Smith algorithm was used for minimizing the Gibbs free energy. The model returned the molar fractions of the permanent gases, the heating values and the Wobbe Index. For mixtures of hydrogen and producer gas on a 1:0.9 ratio the increase of the heating value is maximized with an increase of 78%. For ratios higher than 1:3, the Wobbe index increases significantly and surpasses the value of 30 MJ/Nm 3 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. CO-PRODUCTION OF HYDROGEN AND ELECTRICITY USING PRESSURIZED CIRCULATING FLUIDIZED BED GASIFICATION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Zhen Fan

    2006-05-30

    Foster Wheeler has completed work under a U.S. Department of Energy cooperative agreement to develop a gasification equipment module that can serve as a building block for a variety of advanced, coal-fueled plants. When linked with other equipment blocks also under development, studies have shown that Foster Wheeler's gasification module can enable an electric generating plant to operate with an efficiency exceeding 60 percent (coal higher heating value basis) while producing near zero emissions of traditional stack gas pollutants. The heart of the equipment module is a pressurized circulating fluidized bed (PCFB) that is used to gasify the coal; it can operate with either air or oxygen and produces a coal-derived syngas without the formation of corrosive slag or sticky ash that can reduce plant availabilities. Rather than fuel a gas turbine for combined cycle power generation, the syngas can alternatively be processed to produce clean fuels and or chemicals. As a result, the study described herein was conducted to determine the performance and economics of using the syngas to produce hydrogen for sale to a nearby refinery in a hydrogen-electricity co-production plant setting. The plant is fueled with Pittsburgh No. 8 coal, produces 99.95 percent pure hydrogen at a rate of 260 tons per day and generates 255 MWe of power for sale. Based on an electricity sell price of $45/MWhr, the hydrogen has a 10-year levelized production cost of $6.75 per million Btu; this price is competitive with hydrogen produced by steam methane reforming at a natural gas price of $4/MMBtu. Hence, coal-fueled, PCFB gasifier-based plants appear to be a viable means for either high efficiency power generation or co-production of hydrogen and electricity. This report describes the PCFB gasifier-based plant, presents its performance and economics, and compares it to other coal-based and natural gas based hydrogen production technologies.

  2. Porous filtering media comparison through wet and dry sampling of fixed bed gasification products

    Science.gov (United States)

    Allesina, G.; Pedrazzi, S.; Montermini, L.; Giorgini, L.; Bortolani, G.; Tartarini, P.

    2014-11-01

    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.

  3. Bed Bugs FAQs

    Science.gov (United States)

    ... Europe. Bed bugs have been found in five-star hotels and resorts and their presence is not ... Health – Division of Parasitic Diseases Email Recommend Tweet YouTube Instagram Listen Watch RSS ABOUT About CDC Jobs ...

  4. Bed Bug Information Clearinghouse

    Science.gov (United States)

    Its purpose is to help states, communities, and consumers in efforts to prevent and control bed bug infestations. Currently includes only reviewed material from federal/state/local government agencies, extension services, and universities.

  5. Particle fuel bed tests

    International Nuclear Information System (INIS)

    Horn, F.L.; Powell, J.R.; Savino, J.M.

    1985-01-01

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss

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

    International Nuclear Information System (INIS)

    Kalinci, Y.; Hepbasli, A.; Dincer, I.

    2009-01-01

    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 NH 3 contents of the six biomass fuels and their stack gas compositions. (author)

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

    International Nuclear Information System (INIS)

    Nouni, M.R.; Mullick, S.C.; Kandpal, T.C.

    2007-01-01

    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

  8. Experimental study on two-stage air supply downdraft gasifier and dual fuel engine system

    Energy Technology Data Exchange (ETDEWEB)

    Nhuchhen, Daya Ram; Salam, P.A. [Asian Institute of Technology, Energy Field of Study, School of Environment Resource and Development, P. O. Box 4, Klong Luang, Pathumthani (Thailand)

    2012-06-15

    Biomass is a widely used renewable energy resource with net balanced carbon dioxide absorptions and emissions. An inefficient use of solid biomass in combustion process emits more gaseous pollutants, increasing the pollution level. Biomass gasification is one of the techniques to support efficient use of biomass. Multistage gasification is a method of gasification to improve quality of the producer gas in which two separate reactors are designed for separating gasification reactions. This study presents experimental results of gasification using Eucalyptus wood in a single long cylindrical reactor with two air supply ports, i.e., primary and secondary. The effect of different air supply rates on the heating values of the producer gas was studied. Optimum primary and secondary air supply rate of 100 and 80 l/min at equivalence ratio of 0.38 was observed with producer gas lower heating value of 4.72 MJ Nm{sup -3}. The performance of a diesel engine in the dual fuel mode was also evaluated. The overall gasifier engine system efficiency was 13.86 % at an electrical load of 10.54 kW{sub e} with specific energy consumption of 16.22 MJ kWh{sup -1}. The heat recovery system was designed and tested to recover heat from producer gas in the form of hot water. (orig.)

  9. Gasification of municipal solid waste in a downdraft gasifier: Analysis of tar formation

    Directory of Open Access Journals (Sweden)

    Tabitha Geoffrey Etutu

    2016-04-01

    Full Text Available In this study, municipal solid waste (MSW from a dumpsite was converted into refuse derived fuel (RDF and used as feedstock for an air-blown gasification process. The gasification process was conducted in a 10 kg.hr -1 downdraft gasifier at different air flow rates of 300, 350, 400, 450 and 550 NL.min1 at atmospheric pressure in order to investigate the quantity and quality of tar formed. It was shown that the increase in the air flow rate from 300 NL.min1 to 550 NL.min1 led to an increase in the oxidation temperature from 719°C to 870°C and an increase in the reduction temperature from 585°C to 750°C, respectively. Tar was reduced from 15 g.Nm3 to 4.7 g.Nm3 respectively. Heavy tar compounds (>C17 e.g. pyrene and phenathrene, decreased with the increase in the light tar compounds (

  10. Correction of Dynamic Characteristics of SAR Cryogenic GTE on Consumption of Gasified Fuel

    Science.gov (United States)

    Bukin, V. A.; Gimadiev, A. G.; Gangisetty, G.

    2018-01-01

    When the gas turbine engines (GTE) NK-88 were developed for liquid hydrogen and NK-89 for liquefied natural gas, performance of the systems with a turbo-pump unitary was improved and its proved without direct regulation of the flow of a cryogenic fuel, which was supplied by a centrifugal pump of the turbo-pump unit (TPU) Command from the “kerosene” system. Such type of the automatic control system (SAR) has the property of partial “neutralization” of the delay caused by gasification of the fuel. This does not require any measurements in the cryogenic medium, and the failure of the centrifugal cryogenic pump does not lead to engine failure. On the other hand, the system without direct regulation of the flow of cryogenic fuel has complex internal dynamic connections, their properties are determined by the characteristics of the incoming units and assemblies, and it is difficult to maintain accurate the maximum boundary level and minimum fuel consumption due to the influence of a booster pressure change. Direct regulation of the consumption of cryogenic fuel (prior to its gasification) is the preferred solution, since for using traditional liquid and gaseous fuels this is the main and proven method. The scheme of correction of dynamic characteristics of a single-loop SAR GTE for the consumption of a liquefied cryogenic fuel with a flow rate correction in its gasified state, which ensures the dynamic properties of the system is not worse than for NK-88 and NK-89 engines.

  11. Development of a micro-turbine plant to run on gasifier producer gas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This report presents the results of a work programme to test a Capstone micro gas turbine using producer gas (1) in a test facility using synthetic producer gas at Advantca's research laboratories and (2) at the premises of Biomass Engineering Ltd where the micro gas turbine was coupled to an existing 80 kWe downdraft gasifier operating on clean wood and wood wastes. The initial tests at Advantica achieved successful operation of the Capstone micro gas turbine on 100% producer gas at a net electrical output of 5.5 kWe and with very low NOx emissions (<2 ppm). The micro turbine was then moved and recommissioned at a site belonging to Biomass Engineering where 350 hours of operation were achieved using producer gas and over 800 hours using natural gas. Problems were experienced during start-up due to limited access to control software and late delivery of the gas compressor for the micro turbine. Gas emissions and performance were deemed satisfactory. The report describes the test work at Advantica and at Biomass Engineering and discusses the technical and economic aspects of biomass gasification and micro turbine systems.

  12. CFD-Modeling of the Multistage Gasifier Capacity of 30 KW

    Science.gov (United States)

    Levin, A. A.; Kozlov, A. N.; Svishchev, D. A.; Donskoy, I. G.

    2017-11-01

    Single-stage fuel gasification processes have been developed and widely studied in Russia and abroad throughout the 20th century. They are fundamental to the creation and design of modern gas generator equipment. Many studies have shown that single-stage gasification process, have already reached the limit of perfection, which was a significant improvement in their performance becomes impossible and unprofitable. The most fully meet modern technical requirements of multistage gasification technology. In the first step of the process, is organized allothermic biomass pyrolysis using heat of exhaust gas and generating power plant. At this stage, the yield of volatile products (gas and tar) of fuel. In the second step, the layer of fuel is, the tar is decomposed by the action of hot air and steam, steam-gas mixture is formed further reacts with the charcoal in the third process stage. The paper presents a model developed by the authors of the multi-stage gasifier for wood chips. The model is made with the use of CFD-modeling software package (COMSOL Multiphisics). To describe the kinetics of wood pyrolysis and gasification of charcoal studies were carried out using a set of simultaneous thermal analysis. For this complex developed original methods of interpretation of measurements, including methods of technical analysis of fuels and determine the parameters of the detailed kinetics and mechanism of pyrolysis.

  13. Phosphorus leaching from soils amended with thermally gasified piggery waste ash

    DEFF Research Database (Denmark)

    Kuligowski, Ksawery; Poulsen, Tjalfe

    2009-01-01

    In regions with intensive livestock farming, thermal treatment for local energy extraction from the manure and export of the P rich ash as a fertilizer has gained interest. One of the main risks associated with P fertilizers is eutrophication of water bodies. In this study P and K mobility in ash...... from anaerobically digested, thermally gasified (GA) and incinerated (IA) piggery waste has been tested using water loads ranging from 0.1 to 200 ml g−1. Leaching of P from soil columns amended with GA was investigated for one P application rate (205 kg P ha−1 corresponding to 91 mg P kg−1 soil dry...... matter) as a function of precipitation rate (9.5 and 2.5 mm h−1), soil type (Jyndevad agricultural soil and sand), amount of time elapsed between ash amendment and onset of precipitation (0 and 5 weeks) and compared to leaching from soils amended with a commercial fertilizer (Na2HPO4). Water soluble P...

