WorldWideScience

Sample records for biomass gas steam

  1. Parametric Optimization of Biomass Steam-and-Gas Plant

    Directory of Open Access Journals (Sweden)

    V. Sednin

    2013-01-01

    Full Text Available The paper contains a parametric analysis of the simplest scheme of a steam-and gas plant for the conditions required for biomass burning. It has been shown that application of gas-turbine and steam-and-gas plants can significantly exceed an efficiency of steam-power supply units which are used at the present moment. Optimum thermo-dynamical conditions for application of steam-and gas plants with the purpose to burn biomass require new technological solutions in the field of heat-exchange equipment designs.

  2. 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

  3. Hydrogen production from biomass pyrolysis gas via high temperature steam reforming process

    International Nuclear Information System (INIS)

    Wongchang, Thawatchai; Patumsawad, Suthum

    2010-01-01

    Full text: The aim of this work has been undertaken as part of the design of continuous hydrogen production using the high temperature steam reforming process. The steady-state test condition was carried out using syngas from biomass pyrolysis, whilst operating at high temperatures between 600 and 1200 degree Celsius. The main reformer operating parameters (e.g. temperature, resident time and steam to biomass ratio (S/B)) have been examined in order to optimize the performance of the reformer. The operating temperature is a key factor in determining the extent to which hydrogen production is increased at higher temperatures (900 -1200 degree Celsius) whilst maintaining the same as resident time and S/B ratio. The effects of exhaust gas composition on heating value were also investigated. The steam reforming process produced methane (CH 4 ) and ethylene (C 2 H 4 ) between 600 to 800 degree Celsius and enhanced production ethane (C 2 H 6 ) at 700 degree Celsius. However carbon monoxide (CO) emission was slightly increased for higher temperatures all conditions. The results show that the use of biomass pyrolysis gas can produce higher hydrogen production from high temperature steam reforming. In addition the increasing reformer efficiency needs to be optimized for different operating conditions. (author)

  4. Hydrogen from biomass gas steam reforming for low temperature fuel cell: energy and exergy analysis

    Directory of Open Access Journals (Sweden)

    A. Sordi

    2009-03-01

    Full Text Available This work presents a method to analyze hydrogen production by biomass gasification, as well as electric power generation in small scale fuel cells. The proposed methodology is the thermodynamic modeling of a reaction system for the conversion of methane and carbon monoxide (steam reforming, as well as the energy balance of gaseous flow purification in PSA (Pressure Swing Adsorption is used with eight types of gasification gases in this study. The electric power is generated by electrochemical hydrogen conversion in fuel cell type PEMFC (Proton Exchange Membrane Fuel Cell. Energy and exergy analyses are applied to evaluate the performance of the system model. The simulation demonstrates that hydrogen production varies with the operation temperature of the reforming reactor and with the composition of the gas mixture. The maximum H2 mole fraction (0.6-0.64 mol.mol-1 and exergetic efficiency of 91- 92.5% for the reforming reactor are achieved when gas mixtures of higher quality such as: GGAS2, GGAS4 and GGAS5 are used. The use of those gas mixtures for electric power generation results in lower irreversibility and higher exergetic efficiency of 30-30.5%.

  5. Thermodynamic simulation of biomass gas steam reforming for a solid oxide fuel cell (SOFC system

    Directory of Open Access Journals (Sweden)

    A. Sordi

    2009-12-01

    Full Text Available This paper presents a methodology to simulate a small-scale fuel cell system for power generation using biomass gas as fuel. The methodology encompasses the thermodynamic and electrochemical aspects of a solid oxide fuel cell (SOFC, as well as solves the problem of chemical equilibrium in complex systems. In this case the complex system is the internal reforming of biomass gas to produce hydrogen. The fuel cell input variables are: operational voltage, cell power output, composition of the biomass gas reforming, thermodynamic efficiency, electrochemical efficiency, practical efficiency, the First and Second law efficiencies for the whole system. The chemical compositions, molar flows and temperatures are presented to each point of the system as well as the exergetic efficiency. For a molar water/carbon ratio of 2, the thermodynamic simulation of the biomass gas reforming indicates the maximum hydrogen production at a temperature of 1070 K, which can vary as a function of the biomass gas composition. The comparison with the efficiency of simple gas turbine cycle and regenerative gas turbine cycle shows the superiority of SOFC for the considered electrical power range.

  6. Integrated gasification combined cycle and steam injection gas turbine powered by biomass joint-venture evaluation

    International Nuclear Information System (INIS)

    Sterzinger, G.J.

    1994-05-01

    This report analyzes the economic and environmental potential of biomass integrated gasifier/gas turbine technology including its market applications. The mature technology promises to produce electricity at $55--60/MWh and to be competitive for market applications conservatively estimated at 2000 MW. The report reviews the competitiveness of the technology of a stand-alone, mature basis and finds it to be substantial and recognized by DOE, EPRI, and the World Bank Global Environmental Facility

  7. The study of reactions influencing the biomass steam gasification process

    Energy Technology Data Exchange (ETDEWEB)

    C. Franco; F. Pinto; I. Gulyurtlu; I. Cabrita [INETI-DEECA, Lisbon (Portugal)

    2003-05-01

    Steam gasification studies were carried out in an atmospheric fluidised bed. The gasifier was operated over a temperature range of 700 900{sup o}C whilst varying a steam/biomass ratio from 0.4 to 0.85 w/w. Three types of forestry biomass were studied: Pinus pinaster (softwood), Eucalyptus globulus and holm-oak (hardwood). The energy conversion, gas composition, higher heating value and gas yields were determined and correlated with temperature, steam/biomass ratio, and species of biomass used. The results obtained seemed to suggest that the operating conditions were optimised for a gasification temperature around 830{sup o}C and a steam/biomass ratio of 0.6 0.7 w/w, because a gas richer in hydrogen and poorer in hydrocarbons and tars was produced. These conditions also favoured greater energy and carbon conversions, as well the gas yield. The main objective of the present work was to determine what reactions were dominant within the operation limits of experimental parameters studied and what was the effect of biomass type on the gasification process. As biomass wastes usually have a problem of availability because of seasonal variations, this work analysed the possibility of replacing one biomass species by another, without altering the gas quality obtained. 19 refs., 8 figs. 2 tabs.

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

    NARCIS (Netherlands)

    Siedlecki, M.

    2011-01-01

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

  9. Development of biomass gasification systems for gas turbine power generation

    International Nuclear Information System (INIS)

    Larson, E.D.; Svenningsson, P.

    1991-01-01

    Gas turbines are of interest for biomass applications because, unlike steam turbines, they have relatively high efficiencies and low unit capital costs in the small sizes appropriate for biomass installations. Gasification is a simple and efficient way to make biomass usable in gas turbines. The authors evaluate here the technical requirements for gas turbine power generation with biomass gas and the status of pressurized biomass gasification and hot gas cleanup systems. They also discuss the economics of gasifier-gas turbine cycles and make some comparisons with competing technologies. Their analysis indicates that biomass gasifiers fueling advanced gas turbines are promising for cost-competitive cogeneration and central station power generation. Gasifier-gas turbine systems are not available commercially, but could probably be developed in 3 to 5 years. Extensive past work related to coal gasification and pressurized combustion of solid fuels for gas turbines would be relevant in this effort, as would work on pressurized biomass gasification for methanol synthesis

  10. Energy efficient thermochemical conversion of very wet biomass to biofuels by integration of steam drying, steam electrolysis and gasification

    DEFF Research Database (Denmark)

    Clausen, Lasse Røngaard

    2017-01-01

    A novel system concept is presented for the thermochemical conversion of very wet biomasses such as sewage sludge and manure. The system integrates steam drying, solid oxide electrolysis cells (SOEC) and gasification for the production of synthetic natural gas (SNG). The system is analyzed...

  11. Gasification of biomass chars in steam-nitrogen mixture

    International Nuclear Information System (INIS)

    Haykiri-Acma, H.; Yaman, S.; Kucukbayrak, S.

    2006-01-01

    Some agricultural and waste biomass samples such as sunflower shell, pinecone, rapeseed, cotton refuse and olive refuse were first pyrolyzed in nitrogen, and then, their chars were gasified in a gas mixture of steam and nitrogen. Experiments were performed using the thermogravimetric analysis technique. Pyrolysis of the biomass samples was performed at a heating rate of 20 K/min from ambient to 1273 K in a dynamic nitrogen atmosphere of 40 cm 3 min -1 . The obtained chars were cooled to ambient temperature and then gasified up to 1273 K in a dynamic atmosphere of 40 cm 3 min -1 of a mixture of steam and nitrogen. Derivative thermogravimetric analysis profiles from gasification of the chars were derived, and the mass losses from the chars were interpreted in terms of temperature. It was concluded that gasification characteristics of biomass chars were fairly dependent on the biomass properties such as ash and fixed carbon contents and the constituents present in the ash. Different mechanisms in the three temperature intervals, namely water desorption at lower temperatures, decomposition of hydroxide minerals to oxide minerals and formation of carbon monoxide at medium temperatures and production of hydrogen at high temperatures govern the behavior of the char during the gasification process. The chars from pinecone and sunflower shell could be easily gasified under the mentioned conditions. In order to further raise the conversion yields, long hold times should be applied at high temperatures. However, the chars from rapeseed and olive refuse were not gasified satisfactorily. Low ash content and high fixed carbon content biomass materials are recommended for use in gasification processes when char from pyrolysis at elevated temperatures is used as a feedstock

  12. Steam gasification of plant biomass using molten carbonate salts

    International Nuclear Information System (INIS)

    Hathaway, Brandon J.; Honda, Masanori; Kittelson, David B.; Davidson, Jane H.

    2013-01-01

    This paper explores the use of molten alkali-carbonate salts as a reaction and heat transfer medium for steam gasification of plant biomass with the objectives of enhanced heat transfer, faster kinetics, and increased thermal capacitance compared to gasification in an inert gas. The intended application is a solar process in which concentrated solar radiation is the sole source of heat to drive the endothermic production of synthesis gas. The benefits of gasification in a molten ternary blend of lithium, potassium, and sodium carbonate salts is demonstrated for cellulose, switchgrass, a blend of perennial plants, and corn stover through measurements of reaction rate and product composition in an electrically heated reactor. The feedstocks are gasified with steam at 1200 K in argon and in the molten salt. The use of molten salt increases the total useful syngas production by up to 25%, and increases the reactivity index by as much as 490%. Secondary products, in the form of condensable tar, are reduced by 77%. -- Highlights: ► The presence of molten salt increases the rate of gasification by up to 600%. ► Reaction rates across various feedstocks are more uniform with salt present. ► Useful syngas yield is increased by up to 30% when salt is present. ► Secondary production of liquid tars are reduced by 77% when salt is present.

  13. Evaluation of Hybrid Power Plants using Biomass, Photovoltaics and Steam Electrolysis for Hydrogen and Power Generation

    Science.gov (United States)

    Petrakopoulou, F.; Sanz, J.

    2014-12-01

    Steam electrolysis is a promising process of large-scale centralized hydrogen production, while it is also considered an excellent option for the efficient use of renewable solar and geothermal energy resources. This work studies the operation of an intermediate temperature steam electrolyzer (ITSE) and its incorporation into hybrid power plants that include biomass combustion and photovoltaic panels (PV). The plants generate both electricity and hydrogen. The reference -biomass- power plant and four variations of a hybrid biomass-PV incorporating the reference biomass plant and the ITSE are simulated and evaluated using exergetic analysis. The variations of the hybrid power plants are associated with (1) the air recirculation from the electrolyzer to the biomass power plant, (2) the elimination of the sweep gas of the electrolyzer, (3) the replacement of two electric heaters with gas/gas heat exchangers, and (4) the replacement two heat exchangers of the reference electrolyzer unit with one heat exchanger that uses steam from the biomass power plant. In all cases, 60% of the electricity required in the electrolyzer is covered by the biomass plant and 40% by the photovoltaic panels. When comparing the hybrid plants with the reference biomass power plant that has identical operation and structure as that incorporated in the hybrid plants, we observe an efficiency decrease that varies depending on the scenario. The efficiency decrease stems mainly from the low effectiveness of the photovoltaic panels (14.4%). When comparing the hybrid scenarios, we see that the elimination of the sweep gas decreases the power consumption due to the elimination of the compressor used to cover the pressure losses of the filter, the heat exchangers and the electrolyzer. Nevertheless, if the sweep gas is used to preheat the air entering the boiler of the biomass power plant, the efficiency of the plant increases. When replacing the electric heaters with gas-gas heat exchangers, the

  14. Integration of mixed conducting membranes in an oxygen–steam biomass gasification process

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Soprani, Stefano; Søgaard, Martin

    2013-01-01

    . The two configurations demonstrating the highest efficiency are then thermally integrated into an oxygen– steam biomass gasification plant. The energy demand for oxygen production and the membrane area required for a 6 MWth biomass plant are calculated for different operating conditions. Increasing......Oxygen–steam biomass gasification produces a high quality syngas with a high H2/CO ratio that is suitable for upgrading to liquid fuels. Such a gas is also well suited for use in conjunction with solid oxide fuel cells giving rise to a system yielding high electrical efficiency based on biomass...... distillation, especially for small to medium scale plants. This paper examines different configurations for oxygen production using MIEC membranes where the oxygen partial pressure difference is achieved by creating a vacuum on the permeate side, compressing the air on the feed side or a combination of the two...

  15. Production of hydrogen from biomass by catalytic steam reforming of fast pyrolysis oil

    Energy Technology Data Exchange (ETDEWEB)

    Czernik, S.; Wang, D.; Chornet, E. [National Renewable Energy Lab., Golden, CO (United States). Center for Renewable Chemical Technologies and Materials

    1998-08-01

    Hydrogen is the prototype of the environmentally cleanest fuel of interest for power generation using fuel cells and for transportation. The thermochemical conversion of biomass to hydrogen can be carried out through two distinct strategies: (a) gasification followed by water-gas shift conversion, and (b) catalytic steam reforming of specific fractions derived from fast pyrolysis and aqueous/steam processes of biomass. This paper presents the latter route that begins with fast pyrolysis of biomass to produce bio-oil. This oil (as a whole or its selected fractions) can be converted to hydrogen via catalytic steam reforming followed by a water-gas shift conversion step. Such a process has been demonstrated at the bench scale using model compounds, poplar oil aqueous fraction, and the whole pyrolysis oil with commercial Ni-based steam reforming catalysts. Hydrogen yields as high as 85% have been obtained. Catalyst initial activity can be recovered through regeneration cycles by steam or CO{sub 2} gasification of carbonaceous deposits.

  16. Biomass steam gasification for production of SNG – Process design and sensitivity analysis

    International Nuclear Information System (INIS)

    Gröbl, Thomas; Walter, Heimo; Haider, Markus

    2012-01-01

    Highlights: ► A model for the SNG-production process from biomass to raw-SNG is prepared. ► A thermodynamic equilibrium model of the Biomass-Heatpipe-Reformer is developed. ► A sensitivity analysis on the most important operation parameters is carried out. ► Adopting the steam excess ratio a syngas ideally suitable for SNG production is generated. ► Thermodynamic equilibrium models are a useful tool for process design. -- Abstract: A process design for small-scale production of Substitute Natural Gas (SNG) by steam gasification of woody biomass is performed. In the course of this work, thermodynamic models for the novel process steps are developed and implemented into an already existing model library of commercial process simulation software IPSEpro. Mathematical models for allothermal steam gasification of biomass as well as for cleaning and methanation of product gas are provided by applying mass balances, energy balances and thermodynamic equilibrium equations. Using these models the whole process is integrated into the simulation software, a flowsheet for an optimum thermal integration of the single process steps is determined and energy savings are identified. Additionally, a sensitivity study is carried out in order to analyze the influence of various operation parameters. Their effects on amount and composition of the product gas and process efficiency are evaluated and discussed within this article.

  17. Synthesis gas production via hybrid steam reforming of natural gas and bio-liquids

    OpenAIRE

    Balegedde Ramachandran, P.

    2013-01-01

    This thesis deals with (catalytic) steam reforming of bio-liquids for the production of synthesis gas. Glycerol, both crude from the biodiesel manufacturing and refined, and pyrolysis oil are tested as bio-based feedstocks. Liquid bio-based feeds could be preferred over inhomogeneous fibrous solid biomass because of their logistic advantages, better mineral balance, and better processability. Especially the ease of pressurization, which is required for large scale synthesis gas production, is...

  18. Study of the Apparent Kinetics of Biomass Gasification Using High-Temperature Steam

    Energy Technology Data Exchange (ETDEWEB)

    Alevanau, Aliaksandr

    2010-10-15

    Among the latest achievements in gasification technology, one may list the development of a method to preheat gasification agents using switched ceramic honey combs. The best output from this technology is achieved with use of water steam as a gasification agent, which is heated up to 1600 deg C. The application of these temperatures with steam as a gasification agent provides a cleaner syngas (no nitrogen from air, cracked tars) and the ash melts into easily utilised glass-like sludge. High hydrogen content in output gas is also favourable for end-user applications.Among the other advantages of this technology is the presumable application of fixed-bed-type reactors fed by separately produced and preheated steam. This construction assumes relatively high steam flow rates to deliver the heat needed for endothermic reactions involving biomass. The biomass is to be heated uniformly and evenly in the volume of the whole reactor, providing easier and simpler control and operation in comparison to other types of reactors. To provide potential constructors and exploiters of these reactors with the kinetic data needed for the calculations of vital parameters for both reactor construction and exploitation, basic experimental research of high-temperature steam gasification of four types of industrially produced biomass has been conducted.Kinetic data have been obtained for straw and wood pellets, wood-chip charcoal and compressed charcoal of mixed origin

  19. Reaction Mechanism of Tar Evolution in Biomass Steam Gasification for Hydrogen Production

    International Nuclear Information System (INIS)

    Shingo Katayama; Masahiro Suzuki; Atsushi Tsutsumi

    2006-01-01

    Reaction mechanism of tar evolution in steam gasification of biomass was investigated with a continuous cross-flow moving bed type differential reactor, in which tar and gases can be fractionated according to reaction time. We estimated that time profile of tar and gas evolution in the gasification of cellulose, xylan, and lignin, and compared it with experimental product time profile of real biomass gasification. The experimental tar evolution rate is different from estimated tar evolution rate. The estimated tar evolution rate has a peak at 20 s. On the other hand, the experimental tar evolution rate at 20 s is little, and tar at initial stage includes more water-soluble and water-insoluble compounds. It can be concluded that in the real biomass steam gasification the evolution of tar from cellulose and lignin component was found to be precipitated by that from hemi-cellulose component. (authors)

  20. Hydrogen production from algal biomass via steam gasification.

    Science.gov (United States)

    Duman, Gozde; Uddin, Md Azhar; Yanik, Jale

    2014-08-01

    Algal biomasses were tested as feedstock for steam gasification in a dual-bed microreactor in a two-stage process. Gasification experiments were carried out in absence and presence of catalyst. The catalysts used were 10% Fe₂O₃-90% CeO₂ and red mud (activated and natural forms). Effects of catalysts on tar formation and gasification efficiencies were comparatively investigated. It was observed that the characteristic of algae gasification was dependent on its components and the catalysts used. The main role of the catalyst was reforming of the tar derived from algae pyrolysis, besides enhancing water gas shift reaction. The tar reduction levels were in the range of 80-100% for seaweeds and of 53-70% for microalgae. Fe₂O₃-CeO₂ was found to be the most effective catalyst. The maximum hydrogen yields obtained were 1036 cc/g algae for Fucus serratus, 937 cc/g algae for Laminaria digitata and 413 cc/g algae for Nannochloropsis oculata. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Biomass combustion gas turbine CHP

    Energy Technology Data Exchange (ETDEWEB)

    Pritchard, D.

    2002-07-01

    This report summarises the results of a project to develop a small scale biomass combustor generating system using a biomass combustor and a micro-gas turbine indirectly fired via a high temperature heat exchanger. Details are given of the specification of commercially available micro-turbines, the manufacture of a biomass converter, the development of a mathematical model to predict the compatibility of the combustor and the heat exchanger with various compressors and turbines, and the utilisation of waste heat for the turbine exhaust.

  2. Hydrogen production from biomass tar by catalytic steam reforming

    International Nuclear Information System (INIS)

    Yoon, Sang Jun; Choi, Young-Chan; Lee, Jae-Goo

    2010-01-01

    The catalytic steam reforming of model biomass tar, toluene being a major component, was performed at various conditions of temperature, steam injection rate, catalyst size, and space time. Two kinds of nickel-based commercial catalyst, the Katalco 46-3Q and the Katalco 46-6Q, were evaluated and compared with dolomite catalyst. Production of hydrogen generally increased with reaction temperature, steam injection rate and space time and decreased with catalyst size. In particular, zirconia-promoted nickel-based catalyst, Katalco 46-6Q, showed a higher tar conversion efficiency and shows 100% conversion even relatively lower temperature conditions of 600 deg. C. Apparent activation energy was estimated to 94 and 57 kJ/mol for dolomite and nickel-based catalyst respectively.

  3. Study on pore structure properties of steam activated biomass chars

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Tong; Lu, Fei; Wang, Qinchao; Lu, Ping [Nanjing Normal Univ. (China). School of Energy and Mechanical Engineering

    2013-07-01

    Wheat straw and rice husk chars were prepared in a fixed bed reactor at different pyrolysis temperatures (673, 873 and 1,073K) and different pyrolysis procedure. The steam activated chars were also prepared in a fixed bed reactor at the following conditions: activation temperature is 1,073K, the flow rate of N{sub 2} is 5L/min, and N{sub 2} and H{sub 2}O molar ratio is 1:1. The specific surface area, pore structure and micro-morphology of different kinds of prepared biomass chars were measured by NOVA1000e analysis instrument and JSM-5610LV scanning electron microscopy (SEM), respectively. Results indicated that the internal structure was improved significantly by steam activation through enlarging the specific surface area and enriching the porosity. The wheat straw char prepared by both rapid pyrolysis at 873K and activation by steam is better than others, whose DR surface area increases from 3.10 to 1099.99m{sup 2}/g. The N{sub 2} adsorption volume of steam activated biomass chars has been significant promoted.

  4. Assessment on steam gasification of municipal solid waste against biomass substrates

    International Nuclear Information System (INIS)

    Couto, Nuno Dinis; Silva, Valter Bruno; Rouboa, Abel

    2016-01-01

    Highlights: • Steam gasification as an alternative for MSW treatment was studied. • A previously developed numerical model for MSW gasification was used. • Results were validated with data gathered from the literature. • Results were compared with previously studied biomass substrates. • Environment and economic assessment based on the results was conducted. - Abstract: Waste management is becoming one of the main concerns of our time. Not only does it takes up one of the largest portions of municipal budgets but it also entails extensive land use and pollution to the environment using current treatment methods. Steam gasification of Portuguese municipal solid wastes was studied using a previously developed computational fluid dynamics (CFD) model, and experimental and numerical results were found to be in agreement. To assess the potential of Portuguese wastes, these results were compared to those obtained from previously investigated Portuguese biomass substrates and steam-to-biomass ratio was used to characterize and understand the effects of steam in the gasification process. The properties of syngas produced from municipal solid waste and from biomass substrates were compared and results demonstrated that wastes present the lowest carbon conversion, gas yield and cold gas efficiency with the highest tar content. Nevertheless, the pre-existing collection and transportation infrastructure that is currently available for municipal waste does not exist for the compared biomass resources which makes it an interesting process. In addition a detailed economic study was carried out to estimate the environmental and economic benefits of installing the described system. The hydrogen production cost was also estimated and compared with alternative methods.

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

    International Nuclear Information System (INIS)

    Rizkiana, Jenny; Guan, Guoqing; Widayatno, Wahyu Bambang; Hao, Xiaogang; Li, Xiumin; Huang, Wei; Abudula, Abuliti

    2014-01-01

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

  6. Third steam-gas plant in Slovakia

    International Nuclear Information System (INIS)

    Haluza, I.

    2006-01-01

    There are currently two large steam/gas plants in Slovakia, in Bratislava and Ruzomberok, and a third company is to start producing electricity and heat using natural gas. Although Siemens and the Swiss company, Advanced Power, have been discussing creating a steam/gas plant in Malzenice close to Trnava, it seems that Adato, Levice will be the first to launch production. Adato plans to build a facility worth 2 bil. Sk (54.05 mil. EUR) at the Gena industrial park in Levice. Although it is to employ only 35 people, the whole region would benefit. Levice wants to attract more investors that will need more electricity and according to the Mayor of Levice, Stefan Misak, the heat produced by the steam/gas plant will represent a good option for old town boilers. The executive officer and sole owner of Adato, Miroslav Gazo, stressed that the company could not cover the whole costs of the planned investment on its own. Several investors have already shown interest in financing the project and one foreign and two local investors are in negotiations. Adato has a state permit, has signed a contract with the town, has found suppliers of technologies abroad and has signed a preliminary contract with energy consumers. The company is not rushing into the project without having a risk assessment in place. W e know that gas prices are going up. But our project will be profitable even under the least optimistic scenarios of gas price development,' said M. Gazo. He is negotiating with the gas utility, Slovensky plynarensky priemysel, and other gas suppliers. (authors)

  7. Investigation on the reactions influencing biomass air and air/steam gasification for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J.F.; Roman, S.; Bragado, D. [Departamento de Fisica Aplicada, University of Extremadura, 06071 (Spain); Calderon, M. [Departamento de Electronica e Ingenieria Electromecanica, University of Extremadura, 06071 (Spain)

    2008-08-15

    Hydrogen could be the energy carrier of the next world scene provided that its production, transportation and storage are solved. In this work the production of an hydrogen-rich gas by air/steam and air gasification of olive oil waste was investigated. The study was carried out in a laboratory reactor at atmospheric pressure over a temperature range of 700 - 900 C using a steam/biomass ratio of 1.2 w/w. The influence of the catalysts ZnCl{sub 2} and dolomite was also studied at 800 and 900 C. The solid, energy and carbon yield (%), gas molar composition and high heating value of the gas (kJ NL{sup -} {sup 1}), were determined for all cases and the differences between the gasification process with and without steam were established. Also, this work studies the different equilibria taking place, their predominance in each process and how the variables considered affect the final gas hydrogen concentration. The results obtained suggest that the operating conditions were optimized at 900 C in steam gasification (a hydrogen molar fraction of 0.70 was obtained at a residence time of 7 min). The use of both catalysts resulted positive at 800 C, especially in the case of ZnCl{sub 2} (attaining a H{sub 2} molar fraction of 0.69 at a residence time of 5 min). (author)

  8. Steam gasification of acid-hydrolysis biomass CAHR for clean syngas production.

    Science.gov (United States)

    Chen, Guanyi; Yao, Jingang; Yang, Huijun; Yan, Beibei; Chen, Hong

    2015-03-01

    Main characteristics of gaseous product from steam gasification of acid-hydrolysis biomass CAHR have been investigated experimentally. The comparison in terms of evolution of syngas flow rate, syngas quality and apparent thermal efficiency was made between steam gasification and pyrolysis in the lab-scale apparatus. The aim of this study was to determine the effects of temperature and steam to CAHR ratio on gas quality, syngas yield and energy conversion. The results showed that syngas and energy yield were better with gasification compared to pyrolysis under identical thermal conditions. Both high gasification temperature and introduction of proper steam led to higher gas quality, higher syngas yield and higher energy conversion efficiency. However, excessive steam reduced hydrogen yield and energy conversion efficiency. The optimal value of S/B was found to be 3.3. The maximum value of energy ratio was 0.855 at 800°C with the optimal S/B value. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Exergoeconomic analysis of small-scale biomass steam cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Sotomonte, Cesar Adolfo; Lora, Electo Eduardo Silva [Universidade Federal de Itajuba, MG (Brazil)], e-mails: c.rodriguez32@unifei.edu.br, electo@unifei.edu.br; Venturini, Osvaldo Jose; Escobar, Jose Carlos [Universidad Federal de Itajuba, MG (Brazil)], e-mail: osvaldo@unifei.edu.br

    2010-07-01

    The principal objective of this work is to develop a calculation process, based on the second law of thermodynamics, for evaluating the thermoeconomic potential of a small steam cogeneration plant using waste from pulp processing and/or sawmills as fuel. Four different configurations are presented and assessed. The exergetic efficiency of the cycles that use condensing turbines is found to be around 11%, which has almost 3 percent higher efficiency than cycles with back pressure turbines. The thermoeconomic equations used in this paper estimated the production costs varying the fuel price. The main results show that present cost of technologies in a small-scale steam cycle cogeneration do not justify the implementation of more efficient systems for biomass prices less than 100 R$/t. (author)

  10. Catalytic destruction of tar in biomass derived producer gas

    International Nuclear Information System (INIS)

    Zhang Ruiqin; Brown, Robert C.; Suby, Andrew; Cummer, Keith

    2004-01-01

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

  11. Thermodynamic analysis of steam-injected advanced gas turbine cycles

    Science.gov (United States)

    Pandey, Devendra; Bade, Mukund H.

    2017-12-01

    This paper deals with thermodynamic analysis of steam-injected gas turbine (STIGT) cycle. To analyse the thermodynamic performance of steam-injected gas turbine (STIGT) cycles, a methodology based on pinch analysis is proposed. This graphical methodology is a systematic approach proposed for a selection of gas turbine with steam injection. The developed graphs are useful for selection of steam-injected gas turbine (STIGT) for optimal operation of it and helps designer to take appropriate decision. The selection of steam-injected gas turbine (STIGT) cycle can be done either at minimum steam ratio (ratio of mass flow rate of steam to air) with maximum efficiency or at maximum steam ratio with maximum net work conditions based on the objective of plants designer. Operating the steam injection based advanced gas turbine plant at minimum steam ratio improves efficiency, resulting in reduction of pollution caused by the emission of flue gases. On the other hand, operating plant at maximum steam ratio can result in maximum work output and hence higher available power.

  12. Application of CaO-Based Bed Material for Dual Fluidized Bed Steam Biomass Gasification

    Science.gov (United States)

    Koppatz, S.; Pfeifer, C.; Kreuzeder, A.; Soukup, G.; Hofbauer, H.

    Gasification of biomass is a suitable option for decentralized energy supply based on renewable sources in the range of up to 50 MW fuel input. The paper presents the dual fluidized bed (DFB) steam gasification process, which is applied to generate high quality and nitrogen-free product gas. Essential part of the DFB process is the bed material used in the fluidized reactors, which has significant impact on the product gas quality. By the use of catalytically active bed materials the performance of the overall process is increased, since the bed material favors reactions of the steam gasification. In particular, tar reforming reactions are favored. Within the paper, the pilot plant based on the DFB process with 100kW fuel input at Vienna University of Technology, Austria is presented. Actual investigations with focus on CaO-based bed materials (limestone) as well as with natural olivine as bed material were carried out at the pilot plant. The application of CaO-based bed material shows mainly decreased tar content in the product gas in contrast to experiments with olivine as bed material. The paper presents the results of steam gasification experiments with limestone and olivine, whereby the product gas composition as well as the tar content and the tar composition are outlined.

  13. Biomass-to-hydrogen via fast pyrolysis and catalytic steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Chornet, E.; Wang, D.; Czernik, S. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-10-01

    Pyrolysis of lignocellulosic biomass and reforming the pyroligneous oils is being studied as a strategy for producing hydrogen. Novel technologies for the rapid pyrolysis of biomass have been developed in the past decade. They provide compact and efficient systems to transform biomass into vapors that are condensed to oils, with yields as high as 75-80 wt.% of the anhydrous biomass. This {open_quotes}bio-oil{close_quotes} is a mixture of aldehydes, alcohols, acids, oligomers from the constitutive carbohydrates and lignin, and some water derived from the dehydration reactions. Hydrogen can be produced by reforming the bio-oil or its fractions with steam. A process of this nature has the potential to be cost competitive with conventional means of producing hydrogen. The reforming facility can be designed to handle alternate feedstocks, such as natural gas and naphtha, if necessary. Thermodynamic modeling of the major constituents of the bio-oil has shown that reforming is possible within a wide range of temperatures and steam-to-carbon ratios. Existing catalytic data on the reforming of oxygenates have been studied to guide catalyst selection. Tests performed on a microreactor interfaced with a molecular beam mass spectrometer showed that, by proper selection of the process variables: temperature, steam-to-carbon ratio, gas hourly space velocity, and contact time, almost total conversion of carbon in the feed to CO and CO{sub 2} could be obtained. These tests also provided possible reaction mechanisms where thermal cracking competes with catalytic processes. Bench-scale, fixed bed reactor tests demonstrated high hydrogen yields from model compounds and carbohydrate-derived pyrolysis oil fractions. Reforming bio-oil or its fractions required proper dispersion of the liquid to avoid vapor-phase carbonization of the feed in the inlet to the reactor. A special spraying nozzle injector was designed and successfully tested with an aqueous fraction of bio-oil.

  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. Steam reforming of biomass derived oxygenates to hydrogen : Importance of metal-support boundary

    NARCIS (Netherlands)

    Takanabe, K.; Aika, Ken-ichi; Seshan, Kulathu Iyer; Lefferts, L.

    2006-01-01

    Steam reforming of acetic acid over Pt/ZrO2 catalysts was studied as a model reaction of steam reforming of biomass derived oxygenates. Pt/ZrO2 catalysts were very active; however, the catalyst deactivated in time by formation of oligomers which block the active sites for steam reforming.

  17. International Seminar on Gasification 2009 - Biomass Gasification, Gas Clean-up and Gas Treatment

    Energy Technology Data Exchange (ETDEWEB)

    2009-10-15

    During the seminar international and national experts gave presentations concerning Biomass gasification, Gas cleaning and gas treatment; and Strategy and policy issues. The presentations give an overview of the current status and what to be expected in terms of development, industrial interest and commercialization of different biomass gasification routes. The following PPT presentations are reproduced in the report: Black Liquor Gasification (Chemrec AB.); Gasification and Alternative Feedstocks for the Production of Synfuels and 2nd Generation Biofuels (Lurgi GmbH); Commercial Scale BtL Production on the Verge of Becoming Reality (Choren Industries GmbH.); Up-draft Biomass Gasification (Babcock and Wilcox Voelund A/S); Heterogeneous Biomass Residues and the Catalytic Synthesis of Alcohols (Enerkem); Status of the GoBiGas-project (Goeteborg Energi AB.); On-going Gasification Activities in Spain (University of Zaragoza,); Biomass Gasification Research in Italy (University of Perugia.); RDandD Needs and Recommendations for the Commercialization of High-efficient Bio-SNG (Energy Research Centre of the Netherlands.); Cleaning and Usage of Product Gas from Biomass Steam Gasification (Vienna University of Technology); Biomass Gasification and Catalytic Tar Cracking Process Development (Research Triangle Institute); Syngas Cleaning with Catalytic Tar Reforming (Franhofer UMSICHT); Biomass Gas Cleaning and Utilization - The Topsoee Perspective (Haldor Topsoee A/S); OLGA Tar Removal Technology (Dahlman); Bio-SNG - Strategy and Activities within E.ON (E.ON Ruhrgas AG); Strategy and Gasification Activities within Sweden (Swedish Energy Agency); 20 TWh/year Biomethane (Swedish Gas Association)

  18. Numerical Analysis on Transient of Steam-gas Pressurizer

    International Nuclear Information System (INIS)

    Kim, Jong-Won; Lee, Yeon-Gun; Park, Goon-Cherl

    2008-01-01

    In nuclear reactors, various pressurizers are adopted to satisfy their characteristics and uses. The additional active systems such as heater, pressurizer cooler, spray and insulator are essential for a steam or a gas pressurizer. With a steam-gas pressurizer, additional systems are not required due to the use of steam and non-condensable gas as pressure-buffering materials. The steam-gas pressurizer in integrated small reactors experiences very complicated thermal-hydraulic phenomena. To ensure the integrity of this pressurizer type, the analysis on the transient behavior of the steam-gas pressure is indispensable. For this purpose, the steam-gas pressurizer model is introduced to predict the accurate system pressure. The proposed model includes bulk flashing, rainout, inter-region heat and mass transfer and wall condensation with non-condensable gas. However, the ideal gas law is not applied because of significant interaction at high pressure between steam and non-condensable gas. The results obtained from this proposed model agree with those from pressurizer tests. (authors)

  19. 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.

  20. 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

  1. Gas--steam turbine combined cycle power plants

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.

    1978-10-01

    The purpose of this technology evaluation is to provide performance and cost characteristics of the combined gas and steam turbine, cycle system applied to an Integrated Community Energy System (ICES). To date, most of the applications of combined cycles have been for electric power generation only. The basic gas--steam turbine combined cycle consists of: (1) a gas turbine-generator set, (2) a waste-heat recovery boiler in the gas turbine exhaust stream designed to produce steam, and (3) a steam turbine acting as a bottoming cycle. Because modification of the standard steam portion of the combined cycle would be necessary to recover waste heat at a useful temperature (> 212/sup 0/F), some sacrifice in the potential conversion efficiency is necessary at this temperature. The total energy efficiency ((electric power + recovered waste heat) divided by input fuel energy) varies from about 65 to 73% at full load to 34 to 49% at 20% rated electric power output. Two major factors that must be considered when installing a gas--steam turbine combines cycle are: the realiability of the gas turbine portion of the cycle, and the availability of liquid and gas fuels or the feasibility of hooking up with a coal gasification/liquefaction process.

  2. CO Emissions from Gas Engines Operating on Biomass Producer Gas

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Jensen, T. K.; Henriksen, Ulrik Birk

    2004-01-01

    High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. CO emissions from engines operating on biomass producer gases are high, especially at very lean conditions where...

  3. High Temperature Air/Steam Gasification of Biomass Wastes - Stage 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Blasiak, Wlodzimierz; Szewczyk, Dariusz; Lucas, Carlos; Rafidi, Nabil; Abeyweera Ruchira; Jansson, Anna; Bjoerkman, Eva [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Materials Science and Engineering

    2003-05-01

    In Jan 2002 the Division of Energy and Furnace Technology started the project High Temperature Air an Steam Gasification (HTAG) of biomass wastes, following the approval made by Swedish Energy Agency. The research proved successful; with the fixed bed updraft gasifier coupled to the highly regenerative preheater equipment able to produce a fuel gas not only from wood pellets but also from wood chips, bark and charcoal with considerably reduced amount of tar. This report provides information on solid biomass conversion into fuel gas as a result of air and steam gasification process performed in a fixed bed updraft gasifier. The first chapter of the report presents the overall objectives and the specific objectives of the work. Chapter 2 summarizes state-of-the-art on the gasification field stating some technical differences between low and high temperature gasification processes. Description and schemes of the experimental test rig are provided in Chapter 3. The equipment used to perform measurements of different sort and that installed in the course of the work is described in Chapter 4. Chapter 5 describes the methodology of experiments conducted whose results were processed and evaluated with help of the scheme of equations presented in Chapter 6, called raw data evaluation. Results of relevant experiments are presented and discussed in Chapter 7. A summary discussion of the tar analysis is presented in Chapter 8. Chapter 9 summarizes the findings of the research work conducted and identifies future efforts to ensure the development of next stage. Final chapter provides a summary of conclusions and recommendations of the work. References are provided at the end of the report. Aimed to assist the understanding of the work done, tables and graphs of experiments conducted, irrespective to their quality, are presented in appendices.

  4. Steam explosion and its combinatorial pretreatment refining technology of plant biomass to bio-based products.

    Science.gov (United States)

    Chen, Hong-Zhang; Liu, Zhi-Hua

    2015-06-01

    Pretreatment is a key unit operation affecting the refinery efficiency of plant biomass. However, the poor efficiency of pretreatment and the lack of basic theory are the main challenges to the industrial implementation of the plant biomass refinery. The purpose of this work is to review steam explosion and its combinatorial pretreatment as a means of overcoming the intrinsic characteristics of plant biomass, including recalcitrance, heterogeneity, multi-composition, and diversity. The main advantages of the selective use of steam explosion and other combinatorial pretreatments across the diversity of raw materials are introduced. Combinatorial pretreatment integrated with other unit operations is proposed as a means to exploit the high-efficiency production of bio-based products from plant biomass. Finally, several pilot- and demonstration-scale operations of the plant biomass refinery are described. Based on the principle of selective function and structure fractionation, and multi-level and directional composition conversion, an integrated process with the combinatorial pretreatments of steam explosion and other pretreatments as the core should be feasible and conform to the plant biomass refinery concept. Combinatorial pretreatments of steam explosion and other pretreatments should be further exploited based on the type and intrinsic characteristics of the plant biomass used, the bio-based products to be made, and the complementarity of the processes. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Modelling of steam condensation in the primary flow channel of a gas-heated steam generator

    International Nuclear Information System (INIS)

    Kawamura, H.; Meister, G.

    1982-10-01

    A new simulation code has been developed for the analysis of steam ingress accidents in high temperatures reactors which evaluates the heat transfer in a steam generator headed by a mixture of helium and water steam. Special emphasis is laid on the analysis of steam condensation in the primary circuit of the steam generator. The code takes wall and bulk condensation into account. A new method is proposed to describe the entrainment of water droplets in the primary gas flow. Some typical results are given. Steam condensation in the primary channel may have a significant effect on temperature distributions. The effect on the heat transferred by the steam generator, however, is found to be not so prominent as might be expected. The reason is discussed. A simplified code will also be described, which gives results with reasonable accuracy within much shorter execution times. This code may be used as a program module in a program simulating the total primary circuit of a high temperature reactor. (orig.) [de

  6. Combined gas and steam power plant

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, D T; Davis, J P

    1977-06-02

    The invention concerns a combination of internal combustion engine and steam turbine, where not only the heat of the hot exhaust gases of the internal combustion engine, but also the heat in the coolant of the internal combustion engine is used for power generation. The working fluid of the steam turbine is an organic fluid of low boiling point. A mixture of 85 mol% of tri-fluoro ethanol and 15 mol% of water is the most suitable fluid. The combustion engine (a Diesel engine is the most suitable), drives a working machine, e.g. a generator. The hot combustion exhaust gases produce evaporation of the working fluid in an HP evaporator. The superheated steam gives up its energy in the HP turbine stage, flows through the feed preheater of the fluid, and is condensed in the condenser. A pump pumps the fluid via control valve to heat the feed preheater of the fluid, from which it returns to the HP evaporator. At the same time evaporated coolant flows into an LP evaporator in counter-flow to the working fluid, condenses, and is returned to the cooling circuit of the combustion engine. The working fluid in the LP evaporator is heated to its boiling point, gives up its energy in the LP stage of the steam turbine is condensed, pumped to the preheater and returns to the LP evaporator. The two rotors of the turbine stages (HP and LP stages) are mounted on the same shaft, which drives a working machine or a generator.

  7. Combustion of biomass-derived, low caloric value, fuel gas in a gasturbine combustor

    Energy Technology Data Exchange (ETDEWEB)

    Andries, J; Hoppesteyn, P D.J.; Hein, K R.G. [Technische Univ. Delf (Netherlands)

    1998-09-01

    The use of biomass and biomass/coal mixtures to produce electricity and heat reduces the net emissions of CO{sub 2}, contributes to the restructuring of the agricultural sector, helps to reduce the waste problem and saves finite fossil fuel reserves. Pressurised fluidised bed gasification followed by an adequate gas cleaning system, a gas turbine and a steam turbine, is a potential attractive way to convert biomass and biomass/coal mixtures. To develop and validate mathematical models, which can be used to design and operate Biomass-fired Integrated Gasification Combined Cycle (BIGCC) systems, a Process Development Unit (PPDU) with a maximum thermal capacity of 1.5 MW{sub th}, located at the Laboratory for Thermal Power Engineering of the Delft University of Technology in The Netherlands is being used. The combustor forms an integral part of this facility. Recirculated flue gas is used to cool the wall of the combustor. (orig.)

  8. Greenhouse gas and energy analysis of substitute natural gas from biomass for space heat

    Energy Technology Data Exchange (ETDEWEB)

    Pucker, J.; Jungmeier, G. [JOANNEUM RESEARCH Forschungsgesellschaft mbH, RESOURCES - Institute for Water, Energy and Sustainability, Steyrergasse 17, 8010 Graz (Austria); Zwart, R. [Energy Research Centre of The Netherlands (ECN), Westerduinweg 3, 1755 LE Petten (Netherlands)

    2012-03-15

    In this paper, the greenhouse gas and energy balances of the production and use for space heating of substitute natural gas from biomass (bio-SNG) for space heat are analysed. These balances are compared to the use of natural gas and solid biomass as wood chips to provide the same service. The reduction of the greenhouse gas emissions (CO{sub 2}-eq.) - carbon dioxide, methane and nitrous oxide - and of the fossil primary energy use is investigated in a life cycle assessment (LCA). This assessment was performed for nine systems for bio-SNG; three types of gasification technologies (O{sub 2}-blown entrained flow, O{sub 2}-blown circulating fluidised bed and air-steam indirect gasification) with three different types of feedstock (forest residues, miscanthus and short rotation forestry). The greenhouse gas analysis shows that forest residues using the air-steam indirect gasification technology result in the lowest greenhouse gas emissions (in CO{sub 2}-eq. 32 kg MWh{sup -1} of heat output). This combination results in 80% reduction of greenhouse gas emissions when compared to natural gas and a 29% reduction of greenhouse gases if the forest residues were converted to wood chips and combusted. The gasification technologies O{sub 2}-blown entrained flow and O{sub 2}-blown circulating fluidised bed gasification have higher greenhouse gas emissions that range between in CO{sub 2}-eq. 41 to 75 kg MWh{sup -1} of heat output depending on the feedstock. When comparing feedstocks in the bio-SNG systems, miscanthus had the highest greenhouse gas emissions bio-SNG systems producing in CO2-eq. 57-75 kg MWh{sup -1} of heat output. Energy analysis shows that the total primary energy use is higher for bio-SNG systems (1.59-2.13 MWh MWh{sup -1} of heat output) than for the reference systems (in 1.37-1.51 MWh MWh{sup -1} of heat output). However, with bio-SNG the fossil primary energy consumption is reduced compared to natural gas. For example, fossil primary energy use is reduced by

  9. ISOLATION AND CHARACTERIZATION OF CELLULOSE AND LIGNIN FROM STEAM-EXPLODED LIGNOCELLULOSIC BIOMASS

    OpenAIRE

    Maha M. Ibrahim; Foster A. Agblevor; Waleed K. El-Zawawy

    2010-01-01

    The isolation of cellulose from different lignocellulosic biomass sources such as corn cob, banana plant, cotton stalk, and cotton gin waste, was studied using a steam explosion technology as a pre-treatment process for different times followed by alkaline peroxide bleaching. The agricultural residues were steam-exploded at 220 ºC for 1-4 min for the corn cob, 2 and 4 min for the banana plant, 3-5 min for the cotton gin waste, and for 5 min for the cotton stalk. The steamed fibers were water ...

  10. Effect on non-condensable gas on steam injector

    International Nuclear Information System (INIS)

    Kawamoto, Y.; Abe, Y.; Iwaki, C.; Narabayashi, T.; Mori, M.; Ohmori, S.

    2004-01-01

    Next-generation reactor systems have been under development aiming at simplified system and improvement of safety and credibility. A steam injector has a function of a passive pump without large motor or turbo-machinery, and has been investigated as one of the most important component of the next-generation reactor. Its performance as a pump depends on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. Although non-condensable gases are well known for reducing heat transfer, the effect of the non-condensable gas on the condensation of supersonic steam on high-speed water jet has not been cleared. The present paper presents an experimental study of condensation of supersonic steam around turbulent water jet with model steam injector made by transparent plastic. The experimental apparatus is described. The visual observation was carried out by using high-speed camera. The non-condensable gas effect on the pump performance and flow characteristics are clarified by the image processing technique for the jet shape and gas-liquid interface behavior. (authors)

  11. Greenhouse gas balances of biomass energy systems

    International Nuclear Information System (INIS)

    Marland, G.; Schlamadinger, B.

    1996-01-01

    A full energy-cycle analysis of greenhouse gas emissions of biomass energy systems requires analysis well beyond the energy sector. For example, production of biomass fuels impacts on the global carbon cycle by altering the amount of carbon stored in the biosphere and often by producing a stream of by-products or co-products which substitute for other energy-intensive products like cement, steel, concrete or, in case of ethanol form corn, animal feed. It is necessary to distinguish between greenhouse gas emissions associated with the energy product as opposed to those associated with other products. Production of biomass fuels also has an opportunity cost because it uses large land areas which could have been used otherwise. Accounting for the greenhouse gas emissions from biomass fuels in an environment of credits and debits creates additional challenges because there are large non-linearities in carbon flows over time. This paper presents some of the technical challenges of comprehensive greenhouse gas accounting and distinguishes between technical and public policy issues. (author). 5 refs, 5 figs

  12. Greenhouse gas balances of biomass energy systems

    International Nuclear Information System (INIS)

    Marland, G.; Schlamadinger, B.

    1994-01-01

    A full energy-cycle analysis of greenhouse gas emissions of biomass energy systems requires analysis well beyond the energy sector. For example, production of biomass fuels impacts on the global carbon cycle by altering the amount of carbon stored in the biosphere and often by producing a stream of by-products or co-products which substitute for other energy-intensive products like cement, steel, concrete or, in case of ethanol from corn, animal feed. It is necessary to distinguish between greenhouse gas emissions associated with the energy product as opposed to those associated with other products. Production of biomass fuels also has an opportunity cost because it uses large land areas which could have been used otherwise. Accounting for the greenhouse gas emissions from biomass fuels in an environment of credits and debits creates additional challenges because there are large nonlinearities in the carbon flows over time. This paper presents some of the technical challenges of comprehensive greenhouse gas accounting and distinguishes between technical and public policy issues

  13. 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.

  14. Power Plants, Steam and Gas Turbines WebQuest

    Science.gov (United States)

    Ulloa, Carlos; Rey, Guillermo D.; Sánchez, Ángel; Cancela, Ángeles

    2012-01-01

    A WebQuest is an Internet-based and inquiry-oriented learning activity. The aim of this work is to outline the creation of a WebQuest entitled "Power Generation Plants: Steam and Gas Turbines." This is one of the topics covered in the course "Thermodynamics and Heat Transfer," which is offered in the second year of Mechanical…

  15. Adsorption characteristics of SO{sub 2}, NO by steam activated biomass chars

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Fei; Shu, Tong; Wang, Kuan; Lu, Ping [Nanjing Normal Univ. (China). School of Energy and Mechanical Engineering

    2013-07-01

    Wheat straw and rice husk collected from the suburb of Nanjing, China, were prepared to different kinds of steam activated biomass-based chars, and the adsorption characteristics of the biomass-based chars was carried out in a fixed bed reactor. The specific surface area and pore structure of different biomass chars were measured by nitrogen adsorption-desorption analysis instrument at 77K. The effects of biomass type, pyrolysis temperature, heating rate, activation temperature and concentration of SO{sub 2}, NO on the adsorption efficiency of SO{sub 2}, NO were analyzed. The results indicated that the steam activation has significant effects on the specific surface area, total pore volume and micro-morphology of biomass chars by improving the internal structure. The adsorption efficiency of SO{sub 2}, NO increased with the decreasing of SO{sub 2}, NO concentration in the experimental range. The optimal condition of char preparation (873K, fast pyrolysis) and steam activation (1,073K) was proposed based on the adsorption efficiency and adsorption volume of SO{sub 2}, NO. It builds a theoretical basis for industrial applications of biomass.

  16. Automation of steam generator services at public service electric & gas

    Energy Technology Data Exchange (ETDEWEB)

    Cruickshank, H.; Wray, J.; Scull, D. [Public Service Electric & Gas, Hancock`s Bridge, NJ (United States)

    1995-03-01

    Public Service Electric & Gas takes an aggressive approach to pursuing new exposure reduction techniques. Evaluation of historic outage exposure shows that over the last eight refueling outages, primary steam generator work has averaged sixty-six (66) person-rem, or, approximately tewenty-five percent (25%) of the general outage exposure at Salem Station. This maintenance evolution represents the largest percentage of exposure for any single activity. Because of this, primary steam generator work represents an excellent opportunity for the development of significant exposure reduction techniques. A study of primary steam generator maintenance activities demonstrated that seventy-five percent (75%) of radiation exposure was due to work activities of the primary steam generator platform, and that development of automated methods for performing these activities was worth pursuing. Existing robotics systems were examined and it was found that a new approach would have to be developed. This resulted in a joint research and development project between Westinghouse and Public Service Electric & Gas to develop an automated system of accomplishing the Health Physics functions on the primary steam generator platform. R.O.M.M.R.S. (Remotely Operated Managed Maintenance Robotics System) was the result of this venture.

  17. Effects of electric current upon catalytic steam reforming of biomass gasification tar model compounds to syngas

    International Nuclear Information System (INIS)

    Tao, Jun; Lu, Qiang; Dong, Changqing; Du, Xiaoze; Dahlquist, Erik

    2015-01-01

    Highlights: • ECR technique was proposed to convert biomass gasification tar model compounds. • Electric current enhanced the reforming efficiency remarkably. • The highest toluene conversion reached 99.9%. • Ni–CeO 2 /γ-Al 2 O 3 exhibited good stability during the ECR performance. - Abstract: Electrochemical catalytic reforming (ECR) technique, known as electric current enhanced catalytic reforming technique, was proposed to convert the biomass gasification tar into syngas. In this study, Ni–CeO 2 /γ-Al 2 O 3 catalyst was prepared, and toluene was employed as the major feedstock for ECR experiments using a fixed-bed lab-scale setup where thermal electrons could be generated and provided to the catalyst. Several factors, including the electric current intensity, reaction temperature and steam/carbon (S/C) ratio, were investigated to reveal their effects on the conversion of toluene as well as the composition of the gas products. Moreover, toluene, two other tar model compounds (benzene and 1-methylnaphthalene) and real tar (tar-containing wastewater) were subjected to the long period catalytic stability tests. All the used catalysts were analyzed to determine their carbon contents. The results indicated that the presence of electric current enhanced the catalytic performance remarkably. The toluene conversion reached 99.9% under the electric current of 4 A, catalytic temperature of 800 °C and S/C ratio of 3. Stable conversion performances of benzene, 1-methylnaphthalene and tar-containing wastewater were also observed in the ECR process. H 2 and CO were the major gas products, while CO 2 and CH 4 were the minor ones. Due to the promising capability, the ECR technique deserves further investigation and application for efficient tar conversion

  18. 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

  19. Adding gas from biomass to the gas grid

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, Martin; Polman, Erik [GASTEC NV (Netherlands); Jensen, Jan K.; Myken, Asger [Danish Gas Technology Center A/S, Hoersholm (Denmark); Joensson, Owe; Dahl, Anders [Swedish Gas Center AB, Malmoe (Sweden)

    2001-07-01

    The aim of this project carried out in the framework of the Altener programme is to provide an overview of technologies for cleaning and upgrading of biogas for remote use. A further aim is to determine to what extent gases produced from biomass (digestion or gasification)can be added to the gas grid and what additional safety regulations are necessary. Finally, existing European standards and national legislation have been studied in order to determine the possibility of conflicting and/or missing regulations with the intended approach.The information collected in this project can be used to select promising technologies and may serve as background information for developing harmonised standards. This report describes the various production and cleaning techniques and the present requirements for the use of biogas. The technology for adding gas from biomass to the gas grid on a larger scale can contribute to a higher share of biomass in the energy supply and will also allow a highly efficient use of the energy contained in the biomass.Moderate tax incentives will make the use of gas from biomass economically attractive for large groups of end-users.

  20. High-efficiency condenser of steam from a steam-gas mixture

    Science.gov (United States)

    Milman, O. O.; Krylov, V. S.; Ptakhin, A. V.; Kondratev, A. V.; Yankov, G. G.

    2017-12-01

    The design of a module for a high-efficiency condenser of steam with a high content (up to 15%) of noncondensable gases (NCGs) with a nearly constant steam-gas mixture (SGM) velocity during the condensation of steam has been developed. This module provides the possibility to estimate the operational efficiency of six condenser zones during the motion of steam from the inlet to the SGM suction point. Some results of the experimental tests of the pilot high-efficiency condenser module are presented. The dependence of the average heat transfer coefficient k¯ on the volumetric NCG concentration v¯ has been derived. It is shown that the high-efficiency condenser module can provide a moderate decrease in k¯ from 4400-4600 to 2600-2800 W/(m2 K) at v¯ ≈ 0.5-9.0%. The heat transfer coefficient distribution over different module zones at a heat duty close to its nominal value has been obtained. From this distribution, it can be seen that the average heat transfer coefficient decreases to 2600 W/(m2 K) at an NCG concentration v¯ = 7.5%, but the first condenser sections ( 1- 3) retain high values of k¯ at a level of no lower than 3200 W/(m2 K), and the last sections operate less well, having k¯ at a level of 1700 W/(m2 K). The dependence of the average heat transfer coefficient on the water velocity in condenser tubes has been obtained at a nearly nominal duty such that the extrapolation of this dependence to the water velocity of 2 m/s may be expected to give k¯ = 5000 W/(m2 K) for relatively pure steam, but an increase in k¯ at v¯ = 8% will be smaller. The effect of the gas removal device characteristic on the operation of the high-efficiency condenser module is described. The design developed for the steam condenser of a gas-turbine plant with a power of 25 MW, a steam flow rate of 40.2 t/h, and a CO2 concentration of up to 12% with consideration for the results of performed studies is presented.

  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. Substitute natural gas from biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-15

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

  3. Greenhouse gas and energy analysis of substitute natural gas from biomass for space heat

    International Nuclear Information System (INIS)

    Pucker, Johanna; Zwart, Robin; Jungmeier, Gerfried

    2012-01-01

    In this paper, the greenhouse gas and energy balances of the production and use for space heating of substitute natural gas from biomass (bio-SNG) for space heat are analysed. These balances are compared to the use of natural gas and solid biomass as wood chips to provide the same service. The reduction of the greenhouse gas emissions (CO 2 -eq.) – carbon dioxide, methane and nitrous oxide – and of the fossil primary energy use is investigated in a life cycle assessment (LCA). This assessment was performed for nine systems for bio-SNG; three types of gasification technologies (O 2 -blown entrained flow, O 2 -blown circulating fluidised bed and air–steam indirect gasification) with three different types of feedstock (forest residues, miscanthus and short rotation forestry). The greenhouse gas analysis shows that forest residues using the air–steam indirect gasification technology result in the lowest greenhouse gas emissions (in CO 2 -eq. 32 kg MWh −1 of heat output). This combination results in 80% reduction of greenhouse gas emissions when compared to natural gas and a 29% reduction of greenhouse gases if the forest residues were converted to wood chips and combusted. The gasification technologies O 2 -blown entrained flow and O 2 -blown circulating fluidised bed gasification have higher greenhouse gas emissions that range between in CO 2 -eq. 41 to 75 kg MWh −1 of heat output depending on the feedstock. When comparing feedstocks in the bio-SNG systems, miscanthus had the highest greenhouse gas emissions bio-SNG systems producing in CO 2 -eq. 57–75 kg MWh −1 of heat output. Energy analysis shows that the total primary energy use is higher for bio-SNG systems (1.59–2.13 MWh MWh −1 of heat output) than for the reference systems (in 1.37–1.51 MWh MWh −1 of heat output). However, with bio-SNG the fossil primary energy consumption is reduced compared to natural gas. For example, fossil primary energy use is reduced by 92% when air–steam

  4. Natural Gas and Cellulosic Biomass: A Clean Fuel Combination? Determining the Natural Gas Blending Wall in Biofuel Production.

    Science.gov (United States)

    M Wright, Mark; Seifkar, Navid; Green, William H; Román-Leshkov, Yuriy

    2015-07-07

    Natural gas has the potential to increase the biofuel production output by combining gas- and biomass-to-liquids (GBTL) processes followed by naphtha and diesel fuel synthesis via Fischer-Tropsch (FT). This study reflects on the use of commercial-ready configurations of GBTL technologies and the environmental impact of enhancing biofuels with natural gas. The autothermal and steam-methane reforming processes for natural gas conversion and the gasification of biomass for FT fuel synthesis are modeled to estimate system well-to-wheel emissions and compare them to limits established by U.S. renewable fuel mandates. We show that natural gas can enhance FT biofuel production by reducing the need for water-gas shift (WGS) of biomass-derived syngas to achieve appropriate H2/CO ratios. Specifically, fuel yields are increased from less than 60 gallons per ton to over 100 gallons per ton with increasing natural gas input. However, GBTL facilities would need to limit natural gas use to less than 19.1% on a LHV energy basis (7.83 wt %) to avoid exceeding the emissions limits established by the Renewable Fuels Standard (RFS2) for clean, advanced biofuels. This effectively constitutes a blending limit that constrains the use of natural gas for enhancing the biomass-to-liquids (BTL) process.

  5. Power-generation method using combined gas and steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C; Radtke, K; Keller, H J

    1997-03-20

    The invention concerns a method of power generation using a so-called COGAS (combined gas and steam) turbine installation, the aim being to improve the method with regard to the initial costs and energy consumption so that power can be generated as cheaply as possible. This is achieved by virtue of the fact that air taken from the surrounding atmosphere is splint into an essentially oxygen-containing stream and an essentially nitrogen-containing stream and the two streams fed further at approximately atmospheric pressure. The essentially nitrogen-containing stream is mixed with an air stream to form a mixed nitrogen/air stream and the mixed-gas stream thus produced is brought to combustion chamber pressure in the compressor of the gas turbine, the combustion of the combustion gases in the combustion chamber of the gas turbine being carried out with the greater part of this compressed mixed-gas stream. (author) figs.

  6. Criteria for selection of dolomites and catalysts for tar elimination from biomass gasification gas. Kinetic constants

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

    Calcined dolomites and commercial steam reforming catalysts are used downstream biomass gasifiers for hot catalytic raw gas cleaning. To further compare these solids under a rigorous basis, a reaction network and a kinetic model are presented. The apparent kinetic constant for the tar reduction is here proposed as a basis of comparison. Tar sampling and analysis, and the units used for the space-time in the catalytic reactor affect the kinetic constants observed. (author) (2 refs.)

  7. Criteria for selection of dolomites and catalysts for tar elimination from biomass gasification gas. Kinetic constants

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

    Calcined dolomites and commercial steam reforming catalysts are used downstream biomass gasifiers for hot catalytic raw gas cleaning. To further compare these solids under a rigorous basis, a reaction network and a kinetic model are presented. The apparent kinetic constant for the tar reduction is here proposed as a basis of comparison. Tar sampling and analysis, and the units used for the space-time in the catalytic reactor affect the kinetic constants observed. (author) (2 refs.)

