WorldWideScience

Sample records for fluidised bed gasification

  1. Fluidised-bed combustion of gasification residue

    Energy Technology Data Exchange (ETDEWEB)

    Korpela, T.; Kudjoi, A.; Hippinen, I.; Heinolainen, A.; Suominen, M.; Lu Yong [Helsinki Univ. of Technology (Finland). Lab of Energy Economics and Power Plant Engineering

    1996-12-01

    Partial gasification processes have been presented as possibilities for future power production. In the processes, the solid materials removed from a gasifier (i.e. fly ash and bed material) contain unburnt fuel and the fuel conversion is increased by burning this gasification residue either in an atmospheric or a pressurised fluidised-bed. In this project, which is a part of European JOULE 2 EXTENSION research programme, the main research objectives are the behaviour of calcium and sulphur compounds in solids and the emissions of sulphur dioxide and nitrogen oxides (NO{sub x} and N{sub 2}O) in pressurised fluidised-bed combustion of gasification residues. (author)

  2. Biofluid process: fluidised-bed gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  3. Characterisation of coal and chars in fluidised bed gasification

    CSIR Research Space (South Africa)

    Oboirien, BO

    2009-03-01

    Full Text Available residual char generated from some selected high-ash South African coals. The selected coals are different in rank, maceral and mineral matter composition. Pilotscale fluidised bed gasification tests were carried out on the selected coals within a...

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

    CSIR Research Space (South Africa)

    Engelbrecht, AS

    2011-11-01

    Full Text Available The gasification of two high-ash coals were studied using a pilot scale fluidised bed gasifier using oxygen enrich air and steam as the gasification agents. The results of the tests show that the fixed carbon conversion and calorific value increases...

  5. Biomass ash - bed material interactions leading to agglomeration in fluidised bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Visser, H.J.M.; Hofmans, H.; Huijnen, R.; Kastelein, R.; Kiel, J.H.A. [ECN Biomass, Petten (Netherlands)

    2000-07-01

    The present study has been aimed at improving the fundamental understanding of mechanisms underlying agglomeration and defluidisation in fluidised bed combustion and gasification of biomass and waste. To this purpose dedicated lab-scale static heating and fluidisation experiments have been conducted with carefully selected and prepared ashes and bed materials, viz. straw ash/sand and willow ash/sand mixtures, mullite subjected to straw gasification and artificially coated mullite. The main conclusion is that ash/bed material interaction processes are very important and often determine the bed agglomeration and defluidisation tendency. In the static heating experiments with both ash/sand mixtures, partial melting-segregation of ash components and dissolution/reaction with the bed material are processes that determine the melt composition. This melt composition and behaviour can deviate considerably form expectations based on ash-only data. Artificially coated bed materials prove to be very useful for systematic studies on the influence of coating composition and thickness on agglomeration tendency. For the coated mullite samples, different stages in the defluidisation process are identified and the influence of coating properties (thickness, composition, morphology) and operating parameters is elucidated. The behaviour of the mullite appears to be dominated by a remnant glass phase. On the one hand, this glass phase accounts for an alkali-getter capability, while on the other hand it is mainly responsible for agglomeration at temperatures {>=} 800C. 3 refs.

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

    Science.gov (United States)

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

    2014-10-01

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

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

    CSIR Research Space (South Africa)

    Oboirien, BO

    2011-04-01

    Full Text Available The gasification characteristics of three South African bituminous coals were investigated in a bubbling fluidised bed reactor. The three coals are similar in rank, but two are inertinite-rich coals and the third has a high vitrinite content...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

  9. Thermodynamic study of alkali metals release in pressurised fluidised-bed combustion and gasification of peat

    Energy Technology Data Exchange (ETDEWEB)

    Mojtahedi, W.; Backman, R.; Korhonen, M.

    1988-01-01

    A combined-cycle power generation system incorporating pressurised fluidised-bed combustion (PFBC) or gasification is considered a promising approach for electricity generation using solid fuels such as peat. In these systems, the high-pressure hot flue gas is expanded in a gas turbine. Peat contains sodium and potassium which are released in combustion and gasification. These are corrosive elements that can cause severe damage to the turbine blades if not suppressed. Multicomponent, multiphase equilibrium calculations were carried out for atmospheric and pressurised fluidised-bed operating conditions to determine the relative distribution of the two metals (Na and K) in the gas and condensed phases. Dependence of the alkali volatilisation on the operating temperature, pressure, the chlorine-content and the total alkali-content of the feedstock was studied. The results show that the alkali release in the vapour-phase could be much higher than acceptable to a gas turbine, particularly under gasification conditions. Hence the necessity to remove the volatilised alkali-metal compounds is more acute in gasification than in combustion. Both sodium and potassium are present as chlorides and to a lesser extent as hydroxides in the gas phase in both modes of operation (i.e. combustion and gasification). However, whereas under combustion conditions both metals seem to condense as sulphates (Na/sub 2/SO4 and K/sub 2/SO4), in gasification, chlorides and carbonates dominate in the condensed phase. The alkali-metals volatilisation shows strong dependence on the operating pressure of the system as well as on the chlorine-content of the feedstock. It decreases markedly with the former but increases sharply with the latter.

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

    Science.gov (United States)

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

    2008-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hannula, I.; Kurkela, E.

    2013-04-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-01

    The research is directed towards methods of producing transportation bio-fuels via the synthesis-gas route, with emphasis on the synthesis-gas production and gas cleaning steps. The project will both broaden and deepen the knowledge base and, in particular, will generate new fundamental information about the most critical process steps from the point of view of the realisation of the technology. The results will be exploited in the ongoing industrial-driven development and demonstration projects. The subtopics of the research project are (1) fuel characterisation and ash behaviour in the gasification step, (2) reaction mechanisms related to gas cleaning, in particular the reactions of hydrocarbons at gasification temperatures, during hot-gas filtration and on catalytic surfaces, (3) evaluations of alternative process configurations and applications and (4) monitoring of developments elsewhere in the world. In addition VTT itself finances two additions subtopics (5) new analysis techniques and (6) hydrogen from biomass via gasification. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Reinikainen, M.; Moilanen, A.; Simell, P.; Hannula, I.; Kurkela, E. (VTT Technical Research Centre of Finland, Espoo (Finland)), e-mail: matti.reinikainen@vtt.fi; Suominen, T. P. (Aabo Akademi, Turku (Finland), Teknisk Kemi och Reaktionsteknik), e-mail: timo.suominen@abo.fi; Linnekoski, J. (Aalto Univ., School of Science and Technology, Espoo (Finland), Lab. of Industrial Chemistry)

    2011-11-15

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

  17. Application of active powders at fluidised bed heat treatment technologies

    OpenAIRE

    Babul, T.; Kucharieva, N.

    2014-01-01

    The paper describes the principles and conditions of carrying out of a new type of fluidised bed thermochemical treatment in chemically active powders with different ways of fluidisation. These new fluidised bed thermochemical treatments in chemically active powders are primarily for the formation of surface diffusion layers on parts made of constructional and tool steel. This method can be used for sherardising, alitising, carbonitriding, nitrocarburising, carburising or boronising. Chara...

  18. Fluidized-bed combustion of gasification residue

    Energy Technology Data Exchange (ETDEWEB)

    Kudjoi, A.; Heinolainen, A.; Hippinen, I.; Lu, Y. [Helsinki University of Technology, Espoo (Finland). Lab. of Energy Economics and Power Plant Engineering

    1998-12-31

    Hybrid combined cycle processes have been presented as possibilities for power generation in the future. In the processes based on partial gasification of coal, the solid materials removed from a gasifier (i.e. fly ash and bed char) contain unburned fuel, which is burned either in an atmospheric or a pressurised fluidised-bed. Pressurised fluidised-bed (PFB) combustion of gasification residues were studied experimentally by Helsinki University of Technology. The gasification residues, i.e. cyclone fines and bed chars, came from pilot scale PFB gasification tests of bituminous coals. The combustion efficiency was high in cyclone fines combustion. The calcium sulphide oxidised effectively to calcium sulphate in the combustion of cyclone fines. In bed char combustion the residual sulphide contents in solids after combustion were still relatively high. In general, sulphur dioxide emissions in residue combustion were low. The recarbonation of calcium oxide was observed in bed char combustion. Fuel-N conversion to NO{sub x} during bed char combustion and in most of the test runs with cyclone fines was higher than in bituminous coal combustion. In bed char combustion the conversion was significantly higher than in cyclone fines combustion. NO{sub x} emissions increased with increasing excess air for both residues, as was expected. In bed char combustion the highest NO{sub x} emissions were measured at higher pressure. Calculated mass reactivity values of equal particle size of all bed chars studied had similar trends with burnout. The biggest particles had the lowest reactivity values throughout the combustion, while reactivity for finer particles was at considerably higher level and sharply increases with burnout. In the constant combustion conditions used in the tests, no significant differences were observed in rate-controlling mechanisms for bed char fractions studied. 25 refs., 13 figs., 15 tab.

  19. Thermal degradation of PMMA in fluidised beds.

    Science.gov (United States)

    Smolders, K; Baeyens, J

    2004-01-01

    In recent years, the production and consumption of plastics have increased significantly and wastes are commonly incinerated or dumped in a landfill. Plastics pyrolysis, on the other hand, may provide an alternative means for disposal of plastic wastes with recovery of valuable gasoline-range hydrocarbons or the monomer. Pyrolysis of polymethyl methacrylate (PMMA) may result in very high recycling rates (90-98%) of the monomer methylmethacrylate (MMA) since the cracking of MMA to lighter molecules (CO2, CO and light hydrocarbons) is limited. The MMA-yield is mainly dependent on the residence time of the gas in the reactor and to a lesser extent on the operating temperature. The paper presents experimental work performed in a lead bath and in a fluidised bed. At low temperatures, the reaction is kinetically controlled, whereas at high temperatures, heat transfer restricts the overall reaction rate. It was demonstrated that the heat transfer in the fluid bed could be estimated by the equation of Kothari. A design procedure for a fluid bed PMMA-depolymerisation reactor is outlined and illustrated for a process of 1 tpd PMMA.

  20. New Developments in Spinning Fluidised Bed Incineration Technology

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    At the present time, the sewage treatment plants in the UK produce about 25 million tons of sewage sludge each year at a concentration of 4% solids. New regulations forbid sea dumping and in the near future new incinerators will be required to dispose of about 5 million tons per year. Bubbling fluidised bed incinerators are widely used to burn sewage sludge at a typical consumption rate of about 0.02kg(dry)·s-1·m2, and it follows that over 300 conventional fluidised bed incinerators of 3m diameter could be required to cope with the increased demand.At Sheffield University Waste Incineration Centre (SUWIC) research work is being carried out to develop a novel spinning fluidised bed incinerator. The key factor to note is that when air flows up through a bed of near mono-sized particles, it fluidises when the pressure drop across the bed is equal to the weight of the bed. Normally, the weight of the bed is determined by gravity. However, if the bed is contained by a cylindrical air distributor 'plate' that is rotating rapidly about its axis, then the effective weight of the bed can be increased dramatically. The airflow passing through the bed can be increased proportionally to the "g" level produced by the rotation and it follows that the process has been intensified. In exploratory tests with a spinning fluidised bed we have achieved combustion intensities with coal combustion as high as 100MW/m3. A problem with burning coal is that it was difficult to remove the heat and rotating water seals had to be used to transfer cooling water into the bed. In the case of sewage and other sludges, this problem does not exist since the flue gases can remove the small amount of heat released. The rotating fluidised bed sludge incinerator is a novel device, which is very compact. It is able to solve the turndown problem encountered with conventional fluidised beds by simply changing the rotation speed. Bearing in mind that a centrifugal sludge de-watering unit is already used

  1. Discrete element modelling of fluidised bed spray granulation

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Weijers, G.G.C.; Boerefijn, R.; Kuipers, J.A.M.

    2003-01-01

    A novel discrete element spray granulation model capturing the key features of fluidised bed hydrodynamics, liquid¿solid contacting and agglomeration is presented. The model computes the motion of every individual particle and droplet in the system, considering the gas phase as a continuum. Microsca

  2. Discrete element modelling of fluidised bed spray granulation

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Weijers, G.G.C.; Boerefijn, R.; Kuipers, J.A.M.

    2002-01-01

    A novel discrete element spray granulation model capturing the key features of fluidised bed hydrodynamics, liquid-solid contacting and agglomeration is presented. The model computes the motion of every individual particle and droplet in the system, considering the gas phase as a continuum. Micro sc

  3. Modelling the bed characteristics in fluidised-beds for top-spray coating processes

    Institute of Scientific and Technical Information of China (English)

    Mike Vanderroost; Frederik Ronsse; Koen Dewettinck; Jan G.Pieters

    2012-01-01

    A particle sub-model describing the bed characteristics of a bubbling fluidised bed is presented.Atomisation air,applied at high pressures via a nozzle positioned above the bed for s pray formation,is incorporated in the model since its presence has a profound influence on the bed characteristics,though the spray itself is not yet considered.A particle sub-model is developed using well-known empirical relations for particle drag force,bubble growth and velocity and particle distribution above the fluidised-bed surface.Simple but effective assumptions and abstractions were made concerning bubble distribution,particle ejection at the bed surface and the behaviour of atomisation air flow upon impacting the surface of a bubbling fluidised bed.The model was shown to be capable of predicting the fluidised bed characteristics in terms of bed heights,voidage distributions and solids volume fractions with good accuracy in less than 5 min of calculation time on a regular desktop PC.It is therefore suitable for incorporation into general process control models aimed at dynamic control for process efficiency and product quality in top-spray fluidised bed coating processes.

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

    CSIR Research Space (South Africa)

    Engelbrecht, AD

    2010-08-31

    Full Text Available South Africa has abundant resources of high-ash and other low-quality coals. The aim of this work is to investigate the possibility of using fluidised bed gasification technology to convert these coals into clean fuel gas. The fuel gas can be used...

  5. A CFD Model for Fluid Dynamics in a Gas-fluidised Bed

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kai; Stefano Brandani

    2004-01-01

    A modified particle bed model derived from the two-fluid momentum balance equations was employed to predict the gas-fluidised bed behaviour. Additional terms are included in both the fluid and the particle momentum balance equations to take into account the effect of the dispersed solid phase. This model has been extended to two-dimensional formulations and has been implemented in the commercial code CFX 4.3. The model correctly simulates the homogeneous fluidisation of Geldart Group A and the bubbling fluidisation of Geldart Group B in gas-solid fluidised beds.

  6. Effect of pressure on combustion of char in fluidised beds

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, E.; Blackshaw, H.W.; Davidson, J.F.; Goodyer, P.T.Y.; Hopes, R.B.; Kossakowski, E.R.

    1984-07-01

    Measurements of burn-out time are reported, for 0.25-1.7 mm carbon particles in an air-fluidised 100 mm dia bed of sand at pressures up to 17 bar absolute and bed temperatures of 1023-1173 K. A variety of carbons was used including (i) coke (ii) chars formed from coals of different ranks: thus the carbons had various porosities and surface areas. The effect of increased pressure is to increase the combustion rate, because of the higher oxygen concentration which accelerates the chemical reactions of combustion. On the other hand, pressure has virtually no influence on diffusion of oxygen towards a burning particle, because the higher oxygen concentration is offset by a proportionately lower diffusion coefficient. The overall effect is that as pressure increases, the chemical rate controlling steps become less important, so at very high pressure, combustion is diffusion controlled.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  8. Combustion of poultry litter in a fluidised bed combustor

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-04-01

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

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

    DEFF Research Database (Denmark)

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

    2002-01-01

    The fluidisation and dispersion properties of various agarose-based expanded bed matrices-small high density stainless steel cored prototypes and standard commercial types-were studied in I-cm diameter expanded bed contactors in which fluid entering the column base is locally stirred. In all cases...

  10. Computational fluid dynamics simulation of laboratory scale reactor of fast pyrolysis fluidised bed

    Science.gov (United States)

    Amirmostafa Jourabchi, Seyed; Kiat Ng, Hoon; Gan, Suyin; Tan, Zhong Jian

    2017-04-01

    Euler-Eulerian two-fluid model (EE-TFM), among the computational fluid dynamics (CFD) techniques and module available on the market, have been chosen to study and obtain the operational parameters required for the fluidisation of different materials and different particle diameters of the fluidised bed model. In the present work, the effect of the material, namely stainless steel and sand with the respective diameters of 0.5 and 1 mm have been investigated with the aid of ANSYS FLUENT 15. From the simulation, it has found that the minimum required superficial velocity of the driving gas for fluidisation of steel beads are 70 cm/s and 140 cm/s respectively for diameter of 0.5 and 1.0 mm. On the other hand, the minimum required superficial velocities to fluidise the less dense sand beads are 30 cm/s and 70 cm/s for particle diameter of 0.5 and 1.0 mm respectively. The results show that the minimum fluidisation velocity increases as the density of the particle material increases; while it also increases, when the particle diameter increases. It is concluded that the drag force required to fluidise the specific solid bead material is proportional to both the density and the diameter of the particle chosen.

  11. Dual Fluidized Bed Biomass Gasification

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-09-30

    The dual fluidized bed reactor is a recirculating system in which one half of the unit operates as a steam pyrolysis device for biomass. The pyrolysis occurs by introducing biomass and steam to a hot fluidized bed of inert material such as coarse sand. Syngas is produced during the pyrolysis and exits the top of the reactor with the steam. A crossover arm, fed by gravity, moves sand and char from the pyrolyzer to the second fluidized bed. This sand bed uses blown air to combust the char. The exit stream from this side of the reactor is carbon dioxide, water and ash. There is a second gravity fed crossover arm to return sand to the pyrolysis side. The recirculating action of the sand and the char is the key to the operation of the dual fluidized bed reactor. The objective of the project was to design and construct a dual fluidized bed prototype reactor from literature information and in discussion with established experts in the field. That would be appropriate in scale and operation to measure the relative performance of the gasification of biomass and low ranked coals to produce a high quality synthesis gas with no dilution from nitrogen or combustion products.

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

    NARCIS (Netherlands)

    Hoomans, B.P.B.; Kuipers, J.A.M.; Swaaij, van W.P.M.

    2000-01-01

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

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    2SO4 using Dextrin as binder in three top-spray fluidised bed scales, i.e. a small-scale (type: GEA Aeromatic-Fielder Strea-1), medium-scale (type: Niro MP-1) and large-scale (type: GEA MP-2/3). Following the parameter guidelines adapted from the original patent description, the flux number...

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

    CSIR Research Space (South Africa)

    Oboirien, BO

    2013-09-01

    Full Text Available -1 International Conference of Coal Science and Technology, State College, Pennysylvania, USA, 29 September- 3 October 2013 Microwave-assisted synthesis of geopolymers from fluidised bed gasifier bottom ash B.O. Oboirien1, B.C. North1 and E. R. Sadiku2...

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

    CSIR Research Space (South Africa)

    Hadley, TD

    2006-02-01

    Full Text Available The CSIR has had a strong drive in fluidised bed technology for over two decades. During this period collaboration has been fostered with numerous partners and clients. By being able to draw on their resources, skills, test and other facilities...

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

    NARCIS (Netherlands)

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

    2004-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Błaszczuk Artur

    2014-06-01

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

  18. Co-combustion of waste from olive oil production with coal in a fluidised bed.

    Science.gov (United States)

    Cliffe, K R; Patumsawad, S

    2001-01-01

    Waste from olive oil production was co-fired with coal in a fluidised bed combustor to study the feasibility of using this waste as an energy source. The combustion efficiency and CO emission were investigated and compared to those of burning 100% of coal. Olive oil waste with up to 20% mass concentration can be co-fired with coal in a fluidised bed combustor designed for coal combustion with a maximum drop of efficiency of 5%. A 10% olive oil waste concentration gave a lower CO emission than 100% coal firing due to improved combustion in the freeboard region. A 20% olive oil waste mixture gave a higher CO emission than both 100% coal firing and 10% olive oil waste mixture, but the combustion efficiency was higher than the 10% olive oil waste mixture due to lower elutriation from the bed.

  19. CFD-DEM Analysis of Particle Attrition in a Jet in a Fluidised Bed

    Science.gov (United States)

    Fulchini, F.; Nan, W.; Ghadiri, M.; Yazdan Panah, M.; Bertholin, S.; Amblard, B.; Cloupet, A.; Gauthier, T.

    2017-06-01

    In fluidised bed processes, the solids are in vigorous motion and thus inevitably subjected to mechanical stresses due to inter-particle and particle-wall impacts. These stresses lead to a gradual degradation of the particles by surface wear, abrasion and body fragmentation commonly termed attrition. One significant contribution of attrition comes from the air jets of the fluidised bed distributor. Particles are entrained into the air jet, where they get accelerated and impacted onto the fluidised bed particles. The jet induced attrition only affects the part of the bed which is limited by the jet length, where the mode of attrition is largely collisional. The overall jet attrition rate is therefore the result of the combination of the single particle damage and the flux of particles entering into that region. The attrition behaviour of particles in the jet region is analysed by evaluating their propensity of breakage experimentally and by simulating an air-jet in a bed of particles by CFD-DEM. The frequency of collisions and impact velocities are estimated from which the attrition due to a single air-jet is predicted.

  20. Hydrodynamic modeling of dense gas-fluidised beds using the kinetic theory of granular flow: effect of coefficient of restitution on bed dynamics

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria

    2000-01-01

    A two-dimensional multi-fluid Eulerian CFD model with closure laws according to the kinetic theory of granular flow has been applied to study the influence of the coefficient of restitution on the hydrodynamics of dense gas-fluidised beds. It is demonstrated that hydrodynamics of dense gas-fluidised

  1. Hydrodynamic modeling of dense gas-fluidised beds using the kinetic theory of granular flow: effect of coefficient of restitution on bed dynamics.

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria

    2001-01-01

    A two-dimensional multi-fluid Eulerian CFD model with closure laws according to the kinetic theory of granular flow has been applied to study the influence of the coefficient of restitution on the hydrodynamics of dense gas-fluidised beds. It is demonstrated that hydrodynamics of dense gas-fluidised

  2. Hydrodynamic modeling of dense gas-fluidised beds using the kinetic theory of granular flow: effect of coefficient of restitution on bed dynamics

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Kuipers, J.A.M.; Swaaij, van W.P.M.

    2000-01-01

    A two-dimensional multi-fluid Eulerian CFD model with closure laws according to the kinetic theory of granular flow has been applied to study the influence of the coefficient of restitution on the hydrodynamics of dense gas-fluidised beds. It is demonstrated that hydrodynamics of dense gas-fluidised

  3. Hydrodynamic modelling of dense gas-fluidised beds using the kinetic theory of granular flow: effect of coefficient of restitution on bed dynamics.

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Kuipers, J.A.M.; Swaaij, van W.P.M.