  14. Gasification of bio char from empty fruit bunch in a fluidized bed

    International Nuclear Information System (INIS)

    Nsamba Hussein Kisiki; Amran Mohammad Salleh; Wan Azlina; Hamdan Yusof

    2010-01-01

    Full text: Bio char from empty fruit bunch was gasified in a fluidized bed reactor using compressed air as a gasifying agent. The experiment was conducted in the temperature ranges of 500-850 degree Celsius and the equivalence ratio, temperature and size of the feedstock was varied. A series of parameters such as gas yield, overall carbon conversion, gas quality, and composition, were measured as a function of temperature, equivalence ratio and temperature. Results obtained were compared to the actual values of coal and other gasification feedstock reveal that, bio char has the potential to replace coal as a gasification agent in power plants .Hydrogen gas from bio char was also optimized during the experiment. There is great potential of making Hydrogen from Bio char through thermo chemical gasification It was observed that it has a very great potential of being upgraded to Fischer Tropsh fuels. There is a great opportunity of using this char from empty fruit bunch as an alternative fuel in power plants and all the adverse effects of coal gasification can be counteracted. (author)

  15. Advanced sorbent development progam; development of sorbents for moving-bed and fluidized-bed applications

    International Nuclear Information System (INIS)

    Ayala, R.E.; Venkataramani, V.S.

    1998-01-01

    The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 C (900-1000F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 C (650 F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 C (650-1000 F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost assessment and

  16. Pebble-bed reactor

    International Nuclear Information System (INIS)

    Lohnert, G.; Mueller-Frank, U.; Heil, J.

    1976-01-01

    A pebble-bed nuclear reactor of large power rating comprises a container having a funnel-shaped bottom forming a pebble run-out having a centrally positioned outlet. A bed of downwardly-flowing substantially spherical nuclear fuel pebbles is positioned in the container and forms a reactive nuclear core maintained by feeding unused pebbles to the bed's top surface while used or burned-out pebbles run out and discharge through the outlet. A substantially conical body with its apex pointing upwardly and its periphery spaced from the periphery of the container spreads the bottom of the bed outwardly to provide an annular flow down the funnel-shaped bottom forming the runout, to the discharge outlet. This provides a largely constant downward velocity of the spheres throughout the diameter of the bed throughout a substantial portion of the down travel, so that all spheres reach about the same burned-out condition when they leave the core, after a single pass through the core area

  17. The burning of automotive shredder residue (ASR) using fluidized bed technology

    Energy Technology Data Exchange (ETDEWEB)

    Abelha, Pedro; Gulyurtlu, Ibrahim; Lopes, H.; Cabrita, I. [INETI/DEECA, Lisboa (Portugal)

    2005-07-01

    The objective of this work was to demonstrate the feasibility and the environmental performance of FBC technology to burn a fluff fraction of an ASR from a Portuguese vehicle dismantling plant. The combustion studies were carried out on the pilot installation at INETI. The results obtained suggest that the Portuguese ASR has a very high mineral content (70%) and the combustion had to be sustained with the use of an auxiliary fuel (propane); the combustion efficiency was very high; the gaseous pollutants could easily be controlled below the permitted limits and sulphur and chlorine emissions were low. ASR could give rise to fluidising problems due to the accumulation of ashes in the bed; therefore, it is essential that a more efficient metal separation method be used during dismantling process; there was an enrichment of heavy metals (Pb, Cu, Mn and Zn) on ashes retained in the cyclones, specially in the smaller particle size range (less than 10 m); however, the ashes did not have a tendency for leaching.

  18. in Spouted Bed

    Directory of Open Access Journals (Sweden)

    Bronislaw Buczek

    2013-01-01

    Full Text Available Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were investigated. The outer layers of both coke particles were separately removed by comminution in a spouted bed. The samples of both active cokes were analysed by means of densities, mercury porosimetry, and adsorption technique. Remaining cores were examined to determine the degree of consumption of coke by the sorption of hazardous emissions (SO2, HCl, and heavy metals through its bed. Differences in contamination levels within the porous structure of the particles were estimated. The study demonstrated the effectiveness of commercial active coke in the cleaning of flue gases.

  19. The Safety of Hospital Beds

    Science.gov (United States)

    Gervais, Pierre; Pooler, Charlotte; Merryweather, Andrew; Doig, Alexa K.; Bloswick, Donald

    2015-01-01

    To explore the safety of the standard and the low hospital bed, we report on a microanalysis of 15 patients’ ability to ingress, move about the bed, and egress. The 15 participants were purposefully selected with various disabilities. Bed conditions were randomized with side rails up or down and one low bed with side rails down. We explored the patients’ use of the side rails, bed height, ability to lift their legs onto the mattress, and ability to turn, egress, and walk back to the chair. The standard bed was too high for some participants, both for ingress and egress. Side rails were used by most participants when entering, turning in bed, and exiting. We recommend that side rails be reconsidered as a means to facilitate in-bed movement, ingress, and egress. Furthermore, single deck height settings for all patients are not optimal. Low beds as a safety measure must be re-evaluated. PMID:28462302

  20. Effects of upgrading systems on energy conversion efficiency of a gasifier - fuel cell - gas turbine power plant

    International Nuclear Information System (INIS)

    Pedrazzi, Simone; Allesina, Giulio; Tartarini, Paolo

    2016-01-01

    Highlights: • An advanced gasifier-SOFC-MGT system is modeled. • An overall electrical efficiency of 32.81% is reached. • Influence of all the sub-system modeled on the power plant efficiency is discussed. • Compression storage of syngas is taken into account. - Abstract: This work focuses on a DG-SOFC-MGT (downdraft gasifier - solid oxide fuel cell - micro gas turbine) power plant for electrical energy production and investigates two possible performance-upgrading systems: polyphenylene oxide (PPO) membrane and zeolite filters. The first is used to produce oxygen-enriched air used in the reactor, while the latter separates the CO_2 content from the syngas. In order to prevent power plant shutdowns during the gasifier reactor scheduled maintenance, the system is equipped with a gas storage tank. The generation unit consists of a SOFC-MGT system characterized by higher electrical efficiency when compared to conventional power production technology (IC engines, ORC and EFGT). Poplar wood chips with 10% of total moisture are used as feedstock. Four different combinations with and without PPO and zeolite filtrations are simulated and discussed. One-year energy and power simulation were used as basis for comparison between all the cases analyzed. The modeling of the gasification reactions gives results consistent with literature about oxygen-enriched processes. Results showed that the highest electrical efficiency obtained is 32.81%. This value is reached by the power plant equipped only with PPO membrane filtration. Contrary to the PPO filtering, zeolite filtration does not increase the SOFC-MGT unit performance while it affects the energy balance with high auxiliary electrical consumption. This solution can be considered valuable only for future work coupling a CO_2 sequestration system to the power plant.

  1. Apparatus for controlling fluidized beds

    Science.gov (United States)

    Rehmat, A.G.; Patel, J.G.

    1987-05-12

    An apparatus and process are disclosed for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance. 2 figs.

  2. Effect of reverse Boudouard reaction catalyst on the performance of solid oxide carbon fuel cells integrated with a dry gasifier

    International Nuclear Information System (INIS)

    Kim, Sun-Kyung; Mehran, Muhammad Taqi; Mushtaq, Usman; Lim, Tak-Hyoung; Lee, Jong-Won; Lee, Seung-Bok; Park, Seok-Joo; Song, Rak-Hyun

    2016-01-01

    Highlights: • The addition of K_2CO_3 catalyst in carbon fuel improves the performance of SO-CFC. • Thermal and electrochemical analyses done to elucidate the catalytic enhancement. • Material characterization of SO-CFC performed after long-term degradation test. - Abstract: A solid oxide carbon fuel cell (SO-CFC) integrated with a dry gasifier was operated on activated carbon fuel and the effect of adding a reverse Boudouard gasification catalyst on the performance and long-term operation characteristics of the SO-CFC was investigated. The reactivity of the carbon fuels for the Boudouard gasification reaction was analyzed by a thermal analysis at various operating conditions. The SO-CFC was then operated on gasified fuel gas consisting of CO_2 and CO obtained from the integrated dry gasifier. The SO-CFC operated on activated carbon fuel with 5 wt.% K_2CO_3 achieved a maximum power density of 202, 262, and 271 mW/cm"2 at 750, 800, and 850 °C, respectively; the SO-CFC fueled with activated carbon fuel without a catalyst meanwhile yielded maximum power density of 168 mW/cm"2 at 850 °C. By using electrochemical impedance spectroscopy, the effect of adding the catalyst on the gasification products and subsequently on the performance of the SO-CFC was studied. A long-term degradation test was conducted by continuously operating the SO-CFC at 50 mA/cm"2 for 518 h at 750 °C. During the long-term degradation test, the average degradation rate of the SO-CFC was found to be 183 mV/kh. The post-mortem SEM and XRD analyses of the SO-CFC after the long-term test revealed the presence of carbon deposits and oxidation of Ni at the anode, causing a relatively higher degree of degradation in the SO-CFC integrated with the dry gasifier during the long-term operation. The addition of the K_2CO_3 based dry gasification catalyst significantly enhances the performance of the SO-CFC integrated with dry gasification, but during long-term operation, the degradation rate is found

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

    International Nuclear Information System (INIS)

    Pla Duparté, Manuel

    2015-01-01

    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)

  4. Fluidized bed calciner

    International Nuclear Information System (INIS)

    Sheely, W.F.

    1986-01-01

    A unique way to convert radioactive scrap into useful nuclear fuel products was developed for the Department of Energy at Hanford. An advanced, fluidized bed calciner is used to convert metallic nitrate scrap or waste solutions into benign, solid and gaseous products. There are broad potential applications of this concept beyond those in the nuclear industry

  5. Nail Bed Injuries

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Nail Bed Injuries Email to a friend * required ...

  6. Bed Bug Myths

    Science.gov (United States)

    Learn the truth about bed bugs, such as how easy they are to see with the naked eye, their preferred habitat, whether they transmit diseases, their public health effects, and whether pesticides are the best way to deal with an infestation.

  7. Conversion of metallurgical coke and coal using a Coal Direct Chemical Looping (CDCL) moving bed reactor

    International Nuclear Information System (INIS)

    Luo, Siwei; Bayham, Samuel; Zeng, Liang; McGiveron, Omar; Chung, Elena; Majumder, Ankita; Fan, Liang-Shih

    2014-01-01

    Highlights: • Accumulated more than 300 operation hours were accomplished for the moving bed reducer reactor. • Different reactor operation variables were investigated with optimal conditions identified. • High conversions of sub-bituminous coal and bituminous coal were achieved without flow problems. • Co-current and counter-current contact modes were tested and their applicability was discussed. - Abstract: The CLC process has the potential to be a transformative commercial technology for a carbon-constrained economy. The Ohio State University Coal Direct Chemical Looping (CDCL) process directly converts coal, eliminating the need for a coal gasifier oran air separation unit (ASU). Compared to other solid-fuel CLC processes, the CDCL process is unique in that it consists of a countercurrent moving bed reducer reactor. In the proposed process, coal is injected into the middle of the moving bed, whereby the coal quickly heats up and devolatilizes, splitting the reactor roughly into two sections with no axial mixing. The top section consists of gaseous fuel produced from the coal volatiles, and the bottom section consists of the coal char mixed with the oxygen carrier. A bench-scale moving bed reactor was used to study the coal conversion with CO 2 as the enhancing gas. Initial tests using metallurgical cokefines as feedstock were conducted to test the effects of operational variables in the bottom section of the moving bed reducer, e.g., reactor temperature, oxygen carrier to char ratio, enhancer gas CO 2 flow rate, and oxygen carrier flow rates. Experiments directly using coal as the feedstock were subsequently carried out based on these test results. Powder River Basin (PRB) coal and Illinois #6 coal were tested as representative sub-bituminous and bituminous coals, respectively. Nearly complete coal conversion was achieved using composite iron oxide particles as the oxygen carriers without any flow problems. The operational results demonstrated that a

  8. 7 CFR 2902.15 - Bedding, bed linens, and towels.