  8. Hydrogen production by biomass steam gasification in fluidized bed reactor with Co catalyst

    International Nuclear Information System (INIS)

    Kazuhiko Tasaka; Atsushi Tsutsumi; Takeshi Furusawa

    2006-01-01

    The catalytic performances of Co/MgO catalysts were investigated in steam gasification of cellulose and steam reforming of tar derived from cellulose gasification. For steam reforming of cellulose tar in a secondary fixed bed reactor, 12 wt.% Co/MgO catalyst attained more than 80% of tar reduction. The amount of produced H 2 and CO 2 increased with the presence of catalyst, and kept same level during 2 hr at 873 K. It is indicated that steam reforming of cellulose tar proceeds sufficiently over Co/MgO catalyst. For steam gasification of cellulose in a fluidized bed reactor, it was found that tar reduction increases with Co loading amount and 36 wt.% Co/MgO catalyst showed 84% of tar reduction. The amounts of produced gas kept for 2 hr indicating that 36 wt.% Co/MgO catalyst is stable during the reaction. It was concluded that these Co catalysts are promising systems for the steam gasification of cellulose and steam reforming of cellulose tar. (authors)

  9. Olivine, dolomite and ceramic filters in one vessel to produce clean gas from biomass.

    Science.gov (United States)

    Rapagnà, Sergio; Gallucci, Katia; Foscolo, Pier Ugo

    2018-01-01

    Heavy organic compounds produced during almond shells gasification in a steam and/or air atmosphere, usually called tar, are drastically reduced in the product gas by using simultaneously in one vessel a ceramic filter placed in the freeboard and a mixture of olivine and dolomite particles in the fluidized bed of the gasifier. The content of tar in the product gas during a reference gasification test with air, in presence of fresh olivine particles only, was 8600mg/Nm 3 of dry gas. By gasifying biomass with steam at the same temperature level of 820°C in a bed of olivine and dolomite (20% by weight), and in the presence of a catalytic ceramic filter inserted in the freeboard of the fluidized bed gasifier, the level of tar was brought down to 57mg/Nm 3 of dry producct gas, with a decrease of more than two orders of magnitude. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Gas generation from biomass for decentralized power supply systems; Gaserzeugung fuer dezentrale Energiesysteme auf der Basis von Biomasse

    Energy Technology Data Exchange (ETDEWEB)

    Kubiak, H.; Papamichalis, A.; Heek, K.H. van [DMT-Inst. fuer Kokserzeugung und Brennstofftechnik, Essen (Germany)

    1996-12-31

    By a reaction with steam, bioresidues and plants can be converted into a gas consisting mainly of hydrogen, carbon monoxide and methane which can be used for electric power generation in gas engines, gas turbins and fuel cells. The conversion processes, especially the fuel cell process, are environment-friendly and efficient. For decentralized applications (i.e. for biomass volumes of 0.5 to 1 t/h), an allothermal process is recommended which is described in detail. (orig) [Deutsch] Durch Reaktion mit Wasserdampf lassen sich Bioreststoffe und Energiepflanzen zu einem Gas umsetzen, das im wesentlichen aus Wasserstoff, Kohlenmonoxid und Methan besteht und z.B. ueber Gasmotoren, Gasturbinen, vorzugsweise aber Brennstoffzellen zu Strom umgewandelt werden kann. Die Umwandlungsverfahren, insbesondere unter Benutzung von Brennstoffzellen, sind umweltfreundlich und haben einen hohen Wirkungsgrad. Als Vergasungsverfahren eignet sich fuer die dezentrale Anwendung. - d.h. fuer eine Biomassemenge von 0,5 bis 1 t/h - insbesondere das hier beschriebene allotherme Verfahren. (orig)

  11. Gas generation from biomass for decentralized power supply systems; Gaserzeugung fuer dezentrale Energiesysteme auf der Basis von Biomasse

    Energy Technology Data Exchange (ETDEWEB)

    Kubiak, H; Papamichalis, A; Heek, K.H. van [DMT-Inst. fuer Kokserzeugung und Brennstofftechnik, Essen (Germany)

    1997-12-31

    By a reaction with steam, bioresidues and plants can be converted into a gas consisting mainly of hydrogen, carbon monoxide and methane which can be used for electric power generation in gas engines, gas turbins and fuel cells. The conversion processes, especially the fuel cell process, are environment-friendly and efficient. For decentralized applications (i.e. for biomass volumes of 0.5 to 1 t/h), an allothermal process is recommended which is described in detail. (orig) [Deutsch] Durch Reaktion mit Wasserdampf lassen sich Bioreststoffe und Energiepflanzen zu einem Gas umsetzen, das im wesentlichen aus Wasserstoff, Kohlenmonoxid und Methan besteht und z.B. ueber Gasmotoren, Gasturbinen, vorzugsweise aber Brennstoffzellen zu Strom umgewandelt werden kann. Die Umwandlungsverfahren, insbesondere unter Benutzung von Brennstoffzellen, sind umweltfreundlich und haben einen hohen Wirkungsgrad. Als Vergasungsverfahren eignet sich fuer die dezentrale Anwendung. - d.h. fuer eine Biomassemenge von 0,5 bis 1 t/h - insbesondere das hier beschriebene allotherme Verfahren. (orig)

  12. Synthesis gas production from various biomass feedstocks

    Directory of Open Access Journals (Sweden)

    Juan A. Conesa

    2013-10-01

    Full Text Available The decomposition of five different biomass samples was studied in a horizontal laboratory reactor. The samples consisted of esparto grass, straw, Posidonea Oceanic seaweed, waste from urban and agricultural pruning and waste from forest pruning. Both pyrolysis in inert atmosphere and combustion in the presence of oxygen were studied. Different heating rates were used by varying the input speed. Major gas compounds were analyzed. The experimental results show that the amount of CO formed is lower in less dense species. It is also found that there is an increase of hydrocarbons formed at increasing feeding rates, in particular methane, while there is a decrease in the production of hydrogen.

  13. Gas turbines: gas cleaning requirements for biomass-fired systems

    Directory of Open Access Journals (Sweden)

    Oakey John

    2004-01-01

    Full Text Available Increased interest in the development of renewable energy technologies has been hencouraged by the introduction of legislative measures in Europe to reduce CO2 emissions from power generation in response to the potential threat of global warming. Of these technologies, biomass-firing represents a high priority because of the modest risk involved and the availability of waste biomass in many countries. Options based on farmed biomass are also under development. This paper reviews the challenges facing these technologies if they are to be cost competitive while delivering the supposed environmental benefits. In particular, it focuses on the use of biomass in gasification-based systems using gas turbines to deliver increased efficiencies. Results from recent studies in a European programme are presented. For these technologies to be successful, an optimal balance has to be achieved between the high cost of cleaning fuel gases, the reliability of the gas turbine and the fuel flexibility of the overall system. Such optimisation is necessary on a case-by-case basis, as local considerations can play a significant part.

  14. ASTRID power conversion system: Assessment on steam and gas options

    International Nuclear Information System (INIS)

    Laffont, Guy; Cachon, Lionel; Jourdain, Vincent; Fauque, Jean Marie

    2013-01-01

    Conclusion: ◆ Two power conversion systems have been investigated for the ASTRID prototype. ◆ Steam PCS: • Most mature system based on a well-developed turbomachinery technology. • High plant efficiency. • Studies on steam generators designs and leak detection systems in progress with the aim of reducing the risk of large SWRs and of limiting its consequences. • Design and licensing safety assessment of a SFR must deal with the Sodium Water Air reaction (SWAR). ◆ Gas PCS: • Strong advantage as it inherently eliminates the SWR and SWAR risks. • Very innovative option: major breakthroughs but feasibility and viability not yet demonstrated. • Remaining technological challenges but no showstopper indentified. • General architecture: investigations in progress to improve performances, operability and maintainability

  15. Investigation of a combined gas-steam system with flue gas recirculation

    Directory of Open Access Journals (Sweden)

    Chmielniak Tadeusz

    2016-06-01

    Full Text Available This article presents changes in the operating parameters of a combined gas-steam cycle with a CO2 capture installation and flue gas recirculation. Parametric equations are solved in a purpose-built mathematical model of the system using the Ebsilon Professional code. Recirculated flue gases from the heat recovery boiler outlet, after being cooled and dried, are fed together with primary air into the mixer and then into the gas turbine compressor. This leads to an increase in carbon dioxide concentration in the flue gases fed into the CO2 capture installation from 7.12 to 15.7%. As a consequence, there is a reduction in the demand for heat in the form of steam extracted from the turbine for the amine solution regeneration in the CO2 capture reactor. In addition, the flue gas recirculation involves a rise in the flue gas temperature (by 18 K at the heat recovery boiler inlet and makes it possible to produce more steam. These changes contribute to an increase in net electricity generation efficiency by 1%. The proposed model and the obtained results of numerical simulations are useful in the analysis of combined gas-steam cycles integrated with carbon dioxide separation from flue gases.

  16. Assessment of the technical and economic potentials of biomass use for the production of steam, chemicals and polymers

    NARCIS (Netherlands)

    Saygin, D.; Gielen, D. J.; Draeck, M.; Worrell, E.; Patel, M. K.

    2014-01-01

    Fossil fuel substitution with biomass is one of the measures to reduce carbon dioxide (CO2) emissions. This paper estimates the cost-effectiveness of raising industrial steam and producing materials (i.e. chemicals, polymers) from biomass. We quantify their long-term global potentials in terms of

  17. Steam generation unit in a simple version of biomass based small cogeneration unit

    Directory of Open Access Journals (Sweden)

    Sornek Krzysztof

    2014-01-01

    Full Text Available The organic Rankine cycle (ORC is a very promising process for the conversion of low or medium temperature heat to electricity in small and micro scale biomass powered systems. Classic ORC is analogous to Clausius–Rankine cycle in a steam power plant, but instead of water it uses low boiling, organic working fluids. Seeking energy and economical optimization of biomass-based ORC systems, we have proposed some modifications e.g. in low boiling fluid circuit construction. Due to the fact that the operation of a micro steam turbine is rather inefficient from the technical and economic point of view, a specially modified air compressor can be used as a steam piston engine. Such engine should be designed to work at low pressure of the working medium. Studies regarding the first version of the prototype installation were focused on the confirmation of applicability of a straw boiler in the prototype ORC power system. The results of the previous studies and the studies described in the paper (on the new cogeneration unit confirmed the high potential of the developed solution. Of course, many further studies have to be carried out.

  18. An experimental investigation of the isochoric heat capacity of superheated steam and mixtures of superheated steam and hydrogen gas

    International Nuclear Information System (INIS)

    Nowak, E.S.; Chan, J.S.

    1975-01-01

    Measurements on the specific heat at constant volume of superheated steam and hydrogen gas mixtures at concentrations varying from 1.6 to 0.8 moles of water vapor per mole of hydrogen gas were made for temperatures ranging from 240 to 400 deg C. It was found that the experimental specific heat values of the mixtures are in good agreement with the ideal mixture values only near the saturation temperature of steam. The difference between the measured and the calculated ideal mixture values is a function of temperature, pressure and composition varying from about 11 to 24% at conditions far removed from the saturation temperature of steam. This indicates the heat of mixing is of significance in the steam-hydrogen system

  19. Techno-economic evaluation of hybrid systems for hydrogen production from biomass and natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Kassem, N. [Royal Institute of Technology, Stockholm (Sweden). Dept. of Energy Processes

    2001-07-01

    Hydrogen (H{sub 2}) is an alternative energy carrier, which is expected to significantly contribute to globally sustainable energy systems. It is environmentally friendly with high-energy density that makes it an excellent integrating fuel in transportation and power generation systems. This paper presents an assessment of the techno-economic viability of H{sub 2} production technologies based on hybrid systems using gasified biomass and natural gas combined with high temperature electrochemical shift. Assessment of the well-established thermal processes, high-temperature steam electrolysis (HTEL), and the plasma catalytic reforming (PCR) of light hydrocarbons developed at MIT are included for comparison. The results show that the PCR and HTEL processes are as cost-effective as the thermal steam reforming for H{sub 2} production when deployed on a commercial scale. The natural gas steam reforming (NGSR) is still the most favorable choice in energy and financial terms, while gasified biomass (GB) provides the highest production costs due to the intensive capital cost investments. The cost of H{sub 2} storage in the form of compressed gas or liquefied H{sub 2} also contributes significantly to total cost per kg produced H{sub 2}. 9 refs., 7 figs., 2 tabs.

  20. Studying heat integration options for steam-gas power plants retrofitted with CO2 post-combustion capture

    International Nuclear Information System (INIS)

    Carapellucci, Roberto; Giordano, Lorena; Vaccarelli, Maura

    2015-01-01

    Electricity generation from fossil fuels has become a focal point of energy and climate change policies due to its central role in modern economics and its leading contribution to greenhouse gas emissions. Carbon capture and sequestration (CCS) is regarded by the International Energy Agency as an essential part of the technology portfolio for carbon mitigation, as it can significantly reduce CO 2 emissions while ensuring electricity generation from fossil fuel power plants. This paper studies the retrofit of natural gas combined cycles (NGCCs) with an amine-based post-combustion carbon capture system. NGCCs with differently rated capacities were analysed under the assumptions that the heat requirement of the capture system was provided via a steam extraction upstream of the low-pressure steam turbine or by an auxiliary unit that was able to reduce the power plant derating related to the energy needs of the CCS system. Different types of auxiliary units were investigated based on power plant size, including a gas turbine cogeneration plant and a supplementary firing unit or boiler fed by natural gas or biomass. Energy and economic analyses were performed in order to evaluate the impact of type and layout of retrofit option on energy, environmental and economic performance of NGCCs with the CCS system. - Highlights: • Steam-gas power plants with an amine-based CO 2 capture unit are examined. • The study concerns three combined cycles with different capacity and plant layout. • Several options to fulfil the heat requirement of the CCS system are explored. • Steam extraction significantly reduces the capacity of steam-gas power plant. • An auxiliary combined heat and power unit allows to reduce power plant derating

  1. Synthesis gas production via hybrid steam reforming of natural gas and bio-liquids

    NARCIS (Netherlands)

    Balegedde Ramachandran, P.

    2013-01-01

    This thesis deals with (catalytic) steam reforming of bio-liquids for the production of synthesis gas. Glycerol, both crude from the biodiesel manufacturing and refined, and pyrolysis oil are tested as bio-based feedstocks. Liquid bio-based feeds could be preferred over inhomogeneous fibrous solid

  2. Steam reforming of different biomass tar model compounds over Ni/Al_2O_3 catalysts

    International Nuclear Information System (INIS)

    Artetxe, Maite; Alvarez, Jon; Nahil, Mohamad A.; Olazar, Martin; Williams, Paul T.

    2017-01-01

    Highlights: • Order of reactivity: anisole > furfural > indene > phenol > toluene > methyl naphthalene. • Higher coke deposition for oxygenates (1.5–2.8%) than for aromatics (0.5–0.8%). • Amorphous coke is deposited for oxygenates and filamentous carbon for aromatics. • Ni content of 20 wt.% shows the higher conversion (90%) and H_2 potential (63%). - Abstract: This work focuses on the removal of the tar derived from biomass gasification by catalytic steam reforming on Ni/Al_2O_3 catalysts. Different tar model compounds (phenol, toluene, methyl naphthalene, indene, anisole and furfural) were individually steam reformed (after dissolving each one in methanol), as well as a mixture of all of them, at 700 °C under a steam/carbon (S/C) ratio of 3 and 60 min on stream. The highest conversions and H_2 potential were attained for anisole and furfural, while methyl naphthalene presented the lowest reactivity. Nevertheless, the higher reactivity of oxygenates compared to aromatic hydrocarbons promoted carbon deposition on the catalyst (in the 1.5–2.8 wt.% range). When the concentration of methanol is decreased in the feedstock and that of toluene or anisole is increased, the selectivity to CO is favoured in the gaseous products, thus increasing coke deposition on the catalyst and decreasing catalyst activity for the steam reforming reaction. Moreover, an increase in Ni loading in the catalyst from 5 to 20% enhances carbon conversion and H_2 formation in the steam reforming of a mixture of all the model compounds studied, but these values decrease for a Ni content of 40%. Coke formation also increased by increasing Ni loading, attaining its maximum value for 40% Ni (6.5 wt.%).

  3. Performance evaluation of a biomass boiler on the basis of heat loss method and total heat values of steam

    International Nuclear Information System (INIS)

    Munir, A.; Alvi, J.Z.; Ashfaq, S.; Ghafoor, A.

    2014-01-01

    Pakistan being an agricultural country has large resources of biomass in the form of crop residues like wood, wheat straw, rice husk, cotton sticks and bagasse. Power generation using biomass offers an excellent opportunity to overcome current scenario of energy crises. Of the all biomass resources, bagasse is one of the potential energy sources which can be successfully utilized for power generation. During the last decade, bagasse fired boilers attained major importance due to increasing prices of primary energy (e.g. fossil fuels). Performance of a bagasse fired boiler was evaluated at Shakarganj Sugar Mill, Bhone-Jhang having steam generation capacity of 80 tons h/sup -1/at 25 bar working pressure. The unit was forced circulation and bi-drum type water tube boiler which was equipped with all accessories like air heater, economizer and super-heater. Flue gas analyzer and thermocouples were used to record percent composition and temperature of flue gases respectively. Physical analysis of bagasse showed gross calorific value of bagasse as 2326 kCal kg/sup -1/. Ultimate analysis of bagasse was performed and the actual air supplied to the boiler was calculated to be 4.05 kg per kg of bagasse under the available resources of the plant. Performance evaluation of the boiler was carried out and a complete heat balance sheet was prepared to investigate the different sources of heat losses. The efficiency of the boiler was evaluated on the basis of heat losses through boiler and was found to be 56.08%. It was also determined that 2 kg of steam produced from 1 kg of bagasse under existing condition of the boiler. The performance evaluation of the boiler was also done on the basis of total heat values of steam and found to be 55.98%. The results obtained from both the methods were found almost similar. Effects of excess air, stack and ambient temperature on the efficiency of boiler have also been evaluated and presented in the manuscript. (author)

  4. Compatibility of gas turbine materials with steam cooling

    Energy Technology Data Exchange (ETDEWEB)

    Desai, V.; Tamboli, D.; Patel, Y. [Univ. of Central Florida, Orlando, FL (United States)

    1995-10-01

    Gas turbines had been traditionally used for peak load plants and remote locations as they offer advantage of low installation costs and quick start up time. Their use as a base load generator had not been feasible owing to their poor efficiency. However, with the advent of gas turbines based combined cycle plants (CCPs), continued advances in efficiency are being made. Coupled with ultra low NO{sub x} emissions, coal compatibility and higher unit output, gas turbines are now competing with conventional power plants for base load power generation. Currently, the turbines are designed with TIT of 2300{degrees}F and metal temperatures are maintained around 1700{degrees}F by using air cooling. New higher efficiency ATS turbines will have TIT as high as 2700{degrees}F. To withstand this high temperature improved materials, coatings, and advances in cooling system and design are warranted. Development of advanced materials with better capabilities specifically for land base applications are time consuming and may not be available by ATS time frame or may prove costly for the first generation ATS gas turbines. Therefore improvement in the cooling system of hot components, which can take place in a relatively shorter time frame, is important. One way to improve cooling efficiency is to use better cooling agent. Steam as an alternate cooling agent offers attractive advantages because of its higher specific heat (almost twice that of air) and lower viscosity.

  5. 16 CFR Appendix G5 to Part 305 - Boilers-Gas (Except Steam)

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Boilers-Gas (Except Steam) G5 Appendix G5 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE... Appendix G5 to Part 305—Boilers—Gas (Except Steam) Manufacturer's rated heating capacities (Btu's/hr...

  6. 16 CFR Appendix G6 to Part 305 - Boilers-Gas (Steam)

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Boilers-Gas (Steam) G6 Appendix G6 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE... Appendix G6 to Part 305—Boilers—Gas (Steam) Manufacturer's rated heating capacities (Btu's/hr.) Range of...

  7. Gas chromatographic measurement in water-steam circuits

    International Nuclear Information System (INIS)

    Zschetke, J.; Nieder, R.

    1984-01-01

    A gas chromatographic technique for measurements in water-steam circuits, which has been well known for many years, has been improved by design modifications. A new type of equipment developed for special measuring tasks on nuclear engineering plant also has a general application. To date measurements have been carried out on the ''Otto Hahn'' nuclear powered ship, on the KNK and AVR experimental nuclear power plants at Karlsruhe and Juelich respectively and on experimental boiler circuits. The measurements at the power plants were carried out under different operating conditions. In addition measurements during the alkali operating mode and during combined cycle operation were carried out on the AVR reactor. It has been possible to draw new conclusion from the many measurements undertaken. (orig.) [de

  8. Numerical Research of Steam and Gas Plant Efficiency of Triple Cycle for Extreme North Regions

    Directory of Open Access Journals (Sweden)

    Galashov Nikolay

    2016-01-01

    Full Text Available The present work shows that temperature decrease of heat rejection in a cycle is necessary for energy efficiency of steam turbine plants. Minimum temperature of heat rejection at steam turbine plant work on water steam is 15°C. Steam turbine plant of triple cycle where lower cycle of steam turbine plant is organic Rankine cycle on low-boiling substance with heat rejection in air condenser, which safely allows rejecting heat at condensation temperatures below 0°C, has been offered. Mathematical model of steam and gas plant of triple cycle, which allows conducting complex researches with change of working body appearance and parameters defining thermodynamic efficiency of cycles, has been developed. On the basis of the model a program of parameters and index cycles design of steam and gas plants has been developed in a package of electron tables Excel. Numerical studies of models showed that energy efficiency of steam turbine plants of triple cycle strongly depend on low-boiling substance type in a lower cycle. Energy efficiency of steam and gas plants net 60% higher can be received for steam and gas plants on the basis of gas turbine plant NK-36ST on pentane and its condensation temperature below 0°C. It was stated that energy efficiency of steam and gas plants net linearly depends on condensation temperature of low-boiling substance type and temperature of gases leaving reco very boiler. Energy efficiency increases by 1% at 10% decrease of condensation temperature of pentane, and it increases by 0.88% at 15°C temperature decrease of gases leaving recovery boiler.

  9. Interpretation of biomass gasification yields regarding temperature intervals under nitrogen-steam atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Haykiri-Acma, H.; Yaman, S. [Istanbul Technical University, Chemical and Metallurgical Engineering Faculty, Chemical Engineering Department, 34469 Maslak, Istanbul (Turkey)

    2007-04-15

    Gasification of some agricultural waste biomass samples (sunflower shell, pine cone, cotton refuse, and olive refuse) and colza seed was performed using a thermogravimetric analyzer at temperatures up to 1273 K with a constant heating rate of 20 K/min under a dynamic nitrogen-steam atmosphere. Derivative thermogravimetric analysis profiles of the samples were derived from the non-isothermal thermogravimetric analysis data. Gasification yields of the biomass samples at temperature intervals of 473-553 K, 553-653 K, 653-773 K, 773-973 K, and 973-1173 K were investigated considering the successive stages of ''evolution of carbon oxides'', ''start of hydrocarbon evolution'', ''evolution of hydrocarbons'', ''dissociation'', and ''evolution of hydrogen'', respectively. Although, there were some interactions between these stages, some evident relations were observed between the gasification yields in a given stage and the chemical properties of the parent biomass materials. (author)

  10. Methods of increasing thermal efficiency of steam and gas turbine plants

    Science.gov (United States)

    Vasserman, A. A.; Shutenko, M. A.

    2017-11-01

    Three new methods of increasing efficiency of turbine power plants are described. Increasing average temperature of heat supply in steam turbine plant by mixing steam after overheaters with products of combustion of natural gas in the oxygen. Development of this idea consists in maintaining steam temperature on the major part of expansion in the turbine at level, close to initial temperature. Increasing efficiency of gas turbine plant by way of regenerative heating of the air by gas after its expansion in high pressure turbine and before expansion in the low pressure turbine. Due to this temperature of air, entering combustion chamber, is increased and average temperature of heat supply is consequently increased. At the same time average temperature of heat removal is decreased. Increasing efficiency of combined cycle power plant by avoiding of heat transfer from gas to wet steam and transferring heat from gas to water and superheated steam only. Steam will be generated by multi stage throttling of the water from supercritical pressure and temperature close to critical, to the pressure slightly higher than condensation pressure. Throttling of the water and separation of the wet steam on saturated water and steam does not require complicated technical devices.

  11. Optimal placement of biomass fuelled gas turbines for reduced losses

    International Nuclear Information System (INIS)

    Jurado, Francisco; Cano, Antonio

    2006-01-01

    This paper presents a method for the optimal location and sizing of biomass fuelled gas turbine power plants. Both profitability in using biomass and power loss are considered in the cost function. The first step is to assess the plant size that maximizes the profitability of the project. The second step is to determine the optimal location of the gas turbines in the electric system to minimize the power loss of the system

  12. Green gas. Gas of natural gas quality from biomass. Update of the 2004 study

    International Nuclear Information System (INIS)

    Welink, Jan-Henk; Dumont, M.; Kwant, K.

    2007-01-01

    In 2004 a study was published on green gas. Green gas is defined as a gaseous energy carrier from renewable biomass with a similar quality as natural gas. As a result of new developments in the field of co-digestion/fermentation the Dutch Ministry of Economic Affairs asked it's agency SenterNovem to update the 2004 study. The aim of the update is (1) to gain insight into operational aspects of green gas projects, e.g. reliability, efficiency and maintenance aspects; (2) stimulate the production of green gas, taking into account the economics of green gas projects, calculation of the financial gap of green gas production, efficient use of biogas (conversion to electricity or directly input into the natural gas distribution systems, and aspects with regard to commercialization and the market; and (3) the potential of green gas [nl

  13. Biomass gasification hot gas cleanup for power generation

    Energy Technology Data Exchange (ETDEWEB)

    Wiant, B.C.; Bachovchin, D.M. [Westinghouse Electric Corp., Orlando, FL (United States); Carty, R.H.; Onischak, M. [Institute of Gas Technology, Chicago, IL (United States); Horazak, D.A. [Gilbert/Commonwealth, Reading, PA (United States); Ruel, R.H. [The Pacific International Center for High Technology Research, Honolulu, HI (United States)

    1993-12-31

    In support of the US Department of Energy`s Biomass Power Program, a Westinghouse Electric led team consisting of the Institute of Gas Technology (IGT), Gilbert/Commonwealth (G/C), and the Pacific International Center for High Technology Research (PICHTR), is conducting a 30 month research and development program. The program will provide validation of hot gas cleanup technology with a pressurized fluidized bed, air-blown, biomass gasifier for operation of a gas turbine. This paper discusses the gasification and hot gas cleanup processes, scope of work and approach, and the program`s status.

  14. Catalytic Steam Reforming of Toluene as a Model Compound of Biomass Gasification Tar Using Ni-CeO2/SBA-15 Catalysts

    Directory of Open Access Journals (Sweden)

    Erik Dahlquist

    2013-07-01

    Full Text Available Nickel supported on SBA-15 doped with CeO2 catalysts (Ni-CeO2/SBA-15 was prepared, and used for steam reforming of toluene which was selected as a model compound of biomass gasification tar. A fixed-bed lab-scale set was designed and employed to evaluate the catalytic performances of the Ni-CeO2/SBA-15 catalysts. Experiments were performed to reveal the effects of several factors on the toluene conversion and product gas composition, including the reaction temperature, steam/carbon (S/C ratio, and CeO2 loading content. Moreover, the catalysts were subjected to analysis of their carbon contents after the steam reforming experiments, as well as to test the catalytic stability over a long experimental period. The results indicated that the Ni-CeO2/SBA-15 catalysts exhibited promising capabilities on the toluene conversion, anti-coke deposition and catalytic stability. The toluene conversion reached as high as 98.9% at steam reforming temperature of 850 °C and S/C ratio of 3 using the Ni-CeO2(3wt%/SBA-15 catalyst. Negligible coke formation was detected on the used catalyst. The gaseous products mainly consisted of H2 and CO, together with a little CO2 and CH4.

  15. Gas, power and heat generation from biomass by allothermal gasification; Gas-, Strom- und Waermeerzeugung aus Biomasse durch allotherme Vergasung

    Energy Technology Data Exchange (ETDEWEB)

    Yaqub Chughtai, M [H und C Engineering GmbH, Gummersbach (Germany); Muehlen, H J [DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany)

    1998-09-01

    The allothermal DMT gasification process for biomass is a newcomer. The process, its initial materials, the uses of the product gas, and advantages of the allothermal process are described here. (orig./SR) [Deutsch] Der Einsatz des allothermen DMT-Vergasungsverfahrens fuer Biomasse ist neu. Verfahren, Einsatzstoffe und Produktgasnutzung, sowie Vorteile des allothermen Verfahrens werden hier beschrieben. (orig./SR)

  16. The kinetics of steam-carbon dioxide conversion, rational ways and production catalysts of process gas

    International Nuclear Information System (INIS)

    Khamroev, F.B.

    2016-01-01

    The purpose of the present work is to study the kinetics of steam-carbon dioxide conversion, rational ways and production catalysts of process gas. The experimental equation of steam-carbon methane conversion, heat stability increasing and catalyst efficiency, decreasing of hydrodynamical resistance of catalyst layer were determined.

  17. Preliminary assessment of synthesis gas production via hybrid steam reforming of methane and glycerol

    NARCIS (Netherlands)

    Balegedde Ramachandran, P.; van Rossum, G.; Kersten, Sascha R.A.; van Swaaij, Willibrordus Petrus Maria

    2012-01-01

    In this article, hybrid steam reforming (HSR) of desulphurized methane, together with crude glycerol, in existing commercial steam reformers to produce synthesis gas is proposed. The proposed concept consists of a gasifier to produce vapors, gases, and char from crude glycerol, which is coupled with

  18. Hydrogen-rich gas production by cogasification of coal and biomass in an intermittent fluidized bed.

    Science.gov (United States)

    Wang, Li-Qun; Chen, Zhao-Sheng

    2013-01-01

    This paper presents the experimental results of cogasification of coal and biomass in an intermittent fluidized bed reactor, aiming to investigate the influences of operation parameters such as gasification temperature (T), steam to biomass mass ratio (SBMR), and biomass to coal mass ratio (BCMR) on hydrogen-rich (H2-rich) gas production. The results show that H2-rich gas free of N2 dilution is produced and the H2 yield is in the range of 18.25~68.13 g/kg. The increases of T, SBMR, and BCMR are all favorable for promoting the H2 production. Higher temperature contributes to higher CO and H2 contents, as well as H2 yield. The BCMR has a weak influence on gas composition, but the yield and content of H2 increase with BCMR, reaching a peak at the BCMR of 4. The H2 content and yield in the product gas increase with SBMR, whilst the content of CO increases first and then decreases correspondingly. At a typical case, the relative linear sensitivity coefficients of H2 production efficiency to T, SBMR, and BCMR were calculated. The results reveal that the order of the influence of the operation parameters on H2 production efficiency is T > SBMR > BCMR.

  19. Biomass Gas Cleanup Using a Therminator

    Energy Technology Data Exchange (ETDEWEB)

    Dayton, David C; Kataria, Atish; Gupta, Rabhubir

    2012-03-06

    The objective of the project is to develop and demonstrate a novel fluidized-bed process module called a Therminator to simultaneously destroy and/or remove tar, NH3 and H2S from raw syngas produced by a fluidized-bed biomass gasifier. The raw syngas contains as much as 10 g/m3 of tar, 4,000 ppmv of NH3 and 100 ppmv of H2S. The goal of the Therminator module would be to use promising regenerable catalysts developed for removing tar, ammonia, and H2S down to low levels (around 10 ppm). Tars are cracked to a non-condensable gas and coke that would deposit on the acid catalyst. We will deposit coke, much like a fluid catalytic cracker (FCC) in a petroleum refinery. The deposited coke fouls the catalyst, much like FCC, but the coke would be burned off in the regenerator and the regenerated catalyst would be returned to the cracker. The rapid circulation between the cracker and regenerator would ensure the availability of the required amount of regenerated catalyst to accomplish our goal. Also, by removing sulfur down to less than 10 ppmv, NH3 decomposition would also be possible in the cracker at 600-700°C. In the cracker, tar decomposes and lays down coke on the acid sites of the catalyst, NH3 is decomposed using a small amount of metal (e.g., nickel or iron) catalyst incorporated into the catalyst matrix, and H2S is removed by a small amount of a metal oxide (e.g. zinc oxide or zinc titanate) by the H2S-metal oxide reaction to form metal sulfide. After a tolerable decline in activity for these reactions, the catalyst particles (and additives) are transported to the regenerator where they are exposed to air to remove the coke and to regenerate the metal sulfide back to metal oxide. Sulfate formation is avoided by running the regeneration with slightly sub-stoichiometric quantity of oxygen. Following regeneration, the catalyst is transported back to the cracker and the cycling continues. Analogous to an FCC reactor system, rapid cycling will allow the use of very

  20. Power Plants, Steam and Gas Turbines WebQuest

    Directory of Open Access Journals (Sweden)

    Carlos Ulloa

    2012-10-01

    Full Text Available A WebQuest is an Internet-based and inquiry-oriented learning activity. The aim of this work is to outline the creation of a WebQuest entitled “Power Generation Plants: Steam and Gas Turbines.” This is one of the topics covered in the course “Thermodynamics and Heat Transfer,” which is offered in the second year of Mechanical Engineering at the Defense University Center at the Naval Academy in Vigo, Spain. While participating in the activity, students will be divided into groups of no more than 10 for seminars. The groups will create PowerPoint presentations that include all of the analyzed aspects. The topics to be discussed during the workshop on power plant turbines are the: (1 principles of operation; (2 processes involved; (3 advantages and disadvantages; (4 efficiency; (5 combined cycle; and (6 transversal competences, such as teamwork, oral and written presentations, and analysis and synthesis of information. This paper presents the use of Google Sites as a guide to the WebQuest so that students can access all information online, including instructions, summaries, resources, and information on qualifications.

  1. Gas turbines: gas cleaning requirements for biomass-fired systems

    OpenAIRE

    Oakey, John; Simms, Nigel; Kilgallon, Paul

    2004-01-01

    Increased interest in the development of renewable energy technologies has been hencouraged by the introduction of legislative measures in Europe to reduce CO2 emissions from power generation in response to the potential threat of global warming. Of these technologies, biomass-firing represents a high priority because of the modest risk involved and the availability of waste biomass in many countries. Options based on farmed biomass are also under development. This paper reviews the challenge...

  2. CPFD simulations of an industrial-sized dual fluidized bed steam gasification system of biomass with 8 MW fuel input

    International Nuclear Information System (INIS)

    Kraft, Stephan; Kirnbauer, Friedrich; Hofbauer, Hermann

    2017-01-01

    Highlights: • We simulated an 8 MWth steam gasification system with the CPFD code Barracuda. • The prediction of the hydrodynamics depends strongly upon the chosen drag law. • The EMMS drag law predicted best the bed material recirculation and pressure drops. • The model of the DFB plant is able to predict the operation accurately. - Abstract: Dual fluidized bed (DFB) systems for biomass gasification consist of two connected fluidized beds with a circulating bed material in between. Inside such reactor systems, rough conditions occur due to the high temperatures and the movement of the bed material. Computational fluid dynamics calculations are a useful tool for investigating fluid dynamics inside such a reactor system. In this study, an industrial-sized DFB system was simulated with the commercial code CPFD Barracuda. The DFB system is part of the combined heat and power (CHP) plant at Güssing, situated in Austria, and has a total fuel input of 8 MW_t_h. The model was set up according to geometry and operating data which allows a realistic description of the hot system in the simulation environment. Furthermore, a conversion model for the biomass particles was implemented which covers the drying and devolatilization processes. Homogeneous and heterogeneous reactions were considered. Since drag models have an important influence on fluidization behavior, four drag models were tested. It was found that the EMMS drag model fits best, with an error of below 20%, whereas the other drag models produced much larger errors. Based on this drag law, further simulations were conducted. The simulation model correctly predicts the different fluidization regimes and pressure drops in the reactor system. It is also able to predict the compositions of the product and flue gas, as well as the temperatures inside the reactor, with reasonable accuracy. Due to the results obtained, Barracuda seems suitable for further investigations regarding the fluid mechanics of such

  3. Hydrogen rich gas production by thermocatalytic decomposition of kenaf biomass

    Energy Technology Data Exchange (ETDEWEB)

    Irmak, Sibel; Oeztuerk, ilker [Department of Chemistry, Cukurova University, Arts and Sciences Faculty, Adana 01330 (Turkey)

    2010-06-15

    Kenaf (Hibiscus cannabinus L.), a well known energy crop and an annual herbaceous plant grows very fast with low lodging susceptibility was used as representative lignocellulosic biomass in the present work. Thermocatalytic conversions were performed by aqueous phase reforming (APR) of kenaf hydrolysates and direct gasification of solid biomass of kenaf using 5% Pt on activated carbon as catalyst. Hydrolysates used in APR experiments were prepared by solubilization of kenaf biomass in subcritical water under CO{sub 2} gas pressure. APR of kenaf hydrolysate with low molecular weight polysaccharides in the presence of the reforming catalyst produced more gas compared to the hydrolysate that had high molecular weight polysaccharides. APR experiments of kenaf biomass hydrolysates and glucose, which was used as a simplest biomass model compound, in the presence of catalyst produced various amounts of gas mixtures that consisted of H{sub 2}, CO, CO{sub 2}, CH{sub 4} and C{sub 2}H{sub 6}. The ratios of H{sub 2} to other gases produced were 0.98, 1.50 and 1.35 for 150 C and 250 C subcritical water-treated kenaf hydrolysates and glucose, respectively. These ratios indicated that more the degraded organic content of kenaf hydrolysate the better selectivity for hydrogen production. Although APR of 250 C-kenaf hydrolysate resulted in similar gas content and composition as glucose, the gas volume produced was three times higher in glucose feed. The use of solid kenaf biomass as starting feedstock in APR experiments resulted in less gas production since the activity of catalyst was lowered by solid biomass particles. (author)

  4. Hydrogen Production by Steam Reforming of Natural Gas Over Vanadium-Nickel-Alumina Catalysts.

    Science.gov (United States)

    Yoo, Jaekyeong; Park, Seungwon; Song, Ji Hwan; Song, In Kyu

    2018-09-01

    A series of vanadium-nickel-alumina (xVNA) catalysts were prepared by a single-step sol-gel method with a variation of vanadium content (x, wt%) for use in the hydrogen production by steam reforming of natural gas. The effect of vanadium content on the physicochemical properties and catalytic activities of xVNA catalysts in the steam reforming of natural gas was investigated. It was found that natural gas conversion and hydrogen yield showed volcano-shaped trends with respect to vanadium content. It was also revealed that natural gas conversion and hydrogen yield increased with decreasing nickel crystallite size.

  5. Biomass energy: Sustainable solution for greenhouse gas emission

    Science.gov (United States)

    Sadrul Islam, A. K. M.; Ahiduzzaman, M.

    2012-06-01

    sustainable carbon sink will be developed. Clean energy production from biomass (such as ethanol, biodiesel, producer gas, bio-methane) could be viable option to reduce fossil fuel consumption. Electricity generation from biomass is increasing throughout the world. Co-firing of biomass with coal and biomass combustion in power plant and CHP would be a viable option for clean energy development. Biomass can produce less emission in the range of 14% to 90% compared to emission from fossil for electricity generation. Therefore, biomass could play a vital role for generation of clean energy by reducing fossil energy to reduce greenhouse gas emissions. The main barriers to expansion of power generation from biomass are cost, low conversion efficiency and availability of feedstock. Internationalization of external cost in power generation and effective policies to improve energy security and carbon dioxide reduction is important to boost up the bio-power. In the long run, bio-power will depend on technological development and on competition for feedstock with food production and arable land use.

  6. Calculating the flue gas dew point for raw brown coal fired steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Schinkel, W.

    1977-01-01

    The paper analyzes parameters influencing the sulfuric acid dew point in flue gas of steam generators. Sulfur content and alkaline earths content in the fuel air ratio during combustion, fly ash content in the flue gas (which absorbs sulfur dioxide and sulfur trioxide) and combustion conditions in steam generators are relevant parameters in the combustion process. A thermodynamic and reaction kinetic calculation of the sulfuric acid dew point is, however, not yet possible. A statistical evaluation of dew point measurements in steam generators is, therefore, employed. Various diagrams show results of dew point measurements carried out at generators with steam capacities ranging from 40 to 660 t/h, which demonstrate relations of these parameters to flue gas dew points, in particular the relative sulfur content (sulfur content in the raw brown coal compared to coal ash content and alkaline earths content). A function is derived for the conversion of fuel sulfur to sulfur trioxide. A diagram presents the relation of the flue gas dew point to partial pressures of sulfuric acid and steam. Direct calculation of the flue gas dew point was achieved by the proposed method. It is applied in steam generator design. (17 refs.)

  7. An experimental approach aiming the production of a gas mixture composed of hydrogen and methane from biomass as natural gas substitute in industrial applications.

    Science.gov (United States)

    Kraussler, Michael; Schindler, Philipp; Hofbauer, Hermann

    2017-08-01

    This work presents an experimental approach aiming the production of a gas mixture composed of H 2 and CH 4 , which should serve as natural gas substitute in industrial applications. Therefore, a lab-scale process chain employing a water gas shift unit, scrubbing units, and a pressure swing adsorption unit was operated with tar-rich product gas extracted from a commercial dual fluidized bed biomass steam gasification plant. A gas mixture with a volumetric fraction of about 80% H 2 and 19% CH 4 and with minor fractions of CO and CO 2 was produced by employing carbon molecular sieve as adsorbent. Moreover, the produced gas mixture had a lower heating value of about 15.5MJ·m -3 and a lower Wobbe index of about 43.4MJ·m -3 , which is similar to the typical Wobbe index of natural gas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Gas Phase Sulfur, Chlorine and Potassium Chemistry in Biomass Combustion

    DEFF Research Database (Denmark)

    Løj, Lusi Hindiyarti

    2007-01-01

    Gas Phase Sulfur, Chlorine and Alkali Metal Chemistry in Biomass Combustion Concern about aerosols formation, deposits, corrosion, and gaseous emissions during biomass combustion, especially straw, continues to be a driving force for investigation on S, Cl, K-containing species under combustions...... conditions. These trace species contained in the biomass structure will be released to the gas phase during combustion and contribute to the problems generated during the process. The investigation during this PhD project is done to stepwise improve the understanding in the chemistry and reduce...... the uncertainties. In the present work, the detailed kinetic model for gas phase sulfur, chlorine, alkali metal, and their interaction has been updated. The K/O/H/Cl chemistry, S chemistry, and their interaction can reasonably predict a range of experimental data. In general, understanding of the interaction...

  9. Steam conversion of liquefied petroleum gas and methane in microchannel reactor

    Science.gov (United States)

    Dimov, S. V.; Gasenko, O. A.; Fokin, M. I.; Kuznetsov, V. V.

    2018-03-01

    This study presents experimental results of steam conversion of liquefied petroleum gas and methane in annular catalytic reactor - heat exchanger. The steam reforming was done on the Rh/Al2O3 nanocatalyst with the heat applied through the microchannel gap from the outer wall. Concentrations of the products of chemical reactions in the outlet gas mixture are measured at different temperatures of reactor. The range of channel wall temperatures at which the ratio of hydrogen and carbon oxide in the outlet mixture grows substantially is determined. Data on the composition of liquefied petroleum gas conversion products for the ratio S/C = 5 was received for different GHVS.

  10. Integration of steam injection and inlet air cooling for a gas turbine generation system

    International Nuclear Information System (INIS)

    Wang, F.J.; Chiou, J.S.

    2004-01-01

    The temperature of exhaust gases from simple cycle gas turbine generation sets (GENSETs) is usually very high (around 500 deg. C), and a heat recovery steam generator (HRSG) is often used to recover the energy from the exhaust gases and generate steam. The generated steams can be either used for many useful processes (heating, drying, separation etc.) or used back in the power generation system for enhancing power generation capacity and efficiency. Two well-proven techniques, namely steam injection gas turbine (STIG) and inlet air cooling (IAC) are very effective features that can use the generated steam to improve the power generation capacity and efficiency. Since the energy level of the generated steam needed for steam injection is different from that needed by an absorption chiller to cool the inlet air, a proper arrangement is required to implement both the STIG and the IAC features into the simple cycle GENSET. In this study, a computer code was developed to simulate a Tai power's Frame 7B simple cycle GENSET. Under the condition of local summer weather, the benefits obtained from the system implementing both STIG and IAC features are more than a 70% boost in power and 20.4% improvement in heat rate

  11. Optimization of the steam generator project of a gas cooled nuclear reactor

    International Nuclear Information System (INIS)

    Sakai, Massao

    1978-01-01

    The present work is concerned with the modeling of the primary and secondary circuits of a gas cooled nuclear reactor in order to obtain the relation between the parameters of the two cycles and the steam generator performance. The procedure allows the optimization of the steam generator, through the maximization of the plant net power, and the application of the optimal control theory of dynamic systems. The heat balances for the primary and secondary circuits are carried out simultaneously with the optimized - design parameters of the steam generator, obtained using an iterative technique. (author)

  12. Catalytic Steam Reforming of Bio-Oil to Hydrogen Rich Gas

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus

    heating value and high content of oxygen, which makes it unsuited for direct utilization in engines. One prospective technology for upgrading of bio-oil is steam reforming (SR), which can be used to produce H2 for upgrading of bio-oil through hydrodeoxygenation or synthesis gas for processes like......-oil. There are two main pathways to minimize carbon deposition in steam reforming; either through optimization of catalyst formulation or through changes to the process parameters, like changes in temperature, steam to carbon ratio (S/C), or adding O2 or H2 to the feed. In this thesis both pathways have been...

  13. Radiation from Large Gas Volumes and Heat Exchange in Steam Boiler Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, A. N., E-mail: tgtu-kafedra-ese@mail.ru [Tver State Technical University (Russian Federation)

    2015-09-15

    Radiation from large cylindrical gas volumes is studied as a means of simulating the flare in steam boiler furnaces. Calculations of heat exchange in a furnace by the zonal method and by simulation of the flare with cylindrical gas volumes are described. The latter method is more accurate and yields more reliable information on heat transfer processes taking place in furnaces.

  14. 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

  15. Economic evaluation of externally fired gas turbine cycles for small-scale biomass cogeneration

    Energy Technology Data Exchange (ETDEWEB)

    Anheden, Marie [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2001-01-01

    In this conceptual study, externally fired gas turbine (EFGT) cycles in combination with a biomass-fueled, atmospheric circulating fluidized bed (CFB) furnace are investigated for small scale heat and power production ({approx} 8 MW fuel input). Three cycle configurations are considered: closed cycle, with nitrogen, helium, and a helium/carbon dioxide mixture as working fluids; open cycle operating in parallel to the CFB system; and open cycle with a series connection to the CFB system. Intercooling, postcooling, and recuperation are employed with the goal of maximizing efficiency. Aside from a thermodynamic performance analysis, the study includes an economic analysis of both the closed and open externally fired gas turbine configurations, and comparisons are made with existing and emerging alternatives for small-scale biomass cogeneration. Simulation results show that thermodynamic performance varies slightly between the different configurations and working fluids, with electrical efficiencies of 31-38% (LHV) and total efficiency of 85-106% (LHV). The economic evaluation shows that the turbomachinery and the CFB furnace dominate the total plant cost, with each contributing about 1/3 of the total installed equipment cost. The specific capital cost for installation in Sweden in 1998 currency is calculated as 26-31 kSEK/kW{sub e} which is equivalent to 3 200-3 900 USD/kW{sub e} or 2 700-3 300 EUR/kW{sub e} .The cost of electricity, COE, is estimated to 590-670 SEK/MWh{sub e} (equivalent to 73-84 USD/MWh{sub e} or 62-71 EUR/MWh{sub e}) for 4 000 full load hours per year in a cogeneration application. Comparing the economic results for the externally fired gas turbine cycles in a slightly larger scale (40-50 MW{sub f}) to the economics of conventional biomass fired steam turbine cycles shows that the cost of electricity for the two plant configurations are roughly the same with a COE of 300-350 SEK/MWh{sub e}. It is believed that the economic performance of the EFGT

  16. Steam-exploded biomass saccharification is predominately affected by lignocellulose porosity and largely enhanced by Tween-80 in Miscanthus.

    Science.gov (United States)

    Sun, Dan; Alam, Aftab; Tu, Yuanyuan; Zhou, Shiguang; Wang, Yanting; Xia, Tao; Huang, Jiangfeng; Li, Ying; Zahoor; Wei, Xiaoyang; Hao, Bo; Peng, Liangcai

    2017-09-01

    In this study, total ten Miscanthus accessions exhibited diverse cell wall compositions, leading to largely varied hexoses yields at 17%-40% (% cellulose) released from direct enzymatic hydrolysis of steam-exploded (SE) residues. Further supplied with 2% Tween-80 into the enzymatic digestion, the Mis7 accession showed the higher hexose yield by 14.8-fold than that of raw material, whereas the Mis10 had the highest hexoses yield at 77% among ten Miscanthus accessions. Significantly, this study identified four wall polymer features that negatively affect biomass saccharification as pbiomass enzymatic digestion. Hence, this study provides the potential strategy to enhance biomass saccharification using optimal biomass process technology and related genetic breeding in Miscanthus and beyond. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Steam generator materials performance in high temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Chafey, J.E.; Roberts, D.I.

    1980-11-01

    This paper reviews the materials technology aspects of steam generators for HTGRs which feature a graphite-moderated, uranium-thorium, all-ceramic core and utilizes high-pressure helium as the primary coolant. The steam generators are exposed to gas-side temperatures approaching 760 0 C and produce superheated steam at 538 0 C and 16.5 MPa (2400 psi). The prototype Peach Bottom I 40-MW(e) HTGR was operated for 1349 EFPD over 7 years. Examination after decommissioning of the U-tube steam generators and other components showed the steam generators to be in very satisfactory condition. The 330-MW(e) Fort St. Vrain HTGR, now in the final stages of startup, has achieved 70% power and generated more than 1.5 x 10 6 MWh of electricity. The steam generators in this reactor are once-through units of helical configuration, requiring a number of new materials factors including creep-fatigue and water chemistry control. Current designs of larger HTGRs also feature steam generators of helical once-through design. Materials issues that are important in these designs include detailed consideration of time-dependent behavior of both base metals and welds, as required by current American Society of Mechanical Engineers (ASME) Code rules, evaluation of bimetallic weld behavior, evaluation of the properties of large forgings, etc

  18. Analysis of Precooling Injection Transient of Steam Generator for High Temperature Gas Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2017-01-01

    Full Text Available After a postulated design basis accident leads high temperature gas cooled reactor to emergency shutdown, steam generator still remains with high temperature level and needs to be cooled down by a precooling before reactor restarts with clearing of fault. For the large difference of coolant temperature between inlet and outlet of steam generator in normal operation, the temperature distribution on the components of steam generator is very complicated. Therefore, the temperature descending rate of the components in steam generator needs to be limited to avoid the potential damage during the precooling stage. In this paper, a pebble-bed high temperature gas cooled reactor is modeled by thermal-hydraulic system analysis code and several postulated precooling injection transients are simulated and compared to evaluate their effects, which will provide support for the precooling design. The analysis results show that enough precooling injection is necessary to satisfy the precooling requirements, and larger mass flow rate of precooling water injection will accelerate the precooling process. The temperature decrease of steam generator is related to the precooling injection scenarios, and the maximal mass flow rate of the precooling injection should be limited to avoid the excessively quick temperature change of the structures in steam generator.

  19. Processing of biomass to Hydrocarbons – using a new catalytic steam pyrolysis route

    OpenAIRE

    Mellin, Pelle; Kantarelis, Efthymios; Yang, Weihong

    2014-01-01

    Obtaining renewable transportation fuel has been identified as one of the main challenges for a sustainable society. Catalytic pyrolysis followed by hydrotreatment has been demonstrated as one possible route for producing transportation fuels. Using steam in this process could have a number of benefits as given by our research effort. For this paper, we will show that a catalyst together with steam prolongs the activity of the catalyst by preventing coking. This means that both steam and cata...

  20. High-temperature gas-cooled reactor steam cycle/cogeneration application study update

    International Nuclear Information System (INIS)

    1981-09-01

    Since publication of a report on the application of a High Temperature Gas-Cooled Reactor Steam Cycle/Cogeneration (HTGR-SC/C) plant in December of 1980, progress has continued on application related activities. In particular, a reference plant and an application identification effort has been performed, a variable cogeneration cycle balance-of-plant design was developed and an updated economic analysis was prepared. A reference HTGR-SC/C plant size of 2240 MW(t) was selected, primarily on the basis of 2240 MW(t) being in the mid-range of anticipated application needs and the availability of the design data from the 2240 MW(t) Steam Cycle/Electric generation plant design. A variable cogeneration cycle plant design was developed having the capability of operating at a range of process steam loads between the reference design load (full cogeneration) and the no process steam load condition

  1. Catalytic Production of Ethanol from Biomass-Derived Synthesis Gas

    Energy Technology Data Exchange (ETDEWEB)

    Trewyn, Brian G. [Colorado School of Mines, Golden, CO (United States); Smith, Ryan G. [Iowa State Univ., Ames, IA (United States)

    2016-06-01

    Heterogeneous catalysts have been developed for the conversion of biomass-derived synthetic gas (syngas) to ethanol. The objectives of this project were to develop a clean synthesis gas from biomass and develop robust catalysts with high selectivity and lifetime for C2 oxygenate production from biomass-derived syngas and surrogate syngas. During the timeframe for this project, we have made research progress on the four tasks: (1) Produce clean bio-oil generated from biomass, such as corn stover or switchgrass, by using fast pyrolysis system, (2) Produce clean, high pressure synthetic gas (syngas: carbon monoxide, CO, and hydrogen, H2) from bio-oil generated from biomass by gasification, (3) Develop and characterize mesoporous mixed oxide-supported metal catalysts for the selective production of ethanol and other alcohols, such as butanol, from synthesis gas, and (4) Design and build a laboratory scale synthesis gas to ethanol reactor system evaluation of the process. In this final report, detailed explanations of the research challenges associated with this project are given. Progress of the syngas production from various biomass feedstocks and catalyst synthesis for upgrading the syngas to C2-oxygenates is included. Reaction properties of the catalyst systems under different reaction conditions and different reactor set-ups are also presented and discussed. Specifically, the development and application of mesoporous silica and mesoporous carbon supports with rhodium nanoparticle catalysts and rhodium nanoparticle with manganese catalysts are described along with the significant material characterizations we completed. In addition to the synthesis and characterization, we described the activity and selectivity of catalysts in our micro-tubular reactor (small scale) and fixed bed reactor (larger scale). After years of hard work, we are proud of the work done on this project, and do believe that this work will provide a solid

  2. Hynol: An economic process for methanol production from biomass and natural gas with reduced CO2 emission

    Science.gov (United States)

    Steinberg, M.; Dong, Yuanji

    1993-10-01

    The Hynol process is proposed to meet the demand for an economical process for methanol production with reduced CO2 emission. This new process consists of three reaction steps: (1) hydrogasification of biomass, (2) steam reforming of the produced gas with additional natural gas feedstock, and (3) methanol synthesis of the hydrogen and carbon monoxide produced during the previous two steps. The H2-rich gas remaining after methanol synthesis is recycled to gasify the biomass in an energy neutral reactor so that there is no need for an expensive oxygen plant as required by commercial steam gasifiers. Recycling gas allows the methanol synthesis reactor to perform at a relatively lower pressure than conventional while the plant still maintains high methanol yield. Energy recovery designed into the process minimizes heat loss and increases the process thermal efficiency. If the Hynol methanol is used as an alternative and more efficient automotive fuel, an overall 41% reduction in CO2 emission can be achieved compared to the use of conventional gasoline fuel. A preliminary economic estimate shows that the total capital investment for a Hynol plant is 40% lower than that for a conventional biomass gasification plant. The methanol production cost is $0.43/gal for a 1085 million gal/yr Hynol plant which is competitive with current U.S. methanol and equivalent gasoline prices. Process flowsheet and simulation data using biomass and natural gas as cofeedstocks are presented. The Hynol process can convert any condensed carbonaceous material, especially municipal solid waste (MSW), to produce methanol.

  3. A comparative economic assessment of hydrogen production from coke oven gas, water electrolysis and steam reforming of natural gas

    International Nuclear Information System (INIS)

    Nguyen, Y.V.; Ngo, Y.A.; Tinkler, M.J.; Cowan, N.

    2003-01-01

    This paper presents the comparative economics of producing hydrogen for the hydrogen economy by recovering it from waste gases from the steel industry, by water electrolysis and by conventional steam reforming of natural gas. Steel makers produce coke for their blast furnace operation by baking coal at high temperature in a reduced environment in their coke ovens. These ovens produce a coke oven gas from the volatiles in the coal. The gas, containing up to 60% hydrogen, is commonly used for its heating value with some of it being flared. The feasibility of recovering this hydrogen from the gas will be presented. A comparison of this opportunity with that of hydrogen from water electrolysis using low cost off-peak electricity from nuclear energy will be made. The impact of higher daily average electricity rate in Ontario will be discussed. The benefits of these opportunities compared with those from conventional steam reforming of natural gas will be highlighted. (author)

  4. Development of a nuclear steam generator system for gas-cooled reactors for application in oil sands extraction

    International Nuclear Information System (INIS)

    Smith, J.; Hart, R.; Lazic, L.

    2009-01-01

    Canada has vast energy reserves in the Oil Sands regions of Alberta and Saskatchewan. Present extraction technologies, such as strip mining, where oil deposits are close to the surface, and Steam Assisted Gravity Drainage (SAGD) technologies for deeper deposits consume significant amounts of energy to produce the bitumen and upgraded synthetic crude oil. Studies have been performed to assess the feasibility of using nuclear reactors as primary energy sources to produce, in particular the steam required for the SAGD deeper deposit extraction process. Presently available reactors fall short of meeting the requirements, in two areas: the steam produced in a 'standard' reactor is too low in pressure and temperature for the SAGD process. Requirements can be for steam as high as 12MPa pressure with superheat; and, 'standard' reactors are too large in total output. Ideally, reactors of output in the range of 400 to 500 MWth, in modules are better suited to Oil Sands applications. The above two requirements can be met using gas-cooled reactors. Generally, newer generation gas-cooled reactors have been designed for power generation, using Brayton Cycle gas turbines run directly from the heated reactor coolant (helium). Where secondary steam is required, heat recovery steam generators have been used. In this paper, a steam generating system is described which uses the high temperature helium from the reactor directly for steam generation purposes, with sufficient quantities of steam produced to allow for SAGD steam injection, power generation using a steam turbine-generator, and with potential secondary energy supply for other purposes such as hydrogen production for upgrading, and environmental remediation processes. It is assumed that the reactors will be in one central location, run by a utility type organization, providing process steam and electricity to surrounding Oil Sands projects, so steam produced is at very high pressure (12 MPa), with superheat, in order to

  5. Greenhouse gas emissions of Dutch biomass. Quantification of greenhouse gases emission of Dutch biomass for electricity and heat

    International Nuclear Information System (INIS)

    Koop, K.; Yildiz, I.

    2010-09-01

    The greenhouse gas emissions of all available flows of the biomass chain have been established. This report has the following aims: (1) to establish the greenhouse gas emission of Dutch biomass available for generating electricity and heat; (2) to obtain insight in the opportunities and threats for using the potential of the biomass chains that have the highest potential to reduce greenhouse gas emissions. This report can be seen as a supplement to the report 'Availability of Dutch biomass for electricity and heat in 2020' (2009) [nl

  6. A system for regulating the pressure of resuperheated steam in high temperature gas-cooled reactor power stations

    International Nuclear Information System (INIS)

    Braytenbah, A.S.; Jaegines, K.O.

    1975-01-01

    The invention relates to a system for regulating steam-pressure in the re-superheating portion of a steam-boiler receiving heat from a gas-cooled high temperature nuclear reactor, provided with gas distributing pumps driven by steam-turbines. The system comprises means for generating a pressure signal of desired magnitude for the re-superheating portion, and means for providing a real pressure in the re-superheating portion, means (including a by-passing device) for generating steam-flow rate signal of desired magnitude, a turbine by-pass device comprising a by-pass tapping means for regulating the steam-flow-rate in said turbine according to the desired steam-flow rate signal and means for controlling said by-pass tapping means according to said desired steam-flow-rate signal [fr

  7. Technology of steam generators for gas-cooled reactors. Proceedings of a specialists' meeting

    International Nuclear Information System (INIS)

    1988-01-01

    The activity of the IAEA in the field of the technology of gas-cooled reactors was formalized by formation of an International Working Group on Gas-Cooled Reactors (IWGCR). The gas cooled reactor program considered by the IWGCR includes carbon-dioxide-cooled thermal reactors, helium cooled thermal high temperature reactors for power generation and for process heat applications and gas-cooled fast breeder reactors. This report covers the papers dealing with operating experience, steam generators for next generation of gas-cooled reactors, material development and corrosion problems, and thermohydraulics

  8. Technology of steam generators for gas-cooled reactors. Proceedings of a specialists' meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-07-01

    The activity of the IAEA in the field of the technology of gas-cooled reactors was formalized by formation of an International Working Group on Gas-Cooled Reactors (IWGCR). The gas cooled reactor program considered by the IWGCR includes carbon-dioxide-cooled thermal reactors, helium cooled thermal high temperature reactors for power generation and for process heat applications and gas-cooled fast breeder reactors. This report covers the papers dealing with operating experience, steam generators for next generation of gas-cooled reactors, material development and corrosion problems, and thermohydraulics.

  9. On economic efficiency of nuclear power unit life extension using steam-gas topping plant

    International Nuclear Information System (INIS)

    Kuznetsov, Y.N.; Lisitsa, F.D.; Smirnov, V.G.

    2001-01-01

    The different options for life extension of the operating nuclear power units have been analyzed in the report with regard for their economic efficiency. A particular attention is given to the option envisaging the reduction of reactor power output and its subsequent compensation with a steam-gas topping plant. Steam generated at its heat-recovery boilers is proposed to be used for the additional loading of the nuclear plant turbine so as to reach its nominal output. It would be demonstrated that the implementation of this option allows to reduce total costs in the period of power plant life extension by 24-29% as compared with the alternative use of the replacing steam-gas unit and the saved resources could be directed, for instance, for decommissioning of a reactor facility. (authors)

  10. Investigation on syngas production via biomass conversion through the integration of pyrolysis and air–steam gasification processes

    International Nuclear Information System (INIS)

    Alipour Moghadam, Reza; Yusup, Suzana; Azlina, Wan; Nehzati, Shahab; Tavasoli, Ahmad

    2014-01-01

    Highlights: • Innovation in gasifier design. • Integration of pyrolysis and steam gasification processes. • Energy saving, improvement of gasifier efficiency, syngas and hydrogen yield. • Overall investigation on gasification parameters. • Optimization conditions of integration of pyrolysis and gasification process. - Abstract: Fuel production from agro-waste has become an interesting alternative for energy generation due to energy policies and greater understanding of the importance of green energy. This research was carried out in a lab-scale gasifier and coconut shell was used as feedstock in the integrated process. In order to acquire the optimum condition of syngas production, the effect of the reaction temperature, equivalence ratio (ER) and steam/biomass (S/B) ratio was investigated. Under the optimized condition, H 2 and syngas yield achieved to 83.3 g/kg feedstock and 485.9 g/kg feedstock respectively, while LHV of produced gases achieved to 12.54 MJ/N m 3

  11. 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.)

  12. 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.)

  13. Frequency and distribution of leakages in steam generators of gas-cooled reactors

    International Nuclear Information System (INIS)

    Bongratz, R.; Breitbach, G.; Wolters, J.