    2001-01-01

    A two-dimensional multi-fluid Eulerian CFD model with closure laws according to the kinetic theory of granular flow has been applied to study the influence of the coefficient of restitution on the hydrodynamics of dense gas-fluidised beds. It is demonstrated that hydrodynamics of dense gas-fluidised

  4. Magnetic resonance studies of jets in a gas-solid fluidised bed

    Institute of Scientific and Technical Information of China (English)

    Meenal Pore; Lynn F. Gladden; John S. Dennis; Thusara C. Chandrasekera; Daniel J. Holland; Aining Wang; Fei Wang; Qussai Marashdeh; Michael D. Mantle; Andrew J. Sederman; Liang-Shih Fan

    2012-01-01

    Magnetic resonance imaging (MRI) has been used to study the behaviour of jets at the distributor of a 50 mm diameter fluidised bed of 0.5 mm diameter poppy seeds.Two perforated-plate distributors were examined,containing either 10 or 14 holes,each 1 mm diameter.Ultra-fast MR imaging was able to show the transient nature of the upper parts of the jets,where discrete bubbles are formed.Imaging in 3D showed that the central jets were the longest for flow rates below minimum fluidisation.Above minimum fluidisation,the outer jets,nearest the wall of the fluidised bed,arched inward towards the central axis.In this latter case,interpretation of the time-averaged 3D image required the use of ultra-fast MR imaging to identify the approximate height above the distributor at which discrete bubbles were formed.The apparently continuous void extending along the central axis above this height in the time-averaged 3D image was thus identified,using ultra-fast MR imaging,as representing the averaged paths of released bubbles.Time-averaged MR velocity mapping was also used to identify dead zones of stationary particles resting on the distributor between the jets.The dead zones could be observed when the superficial velocity of the gas approached minimum fluidisation,but they were smaller than those observed at lower gas superficial velocity.Comparable images of a single jet through 1.2 mm diameter poppy seeds from MRI and electrical capacitance volume tomography (ECVT) are also demonstrated.

  5. Computational fluid dynamics modelling of biomass fast pyrolysis in fluidised bed reactors, focusing different kinetic schemes.

    Science.gov (United States)

    Ranganathan, Panneerselvam; Gu, Sai

    2016-08-01

    The present work concerns with CFD modelling of biomass fast pyrolysis in a fluidised bed reactor. Initially, a study was conducted to understand the hydrodynamics of the fluidised bed reactor by investigating the particle density and size, and gas velocity effect. With the basic understanding of hydrodynamics, the study was further extended to investigate the different kinetic schemes for biomass fast pyrolysis process. The Eulerian-Eulerian approach was used to model the complex multiphase flows in the reactor. The yield of the products from the simulation was compared with the experimental data. A good comparison was obtained between the literature results and CFD simulation. It is also found that CFD prediction with the advanced kinetic scheme is better when compared to other schemes. With the confidence obtained from the CFD models, a parametric study was carried out to study the effect of biomass particle type and size and temperature on the yield of the products.

  6. Process intensification by direct product sequestration from batch fermentations: application of a fluidised bed, multi-bed external loop contactor

    Science.gov (United States)

    Hamilton; Morton; Young; Lyddiatt

    1999-08-01

    A critical comparison has been made of the relative efficacy of the primary purification of an extracellular acid protease produced by the yeast Yarrowia lipolytica. The performance of conventional, discrete sequences of fermentation, broth clarification and fixed bed, anion exchange chromatography has been compared with fluidised bed adsorption directly interfaced with post-term fermentation broth and fluidised bed adsorption directly integrated with productive fermentations (so-called direct product sequestration; DPS). Advantages of the latter, in terms of the improved yield and molecular quality of the protease end product are discussed in terms of the design, assembly and operation of component parts of DPS devices and their generic application to other extracellular bioproducts of microbial fermentations. Copyright 1999 John Wiley & Sons, Inc.

  7. Thermal waste utilisation by means of rotating fluidised beds. Thermische Abfallverwertung mit rotierender Wirbelschicht

    Energy Technology Data Exchange (ETDEWEB)

    Kitzerow, H.G. (Hoelter-ABT GmbH, Gladbeck (Germany))

    1994-10-01

    The legal requirement of material and thermal waste utilisation prior to disposal opens up a wide field of application for the rotating fluidised-bed technique. The advantages of this method are its applicability to processing plants for different types of waste and the large range of possible plant capacity from 0.8 MW upwards. The article presents a special variation of the process and gives application examples. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

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

  9. Investigation of pollutant formation of Sweet Sorghum-lignite (Orhaneli) mixtures in fluidised beds

    Energy Technology Data Exchange (ETDEWEB)

    Cubuk, M.H.; Heperkan, H.A. [Yildiz Technical University, Istanbul (Turkey)

    2004-07-01

    Most of the Turkish lignites have undesired fuel properties and they are extremely polluting. In this study, Sweet Sorghum was chosen as the energy plant. Combustion experiments of lignite and lignite-Sweet Sorghum mixtures were carried out in a fluidised bed system. The fuel-feeding ratio was set such that the thermal output of the system remained constant. Addition of Sweet Sorghum to the lignite reduces the pollutant concentration. The results were supported by experimental results.

  10. A simplified approach to the drying of solids in a batch fluidised bed

    Directory of Open Access Journals (Sweden)

    C. Srinivasakannan

    2002-07-01

    Full Text Available A simplified model for drying solids in the constant rate period in a batch fluidised bed was developed.It assumes the bed to be divided into dense and bubble phases with heat and mass transfer between the phases.The model predicts the constant-rate drying period, provided the fluid bed shape and material characteristics are known.The model is compared with experimental data reported in the literature covering a wide range of materials, gas flow rates, column diameters, material hold-ups, air temperatures and humidities.Model predictions compare satisfactorily with the experimental data.

  11. Emissions modeling of fluidised bed co-combustion of poultry litter and peat

    Energy Technology Data Exchange (ETDEWEB)

    Henihan, A.M.; Leahy, J.J.; Kelleher, B.P. [University of Limerick (Ireland). Dept. of Chemical and Environmental Science; Leahy, M.J. [University of Limerick (Ireland). Dept. of Physics; Cummins, E. [University College, Dublin (Ireland). Dept. of Agricultural and Food Engineering

    2003-05-01

    Gaseous emissions from the fluidised bed co-combustion of 50% w/w chicken litter and peat were monitored and recorded. Emission data were used to create a dispersion model for a proposed site on a poultry farm in Ireland. Variables within the combustion unit influenced both combustion and emission levels of pollutants such as SO{sub 2} and NO{sub x}, CO. Concentrations of atmospheric pollutants decreased with use of the correct ratio between fluidising and secondary air. Dispersion modelling of combustion at a proposed poultry unit predicted that ground level concentrations for the set of emissions data would be below the limits and guidelines set by air quality standards. (author)

  12. Fluidised bed gasification of low grade South African coals

    CSIR Research Space (South Africa)

    North, BC

    2006-09-01

    Full Text Available technologies, it is a fact that South Africa will continue to exploit its abundant coal reserves. The challenge, therefore, is to utilise the coal as efficiently as possible, in order to reduce carbon dioxide emissions. This paper describes an on...

  13. Combustion of coal residue in a fluidised bed part I - design parameters. Combustion de residuos de carbon en lecho fluidizado - parte I; parametros de diseno

    Energy Technology Data Exchange (ETDEWEB)

    Fuertes, A.B.; Pis, J.J.; Jul, J.J.; Alvarez, F.J.; Canibano, J.G. (Inst. Nacional del Carbon, Oviedo (Spain))

    1988-07-01

    Fluidised bed combustion is a method used to reduce environmental problems caused by deposits of both solid and liquid residue by allowing the energy content of the deposits to be recovered. Fluidised bed combustors are capable of burning solid or liquid residue with up to 85% inert material. 10 refs., 10 figs., 2 tabs.

  14. Hydrodynamic modelling of dense gas-fluidised beds: comparison and validation of 3D discrete particle and continuum models

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Beetstra, R.; Kuipers, J.A.M.

    2004-01-01

    A critical comparison of a hard-sphere discrete particle model, a two-fluid model with kinetic theory closure equations and experiments performed in a pseudo-two-dimensional gas-fluidised bed is made. Bubble patterns, time-averaged particle distributions and bed expansion dynamics measured with a no

  15. Temperature control of electronic components using fluidised beds

    Science.gov (United States)

    Bean, R.

    1981-06-01

    This paper introduces the concept of fluidized bed cooling applied to electronic systems. It is shown that, when fluidized with air, the cooling efficiency and the pumping power are principally dependent on particle characteristics; in particular the mean diameter should not be less than 100 microns. Design rules are developed and applied to two types of fluid-bed systems: (1) a small bed of alumina particles cooling single devices of 40 W power dissipation where the fluidizing air is the main heat transporting medium, and (2) a large bed of cenospheres with a simple integrated heat exchanger to extract more than 1 KW of heat from complete sub-rack assemblies of up to 40 printed circuit boards, for a fluidizing power of about 3 W. The effect of board spacing on the overall thermal performance is considered, and a minimum spacing of 10-20 mm is shown to be required to maintain cooling efficiency.

  16. Formation of abrasive hollow particles in lignite-fired fluidised bed boilers; Bildung abrasiver Hohlpartikel in braunkohlenbefeuerten Wirbelschichtkessel

    Energy Technology Data Exchange (ETDEWEB)

    Kappler, Uta [RWE Power AG, Koeln (Germany). Forschung und Entwicklung Hauptverwaltung; Roeper, Bernhard [RWE Power AG, Grevenbroich (Germany). Technische Dienste Kraftwerk Frimmersdorf; Voss, Petra [RWE Power AG, Bergheim (Germany). Forschung und Entwicklung Kraftwerk Niederaussem

    2013-04-01

    The formation of voluminous and highly abrasive hollow particles in raw-lignite-fired circulating fluidised-bed (CFB) boilers of RWE Power AG is a well-known phenomenon. Operational measures were taken to avoid particle formation and related damage. By the end of 2011 another boiler damage occurred. Within the scope of root cause analyses the hollow particles were investigated and a model for particle genesis was developed. Based on these results further measures for the avoidance of particle formation were shown. The formation probability of similar hollow particles in biomass-fired fluidised-bed plants was assessed theoretically.

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  18. Single-stage fluidized-bed gasification

    Science.gov (United States)

    Lau, F. S.; Rue, D. M.; Weil, S. A.; Punwani, D. V.

    1982-04-01

    The single-stage fluidized-bed gasification process, in addition to being a simple system, maximizes gas production and allows the economic exploitation of small peat deposits. The objective of this gasification project is to conduct experiments in order to obtain data for designing a single-stage fluidized-bed gasifier, and to evaluate the economics of converting peat to synthesis gas and to SNG by this process. An existing high-temperature and high-pressure process development unit (PDU) was modified to permit the direct feeding of peat to the fluidized bed. Peat flows by gravity from the feed hopper through a 6-inch line to the screw-feeder conveyor. From there, it is fed to the bottom tee section of the reactor and transported into the gasification zone. Oxygen and steam are fed through a distributing ring into the reactor. Gasification reactions occur in the annulus formed by the reactor tube and a central standpipe. Peat ash is discharged from the reactor by overflowing into the standpipe and is collected in a solids receiver.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-03-01

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

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

    NARCIS (Netherlands)

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

    2005-01-01

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

  1. Experimental validation of granular dynamics simulations of gas-fluidised beds with homogeneous inflow conditions using Positron Emission Particle Tracking

    NARCIS (Netherlands)

    Hoomans, B.P.B.; Kuipers, J.A.M.; Mohd Salleh, M.; Seville, J.P.

    2001-01-01

    A hard-sphere granular dynamics model of a two-dimensional gas-fluidised bed was experimentally validated using Positron Emission Particle Tracking (PEPT). In the model the Newtonian equations of motion are solved for each solid particle while taking into account the particle¿particle and particle¿w

  2. Nitrogen alloying of steel powder using ammonia gas in the fluidised bed

    Energy Technology Data Exchange (ETDEWEB)

    Virta, J.; Hannula, S.-P. [VTT Manuf. Technol. (Finland)

    1999-07-01

    Powder nitriding method utilising ammonia gas and fluidised bed technique was developed. The expected advantages of this method are the short processing time, low processing temperature and homogeneous nitrogen content of the powder charge. The nitrogen content of 0.4 wt.-% was achieved in 10 minutes at the temperature of 570 C for AISI 316 L powder. The nitrogen content increased linearly with the nitriding time being 6.8 wt.-% after two hours. For the control of the nitrogen content the heating-up and cooling of the powder must occur in an inert atmosphere. Because of the low processing temperatures nitrogen gas could be used. The short processing times, low processing temperatures and the use of inexpensive processing gases makes the method economically very attractive. (orig.)

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

    DEFF Research Database (Denmark)

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

    2003-01-01

    The parameters with effect on maximum spray rate and maximum relative outlet air humidity when coating pellets in a fluidised bed were investigated. The tested variables include type of water based modified release film coating (Eudragit® NE 30D, Eudragit® RS 30D, Aquacoat ECD®) coating principle...... (top spray, bottom spray), inlet air humidity and type of pellets (sugar spheres, microcrystalline cellulose pellets). The maximum spray rate was not influenced by the coating principles. The highest spray rate was obtained for the film polymer with the lowest tackiness which is assumed......-process calculation of degree of utilisation of the potential evaporation energy (DUE) of the outlet air and the relative outlet air humidity (RH). The spray rate is maximised using set points of DUE and RH as control parameters. The product temperature is controlled simultaneously by regulating the inlet air...

  4. Fixed bed gasification of solid biomass fuels

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  5. Gasification of wood in a fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, L.C. de; Marti, T.; Frankenhaeuser, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    A first series of gasification experiments with our fluidized bed gasifier was performed using clean sawdust as fuel. The installation and the analytical systems were tested in a parametric study in which gasification temperature and equivalence ratio were varied. The data acquired will serve to establish the differences between the gasification of clean wood and the gasification of Altholz (scrapwood) and wood/plastics mixtures. (author) 1 fig., 3 tabs., 5 refs.

  6. Modeling biomass gasification in circulating fluidized beds

    Science.gov (United States)

    Miao, Qi

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

  7. Influence of medium composition on the characteristics of a denitrifying biofilm formed by Alcaligenes denitrificans in a fluidised bed reactor

    OpenAIRE

    Alves, C. F.; Melo, L. F.; Vieira, M. J.

    2002-01-01

    The influence of the ratio carbon/nitrogen and phosphorus concentration on the performance of a biofilm fluidised bed reactor used for denitrification and on the properties of the biofilm was studied. Although the removal efficiencies of C and N reached steady-state values, the thickness of the biofilm steadily increased. The dry density of the biofilm did not seem to be dependent on the loading conditions, although a denser biofilm was obtained when there was no nutrient limitation ...

  8. Trace elements release during fluidised bed (co-)pyrolysis of sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Jaakko Savolahti; Loay Saeed; Ron Zevenhoven [Helsinki University of Technology, Espoo (Finland). Laboratory of Energy Engineering and Environmental Protection

    2006-07-01

    The objective of this work was to investigate the release of mercury (Hg) and other trace elements (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, Tl, V, Zn, Ti and Se) from sewage sludge during pyrolysis in a laboratory scale bubbling fluidised bed reactor. Coal and coal-car tyre scrap was also co-pyrolysed with the sewage sludge. Mercury emissions were measured by the Ontario Hydro Method or by EON-developed dry sampling method. Other trace elements were sampled by directing the flue gas flow through a scrubber tank containing fifteen litres of HNO{sub 3}/H{sub 2}O{sub 2} liquid, from which samples were taken during the test. The compositions of bed sand, fuel and char were also analysed. FT-IR gas analysis was used to measure concentrations of about twenty gaseous species in the pyrolysis product gas. From our experiments it was found that all of the mercury was vaporised from the fuel already at temperatures below 300{sup o}C. The mercury was found to be almost exclusively in the elemental form. Se and As showed significant vaporisation behaviour. 14 refs., 4 figs., 4 tabs.

  9. Fixed-bed gasification research using US coals. Volume 10. Gasification of Benton lignite

    Energy Technology Data Exchange (ETDEWEB)

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the tenth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Benton lignite. The period of gasification test was November 1-8, 1983. 16 refs., 22 figs., 19 tabs.

  10. Biomass gasification in ABFB : Tar mitigation

    OpenAIRE

    Vera, Nemanova

    2014-01-01

    Biomass gasification may be an attractive alternative for meeting future energy demand. Although gasification is a mature technology, it has yet to be fully commercialised due to tar formation. This study focuses on the tar mitigation in gas produced in an atmospheric bubbling fluidised bed (ABFB) gasification system. Previous studies indicated significant tar variability along the system. In this work the experimental procedure has been improved for reliable results and better understanding ...

  11. Fluidized bed gasification of industrial solid recovered fuels.

    Science.gov (United States)

    Arena, Umberto; Di Gregorio, Fabrizio

    2016-04-01

    The study evaluates the technical feasibility of the fluidized bed gasification of three solid recovered fuels (SRFs), obtained as co-products of a recycling process. The SRFs were pelletized and fed to a pilot scale bubbling fluidized bed reactor, operated in gasification and co-gasification mode. The tests were carried out under conditions of thermal and chemical steady state, with a bed of olivine particles and at different values of equivalence ratio. The results provide a complete syngas characterization, in terms of its heating value and composition (including tars, particulates, and acid/basic pollutants) and of the chemical and physical characterization of bed material and entrained fines collected at the cyclone outlet. The feasibility of the fluidized bed gasification process of the different SRFs was evaluated with the support of a material and substance flow analysis, and a feedstock energy analysis. The results confirm the flexibility of fluidized bed reactor, which makes it one of the preferable technologies for the gasification of different kind of wastes, even in co-gasification mode. The fluidized bed gasification process of the tested SRFs appears technically feasible, yielding a syngas of valuable quality for energy applications in an appropriate plant configuration.

  12. Optimally controlled heating of solid particles in a fluidised bed with a dispersive flow of the solid

    Directory of Open Access Journals (Sweden)

    Poświata Artur

    2016-03-01

    Full Text Available In this study the authors minimise the total process cost for the heating of solid particles in a horizontal fluidised bed by an optimal choice of the inlet heating gas temperature profile and the total gas flow. Solid particles flowed along the apparatus and were heated by a hot gas entering from the bottom of the fluidised apparatus. The hydrodynamics of the fluidised bed is described by a two-phase Kunii - Levenspiel model. We assumed that the gas was flowing only vertically, whereas solid particles were flowing horizontally and because of dispersion they could be additionally mixed up in the same direction. The mixing rate was described by the axial dispersion coefficient. As any economic values of variables describing analysing process are subject to local and time fluctuations, the accepted objective function describes the total cost of the process expressed in exergy units. The continuous optimisation algorithm of the Maximum Principle was used for calculations. A mathematical model of the process, including boundary conditions in a form convenient for optimisation, was derived and presented. The optimization results are presented as an optimal profile of inlet gas temperature. The influence of heat transfer kinetics and dispersion coefficients on optimal runs of the heating process is discussed. Results of this discussion constitute a novelty in comparison to information presented in current literature.

  13. Experimental investigation of fluidised bed co-combustion of meat and bone meal with coals and olive bagasse

    Energy Technology Data Exchange (ETDEWEB)

    L. Fryda; K. Panopoulos; P. Vourliotis; E. Pavlidou; E. Kakaras [National Technical University of Athens, Athens (Greece). Laboratory of Steam Boilers and Thermal Plants, School of Mechanical Engineering

    2006-09-15

    Meat and bone meal (MBM) were co-fired in a laboratory scale fluidised bed combustion (FBC) apparatus together with three different primary fuels: two coal types and olive bagasse residues. Several two component fuel blends were tested under different combustion conditions to study how primary fuel substitution by MBM affects flue gas emissions as well as fluidised bed (FB) agglomeration tendency. MBM, being a highly volatile fuel, caused significant increase of CO emissions and secondary air should be used in industrial scale applications to conform to regulations. The high N-content of MBM is moderately reflected on the increase of nitrogen oxides emissions, which are reduced by MBM derived volatiles. The MBM ash, although containing bone material rich in Ca, did not create any noteworthy desulphurisation effect. The observed slight decrease in SO{sub 2} emissions is predominantly attributed to the lower sulphur content in the coal/MBM fuel mixtures. The experimental work is evaluated with bed agglomeration indices from literature. The SEM/EDS analysis of bed material samples from the coal/MBM tests revealed the formation of conglomerates of bed material debris and ash with sizes that do not greatly exceed the original bed inventory and thus are not problematic. On the contrary, the co-combustion tests of olive bagasse residues with MBM led to a prompt loss of fluidisation, as a consequence of the high potassium and silicon content of the olive bagasse, the chlorine contents in both MBM and olive bagasse, and the high phosphorus content in the MBM also forming eutectics with potassium. 44 refs., 17 figs., 5 tabs.

  14. Thermal treatment of electronic waste in a fluidised bed and chemical digestion of solid products.

    Science.gov (United States)

    Woynarowska, Amelia; Żukowski, Witold; Żelazny, Sylwester

    2016-07-01

    The article presents the results of e-waste thermal treatment in a fluidised bed reactor and solid products digestion under acidic conditions. During the processes, measurements of carbon monoxide, carbon dioxide, volatile organic compounds, nitrogen oxides, sulphur dioxide, hydrogen chloride, hydrogen bromide, hydrogen cyanide, ammonia, phenol, aliphatic and aromatic hydrocarbons, hydrogen fluoride and phosgene were carried out. Several digestion tests of the solid residue in sulphuric acid (VI) at 25 °C-65 °C, for 55 min-24 h were conducted. In each case, the dilution method was used, i.e. preliminary digestion in concentrated sulphuric acid (VI) (95%) for 40 min, and then dilution to expected concentrations (30%-50%). Most preferred results were obtained using sulphuric acid (VI) with a target concentration of 40% at 65 °C, where the leaching degrees were 76.56% for copper, 71.67% for iron, 91.89% for zinc and 97.40% for tin. The time necessary to effectively carry out the digestion process was 220 min.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  16. Behaviour of meat and bonemeal/peat pellets in a bench scale fluidised bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    McDonnell, K.; Desmond, J.; Leahy, J.J.; Howard-Hildige, R.; Ward, S. [University College Dublin, Dublin (Ireland). Agriculture and Food Engineering Department

    2001-01-01

    As a result of the recent Bovine Spongiform Encephalopathy crisis in the European beef industry, safe animal by-product disposal is currently being addressed. One such disposal option is the combustion of by-product material such as meat and bone meal (MBM) in a fluidised bed combustor (FBC) for the purpose of energy recovery. Two short series of combustion tests were conducted on a FBC at the University of Twente, the Netherlands. In the first series, pellets (10 mm in diameter and approximately 10 mm in length) were made from a mixture of MBM and milled peat, at MBM inclusion rates of 0%, 30%, 50%, 70% and 100%. In the second series of tests, the pellets were commercially made and were 4.8 mm in diameter and between 12 and 15 mm long. These pellets had a weight of about 0.3 g and contained 0%, 25%, 35%, 50% and 100% MBM inclusion with the peat. Both sets of pellets were combusted at 800{degree}C. The residence times in the FBC varied from 300 s (25% MBM inclusion) to 120 s (100% MBM inclusion) for the first series of pellets. Increasing compaction pressure increased the residence time. For the second series of pellets, the residence time varied from about 300 s (25% MBM inclusion) to 100 s (100% MBM inclusion). MBM was found to be a volatile product (about 65%) and co-firing it with milled peat in a pelleted feed format reduces its volatile intensity. Pellets made from 100% bone based meal remained intact within the bed and are thought to have undergone a process of calcination during combustion. A maximum MBM inclusion rate of 35% with milled peat in a pellet is recommended.