    Science.gov (United States)

    2010-01-01

    ... PROCUREMENT Designated Items § 2902.15 Bedding, bed linens, and towels. (a) Definition. (1) Bedding is that... minimum biobased content is 12 percent and shall be based on the amount of qualifying biobased carbon in..., and silk are not qualifying biobased feedstocks for the purpose of determining the biobased content of...

  9. VA National Bed Control System

    Data.gov (United States)

    Department of Veterans Affairs — The VA National Bed Control System records the levels of operating, unavailable and authorized beds at each VAMC, and it tracks requests for changes in these levels....

  10. Getting Rid of Bed Bugs

    Science.gov (United States)

    ... Directory Planning, Budget and Results Jobs and Internships Headquarters Offices Regional Offices Labs and Research Centers Bed ... to be careful in how you select a company. Related Information Collaborative Strategy on Bed Bugs - highlights ...

  11. 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

  12. Plasma gasification of refuse derived fuel in a single-stage system using different gasifying agents.

    Science.gov (United States)

    Agon, N; Hrabovský, M; Chumak, O; Hlína, M; Kopecký, V; Masláni, A; Bosmans, A; Helsen, L; Skoblja, S; Van Oost, G; Vierendeels, J

    2016-01-01

    The renewable evolution in the energy industry and the depletion of natural resources are putting pressure on the waste industry to shift towards flexible treatment technologies with efficient materials and/or energy recovery. In this context, a thermochemical conversion method of recent interest is plasma gasification, which is capable of producing syngas from a wide variety of waste streams. The produced syngas can be valorized for both energetic (heat and/or electricity) and chemical (ammonia, hydrogen or liquid hydrocarbons) end-purposes. This paper evaluates the performance of experiments on a single-stage plasma gasification system for the treatment of refuse-derived fuel (RDF) from excavated waste. A comparative analysis of the syngas characteristics and process yields was done for seven cases with different types of gasifying agents (CO2+O2, H2O, CO2+H2O and O2+H2O). The syngas compositions were compared to the thermodynamic equilibrium compositions and the performance of the single-stage plasma gasification of RDF was compared to that of similar experiments with biomass and to the performance of a two-stage plasma gasification process with RDF. The temperature range of the experiment was from 1400 to 1600 K and for all cases, a medium calorific value syngas was produced with lower heating values up to 10.9 MJ/Nm(3), low levels of tar, high levels of CO and H2 and which composition was in good agreement to the equilibrium composition. The carbon conversion efficiency ranged from 80% to 100% and maximum cold gas efficiency and mechanical gasification efficiency of respectively 56% and 95%, were registered. Overall, the treatment of RDF proved to be less performant than that of biomass in the same system. Compared to a two-stage plasma gasification system, the produced syngas from the single-stage reactor showed more favourable characteristics, while the recovery of the solid residue as a vitrified slag is an advantage of the two-stage set-up. Copyright

  13. Attrition of limestone by impact loading in fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Fabrizio Scala; Fabio Montagnaro; Piero Salatino [Consiglio Nazionale delle Ricerche, Napoli (Italy). Istituto di Ricerche sulla Combustione

    2007-09-15

    The present study addresses limestone attrition and fragmentation associated with impact loading, a process which may occur extensively in various regions of fluidized bed (FB) combustors/gasifiers, primarily the jetting region of the bottom bed, the exit region of the riser, and the cyclone. An experimental protocol for the characterization of the propensity of limestone to undergo attrition/fragmentation by impact loading is reported. The application of the protocol is demonstrated with reference to an Italian limestone whose primary fragmentation and attrition by surface wear have already been characterized in previous studies. The experimental procedure is based on the characterization of the amount and particle size distribution of the debris generated upon the impact of samples of sorbent particles against a target. Experiments were carried out at a range of particle impact velocities between 10 and 45 m/s, consistent with jet velocities corresponding to typical pressure drops across FB gas distributors. The protocol has been applied to either raw or preprocessed limestone samples. In particular, the effect of calcination, sulfation, and calcination/recarbonation cycles on the impact damage suffered by sorbent particles has been assessed. The measurement of particle voidage and pore size distribution by mercury intrusion was also accomplished to correlate fragmentation with the structural properties of the sorbent samples. Fragmentation by impact loading of the limestone is significant. Lime displays the largest propensity to undergo impact damage, followed by the sorbent sulfated to exhaustion, the recarbonated sorbent, and the raw limestone. Fragmentation of the raw limestone and of the sulfated lime follows a pattern typical of the failure of brittle materials. The fragmentation behavior of lime and recarbonated lime better conforms to a disintegration failure mode, with an extensive generation of very fine fragments. 27 refs., 9 figs. 1 tab.

  14. Staged fluidized-bed coal combustor for boiler retrofit

    International Nuclear Information System (INIS)

    Rehmat, A.; Dorfman, L.; Shibayama, G.; Waibel, R.

    1991-01-01

    The Advanced Staged Fluidized-Bed Coal Combustion System (ASC) is a novel clean coal technology for either coal-fired repowering of existing boilers or for incremental power generation using combined-cycle gas turbines. This new technology combines staged combustion for gaseous emission control, in-situ sulfur capture, and an ash agglomeration/vitrification process for the agglomeration/vitrification of ash and spent sorbent, thus rendering solid waste environmentally benign. The market for ASC is expected to be for clean coal-fired repowering of generating units up to 250 MW, especially for units where space is limited. The expected tightening of the environmental requirements on leachable solids residue by-products could considerably increase the marketability for ASC. ASC consists of modular low-pressure vessels in which coal is partially combusted and gasified using stacked fluidized-bed processes to produce low-to-medium-Btu, high-temperature gas. This relatively clean fuel gas is used to repower/refuel existing pulverized-coal, natural gas, or oil-fired boilers using bottom firing and reburning techniques. The benefits of ASC coal-fired repowering include the ability to repower boilers without obtaining additional space while meeting the more stringent environmental requirements of the future. Low NO x , SO x , and particulate levels are expected while a nonleachable solid residue with trace metal encapsulation is produced. ASC also minimizes boiler modification and life-extension expenditures. Repowered efficiencies can be restored to the initial operating plant efficiency, and the existing boiler capacity can be increased by 10%. Preliminary cost estimates indicate that ASC will have up to a $250/kW capital cost advantage over existing coal-fired repowering options. 4 figs., 4 tabs

  15. 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)

  16. Geomechanics of bedded salt

    International Nuclear Information System (INIS)

    Serata, S.; Milnor, S.W.

    1979-01-01

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained

  17. International evaluation of the programme on fluid bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H [Ruhr Univ., Bochum (Germany); Magnusson, B F [Norwegian Univ. of Science and Technology, Trondheim (Norway); Reed, T [Colorado School of Mines (United States)

    1997-12-31

    This report on the Swedish National Program on Fluid Bed Combustion and Gasification is part of the on-going evaluation process adopted by the funding organization NUTEK. This agency has invited the undersigned to act as members of an international panel responsible for evaluating the progress made in 9 projects initiated between 1993-1996. The output of this evaluation procedure is given in this report. The main aim of the Fluid Bed Combustion and Gasification Program is to develop industrially relevant knowledge and competence in experimental and computational techniques capable of characterizing the flow, heat transfer, combustion, gasification, ash formation and deposition and emissions in fluid bed gasifiers and combustors. To achieve this aim NUTEK is sponsoring research in a number of universities and encourages close cooperation between universities and industry. In the evaluation of the various sponsored research programs, the evaluation committee has considered the following key points: relevance of research to industrial needs; originality of research; program management; adequacy of resources; degree of collaboration between industry and academia; international standing of research. In this report comments and recommendations are made on individual projects as well as on the programme in general and they express the unanimous view of the panel members

  18. International evaluation of the programme on fluid bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H. [Ruhr Univ., Bochum (Germany); Magnusson, B.F. [Norwegian Univ. of Science and Technology, Trondheim (Norway); Reed, T. [Colorado School of Mines (United States)

    1996-12-31

    This report on the Swedish National Program on Fluid Bed Combustion and Gasification is part of the on-going evaluation process adopted by the funding organization NUTEK. This agency has invited the undersigned to act as members of an international panel responsible for evaluating the progress made in 9 projects initiated between 1993-1996. The output of this evaluation procedure is given in this report. The main aim of the Fluid Bed Combustion and Gasification Program is to develop industrially relevant knowledge and competence in experimental and computational techniques capable of characterizing the flow, heat transfer, combustion, gasification, ash formation and deposition and emissions in fluid bed gasifiers and combustors. To achieve this aim NUTEK is sponsoring research in a number of universities and encourages close cooperation between universities and industry. In the evaluation of the various sponsored research programs, the evaluation committee has considered the following key points: relevance of research to industrial needs; originality of research; program management; adequacy of resources; degree of collaboration between industry and academia; international standing of research. In this report comments and recommendations are made on individual projects as well as on the programme in general and they express the unanimous view of the panel members

  19. Three-stage steady-state model for biomass gasification in a dual circulating fluidized-bed

    International Nuclear Information System (INIS)

    Nguyen, Thanh D.B.; Ngo, Son Ich; Lim, Young-Il; Lee, Jeong Woo; Lee, Uen-Do; Song, Byung-Ho

    2012-01-01

    Highlights: ► Steam gasification of woodchips is examined in dual circulating fluidized-bed (DFB). ► We develop a three-stage model (TSM) for process performance evaluation. ► Effect of gasification temperature and steam to fuel ratio is investigated. ► Several effective operating conditions are found by parametric study. - Abstract: A three-stage steady state model (TSM) was developed for biomass steam gasification in a dual circulating fluidized-bed (DFB) to calculate the composition of producer gas, carbon conversion, heat recovery, cost efficiency, and heat demand needed for the endothermic gasification reactions. The model was divided into three stages including biomass pyrolysis, char–gas reactions, and gas–phase reaction. At each stage, an empirical equation was estimated from experimental data. It was assumed that both unconverted char and additional fuel were completely combusted at 950 °C in the combustor (riser) and the heat required for gasification reactions was provided by the bed material (silica sand). The model was validated with experimental data taken from the literature. The parametric study of the gasification temperature (T) and the steam to fuel ratio (γ) was then carried out to evaluate performance criteria of a 1.8 MW DFB gasifier using woodchips as a feedstock for the electric power generation. Effective operating conditions of the DFB gasifier were proposed by means of the contour of the solid circulation ratio, the heat recovery, the additional fuel ratio and the cost efficiency with respect to T and γ.