    1988-01-01

    In gas cooled reactors with graphitic primary circuit structures - such as HTR, AGR or Magnox - the water ingress is an event of great safety concern. Water or steam entering the primary circuit react with the hot graphite and carbon-oxide and hydrogen are produced. As the most important initiating event a leak in a steam generator must be taken into account. From the safety point of view as well as for availability reasons it is necessary to construct reliable boilers. Thus the occurrence of a boiler leak should be a rare event. In the context of a probabilistic safety study for an HTR-Project much effort was invested to get information about the frequency and the size distribution of tube failures in steam generators of gas cooled reactors. The main data base was the boiler tube failure statistics of United Kingdom gas cooled reactors. The data were selected and applied to a modern HTR steam generator design. A review of the data showed that the failure frequency is not connected with the load level (pressures, temperatures) or with the geometric size of the heating surface of the boiler. Design, construction, fabrication, examination and operation conditions have the greatest influence an the failure frequency but they are practically not to be quantified. The typical leak develops from smallest size. By erosion effects of the entering water or steam it is enlarged to perhaps some mm 2 , then usually it is detected by moisture monitors. Sudden tube breaks were not reported in the investigated period. As a rule boiler leaks in gas cooled reactors are much more, rare then leaks in steam generators of light water reactors and fossil fired boilers. (author)

  14. Improvement of degradation with non-condensable gas in micro steam injector

    International Nuclear Information System (INIS)

    Saihara, Atsushi; Horiki, Sachiyo; Osakabe, Masahiro; Ohmori, Shuichi

    2007-01-01

    Effect of non-condensable gas on a micro steam injector (MSI) to obtain a vacuum was experimentally studied. When a pure steam was used in the MSI, the high vacuum condition was obtained. However when the mass fraction of air included in the steam was larger than a cartain value, the MSI became unstable and the vacuum condition could not be obtained. It is considered that the malfunction is due to the instability triggered with the uncondensed steam remained at the throat in downstream of the condensing region. The water nozzle was expected to be a key component to mitigate the effect of non-condensable gas. Three kinds of water nozzle whose flow areas were round, star and screw shapes were used in the present experiment. The star-shaped nozzle where the increased surface area could be expected to compensate the degradation of condensation failed to improve the malfunction of MSI with the non-condensable gas. The screw nozzle expected to drive air away outside the condensing surface could mitigate the effect of non-condensable gas. (author)

  15. Life Cycle Assessment of Hydrogen Production via Natural Gas Steam Reforming; TOPICAL

    International Nuclear Information System (INIS)

    Spath, P. L.; Mann, M. K.

    2000-01-01

    A life cycle assessment of hydrogen production via natural gas steam reforming was performed to examine the net emissions of greenhouse gases as well as other major environmental consequences. LCA is a systematic analytical method that helps identify and evaluate the environmental impacts of a specific process or competing processes

  16. Gas Flow Validation with Panda Tests from the OECD SETH Benchmark Covering Steam/Air and Steam/Helium/Air Mixtures

    International Nuclear Information System (INIS)

    Royl, P.; Travis, J.R.; Breitung, W.; Kim, J.; Kim, S.B.

    2009-01-01

    The CFD code GASFLOW solves the time-dependent compressible Navier-Stokes Equations with multiple gas species. GASFLOW was developed for nonnuclear and nuclear applications. The major nuclear applications of GASFLOW are 3D analyses of steam/hydrogen distributions in complex PWR containment buildings to simulate scenarios of beyond design basis accidents. Validation of GASFLOW has been a continuously ongoing process together with the development of this code. This contribution reports the results from the open posttest GASFLOW calculations that have been performed for new experiments from the OECD SETH Benchmark. Discussed are the steam distribution tests 9 and 9 bis, 21 and 21 bis involving comparable sequences with and without steam condensation and the last SETH test 25 with steam/helium release and condensation. The latter one involves lighter gas mixture sources like they can result in real accidents. The helium is taken as simulant for hydrogen

  17. Ethanol from lignocellulosic biomasses; Etanolo da biomasse lignocellulosiche. Produzione di etanolo da paglia di grano mediante pretrattamento di steam explosion, idrolisi enzimatica e fermentazione

    Energy Technology Data Exchange (ETDEWEB)

    Ricci, E.; Viola, E.; Zimbardi, F.; Braccio, G. [ENEA, Divisione Fonti Rinnovabili di Energia, Centro Ricerche Trisaia, Policoro, Matera (Italy); Cuna, D. [Faucitano Srl, Milan (Italy)

    2001-07-01

    In this report are presented results achieved on the process optimisation of bioethanol production from wheat straw, carried out within the ENEA's project of biomass exploitation for renewable energy. The process consists of three main steps: 1) biomass pretreatment by means of steam explosion; 2) enzymatic hydrolysis of the cellulose fraction; 3) fermentation of glucose. To perform the hydrolysis step, two commercial enzymatic mixtures have been employed, mainly composed by {beta}-glucosidase (cellobiase), endo-glucanase and exo-glucanase. The ethanologenic yeast Saccharomyces cerevisiae has been used to ferment the glucose in he hydrolyzates. Hydrolysis yield of 97% has been obtained with steam exploded wheat straw treated at 220{sup 0}C for 3 minutes and an enzyme to substrate ratio of 4%. It has been pointed out the necessity of washing with water the pretreated what straw, in order to remove the biomass degradation products, which have shown an inhibition effect on the yeast. At the best process conditions, a fermentation yield of 95% has been achieved. In the Simultaneous Saccharification and Fermentation process, a global conversion of 92% has been obtained, which corresponds to the production of about 170 grams of ethanol per kilogram of exploded straw. [Italian] Si riportano i risultati di un'attivita' di ricerca finalizzata all'ottimizzazione del processo di produzione di etanolo da paglia di grano. Il processo esaminato consta di un pretrattamento mediante steam explosion della paglia, seguito da idrolisi enzimatica della cellulosa e fermentazione del glucosio ottenuto. Per effettuare l'idrolisi sono stati utilizzati due preparati enzimatici disponibili commercialmente, costituiti da {beta}-glucosidasi, endo-glucanasi ed eso-glucanasi. Per la fermentazione del glucosio negli idrolizzati e' stato impiegato il lievito Saccharomyces cerevisae. E' stata raggiunta un'efficienza massima di idrolisi del 97% utilizzando

  18. Cleaning of biomass derived product gas for engine applications and for co-firing in PC-boilers

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

    The conventional fluidized-bed combustion has become commercially available also to relatively small scale (5 MWe), but this technology has rather low power-to-heat ratio and consequently it`s potential is limited to applications where district or process heat is the main product. Thus, there seems to be a real need to develop more efficient methods for small-scale power production from biomass. Gasification diesel power plant is one alternative for the small-scale power production, which has clearly higher power-to-heat ratio than can be reached in conventional steam cycles. The main technical problem in this process is the gas cleaning from condensable tars. In addition to the diesel-power plants, there are several other interesting applications for atmospheric-pressure clean gas technology. One alternative for cost-effective biomass utilization is co-firing of biomass derived product gas in existing pulverized coal fired boilers (or other types of boilers and furnaces). The aim of the project is to develop dry gas cleaning methods for gasification-diesel power plants and for other atmospheric-pressure applications of biomass and waste gasification. The technical objectives of the project are as follows: To develop and test catalytic gas cleaning methods for engine. To study the removal of problematic ash species of (CFE) gasification with regard to co-combustion of the product gas in PC boilers. To evaluate the technical and economical feasibility of different small-scale power plant concepts based on fixed-bed updraft and circulating fluidized- bed gasification of biomass and waste. (orig.)

  19. Quantitative indexes of gas-steam thermo electrical power plants thermodynamical cycles; Indices quantitativos de ciclos termodinamicos de centrais termoeletricas de gas-vapor

    Energy Technology Data Exchange (ETDEWEB)

    Vlassov, D.; Vargas, J.V.C. [Parana Univ., Curitiba, PR (Brazil). Dept. de Engenharia Mecanica]. E-mails: vlassov@demec.ufpr.br; jvargas@demec.ufpr.br

    2002-07-01

    This paper analyses various thermal schemes of the world wide most used cycles in gas-steam thermoelectric power plants. The combination of gas turbine cycle with the steam-gas cycle in thermoelectric power plants is performed in several ways, resulting in different thermal schemes, used equipment and operation plant basic characteristics. The thermal scheme of a gas-steam power plant is a determinant factor for the definition of energetic, economic and ecological characteristics. For the comparative analysis various quantitative indexes are presented, as for example: the heat fraction supplied to the gas turbine cycle and the cycle binary rate.

  20. HTCC - a heat transfer model for gas-steam mixtures

    International Nuclear Information System (INIS)

    Papadimitriou, P.

    1983-01-01

    The mathematical model HTCC (Heat Transfer Coefficient in Containment) has been developed for RALOC after a loss-of-coolant accident in order to determine the local heat transfer coefficients for transfer between the containment atmosphere and the walls of the reactor building. The model considers the current values of room and wall temperature, the concentration of steam and non-condensible gases, geometry data and those of fluid dynamics together with thermodynamic parameters and from these determines the heat transfer mechanisms due to convection, radiation and condensation. The HTCC is implemented in the RALOC program. Comparative analyses of computed temperature profiles, for HEDL Standard problems A and B on hydrogen distribution, and of computed temperature profiles determined during the heat-up phase in the CSE-A5 experiment show a good agreement with experimental data. (orig.) [de

  1. Study on methane separation from steam reforming product gas with polyimide membrane

    International Nuclear Information System (INIS)

    Koiso, Hiroshi; Inagaki, Yoshiyuki; Aita, Hideki; Sekita, Kenji; Haga, Katsuhiro; Hino, Ryutaro.

    1997-10-01

    In the HTTR hydrogen production system by steam reforming of natural gas (main component: CH 4 ), CH 4 conversion rate is limited to approximately 65% due to high pressure and low temperature conditions (4.5 MPa, 800degC). The one of the measures to improve CH 4 conversion is recycling of residual CH 4 extracted from steam reforming product gas with a gas separator. Experimental and analytical studies on CH 4 separation from gas mixture composed of CH 4 , H 2 , CO 2 and CO were carried out to investigate gas separation characteristics of a polyimide membrane gas separator. Measured permeability of each gas in gas mixture was reduced from 1/3 to 1/14 of that obtained with a single gas (catalog value). The polyimide membrane could extracted CH 4 of approximately 80% from gas mixture, then, H 2 and CO 2 more than 98% were removed. It was confirmed that the polyimide membrane could be available to residual CH 4 recycling. The analytical results by a difference method gave good prospects of experimental results such as permeated flow rate, mol-fraction profiles and so on. Therefore, it can be said the analysis method was established. (author)

  2. Dynamic simulation of a furnace of steam reforming of natural gas

    International Nuclear Information System (INIS)

    Acuna, A; Fuentes, C; Smith, C A

    1999-01-01

    Steam reforming of natural gas is a very important industrial process in refineries and ammonia and methanol plants. Hydrogen is produced by reforming methane with steam. This hydrogen is essential in the hydro-treating process in the refineries thus, it is important to supervise and control the performance of the hydrogen plant. Mathematical models of refineries and chemical plants are used to simulate the behavior of the process units. However, the models especially of reactors like reformers are not very reliable. This paper presents a dynamic model of a furnace-reactor. The simulation results are validated with industrial data

  3. Investigation of Continuous Gas Engine CHP Operation on Biomass Producer Gas

    DEFF Research Database (Denmark)

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

    2005-01-01

    More than 2000 hours of gas engine operation with producer gas from biomass as fuel has been conducted on the gasification CHP demonstration and research plant, named “Viking” at the Technical University of Denmark. The gas engine is an integrated part of the entire gasification plant. The excess...... operates with varying excess of air due to variation in gas composition and thus stoichiometry, and a second where the excess of air in the exhaust gas is fixed and the flow rate of produced gas from the gasifier is varying. The interaction between the gas engine and the gasification system has been...... investigated. The engine and the plant are equipped with continuously data acquisition that monitors the operation including the composition of the producer gas and the flow. Producer gas properties and contaminations have been investigated. No detectable tar or particle content was observed...

  4. CFD simulation of gas and particles combustion in biomass furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Griselin, Nicolas

    2000-11-01

    In this thesis, gas and particle combustion in biomass furnaces is investigated numerically. The aim of this thesis is to use Computational Fluid Dynamics (CFD) technology as an effective computer based simulation tool to study and develop the combustion processes in biomass furnaces. A detailed model for the numerical simulation of biomass combustion in a furnace, including fixed-bed modeling, gas-phase calculation (species distribution, temperature field, flow field) and gas-solid two-phase interaction for flying burning particles is presented. This model is used to understand the mechanisms of combustion and pollutant emissions under different conditions in small scale and large scale furnaces. The code used in the computations was developed at the Division of Fluid Mechanics, LTH. The flow field in the combustion enclosure is calculated by solving the Favre-averaged Navier-Stokes equations, with standard {kappa} - {epsilon} turbulence closure, together with the energy conservation equation and species transport equations. Discrete transfer method is used for calculating the radiation source term in the energy conservation equation. Finite difference is used to solve the general form of the equation yielding solutions for gas-phase temperatures, velocities, turbulence intensities and species concentrations. The code has been extended through this work in order to include two-phase flow simulation of particles and gas combustion. The Favre-averaged gas equations are solved in a Eulerian framework while the submodels for particle motion and combustion are used in the framework of a Lagrangian approach. Numerical simulations and measurement data of unburned hydrocarbons (UHC), CO, H{sub 2}, O{sub 2} and temperature on the top of the fixed bed are used to model the amount of tar and char formed during pyrolysis and combustion of biomass fuel in the bed. Different operating conditions are examined. Numerical calculations are compared with the measured data. It is

  5. Tar Removal from Biomass Producer Gas by Using Biochar

    DEFF Research Database (Denmark)

    Ravenni, Giulia; Henriksen, Ulrik Birk; Ahrenfeldt, Jesper

    2017-01-01

    The biomass-derived char (biochar) produced in the gasifier as a residue, is a potential solution for removing tars from producer gas. This work investigates the interaction between tar compounds and biochar. Residual biochar from a TwoStage gasifier was tested as bed material in a laboratory setup....... Phenol and naphthalene were chosen as model tars, and entrained in a nitrogen flow. The gaseous stream was sampled before and after the biochar bed to evaluate the extent of conversion. The biochar bed (30g) was tested at 250°C, 500°C and 600°C, with for 3 consecutive hours. The compounds concentration...... in the gas phase was quantified by stable isotope dilution analysis, using Gas Chromatography-Mass Spectrometry (GC-MS). Results showed a significant effect of biochar on the removal of phenol, at all temperatures. Naphthalene was removed less efficiently at higher temperature, and this trend was even more...

  6. Hydrogen-Rich Gas Production by Sorption Enhanced Steam Reforming of Woodgas Containing TAR over a Commercial Ni Catalyst and Calcined Dolomite as CO2 Sorbent

    Directory of Open Access Journals (Sweden)

    Vincenzo Naso

    2013-07-01

    Full Text Available The aim of this work was the evaluation of the catalytic steam reforming of a gaseous fuel obtained by steam biomass gasification to convert topping atmosphere residue (TAR and CH4 and to produce pure H2 by means of a CO2 sorbent. This experimental work deals with the demonstration of the practical feasibility of such concepts, using a real woodgas obtained from fluidized bed steam gasification of hazelnut shells. This study evaluates the use of a commercial Ni catalyst and calcined dolomite (CaO/MgO. The bed material simultaneously acts as reforming catalyst and CO2 sorbent. The experimental investigations have been carried out in a fixed bed micro-reactor rig using a slipstream from the gasifier to evaluate gas cleaning and upgrading options. The reforming/sorption tests were carried out at 650 °C while regeneration of the sorbent was carried out at 850 °C in a nitrogen environment. Both combinations of catalyst and sorbent are very effective in TAR and CH4 removal, with conversions near 100%, while the simultaneous CO2 sorption effectively enhances the water gas shift reaction producing a gas with a hydrogen volume fraction of over 90%. Multicycle tests of reforming/CO2 capture and regeneration were performed to verify the stability of the catalysts and sorbents to remove TAR and capture CO2 during the duty cycle.

  7. Comparative biochemical analysis after steam pretreatment of lignocellulosic agricultural waste biomass from Williams Cavendish banana plant (Triploid Musa AAA group).

    Science.gov (United States)

    Kamdem, Irénée; Jacquet, Nicolas; Tiappi, Florian Mathias; Hiligsmann, Serge; Vanderghem, Caroline; Richel, Aurore; Jacques, Philippe; Thonart, Philippe

    2015-11-01

    The accessibility of fermentable substrates to enzymes is a limiting factor for the efficient bioconversion of agricultural wastes in the context of sustainable development. This paper presents the results of a biochemical analysis performed on six combined morphological parts of Williams Cavendish Lignocellulosic Biomass (WCLB) after steam cracking (SC) and steam explosion (SE) pretreatments. Solid (S) and liquid (L) fractions (Fs) obtained from SC pretreatment performed at 180°C (SLFSC180) and 210°C (SLFSC210) generated, after diluted acid hydrolysis, the highest proportions of neutral sugar (NS) contents, specifically 52.82 ± 3.51 and 49.78 ± 1.39%w/w WCLB dry matter (DM), respectively. The highest proportions of glucose were found in SFSC210 (53.56 ± 1.33%w/w DM) and SFSC180 (44.47 ± 0.00%w/w DM), while the lowest was found in unpretreated WCLB (22.70 ± 0.71%w/w DM). Total NS content assessed in each LF immediately after SC and SE pretreatments was less than 2%w/w of the LF DM, thus revealing minor acid autohydrolysis consequently leading to minor NS production during the steam pretreatment. WCLB subjected to SC at 210 °C (SC210) generated up to 2.7-fold bioaccessible glucan and xylan. SC and SE pretreatments showed potential for the deconstruction of WCLB (delignification, depolymerization, decrystallization and deacetylation), enhancing its enzymatic hydrolysis. The concentrations of enzymatic inhibitors, such as 2-furfuraldehyde and 5-(hydroxymethyl)furfural from LFSC210, were the highest (41 and 21 µg ml(-1), respectively). This study shows that steam pretreatments in general and SC210 in particular are required for efficient bioconversion of WCLB. Yet, biotransformation through biochemical processes (e.g., anaerobic digestion) must be performed to assess the efficiency of these pretreatments. © The Author(s) 2015.

  8. The gas chimney formation during the steam explosion premixing phase

    International Nuclear Information System (INIS)

    Leskovar, M.

    2001-01-01

    The crucial part in isothermal premixing experiment simulation is the correct prediction of the gas chimney, which forms when the spheres penetrate into water. The first simulation results with the developed original combined multiphase model showed that the gas chimney starts to close at the wrong place at the top of the chimney and not in the middle, like it was observed in the experiments. To find the physical explanation for this identified weakness of our numerical model a comprehensive parametric analysis (mesh size, initial water-air surface thickness, water density, momentum coupling starting position) has been performed. It was established that the reason for the unphysical gas chimney closing at the top could be the gradual air-water density transition in the experiment model, since there is due to the finite differences description always a transition layer with intermediate phases density over the pure water phase. It was shown that this difference between our numerical model and the experiment can be somewhat compensated if the spheres interfacial drag coefficient at the upmost mesh plane of the unphysical air-water transition layer is artificially risen. On this way a more correct gas chimney formation can be obtained.(author)

  9. Towards H2-rich gas production from unmixed steam reforming of methane: Thermodynamic modeling

    Science.gov (United States)

    Lima da Silva, Aline; Müller, Iduvirges Lourdes

    2011-10-01

    In this work, the Gibbs energy minimization method is applied to investigate the unmixed steam reforming (USR) of methane to generate hydrogen for fuel cell application. The USR process is an advanced reforming technology that relies on the use of separate air and fuel/steam feeds to create a cyclic process. Under air flow (first half of the cycle), a bed of Ni-based material is oxidized, providing the heat necessary for the steam reforming that occurs subsequently during fuel/steam feed stage (second half of the cycle). In the presence of CaO sorbent, high purity hydrogen can be produced in a single reactor. In the first part of this work, it is demonstrated that thermodynamic predictions are consistent with experimental results from USR isothermal tests under fuel/steam feed. From this, it is also verified that the reacted NiO to CH4 (NiOreacted/CH4) molar ratio is a very important parameter that affects the product gas composition and decreases with time. At the end of fuel/steam flow, the reforming reaction is the most important chemical mechanism, with H2 production reaching ∼75 mol%. On the other hand, at the beginning of fuel/steam feed stage, NiO reduction reactions dominate the equilibrium system, resulting in high CO2 selectivity, negative steam conversion and low concentrations of H2. In the second part of this paper, the effect of NiOreacted/CH4 molar ratio on the product gas composition and enthalpy change during fuel flow is investigated at different temperatures for inlet H2O/CH4 molar ratios in the range of 1.2-4, considering the USR process operated with and without CaO sorbent. During fuel/steam feed stage, the energy demand increases as time passes, because endothermic reforming reaction becomes increasingly important as this stage nears its end. Thus, the duration of the second half of the cycle is limited by the conditions under which auto-thermal operation can be achieved. In absence of CaO, H2 at concentrations of approximately 73 mol% can

  10. Performance and environment as objectives in multi-criterion optimization of steam injected gas turbine cycles

    International Nuclear Information System (INIS)

    Kayadelen, Hasan Kayhan; Ust, Yasin

    2014-01-01

    Rapidly growing demand for gas turbines promotes research on their performance improvement and reducing their exhaust pollutants. Even small increments in net power or thermal efficiency and small changes in pollutant emissions have become significant concerns for both new designs and cycle modifications. To fulfill these requirements an accurate performance evaluation method which enables to see the effects on the exhaust gas composition is an important necessity. To fill this gap, a thermo-ecologic performance evaluation approach for gas turbine cycles with chemical equilibrium approximation which enables performance and environmental aspects to be considered simultaneously, is presented in this work. Steam injection is an effective modification to boost power and limit NO x emissions for gas turbine systems. Steam injection also increases thermal efficiency so less fuel is burnt to maintain the same power output. Because of its performance related and environmental advantages, presented approach is applied on the steam injected gas turbine cycle and a precise multi-criterion optimization is carried out for varying steam injection, as well as equivalence and pressure ratios. Irreversibilities and pressure losses are also considered. Effects of each parameter on the net work and thermal efficiency as well as non-equilibrium NO x and CO emissions are demonstrated. Precision improvement of the presented thermo-ecological model is shown and two main concerns; constant turbine inlet condition for higher net work output and constant net work output condition for lower fuel consumption are compared. - Highlights: • A thermodynamically precise performance estimation tool for GT cycles is presented. • STIG application is provided to show its flexibility for any GT cycle and diluents. • Constant TIT and net work output conditions have been compared and discussed. • The model provides results to evaluate economic and environmental aspects together. • It provides a

  11. Opportunities for Green Gas. Competition of Green Gas with other Biomass Options

    International Nuclear Information System (INIS)

    Bergsma, G.C.; Croezen, H.J.

    2011-04-01

    Green biogas seems to be an interesting option to make the Dutch economy, with a large share of gas in the energy system, more sustainable. Biomass that is used as feedstock for biogas can also be deployed for the production of Electricity, biodiesel, bio-ethanol, bio-plastics, bio-chemical products and even bio-steel. This memo compares the main characteristics of biomass uses for production of gas with alternative uses in other sectors. The comparison shows that wet biomass flows in particular (e.g. manure and KGW) are suitable for conversion in biogas. This leads to a potential of 1 to 1.5 billion Nm 3 of gas in 2020. Gasification of dry biomass may also become interesting in the future. However, this fuel is subjected to fierce competition with the electricity sector, which can use solid biomass for combustion purposes. Moreover, the steel, chemical and transport sector may also be able to use the feedstock in time. [nl

  12. Catalytic steam gasification of biomass in fluidized bed at low temperature: Conversion from livestock manure compost to hydrogen-rich syngas

    International Nuclear Information System (INIS)

    Xiao, Xianbin; Le, Duc Dung; Li, Liuyun; Meng, Xianliang; Cao, Jingpei; Morishita, Kayoko; Takarada, Takayuki

    2010-01-01

    Utilizing large amounts of animal waste as a source of renewable energy has the potential to reduce its disposal problems and associated pollution issues. Gasification characteristics of the manure compost make it possible for low temperature gasification. In this paper, an energy efficient approach to hydrogen-rich syngas from manure compost is represented at relatively low temperature, around 600 o C, in a continuous-feeding fluidized bed reactor. The effects of catalyst performance, reactor temperature, steam, and reaction type on gas yield, gas composition, and carbon conversion efficiency are discussed. The Ni-Al 2 O 3 catalyst simultaneously promotes tar cracking and steam reforming. Higher temperature contributes to higher gas yield and carbon conversion. The steam introduction increases hydrogen yield, by steam reforming and water-gas shift reaction. Two-stage gasification is also tried, showing the advantage of better catalyst utilization and enhancing the catalytic reactions to some extent.

  13. Fabrication of remote steam atomized scrubbers for DWPF off-gas system

    International Nuclear Information System (INIS)

    Nielsen, M.G.; Lafferty, J.D.

    1988-01-01

    The defense waste processing facility (DWPF) is being constructed for the purpose of processing high-level waste from sludge to a vitrified borosilicate glass. In the operation of continuous slurry-fed melters, off-gas aerosols are created by entrainment of feed slurries and the vaporization of volatile species from the molten glass mixture. It is necessary to decontaminate these aerosols in order to minimize discharge of airborne radionuclide particulates. A steam atomized scrubber (SAS) has been developed for DWPF which utilizes a patented hydro- sonic system gas scrubbing method. The Hydro-Sonic System utilizes a steam aspirating-type venturi scrubber that requires very precise fabrication tolerances in order to obtain acceptable decontamination factors. In addition to the process-related tolerances, precision mounting and nozzle tolerances are required for remote service at DWPF

  14. Membrane steam reforming of natural gas for hydrogen production by utilization of medium temperature nuclear reactor

    International Nuclear Information System (INIS)

    Djati Hoesen Salimy

    2010-01-01

    The assessment of steam reforming process with membrane reactor for hydrogen production by utilizing of medium temperature nuclear reactor has been carried out. Difference with the conventional process of natural gas steam reforming that operates at high temperature (800-1000°C), the process with membrane reactor operates at lower temperature (~500°C). This condition is possible because the use of perm-selective membrane that separate product simultaneously in reactor, drive the optimum conversion at the lower temperature. Besides that, membrane reactor also acts the role of separation unit, so the plant will be more compact. From the point of nuclear heat utilization, the low temperature of process opens the chance of medium temperature nuclear reactor utilization as heat source. Couple the medium temperature nuclear reactor with the process give the advantage from the point of saving fossil fuel that give direct implication of decreasing green house gas emission. (author)

  15. Fuel gas production from animal and agricultural residues and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Wise, D. L; Wentworth, R. L

    1978-05-30

    Progress was reported by all contractors. Topics presented include: solid waste to methane gas; pipeline fuel gas from an environmental cattle feed lot; heat treatment of organics for increasing anaerobic biodegradability; promoting faster anaerobic digestion; permselective membrane control of algae and wood digesters for increased production and chemicals recovery; anaerobic fermentation of agricultural residues; pilot plant demonstration of an anaerobic, fixed-film bioreactor for wastewater treatment; enhancement of methane production in the anaerobic diegestion of sewage; evaluation of agitation concepts for biogasification of sewage sludge; operation of a 50,000 gallon anaerobic digester; biological conversion of biomass to methane; dirt feedlot residue experiments; anaerobic fermentation of livestock and crop residues; current research on methanogenesis in Europe; and summary of EPA programs in digestion technology. (DC)

  16. Performance analysis of a small regenerative gas turbine system adopting steam injection and side-wall in finned tube evaporator

    International Nuclear Information System (INIS)

    Kang, Soo Young; Lee, Jong Jun; Kim, Tong Seop

    2009-01-01

    Small gas turbines in power range of several MWs are quite suitable for application in distributed generation as well as Community Energy Systems (CES). Humidification is an effective way to improve gas turbine performance, and steam injection is the most general and practically feasible method. This study intended to examine the effect of steam injection on the performance of several MW class gas turbines. A primary concern is given to the regenerative cycle gas turbine. The steam injection effect on the performance of a system without the regenerator (i.e. a simple cycle) is also examined. In addition, the influence of bypass of some of the exhaust gas on the performance of the gas turbine, especially the regenerative cycle gas turbine, is evaluated.

  17. Sound speed models for a noncondensible gas-steam-water mixture

    International Nuclear Information System (INIS)

    Ransom, V.H.; Trapp, J.A.

    1984-01-01

    An analytical expression is derived for the homogeneous equilibrium speed of sound in a mixture of noncondensible gas, steam, and water. The expression is based on the Gibbs free energy interphase equilibrium condition for a Gibbs-Dalton mixture in contact with a pure liquid phase. Several simplified models are discussed including the homogeneous frozen model. These idealized models can be used as a reference for data comparison and also serve as a basis for empirically corrected nonhomogeneous and nonequilibrium models

  18. An approach for exhaust gas energy recovery of internal combustion engine: Steam-assisted turbocharging

    International Nuclear Information System (INIS)

    Fu, Jianqin; Liu, Jingping; Deng, Banglin; Feng, Renhua; Yang, Jing; Zhou, Feng; Zhao, Xiaohuan

    2014-01-01

    Highlights: • The calculation method for SAT engine was developed and introduced. • SAT can effectively promote the low-speed performances of IC engine. • At 1500 r/min, intake pressure reaches target value and torque is increased by 25%. • The thermal efficiency of SAT engine only has a slight increase. - Abstract: An approach for IC engine exhaust gas energy recovery, named as steam-assisted turbocharging (SAT), is developed to assist the exhaust turbocharger. A steam generating plant is coupled to the exhaust turbocharged engine’s exhaust pipe, which uses the high-temperature exhaust gas to generate steam. The steam is injected into turbine inlet and used as the supplementary working medium for turbine. By this means, turbine output power and then boosting pressure can be promoted due to the increase of turbine working medium. To reveal the advantages and energy saving potentials of SAT, this concept was applied to an exhaust turbocharging engine, and a parameter analysis was carried out. Research results show that, SAT can effectively promote the low-speed performances of IC engine, and make the peak torque shift to low-speed area. At 1500 r/min, the intake gas pressure can reach the desired value and the torque can be increased by 25.0% over the exhaust turbocharging engine, while the pumping mean effective pressure (PMEP) and thermal efficiency only have a slight increase. At 1000 r/min, the improvement of IC engine performances is very limited due to the low exhaust gas energy

  19. For effective thermodynamic calculation of turbines flow-through by gas and steam

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, S; Hultsch, M

    1982-03-01

    A programme system for the medium and multiple section calculation of axial-flow turbines is explained. It allows calculations of turbine flow-through by gas and steam at designing and partial load states. The algorithms are independent upon the formulation of thermodynamic function, so that the programmes can be used for any means of production. The highest accuracy and efficiency can be guaranteed by the use of formulations of thermodynamic functions of water.

  20. Policy Considerations for Commercializing Natural Gas and Biomass CCUS

    Science.gov (United States)

    Abrahams, L.; Clavin, C.

    2017-12-01

    Captured CO2 from power generation has been discussed as an opportunity to improve the environmental sustainability of fossil fuel-based electricity generation and likely necessary technological solution necessary for meeting long-term climate change mitigation goals. In our presentation, we review the findings of a study of natural gas CCUS technology research and development and discuss their applications to biomass CCUS technology potential. Based on interviews conducted with key stakeholders in CCUS technology development and operations, this presentation will discuss these technical and economic challenges and potential policy opportunities to support commercial scale CCUS deployment. In current domestic and electricity and oil markets, CCUS faces economic challenges for commercial deployment. In particular, the economic viability of CCUS has been impacted by the sustained low oil prices that have limited the potential for enhanced oil recovery (EOR) to serve as a near-term utilization opportunity for the captured CO2. In addition, large scale commercial adoption of CCUS is constrained by regulatory inconsistencies and uncertainties across the United States, high initial capital costs, achieving familiarity with new technology applications to existing markets, developing a successful performance track record to acquire financing agreements, and competing against well-established incumbent technologies. CCUS also has additional technical hurdles for measurement, verification, and reporting within states that have existing policy and regulatory frameworks for climate change mitigation. In addition to fossil-fuel based CCUS, we will discuss emerging opportunities to utilize CCUS fueled by gasified biomass resulting in carbon negative power generation with expanded economic opportunities associated with the enhanced carbon sequestration. Successful technology development of CCUS technology requires a portfolio of research leading to technical advances, advances in

  1. Gas-steam turbine plant for cogenerative process at 'Toplifikacija' - Skopje (Joint-Stock Co. for district heating - Macedonia)

    International Nuclear Information System (INIS)

    Cvetkovski, Andrijan

    2003-01-01

    The gas-steam power plant for combined heat and electric power production at A.D. 'Toplifikacija' Skopje - TO 'Zapad' is analyzed and determined. The analyzed plant is consisted of gas turbine, heat recovery steam generator (HRSG) and condensate steam turbine with controlled steam extraction. It operates on natural gas as a main fuel source. The heating of the water for the district heating is dine in the heat exchanger, with // heat of controlled extraction from condensate turbine. The advantages of the both binary plant and centralized co generative production compared with the individual are analyzed. The natural gas consumption of for both specific heating and electrical capacity in join production as well as fuel savings compared to the separate production of the same quantity of energy is also analyzed. (Original)

  2. A gas dynamic and thermochemical model of steam/sodium microleak phenomena

    International Nuclear Information System (INIS)

    Perkins, R.; Airey, R.; Daniels, L.C.

    1985-06-01

    Conflicting findings have been reported by 3 UK laboratories for the blockage or rapid escalation of steam/sodium microleaks. In an earlier paper it was shown that this discrepancy could be resolved through the influence on the steam flow of the geometry of the leak paths; the geometry being dependent upon the method of manufacture. The application of gas dynamics and thermochemical methods could account for the rapid escalation of some leaks in terms of the presence of shock waves in the gas flow within the leak path. In this paper the gas dynamic and thermochemical theories are re-stated and a series of leak experiments conducted to test the validity of the theory is described. The theory predicts that for some leaks of variable area of cross-section the blockage/escalation behaviour is determined by small changes in the sodium-side pressure; this effect was found and is discussed as a validation of the theory. Other aspects of leak phenomena are discussed and conclusions are drawn with emphasis on implications for further programmes of leak study and for leaks in LMFBR steam generators in service. (author)

  3. Thermal analysis of cylindrical natural-gas steam reformer for 5 kW PEMFC

    Science.gov (United States)

    Jo, Taehyun; Han, Junhee; Koo, Bonchan; Lee, Dohyung

    2016-11-01

    The thermal characteristics of a natural-gas based cylindrical steam reformer coupled with a combustor are investigated for the use with a 5 kW polymer electrolyte membrane fuel cell. A reactor unit equipped with nickel-based catalysts was designed to activate the steam reforming reaction without the inclusion of high-temperature shift and low-temperature shift processes. Reactor temperature distribution and its overall thermal efficiency depend on various inlet conditions such as the equivalence ratio, the steam to carbon ratio (SCR), and the fuel distribution ratio (FDR) into the reactor and the combustor components. These experiments attempted to analyze the reformer's thermal and chemical properties through quantitative evaluation of product composition and heat exchange between the combustor and the reactor. FDR is critical factor in determining the overall performance as unbalanced fuel injection into the reactor and the combustor deteriorates overall thermal efficiency. Local temperature distribution also influences greatly on the fuel conversion rate and thermal efficiency. For the experiments, the operation conditions were set as SCR was in range of 2.5-4.0 and FDR was in 0.4-0.7 along with equivalence ratio of 0.9-1.1; optimum results were observed for FDR of 0.63 and SCR of 3.0 in the cylindrical steam reformer.

  4. Welding repair of the steam and gas turbines rotors made of Cr-Mo-V steel

    International Nuclear Information System (INIS)

    Mazur, Z.; Kubiak, J.; Hernandez, A.

    1999-01-01

    An analysis of typical steam turbine and gas turbine rotor failures is carried out. On the base of the rotors different failure causes and their mode of occurring, an evaluation of the weldability of the Cr-Mo-V steels and the classification of the common turbine rotors repair possibilities is presented. The developing of specific in-situ welding repair process of the damaged 20.65 MW gas turbine rotor is described. After repair, the rotor was put back into service. (Author) 15 refs

  5. OPERATING SPECIFICATIONS OF CATALYTIC CLEANING OF GAS FROM BIOMASS GASIFICATION

    Directory of Open Access Journals (Sweden)

    Martin Lisý

    2015-12-01

    Full Text Available The paper focuses on the theoretical description of the cleaning of syngas from biomass and waste gasification using catalytic methods, and on the verification of the theory through experiments. The main obstruction to using syngas from fluid gasification of organic matter is the presence of various high-boiling point hydrocarbons (i.e., tar in the gas. The elimination of tar from the gas is a key factor in subsequent use of the gas in other technologies for cogeneration of electrical energy and heat. The application of a natural or artificial catalyst for catalytic destruction of tar is one of the methods of secondary elimination of tar from syngas. In our experiments, we used a natural catalyst (dolomite or calcium magnesium carbonate from Horní Lánov with great mechanical and catalytic properties, suitable for our purposes. The advantages of natural catalysts in contrast to artificial catalysts include their availability, low purchase prices and higher resilience to the so-called catalyst poison. Natural calcium catalysts may also capture undesired compounds of sulphure and chlorine. Our paper presents a theoretical description and analysis of catalytic destruction of tar into combustible gas components, and of the impact of dolomite calcination on its efficiency. The efficiency of the technology is verified in laboratories. The facility used for verification was a 150 kW pilot gasification unit with a laboratory catalytic filter. The efficiency of tar elimination reached 99.5%, the tar concentration complied with limits for use of the gas in combustion engines, and the tar content reached approximately 35 mg/mn3. The results of the measurements conducted in laboratories helped us design a pilot technology for catalytic gas cleaning.

  6. Material problems related to large scale firing of biomass. Steam oxidation of TP 347H FG and X20

    Energy Technology Data Exchange (ETDEWEB)

    Noergaard Hansson, A.

    2009-07-01

    TP 347 H and X20 is often used as construction material in biomass-fired boilers. The corrosion rate of the alloys is affected by the metal temperature. In this project, the oxidation behaviour of TP 347H FG and X20 is studied by field-testing, laboratory exposures, and thermodynamic/kinetic modelling. The long term oxidation behaviour of TP 347H FG at ultra supercritical steam conditions was assessed by exposing the steel in 4 test superheater loops in a coal-fired power plant. The steel was exposed for 7720, 22985, 29588, and 57554 h at metal temperatures between 499 and 650 deg. C. In the laboratory furnace, the oxidation behaviour of TP 347H FG, TP 347H CG, and X20 was studied in water vapour containing environments (8 or 46%) in the temperature range 500-700 deg. C. Air, Ar and Ar+7% H{sub 2} were used as carrier gas. The microstructure of the oxide layer and the subjacent alloy was investigated with X-ray diffraction (XRD), reflective light microscopy (RLM), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM) equipped with electron diffraction (ED) and EDS. Double-layered oxides developed during steam oxidation of TP 347H FG both during field-testing and during laboratory exposures. TEM investigation suggested that the interior of the alloy grain was oxidised internally, forming particles of metallic Ni/Fe and Fe-Cr spinel. A FeCr{sub 2}O{sub 4} layer developed along the former alloy grain boundaries. Cr{sub 2}O{sub 3} developed in between this layer and the alloy during field-testing, and its formation was promoted by higher temperature. The morphology of the inner layer for the samples oxidised below and above approx. 585 deg. C looked very different in SEM (field-testing). It is suggested that more Cr is incorporated into the oxide layer at higher temperature, gradually transforming the morphology of the inner oxide layer. The alloy beneath the oxide layer was depleted in Cr

  7. An investigation of condensation from steam-gas mixtures flowing downward inside a vertical tube

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, S.Z.; Schrock, V.E.; Peterson, P.F. [Univ. of California, Berkeley, CA (United States)

    1995-09-01

    Previous experiments have been carried out by Vierow, Ogg, Kageyama and Siddique for condensation from steam/gas mixtures in vertical tubes. In each case the data scatter relative to the correlation was large and there was not close agreement among the three investigations. A new apparatus has been designed and built using the lessons learned from the earlier studies. Using the new apparatus, an extensive new data base has been obtained for pure steam, steam-air mixtures and steam-helium mixtures. Three different correlations, one implementing the degradation method initially proposed by Vierow and Schrock, a second diffusion layer theory initially proposed by Peterson, and third mass transfer conductance model are presented in this paper. The correlation using the simple degradation factor method has been shown, with some modification, to give satisfactory engineering accuracy when applied to the new data. However, this method is based on very simplified arguments that do not fully represent the complex physical phenomena involved. Better representation of the data has been found possible using modifications of the more complex and phenomenologically based method which treats the heat transfer conductance of the liquid film in series with the conductance on the vapor-gas side with the latter comprised of mass transfer and sensible heat transfer conductance acting in parallel. The mechanistic models, based on the modified diffusion layer theory or classical mass transfer theory for mass transfer conductance with transpiration successfully correlate the data for the heat transfer of vapor-gas side. Combined with the heat transfer of liquid film model proposed by Blangetti, the overall heat transfer coefficients predicted by the correlations from mechanistic models are in close agreement with experimental values.

  8. Thermodynamic analyses of hydrogen production from sub-quality natural gas. Part II: Steam reforming and autothermal steam reforming

    Science.gov (United States)

    Huang, Cunping; T-Raissi, Ali

    Part I of this paper analyzed sub-quality natural gas (SQNG) pyrolysis and autothermal pyrolysis. Production of hydrogen via direct thermolysis of SQNGs produces only 2 mol of hydrogen and 1 mol of carbon per mole of methane (CH 4). Steam reforming of SQNG (SRSQNG) could become a more effective approach because the processes produce two more moles of hydrogen via water splitting. A Gibbs reactor unit operation in the AspenPlus™ chemical process simulator was employed to accomplish equilibrium calculations for the SQNG + H 2O and SQNG + H 2O + O 2 systems. The results indicate that water and oxygen inlet flow rates do not significantly affect the decomposition of hydrogen sulfide (H 2S) at temperatures lower than 1000 °C. The major co-product of the processes is carbonyl sulfide (COS) while sulfur dimer (S 2) and carbon disulfide (CS 2) are minor by-products within this temperature range. At higher temperatures (>1300 °C), CS 2 and S 2 become major co-products. No sulfur dioxide (SO 2) or sulfur trioxide (SO 3) is formed during either SRSQNG or autothermal SRSQNG processes, indicating that no environmentally harmful acidic gases are generated.

  9. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    David Liscinsky

    2002-10-20

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

  11. Hydrogen-rich gas production from waste plastics by pyrolysis and low-temperature steam reforming over a ruthenium catalyst

    International Nuclear Information System (INIS)

    Namioka, Tomoaki; Saito, Atsushi; Inoue, Yukiharu; Park, Yeongsu; Min, Tai-jin; Roh, Seon-ah; Yoshikawa, Kunio

    2011-01-01

    Operating conditions for low-temperature pyrolysis and steam reforming of plastics over a ruthenium catalyst were investigated. In the range studied, the highest gas and lowest coke fractions for polystyrene (PS) with a 60 g h -1 scale, continuous-feed, two-stage gasifier were obtained with a pyrolyzer temperature of 673 K, steam reforming temperature of 903 K, and weight hourly space velocity (WHSV) of 0.10 g-sample g-catalyst -1 h -1 . These operating conditions are consistent with optimum conditions reported previously for polypropylene. Our results indicate that at around 903 K, the activity of the ruthenium catalyst was high enough to minimize the difference between the rates of the steam reforming reactions of the pyrolysates from polystyrene and polypropylene. The proposed system thus has the flexibility to compensate for differences in chemical structures of municipal waste plastics. In addition, the steam reforming temperature was about 200 K lower than the temperature used in a conventional Ni-catalyzed process for the production of hydrogen. Low-temperature steam reforming allows for lower thermal input to the steam reformer, which results in an increase in thermal efficiency in the proposed process employing a Ru catalyst. Because low-temperature steam reforming can be also expected to reduce thermal degradation rates of the catalyst, the pyrolysis-steam reforming process with a Ru catalyst has the potential for use in small-scale production of hydrogen-rich gas from waste plastics that can be used for power generation.

  12. Steam explosion distinctively enhances biomass enzymatic saccharification of cotton stalks by largely reducing cellulose polymerization degree in G. barbadense and G. hirsutum.

    Science.gov (United States)

    Huang, Yu; Wei, Xiaoyang; Zhou, Shiguang; Liu, Mingyong; Tu, Yuanyuan; Li, Ao; Chen, Peng; Wang, Yanting; Zhang, Xuewen; Tai, Hongzhong; Peng, Liangcai; Xia, Tao

    2015-04-01

    In this study, steam explosion pretreatment was performed in cotton stalks, leading to 5-6 folds enhancements on biomass enzymatic saccharification distinctive in Gossypium barbadense and Gossypium hirsutum species. Sequential 1% H2SO4 pretreatment could further increase biomass digestibility of the steam-exploded stalks, and also cause the highest sugar-ethanol conversion rates probably by releasing less inhibitor to yeast fermentation. By comparison, extremely high concentration alkali (16% NaOH) pretreatment with raw stalks resulted in the highest hexoses yields, but it had the lowest sugar-ethanol conversion rates. Characterization of wall polymer features indicated that biomass saccharification was enhanced with steam explosion by largely reducing cellulose DP and extracting hemicelluloses. It also showed that cellulose crystallinity and arabinose substitution degree of xylans were the major factors on biomass digestibility in cotton stalks. Hence, this study has provided the insights into cell wall modification and biomass process technology in cotton stalks and beyond. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. H_2 production by the steam reforming of excess boil off gas on LNG vessels

    International Nuclear Information System (INIS)

    Fernández, Ignacio Arias; Gómez, Manuel Romero; Gómez, Javier Romero; López-González, Luis M.

    2017-01-01

    Highlights: • BOG excess in LNG vessels is burned in the GCU without energy use. • The gas management plants need to be improved to increase efficiency. • BOG excess in LNG vessels is used for H_2 production by steam reforming. • The availability of different fuels increases the versatility of the ship. - Abstract: The gas management system onboard LNG (Liquid Natural Gas) vessels is crucial, since the exploitation of the BOG (Boil Off Gas) produced is of utmost importance for the overall efficiency of the plant. At present, LNG ships with no reliquefaction plant consume the BOG generated in the engines, and the excess is burned in the GCU (Gas Combustion Unit) without any energy use. The need to improve the gas management system, therefore, is evident. This paper proposes hydrogen production through a steam reforming plant, using the excess BOG as raw material and thus avoiding it being burned in the GCU. To test the feasibility of integrating the plant, an actual study of the gas management process on an LNG vessel with 4SDF (4 Stroke Dual Fuel) propulsion and with no reliquefaction plant was conducted, along with a thermodynamic simulation of the reforming plant. With the proposed gas management system, the vessel disposes of different fuels, including H_2, a clean fuel with zero ozone-depleting emissions. The availability of H_2 on board in areas with strict anti-pollution regulations, such as ECAs (Emission Control Area), means that the vessel may be navigated without using fossil fuels which generate CO_2 and SO_X emissions. Moreover, while at port, Cold Ironing is avoided, which entails high costs. Thus it is demonstrated that the installation of a reforming plant is both energetically viable and provides greater versatility to the ship.

  14. Biomass utilization at Northern States Power Company

    International Nuclear Information System (INIS)

    Ellis, R.P.

    1994-01-01

    Northern States Power Company (open-quotes NSPclose quotes) generates, transmits and distributes electricity and distributes natural gas to customers in Minnesota, Wisconsin, North Dakota, South Dakota and Michigan. An important and growing component of the fuel needed to generate steam for electrical production is biomass. This paper describes NSP's historical use of biomass, current biomass resources and an overview of how NSP plans to expand its use of biomass in the future

  15. Lignocellulosic biomass-Thermal pretreatment with steam: Pretreatment techniques for biofuels and biorefineries

    DEFF Research Database (Denmark)

    Toor, Saqib; Rosendahl, Lasse; Hoffmann, Jessica

    2013-01-01

    With the ever rising demand for more energy and the limited availability of depleted world resources, many are beginning to look for alternatives to fossil fuels. Liquid biofuel, in particular, is of key interest to decrease our dependency on fuels produced from imported petroleum. Biomass pre......-treatment remains one of the most pressing challenges in terms of cost-effective production of biofuels. The digestibility of lingo-cellulosic biomass is limited by different factors such as the lignin content, the crystallinity of cellulose, and the available cellulose accessibility to hydrolytic enzymes. A number...

  16. Gas chromatographic determination of residual hydrazine and morpholine in boiler feed water and steam condensates

    International Nuclear Information System (INIS)

    Vatsala, S.; Bansal, V.; Tuli, D.K.; Rai, M.M.; Jain, S.K.; Srivastava, S.P.; Bhatnagar, A.K.

    1994-01-01

    Hydrazine, an oxygen scavenger in boiler water, was derivatised to the corresponding acetone azine and determined at the ng ml -1 level by gas chromatography. Morpholine, a corrosion inhibitor used in steam boilers, was estimated either directly (if >2.0 μg ml -1 ) or by quantitative preconcentration (0.1 ng-2.0 μg ml -1 ). To obtain symmetrical peaks for these amines, the column packing was coated with KOH. Use of a nitrogen-specific detector improved accuracy of estimation of hydrazine and morpholine, giving a RSD of 1.9-3.6%. Chromatographic analysis of these amines in boiler feed water and steam condensate samples collected from boilers servicing a pertroleum refinery is described. Environmental safety regulations calls for monitoring of hydrazine and the methods developed can easily be adapted for this purpose. (orig.)

  17. Experiment Plan of High Temperature Steam and Carbon dioxide Co-electrolysis for Synthetic Gas Production

    International Nuclear Information System (INIS)

    Yoon, Duk-Joo; Ko, Jae-Hwa

    2008-01-01

    Currently, Solid oxide fuel cells (SOFC) come into the spotlight in the middle of the energy technologies of the future for highly effective conversion of fossil fuels into electricity without carbon dioxide emission. The SOFC is a reversible cell. By applying electrical power to the cell, which is solid oxide electrolysis cell (SOEC), it is possible to produce synthetic gas (syngas) from high temperature steam and carbon dioxide. The produced syngas (hydrogen and carbon monoxide) can be used for synthetic fuels. This SOEC technology can use high temperature from VHTRs for high efficiency. This paper describes KEPRI's experiment plan of high temperature steam and carbon co-electrolysis for syngas production using SOEC technology

  18. Integration of biomass fast pyrolysis and precedent feedstock steam drying with a municipal combined heat and power plant

    International Nuclear Information System (INIS)

    Kohl, Thomas; Laukkanen, Timo P.; Järvinen, Mika P.

    2014-01-01

    Biomass fast pyrolysis (BFP) is a promising pre-treatment technology for converting biomass to transport fuel and in the future also for high-grade chemicals. BFP can be integrated with a municipal combined heat and power (CHP) plant. This paper shows the influence of BFP integration on a CHP plant's main parameters and its effect on the energetic and environmental performance of the connected district heating network. The work comprises full- and part-load operation of a CHP plant integrated with BFP and steam drying. It also evaluates different usage alternatives for the BFP products (char and oil). The results show that the integration is possible and strongly beneficial regarding energetic and environmental performance. Offering the possibility to provide lower district heating loads, the operation hours of the plant can be increased by up to 57%. The BFP products should be sold rather than applied for internal use as this increases the district heating network's primary energy efficiency the most. With this integration strategy future CHP plants can provide valuable products at high efficiency and also can help to mitigate global CO 2 emissions. - Highlights: • Part load simulation of a cogeneration plant integrated with biomas fast pyrolysis. • Analysis of energetic and environmental performance. • Assessment of different uses of the pyrolysis products

  19. Theoretical modeling of steam condensation in the presence of a noncondensable gas in horizontal tubes

    International Nuclear Information System (INIS)

    Lee, Kwon-Yeong; Kim, Moo Hwan; Kim, Moo Hwan

    2008-01-01

    A theoretical model was developed to investigate a steam condensation with a noncondensable gas in a horizontal tube. The heat transfer through the vapor/noncondensable gas mixture boundary layer consists of the sensible heat transfer and the latent heat transfer given up by the condensing vapor, and it must equal that from the condensate film to the tube wall. Therefore, the total heat transfer coefficient is given by the film, condensation and sensible heat transfer coefficients. The film heat transfer coefficients of the upper and lower portions of the tube were calculated separately from Rosson and Meyers (1965) correlation. The heat and mass transfer analogy was used to analyze the steam/noncondensable gas mixture boundary layer. Here, the Nusselt and Sherwood numbers in the gas phase were modified to incorporate the effects of condensate film roughness, suction, and developing flow. The predictions of the theoretical model for the experimental heat transfer coefficients at the top and bottom of the tube were reasonable. The calculated heat transfer coefficients at the top of the tube were higher than those at the bottom of it, as experimental results. As the temperature potential at the top of tube was lower than that at the bottom of it, the heat fluxes at the upper and lower portions of the tube were similar to each other. Generally speaking, however, the model predictions showed a good agreement with experimental data. The new empirical correlation proposed by Lee and Kim (2008) for the vertical tube was applied to the condensation of steam/noncondensable mixture in a horizontal tube. Nusselt theory and Chato correlation were used to calculate the heat transfer coefficients at top and bottom of the horizontal tube, respectively. The predictions of the new empirical correlation were good and very similar with the theoretical model. (author)

  20. a Study of Using Hydrogen Gas for Steam Boiler in CHOLOR- Alkali Manufacturing

    Science.gov (United States)

    Peantong, Sasitorn; Tangjitsitcharoen, Somkiat

    2017-06-01

    Main products of manufacturing of Cholor - Alkali, which commonly known as industrial chemical, are chlorine gas (Cl2), Sodium Hydroxide (NaOH) and hydrogen gas (H2). Chorine gas and sodium hydroxide are two main products for commercial profit; where hydrogen gas is by product. Most industries release hydrogen gas to atmosphere as it is non-profitable and less commercial scale. This study aims to make the most use of hydrogen as a substitute energy of natural gas for steam boiler to save energy cost. The second target of this study is to reduce level of CO2 release to air as a consequence of boiler combustion. This study suggests to install boiler that bases on hydrogen as main power with a high turndown ratio of at least 1:6. However, this case study uses boiler with two mode such as natural gas (NG) mode and mixed mode as they need to be flexible for production. Never the less, the best boiler selection is to use single mode energy of hydrogen. The most concerned issue about hydrogen gas is explosion during combustion stage. Stabilization measures at emergency stop is introduced to control H2 pressure to protect the explosion. This study varies ratio of natural gas to hydrogen gas to find the optimal level of two energy sources for boiler and measure total consumption through costing model; where CO2 level is measured at the boiler stack. The result of this study shows that hydrogen gas can be a substitute energy with natural gas and can reduce cost. Natural gas cost saving is 248,846 baht per month and reduce level of NOx is 80 ppm 7% O2 and 2 % of CO2 release to air as a consequence of boiler combustion.

  1. Gas quality prediction in ligno-cellulosic biomass gasification in a co-current gas producer

    International Nuclear Information System (INIS)

    Martin, J.; Nganhou, J.; Amie Assouh, A.

    2008-01-01

    Our research covers the energetic valuation of the biomass for electricity production. As electrical energy production is the main drive behind a modern economy, we wanted to make our contribution to the debate by describing a tried technique, whose use on an industrial scale can still be perfected, failing control over the basic principles that support the gasification processes called upon in this industry. Our study describes gasification, which is a process to transform a solid combustible into a gas combustible. The resulting gas can be used as combustible in an internal combustion motor and produce electricity. Our work interprets the experimental results of gasification tests conducted on an available and functional experimental centre and the ENSPY's Decentralized Energy Production Lab. The work involved developing a tool to appreciate the results of the gasification of the ligneous biomass from the stoichiometric composition of the combustible to be gasified and the chemical and mathematical bases of the gasification process. It is an investigation with a view to elaborating a mathematical model based on the concept of compatibility. Its original lies in the quality prediction method for the gas obtained through the gasification of a biomass whose chemical composition is known. (authors)

  2. Layout of an internally heated gas generator for the steam gasification of coal

    International Nuclear Information System (INIS)

    Feistel, P.P.; Duerrfeld, R.; Heck, K.H. van; Juentgen, H.

    1975-01-01

    Industrial-scale steam gasification of coal using heat from high temperature reactors requires research and development on allothermal gas generators. Bergbau-Forschung GmbH, Essen, does theoretical and experimental work in this field. The experiments deal with reaction kinetics, heat transfer and material tests. Their significance for the layout of a full-scale gas generator is shown. Including material specifications, the feasibility of a gasifier, characterized by a fluid bed volume of 318 m 3 and a heat transferring area of 4000 m 2 , results. The data, now available, are used to determine the gasification throughput from the heat balance, i.e. the equality of heat consumed and heat transferred. Throughputs of about 50 t/hr of coal are possible for a single gas generator, the helium outlet temperature of the HTR being 950 0 C/ Bergbau-Forschung has commissioned a medium-scale pilot plant (200 kg/hr). (Auth.)

  3. Oil and gas platforms with steam bottoming cycles: System integration and thermoenvironomic evaluation

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Tock, Laurence; Breuhaus, Peter

    2014-01-01

    The integration of steam bottoming cycles on oil and gas platforms is currently regarded as the most promising option for improving the performance of these energy-intensive systems. In this paper, a North Sea platform is taken as case study, and a systematic analysis of its energy requirements...... cooling utility, and (iv) the weight limitations on the platform are quantitatively assessed. The results illustrate the benefits of converting the gas turbine process into a combined cycle, since the fuel gas consumption and the total CO2-emissions can be reduced by more than 15 %. Using the cooling...... water from the processing plant reveals to be more profitable than using seawater, as the additional pumping power outweighs the benefit of using a cooling medium at a temperature of about 8 °C lower. This study highlights thereby the importance of analysing energy savings and recovery options...

  4. Study of Catalyst Variation Effect in Glycerol Conversion Process to Hydrogen Gas by Steam Reforming

    Science.gov (United States)

    Widayat; Hartono, R.; Elizabeth, E.; Annisa, A. N.

    2018-04-01

    Along with the economic development, needs of energy being increase too. Hydrogen as alternative energy has many usages. Besides that, hydrogen is one source of energy that is a clean fuel, but process production of hydrogen from natural gas as a raw material has been used for a long time. Therefore, there is need new invention to produce hydrogen from the others raw material. Glycerol, a byproduct of biodiesel production, is a compound which can be used as a raw material for hydrogen production. By using glycerol as a raw material of hydrogen production, we can get added value of glycerol as well as an energy source solution. The process production of hydrogen by steam reforming is a thermochemical process with efficiency 70%. This process needs contribution of catalyst to improve its efficiency and selectivity of the process. In this study will be examined the effect variation of catalyst for glycerol conversion process to hydrogen by steam reforming. The method for catalyst preparation was variation of catalyst impregnation composition, catalyst calcined with difference concentration of hydrochloric acid and calcined with difference hydrochloric acid ratio. After that, all of catalyst which have been prepared, used for steam reforming process for hydrogen production from glycerol as a raw material. From the study, the highest yield of hydrogen gas showed in the process production by natural zeolite catalyst with 1:15 Hydrochloric acid ratio was 42.28%. Hydrogen yield for 2M calcined natural zeolite catalyst was 38.37%, for ZSM-5 catalyst was 15.83%, for 0.5M calcined natural zeolite was 13.09% and for ultrasonic natural zeolite was 11.43%. The lowest yield of hydrogen gas showed in catalyst 2Zn/ZSM-5 with 11.22%. This result showed that hydrogen yield product was affected by catalyst variation because of the catalyst has difference characteristic and difference catalytic activity after the catalyst preparation process.

  5. Steam generator materials constraints in UK design gas-cooled reactors

    International Nuclear Information System (INIS)

    James, D.W.

    1988-01-01

    A widely reported problem with Magnox-type reactors was the oxidation of carbon steel components in gas circuits and steam generators. The effects of temperature, pressure, gas composition and steel composition on oxidation kinetics have been determined, thus allowing the probabilities of failure of critical components to be predicted for a given set of operating conditions. This risk analysis, coupled with regular inspection of reactor and boiler internals, has allowed continued operation of all U.K. Magnox plant. The Advanced Gas Cooled Reactor (AGR) is a direct development of the Magnox design. The first four AGRs commenced operation in 1976, at Hinkley Point 'B' and at Hunterston 'B'. All known materials problems with the steam generators have been diagnosed and solved by the development of appropriate operational strategies, together with minor plant modifications. Materials constraints no longer impose any restrictions to full load performance from the steam generators throughout the predicted life of the plant. Problems discussed in detail are: 1. oxidation of the 9 Cr - 1 Mo superheater. 2. Stress corrosion of the austenitic superheater. 3. Creep of the transition joints between the 9 Cr - 1 Mo and austenitic sections. With the 9 Cr - 1 Mo oxidation maximum temperature restriction virtually removed and creep constraints properly quantified, boiler operation in now favourably placed. Stress corrosion research has allowed the risk of tube failure to be related to time, temperature, stress and chemistry. As a result, the rigorous 'no wetting' policy has been relaxed for the normally high quality AGR feedwater, and the superheat margin has been reduced to 23 deg. C. This has increased the size of the operating window and reduced the number of expensive, and potentially harmful, plant trips. (author)

  6. Economic evaluation of the steam-cycle high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    1983-07-01

    The High Temperature Gas-Cooled Reactor is unique among current nuclear technologies in its ability to generate energy in temperature regimes previously limited to fossil fuels. As a result, it can offer commercial benefits in the production of electricity, and at the same time, expand the role of nuclear energy to the production of process heat. This report provides an evaluation of the HTGR-Steam Cycle (SC) system for the production of baseloaded electricity, as well as cogenerated electricity and process steam. In each case the HTGR-SC system has been evaluated against appropriate competing technologies. The computer code which was developed for this evaluation can be used to present the analyses on a cost of production or cash flow basis; thereby, presenting consistent results to a utility, interested in production costs, or an industrial steam user or third party investor, interested in returns on equity. Basically, there are two economic evaluation methodologies which can be used in the analysis of a project: (1) minimum revenue requirements, and (2) discounted cash flow

  7. The effect of non-condensable gas on direct contact condensation of steam/air mixture

    International Nuclear Information System (INIS)

    Lee, H. C.; Park, S. K.; Kim, M. H.

    1998-01-01

    To investigate the effects of noncondensable gas on the direct contact film condensation of vapor mixture, a series of experiments has been carried out. The rectangular duct inclined 87.deg. to the horizontal plane was used for this experiment. The average heat transfer coefficient of the steam-air mixture was obtained at the atmospheric pressure with four main parameters, air-mass fraction, vapor velocity, film Reynolds number,and the degree of water film subcooling having an influence on the condensation heat transfer coefficient. With the analysis on 88 cases of experiments, a correlation of the average Nusselt number for direct contact film condensation of steam-air mixture at a vertical wall proposed as functions of film Reynolds number, mixture Reynolds number, air mass fraction, and Jacob number. The average heat transfer coefficient for steam-air mixture condensation decreased significantly while air mass fraction increases with the same inlet mixture velocity and inlet film temperature. The average heat transfer coefficients also decreased with the degree of film subcooling increasing and were scarcely affected by film Reynolds number below the mixture Reynolds number about 30,000

  8. Thermo-economic assessment of externally fired micro-gas turbine fired by natural gas and biomass: Applications in Italy

    International Nuclear Information System (INIS)

    Pantaleo, A.M.; Camporeale, S.M.; Shah, N.