  17. Incineration of wool-scouring sludge in a vertical-axis-spinning fluidised-bed incinerator

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Y.; Wong, W.Y.; Nasserzadeh, V.; Swithenbank, J. [Sheffield Univ. Waste Incineration Centre (SUWIC), Dept. of Chemical and Process Engineering, Sheffield (United Kingdom); Shaw, T.; Madden, M. [Wool Development International (ENCO) Ltd., Ilkley (United Kingdom)

    2000-09-01

    The main purposes of this research was to investigate the feasibility of incineration of wool-scouring sludge in a novel vertical-axis-rotating fluidised bed (RFB). The experiment was carried out in a RFB with an internal diameter (ID) of 200 mm and height of 50 mm. A cold test was first conducted to investigate the fluidization performance of the RFB via parameters such as the bubbling, gas distribution, bed shape and pressure drop. The tumbling phenomena was observed in the bed, and this effectively enhanced the axial mixing. The appropriate range of bed thickness, rotating speed and sand particle size were identified to ensure the full fluidization and reduce the particle elutriation. Four wool-scouring sludges from different processes were incinerated in the RFB. With 5% support methane, all sludges with a maximum moisture up to 70% as received could be successfully burned in the RFB at rotating speeds of 200 and 300 rpm. The combustion was found to be intense with a high efficiency due to the good turbulence and mixing in the RFB. The effects of moisture content, feeding rate and rotating speed were investigated. It was found that for sludge (sample B2) with a moisture content of 5%, the combustion could be sustained at a bed surface temperature of around 500 degC and freeboard temperature of 900 degC without the support of methane. To investigate the special advantages of swirling flow in the RFB on the combustion and particle elutriation, a CFD model was used. In the calculated flow field, two flow regions were identified, viz, the outer free vortex region and the forced vortex flow near the axis. Recirculation and turbulence of flow were generated by the pressure gradients and shear layers, respectively. The modelling of premixed methane and air combustion, which was used to simulate the volatile burning in the freeboard of the RFB, showed two high-temperature zones near the exit and at the bottom of the chamber near the core in accordance with the flow

  18. Pressurised fluidised bed combustion: an alternative for the clean use of coal. La combustion en lecho fluido a presion, una alternativa de uso limpio del carbon en desarrollo

    Energy Technology Data Exchange (ETDEWEB)

    Beucom O Perez-Zamora, V.; Menendez Perez, J.A.E. (ENDESA, Madrid (Spain))

    1988-11-01

    Atmospheric fluidised bed combustion is an alternative worthy of consideration. It is a solution which maintains or even increases output slightly and, in the circulating fluidised bed variety, has the advantage of being able to burn an inconsistent quality of coal with a high sulphur content. The most important question is to what output this method can be developed whilst remaining competitive with other systems. There is a tendency to assume that atmospheric fluidised bed combustors can be developed up to 250 MW and that more powerful installations for electricity generation use systems with a higher output. In any case, this is no more than a general and preliminary observation. Its validity will be proved by the technical and economic results achieved with high output systems and by the availability of coal of the required mix of quality and price. 10 tabs., 10 figs.

  19. An Analytical Solution Applied to Heat and Mass Transfer in a Vibrated Fluidised Bed Dryer

    Energy Technology Data Exchange (ETDEWEB)

    Picado, Apolinar

    2011-07-01

    A mathematical model for the drying of particulate solids in a continuous vibrated fluidised bed dryer was developed and applied to the drying of grain wetted with a single liquid and porous particles containing multicomponent liquid mixtures. Simple equipment and material models were applied to describe the process. In the plug-flow equipment model, a thin layer of particles moving forward and well mixed in the direction of the gas flow was regarded; thus, only the longitudinal changes of particle moisture content and composition as well as temperature along the dryer were considered. Concerning the material model, mass and heat transfer in a single isolated particle was studied. For grain wetted with a single liquid, mass and heat transfer within the particles was described by effective transfer coefficients. Assuming a constant effective mass transport coefficient and effective thermal conductivity of the wet particles, analytical solutions of the mass and energy balances were obtained. The variation of both transport coefficients along the dryer was taken into account by a stepwise application of the analytical solution in space intervals with non-uniform inlet conditions and averaged coefficients from previous locations in the dryer. Calculation results were verified by comparison with experimental data from the literature. There was fairly good agreement between experimental data and simulation but the results depend strongly on the correlation used to calculate heat and mass transfer coefficients. For the case of particles containing a multicomponent liquid mixture dried in the vibrated fluidised bed dryer, interactive diffusion and heat conduction were considered the main mechanisms for mass and heat transfer within the particles. Assuming a constant matrix of effective multicomponent diffusion coefficients and thermal conductivity of the wet particles, analytical solutions of the diffusion and conduction equations were obtained. The equations for mass

  20. Fixed-bed gasification research using US coals. Volume 14. Gasification of Kemmerer subbituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) group. This report is the fourteen volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Kemmerer subbituminous coal, from August 11, 1984 to August 15, 1984. 4 refs., 20 figs., 13 tabs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-01

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

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

    CSIR Research Space (South Africa)

    Oboirien, BO

    2013-02-01

    Full Text Available to the large coal particle size fraction (1.5–2 mm) used. Minimal damage to the fungal culture was observed. However, clogging of bed by fungi resulted in channelling or misdistribution that ultimately leads to poor and unpredictable internal mass transport....

  4. Using the Box-Behnken experimental design to optimise operating parameters in pulsed spray fluidised bed granulation.

    Science.gov (United States)

    Liu, Huolong; Wang, Ke; Schlindwein, Walkiria; Li, Mingzhong

    2013-05-20

    In this work, the influence factors of pulsed frequency, binder spray rate and atomisation pressure of a top-spray fluidised bed granulation process were studied using the Box-Behnken experimental design method. Different mathematical models were developed to predict the mean size of granules, yield, relative width of granule distribution, Hausner ratio and final granule moisture content. The study has supported the theory that the granule size can be controlled through the liquid feed pulsing. However, care has to be taken when the pulsed frequency is chosen for controlling the granule size due to the nonlinear quadratic relation in the regression model. The design space of the ranges of operating parameters has been determined based on constraints of the mean size of granules and granule yield. High degree of prediction obtained from validation experiments has shown the reliability and effectiveness of using the Box-Behnken experimental design method to study a fluidised bed granulation process. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Gasification of sawdust in pressurised internally circulating fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Maartensson, R.; Lindblom, M. [Lund Univ. (Sweden). Dept. of Chemical Engineering

    1996-12-31

    A test plant for pressurised gasification of biofuels in a internally circulating fluidized bed has been built at the department of Chemical Engineering II at the University of Lund. The design performance is set to maximum 20 bar and 1 050 deg C at a thermal input of 100 kW or a maximum fuel input of 18 kg/in. The primary task is to study pressurised gasification of biofuels in relation to process requirements of the IGCC concept (integrated gasification combined cycle processes), which includes studies in different areas of hot gas clean-up in reducing atmosphere for gas turbine applications. (orig.)

  6. Fixed-bed gasification research using US coals. Volume 4. Gasification of Leucite Hills subbituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-03-31

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the fourth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of Leucite Hills subbituminous coal from Sweetwater County, Wyoming. The period of the gasification test was April 11-30, 1983. 4 refs., 23 figs., 27 tabs.

  7. Hydrodynamic modelling of dense gas-fluidised beds: comparison of the kinetic theory of granular flow with 3D hard-sphere discrete particle simulations

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Beetstra, R.; Kuipers, J.A.M.

    2002-01-01

    A novel technique to sample particle velocity distributions and collision characteristics from dynamic discrete particle simulations of intrinsically unsteady, non-homogeneous systems, such as those encountered in dense gas-fluidised beds, is presented. The results are compared to the isotropic Maxw

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

    NARCIS (Netherlands)

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

    1996-01-01

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

  9. Development of a multi-fluid model for poly-disperse dense gas–solid fluidised beds, Part I: Model derivation and numerical implementation

    NARCIS (Netherlands)

    van Sint Annaland, M.; Bokkers, G.A.; Goldschmidt, M.J.V.; Olaofe, O.O.; van der Hoef, Martin Anton; Kuipers, J.A.M.

    2009-01-01

    We have derived a new set of closure equations for the rheologic properties of a dense gas–solid fluidised bed consisting of a multi-component mixture of slightly inelastic spheres, using the Chapman–Enskog solution procedure of successive approximations, where the particle velocity distribution of

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-06-01

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

  11. Process for fixed bed coal gasification

    Science.gov (United States)

    Sadowski, Richard S.

    1992-01-01

    The combustion of gas produced from the combination of coal pyrolysis and gasification involves combining a combustible gas coal and an oxidant in a pyrolysis chamber and heating the components to a temperature of at least 1600.degree. F. The products of coal pyrolysis are dispersed from the pyrolyzer directly into the high temperature gasification region of a pressure vessel. Steam and air needed for gasification are introduced in the pressure vessel and the materials exiting the pyrolyzer flow down through the pressure vessel by gravity with sufficient residence time to allow any carbon to form carbon monoxide. Gas produced from these reactions are then released from the pressure vessel and ash is disposed of.

  12. Bio-oil production via fast pyrolysis of biomass residues from cassava plants in a fluidised-bed reactor.

    Science.gov (United States)

    Pattiya, Adisak

    2011-01-01

    Biomass residues from cassava plants, namely cassava stalk and cassava rhizome, were pyrolysed in a fluidised-bed reactor for production of bio-oil. The aims of this work were to investigate the yields and properties of pyrolysis products produced from both feedstocks as well as to identify the optimum pyrolysis temperature for obtaining the highest organic bio-oil yields. Results showed that the maximum yields of the liquid bio-oils derived from the stalk and rhizome were 62 wt.% and 65 wt.% on dry basis, respectively. The pyrolysis temperatures that gave highest bio-oil yields for both feedstocks were in the range of 475-510 °C. According to the analysis of the bio-oils properties, the bio-oil derived from cassava rhizome showed better quality than that derived from cassava stalk as the former had lower oxygen content, higher heating value and better storage stability.

  13. Ash formation, transformations and deposition during fluidized bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Kauppinen, E.; Lind, T.; Kurkela, J.; Latva-Somppi, J.; Lyyraenen, J.; Valmari, T. [VTT Chemical Technology, Espoo (Finland). Aerosol Technology Group

    1998-12-31

    In this work, ash formation and transformations as well as bed agglomeration and fly ash deposition onto the heat exchanger tubes during fluidised bed combustion and gasification were studied using experimental methods and chemical equilibrium calculations. The fuels were coal and pulp and paper mill sludges as well as different wood-based waste materials. The volatilized heavy metal behaviour during pressurized combustion and gasification was studied using chemical equilibrium calculations. The classification of trace elements into four groups presented in this report matched well with the former studies. The release of ash-forming compounds during pyrolysis was studied experimentally in a heated grid reactor. Very small fractions of Si, Al, Fe, Ca, Mg, Na, and K were released from the biomass fuels, peat, and coals during pyrolysis at 900 deg C. Bottom ash during combustion of biomass fuels was found to be formed from bed material and ash-forming compounds. Ash-forming compounds were found to adhere to the bed material by two mechanisms: (i) by deposition of the non-volatile ash compounds as particles onto the bed particle surface, and (ii) by chemical reactions of the volatile ash compounds, e.g., K and Pb, with the bed particles. The size distributions of the fly ash particles were bimodal. The fine mode particles (Dp < 1 {mu}m) were formed by nucleation of the volatilised refractory oxides, e.g., SiO{sub 2}. The nucleated particles grew further by coagulation and condensation of the volatile ash compounds. The coarse fly ash fraction (Dp > 1 {mu}m) was formed from the non-volatile ash compounds, e.g., Ca and Si. The coarse mode particles were agglomerated and irregular in shape. During sludge combustion, the fly ash was mostly in the supermicron size range. This is beneficial for conventional flue gas cleaning devices that are most effective in this particle size. This is especially true for paper mill sludges, producing negligible concentrations of submicron

  14. 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.

  15. Method for using fast fluidized bed dry bottom coal gasification

    Science.gov (United States)

    Snell, George J.; Kydd, Paul H.

    1983-01-01

    Carbonaceous solid material such as coal is gasified in a fast fluidized bed gasification system utilizing dual fluidized beds of hot char. The coal in particulate form is introduced along with oxygen-containing gas and steam into the fast fluidized bed gasification zone of a gasifier assembly wherein the upward superficial gas velocity exceeds about 5.0 ft/sec and temperature is 1500.degree.-1850.degree. F. The resulting effluent gas and substantial char are passed through a primary cyclone separator, from which char solids are returned to the fluidized bed. Gas from the primary cyclone separator is passed to a secondary cyclone separator, from which remaining fine char solids are returned through an injection nozzle together with additional steam and oxygen-containing gas to an oxidation zone located at the bottom of the gasifier, wherein the upward gas velocity ranges from about 3-15 ft/sec and is maintained at 1600.degree.-200.degree. F. temperature. This gasification arrangement provides for increased utilization of the secondary char material to produce higher overall carbon conversion and product yields in the process.

  16. An Experimental and Numerical Investigation of Fluidized Bed Gasification of Solid Waste

    OpenAIRE

    Sharmina Begum; Mohammad G. Rasul; Delwar Akbar; David Cork

    2013-01-01

    Gasification is a thermo-chemical process to convert carbon-based products such as biomass and coal into a gas mixture known as synthetic gas or syngas. Various types of gasification methods exist, and fluidized bed gasification is one of them which is considered more efficient than others as fuel is fluidized in oxygen, steam or air. This paper presents an experimental and numerical investigation of fluidized bed gasification of solid waste (SW) (wood). The experimental measurement of syngas...

  17. Combustion of coal residue in a fluidised bed Part II - experiment results. Combustion de residuos de carbon en lecho fluidizado parte II; resultados experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Pis, J.J.; Fuertes, A.B.; Alvarez, F.J.; Jul, J.J.; Canibano, J.G. (Inst. Nacional del Carbon, Oviedo (Spain))

    1988-09-01

    A study is being carried out at the National Coal Institute on the fluidised bed combustion of fine tailings. The purpose of the study is to assess the possibilities for using this technology as a means for reducing the environmental impact of this type of material and for recovering its energy content. The article gives the results obtained in various experiments carried out with this type of residue. 9 refs., 6 figs., 2 tabs.

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

    Science.gov (United States)

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

    2017-04-01

    Combustion of residual forest biomass (RFB) derived from eucalypt (Eucalyptus globulus), pine (Pinus pinaster) and golden wattle (Acacia longifolia) was evaluated in a pilot-scale bubbling fluidised bed reactor (BFBR). During the combustion experiments, monitoring of temperature, pressure and exhaust gas composition has been made. Ash samples were collected at several locations along the furnace and flue gas treatment devices (cyclone and bag filter) after each combustion experiment and were analysed for their unburnt carbon content and chemical composition. Total suspended particles (TSP) in the combustion flue gas were evaluated at the inlet and outlet of cyclone and baghouse filter and further analysed for organic and elemental carbon, carbonates and 57 chemical elements. High particulate matter collection efficiencies in the range of 94-99% were observed for the baghouse, while removal rates of only 1.4-17% were registered for the cyclone. Due to the sand bed, Si was the major element in bottom ashes. Fly ashes, in particular those from eucalypt combustion, were especially rich in CaO, followed by relevant amounts of SiO2, MgO and K2O. Ash characteristics varied among experiments, showing that their inorganic composition strongly depends on both the biomass composition and combustion conditions. Inorganic constituents accounted for TSP mass fractions up to 40 wt%. Elemental carbon, organic matter and carbonates contributed to TSP mass fractions in the ranges 0.58-44%, 0.79-78% and 0.01-1.7%, respectively.

  19. Fluidized bed gasification ash reduction and removal process

    Science.gov (United States)

    Schenone, Carl E.; Rosinski, Joseph

    1984-12-04

    In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

  20. Fluidized bed gasification ash reduction and removal system

    Science.gov (United States)

    Schenone, Carl E.; Rosinski, Joseph

    1984-02-28

    In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

  1. Gas mixing in a pilot scale (500 KW{sub th}) air blown circulating fluidised bed biomass gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Kersten, S.R.A.; Moonen, R.H.W.; Oosting, T.P. [ECN Biomass, Petten (Netherlands); Prins, W.; Van Swaaij, W.P.M. [Faculty of Chemical Engineering, University of Twente, Enschede (Netherlands)

    2000-07-01

    To study the gas mixing capacity of circulating fluidised bed (CFB) biomass gasifiers, radial and axial gas concentration profiles have been measured and interpreted in both a hot pilot scale biomass gasifier (100 kg/hr fuel) and a cold-flow set-up. The presented data of the pilot scale gasifier are unique and provide new insight in the radial gas mixing capacity of circulating fluidised bed gasifiers. Gas mixing is an important process because the effectiveness of a CFB biomass gasifier, regarding conversion of carbon and tars in the product gas, depends among other things on the degree of reactant mixing. At five different axial positions, in the pilot plant, especially developed probes are installed to withdraw gases from the interior of the reactor. They can be moved freely over the reactor diameter, so full radial profiles can be obtained at each axial position. In the cold-flow set-up similar probes are used to determine radial dispersion coefficients as a function of process variables such as solids flux, gas velocity and additional internals. Considerable radial gas phase concentration gradients have been observed in the pilot plant gasifier, with a difference between wall and centre concentrations up to a factor 3. It must be concluded that the radial gas mixing is far from ideal. On basis of these pilot plant data and a suitable reactor model it can be concluded that the radial Peclet number of the dilute region is in the order of 1000. Such a value excludes the radial mixing of gases almost entirely. Simulations indicate that the occurrence of a parabolic gas velocity profile (also observed in earlier hydrodynamic studies) and a possibly non-uniform biomass distribution, are major causes for steep gradients in the radial gas concentration profiles. From the experiments in the cold-flow set-up it can be concluded that in the dilute region of the riser the radial mixing intensity decreases due to presence of solids. This can be ascribed to a reducing

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

    Directory of Open Access Journals (Sweden)

    Chr. Christodoulou

    2014-11-01

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

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

    NARCIS (Netherlands)

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

    1979-01-01

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

  4. Waste-gasification efficiency of a two-stage fluidized-bed gasification system.

    Science.gov (United States)

    Liu, Zhen-Shu; Lin, Chiou-Liang; Chang, Tsung-Jen; Weng, Wang-Chang

    2016-02-01

    This study employed a two-stage fluidized-bed gasifier as a gasification reactor and two additives (CaO and activated carbon) as the Stage-II bed material to investigate the effects of the operating temperature (700°C, 800°C, and 900°C) on the syngas composition, total gas yield, and gas-heating value during simulated waste gasification. The results showed that when the operating temperature increased from 700 to 900°C, the molar percentage of H2 in the syngas produced by the two-stage gasification process increased from 19.4 to 29.7mol% and that the total gas yield and gas-heating value also increased. When CaO was used as the additive, the molar percentage of CO2 in the syngas decreased, and the molar percentage of H2 increased. When activated carbon was used, the molar percentage of CH4 in the syngas increased, and the total gas yield and gas-heating value increased. Overall, CaO had better effects on the production of H2, whereas activated carbon clearly enhanced the total gas yield and gas-heating value. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  5. Fixed-bed gasification research using US coals. Volume 11. Gasification of Minnesota peat. [Peat pellets and peat sods

    Energy Technology Data Exchange (ETDEWEB)

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a coooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the eleventh volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of peat pellets and peat sods during 3 different test periods. 2 refs., 20 figs., 13 tabs.

  6. NOx and N{sub 2}O emission characteristics from fluidised bed combustion of semi-dried municipal sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Saenger, M.; Werther, J.; Ogada, T. [Technical University Hamburg-Harburg, Hamburg (Germany). Chemical Engineering

    2001-01-01

    Incineration is one of the major methods for the disposal of sewage sludge. Currently, several plants are incinerating mechanically dewatered (wet) sludge (20-40 wt.% d.m.) or semi-dried sewage sludge (3-55 wt.% d.m.), although some plants burn dry sludge (with more than 80 wt.% d.m.). Whereas significant information is available on NOx and N{sub 2}O emissions characteristics of wet and dry sludge, not much has been reported on semi-dried sludge. This paper presents some of the results obtained from the combustion of semi-dried sludge in a semi-pilot scale fluidised bed combustor (150 mm in diameter and 9 m high) together with some measurements from a large-scale FBC incineration plant (7 m{sup 2} bed area, 9 m high and a capacity of 3 t/h dry sludge). The investigations have shown that semi-dried sludge exhibit emission characteristics which are similar to those of wet sludge. NOx decreases slightly whereas N{sub 2}O remains more or less the same with increase in oxygen concentrations. Just like wet sludge, staged combustion was not effective for the reduction of NOx and N{sub 2}O. However, increasing the freeboard temperature led to rapid reduction of N{sub 2}O and some NOx reduction was achieved using flue gas recycling technique. Comparison shows that the results from the test rig were more or less similar to those obtained from the large-scale plants. 28 refs., 14 figs., 2 tabs.

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

    CSIR Research Space (South Africa)

    Engelbrecht, A

    2011-06-01

    Full Text Available undertaken pinch analysis to optimize the use of energy generated by IGCC power plants. The focus was on the steam path (subsystem) of IGCC power plants and no alterations were done on the syngas path of the plant. A case study on the world’s largest capacity...

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

    NARCIS (Netherlands)

    De Jong, W.