  20. Electrical Power and Heat from Crew Waste Using an Integrated Solid Oxide Fuel Cell and Fixed-Bed Gasifier, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — ITN Energy Systems, Inc., along with the Energy and Environmental Research Center (EERC), proposes to develop a highly efficient power generation system capable of...

  1. LT-CFB. Further development and commercialization. Final report. [Low Temperature Circulating Fluid Bed gasifier]; LT-CFB. Videreudvikling og kommercialisering. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Stoholm, P. [DFBT, Roskilde (Denmark); Birk Henriksen, U.; Ahrentfeldt, J. [Technical Univ. of Denmark. DTU Chemical Engineering, CHEC Research Centre, Roskilde (Denmark); Cramer, J.; Dietrich, J.; Christiansen, Knud [FORCE Technology, Kgs. Lyngby (Denmark); Krogh, J. [Anhydro A/S, Soeborg (Denmark)

    2011-12-15

    The starting point for the project was the good results achieved in a previous project, in which a series of experiments were carried out with a 500 kW pilot plant at teh Technical University of Denmark. The main task was then to find a way forward towards further scale-up, demonstration and commercialization. The project's partners chose to study three possible sites for demonstration. However, during the project both framework conditions as well as DONG Energy's strategy changed, which resulted in the company taking over the LT-CFB technology in December 2009. As a first step a 6 MW demonstration plant will now be set up at the Asnaes power plant expected to start in spring 2011. The project has also been buit a new mobile 100 kW LT-CFB plant for the further optimization of the process and for short-term trials of new fuels. At the new plant a number of successful trials were performed with straw and residual fibers. Furthermore, it is experimentally demonstrated that it is possible to cool the tar-containing gas to approx. 300 degrees C and purify the gas in a bag filter, so it can be used in natural gas-fired power plant boilers. With the new mobile system, it will now be easier to perform experiments with a number of new fuels such as unsorted municipal waste, bone meal and dried sewage sludge. (LN)

  2. Adoption and use of a semi-gasifier cooking and water heating stove and fuel intervention in the Tibetan Plateau, China

    Science.gov (United States)

    Clark, S.; Carter, E.; Shan, M.; Ni, K.; Niu, H.; Tseng, J. T. W.; Pattanayak, S. K.; Jeuland, M.; Schauer, J. J.; Ezzati, M.; Wiedinmyer, C.; Yang, X.; Baumgartner, J.

    2017-07-01

    Improved cookstoves and fuels, such as advanced gasifier stoves, carry the promise of improving health outcomes, preserving local environments, and reducing climate-forcing air pollutants. However, low adoption and use of these stoves in many settings has limited their benefits. We aimed to improve the understanding of improved stove use by describing the patterns and predictors of adoption of a semi-gasifier stove and processed biomass fuel intervention in southwestern China. Of 113 intervention homes interviewed, 79% of homes tried the stove, and the majority of these (92%) continued using it 5-10 months later. One to five months after intervention, the average proportion of days that the semi-gasifier stove was in use was modest (40.4% [95% CI 34.3-46.6]), and further declined over 13 months. Homes that received the stove in the first batch used it more frequently (67.2% [95% CI 42.1-92.3] days in use) than homes that received it in the second batch (29.3% [95% CI 13.8-44.5] days in use), likely because of stove quality and user training. Household stove use was positively associated with reported cooking needs and negatively associated with age of the main cook, household socioeconomic status, and the availability of substitute cleaner-burning stoves. Our results show that even a carefully engineered, multi-purpose semi-gasifier stove and fuel intervention contributed modestly to overall household energy use in rural China.

  3. Coal Bed Methane Primer

    Energy Technology Data Exchange (ETDEWEB)

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of

  4. Design of structure and simulation of the three-zone gasifier of dense layer of the inverted process

    Science.gov (United States)

    Zagrutdinov, R. Sh; Negutorov, V. N.; Maliykhin, D. G.; Nikishanin, M. S.; Senachin, P. K.

    2017-11-01

    Experts of LLC “New Energy Technologies” have developed gasifiers designs, with the implementation of the three-zone gasification method, which satisfy the following conditions: 1) the generated gas must be free from tar, soot and hydrocarbons, with a given ratio of CO/H2; 2) to use as the fuel source a wide range of low-grade low-value solid fuels, including biomass and various kinds of carbonaceous wastes; 3) have high reliability in operation, do not require qualified operating personnel, be relatively inexpensive to produce and use steam-air blowing instead of expensive steam-oxygen one; 4) the line of standard sizes should be sufficiently wide (with a single unit capacity of fuel from 1 to 50-70 MW). Two models of gas generators of the inverted gasification process with three combustion zones operating under pressure have been adopted for design: 1) gas generator with a remote combustion chamber type GOP-VKS (two-block version) and 2) a gas generator with a common combustion chamber of the GOP-OK type (single-block version), which is an almost ideal model for increasing the unit capacity. There have been worked out various schemes for the preparation of briquettes from practically the entire spectrum of low-grade fuel: high-ash and high-moisture coals, peat and biomass, including all types of waste - solid household waste, crop, livestock, poultry, etc. In the gas generators there are gasified the cylindrical briquettes with a diameter of 20-25 mm and a length of 25-35 mm. There have been developed a mathematical model and computer code for numerical simulation of synthesis gas generation processes in a gasifier of a dense layer of inverted process during a steam-air blast, including: continuity equations for the 8 gas phase components and for the solid phase; the equation of the heat balance for the entire heterogeneous system; the Darcy law equation (for porous media); equation of state for 8 components of the gas phase; equations for the rates of 3 gas

  5. Infant's bed climate and bedding in the Japanese home.

    Science.gov (United States)

    Nakamura Ikeda, Rie; Fukai, Kiyoko; Okamoto Mizuno, Kazue

    2012-06-01

    to assess the bed climate of infants in their homes in Japan. descriptive, exploratory, non-experimental research design. the data were collected at the participants' homes under normal circumstances. nineteen healthy infants between the ages of two and five months. Their mothers, who joined a parenting class organised by a maternity clinic in Okayama, Japan, consented to participate in this study. we visited the infants' homes and interviewed their mothers concerning the types and use of bedding. The temperature and relative humidity of the bed climate at the back and foot of the bedding, and in the room were measured every minute for four consecutive days. Differences among the bed climates measured during three seasons (spring, summer, and autumn) were assessed by one-way analysis of variance. The bed temperature was higher for infants than for adults. No significant difference in temperature was noted among the three seasons. The bed temperature was about 36.0°C when waterproof sheets and futon mattresses for children or adult were used. The average relative humidity of the bed climate at the back was highest in summer, followed by that in spring and autumn; the differences were significant. The use of waterproof sheets and futon mattresses for children in summer increased the relative humidity to 80% or more. The use of infant beds, sunoko drainboards, and cotton futon mattresses in summer was effective in reducing the bed humidity. these results suggest that nurse-midwives should advise the parents on comfortable bed climates for their infants, as well as how to select and use bedding for them. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. 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.

  7. Particle bed reactor modeling

    Science.gov (United States)

    Sapyta, Joe; Reid, Hank; Walton, Lew

    The topics are presented in viewgraph form and include the following: particle bed reactor (PBR) core cross section; PBR bleed cycle; fuel and moderator flow paths; PBR modeling requirements; characteristics of PBR and nuclear thermal propulsion (NTP) modeling; challenges for PBR and NTP modeling; thermal hydraulic computer codes; capabilities for PBR/reactor application; thermal/hydralic codes; limitations; physical correlations; comparison of predicted friction factor and experimental data; frit pressure drop testing; cold frit mask factor; decay heat flow rate; startup transient simulation; and philosophy of systems modeling.

  8. Boiler plants completed in record time

    International Nuclear Information System (INIS)

    Anon.

    2001-01-01

    Bubbling fluidised bed (BFB) combustion has steadily increased its share of the boiler market in recent years, particularly in the Nordic region, where it is particularly well-suited to handling the high moisture content biofuels produced and used by the forest products industry. Foster Wheeler is the world's leading supplier of fluidised bed combustion technology. Over 200 of the more than 300 fluidised bed boilers supplied by the company are circulating fluidised bed (CFB) designs, a market in which Foster Wheeler has more than a 40% share. Foster Wheeler Energia Oy supplied the Myllykoski project at Anjalankoski with a fluidised bed boiler, auxiliary steam boilers, and flue gas scrubber systems

  9. 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)

  10. Biofuel gasifier feedstock reactivity - explaining the differences and creating prediction models

    Energy Technology Data Exchange (ETDEWEB)

    Konttinen, J. (Jyvaeskylae Univ. (Finland)), Email: jukontti@jyu.fi; Moilanen, A. (VTT Processes, Espoo (Finland)); DeMartini, N.; Hupa, M. (AaboAkademi Univ., Turku (Finland))

    2009-07-01

    In this project in progress, the objective is to generate a method with reasonable cost and effort, to predict the gasification behavior of biomass fuels in a gasification reactor. The results of the project will help to understand the differences in the gasification behavior of biomass fuels. An essential hypothesis in the project is that the decrease of the catalysis properties of biomass ash will decrease biomass char gasification reactivity and thus the final carbon conversion. The project will involve TGA experiments to characterize char reactivity from 3 biomass fuels, ash characterization by fuel fractionation and SEM analysis; bench scale fluidized bed gasification for the 3 fuels; and kinetic modeling to include the change in the carbon conversion rate for different fuels as carbon gasification proceeds to completion. The constants and reactivity models will be used as part of a fluidized-bed gasification reactor model called. 'Carbon conversion predictor', in order to predict the effect of fuel ash composition on the gasification kinetics of biomass char. The University of Jyvaeskylae, Aabo Akademi University and VTT processes will work in cooperation with the private companies in Finland in the field of gasification. Also some cooperation in the USA will possibly be generated. The results of this project can be used in the design of commercial-scale biomass gasification reactors firing a variety of biomass fuels. (orig.)

  11. 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.

  12. 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)

  13. Fluidized bed boiler feed system

    Science.gov (United States)

    Jones, Brian C.

    1981-01-01

    A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

  14. Gasification and co-gasification of biomass wastes: Effect of the biomass origin and the gasifier operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lapuerta, Magin; Hernandez, Juan J.; Pazo, Amparo; Lopez, Julio [Universidad de Castilla-La Mancha, Escuela Tecnica Superior de Ingenieros Industriales (Edificio Politecnico), Avenida Camilo Jose Cela s/n. 13071 Ciudad Real (Spain)

    2008-09-15

    Air gasification of different biomass fuels, including forestry (pinus pinaster pruning) and agricultural (grapevine and olive tree pruning) wastes as well as industry wastes (sawdust and marc of grape), has been carried out in a circulating flow gasifier in order to evaluate the potential of using these types of biomass in the same equipment, thus providing higher operation flexibility and minimizing the effect of seasonal fuel supply variations. The potential of using biomass as an additional supporting fuel in coal fuelled power plants has also been evaluated through tests involving mixtures of biomass and coal-coke, the coke being a typical waste of oil companies. The effect of the main gasifier operating conditions, such as the relative biomass/air ratio and the reaction temperature, has been analysed to establish the conditions allowing higher gasification efficiency, carbon conversion and/or fuel constituents (CO, H{sub 2} and CH{sub 4}) concentration and production. Results of the work encourage the combined use of the different biomass fuels without significant modifications in the installation, although agricultural wastes (grapevine and olive pruning) could to lead to more efficient gasification processes. These latter wastes appear as interesting fuels to generate a producer gas to be used in internal combustion engines or gas turbines (high gasification efficiency and gas yield), while sawdust could be a very adequate fuel to produce a H{sub 2}-rich gas (with interest for fuel cells) due to its highest reactivity. The influence of the reaction temperature on the gasification characteristics was not as significant as that of the biomass/air ratio, although the H{sub 2} concentration increased with increasing temperature. (author)

  15. Management bedding : vrijloopstal met composterende bedding van houtsnippers

    NARCIS (Netherlands)

    Boer, de H.C.; Wiersma, M.; Galama, P.J.; Szanto, G.L.