    2013-01-01

    Highlights: • A thermo-economic analysis of natural gas/biomass fired microturbine is proposed. • Energy efficiency, capex, opex and electricity revenues trade-offs are assessed. • The optimal biomass energy input is 70% of total CHP consumption. • Industrial/tertiary heat demand and baseload/heat driven operation is assessed. • The main barriers of small scale CHP systems in Italy are overviewed. - Abstract: This paper proposes a thermo-economic assessment of small scale (100 kWe) combined heat and power (CHP) plants fired by natural gas and solid biomass. The focus is on dual fuel gas turbine cycle, where compressed air is heated in a high temperature heat exchanger (HTHE) using the hot gases produced in a biomass furnace, before entering the gas combustion chamber. The hot air expands in the turbine and then feeds the internal pre-heater recuperator, Various biomass/natural gas energy input ratios are modeled, ranging from 100% natural gas to 100% biomass. The research assesses the trade-offs between: (i) lower energy conversion efficiency and higher investment cost of high biomass input rate and (ii) higher primary energy savings and revenues from bio-electricity feed-in tariff in case of high biomass input rate. The influence of fuel mix and biomass furnace temperature on energy conversion efficiencies, primary energy savings and profitability of investments is assessed. The scenarios of industrial vs. tertiary heat demand and baseload vs. heat driven plant operation are also compared. On the basis of the incentives available in Italy for biomass electricity and for high efficiency cogeneration (HEC), the maximum investment profitability is achieved for 70% input biomass percentage. The main barriers of these embedded cogeneration systems in Italy are also discussed

  9. Characterization of biomass producer gas as fuel for stationary gas engines in combined heat and power production

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper

    2008-01-01

    The aim of this project has been the characterization of biomass producer gas as a fuel for stationary gas engines in heat and power production. More than 3200 hours of gas engine operation, with producer gas as fuel, has been conducted at the biomass gasification combined heat and power (CHP...... different measuring methods. Likewise, no particles were detected in the gas. Considerable amounts of NH3 were measured in the produced gas.An analysis of engine operation at varying load has been carried out. Standard emissions, load and efficiency have been measured at varying operating conditions ranging...... from 50% to 90% load. Biomass producer gas is an excellent lean burn engine fuel: Operation of a natural aspirated engine has been achieved for 1.2...

  10. Steam condenser

    International Nuclear Information System (INIS)

    Masuda, Fujio

    1980-01-01

    Purpose: To enable safe steam condensation by providing steam condensation blades at the end of a pipe. Constitution: When high temperature high pressure steam flows into a vent pipe having an opening under water in a pool or an exhaust pipe or the like for a main steam eacape safety valve, non-condensable gas filled beforehand in the steam exhaust pipe is compressed, and discharged into the water in the pool. The non-condensable gas thus discharged from the steam exhaust pipe is introduced into the interior of the hollow steam condensing blades, is then suitably expanded, and thereafter exhausted from a number of exhaust holes into the water in the pool. In this manner, the non-condensable gas thus discharged is not directly introduced into the water in the pool, but is suitable expanded in the space of the steam condensing blades to suppress extreme over-compression and over-expansion of the gas so as to prevent unstable pressure vibration. (Yoshihara, H.)

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

    Directory of Open Access Journals (Sweden)

    Kinya Sakanishi

    2012-05-01

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

  12. AREVA Modular Steam Cycle – High Temperature Gas-Cooled Reactor Development Progress

    International Nuclear Information System (INIS)

    Lommers, L.; Shahrokhi, F.; Southworth, F.; Mayer, J. III

    2014-01-01

    The AREVA Steam Cycle – High Temperature Gas-Cooled Reactor (SCHTGR) is a modular graphite-moderated gas-cooled reactor currently being developed to support a wide variety of applications including industrial process heat, high efficiency electricity generation, and cogeneration. It produces high temperature superheated steam which makes it a good match for many markets currently dependent on fossil fuels for process heat. Moreover, the intrinsic safety characteristics of the SC-HTGR make it uniquely qualified for collocation with large industrial process heat users which is necessary for serving these markets. The NGNP Industry Alliance has selected the AREVA SC-HTGR as the basis for future development work to support commercial HTGR deployment. This paper provides a concise description of the SC-HTGR concept, followed by a summary of recent development activities. Since this concept was introduced, ongoing design activities have focused primarily on confirming key system capabilities and the suitability for potential future markets. These evaluations continue to confirm the suitability of the SC-HTGR for a variety of potential applications that are currently dependent on fossil fuels. (author)

  13. Energy analysis and design of mixed CO{sub 2}/steam gas turbine cycles

    Energy Technology Data Exchange (ETDEWEB)

    Bram, S; De Ruyck, J [Vrije Universiteit Brussel, Brussels (Belgium). Dept. of Mechanics

    1995-06-01

    The capturing and disposal of CO{sub 2} from power plant exhaust gases is a possible route for reducing CO{sub 2} emissions. The present paper investigates the full recirculation of exhaust gases in a gas turbine cycle, combined with the injection of steam or water. Such recirculation leads to an exhaust gas with very high CO{sub 2} concentration (95% or more). Different regenerative cycle layouts are proposed and analyzed for efficiency, exergy destruction and technical feasibility. Pinch Technology methods are next applied to find the best configuration for heat regeneration and injection of water. From this analysis, dual pressure evaporation with water injection in the intercooler emerges as an interesting option. 3 refs., 2 figs., 1 tab.

  14. PdZnAl Catalysts for the Reactions of Water-Gas-Shift, Methanol Steam Reforming, and Reverse-Water-Gas-Shift

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, Robert A.; Platon, Alexandru; Datye, Abhaya K.; Vohs, John M.; Wang, Yong; Palo, Daniel R.

    2008-03-07

    Pd/ZnO/Al2O3 catalysts were studied for water-gas-shift (WGS), methanol steam reforming, and reverse-water-gas-shift (RWGS) reactions. WGS activity was found to be dependent on the Pd:Zn ratio with a maximum activity obtained at approximately 0.50, which was comparable to that of a commercial Pt-based catalyst. The catalyst stability was demonstrated for 100 hours time-on-stream at a temperature of 3600C without evidence of metal sintering. WGS reaction rates were approximately 1st order with respect to CO concentration, and kinetic parameters were determined to be Ea = 58.3 kJ mol-1 and k0 = 6.1x107 min-1. During methanol steam reforming, the CO selectivities were observed to be lower than the calculated equilibrium values over a range of temperatures and steam/carbon ratios studied while the reaction rate constants were approximately of the same magnitude for both WGS and methanol steam reforming. These results indicate that although Pd/ZnO/Al2O3 are active WGS catalysts, WGS is not involved in methanol steam reforming. RWGS rate constants are on the order of about 20 times lower than that of methanol steam reforming, suggesting that RWGS reaction could be one of the sources for small amount of CO formation in methanol steam reforming.

  15. Increased power to heat ratio of small scale CHP plants using biomass fuels and natural gas

    International Nuclear Information System (INIS)

    Savola, Tuula; Fogelholm, Carl-Johan

    2006-01-01

    In this paper, we present a systematic study of process changes for increased power production in 1-20 MW e combined heat and power (CHP) plants. The changes are simulated, and their economic feasibility evaluated by using existing small scale CHP case plants. Increasing power production in decentralised CHP plants that operate according to a certain heat demand could reduce the fuel consumption and CO 2 emissions per power unit produced and improve the feasibility of CHP plant investments. The CHP plant process changes were simulated under design and off design conditions and an analysis of power and heat production, investment costs and CO 2 emissions was performed over the whole annual heat demand. The results show that using biomass fuels, there are profitable possibilities to increase the current power to heat ratios, 0.23-0.48, of the small scale CHP plants up to 0.26-0.56, depending on the size of the plant. The profitable changes were a two stage district heat exchanger and the addition of a steam reheater and a feed water preheater. If natural gas is used as an additional fuel, the power to heat ratio may be increased up to 0.35-0.65 by integrating a gas engine into the process. If the CO 2 savings from the changes are also taken into account, the economic feasibility of the changes increases. The results of this work offer useful performance simulation and investment cost knowledge for the development of more efficient and economically feasible small scale CHP processes

  16. Performance analysis of an integrated gas-, steam- and organic fluid-cycle thermal power plant

    International Nuclear Information System (INIS)

    Oko, C.O.C.; Njoku, I.H.

    2017-01-01

    This paper presents the performance analysis of an existing combined cycle power plant augmented with a waste heat fired organic Rankine cycle power plant for extra power generation. This was achieved by performing energy and exergy analysis of the integrated gas-, steam- and organic fluid-cycle thermal power plant (IPP). Heat source for the subcritical organic Rankine cycle (ORC) was the exhaust flue gases from the heat recovery steam generators of a 650 MW natural gas fired combined cycle power plant. The results showed that extra 12.4 MW of electricity was generated from the attached ORC unit using HFE7100 as working fluid. To select ORC working fluid, ten isentropic fluids were screened and HFE7100 produced the highest net power output and cycle efficiency. Exergy and energy efficiencies of the IPP improved by 1.95% and 1.93%, respectively. The rate of exergy destruction in the existing combined cycle plant was highest in the combustion chamber, 59%, whereas in the ORC, the highest rate of exergy destruction occurred in the evaporator, 62%. Simulations showed exergy efficiency of the IPP decreased with increasing ambient temperature. Exit stack flue gas temperature reduced from 126 °C in the combined cycle power plant to 100 °C in the integrated power plant. - Highlights: • Combined cycle plant retrofitted with ORC produced extra 12.4 MW electric power. • ORC is powered with low temperature flue gas from an existing combined cycle plant. • Exergy destruction rate in integrated plant(IPP) is less than in combined plant. • Exit stack temperature of the IPP has less environmental thermal pollution. • Exergy and energy efficiencies of the IPP improved by 1.95% and 1.93%, respectively.

  17. Effect of bioleaching on hydrogen-rich gas production by steam gasification of sewage sludge

    International Nuclear Information System (INIS)

    Li, Hanhui; Chen, Zhihua; Huo, Chan; Hu, Mian; Guo, Dabin; Xiao, Bo

    2015-01-01

    Highlights: • Bioleaching can modify the physicochemical property of sewage sludge. • The enhancement is mainly hydrogen. • Bioleaching can enhance the gas production in gasification of sewage sludge. • Study provides an insight for future application of bioleached sewage sludge. - Abstract: Effect of bioleaching on hydrogen-rich gas production by steam gasification of sewage sludge was carried out in a lab-scale fixed-bed reactor. The influence of sewage sludge solids concentrations (6–14% (w/v) in 2% increments) during the bioleaching process and reactor temperature (600–900 °C in 100 °C increments) on gasification product yields and gas composition were studied. Characterization of samples showed that bioleaching treatment, especially in 6% (w/v) sludge solids concentration, led to metal removal effectively and modifications in the physicochemical property of sewage sludge which was favored for gasification. The maximum gas yield (49.4%) and hydrogen content (46.4%) were obtained at 6% (w/v) sludge solids concentration and reactor temperature of 900 °C. Sewage sludge after the bioleaching treatment may be a feasible feedstock for hydrogen-rich gas product.

  18. Combination of Superheated Steam with Laccase Pretreatment Together with Size Reduction to Enhance Enzymatic Hydrolysis of Oil Palm Biomass

    Directory of Open Access Journals (Sweden)

    Nur Fatin Athirah Ahmad Rizal

    2018-04-01

    Full Text Available The combination of superheated steam (SHS with ligninolytic enzyme laccase pretreatment together with size reduction was conducted in order to enhance the enzymatic hydrolysis of oil palm biomass into glucose. The oil palm empty fruit bunch (OPEFB and oil palm mesocarp fiber (OPMF were pretreated with SHS and ground using a hammer mill to sizes of 2, 1, 0.5 and 0.25 mm before pretreatment using laccase to remove lignin. This study showed that reduction of size from raw to 0.25 mm plays important role in lignin degradation by laccase that removed 38.7% and 39.6% of the lignin from OPEFB and OPMF, respectively. The subsequent saccharification process of these pretreated OPEFB and OPMF generates glucose yields of 71.5% and 63.0%, which represent a 4.6 and 4.8-fold increase, respectively, as compared to untreated samples. This study showed that the combination of SHS with laccase pretreatment together with size reduction could enhance the glucose yield.

  19. Exergy Steam Drying and Energy Integration

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Prem; Muenter, Claes (Exergy Engineering and Consulting, SE-417 55 Goeteborg (Sweden)). e-mail: verma@exergyse.com

    2008-10-15

    Exergy Steam Drying technology has existed for past 28 years and many new applications have been developed during this period. But during past few years the real benefits have been exploited in connection with bio-fuel production and energy integration. The steam dryer consists of a closed loop system, where the product is conveyed by superheated and pressurised carrier steam. The carrier steam is generated by the water vapours from the product being dried, and is indirectly superheated by another higher temperature energy source such as steam, flue gas, thermal oil etc. Besides the superior heat transfer advantages of using pressurised steam as a drying medium, the energy recovery is efficient and simple as the recovered energy (80-90%) is available in the form of steam. In some applications the product quality is significantly improved. Examples presented in this paper: Bio-Combine for pellets production: Through integration of the Exergy Steam Dryer for wood with a combined heat and power (CHP) plant, together with HP steam turbine, the excess carrier steam can be utilised for district heating and/or electrical power production in a condensing turbine. Bio-ethanol production: Both for first and second generation of ethanol can the Exergy process be integrated for treatment of raw material and by-products. Exergy Steam Dryer can dry the distillers dark grains and solubles (DDGS), wood, bagasse and lignin. Bio-diesel production: Oil containing seeds and fruits can be treated in order to improve both the quality of oil and animal feed protein, thus minimizing further oil processing costs and increasing the sales revenues. Sewage sludge as bio-mass: Municipal sewage sludge can be considered as a renewable bio-fuel. By drying and incineration, the combustion heat value of the sludge is sufficient for the drying process, generation of electrical energy and production of district heat. Keywords; Exergy, bio-fuel, bio-mass, pellets, bio-ethanol, biodiesel, bio

  20. CO and PAH Emissions from Engines Operating on Biomass Producer Gas

    DEFF Research Database (Denmark)

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

    2003-01-01

    High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. The standing regulations concerning CO emissions from producer gas engine based power plants in most EU countrie...

  1. Evaluation of materials' corrosion and chemistry issues for advanced gas cooled reactor steam generators using full scale plant simulations

    International Nuclear Information System (INIS)

    Woolsey, I.S.; Rudge, A.J.; Vincent, D.J.

    1998-01-01

    Advanced Gas Cooled Reactors (AGRS) employ once-through steam Generators of unique design to provide steam at approximately 530 degrees C and 155 bar to steam turbines of similar design to those of fossil plants. The steam generators are highly compact, and have either a serpentine or helical tube geometry. The tubes are heated on the outside by hot C0 2 gas, and steam is generated on the inside of the tubes. Each individual steam generator tube consists of a carbon steel feed and primary economiser section, a 9%Cr steel secondary economiser, evaporator and primary superheater, and a Type 316L austenitic stainless steel secondary superheater, all within a single tube pass. The multi-material nature of the individual tube passes, the need to maintain specific thermohydraulic conditions within the different material sections, and the difficulties of steam generator inspection and repair, have required extensive corrosion-chemistry test programmes to ensure waterside corrosion does not present a challenge to their integrity. A major part of these programmes has been the use of a full scale steam generator test facility capable of simulating all aspects of the waterside conditions which exist in the plant. This facility has been used to address a wide variety of possible plant drainage/degradation processes. These include; single- and two-phase flow accelerated corrosion of carbon steel, superheat margins requirements and the stress-corrosion behaviour of the austenitic superheaters, on-load corrosion of the evaporator materials, and iron transport and oxide deposition behaviour. The paper outlines a number of these, and indicates how they have been of value in helping to maintain reliable operation of the plant. (author)

  2. Investigations of the gas-side heat transfer and flow characteristics of steam generators in AGR stations

    Energy Technology Data Exchange (ETDEWEB)

    Lis, J [Central Electricity Research Laboratories, Leatherhead, Surrey (United Kingdom)

    1984-07-01

    This paper describes the experimental and analytical investigations of the gas-side heat transfer and flow characteristics of steam generators in the AGR stations carried out by CERL. The majority of the experimental work on heat transfer and flow characteristics of close-packed tube arrangements in cross-flow of gases is carried out in a pressurised heat exchanger rig. The rig is operated on-line by a dedicated PDP 11/40 computer over the range of Reynolds number 10{sup 4} to 3x10{sup 5}. Atmospheric wind tunnels employing either small or large scale models of the specific sections of steam generators are used for a variety of supplementary and development studies. Various measurements techniques and, in particular, LDA and hot wire anemometry employed in these studies are described. The more important aspects of various investigations are illustrated by typical results. In order to ensure the efficient operation and integrity of steam generators under asymmetric boundary conditions a MIX suite of 2-dimensional codes has been developed. The codes calculate the gas and water/steam flow and temperature distributions in each channel of the steam generator taking into account thermal mixing in the gas as it passes through the generator. Application of the MIX codes to the solution of various operational problems is illustrated by typical examples and the continuing exercise of validating the codes against plant operational data is discussed. (author)

  3. Investigations of the gas-side heat transfer and flow characteristics of steam generators in AGR stations

    International Nuclear Information System (INIS)

    Lis, J.

    1984-01-01

    This paper describes the experimental and analytical investigations of the gas-side heat transfer and flow characteristics of steam generators in the AGR stations carried out by CERL. The majority of the experimental work on heat transfer and flow characteristics of close-packed tube arrangements in cross-flow of gases is carried out in a pressurised heat exchanger rig. The rig is operated on-line by a dedicated PDP 11/40 computer over the range of Reynolds number 10 4 to 3x10 5 . Atmospheric wind tunnels employing either small or large scale models of the specific sections of steam generators are used for a variety of supplementary and development studies. Various measurements techniques and, in particular, LDA and hot wire anemometry employed in these studies are described. The more important aspects of various investigations are illustrated by typical results. In order to ensure the efficient operation and integrity of steam generators under asymmetric boundary conditions a MIX suite of 2-dimensional codes has been developed. The codes calculate the gas and water/steam flow and temperature distributions in each channel of the steam generator taking into account thermal mixing in the gas as it passes through the generator. Application of the MIX codes to the solution of various operational problems is illustrated by typical examples and the continuing exercise of validating the codes against plant operational data is discussed. (author)

  4. Effect of non-condensable gas on heat transfer in steam turbine condenser and modelling of ejector pump system by controlling the gas extraction rate through extraction tubes

    International Nuclear Information System (INIS)

    Strušnik, Dušan; Golob, Marjan; Avsec, Jurij

    2016-01-01

    Graphical abstract: Control of the amount of the pumped gases through extraction tubes. The connecting locations interconnect the extraction tubes for STC gas pumping. The extraction tubes are fitted with 3 control valves to control the amount of the pumped gas depending on the temperature of the pumped gas. The amount of the pumped gas increases through the extraction tubes, where the pumped gases are cooler and decreases, at the same time, through the extraction tubes, where the pumped gases are warmer. As a result, pumping of a larger amount of NCG is ensured and of a smaller amount of CG, given that the NCG concentration is the highest on the colder places. This way, the total amount of the pumped gases from the STC can be reduced, the SEPS operates more efficiently and consumes less energy for its operation. - Highlights: • Impact of non-condensable gas on heat transfer in a steam turbine condenser. • The ejector system is optimised by selecting a Laval nozzle diameter. • Simulation model of the control of the amount of pumped gases through extraction tubes. • Neural network and fuzzy logic systems used to control gas extraction rate. • Simulation model was designed by using real process data from the thermal power plant. - Abstract: The paper describes the impact of non-condensable gas (NCG) on heat transfer in a steam turbine condenser (STC) and modelling of the steam ejector pump system (SEPS) by controlling the gas extraction rate through extraction tubes. The ideal connection points for the NCG extraction from the STC are identified by analysing the impact of the NCG on the heat transfer and measuring the existing system at a thermal power plant in Slovenia. A simulation model is designed using the Matlab software and Simulink, Neural Net Work, Fuzzy Logic and Curve Fitting Toolboxes, to control gas extraction rate through extraction tubes of the gas pumped from the STC, thus optimising the operation of the steam ejector pump system (SEPS). The

  5. Greenhouse gas credits trade versus biomass trade – weighing (Workshop Summary)

    NARCIS (Netherlands)

    Junginger, H.M.; Faaij, A.P.C.; Robertson, K.; Woes-Gallasch, S.; Schlamadinger, B.

    2006-01-01

    A workshop entitled ‘Greenhouse gas credits trade versus biomass trade – weighing the benefits’, jointly organised by IEA Bioenergy Tasks 38 (GHG Balances of Biomass and Bioenergy Systems) and 40 (Sustainable International Bioenergy Trade: Securing Supply and Demand), and ENOVA, took place in

  6. Optimisation of environmental gas cleaning routes for solid wastes cogeneration systems. Part II - Analysis of waste incineration combined gas/steam cycle

    International Nuclear Information System (INIS)

    Holanda, Marcelo R.; Perrella Balestieri, Jose A.

    2008-01-01

    In the first paper of this paper (Part I), conditions were presented for the gas cleaning technological route for environomic optimisation of a cogeneration system based in a thermal cycle with municipal solid waste incineration. In this second part, an environomic analysis is presented of a cogeneration system comprising a combined cycle composed of a gas cycle burning natural gas with a heat recovery steam generator with no supplementary burning and a steam cycle burning municipal solid wastes (MSW) to which will be added a pure back pressure steam turbine (another one) of pure condensation. This analysis aims to select, concerning some scenarios, the best atmospheric pollutant emission control routes (rc) according to the investment cost minimisation, operation and social damage criteria. In this study, a comparison is also performed with the results obtained in the Case Study presented in Part I

  7. Integrated Biorefinery for Conversion of Biomass to Ethanol, Synthesis Gas, and Heat

    Energy Technology Data Exchange (ETDEWEB)

    Leon, Gerson [Abengoa Bioenergy, Hugoton, KS (United States)

    2017-06-20

    Goal of the project was to Design, build and operate a commercial scale bioethanol facility that uses sustainable biomass feedstock, drastically reduces greenhouse gas (GHG) emissions while achieving output production, yield and cost targets.

  8. Entrained Flow Gasification of Biomass

    DEFF Research Database (Denmark)

    Qin, Ke

    The present Ph. D. thesis describes experimental and modeling investigations on entrained flow gasification of biomass and an experimental investigation on entrained flow cogasification of biomass and coal. A review of the current knowledge of biomass entrained flow gasification is presented....... Biomass gasification experiments were performed in a laboratory-scale atmospheric pressure entrained flow reactor with the aim to investigate the effects of operating parameters and biomass types on syngas products. A wide range of operating parameters was involved: reactor temperature, steam/carbon ratio......, excess air ratio, oxygen concentration, feeder gas flow, and residence time. Wood, straw, and lignin were used as biomass fuels. In general, the carbon conversion was higher than 90 % in the biomass gasification experiments conducted at high temperatures (> 1200 °C). The biomass carbon...

  9. METHANE STEAM REACTION OVER NICKEL CATALYSTS IN THE HYNOL PROCESS

    Science.gov (United States)

    The report discusses the reaction of methane-steam over nickel catalysts in the Hynol process, a process that uses biomass and natural gas as feedstocks to maximize methanol yields and minimize greenhouse gas emissions. EPA's APPCD has established a laboratory in which to conduct...

  10. Torrefaction of empty fruit bunches under biomass combustion gas atmosphere.

    Science.gov (United States)

    Uemura, Yoshimitsu; Sellappah, Varsheta; Trinh, Thanh Hoai; Hassan, Suhaimi; Tanoue, Ken-Ichiro

    2017-11-01

    Torrefaction of oil palm empty fruit bunches (EFB) under combustion gas atmosphere was conducted in a batch reactor at 473, 523 and 573K in order to investigate the effect of real combustion gas on torrefaction behavior. The solid mass yield of torrefaction in combustion gas was smaller than that of torrefaction in nitrogen. This may be attributed to the decomposition enhancement effect by oxygen and carbon dioxide in combustion gas. Under combustion gas atmosphere, the solid yield for torrefaction of EFB became smaller as the temperature increased. The representative products of combustion gas torrefaction were carbon dioxide and carbon monoxide (gas phase) and water, phenol and acetic acid (liquid phase). By comparing torrefaction in combustion gas with torrefaction in nitrogen gas, it was found that combustion gas can be utilized as torrefaction gas to save energy and inert gas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Numerical analysis of gas-liquid two-phase flow in secondary side of steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Murase, Michio; Nakamura, Akira; Yagi, Yoshinori [Inst. of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2002-09-01

    The steam generator (SG) in a pressurized water reactor (PWR) is an important two-phase flow component as the boundary between the primary loop and the secondary loop. In this study, we performed gas-liquid two-phase flow analyses for SG reliability tests conduced by Nuclear Power Engineering Corporation (NUPEC) using the two-fluid model of a thermal-hydraulic computer code PHOENICS. In order to calculate the location of the boiling initiation accurately, detailed inputs were required for the friction coefficients affecting the velocity distribution and the heat transfer distribution. However, the velocity and heat transfer distributions did not greatly affect the void fractions in the upper region of the heat transfer tubes. The calculated void fractions agreed with the measured values within 4% as the local average and within 2% as an average in a cross-section, except the region of low void fractions. (author)

  12. Digital simulation of a commercial scale high temperature gas-cooled reactor (HTGR) steam power plant

    International Nuclear Information System (INIS)

    Ray, A.; Bowman, H.F.

    1978-01-01

    A nonlinear dynamic model of a commercial scale high temperature gas-cooled reactor (HTGR) steam power plant was derived in state-space form from fundamental principles. The plant model is 40th order, time-invariant, deterministic and continuous-time. Numerical results were obtained by digital simulation. Steady-state performance of the nonlinear model was verified with plant heat balance data at 100, 75 and 50 percent load levels. Local stability, controllability and observability were examined in this range using standard linear algorithms. Transfer function matrices for the linearized models were also obtained. Transient response characteristics of 6 system variables for independent step distrubances in 2 different input variables are presented as typical results

  13. The hydrogen generated as a gas and storage in Zircaloy during steam quenching

    International Nuclear Information System (INIS)

    Garcia, Eduardo A.

    2000-01-01

    A simple one-dimensional diffusion model has been developed for the complex process of Zircaloy oxidation during steam quenching, calculating the hydrogen liberated as a gas and the hydrogen stored in the metal. The model was developed on the basis of small-scale separate-effects quench experiments performed at Forschungszentrum Karlsruhe. The new oxide surface and the new metallic surface produced by cracking of the oxide during quenching are calculated for each experiment performed at 1200 centigrade, 1400 centigrade and 1600 centigrade using as-received Zircaloy-4 (no pre-oxidation) and with Zircaloy specimens pre-oxidized to give oxide thickness of 100μm and 300μm. The results are relevant to accident management in nuclear power plants. (author)

  14. Fugitive gas adsorption capacity of biomass and animal-manure derived biochars

    Science.gov (United States)

    This research characterized and investigated ammonia and hydrogen sulfide gas adsorption capacities of low- and high-temperature biochars made from wood shavings and chicken litter. The biochar samples were activated with steam or phosphoric acid. The specific surface areas and pore volumes of the a...

  15. Second Generation Gaseous Biofuels: from Biomass to Gas Grid

    International Nuclear Information System (INIS)

    Guerrini, O.; Perrin, M.; Marchand, B.; Prieur-Vernat, A.

    2013-01-01

    Gaseous biofuels and biomethane production by thermochemical pathway has many assets and, already, it should be seen as an essential component of future French and European energy panorama by 2020. As a biomass gasification process is used, a very wide range of biomass is accessible, guaranteeing a significant development potential of the sector. Because of the inherent advantages of the methanation reaction, methanation processes have very high overall energy efficiency, today comparable to other technologies for energy recovery from biomass. Moreover, these can be further enhanced by a waste heat valorization. The existence of technology adapted to installations of medium size (20-80 MW biomethane) promotes strong integration in the local area and is exemplary in a framework of sustainable development. Most of the steps of the process of biomethane production from biomass are at present commercially available. However, the technical feasibility of the whole production line of biomethane was not demonstrated to an industrial scale yet. (authors)

  16. Effect of steam explosion on in vitro gas production kinetics and rumen fermentation profiles of three common straws

    Directory of Open Access Journals (Sweden)

    Li Wen He

    2015-12-01

    Full Text Available To investigate the effect of steam explosion on in vitro gas production (GP and rumen fermentation profiles of common straws, in vitro cultivation was conducted for 96 h with the rumen fluid collected from steers. Different types of straw had various chemical compositions, which were affected by steam explosion (P<0.01. Steam explosion increased (P<0.01 the rate and volume of GP, lag time disappeared and asymptotic GP decreased, which were also affected (P<0.01 by the type of straw. The type of straw influenced (P<0.05 the final pH, while steam explosion exerted an effect (P<0.01 on the ammonia-nitrogen concentration. The proportions of individual volatile fatty acid (VFA, except acetate (A, differed (P<0.05 among the feeds. Steam explosion increased total VFA production and the proportion of propionate (P, while decreased the proportions of A, isobutyrate and valerate as well as the ratio A/P (P<0.01. The type of straw had an effect (P<0.05 on the activities of avicelase and carboxymethyl cellulase (CMCase, while steam explosion increased (P<0.01 the activities of avicelase, CMCase, β-glucanase and xylanase. The available energy concentrations and digestibilities differed (P<0.01 in the feeds and were increased (P<0.05 with steam explosion processing. The interaction straw type×treatments was significant (P<0.05 for most monitored parameters. These results suggest that steam explosion could improve rumen fermentability and energy utilisation of straw, being an effective pre-treatment method in feed industry.

  17. Pressurised combustion of biomass-derived, low calorific value, fuel gas

    Energy Technology Data Exchange (ETDEWEB)

    Andries, J.; Hoppesteyn, P.D.J.; 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 pressurised combustion of biomass-derived, low calorific flue fuel gas. The objects of the project are: To design, manufacture and test a pressurised, high temperature gas turbine combustor for biomass derived LCV fuel gas; to develop a steady-state and dynamic model describing a combustor using biomass-derived, low calorific value fuel gases; to gather reliable experimental data on the steady-state and dynamic characteristics of the combustor; to study the steady-state and dynamic plant behaviour using a plant layout wich incorporates a model of a gas turbine suitable for operation on low calorific value fuel gas. (orig)

  18. Pressurised combustion of biomass-derived, low calorific value, fuel gas

    Energy Technology Data Exchange (ETDEWEB)

    Andries, J; Hoppesteyn, P D.J.; 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 pressurised combustion of biomass-derived, low calorific flue fuel gas. The objects of the project are: To design, manufacture and test a pressurised, high temperature gas turbine combustor for biomass derived LCV fuel gas; to develop a steady-state and dynamic model describing a combustor using biomass-derived, low calorific value fuel gases; to gather reliable experimental data on the steady-state and dynamic characteristics of the combustor; to study the steady-state and dynamic plant behaviour using a plant layout wich incorporates a model of a gas turbine suitable for operation on low calorific value fuel gas. (orig)

  19. Effect of thermal barrier coatings on the performance of steam and water-cooled gas turbine/steam turbine combined cycle system

    Science.gov (United States)

    Nainiger, J. J.

    1978-01-01

    An analytical study was made of the performance of air, steam, and water-cooled gas-turbine/steam turbine combined-cycle systems with and without thermal-barrier coatings. For steam cooling, thermal barrier coatings permit an increase in the turbine inlet temperature from 1205 C (2200 F), resulting in an efficiency improvement of 1.9 percentage points. The maximum specific power improvement with thermal barriers is 32.4 percent, when the turbine inlet temperature is increased from 1425 C (2600 F) to 1675 C (3050 F) and the airfoil temperature is kept the same. For water cooling, the maximum efficiency improvement is 2.2 percentage points at a turbine inlet temperature of 1683 C (3062 F) and the maximum specific power improvement is 36.6 percent by increasing the turbine inlet temperature from 1425 C (2600 F) to 1730 C (3150 F) and keeping the airfoil temperatures the same. These improvements are greater than that obtained with combined cycles using air cooling at a turbine inlet temperature of 1205 C (2200 F). The large temperature differences across the thermal barriers at these high temperatures, however, indicate that thermal stresses may present obstacles to the use of coatings at high turbine inlet temperatures.

  20. Gas and Isotope Geochemistry of 81 Steam Samples from Wells in The Geysers Geothermal Field, Sonoma and Lake Counties, California

    Science.gov (United States)

    Lowenstern, Jacob B.; Janik, Cathy J.; Fahlquist, Lynne; Johnson, Linda S.

    1999-01-01

    The Geysers geothermal field in northern California, with about 2000-MW electrical capacity, is the largest geothermal field in the world. Despite its importance as a resource and as an example of a vapor-dominated reservoir, very few complete geochemical analyses of the steam have been published (Allen and Day, 1927; Truesdell and others, 1987). This report presents data from 90 steam, gas, and condensate samples from wells in The Geysers geothermal field in northern California. Samples were collected between 1978 and 1991. Well attributes include sampling date, well name, location, total depth, and the wellhead temperature and pressure at which the sample was collected. Geochemical characteristics include the steam/gas ratio, composition of noncondensable gas (relative proportions of CO2, H2S, He, H2, O2, Ar, N2, CH4, and NH3), and isotopic values for deltaD and delta18O of H2O, delta13C of CO2, and delta34S of H2S. The compilation includes 81 analyses from 74 different production wells, 9 isotopic analyses of steam condensate pumped into injection wells, and 5 complete geochemical analyses on gases from surface fumaroles and bubbling pools. Most samples were collected as saturated steam and plot along the liquid-water/steam boiling curve. Steam-togas ratios are highest in the southeastern part of the geothermal field and lowest in the northwest, consistent with other studies. Wells in the Northwest Geysers are also enriched in N2/Ar, CO2 and CH4, deltaD, and delta18O. Well discharges from the Southeast Geysers are high in steam/gas and have isotopic compositions and N2/Ar ratios consistent with recharge by local meteoric waters. Samples from the Central Geysers show characteristics found in both the Southeast and Northwest Geysers. Gas and steam characteristics of well discharges from the Northwest Geysers are consistent with input of components from a high-temperature reservoir containing carbonrich gases derived from the host Franciscan rocks. Throughout the

  1. Biomass fueled closed cycle gas turbine with water injection

    Energy Technology Data Exchange (ETDEWEB)

    Bardi, Silvia [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2001-01-01

    Direct water injection has been studied for a small scale ({approx} 8 MW fuel input) closed cycle gas turbine coupled to a biomass fueled CFB furnace. Two different working fluids have been considered (helium-water mixture and nitrogen-water mixture). The water injection could take place between the compressor stages, as an intercooler, or after the high pressure compressor, as an aftercooler. Both this options have been studied, varying the relative humidity levels after the injection and the temperatures of the injected water. The effect of water injection on thermodynamic properties of the working fluids has been studied, together with its effect on turbomachinery isentropic efficiency. A sensitivity analysis on turbomachinery efficiency and cycle base pressure has been included. The results from this study have been compared to the performance of a dry closed cycle without water injection. The wet cycle shows an electric efficiency in the range 29-32% with helium-water mixture as working fluid and 30-32% with nitrogen-water mixture as working fluid, while the total efficiency (referring to the fuel LHV) is always higher than 100%. In the non-injected cycle the electric efficiency is 30-35% with helium and 32-36 with nitrogen. The total efficiency in the dry case with two level intercooling and postcooling is 87-89%, while is higher than 100% when only one stage inter- and postcooling is present. Aside from this, the study also includes a sizing of the heat exchangers for the different cycle variations. The heat transfer area is very sensible to the working fluid and to the amount of injected water and it's always higher when a nitrogen-water mixture is used. Compared to the cycle without water injection, by the way, the number of heat exchangers is reduced. This will lead to a lower pressure drop and a simpler plant layout. The total heat transfer area, however, is higher in the wet cycle than in the dry cycle.

  2. HTGR steam generator development

    International Nuclear Information System (INIS)

    Schuetzenduebel, W.G.; Hunt, P.S.; Weber, M.

    1976-01-01

    More than 40 gas-cooled reactor plants have produced in excess of 400 reactor years of operating experience which have proved a reasonably high rate of gas-cooled reactor steam generator availability. The steam generators used in these reactors include single U-tube and straight-tube steam generators as well as meander type and helically wound or involute tube steam generators. It appears that modern reactors are being equipped with helically wound steam generators of the once-through type as the end product of steam generator evolution in gas-cooled reactor plants. This paper provides a general overview of gas-cooled reactor steam generator evolution and operating experience and shows how design criteria and constraints, research and development, and experience data are factored into the design/development of modern helically wound tube steam generators for the present generation of gas-cooled reactors

  3. Nondestructive testing of welds in steam generators for advanced gas cooled reactors at Heyshamm II and Torness

    International Nuclear Information System (INIS)

    Parkin, K.; Bainbridge, A.; Carver, K.; Hammell, R.; Lack, B.J.

    1985-01-01

    The paper concerns non-destructive testing (NDT) of welds in advanced gas cooled steam generators for Heysham II and Torness nuclear power stations. A description is given of the steam generator. The selection of NDT techniques is also outlined, including the factors considered to ascertain the viability of a technique. Examples are given of applied NDT methods which match particular fabrication processes; these include: microfocus radiography, ultrasonic testing of austenitic tube butt welds, gamma-ray isotope projection system, surface crack detection, and automated radiography. Finally, future trends in this field of NDT are highlighted. (UK)

  4. Mechanical problems in turbomachines, steam and gas turbines. Large steam turbine manufacturing requirements to fulfill customer needs for electric power

    International Nuclear Information System (INIS)

    Brazzini, R.

    1975-01-01

    The needs of the customers in large steam turbines for electric power are examined. The choices and decisions made by the utility about the equipments are dealt with after considering the evolution of power demand on the French network. These decisions and choices mainly result from a technical and economic optimization of production equipments: choice of field-proven solutions, trend to lower steam characteristics, trend to higher output of the units (i.e. size effect), spreading out standardization of machines and components (policy of technical as well as technological levels, i.e. mass production effect). Standardization of external characteristics of units of same level of output and even standardization of some main components. The requirements turbine manufacturers have to meet may fall in two categories: on one side: gaining experience and know-how, capability of making high quality experiments, out put capacity, will to hold a high efficiency level; on the other side: meeting the technical requirements related to the contracts. Among these requirements, one can differentiate those dealing with the service expected from the turbine and that resulting in the responsibility limits of the manufacturer and those tending to gain interchangeability, to improve availability of the equipment, to increase safety, and to make operation and maintenance easier [fr

  5. Biomass pyrolysis/gasification for product gas production: the overall investigation of parametric effects

    International Nuclear Information System (INIS)

    Chen, G.; Andries, J.; Luo, Z.; Spliethoff, H.

    2003-01-01

    The conventional biomass pyrolysis/gasification process for production of medium heating value gas for industrial or civil applications faces two disadvantages, i.e. low gas productivity and the accompanying corrosion of downstream equipment caused by the high content of tar vapour contained in the gas phase. The objective of this paper is to overcome these disadvantages, and therefore, the effects of the operating parameters on biomass pyrolysis are investigated in a laboratory setup based on the principle of keeping the heating value of the gas almost unchanged. The studied parameters include reaction temperature, residence time of volatile phase in the reactor, physico-chemical pretreatment of biomass particles, heating rate of the external heating furnace and improvement of the heat and mass transfer ability of the pyrolysis reactor. The running temperature of a separate cracking reactor and the geometrical configuration of the pyrolysis reactor are also studied. However, due to time limits, different types of catalysts are not used in this work to determine their positive influences on biomass pyrolysis behaviour. The results indicate that product gas production from biomass pyrolysis is sensitive to the operating parameters mentioned above, and the product gas heating value is high, up to 13-15 MJ/N m 3

  6. The Integration of Gasification Systems with Gas Engine to Produce Electrical Energy from Biomass

    Science.gov (United States)

    Siregar, K.; Alamsyah, R.; Ichwana; Sholihati; Tou, S. B.; Siregar, N. C.

    2018-05-01

    The need for energy especially biomass-based renewable energy continues to increase in Indonesia. The objective of this research was to design downdraft gasifier machine with high content of combustible gas on gas engine. Downdraft gasifier machine was adjusted with the synthetic gas produced from biomass. Besides that, the net energy ratio, net energy balance, renewable index, economic analysis, and impact assessment also been conducted. Gas engine that was designed in this research had been installed with capacity of 25 kW with diameter and height of reactor were 900 mm and 1000 mm respectively. The method used here were the design the Detailed Engineering Design (DED), assembly, and performance test of gas engine. The result showed that gas engine for biomass can be operated for 8 hours with performance engine of 84% and capacity of 25 kW. Net energy balance, net energy ratio, and renewable index was 30 MJ/kWh-electric; 0.89; 0.76 respectively. The value of GHG emission of Biomass Power Generation is 0.03 kg-CO2eq/MJ. Electrical production cost for Biomass Power Generation is about Rp.1.500,/kWh which is cheaper than Solar Power Generation which is about of Rp. 3.300,-/kWh.

  7. Thermodynamic Performance Study of Biomass Gasification, Solid Oxide Fuel Cell and Micro Gas Turbine Hybrid Systems

    DEFF Research Database (Denmark)

    Bang-Møller, Christian; Rokni, Masoud

    2010-01-01

    A system level modelling study of three combined heat and power systems based on biomass gasification is presented. Product gas is converted in a micro gas turbine (MGT) in the first system, in a solid oxide fuel cell (SOFC) in the second system and in a combined SOFC–MGT arrangement in the third...

  8. Molten salt fueled nuclear facility with steam-and gas turbine cycles of heat transformation

    International Nuclear Information System (INIS)

    Ananich, P.I.; Bunin, E.N.; Kazazyan, V.T.; Nemtsev, V.A.; Sikorin, S.N.

    2001-01-01

    The molten salt fueled nuclear facilities with fuel circulating in the primary circuit have a series of the potential advantages in comparison with the traditional thermal and fast reactors with solid fuel elements. These advantages are ensured by the possibility to receive effective neutron balance in the core, minimum margin reactivity, more deep fuel burnup, unbroken correctness of the fuel physical and chemical properties and by low prices of the fuel cycle. The neutron and thermal-physical calculations of the various variants of the MSFNF with steam-water and gas turbine power circuits and their technical and economical comparison are carried out in this article. Calculations of molten salt nuclear power plant with gas turbine power circuit have been carried out using chemically reacting working body ''nitrin'' (N304 + 1%NO). The molten salt fueled reactors with the thermal power near of 2300 MW with two fuel compositions have been considered. The base variant has been taken the design of NPP with VVER NP-1000 when comparing the results of the calculations. Its economical performances are presented in prices of 1990. The results of the calculations show that it is difficult to determine the advantages of any one of the variants considered in a unique fashion. But NPP with MSR possesses large reserves in the process of optimization of cycle and energy equipment parameters that can improve its technical and economical performances sufficiently. (author)

  9. Primary methods in biomass gasification for gas conditioning and cleaning

    NARCIS (Netherlands)

    Vilela, C.F.M.

    2012-01-01

    The substitution of natural gas by a renewable equivalent is an interesting option to reduce the use of fossil fuels and the accompanying greenhouse gas emissions, as well as from the point of view of security of supply. Green gas is the renewable alternative. It comprises biogas (1st generation

  10. Optical Absorption Spectroscopy for Gas Analysis in Biomass Gasification

    DEFF Research Database (Denmark)

    Grosch, Helge

    important gas species of the low-temperature circulating fluidized bed gasifier. At first, a special gas cell,the hot gas flow cell (HGC), was build up and veried. In this custom-made gas cell, the optical properties, the so-called absorption cross-sections, of the most important sulfur and aromatic...... compounds were determined in laboratory experiments. By means of the laboratory results and spectroscopic databases,the concentrations of the major gas species and the aromatic compounds phenol and naphthalene were determined in extraction and in-situ measurements....

  11. Thermo-economic comparative analysis of gas turbine GT10 integrated with air and steam bottoming cycle

    Science.gov (United States)

    Czaja, Daniel; Chmielnak, Tadeusz; Lepszy, Sebastian

    2014-12-01

    A thermodynamic and economic analysis of a GT10 gas turbine integrated with the air bottoming cycle is presented. The results are compared to commercially available combined cycle power plants based on the same gas turbine. The systems under analysis have a better chance of competing with steam bottoming cycle configurations in a small range of the power output capacity. The aim of the calculations is to determine the final cost of electricity generated by the gas turbine air bottoming cycle based on a 25 MW GT10 gas turbine with the exhaust gas mass flow rate of about 80 kg/s. The article shows the results of thermodynamic optimization of the selection of the technological structure of gas turbine air bottoming cycle and of a comparative economic analysis. Quantities are determined that have a decisive impact on the considered units profitability and competitiveness compared to the popular technology based on the steam bottoming cycle. The ultimate quantity that can be compared in the calculations is the cost of 1 MWh of electricity. It should be noted that the systems analyzed herein are power plants where electricity is the only generated product. The performed calculations do not take account of any other (potential) revenues from the sale of energy origin certificates. Keywords: Gas turbine air bottoming cycle, Air bottoming cycle, Gas turbine, GT10

  12. A Comparison of Producer Gas, Biochar, and Activated Carbon from Two Distributed Scale Thermochemical Conversion Systems Used to Process Forest Biomass

    Directory of Open Access Journals (Sweden)

    Nathaniel Anderson

    2013-01-01

    Full Text Available Thermochemical biomass conversion systems have the potential to produce heat, power, fuels and other products from forest biomass at distributed scales that meet the needs of some forest industry facilities. However, many of these systems have not been deployed in this sector and the products they produce from forest biomass have not been adequately described or characterized with regards to chemical properties, possible uses, and markets. This paper characterizes the producer gas, biochar, and activated carbon of a 700 kg h−1 prototype gasification system and a 225 kg h−1 pyrolysis system used to process coniferous sawmill and forest residues. Producer gas from sawmill residues processed with the gasifier had higher energy content than gas from forest residues, with averages of 12.4 MJ m−3 and 9.8 MJ m−3, respectively. Gases from the pyrolysis system averaged 1.3 MJ m−3 for mill residues and 2.5 MJ m−3 for forest residues. Biochars produced have similar particle size distributions and bulk density, but vary in pH and carbon content. Biochars from both systems were successfully activated using steam activation, with resulting BET surface area in the range of commercial activated carbon. Results are discussed in the context of co-locating these systems with forest industry operations.

  13. Biomass

    Science.gov (United States)

    Bernard R. Parresol

    2001-01-01

    Biomass, the contraction for biological mass, is the amount of living material provided by a given area or volume of the earth's surface, whether terrestrial or aquatic. Biomass is important for commercial uses (e.g., fuel and fiber) and for national development planning, as well as for scientific studies of ecosystem productivity, energy and nutrient flows, and...

  14. Synthesis gas from biomass for fuels and chemicals

    International Nuclear Information System (INIS)

    Van der Drift, A.; Boerrigter, H.

    2006-01-01

    Making H2 and CO (syngas) from biomass is widely recognised as a necessary step in the production of various second generation biofuels. There are two major ways to produce a biosyngas: fluidised bed gasification with catalytic reformer or entrained flow gasification. The latter option requires extensive pre-treatment such as flash pyrolysis, slow pyrolysis, torrefaction, or fluidized bed gasification at a low temperature. Cleaned and conditioned biosyngas can be used to synthesize second generation biofuels such as Fischer-Tropsch fuels, methanol, DME, mixed alcohols, and even pure hydrogen. The report describes the different technical options to produce, clean and condition bio-syngas. Furthermore, issues related to scale and biomass transport are covered shortly

  15. Approaches to greenhouse gas accounting methods for biomass carbon

    International Nuclear Information System (INIS)

    Downie, Adriana; Lau, David; Cowie, Annette; Munroe, Paul

    2014-01-01

    This investigation examines different approaches for the GHG flux accounting of activities within a tight boundary of biomass C cycling, with scope limited to exclude all other aspects of the lifecycle. Alternative approaches are examined that a) account for all emissions including biogenic CO 2 cycling – the biogenic method; b) account for the quantity of C that is moved to and maintained in the non-atmospheric pool – the stock method; and c) assume that the net balance of C taken up by biomass is neutral over the short-term and hence there is no requirement to include this C in the calculation – the simplified method. This investigation demonstrates the inaccuracies in both emissions forecasting and abatement calculations that result from the use of the simplified method, which is commonly accepted for use. It has been found that the stock method is the most accurate and appropriate approach for use in calculating GHG inventories, however short-comings of this approach emerge when applied to abatement projects, as it does not account for the increase in biogenic CO 2 emissions that are generated when non-CO 2 GHG emissions in the business-as-usual case are offset. Therefore the biogenic method or a modified version of the stock method should be used to accurately estimate GHG emissions abatement achieved by a project. This investigation uses both the derivation of methodology equations from first principles and worked examples to explore the fundamental differences in the alternative approaches. Examples are developed for three project scenarios including; landfill, combustion and slow-pyrolysis (biochar) of biomass. -- Highlights: • Different approaches can be taken to account for the GHG emissions from biomass. • Simplification of GHG accounting methods is useful, however, can lead to inaccuracies. • Approaches used currently are often inadequate for practises that store carbon. • Accounting methods for emissions forecasting can be inadequate for

  16. The impact of steam and current density on carbon formation from biomass gasification tar on Ni/YSZ, and Ni/CGO solid oxide fuel cell anodes

    Science.gov (United States)

    Mermelstein, Joshua; Millan, Marcos; Brandon, Nigel

    The combination of solid oxide fuel cells (SOFCs) and biomass gasification has the potential to become an attractive technology for the production of clean renewable energy. However the impact of tars, formed during biomass gasification, on the performance and durability of SOFC anodes has not been well established experimentally. This paper reports an experimental study on the mitigation of carbon formation arising from the exposure of the commonly used Ni/YSZ (yttria stabilized zirconia) and Ni/CGO (gadolinium-doped ceria) SOFC anodes to biomass gasification tars. Carbon formation and cell degradation was reduced through means of steam reforming of the tar over the nickel anode, and partial oxidation of benzene model tar via the transport of oxygen ions to the anode while operating the fuel cell under load. Thermodynamic calculations suggest that a threshold current density of 365 mA cm -2 was required to suppress carbon formation in dry conditions, which was consistent with the results of experiments conducted in this study. The importance of both anode microstructure and composition towards carbon deposition was seen in the comparison of Ni/YSZ and Ni/CGO anodes exposed to the biomass gasification tar. Under steam concentrations greater than the thermodynamic threshold for carbon deposition, Ni/YSZ anodes still exhibited cell degradation, as shown by increased polarization resistances, and carbon formation was seen using SEM imaging. Ni/CGO anodes were found to be more resilient to carbon formation than Ni/YSZ anodes, and displayed increased performance after each subsequent exposure to tar, likely due to continued reforming of condensed tar on the anode.

  17. Development and Test of a new Concept for Biomass Producer Gas Engines

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Foged, Esben Vendelbo; Strand, Rune

    The technical requirements and the economical assessment of converting commercial diesel engine gen-sets into high compression spark ignition operation on biomass producer gas have been investigated. Assessments showed that for a 200 kWe gen-set there would be a financial benefit of approximately...... 600.000 DKK corresponding to a reduction of 60% in investment costs compared to the price of a conventional gas engine gen-set. Experimental investigations have been conducted on two identical small scale SI gas engine gen-sets operating on biomass producer gas from thermal gasification of wood....... The engines were operated with two different compression ratios, one with the original compression ratio for natural gas operation 9.5:1, and the second with a compression ratio of 18.5:1 (converted diesel engine). It was shown that high compression ratio SI engine operation was possible when operating...

  18. Greenhouse-gas emissions from biomass energy use: Comparison with other energy technologies

    International Nuclear Information System (INIS)

    Morris, G.P.; Norman, N.A.; Gleick, P.H.

    1991-01-01

    Recently a major new concern has arisen: the accumulation of greenhouse gases in the atmosphere. It is now generally believed that continued emissions of these gases are current or increasing levels will lead to significant climatic changes with the potential for dramatic, adverse impacts. Since the major anthropogenic source of greenhouse gas emissions is energy production and use, it is essential to future energy policy to understand how energy sources differ with respect to greenhouse gas emissions. Characterizing the greenhouse gas emissions associated with biomass energy use is extremely complicated. It is necessary to consider both the source and alternative use of the biomass material and its alternative disposal (if any), as well as the biomass energy application itself. It is desirable also to consider not just CO 2 emissions, but also CH 4 and N 2 O, both potent greenhouse gases. The authors' analysis shows that in many cases biomass energy use can actually help to ameliorate the greenhouse effect by converting emissions that would have been CH 4 into the less potent greenhouse gas CO 2 . In many cases the beneficial effect is very dramatic. This major new research result should help increase public support for biomass research and development, and for further development of waste conversion technology and installations

  19. Plasma steam reforming of E85 for hydrogen rich gas production

    International Nuclear Information System (INIS)

    Zhu Xinli; Hoang Trung; Lobban, Lance L; Mallinson, Richard G

    2011-01-01

    E85 (85 vol% ethanol and 15 vol% gasoline) is a partly renewable fuel that is increasing in supply availability. Hydrogen production from E85 for fuel cell or internal combustion engine applications is a potential method for reducing CO 2 emissions. Steam reforming of E85 using a nonthermal plasma (pulse corona discharge) reactor has been exploited at low temperature (200-300 0 C) without external heating, diluent gas, oxidant or catalyst in this work. Several operational parameters, including the discharge current, E85 concentration and feed flow rate, have been investigated. The results show that hydrogen rich gases (63-67% H 2 and 22-29% CO, with small amounts of CO 2 , C 2 hydrocarbons and CH 4 ) can be produced by this method. A comparison with ethanol reforming and gasoline reforming under identical conditions has also been made and the behaviour of E85 reforming is found to be close to that of ethanol reforming with slightly higher C 2 hydrocarbons yields.

  20. Thermionic combustor application to combined gas and steam turbine power plants

    International Nuclear Information System (INIS)

    Miskolczy, G.; Wang, C.C.; Lieb, D.P.

    1981-01-01

    A design for the insertion of thermionic converters into the wall of a conventional combustor to produce electricity in a topping cycle is described, and a study for applications in gas and steam generators of 70 and 30 MW is evaluated for engineering and economic feasibility. Waste heat from the thermionic elements is used to preheat the combustor air, the heat absorbed by the elements plus further quenching of the exhaust gases with ammonia is projected to reduce NO(x) emissions to acceptable levels. Schematics, flow diagrams, and components of a computer model for cost projections are provided. It was found that temperatures around the emitters must be maintained above 1,600 K, with maximum efficiency and allowable temperature at 1,800 K, while collectors generate maximally at 950 K, with a corresponding work function of 1.5 eV. Cost sensitive studies indicate an installed price of $475/kW for the topping cycle, with improvements in thermionic converter characteristics bringing the cost to $375/kW at a busbar figure of 500 mills/kWh

  1. Thermionic combustor application to combined gas and steam turbine power plants

    Science.gov (United States)

    Miskolczy, G.; Wang, C. C.; Lieb, D. P.; Margulies, A. E.; Fusegni, L. J.; Lovell, B. J.

    A design for the insertion of thermionic converters into the wall of a conventional combustor to produce electricity in a topping cycle is described, and a study for applications in gas and steam generators of 70 and 30 MW is evaluated for engineering and economic feasibility. Waste heat from the thermionic elements is used to preheat the combustor air; the heat absorbed by the elements plus further quenching of the exhaust gases with ammonia is projected to reduce NO(x) emissions to acceptable levels. Schematics, flow diagrams, and components of a computer model for cost projections are provided. It was found that temperatures around the emitters must be maintained above 1,600 K, with maximum efficiency and allowable temperature at 1,800 K, while collectors generate maximally at 950 K, with a corresponding work function of 1.5 eV. Cost sensitive studies indicate an installed price of $475/kW for the topping cycle, with improvements in thermionic converter characteristics bringing the cost to $375/kW at a busbar figure of 500 mills/kWh.

  2. Allocation of biomass resources for minimising energy system greenhouse gas emissions

    International Nuclear Information System (INIS)

    Bentsen, Niclas Scott; Jack, Michael W.; Felby, Claus; Thorsen, Bo Jellesmark

    2014-01-01

    The European Union (EU) energy policy has three targets: supply security, development of a competitive energy sector and environmental sustainability. The EU countries have issued so-called National Renewable Energy Action Plans (NREAP) for increased renewable energy generation. Biomass is stipulated to account for 56% of renewable energy generation by 2020, corresponding to an increase in bioenergy generation from 2.4 × 10 9  GJ in 2005 to 5.7 × 10 9  GJ in 2020. There is uncertainty about the amounts of biomass available in the EU, and import challenges policy targets on supply security and sustainability. We address issues about how, from a technical point of view, the EU may deploy its biomass resources to reduce greenhouse gas (GHG) emissions from energy consumption. We investigate if deployment patterns depend on resource availability and technological development. In situations with adequate biomass availability the analysis suggests that liquid fuel production should be based on agricultural residues. Electricity production should be based on forest residues and other woody biomass and heat production on forest and agricultural residues. Improved conversion technologies implicitly relax the strain on biomass resources and improve supply security. - Highlights: • Optimal allocation of biomass to energy is analysed conceptually for the EU by 2020. • Allocation is influenced not only by GHG performance, also by resource availability. • Surplus biomass could be allocated to electricity generation to reduce GHG emissions

  3. Utilization of acetone-butanol-ethanol-water mixture obtained from biomass fermentation as renewable feedstock for hydrogen production via steam reforming: Thermodynamic and energy analyses.

    Science.gov (United States)

    Kumar, Brajesh; Kumar, Shashi; Sinha, Shishir; Kumar, Surendra

    2018-08-01

    A thermodynamic equilibrium analysis on steam reforming process to utilize acetone-butanol-ethanol-water mixture obtained from biomass fermentation as biorenewable fuel has been performed to produce clean energy carrier H 2 via non-stoichiometric approach namely Gibbs free energy minimization method. The effect of process variables such as temperature (573-1473 K), pressure (1-10 atm), and steam/fuel molar feed ratio (F ABE  = 5.5-12) have been investigated on equilibrium compositions of products, H 2 , CO, CO 2 , CH 4 and solid carbon. The best suitable conditions for maximization of desired product H 2 , suppression of CH 4 , and inhibition of solid carbon are 973 K, 1 atm, steam/fuel molar feed ratio = 12. Under these conditions, the maximum molar production of hydrogen is 8.35 with negligible formation of carbon and methane. Furthermore, the energy requirement per mol of H 2 (48.96 kJ), thermal efficiency (69.13%), exergy efficiency (55.09%), exergy destruction (85.36 kJ/mol), and generated entropy (0.29 kJ/mol.K) have been achieved at same operating conditions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Analyses of Gas, Steam and Water Samples Collected in and Around Lassen Volcanic National Park, California, 1975-2002

    Science.gov (United States)

    Janik, Cathy J.; Bergfeld, D.

    2010-01-01

    This report contains physical and chemical data from gas, steam, and water samples collected between July 1975 and September 2002 from locations in and around Lassen Volcanic National Park, California. Data are compiled as tables in Excel spreadsheets and are organized by locale. Most data are keyed to 1 of 107 site codes that are shown on local- and regional-scale maps. Brief descriptions of terminology, sampling, and analytical methods are provided.

  5. Annual energy and environment analysis of solarized steam injection gas turbine (STIG) cycle for Indian regions

    International Nuclear Information System (INIS)

    Selwynraj, A. Immanuel; Iniyan, S.; Suganthi, L.; Livshits, Maya; Polonsky, Guy; Kribus, Abraham

    2016-01-01

    Highlights: • Study on the influence of local climatic conditions on solar STIG cycle is presented. • The annual solar to electricity efficiency ranges between 11.2 and 17.1% and the solar fraction ranges 9.3–41.7%. • The range of annual specific CO_2 emission is 312–408 kg/MWh and incremental CO_2 avoidance is 4.2–104 kg/MWh. • The levelized tariff (LT) is 0.2–0.23 $/kWh, and the solar levelized tariff (SLT) ranges from 0.11 to 0.27 $/kWh. - Abstract: The solarized steam injection gas turbine (STIG) cycle uses both the fuel and solar heat simultaneously for power generation. The annual thermodynamic performances of the cycle for sites in India with local climatic conditions such as ambient temperature, relative humidity and availability of direct normal irradiance (DNI) to the solar concentrators under two modes of constant and variable power are presented in this paper. The results reveal that the solar to electricity efficiency of solar hybrid STIG plant with a simple parabolic trough collector (PTC) is similar to existing solar thermal technologies, and also higher solar share is obtained. The study also reveals that the annual CO_2 emission is similar to combined cycle plants and lower than gas turbine technologies. The incremental CO_2 avoidance is also computed due to solar participation. The annual values of exergetic solar fraction and exergetic efficiency at Indore are higher than Jaipur. Results of an improved economic assessment show that the levelized tariff (LT) of solar hybrid STIG plant is 0.2–0.23 $/kWh and the levelized tariff (solar only) or solar levelized tariff (SLT) of solar STIG plant ranges from 0.11 to 0.27 $/kWh for both constant and variable power scenarios.

  6. Study on condensation of biomass pyrolysis gas by spray bio-oil droplets

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Kun; Cheng, Wen-Long [University of Science and Technology of China (China)], email: wlcheng@ustc.edu.cn; Chen, Jing [Anhui Electric Power Design Institute (China); Shi, Wen-Jing [Anhui Heli Co., Ltd (China)

    2011-07-01

    This is a study of bio-oil generated by fast pyrolysis; a biomass feedstock is heated to pyrolyze at a rapid rate, the gas pyrolyzed is then condensed rapidly. The interesting result is a potential alternative fuel oil. An analysis was made of the effects of the initial pyrolysis gas temperatures, the initial bio-oil droplets temperatures and diameters, and the flow ratio of the gas and the liquid droplets on the heat and mass transfer between the gas and the liquid droplets. A few criterion equations were achieved with respect to the spray condenser. This paper established the gas-liquid phase equilibrium of an aqueous multi-composition system and the spray condensation model coupling heat and mass transfer. Model calculation and analysis showed that: spray condensation can effectively cool the high-temperature pyrolysis gas quickly; with gas liquid flowing, mass transfer rate reduces; and the relationship of gas and liquid flow ratio can achieve good accuracy.

  7. Thermodynamic evaluation of hydrogen production for fuel cells by using bio-ethanol steam reforming: Effect of carrier gas addition

    Science.gov (United States)

    Hernández, Liliana; Kafarov, Viatcheslav

    Omitting the influence of the addition of carrier gas to the reaction system for hydrogen production by bio-ethanol steam reforming can lead to wrong conclusions, especially when it is going to be made to scale. The effect of carrier gas addition to produce hydrogen using bio-ethanol steam reforming to feed fuel cells was evaluated. Thermodynamic calculations in equilibrium conditions were made, however the analysis derived from them can also be applied to kinetic conditions. These calculations were made by using the Aspen-HYSYS software at atmospheric pressure and different values of temperature, water/ethanol molar ratios, and inert (argon)/(water/ethanol) molar ratios. The addition of inert carrier gas modifies the concentrations of the reaction products in comparison to those obtained without its presence. This behavior occurs because most of the reactions which take place in bio-ethanol steam reforming have a positive difference of moles. This fact enhances the system sensitivity to inert concentration at low and moderated temperatures (<700 °C). At high values of temperature, the inert addition does not influence the composition of the reaction products because of the predominant effect of inverse WGS reaction.