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  10. Moving Bed Gasification of Low Rank Alaska Coal

    Directory of Open Access Journals (Sweden)

    Mandar Kulkarni

    2012-01-01

    Full Text Available This paper presents process simulation of moving bed gasifier using low rank, subbituminous Usibelli coal from Alaska. All the processes occurring in a moving bed gasifier, drying, devolatilization, gasification, and combustion, are included in this model. The model, developed in Aspen Plus, is used to predict the effect of various operating parameters including pressure, oxygen to coal, and steam to coal ratio on the product gas composition. The results obtained from the simulation were compared with experimental data in the literature. The predicted composition of the product gas was in general agreement with the established results. Carbon conversion increased with increasing oxygen-coal ratio and decreased with increasing steam-coal ratio. Steam to coal ratio and oxygen to coal ratios impacted produced syngas composition, while pressure did not have a large impact on the product syngas composition. A nonslagging moving bed gasifier would have to be limited to an oxygen-coal ratio of 0.26 to operate below the ash softening temperature. Slagging moving bed gasifiers, not limited by operating temperature, could achieve carbon conversion efficiency of 99.5% at oxygen-coal ratio of 0.33. The model is useful for predicting performance of the Usibelli coal in a moving bed gasifier using different operating parameters.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-12-15

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

  12. Fixed bed gasification for production of industrial fuel gas

    Energy Technology Data Exchange (ETDEWEB)

    1977-10-01

    This report summarizes the results of technical and economic evaluations of six commercially available, fixed-bed coal gasification processes for the production of industrial fuel gas. The study was performed for DOE and is intended to assist industrial companies in exploring the feasibility of producing gaseous fuels for both retrofit and new industrial plant situations. The report includes a technical analysis of the physical configuration, performance capabilities, and commercial experiments to-date for both air-blown and oxygen-blown fixed bed gasifiers. The product gas from these gasifiers is analyzed economically for three different degrees of cleanliness: (1) hot raw gas, (2) dust-, tar-, and oil-free gas, and (3) dust-, tar-, oil-free and desulfurized gas. The evaluations indicate that low-Btu gases produced from fixed bed gasifiers constitute one of the most logical short-term solutions for helping ease the shortage of natural gas for industrial fuel applications because the technology is well-proven and has been utilized on a commercial scale for several decades both in this country and overseas; time from initiation of design to commercial operation is about two years; the technology is not complicated to construct, operate, or maintain; and a reliable supply of product gas can be generated on-site. The advantages and disadvantages of fixed bed gasification technology are listed. The cost of the low Btu gas is estimated at $2 to $4 per MM Btu depending on gas purity, cost of coal ($20 to $50 per ton) and a number of specified assumptions with respect to financing, reliability, etc. (LTN)

  13. Pressurised fluidised bed combustion: an alternative clean coal technology. La combustion en lecho fluido a presion, una alternativa de uso limpio del carbon en desarollo

    Energy Technology Data Exchange (ETDEWEB)

    Bencomo Perez-Zamora, V.; Menendez Perez, J.A.E. (ENDESA, Madrid (Spain))

    1988-11-01

    The primary aim of thistechnology is to reduce emissions of sulphur and nitrous oxides. Pilot plant tests have achieved a sulphur fixing rate of over 95%. Pressurised fluidised bed combustion also has advantages with regard to the emission of contaminants. Halogens, fluorine and chlorine, which in conventional combustion methods are released in the gases, to a large degree remain in the ash as do trace elements, such as arsenic, which usually vapourise at high temperatures in pulverised coal combustors. This technology also has a high output of between 38 and 40% net according to the type of coal used. 10 figs., 10 tabs.

  14. A combination of a stationary fluidised bed with an externally fired {mu}-(gas) turbine; Kombination einer stationaeren Wirbelschichtfeuerung mit einer extern gefeuerten {mu}-(Gas) Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Steinbrecht, D.; Vincent, T. [Rostock Univ. (Germany); Dielmann, K.; Betsch, M. [FH Aachen (Germany)

    2009-07-01

    In this paper description a decentralized energy system with a small energy performance is presented. The energy system consists of a {mu}-gasturbine, which is modified to an externally fired machine and is connected to a stationary fluidised bed combustion system by a high temperature heat exchanger. By the connection of the two systems the application spectrum of useable fuels for the {mu}-gasturbine is significantly increased. Not only natural gas or diesel-oil can be burned but also low caloric gas with a methane concentration down to 15 Vol.% or biological fuels can be used for chp applications (heat /power). (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  16. Power generation by the revolving fluidised bed combustion of urban solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Buckle, David (Hoelter-ABT Ltd. (United Kingdom))

    1994-03-01

    A brief article describes the waste plant in Madrid which deals with urban solid waste. The first stage of treatment is recycling; the remaining waste is transferred to rotary screens where less than 100 mm is sieved out and after removal by hand of glass, aluminium and ferrous metals, the rest goes to composting; the larger than 100 mm, after hand picking, is composted on a revolving fluidized bed. The bed is supplied with dolomite at a continuous rate to absorb sulphur oxides and hydrogen chloride. (UK)

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

    CSIR Research Space (South Africa)

    North, BC

    2007-06-28

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

  18. Development of pressurised fluidised bed combustion technique for coal-fired gas/steam processes; Entwicklung der Druckwirbelschicht-Feuerungstechnik fuer kohlegefeuerte Gas-Dampfprozesse

    Energy Technology Data Exchange (ETDEWEB)

    Pitt, R.; Steven, H.

    1992-12-31

    The investigations for the development of the pressurized fluidized bed technique have shown that it is possible, in principle, to keep within the emission limits with the steady state pressurised fluidised bed combustion, even at low part load. However, the construction expense is considerable and the type of coal and grain size must comply relatively exactly with the design values. Not every fuel is suitable for fluidised bed combustion regarding emission. The most important parameter for emission is the temperature profile for this component, which should be as even as possible at a high temperature level. A sufficient dwell time of the gas and the particles is decisive for CO emission, where a minimum reaction time is required for both phases. (orig.) [Deutsch] Die Untersuchungen zur Entwicklung der Druckwirbelschichttechnik haben gezeigt, dass es prinzipiell moeglich ist, mit der stationaeren druckaufgeladenen Wirbelschichtfeuerung die Emissionsgrenzwerte auch bei geringer Teillast einzuhalten, allerdings ist der bauliche Aufwand erheblich und auch die Kohleart und Koernung muessen relativ genau den Auslegungswerten entsprechen. Auch hinsichtlich der Emissionen ist nicht jeder Brennstoff fuer die Wirbelschichtfeuerung geeignet. Wichtigster Einflusspartner auf die Emission ist auch bei dieser Komponente das Temperaturprofil, das moeglichst gleichmaessig auf hohem Temperaturniveau liegen sollte. Ausreichende Verweilzeit des Gases und der Partikel sind fuer die CO-Emission entscheidend, wobei fuer beide Phasen eine Mindestreaktionszeit erforderlich ist. (orig.)

  19. Fixed-bed gasification research using US coals. Volume 8. Gasification of River King Illinois No. 6 bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the eighth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of River King Illinois No. 6 bituminous coal. The period of gasification test was July 28 to August 19, 1983. 6 refs., 23 figs., 25 tabs.

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

    Directory of Open Access Journals (Sweden)

    W. A. WAN AB KARIM GHANI

    2009-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2002-03-29

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

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

    CSIR Research Space (South Africa)

    Oboirien, BO

    2009-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Niklasson, Fredrik

    2009-01-15

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

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

    Science.gov (United States)

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

    2017-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Taxil, I.

    1996-12-20

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  7. Fluid bed gasification pilot plant fuel feeding system evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, W.A.; Fonstad, T.; Pugsley, T.; Gerspacher, R. (Univ. of Saskatchewan, Saskatoon (Canada)), Email: wac132@mail.usask.ca; Wang Zhiguo (Saskatchewan Research Council, Saskatoon (Canada)), Email: zhiguo.wang@src.sk.ca

    2009-07-01

    Fluidized bed gasification (FBG) is a method for thermally converting solid biomass to a gaseous product termed syngas, which can be used as fuel for heat or electricity generation. Accurate and consistent feeding of biomass fuel into biomass FBG converters is a continuing, challenge, and was the subject of experimentation at the University of Saskatchewan biomass FBG pilot plant. The 2-conveyor feeding system for this pilot plant was tested using meat and bone meal (MBM) as feedstock, by conveying the feedstock through the system, and measuring the output rate as the fuel was discharged. The relationship between average mass-flowrate (F{sub M}) and conveyor speed (S) for the complete feeding system was characterized to be F{sub M}=0.2188S-0.42 for the tests performed. Testing of the metering conveyor coupled to the injection conveyor showed that operating these conveyors at drive synchronized speeds, air pulsed into the injection hopper, and 50 slpm injection air, produced the most consistent feed output rate. Hot fluidized bed tests followed, which showed that plugging of the injection nozzle occurred as bed temperatures increased past 700C, resulting in loss of fuel flow. The pneumatic injection nozzle was subsequently removed, and the system was found to perform adequately with it absent. (orig.)

  8. An Experimental Investigation of Sewage Sludge Gasification in a Fluidized Bed Reactor

    Science.gov (United States)

    Calvo, L. F.; García, A. I.; Otero, M.

    2013-01-01

    The gasification of sewage sludge was carried out in a simple atmospheric fluidized bed gasifier. Flow and fuel feed rate were adjusted for experimentally obtaining an air mass : fuel mass ratio (A/F) of 0.2 gasification. This allowed improving the process heat transfer and, therefore, gasification efficiency. The heating value of the produced gas was 8.4 MJ/Nm, attaining a hot gas efficiency of 70% and a cold gas efficiency of 57%. PMID:24453863

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

    Energy Technology Data Exchange (ETDEWEB)

    Kassman, Haakan

    2012-11-01

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

  10. Fluidized bed gasification of biomass, waste, and coal, for different applications

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E. [VTT Energy, Espoo (Finland). Gasification and Gas Cleaning Group

    1998-12-31

    Various energy production systems based on biomass and waste gasification are being developed in Finland by VTT and its industrial partners. In 1986 - 1995, the Finnish gasification R and D activities were almost fully devoted to the development of simplified IGCC power systems suitable to large-scale power production based on pressurised fluid bed gasification, hot gas cleaning, and a combined-cycle process. Within the LIEKKI 2 programme, VTT continued this R and D by carrying out cogasification tests with coal and biomass fuels and by studying the formation of gas contaminants in fluidized bed gasification. In the mid-1990`s, the atmospheric pressure gasification activities aiming at small- and medium-size power plants based on gas/diesel engines were restarted in Finland. Since 1995, intensive R and D is also focused on atmospheric pressure circulating fluidized bed gasification of biomass residues and wastes. This gasification technology earlier commercialised for lime kiln applications is now aiming to co-utilise locally-available residues and wastes in existing pulverised-coal-fired boilers. The research at VTT in this field is related to the gasification of biofuels with problematic ash behaviour and to gas cleaning from alkali/heavy metals and chlorine. The experimental gasification R and D was complemented by techno-economic and market studies focusing on the potentials of different process alternatives. (orig.) 12 refs.

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

    Directory of Open Access Journals (Sweden)

    Zhiliang Chen

    2016-09-01

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

  12. Prevention of the ash deposits by means of process conditions in biomass gasification; Biomassapolttoaineiden tuhkan kuonaantumiskaeyttaeytymisen estaeminen prosessiolosuhteiden avulla

    Energy Technology Data Exchange (ETDEWEB)

    Moilanen, A.; Laatikainen-Luntama, J.; Nieminen, M.; Kurkela, E.; Korhonen, J. [VTT Energy, Espoo (Finland)

    1997-10-01

    In fluidised-bed gasification, various types of deposits and agglomerates may be formed by biomass ash in the bed, in upper zones of the reactor, for instance in cyclones. These may decisively hamper the operation of the process. The aim of the project was to obtain data on the detrimental fouling behaviour of the ash of different types of biomass in fluidised-bed gasification, and on the basis of these data to determine the process conditions and ways of preventing this kind of behaviour. Different types of biomass fuel relevant to energy production such as straw, wood residue were be used as samples. The project consisted of laboratory studies and fluidised-bed reactor tests including ash behaviour studied both in the bed and freeboard. In laboratory tests, the sample material was characterised as a function of different process parameters. In fluid-bed reactors, the most harmful biomasses were tested using process variables such as temperature, bed material and the gasification agents. Bubbling fluidised-bed gasification tests with wheat straw showed that agglomerates with different sizes and structures formed in the bed depending on the temperature, the feed gas composition and bed material. Agglomerates consisted of molten ash which sintered with bed material and other solids. In all BFB tests, freeboard walls were slicked by ash agglomerates (different amounts) which, however, were easily removable. The results of this project and the earlier pilot-scale gasification experience obtained with the same feedstocks showed that useful characteristic data about ash behaviour can be obtained using laboratory tests and small scale reactors. (orig.)

  13. Mathematical Modelling of the Fixed-Bed Biomass-Coal Co-Gasification Process

    Directory of Open Access Journals (Sweden)

    Donskoy Igor G.

    2016-01-01

    Full Text Available The paper considers mathematical modelling of downdraft fixed-bed gasification process of the mixtures of woody biomass and coal. Biomass/coal ratio, biomass moisture content and air equivalence ratio are varying parameters. Boundaries of the efficient gasification regimes are estimated.

  14. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge

    DEFF Research Database (Denmark)

    Thomsen, Tobias Pape; Hauggaard-Nielsen, Henrik; Gøbel, Benny

    2017-01-01

    The study is part 2 of 2 in an investigation of gasification and co-gasification of municipal sewage sludge in low temperature gasifiers. In this work, solid residuals from thermal gasification and co-gasification of municipal sewage sludge were investigated for their potential use as fertilizer...... to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottom ashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded that LT-CFB gasification and co-gasification is a highly effective way to purify...

  15. Fixed-bed gasification research using US coals. Volume 12. Gasification of Absaloka/Robinson subbituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial particpants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the twelfth volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. this specific reports describes the gasification of Absaloka/Robinson subbituminous coal. This volume covers the test period June 18, 1984 to June 30, 1984. 4 refs., 20 figs., 18 tabs.

  16. Physical-Mathematical Model for Fixed-Bed Solid Fuel Gasification Process Simulation

    OpenAIRE

    Slyusarskiy Konstantin V.; Korotkikh Alexander G.; Sorokin Ivan V.

    2017-01-01

    Phycial-mathmatical model for fixed-bed coal gasification process simulation is proposed. The heterogeneous carbon oxidation chemical reactions were simulated via Arrhenius equation while homogeneous reactions in gas phase were calculated using Gibbs free energy minimization procedure. The syngas component concentration field and fuel conversion distribution as well as syngas final temperature and composition were defined for fixed bed gasification of T-grade coal of Kuznetskiy deposit. The o...

  17. Effects of gasifying conditions and bed materials on fluidized bed steam gasification of wood biomass.

    Science.gov (United States)

    Weerachanchai, Piyarat; Horio, Masayuki; Tangsathitkulchai, Chaiyot

    2009-02-01

    The effect of steam gasification conditions on products properties was investigated in a bubbling fluidized bed reactor, using larch wood as the starting material. For bed material effect, calcined limestone and calcined waste concrete gave high content of H(2) and CO(2), while silica sand provided the high content of CO. At 650 degrees C, calcined limestone proved to be most effective for tar adsorption and showed high ability to adsorb CO(2) in bed. At 750 degrees C it could not capture CO(2) but still gave the highest cold gas efficiency (% LHV) of 79.61%. Steam gasification gave higher amount of gas product and higher H(2)/CO ratio than those obtained with N(2) pyrolysis. The combined use of calcined limestone and calcined waste concrete with equal proportion contributed relatively the same gas composition, gas yield and cold gas efficiency as those of calcined limestone, but showed less attrition, sintering, and agglomeration propensities similar to the use of calcined waste concrete alone.

  18. Gasification reactivity and ash behaviour of biomass fuels

    Energy Technology Data Exchange (ETDEWEB)

    Moilanen, A.; Kurkela, E. [VTT Energy, Espoo (Finland)

    1998-12-31

    Measuring data required for describing the reactivity and ash sintering behaviour of biomass-based solid fuels for atmospheric and pressurised gasification are discussed. The measurements were carried out in a pressurisable thermobalance and bench-scale fluidised bed reactors. The main variables were temperature and partial pressures of H{sub 2}O and H{sub 2}, and CO{sub 2} and CO. The reaction rates were determined in binary gas mixtures H{sub 2}O-H{sub 2}, and CO{sub 2}-CO as well as in product gas mixtures H{sub 2}O-H{sub 2}-CO{sub 2}-CO. The total pressure range was 1-30 bar and the temperature range 650-950 deg C. For wood, kinetic parameters were determined using the Langmuir-Hinshelwood kinetics, which takes into account the effect of the product gases on the reaction rate. The results indicated that the H{sub 2}O-H{sub 2} system was well in conformity with this kinetics, while the reaction rates measured for the CO{sub 2}-CO system required the description of the catalytic effects of the ash-forming material. In the gasification of wood as well as of other biomasses, the behaviour of catalytically active ash components is more complex during char gasification. Experimental set-ups used for gasification reactivity measurements were compared in Aabo Akademi University and in VTT. The set-ups were pressurised thermogravimetric reactor (PTG), pressurised grid heater (PGH), pressurised bench-scale fluidised bed reactor (PFB), and pressurised entrained flow reactor (PEF). In addition, the effect of stabilising heat treatment was tested. The samples used in the study were wood, black liquor, peat, and coal. The gasification reactivity measurements were carried out in the temperature range of 700-950 deg C, and in the pressure range of 1-10 bar. The gasification agent was either CO{sub 2} in N{sub 2} or CO-CO{sub 2} mixture in N{sub 2}. In the pyrolysis carried out in different devices, mainly the same pressure and temperature were used as in the char gasification

  19. The Modelling of Flat Fluidised Photoreactors.

    Science.gov (United States)

    Iatridis, D.

    Available from UMI in association with The British Library. The present research constitutes a systematic study towards the modelling and design of flat plate fluidised photoreactors. Light transmitted through a fluidised photoreactor (transmittance) and light reflected from the reactor (reflectance) have been measured by new optical techniques. These two important design variables were correlated with relevant fluidisation parameters. The average light transmittance was found to increase with bed expansion, the square root of particle diameter and inversely with bed thickness. On the other hand, the average light reflectance was found to decrease with bed height and particle diameter. The correlations found for light transmittance and reflectance with the fluidised parameters were tested with experimental data using two types of particles of different optical characteristics. The form of these correlations was not affected by the type of particles used. The light energy retained within a fluidised photoreactor, "light absorption", was evaluated by an energy balance from the measured values of light transmittance and reflectance. The light absorption data obtained were regressed for two different types of particles. For 13X zeolites the average light absorption by the bed was found to increase with the second power of bed height and the square root of particle diameter and reactor thickness. For Co-Mo-Al_2O _3 the average light absorption by the bed was found to increase with particle diameter and inversely with bed height. A theoretical study was made using the light energy retained within the reactor to promote a photochemical reaction of first order with respect to reactant concentration and to light absorption. The fluidised bed was treated as a single phase continuously stirred tank reactor (CSTR). The conversion of the reactant was found to increase with the light absorption and decrease with flow rate. This modelling approach may be extended to more complex

  20. Gasification of lignocellulosic biomass in fluidized beds for renewable energy development: A review

    Energy Technology Data Exchange (ETDEWEB)

    Alauddin, Zainal Alimuddin Bin Zainal; Lahijani, Pooya [School of Mechanical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Mohammadi, Maedeh; Mohamed, Abdul Rahman [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2010-12-15

    A literature review on gasification of lignocellulosic biomass in various types of fluidized bed gasifiers is presented. The effect of several process parameters such as catalytic bed material, bed temperature and gasifying agent on the performance of the gasifier and quality of the producer gas is discussed. Based on the priorities of researchers, the optimum values of various desired outputs in the gasification process including improved producer gas composition, enhanced LHV, less tar and char content, high gas yield and enhanced carbon conversion and cold gas efficiency have been reported. The characteristics and performance of different fluidized bed gasifiers were assessed and the obtained results from the literature have been extensively reviewed. Survey of literature revealed that several industrial biomass gasification plants using fluidized beds are currently conducting in various countries. However, more research and development of technology should be devoted to this field to enhance the economical feasibility of this process for future exploitations. (author)

  1. Air-based coal gasification in a two-chamber gas reactor with circulating fluidized bed

    Science.gov (United States)

    Dubinin, A. M.; Tuponogov, V. G.; Kagramanov, Y. A.

    2017-01-01

    During the bed gasification of solid fuels, the process temperature in the reaction zone is not high enough for reaching the maximum rate of the chemical efficiency factor of the gasification process. In order to increase the chemical efficiency factor, it is necessary to supply extra heat to the reaction zone to increase the reaction temperature. In this article, coal gasification in a chamber with forced fluidized bed is considered and it is proposed to supply extra heat with a circulating flow of an inert particulate heat transfer agent. Circulating inert particulate material is successively heated by coal combustion in a cone chamber with bubbling fluidized bed and in a combustion chamber with a spherical nozzle that inhibits the forced fluidized bed. After that, the heat transfer agent heated to 930-950°C enters first in a gasification chamber with bubbling bed and then in a chamber with forced fluidized bed, where it transfers the physical heat to the air fuel mixture. The experiments conducted with crushed Borodinsky coal and inert particulate heat transfer agent (electrocorundum) showed the temperature rise in a gasification chamber with from 760 to 870°C and the increase in the combustible component (CO) concentration in the gasification products by 5.5%. Based on the kinetic equations of the fuel combustion reactions and the CO2 reduction to CO and on the thermal balance equations of combustion and gasification chambers, the simulation model for the gas composition and the temperature rate calculated by the height of reaction chambers was developed. The experimental temperature rates and product gas compositions are in good agreement with the simulation results based on the proposed kinetic gasification model.

  2. Gasification process of refuse derived fuel in circulating fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, S.; Kinoshita, Y.; Lee, C.W.; Itaya, Y.; Mori, S. [Nagoya Univ., Nagoya (Japan). Dept. of Chemical Engineering

    2002-07-01

    This paper presents a fuel gas production system involving gasification of refuse-derived fuel (RDF) in a circulating fluidized bed (CFB). Although RDF is considered to be a viable source of energy, combustion of RDF has not spread widely because of a lack of conventional incinerators, erosion due to hydrogen chloride, and emissions of dioxin. This paper presents the results of an experimental study of the pyrolysis behaviour of 3 kinds of RDF and the particle motion in a cold model CFB. The objective was to clarify operating parameters for optimum control. It was shown that an increase in combustion temperature improves the yield of the combustible gas components and the energy recycling efficiency from the RDF. The highest heating value of pyrolysis gas was obtained at 873 to 973 degrees K. The gas flow rate in the pneumatic valve of the CFB was an important control factor for the circulation flux and solids holdup in the riser. High holdups were observed when minute silica sand particles were used in the CFB. 15 refs., 1 tab., 8 figs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

  4. Fixed-bed gasification research using US coals. Volume 3. Gasification of Rosebud sub-bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-03-31

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a cooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the third volume in a series of documents prepared by Black, Sivalls and Bryson, Incorporated and describes the gasification of Rosebud subbituminous coal during the time period November 2-20, 1982. Test results and data are presented for the gasification of the coal and the operation of a slipstream tar scrubber to cool the gas and remove condensed tar. 5 refs., 29 figs., 18 tabs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Gaston

    2011-07-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-01

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

  7. Physical-Mathematical Model for Fixed-Bed Solid Fuel Gasification Process Simulation

    Directory of Open Access Journals (Sweden)

    Slyusarskiy Konstantin V.

    2017-01-01

    Full Text Available Phycial-mathmatical model for fixed-bed coal gasification process simulation is proposed. The heterogeneous carbon oxidation chemical reactions were simulated via Arrhenius equation while homogeneous reactions in gas phase were calculated using Gibbs free energy minimization procedure. The syngas component concentration field and fuel conversion distribution as well as syngas final temperature and composition were defined for fixed bed gasification of T-grade coal of Kuznetskiy deposit. The optimal fuel residence time and gasifyer specific productivity were defined. The prevail reactions in oxidizing and reduction zones together with its height were defined.