    2015-01-01

    In de vrijloopstal liggen de koeien meestal op een organische bedding en scheiden daar mest (feces en urine) uit. Om de bedding voldoende droog en schoon te houden wordt er regelmatig nieuw strooisel aangevoerd en wordt de toplaag bewerkt. Op basis van onderzoek- en praktijkervaringen tot nu toe

  16. The development of solid fuel gasification systems for cost-effective power generation with low environmental impacts

    Energy Technology Data Exchange (ETDEWEB)

    Nieminen, M; Kurkela, E; Staahlberg, P; Laatikainen-Luntama, J; Ranta, J; Hepola, J; Kangasmaa, K [VTT Energy, Espoo (Finland). Gasification and Advanced Combustion

    1997-10-01

    Relatively low carbon conversion is a disadvantage related to the air-blown fluidised-bed coal-biomass co-gasification process. Low carbon conversion is due to different reactivities and ash sintering behaviour of coal and biomass which leads to compromises in definition of gasification process conditions. In certain cases co-gasification may also lead to unexpected deposit formations or corrosion problems in downstream components especially when high alkali metal or chlorine containing biomass feedstocks are co-gasified with coal. During the reporting period, the work focused on co-gasification of coal and wood waste. The objectives of the present work were to find out the optimum conditions for improving the carbon conversion and to study the formation of different gas impurities. The results based on co-gasification tests with a pressurised fluidised-bed gasifies showed that in co-gasification even with only 15 % coal addition the heavy tar concentration was decreased significantly and, simultaneously, an almost total carbon conversion was achieved by optimising the gasification conditions. The study of filter fines recirculation and solid residues utilisation was started by characterizing filter dust. The work was carried out with an entrained-flow reactor in oxidising, inert and reducing gas conditions. The aim was to define the conditions required for achieving increased carbon conversion in different reactor conditions

  17. Effectiveness of Bed Bug Pesticides

    Science.gov (United States)

    Before EPA allows a bed bug claim on a label, the product must be supported by data showing it will kill bed bugs when applied according to the label. Also consider factors such as extent of infestation, site preparation, and insect life stages.

  18. Experimental investigation on the changes in bed properties of a ...

    African Journals Online (AJOL)

    user

    International Journal of Engineering, Science and Technology ... research and development, many researchers have reported their results on temperature ... The biomass feeding port is kept closed during operation of gasifier and it is opened ...

  19. Environmental impact assessment for steeply dipping coal beds: North Knobs site

    Energy Technology Data Exchange (ETDEWEB)

    1978-11-08

    The US Department of Energy is funding an underground coal gasification (UCG) project in steeply dipping coal beds (SDB), at North Knobs, about 8 miles west of Rawlins, Carbon County, Wyoming. The project is being conducted to determine the technical, economic and environmental viability of such a technology. The development of SDB is an interesting target for UCG since such beds contain coals not normally mineable economically by ordinary techniques. Although the underground gasification of SDB has not been attempted in the US, Soviet experience and theoretical work indicate that the gasification of SDB in place offers all the advantages of underground gasification of horizontal coal seams plus some unique characteristics. The steep angle of dip helps to channel the produced gases up dip to offtake holes and permits the ash and rubble to fall away from the reaction zone helping to mitigate the blocking of the reaction zone in swelling coals. The intersection of SDB with the surface makes the seam accessible for drilling and other preparation. The tests at the North Knobs site will consist of three tests, lasting 20, 80 and 80 days, respectively. A total of 9590 tons of coal is expected to be gasified, with surface facilities utilizing 15 acres of the total section of land. The environmental effects of the experiment are expected to be very small. The key environmental impact is potential groundwater contamination by reaction products from coal gasification. There is good evidence that the surrounding coal effectively blocks the migration of these contaminants.

  20. Artificial neural network based modelling approach for municipal solid waste gasification in a fluidized bed reactor.

    Science.gov (United States)

    Pandey, Daya Shankar; Das, Saptarshi; Pan, Indranil; Leahy, James J; Kwapinski, Witold

    2016-12-01

    In this paper, multi-layer feed forward neural networks are used to predict the lower heating value of gas (LHV), lower heating value of gasification products including tars and entrained char (LHV p ) and syngas yield during gasification of municipal solid waste (MSW) during gasification in a fluidized bed reactor. These artificial neural networks (ANNs) with different architectures are trained using the Levenberg-Marquardt (LM) back-propagation algorithm and a cross validation is also performed to ensure that the results generalise to other unseen datasets. A rigorous study is carried out on optimally choosing the number of hidden layers, number of neurons in the hidden layer and activation function in a network using multiple Monte Carlo runs. Nine input and three output parameters are used to train and test various neural network architectures in both multiple output and single output prediction paradigms using the available experimental datasets. The model selection procedure is carried out to ascertain the best network architecture in terms of predictive accuracy. The simulation results show that the ANN based methodology is a viable alternative which can be used to predict the performance of a fluidized bed gasifier. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Corn Drying with Zeolite in The Fluidized Bed Dryer under Medium Temperature

    Directory of Open Access Journals (Sweden)

    Mohamad Djaeni

    2013-08-01

    Full Text Available Drying is an important step to find high quality of corn. Based on Standard of National Industry, populer as SNI, number 01-3920-1995, the corn was well stored at moisture content 14% or below (wet basis. However, conventional corn drying dealed with in-efficient energy process and corn quality degradation. This research evaluated the performance of corn drying assisted by zeolite as moisture adsorbent. In this process, the zeolite and corn were placed in the dryer fluidized by warm air as drying medium under 40 - 50oC. The air evaporated water product from corn, and at same time the zeolite adsorbed moisture in air. So, the relative humidity of air in dryer can be kept low in which enhanced the driving force for drying. Beside that, the moisture adsoprtion by zeolite was exothermic process that can supply the energy for drying or keep the dryer temperature. Thus, the drying rate can be faster. This work foccussed to observe the effect of drying temperature, air velocity, and corn to zeolite ratio on drying time as well as corn quality. As indicators, the drying rate was estimated and the proxymates content such as protein, fat, and carbohydrate content were analyzed. The results showed that compared with conventional fluidised bed dryer, corn drying with zeolite, can speed up drying time as well as improving the constant of drying rate. In addition, the corn proximate nutrition content can be well retained. At operating temperature 40oC, air velocity 9 m.s-1, and zeolite to corn ratio 1:2, the drying time can be 60 minutes shorter compared to that without zeolite.

  2. Protecting Your Home from Bed Bugs

    Science.gov (United States)

    ... your home: Inspect the luggage rack in your hotel room for bed bugs. Check secondhand furniture, beds, ... with Bed Bug Problems Discover. Accessibility EPA Administrator Budget & Performance Contracting Grants January 19, 2017 Web Snapshot ...

  3. Co-combustion of gasified contaminated waste wood in a coal fired power plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This project demonstrates the technical and economical feasibility of the producing and cofiring of product gas from demolition waste wood. For this purpose LCV product gas is generated in an atmospheric circulating fluidized bed (CFB) gasification plant, cooled and cleaned and transported to the boiler of a 600 MWe pulverized coal fired power plant. Gas cooling and cleaning takes place in a waste heat boiler and a multi stage wet gas cleaning train. Steam raised in the waste heat boiler is exported to the power plant. On an annual basis 70,000 tons of steam coal are substituted by 150,000 tons of contaminated demolition waste wood (50,000 tons oil equivalent), resulting in a net CO2 emission reduction of 170,000 tons per year, while concurrently generating 205 GWh of electrical power. The wood gasification plant was built by NV EPZ (now incorporated in Essent Energi BV) for Amergas BV, now a 100% subsidiary of Essent Energie BV. The gasification plant is located at the Amer Power Station of NV EPZ Production (now Essent Generation) at Geertruidenberg, The Netherlands. Demonstrating several important design features in wood gasification, the plant started hot service in the Spring of 2000, with first gasification accomplished in the Summer of 2000 and is currently being optimized. (au)

  4. Chaotic hydrodynamics of fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Van der Stappen, M.L.M. [Unit Process and Systems Engineering, Advanced Manufacturing Technology Group, Unilever Research Laboratorium, Vlaardingen (Netherlands)

    1996-12-31

    The major goals of this thesis are: (1) to develop and evaluate an analysis method based on techniques from non-linear chaos theory to characterize the nonlinear hydrodynamics of gas-solids fluidized beds quantitatively; and (2) to determine the dependence of the chaotic invariants on the operating conditions and investigate how the chaos analysis method can be profitably applied to improve scale-up and design of gas-solids fluidized bed reactors. Chaos theory is introduced in chapter 2 with emphasis on analysis techniques for (experimental) time series, known from literature at the start of this work (1990-1991). In chapter 3, the testing of existing and newly developed techniques on both model and fluidized bed data is described. This leads to the development of the chaos analysis method to analyze measured pressure fluctuations time series of a fluidized bed. Following, in chapter 4, this method is tested and all choices for the parameters are evaluated. The influence of the experimental parameters and external disturbances on the measurements and analysis results is discussed and quantified. The result is a chaos measurement and analysis protocol, which is further used in this work. In chapter 5, the applications to fluidized beds are discussed. It is shown that the entropy is a good measure for the characterization of the dynamical behavior of gas-solids bubbling/slugging fluidized beds. Entropy is applied to characterize the influence of the operating conditions, to assess regime transitions and to analyze dimensionless similar beds of different scale. Quantitative design correlations that relate entropy to the operating parameters (including the bed diameter) are described. Finally, it is discussed how the results of this work might be used in scaling up the chaotic dynamics of fluidized beds. The overall conclusions and outlook from this work are presented in chapter 6. 182 refs.