  8. Thermodynamic evaluation of hydrogen production for fuel cells by using bio-ethanol steam reforming: Effect of carrier gas addition

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Liliana; Kafarov, Viatcheslav [Universidad Industrial de Santander, Escuela de Ingenieria Quimica, Bucaramanga 678 (Colombia)

    2009-07-01

    Omitting the influence of the addition of carrier gas to the reaction system for hydrogen production by bio-ethanol steam reforming can lead to wrong conclusions, especially when it is going to be made to scale. The effect of carrier gas addition to produce hydrogen using bio-ethanol steam reforming to feed fuel cells was evaluated. Thermodynamic calculations in equilibrium conditions were made, however the analysis derived from them can also be applied to kinetic conditions. These calculations were made by using the Aspen-HYSYS software at atmospheric pressure and different values of temperature, water/ethanol molar ratios, and inert (argon)/(water/ethanol) molar ratios. The addition of inert carrier gas modifies the concentrations of the reaction products in comparison to those obtained without its presence. This behavior occurs because most of the reactions which take place in bio-ethanol steam reforming have a positive difference of moles. This fact enhances the system sensitivity to inert concentration at low and moderated temperatures (<700 C). At high values of temperature, the inert addition does not influence the composition of the reaction products because of the predominant effect of inverse WGS reaction. (author)

  9. Biomass consumption and CO2, CO and main hydrocarbon gas emissions in an Amazonian forest clearing fire

    Science.gov (United States)

    T. G. Soares Neto; J. A. Carvalho; C. A. G. Veras; E. C. Alvarado; R. Gielow; E. N. Lincoln; T. J. Christian; R. J. Yokelson; J. C. Santos

    2009-01-01

    Biomass consumption and CO2, CO and hydrocarbon gas emissions in an Amazonian forest clearing fire are presented and discussed. The experiment was conducted in the arc of deforestation, near the city of Alta Floresta, state of Mato Grosso, Brazil. The average carbon content of dry biomass was 48% and the estimated average moisture content of fresh biomass was 42% on...

  10. Producer gas fuelling of a 20kW output engine by gasification of solid biomass

    Energy Technology Data Exchange (ETDEWEB)

    Hollingdale, A C; Breag, G R; Pearce, D

    1988-11-01

    Motive power requirements in the range up to 100 kW shaft power are common in developing country processing operations. Producer gas-fuelled systems based upon a relatively cheap and simple manually operated gasifier or reactor using readily available biomass feedstock can offer in some cases an attractive alternative to fossil-fuelled power units. This bulletin outlines research and development work by the Industrial Development Department of the Overseas Development Natural Resources Institute for 20 kW shaft power output from producer gas derived from solid biomass. Biomass materials such as wood or shells can be carbonized to form charcoal or left in the natural uncarbonized state. In this work both carbonized and uncarbonized biomass fuel has been used to provide producer gas to fuel a Ford 2274E engine, an industrial version of a standard vehicle spark-ignition engine. Cross-draught and down-draught reactor designs were evaluated during trials with this engine. Also different gas cleaning and cooling arrangements were tested. Particular emphasis was placed on practical aspects of reactor/engine operation. This work follows earlier work with a 4 kW shaft power output system using charcoal-derived producer gas. (author).

  11. Sustainable synthesis gas from biomass. A bridge to a sustainable supply of energy and resources

    International Nuclear Information System (INIS)

    Den Uil, H.; Van Ree, R.; Van der Drift, A.; Boerrigter, H.

    2004-04-01

    Synthesis gas is currently primarily used in the (petro)chemical industry and for the production of liquid fuels. Smaller amounts are being used for electricity and synthetic natural gas (=SNG) production. Finite fossil resources, the dependence on political instable regimes and the Kyoto-protocol are drivers for the attention for renewable synthesis gas. In this report the market for, production of, use of and economy of renewable synthesis gas are analysed. Current synthesis gas use is limited to about 3% of the Dutch primary energy consumption; worldwide this is about 2%. Driven by the targets for renewable energy and the wide range of possible uses, the market for renewable synthesis gas has a large potential. When using synthesis gas for the production of SNG, electricity, liquid fuels and chemicals, the Dutch market for renewable synthesis gas can be 150 PJ in 2010, doubling about every decade to 1500 PJ in 2040. SNG and electricity, together about 80%. To reach these market volumes, import of biomass will be required due to the limited availability of local biomass resources in the Netherlands. The specifications for synthesis gas are dependent on the application. For (petro)chemical use and the production of liquid fuels high H2 and CO concentrations are required, for SNG and electricity production high CH4 concentrations are preferred. Due to the different specifications the names synthesis gas and product gas are used in this study. The name synthesis gas is claimed for a large number of gasification processes under development. But only for a number of processes this claim is justified. The gasification temperature determines the type of gas produced. At high temperatures, above 1300C, synthesis gas is produced, at low temperatures, 700-1000C, so-called product gas is being produced. Entrained-flow gasification is the only possibility for large-scale synthesis gas production in one step. For this process the particle size of the feed has to be small

  12. Green gas. Gas of natural gas quality from biomass. Update of the 2004 study; Groen Gas. Gas van aardgaskwaliteit uit biomassa. Update van de studie uit 2004

    Energy Technology Data Exchange (ETDEWEB)

    Welink, Jan-Henk; Dumont, M.; Kwant, K. Datum januari 2007

    2007-01-15

    In 2004 a study was published on green gas. Green gas is defined as a gaseous energy carrier from renewable biomass with a similar quality as natural gas. As a result of new developments in the field of co-digestion/fermentation the Dutch Ministry of Economic Affairs asked it's agency SenterNovem to update the 2004 study. The aim of the update is (1) to gain insight into operational aspects of green gas projects, e.g. reliability, efficiency and maintenance aspects; (2) stimulate the production of green gas, taking into account the economics of green gas projects, calculation of the financial gap of green gas production, efficient use of biogas (conversion to electricity or directly input into the natural gas distribution systems, and aspects with regard to commercialization and the market; and (3) the potential of green gas. [Dutch] De laatste jaren wordt er gewerkt aan initiatieven om groen gas te produceren. Een recent initiatief is het opwaarderen van biogas tot aardgaskwaliteit door Biogast, wat er toe zal leiden dat al deze zomer Eneco op kleinschalig niveau duurzaam gas levert aan eindverbruikers. Het potentieel aan groen gas dat mogelijk gemaakt zou kunnen worden, is de laatste jaren ook veranderd. Met name de voorspoedige ontwikkelingen op het gebied van co-vergisting met mest zorgen voor een toename van het potentieel. In 2004 is een studie gemaakt over groen gas. Vanwege de voorspoedige ontwikkelingen op het gebied van co-vergisting is de situatie die gold voor het rapport uit 2004 veranderd. Het ministerie van Economische Zaken heeft SenterNovem gevraagd om een update te maken van de studie over groen gas uit 2004. De doelstelling van de update van deze studie Groen Gas is (1) het verkrijgen van inzicht op basis van de huidige ontwikkelingen, in: de bedrijfstechnische aspecten van dergelijke projecten, zoals betrouwbaarheid, rendement en onderhoudsaspecten; (2) aspecten voor het mogelijk stimuleren van de productie van groen gas. Hierbij hoort: (a

  13. Materials for higher steam temperatures (up to 600 deg C) in biomass and waste fired plant. A review of present knowledge; Material foer hoegre aangtemperaturer (upp till 600 grader C) i bio- och avfallseldade anlaeggningar

    Energy Technology Data Exchange (ETDEWEB)

    Staalenheim, Annika; Henderson, Pamela

    2011-02-15

    A goal for the Swedish power industry is to build a demonstration biomass-fired plant with 600 deg C steam data in 2015. Vaermeforsk also has a goal to identify materials that can be used in such a plant. This project involves a survey of present knowledge and published articles concerning materials that are suitable for use in biomass and wastefired plants with steam data up to 600 deg C. The information has been gathered from plants presently in operation, and from field tests previously performed with probes. Plants firing only household waste are excluded. The components considered are waterwalls/furnace walls (affected because of higher steam pressures) and superheaters. Fireside corrosion and steam-side oxidation are dealt with. Candidate materials (or coatings) are suggested and areas for further research have been identified. The purpose of this project is to give state-of-the-art information on what materials could be used in biomass and waste-fired plant to reach a maximum steam temperature of 600 deg C. This report is aimed at suppliers of boilers and materials, energy utility companies and others involved in building new plant with higher steam data. In accordance with the goals of this project: - Materials suitable for use at higher steam temperatures (up to 600 deg C steam) in wood-based biomass and waste-fired plant have been identified. Austenitic stainless steels HR3C, TP 347 HFG and AC66 all have adequate strength, steam-side oxidation and fireside corrosion resistance for use as superheaters. AC66 and HR3C have better steam-side oxidation resistance than TP 347 HFG , but TP 347 HFG has better fireside corrosion resistance. It is recommended that TP 347 HFG be shot-peened on the inside to improve the oxidation resistance if in service with steam temperatures above 580 deg C. - Furnace walls coated with Ni-based alloys or a mixture of Ni- alloy and ceramic show good corrosion resistance at lower temperatures and should be evaluated at higher

  14. Device for the treatment of biomass for obtaining methane gas. Vorrichtung fuer die Behandlung von Biomasse zur Methangasgewinnung

    Energy Technology Data Exchange (ETDEWEB)

    Mergen, R

    1983-06-09

    This is a device for the treatment of biomass from all organic materials for obtaining methane gas by anaerobic fermentation, characterized by the fact that a water-cooled internal combustion engine carries out three main functions: it drives the chopper, it drives the stirrer and, together with a rake, it destroys the floating surface and heats the fermentation area, where the device is made as a direct waste gas heating system, is controlled via a thermostat control. It gives the pulse for starting and shutting down the internal combustion engine and the waste heat of the engine and the heat of the waste gas from the internal combustion engine are used to heat the service water heat, characterized by the fact that for large plants with biogas flow, the generator engine with its exhaust gas heat takes over the function of the fermentation area heater, that the exhaust gas heat is also used to heat the service water and that a heating circuit is connected to the water cooling system of the generator engine, also characterized by the fact that an effective layer of insulation made of hard foam surrounds an iron skeleton frame, the fermentation container, fixes the supports of the heating coils, acts as a sealed protective trough and as transport packing or outside of a compact ready to use plant.

  15. The effect of assessment scale and metric selection on the greenhouse gas benefits of woody biomass

    International Nuclear Information System (INIS)

    Galik, Christopher S.; Abt, Robert C.

    2012-01-01

    Recent attention has focused on the net greenhouse gas (GHG) implications of using woody biomass to produce energy. In particular, a great deal of controversy has erupted over the appropriate manner and scale at which to evaluate these GHG effects. Here, we conduct a comparative assessment of six different assessment scales and four different metric calculation techniques against the backdrop of a common biomass demand scenario. We evaluate the net GHG balance of woody biomass co-firing in existing coal-fired facilities in the state of Virginia, finding that assessment scale and metric calculation technique do in fact strongly influence the net GHG balance yielded by this common scenario. Those assessment scales that do not include possible market effects attributable to increased biomass demand, including changes in forest area, forest management intensity, and traditional industry production, generally produce less-favorable GHG balances than those that do. Given the potential difficulty small operators may have generating or accessing information on the extent of these market effects, however, it is likely that stakeholders and policy makers will need to balance accuracy and comprehensiveness with reporting and administrative simplicity. -- Highlights: ► Greenhouse gas (GHG) effects of co-firing forest biomass with coal are assessed. ► GHG effect of replacing coal with forest biomass linked to scale, analytic approach. ► Not accounting for indirect market effects yields poorer relative GHG balances. ► Accounting systems must balance comprehensiveness with administrative simplicity.

  16. Thermoeconomic Modeling and Parametric Study of Hybrid Solid Oxide Fuel Cell â Gas Turbine â Steam Turbine Power Plants Ranging from 1.5 MWe to 10 MWe

    OpenAIRE

    Arsalis, Alexandros

    2007-01-01

    Detailed thermodynamic, kinetic, geometric, and cost models are developed, implemented, and validated for the synthesis/design and operational analysis of hybrid solid oxide fuel cell (SOFC) â gas turbine (GT) â steam turbine (ST) systems ranging in size from 1.5 MWe to 10 MWe. The fuel cell model used in this thesis is based on a tubular Siemens-Westinghouse-type SOFC, which is integrated with a gas turbine and a heat recovery steam generator (HRSG) integrated in turn with a steam turbi...

  17. Uncertainties in Life Cycle Greenhouse Gas Emissions from Advanced Biomass Feedstock Logistics Supply Chains in Kansas

    Directory of Open Access Journals (Sweden)

    Long Nguyen

    2014-11-01

    Full Text Available To meet Energy Independence and Security Act (EISA cellulosic biofuel mandates, the United States will require an annual domestic supply of about 242 million Mg of biomass by 2022. To improve the feedstock logistics of lignocellulosic biofuels in order to access available biomass resources from areas with varying yields, commodity systems have been proposed and designed to deliver quality-controlled biomass feedstocks at preprocessing “depots”. Preprocessing depots densify and stabilize the biomass prior to long-distance transport and delivery to centralized biorefineries. The logistics of biomass commodity supply chains could introduce spatially variable environmental impacts into the biofuel life cycle due to needing to harvest, move, and preprocess biomass from multiple distances that have variable spatial density. This study examines the uncertainty in greenhouse gas (GHG emissions of corn stover logistics within a bio-ethanol supply chain in the state of Kansas, where sustainable biomass supply varies spatially. Two scenarios were evaluated each having a different number of depots of varying capacity and location within Kansas relative to a central commodity-receiving biorefinery to test GHG emissions uncertainty. The first scenario sited four preprocessing depots evenly across the state of Kansas but within the vicinity of counties having high biomass supply density. The second scenario located five depots based on the shortest depot-to-biorefinery rail distance and biomass availability. The logistics supply chain consists of corn stover harvest, collection and storage, feedstock transport from field to biomass preprocessing depot, preprocessing depot operations, and commodity transport from the biomass preprocessing depot to the biorefinery. Monte Carlo simulation was used to estimate the spatial uncertainty in the feedstock logistics gate-to-gate sequence. Within the logistics supply chain GHG emissions are most sensitive to the

  18. 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.

  19. Experimental investigation on flue gas emissions of a domestic biomass boiler under normal and idle combustion conditions-super-†

    OpenAIRE

    Hao Liu; Guoquan Qiu; Yingjuan Shao; Saffa B. Riffat

    2010-01-01

    Biomass plays an important role in the world primary energy supplies, currently providing ∼14% of the world's primary energy needs and being the fourth largest contributor following coal, oil and natural gas. Over the past decade, domestic biomass heating has received more governmental and public supports than ever before in many developed countries, such as the UK. Although biomass combustion releases some combustion pollutants, biomass is renewable and produces little net CO 2 emissions to ...

  20. Natural gas adsorption on biomass derived activated carbons: A mini review

    Directory of Open Access Journals (Sweden)

    Hamza Usman D.

    2016-01-01

    Full Text Available Activated carbon materials are good candidates for natural gas storage due excellent textural properties that are easy to enhance and modify. Natural gas is much cleaner fuel than coal and other petroleum derivatives. Storage of natural gas on porous sorbents at lower pressure is safer and cheaper compared to compressed and liquefied natural gas. This article reviews some works conducted on natural gas storage on biomass based activated carbon materials. Methane storage capacities and deliveries of the various sorbents were given. The effect of factors such as surface area, pore characteristic, heat of adsorption, packing density on the natural gas storage capacity on the activated carbons are discussed. Challenges, improvements and future directions of natural gas storage on porous carbonaceous materials are highlighted.

  1. Development and test of a new concept for biomass producer gas engines

    Energy Technology Data Exchange (ETDEWEB)

    Ahrenfeldt, J.; Vendelbo Foged, E.; Strand, R.; Birk Henriksen, U.

    2010-02-15

    The technical requirements and the economical assessment of converting commercial diesel engine gen-sets into high compression spark ignition operation on biomass producer gas have been investigated. Assessments showed that for a 200 kW{sub e} gen-set there would be a financial benefit of approximately 600.000 DKK corresponding to a reduction of 60% in investment costs compared to the price of a conventional gas engine gen-set. Experimental investigations have been conducted on two identical small scale SI gas engine gen-sets operating on biomass producer gas from thermal gasification of wood. The engines were operated with two different compression ratios, one with the original compression ratio for natural gas operation 9.5:1, and the second with a compression ratio of 18.5:1 (converted diesel engine). It was shown that high compression ratio SI engine operation was possible when operating on this specific biomass producer gas. The results showed an increase in the electrical efficiency from 30% to 34% when the compression ratio was increased. (author)

  2. Development of a fermentation-based process for biomass conversion to hydrogen gas

    NARCIS (Netherlands)

    Claassen, P.A.M.; Vrije, de G.J.; Urbaniec, K.; Grabarczyk, R.

    2010-01-01

    The production of hydrogen gas from biomass to meet the foreseen demand arising from the expected introduction of fuel cells is envisaged. Apart from the well-known gasification method, fermentative conversion can also be applied for this purpose. Two options of the latter method, that is,

  3. Tar removal from biomass derived fuel gas by pulsed corona discharges: chemical kinetic study II

    NARCIS (Netherlands)

    Nair, S.A.; Yan, K.; Pemen, A.J.M.; Heesch, van E.J.M.; Ptasinski, K.J.; Drinkenburg, A.A.H.

    2005-01-01

    Tar (heavy hydrocarbon or poly aromatic hydrocarbon (PAH)) removal from biomass derived fuel gas is one of the biggest obstacles in its utilization for power generation. We have investigated pulsed corona as a method for tar removal. Our previous experimental results indicate the energy consumption

  4. The influence of biomass supply chains and by-products on the greenhouse gas emissions from gasification-based bio-SNG production systems

    International Nuclear Information System (INIS)

    Holmgren, Kristina M.; Berntsson, Thore S.; Andersson, Eva; Rydberg, Tomas

    2015-01-01

    This study analyses the impact on the GHG (greenhouse gas) emissions of the raw material supply chain, the utilisation of excess heat and CO 2 storage for a bio-SNG (biomass gasification-based synthetic natural gas) system by applying a consequential life cycle assessment approach. The impact of the biomass supply chain is analysed by assessing GHG emissions of locally produced woodchips and pellets with regional or transatlantic origin. Results show that the supply area for the gasification plant can be substantially increased with only modest increases in overall GHG emissions (3–5%) by using regionally produced pellets. The transatlantic pellet chains contribute to significantly higher GHG emissions. Utilising excess heat for power generation or steam delivery for industrial use contributes to lower emissions from the system, whereas delivery of district heating can contribute to either increased or decreased emissions. The production technology of the replaced heat and the carbon intensity of the reference power production were decisive for the benefits of the heat deliveries. Finally, the storage of CO 2 separated from the syngas upgrading and from the flue gases of the gasifier can nearly double the GHG emission reduction potential of the bio-SNG system. - Highlights: • Greenhouse gas emission evaluation of gasification-based bio-SNG system is made. • The impact of biomass supply chains and utilisation of excess heat is in focus. • Locally produced woodchips result in lowest overall greenhouse gas emissions. • Regionally produced pellets have small impact on overall greenhouse gas emissions. • Storing separated CO 2 from the bio-SNG process reduces the GHG impact significantly.

  5. Role of sodium hydroxide in the production of hydrogen gas from the hydrothermal gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Onwudili, Jude A.; Williams, Paul T. [Energy and Resources Research Institute, University of Leeds, Leeds, LS2 9JT (United Kingdom)

    2009-07-15

    The role of sodium hydroxide as a promoter of hydrogen gas production during the hydrothermal gasification of glucose and other biomass samples has been investigated. Experiments were carried out in a batch reactor with glucose and also in the presence of the alkali from 200 C, 2 MPa to 450 C, 34 MPa at constant water loading. Without sodium hydroxide, glucose decomposed to produce mainly carbon dioxide, water, char and tar. Furfural, its derivatives and reaction products dominated the ethyl acetate extract of the water (organic fraction) at lower reaction conditions. This indicated that the dehydration of glucose to yield these products was unfavourable to hydrogen gas production. In the presence of sodium hydroxide however, glucose initially decomposed to form mostly alkylated and hydroxylated carbonyl compounds, whose further decomposition yielded hydrogen gas. It was observed that at 350 C, 21.5 MPa, half of the optimum hydrogen gas yield had formed and at 450 C, 34 MPa, more than 80 volume percent of the gaseous effluent was hydrogen gas, while the balance was hydrocarbon gases, mostly methane ({>=}10 volume percent). Other biomass samples were also comparably reacted at the optimum conditions observed for glucose. The rate of hydrogen production for the biomass samples was in the following order; glucose > cellulose, starch, rice straw > potato > rice husk. (author)

  6. Hydrogen production from biomass by thermochemical recuperative energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Fushimi, C.; Araki, K.; Yamaguchi, Y.; Tsutsumi, A. [Tokyo Univ. (Japan). Dept. of Chemical System Engineering

    2002-07-01

    The authors conducted, using a thermogravimetric reactor, a kinetic study of production of thermochemical recuperative hydrogen from biomass. The four different biomass materials used were: cellulose, lignin, metroxylon stem, and coconut husk. Under both rapid heating and slow heating conditions, the weight changes of the biomass samples during the steam gasification or pyrolysis were measured at 973 Kelvin. Simultaneously, measurements of the evolution rates of low-molecular-weight gas products such as hydrogen, methane, carbon monoxide, and carbon dioxide were taken with the help of a mass spectrometer and a micro gas chromatograph (GC). The steam gasification of char significantly increased the amount of hydrogen and carbon dioxide production. The results also indicated that at higher heating rate, the cold gas efficiency of steam gasification was increased. This can be explained by the suppression of the tar production at lower temperature. 25 refs., 2 tabs., 10 figs.

  7. One Step Biomass Gas Reforming-Shift Separation Membrane Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Michael J. [Gas Technology Institute; Souleimanova, Razima [Gas Technology Institute

    2012-12-28

    GTI developed a plan where efforts were concentrated in 4 major areas: membrane material development, membrane module development, membrane process development, and membrane gasifier scale-up. GTI assembled a team of researchers to work in each area. Task 1.1 Ceramic Membrane Synthesis and Testing was conducted by Arizona State University (ASU), Task 1.2 Metallic Membrane Synthesis and Testing was conducted by the U.S. National Energy Technology Laboratory (NETL), Task 1.3 was conducted by SCHOTT, and GTI was to test all membranes that showed potential. The initial focus of the project was concentrated on membrane material development. Metallic and glass-based membranes were identified as hydrogen selective membranes under the conditions of the biomass gasification, temperatures above 700C and pressures up to 30 atmospheres. Membranes were synthesized by arc-rolling for metallic type membranes and incorporating Pd into a glass matrix for glass membranes. Testing for hydrogen permeability properties were completed and the effects of hydrogen sulfide and carbon monoxide were investigated for perspective membranes. The initial candidate membrane of Pd80Cu20 chosen in 2008 was selected for preliminary reactor design and cost estimates. Although the H2A analysis results indicated a $1.96 cost per gge H2 based on a 5A (micron) thick PdCu membrane, there was not long-term operation at the required flux to satisfy the go/no go decision. Since the future PSA case yielded a $2.00/gge H2, DOE decided that there was insufficient savings compared with the already proven PSA technology to further pursue the membrane reactor design. All ceramic membranes synthesized by ASU during the project showed low hydrogen flux as compared with metallic membranes. The best ceramic membrane showed hydrogen permeation flux of 0.03 SCFH/ft2 at the required process conditions while the metallic membrane, Pd80Cu20 showed a flux of 47.2 SCFH/ft2 (3 orders of magnitude difference). Results from

  8. Continuous biological waste gas treatment in stirred trickle-bed reactor with discontinuous removal of biomass.

    Science.gov (United States)

    Laurenzis, A; Heits, H; Wübker, S; Heinze, U; Friedrich, C; Werner, U

    1998-02-20

    A new reactor for biological waste gas treatment was developed to eliminate continuous solvents from waste gases. A trickle-bed reactor was chosen with discontinuous movement of the packed bed and intermittent percolation. The reactor was operated with toluene as the solvent and an optimum average biomass concentration of between 5 and 30 kg dry cell weight per cubic meter packed bed (m3pb). This biomass concentration resulted in a high volumetric degradation rate. Reduction of surplus biomass by stirring and trickling caused a prolonged service life and prevented clogging of the trickle bed and a pressure drop increase. The pressure drop after biomass reduction was almost identical to the theoretical pressure drop as calculated for the irregular packed bed without biomass. The reduction in biomass and intermittent percolation of mineral medium resulted in high volumetric degradation rates of about 100 g of toluene m-3pb h-1 at a load of 150 g of toluene m-3pb h-1. Such a removal rate with a trickle-bed reactor was not reported before. Copyright 1998 John Wiley & Sons, Inc.

  9. Sustainable Transportation Fuels from Natural Gas (H{sub 2}), Coal and Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Huffman, Gerald

    2012-12-31

    This research program is focused primarily on the conversion of coal, natural gas (i.e., methane), and biomass to liquid fuels by Fischer-Tropsch synthesis (FTS), with minimum production of carbon dioxide. A complementary topic also under investigation is the development of novel processes for the production of hydrogen with very low to zero production of CO{sub 2}. This is in response to the nation's urgent need for a secure and environmentally friendly domestic source of liquid fuels. The carbon neutrality of biomass is beneficial in meeting this goal. Several additional novel approaches to limiting carbon dioxide emissions are also being explored.

  10. Performance Comparison on Repowering of a Steam Power Plant with Gas Turbines and Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2016-01-01

    Repowering is a process for transforming an old power plant for greater capacity and/or higher efficiency. As a consequence, the repowered plant is characterized by higher power output and less specific CO2 emissions. Usually, repowering is performed by adding one or more gas turbines into an exi......Repowering is a process for transforming an old power plant for greater capacity and/or higher efficiency. As a consequence, the repowered plant is characterized by higher power output and less specific CO2 emissions. Usually, repowering is performed by adding one or more gas turbines...... into an existing steam cycle which was built decades ago. Thus, traditional repowering results in combined cycles (CC). High temperature fuel cells (such as solid oxide fuel cell (SOFC)) could also be used as a topping cycle, achieving even higher global plant efficiency and even lower specific CO2 emissions....... Decreasing the operating temperature in a SOFC allows the use of less complex materials and construction methods, consequently reducing plant and the electricity costs. A lower working temperature makes it also suitable for topping an existing steam cycle, instead of gas turbines. This is also the target...

  11. Numerical analysis of performance of steam reformer of methane reforming hydrogen production system connected with high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Yin Huaqiang; Jiang Shengyao; Zhang Youjie

    2007-01-01

    Methane conversion rate and hydrogen output are important performance indexes of the steam reformer. The paper presents numerical analysis of performance of the reformer connected with high-temperature gas-cooled reactor HTR-10. Setting helium inlet flow rate fixed, performance of the reformer was examined with different helium inlet temperature, pressure, different process gas temperature, pressure, flow rate, and different steam to carbon ratio. As the range concerned, helium inlet temperature has remarkable influence on the performance, and helium inlet temperature, process gas temperature and pressure have little influence on the performance, and improving process gas flow rate, methane conversion rate decreases and hydrogen output increases, however improving steam to carbon ratio has reverse influence on the performance. (authors)

  12. Effects of non-condensable gas on the condensation of steam

    International Nuclear Information System (INIS)

    Jackson, J.D.; An, P.; Reinert, A.; Ahmadinejad, M.

    2000-01-01

    The experimental work reported here was undertaken with the aim of extending the database currently available on the condensation of steam in the presence of non-condensable gases and thereby improving the empirical input to thermal-hydraulic codes which might be used for design and safety assessment of advanced water-cooled nuclear reactors. Heat was removed from flowing mixtures of steam and air in a test section by means of a water-cooled condensing plate. The test facility constructed for the study incorporates a degassing unit which supplies water to a boiler. This delivers steam steadily to a mixing chamber where it joins with a flow of preheated air. The mixture of steam and air is supplied to the bottom of a cylindrical test section in which it flows upwards over a double sided condensing plate which can be vertical, inclined or horizontal, The rate at which heat is removed by cooling water flowing through internal passages in the plate can de determined calorimetrically knowing the flow rate of the water and its temperature rise. After commissioning experiments had shown that reliable measurements of condensation heat transfer rate could be made using the test facility, a programme of development work followed in the course of which three different designs of condensing plate were evaluated in turn. The version eventually used in the main programme of experiments which followed was made from copper. However, its surfaces were coated with a thin layer of nickel and then with one of chromium. It was found that such a surface consistently promoted dropwise condensation and showed no signs of deterioration after lengthy periods of use. The rate of heat removal from pure steam and from mixtures of steam and air in varying proportions was measured as a function of plate sub-cooling for a variety of plate orientations. (author)

  13. The production of synthetic material gas (SNG) from pit coal by a combined auto-allothermic steam gasification

    International Nuclear Information System (INIS)

    Buch, A.

    1975-01-01

    The steam gasification of pit coal requires temperatures which cannot yet be reached with the present state of HTGR technology for material technical reasons. The use of nuclear heat thus remains limited to some fields of application outside the gasifier, which are specified. The production costs of synthetic natural gas from autothermal gasification on the one hand, and from combined auto-allothermal gasification on the other hand are calculated considering the heat price of pit coal and of the selling price of electrical energy and are compared. (GG/LH) [de

  14. Simultaneous flue gas bioremediation and reduction of microalgal biomass production costs

    Energy Technology Data Exchange (ETDEWEB)

    Douskova, I.; Doucha, J.; Livansky, K.; Umysova, D.; Zachleder, V.; Vitova, M. [Academy of Sciences of the Czech Republic, Trebon (Czech Republic). Laboratory of Cell Cycles of Algae; Machat, J. [Masaryk University, Brno (Czech Republic). Research Centre for Environmental Chemistry and Ecotoxicology; Novak, P. [Termizo Inc., Liberec (Czech Republic)

    2009-02-15

    A flue gas originating from a municipal waste incinerator was used as a source of CO{sub 2} for the cultivation of the microalga Chlorella vulgaris, in order to decrease the biomass production costs and to bioremediate CO{sub 2} simultaneously. The utilization of the flue gas containing 10-13% ({nu}/{nu}) CO2 and 8-10% ({nu}/{nu}) O{sub 2} for the photobioreactor agitation and CO{sub 2} supply was proven to be convenient. The growth rate of algal cultures on the flue gas was even higher when compared with the control culture supplied by a mixture of pure CO{sub 2} and air (11% ({nu}/{nu}) CO{sub 2}). Correspondingly, the CO{sub 2} fixation rate was also higher when using the flue gas (4.4 g CO{sub 2} l{sup -1} 24 h{sup -1}) than using the control gas (3.0 g CO{sub 2} l{sup -1} 24 h{sup -1}). The toxicological analysis of the biomass produced using untreated flue gas showed only a slight excess of mercury while all the other compounds (other heavy metals, polycyclic aromatic hydrocarbons, polychlorinated dibenzodioxins and dibenzofurans, and polychlorinated biphenyls) were below the limits required by the European Union foodstuff legislation. Fortunately, extending the flue gas treatment prior to the cultivation unit by a simple granulated activated carbon column led to an efficient absorption of gaseous mercury and to the algal biomass composition compliant with all the foodstuff legislation requirements. (orig.)

  15. Integrated biomass gasification combined cycle distributed generation plant with reciprocating gas engine and ORC

    International Nuclear Information System (INIS)

    Kalina, Jacek

    2011-01-01

    The paper theoretically investigates the performance of a distributed generation plant made up of gasifier, Internal Combustion Engine (ICE) and Organic Rankine Cycle (ORC) machine as a bottoming unit. The system can be used for maximization of electricity production from biomass in the case where there is no heat demand for cogeneration plant. To analyze the performance of the gasifier a model based on the thermodynamic equilibrium approach is used. Performance of the gas engine is estimated on the basis of the analysis of its theoretical thermodynamic cycle. Three different setups of the plant are being examined. In the first one the ORC module is driven only by the heat recovered from engine exhaust gas and cooling water. Waste heat from a gasifier is used for gasification air preheating. In the second configuration a thermal oil circuit is applied. The oil transfers heat from engine and raw gas cooler into the ORC. In the third configuration it is proposed to apply a double cascade arrangement of the ORC unit with a two-stage low temperature evaporation of working fluid. This novel approach allows utilization of the total waste heat from the low temperature engine cooling circuit. Two gas engines of different characteristics are taken into account. The results obtained were compared in terms of electric energy generation efficiency of the system. The lowest obtained value of the efficiency was 23.6% while the highest one was 28.3%. These are very favorable values in comparison with other existing small and medium scale biomass-fuelled power generation plants. - Highlights: →The study presents performance analysis of a biomass-fuelled local power plant. →Downdraft wood gasifier, gas engine and ORC module are modelled theoretically. →Method for estimation of the producer gas fired engine performance is proposed. →Two gas engines of different characteristics are taken into account. →Different arrangements of the bottoming ORC cycle ere examined.

  16. Chemical hot gas purification for biomass gasification processes; Chemische Heissgasreinigung bei Biomassevergasungsprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Stemmler, Michael

    2010-07-01

    The German government decided to increase the percentage of renewable energy up to 20 % of all energy consumed in 2020. The development of biomass gasification technology is advanced compared to most of the other technologies for producing renewable energy. So the overall efficiency of biomass gasification processes (IGCC) already increased to values above 50 %. Therefore, the production of renewable energy attaches great importance to the thermochemical biomass conversion. The feedstock for biomass gasification covers biomasses such as wood, straw and further energy plants. The detrimental trace elements released during gasification of these biomasses, e.g. KCl, H{sub 2}S and HCl, cause corrosion and harm downstream devices. Therefore, gas cleaning poses an especial challenge. In order to improve the overall efficiency this thesis aims at the development of gas cleaning concepts for the allothermic, water blown gasification at 800 C and 1 bar (Guessing-Process) as well as for the autothermic, water and oxygen blown gasification at 950 C and 18 bar (Vaernamo-Process). Although several mechanisms for KCl- and H{sub 2}S-sorption are already well known, the achievable reduction of the contamination concentration is still unknown. Therefore, calculations on the produced syngas and the chemical hot gas cleaning were done with a thermodynamic process model using SimuSage. The syngas production was included in the calculations because the knowledge of the biomass syngas composition is very limited. The results of these calculations prove the dependence of syngas composition on H{sub 2}/C-ratio and ROC (Relative Oxygen Content). Following the achievable sorption limits were detected via experiments. The KCl containing syngases were analysed by molecular beam mass spectrometry (MBMS). Furthermore, an optimised H{sub 2}S-sorbent was developed because the examined sorbents exceeded the sorption limit of 1 ppmv. The calculated sorption limits were compared to the limits

  17. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Sathre, Roger [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Gustavsson, Leif [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

    2010-04-15

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

  18. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    International Nuclear Information System (INIS)

    Sathre, Roger; Gustavsson, Leif; Bergh, Johan

    2010-01-01

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO 2equiv if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

  19. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Sathre, Roger; Gustavsson, Leif [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

    2010-04-15

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission. (author)

  20. Incorporating uncertainty analysis into life cycle estimates of greenhouse gas emissions from biomass production

    International Nuclear Information System (INIS)

    Johnson, David R.; Willis, Henry H.; Curtright, Aimee E.; Samaras, Constantine; Skone, Timothy

    2011-01-01

    Before further investments are made in utilizing biomass as a source of renewable energy, both policy makers and the energy industry need estimates of the net greenhouse gas (GHG) reductions expected from substituting biobased fuels for fossil fuels. Such GHG reductions depend greatly on how the biomass is cultivated, transported, processed, and converted into fuel or electricity. Any policy aiming to reduce GHGs with biomass-based energy must account for uncertainties in emissions at each stage of production, or else it risks yielding marginal reductions, if any, while potentially imposing great costs. This paper provides a framework for incorporating uncertainty analysis specifically into estimates of the life cycle GHG emissions from the production of biomass. We outline the sources of uncertainty, discuss the implications of uncertainty and variability on the limits of life cycle assessment (LCA) models, and provide a guide for practitioners to best practices in modeling these uncertainties. The suite of techniques described herein can be used to improve the understanding and the representation of the uncertainties associated with emissions estimates, thus enabling improved decision making with respect to the use of biomass for energy and fuel production. -- Highlights: → We describe key model, scenario and data uncertainties in LCAs of biobased fuels. → System boundaries and allocation choices should be consistent with study goals. → Scenarios should be designed around policy levers that can be controlled. → We describe a new way to analyze the importance of covariance between inputs.

  1. Solar membrane natural gas steam-reforming process: evaluation of reactor performance

    NARCIS (Netherlands)

    de Falco, M.; Basile, A.; Gallucci, F.

    2010-01-01

    In this work, the performance of an innovative plant for efficient hydrogen production using solar energy for the process heat duty requirements has been evaluated via a detailed 2D model. The steam-reforming reactor consists of a bundle of coaxial double tubes assembled in a shell. The annular

  2. Solar membrane natural gas steam-reforming process : evaluation of reactor performance

    NARCIS (Netherlands)

    Falco, de M.; Basile, A.; Gallucci, F.

    2010-01-01

    In this work, the performance of an innovative plant for efficient hydrogen production using solar energy for the process heat duty requirements has been evaluated via a detailed 2D model. The steam-reforming reactor consists of a bundle of coaxial double tubes assembled in a shell. The annular

  3. Flash pyrolysis at high temperature of ligno-cellulosic biomass and its components - production of synthesis gas

    International Nuclear Information System (INIS)

    Couhert, C.

    2007-11-01

    Pyrolysis is the first stage of any thermal treatment of biomass and governs the formation of synthesis gas for the production of electricity, hydrogen or liquid fuels. The objective of this work is to establish a link between the composition of a biomass and its pyrolysis gas. We study experimental flash pyrolysis and fix the conditions in which quantities of gas are maximal, while aiming at a regime without heat and mass transfer limitations (particles about 100 μm): temperature of 950 C and residence time of about 2 s. Then we try to predict gas yields of any biomass according to its composition, applicable in this situation where thermodynamic equilibrium is not reached. We show that an additivity law does not allow correlating gas yields of a biomass with fractions of cellulose, hemi-cellulose and lignin contained in this biomass. Several explanations are suggested and examined: difference of pyrolytic behaviour of the same compound according to the biomass from which it is extracted, interactions between compounds and influence of mineral matter. With the aim of industrial application, we study pyrolysis of millimetric and centimetric size particles, and make a numerical simulation of the reactions of pyrolysis gases reforming. This simulation shows that the choice of biomass affects the quantities of synthesis gas obtained. (author)

  4. Pilot scale testing of biomass feedstocks for use in gasification/gas turbine based power generation systems

    Energy Technology Data Exchange (ETDEWEB)

    Najewicz, D.J.; Furman, A.H. [General Electric Corporate Research and Development Center, Schenectady, NY (United States)

    1993-12-31

    A biomass gasification pilot program was performed at the GE Corporate Research and Development Center using two types of biomass feedstock. The object of the testing was to determine the properties of biomass product gas and its` suitability as a fuel for gas turbine based power generation cycles. The test program was sponsored by the State of Vermont, the US Environmental Protection Agency, the US Department of Energy and Winrock International/US Agency for International Development. Gasification of bagasse and wood chip feedstock was performed at a feed rate of approximately one ton per hour, using the Ge pressurized fixed bed gasifier and a single stage of cyclone particulate removal, operating at a temperature of 1,000 F. Both biomass feedstocks were found to gasify easily, and gasification capacity was limited by volumetric capacity of the fuel feed equipment. The biomass product gas was analyzed for chemical composition, particulate loading, fuel bound nitrogen levels, sulfur and alkali metal content. The results of the testing indicated the combustion characteristics of the biomass product gas are compatible with gas turbine combustor requirements. However, the particulate removal performance of the pilot facility single stage cyclone was found to be inadequate to meet turbine particulate contamination specifications. In addition, alkali metals found in biomass based fuels, which are known to cause corrosion of high temperature gas turbine components, were found to exceed allowable levels in the fuel gas. These alkali metal compounds are found in the particulate matter (at 1000 F) carried over from the gasifier, thus improved particulate removal technology, designed specifically for biomass particulate characteristics could meet the turbine requirements for both particulate and alkali loading. The paper will present the results of the biomass gasification testing and discuss the development needs in the area of gas clean-up and turbine combustion.

  5. Commercial demonstration of atmospheric medium BTU fuel gas production from biomass without oxygen the Burlington, Vermont Project

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, J.W. [Zurn/NEPCO, South Portland, MA (United States); Paisley, M. [Battelle Laboratories, Columbus, OH (United States)

    1995-12-31

    The first U.S. demonstration of a gas turbine operating on fuel gas produced by the thermal gasification of biomass occurred at Battelle Columbus Labs (BCL) during 1994 using their high throughput indirect medium Btu gasification Process Research Unit (PRU). Zurn/NEPCO was retained to build a commercial scale gas plant utilizing this technology. This plant will have a throughput rating of 8 to 12 dry tons per hour. During a subsequent phase of the Burlington project, this fuel gas will be utilized in a commercial scale gas turbine. It is felt that this process holds unique promise for economically converting a wide variety of biomass feedstocks efficiently into both a medium Btu (500 Btu/scf) gas turbine and IC engine quality fuel gas that can be burned in engines without modification, derating or efficiency loss. Others are currently demonstrating sub-commercial scale thermal biomass gasification processes for turbine gas, utilizing both atmospheric and pressurized air and oxygen-blown fluid bed processes. While some of these approaches hold merit for coal, there is significant question as to whether they will prove economically viable in biomass facilities which are typically scale limited by fuel availability and transportation logistics below 60 MW. Atmospheric air-blown technologies suffer from large sensible heat loss, high gas volume and cleaning cost, huge gas compressor power consumption and engine deratings. Pressurized units and/or oxygen-blown gas plants are extremely expensive for plant scales below 250 MW. The FERCO/BCL process shows great promise for overcoming the above limitations by utilizing an extremely high throughout circulation fluid bed (CFB) gasifier, in which biomass is fully devolitalized with hot sand from a CFB char combustor. The fuel gas can be cooled and cleaned by a conventional scrubbing system. Fuel gas compressor power consumption is reduced 3 to 4 fold verses low Btu biomass gas.

  6. Hydrogen production from palm kernel shell via integrated catalytic adsorption (ICA) steam gasification

    International Nuclear Information System (INIS)

    Khan, Zakir; Yusup, Suzana; Ahmad, Murni Melati; Chin, Bridgid Lai Fui

    2014-01-01

    Highlights: • The paper presents integrated catalytic adsorption (ICA) steam gasification for H 2 yield. • Effects of adsorbent to biomass, biomass particle size and fluidization velocity on H 2 yield are examined. • The present study produces higher H 2 yield as compared to that obtained in literatures. • The ICA provides enhancement of H 2 yield as compared to independent catalytic and CO 2 adsorption gasification systems. - Abstract: The present study investigates the integrated catalytic adsorption (ICA) steam gasification of palm kernel shell for hydrogen production in a pilot scale atmospheric fluidized bed gasifier. The biomass steam gasification is performed in the presence of an adsorbent and a catalyst in the system. The effect of adsorbent to biomass (A/B) ratio (0.5–1.5 wt/wt), fluidization velocity (0.15–0.26 m/s) and biomass particle size (0.355–2.0 mm) are studied at temperature of 675 °C, steam to biomass (S/B) ratio of 2.0 (wt/wt) and biomass to catalyst ratio of 0.1 (wt/wt). Hydrogen composition and yield, total gas yield, and lower product gas heating values (LHV gas ) increases with increasing A/B ratio, while particle size has no significant effect on hydrogen composition and yield, total gas and char yield, gasification and carbon conversion efficiency. However, gas heating values increased with increasing biomass particle size which is due to presence of high methane content in product gas. Meanwhile, medium fluidization velocity of 0.21 m/s favoured hydrogen composition and yield. The results showed that the maximum hydrogen composition and yield of 84.62 vol% and 91.11 g H 2 /kg biomass are observed at A/B ratio of 1.5, S/B ratio of 2.0, catalyst to biomass ratio of 0.1 and temperature of 675 °C. The product gas heating values are observed in the range of 10.92–17.02 MJ/N m 3 . Gasification and carbon conversion efficiency are observed in the range of 25.66–42.95% and 20.61–41.95%, respectively. These lower

  7. Thermodynamic modeling and evaluation of high efficiency heat pipe integrated biomass Gasifier–Solid Oxide Fuel Cells–Gas Turbine systems

    International Nuclear Information System (INIS)

    Santhanam, S.; Schilt, C.; Turker, B.; Woudstra, T.; Aravind, P.V.

    2016-01-01

    This study deals with the thermodynamic modeling of biomass Gasifier–SOFC (Solid Oxide Fuel Cell)–GT (Gas Turbine) systems on a small scale (100 kW_e). Evaluation of an existing biomass Gasifier–SOFC–GT system shows highest exergy losses in the gasifier, gas turbine and as waste heat. In order to reduce the exergy losses and increase the system's efficiency, improvements are suggested and the effects are analyzed. Changing the gasifying agent for air to anode gas gave the largest increase in the electrical efficiency. However, heat is required for an allothermal gasification to take place. A new and simple strategy for heat pipe integration is proposed, with heat pipes placed in between stacks in series, rather than the widely considered approach of integrating the heat pipes within the SOFC stacks. The developed system based on a Gasifier–SOFC–GT combination improved with heat pipes and anode gas recirculation, increases the electrical efficiency from approximately 55%–72%, mainly due to reduced exergy losses in the gasifier. Analysis of the improved system shows that operating the system at possibly higher operating pressures, yield higher efficiencies within the range of the operating pressures studied. Further the system was scaled up with an additional bottoming cycle achieved electrical efficiency of 73.61%. - Highlights: • A new and simple strategy for heat pipe integration between SOFC and Gasifier is proposed. • Anode exhaust gas is used as a gasifying agent. • The new proposed Gasifier–SOFC–GT system achieves electrical efficiency of 72%. • Addition of steam rankine bottoming cycle to proposed system increases electrical efficiency to 73.61%.

  8. Thermo-economic optimization of heat recovery steam generator for a range of gas turbine exhaust temperatures

    International Nuclear Information System (INIS)

    Nadir, Mahmoud; Ghenaiet, Adel; Carcasci, Carlo

    2016-01-01

    Highlights: • Thermo-economic optimization of HRSG configurations. • The maximum value of the net present value was targeted for the economic optimization. • Three level HRSG is the best option in respect of power output and high priced medium. • Two level HRSG is the best for net benefit in low and intermediate priced mediums. - Abstract: This paper illustrates the effect of selling price on the optimum design parameters of a heat recovery steam generator (HRSG) and the selection of its ideal configuration for an outlet temperature range of 350–650 °C. The Particle Swarm Optimization (PSO) method was used, considering the steam cycle specific work as an objective to be maximized, the net present value as another objective to be maximized for the economic optimization and a combination of both. Three configurations of heat recovery steam generators are considered with one, two and three pressure levels and a reheat. The results show that, the three pressure level system is the best configuration from a thermodynamic point of view, but with respect to the economical aspect the two pressure levels is the best configuration for the low and medium selling prices (0.04 $/kW h, 0.08 $/kW h and 0.2 $/kW h), whereas the three pressure level configuration would only be interesting for a high selling price of 0.3 $/kW h and a temperature range 450–600 °C. For a temperature of 650 °C, the high cost of the three level system leads to a decrease in the net present value. As the selling price increases the optimized design parameters of the three pressure level HRSG based on economic or thermodynamic optimization are similar. The obtained results are used to elaborate a new correlation relating the net present value with the gas turbine outlet temperature, gas mass flow rate, number of levels of HRSG and selling price.

  9. Gas-steam combined cycles for power generation: Current state-of-the-art and future prospects

    International Nuclear Information System (INIS)

    Macchi, E.; Chiesa, P.; Consonni, S.; Lozza, G.

    1992-01-01

    The first part of this paper points out the many factors which, after years of stagnation in the electric power industry, are giving rise to a true revolution in power generation engineering: the passing from closed cycles, using steam as the working fluid and energy sources external to the power cycle, to the use of open cycles, in which the primary energy source, in the form of a fuel, is directly immersed in the working fluid of the engine. Attention is given to the advantages in terms of energy and cost savings, greater flexibility in energy policy options and pollution abatement which are now being afforded through the use of gas turbines with combined gas-steam cycles. The second part of the paper deals with an assessment of the current state-of-the-art of the technology relative to these innovative power systems. The assessment is followed by a review of foreseen developments in combined cycle system design, choice of construction materials, type of cooling systems, operating temperatures and performance capabilities

  10. Large-scale production of Fischer-Tropsch diesel from biomass. Optimal gasification and gas cleaning systems

    International Nuclear Information System (INIS)

    Boerrigter, H.; Van der Drift, A.

    2004-12-01

    The paper is presented in the form of copies of overhead sheets. The contents concern definitions, an overview of Integrated biomass gasification and Fischer Tropsch (FT) systems (state-of-the-art, gas cleaning and biosyngas production, experimental demonstration and conclusions), some aspects of large-scale systems (motivation, biomass import) and an outlook

  11. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 5: Combined gas-steam turbine cycles. [energy conversion efficiency in electric power plants

    Science.gov (United States)

    Amos, D. J.; Foster-Pegg, R. W.; Lee, R. M.

    1976-01-01

    The energy conversion efficiency of gas-steam turbine cycles was investigated for selected combined cycle power plants. Results indicate that it is possible for combined cycle gas-steam turbine power plants to have efficiencies several point higher than conventional steam plants. Induction of low pressure steam into the steam turbine is shown to improve the plant efficiency. Post firing of the boiler of a high temperature combined cycle plant is found to increase net power but to worsen efficiency. A gas turbine pressure ratio of 12 to 1 was found to be close to optimum at all gas turbine inlet temperatures that were studied. The coal using combined cycle plant with an integrated low-Btu gasifier was calculated to have a plant efficiency of 43.6%, a capitalization of $497/kW, and a cost of electricity of 6.75 mills/MJ (24.3 mills/kwh). This combined cycle plant should be considered for base load power generation.

  12. Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup, and Oxygen Separation Equipment; Task 1: Cost Estimates of Small Modular Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nexant Inc.

    2006-05-01

    This deliverable is the Final Report for Task 1, Cost Estimates of Small Modular Systems, as part of NREL Award ACO-5-44027, ''Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup and Oxygen Separation Equipment''. Subtask 1.1 looked into processes and technologies that have been commercially built at both large and small scales, with three technologies, Fluidized Catalytic Cracking (FCC) of refinery gas oil, Steam Methane Reforming (SMR) of Natural Gas, and Natural Gas Liquids (NGL) Expanders, chosen for further investigation. These technologies were chosen due to their applicability relative to other technologies being considered by NREL for future commercial applications, such as indirect gasification and fluidized bed tar cracking. Research in this subject is driven by an interest in the impact that scaling has on the cost and major process unit designs for commercial technologies. Conclusions from the evaluations performed could be applied to other technologies being considered for modular or skid-mounted applications.

  13. Exergy analysis of biomass-to-synthetic natural gas (SNG) process via indirect gasification of various biomass feedstock

    NARCIS (Netherlands)

    Vitasari, C.R.; Jurascik, M.; Ptasinski, K.J.

    2011-01-01

    This paper presents an exergy analysis of SNG production via indirect gasification of various biomass feedstock, including virgin (woody) biomass as well as waste biomass (municipal solid waste and sludge). In indirect gasification heat needed for endothermic gasification reactions is produced by

  14. Biomass gasification for CHP with dry gas cleaning and regenerative heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-05-01

    Small scale CHP plants based on biomass gasification technologies are generally expensive and not very efficient due to gas quality problems which increase operation and maintenance cost as well as breakdown. To overcome this situation the team has developed, integrated and tested a complete biomass gasification combine heat and power prototype plant of 250 kWth equipped with a specifically developed dry gas cleaning and heat recovery system. The dry gas cleaning device is a simple dry gas regenerative heat exchanger where tars are stopped by condensation but working at a temperature above due point in order to avoid water condensation. Two types of heat particles separation devices have been tested in parallel multi-cyclone and ceramic filters. After several month spent on modelling design, construction and optimisation, a full test campaign of 400 hours continuous monitoring has been done where all working parameters has been monitored and gas cleaning device performances has been assessed. Results have shown: Inappropriateness of the ceramic filters for the small scale unit due to operation cost and too high sensibility of the filters to the operation conditions fluctuating in a wide range, despite a very high particle separation efficiency 99 %; Rather good efficiency of the multi-cyclone 72% but not sufficient for engine safety. Additional conventional filters where necessary for the finest part; Inappropriateness of the dry gas heat exchanger device for tar removal partly due to a low tar content of the syngas generated, below 100 mg/Nm{sup 3} , but also due to their composition which would have imposed, to be really efficient, a theoretical condensing temperature of 89 C below the water condensation temperature. These results have been confirmed by laboratory tests and modelling. However the tar cracking phase have shown very interesting results and proved the feasibility of thermal cracking with full cleaning of the heat exchanger without further mechanical

  15. Identifying key drivers of greenhouse gas emissions from biomass feedstocks for energy production

    International Nuclear Information System (INIS)

    Johnson, David R.; Curtright, Aimee E.; Willis, Henry H.

    2013-01-01

    Highlights: • Production emissions dominate transportation and processing emissions. • Choice of feedstock, geographic location and prior land use drive emissions profile. • Within scenarios, emissions variability is driven by uncertainty in yields. • Favorable scenarios maximize carbon storage from direct land-use change. • Similarly, biomass production should attempt to minimize indirect land-use change. -- Abstract: Many policies in the United States, at both the federal and state levels, encourage the adoption of renewable energy from biomass. Though largely motivated by a desire to reduce greenhouse gas emissions, these policies do not explicitly identify scenarios in which the use of biomass will produce the greatest benefits. We have modeled “farm-to-hopper” emissions associated with seven biomass feedstocks, under a wide variety of scenarios and production choices, to characterize the uncertainty in emissions. We demonstrate that only a handful of factors have a significant impact on life cycle emissions: choice of feedstock, geographic location, prior land use, and time dynamics. Within a given production scenario, the remaining variability in emissions is driven by uncertainty in feedstock yields and the release rate of N 2 O into the atmosphere from nitrogen fertilizers. With few exceptions, transport and processing choices have relatively little impact on total emissions. These results illustrate the key decisions that will determine the success of biomass programs in reducing the emissions profile of energy production, and our publicly available model provides a useful tool for identifying the most beneficial production scenarios. While model data and results are restricted to biomass production in the contiguous United States, we provide qualitative guidance for identifying favorable production scenarios that should be applicable in other regions

  16. Effect of non-condensation gas on pressure oscillation of submerged steam jet condensation

    International Nuclear Information System (INIS)

    Zhao, Quanbin; Cong, Yuelei; Wang, Yingchun; Chen, Weixiong; Chong, Daotong; Yan, Junjie

    2016-01-01

    Highlights: • Oscillation intensity of steam–air jet increases with rise of water temperature. • Oscillation intensity reduces obviously when air is mixed. • Both first and second dominant frequencies decrease with rise of air mass fraction. • Air has little effect on power of 1st & 2nd frequency bands under low temperature. • The maximum oscillation power occurs under case of A = 1% and T ⩾ 50 °C. - Abstract: The effect of air with low mass fraction on the oscillation intensity and oscillation frequency of a submerged steam jet condensation is investigated under stable condensation region. With air mixing in steam, an obvious dynamic pressure peak appears along the jet direction. The intensity peak increases monotonously with the rise of steam mass flux and water temperature. Peak position moves downstream with the rise of air mass fraction. Moreover, when compared with that of pure steam jet, the oscillation intensity clearly decreases as air is mixed. However, when water temperature is lower than approximately 45 °C, oscillation intensity increases slightly with the rise of air mass fraction, and when water temperature is higher than 55 °C, the oscillation intensity decreases greatly with the rise of air mass fraction. Both the first and second dominant frequencies decrease with rise of air mass fraction. Finally, effect of air mass fractions on the oscillation power of the first and second dominant frequency bands shows similar trends. Under low water temperature, the mixed air has little effect on the oscillation power of both first and second frequency bands. However, when water temperature is high, the oscillation power of both first and second frequency bands appears an obvious peak when air mass fraction is about 1%. With further rise of air mass fraction, the oscillation power decreases gradually.

  17. Modeling and performance analysis of CCHP (combined cooling, heating and power) system based on co-firing of natural gas and biomass gasification gas

    International Nuclear Information System (INIS)

    Wang, Jiangjiang; Mao, Tianzhi; Sui, Jun; Jin, Hongguang

    2015-01-01

    Co-firing biomass and fossil energy is a cost-effective and reliable way to use renewable energy and offer advantages in flexibility, conversion efficiency and commercial possibility. This study proposes a co-fired CCHP (combined cooling, heating and power) system based on natural gas and biomass gasification gas that contains a down-draft gasifier, ICE (internal combustion engine), absorption chiller and heat exchangers. Thermodynamic models are constructed based on a modifying gasification thermochemical equilibrium model and co-fired ICE model for electricity and heat recovery. The performance analysis for the volumetric mixture ratio of natural gas and product gas indicates that the energy and exergy efficiencies are improved by 9.5% and 13.7%, respectively, for an increasing mixture ratio of 0–1.0. Furthermore, the costs of multi-products, including electricity, chilled water and hot water, based on exergoeconomic analysis are analyzed and discussed based on the influences of the mixture ratio of the two gas fuels, investment cost and biomass cost. - Highlights: • Propose a co-fired CCHP system by natural gas and biomass gasification gas. • Modify biomass gasification and co-fired ICE models. • Present the thermodynamic analysis of the volumetric mixture ratios of two gas fuels. • Energy and exergy efficiencies are improved 9.5% and 13.7%. • Discuss multi-products’ costs influenced by investment and fuel costs.

  18. Biological conversion of forage sorghum biomass to ethanol by steam explosion pretreatment and simultaneous hydrolysis and fermentation at high solid content

    Energy Technology Data Exchange (ETDEWEB)

    Manzanares, Paloma; Ballesteros, Ignacio; Negro, Maria Jose; Oliva, Jose Miguel; Gonzalez, Alberto; Ballesteros, Mercedes [Renewable Energy Department-CIEMAT, Biofuels Unit, Madrid (Spain)

    2012-06-15

    In this work, forage sorghum biomass was studied as feedstock for ethanol production by a biological conversion process comprising the steps of hydrothermal steam explosion pretreatment, enzymatic hydrolysis with commercial enzymes, and fermentation with the yeast Saccharomyces cerevisiae. Steam explosion conditions were optimized using a response surface methodology considering temperature (180-230 C) and time (2-10 min). Sugar recovery in the pretreatment and the enzymatic digestibility of the pretreated solid were used to determine the optimum conditions, i.e., 220 C and 7 min. At these conditions, saccharification efficiency attained 89 % of the theoretical and the recovery of xylose in the prehydrolyzate accounted for 35 % of the amount of xylose present in raw material. Then, a simultaneous hydrolysis and fermentation (SSF) process was tested at laboratory scale on the solid fraction of forage sorghum pretreated at optimum condition, in order to evaluate ethanol production. The effect of the enzyme dose and the supplementation with xylanase enzyme of the cellulolytic enzyme cocktail was studied at increasing solid concentration up to 18 % (w/w) in SSF media. Results show good performance of SSF in all consistencies tested with a significant effect of increasing enzyme load in SSF yield and final ethanol concentration. Xylanase supplementation allows increasing solid concentration up to 18 % (w/w) with good SSF performance and final ethanol content of 55 g/l after 4-5 days. Based on this result, about 190 l of ethanol could be obtained from 1 t of untreated forage sorghum, which means a transformation yield of 85 % of the glucose contained in the feedstock. (orig.)

  19. Biomass-Ash-Induced Agglomeration in a Fluidized Bed. Part 1: Experimental Study on the Effects of a Gas Atmosphere

    DEFF Research Database (Denmark)

    Ma, Teng; Fan, Chuigang; Hao, Lifang

    2016-01-01

    . The agglomerates are analyzed by scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM–EDS) for morphology and elemental composition. Significant differences are observed on the defluidization temperature (Td) and agglomeration mechanisms in different gas atmospheres. Td in H2 and steam...

  20. Relative Sustainability of Natural Gas Assisted High-Octane Gasoline Blendstock Production from Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Eric C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Yi Min [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cai, Hao [Argonne National Laboratory

    2017-11-01

    Biomass-derived hydrocarbon fuel technologies are being developed and pursued for better economy, environment, and society benefits underpinning the sustainability of transportation energy. Increasing availability and affordability of natural gas (NG) in the US can play an important role in assisting renewable fuel technology development, primarily in terms of economic feasibility. When a biorefinery is co-processing NG with biomass, the current low cost of NG coupled with the higher NG carbon conversion efficiency potentially allow for cost competitiveness of the fuel while achieving a minimum GHG emission reduction of 50 percent or higher compared to petroleum fuel. This study evaluates the relative sustainability of the production of high-octane gasoline blendstock via indirect liquefaction (IDL) of biomass (and with NG co-feed) through methanol/dimethyl ether intermediates. The sustainability metrics considered in this study include minimum fuel selling price (MFSP), carbon conversion efficiency, life cycle GHG emissions, life cycle water consumption, fossil energy return on investment (EROI), GHG emission avoidance cost, and job creation. Co-processing NG can evidently improve the MFSP. Evaluation of the relative sustainability can shed light on the biomass-NG synergistic impacts and sustainability trade-offs associated with the IDL as high-octane gasoline blendstock production.

  1. Refining Bio-Gas Produced from Biomass: An Alternative to Cooking Gas

    Directory of Open Access Journals (Sweden)

    A. S. ABDULKAREEM

    2005-06-01

    Full Text Available Our life is completely dependent on a reliable and adequate supply of energy. In other to reduce dependence on fossil fuels, the use of animal dung in producing a renewable alternative source of energy has been proved using cow dung. This work is aimed at produced and refined bio - gas from animal dung by reduces the H2S and CO2 content of bio - gas in other to improved the quality of the bio - gas to be used as an alternative to the petroleum based produces in use now. The sample of gas produced was passed through the gas chromatography to determine the percentage composition (mol % dry basis of the bio - gas contents. The results of the bio - gas before refinement were 54.09% mole dry CH4, 40.02mole % dry CO2 and 0.80mole % dry H2S which conformed with the literature values of 50 - 65 % mole dry CH4, 35 - 50 % mole dry CO2 and 0.1 - 1.0 % mole dry H2S. After refining, the composition of bio - gas on dry basis were 54.09% mole dry CH4, 4.01% mole dry CO2, 0.02% mole dry O2, 0.05% mole dry NH3, 0.01% mole dry H2S, 0.5% mole dry H2 and 2.54% mole dry N2. Analysis of the remnant indicated that it could be used for plant nutrient.

  2. Preliminary Screening -- Technical and Economic Assessment of Synthesis Gas to Fuels and Chemicals with Emphasis on the Potential for Biomass-Derived Syngas

    Energy Technology Data Exchange (ETDEWEB)

    Spath, P. L.; Dayton, D. C.