  8. A semi-empirical model for pressurised air-blown fluidized-bed gasification of biomass.

    Science.gov (United States)

    Hannula, Ilkka; Kurkela, Esa

    2010-06-01

    A process model for pressurised fluidized-bed gasification of biomass was developed using Aspen Plus simulation software. Eight main blocks were used to model the fluidized-bed gasifier, complemented with FORTRAN subroutines nested in the programme to simulate hydrocarbon and NH(3) formation as well as carbon conversion. The model was validated with experimental data derived from a PDU-scale test rig operated with various types of biomass. The model was shown to be suitable for simulating the gasification of pine sawdust, pine and eucalyptus chips as well as forest residues, but not for pine bark or wheat straw.

  9. An Experimental and Numerical Investigation of Fluidized Bed Gasification of Solid Waste

    Directory of Open Access Journals (Sweden)

    Sharmina Begum

    2013-12-01

    Full Text Available Gasification is a thermo-chemical process to convert carbon-based products such as biomass and coal into a gas mixture known as synthetic gas or syngas. Various types of gasification methods exist, and fluidized bed gasification is one of them which is considered more efficient than others as fuel is fluidized in oxygen, steam or air. This paper presents an experimental and numerical investigation of fluidized bed gasification of solid waste (SW (wood. The experimental measurement of syngas composition was done using a pilot scale gasifier. A numerical model was developed using Advanced System for Process ENgineering (Aspen Plus software. Several Aspen Plus reactor blocks were used along with user defined FORTRAN and Excel code. The model was validated with experimental results. The study found very similar performance between simulation and experimental results, with a maximum variation of 3%. The validated model was used to study the effect of air-fuel and steam-fuel ratio on syngas composition. The model will be useful to predict the various operating parameters of a pilot scale SW gasification plant, such as temperature, pressure, air-fuel ratio and steam-fuel ratio. Therefore, the model can assist researchers, professionals and industries to identify optimized conditions for SW gasification.

  10. Temporal measurements and kinetics of selenium release during coal combustion and gasification in a fluidized bed.

    Science.gov (United States)

    Shen, Fenghua; Liu, Jing; Zhang, Zhen; Yang, Yingju

    2016-06-05

    The temporal release of selenium from coal during combustion and gasification in a fluidized bed was measured in situ by an on-line analysis system of trace elements in flue gas. The on-line analysis system is based on an inductively coupled plasma optical emission spectroscopy (ICP-OES), and can measure concentrations of trace elements in flue gas quantitatively and continuously. The results of on-line analysis suggest that the concentration of selenium in flue gas during coal gasification is higher than that during coal combustion. Based on the results of on-line analysis, a second-order kinetic law r(x)=0.94e(-26.58/RT)(-0.56 x(2) -0.51 x+1.05) was determined for selenium release during coal combustion, and r(x)=11.96e(-45.03/RT)(-0.53 x(2) -0.56 x+1.09) for selenium release during coal gasification. These two kinetic laws can predict respectively the temporal release of selenium during coal combustion and gasification with an acceptable accuracy. Thermodynamic calculations were conducted to predict selenium species during coal combustion and gasification. The speciation of selenium in flue gas during coal combustion differs from that during coal gasification, indicating that selenium volatilization is different. The gaseous selenium species can react with CaO during coal combustion, but it is not likely to interact with mineral during coal gasification.

  11. Granular bed filtration of high temperature biomass gasification gas.

    Science.gov (United States)

    Stanghelle, Daniel; Slungaard, Torbjørn; Sønju, Otto K

    2007-06-18

    High temperature cleaning of producer gas from biomass gasification has been investigated with a granular filter. Field tests were performed for several hours on a single filter element at about 550 degrees C. The results show cake filtration on the granular material and indicate good filtration of the biomass gasification producer gas. The relatively low pressure drop over the filter during filtration is comparable to those of bag filters. The granular filter can operate with high filtration velocities compared to bag filters and maintain high efficiency and a low residual pressure. This work is a part of the BioSOFC-up project that has a goal of utilizing the producer gas from the gasification plant in a solid oxide fuel cell (SOFC). The BioSOFC-up project will continue to the end of 2007.

  12. Gasification of palm empty fruit bunch in a bubbling fluidized bed: a performance and agglomeration study.

    Science.gov (United States)

    Lahijani, Pooya; Zainal, Zainal Alimuddin

    2011-01-01

    Gasification of palm empty fruit bunch (EFB) was investigated in a pilot-scale air-blown fluidized bed. The effect of bed temperature (650-1050 °C) on gasification performance was studied. To explore the potential of EFB, the gasification results were compared to that of sawdust. Results showed that maximum heating values (HHV) of 5.37 and 5.88 (MJ/Nm3), dry gas yield of 2.04 and 2.0 (Nm3/kg), carbon conversion of 93% and 85 % and cold gas efficiency of 72% and 71 % were obtained for EFB and sawdust at the temperature of 1050 °C and ER of 0.25. However, it was realized that agglomeration was the major issue in EFB gasification at high temperatures. To prevent the bed agglomeration, EFB gasification was performed at temperature of 770±20 °C while the ER was varied from 0.17 to 0.32. Maximum HHV of 4.53 was obtained at ER of 0.21 where no agglomeration was observed.

  13. Theoretical investigations on operational performance of one- and two-shaft gas turbines used in circulating pressure fluidised bed firing; Theoretische Untersuchungen zum Betriebsverhalten von ein- und zweiwelligen Gasturbinen beim Einsatz in der zirkulierenden Druckwirbelschichtfeuerung

    Energy Technology Data Exchange (ETDEWEB)

    Nemet, A.; Fett, F.N. [Siegen Univ. (Gesamthochschule) (Germany). Inst. fuer Energietechnik

    1999-12-01

    By means of simulation calculations the stationary and instationary operating performance of two gas turbine connections with one and two shafts and their interaction with circulating pressure fluidised bed firing has been investigated in the present paper. It could be shown that the construction type and properties of the gas turbine considerably influences the partial load and transition performance of a circulating pressure fluidised bed firing plant. The properties of the gas turbine have a strong influence on the gas/solid flow in the circulating pressure fluidised bed. The investigated gas turbine with one shaft is limited in its adaptability to the demands of the circulating pressure fluidised bed below the LS-point, however it shows a good operating performance in all partial load ranges. The two-shaft gas turbine shows better adaptability and flexibility, however the potential of the circulating pressure fluidised bed firing generating an almost constant smoke gas temperature in partial load operation can not be fully utilised in the lower partial load range (< 50%) because the operating point of the high pressure compressor moves towards the pump limit with decreasing load. (orig.) [Deutsch] Anhand von Simulationsrechnungen wurde in dem vorliegenden Beitrag das stationaere und instationaere Betriebsverhalten zweier Gasturbinenschaltungen in ein- und zweiwelliger Bauart und ihr Zusammenspiel mit einer zirkulierenden Druckwirbelschichtfeuerung untersucht. Es konnte gezeigt werden, dass die Gasturbinenbauart und -charakteristik in erheblichem Masse das Teillast- und Uebergangsverhalten einer ZDWSF-Anlage mitbestimmt. Insbesondere hat die Gasturbinencharakteristik einen wesentlichen Einfluss auf die Gas/Feststoff-Stroemung in zirkulierenden Druckwirbelschichtfeuerungen. Die untersuchte Gasturbine in einwelliger Bauart ist unterhalb des LS-Eckpunkts in ihrer Anpassungsfaehigkeit an die Anforderungen der zirkulierenden Druckwirbelschicht zwar eingeschraenkt

  14. Conbustion and gasification technologies

    Energy Technology Data Exchange (ETDEWEB)

    Egsgaard, H. [Risoe National Lab., Plant Res. Dept., Roskilde (Denmark); Hansen, U. [Univ. Rostock (Germany); Arendt Jensen, P.; Glarborg, P. [Technical Univ. of Denmark, Kgs. Lyngby (Denmark); Nielsen, C. [ELSAM, Fredericia (Denmark)

    2003-11-01

    The combustion of solid biomass to produce heat is an established technology, be it either the direct generation of heat or some complex process with intermediate conversion steps yielding motive power or electric energy. Traditionally biomass has been converted in grate or stoker type boilers. Use of biomass in simple stoves in developing countries accounts for a large fraction of the global consumption of energy. Modern energy conversion machines are not well suited to burn biofuels as they are designed and optimised for clean gaseous and liquid fuels. During the last twenty years combustion technologies like suspension firing and fluidized bed have been applied. Gasification of wood fuel has a long tradition, especially in small units. A considerable effort has been made towards the use of gasification as part of CHP strategies. One reason for considering gasification is that the combustion of solid biomass is changed into the more attractive process of burning gas and the inorganic material in the biomass does not enter the final combustion zone. The gasifiers fall into three categories: Fixed bed gasifiers, fluidised bed gasifiers and entrained flow gasifiers. Electricity production by SOFC fuel is a way to obtain high efficiency in electricity production. Gasification and SOFC fuel cell conversion systems based on biomass should be considered. The highly purified gasification gas has the potential to be used directly in SOFC cells or alternatively steam-reformed. Thermal conversion of biomass has been investigated for many years as a possible source of renewable liquid fuels. Fast pyrolysis is an advanced process that gives a yield of Biofuels up to 80% on dry feed, typically 65% liquids and 10% non-condensable gases. (BA)

  15. Design and preliminary test of a fluidised bed photoreactor for ethylene oxidation on mesoporous mixed SiO2/TiO2 nanocomposites under UV-A illumination

    Directory of Open Access Journals (Sweden)

    Maria Lucia V. de Chiara

    2014-12-01

    Full Text Available Ethylene (C2H4 is a plant hormone that has numerous effects on many horticultural and ornamental crops. It accelerates senescence, stimulates chlorophyll loss, enhances excessive softening, promotes discoloration and browning during storage of fresh produce. Among the techniques used to remove or inhibit ethylene action during postharvest handling of fresh products (potassium-based system, high temperature catalytic oxidation, inhibition of ethylene receptors, the use of titanium oxide (TiO2-based materials with photocatalytic activity under ultraviolet (UV light is one of the most promising. A fluidised-bed photoreactor (FBP was designed to decompose ethylene in the storage room atmosphere, and the relative prototype was manufactured. Since TiO2 powder alone is not suitable for use within a fluidised bed, preliminary tests to select the best support were performed. Alumina microspheres showed a good fluidisation behavior; its functionality was tested with different kind of support material and actual photocatalytic activity was tested using SiO2/TiO2-coated alumina microspheres. A reduction of approximately 72% of ethylene concentration in the tested 40 ppm ethylene gas mixture was observed after 4.5 h of 36W UV light exposure. FBP resulted to be suitable to avoid the detrimental presence of C2H4 in the atmosphere surrounding fresh products within cold storage rooms.

  16. Clean coal technologies handbook: fluidized bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    1999-01-01

    The term fluidisation is used to describe a type or mode of contact between fluids and granular solids, in such a way that solid particles appear as suspended in the moving fluid. The fluid moves vertically upwards through the bed formed by the particles. The reason to use the word fluidisation is that, when a solid particles bed is treated in the above mentioned way, it acquires an aspect very similar to that of a boiling liquid, and it has properties similar to those of a liquid. Thus, a bed in such conditions is called fluidised bed; the name fluidisation is reserved to the operation required to reach such state. This contacting method shows a number of fetaures which make it very useful to carry on many important processes in the fields of Chemical Engineering and Extractive Metallurgy; for that reason it has been studied very deeply in the last year, on the theoretical aspect and on its practical applications as well. Going back in time to the origin of the fluidisation, as it is known at present, we find that is started to develop at the beginning of the 1940's. The first application of fluidisation is described by Agricola in his famous book De re metallica, which must have been written in XVI the century. In this book there is the mention of the concentration of metallic ores by means of an expansion of the bed produced by a vertical upwards water flow which passes through the layer of rough mineral. From the beginning of its development, fluidisation has had many applications, such as water clarification, pulverised coal gasification, catalytic cracking chemical processes, drying of pulverulent materials and incineration of solid residues, among others. Until the end of 1950 the application was not used to coal combustion; it has strongly development after the energy crisis. Starting in the 1970's a great effort at world level is being made to develop the technology of Fluidised Bed Combustion (FBC), pushed on by two main reasons.: 1) Reduction

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    bed gasifier can be successfully predicted by applying neural networks. ANNs models use in the input layer the biomass composition and few operating parameters, two neurons in the hidden layer and the backpropagation algorithm. The results obtained by these ANNs show high agreement with published......Artificial neural networks (ANNs) have been applied for modeling biomass gasification process in fluidized bed reactors. Two architectures of ANNs models are presented; one for circulating fluidized bed gasifiers (CFB) and the other for bubbling fluidized bed gasifiers (BFB). Both models determine...

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

    NARCIS (Netherlands)

    Christodoulou, C.; Tsekos, C.; Tsalidis, G.A.; Fantini, M.; Panopoulos, K.D.; De Jong, W.; Kakaras, E.

    2014-01-01

    Few tests have been carried out in order to evaluate the use of cardoon in gasification and combustion applications most of the researchers dealt with agglomeration problems. The aim of this work is to deal with the agglomeration problem and to present a solution for the utilization of this biofuel

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

  20. Fluidized-Bed Gasification of Plastic Waste, Wood, and Their Blends with Coal

    Directory of Open Access Journals (Sweden)

    Lucio Zaccariello

    2015-08-01

    Full Text Available The effect of fuel composition on gasification process performance was investigated by performing mass and energy balances on a pre-pilot scale bubbling fluidized bed reactor fed with mixtures of plastic waste, wood, and coal. The fuels containing plastic waste produced less H2, CO, and CO2 and more light hydrocarbons than the fuels including biomass. The lower heating value (LHV progressively increased from 5.1 to 7.9 MJ/Nm3 when the plastic waste fraction was moved from 0% to 100%. Higher carbonaceous fines production was associated with the fuel containing a large fraction of coal (60%, producing 87.5 g/kgFuel compared to only 1.0 g/kgFuel obtained during the gasification test with just plastic waste. Conversely, plastic waste gasification produced the highest tar yield, 161.9 g/kgFuel, while woody biomass generated only 13.4 g/kgFuel. Wood gasification showed a carbon conversion efficiency (CCE of 0.93, while the tests with two fuels containing coal showed lowest CCE values (0.78 and 0.70, respectively. Plastic waste and wood gasification presented similar cold gas efficiency (CGE values (0.75 and 0.76, respectively, while that obtained during the co-gasification tests varied from 0.53 to 0.73.

  1. Treatment of Mixed Wastes via Fixed Bed Gasification

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-10-28

    This report outlines the details of research performed under USDOE Cooperative Agreement DE-FC21-96MC33258 to evaluate the ChemChar hazardous waste system for the destruction of mixed wastes, defined as those that contain both RCRA-regulated haz- ardous constituents and radionuclides. The ChemChar gasification system uses a granular carbonaceous char matrix to immobilize wastes and feed them into the gasifier. In the gasifier wastes are subjected to high temperature reducing conditions, which destroy the organic constituents and immobilize radionuclides on the regenerated char. Only about 10 percent of the char is consumed on each pass through the gasifier, and the regenerated char can be used to treat additional wastes. When tested on a 4-inch diameter scale with a continuous feed unit as part of this research, the ChemChar gasification system was found to be effective in destroying RCRA surrogate organic wastes (chlorobenzene, dichloroben- zene, and napht.halene) while retaining on the char RCRA heavy metals (chromium, nickel, lead, and cadmium) as well as a fission product surrogate (cesium) and a plutonium surrogate (cerium). No generation of harmful byproducts was observed. This report describes the design and testing of the ChemChar gasification system and gives the operating procedures to be followed in using the system safely and effectively for mixed waste treatment.

  2. Calculation of the fixed bed coal gasification regimes by the use of thermodynamic model with macrokinetic constraints

    Science.gov (United States)

    Donskoi, I. G.; Keiko, A. V.; Kozlov, A. N.; Svishchev, D. A.; Shamanskii, V. A.

    2013-12-01

    We discuss an equilibrium model of a fixed-bed solid fuel gasification process that takes into account macrokinetic constraints imposed on the rates of heterophase processes and allows the pyrolysis and gasification processes to be described in a fairly simple manner with the use of thermal analysis data. The results of calculations are compared with the measured parameters characterizing the Azeisk coal steam-air gasification process that were obtained in experiments on a laboratory setup.

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

    Science.gov (United States)

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

    2014-05-01

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

  4. Combined-cycle power stations using ``clean-coal-technologies``: Thermodynamic analysis of full gasification vs. fluidized bed combustion with partial gasification

    Energy Technology Data Exchange (ETDEWEB)

    Lozza, G.; Chiesa, P. [Politecnico di Milano, Milan (Italy). Dept. of Energetics; DeVita, L. [Eniricerche, Milan (Italy)

    1994-12-31

    A novel class of power plants for clean conversion of coal into power has been recently proposed, based on the concept of partial coal gasification and fluidized-bed combustion of unconverted char from gasification. This paper focuses on the thermodynamic aspects of these plants, in comparison with full gasification cycles, assessing their performance on the basis of a common advanced power plant technology level. Several plant configurations are considered, including pressurized or atmospheric fluidized-bed, air- or steam-cooled, with different carbon conversion in the gasifier. The calculation method, used for reproducing plant energy balances and for performance prediction, is described in the paper. A complete second-law analysis is carried out, pointing out the efficiency loss breakdown for both technologies. Results show that partial gasification plants can achieve efficiencies consistently higher than IGCC, depending on plant configuration and carbon conversion, making this solution a viable and attractive option for efficient coal utilization.

  5. Combined-cycle power stations using clean-coal technologies: Thermodynamic analysis of full gasification versus fluidized bed combustion with partial gasification

    Energy Technology Data Exchange (ETDEWEB)

    Lozza, G.; Chiesa, P. [Politecnico di Milano, Milan (Italy). Dept. of Energetics; DeVita, L. [Eniricerche, Milan (Italy)

    1996-10-01

    A novel class of power plants for clean conversion of coal into power has been recently proposed, based on the concept of partial coal gasification and fluidized-bed combustion of unconverted char from gasification. This paper focuses on the thermodynamic aspects of these plants, in comparison with full gasification cycles, assessing their performance on the basis of a common advanced power plant technology level. Several plant configurations are considered, including pressurized or atmospheric fluidized-bed, air- or steam-cooled, with different carbon conversion in the gasifier. The calculation method, used for reproducing plant energy balances and for performance prediction, is described in the paper. A complete second-law analysis is carried out, pointing out the efficiency loss breakdown for both technologies. Results show that partial gasification plants can achieve efficiencies consistently higher than IGCC, depending on plant configuration and carbon conversion, making this solution a viable and attractive option for efficient coal utilization.

  6. The development of solid fuel gasification systems for cost-effective power generation with low environmental impacts

    Energy Technology Data Exchange (ETDEWEB)

    Nieminen, M.; Kurkela, E.; Staahlberg, P.; Laatikainen-Luntama, J.; Ranta, J.; Hepola, J.; Kangasmaa, K. [VTT Energy, Espoo (Finland). Gasification and Advanced Combustion

    1997-10-01

    Relatively low carbon conversion is a disadvantage related to the air-blown fluidised-bed coal-biomass co-gasification process. Low carbon conversion is due to different reactivities and ash sintering behaviour of coal and biomass which leads to compromises in definition of gasification process conditions. In certain cases co-gasification may also lead to unexpected deposit formations or corrosion problems in downstream components especially when high alkali metal or chlorine containing biomass feedstocks are co-gasified with coal. During the reporting period, the work focused on co-gasification of coal and wood waste. The objectives of the present work were to find out the optimum conditions for improving the carbon conversion and to study the formation of different gas impurities. The results based on co-gasification tests with a pressurised fluidised-bed gasifies showed that in co-gasification even with only 15 % coal addition the heavy tar concentration was decreased significantly and, simultaneously, an almost total carbon conversion was achieved by optimising the gasification conditions. The study of filter fines recirculation and solid residues utilisation was started by characterizing filter dust. The work was carried out with an entrained-flow reactor in oxidising, inert and reducing gas conditions. The aim was to define the conditions required for achieving increased carbon conversion in different reactor conditions

  7. A Modified Gibbs Free Energy Minimisation Model for Fluid Bed Coal Gasification

    Directory of Open Access Journals (Sweden)

    Ściążko Marek

    2015-03-01

    Full Text Available A modified approach to equilibrium modelling of coal gasification is presented, based on global thermodynamic analysis of both homogeneous and heterogeneous reactions occurring during a gasification process conducted in a circulating fluid bed reactor. The model is based on large-scale experiments (ca. 200 kg/h with air used as a gasification agent and introduces empirical modifications governing the quasi-equilibrium state of two reactions: water-gas shift and Boudouard reaction. The model predicts the formation of the eight key gaseous species: CO, CO2, H2O, H2, H2S, N2, COS and CH4, volatile hydrocarbons represented by propane and benzene, tar represented by naphthalene, and char containing the five elements C, H, O, N, S and inorganic matter.

  8. Gasification of biomass in a fixed bed downdraft gasifier--a realistic model including tar.

    Science.gov (United States)

    Barman, Niladri Sekhar; Ghosh, Sudip; De, Sudipta

    2012-03-01

    This study presents a model for fixed bed downdraft biomass gasifiers considering tar also as one of the gasification products. A representative tar composition along with its mole fractions, as available in the literature was used as an input parameter within the model. The study used an equilibrium approach for the applicable gasification reactions and also considered possible deviations from equilibrium to further upgrade the equilibrium model to validate a range of reported experimental results. Heat balance was applied to predict the gasification temperature and the predicted values were compared with reported results in literature. A comparative study was made with some reference models available in the literature and also with experimental results reported in the literature. Finally a predicted variation of performance of the gasifier by this validated model for different air-fuel ratio and moisture content was also discussed.

  9. DEVELOPMENT OF PRESSURIZED CIRCULATING FLUDIZED BED PARTIAL GASIFICATION MODULE (PGM)

    Energy Technology Data Exchange (ETDEWEB)

    Archie Robertson

    2002-07-10

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building bock that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the April 1--June 30, 2002 time period.

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

    Energy Technology Data Exchange (ETDEWEB)

    Archie Robertson

    2003-10-29

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building bock that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the July 1--September 30, 2003 time period.

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

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2003-01-30

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building bock that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the October 1--December 31, 2002 time period.

  12. Development of Pressurized Circulating Fluidized Bed Partial Gasification Module (PGM)

    Energy Technology Data Exchange (ETDEWEB)

    A. Robertson

    2002-09-30

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building bock that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the July 1-September 30, 2002 time period.

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

    Energy Technology Data Exchange (ETDEWEB)

    Archie Robertson

    2003-07-23

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building bock that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the April 1--June 30, 2003 time period.