  5. Biomass oxygen/steam gasification in a pressurized bubbling fluidized bed: Agglomeration behavior

    International Nuclear Information System (INIS)

    Zhou, Chunguang; Rosén, Christer; Engvall, Klas

    2016-01-01

    Highlights: • Dolomite is a superior material in preventing bed agglomeration. • Small molten ash particles deposited on magnesite at bed temperatures above 1000 °C. • The performance, when using magnesite, is sensitive to temperature disturbances. • The anti-agglomeration mechanisms of Ca- and Mg-bearing materials were discussed. - Abstract: In this study, the anti-agglomeration abilities of Ca- and Mg-containing bed materials, including dolomite and magnesite, in a pressurized bubbling fluidized bed gasifier using pine pellets and birch chips as feedstock, is investigated. The most typical bed material—silica sand—was also included as a reference for comparison. The sustainability of the operation was evaluated via analyzing the temperatures at different levels along the bed height. During the performances, the aim was to keep the temperature at the bottom zone of the reactor at around 870 °C. However, the success highly depends on the bed materials used in the bed and the temperature can vary significantly in case of agglomeration or bad mixing of bed materials and char particles. Both Glanshammar and Sala dolomites performed well with no observed agglomeration tendencies. In case of magnesite, the bed exhibited a high agglomeration tendency. Silica sand displayed the most severe agglomeration among all bed materials, even when birch chips with a low silica content was fed at a relatively low temperature. The solid samples of all the bed materials were inspected by light microscopy and Scanning Electron Microscopy (SEM). The Energy Dispersive Spectroscopy (EDS) detector was used to detect the elemental distribution in the surface. The crystal chemical structure was analyzed using X-ray Diffraction (XRD). Magnesite agglomerates glued together by big molten ash particles. There was no coating layer detected on magnesite particles at bed temperatures – below 870 °C. But when the temperature was above 1000 °C, a significant amount of small molten

  6. Bed retained products in swept fixed bed (SFB) coal hydropyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Perez-Surio, M.J. [CSIC, Zaragosa (Spain). Inst. de Carboquimica

    1997-12-31

    The hydropyrolysis of a low rank coal in a swept fixed bed (SFB) reactor is carried out by fixing the hydrogen pressure (40 kg/cm{sup 2}), the hydrogen flow (2 l/min) and the residence time (10 min) at increasing temperatures (400 C, 500 C and 600 C) and coal bed heights (h, 1.5h, 2h, 2.5h and 3h). It is shown that the percentages of tars and char directly depend on the coal bed height and that there is not only a quantitative dependence, but also the height of the coal bed is very important and plays a relevant role on the nature of the conversion products. (orig.)

  7. Bed diameter effects and incipient slugging in gas fluidized beds

    International Nuclear Information System (INIS)

    Agarwal, P.K.

    1986-01-01

    The coalescence and growth of bubble swarms formed at the distributor of a fluidized bed gives rise to lateral as well as vertical distributions of bubble properties. However, existing models employ average bubble properties obtained largely from semi-empirical considerations. In a recent Paper, the author developed a bubble growth model based on a population balance approach. Analytical expressions were derived for the bubble characteristic distributions and averages. However, the model, developed for unconstrained growth, did not take into account the effect of the bed diameter and the possibility of slugging. In this Paper, the model is extended to take these aspects into account. A slugging criterion is also developed which is expected to be valid for the regime where incipient slugging depends on the bed height as well as the region where bed height does not significantly affect minimum slugging conditions

  8. Inhalation exposure and risk of polycyclic aromatic hydrocarbons (PAHs) among the rural population adopting wood gasifier stoves compared to different fuel-stove users

    Science.gov (United States)

    Lin, Nan; Chen, Yuanchen; Du, Wei; Shen, Guofeng; Zhu, Xi; Huang, Tianbo; Wang, Xilong; Cheng, Hefa; Liu, Junfeng; Xue, Chunyu; Liu, Guangqing; Zeng, Eddy Y.; Xing, Baoshan; Tao, Shu

    2016-12-01

    Polycyclic aromatica hydrocarbons (PAHs) are a group of compounds with carcinogenic potentials and residential solid fuel combustion is one major source of PAHs in most developing countries. Replacement of traditional stoves with improved ones is believed to be a practical approach to reduce pollutant emissions, however, field assessments on the performance and consequent impacts on air quality and human health after adopting improved stoves are rare. The study is the first time to quantify inhalation exposure to PAHs among the residents who adopted wood gasifier stoves. The results were compared to those still burning coals in the region and compared to exposure levels for different fuel/stove users in literature. The results showed that the PAHs exposure levels for the wood gasifier stove users were significantly lower than the values for those using traditional wood stoves reported in literature, and the daily exposure concentrations of BaPeq (Benzo[a]pyrene equivalent concentration) can be reduced by 48%-91% if traditional wood stoves were replaced by wood gasifier stoves. The corresponding Incremental Lifetime Cancer Risk (ILCR) decreased approximately four times from 1.94 × 10-4 to 5.17 × 10-5. The average concentration of the total 26 PAHs for the wood users was 1091 ± 722 ng/m3, which was comparable to 1060 ± 927 ng/m3 for those using anthracite coals, but the composition profiles were considerably different. The average BaPeq were 116 and 25.8 ng/m3 for the wood and coal users, respectively, and the corresponding ILCR of the anthracite coal users was 1.69 × 10-5, which was nearly one third of those using the wood gasifier stoves. The wood users exposed to not only high levels of high molecular weight PAHs, but relatively high fractions of particulate phase PAHs in small particles compared to the coal users, resulting in high exposure risks.

  9. Using multiple bed load measurements: Toward the identification of bed dilation and contraction in gravel-bed rivers

    Science.gov (United States)

    Marquis, G. A.; Roy, A. G.

    2012-02-01

    This study examines bed load transport processes in a small gravel-bed river (Béard Creek, Québec) using three complementary methods: bed elevation changes between successive floods, bed activity surveys using tags inserted into the bed, and bed load transport rates from bed load traps. The analysis of 20 flood events capable of mobilizing bed material led to the identification of divergent results among the methods. In particular, bed elevation changes were not consistent with the bed activity surveys. In many cases, bed elevation changes were significant (1 to 2 times the D50) even if the bed surface had not been activated during the flood, leading to the identification of processes of bed dilation and contraction that occurred over 10% to 40% of the bed surface. These dynamics of the river bed prevent accurate derivation of bed load transport rates from topographic changes, especially for low magnitude floods. This paper discusses the mechanisms that could explain the dilation and contraction of particles within the bed and their implications in fluvial dynamics. Bed contraction seems to be the result of the winnowing of the fine sediments under very low gravel transport. Bed dilation seems to occur on patches of the bed at the threshold of motion where various processes such as fine sediment infiltration lead to the maintenance of a larger sediment framework volume. Both processes are also influenced by flood history and the initial local bed state and in turn may have a significant impact on sediment transport and morphological changes in gravel-bed rivers.

  10. Better backs by better beds?

    DEFF Research Database (Denmark)

    Bergholdt, Kim; Fabricius, Rasmus N; Bendix, Tom

    2008-01-01

    mattresses have a positive effect on LBP, and especially a hard mattress is commonly believed to have a positive effect. METHODS: One hundred sixty CLBP patients were randomized to 1 of 3 groups, having a mattress/bed mounted in their sleeping room for 1 month. The beds were: (1) waterbed (Akva), (2) body......-conforming foam mattress (Tempur), and (3) a hard mattress (Innovation Futon). At baseline and after 4 weeks, a blinded observer interviewed the patients on LBP levels (0-10), daily function (activities of daily living, 0-30), and on the amount of sleeping hours/night. RESULTS: Because of dropout of 19 patients...... using the probably most relevant "worst case" data. There were no relevant difference between the effects of the water bed and the foam bed. CONCLUSION: The Waterbed and foam mattress' did influence back symptoms, function and sleep more positively as apposed to the hard mattress, but the differences...

  11. Top Ten Bed Bug Tips

    Science.gov (United States)

    ... Directory Planning, Budget and Results Jobs and Internships Headquarters Offices Regional Offices Labs and Research Centers Bed ... you hire an expert, be sure it’s a company with a good reputation and request that it ...

  12. Torsion testing of bed joints

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg; Pedersen, Carsten Mørk

    2008-01-01

    This paper describes a simple test method for determining the torsion strength of a single bed joint between two bricks and presents results from testing using this test method. The setup for the torsion test is well defined, require minimal preparation of the test specimen and the test can...... be carried out directly in a normal testing machine. The torsion strength is believed to be the most important parameter in out-of-plane resistance of masonry walls subjected to bending about an axis perpendicular to the bed joints. The paper also contains a few test results from bending of small walls about...... an axis perpendicular to the bed joints, which indicate the close connection between these results and results from torsion tests. These characteristics make the torsion strength well suited to act as substitute parameter for the bending strength of masonry about an axis perpendicular to the bed joints....

  13. Sea bed mapping and inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  14. Pressured fluidized-bed gasification experiments with wood, peat and coal at VTT in 1991-1992. Test facilities and gasification experiments with sawdust

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E; Staahlberg, P; Laatikainen, J [Technical Research Centre of Finland, Espoo (Finland). Lab. of Fuel and Process Technology

    1994-12-31

    Fluidized-bed air gasification of Finnish pine saw dust was studied in the PDU-scale test facilities of VTT to support the development of simplified integrated gasification combined-cycle processes by providing new information on the formation and behaviour of different gas impurities in wood gasification. The gasifier was operated at 4-5 bar pressure and at 880-1 020 deg C Product gas was cleaned by ceramic candle filters operated at 490-715 deg C. Concentrations of tars, fixed nitrogen species and vapour-phase alkali metals were determined in different operating conditions. Carbon conversion exceeded 95 deg C in all test periods although the gasifier was operated without recycling the cyclone or filter fines back to the reactor. However, at the gasification temperature of 880-900 deg C more than 5 deg C of the wood carbon was converted to tars. The total concentration of tars (compounds heavier than benzene) was reduced from 6 000 to 3 000 mg/m{sup 3}n by increasing the gasification temperature from 880 deg C to 1 000 deg C. The expected catalytic effects of calcium on tar decomposition could not be achieved in these experiments by feeding coarse dolomite into the bed. The use of sand or aluminium oxide as an inert bed material did neither lead to any decrease in tar concentrations. However, the tar concentrations were dramatically reduced in the cogasification experiments, when a mixture of approximately 50 deg C/50 deg C wood and coal was used as the feed stock. Wood nitrogen was mainly converted into ammonia, while the concentrations of HCN and organic nitrogen containing compounds were very low

  15. Pressured fluidized-bed gasification experiments with wood, peat and coal at VTT in 1991-1992. Test facilities and gasification experiments with sawdust

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Staahlberg, P.; Laatikainen, J. [Technical Research Centre of Finland, Espoo (Finland). Lab. of Fuel and Process Technology

    1993-12-31

    Fluidized-bed air gasification of Finnish pine saw dust was studied in the PDU-scale test facilities of VTT to support the development of simplified integrated gasification combined-cycle processes by providing new information on the formation and behaviour of different gas impurities in wood gasification. The gasifier was operated at 4-5 bar pressure and at 880-1 020 deg C Product gas was cleaned by ceramic candle filters operated at 490-715 deg C. Concentrations of tars, fixed nitrogen species and vapour-phase alkali metals were determined in different operating conditions. Carbon conversion exceeded 95 deg C in all test periods although the gasifier was operated without recycling the cyclone or filter fines back to the reactor. However, at the gasification temperature of 880-900 deg C more than 5 deg C of the wood carbon was converted to tars. The total concentration of tars (compounds heavier than benzene) was reduced from 6 000 to 3 000 mg/m{sup 3}n by increasing the gasification temperature from 880 deg C to 1 000 deg C. The expected catalytic effects of calcium on tar decomposition could not be achieved in these experiments by feeding coarse dolomite into the bed. The use of sand or aluminium oxide as an inert bed material did neither lead to any decrease in tar concentrations. However, the tar concentrations were dramatically reduced in the cogasification experiments, when a mixture of approximately 50 deg C/50 deg C wood and coal was used as the feed stock. Wood nitrogen was mainly converted into ammonia, while the concentrations of HCN and organic nitrogen containing compounds were very low

  16. Dispersion of Bed Load Particles

    OpenAIRE

    SAWAI, Kenji

    1987-01-01

    The motion of bed load particles is so irregular that they disperse remarkably with time.In this study, some flume tests using painted tracer particles were carried out, in which thedispersive property of tracers changed variously with sediment feed rate.In analysing this process, a stochastic simulation model is proposed where it is discussedabout the degree of exposure of individual particle near the bed surface and about the variationof its pick up rate. The exponential distribution of ste...