    2003-12-01

    In principle, syngas (primarily consisting of CO and H2) can be produced from any hydrocarbon feedstock, including: natural gas, naphtha, residual oil, petroleum coke, coal, and biomass. The lowest cost routes for syngas production, however, are based on natural gas, the cheapest option being remote or stranded reserves. Economic considerations dictate that the current production of liquid fuels from syngas translates into the use of natural gas as the hydrocarbon source. Nevertheless, the syngas production operation in a gas-to-liquids plant amounts to greater than half of the capital cost of the plant. The choice of technology for syngas production also depends on the scale of the synthesis operation. Syngas production from solid fuels can require an even greater capital investment with the addition of feedstock handling and more complex syngas purification operations. The greatest impact on improving the economics of gas-to liquids plants is through (1) decreasing capital costs associated with syngas production and (2) improving the thermal efficiency with better heat integration and utilization. Improved thermal efficiency can be obtained by combining the gas-to-liquids plant with a power generation plant to take advantage of the availability of low-pressure steam. The extensive research and development efforts devoted to syngas conversion to fuels and chemicals are documented in a vast amount of literature that tracks the scientific and technological advancements in syngas chemistry. The purpose of this report is to review the many syngas to products processes and summarize the salient points regarding the technology status and description, chemistry, catalysts, reactors, gas cleanliness requirements, process and environmental performances, and economics. Table 1 lists the products examined in this study and gives some facts about the technology as well as advantages and disadvantages. Table 2 summarizes the catalysts, process conditions, conversions, and

  3. Thermo Dynamics and Economics Evaluations: Substitution of the Extraction Steam with the Wasted Heat of Flue Gas

    Science.gov (United States)

    Hao, Lifen; Qiu, Lixia; Li, Jinping; Li, Dongxiong

    2018-01-01

    A new heat supplying system is proposed that utilizes the exhausted gas of the boiler to substitute the extraction steam from the turbine as the driving force for the adsorption heat pump regarding the recovery of the condensation heat of power plant. However, our system is not subject to the low efficiency of wasted heat utilization due to the low temperature of flue gas, which hence possesses higher performance in COP factors in the utilization of heat than that of the conventional techniques of using flues gas, so the amount of extracted gas from turbine can be reduced and the power generate rate be enhanced. Subsequently, detailed evaluation of the performance of this system in the point of views of thermodynamics and economics are presented in this work. For the instance of a 330 MW heat supply unit, 5 sample cities are chosen to demonstrate and confirm our economic analysis. It is revealed that when the heating coefficient of the heat pump is 1.8, the investment payback periods for these 5 cities are within the range of 2.4 to 4.8 years, which are far below the service year of the heat pump, demonstrating remarkable economic benefits for our system.

  4. Parametric simulation on enhancement of the Regenerative Gas Turbine performance by effect of Inlet Air Cooling system and Steam Injection

    Directory of Open Access Journals (Sweden)

    Aadel Abdulrazzaq Alkumait

    2016-02-01

    Full Text Available Iraq being one of the developing countries of the world considers energy efficiency and the impact of its generation on the environment an imperative process in improvement of its power generation policies. Iraq bearing high temperatures all year long results in reduction of air density, therefore, Inlet air Cooling and Steam Injection Gas Turbines are a striking addition to the regenerative gas turbines. Regenerating Gas turbines tend to have a high back work ratio and a high exhaust temperature, thus, it leads to a low efficiency in power generation in hotter climate. Moreover, STIG and IAC through fog cooling have known to be the best retrofitting methods available in the industry which improve the efficiency of generation from 30.5 to 43% and increase the power output from 22MW to 33.5MW as the outcomes of computer simulations reveal. Additionally, this happens without bringing about much extensive change to original features of the power generation cycle. Furthermore, STIG and spray coolers have also resulted in power boosting and exceeding generation efficiency of gas turbine power plant.

  5. Parametric Simulation on Enhancement of the Regenerative Gas Turbine Performance by Effect of Inlet Air Cooling System and Steam Injection

    Directory of Open Access Journals (Sweden)

    Aadel A. Alkumait

    2016-02-01

    Full Text Available Aadel Abdulrazzaq Alkumait/Tikrit Journal of Engineering Sciences 22(1 (201538-44Iraq being one of the developing countries of the world considers energy efficiency and the impact of its generation on the environment an imperative process in improvement of its power generation policies. Iraq bearing high temperatures all year long results in reduction of air density, therefore, Inlet air Cooling and Steam Injection Gas Turbines are a striking addition to the regenerative gas turbines. Regenerating Gas turbines tend to have a high back work ratio and a high exhaust temperature, thus, it leads to a low efficiency in power generation in hotter climate. Moreover, STIG and IAC through fog cooling have known to be the best retrofitting methods available in the industry which improve the efficiency of generation from 30.5 to 43% and increase the power output from 22MW to 33.5MW as the outcomes of computer simulations reveal. Additionally, this happens without bringing about much extensive change to original features of the power generation cycle. Furthermore, STIG and spray coolers have also resulted in power boosting and exceeding generation efficiency of gas turbine power plant.

  6. Herbaceous biomass supply chains : assessing the greenhouse gas balance, economics and ILUC effects of Ukrainian biomass for domestic and Dutch energy markets

    NARCIS (Netherlands)

    Poppens, R.P.; Lesschen, J.P.; Galytska, M.; Jamblinne, de P.; Kraisvitnii, P.; Elbersen, H.W.

    2013-01-01

    This report describes the supply chain performance for three types of biomass feedstock (reed, straw and switchgrass) and for three sustainability aspects, i.e. the greenhouse gas balance, economics and Indirect Land Use change effects (ILUC). Calculations are based on a fictional supply chain

  7. Latest information about development of gas-fueled steam convection ovens; Ou en est la mise au point du four a gaz a convection de vapeur au Japon

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, T. [Tokyo-gas co., Ltd. (Japan)

    2000-07-01

    In Japan, gas has been the main source of heat for heating-type culinary equipment in the food service industry, however, this situation has been recently changing. One reason for this is the introduction of electric steam convection ovens. To promote the use of gas steam convection ovens that can compete with electric appliances, Tokyo Gas has conducted the following development projects. Firstly, we set development targets for gas appliances to out-perform the best electric appliances, and were able to develop appliance products that met the targets. Secondly, in order to develop new markets for gas appliances, we worked on the development of compact appliances with a comparatively low initial cost, launching the world's smallest product in this category in October 1998. Thirdly, in order to make gas appliances as widely used here as they are in Europe and America, we developed appliances with costs cut by 30%, and in October 1999 we launched the cheapest gas steam convection oven in the domestic market. We plan to continue providing technological expertise to domestic manufacturers, enhancing our line-up with top performance gas appliances at even lower cost. (author)

  8. The cycle use test of Pt based catalyst for the steam reforming of naphthalene / benzene as model tar compounds of biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Furusawa, Takeshi; Saito, Katsuhiko; Sato, Masahide; Suzuki, Noboru [Utsunomiya Univ. (Japan). Graduate School of Engineering

    2010-07-01

    Although Pt/Al{sub 2}O{sub 3} catalyst showed high and stable activity (carbon conv. to gas: 90%) for steam reforming of naphthalene/benzene at 1073 K with S/C=3, this catalyst gradually lost its activity at 1023 K with S/C=3 due to deposition of carboneous species. Two kinds of regeneration treatment was conducted to enlongate the life time of Pt/Al{sub 2}O{sub 3} catalyst. Although regeneration treatment completely remove the carboneous species from catalyst, mild oxidation treatment led to decrease activity due to sintering of Pt particles. On the contrary, hydrogen treatment led to maintain activity until 5th cycle test. It was concluded from these obtained results that hydrogen treatment is suitable regeneration method during cycle test in the case of Pt/Al{sub 2}O{sub 3} catalyst. (orig.)

  9. ORTAP: a nuclear steam supply system simulation for the dynamic analysis of high temperature gas cooled reactor transients

    International Nuclear Information System (INIS)

    Cleveland, J.C.; Hedrick, R.A.; Ball, S.J.; Delene, J.G.

    1977-01-01

    ORTAP was developed to predict the dynamic behavior of the high temperature gas cooled reactor (HTGR) Nuclear Steam Supply System for normal operational transients and postulated accident conditions. It was developed for the Nuclear Regulatory Commission (NRC) as an independent means of obtaining conservative predictions of the transient response of HTGRs over a wide range of conditions. The approach has been to build sufficient detail into the component models so that the coupling between the primary and secondary systems can be accurately represented and so that transients which cover a wide range of conditions can be simulated. System components which are modeled in ORTAP include the reactor core, a typical reheater and steam generator module, a typical helium circulator and circulator turbine and the turbine generator plant. The major plant control systems are also modeled. Normal operational transients which can be analyzed with ORTAP include reactor start-up and shutdown, normal and rapid load changes. Upset transients which can be analyzed with ORTAP include reactor trip, turbine trip and sudden reduction in feedwater flow. ORTAP has also been used to predict plant response to emergency or faulted conditions such as primary system depressurization, loss of primary coolant flow and uncontrolled removal of control poison from the reactor core

  10. Simulation of Synthesis Gas Production from Steam Oxygen Gasification of Colombian Coal Using Aspen Plus®

    Directory of Open Access Journals (Sweden)

    Jorge E. Preciado

    2012-11-01

    Full Text Available A steady state simulation of syngas production from a Steam Oxygen Gasification process using commercial technologies was performed using Aspen Plus®. For the simulation, the average proximate and ultimate compositions of bituminous coal obtained from the Colombian Andean region were employed. The simulation was applied to conduct sensitivity analyses in the O2 to coal mass ratio, coal slurry concentration, WGS operating temperature and WGS steam to dry gas molar ratio (SDG over the key parameters: syngas molar composition, overall CO conversion in the WGS reactors, H2 rich-syngas lower heating value (LHV and thermal efficiency. The achieved information allows the selection of critical operating conditions leading to improve system efficiency and environmental performance. The results indicate that the oxygen to carbon ratio is a key variable as it affects significantly both the LHV and thermal efficiency. Nevertheless, the process becomes almost insensitive to SDG values higher than 2. Finally, a thermal efficiency of 62.6% can be reached. This result corresponds to a slurry solid concentration of 0.65, a WGS process SDG of 0.59, and a LTS reactor operating temperature of 473 K. With these fixed variables, a syngas with H2 molar composition of 92.2% and LHV of 12 MJ Nm−3 was attained.

  11. Hydrogen production by steam reforming of liquefied natural gas over a nickel catalyst supported on mesoporous alumina xerogel

    Science.gov (United States)

    Seo, Jeong Gil; Youn, Min Hye; Cho, Kyung Min; Park, Sunyoung; Song, In Kyu

    Mesoporous alumina xerogel (A-SG) is prepared by a sol-gel method for use as a support for a nickel catalyst. The Ni/A-SG catalyst is then prepared by an impregnation method, and is applied to hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of the mesoporous alumina xerogel support on the catalytic performance of Ni/A-SG catalyst is investigated. For the purpose of comparison, a nickel catalyst supported on commercial alumina (A-C) is also prepared by an impregnation method (Ni/A-C). Both the hydroxyl-rich surface and the electron-deficient sites of the A-SG support enhance the dispersion of the nickel species on the support during the calcination step. The formation of the surface nickel aluminate phase in the Ni/A-SG catalyst remarkably increases the reducibility and stability of the catalyst. Furthermore, the high-surface area and the well-developed mesoporosity of the Ni/A-SG catalyst enhance the gasification of surface hydrocarbons that are adsorbed in the reaction. In the steam reforming of LNG, the Ni/A-SG catalyst exhibits a better catalytic performance than the Ni/A-C catalyst in terms of LNG conversion and hydrogen production. Moreover, the Ni/A-SG catalyst shows strong resistance toward catalyst deactivation.

  12. Hot Gas Conditioning: Recent Progress with Larger-Scale Biomass Gasification Systems; Update and Summary of Recent Progress

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, D. J.

    2001-09-01

    As a result of environmental and policy considerations, there is increasing interest in using renewable biomass resources as feedstock for power, fuels, and chemicals and hydrogen. Biomass gasification is seen as an important technology component for expanding the use of biomass. Advanced biomass gasification systems provide clean products that can be used as fuel or synthesis gases in a variety of environmentally friendly processes. Advanced end-use technologies such as gas turbines or synthesis gas systems require high quality gases with narrowly defined specifications. Other systems such as boilers may also have fuel quality requirements, but they will be substantially less demanding. The gas product from biomass gasifiers contains quantities of particulates, tars, and other constituents that may exceed these specified limits. As a result, gas cleaning and conditioning will be required in most systems. Over the past decade, significant research and development activities have been conducted on the topic of gas cleanup and conditioning. This report provides an update of efforts related to large-scale biomass gasification systems and summarizes recent progress. Remaining research and development issues are also summarized.

  13. A CFD study of wave influence on film steam condensation in the presence of non-condensable gas

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianmao, E-mail: xm-wang11@mails.tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Chang, Huajian, E-mail: changhj@tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Corradini, Michael, E-mail: corradini@engr.wisc.edu [Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States)

    2016-08-15

    Highlights: • A condensation model is incorporated in the ANSYS FLUENT. • Different turbulence models are evaluated for flows over wavy surfaces. • Wavy surfaces with and without moving velocities are used to model the wave. • Various wavy surfaces with different wave heights and wavelengths are selected. • Wave influence on film steam condensation is investigated. - Abstract: Steam condensation plays an important role in removing heat from the containment of a nuclear plant during postulated accidents. However, due to the presence of non-condensable gases such as air and hydrogen in the containment, the condensation rate can decrease dramatically. Under certain conditions, the condensate film on the cold containment walls can affect the overall heat transfer rate. The wavy interface of the condensate film is a factor and is usually believed to enhance the condensation rate, since the waves can both increase the interfacial area and disturb the non-condensable gas boundary layer. However, it is not clear how to properly account for this factor and what is its quantitative influence in experiments. In this work, a CFD approach is applied to study the wave effects on film condensation in the presence of non-condensable gas. Wavy surfaces with and without moving velocities are used to replace the wavy interface of the falling film. A condensation model is incorporated in the ANSYS FLUENT simulation and a realizable k–ε turbulence model is applied. Various wavy surfaces with different wave heights and wavelengths are selected to conduct numerical experiments with a wide range of gas velocities. The results show that the wave structure can enhance condensation rate up to ten percent mainly due to the alteration of local flow structures in the gas phase. The increments of the condensation rate due to the wavy interface can vary with different gas velocities. The investigation shows that a multiplication factor accounts for the wave effects on film

  14. Numerical analysis and field study of time dependent exergy-energy of a gas-steam combined cycle

    Directory of Open Access Journals (Sweden)

    Barari Bamdad

    2012-01-01

    Full Text Available In this study, time dependent exergy analysis of the Fars Combined Power Plant Cycle has been investigated. Exergy analysis has been used for investigating each part of actual combined cycle by considering irreversibility from Apr 2006 to Oct 2010. Performance analysis has been done for each part by evaluating exergy destruction in each month. By using of exergy analysis, aging of each part has been evaluated respect to time duration. In addition, the rate of lost work for each month has been calculated and variation of this parameter has been considered as a function of aging rate. Finally, effects of exergy destruction of each part have been investigated on exergy destruction of whole cycle. Entire analysis has been done for Unit 3 and 4 of gas turbine cycle which combined by Unit B of steam cycle in Fars Combined Power Plant Cycle located in Fars province in Iran.

  15. Effect of technological deviation on aerodynamic efficiency of reaction blades of steam and gas turbines at high Mach nos

    International Nuclear Information System (INIS)

    Husain, Z.

    1991-01-01

    During manufacture and assembly of steam and gas turbine blades there are always some technological deviation and is meant local increase or decrease in dimension at certain sections of the profile improper stagger angle of long blades during assembly etc. In this paper the effect of oversize in dimensions at certain important places along a reaction profile has been studied. The technological deviation has been made by sticking thin aluminium foils of 0.3 mm thickness and 15 mm width at inlet and exit tips of reactive profiles and its effect on aerodynamic efficiency at mach. nos ranging from 0.7 to 1.1. The object of performing these tests was to obtain comprehensive data based on which information suitable tolerances could be recommended during manufacture of these blades

  16. Energetic use of renewable fuels. Logistics of energy carrier supply, technologies of usage, boundary conditions for economically efficient use of biomass. Proceedings; Energetische Nutzung nachwachsender Rohstoffe. Logistik der Energietraegerbereitstellung, Technologien der Energietraegernutzung, Rahmenbedingungen fuer den wirtschaftlichen Einsatz von Biomasse. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Authors of the conference reported on recent developments in utilization of renewable energy sources: resource potential of biomass, wood fuels, pollution limits, dedusting and purification of flue gas, heat recovery, straw combustion in small boilers, logistics and market of wood fuels, fluidized bed steam gasification, design of biomass-fueled power plants, organic Rankine cycle, operating experience in pilot plants. (uke)

  17. Review of the cost estimate and schedule for the 2240-MWt high-temperature gas-cooled reactor steam-cycle/cogeneration lead plant

    International Nuclear Information System (INIS)

    1983-09-01

    This report documents Bechtel's review of the cost estimate and schedule for the 2240 MWt High Temperature Gas-Cooled Reactor Steam Cycle/Cogeneration (HTGR-SC/C) Lead Plant. The overall objective of the review is to verify that the 1982 update of the cost estimate and schedule for the Lead Plant are reasonable and consistent with current power plant experience

  18. On the atomization and combustion of liquid biofuels in gas turbines: towards the application of biomass-derived pyrolysis oil

    NARCIS (Netherlands)

    Sallevelt, J.L.H.P.

    2015-01-01

    The combustion of liquid biofuels in gas turbines is an efficient way of generating heat and power from biomass. Gas turbines play a major role in the global energy supply and are suitable for a wide range of applications. However, biofuels generally have different properties compared to

  19. The Integration of Gasification Systems with Gas Engine by Developing Wet Tar Scrubbers and Gas Filter to Produce Electrical Energy from Biomass

    Directory of Open Access Journals (Sweden)

    Siregar Kiman

    2018-01-01

    Full Text Available The need for energy especially biomass-based renewable energy continues to increase in Indonesia. The objective of this research was to design downdraft gasifier machine with high content of combustible gas on gas engine. Downdraft gasifier machine was adjusted with the synthetic gas produced from biomass. Besides that, the net energy ratio, net energy balance, renewable index, economic analysis and impact assessment also been conducted. Gas engine that was designed in this research had been installed with capacity of 25 kW with diameter and height of reactorwere 900 mm and 1 000 mm respectively. The method used here werethe design the Detailed Engineering Design, assembly, and performance test of gas engine. The result showed that gas engine for biomass can be operated for 8 h with performance engine of 84 % and capacity of 25 kW. Net energy balance, net energy ratio, and renewable index was 30 MJ/kW h electric; 0.89; 0.76 respectively. The value of GHG emission of Biomass Power Generation is 0.03 kg-CO2 eq per MJ. Electrical production cost for Biomass Power Generation is about IDR 1 500 per kW h which is cheaper than solar power generation which is about of IDR 3 300 per kW h.

  20. Catalytic hydrothermal gasification of biomass for the production of synthetic natural gas[Dissertation 17100

    Energy Technology Data Exchange (ETDEWEB)

    Waldner, M H

    2007-07-01

    Energy from biomass is a CO{sub 2} neutral, sustainable form of energy. Anaerobic digestion is an established technology for converting biomass to biogas, which contains around 60% methane, besides CO{sub 2} and various contaminants. Most types of biomass contain material that cannot be digested; in woody biomass, this portion is particularly high. Therefore, conventional anaerobic digestion is not suited for the production of biogas from woody biomass. While wood is already being converted to energy by conventional thermal methods (gasification with subsequent methanation), dung, manure, and sewage sludge represent types of biomass whose energy potential remains largely untapped (present energetic use of manure in Switzerland: 0.4%). Conventional gas phase processes suffer from a low efficiency due to the high water content of the feed (enthalpy of vaporization). An alternative technology is the hydrothermal gasification: the water contained within the biomass serves as reaction medium, which at high pressures of around 30 MPa turns into a supercritical fluid that exhibits apolar properties. Under these conditions, tar precursors, which cause significant problems in conventional gasification, can be solubilized and gasified. The need to dry the biomass prior to gasification is obsolete, and as a consequence high thermal process efficiencies (65 - 70%) are possible. Due to their low solubility in supercritical water, the inorganics that are present in the biomass (up to 20 wt % of the dry matter of manure) can be separated and further used as fertilizer. The biomass is thus not only converted into an energy carrier, but it allows valuable substances contained in the biomass to be extracted and re-used. Furthermore, the process can be used for aqueous waste stream destruction. The aim of this project at the Paul Scherrer Institute was to develop a catalytic process that demonstrates the gasification of wet biomass to synthetic natural gas (SNG) in a continuously

  1. Respiratory involvements among women exposed to the smoke of traditional biomass fuel and gas fuel in a district of Bangladesh.

    Science.gov (United States)

    Alim, Md Abdul; Sarker, Mohammad Abul Bashar; Selim, Shahjada; Karim, Md Rizwanul; Yoshida, Yoshitoku; Hamajima, Nobuyuki

    2014-03-01

    Burning of biomass fuel (cow-dung, crop residue, dried leaves, wood, etc.) in the kitchen releases smoke, which may impair the respiratory functions of women cooking there. This paper aimed to compare the respiratory symptoms between biomass fuel users and gas fuel users in Bangladesh. A cross-sectional survey was conducted through face-to-face interviews and chest examination of 224 adult women using biomass fuel in a rural village and 196 adult women using gas fuel in an urban area. The prevalence of respiratory involvement (at least one among nine symptoms and two diseases) was significantly higher among biomass users than among gas users (29.9 vs. 11.2 %). After adjustment for potential confounders by a logistic model, the odds ratio (OR) of the biomass users for the respiratory involvement was significantly higher (OR = 3.23, 95 % confidence interval 1.30-8.01). The biomass fuel use elevated symptoms/diseases significantly; the adjusted OR was 3.04 for morning cough, 7.41 for nasal allergy, and 5.94 for chronic bronchitis. The mean peak expiratory flow rate of biomass users (253.83 l/min) was significantly lower than that of gas users (282.37 l/min). The study shows significant association between biomass fuel use and respiratory involvement among rural women in Bangladesh, although the potential confounding of urban/rural residency could not be ruled out in the analysis. The use of smoke-free stoves and adequate ventilation along with health education to the rural population to increase awareness about the health effects of indoor biomass fuel use might have roles to prevent these involvements.

  2. Life cycle assessment of biomass-to-energy systems in Ireland modelled with biomass supply chain optimisation based on greenhouse gas emission reduction

    International Nuclear Information System (INIS)

    Murphy, Fionnuala; Sosa, Amanda; McDonnell, Kevin; Devlin, Ger

    2016-01-01

    The energy sector is the major contributor to GHG (greenhouse gas emissions) in Ireland. Under EU Renewable energy targets, Ireland must achieve contributions of 40%, 12% and 10% from renewables to electricity, heat and transport respectively by 2020, in addition to a 20% reduction in GHG emissions. Life cycle assessment methodology was used to carry out a comprehensive, holistic evaluation of biomass-to-energy systems in 2020 based on indigenous biomass supply chains optimised to reduce production and transportation GHG emissions. Impact categories assessed include; global warming, acidification, eutrophication potentials, and energy demand. Two biomass energy conversion technologies are considered; co-firing with peat, and biomass CHP (combined heat and power) systems. Biomass is allocated to each plant according to a supply optimisation model which ensures minimal GHG emissions. The study shows that while CHP systems produce lower environmental impacts than co-firing systems in isolation, determining overall environmental impacts requires analysis of the reference energy systems which are displaced. In addition, if the aims of these systems are to increase renewable energy penetration in line with the renewable electricity and renewable heat targets, the optimal scenario may not be the one which achieves the greatest environmental impact reductions. - Highlights: • Life cycle assessment of biomass co-firing and CHP systems in Ireland is carried out. • GWP, acidification and eutrophication potentials, and energy demand are assessed. • Biomass supply is optimised based on minimising GHG emissions. • CHP systems cause lower environmental impacts than biomass co-firing with peat. • Displacing peat achieves higher GHG emission reductions than replacing fossil heat.

  3. Steampunk: Full Steam Ahead

    Science.gov (United States)

    Campbell, Heather M.

    2010-01-01

    Steam-powered machines, anachronistic technology, clockwork automatons, gas-filled airships, tentacled monsters, fob watches, and top hats--these are all elements of steampunk. Steampunk is both speculative fiction that imagines technology evolved from steam-powered cogs and gears--instead of from electricity and computers--and a movement that…

  4. Thermodynamic model of a diesel engine to work with gas produced from biomass gasification

    International Nuclear Information System (INIS)

    Lesme Jaén, René; Silva Jardines, Fernando; Rodríguez Ortíz, Leandro Alexei; García Faure, Luis Gerónimo; Peralta Campos, Leonel Grave de; Oliva Ruiz, Luis; Iglesias Vaillant, Yunier

    2017-01-01

    The poor gas, obtained from the gasification of the biomass with air, has a high content of volatile substances, high stability to the ignition and can be used in internal combustion engines. In the present work the results of a thermodynamic model for a Diesel engine AshokLeyland, installed in 'El Brujo' sawmill of the Gran Piedra Baconao Forestry Company of Santiago de Cuba. From the composition and the combustion equation of the poor gas, the thermodynamic cycle calculation and the energy balance of the engine for different loads. Cycle parameters, fuel air ratio, CO2 emissions, engine power and performance were determined. As the main result of the work, the engine had an effective efficiency of 22.3%, consumed 3605.5 grams of fuel / KWh and emits 2055 grams of CO2 / kWh. (author)

  5. Combustion gas from biomass - innovative plant concepts on the basis of circulating fluidized bed gasification; Brenngas aus Biomasse - innovative Anlagenkonzepte auf Basis der Zirkulierenden Wirbelschichtvergasung

    Energy Technology Data Exchange (ETDEWEB)

    Greil, C; Hirschfelder, H [Lurgi Umwelt GmbH, Frankfurt am Main (Germany)

    1998-09-01

    The contribution describes the applications of the Lurgi-ZWS gas generator. There are three main fields of application: Direct feeding of combustion gas, e.g. into a rotary kiln, as a substitute for coal or oil, without either dust filtering or gas purification. - Feeding of the combustion gas into the steam generator of a coal power plant after dust filtering and, if necessar, filtering of NH{sub 3} or H{sub 2}S. - Combustion in a gas turbine or gas engine after gas purification according to specifications. The applications are described for several exemplary projects. (orig./SR) [Deutsch] Im folgenden wird ueber die Anwendung des Lurgi-ZWS-Gaserzeugers berichtet. Nach heutiger Sicht stehen drei Anwendungsgebiete im Vordergrund: - direkte Einspeisung des Brenngases in z.B. einen Zementdrehrohrofen zur Substitution von Kohle oder Oel, ohne Entstaubung und Gasreinigung. - Einspeisung des Brenngases nach Entstaubung und gegebenenfalls Entfernung weiterer Komponenten wie NH{sub 3} oder H{sub 2}S in den Dampferzeuger eines Kohlekraftwerkes - Einsatz des Brenngases in einer Gasturbine oder Gasmotor nach spezifikationsgerechter Gasreinigung. Die aufgefuehrten Einsatzmoeglichkeiten werden am Beispiel von Projekten beschrieben. (orig./SR)

  6. Thermodynamic simulation of a multi-step externally fired gas turbine powered by biomass

    International Nuclear Information System (INIS)

    Durante, A.; Pena-Vergara, G.; Curto-Risso, P.L.; Medina, A.; Calvo Hernández, A.

    2017-01-01

    Highlights: • A realistic model for an EFGT fueled with solid biomass is presented. • Detailed submodels for the HTHE and the chemical reactions are incorporated. • An arbitrary number of compression and expansion stages is considered. • Model validation leads to good agreement with experimental results. • A layout with two-stage compression leads to good efficiencies and power output. - Abstract: A thermodynamic model for a realistic Brayton cycle, working as an externally fired gas turbine fueled with biomass is presented. The use of an external combustion chamber, allows to burn dirty fuels to preheat pure air, which is the working fluid for the turbine. It also avoids direct contact of ashes with the turbine blades, resulting in a higher life cycle for the turbine. The model incorporates a high temperature heat exchanger and an arbitrary number of turbines and compressors, with the corresponding number of intercoolers and reheaters. It considers irreversibilities such as non-isentropic compressions and expansions, and pressure losses in heat input and release. The composition and temperature of the combustion gases, as well as the variable flow rate of air and combustion gases, are calculated for specific biomasses. The numerical model for a single stage configuration has been validated by comparing its predictions with the data sheets of two commercial turbines. Results are in good agreement. Curves on the dependence of thermal efficiency and power output with the overall pressure ratio will be shown for several plant configurations with variable number of compression/expansion stages. Also the influence of different types of biomasses and their moisture will be analyzed on parameters such as fuel consumption and exhaust gases temperature. For a single step plant layout fueled with eucalyptus wood an efficiency of 23% is predicted, whereas for a configuration with two compressors and one turbine efficiency increases up to 25%. But it is remarkable

  7. Biomass use, production, feed efficiencies, and greenhouse gas emissions from global livestock systems

    Science.gov (United States)

    Herrero, Mario; Havlík, Petr; Valin, Hugo; Notenbaert, An; Rufino, Mariana C.; Thornton, Philip K.; Blümmel, Michael; Weiss, Franz; Grace, Delia; Obersteiner, Michael

    2013-01-01

    We present a unique, biologically consistent, spatially disaggregated global livestock dataset containing information on biomass use, production, feed efficiency, excretion, and greenhouse gas emissions for 28 regions, 8 livestock production systems, 4 animal species (cattle, small ruminants, pigs, and poultry), and 3 livestock products (milk, meat, and eggs). The dataset contains over 50 new global maps containing high-resolution information for understanding the multiple roles (biophysical, economic, social) that livestock can play in different parts of the world. The dataset highlights: (i) feed efficiency as a key driver of productivity, resource use, and greenhouse gas emission intensities, with vast differences between production systems and animal products; (ii) the importance of grasslands as a global resource, supplying almost 50% of biomass for animals while continuing to be at the epicentre of land conversion processes; and (iii) the importance of mixed crop–livestock systems, producing the greater part of animal production (over 60%) in both the developed and the developing world. These data provide critical information for developing targeted, sustainable solutions for the livestock sector and its widely ranging contribution to the global food system. PMID:24344273

  8. Thermoeconomic analysis of Biomass Integrated Gasification Gas Turbine Combined Cycle (BIG GT CC) cogeneration plant

    Energy Technology Data Exchange (ETDEWEB)

    Arrieta, Felipe Raul Ponce; Lora, Electo Silva [Escola Federal de Engenharia de Itajuba, MG (Brazil). Nucleo de Estudos de Sistemas Termicos]. E-mails: aponce@iem.efei.br; electo@iem.efei.br; Perez, Silvia Azucena Nebra de [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mail: sanebra@fem. unicamp.br

    2000-07-01

    Using thermoeconomics as a tool to identify the location and magnitude of the real thermodynamic losses (energy waste, or exergy destruction and exergy losses) it is possible to assess the production costs of each product (electric power and heat) and the exergetic and exergoeconomic cost of each flow in a cogeneration plant to assist in decision-marketing procedures concerning to plant design, investment, operation and allocations of research funds. Thermo economic analysis of Biomass Integrated Gasification Gas Turbine Combined Cycle (BIG GT CC) cogeneration plant for its applications in sugar cane mills brings the following results: the global exergetic efficiency is low; the highest irreversibilities occur in the following equipment, by order: scrubber (38%), gas turbine (16%), dryer (12%), gasifier and HRSG (6%); due to the adopted cost distribution methodology, the unit exergetic cost of the heat (4,11) is lower than electricity (4,71); the lower market price of biomass is one of the most sensible parameter in the possible implementation of BIG-GT technology in sugar cane industry; the production costs are 31 US$/MWh and 32 US$/MWh for electricity and heat, respectively. The electricity cost is, after all, competitive with the actual market price. The electricity and heat costs are lower or almost equal than other values reported for actual Rankine cycle cogeneration plants. (author)

  9. Use of biomass sorbents for oil removal from gas station runoff.

    Science.gov (United States)

    Khan, Eakalak; Virojnagud, Wanpen; Ratpukdi, Thunyalux

    2004-11-01

    The use of biomass sorbents, which are less expensive and more biodegradable than synthetic sorbents, for oil removal from gas station runoff was investigated. A bench-scale flume experiment was conducted to evaluate the oil removal and retention capabilities of the biomass sorbents which included kapok fiber, cattail fiber, Salvinia sp., wood chip, rice husk, coconut husk, and bagasse. Polyester fiber, a commercial synthetic sorbent, was also experimented for comparison purpose. Oil sorption and desorption tests were performed at a water flow rate of 20 lmin-1. In the oil sorption tests, a 50 mgl(-1) of used engine oil-water mixture was synthesized to simulate the gas station runoff. The mass of oil sorbed for all sorbents, except coconut husk and bagasse, was greater than 70%. Cattail fiber and polyester fiber were the sorbents that provided the least average effluent oil concentrations. Oil selectivity (hydrophobic properties) and physical characteristics of the sorbents are the two main factors that influence the oil sorption capability. The used sorbents from the sorption tests were employed in the desorption tests. Results indicated that oil leached out of all the sorbents tested. Polyester fiber released the highest amount of oil, approximately 4% (mass basis) of the oil sorbed. copyright 2004 Elsevier Ltd.

  10. Biomass use, production, feed efficiencies, and greenhouse gas emissions from global livestock systems.

    Science.gov (United States)

    Herrero, Mario; Havlík, Petr; Valin, Hugo; Notenbaert, An; Rufino, Mariana C; Thornton, Philip K; Blümmel, Michael; Weiss, Franz; Grace, Delia; Obersteiner, Michael

    2013-12-24

    We present a unique, biologically consistent, spatially disaggregated global livestock dataset containing information on biomass use, production, feed efficiency, excretion, and greenhouse gas emissions for 28 regions, 8 livestock production systems, 4 animal species (cattle, small ruminants, pigs, and poultry), and 3 livestock products (milk, meat, and eggs). The dataset contains over 50 new global maps containing high-resolution information for understanding the multiple roles (biophysical, economic, social) that livestock can play in different parts of the world. The dataset highlights: (i) feed efficiency as a key driver of productivity, resource use, and greenhouse gas emission intensities, with vast differences between production systems and animal products; (ii) the importance of grasslands as a global resource, supplying almost 50% of biomass for animals while continuing to be at the epicentre of land conversion processes; and (iii) the importance of mixed crop–livestock systems, producing the greater part of animal production (over 60%) in both the developed and the developing world. These data provide critical information for developing targeted, sustainable solutions for the livestock sector and its widely ranging contribution to the global food system.

  11. Biomass gasification for energy production

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  12. Biomass gasification for energy production

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

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

  13. Minimization of steam requirements and enhancement of water-gas shift reaction with warm gas temperature CO2 removal

    Science.gov (United States)

    Siriwardane, Ranjani V; Fisher, II, James C

    2013-12-31

    The disclosure utilizes a hydroxide sorbent for humidification and CO.sub.2 removal from a gaseous stream comprised of CO and CO.sub.2 prior to entry into a water-gas-shift reactor, in order to decrease CO.sub.2 concentration and increase H.sub.2O concentration and shift the water-gas shift reaction toward the forward reaction products CO.sub.2 and H.sub.2. The hydroxide sorbent may be utilized for absorbtion of CO.sub.2 exiting the water-gas shift reactor, producing an enriched H.sub.2 stream. The disclosure further provides for regeneration of the hydroxide sorbent at temperature approximating water-gas shift conditions, and for utilizing H.sub.2O product liberated as a result of the CO.sub.2 absorption.

  14. An Effective Continuum Model for the Gas Evolution in Internal Steam Drives

    Energy Technology Data Exchange (ETDEWEB)

    Tsimpanogiannis, Ioannis N.; Yortsos, Yanis C.

    2002-06-11

    This report examines the gas phase growth from a supersaturated, slightly compressible, liquid in a porous medium, driven by heat transfer and controlled by the application of a constant-rate decline of the system pressure.

  15. The impact of dry matter loss during herbaceous biomass storage on net greenhouse gas emissions from biofuels production

    International Nuclear Information System (INIS)

    Emery, Isaac R.; Mosier, Nathan S.

    2012-01-01

    Life cycle inventory models of greenhouse gas emissions from biofuel production have become tightly integrated into government mandates and other policies to encourage biofuel production. Current models do not include life cycle impacts of biomass storage or reflect current literature on emissions from soil and biomass decomposition. In this study, the GREET model framework was used to determine net greenhouse gas emissions during ethanol production from corn and switchgrass via three biomass storage systems: wet ensiling of whole corn, and indoor and outdoor dry bale storage of corn stover and switchgrass. Dry matter losses during storage were estimated from the literature and used to modify GREET inventory analysis. Results showed that biomass stability is a key parameter affecting fuel production per farmed hectare and life cycle greenhouse gas emissions. Corn silage may generate 5358 L/ha of ethanol at 26.5 g CO 2 eq/MJ, relative to 5654 L/ha at 52.3 g CO 2 eq/MJ from combined corn stover and conventional grain corn ethanol production, or 3919 L/ha at 21.3 g CO 2 eq/MJ from switchgrass. Dry matter losses can increase net emissions by 3–25% (ensiling), 5–53% (bales outdoors), or 1–12% (bales indoors), decreasing the net GHG reduction of ethanol over gasoline by up to 10.9%. Greater understanding of biomass storage losses and greenhouse gas fluxes during storage is necessary to accurately assess biomass storage options to ensure that the design of biomass supply logistics systems meet GHG reduction mandates for biofuel production. -- Highlights: ► Analyzed the impact of biomass loss during storage. ► Probable dry matter losses strongly depend on storage method and infrastructure. ► Assessed impact of storage losses on LCA for cellulosic ethanol production. ► Storage losses increase GHG emissions by 1–53% depending upon storage conditions.

  16. Determining greenhouse gas balances of biomass fuel cycles. Results to date from task 15 of IEA bio-energy

    International Nuclear Information System (INIS)

    Schlamadinger, B.; Spitzer, J.

    1997-01-01

    Selected activities of IEA Bio-energy Task 15 are described. Task 15 of IEA Bio-energy, entitled 'Greenhouse Gas Balances of Bio-energy Systems', aims at investigating processes involved in the use of bio-energy systems on a full fuel-cycle basis to establish overall greenhouse gas balances. The work of Task 15 includes, among other things, a compilation of existing data on greenhouse gas emissions from various biomass production and conversion processes, a standard methodology for greenhouse gas balances of bio-energy systems, a bibliography, and recommendations for selection of appropriate national strategies for greenhouse gas mitigation. (K.A.)

  17. Effects of Irrigating with Treated Oil and Gas Product Water on Crop Biomass and Soil Permeability

    Energy Technology Data Exchange (ETDEWEB)

    Terry Brown; Jeffrey Morris; Patrick Richards; Joel Mason

    2010-09-30

    Demonstrating effective treatment technologies and beneficial uses for oil and gas produced water is essential for producers who must meet environmental standards and deal with high costs associated with produced water management. Proven, effective produced-water treatment technologies coupled with comprehensive data regarding blending ratios for productive long-term irrigation will improve the state-of-knowledge surrounding produced-water management. Effective produced-water management scenarios such as cost-effective treatment and irrigation will discourage discharge practices that result in legal battles between stakeholder entities. The goal of this work is to determine the optimal blending ratio required for irrigating crops with CBNG and conventional oil and gas produced water treated by ion exchange (IX), reverse osmosis (RO), or electro-dialysis reversal (EDR) in order to maintain the long term physical integrity of soils and to achieve normal crop production. The soils treated with CBNG produced water were characterized with significantly lower SAR values compared to those impacted with conventional oil and gas produced water. The CBNG produced water treated with RO at the 100% treatment level was significantly different from the untreated produced water, while the 25%, 50% and 75% water treatment levels were not significantly different from the untreated water. Conventional oil and gas produced water treated with EDR and RO showed comparable SAR results for the water treatment technologies. There was no significant difference between the 100% treated produced water and the control (river water). The EDR water treatment resulted with differences at each level of treatment, which were similar to RO treated conventional oil and gas water. The 100% treated water had SAR values significantly lower than the 75% and 50% treatments, which were similar (not significantly different). The results of the greenhouse irrigation study found the differences in biomass

  18. 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.

  19. Stepping on the gas for district heating in Germany. Gas and steam turbines for cogeneration; Gas geben fuer Fernwaerme in Deutschland. Gas- und Dampfturbinen fuer die KWK

    Energy Technology Data Exchange (ETDEWEB)

    Bohtz, Christian [Alstom Power, Baden (Switzerland). Marketing and Product Management Gas Business

    2011-07-15

    Measured by its intensive efforts to lower CO{sub 2} emissions Germany is one of the leading countries in the EU. One contribution to this end is to be had from cogeneration. As a provider of cogeneration plants Alstom is working to improve the fuel efficiency as well as the overall efficiency and flexibility of its products. The author explains the technology of gas-fired cogeneration plants and gives three examples of their use.

  20. High-temperature gas-cooled reactor steam cycle/cogeneration: lead project strategy plan

    International Nuclear Information System (INIS)

    1982-07-01

    The strategy, contained herein, for developing the HTGR system and introducing it into the energy marketplace is based on using the most developed technology path to establish a HTGR-Steam Cycle/Cogeneration (SC/C) Lead Project. Given the status of the HTGR-SC/C technology, a Lead Plant could be completed and operational by the mid 1990s. While there is remaining design and technology development that must be accomplished to fulfill technical and licensing requirements for a Lead Project commitment, the major barriers to the realization a HTGR-SC/C Lead Project are institutional in nature, e.g. budget priorities and constraints, cost/risk sharing between the public and private sector, Project organization and management, and Project financing. These problems are further complicated by the overall pervading issues of economic and regulatory instability that presently confront the utility and nuclear industries. This document addresses the major institutional issues associated with the HTGR-SC/C Lead Project and provides a starting point for discussions between prospective Lead Project participants toward the realization of such a Project

  1. A generic model for estimating biomass accumulation and greenhouse gas emissions from perennial crops

    Science.gov (United States)

    Ledo, Alicia; Heathcote, Richard; Hastings, Astley; Smith, Pete; Hillier, Jonathan

    2017-04-01

    Agriculture is essential to maintain humankind but is, at the same time, a substantial emitter of greenhouse gas (GHG) emissions. With a rising global population, the need for agriculture to provide secure food and energy supply is one of the main human challenges. At the same time, it is the only sector which has significant potential for negative emissions through the sequestration of carbon and offsetting via supply of feedstock for energy production. Perennial crops accumulate carbon during their lifetime and enhance organic soil carbon increase via root senescence and decomposition. However, inconsistency in accounting for this stored biomass undermines efforts to assess the benefits of such cropping systems when applied at scale. A consequence of this exclusion is that efforts to manage this important carbon stock are neglected. Detailed information on carbon balance is crucial to identify the main processes responsible for greenhouse gas emissions in order to develop strategic mitigation programs. Perennial crops systems represent 30% in area of total global crop systems, a considerable amount to be ignored. Furthermore, they have a major standing both in the bioenergy and global food industries. In this study, we first present a generic model to calculate the carbon balance and GHGs emissions from perennial crops, covering both food and bioenergy crops. The model is composed of two simple process-based sub-models, to cover perennial grasses and other perennial woody plants. The first is a generic individual based sub-model (IBM) covering crops in which the yield is the fruit and the plant biomass is an unharvested residue. Trees, shrubs and climbers fall into this category. The second model is a generic area based sub-model (ABM) covering perennial grasses, in which the harvested part includes some of the plant parts in which the carbon storage is accounted. Most second generation perennial bioenergy crops fall into this category. Both generic sub

  2. Biomass energy conversion: conventional and advanced technologies

    Energy Technology Data Exchange (ETDEWEB)

    Young, B C; Hauserman, W B [Energy and Environmental Research Center, University of North Dakota, Grand Forks, ND (United States)

    1995-12-01

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

  3. Biomass energy conversion: conventional and advanced technologies

    International Nuclear Information System (INIS)

    Young, B.C.; Hauserman, W.B.

    1995-01-01

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

  4. Power generation from a 7700C heat source by means of a main steam cycle, a topping closed gas cycle and a ammonia bottoming cycle

    International Nuclear Information System (INIS)

    Tilliette, Z.P.

    1981-03-01

    For power generation, steam cycles make an efficient use of medium temperature heat sources. They can be adapted to dry cooling, higher power ratings and output increase in winter by addition of an ammonia bottoming cycle. Active development is carried out in this field by 'Electricite de France'. As far as heat sources at higher temperatures are concerned, particularly related to coal-fired or nuclear power plants, a more efficient way of converting energy is at first to expand a hot working fluid through a gas turbine. It is shown in this paper that a satisfactory result, for heat sources of about 770 0 C, is obtained with a topping closed gas cycle of moderate power rating, rejecting its waste heat into the main steam cycle. Attention has to be paid to this gas cycle waste heat recovery and to the coupling of the gas and steam cycles. This concept drastically reduces the importance of new technology components. The use and the significance of an ammonia bottoming cycle in this case are investigated

  5. Cleaning of biomass derived product gas for engine applications and for co-firing in PC-boilers

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-01

    The main constituents rendering the engine use of gas produced from biomass are the tar content of the gases (condensing hydrocarbons), which cause problems for pipings, nozzles, and control of combustion. Purification methods, based on catalytic cracking of tars are investigated in the research in order to eliminate these problems. The target of the project is to demonstrate the developed gasification/gas purification process with engine test using PDU-scale equipment. Impurities of biomasses and biomass wastes (alkalis, chlorine, heavy metals), and the ash melting properties restrict in many cases the combined utilisation of biomasses and coal in power plant boilers. The second main task of this research is to investigate the removal of the problematic gas and ash components from the product gas. The sufficient degree of purification should be achieved by as simple and as cheap purification methods as possible. The main tasks of the first year of the project were (a) determination of the dimensioning characteristics of ambient pressure PDU scale cell-catalyst reactor (tests with laboratory-scale equipment), designing and construction of the reactor, (b) to investigate the operation of a cell-catalyst in purification of pre-cracked down-draft gasification gas, (c) acquisition of dimensioning data for dolomite-cracker based on fluidized bed principle, and (d) gasification of the Dutch building demolition waste and Danish straw, and the purification tests with the gases

  6. Status on the Component Models Developed in the Modelica Framework: High-Temperature Steam Electrolysis Plant & Gas Turbine Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Suk Kim, Jong [Idaho National Lab. (INL), Idaho Falls, ID (United States); McKellar, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bragg-Sitton, Shannon M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Boardman, Richard D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-10-01

    This report has been prepared as part of an effort to design and build a modeling and simulation (M&S) framework to assess the economic viability of a nuclear-renewable hybrid energy system (N-R HES). In order to facilitate dynamic M&S of such an integrated system, research groups in multiple national laboratories have been developing various subsystems as dynamic physics-based components using the Modelica programming language. In fiscal year (FY) 2015, Idaho National Laboratory (INL) performed a dynamic analysis of two region-specific N-R HES configurations, including the gas-to-liquid (natural gas to Fischer-Tropsch synthetic fuel) and brackish water reverse osmosis desalination plants as industrial processes. In FY 2016, INL has developed two additional subsystems in the Modelica framework: a high-temperature steam electrolysis (HTSE) plant and a gas turbine power plant (GTPP). HTSE has been proposed as a high priority industrial process to be integrated with a light water reactor (LWR) in an N-R HES. This integrated energy system would be capable of dynamically apportioning thermal and electrical energy (1) to provide responsive generation to the power grid and (2) to produce alternative industrial products (i.e., hydrogen and oxygen) without generating any greenhouse gases. A dynamic performance analysis of the LWR/HTSE integration case was carried out to evaluate the technical feasibility (load-following capability) and safety of such a system operating under highly variable conditions requiring flexible output. To support the dynamic analysis, the detailed dynamic model and control design of the HTSE process, which employs solid oxide electrolysis cells, have been developed to predict the process behavior over a large range of operating conditions. As first-generation N-R HES technology will be based on LWRs, which provide thermal energy at a relatively low temperature, complementary temperature-boosting technology was suggested for integration with the

  7. Gas treatment in trickle-bed biofilters: biomass, how much is enough?

    Science.gov (United States)

    Alonso, C; Suidan, M T; Sorial, G A; Smith, F L; Biswas, P; Smith, P J; Brenner, R C

    1997-06-20

    The objective of this article is to define and validate a mathematical model that desribes the physical and biological processes occurring in a trickle-bed air biofilter for waste gas treatment. This model considers a two-phase system, quasi-steady-state processes, uniform bacterial population, and one limiting substrate. The variation of the specific surface area with bacterial growth is included in the model, and its effect on the biofilter performance is analyzed. This analysis leads to the conclusion that excessive accumulation of biomass in the reactor has a negative effect on contaminant removal efficiency. To solve this problem, excess biomass is removed via full media fluidization and backwashing of the biofilter. The backwashing technique is also incorporated in the model as a process variable. Experimental data from the biodegradation of toluene in a pilot system with four packed-bed reactors are used to validate the model. Once the model is calibrated with the estimation of the unknown parameters of the system, it is used to simulate the biofilter performance for different operating conditions. Model predictions are found to be in agreement with experimental data. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 54: 583-594, 1997.

  8. Insights into pyrolysis and co-pyrolysis of biomass and polystyrene: Thermochemical behaviors, kinetics and evolved gas analysis

    International Nuclear Information System (INIS)

    Özsin, Gamzenur; Pütün, Ayşe Eren

    2017-01-01

    Highlights: • TGA/MS/FT-IR was used to explore effect of polystyrene on pyrolytic decomposition of biomass. • The model-free iso-conversional methods were used for kinetic analysis. • Interactions occurred depending on the characteristics of the biomass. • TGA/MS and TGA/FT-IR coupling were used for gas analysis of co-pyrolysis for the first time. - Abstract: The purpose of this study was to investigate the effect on polystyrene (PS) during co-pyrolysis with biomass through thermal decomposition. The model-free iso-conversional methods (Kissinger, Friedman, Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, Starink and Vyazovkin) were adopted to calculate activation energy of the pyrolysis and co-pyrolysis process of two biomass samples (walnut shell: WS and peach stones: PST) with PS. It is found that biomass blending to PS decreased activation energy values and resulted in multi-step reaction mechanisms. Furthermore, changes in the evolution profiles of methyl, water, methoxy, carbon dioxide, benzene and styrene was monitored through evolved gas analysis via TGA/FT-IR and TGA/MS. Detection of temperature dependent release of volatiles indicated the differences occur as a result of compositional differences of biomass.

  9. Method to produce combustible gas with low tar content out of biomass. Foerfarande foer att ur biomassa framstaella en tjaerfattig braennbar gas

    Energy Technology Data Exchange (ETDEWEB)

    Lindman, N

    1988-01-11

    The gas is led in a controlled flow to a vertical reactor shaft with a circulating fluidized bed containing dispersed calcined limestone. The biomass is pyrolyzed by means of the reactor heat in order to produce tarry gas and charcoal. While the gas flows upward in the reactor shaft the tar is gasified in a heterogeneous catalytic reaction with limestone. Charcoal and limestone are separated from the gas at the top of the reactor shaft and brought back to the fluidized bed for combustion. (L.F.).

  10. Hydrogen-based power generation from bioethanol steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Tasnadi-Asztalos, Zs., E-mail: tazsolt@chem.ubbcluj.ro; Cormos, C. C., E-mail: cormos@chem.ubbcluj.ro; Agachi, P. S. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos, Postal code: 400028, Cluj-Napoca (Romania)

    2015-12-23

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO{sub 2} emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  11. Hydrogen-based power generation from bioethanol steam reforming

    International Nuclear Information System (INIS)

    Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

    2015-01-01

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO 2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint

  12. Hydrogen-based power generation from bioethanol steam reforming

    Science.gov (United States)

    Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

    2015-12-01

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  13. Biogas from lignocellulosic biomass

    Energy Technology Data Exchange (ETDEWEB)

    Berglund Odhner, Peter; Schabbauer, Anna [Grontmij AB, Stockholm (Sweden); Sarvari Horvath, Ilona; Mohseni Kabir, Maryam [Hoegskolan i Boraas, Boraas (Sweden)

    2012-01-15

    Grontmij AB has cooperated with the University of Boraas to evaluate the technological and economical possibilities for biogas production from substrates containing lignocellulose, such as forest residues, straw and paper. The state of knowledge regarding biogas production from cellulosic biomass has been summarized. The research in the field has been described, especially focusing on pretreatment methods and their results on increased gas yields. An investigation concerning commercially available pretreatment methods and the cost of these technologies has been performed. An economic evaluation of biogas production from lignocellulosic materials has provided answers to questions regarding the profitability of these processes. Pretreatment with steam explosion was economically evaluated for three feedstocks - wood, straw and paper - and a combination of steam explosion and addition of NaOH for paper. The presented costs pertain to costs for the pretreatment step as it, in this study, was assumed that the pretreatment would be added to an existing plant and the lignocellulosic substrates would be part of a co-digestion process. The results of the investigation indicate that it is difficult to provide a positive net result when comparing the cost of pretreatment versus the gas yield (value) for two of the feedstocks - forest residues and straw. This is mainly due to the high cost of the raw material. For forest residues the steam pretreatment cost exceeded the gas yield by over 50 %, mainly due to the high cost of the raw material. For straw, the production cost was similar to the value of the gas. Paper showed the best economic result. The gas yield (value) for paper exceeded the pretreatment cost by 15 %, which makes it interesting to study paper further.

  14. ALTENER - Biomass event in Finland

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

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

  15. ALTENER - Biomass event in Finland

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

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

  16. Reducing life cycle greenhouse gas emissions of corn ethanol by integrating biomass to produce heat and power at ethanol plants

    International Nuclear Information System (INIS)

    Kaliyan, Nalladurai; Morey, R. Vance; Tiffany, Douglas G.

    2011-01-01

    A life-cycle assessment (LCA) of corn ethanol was conducted to determine the reduction in the life-cycle greenhouse gas (GHG) emissions for corn ethanol compared to gasoline by integrating biomass fuels to replace fossil fuels (natural gas and grid electricity) in a U.S. Midwest dry-grind corn ethanol plant producing 0.19 hm 3 y -1 of denatured ethanol. The biomass fuels studied are corn stover and ethanol co-products [dried distillers grains with solubles (DDGS), and syrup (solubles portion of DDGS)]. The biomass conversion technologies/systems considered are process heat (PH) only systems, combined heat and power (CHP) systems, and biomass integrated gasification combined cycle (BIGCC) systems. The life-cycle GHG emission reduction for corn ethanol compared to gasoline is 38.9% for PH with natural gas, 57.7% for PH with corn stover, 79.1% for CHP with corn stover, 78.2% for IGCC with natural gas, 119.0% for BIGCC with corn stover, and 111.4% for BIGCC with syrup and stover. These GHG emission estimates do not include indirect land use change effects. GHG emission reductions for CHP, IGCC, and BIGCC include power sent to the grid which replaces electricity from coal. BIGCC results in greater reductions in GHG emissions than IGCC with natural gas because biomass is substituted for fossil fuels. In addition, underground sequestration of CO 2 gas from the ethanol plant's fermentation tank could further reduce the life-cycle GHG emission for corn ethanol by 32% compared to gasoline.

  17. Study on waste heat recovery from exhaust gas spark ignition (S.I. engine using steam turbine mechanism

    Directory of Open Access Journals (Sweden)

    Talib Kamarulhelmy

    2017-01-01

    Full Text Available The issue of global warming has pushed the effort of researchers not only to find alternative renewable energy, but also to improve the machine’s energy efficiency. This includes the utilization of waste energy into ‘useful energy’. For a vehicle using internal combustion engine (ICE, the waste energy produce by exhaust gas can be utilize to ‘useful energy’ up to 34%. The energy from the automotive exhaust can be harness by implementing heat pipe heat exchanger in the automotive system. In order to maximize the amount of waste energy that can be turned to ‘useful energy’, the used of appropriate fluid in the heat exchanger is important. In this study, the fluid used is water, thus converting the fluid into steam and thus drive the turbine that coupling with generator. The paper will explore the performance of a naturally aspirated spark ignition (S.I. engine equipped with waste heat recovery mechanism (WHRM that used water as the heat absorption medium. The experimental and simulation test suggest that the concept is thermodynamically feasible and could significantly enhance the system performance depending on the load applied to the engine.

  18. The use of flue gas for the growth of microalgal biomass

    International Nuclear Information System (INIS)

    Zeiler, K.G.; Kadam, K.L.; Heacox, D.A.

    1995-01-01

    Capture and utilization of carbon dioxide (CO 2 ) by microalgae is a promising technology to help reduce emissions from fossil fuel-fired power plants. Microalgae are of particular interest because of their rapid growth rates and tolerance to varying environmental conditions. Laboratory work is directed toward investigating the effects of simulated flue gas on microalgae, while engineering studies have focused on the economics of the technology. One strain of a green algae, Monoraphidium minutum, has shown excellent tolerance and growth when exposed to simulated flue gas which meets the requirements of the 1990 Clean Air Act Amendments (1990 CAAA). Biomass concentrations of ∼2g/L have been measured in batch culture. Several other microalgae have also shown tolerance to simulated flue gas; however, the growth of these strains is not equivalent to that observed for M. minutum. Coupling the production of biodiesel or other microalgae-derived commodity chemicals with the use of flue gas carbon dioxide is potentially a zero-cost method of reducing the amount of carbon dioxide contributed to the atmosphere by fossil fuel-fired power plants. We have identified two major biological performance parameters which can provide sufficient improvement in this technology to render it cost-competitive with other existing CO x mitigation technologies. These are algal growth rate and lipid content. An updated economic analysis shows that growth rate is the more important of the two, and should be the focus of near term research activities. The long term goal of achieving zero cost will require other, non-biological, improvements in the process

  19. The use of flue gas for the growth of microalgal biomass

    Energy Technology Data Exchange (ETDEWEB)

    Zeiler, K.G.; Kadam, K.L.; Heacox, D.A. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1995-11-01

    Capture and utilization of carbon dioxide (CO{sub 2}) by microalgae is a promising technology to help reduce emissions from fossil fuel-fired power plants. Microalgae are of particular interest because of their rapid growth rates and tolerance to varying environmental conditions. Laboratory work is directed toward investigating the effects of simulated flue gas on microalgae, while engineering studies have focused on the economics of the technology. One strain of a green algae, Monoraphidium minutum, has shown excellent tolerance and growth when exposed to simulated flue gas which meets the requirements of the 1990 Clean Air Act Amendments (1990 CAAA). Biomass concentrations of {similar_to}2g/L have been measured in batch culture. Several other microalgae have also shown tolerance to simulated flue gas; however, the growth of these strains is not equivalent to that observed for M. minutum. Coupling the production of biodiesel or other microalgae-derived commodity chemicals with the use of flue gas carbon dioxide is potentially a zero-cost method of reducing the amount of carbon dioxide contributed to the atmosphere by fossil fuel-fired power plants. We have identified two major biological performance parameters which can provide sufficient improvement in this technology to render it cost-competitive with other existing CO{sub x} mitigation technologies. These are algal growth rate and lipid content. An updated economic analysis shows that growth rate is the more important of the two, and should be the focus of near term research activities. The long term goal of achieving zero cost will require other, non-biological, improvements in the process.

  20. Biomass Energy Basics | NREL

    Science.gov (United States)

    Biomass Energy Basics Biomass Energy Basics We have used biomass energy, or "bioenergy" keep warm. Wood is still the largest biomass energy resource today, but other sources of biomass can landfills (which are methane, the main component in natural gas) can be used as a biomass energy source. A

  1. The effect of water chemistry on a change in the composition of gas phase in the steam-water path of a supercritical-pressure boiler

    Science.gov (United States)

    Belyakov, I. I.; Belokonova, A. F.

    2010-07-01

    We present the results from an experimental research work on studying the behavior of the gas phase in the path of a supercritical-pressure boiler during its operation with different water chemistries, including all-volatile (hydrazine-ammonia), complexone, neutral oxygenated, and combined oxygenated-ammonia chemistries. It is shown that the minimal content of hydrogen in steam is achieved if feedwater is treated with oxygen.

  2. Integrated biomass utilization system developments (Kyoto-Bio-Cycle Project) and the effects of greenhouse gas reduction

    International Nuclear Information System (INIS)

    Nakamura, Kazuo; Hori, Hiroaki; Deguchi, Shinguo; Yano, Junya; Sakai, Shinichi

    2010-01-01

    Full text: The biomass available in Kyoto City located in urban area of Japan was estimated to be 2.02x10 6 t-wet/ yr (0.14x10 6 k liter/ yr oil equivalent), of which waste paper, waste timber, waste food, unused forest wood from the surrounding mountains and sewage sludge account for the largest amounts on an energy basis. These types of biomass can contribute to utilize for the reduction of fossil fuel consumption and for the reduction of greenhouse gas (GHG) emission. Therefore we started the Kyoto-Bio-Cycle Project (FY 2007-2009), which is the demonstration of renewable energy conversion technologies from the biomass. Specifically, we aimed for the greening of necessary materials such as methanol and the cyclic use of byproducts, with the bio diesel fuel production from used cooking oil (5 k liter-methyl ester/ day) as the core activity. Two technologies are being developed as part of the project. One is gasification and methanol synthesis to synthesize methanol with the pyrolytic gas generated from woody biomass. The other is high efficiency bio gasification that treats waste food, waste paper, and waste glycerin. This technology can improve the production rate of biogas and reduce the residue through the introduction of 80 degree Celsius-hyper-thermophilic hydrolysis in the 55 degree Celsius-thermophilic anaerobic fermentation process. These systems can produce 4 types of renewable energy such as bio diesel fuel, biogas, electricity and heat. And we conducted the life-cycle system analysis of GHG reduction effect for the demonstrating technologies, additionally we examined an optimum method of biomass utilization in the future low-carbon-society. As a result, the method that produces the liquid fuel (methanol, Ft oil) from dry biomass (waste timber, etc.) and the biogas from wet biomass (waste food, etc.) can reduce GHG emission highly at present and in the future, compared with the current direct combustion of biomass for the power generation. (author)

  3. Steam generators and fuel engineering utilizing solid, liquid, gaseous and special fuels

    Energy Technology Data Exchange (ETDEWEB)

    Thor, G

    1983-01-01

    Provided were technological specifications and details in the design of brown coal fired steam generators, produced in the German Democratic Republic. These steam generators range in their capacity between 1.6 and more than 1,000 t/h. The appropriate coal feeding systems, water supply and cleaning equipment, coal pulverizers and ash removal units are also manufactured. Various schemes show the design of a 25 to 64 t/h, a 320 t/h and an 815 t/h brown coal steam generator. Specifications are given for series of fuel pulverizers available, for the water circulation system and steam evaporators. The VEB Dampferzeugerbau Berlin also offers steam generators for saliniferous brown coal with a steam capacity up to 125 t/h, steam generators for pulverized black coal with a capacity up to 350 t/h and oil and gas fired generators up to 250 t/h. The company has experience in combustion of biomass (sugar cane waste) with oil in steam generators of more than 100 t/h capacity, and in projecting firing systems for other biofuels including rice, peanut and coconut hulls, wood and bark. Multi-biofuel firing in combination with coal for steam generation is also regarded as possible. (In English)

  4. Pyrolysis/gasification of biomass for synthetic fuel production using a hybrid gas- water stabilized plasma torch

    Czech Academy of Sciences Publication Activity Database

    Van Oost, G.; Hrabovský, Milan; Kopecký, Vladimír; Konrád, Miloš; Hlína, Michal; Kavka, Tetyana

    2008-01-01

    Roč. 83, č. 1 (2008), s. 209-212 ISSN 0042-207X R&D Projects: GA ČR GA202/08/1084 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal plasma * pyrolysis * biomass gasification Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.114, year: 2008

  5. Pyrolysis/gasification of biomass for synthetic fuel production using a hybrid gas- water stabilized plasma torch

    Czech Academy of Sciences Publication Activity Database

    Van Oost, G.; Hrabovský, Milan; Kopecký, Vladimír; Konrád, Miloš; Hlína, Michal; Kavka, Tetyana; Beeckman, E.; Verstraeten, J.