  14. A high temperature drop-tube and packed-bed solar reactor for continuous biomass gasification

    Science.gov (United States)

    Bellouard, Quentin; Abanades, Stéphane; Rodat, Sylvain; Dupassieux, Nathalie

    2017-06-01

    Biomass gasification is an attractive process to produce high-value syngas. Utilization of concentrated solar energy as the heat source for driving reactions increases the energy conversion efficiency, saves biomass resource, and eliminates the needs for gas cleaning and separation. A high-temperature tubular solar reactor combining drop tube and packed bed concepts was used for continuous solar-driven gasification of biomass. This 1 kW reactor was experimentally tested with biomass feeding under real solar irradiation conditions at the focus of a 2 m-diameter parabolic solar concentrator. Experiments were conducted at temperatures ranging from 1000°C to 1400°C using wood composed of a mix of pine and spruce (bark included) as biomass feedstock. The aim of this study was to demonstrate the feasibility of syngas production in this reactor concept and to prove the reliability of continuous biomass gasification processing using solar energy. The study first consisted of a parametric study of the gasification conditions to obtain an optimal gas yield. The influence of temperature and oxidizing agent (H2O or CO2) on the product gas composition was investigated. The study then focused on solar gasification during continuous biomass particle injection for demonstrating the feasibility of a continuous process. Regarding the energy conversion efficiency of the lab scale reactor, energy upgrade factor of 1.21 and solar-to-fuel thermochemical efficiency up to 28% were achieved using wood heated up to 1400°C.

  15. Impact of feedstock properties and operating conditions on sewage sludge gasification in a fixed bed gasifier.

    Science.gov (United States)

    Werle, Sebastian

    2014-10-01

    This work presents results of experimental studies on the gasification process of granulated sewage sludge in a laboratory fixed bed gasifier. Nowadays, there is a large and pressing need for the development of thermal methods for sewage sludge disposal. Gasification is an example of thermal method that has several advantages over the traditional combustion. Gasification leads to a combustible gas, which can be used for the generation of useful forms of final energy. It can also be used in processes, such as the drying of sewage sludge directly in waste treatment plant. In the present work, the operating parameters were varied over a wide range. Parameters, such as air ratio λ = 0.12 to 0.27 and the temperature of air preheating t = 50 °C to 250 °C, were found to influence temperature distribution and syngas properties. The results indicate that the syngas heating value decreases with rising air ratio for all analysed cases: i.e. for both cold and preheated air. The increase in the concentration of the main combustible components was accompanied by a decrease in the concentration of carbon dioxide. Preheating of the gasification agent supports the endothermic gasification and increases hydrogen and carbon monoxide production. © The Author(s) 2014.

  16. Pyrolysis and gasification of biomass in a two-stage bluid bed gasification unit; Pyrolyse og forgasning af biomasse i en to-trins fluid bed forgasser

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, M.W.; Henriksen, U. [Danmarks Tekniske Universitet (Denmark); Houmoeller, S. [dk-TEKNIK (Denmark)

    1997-07-01

    A new two-stage atmospheric bubbling fluid bed pyrolysis and gasification unit has been developed to convert straw and wood into a gas to be combusted in engines used for combined heat and power production. The unit combines the known two-stage process based on the fixed bed principle developed at the Department of Energy Engineering at the Technical University of Denmark, with the more compact and easy-to-scale fluid bed technique. The advantages of this combined concept is a relatively simple and easy to scale plant able to convert a wide range of fuels and producing a clean gas with extremely low tar content. Even straw can be converted which is of great importance in Denmark. The first stage, the pyrolysis unit, has been tested extensively as a means of pre-treating the biomass before co-combusting straw with fossil fuels in power plant boilers and it can eliminate the traditional corrosion problems on the boilers. The fluid bed pyrolysis unit converts the biomass into two fractions: A gas fraction to be combusted in the power plant boiler and a solids fraction, containing the major part of alkali and chlorine, to be converted otherwise. The gas fraction contains up to 75 percent of the energy of the input biomass. The idea is to avoid feeding the harmful components as potassium, sodium and chlorine present in the biomass into the boiler, as these components can cause corrosion damages to the super heater, but still supply the boiler with most of the biomass energy. This paper presents the concluded work on the co-combustion unit and the first results on the two-stage fluid bed pyrolysis and gasification unit. (EG)

  17. Simulation of circulating fluidized bed gasification for characteristic study of pakistani coal

    Directory of Open Access Journals (Sweden)

    Ramzan Naveed

    2015-03-01

    Full Text Available A process model for turbulent pressurized circulating fluidized-bed coal gasifier is created using ASPEN PLUS software. Both hydrodynamic and reaction kinetics parameter are taken into account, whose expressions for fluidized bed are adopted from the literature. Various reactor models available in ASPEN PLUS with calculator as External Block are nested to solve hydrodynamics and kinetics. Multiple operational parameters for a pilot-plant circulating fluidized-bed coal gasifier are used to demonstrate the effects on coal gasification characteristics. This paper presents detailed information regarding the simulation model, including robust analysis of the effect of stoichiometric ratio, steam to coal ratio, gasification temperature and gasification agent temperature. It is observed that, with the increase in the flow rate of air, the components hydrogen, carbon monoxide, carbon dioxide and methane reduce, which causes the Lower Heating Value (LHV of synthesis gas (Syn. Gas to decrease by about 29.3%, while increment in the steam flow rate shows a minute increase in heating value of only 0.8%. Stoichiometric ratio has a direct relationship to carbon conversion efficiency and carbon dioxide production. Increasing the steam to coal ratio boosts the production of hydrogen and carbon monoxide, and causes a drop in both carbon dioxide concentration and the conversion efficiency of carbon. High gasifying agent temperature is desired because of high concentration of CO and H2, increasing carbon conversion and LHV. A high gasifying agent temperature is the major factor that affects the coal gasification to enhance H2 and CO production rapidly along with other gasification characteristics.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

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

    Directory of Open Access Journals (Sweden)

    R.K. Thapa, C. Pfeifer, B. M. Halvorsen

    2014-01-01

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

  20. Design and simulation of a circulating fluidized bed to clean the products of biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Uchoa Neto, Moises; Carvalho, Yuri de Araujo [Dept. de Engenharia Mecanica. Faculdade de Tecnologia. Universidade de Brasilia, DF (Brazil); Oliveira, Taygoara Felamingo de; Barcelos, Manuel [Faculdade do Gama. Universidade de Brasilia, Gama, DF (Brazil)], e-mail: taygoara@unb.br

    2010-07-01

    The main goal of this work is to design a workbench circulating fluidized bed to study the cracking of tar in gases from the processes of biomass gasification. For this, a design methodology based on analytical results and empirical correlations for fluidized beds was employed. In parallel, a numerical code of open source technology (MFIX) for the solution of the transport equations of the multiphase flow in the column of a fluidized bed was used to give support to the choice of the design elements. The whole project of the workbench fluidized bed was completely developed, whose operation parameters such as bed geometry, gas velocity, circulating ratio and void fraction characterize a fast fluidization process. A preliminary mesh convergence study was executed with the numerical tool, that was validated comparing with analytical results. Among the most important results, the code computed the predicted value for the minimum fluidization. (author)

  1. Ash agglomeration during fluidized bed gasification of high sulphur content lignites

    Energy Technology Data Exchange (ETDEWEB)

    Marinov, V.; Marinov, S.P.; Lazarov, L.; Stefanova, M. (SRTI Energydesign, Sofia (Bulgaria))

    1992-09-01

    Intensive ash agglomeration has hampered the fluidized bed gasification of lignites from the Elhovo deposit (Bulgaria) containing 5.9 wt% sulphur in the dry state. Samples of slag and agglomerates from the pilot plant have been examined by means of chemical, X-ray analysis, IR spectroscopy and scanning electron microscopy. Pyrrhotite (FeS) and wustite (FeO) have been established in the agglomerates, where junctions between ash particles have been found to consist of magnetite, spinel and garnet grains. The chemical reactions leading to garnet formation have been studied. Centres of sintering and centres of melting during the ash agglomeration process have been distinguished. The pyrite product, an eutectic of FeS and FeO melting at 924[degree]C, is assumed to be responsible for the cessation of lignite gasification with steam and air under pressure at a bed temperature of 930[degree]. 11 refs., 3 figs., 6 tabs.

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

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

  3. 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% H2, 20% CO, 20% CO2 and 5% CH4.

  4. Effect of pressure on gas-solid flow behavior in dense gas-fluidised beds: a discrete particle simulation study

    NARCIS (Netherlands)

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

    2002-01-01

    A computational study has been carried out to assess the influence of pressure on the flow structures and regime transitions in dense gas-fluidized beds using the discrete particle simulation (DPS) approach. By employing particle level simulation, the particle–particle–fluid interactions were analyz

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  6. Physicochemical properties and gasification reactivity of the ultrafine semi-char derived from a bench-scale fluidized bed gasifier

    Science.gov (United States)

    Zhang, Yukui; Zhang, Haixia; Zhu, Zhiping; Na, Yongjie; Lu, Qinggang

    2017-08-01

    Zhundong coalfield is the largest intact coalfield worldwide and fluidized bed gasification has been considered as a promising way to achieve its clean and efficient utilization. The purpose of this study is to investigate the physicochemical properties and gasification reactivity of the ultrafine semi-char, derived from a bench-scale fluidized bed gasifier, using Zhundong coal as fuel. The results obtained are as follows. In comparison to the raw coal, the carbon and ash content of the semi-char increase after partial gasification, but the ash fusion temperatures of them show no significant difference. Particularly, 76.53% of the sodium in the feed coal has released to the gas phase after fluidized bed gasification. The chemical compositions of the semi-char are closely related to its particle size, attributable to the distinctly different natures of diverse elements. The semi-char exhibits a higher graphitization degree, higher BET surface area, and richer meso- and macropores, which results in superior gasification reactivity than the coal char. The chemical reactivity of the semi-char is significantly improved by an increased gasification temperature, which suggests the necessity of regasification of the semi-char at a higher temperature. Consequently, it will be considered feasible that these carbons in the semi-char from fluidized bed gasifiers are reclaimed and reused for the gasification process.

  7. Characteristics and utilisation of high-temperature (HTHP) filter dusts from pfb gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Ranta, J. [VTT Energy, Espoo (Finland)

    1996-12-31

    The aim of the study was to survey characteristics, utilisation and possible environmental impacts of solid wastes, i.e., in case of biomass, mainly high-temperature filter ash (HTHP) from pressurised fluidised-bed gasification (PFBG). The aim is to utilise solid wastes (slag, filter dust, additives) from biomass gasification instead of dumping. One alternative is recycling to the soil as liming material or fertiliser. It is expected that the ash recycled to forest soils changes the environment less than non-recycled ash. (orig.) 3 refs.

  8. Theoretical and experimental studies of fixed-bed coal gasification reactors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, B.; Bhattacharya, A.; Salam, L.; Dudukovic, M.P.

    1983-09-01

    A laboratory fixed-bed gasification reactor was designed and built with the objective of collecting operational data for model validation and parameter estimation. The reactor consists of a 4 inch stainless steel tube filled with coal or char. Air and steam is fed at one end of the reactor and the dynamic progress of gasification in the coal or char bed is observed through thermocouples mounted at various radial and axial locations. Product gas compositions are also monitored as a function of time. Results of gasification runs using Wyoming coal are included in this report. In parallel with the experimental study, a two-dimensional model of moving bed gasifiers was developed, coded into a computer program and tested. This model was used to study the laboratory gasifier by setting the coal feed rate equal to zero. The model is based on prior work on steady state and dynamic modeling done at Washington University and published elsewhere in the literature. Comparisons are made between model predictions and experimental results. These are also included in this report. 23 references, 18 figures, 6 tables.

  9. International evaluation of the programme on fluid bed combustion and gasification

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H. [Ruhr Univ., Bochum (Germany); Magnusson, B.F. [Norwegian Univ. of Science and Technology, Trondheim (Norway); Reed, T. [Colorado School of Mines (United States)

    1996-12-31

    This report on the Swedish National Program on Fluid Bed Combustion and Gasification is part of the on-going evaluation process adopted by the funding organization NUTEK. This agency has invited the undersigned to act as members of an international panel responsible for evaluating the progress made in 9 projects initiated between 1993-1996. The output of this evaluation procedure is given in this report. The main aim of the Fluid Bed Combustion and Gasification Program is to develop industrially relevant knowledge and competence in experimental and computational techniques capable of characterizing the flow, heat transfer, combustion, gasification, ash formation and deposition and emissions in fluid bed gasifiers and combustors. To achieve this aim NUTEK is sponsoring research in a number of universities and encourages close cooperation between universities and industry. In the evaluation of the various sponsored research programs, the evaluation committee has considered the following key points: relevance of research to industrial needs; originality of research; program management; adequacy of resources; degree of collaboration between industry and academia; international standing of research. In this report comments and recommendations are made on individual projects as well as on the programme in general and they express the unanimous view of the panel members

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

    Directory of Open Access Journals (Sweden)

    M. Peglow

    2005-06-01

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

  11. Experimental study on temperature profile of fixed - bed gasification of oil-palm fronds

    Science.gov (United States)

    Atnaw, Samson M.; Sulaiman, Shaharin A.; Moni, M. Nazmi Z.

    2012-06-01

    Currently the world's second largest palm oil producer Malaysia produces large amount of oil palm biomass each year. The abundance of the biomass introduces a challenge to utilize them as main feedstock for heat and energy generation. Although some oil palm parts and derivatives like empty fruit bunch and fibre have been commercialized as fuel, less attention has been given to oil palm fronds (OPF). Initial feasibility and characterization studies of OPF showed that it is highly feasible as fuel for gasification to produce high value gaseous fuel or syngas. This paper discusses the experimental gasification attempt carried out on OPF using a 50 kW lab scale downdraft gasifier and its results. The conducted study focused on the temperature distributions within the reactor and the characteristics of the dynamic temperature profile for each temperature zones during operation. OPF feedstock of one cubic inch in individual size with 15% average moisture content was utilized. An average pyrolysis zone temperature of 324°Cand an average oxidation zone temperature of 796°Cwere obtained over a total gasification period of 74 minutes. A maximum oxidation zone temperature of 952°Cwas obtained at 486 lpm inlet air flow rate and 10 kg/hr feedstock consumption rate. Stable bluish flare was produced for more than 70% of the total gasification time. The recorded temperature profiles produced closely similar patterns with the temperature profiles recorded from the gasification of woody materials. Similar temperature profile was obtained comparing the results from OPF gasification with that of woody biomass. Furthermore, the successful ignition of the syngas produced from OPF gasification ascertained that OPF indeed has a higher potential as gasification feedstock. Hence, more detailed studies need to be done for better understanding in exploiting the biomass as a high prospect alternative energy solution. In addition, a study of the effect of initial moisture content of OPF

  12. Performance analysis of RDF gasification in a two stage fluidized bed-plasma process.

    Science.gov (United States)

    Materazzi, M; Lettieri, P; Taylor, R; Chapman, C

    2016-01-01

    The major technical problems faced by stand-alone fluidized bed gasifiers (FBG) for waste-to gas applications are intrinsically related to the composition and physical properties of waste materials, such as RDF. The high quantity of ash and volatile material in RDF can provide a decrease in thermal output, create high ash clinkering, and increase emission of tars and CO2, thus affecting the operability for clean syngas generation at industrial scale. By contrast, a two-stage process which separates primary gasification and selective tar and ash conversion would be inherently more forgiving and stable. This can be achieved with the use of a separate plasma converter, which has been successfully used in conjunction with conventional thermal treatment units, for the ability to 'polish' the producer gas by organic contaminants and collect the inorganic fraction in a molten (and inert) state. This research focused on the performance analysis of a two-stage fluid bed gasification-plasma process to transform solid waste into clean syngas. Thermodynamic assessment using the two-stage equilibrium method was carried out to determine optimum conditions for the gasification of RDF and to understand the limitations and influence of the second stage on the process performance (gas heating value, cold gas efficiency, carbon conversion efficiency), along with other parameters. Comparison with a different thermal refining stage, i.e. thermal cracking (via partial oxidation) was also performed. The analysis is supported by experimental data from a pilot plant.

  13. Artificial neural network based modelling approach for municipal solid waste gasification in a fluidized bed reactor.

    Science.gov (United States)

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

    2016-12-01

    In this paper, multi-layer feed forward neural networks are used to predict the lower heating value of gas (LHV), lower heating value of gasification products including tars and entrained char (LHVp) and syngas yield during gasification of municipal solid waste (MSW) during gasification in a fluidized bed reactor. These artificial neural networks (ANNs) with different architectures are trained using the Levenberg-Marquardt (LM) back-propagation algorithm and a cross validation is also performed to ensure that the results generalise to other unseen datasets. A rigorous study is carried out on optimally choosing the number of hidden layers, number of neurons in the hidden layer and activation function in a network using multiple Monte Carlo runs. Nine input and three output parameters are used to train and test various neural network architectures in both multiple output and single output prediction paradigms using the available experimental datasets. The model selection procedure is carried out to ascertain the best network architecture in terms of predictive accuracy. The simulation results show that the ANN based methodology is a viable alternative which can be used to predict the performance of a fluidized bed gasifier. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    S.BASKARA SETHUPATHY

    2012-01-01

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

  15. Development of novel fixed-bed gasification for biomass residues and agrobiofuels

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Simell, P.; Staahlberg, P. [VTT Energy, Espoo (Finland). New Energy Technologies; Berna, G. [Finesport Engineering (Italy); Barbagli, F. [Antiche Terre (Italy); Haavisto, I. [Condens Oy (Finland)

    2000-11-01

    The project concerned three different approaches to achieve reliable operation in fixed-bed gasification of available biomass residues. The first approach was based on the pretreatment of fuels for use in standard downdraft gasifiers. The second one was based on using a commercially available updraft fixed-bed gasifier for heating applications. The third was based on the development of a new type of gasifier that were independent of the natural descending fuel flow caused by gravity. The downdraft gasification tests were carried out in Italy in a gasifier-engine-generator facility with a range of Italian biofuels, the aim being to create criteria for fuel selection, collect reliable performance data with suitable fuels and to identify technical possibilities for broadening the feedstock basis by using mixture fuels and additives. The test results and experiences clearly demonstrated the limitations of this type of commercial gasification technology. Operation experiences of commercial updraft gasifiers operating in Finland and Sweden were collected and evaluated. These updraft gasifiers operate well with sod peat and wood chips. However, these gasifiers cannot operate reliably with low-bulk density fibours fuels like bark, sawdust and shavings. The third technical approach was realised by designing, constructing and testing a pilot plant of a new type of gasifier, based on forced fuel flow and suitable for low-bulk-density fibrous biomass fuels. The pilot plant was connected to a secondary catalytic gas cleaning device, which made it possible to produce tar-free gas suitable for engine use. This new fixed-bed gasifier makes it possible to utilise such biomass residues and energy crops that cannot be used in the presently available fixed-bed gasifiers, like forest residue chips, sawdust and crushed bark. However, further work is required to demonstrate the whole gasifier, gas cleaning and engine concept and to define the lifetime and availability of the catalytic

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-03-15

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

  17. Alkali activation of recovered fuel-biofuel fly ash from fluidised-bed combustion: Stabilisation/solidification of heavy metals.

    Science.gov (United States)

    Yliniemi, Juho; Pesonen, Janne; Tiainen, Minna; Illikainen, Mirja

    2015-09-01

    Recovered fuel-biofuel fly ash from a fluidized bed boiler was alkali-activated and granulated with a sodium-silicate solution in order to immobilise the heavy metals it contains. The effect of blast-furnace slag and metakaolin as co-binders were studied. Leaching standard EN 12457-3 was applied to evaluate the immobilisation potential. The results showed that Ba, Pb and Zn were effectively immobilised. However, there was increased leaching after alkali activation for As, Cu, Mo, Sb and V. The co-binders had minimal or even negative effect on the immobilisation. One exception was found for Cr, in which the slag decreased leaching, and one was found for Cu, in which the slag increased leaching. A sequential leaching procedure was utilized to gain a deeper understanding of the immobilisation mechanism. By using a sequential leaching procedure it is possible fractionate elements into watersoluble, acid-soluble, easily-reduced and oxidisable fractions, yielding a total 'bioavailable' amount that is potentially hazardous for the environment. It was found that the total bioavailable amount was lower following alkali activation for all heavy metals, although the water-soluble fraction was higher for some metals. Evidence from leaching tests suggests the immobilisation mechanism was chemical retention, or trapping inside the alkali activation reaction products, rather than physical retention, adsorption or precipitation as hydroxides.

  18. H₂-rich syngas production by fluidized bed gasification of biomass and plastic fuel.

    Science.gov (United States)

    Ruoppolo, G; Ammendola, P; Chirone, R; Miccio, F

    2012-04-01

    This paper reports the results of gasification tests using a catalytic fluidized bed gasifier to obtain a H(2)-rich stream by feeding different pellets made of wood, biomass/plastic and olive husks to the gasifier. The effects of both the steam supply and an in-bed catalyst on gasifier performance have been investigated. In general, pelletization was an effective pre-treatment for improving the homogeneity of the fuel and the reliability of the feeding devices. The use of biomass/plastic pellets in a catalyst bed yielded good results in terms of the hydrogen concentration (up to 32%vol.), even if an increase in tar production and in the fine/carbon elutriation rate was observed in comparison with wood pellets.

  19. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer.

    Science.gov (United States)

    Thomsen, Tobias Pape; Hauggaard-Nielsen, Henrik; Gøbel, Benny; Stoholm, Peder; Ahrenfeldt, Jesper; Henriksen, Ulrik B; Müller-Stöver, Dorette Sophie

    2017-08-01

    The study is part 2 of 2 in an investigation of gasification and co-gasification of municipal sewage sludge in low temperature gasifiers. In this work, solid residuals from thermal gasification and co-gasification of municipal sewage sludge were investigated for their potential use as fertilizer. Ashes from five different low temperature circulating fluidized bed (LT-CFB) gasification campaigns including two mono-sludge campaigns, two sludge/straw mixed fuels campaigns and a straw reference campaign were compared. Experiments were conducted on two different LT-CFBs with thermal capacities of 100kW and 6MW, respectively. The assessment included: (i) Elemental composition and recovery of key elements and heavy metals; (ii) content of total carbon (C) and total nitrogen (N); (iii) pH; (iv) water extractability of phosphorus after incubation in soil; and (v) plant phosphorus response measured in a pot experiment with the most promising ash material. Co-gasification of straw and sludge in LT-CFB gasifiers produced ashes with a high content of recalcitrant C, phosphorus (P) and potassium (K), a low content of heavy metals (especially cadmium) and an improved plant P availability compared to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottom ashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded that LT-CFB gasification and co-gasification is a highly effective way to purify and sanitize sewage sludge for subsequent use in agricultural systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Development of ultraclean gas technologies for biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Simell, P.; McKeough, P.; Kurkela, M. (VTT Technical Research Centre of Finland, Espoo (Finland))

    2009-07-01

    New innovative biomass gasification and gas cleaning technologies were studied and developed for the production of synthesis gas and ultra clean fuel gas. The experimental work was focused on fluidised-bed gasification, followed by catalytic reforming and optimised gas conditioning processes. The main aim of the project was to develop processes which can be applied in producing liquid biofuels from biomass andwaste fuels. This three-year project, Development of ultra clean gas (UCG) technologies for biomass gasification, was realised in years 2004-2007. In 2004-05, the experimental work was carried out on laboratory and bench-scale equipment, while in 2006-07 the main emphasis was shifted to the work on the new Process Development Unit (PDU) of VTT. In addition to experimental R&D work, system studies have been carried out in order to define optimal process concepts for producing liquid biofuels in Finnish and Central European conditions. Especially, the integration of syngas technologies to the pulp and paper industries and combined power and heat production has been studied. Different liquid biofuel production concepts were assessed and a promising method for producing transportation fuels with ca. 50 eurocents/l has been introduced. This concept is based on fluidised-bed gasification of biomass at 200-300 MW scale with efficient energy integration to a pulp and paper mill. The 500 kW PDU plant for the new gasification and gas cleaning process was designed, constructed and operated at VTT. Product gas reforming has been studied and tested in laboratory scale and a PDU-scale reformer has been constructed and successfully operated. The test runs carried out in spring 2007 proved that the gasification and gas cleaning process could be successfully operated and the main targets of the project were achieved. (orig.)