  17. Comparison between externally fired gas turbine and gasifier-gas turbine system for the olive oil industry

    International Nuclear Information System (INIS)

    Vera, D.; Jurado, F.; Mena, B. de; Schories, G.

    2011-01-01

    The olive oil industry generates during the extraction process several solid wastes as olive tree leaves and prunings, exhausted pomace and olive pits. These renewable wastes could be used for power and heat applications. The aim of this paper is to compare the performance of two small-scale CHP systems: a gasification- gas turbine system and an EFGT (externally fired gas turbine system). For this reason, several parameters have been calculated: generated heat and power, electric and overall efficiencies, biomass consumption, exergy efficiency, optimum pressure ratio, etc. These systems provide 30 kW e and about 60kW th . Simulation results show that the electrical and overall efficiencies achieved in EFGT system (19.1% and 59.3%, respectively) are significantly higher than those obtained in the gasification plant (12.3% and 45.4%). The proposed CHP systems have been modeled using Cycle-Tempo ® software. -- Highlights: ► Comparison between externally fired gas turbine and gasifier-gas turbine system. ► Olive oil industry generates several solid wastes as olive tree leaves and prunings. ► Thermodynamic parameters have been calculated. ► Systems have been modeled using Cycle-Tempo ® software. ► Simulation results show electrical and overall efficiencies achieved in the systems.

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

    International Nuclear Information System (INIS)

    Mann, M.K.

    1995-08-01

    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

  19. 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.

  20. 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.

  1. Heat transfer to immersed horizontal tubes in gas fluidized bed dryers

    Energy Technology Data Exchange (ETDEWEB)

    Jonassen, Ola

    1999-10-01

    The main objective of this study was to construct heat pump fluidized bed dryers of the FHT type with improved dewatering capacity for a given size of the dryer. The use of heat exchangers immersed in the fluidized bed drying chambers is an important part of the FHT (Fluidized Bed High Temperature Heat Pump Dryer) concept. A pilot plant FHT dryer was built and successfully tested on fish meal raw material and seaweed. The plant included two fluidized bed drying chambers with immersed heat exchangers. The gain in water vapor of the drying air through the chambers was increased up to four times that of adiabatic drying. The energy saving concept was retained as a SMER ratio of 3.5 to 4.7 was measured in the same tests. Therefore optimization of the immersed heat exchangers was considered the most important single objective for this work. The optimization study of the heat exchangers was confined to the actual operating conditions for the dryers using: (1) Bubbling gas fluidized beds were used, (2) air as the only type of fluidising gas, (3) beds at atmospheric pressure, (4) bed temperatures below 100 {sup o}C, (5) fluidized particles of Geldart classes B and D, (6) horizontal tube banks for the immersed heat exchanger, and the influence of radiation heat transfer was ignored. The heat transfer study was confined to the fluidized bed side of the heat exchanger surface. It was concluded early in this work that the bubbles play a major role in generating the particle circulation inside the bed and hence also in heat transfer. Publications describing the most important bubble induced mechanisms contributing to high rates of heat transfer were found to be limited. Therefore the first part of this study was aimed at establishing a method for locating and measuring the size and rise velocity of bubbles inside the bed. The method established through this work using differential pressure measurements from two static pressure probes was used later in the study of heat transfer

  2. Utility of Recycled Bedding for Laboratory Rodents

    OpenAIRE

    Miyamoto, Toru; Li, Zhixia; Kibushi, Tomomi; Okano, Shinya; Yamasaki, Nakamichi; Kasai, Noriyuki

    2009-01-01

    Animal facilities generate a large amount of used bedding containing excrement as medical waste. We developed a recycling system for used bedding that involves soft hydrothermal processing. In this study, we examined the effects of bedding type on growth, hematologic and serum biochemical values, and organ weights of female and male mice reared on either recycled or fresh bedding from 3 to 33 wk of age. Neither growth nor physiology differed between mice housed on recycled bedding compared wi...

  3. Fluid bed porosity equation for an inverse fluidized bed bioreactor with particles growing biofilm

    International Nuclear Information System (INIS)

    Campos-Diaz, K. E.; Limas-Ballesteros, R.

    2009-01-01

    Fluid Bed Bioreactor performance is strongly affected by bed void fraction or bed porosity fluctuations. Particle size enlargement due to biofilm growth is an important factor that is involved in these variations and until now there are no mathematical equations that consider biofilm growth. In this work a mathematical equation is proposed to calculate bed void fraction in an inverse fluid bed bioreactor. (Author)

  4. Experimental study of the drying in dense fluidized beds of a synthetic mud coated with support particulates; Etude experimentale du sechage en lit fluidise dense d'une boue synthetique enrobee sur des particules supports

    Energy Technology Data Exchange (ETDEWEB)

    Gode, C.; Shakourzadeh, K. [Universite de Technologie de Compiegne, L.G.P.I., 60 (France)

    2001-07-01

    This article presents the results of an experimental study of a new drying process for muddy materials and based on the fluidization technique. The granular phase has been obtained by the coating with mud of a porous mineral support, inert and recyclable in the process. Activated porous particulates of alumina (2-5 mm) have been chosen because of their heat transfer properties. A first part of the experimental study concerns the drying process. The second part concerns the attrition and elutriation mechanisms. The experimental measurements have been performed with a laboratory fluidized column (internal diameter = 150 mm) and with a fluidized column (internal diameter = 400 mm) from a semi-industrial facility. The air velocity and the drying temperature are the main adjustment parameters. The working temperatures have been fixed between 20 and 150 deg. C. (J.S.)

  5. Clinical physiology of bed rest

    Science.gov (United States)

    Greenleaf, John E.

    1993-01-01

    Maintenance of optimal health in humans requires the proper balance between exercise, rest, and sleep as well as time in the upright position. About one-third of a lifetime is spent sleeping; and it is no coincidence that sleeping is performed in the horizontal position, the position in which gravitational influence on the body is minimal. Although enforced bed rest is necessary for the treatment of some ailments, in some cases it has probably been used unwisely. In addition to the lower hydrostatic pressure with the normally dependent regions of the cardiovascular system, body fuid compartments during bed rest in the horizontal body position, and virtual elimination of compression on the long bones of the skeletal system during bed rest (hypogravia), there is often reduction in energy metabolism due to the relative confinement (hypodynamia) and alteration of ambulatory circadian variations in metabolism, body temperature, and many hormonal systems. If patients are also moved to unfamiliar surroundings, they probably experience some feelings of anxiety and some sociopsychological problems. Adaptive physiological responses during bed rest are normal for that environment. They are attempts by the body to reduce unnecessary energy expenditure, to optimize its function, and to enhance its survival potential. Many of the deconditioning responses begin within the first day or two of bed rest; these early responses have prompted physicians to insist upon early resumption of the upright posture and ambulation of bedridden patients.

  6. 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.)

  7. FY 1989 report on the results of the development of the entrained bed coal gasification power plant. Part 3. Fabrication/installation of pilot plant (Fabrication/installation drawings and fabrication/installation pictures - 1/2); 1989 nendo seika hokokusho. Funryusho sekitan gaska hatsuden plant kaihatsu - Sono 3. Pilot plant seisaku suetsuke hen (Seisaku suetsukezu oyobi seisaku suetsuke shashin) (1/2)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-03-01

    For the purpose of establishing the technology of the integrated coal gasification combined cycle power generation, the fabrication, installation work, etc. were conducted of a 200t/d entrained bed coal gasification pilot plant, and drawings of fabrication/installation in the FY 1989 were summarized. In fabrication/installation drawings, drawings of the following were included: layout of the total system and the yard, gasifier facilities (assembly drawing of the pressure part of gasifier, drawing of machinery arrangement of gasifier facilities, system diagram of raw coal receiving device, system diagram of pulverized coal feed equipment, system diagram of char feed equipment, etc.), gas refining facilities - dry desulfurizer (assembly drawing of desulfurizing agent carrying filter, assembly drawing of regeneration tower filter, structural drawing of SO{sub 2} reduction tower filter, assembly drawing of start-up heater, etc.), gas refining facilities - dry dust removal system (assembly drawing of No.1 dust separation filter, installation drawing of elevator, etc.), gas turbine facilities (cross section of gas turbine, front view of gas turbine, structural cross section of gas turbogenerator, etc.), actual-pressure/actual-size combustor test equipment (structural drawing of test stand, structural drawing of exhaust temperature reduction device, assembly/sectioned drawing of low-pressure air compressor, etc.) (NEDO)

  8. Particle Bed Reactor scaling relationships

    International Nuclear Information System (INIS)

    Slovik, G.; Araj, K.; Horn, F.L.; Ludewig, H.; Benenati, R.

    1987-01-01

    Scaling relationships for Particle Bed Reactors (PBRs) are discussed. The particular applications are short duration systems, i.e., for propulsion or burst power. Particle Bed Reactors can use a wide selection of different moderators and reflectors and be designed for such a wide range of power and bed power densities. Additional design considerations include the effect of varying the number of fuel elements, outlet Mach number in hot gas channel, etc. All of these variables and options result in a wide range of reactor weights and performance. Extremely light weight reactors (approximately 1 kg/MW) are possible with the appropriate choice of moderator/reflector and power density. Such systems are very attractive for propulsion systems where parasitic weight has to be minimized

  9. Fluidized-bed nuclear reactor

    International Nuclear Information System (INIS)

    Grimmett, E.S.; Kunze, J.F.

    1975-01-01

    A reactor vessel containing a fluidized-bed region of particulate material including both a neutron-moderating and a fertile substance is described. A gas flow including fissile material passes through the vessel at a sufficient rate to fluidize the particulate material and at a sufficient density to support a thermal fission reaction within the fluidized-bed region. The high-temperature portion of a heat transfer system is located within the fluidized-bed region of the reactor vessel in direct contact with the fluidized particles. Heat released by fission is thereby transferred at an enhanced rate to a coolant circulating within the heat transfer system. Fission products are continuously removed from the gas flow and supplemental fissile material added during the reactor operation. (U.S.)