    2007-01-01

    Roč. 6, č. 1 (2007), s. 9-12. ISBN 978-4-9900642-5-9 R&D Projects: GA ČR GA202/05/0669 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal plasma * pyrolysis * biomass gasification Subject RIV: BL - Plasma and Gas Discharge Physics

  6. Biomass and leaf-level gas exchange characteristics of three African savanna C4 grass species under optimum growth conditions

    NARCIS (Netherlands)

    Mantlana, K.B.; Veenendaal, E.M.; Arneth, A.; Grispen, V.; Bonyongo, C.M.; Heitkönig, I.M.A.; Lloyd, J.

    2009-01-01

    C4 savanna grass species, Digitaria eriantha, Eragrostis lehmanniana and Panicum repens, were grown under optimum growth conditions with the aim of characterizing their above- and below-ground biomass allocation and the response of their gas exchange to changes in light intensity, CO2 concentration

  7. Device for extracting steam or gas from the primary coolant line leading from a reactor pressure vessel to a straight through boiler or from the top primary boiler chamber of a water-cooled nuclear reactor

    International Nuclear Information System (INIS)

    Schatz, K.

    1982-01-01

    In such a nuclear reactor, a steam or gas cushion can form when the primary system is refilled, which can cause blocking of the natural circulation or filling of the system in the area of the hot primary coolant pipe or in the top primary boiler chamber. In order to remove such a steam or gas cushion, a ventilation pipe starting from the bend of the primary coolant line is connected to the feed pipe for introducing water into the primary system. The feed pipe is designed on the principle of the vacuum pump in the area of the opening of the ventilation pipe. There is a sub-pressure in the ventilation pipe, which makes it possible to extract the steam or gas. After mixing in the area of the opening, the steam condenses or is distributed with the gas in the primary coolant. (orig.) [de

  8. 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...

  9. Flash pyrolysis at high temperature of ligno-cellulosic biomass and its components - production of synthesis gas; Pyrolyse flash a haute temperature de la biomasse ligno-cellulosique et de ses composes - production de gaz de synthese

    Energy Technology Data Exchange (ETDEWEB)

    Couhert, C

    2007-11-15

    Pyrolysis is the first stage of any thermal treatment of biomass and governs the formation of synthesis gas for the production of electricity, hydrogen or liquid fuels. The objective of this work is to establish a link between the composition of a biomass and its pyrolysis gas. We study experimental flash pyrolysis and fix the conditions in which quantities of gas are maximal, while aiming at a regime without heat and mass transfer limitations (particles about 100 {mu}m): temperature of 950 C and residence time of about 2 s. Then we try to predict gas yields of any biomass according to its composition, applicable in this situation where thermodynamic equilibrium is not reached. We show that an additivity law does not allow correlating gas yields of a biomass with fractions of cellulose, hemi-cellulose and lignin contained in this biomass. Several explanations are suggested and examined: difference of pyrolytic behaviour of the same compound according to the biomass from which it is extracted, interactions between compounds and influence of mineral matter. With the aim of industrial application, we study pyrolysis of millimetric and centimetric size particles, and make a numerical simulation of the reactions of pyrolysis gases reforming. This simulation shows that the choice of biomass affects the quantities of synthesis gas obtained. (author)

  10. Greenhouse gas mitigation potential of biomass energy technologies in Vietnam using the long range energy alternative planning system model

    International Nuclear Information System (INIS)

    Kumar, Amit; Bhattacharya, S.C.; Pham, H.L.

    2003-01-01

    The greenhouse gas (GHG) mitigation potentials of number of selected Biomass Energy Technologies (BETs) have been assessed in Vietnam. These include Biomass Integrated Gasification Combined Cycle (BIGCC) based on wood and bagasse, direct combustion plants based on wood, co-firing power plants and Stirling engine based on wood and cooking stoves. Using the Long-range Energy Alternative Planning (LEAP) model, different scenarios were considered, namely the base case with no mitigation options, replacement of kerosene and liquefied petroleum gas (LPG) by biogas stove, substitution of gasoline by ethanol in transport sector, replacement of coal by wood as fuel in industrial boilers, electricity generation with biomass energy technologies and an integrated scenario including all the options together. Substitution of coal stoves by biogas stove has positive abatement cost, as the cost of wood in Vietnam is higher than coal. Replacement of kerosene and LPG cookstoves by biomass stove also has a positive abatement cost. Replacement of gasoline by ethanol can be realized after a few years, as at present the cost of ethanol is more than the cost of gasoline. The replacement of coal by biomass in industrial boiler is also not an attractive option as wood is more expensive than coal in Vietnam. The substitution of fossil fuel fired plants by packages of BETs has a negative abatement cost. This option, if implemented, would result in mitigation of 10.83 million tonnes (Mt) of CO 2 in 2010

  11. Biomass sustainability criteria: Greenhouse gas accounting issues for biogas and biomethane facilities

    International Nuclear Information System (INIS)

    Adams, P.W.R.; Mezzullo, W.G.; McManus, M.C.

    2015-01-01

    Biomass sustainability criteria were introduced in the UK following the EU Renewable Energy Directive. Criteria are now applicable to solid biomass and biogas, however because it is not mandatory criteria can be adapted by member states with the risk of different interpretation. Operators are required to report greenhouse gas (GHG) emissions for every MJ of energy produced. This paper provides a rigorous analysis of the current GHG emissions accounting methodology for biogas facilities to assess expected compliance for producers. This research uses data from operating CHP and biomethane facilities to calculate GHG emissions using the existing methodology and Government calculator. Results show that whilst many biogas facilities will meet GHG thresholds, as presently defined by Government, several operators may not comply due to methodological uncertainties and chosen operating practices. Several GHG accounting issues are identified which need to be addressed so the biogas industry achieves its reporting obligations and is represented objectively with other bioenergy technologies. Significant methodological issues are highlighted; including consignment definition, mass balance allocation, measurement of fugitive methane emissions, accounting for digestate co-products, fossil fuel comparators, and other accounting problems. Recommendations are made to help address the GHG accounting issues for policy makers and the biogas industry. - Highlights: • GHG accounting issues identified that affect potential compliance with legislation. • Appropriate recognition of digestate value is a key issue for biogas industry. • Fugitive methane emissions measurement is critical for sustainability criteria. • Chosen fossil fuel comparator value determines the potential GHG saving. • Rigorous analysis of GHG accounting methodology for biogas and biomethane systems.

  12. Experimental investigation of condensation and mixing during venting of a steam / non-condensable gas mixture into a pressure suppression pool

    Energy Technology Data Exchange (ETDEWEB)

    De Walsche, C.; Cachard, F. de

    2000-07-01

    Experiments have been performed in the LINX facility to investigate condensation and mixing phenomena in pressure Suppression Pools (SPs), in the context of the European Simplified Boiling Water Reactor (ESBWR) study. As a contribution to the TEPSS project of the 4th European Framework Programme, eight medium-scale, separate-effect tests were carried out in which constant steam/air flow rates were injected below the surface of a two-metre diameter water pool, maintained at constant pressure, through a large downward vent. The vessel pressure was regulated, the pool temperature rising until equilibrium conditions with the incoming gas were reached. The SP temperature distribution was measured, as well as the inlet and outlet gas flow rates, and the overall condensation rate was estimated using mass and heat balances. The test matrix was based on steam mass floret and air mass fraction of the injected gas, the vent immersion depth, and the vessel pressure. Overall, the condensation was shown to be efficient for all tests performed, even for high non-condensable gas concentrations of the injected gas. Thermal stratification above the vent outlet was shown to be moderate. The tests performed allowed a better understanding to be gained of the mechanisms of condensation and mixing in the SP and Wetwell, and results were incorporated into an ORACLE database, to be used for further model development. (authors)

  13. Failure of the component additivity rule to predict gas yields of biomass in flash pyrolysis at 950 deg. C

    International Nuclear Information System (INIS)

    Couhert, Carole; Commandre, Jean-Michel; Salvador, Sylvain

    2009-01-01

    Ligno-cellulosic biomass from different sources presents variable composition. The main aim of this work was to develop a method to predict the gas yields after flash pyrolysis (and tar cracking) at 950 deg. C in an Entrained Flow Reactor of any biomass from its composition in the three main components - cellulose, hemicellulose and lignin. For this approach to be successful, three conditions need to be met: (C 1 )Pyrolytic behaviour of celluloses from different biomasses is similar, as is hemicellulose and lignin behaviour. (C 2 )There is no interaction between the components. (C 3 )Extractives and ashes have no impact on the pyrolysis process. Two approaches were chosen to investigate the condition C 1 : (i)Celluloses, hemicelluloses and lignins of various sources were pyrolysed. Results show that hemicelluloses and lignins from different sources do not form the same quantities of gases. (ii)An attempt was made to identify the gas yields of 'theoretical components' that are able to predict flash pyrolytic behaviour of any biomass. Results tend to show that this is not possible. The condition C 2 is investigated by comparing the gas yields of the components taken separately and the gas yields of mixes of the components. Two types of mixing were carried out: simple mixing and intimate mixing. Results show that interactions occur between the components during flash pyrolysis. The condition C 3 was not investigated here; it can nevertheless be concluded that the behaviour of a biomass during flash pyrolysis at high temperature cannot be predicted from its composition in cellulose, hemicellulose and lignin

  14. Biomass torrefaction mill

    Science.gov (United States)

    Sprouse, Kenneth M.

    2016-05-17

    A biomass torrefaction system includes a mill which receives a raw biomass feedstock and operates at temperatures above 400 F (204 C) to generate a dusty flue gas which contains a milled biomass product.

  15. 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.

  16. A symbiotic gas exchange between bioreactors enhances microalgal biomass and lipid productivities: taking advantage of complementary nutritional modes.

    Science.gov (United States)

    Santos, C A; Ferreira, M E; da Silva, T Lopes; Gouveia, L; Novais, J M; Reis, A

    2011-08-01

    This paper describes the association of two bioreactors: one photoautotrophic and the other heterotrophic, connected by the gas phase and allowing an exchange of O(2) and CO(2) gases between them, benefiting from a symbiotic effect. The association of two bioreactors was proposed with the aim of improving the microalgae oil productivity for biodiesel production. The outlet gas flow from the autotrophic (O(2) enriched) bioreactor was used as the inlet gas flow for the heterotrophic bioreactor. In parallel, the outlet gas flow from another heterotrophic (CO(2) enriched) bioreactor was used as the inlet gas flow for the autotrophic bioreactor. Aside from using the air supplied from the auto- and hetero-trophic bioreactors as controls, one mixotrophic bioreactor was also studied and used as a model, for its claimed advantage of CO(2) and organic carbon being simultaneously assimilated. The microalga Chlorella protothecoides was chosen as a model due to its ability to grow under different nutritional modes (auto, hetero, and mixotrophic), and its ability to attain a high biomass productivity and lipid content, suitable for biodiesel production. The comparison between heterotrophic, autotrophic, and mixotrophic Chlorella protothecoides growth for lipid production revealed that heterotrophic growth achieved the highest biomass productivity and lipid content (>22%), and furthermore showed that these lipids had the most suitable fatty acid profile in order to produce high quality biodiesel. Both associations showed a higher biomass productivity (10-20%), when comparing the two separately operated bioreactors (controls) which occurred on the fourth day. A more remarkable result would have been seen if in actuality the two bioreactors had been inter-connected in a closed loop. The biomass productivity gain would have been 30% and the lipid productivity gain would have been 100%, as seen by comparing the productivities of the symbiotic assemblage with the sum of the two

  17. Exploring the assumed invariance of implied emission factors for forest biomass in greenhouse gas inventories

    International Nuclear Information System (INIS)

    Smith, James E.; Heath, Linda S.

    2010-01-01

    Reviews of each nation's annual greenhouse gas inventory submissions including forestland are part of the ongoing reporting process of the United Nations Framework Convention on Climate Change. Goals of these reviews include improving quality and consistency within and among reports. One method of facilitating comparisons is the use of a standard index such as an implied emission factor (IEF), which for forest biomass indicates net rate of carbon emission or sequestration per area. Guidance on the use of IEFs in reviews is limited, but there is an expectation that values should be relatively constant both over time and across spatial scales. To address this hypothesis, we examine IEFs over time, derived from U.S. forests at plot-, state-, and national-levels. Results show that at increasingly aggregated levels, relative heterogeneity decreases but can still be substantial. A net increase in U.S. whole-forest IEFs over time is consistent with results from temperate forests of nations in the European Community. IEFs are better viewed as a distribution of values rather than one constant value principally because of sensitivities to productivity, disturbance, and land use change, which can all vary considerably across a nation's forest land.

  18. Novel pathways for fuels and lubricants from biomass optimized using life-cycle greenhouse gas assessment

    Science.gov (United States)

    Balakrishnan, Madhesan; Sacia, Eric R.; Sreekumar, Sanil; Gunbas, Gorkem; Gokhale, Amit A.; Scown, Corinne D.; Toste, F. Dean; Bell, Alexis T.

    2015-01-01

    Decarbonizing the transportation sector is critical to achieving global climate change mitigation. Although biofuels will play an important role in conventional gasoline and diesel applications, bioderived solutions are particularly important in jet fuels and lubricants, for which no other viable renewable alternatives exist. Producing compounds for jet fuel and lubricant base oil applications often requires upgrading fermentation products, such as alcohols and ketones, to reach the appropriate molecular-weight range. Ketones possess both electrophilic and nucleophilic functionality, which allows them to be used as building blocks similar to alkenes and aromatics in a petroleum refining complex. Here, we develop a method for selectively upgrading biomass-derived alkyl methyl ketones with >95% yields into trimer condensates, which can then be hydrodeoxygenated in near-quantitative yields to give a new class of cycloalkane compounds. The basic chemistry developed here can be tailored for aviation fuels as well as lubricants by changing the production strategy. We also demonstrate that a sugarcane biorefinery could use natural synergies between various routes to produce a mixture of lubricant base oils and jet fuels that achieve net life-cycle greenhouse gas savings of up to 80%. PMID:26056307

  19. Thermodynamic Analyses of Biomass Gasification Integrated Externally Fired, Post-Firing and Dual-Fuel Combined Cycles

    Directory of Open Access Journals (Sweden)

    Saeed Soltani

    2015-01-01

    Full Text Available In the present work, the results are reported of the energy and exergy analyses of three biomass-related processes for electricity generation: the biomass gasification integrated externally fired combined cycle, the biomass gasification integrated dual-fuel combined cycle, and the biomass gasification integrated post-firing combined cycle. The energy efficiency for the biomass gasification integrated post-firing combined cycle is 3% to 6% points higher than for the other cycles. Although the efficiency of the externally fired biomass combined cycle is the lowest, it has an advantage in that it only uses biomass. The energy and exergy efficiencies are maximized for the three configurations at particular values of compressor pressure ratios, and increase with gas turbine inlet temperature. As pressure ratio increases, the mass of air per mass of steam decreases for the biomass gasification integrated post-firing combined cycle, but the pressure ratio has little influence on the ratio of mass of air per mass of steam for the other cycles. The gas turbine exergy efficiency is the highest for the three configurations. The combustion chamber for the dual-fuel cycle exhibits the highest exergy efficiency and that for the post-firing cycle the lowest. Another benefit of the biomass gasification integrated externally fired combined cycle is that it exhibits the highest air preheater and heat recovery steam generator exergy efficiencies.

  20. Gas quality prediction in ligno-cellulosic biomass gasification in a co-current gas producer; Prediction de la qualite du gaz en gazeification de la biomasse ligno-cellulosique dans un gazogene a co-courant

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J [Universite Catholique de Louvain (UCL), Faculte des Sciences Appliquees, Dept. de Mecanique, Unite Thermodynamique et Turbomachines, Louvain-la-Neuve (Belgium); Nganhou, J [Universite de Yaounde, Ecole National Superieur Polytechnique de Yaounde, Dept. de Genies Mecanique et Industriel (Cameroon); Amie Assouh, A [Ecole National Superieur Polytechnique de Yaounde, Lab. d' Energetique (Cameroon)

    2008-03-15

    Our research covers the energetic valuation of the biomass for electricity production. As electrical energy production is the main drive behind a modern economy, we wanted to make our contribution to the debate by describing a tried technique, whose use on an industrial scale can still be perfected, failing control over the basic principles that support the gasification processes called upon in this industry. Our study describes gasification, which is a process to transform a solid combustible into a gas combustible. The resulting gas can be used as combustible in an internal combustion motor and produce electricity. Our work interprets the experimental results of gasification tests conducted on an available and functional experimental centre and the ENSPY's Decentralized Energy Production Lab. The work involved developing a tool to appreciate the results of the gasification of the ligneous biomass from the stoichiometric composition of the combustible to be gasified and the chemical and mathematical bases of the gasification process. It is an investigation with a view to elaborating a mathematical model based on the concept of compatibility. Its original lies in the quality prediction method for the gas obtained through the gasification of a biomass whose chemical composition is known. (authors)

  1. Exergetic optimisation of a production process of Fischer-Tropsch fuels from biomass

    NARCIS (Netherlands)

    Prins, M.J.; Ptasinski, K.J.; Janssen, F.J.J.G.

    2005-01-01

    An exergy analysis of Biomass Integrated Gasification-Fischer–Tropsch process is presented. The process combines an air-blown, atmospheric gasifier, using sawdust as feedstock, with a Fischer–Tropsch reactor and a steam-Rankine cycle for electricity generation from the Fischer–Tropsch tail gas.

  2. Comparative study for hardwood and softwood forest biomass: chemical characterization, combustion phases and gas and particulate matter emissions.

    Science.gov (United States)

    Amaral, Simone Simões; de Carvalho, João Andrade; Costa, Maria Angélica Martins; Soares Neto, Turíbio Gomes; Dellani, Rafael; Leite, Luiz Henrique Scavacini

    2014-07-01

    Two different types of typical Brazilian forest biomass were burned in the laboratory in order to compare their combustion characteristics and pollutant emissions. Approximately 2 kg of Amazon biomass (hardwood) and 2 kg of Araucaria biomass (softwood) were burned. Gaseous emissions of CO2, CO, and NOx and particulate matter smaller than 2.5 μm (PM2.5) were evaluated in the flaming and smoldering combustion phases. Temperature, burn rate, modified combustion efficiency, emissions factor, and particle diameter and concentration were studied. A continuous analyzer was used to quantify gas concentrations. A DataRam4 and a Cascade Impactor were used to sample PM2.5. Araucaria biomass (softwood) had a lignin content of 34.9%, higher than the 23.3% of the Amazon biomass (hardwood). CO2 and CO emissions factors seem to be influenced by lignin content. Maximum concentrations of CO2, NOx and PM2.5 were observed in the flaming phase. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Technoeconomic assessment of biomass to energy

    International Nuclear Information System (INIS)

    Mitchell, C.P.; Watters, M.P.

    1995-01-01

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

  4. Heat transfer performance comparison of steam and air in gas turbine cooling channels with different rib angles

    Science.gov (United States)

    Shi, Xiaojun; Gao, Jianmin; Xu, Liang; Li, Fajin

    2013-11-01

    Using steam as working fluid to replace compressed air is a promising cooling technology for internal cooling passages of blades and vanes. The local heat transfer characteristics and the thermal performance of steam flow in wide aspect ratio channels ( W/ H = 2) with different angled ribs on two opposite walls have been experimentally investigated in this paper. The averaged Nusselt number ratios and the friction factor ratios of steam and air in four ribbed channels were also measured under the same test conditions for comparison. The Reynolds number range is 6,000-70,000. The rib angles are 90°, 60°, 45°, and 30°, respectively. The rib height to hydraulic diameter ratio is 0.047. The pitch-to-rib height ratio is 10. The results show that the Nusselt number ratios of steam are 1.19-1.32 times greater than those of air over the range of Reynolds numbers studied. For wide aspect ratio channels using steam as the coolant, the 60° angled ribs has the best heat transfer performance and is recommended for cooling design.

  5. Integrated biomass gasification using the waste heat from hot slags: Control of syngas and polluting gas releases

    International Nuclear Information System (INIS)

    Sun, Yongqi; Seetharaman, Seshadri; Liu, Qianyi; Zhang, Zuotai; Liu, Lili; Wang, Xidong

    2016-01-01

    In this study, the thermodynamics of a novel strategy, i.e., biomass/CO 2 gasification integrated with heat recovery from hot slags in the steel industry, were systemically investigated. Both the target syngas yield and the polluting gas release were considered where the effect of gasifying conditions including temperature, pressure and CO 2 reacted was analyzed and then the roles of hot slags were further clarified. The results indicated that there existed an optimum temperature for the maximization of H 2 production. Compared to blast furnace slags, steel slags remarkably increased the CO yield at 600–1400 °C due to the existence of iron oxides and decreased the S-containing gas releases at 400–700 °C, indicating potential desulfurizing ability. The identification of biomass/CO 2 gasification thermodynamics in presence of slags could thus provide important clues not only for the deep understanding of biomass gasification but also for the industrial application of this emerging strategy from the viewpoint of syngas optimization and pollution control. - Highlights: • Biomass/CO 2 gasification was integrated with the heat recovery from hot slags. • Both syngas yield and polluting gas release during gasification were determined. • There existed an optimum temperature for the maximization of H 2 production. • Steel slags increased CO yield at 600–1400 °C due to the existence of iron oxides. • Steel slags remarkably decreased the releases of S-containing gas at 400–700 °C.

  6. Using Dynamic Simulation to Evaluate Attemperator Operation in a Natural Gas Combined Cycle With Duct Burners in the Heat Recovery Steam Generator

    Energy Technology Data Exchange (ETDEWEB)

    Liese, Eric [National Energy Technology Laboratory,Department of Energy,Systems Engineering and Analysis Division,Morgantown, WV 26507e-mail: eric.liese@netl.doe.gov; Zitney, Stephen E. [National Energy Technology Laboratory,Department of Energy,Systems Engineering and Analysis Division,Morgantown, WV 26507e-mail: stephen.zitney@netl.doe.gov

    2017-09-26

    A generic training simulator of a natural gas combined cycle was modified to match operations at a real plant. The objective was to use the simulator to analyze cycling operations of the plant. Initial operation of the simulator revealed the potential for saturation conditions in the final high pressure superheater as the attemperator tried to control temperature at the superheater outlet during gas turbine loading and unloading. Subsequent plant operational data confirmed simulation results. Multiple simulations were performed during loading and unloading of the gas turbine to determine operational strategies that prevented saturation and increased the approach to saturation temperature. The solutions included changes to the attemperator temperature control setpoints and strategic control of the steam turbine inlet pressure control valve.

  7. Rupture of a high pressure gas or steam pipe in a tunnel: a preliminary investigation of the jet thrust exerted on a tunnel barrier

    International Nuclear Information System (INIS)

    Baum, M.R.

    1988-04-01

    On power plant, if a high pressure pipe containing high temperature gas or steam were to rupture, sensitive equipment necessary for safety shutdown of the plant could possibly be incapacitated if exposed to the subsequent high temperature environment. In many plant configurations the high pressure pipework is contained in tunnels where it is possible to construct barriers which isolate one section of the plant from another, thereby restricting the spread of the high temperature fluid/air mixture. This paper describes a preliminary experimental investigation of the magnitude of the thrust likely to be exerted on such barriers by a gas jet issuing from the failed pipe. Measurements of the thrust exerted on a flat plate by normal impingement of a highly underexpanded gas jet are in agreement with a semi-quantitative analysis assuming conservation of the axial momentum of the jet. (author)

  8. A review of thermo-chemical conversion of biomass into biofuels-focusing on gas cleaning and up-grading process steps

    OpenAIRE

    Brandin, Jan; Hulteberg, Christian; Kusar, Henrik

    2017-01-01

    It is not easy to replace fossil-based fuels in the transport sector, however, an appealing solution is to use biomass and waste for the production of renewable alternatives. Thermochemical conversion of biomass for production of synthetic transport fuels by the use of gasification is a promising way to meet these goals. One of the key challenges in using gasification systems with biomass and waste as feedstock is the upgrading of the raw gas produced in the gasifier. These materials replacin...

  9. Variable electricity and steam from salt, helium and sodium cooled base-load reactors with gas turbines and heat storage - 15115

    International Nuclear Information System (INIS)

    Forsberg, C.; McDaniel, P.; Zohuri, B.

    2015-01-01

    Advances in utility natural-gas-fired air-Brayton combed cycle technology is creating the option of coupling salt-, helium-, and sodium-cooled nuclear reactors to Nuclear air-Brayton Combined Cycle (NACC) power systems. NACC may enable a zero-carbon electricity grid and improve nuclear power economics by enabling variable electricity output with base-load nuclear reactor operations. Variable electricity output enables selling more electricity at times of high prices that increases plant revenue. Peak power is achieved using stored heat or auxiliary fuel (natural gas, bio-fuels, hydrogen). A typical NACC cycle includes air compression, heating compressed air using nuclear heat and a heat exchanger, sending air through a turbine to produce electricity, reheating compressed air, sending air through a second turbine, and exhausting to a heat recovery steam generator (HRSG). In the HRSG, warm air produces steam that is used to produce added electricity. For peak power production, auxiliary heat (natural gas, stored heat) is added before the air enters the second turbine to raise air temperatures and power output. Like all combined cycle plants, water cooling requirements are dramatically reduced relative to other power cycles because much of the heat rejection is in the form of hot air. (authors)

  10. The study on water ingress mass in the steam generator heat-exchange tube rupture accident of modular high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Wang Yan; Shi Lei; Li Fu; Zheng Yanhua

    2012-01-01

    The steam generator heat-exchange tube rupture (SGTR) accident is an important and particular accident which will result in water ingress to the primary loop of reactor. Water ingress will result in chemical reaction of graphite fuel and structure with water, which may cause overpressure due to generation of explosive gaseous in large quantity. The study on the water ingress accident is significant for the verification of the inherent characteristics of high temperature gas-cooled reactor. The previous research shows that the amount of water ingress mass is the dominant key factor on the severity of the accident consequence. The 200 MWe high temperature gas-cooled reactor (HTR-PM), which is the first modular pebble-bed high temperature gas-cooled reactor in China designed by the Institute of Nuclear and New Energy Technology of Tsinghua University, is selected to be analyzed in this paper. The different DBA accident scenarios of double-ended break of single heat-exchange tube are simulated respectively by the thermal-hydraulic analysis code RETRAN-02. The results show the water ingress mass through the broken heat-exchange tube is related to the break location. The amount of water ingress mass is affected obviously by the capacity of the emptier system. With the balance of safety and economical efficiency, the amount of water ingress mass from the secondary side of steam generator into the primary coolant loop will be reduced by increasing properly the diameter of the draining lines. (authors)

  11. A Geothermal Energy Supported Gas-steam Cogeneration Unit as a Possible Replacement for the Old Part of a Municipal CHP Plant (TEKO

    Directory of Open Access Journals (Sweden)

    L. Böszörményi

    2001-01-01

    Full Text Available The need for more intensive utilization of local renewable energy sources is indisputable. Under the current economic circumstances their competitiveness in comparison with fossil fuels is rather low, if we do not take into account environmental considerations. Integrating geothermal sources into combined heat and power production in a municipal CHP plant would be an excellent solution to this problem. This concept could lead to an innovative type of power plant - a gas-steam cycle based, geothermal energy supported cogeneration unit.

  12. Analysis on Storage Off-Gas Emissions from Woody, Herbaceous, and Torrefied Biomass

    Directory of Open Access Journals (Sweden)

    Jaya Shankar Tumuluru

    2015-03-01

    Full Text Available Wood chips, torrefied wood chips, ground switchgrass, and wood pellets were tested for off‑gas emissions during storage. Storage canisters with gas‑collection ports were used to conduct experiments at room temperature of 20 °C and in a laboratory oven set at 40 °C. Commercially-produced wood pellets yielded the highest carbon monoxide (CO emissions at both 20 and 40 °C (1600 and 13,000 ppmv, whereas torrefied wood chips emitted the lowest of about <200 and <2000 ppmv. Carbon dioxide (CO2 emissions from wood pellets were 3000 ppmv and 42,000 ppmv, whereas torrefied wood chips registered at about 2000 and 25,000 ppmv, at 20 and 40 °C at the end of 11 days of storage. CO emission factors (milligrams per kilogram of biomass calculated were lowest for ground switchgrass and torrefied wood chips (2.68 and 4.86 mg/kg whereas wood pellets had the highest CO of about 10.60 mg/kg, respectively, at 40 °C after 11 days of storage. In the case of CO2, wood pellets recorded the lowest value of 55.46 mg/kg, whereas switchgrass recorded the highest value of 318.72 mg/kg. This study concludes that CO emission factor is highest for wood pellets, CO2 is highest for switchgrass and CH4 is negligible for all feedstocks except for wood pellets, which is about 0.374 mg/kg at the end of 11-day storage at 40 °C.

  13. Optimization of radial systems with biomass fueled gas engine from a metaheuristic and probabilistic point of view

    International Nuclear Information System (INIS)

    Ruiz-Rodriguez, F.J.; Gomez-Gonzalez, M.; Jurado, F.

    2013-01-01

    Highlights: ► Loads and distributed generation production are modeled as random variables. ► Distribution system with biomass fueled gas engines. ► Random nature of lower heat value of biomass and load. ► The Cornish–Fisher expansion is used for approximating quantiles of a random variable. ► Computational cost is low enough than that required for Monte Carlo simulation. - Abstract: This paper shows that the technical constraints must be considered in radial distribution networks, where the voltage regulation is one of the primary problems to be dealt in distributed generation systems based on biomass fueled engine. Loads and distributed generation production are modeled as random variables. Results prove that the proposed method can be applied for the keeping of voltages within desired limits at all load buses of a distribution system with biomass fueled gas engines. To evaluate the performance of this distribution system, this paper has developed a probabilistic model that takes into account the random nature of lower heat value of biomass and load. The Cornish–Fisher expansion is used for approximating quantiles of a random variable. This work introduces a hybrid method that utilizes a new optimization method based on swarm intelligence and probabilistic radial load flow. It is demonstrated the reduction in computation time achieved by the more efficient probabilistic load flow in comparison to Monte Carlo simulation. Acceptable solutions are reached in a smaller number of iterations. Therefore, convergence is more rapidly attained and computational cost is significantly lower than that required for Monte Carlo methods.

  14. Hydrodynamic behaviour and comparison of technologies for the removal of excess biomass in gas-phase biofilters.

    Science.gov (United States)

    Mendoza, J A; Prado, O J; Veiga, M C; Kennes, C

    2004-01-01

    The hydrodynamic behaviour of a biofilter fed toluene and packed with an inert carrier was evaluated on start-up and after long-term operation, using both methane and styrene as tracers in Residence Time Distribution experiments. Results indicated some deviation from ideal plug flow behaviour after 2-year operation. It was also observed that the retention time of VOCs gradually increased with time and was significantly longer than the average residence time of the bulk gas phase. Non-ideal hydrodynamic behaviour in packed beds may be due to excess biomass accumulation and affects both reactor modeling and performance. Therefore, several methods were studied for the removal of biomass after long-term biofilter operation: filling with water and draining, backwashing, and air sparging. Several flow rates and temperatures (20-60 degrees C) were applied using either water or different chemicals (NaOH, NaOCl, HTAB) in aqueous solution. Usually, higher flow rates and higher temperatures allowed the removal of more biomass, but the efficiency of biomass removal was highly dependent on the pressure drop reached before the treatment. The filling/draining method was the least efficient for biomass removal, although the treatment did basically not generate any biological inhibition. The efficiency of backwashing and air sparging was relatively similar and was more effective when adding chemicals. However, treatments with chemicals resulted in a significant decrease of the biofilter's performance immediately after applying the treatment, needing periods of several days to recover the original performance. The effect of manually mixing the packing material was also evaluated in duplicate experiments. Quite large amounts of biomass were removed but disruption of the filter bed was observed. Batch assays were performed simultaneously in order to support and quantify the observed inhibitory effects of the different chemicals and temperatures used during the treatments.

  15. Biomass a fast growing energy resource

    International Nuclear Information System (INIS)

    Hansen, Ulf

    2003-01-01

    Biomass as an energy resource is as versatile as the biodiversity suggests. The global net primary production, NPP, describes the annual growth of biomass on land and in the seas. This paper focuses on biomass grown on land. A recent estimate for the NPP on land is 120 billion tons of dry matter. How much of this biomass are available for energy purposes? The potential contribution of wood fuel and energy plants from sustainable production is limited to some 5% of NPP, i.e. 6 Bt. One third of the potential is energy forests and energy plantations which at present are not economic. One third is used in rural areas as traditional fuel. The remaining third would be available for modern biomass energy conversion. Biomass is assigned an expanding role as a new resource in the world's energy balance. The EU has set a target of doubling the share of renewable energy sources by 2010. For biomass the target is even more ambitious. The challenge for biomass utilization lies in improving the technology for traditional usage and expanding the role into other areas like power production and transportation fuel. Various technologies for biomass utilization are available among those are combustion, gasification, and liquefaction. Researchers have a grand vision in which the chemical elements in the hydrocarbon molecules of biomass are separated and reformed to yield new tailored fuels and form the basis for a new world economy. The vision of a new energy system based on fresh and fossilized biomass to be engineered into an environmentally friendly and sustainable fuel is a conceivable technical reality. One reason for replacing exhaustible fossil fuels with biomass is to reduce carbon emissions. The most efficient carbon dioxide emission reduction comes from replacing brown coal in a steam-electric unit, due to the efficiency of the thermal cycle and the high carbon intensity of the coal. The smallest emission reduction comes from substituting natural gas. (BA)

  16. Overview of biomass conversion technologies

    International Nuclear Information System (INIS)

    Noor, S.; Latif, A.; Jan, M.

    2011-01-01

    A large part of the biomass is used for non-commercial purposes and mostly for cooking and heating, but the use is not sustainable, because it destroys soil-nutrients, causes indoor and outdoor pollution, adds to greenhouse gases, and results in health problems. Commercial use of biomass includes household fuelwood in industrialized countries and bio-char (charcoal) and firewood in urban and industrial areas in developing countries. The most efficient way of biomass utilization is through gasification, in which the gas produced by biomass gasification can either be used to generate power in an ordinary steam-cycle or be converted into motor fuel. In the latter case, there are two alternatives, namely, the synthesis of methanol and methanol-based motor fuels, or Fischer-Tropsch hydrocarbon synthesis. This paper deals with the technological overview of the state-of-the-art key biomass-conversion technologies that can play an important role in the future. The conversion routes for production of Heat, power and transportation fuel have been summarized in this paper, viz. combustion, gasification, pyrolysis, digestion, fermentation and extraction. (author)

  17. Experiments about the integrity of BWR relief pipes in postulated radiolysis gas combustion. Scenario No.2. Minor steam leakages without any lowering of the water level

    International Nuclear Information System (INIS)

    Friedrich, A.; Grune, J.; Sempert, K.; Stern, G.; Kuznetsov, M.; Redlinger, R.; Breitung, W.; Franke, T.

    2008-01-01

    The experiments described in this article were performed to study this comprehensive radiolysis gas scenario: - The relief pipe is filled completely with radiolysis gas (2H 2 +O 2 ). - After opening of the S and R valve, the radiolysis gas is compressed adiabatically by the incoming steam without mixing. - Roughly at the point of peak pressure in the relief pipe (20 bar) the radiolysis gas ignites. This dynamic scenario was studied in steady-state model experiments with a test pipe which corresponds to the relief pipes installed in KKP-1 in terms of materials, dimensions, and manufacturing control. The initial conditions and boundary conditions of the experiments were conservative. In the course of the tests, the maximum dynamic strain and the residual plastic deformation of the test pipe were measured via the transient detonation load. The maximum dynamic strain measured was 0.75%, the maximum residual plastic strain reached 0.15%. The pipe suffered no other deformation above and beyond this slight plastic strain. The radiolysis gas detonation was simulated very well numerically. Using the calculated pressure loads in a structural dynamics model also showed good agreement with the measured maximum dynamic pipe strains. In this way, the experimental findings were confirmed theoretically. The experiments and the calculations showed that postulated radiolysis gas reactions during pressure relief cannot jeopardize the integrity of the relief pipe. (orig.)

  18. Analysis of Indirectly Fired Gas Turbine for Wet Biomass Fuels Based on commercial micro gas turbine data

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Qvale, Einar Bjørn

    2002-01-01

    energy, which has been the practice up to now, the low temperature exhaust gases after having served as drying agent, are lead out into the environment; a simple change of process integration that has a profound effect on the performance. Four different cycles have been studied. These are the Simple IFGT...... fueled by dry biomass assuming negligible pressure loss in the heat exchanger and the combustion chamber, the IFGT fueled with wet biomass (Wet IFGT) assuming no pressure losses, and finally both the Simple and the Wet IFGT incorporating typical data for pressure losses of commercially available micro...

  19. Impact of Contaminants Present in Coal-Biomass Derived Synthesis Gas on Water-gas Shift and Fischer-Tropsch Synthesis Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Alptekin, Gokhan [TDA Research, Inc., Wheat Ridge, CO (United States)

    2013-02-15

    Co-gasification of biomass and coal in large-scale, Integrated Gasification Combined Cycle (IGCC) plants increases the efficiency and reduces the environmental impact of making synthesis gas ("syngas") that can be used in Coal-Biomass-to-Liquids (CBTL) processes for producing transportation fuels. However, the water-gas shift (WGS) and Fischer-Tropsch synthesis (FTS) catalysts used in these processes may be poisoned by multiple contaminants found in coal-biomass derived syngas; sulfur species, trace toxic metals, halides, nitrogen species, the vapors of alkali metals and their salts (e.g., KCl and NaCl), ammonia, and phosphorous. Thus, it is essential to develop a fundamental understanding of poisoning/inhibition mechanisms before investing in the development of any costly mitigation technologies. We therefore investigated the impact of potential contaminants (H2S, NH3, HCN, AsH3, PH3, HCl, NaCl, KCl, AS3, NH4NO3, NH4OH, KNO3, HBr, HF, and HNO3) on the performance and lifetime of commercially available and generic (prepared in-house) WGS and FT catalysts.

  20. Steam drums

    International Nuclear Information System (INIS)

    Crowder, R.

    1978-01-01

    Steam drums are described that are suitable for use in steam generating heavy water reactor power stations. They receive a steam/water mixture via riser headers from the reactor core and provide by means of separators and driers steam with typically 0.5% moisture content for driving turbines. The drums are constructed as prestressed concrete pressure vessels in which the failure of one or a few of the prestressing elements does not significantly affect the overall strength of the structure. The concrete also acts as a radiation shield. (U.K.)

  1. Comparison of the efficiency of bacterial and fungal laccases in delignification and detoxification of steam-pretreated lignocellulosic biomass for bioethanol production.

    Science.gov (United States)

    De La Torre, María; Martín-Sampedro, Raquel; Fillat, Úrsula; Eugenio, María E; Blánquez, Alba; Hernández, Manuel; Arias, María E; Ibarra, David

    2017-11-01

    This study evaluates the potential of a bacterial laccase from Streptomyces ipomoeae (SilA) for delignification and detoxification of steam-exploded wheat straw, in comparison with a commercial fungal laccase from Trametes villosa. When alkali extraction followed by SilA laccase treatment was applied to the water insoluble solids fraction, a slight reduction in lignin content was detected, and after a saccharification step, an increase in both glucose and xylose production (16 and 6%, respectively) was observed. These effects were not produced with T. villosa laccase. Concerning to the fermentation process, the treatment of the steam-exploded whole slurry with both laccases produced a decrease in the phenol content by up to 35 and 71% with bacterial and fungal laccases, respectively. The phenols reduction resulted in an improved performance of Saccharomyces cerevisiae during a simultaneous saccharification and fermentation (SSF) process, improving ethanol production rate. This enhancement was more marked with a presaccharification step prior to the SSF process.

  2. Design principles of an integrated natural gas steam reformer for stationary PEMFC systems; Auslegungsprinzipien eines integrierten Erdgas-Dampfreformers fuer stationaere PEM-Brennstoffzellen-Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Grosser, K.

    2006-09-05

    The function, efficiency and economic efficiency of fuel cell systems are defined by various influencing factors, especially in the case of hydrogen production by steam reforming of natural gas. The dissertation describes the design of integrated natural gas steam reformers for PEM fuel cell systems in the electric power range of 1- 10 kW; the influencing factors of the process are investigated and weighted. Design principles are derived from which optimum operating parameters can be defined and which can be used for designing a multitude of components. [German] Die Funktionsfaehigkeit, der Wirkungsgrad und die Wirtschaftlichkeit von Brennstoffzellen-Systemen werden insbesondere bei der Wasserstofferzeugung durch Erdgas-Dampfreformierung durch verschiedene Einflussfaktoren bestimmt. In dieser Dissertation werden die Methodik der Auslegung integrierter Erdgas-Dampfreformer fuer PEM-Brennstoffzellen-Systeme im elektrischen Leistungsbereich von 1-10 kW beschrieben und die prozessbestimmenden Einflussfaktoren untersucht und gewichtet. Daraus werden Auslegungsprinzipien abgeleitet, mit denen sich die optimalen Betriebsparameter ermitteln lassen und die zur konstruktiven Gestaltung einer Vielzahl von Anlagenteilen genutzt werden koennen.

  3. Discussion on amount of water ingress mass in steam generator heat-exchange tube rupture accident of high- temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Wang Yan; Zheng Yanhua; Shi Lei; Li Fu; Sun Ximing

    2009-01-01

    The steam generator heat-exchange tube rupture (SGTR) accident which will result in the water ingress to the primary circuit of reactor is an important and particular accident for high-temperature gas-cooled reactor (HTGR). The analysis of the water ingress accident is significant for verifying the inherent safety characteristics of HTGR. The amount of water ingress mass is one of the decisive factors for the seriousness of the accident consequence. The 250 MW Pebble-bed Modular High-Temperature Gas-cooled Reactor (HTR-PM) designed by Institute of Nuclear and New Energy Technology of Tsinghua University was selected as an example of analysis. The analysis results show that the amount of water ingress mass is not only affected directly with the broken position and the broken area of the tubes, but also related with the diameter of draining piping and restrictor, draining control valve, action setting of emptier system. With reasonable parameters chosen, the water in steam generator could be drained effectively, so it will prevent the primary circuit of reactor from water ingress in large quantity and reduce the radioactive isotopes ingress to the secondary circuit. (authors)

  4. Use of California biomass in the production of transportation-fuel oxygenates: Estimates for reduction in CO2 emissions and greenhouse gas potential on a life cycle basis

    International Nuclear Information System (INIS)

    Kadam, K. L.; Camobreco, V. J.; Glazebrook, B. E.

    1999-01-01

    A set of environmental flows associated with two disposal options for thee types of California biomass - forest biomass, rice straw, chaparral - over their life cycles were studied, the emphasis being on energy consumption and greenhouse gas emissions. The two options studied were: producing ethyl-tertiary-butyl ether (ETBE) from biomass and biomass burning, and producing methyl-tertiary-butyl ether (MTBE) from natural gas. Results showed a lower (by 40 to 50 per cent) greenhouse effect impact, lower net values for carbon dioxide and fossil fuel energy consumption, and higher net values for renewable energy consumption for the ETBE option. Based on these results, the deployment of the biomass-to-ethanol ETBE option is recommended as the one that contributes most to the reduction of GHG emissions. 12 refs., 2 tabs., 5 figs

  5. Steam turbines for the future

    International Nuclear Information System (INIS)

    Trassl, W.

    1988-01-01

    Approximately 75% of the electrical energy produced in the world is generated in power plants with steam turbines (fossil and nuclear). Although gas turbines are increasingly applied in combined cycle power plants, not much will change in this matter in the future. As far as the steam parameters and the maximum unit output are concerned, a certain consolidation was noted during the past decades. The standard of development and mathematical penetration of the various steam turbine components is very high today and is applied in the entire field: For saturated steam turbines in nuclear power plants and for steam turbines without reheat, with reheat and with double reheat in fossil-fired power plants and for steam turbines with and without reheat in combined cycle power plants. (orig.) [de

  6. Effect of partial replacement of diesel or biodiesel with gas from biomass gasification in a diesel engine

    International Nuclear Information System (INIS)

    Hernández, J.J.; Lapuerta, M.; Barba, J.

    2015-01-01

    The injected diesel fuel used in a diesel engine was partially replaced with biomass-derived gas through the intake port, and the effect on performance and pollutant emissions was studied. The experimental work was carried out in a supercharged, common-rail injection, single-cylinder diesel engine by replacing diesel fuel up to 20% (by energy), keeping constant the engine power. Three engine loads (60, 90, 105 Nm), three different EGR (exhaust gas recirculation) ratios (0, 7.5, 15%) and two intake temperatures (45, 60 °C) were tested. Finally, some of the tested conditions were selected to replace diesel injection fuel with biodiesel injection. Although the brake thermal efficiency was decreased and hydrocarbons and carbon monoxide emissions increased with increasing fuel replacement, particulate emissions decreased significantly and NO x emissions decreased slightly at all loads and EGR ratios. Thermodynamic diagnostic results showed higher premixed ratio and lower combustion duration for increasing diesel fuel replacement. High EGR ratios improved both engine performance and emissions, especially when intake temperature was increased, which suggest removing EGR cooling when diesel fuel is replaced. Finally, when biodiesel was used instead of diesel fuel, the gas replacement improved the efficiency and reduced the hydrocarbon, carbon monoxide and particulate emissions. - Highlights: • Replacing injected fuel with gas permits an efficient valorization of waste biomass. • Inlet gas was inefficiently burned after the end of liquid fuel injection. • Engine parameters were combined to simultaneously reduce particle and NO x emissions. • Hot EGR (exhaust gas recirculation) and biodiesel injection are proposed to improve efficiency and emissions

  7. Steam reforming of ethanol

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Dahl, Søren; Jensen, Anker Degn

    2013-01-01

    Steam reforming (SR) of oxygenated species like bio-oil or ethanol can be used to produce hydrogen or synthesis gas from renewable resources. However, deactivation due to carbon deposition is a major challenge for these processes. In this study, different strategies to minimize carbon deposition...

  8. Steam-treated wood pellets: Environmental and financial implications relative to fossil fuels and conventional pellets for electricity generation

    International Nuclear Information System (INIS)

    McKechnie, Jon; Saville, Brad; MacLean, Heather L.

    2016-01-01

    Highlights: • Steam-treated pellets can greatly reduce greenhouse gas emissions relative to coal. • Cost advantage is seen relative to conventional pellets. • Higher pellet cost is more than balanced by reduced retrofit capital requirements. • Low capacity factors further favour steam-treated pellets over conventional pellets. - Abstract: Steam-treated pellets can help to address technical barriers that limit the uptake of pellets as a fuel for electricity generation, but there is limited understanding of the cost and environmental impacts of their production and use. This study investigates life cycle environmental (greenhouse gas (GHG) and air pollutant emissions) and financial implications of electricity generation from steam-treated pellets, including fuel cycle activities (biomass supply, pellet production, and combustion) and retrofit infrastructure to enable 100% pellet firing at a generating station that previously used coal. Models are informed by operating experience of pellet manufacturers and generating stations utilising coal, steam-treated and conventional pellets. Results are compared with conventional pellets and fossil fuels in a case study of electricity generation in northwestern Ontario, Canada. Steam-treated pellet production has similar GHG impacts to conventional pellets as their higher biomass feedstock requirement is balanced by reduced process electricity consumption. GHG reductions of more than 90% relative to coal and ∼85% relative to natural gas (excluding retrofit infrastructure) could be obtained with both pellet options. Pellets can also reduce fuel cycle air pollutant emissions relative to coal by 30% (NOx), 97% (SOx), and 75% (PM 10 ). Lesser retrofit requirements for steam-treated pellets more than compensate for marginally higher pellet production costs, resulting in lower electricity production cost compared to conventional pellets ($0.14/kW h vs. $0.16/kW h). Impacts of retrofit infrastructure become increasingly

  9. Steam 80 steam generator instrumentation

    International Nuclear Information System (INIS)

    Carson, W.H.; Harris, H.H.

    1980-01-01

    This paper describes two special instrumentation packages in an integral economizer (preheater) steam generator of one of the first System 80 plants scheduled to go into commercial operation. The purpose of the instrumentation is to obtain accurate operating information from regions of the secondary side of the steam generator inaccessible to normal plant instrumentation. In addition to verification of the System 80 steam generator design predictions, the data obtained will assist in verification of steam generator thermal/hydraulic computer codes developed for generic use in the industry

  10. Hydrogen production from sewage sludge by steam gasification

    Energy Technology Data Exchange (ETDEWEB)

    Aye, L.; Klinkajorn, P. [Melbourne Univ. International Technologies Centre, Melbourne, Victoria (Australia). Dept. of Civil and Environmental Engineering

    2006-07-01

    Because of the shortage of energy sources in the near future, renewable energy, such as biomass, has become an important source of energy. One of the most common approaches for producing gaseous fuels from biomass is gasification. The main product gases of gasification are hydrogen, carbon monoxide, methane and low molecular weight hydrocarbons. Because of the capability of very low emission at the point of use, the interest in using hydrogen for electrical power generation and in electric-vehicles has been increasing. Hydrogen from biomass steam gasification (SG) is a net zero green house gas emission fuel. Sewage sludge (SS) has a potential to produce hydrogen-rich gaseous fuel. Therefore, hydrogen production from sewage sludge may be a solution for cleaner fuel and the sewage sludge disposal problem. This paper presented the results of a computer model for SSSG by using Gibbs free energy minimization (GFEM) method. The computer model developed was used to determine the hydrogen production limits for various steam to biomass ratios. The paper presented an introduction to renewable energy and gasification and discussed the Gibbs free energy minimization method. The study used a RAND algorithm. It presented the computer model input parameters and discussed the results of the stoichiometric analysis and Gibbs free energy minimization. The energy requirement for hydrogen production was also presented. 17 refs., 1 tab., 6 figs.

  11. Ultra high-temperature solids-free insulating packer fluid for oil and gas production, steam injection and geothermal wells

    Energy Technology Data Exchange (ETDEWEB)

    Ezell, R.G.; Harrison, D.J. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Halliburton Energy Services, Calgary, AB (Canada)

    2008-10-15

    Uncontrolled heat transfer from production/injection tubing during thermal oil recovery via steam injection can be detrimental to the integrity of the casing and to the quality of the steam that is injected into the reservoir. An aqueous-based insulating packer fluid (IPF) was introduced to improve the steam injection process by controlling the total heat loss from the produced fluids to the surrounding wellbore, internal annuli and formation. The IPF was developed for elevated temperature environments through extensive investigation across multidisciplinary technology. The innovative system delivers performance beyond conventional systems of comparable thermal conductivity. Its density range and conductivity measurements were presented in this paper. High-temperature static aging tests showed superior gel integrity without any phase separation after exposure to temperatures higher than 260 degrees C. The new fluids are hydrate inhibitive, non-corrosive and pass oil and grease testing. They are considered to be environmentally sound by Gulf of Mexico standards. It was concluded that the new ultra high-performance insulating packer fluid (HTIPF) reduced the heat loss significantly by both conduction and convection. Heat transfer within the aqueous-based HTIPF was 97 per cent less than that of pure water. It was concluded that the HTIPF can be substituted for conventional packer fluids without compromising any well control issues. 21 refs., 1 tab., 4 figs.

  12. Selling steam

    International Nuclear Information System (INIS)

    Zimmer, M.J.; Goodwin, L.M.

    1991-01-01

    This article addresses the importance of steam sales contract is in financing cogeneration facilities. The topics of the article include the Public Utility Regulatory Policies Act provisions and how they affect the marketing of steam from qualifying facilities, the independent power producers market shift, and qualifying facility's benefits

  13. Steam generator

    International Nuclear Information System (INIS)

    Fenet, J.-C.

    1980-01-01

    Steam generator particularly intended for use in the coolant system of a pressurized water reactor for vaporizing a secondary liquid, generally water, by the primary cooling liquid of the reactor and comprising special arrangements for drying the steam before it leaves the generator [fr

  14. What is geothermal steam worth?

    International Nuclear Information System (INIS)

    Thorhallsson, S.; Ragnarsson, A.

    1992-01-01

    Geothermal steam is obtained from high-temperature boreholes, either directly from the reservoir or by flashing. The value of geothermal steam is similar to that of steam produced in boilers and lies in its ability to do work in heat engines such as turbines and to supply heat for a wide range of uses. In isolated cases the steam can be used as a source of chemicals, for example the production of carbon dioxide. Once the saturated steam has been separated from the water, it can be transported without further treatment to the end user. There are several constraints on its use set by the temperature of the reservoir and the chemical composition of the reservoir fluid. These constraints are described (temperature of steam, scaling in water phase, gas content of steam, well output) as are the methods that have been adopted to utilize this source of energy successfully. Steam can only be transported over relatively short distances (a few km) and thus has to be used close to the source. Examples are given of the pressure drop and sizing of steam mains for pipelines. The path of the steam from the reservoir to the end user is traced and typical cost figures given for each part of the system. The production cost of geothermal steam is estimated and its sensitivity to site-specific conditions discussed. Optimum energy recovery and efficiency is important as is optimizing costs. The paper will treat the steam supply system as a whole, from the reservoir to the end user, and give examples of how the site-specific conditions and system design have an influence on what geothermal steam is worth from the technical and economic points of view

  15. Utilization of high CO2 content formation gas for steam and electricity generation; Aprovechamiento del gas de formacion con alto contenido de CO2 para generacion de vapor y electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Villagomez, Paul; Lamino, Marcelo; Jacome, Jose; Pastor, Santiago [EcuadorTLC, Quito (Ecuador). Grupo PETROBRAS

    2008-07-01

    Ecuador TLC SA, as part of the PETROBRAS Group, respecting its mission to act safe, cost-effectiveness, social and environmental responsibility, currently operates an oil production project in the Ecuatorian Amazon, known as Block 18. In Block 18, the process of gas burning is response for launch approximately 10 MMSCF of the gas associated with 77% CO2 in the environment. For this reason it was built a centralized power generation plants (PGE), of 17.38 MW, taking advantage of the gas with 77% CO2 from boilers to burn it, using it as a source of heat in a combined cycle steam turbines, generating electricity. This project is environmentally efficient with reduced emissions of CO2 and as reducing fuel costs to zero. The results of CO2 reduction is a corporate goal of PETROBRAS and this project will contribute to reducing CO2 emissions by approximately 400,000 Ton over the life of the project.

  16. Hydrogen production by steam reforming of liquefied natural gas (LNG) over nickel catalysts supported on cationic surfactant-templated mesoporous aluminas

    Science.gov (United States)

    Seo, Jeong Gil; Youn, Min Hye; Park, Sunyoung; Jung, Ji Chul; Kim, Pil; Chung, Jin Suk; Song, In Kyu

    Two types of mesoporous γ-aluminas (denoted as A-A and A-S) are prepared by a hydrothermal method under different basic conditions using cationic surfactant (cetyltrimethylammonium bromide, CTAB) as a templating agent. A-A and A-S are synthesized in a medium of ammonia solution and sodium hydroxide solution, respectively. Ni/γ-Al 2O 3 catalysts (Ni/A-A and Ni/A-S) are then prepared by an impregnation method, and are applied to hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of a mesoporous γ-Al 2O 3 support on the catalytic performance of Ni/γ-Al 2O 3 is investigated. The identity of basic solution strongly affects the physical properties of the A-A and A-S supports. The high surface-area of the mesoporous γ-aluminas and the strong metal-support interaction of supported catalysts greatly enhance the dispersion of nickel species on the catalyst surface. The well-developed mesopores of the Ni/A-A and Ni/A-S catalysts prohibit the polymerization of carbon species on the catalyst surface during the reaction. In the steam reforming of LNG, both Ni/A-A and Ni/A-S catalysts give better catalytic performance than the nickel catalyst supported on commercial γ-Al 2O 3 (Ni/A-C). In addition, the Ni/A-A catalyst is superior to the Ni/A-S catalyst. The relatively strong metal-support interaction of Ni/A-A catalyst effectively suppresses the sintering of metallic nickel and the carbon deposition in the steam reforming of LNG. The large pores of the Ni/A-A catalyst also play an important role in enhancing internal mass transfer during the reaction.

  17. Steam generator arrangement

    International Nuclear Information System (INIS)

    Ssinegurski, E.

    1981-01-01

    A steam flow path arrangement for covering the walls of the rear gas pass of a steam generator is disclosed. The entire flow passes down the sidewalls with a minor portion then passing up through the rear wall to a superheater inlet header at an intermediate elevation. The major portion of the flow passes up the front wall and through hanger tubes to a roof header. From there the major portion passes across the roof and down the rear wall to the superheater inlet header at the intermediate elevation

  18. Energy Conservation Alternatives Study (ECAS): Conceptual Design and Implementation Assessment of a Utility Steam Plant with Conventional Furnace and Wet Lime Stack Gas Scrubbers

    Science.gov (United States)

    Brown, Dale H.

    1976-01-01

    A study was performed to estimate the technical/economic characteristics of a steam power plant (3500 pounds per square inch gauge, 1000 degrees Fahrenheit / 1000 degrees Fahrenheit) with a coal-burning radiant furnace and a wet lime stack gas scrubber to control sulfur emissions. Particulate emissions were controlled by an electrostatic precipitator operating at 300 degrees Fahrenheit. The stack gas from the scrubber was reheated from 125 degrees Fahrenheit to 250 degrees Fahrenheit as a base case, and from 125 degrees Fahrenheit to 175 degrees Fahrenheit as an alternate case. The study was performed on a basis consistent with the General Electric ECAS Phase II evaluation of advanced energy conversion systems for electric utility baseload applications using coal or coal-derived fuels. A conceptual design of the power plant was developed, including the on-site calcination of limestone to lime and the provision of sludge ponds to store the products of flue gas scrubbing. From this design, estimates were derived for power plant efficiency, capital cost, environmental intrusion characteristics, natural resource requirements, and cost of electricity at an assumed capacity factor of 65 percent. An implementation assessment was performed where factors affecting applicability of the conceptual design power plant in electric utility generation systems were appraised. At 250 degrees Fahrenheit and 175 degrees Fahrenheit stack gas temperatures respectively, the plants showed a cost of electricity of 39.8 and 37.0 mills per kilowatt-hours and overall plant efficiencies of 32 percent and 34 percent.

  19. Combustion Chamber Deposits and PAH Formation in SI Engines Fueled by Producer Gas from Biomass Gasification

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Schramm, Jesper

    2003-01-01

    Investigations were made concerning the formation of combustion chamber deposits (CCD) in SI gas engines fueled by producer gas. The main objective was to determine and characterise CCD and PAH formation caused by the presence of the light tar compounds phenol and guaiacol in producer gas from an...

  20. Implementation of gas concentration measurement systems using mass spectrometry in containment thermal-hydraulics test facilities: different approaches for calibration and measurement with steam/air/helium mixtures

    International Nuclear Information System (INIS)

    Auban, O.; Malet, J.; Brun, P.; Brinster, J.; Quillico, J. J.; Studer, E.

    2003-01-01

    Thermal-hydraulic test facilities are used to investigate various containment phenomena such as, for example, mixing and stratification of gases or steam condensation in the presence of noncondensable. Experiments are also required for validation of codes possessing capabilities for modelling such three-dimensional effects. The need for advanced instrumentation allowing to measure gas concentration in such conditions (typically: 100-180 .deg. C; 1-10 bar) and to get sufficiently refined information about spatial distribution of the different gas species has become apparent. This paper deals with the implementation of gas analysis systems using some commercial Quadrupole Mass Spectrometers (QMS) that have been recently added to the basic instrumentation in three thermal-hydraulics test facilities namely MISTRA (CEA, France), TOSQAN (IRSN, France) and PANDA (PSI, Switzerland). In recent years, QMS have increasingly been selected for various applications because of attractive metrological characteristics (sensibility, span of concentration range, response time, stability, etc.), relatively compact size and low cost. Although commercial QMS are sold as 'turnkey' systems, these instruments are delicate to bring into operation. As QMS are not absolute instruments, reliable calibration procedures are required for quantitative measurements. A mass spectrometer can be regarded as an ionisation gauge with subsequent separation system for the different ion species. The calculation of gas concentrations considers the partial pressure of a particular gas species to be proportional to the ion current it generates. Anyway, one must know the QMS sensitivity to the gases of interest and the only practical method is to use calibration gases. Calibration must be carried out using mixtures whose compositions are close to any possible sample compositions and the procedure selected should duplicate as closely as possible the measurement conditions established during the real experiment

  1. 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

  2. Economic assessment of solar and conventional biomass gasification technologies: Financial and policy implications under feedstock and product gas price uncertainty

    International Nuclear Information System (INIS)

    Nickerson, Thomas A.; Hathaway, Brandon J.; Smith, Timothy M.; Davidson, Jane H.

    2015-01-01

    Four configurations of a novel solar-heated biomass gasification facility and one configuration of conventional biomass gasification are analyzed through financial and policy scenarios. The purpose of this study is to determine the potential financial position for varying configurations of a novel technology, as compared to the current state-of-the-art gasification technology. Through the use of project finance and policy scenario development, we assess the baseline breakeven syngas price (normalized against natural gas prices and based upon annual feedstock consumption), the sensitivity of major cost components for the novel facilities, and the implications of policy levers on the economic feasibility of the solar facilities. Findings show that certain solar configurations may compete with conventional facilities on a straightforward economic basis. However, with renewable energy policy levers in place the solar technologies become increasingly attractive options. - Highlights: • We model four solar and one conventional biomass gasification systems. • We assess economic feasibility of these systems with and without policy incentives. • Solar facilities compete with the conventional system in certain scenarios. • Feedstock costs are the largest contributor to system cost sensitivity. • Policy incentives create an economically favorable scenario for solar facilities

  3. Aspen Plus simulation of biomass integrated gasification combined cycle systems at corn ethanol plants

    International Nuclear Information System (INIS)

    Zheng, Huixiao; Kaliyan, Nalladurai; Morey, R. Vance

    2013-01-01

    Biomass integrated gasification combined cycle (BIGCC) systems and natural gas combined cycle (NGCC) systems are employed to provide heat and electricity to a 0.19 hm 3 y −1 (50 million gallon per year) corn ethanol plant using different fuels (syrup and corn stover, corn stover alone, and natural gas). Aspen Plus simulations of BIGCC/NGCC systems are performed to study effects of different fuels, gas turbine compression pressure, dryers (steam tube or superheated steam) for biomass fuels and ethanol co-products, and steam tube dryer exhaust treatment methods. The goal is to maximize electricity generation while meeting process heat needs of the plant. At fuel input rates of 110 MW, BIGCC systems with steam tube dryers provide 20–25 MW of power to the grid with system thermal efficiencies (net power generated plus process heat rate divided by fuel input rate) of 69–74%. NGCC systems with steam tube dryers provide 26–30 MW of power to the grid with system thermal efficiencies of 74–78%. BIGCC systems with superheated steam dryers provide 20–22 MW of power to the grid with system thermal efficiencies of 53–56%. The life-cycle greenhouse gas (GHG) emission reduction for conventional corn ethanol compared to gasoline is 39% for process heat with natural gas (grid electricity), 117% for BIGCC with syrup and corn stover fuel, 124% for BIGCC with corn stover fuel, and 93% for NGCC with natural gas fuel. These GHG emission estimates do not include indirect land use change effects. -- Highlights: •BIGCC and natural gas combined cycle systems at corn ethanol plants are simulated. •The best performance results in 25–30 MW power to grid. •The best performance results in 74–78% system thermal efficiencies. •GHG reduction for corn ethanol with BIGCC systems compared to gasoline is over 100%

  4. Solid Oxide Fuel Cells coupled with a biomass gasification unit

    Directory of Open Access Journals (Sweden)

    Skrzypkiewicz Marek

    2016-01-01

    Full Text Available A possibility of fuelling a solid oxide fuel cell stack (SOFC with biomass fuels can be realized by coupling a SOFC system with a self-standing gasification unit. Such a solution enables multi-fuel operation, elasticity of the system as well as the increase of the efficiency of small-scale biomass-to-electricity conversion units. A system of this type, consisting of biomass gasification unit, gas purification unit, SOFC stack, anode off-gas afterburner and peripherals was constructed and operated successfully. During the process, biomass fuel (wood chips was gasified with air as gasification agent. The gasifier was capable of converting up to 30 kW of fuel to syngas with efficiencies up to 75%. Syngas leaving the gasification unit is delivered to a medium temperature adsorber for sulphur compounds removal. Steam is added to the purified fuel to maintain steam to carbon ratio higher than 2. The syngas then is passed to a SOFC stack through a fuel preheater. In such a configuration it was possible to operate a commercial 1.3 kW stack within its working regime. Conducted tests confirmed successful operation of a SOFC stack fuelled by biomass-sourced syngas.