  1. Industrial-scale Fixed-bed Coal Gasification:Modeling, Simulation and Thermodynamic Analysis

    Institute of Scientific and Technical Information of China (English)

    何畅; 冯霄; 李安学; 刘永健

    2014-01-01

    We have developed a process model to simulate the behavior of an industrial-scale pressurized Lurgi fixed-bed coal gasifier using Aspen Plus and General Algebraic Modeling System (GAMS). Reaction characteristics in the fixed-bed gasifier comprising four sequential reaction zones-drying, pyrolysis, combustion and gasification are respectively modeled. A non-linear programming (NLP) model is developed for the pyrolysis zone to estimate the products composition which includes char, coal gases and distillable liquids. A four-stage model with restricted equilibrium temperature is used to study the thermodynamic equilibrium characteristics and calculate the composi-tion of syngas in the combustion and gasification zones. The thermodynamic analysis shows that the exergetic effi-ciency of the fixed-bed gasifier is mainly determined by the oxygen/coal ratio. The exergetic efficiency of the proc-ess will reach an optimum value of 78.3%when the oxygen/coal and steam/coal mass ratios are 0.14 and 0.80, re-spectively.

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

    Science.gov (United States)

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

    2016-04-01

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

  3. Air gasification of biogas-derived digestate in a downdraft fixed bed gasifier.

    Science.gov (United States)

    Chen, Guanyi; Guo, Xiang; Cheng, Zhanjun; Yan, Beibei; Dan, Zeng; Ma, Wenchao

    2017-08-22

    Digestate is a byproduct from biomass anaerobic digestion process. Gasification of dried digestate to produce gasesous product might be a promising route. In this work, air gasification of digestate with high ash content was performed in a downdraft fixed bed gasifier at temperature varying from 600°C to 800°C and air equivalence ratio (ER) ranging from 0.25 to 0.30. The ash melting properties were firstly detected by the Intelligent Ash Melting Point Test, and the by-products (biochar and ash) were analyzed. The results showed that no ash slagging was observed and therefore it is feasible to operate digestate gasification under 800°C and ER ranging from 0.25 to 0.30. High temperature favored gas production, 800°C is proposed for digestate gasification in the present study. ER with a medium value improved gas quality and cold gas efficiency (CGE), and the optimal LHV of 4.78MJ/Nm(3) and CGE of 67.01% were obtained with ER of 0.28. High ER favored the increase of gas yield and decrease of tar concentration, and the optimal gas yield of 2.15 Nm(3)/kg and tar concentration of 1.61g/Nm(3) were achieved with ER of 0.30. Improved molar ratio of H2/CO varying from 1.03 to 1.08 was obtained at 800°C, indicating gaseous product has the potential for chemical synthesis processes (1

  4. Plasma-Augmented Fluidized Bed Gasification of Sub-bituminous Coal in CO2-O2 Atmospheres

    Science.gov (United States)

    Lelievre, C.; Pickles, C. A.; Hultgren, S.

    2016-01-01

    The gasification of a sub-bituminous coal using CO2-O2 gas mixtures was studied in a plasma-augmented fluidized bed gasifier. Firstly, the coal was chemically characterized and the gasification process was examined using Thermogravimetric and Differential Thermal Analysis (TGA/DTA) in CO2, O2 and at a CO2 to O2 ratio of 3 to 1. Secondly, the equilibrium gas compositions were obtained using the Gibbs free energy minimization method (HSC Chemistry®7). Thirdly, gasification tests were performed in a plasma-augmented fluidized bed and the off-gas temperatures and compositions were determined. Finally, for comparison purposes, control tests were conducted using a conventional fluidized bed coal gasifier and these results were compared to those achieved in the plasma-augmented fluidized bed gasifier. The effects of bed temperature and CO2 to O2 ratio were studied. For both gasifiers, at a given bed temperature, the off-gas compositions were in general agreement with the equilibrium values. Also, for both gasifiers, an experimental CO2 to O2 ratio of about 3 to 1 resulted in the highest syngas grade (%CO + %H2). Both higher off-gas temperatures and syngas grades could be achieved in the plasma-augmented gasifier, in comparison to the conventional gasifier. These differences were attributed to the higher bed temperatures in the plasma-augmented fluidized bed gasifier.

  5. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 1: Process performance and gas product characterization.

    Science.gov (United States)

    Thomsen, Tobias Pape; Sárossy, Zsuzsa; Gøbel, Benny; Stoholm, Peder; Ahrenfeldt, Jesper; Frandsen, Flemming Jappe; Henriksen, Ulrik Birk

    2017-08-01

    Results from five experimental campaigns with Low Temperature Circulating Fluidized Bed (LT-CFB) gasification of straw and/or municipal sewage sludge (MSS) from three different Danish municipal waste water treatment plants in pilot and demonstration scale are analyzed and compared. The gasification process is characterized with respect to process stability, process performance and gas product characteristics. All experimental campaigns were conducted at maximum temperatures below 750°C, with air equivalence ratios around 0.12 and with pure silica sand as start-up bed material. A total of 8600kg of MSS dry matter was gasified during 133h of operation. The average thermal loads during the five experiments were 62-100% of nominal capacity. The short term stability of all campaigns was excellent, but gasification of dry MSS lead to substantial accumulation of coarse and rigid, but un-sintered, ash particles in the system. Co-gasification of MSS with sufficient amounts of cereal straw was found to be an effective way to mitigate these issues as well as eliminate thermal MSS drying requirements. Characterization of gas products and process performance showed that even though gas composition varied substantially, hot gas efficiencies of around 90% could be achieved for all MSS fuel types. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Study on biomass circulation and gasification performance in a clapboard-type internal circulating fluidized bed gasifier.

    Science.gov (United States)

    Zhou, Zhao-qiu; Ma, Long-long; Yin, Xiu-li; Wu, Chuang-zhi; Huang, Li-cheng; Wang, Chu

    2009-01-01

    We investigated the solid particle flow characteristics and biomass gasification in a clapboard-type internal circulating fluidized bed reactor. The effect of fluidization velocity on particle circulation rate and pressure distribution in the bed showed that fluidization velocities in the high and low velocity zones were the main operational parameters controlling particle circulation. The maximum internal circulation rates in the low velocity zone came almost within the range of velocities in the high velocity zone, when u(H)/u(mf)=2.2-2.4 for rice husk and u(H)/u(mf)=3.5-4.5 for quartz sand. In the gasification experiment, the air equivalence ratio (ER) was the main controlling parameter. Rice husk gasification gas had a maximum heating value of around 5000 kJ/m(3) when ER=0.22-0.26, and sawdust gasification gas reached around 6000-6500 kJ/m(3) when ER=0.175-0.24. The gasification efficiency of rice husk reached a maximum of 77% at ER=0.28, while the gasification efficiency of sawdust reached a maximum of 81% at ER=0.25.

  7. Thermodynamic analysis of the gasification of coal water slurry fuels for a circulating fluidized bed gasifier

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, H.; Yavuzkurt, S.; Scaroni, A. [National Taiwan University, Taipei (Taiwan)

    2002-07-01

    To validate the concept of coal gasification in the integrated coal gasification combined cycle (IGCC), a novel laboratory gasifier consisting of a circulating fluidized bed and a cyclone combustor has been constructed. This paper reports a thermodynamic analysis conducted to predict the maximum capacity and the condition for best operation of this circulating fluidized bed gasifier, which has an inside diameter of 0.3048 m and a height of 2.5 m. The equilibrium feed rates of materials and the quality of the product gas are described as a function of the reactor temperature, the thermal capacity of the gasifier, and the water concentration in coal water slurry fuel. The results of parametric analysis show that the thermal efficiency decreases, but the efficiency of desulfurization increases as the reactor temperature increases. The thermal capacity of the gasifier has no influence on the quality of the product gas. The thermal efficiency and the efficiency of desulfurization decrease as the water concentration in the coal water slurry increases. The desulfurization in the gasifier at equilibrium conditions is very efficient and meets the EPA regulations of the USA.

  8. Parametric experimental tests of steam gasification of pine wood in a fluidized bed reactor

    Directory of Open Access Journals (Sweden)

    L. Vecchione

    2013-09-01

    Full Text Available Among Renewable Energy Sources (RES, biomass represent one of the most common and suitable solution in order to contribute to the global energy supply and to reduce greenhouse gases (GHG emissions. The disposal of some residual biomass, as pruning from pine trees, represent a problem for agricultural and agro-industrial sectors. But if the residual biomass are used for energy production can become a resource. The most suitable energy conversion technology for the above-mentioned biomass is gasification process because the high C/N ratio and the low moisture content, obtained from the analysis. In this work a small-pilot bubbling-bed gasification plant has been designed, constructed and used in order to obtain, from the pine trees pruning, a syngas with low tar and char contents and high hydrogen content. The activities showed here are part of the activities carried out in the European 7FP UNIfHY project. In particular the aim of this work is to develop experimental test on a bench scale steam blown fluidized bed biomass gasifier. These tests will be utilized in future works for the simulations of a pilot scale steam fluidized bed gasifier (100 kWth fed with different biomass feedstock. The results of the tests include produced gas and tar composition as well gas, tar and char yield. Tests on a bench scale reactor (8 cm I.D. were carried out varying steam to biomass ratio from 0.5, 0.7 and 1 to 830°C.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-01

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

  10. Developmental research study of coal-fines agglomeration for fixed-bed gasification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Elmquist, S.A.; Girimont, J.A.; Korosi, F.A.; Kuby, O.A.; Nelson, S.G.; Paulin, M.O.; Peterson, C.A.; Baker, R.L.; Saller, E.

    1983-05-31

    This report presents the results of an intensive program to develop and evaluate agglomerates made from coal fines for use in a fixed-bed gasifier. There were several tasks completed earlier and their results published prior to this final report. These included: Task 1-A, a literature survey of coal agglomeration, binders and techniques used in coal agglomeration, coal and binder treatments and the results of work done by others; Task 1-B, an examination of performance of lump coals in coal gasification, testing and evaluation of the properties of these coals, and evaluation of mine site coal upgrading methods; and Task 1-C/D, a laboratory investigation of coal agglomerates, including wafers, briquettes and pellets, in which the agglomerated coal fines were formed and tested, and the performance of various coal/binder combinations was recorded and evaluated, and factors affecting commercial scale coal agglomeration and gasification were evaluated. These three prior tasks are presented in this report in condensed form.

  11. Effect of Operating Conditions on Catalytic Gasification of Bamboo in a Fluidized Bed

    Directory of Open Access Journals (Sweden)

    Thanasit Wongsiriamnuay

    2013-01-01

    Full Text Available Catalytic gasification of bamboo in a laboratory-scale, fluidized bed reactor was investigated. Experiments were performed to determine the effects of reactor temperature (400, 500, and 600°C, gasifying medium (air and air/steam, and catalyst to biomass ratio (0 : 1, 1 : 1, and 1.5 : 1 on product gas composition, H2/CO ratio, carbon conversion efficiency, heating value, and tar conversion. From the results obtained, it was shown that at 400°C with air/steam gasification, maximum hydrogen content of 16.5% v/v, carbon conversion efficiency of 98.5%, and tar conversion of 80% were obtained. The presence of catalyst was found to promote the tar reforming reaction and resulted in improvement of heating value, carbon conversion efficiency, and gas yield due to increases in H2, CO, and CH4. The presence of steam and dolomite had an effect on the increasing of tar conversion.

  12. Oxygen Gasification of Municipal Solid Waste in a Fixed-bed Gasifier

    Institute of Scientific and Technical Information of China (English)

    Miaomiao Niu; Yaji Huang⁎; Baosheng Jin; Xinye Wang

    2014-01-01

    abstract Four waste materials, paper, wood, textile and kitchen garbage, in municipal solid waste were gasified separately with oxygen in a fixed bed reactor. The yields of products char, tar and gas, the composition of gas components H2, CO, CO2 and CH4, and the lower heating value (LHV) were examined at temperatures between 700 and 900 °C and equivalence ratio (ER) between 0.14 and 0.32. Characteristics of gas evolution during gasification were inves-tigated. Results show that a higher temperature improves the formation of H2 and CO while lowers the yield of CO2 and CH4. The LHV of syngas increases with temperature and varies in the range of 6-10 MJ·m-3, reaching the maximum at 800 °C or above. As ER increases, both combustible gas component and LHV of syngas decrease while the yield of CO2 rises linearly. The appropriate ER for obtaining high quality gas is in the range of 0.18-0.23. Temperature and ER have significant effects on the product distribution. Higher temperature and ER are favorable for higher gas yield and lower yield of char and tar in the gasification of textile and kitchen garbage. At 800 °C, the gas evolution may be divided into two regions. In the first region, the flow rate of gas increases and then de-creases rapidly, while in the second region the flow rate decreases monotonical y to lower level.

  13. Removal of phenols, thiocyanate and ammonium from coal gasification wastewater using moving bed biofilm reactor

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.Q.; Han, H.J.; Du, M.A.; Wang, W. [Harbin Institute of Technology, Harbin (China)

    2011-04-15

    A laboratory-scale moving bed biofilm reactor (MBBR) with a volume of 4 L was used to study the biodegradation of coal gasification wastewater. Maximum removal efficiencies of 81%, 89%, 94% and 93% were obtained for COD, phenols, SCN{sup -} and NH{sub 4}{sup +}-N, respectively. NO{sub 2}{sup -}-N accumulation induced increase of effluent COD concentration when the hydraulic residence time (HRT) decreased. Phenols removal was not affected when the HRT decreased from 48 to 32 h. Effluent SCN{sup -} and NH{sub 4}{sup +}-N concentration increased with the decrease of the HRT, and decreased gradually when the HRT returned to 48 h. Batch experiments were carried out to study performance of the suspended and attached growth biomass in the MBBR.

  14. Inhibition and recovery of nitrification in treating real coal gasification wastewater with moving bed biofilm reactor

    Institute of Scientific and Technical Information of China (English)

    Huiqiang Li; Hongjun Han; Maoan Du; Wei Wang

    2011-01-01

    Moving bed biofilm reactor (MBBR) was used to treat real coal gasification wastewater.Nitrification of the MBBR was inhibited almost completely during start-up period.Sudden increase of influent total NH3 concentration was the main factor inducing nitrification inhibition.Increasing DO concentration in the bulk liquid (from 2 to 3 mg/L) had little effect on nitrification recovery.Nitrification of the MBBR recovered partially by the addition of nitrifying sludge into the reactor and almost ceased within 5 days.Nitrification ratio of the MBBR achieved 65% within 12 days by increasing dilute ratio of the influent wastewater with tap water.The ratio of nitrification decreased to 25% when infiuent COD concentration increased from 650 to 1000 mg/L after nitrification recovery and recovered 70%for another 4 days.

  15. Removal of phenols, thiocyanate and ammonium from coal gasification wastewater using moving bed biofilm reactor.

    Science.gov (United States)

    Li, Hui-qiang; Han, Hong-jun; Du, Mao-an; Wang, Wei

    2011-04-01

    A laboratory-scale moving bed biofilm reactor (MBBR) with a volume of 4 L was used to study the biodegradation of coal gasification wastewater. Maximum removal efficiencies of 81%, 89%, 94% and 93% were obtained for COD, phenols, SCN(-) and NH(4)(+)-N, respectively. NO(2)(-)-N accumulation induced increase of effluent COD concentration when the hydraulic residence time (HRT) decreased. Phenols removal was not affected when the HRT decreased from 48 to 32 h. Effluent SCN(-) and NH(4)(+)-N concentration increased with the decrease of the HRT, and decreased gradually when the HRT returned to 48 h. Batch experiments were carried out to study performance of the suspended and attached growth biomass in the MBBR.

  16. Inhibition and recovery of nitrification in treating real coal gasification wastewater with moving bed biofilm reactor.

    Science.gov (United States)

    Li, Huiqiang; Han, Hongjun; Du, Maoan; Wang, Wei

    2011-01-01

    Moving bed biofilm reactor (MBBR) was used to treat real coal gasification wastewater. Nitrification of the MBBR was inhibited almost completely during start-up period. Sudden increase of influent total NH3 concentration was the main factor inducing nitrification inhibition. Increasing DO concentration in the bulk liquid (from 2 to 3 mg/L) had little effect on nitrification recovery. Nitrification of the MBBR recovered partially by the addition of nitrifying sludge into the reactor and almost ceased within 5 days. Nitrification ratio of the MBBR achieved 65% within 12 days by increasing dilute ratio of the influent wastewater with tap water. The ratio of nitrification decreased to 25% when influent COD concentration increased from 650 to 1000 mg/L after nitrification recovery and recovered 70% for another 4 days.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-08-15

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

  19. Circulating fluidized bed gasification of low rank coal: Influence of O2/C molar ratio on gasification performance and sulphur transformation

    Science.gov (United States)

    Zhang, Haixia; Zhang, Yukui; Zhu, Zhiping; Lu, Qinggang

    2016-08-01

    To promote the utilization efficiency of coal resources, and to assist with the control of sulphur during gasification and/or downstream processes, it is essential to gain basic knowledge of sulphur transformation associated with gasification performance. In this research we investigated the influence of O2/C molar ratio both on gasification performance and sulphur transformation of a low rank coal, and the sulphur transformation mechanism was also discussed. Experiments were performed in a circulating fluidized bed gasifier with O2/C molar ratio ranging from 0.39 to 0.78 mol/mol. The results showed that increasing the O2/C molar ratio from 0.39 to 0.78 mol/mol can increase carbon conversion from 57.65% to 91.92%, and increase sulphur release ratio from 29.66% to 63.11%. The increase of O2/C molar ratio favors the formation of H2S, and also favors the retained sulphur transforming to more stable forms. Due to the reducing conditions of coal gasification, H2S is the main form of the released sulphur, which could be formed by decomposition of pyrite and by secondary reactions. Bottom char shows lower sulphur content than fly ash, and mainly exist as sulphates. X-ray photoelectron spectroscopy (XPS) measurements also show that the intensity of pyrite declines and the intensity of sulphates increases for fly ash and bottom char, and the change is more obvious for bottom char. During CFB gasification process, bigger char particles circulate in the system and have longer residence time for further reaction, which favors the release of sulphur species and can enhance the retained sulphur transforming to more stable forms.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-30

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

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

    NARCIS (Netherlands)

    Meng, X.

    2012-01-01

    As one of the currently available thermo-chemical conversion technologies, biomass gasification has received considerable interest since it increases options for combining with various power generation systems. The product gas or syngas produced from biomass gasification is environmental friendly

  2. Research on the Gas Reburning in a Circulating Fluidized Bed (CFB System Integrated with Biomass Gasification

    Directory of Open Access Journals (Sweden)

    Changqing Dong

    2012-08-01

    Full Text Available N2O emissions from coal fired fluidized-bed combustion are approximately 30–360 mg/Nm3, much higher than that from pulverized coal combustion (less than 30 mg/Nm3. One approach to reduce the N2O is to reburn the biomass gasification gas in the coal-fired fluidized bed. In this paper, the effects of gasified biomass reburning on the integrated boiler system were investigated by both simulation and experimental methods. The simulation as well as experimental results revealed that the increase of the reburning ratio would decrease the theoretical air volume and boiler efficiency, while it would increase the fuel gas volume, combustion and exhuast gas temperature. The experimental results also indicated that the N2O removal could reach as high as 99% when the heat ratio of biomass gas to coal is 10.5%.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhen Fan

    2006-05-30

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

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

    Science.gov (United States)

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

    2014-11-01

    The syngas produced by fixed bed gasifiers contains high quantities of particulate and tars. This issue, together with its high temperature, avoids its direct exploitation without a proper cleaning and cooling process. In fact, when the syngas produced by gasification is used in an Internal Combustion engine (IC), the higher the content of tars and particulate, the higher the risk to damage the engine is. If these compounds are not properly removed, the engine may fail to run. A way to avoid engine fails is to intensify the maintenance schedule, but these stops will reduce the system profitability. From a clean syngas does not only follow higher performance of the generator, but also less pollutants in the atmosphere. When is not possible to work on the gasification reactions, the filter plays the most important role in the engine safeguard process. This work is aimed at developing and comparing different porous filters for biomass gasifiers power plants. A drum filter was developed and tested filling it with different filtering media available on the market. As a starting point, the filter was implemented in a Power Pallet 10 kW gasifier produced by the California-based company "ALL Power Labs". The original filter was replaced with different porous biomasses, such as woodchips and corn cobs. Finally, a synthetic zeolites medium was tested and compared with the biological media previously used. The Tar Sampling Protocol (TSP) and a modified "dry" method using the Silica Gel material were applied to evaluate the tars, particulate and water amount in the syngas after the filtration process. Advantages and disadvantages of every filtering media chosen were reported and discussed.

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

    CSIR Research Space (South Africa)

    Oboirien, BO

    2012-11-01

    Full Text Available efficiencies in future gasification processes by selecting the most appropriate gaseous environments and (ii) to prevent or minimise the occurrence of slagging in future gasification processes. This is specifically applicable to operations involving fluidised...