  10. On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kristie Cooper; Gary Pickrell; Anbo Wang

    2005-11-01

    This report summarizes technical progress April-September 2005 on the Phase II program ''On-Line Self-Calibrating Single Crystal Sapphire Optical Sensor Instrumentation for Accurate and Reliable Coal Gasifier Temperature Measurement'', funded by the Federal Energy Technology Center of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. The objective of this program is to bring the sensor technology, which has already been demonstrated in the laboratory, to a level where the sensor can be deployed in the harsh industrial environments and will become commercially viable. Due to the difficulties described on the last report, field testing of the BPDI system has not continued to date. However, we have developed an alternative high temperature sensing solution, which is described in this report. The sensing system will be installed and tested at TECO's Polk Power Station. Following a site visit in June 2005, our efforts have been focused on preparing for that field test, including he design of the sensor mechanical packaging, sensor electronics, the data transfer module, and the necessary software codes to accommodate this application.. We are currently ready to start sensor fabrication.

  11. Prediction of bed level variations in nonuniform sediment bed channel

    Indian Academy of Sciences (India)

    B R Andharia

    2018-04-12

    Apr 12, 2018 ... A fully-coupled 1D mobile-bed model (CAR-. ICHAR) was introduced ...... for sediment trap, water level sensor, tail gate operated by lever arm at .... materials were brought back to upstream to feed the same through sediment ...

  12. FY 1991 report on the results of the development of an entrained bed coal gasification power plant. Part 1. Support study for the development of an entrained bed coal gasification power plant (Dismantling study); 1991 nendo seika hokokusho. Funryusho sekitan gaska hatsuden plant kaihatsu (Funryusho sekitan gaska hatsuden plant kaihatsu no shien kenkyu) - Sono 1. Kaitai kenkyu hen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-04-01

    As a support study for the development of an entrained bed coal gasification power plant by a 200 t/d pilot plant, the dismantling study was made for gasifier facilities, desulfurization facilities, dedusting facilities at the existing 40 t/d testing facilities. In the results of the analysis of the specimens sampled from gasifier and peripheral facilities, the corrosion loss of thickness was great in carbon steel/low-alloy steel equipment, and the generation of intergranular corrosion/intergranular crack was recognized in stainless steel equipment. The loss of thickness caused by erosion was also recognized in carrier tubes, etc. As to the high-temperature dry desulfurization system, the damage was totally great, but the effect of taking measures for it was unclear because the loss of thickness by corrosion/abrasion had not been measured regularly. Relating to the high-temperature dry dedusting system, there used to be a lot of troubles from stress corrosion cracking and pitting corrosion, and the best measures for corrosion prevention were taken for each trouble. As to the Al thermal spraying, stabilized thermal treatment, shot-peening, etc., the excellent corrosion prevention effect was recognized on the austenite stainless steel. (NEDO)

  13. Adiabatic Fixed-Bed Gasification of Colombian Coffee Husk Using Air-Steam Blends for Partial Oxidation

    Directory of Open Access Journals (Sweden)

    Javier Bonilla

    2017-01-01

    Full Text Available The increasing energy consumption, mostly supplied by fossil fuels, has motivated the research and development of alternative fuel technologies to decrease the humanity’s dependence on fossil fuels, which leads to pollution of natural sources. Small-scale biomass gasification, using air-steam blends for partial oxidation, is a good alternative since biomass is a neutral carbon feedstock for sustainable energy generation. This research presents results obtained from an experimental study on coffee husk (CH gasification, using air-steam blends for partial oxidation in a 10 kW fixed-bed gasifier. Parametric studies on equivalence ratio (ER (1.53 < ER < 6.11 and steam-fuel (SF ratio (0.23 < SF < 0.89 were carried out. The results show that increasing both SF and ER results in a syngas rich in CH4 and H2 but poor in CO. Also, decreased SF and ER decrease the peak temperature (Tpeak at the gasifier combustion zone. The syngas high heating value (HHV ranged from 3112 kJ/SATPm3 to 5085 kJ/SATPm3 and its maximum value was obtained at SF = 0.87 and ER = 4.09. The dry basis molar concentrations of the species, produced under those operating conditions (1.53 < ER < 6.11 and 0.23 < SF < 0.89, were between 1.12 and 4.1% for CH4, between 7.77 and 13.49% for CO, and between 7.54 and 19.07% for H2. Other species were in trace amount.

  14. Apparatus and process for controlling fluidized beds

    Science.gov (United States)

    Rehmat, Amirali G.; Patel, Jitendra G.

    1985-10-01

    An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

  15. Volatilisation of alkali and alkaline earth metallic species during the gasification of a Victorian brown coal in CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Quyn, Dimple Mody; Li, Chun-Zhu [CRC for Clean Power from Lignite, Department of Chemical Engineering, PO Box 36, Monash University, Victoria 3800 (Australia); Hayashi, Jun-ichiro [Centre for Advanced Research of Energy Conversion Materials, Hokkaido University, N13-W8, Kita-ku, Sapporo 060-8628 (Japan)

    2005-08-25

    A Victorian brown coal was gasified in a bench-scale quartz fluidised-bed/fixed-bed reactor in order to study the volatilisation of Na, Ca, and Mg during devolatilisation and gasification and their roles in the reactivity of chars. It was found that the majority of Na was volatilised at 900 {sup o}C under all conditions and that a Na retention limit was achieved in the char with the progress of CO{sub 2} gasification. In some cases, the presence of CO{sub 2} during devolatilisation enhanced the Na retention in the char. In contrast, the retention of Ca (and Mg) was unaffected by CO{sub 2} during devolatilisation at 900C but decreased drastically upon nascent char gasification. The fundamental differences in volatilisation between the alkali and alkaline earth metallic species are discussed in this paper.

  16. Energy generation by air gasification of two industrial plastic wastes in a pilot scale fluidized bed reactor

    International Nuclear Information System (INIS)

    Arena, Umberto; Di Gregorio, Fabrizio

    2014-01-01

    Two plastic wastes obtained as co-products from an industrial process were fed in a pilot-scale bubbling fluidized bed gasifier, having an internal diameter of 0.38 m and a maximum thermal output of about 400 kW. The experimental runs were carried out by reaching a condition of thermal and chemical steady state under values of equivalence ratio ranging from 0.2 to 0.3. Olivine, a neo-silicate of Fe and Mg, already tested as a good catalyst for tar removal during gasification of polyolefin plastic wastes, was used as bed material. The results provide the complete composition of the syngas, including the tar, particulate and acid/basic gas contents as well as the chemical and physical characterization of the bed material and entrained fines. The gasification process appears technically feasible, yielding a producer gas of valuable quality for energy applications in an appropriate plant configuration. On the other hand, under the experimental conditions tested, olivine particles show a strongly reduced catalytic activity in all the runs. The differences in the gasification behaviour of the two industrial plastics are explained on the basis of the structure and composition of the wastes, taking also into account the results of a combined material and substance flow analysis. - Highlights: • Pilot-scale investigation of fluidized bed gasification of two industrial plastic wastes. • Tests under conditions of thermal/chemical steady state at various equivalence ratios. • Complete composition of the producer gas, including tar, particulate and acid/basic gases. • Differences in the gasification behaviour of plastic wastes. • Material, substance, and feedstock energy flow analysis for different gasification tests

  17. Physiology Of Prolonged Bed Rest

    Science.gov (United States)

    Greenleaf, John E.

    1991-01-01

    Report describes physiological effects of prolonged bed rest. Rest for periods of 24 hours or longer deconditions body to some extent; healing proceeds simultaneously with deconditioning. Report provides details on shifts in fluid electrolytes and loss of lean body mass, which comprises everything in body besides fat - that is, water, muscle, and bone. Based on published research.

  18. How to Find Bed Bugs

    Science.gov (United States)

    Find and correctly identify an infestation early before it becomes widespread. Look for rusty or reddish stains and pinpoint dark spots on bed sheets or mattresses, and search for bugs near the piping, seams and tags of the mattress and box spring.

  19. The NASA Bed Rest Project

    Science.gov (United States)

    Rhodes, Bradley; Meck, Janice

    2005-01-01

    NASA s National Vision for Space Exploration includes human travel beyond low earth orbit and the ultimate safe return of the crews. Crucial to fulfilling the vision is the successful and timely development of countermeasures for the adverse physiological effects on human systems caused by long term exposure to the microgravity environment. Limited access to in-flight resources for the foreseeable future increases NASA s reliance on ground-based analogs to simulate these effects of microgravity. The primary analog for human based research will be head-down bed rest. By this approach NASA will be able to evaluate countermeasures in large sample sizes, perform preliminary evaluations of proposed in-flight protocols and assess the utility of individual or combined strategies before flight resources are requested. In response to this critical need, NASA has created the Bed Rest Project at the Johnson Space Center. The Project establishes the infrastructure and processes to provide a long term capability for standardized domestic bed rest studies and countermeasure development. The Bed Rest Project design takes a comprehensive, interdisciplinary, integrated approach that reduces the resource overhead of one investigator for one campaign. In addition to integrating studies operationally relevant for exploration, the Project addresses other new Vision objectives, namely: 1) interagency cooperation with the NIH allows for Clinical Research Center (CRC) facility sharing to the benefit of both agencies, 2) collaboration with our International Partners expands countermeasure development opportunities for foreign and domestic investigators as well as promotes consistency in approach and results, 3) to the greatest degree possible, the Project also advances research by clinicians and academia alike to encourage return to earth benefits. This paper will describe the Project s top level goals, organization and relationship to other Exploration Vision Projects, implementation

  20. The development of an integrated multistaged fluid-bed retorting process. Final report, September 1990--August 1994

    Energy Technology Data Exchange (ETDEWEB)

    Carter, S.D.; Taulbee, D.N.; Stehn, J.L.; Vego, A.; Robl, T.L.

    1995-02-01

    This summarizes the development of the KENTORT II retorting process, which includes integral fluidized bed zones for pyrolysis, gasification, and combustion of oil shale. Purpose was to design and test the process at the 50-lb/hr scale. The program included bench- scale studies of coking and cracking reactions of shale oil vapors over processed shale particles to address issues of scaleup associated with solid-recycle retorting. The bench-scale studies showed that higher amounts of carbon coverage reduce the rate of subsequent carbon deposition by shale oil vapors onto processed shale particles; however carbon-covered materials were also active in terms of cracking and coking. Main focus was the 50-lb/hr KENTORT II PDU. Cold-flow modeling and shakedown were done before the PDU was made ready for operation. Seven mass-balanced, steady-state runs were completed within the window of design operating conditions. Goals were achieved: shale feedrate, run duration (10 hr), shale recirculation rates (4:1 to pyrolyzer and 10:1 to combustor), bed temperatures (pyrolyzer 530{degree}C, gasifier 750{degree}C, combustor 830{degree}C), and general operating stability. Highest oil yields (up to 109% of Fischer assay) were achieved for runs lasting {ge} 10 hours. High C content of the solids used for heat transfer to the pyrolysis zone contributed to the enhanced oil yield achieved.