  5. The effects of location, feedstock availability, and supply-chain logistics on the greenhouse gas emissions of forest-biomass energy utilization in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Jappinen, E,

    2013-11-01

    Forest biomass represents a geographically distributed feedstock, and geographical location affects the greenhouse gas (GHG) performance of a given forest-bioenergy system in several ways. For example, biomass availability, forest operations, transportation possibilities and the distances involved, biomass end-use possibilities, fossil reference systems, and forest carbon balances all depend to some extent on location. The overall objective of this thesis was to assess the GHG emissions derived from supply and energy-utilization chains of forest biomass in Finland, with a specific focus on the effect of location in relation to forest biomass's availability and the transportation possibilities. Biomass availability and transportation-network assessments were conducted through utilization of geographical information system methods, and the GHG emissions were assessed by means of lifecycle assessment. The thesis is based on four papers in which forest biomass supply on industrial scale was assessed. The feedstocks assessed in this thesis include harvesting residues, smalldiameter energy wood and stumps. The principal implication of the findings in this thesis is that in Finland, the location and availability of biomass in the proximity of a given energyutilization or energy-conversion plant is not a decisive factor in supply-chain GHG emissions or the possible GHG savings to be achieved with forest-biomass energy use. Therefore, for the greatest GHG reductions with limited forest-biomass resources, energy utilization of forest biomass in Finland should be directed to the locations where most GHG savings are achieved through replacement of fossil fuels. Furthermore, one should prioritize the types of forest biomass with the lowest direct supply-chain GHG emissions (e.g., from transport and comminution) and the lowest indirect ones (in particular, soil carbon-stock losses), regardless of location. In this respect, the best combination is to use harvesting residues

  6. Comparing cell viability and ethanol fermentation of the thermotolerant yeast Kluyveromyces marxianus and Saccharomyces cerevisiae on steam-exploded biomass treated with laccase.

    Science.gov (United States)

    Moreno, Antonio D; Ibarra, David; Ballesteros, Ignacio; González, Alberto; Ballesteros, Mercedes

    2013-05-01

    In this study, the thermotolerant yeast Kluyveromyces marxianus CECT 10875 was compared to the industrial strain Saccharomyces cerevisiae Ethanol Red for lignocellulosic ethanol production. For it, whole slurry from steam-exploded wheat straw was used as raw material, and two process configurations, simultaneous saccharification and fermentation (SSF) and presaccharification and simultaneous saccharification and fermentation (PSSF), were evaluated. Compared to S. cerevisiae, which was able to produce ethanol in both process configurations, K. marxianus was inhibited, and neither growth nor ethanol production occurred during the processes. However, laccase treatment of the whole slurry removed specifically lignin phenols from the overall inhibitory compounds present in the slurry and triggered the fermentation by K. marxianus, attaining final ethanol concentrations and yields comparable to those obtained by S. cerevisiae. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Economic and Technical Assessment of Wood Biomass Fuel Gasification for Industrial Gas Production

    Energy Technology Data Exchange (ETDEWEB)

    Anastasia M. Gribik; Ronald E. Mizia; Harry Gatley; Benjamin Phillips

    2007-09-01

    This project addresses both the technical and economic feasibility of replacing industrial gas in lime kilns with synthesis gas from the gasification of hog fuel. The technical assessment includes a materials evaluation, processing equipment needs, and suitability of the heat content of the synthesis gas as a replacement for industrial gas. The economic assessment includes estimations for capital, construction, operating, maintenance, and management costs for the reference plant. To perform these assessments, detailed models of the gasification and lime kiln processes were developed using Aspen Plus. The material and energy balance outputs from the Aspen Plus model were used as inputs to both the material and economic evaluations.

  8. Biomass energy

    International Nuclear Information System (INIS)

    Pasztor, J.; Kristoferson, L.

    1992-01-01

    Bioenergy systems can provide an energy supply that is environmentally sound and sustainable, although, like all energy systems, they have an environmental impact. The impact often depends more on the way the whole system is managed than on the fuel or on the conversion technology. The authors first describe traditional biomass systems: combustion and deforestation; health impact; charcoal conversion; and agricultural residues. A discussion of modern biomass systems follows: biogas; producer gas; alcohol fuels; modern wood fuel resources; and modern biomass combustion. The issue of bioenergy and the environment (land use; air pollution; water; socioeconomic impacts) and a discussion of sustainable bioenergy use complete the paper. 53 refs., 9 figs., 14 tabs

  9. Hydrogen Production via Synthetic Gas by Biomass/Oil Partial Oxidation

    Czech Academy of Sciences Publication Activity Database

    Hanika, Jiří; Lederer, J.; Tukač, V.; Veselý, Václav; Kováč, D.

    176-177, - (2011), s. 286-290 ISSN 1385-8947. [International Conference on Chemical Reactors CHEMREACTOR-19 /19./. Vienna, 05.09.2010-09.09.2010] R&D Projects: GA MPO 2A-2TP1/024 Institutional research plan: CEZ:AV0Z40720504 Keywords : hydrogen * biomass * partial oxidation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.461, year: 2011

  10. Effects of hydrothermal treatment of sewage sludge on pyrolysis and steam gasification

    International Nuclear Information System (INIS)

    Moon, Jihong; Mun, Tae-Young; Yang, Won; Lee, Uendo; Hwang, Jungho; Jang, Ensuk; Choi, Changsik

    2015-01-01

    Highlights: • Hydrothermal treatment (HT) is energy efficient and increases fuel energy density. • Pyrolysis and steam gasification were performed with sewage sludge before/after HT. • Product gases resembled those from wood chips, particularly at high temperature. • HT increases sludge lignin content, possibly enhancing methane yield of product gas. • HT can improve sewage sludge for use as an alternative to biomass and fossil fuels. - Abstract: Hydrothermal treatment is a promising option for pretreatment drying of organic waste, due to its low energy consumption and contribution to increasing fuel energy density. In this study, the characteristics of hydrothermally treated sewage sludge were investigated, and pyrolysis and steam gasification were performed with the sludge before and after hydrothermal treatment. The overall composition of product gases from treated sludge was similar to that obtained from steam gasification of wood chips, particularly under high-temperature conditions. In addition, the increase in lignin content of sewage sludge following hydrothermal treatment could help enhance methane yield in product gas during pyrolysis and steam gasification. The findings suggest that hydrothermal treatment is an appropriate method for improving sewage sludge for use as an alternative to biomass and fossil fuels

  11. Green House Gas Control and Agricultural Biomass for Sustainable Animal Agriculture in Developing Countries

    Directory of Open Access Journals (Sweden)

    J Takahashi

    2010-06-01

    Full Text Available Important green house gases (GHG attributed to animal agriculture are methane (CH4 and nitrous oxide (N2O, though carbon dioxide (CO2 contributes almost half of total greenhouse effect. Rumen CH4 production in an enteric fermentation can be accounted as the biggest anthropogenic source. Some of prebiotics and probiotics have been innovated to mitigate rumen CH4 emission. The possible use of agricultural biomass consisted of non-edible parts of crop plants such as cellulose and hemi cellulose and animal wastes was proposed as a renewable energy and nitrogen sources. The ammonia stripping from digested slurry of animal manure in biogas plant applied three options of nitrogen recycling to mitigate nitrous oxide emission. In the first option of the ammonia stripping, the effect of ammonolysis on feed value of cellulose biomass was evaluated on digestibility, energy metabolism and protein utilization. Saccharification of the NH3 treated cellulose biomass was confirmed in strictly anaerobic incubation with rumen cellulolytic bacteria, Ruminoccous flavefaciens, to produce bio-ethanol as the second option of ammonia stripping. In an attempt of NH3 fuel cell, the reformed hydrogen from the NH3 stripped from 20 liter of digested slurry in thermophilic biogas plant could generate 0.12 W electricity with proton exchange membrane fuel cell (PEM as the third option.

  12. Biomass Thermochemical Conversion Program. 1983 Annual report

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-08-01

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

  13. Process for treating biomass

    Science.gov (United States)

    Campbell, Timothy J.; Teymouri, Farzaneh

    2018-04-10

    This invention is directed to a process for treating biomass. The biomass is treated with a biomass swelling agent within the vessel to swell or rupture at least a portion of the biomass. A portion of the swelling agent is removed from a first end of the vessel following the treatment. Then steam is introduced into a second end of the vessel different from the first end to further remove swelling agent from the vessel in such a manner that the swelling agent exits the vessel at a relatively low water content.

  14. The structure evolution of biochar from biomass pyrolysis and its correlation with gas pollutant adsorption performance.

    Science.gov (United States)

    Chen, Yingquan; Zhang, Xiong; Chen, Wei; Yang, Haiping; Chen, Hanping

    2017-12-01

    Biochar is carbon-rich, porous and with a great potential in gas pollutant controlling. The physical-chemical structure of biochar is important for the application. This paper firstly reviewed the evolution behavior of physical-chemical structure for biochar during pyrolysis. At lower temperature (700°C), it may transit into a "graphite microcrystalline structure", the porosity and functional groups were diminished correspondingly. The modification of biochar and its application as sorbent for gas pollutant were also reviewed. Activation and doping can significantly increase the porosity and special functional groups in biochar, which is favorable for gas pollutant adsorption. With a higher porosity, the adsorption capacity of gas pollutant is bigger, however, the functional groups determined the sorption stability of gas pollutant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. CFD analysis of combustion of natural gas and syngas from biomass pyrolysis in the combustion chamber of a micro gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Fantozzi, Francesco; Laranci, Paolo; D' Alessandro, Bruno [University of Perugia (DII/UNIPG) (Italy). Dept. of Industrial Engineering], Emails: fanto@unipg.it, paolo.laranci@unipg.it, dalessandro@bio-net.it

    2009-07-01

    Micro gas turbines (MGT) can be profitably used for the production of distributed energy (DE), with the possibility to use gaseous fuels with low BTU derived from biomass or waste through the pyrolysis or gasification processes. These synthesis gases (SG) show significant differences with respect to natural gas (NG), in terms of composition, calorific value, content of hydrogen, tar and particulate matter content; such differences can be turn into problems of ignition, instability burning, difficulties in controlling the emissions and fouling. CFD analysis of the combustion process is an essential tool for identifying the main critical arising in using these gases, in order to modify existing geometries and to develop new generation of combustor for use with low BTU gases. This paper describes the activities of experimental and numerical analysis carried out to study the combustion process occurring inside an existing annular Rich-Quench-Lean (RQL) Combustion Chamber (CC) of a 80 kW MGT. In the paper some results of a CFD study of the combustion process performed with an original developed chemical models are reported in terms of temperature and velocity distributions inside the CC and in terms of compositions of turbine inlet gas and of its thermodynamic parameters (mass flow, temperature, pressure). An evaluation of pollutant emissions of CO, CO{sub 2} and NOx and a comparison with the available experimental data relating to the case of combustion of NG is also provided in the paper. Moreover, the carried out investigation concerns the case of operation with a SG fuel derived from biomass in an Integrated Pyrolysis Regenerated Plant (IPRP). (author)

  16. Nitrogen fertilization of switchgrass increases biomass yield and improves net greenhouse gas balance in northern Michigan, U.S.A

    International Nuclear Information System (INIS)

    Nikiema, Paligwende; Rothstein, David E.; Min, Doo-Hong; Kapp, Christian J.

    2011-01-01

    Nitrogen (N) fertilization can increase bioenergy crop production; however, fertilizer production and application can contribute to greenhouse gas (GHG) emissions, potentially undermining the GHG benefits of bioenergy crops. The objective of this study was to evaluate the effects of N fertilization on GHG emissions and biomass production of switchgrass bioenergy crop, in northern Michigan. Nitrogen fertilization treatments included 0 kg ha -1 (control), 56 kg ha -1 (low) and 112 kg ha -1 (high) of N applied as urea. Soil fluxes of CO 2 , N 2 O and CH 4 were measured every two weeks using static chambers. Indirect GHG emissions associated with field activities, manufacturing and transport of fertilizer and pesticides were derived from the literature. Switchgrass aboveground biomass yield was evaluated at the end of the growing season. Nitrogen fertilization contributed little to soil GHG emissions; relative to the control, there were additional global warming potential of 0.7 Mg ha -1 y -1 and 1.5 Mg ha -1 y -1 as CO 2 equivalents (CO 2 eq), calculated using the IPCC values, in the low and high N fertilization treatments, respectively. However, N fertilization greatly stimulated CO 2 uptake by switchgrass, resulting in 1.5- and 2.5-fold increases in biomass yield in the low and high N fertilization treatments, respectively. Nitrogen amendments improved the net GHG benefits by 2.6 Mg ha -1 y -1 and 9.4 Mg ha -1 y -1 as CO 2 eq relative to the control. Results suggest that N fertilization of switchgrass in this region could reduce (15-50%) the land base needed for bioenergy production and decrease pressure on land for food and forage crop production. -- Highlights: → We examine the effects of N fertilization of switchgrass on GHG emissions. → Effects of N fertilization on biomass production of switchgrass bioenergy crop. → N fertilization contributed little to greenhouse gas emissions. → N fertilization greatly stimulated CO 2 uptake by the switchgrass. → N

  17. Proposal and analysis of a polygeneration system for power and methanol based on natural gas and biomass as co-feed

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.Q.; Hong, H.; Jin, H.G.; Cai, R.X. [Chinese Academy of Sciences, Beijing (China). Inst. of Engineering Thermophysics

    2008-07-01

    Biomass is getting increasing attention as a potential source of renewable energy as a result of global issues such as sustainable energy and reduction of greenhouse gases. Biomass is an abundant feedstock containing mainly carbon, oxygen, hydrogen, and volatile matter. The purpose of this paper was to propose a new biomass-natural gas based polygeneration system, with partial recycling unreacted syngas and without the shift process for methanol production and power generation. The paper identified the features of the proposed system and that determine the exergy ratio of chemical production and thermodynamic performance of the system. The paper provided an introduction to individual systems such as the natural gas to methanol system and biomass to methanol system. The paper also presented the suggested polygeneration system based on biomass and natural gas as co-feed. Processes that were described included syngas preparation; distillation process; and power generation. System evaluation criteria and performance were identified. It was concluded that bio-energy made the best utilization and overcame the disadvantages of the polygeneration system, partly taking the place of natural gas which is non-renewable. Bio-energy could reduce carbon dioxide emission for it is carbon neutrality. 18 refs., 3 tabs., 9 figs.

  18. Spatial effects of aboveground biomass on soil ecological parameters and trace gas fluxes in a savannah ecosystem of Mount Kilimanjaro

    Science.gov (United States)

    Becker, Joscha; Gütlein, Adrian; Sierra Cornejo, Natalia; Kiese, Ralf; Hertel, Dietrich; Kuzyakov, Yakov

    2015-04-01

    The savannah biome is a hotspot for biodiversity and wildlife conservation in Africa and recently got in the focus of research on carbon sequestration. Savannah ecosystems are under strong pressure from climate and land-use change, especially around populous areas like the Mt. Kilimanjaro region. Savannah vegetation in this area consists of grassland with isolated trees and is therefore characterized by high spatial variation of canopy cover, aboveground biomass and root structure. Canopy structure is known to affect microclimate, throughfall and evapotranspiration and thereby controls soil moisture conditions. Consequently, the canopy structure is a major regulator for soil ecological parameters and soil-atmospheric trace gas exchange (CO2, N2O, CH4) in water limited environments. The spatial distribution of these parameters and the connection between above and belowground processes are important to understand and predict ecosystem changes and estimate its vulnerability. Our objective was to determine trends and changes of soil parameters and relate their spatial variability to the vegetation structure. We chose three trees from each of the two most dominant species (Acacia nilotica and Balanites aegyptiaca) in our research area. For each tree, we selected transects with nine sampling points of the same relative distances to the stem. Distances were calculated in relation to the crown radius. At these each sampling point a soil core was taken and separated in 0-10 cm and 10-30 cm depth. We measured soil carbon (C) and nitrogen (N) storage, microbial biomass carbon C and N, soil respiration as well as root biomass and -density, soil temperature and soil water content. Each tree was characterized by crown spread, leaf area index and basal area. Preliminary results show that C and N stocks decreased about 50% with depth independently of distance to the tree. Soil water content under the tree crown increased with depth while it decreased under grass cover. Microbial

  19. Biomass thermochemical gasification: Experimental studies and modeling

    Science.gov (United States)

    Kumar, Ajay

    The overall goals of this research were to study the biomass thermochemical gasification using experimental and modeling techniques, and to evaluate the cost of industrial gas production and combined heat and power generation. This dissertation includes an extensive review of progresses in biomass thermochemical gasification. Product gases from biomass gasification can be converted to biopower, biofuels and chemicals. However, for its viable commercial applications, the study summarizes the technical challenges in the gasification and downstream processing of product gas. Corn stover and dried distillers grains with solubles (DDGS), a non-fermentable byproduct of ethanol production, were used as the biomass feedstocks. One of the objectives was to determine selected physical and chemical properties of corn stover related to thermochemical conversion. The parameters of the reaction kinetics for weight loss were obtained. The next objective was to investigate the effects of temperature, steam to biomass ratio and equivalence ratio on gas composition and efficiencies. DDGS gasification was performed on a lab-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Increasing the temperature resulted in increases in hydrogen and methane contents and efficiencies. A model was developed to simulate the performance of a lab-scale gasifier using Aspen Plus(TM) software. Mass balance, energy balance and minimization of Gibbs free energy were applied for the gasification to determine the product gas composition. The final objective was to optimize the process by maximizing the net energy efficiency, and to estimate the cost of industrial gas, and combined heat and power (CHP) at a biomass feedrate of 2000 kg/h. The selling price of gas was estimated to be 11.49/GJ for corn stover, and 13.08/GJ for DDGS. For CHP generation, the electrical and net efficiencies were 37 and 86%, respectively for corn stover, and 34 and 78%, respectively for DDGS. For

  20. Characterization of products obtained from pyrolysis and steam gasification of wood waste, RDF, and RPF.

    Science.gov (United States)

    Hwang, In-Hee; Kobayashi, Jun; Kawamoto, Katsuya

    2014-02-01

    Pyrolysis and steam gasification of woody biomass chip (WBC) obtained from construction and demolition wastes, refuse-derived fuel (RDF), and refuse paper and plastic fuel (RPF) were performed at various temperatures using a lab-scale instrument. The gas, liquid, and solid products were examined to determine their generation amounts, properties, and the carbon balance between raw material and products. The amount of product gas and its hydrogen concentration showed a considerable difference depending on pyrolysis and steam gasification at higher temperature. The reaction of steam and solid product, char, contributed to an increase in gas amount and hydrogen concentration. The amount of liquid products generated greatly depended on temperature rather than pyrolysis or steam gasification. The compositions of liquid product varied relying on raw materials used at 500°C but the polycyclic aromatic hydrocarbons became the major compounds at 900°C irrespective of the raw materials used. Almost fixed carbon (FC) of raw materials remained as solid products under pyrolysis condition whereas FC started to decompose at 700°C under steam gasification condition. For WBC, both char utilization by pyrolysis at low temperature (500°C) and syngas recovery by steam gasification at higher temperature (900°C) might be practical options. From the results of carbon balance of RDF and RPF, it was confirmed that the carbon conversion to liquid products conspicuously increased as the amount of plastic increased in the raw material. To recover feedstock from RPF, pyrolysis for oil recovery at low temperature (500°C) might be one of viable options. Steam gasification at 900°C could be an option but the method of tar reforming (e.g. catalyst utilization) should be considered. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Combustion Chamber Deposits and PAH Formation in SI Engines Fueled by Producer Gas from Biomass Gasification

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Schramm, Jesper

    2003-01-01

    Investigations were made concerning the formation of combustion chamber deposits (CCD) in SI gas engines fueled by producer gas. The main objective was to determine and characterise CCD and PAH formation caused by the presence of the light tar compounds phenol and guaiacol in producer gas from...... on filters and a sorbent was used for collection of vapour phase aromatic compounds. The filters and sorbent were analysed for polycyclic aromatic hydrocarbons (PAH) formed during combustion. The measurements showed that there was no significant increase in particulate PAH emissions due to the tar compounds...

  2. Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup, and Oxygen Separation Equipment; Task 9: Mixed Alcohols From Syngas -- State of Technology

    Energy Technology Data Exchange (ETDEWEB)

    Nexant Inc.

    2006-05-01

    This deliverable is for Task 9, Mixed Alcohols from Syngas: State of Technology, as part of National Renewable Energy Laboratory (NREL) Award ACO-5-44027, ''Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup and Oxygen Separation Equipment''. Task 9 supplements the work previously done by NREL in the mixed alcohols section of the 2003 technical report Preliminary Screening--Technical and Economic Assessment of Synthesis Gas to Fuels and Chemicals with Emphasis on the Potential for Biomass-Derived Syngas.

  3. Hydrogen production from high-moisture content biomass in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Antal, M.J. Jr.; Adschiri, T.; Ekbom, T. [Univ. of Hawaii, Honolulu, HI (United States)] [and others

    1996-10-01

    Most hydrogen is produced by steam reforming methane at elevated pressures. The goal of this research is to develop commercial processes for the catalytic steam reforming of biomass and other organic wastes at high pressures. This approach avoids the high cost of gas compression and takes advantage of the unique properties of water at high pressures. Prior to this year the authors reported the ability of carbon to catalyze the decomposition of biomass and related model compounds in supercritical water. The product gas consists of hydrogen, carbon dioxide, carbon monoxide, methane, and traces of higher hydrocarbons. During the past year the authors have: (a) developed a method to extend the catalyst life, (b) begun studies of the role of the shift reaction, (c) completed studies of carbon dioxide absorption from the product effluent by high pressure water, (d) measured the rate of carbon catalyst gasification in supercritical water, (e) discovered the pumpability of oil-biomass slurries, and (f) completed the design and begun fabrication of a flow reactor that will steam reform whole biomass feedstocks (i.e. sewage sludge) and produce a hydrogen rich synthesis gas at very high pressure (>22 MPa).

  4. Life cycle assessment of fuels for district heating: A comparison of waste incineration, biomass- and natural gas combustion

    International Nuclear Information System (INIS)

    Eriksson, Ola; Finnveden, Goeran; Ekvall, Tomas; Bjoerklund, Anna

    2007-01-01

    The aim of this consequential life cycle assessment (LCA) is to compare district heating based on waste incineration with combustion of biomass or natural gas. The study comprises two options for energy recovery (combined heat and power (CHP) or heat only), two alternatives for external, marginal electricity generation (fossil lean or intense), and two alternatives for the alternative waste management (landfill disposal or material recovery). A secondary objective was to test a combination of dynamic energy system modelling and LCA by combining the concept of complex marginal electricity production in a static, environmental systems analysis. Furthermore, we wanted to increase the methodological knowledge about how waste can be environmentally compared to other fuels in district-heat production. The results indicate that combustion of biofuel in a CHP is environmentally favourable and robust with respect to the avoided type of electricity and waste management. Waste incineration is often (but not always) the preferable choice when incineration substitutes landfill disposal of waste. It is however, never the best choice (and often the worst) when incineration substitutes recycling. A natural gas fired CHP is an alternative of interest if marginal electricity has a high fossil content. However, if the marginal electricity is mainly based on non-fossil sources, natural gas is in general worse than biofuels

  5. Thermo-economic analysis of a solid oxide fuel cell and steam injected gas turbine plant integrated with woodchips gasification

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Rokni, Masoud

    2014-01-01

    cost on the generation cost is also presented. In order to discuss the investment cost, an economic analysis has been carried out and main parameters such as Net Present Value (NPV), internal rate of return (IRR) and Time of Return of Investment (TIR) are calculated and discussed.......% respectively which are significantly greater than conventional 10 MWe plants fed by biomass. Thermo-economic analysis provides an average cost of electricity for best performing layouts close to 6.4 and 9.4 c€/kWe which is competitive within the market. A sensitivity analysis of the influence of SOFC stack...

  6. Probabilistic Load-Flow Analysis of Biomass-Fuelled Gas Engines with Electrical Vehicles in Distribution Systems

    Directory of Open Access Journals (Sweden)

    Francisco J. Ruiz-Rodríguez

    2017-10-01

    Full Text Available Feeding biomass-fueled gas engines (BFGEs with olive tree pruning residues offers new opportunities to decrease fossil fuel use in road vehicles and electricity generation. BFGEs, coupled to radial distribution systems (RDSs, provide renewable energy and power that can feed electric vehicle (EV charging stations. However, the combined impact of BFGEs and EVs on RDSs must be assessed to assure the technical constraint fulfilment. Because of the stochastic nature of source/load, it was decided that a probabilistic approach was the most viable option for this assessment. Consequently, this research developed an analytical technique to evaluate the technical constraint fulfilment in RDSs with this combined interaction. The proposed analytical technique (PAT involved the calculation of cumulants and the linearization of load-flow equations, along with the application of the cumulant method, and Cornish-Fisher expansion. The uncertainties related to biomass stock and its heating value (HV were important factors that were assessed for the first time. Application of the PAT in a Spanish RDS with BFGEs and EVs confirmed the feasibility of the proposal and its additional benefits. Specifically, BFGEs were found to clearly contribute to the voltage constraint fulfilment. The computational cost of the PAT was lower than that associated with Monte-Carlo simulations (MCSs.

  7. Particulate and trace gas emissions from large biomass fires in North America

    International Nuclear Information System (INIS)

    Radke, L.F.; Hegg, D.A.; Hobbs, P.V.; Nance, J.D.; Lyons, J.H.; Laursen, K.K.; Weiss, R.E.; Riggan, P.J.; Ward, D.E.

    1991-01-01

    In this chapter the authors describe the results of airborne studies of smokes from 17 biomass fuel fires, including 14 prescribed fires and 3 wildfires, burned primarily in the temperature zone of North America between 34 degree and 49 degree N latitude. The prescribed fires were in forested lands and logging debris and varied in areas burned from 10 to 700 hectares (ha) (over a few hours). One of the wildfires ultimately consumed 20,000 h a and burned over a period of weeks. The larger fires produced towering columns of smoke and capping water clouds. As an indication of scale, the prescribed fires were visible only as small features in meteorological satellite imagery, but one of the wildfires studied produced a persistent, visible plume more than 1,000 kilometers (km) long. The studies have focused on factors that could impact global climate through alteration of the earth's radiation balance. These include emissions of trace gases and smoke particles from biomass burning, the optical properties of the smoke, and the interaction of the smoke particles with clouds

  8. Integration of Methane Steam Reforming and Water Gas Shift Reaction in a Pd/Au/Pd-Based Catalytic Membrane Reactor for Process Intensification.

    Science.gov (United States)

    Castro-Dominguez, Bernardo; Mardilovich, Ivan P; Ma, Liang-Chih; Ma, Rui; Dixon, Anthony G; Kazantzis, Nikolaos K; Ma, Yi Hua

    2016-09-19

    Palladium-based catalytic membrane reactors (CMRs) effectively remove H₂ to induce higher conversions in methane steam reforming (MSR) and water-gas-shift reactions (WGS). Within such a context, this work evaluates the technical performance of a novel CMR, which utilizes two catalysts in series, rather than one. In the process system under consideration, the first catalyst, confined within the shell side of the reactor, reforms methane with water yielding H₂, CO and CO₂. After reforming is completed, a second catalyst, positioned in series, reacts with CO and water through the WGS reaction yielding pure H₂O, CO₂ and H₂. A tubular composite asymmetric Pd/Au/Pd membrane is situated throughout the reactor to continuously remove the produced H₂ and induce higher methane and CO conversions while yielding ultrapure H₂ and compressed CO₂ ready for dehydration. Experimental results involving (i) a conventional packed bed reactor packed (PBR) for MSR, (ii) a PBR with five layers of two catalysts in series and (iii) a CMR with two layers of two catalysts in series are comparatively assessed and thoroughly characterized. Furthermore, a comprehensive 2D computational fluid dynamics (CFD) model was developed to explore further the features of the proposed configuration. The reaction was studied at different process intensification-relevant conditions, such as space velocities, temperatures, pressures and initial feed gas composition. Finally, it is demonstrated that the above CMR module, which was operated for 600 h, displays quite high H₂ permeance and purity, high CH₄ conversion levels and reduced CO yields.

  9. A review on the use of gas and steam turbine combined cycles as prime movers for large ships. Part I: Background and design

    International Nuclear Information System (INIS)

    Haglind, Fredrik

    2008-01-01

    The aim of the present paper is to review the prospects of using combined cycles as prime movers for large ships, like, container ships, tankers and bulk carriers. The paper is divided into three parts of which this paper constitutes Part I. Here, the environmental and human health concerns of international shipping are outlined. The regulatory framework relevant for shipping and the design of combined cycles are discussed. In Part II, previous work and experience are reviewed, and an overview of the implications of introducing combined cycles as prime movers is included. In Part III, marine fuels are discussed and the pollutant emissions of gas turbines are compared with those of two-stroke, slow-speed diesel engines. Environmental effects of shipping include contributions to the formation of ground-level ozone, acidification, eutrophication and climate impact. Tightening environmental regulations limit the fuel sulphur content and pollutant emissions. For moderate live steam pressures, a vertical HRSG of drum-type mounted directly over the gas turbine, is suggested to be a viable configuration that minimizes ground floor and space requirements

  10. Assesment of the energy quality of the synthesis gas produced from biomass derived fuels conversion: Part I: Liquid Fuels, Ethanol

    International Nuclear Information System (INIS)

    Arteaga Perez, Luis E; Casas, Yannay; Peralta, Luis M; Granda, Daikenel; Prieto, Julio O

    2011-01-01

    The use of biofuels plays an important role to increase the efficiency and energetic safety of the energy processes in the world. The main goal of the present research is to study from the thermodynamics and kinetics the effect of the operational variables on the thermo-conversion processes of biomass derived fuels focused on ethanol reforming. Several models are developed to assess the technological proposals. The minimization of Gibbs free energy is the criterion applied to evaluate the performance of the different alternatives considering the equilibrium constraints. All the models where validated on an experimental data base. The gas composition, HHV and the ratio H2/CO are used as measures for the process efficiency. The operational parameters are studied in a wide range (reactants molar ratio, temperature and oxygen/fuel ratio). (author)

  11. Simulation of a gas jet entering the secondary side of a steam generator during a SGTR sequence: Validation of a FLUENT 6.2 Model

    Energy Technology Data Exchange (ETDEWEB)

    Lopez del Pra, C. Lopez, E-mail: Claudia.lopez@ciemat.e [Unit of Nuclear Safety Research, CIEMAT, Madrid (Spain); Velasco, F.J.S.; Herranz, L.E. [Unit of Nuclear Safety Research, CIEMAT, Madrid (Spain)

    2010-09-15

    This paper summarizes the major insights gained as a result of gas jets entering a tube bundle from either a guillotine or a fish-mouth breach of a steam generator tube. This scenario is highly relevant in nuclear safety since it determines the potential retention of radioactive particles during risk-dominant sequences, the so-called Steam Generator Tube Rupture (SGTR) sequences. The scenario has been modeled with the FLUENT 6.2 code and its predictions have been proven to be grid independent and consistent with the experimental data available. The topology of the jets and the influence of the inlet mass flow rate (from 75 to 250 kg/h) have been studied in terms of velocity profiles. The results show that the breach shape heavily determines the jet topology. Both jets initially describe a quasi-parabolic trajectory, which is affected by the presence of the tubes. A guillotine breach generates a jet with azimuthal symmetry, which vanishes for the fish-mouth breach configuration. In this case, jet expands azimuthally in a pseudo-triangular way with a small angle. This fact diminishes the momentum loss across the bundle, so that for the same inlet mass flow rate the fish-mouth jet penetration is higher than the guillotine one. The normalized maximum radial and axial velocities of the jet from the guillotine breach are found to be self-similar with respect to inlet mass flow rate along the tube row position and axial distance to the breach, respectively. However, in absolute terms higher penetrations are found at higher mass flow rates.

  12. INTEGRATED PYROLYSIS COMBINED CYCLE BIOMASS POWER SYSTEM CONCEPT DEFINITION

    International Nuclear Information System (INIS)

    Sandvig, Eric; Walling, Gary; Brown, Robert C.; Pletka, Ryan; Radlein, Desmond; Johnson, Warren

    2003-01-01

    Advanced power systems based on integrated gasification/combined cycles (IGCC) are often presented as a solution to the present shortcomings of biomass as fuel. Although IGCC has been technically demonstrated at full scale, it has not been adopted for commercial power generation. Part of the reason for this situation is the continuing low price for coal. However, another significant barrier to IGCC is the high level of integration of this technology: the gas output from the gasifier must be perfectly matched to the energy demand of the gas turbine cycle. We are developing an alternative to IGCC for biomass power: the integrated (fast) pyrolysis/ combined cycle (IPCC). In this system solid biomass is converted into liquid rather than gaseous fuel. This liquid fuel, called bio-oil, is a mixture of oxygenated organic compounds and water that serves as fuel for a gas turbine topping cycle. Waste heat from the gas turbine provides thermal energy to the steam turbine bottoming cycle. Advantages of the biomass-fueled IPCC system include: combined cycle efficiency exceeding 37 percent efficiency for a system as small as 7.6 MW e ; absence of high pressure thermal reactors; decoupling of fuel processing and power generation; and opportunities for recovering value-added products from the bio-oil. This report provides a technical overview of the system including pyrolyzer design, fuel clean-up strategies, pyrolysate condenser design, opportunities for recovering pyrolysis byproducts, gas turbine cycle design, and Rankine steam cycle. The report also reviews the potential biomass fuel supply in Iowa, provide and economic analysis, and present a summery of benefits from the proposed system

  13. INTEGRATED PYROLYSIS COMBINED CYCLE BIOMASS POWER SYSTEM CONCEPT DEFINITION

    Energy Technology Data Exchange (ETDEWEB)

    Eric Sandvig; Gary Walling; Robert C. Brown; Ryan Pletka; Desmond Radlein; Warren Johnson

    2003-03-01

    Advanced power systems based on integrated gasification/combined cycles (IGCC) are often presented as a solution to the present shortcomings of biomass as fuel. Although IGCC has been technically demonstrated at full scale, it has not been adopted for commercial power generation. Part of the reason for this situation is the continuing low price for coal. However, another significant barrier to IGCC is the high level of integration of this technology: the gas output from the gasifier must be perfectly matched to the energy demand of the gas turbine cycle. We are developing an alternative to IGCC for biomass power: the integrated (fast) pyrolysis/ combined cycle (IPCC). In this system solid biomass is converted into liquid rather than gaseous fuel. This liquid fuel, called bio-oil, is a mixture of oxygenated organic compounds and water that serves as fuel for a gas turbine topping cycle. Waste heat from the gas turbine provides thermal energy to the steam turbine bottoming cycle. Advantages of the biomass-fueled IPCC system include: combined cycle efficiency exceeding 37 percent efficiency for a system as small as 7.6 MW{sub e}; absence of high pressure thermal reactors; decoupling of fuel processing and power generation; and opportunities for recovering value-added products from the bio-oil. This report provides a technical overview of the system including pyrolyzer design, fuel clean-up strategies, pyrolysate condenser design, opportunities for recovering pyrolysis byproducts, gas turbine cycle design, and Rankine steam cycle. The report also reviews the potential biomass fuel supply in Iowa, provide and economic analysis, and present a summery of benefits from the proposed system.

  14. High capacity Venturi scrubber to separate aerosol-borne radioactivity from an air-gas-steam mixture. Final report

    International Nuclear Information System (INIS)

    Mayinger, F.; Glueckert, U.

    1993-01-01

    All German LWR are equipped with devices which in the case of a hypothetic accident permit a filtered depressurization of the containment precluding failure of the latter and minimizing the release of radioactive materials into the environment. To filter the aerosol charged air-steam mixture from the containment also a venturi scrubber is used. It has the great advantage that it can remove safely and over a certain period of time, even without active cooling systems, the after-heat released from the separated radioactive materials. Those separated radioactive materials are trapped in a scrubbing liquid which, in the event of a temporary failure of all active cooling systems, may partly evaporate and thus remove the heat in a completely passive way. The venturi scrubbers conceived earlier by the reactor manufacturer are of a very simple design and not optimized to achieve highest separation degrees. Therefore development work was started to optimize the separation behaviour of the venturi scrubber precisely with regard to submicron aerosols which are to be expected after a core meltdown accident. To achieve this, a special concept of scrubbing liquid addition developed by the contractor, the so-called multistage concept, was applied adapting it to the specific requirements. (orig./HP) [de

  15. Effect of flue gas composition on deposit induced high temperature corrosion under laboratory conditions mimicking biomass firing. Part II: Exposures in SO2 containing atmospheres

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Kiamehr, Saeed; Montgomery, Melanie

    2017-01-01

    SO2. Scanning electron microscopy (SEM), energy dispersive X-rayspectroscopy (EDS) and X-ray diffraction (XRD) techniques werecomplimentarily applied to characterize the resulting corrosion products. Apartially molten K2SO4-layer formed on KCl coated specimens, and corrosionresulted in localized......In biomass fired power plants, the fast corrosion of superheaters is facilitatedby the presence of corrosive flue gas species, for example, SO2, which arereleased during combustion. To understand the role of the gas species on thecorrosion process, comparative laboratory exposures of deposit (KCl......)-coatedand deposit-free austenitic stainless steel (TP 347H FG) samples to gas mixturescontaining SO2 was carried out, under conditions relevant to biomass-firing.Exposures were conducted isothermally at 560 8C for 72 h, in oxidizingsulphidizing,and oxidizing-sulphidizing-chlorinating gas mixtures containing60 ppmv...

  16. Heat transfer simulation in a furnace for steam reformer. Gas kaishitsu ronai no dennetsu simulation ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, K; Taniguchi, H; Guo, K [Hokkaido Univ., Sapporo (Japan). Faculty of Engineering; Katayama, T; Nagata, T [Tokyo Gas Co. Ltd., Tokyo (Japan)

    1991-01-10

    This paper discusses the heat transfer analysis in a furnace for LPG reforming to produce gas enriched hydrogen. The three-dimensional combined radiative and convective heat transfer processes in a furnace for LPG reforming is simulated by introducing the radiosity concept into the radiative heat ray method for an accurate radiative heat transfer analysis. Together with an analysis of the chemical reaction in the reactor tubes of the furnace, the heat transfer simulation gives the three-dimensional profile of the combustion gas temperature in the furnace, the tube-surface heat-flux distribution and the composition of the reformed gas. From the results of the analysis, it was clarified that increasing the jet angle of the heating burner raises the gas temperature and the tube surface heat flux near the burner entrance, and that the flame shape is the most important factor for deciding the heat flux distribution of the tube surface because the heat transfer effect by flame radiation is much more than that by convection of the combustion gas. 18 refs., 9 figs., 2 tabs.

  17. Corrosion in the Flue Gas Cleaning System of a Biomass-Fired Power Plant

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Olesen, R. E.; Gensmann, P.

    2017-01-01

    After only a few years operation, corrosiondamage was observed in the flue gas cleaning system of abiomass power plant. The corrosion was on the lower partof the gas/gas heat exchanger fabricated from A242weathering steel, where UNS S31600 bolts were used toattach sealing strips to the rotor. Thick...... iron oxides (up to5 mm) had formed on the weathering steel, and theseoxides also contained chlorine and sulfur. In this area of theheat exchanger, weathering steel has not had the optimalwet/dry cycles required to achieve a protective oxide. Dueto the thick growing oxide on the rotor, the UNS S31600......bolts were under stress and this together with the presenceof accumulated chlorine between the sealing strips andbolts resulted in stress corrosion cracking and rupture. Inaddition, Zn-K-Cl deposits were agglomerated in the ductafter the DeNOx unit. Zn was also a constituent of corrosionproducts...

  18. STEAM DALAM PEMBUATAN PAKAN UNTUK KOMODITAS AKUAKULTUR

    Directory of Open Access Journals (Sweden)

    Sukarman Sukarman

    2010-12-01

    Full Text Available Kualitas fisik pakan (pelet untuk hewan akuakultur sangat penting, karena akan dimasukkan ke dalam air dan diharapkan tidak banyak mencemari lingkungan. Salah satu faktor yang berpengaruh dalam menjaga kualitas fisik pakan adalah penambahan dan pengaturan steam pada saat proses pembuatan pelet. Steam adalah aliran gas yang dihasilkan oleh air pada saat mendidih. Steam dibagi menjadi 3 jenis yaitu steam basah, saturated steam, dan superheated steam. Steam yang digunakan dalam proses pembuatan pelet adalah saturated steam. Pengaruh penambahan steam pada kualitas pelet bisa mencapai 20%. Penambahan steam dengan jumlah dan kualitas yang tepat akan menghasilkan pelet berkualitas. Sedangkan jika pengaturan dan penambahannya tidak tepat, maka kualitas fisik pelet akan rendah dan kemungkinan bisa merusak kandungan nutrisi seperti vitamin dan protein. Penambahan steam yang benar bisa dilakukan di dalam kondisioner dengan mengatur retention time, sudut kemiringan paddle conditioner, kecepatan putaran bearing dan menjaga kualitas steam dari mesin boiler sampai dengan kondisioner.

  19. Biomass [updated

    Energy Technology Data Exchange (ETDEWEB)

    Turhollow Jr, Anthony F [ORNL

    2016-01-01

    Biomass resources and conversion technologies are diverse. Substantial biomass resources exist including woody crops, herbaceous perennials and annuals, forest resources, agricultural residues, and algae. Conversion processes available include fermentation, gasification, pyrolysis, anaerobic digestion, combustion, and transesterification. Bioderived products include liquid fuels (e.g. ethanol, biodiesel, and gasoline and diesel substitutes), gases, electricity, biochemical, and wood pellets. At present the major sources of biomass-derived liquid fuels are from first generation biofuels; ethanol from maize and sugar cane (89 billion L in 2013) and biodiesel from vegetable oils and fats (24 billion liters in 2011). For other than traditional uses, policy in the forms of mandates, targets, subsidies, and greenhouse gas emission targets has largely been driving biomass utilization. Second generation biofuels have been slow to take off.

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

    International Nuclear Information System (INIS)

    Facchinetti, Emanuele; Gassner, Martin; D’Amelio, Matilde; Marechal, François; Favrat, Daniel

    2012-01-01

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

  1. Greenhouse gas emission analysis of an Egyptian rice straw biomass-to-energy chain

    NARCIS (Netherlands)

    Poppens, R.P.; Bakker, R.

    2012-01-01

    A common practice in Egypt has been the burning of rice straw, as a measure to prepare agricultural land for follow-up crops. This practice has caused significant greenhouse gas emissions, in addition to aerial pollution. By using straw residue for the production of pellets and shipping these

  2. Radial Microchannel Reactor (RMR) used in Steam Reforming CH4

    Science.gov (United States)

    2013-05-13

    steam reforming natural gas for a wide variety of application from distributed energy production...into synthesis gas . Synthesis gas is used in the production of hydrogen , in GTL and other chemical processes. Steam reforming in an RMR was studied...technology has the potential to have a transformational reduction in cost and size of steam reforming natural gas for a wide variety of application

  3. Bridging gaps in bioenergy: Deploying system analysis to investigate potential biomass supply, demand and greenhouse gas mitigation scenarios from a national, European and global perspective

    NARCIS (Netherlands)

    Hoefnagels, E.T.A.|info:eu-repo/dai/nl/313935998

    2014-01-01

    In transition towards a sustainable energy system with deep reductions in greenhouse gas (GHG) emissions and reduced consumption of fossil fuels, substitution of fossil energy carriers with biomass is considered one of the most important options. In the last decade, fossil energy and GHG mitigation

  4. Large-scale biodiesel production using flue gas from coal-fired power plants with Nannochloropsis microalgal biomass in open raceway ponds.

    Science.gov (United States)

    Zhu, Baohua; Sun, Faqiang; Yang, Miao; Lu, Lin; Yang, Guanpin; Pan, Kehou

    2014-12-01

    The potential use of microalgal biomass as a biofuel source has raised broad interest. Highly effective and economically feasible biomass generating techniques are essential to realize such potential. Flue gas from coal-fired power plants may serve as an inexpensive carbon source for microalgal culture, and it may also facilitate improvement of the environment once the gas is fixed in biomass. In this study, three strains of the genus Nannochloropsis (4-38, KA2 and 75B1) survived this type of culture and bloomed using flue gas from coal-fired power plants in 8000-L open raceway ponds. Lower temperatures and solar irradiation reduced the biomass yield and lipid productivities of these strains. Strain 4-38 performed better than the other two as it contained higher amounts of triacylglycerols and fatty acids, which are used for biodiesel production. Further optimization of the application of flue gas to microalgal culture should be undertaken. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Application of Module System for Processing a Large Capacity of Coal Steam Power Plant Flue gas by Electron Beam Machine

    International Nuclear Information System (INIS)

    Rukijatmo; Munawir Z, M.

    2003-01-01

    Conceptual design of SOx dan NOx flue gas treatment base on 25% of 400 M We capacity and 90% efficiency reduction of SOx, the electron beam machine will be utilized to performed the environment quality standard of air pollution. The technical specification of electron beam machine, processing system and chamber dimension should conformed to the regulation. The discussion is focused on the selection of electron beam machine type and the dimension of radiation vessel for perfect reaction and exact time processing. The design calculation is indicated that we need two electron beam machines of 500 mA, 800 kV installed in parallel and 3 up to 3.4 metres diameter, the speed of flue gas in the vessel around 16.4 up to 18.14 metre per second, 80% treatment of 0,7% sulphur content coal is conform to regulation on emission of flue gas environment, and only 50% of flue gas needed to be treated by 4 modular. (author)

  6. Steam generators

    International Nuclear Information System (INIS)

    Hayden, R.L.J.

    1979-01-01

    Steam generators for nuclear reactors are designed so that deposition of solids on the surface of the inlet side of the tubesheet or the inlet header with the consequent danger of corrosion and eventual tube failure is obviated or substantially reduced. (U.K.)

  7. Thermodynamic approach to biomass gasification

    International Nuclear Information System (INIS)

    Boissonnet, G.; Seiler, J.M.

    2003-01-01

    The document presents an approach of biomass transformation in presence of steam, hydrogen or oxygen. Calculation results based on thermodynamic equilibrium are discussed. The objective of gasification techniques is to increase the gas content in CO and H 2 . The maximum content in these gases is obtained when thermodynamic equilibrium is approached. Any optimisation action of a process. will, thus, tend to approach thermodynamic equilibrium conditions. On the other hand, such calculations can be used to determine the conditions which lead to an increase in the production of CO and H 2 . An objective is also to determine transformation enthalpies that are an important input for process calculations. Various existing processes are assessed, and associated thermodynamic limitations are evidenced. (author)

  8. Study on the associated removal of pollutants from coal-firing flue gas using biomass activated carbon pellets

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cuiping; Yuan, Wanli [Qingdao Univ., Shandong (China). Electrical and Mechanical Engineering College; Qi, Haiying [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering

    2013-07-01

    A pilot-scale multi-layer system was developed for the adsorption of SO{sub 2}/NO{sub x}/Hg from flue gas (real flue gases of an heating boiler house) at various operating conditions, including operating temperature and activated carbon materials. Excellent SO{sub 2}/NO{sub x}/Hg removal efficiency was achieved with the multi-layer design with carbons pellets. The SO{sub 2} removal efficiency achieved with the first layer adsorption bed clearly decreased as the operating temperature was increased due to the decrease of physisorption performance. The NO{sub x} removal efficiency measured at the second layer adsorption bed was very higher when the particle carbon impregnated with NH{sub 3}. The higher amounts of Hg absorbed by cotton-seed-skin activated carbon (CSAC) were mainly contributed by chlorinated congeners content. The simultaneously removal of SO{sub 2}/NO{sub x}/Hg was optimization characterized with different carbon layer functions. Overall, The alkali function group and chloride content in CSAC impelled not only the outstanding physisorption but also better chemisorptions. The system for simultaneously removal of multi-pollutant-gas with biomass activated carbon pellets in multi-layer reactor was achieved and the removal results indicated was strongly depended on the activated carbon material and operating temperature.

  9. Laboratory Investigation of Trace Gas Emissions from Biomass Burning on DoD Bases

    Science.gov (United States)

    Burling, I. R.; Yokelson, R. J.; Griffith, D. W.; Roberts, J. M.; Veres, P. R.; Warneke, C.; Johnson, T. J.

    2009-12-01

    Vegetation representing fuels commonly managed with prescribed fires was collected from five DoD bases and burned under controlled conditions at the USFS Firelab in Missoula, MT. The smoke emissions were measured with a large suite of state-of-the-art instrumentation. Seventy-seven fires were conducted and the smoke composition data will improve DoD land managers’ ability to assess the impact of prescribed fires on local air quality. A key instrument used in the measurement of the gas phase species in smoke was an open-path FTIR (OP-FTIR) spectrometer, built and operated by the Universities of Montana and Wollongong. The OP-FTIR has to date detected and quantified 20 gas phase species - CO2, CO, H2O, N2O, NO2, NO, HONO, NH3, HCl, SO2, CH4, CH3OH, HCHO, HCOOH, C2H2, C2H4, CH3COOH, HCN, propylene and furan. The spectra were analyzed using a non-linear least squares fitting routine that included reference spectra recently acquired at the Pacific Northwest National Laboratories. Preliminary results from the OP-FTIR analysis are reported here. Of particular interest, gas-phase nitrous acid (HONO) was detected simultaneously by the OP-FTIR and negative-ion proton-transfer chemical ionization spectrometer (NI-PT-CIMS), with preliminary fire-integrated molar emission ratios (relative to NOx) ranging from approximately 0.03 to 0.20, depending on the vegetation type. HONO is an important precursor in the production of OH, the primary oxidizing species in the atmosphere. There existed little previous data documenting HONO emissions from either wild or prescribed fires. The non-methane organic emissions were dominated by oxygenated species, which can be further oxidized and thus involved in secondary aerosol formation. Elevated amounts of gas-phase HCl were also detected in the smoke, with the amounts varying depending on location and vegetation type.

  10. Methanol from biomass and hydrogen

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    For Hawaii in the near term, the only liquid fuels indigenous sources will be those that can be made from biomass, and of these, methanol is the most promising. In addition, hydrogen produced by electrolysis can be used to markedly increase the yield of biomass methanol. This paper calculates cost of producing methanol by an integrated system including a geothermal electricity facility plus a plant producing methanol by gasifying biomass and adding hydrogen produced by electrolysis. Other studies cover methanol from biomass without added hydrogen and methanol from biomass by steam and carbon dioxide reforming. Methanol is made in a two-step process: the first is the gasification of biomass by partial oxidation with pure oxygen to produce carbon oxides and hydrogen, and the second is the reaction of gases to form methanol. Geothermal steam is used to generate the electricity used for the electrolysis to produce the added hydrogen

  11. Microalgal biomass production and on-site bioremediation of carbon dioxide, nitrogen oxide and sulfur dioxide from flue gas using Chlorella sp. cultures.

    Science.gov (United States)

    Chiu, Sheng-Yi; Kao, Chien-Ya; Huang, Tzu-Ting; Lin, Chia-Jung; Ong, Seow-Chin; Chen, Chun-Da; Chang, Jo-Shu; Lin, Chih-Sheng

    2011-10-01

    The growth and on-site bioremediation potential of an isolated thermal- and CO₂-tolerant mutant strain, Chlorella sp. MTF-7, were investigated. The Chlorella sp. MTF-7 cultures were directly aerated with the flue gas generated from coke oven of a steel plant. The biomass concentration, growth rate and lipid content of Chlorella sp. MTF-7 cultured in an outdoor 50-L photobioreactor for 6 days was 2.87 g L⁻¹ (with an initial culture biomass concentration of 0.75 g L⁻¹), 0.52 g L⁻¹ d⁻¹ and 25.2%, respectively. By the operation with intermittent flue gas aeration in a double-set photobioreactor system, average efficiency of CO₂ removal from the flue gas could reach to 60%, and NO and SO₂ removal efficiency was maintained at approximately 70% and 50%, respectively. Our results demonstrate that flue gas from coke oven could be directly introduced into Chlorella sp. MTF-7 cultures to potentially produce algal biomass and efficiently capture CO₂, NO and SO₂ from flue gas. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Experimental studies on condensation of steam mixed with noncondensable gas inside the vertical tube in a pool filled with subcooled water

    International Nuclear Information System (INIS)

    Maheshwari, N.K.; Saha, D.; Sinha, R.K.; Aritomi, M.

    2003-01-01

    A passive containment cooling system with immersed condensers has been proposed as one of the alternatives for the advanced heavy water reactor (AHWR) being designed in India. The system removes residual/decay heat released into the containment through the immersed condensers kept in a pool of water following loss of coolant accident. An important aspect of the immersed condensers is the potential degradation of its performance due to the presence of noncondensable gases. Experiments are performed to obtain reliable data on condensation phenomena in presence of air. These experiments are conducted on full-scale tubes of condensers immersed in a pool of water maintaining similar conditions as in the prototype of AHWR. A method has been proposed for the determination of the local heat transfer rate using correlations given in literature. The parametric effects of air mass fraction, pressure, steam flow, etc. on condensation heat transfer in presence of noncondensable gas have been studied. The experimental results are compared with the correlations given in literature. (orig.)

  13. Simultaneously combining AOD and multiple trace gas measurements to identify decadal changes in urban and biomass burning aerosols

    Science.gov (United States)

    Cohen, Jason

    2017-04-01

    This work presents a methodology by which to comprehensively analyze simultaneous tropospheric measurements of AOD and associated trace gasses. It then applies this methodology by focusing over the past 11 years (2006-2016) on one of the most rapidly changing regions of the troposphere: Eastern and Southeastern Asia. The specific work presented incorporates measurements of both aerosol and related gas phase tropospheric measurements across different spectral, spatial, temporal, and passive/active sensors and properties, including: MODIS, MISR, OMI, CALIOP, and others. This new characterization reveals a trio of new information, including a time-invariant urban signal, slowly-time-varying new-urbanization signal, and a rapidly time-varying biomass burning signal. Additionally, due to the different chemical properties of the various species analyzed, analyzing the different spatial domains of the resulting products allows for further information in terms of the amounts of aerosols produced both through primary emissions as well as secondary processing. The end result is a new characterization, in space, time, and magnitude, of both anthropogenic and biomass burning aerosols. These results are then used to drive an advanced modeling system including aerosol chemistry, physics, optics, and transport, and employing an aerosol routine based on multi-modal and both externally mixed and core-shell mixing. The resulting characterization in space, time, and quantity is analyzed and compared against AERONET, NOAA, and other ground networks, with the results comparing consistently to or better than present approaches which set up net emissions separately from urban and biomass burning products. Scientifically, new source regions of emissions are identified, some of which were previously non-urbanized or found to not contain any fire hotspots. This new approach is consistent with the underlying economic and development pathways of expanding urban areas and rapid economic growth

  14. Greenhouse gas balances and mitigation costs of 70 modern Germany-focused and 4 traditional biomass pathways including land-use change effects

    International Nuclear Information System (INIS)

    Sterner, Michael; Fritsche, Uwe

    2011-01-01

    With Germany as the point of energy end-use, 70 current and future modern pathways plus 4 traditional biomass pathways for heat, power and transport have been compiled and examined in one single greenhouse gas (GHG) balancing assessment. This is needed to broaden the narrow focus on biofuels for transport and identify the role of bioenergy in GHG mitigation. Sensitivity analysis for land-use changes and fossil reference systems are included. Co-firing of woody biomass and fermentation of waste biomass are the most cost-efficient and effective biomass applications for GHG emission reduction in modern pathways. Replacing traditional biomass with modern biomass applications offers an underestimated economic potential of GHG emission reduction. The range of maximum CO 2 equivalent GHG reduction potential of bioenergy is identified in a range of 2.5–16 Gt a −1 in 2050 (5–33% of today’s global GHG emissions), and has an economic bioenergy potential of 150 EJ a −1 .

  15. High-Temperature Gas-cooled Reactor steam-cycle/cogeneration lead plant reactor vessel: system design description

    International Nuclear Information System (INIS)

    1983-01-01

    The Reactor Vessel System contains the primary coolant inventory within a gas-tight pressure boundary, and provides the necessary flow paths and overpressure protection for this pressure boundary. The Reactor Vessel System also houses the components of the Reactor System, the Heat Transport System, and the Auxiliary Heat Removal System. The scope of the Reactor Vessel System includes the prestressed concrete reactor vessel (PCRV) structure with its reinforcing steel and prestressing components; liners, penetrations, closures, and cooling water tubes attached to the concrete side of the liner; the thermal barrier (insulation) on the primary coolant side of the liner; instrumentation for structural monitoring; and a pressure relief system. Specifications are presented

  16. Steam Plasma Flows Generated in Gerdien Arc: Environment for Energy Gas Production from Organics and for Surface Coatings

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, Milan

    2011-01-01

    Roč. 6, č. 5 (2011), s. 792-801 ISSN 1880-5558. [Seventh International Conference on Flow Dynamics. Sendai, 01.11.2010-03.11.2010] R&D Projects: GA ČR GAP205/11/2070 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal Plasma * Dc Arc Plasma Torch * Gerdien Arc * Plasma Gasification Subject RIV: BL - Plasma and Gas Discharge Physics http://www.jstage.jst.go.jp/article/jfst/6/5/792/_pdf

  17. 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.

  18. Integration of Methane Steam Reforming and Water Gas Shift Reaction in a Pd/Au/Pd-Based Catalytic Membrane Reactor for Process Intensification

    Directory of Open Access Journals (Sweden)

    Bernardo Castro-Dominguez

    2016-09-01

    Full Text Available Palladium-based catalytic membrane reactors (CMRs effectively remove H2 to induce higher conversions in methane steam reforming (MSR and water-gas-shift reactions (WGS. Within such a context, this work evaluates the technical performance of a novel CMR, which utilizes two catalysts in series, rather than one. In the process system under consideration, the first catalyst, confined within the shell side of the reactor, reforms methane with water yielding H2, CO and CO2. After reforming is completed, a second catalyst, positioned in series, reacts with CO and water through the WGS reaction yielding pure H2O, CO2 and H2. A tubular composite asymmetric Pd/Au/Pd membrane is situated throughout the reactor to continuously remove the produced H2 and induce higher methane and CO conversions while yielding ultrapure H2 and compressed CO2 ready for dehydration. Experimental results involving (i a conventional packed bed reactor packed (PBR for MSR, (ii a PBR with five layers of two catalysts in series and (iii a CMR with two layers of two catalysts in series are comparatively assessed and thoroughly characterized. Furthermore, a comprehensive 2D computational fluid dynamics (CFD model was developed to explore further the features of the proposed configuration. The reaction was studied at different process intensification-relevant conditions, such as space velocities, temperatures, pressures and initial feed gas composition. Finally, it is demonstrated that the above CMR module, which was operated for 600 h, displays quite high H2 permeance and purity, high CH4 conversion levels and reduced CO yields.

  19. Biomass IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Salo, K; Keraenen, H [Enviropower Inc., Espoo (Finland)

    1997-12-31

    Enviropower Inc. is developing a modern power plant concept based on pressurised fluidized-bed gasification and gas turbine combined cycle (IGCC). The process is capable of maximising the electricity production with a variety of solid fuels - different biomass and coal types - mixed or separately. The development work is conducted on many levels. These and demonstration efforts are highlighted in this article. The feasibility of a pressurised gasification based processes compared to competing technologies in different applications is discussed. The potential of power production from biomass is also reviewed. (orig.) 4 refs.

  20. Biomass IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Salo, K.; Keraenen, H. [Enviropower Inc., Espoo (Finland)

    1996-12-31

    Enviropower Inc. is developing a modern power plant concept based on pressurised fluidized-bed gasification and gas turbine combined cycle (IGCC). The process is capable of maximising the electricity production with a variety of solid fuels - different biomass and coal types - mixed or separately. The development work is conducted on many levels. These and demonstration efforts are highlighted in this article. The feasibility of a pressurised gasification based processes compared to competing technologies in different applications is discussed. The potential of power production from biomass is also reviewed. (orig.) 4 refs.

  1. Biomass yield and greenhouse gas emissions from a drained fen peatland cultivated with reed canary grass under different harvest and fertilizer regimes

    DEFF Research Database (Denmark)

    Kandel, Tanka Prasad; Elsgaard, Lars; Karki, Sandhya

    2013-01-01

    Reed canary grass (RCG, Phalaris arundinacea L.) is a suitable energy crop for cultivation in northern peatlands. However, the atmospheric impact of RCG cultivation as influenced by harvest frequency and fertilization is not clear. Here, we compared the biomass yield and greenhouse gas (GHG......) balance for RCG cultivation in peatlands affected by cutting frequency and fertilizer managements. The managements included one-cut (OC) and two-cut (TC) systems that were either fertilized (TC-F) or unfertilized (TC-U) after the first cut in summer. Biomass yield of OC, TC-F and TC-U were 12, 16 and 11...

  2. Mixed convection heat transfer between a steam/non-condensable gas mixture and an inclined finned tube bundle

    Energy Technology Data Exchange (ETDEWEB)

    De Cachard, F.; Lompersky, S.; Monauni, G.R. [Paul Scherrer Institute, Villigen (Switzerland). Thermal Hydraulic Lab.

    1999-07-01

    An experimental and analytical program was performed at PSI (Paul Scherrer Institute) to study the performance of a finned-tube condenser in the presence of non-condensable gases at low gas mass fluxes. The model developed for this application includes mixed convection heat transfer between the vapour/non-condensable mixture and the finned tubes, heat conduction through the fins and tubes, and evaporative heat transfer inside the tubes. On the gas, heat transfer correlations are used, and the condensation rate is calculated using the heat/mass transfer analogy. A combination of various available correlations for forced convection in staggered finned tube bundles is used, together with a correction accounting for superimposed natural convection. For the condensate heat transfer resistance, the beatty and Katz model for gravity driven liquid films on the tubes is used. The fine efficiency is accounted for using classical iterative calculations. Evaporative heat transfer inside the tubes is predicted using the Chen correlation. The finned tube condenser model has been assessed against data obtained at the PSI LINX facility with two test condensers. For the 62 LINX experiments performed, the model predictions are very good, i.e., less then 10% standard deviation between experimental and predicted results.

  3. From the idea to the construction of a biomass fuelled plant. The marketing potential

    Interna