  6. Development of novel fixed-bed gasification methods for biomass residues and agrobiofuels; Kiinteaekerroskaasutustekniikan kehitys biopolttoaineille

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

    The overall aims of this project were: (1) to show that fixed-bed gasifiers can be designed to operate reliably with realistically available woody residues and energy crops, (2) to develop catalytic gas cleaning technique for engine use, and (3) to find suitable markets where the local conditions are favourable for economically competitive small-scale power and heat production based on this technology. The specific objectives of the project are: (a) To define the requirements to the feedstock quality needed to guarantee reliable operation with respect to fuel flow, pressure drop, ash sintering and tar formation in an existing commercial downdraft gasifier; (b) To collect operation experience from the commercial Bioneer updraft gasifiers in order to update earlier pilot-plant findings of VTT (Technical Research Centre of Finland) concerning the requirements for feedstock quality required for long-term reliable operation in this reactor type; (c) To develop and test a new type of fixed-bed gasifies design, which is based on forced fuel flow and consequently allows the use of low-bulk-density fuels; (d) To develop and test on a PDU scale a simple and reliable secondary catalytic reactor required for complete decomposition of tars, and (e) To evaluate the economic feasibility of different fixed-bed gasification systems on a potential local energy production market (low-cost biomass residues available, high cost of external energy). The work is carried out as an EC/Joule 3 project in close co-operation between the following partners: VTT Energy and Condens Oy of Finland and Finesport Engineering and Antiche Terre soc. coop.r.l of Italy. VTT Energy co-ordinates the project. The work programme is scheduled to be carried out during the period of 1 October 1997 - 30 September 1999

  7. Development of novel fixed-bed gasification methods for biomass residues and agrobiofuels

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-01

    The general goals of the project are: (1) to show that fixed-bed gasifiers can be designed to operate reliably with realistically available woody residues and energy crops, (2) to develop catalytic gas cleaning for producing clean gas to the engine use, and (3) to find suitable markets where the local conditions are favorable for economically competitive small-scale power and heat production based on this technology. The specific goals of the project are: to define the requirements to the feedstock quality needed to guarantee reliable operation with respect to the fuel flow, pressure drop, ash sintering and tar formation in an existing commercial downdraft gasifier; to collect experience from the commercial Bioneer updraft gasifiers in order to update earlier pilot-plant findings of VTT concerning requirements for feedstock quality required for long-term reliable operation in this reactor type; to develop and test a new type of the fixed-bed gasifier design, based on forced fuel flow and which consequently allows the use of the low bulk-density fuels; to develop and test on a PDU-scale a simple and reliable secondary catalytic reactor required for complete decomposition of tars; and to evaluate the economic feasibility of different fixed bed gasification systems on a potential local energy production market (low-cost biomass residues available, high cost of external energy). The work is carried out as an EC/Joule 3 project in close co-operation between the following partners: VTT Energy and Condens Oy from Finland, Finesport Engineering and Antiche Terre soc. coop.r.l from Italy. VTT energy coordinates the project. The work programme is scheduled to be carried out during the period Oct. 1st 1997 - Sep. 30th 1999 6 refs. Bioenergy Research programme

  8. Volatilisation of alkali and alkaline earth metallic species during the gasification of a Victorian brown coal in CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Quyn, Dimple Mody; Li, Chun-Zhu [CRC for Clean Power from Lignite, Department of Chemical Engineering, PO Box 36, Monash University, Victoria 3800 (Australia); Hayashi, Jun-ichiro [Centre for Advanced Research of Energy Conversion Materials, Hokkaido University, N13-W8, Kita-ku, Sapporo 060-8628 (Japan)

    2005-08-25

    A Victorian brown coal was gasified in a bench-scale quartz fluidised-bed/fixed-bed reactor in order to study the volatilisation of Na, Ca, and Mg during devolatilisation and gasification and their roles in the reactivity of chars. It was found that the majority of Na was volatilised at 900 {sup o}C under all conditions and that a Na retention limit was achieved in the char with the progress of CO{sub 2} gasification. In some cases, the presence of CO{sub 2} during devolatilisation enhanced the Na retention in the char. In contrast, the retention of Ca (and Mg) was unaffected by CO{sub 2} during devolatilisation at 900C but decreased drastically upon nascent char gasification. The fundamental differences in volatilisation between the alkali and alkaline earth metallic species are discussed in this paper.

  9. Gasification of Biochar from Empty Fruit Bunch in a Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    M. A. Mohd Salleh

    2010-07-01

    Full Text Available A biochar produced from empty fruit bunches (EFB was gasified in a fluidized bed using air to determine gas yield, overall carbon conversion, gas quality, and composition as a function of temperature. The experiment was conducted in the temperature range of 500–850 °C. It was observed that biochar has the potential to replace coal as a gasification agent in power plants. Hydrogen gas from biochar was also optimized during the experiment. High temperatures favor H2 and CO formation. There was an increase of H2 over the temperature range from 500–850 °C from 5.53% to 27.97% (v/v, with a heating value of 30 kJ/g. The C conversion in the same temperature range increased from 76% to 84%. Therefore, there are great prospects for the use of biochar from EFB as an alternative fuel in power plants, as a renewable energy providing an alternative path to biofuels. Results from this work enable us to better understand syn gas production under high treatment temperatures.

  10. Gasification of biochar from empty fruit bunch in a fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mohd Salleh, M. A.; Hussein Kisiki, N.; Yusuf, H. M.; Ghani, W. A. K. [Department of Chemical and Enviromental Engineering University Putra Malaysia, 43400, Serdang (Malaysia)

    2010-07-15

    A biochar produced from empty fruit bunches (EFB) was gasified in a fluidized bed using air to determine gas yield, overall carbon conversion, gas quality, and composition as a function of temperature. The experiment was conducted in the temperature range of 500-850 {sup o}C. It was observed that biochar has the potential to replace coal as a gasification agent in power plants. Hydrogen gas from biochar was also optimized during the experiment. High temperatures favor H{sub 2} and CO formation. There was an increase of H{sub 2} over the temperature range from 500-850 {sup o}C from 5.53% to 27.97% (v/v), with a heating value of 30 kJ/g. The C conversion in the same temperature range increased from 76% to 84%. Therefore, there are great prospects for the use of biochar from EFB as an alternative fuel in power plants, as a renewable energy providing an alternative path to biofuels. Results from this work enable us to better understand syn gas production under high treatment temperatures. (authors)

  11. An innovative example of herb residues recycling by gasification in a fluidized bed.

    Science.gov (United States)

    Guo, Feiqiang; Dong, Yuping; Dong, Lei; Jing, Yuanzhuo

    2013-04-01

    A utilization way of herb residues is designed to convert herb residues to gas fuel in industrial-scale by a circulating fluidized bed gasifier in this paper. The product gas is used in the production of Chinese medicine, and the heat of the flue gas from the boiler can be used in herb residues drying to realize the energy recycling and no herb residues discharge. The gasification characteristics of herb residues in the circulating fluidized bed of 300 kg/h were investigated for about 200 h. The results indicated that the gas composition and tar yield were affected by biomass flow rate, equivalence ratio (ER), moisture content and char circulating. The lower heating value of product gas was 4-5 MJ/m(3) using herb residues as feedstock. When mean biomass flow rate was at 5.5 kg m(-2)s(-1) and ER at 0.35, the product gas reached a good condition with lower heating value of 4.89 MJ/m(3) and cold gas efficiency of 62.36%. When the moisture content changed from 12.5% to 18.7%, the concentrations of H2, CO and CO2 changed from 4.66% to 6.92%, 11.23% to 10.15%, and 16.55% to 17.82% respectively, and the tar content in gas decreased from 15.1g/m(3) to 14.4 g/m(3) when the moisture content increased from 12.5% to 15.4%. There are metal oxides in the ash of herb residues, especially CaO, MgO, K2O, Al2O3, and Fe2O3 which have obvious function on tar catalytic decomposition. The ash that attaches to the char particles can decrease the tar yield and improve the quality of gas after returning to the gasifier.

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

    NARCIS (Netherlands)

    Meng, X.

    2012-01-01

    As one of the currently available thermo-chemical conversion technologies, biomass gasification has received considerable interest since it increases options for combining with various power generation systems. The product gas or syngas produced from biomass gasification is environmental friendly al

  13. Bed Agglomeration During the Steam Gasification of a High Lignin Corn Stover Simultaneous Saccharification and Fermentation (SSF) Digester Residue

    Energy Technology Data Exchange (ETDEWEB)

    Howe, Daniel T.; Taasevigen, Danny J.; Gerber, Mark A.; Gray, Michel J.; Fernandez, Carlos A.; Saraf, Laxmikant; Garcia-Perez, Manuel; Wolcott, Michael P.

    2015-11-13

    This research investigates the bed agglomeration phenomena during the steam gasification of a high lignin residue produced from the simultaneous saccharification and fermentation (SSF) of corn stover in a bubbling fluidized bed. The studies were conducted at 895°C using alumina as bed material. Biomass was fed at 1.5 kg/hr, while steam was fed to give a velocity equal to 2.5 times the minimum fluidization velocity, with a steam/carbon ratio of 0.9. The pelletized feedstock was co-fed with a cooling nitrogen stream to mitigate feed line plugging issues. Tar production was high at 50.3 g/Nm3, and the fraction of C10+ compounds was greater than that seen in the gasification of traditional lignocellulosic feedstocks. Carbon closures over 94 % were achieved for all experiments. Bed agglomeration was found to be problematic, indicated by pressure drop increases observed below the bed and upstream of the feed line. Two size categories of solids were recovered from the reactor, +60 mesh and -60 mesh. After a 2.75-hour experiment, 61.7 wt % was recovered as -60 mesh particles and 38.2 wt% of the recovered reactor solids were +60 mesh. A sizeable percentage, 31.8 wt%, was +20 mesh. The -60 mesh particles were mainly formed by the initial bed material (Al2O3). Almost 50 wt. % of the + 20 mesh particles was found to be formed by organics. The unreacted carbon remaining in the reactor resulted in a low conversion rate to product gas. ICP-AES, SEM, SEM-EDS, and XRD confirmed that the large agglomerates (+ 20 mesh) were not encapsulated bed material but rather un-gasified feedstock pellets with sand particles attached to it.

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

    Science.gov (United States)

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

    2015-03-01

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

  15. Advanced development of a pressurized ash agglomerating fluidized-bed coal gasification system: Topical report, Process analysis, FY 1983

    Energy Technology Data Exchange (ETDEWEB)

    None

    1987-07-31

    KRW Energy Systems, Inc., is engaged in the continuing development of a pressurized, fluidized-bed gasification process at its Waltz Mill Site in Madison, Pennsylvania. The overall objective of the program is to demonstrate the viability of the KRW process for the environmentally-acceptable production of low- and medium-Btu fuel gas from a variety of fossilized carbonaceous feedstocks and industrial fuels. This report presents process analysis of the 24 ton-per-day Process Development Unit (PDU) operations and is a continuation of the process analysis work performed in 1980 and 1981. Included is work performed on PDU process data; gasification; char-ash separation; ash agglomeration; fines carryover, recycle, and consumption; deposit formation; materials; and environmental, health, and safety issues. 63 figs., 43 tabs.

  16. Air gasification of empty fruit bunch for hydrogen-rich gas production in a fluidized-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed, M.A.A.; Salmiaton, A.; Wan Azlina, W.A.K.G.; Mohammad Amran, M.S.; Fakhru' l-Razi, A. [Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2011-02-15

    A study on gasification of empty fruit bunch (EFB), a waste of the palm oil industry, was investigated. The composition and particle size distribution of feedstock were determined and the thermal degradation behaviour was analysed by a thermogravimetric analysis (TGA). Then fluidized bed bench scale gasification unit was used to investigate the effect of the operating parameters on EFB air gasification namely reactor temperature in the range of 700-1000 C, feedstock particle size in the range of 0.3-1.0 mm and equivalence ratio (ER) in the range of 0.15-0.35. The main gas species generated, as identified by a gas chromatography (GC), were H{sub 2}, CO, CO{sub 2} and CH{sub 4}. With temperature increasing from 700 C to 1000 C, the total gas yield was enhanced greatly and reached the maximum value ({proportional_to}92 wt.%, on the raw biomass sample basis) at 1000 C with big portions of H{sub 2} (38.02 vol.%) and CO (36.36 vol.%). Feedstock particle size showed an influence on the upgrading of H{sub 2}, CO and CH{sub 4} yields. The feedstock particle size of 0.3-0.5 mm, was found to obtain a higher H{sub 2} yield (33.93 vol.%), and higher LHV of gas product (15.26 MJ/m{sup 3}). Equivalence ratio (ER) showed a significant influence on the upgrading of hydrogen production and product distribution. The optimum ER (0.25) was found to attain a higher H{sub 2} yield (27.31 vol.%) at 850 C. Due to the low efficiency of bench scale gasification unit the system needs to be scaling-up. The cost analysis for scale-up EFB gasification unit showed that the hydrogen supply cost is RM 6.70/kg EFB (2.11/kg = 0.18/Nm{sup 3}). (author)

  17. Application and research status of fluidized bed biomass gasification technologies%生物质流化床气化技术应用研究现状

    Institute of Scientific and Technical Information of China (English)

    孟凡彬; 刘建冲; 王贵路; 李晓伟; 张大雷

    2011-01-01

    According to the product s of biomass gasification, the purposes of biomass gasification could be classified into hydrogen production,power generation and synthetic liquid fuel This article introduced the features of hydrogen production from biomass steam gasification technology, catalytic gasification technology and supercritical water gasification technology, analyzed the technological and economic feasibility of fluidized bed biomass gasification and summarized the research status of fluidized bed biomass gasification to liquid fuel technology.It points out that the main bottleneck of biomass fluidized bed gasification technology is to change the stoichiometric ratio, to remove tar and to clean the produced synthesis gas It is surely that the oriented gasification will be the main tendency in the future.%按所得产品不同,可将生物质气化技术分为制氢、发电和合成液体燃料3大类.文章介绍了生物质流化床水蒸气气化制氢、催化气化制氢和超临界水气化制氢的工艺特点;分析了生物质流化床气化发电的技术、经济可行性;简述了生物质流化床气化合成液体燃料的研究现状;指出气化产出气化学当量比调变、焦油去除问题和合成气净化是生物质流化床气化技术应用的主要瓶颈,认为定向气化是今后研究的主要方向.

  18. Simulation of Steam Gasification in a Fluidized Bed Reactor with Energy Self-Sufficient Condition

    Directory of Open Access Journals (Sweden)

    Ajaree Suwatthikul

    2017-03-01

    Full Text Available The biomass gasification process is widely accepted as a popular technology to produce fuel for the application in gas turbines and Organic Rankine Cycle (ORC. Chemical reactions of this process can be separated into three reaction zones: pyrolysis, combustion, and reduction. In this study, sensitivity analysis with respect to three input parameters (gasification temperature, equivalence ratio, and steam-to-biomass ratio has been carried out to achieve energy self-sufficient conditions in a steam gasification process under the criteria that the carbon conversion efficiency must be more than 70%, and carbon dioxide gas is lower than 20%. Simulation models of the steam gasification process have been carried out by ASPEN Plus and validated with both experimental data and simulation results from Nikoo & Mahinpey (2008. Gasification temperature of 911 °C, equivalence ratio of 0.18, and a steam-to-biomass ratio of 1.78, are considered as an optimal operation point to achieve energy self-sufficient condition. This operating point gives the maximum of carbon conversion efficiency at 91.03%, and carbon dioxide gas at 15.18 volumetric percentages. In this study, life cycle assessment (LCA is included to compare the environmental performance of conventional and energy self-sufficient gasification for steam biomass gasification.

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

    OpenAIRE

    Meng, X.(Institute of High Energy Physics, Beijing, China)

    2012-01-01

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

  20. Environmental assessment of the atlas bio-energy waste wood fluidized bed gasification power plant. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Holzman, M.I.

    1995-08-01

    The Atlas Bio-Energy Corporation is proposing to develop and operate a 3 MW power plant in Brooklyn, New York that will produce electricity by gasification of waste wood and combustion of the produced low-Btu gas in a conventional package steam boiler coupled to a steam-electric generator. The objectives of this project were to assist Atlas in addressing the environmental permit requirements for the proposed power plant and to evaluate the environmental and economic impacts of the project compared to more conventional small power plants. The project`s goal was to help promote the commercialization of biomass gasification as an environmentally acceptable and economically attractive alternative to conventional wood combustion. The specific components of this research included: (1) Development of a permitting strategy plan; (2) Characterization of New York City waste wood; (3) Characterization of fluidized bed gasifier/boiler emissions; (4) Performance of an environmental impact analysis; (5) Preparation of an economic evaluation; and (6) Discussion of operational and maintenance concerns. The project is being performed in two phases. Phase I, which is the subject of this report, involves the environmental permitting and environmental/economic assessment of the project. Pending NYSERDA participation, Phase II will include development and implementation of a demonstration program to evaluate the environmental and economic impacts of the full-scale gasification project.

  1. Biological removal of organic constituents in quench water from a slagging, fixed-bed coal-gasification pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Stamoudis, V C; Luthy, R G

    1980-02-01

    This study is part of an effort to assess the efficiency of activated-sludge treatment for removal of organic constituents from high-Btu coal-gasification pilot-plant quench waters. A sample of raw-gas quench water was obtained from the Grand Forks Energy and Technology Center's pilot plant, which employs the slagging, fixed-bed gasification process. The quench water generated in the processing of Indian Head lignite was pretreated to reduce ammonia and alkalinity, and then diluted and subjected to long-term biological treatment, followed by detailed characterization and analysis of organic constituents. The pretreated (influent) and treated (effluent) samples were extracted using a methylene chloride, pH-fractionation method to obtain acid, base, and neutral fractions, which were analyzed by capillary-column gas chromatography/mass spectrometry (GC/MS). Over 99% of the total extractable and chromatographable organic material in the influent acid fraction was composed of phenol and alkylated phenols. Biological treatment removed these compounds almost completely. Major components of the influent base fraction were alkylated pyridines, anilines, aminopyrroles, imidazoles and/or pyrazoles, diazines, and quinolines. Removal efficiency of these compounds ranged between 90 and 100%. The influent neutral fraction was composed mainly of cycloalkanes, cycloalkenes, naphthalene, indole, acetophenone, and benzonitrile. Alkylated benzenes were generally absent. Removal efficiencies of these compounds were generally very good, except for certain alkylated cycloalkanes and cycloalkenes. Results are compared with those of a similar study on HYGAS coal-gasification quench water.

  2. Biomass gasification and in-bed contaminants removal: performance of iron enriched olivine and bauxite in a process of steam/O2 gasification.

    Science.gov (United States)

    Barisano, D; Freda, C; Nanna, F; Fanelli, E; Villone, A

    2012-08-01

    A modified Olivine, enriched in iron content (10% Fe/Olivine), and a natural bauxite, were tested in the in-bed reduction of tar and alkali halides (NaCl and KCl) released in a process of biomass steam/O(2) gasification. The tests were carried out at an ICBFB bench scale reactor under the operating conditions of: 855-890 °C, atmospheric pressure, 0.5 steam/biomass and 0.33 ER ratios. From the use of the two materials, a reduction in the contaminant contents of the fuel gas produced was found. For the alkali halides, a decrease up to 70%(wt) was observed for the potassium concentration, while for sodium, the reduction was found to be quite poor. For the organic content, compared to unmodified Olivine, the chromatographically determined total tar quantity showed a removal efficiency of 38%(wt). Moreover, regarding the particulate content a rough doubling in the fuel gas revealed a certain brittleness of the new bed material.

  3. Theoretical investigation of tar conversion in fluidized-bed gasification processes; Theoretische Untersuchung des Teerumsatzes bei der Wirbelschichtvergasung

    Energy Technology Data Exchange (ETDEWEB)

    Hamel, S.; Hasselbach, H.; Krumm, W. [Siegen Univ., Inst. fuer Energietechnik (Germany)

    2002-07-01

    A mathematical model for simulating stationary fluidized-bed systems is used for a theoretical investigation of the influence of various operating parameters of atmospheric air/steam biomass gasification on the tars contained in the product gas. The variation of the evacuated tube velocity in the fluidized bed, the influence of fuel particle size, and the position of fuel supply are investigated in detail, followed by a discussion and plausibility assessment of the results. [German] Ein mathematisches Modell zur Simulation von stationaeren Wirbelschichtvergasern wird herangezogen, um den Einfluss verschiedener Betriebsparameter einer atmosphaerischen Luft/Dampf-Vergasung von Biomasse auf die im Produktgas enthaltenen Teere theoretisch zu untersuchen. Dabei wird neben der Variation der Leerrohrgeschwindigkeit im Wirbelbett, die Stufung der Vergasungsmittelzugabe, der Einfluss der Brennstoffpartikelgroesse und der Position der Brennstoffzufuhr detailliert untersucht. Es erfolgt eine eingehende Diskussion und Plausibilitaetsbetrachtung der Ergebnisse. (orig.)

  4. Fluidized bed gasification of the fuel fraction of municipal solid wastes; Gasificacion en lecho fluidizado de la fraccion combustible de los residuos solidos urbanos

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.; Baldasano, J. M.; Gasso, S. [Universidad Politecnica de Cataluna. Barcelona (Spain)

    1998-12-31

    In this paper, the results obtained in the application of the fluidized-bed gasification to the treatment of solid waste with high heating value. These wastes could be valuable materials in thermo conversion processes such as gasification. The combustible fraction of municipal solid waste (MSW) composed of paper, cardboard, plastics (PET,PVC), referred as refuse derived fuel (RDF), has been considered in this work. The experimental facility consists of an air-blown gasifier operating at atmospheric pressure with a capacity of 50 kg/h. The results obtained show that the gasification of RDF allows to produce a gas with a high heating value (HHV) of 7.8 Mj/Mn3 and recovering more than 80% of the initial HHV of the waste in the cold gas. Solid residue produced in the gasification process is lower than 10% of the initial waste. (Author)

  5. High temperature solid oxide fuel cell integrated with novel allothermal biomass gasification. Part II: Exergy analysis

    Science.gov (United States)

    Panopoulos, K. D.; Fryda, L.; Karl, J.; Poulou, S.; Kakaras, E.

    Biomass gasification derived gas is a renewable fuel, which can be used for SOFC applications. This work investigates the integration of a near atmospheric solid oxide fuel cell (SOFC) with a novel allothermal biomass steam gasification process into a combined heat and power (CHP) system of less than MW e range. Heat for steam gasification is supplied from SOFC depleted fuel in a fluidised bed (FB) combustor via high temperature sodium heat pipes. In the first paper, the integrated system was modelled in Aspen Plus™ and critical aspects for its feasibility were identified. The aim of this second part is the evaluation of the integrated system in exergy terms. Satisfying allothermal gasification heat demand is illustrated by examining each sub-process involved separately as well as combined. For a relatively low STBR = 0.6, the SOFC fuel utilisation for which the system operates under optimum conditions is U f = 0.7. Above that value additional biomass has to be used in the FB combustor to provide gasification heat with considerable exergy losses. For SOFC operation at current density 2500 A m -2, the system uses 90 kg h -1 biomass, operates with electrical exergetic efficiency 32% producing 140 kW e, while the combined electrical and thermal exergetic efficiency is 35%.

  6. Hydrogen production via thermal gasification of biomass in near-to-medium term

    Energy Technology Data Exchange (ETDEWEB)

    Hannula, I.

    2009-09-15

    Dedicated biomass gasification technologies are presently being developed in many countries for the production of second-generation liquid biofuels. Both fluidised-bed gasification and special entrained flow systems are under intensive development. These technologies can also be used for hydrogen production, which may become an interesting alternative in replacing part of fossil fuel input in oil refineries and chemical industries. In addition, fuel cell technology is being developed for hydrogen-rich gases. New and revolutionary production methods, capable of replacing the classical process routes, can not however be foreseen to emerge in the medium-term. Also the new hydrogen separation technologies, presently under development, seem to have only limited potential to reduce the production cost of hydrogen compared to commercially available technology. However, with rising prices of fossil fuels and locally depleting natural gas reserves, gasification route is likely to gain more ground as a credible production technology for hydrogen. The global needs to cut down the CO{sub 2} emissions can also make gasification of biomass an interesting possibility. Several biomass gasification processes are presently at demonstration phase, mostly aimed for the production of liquid transportation fuels. If and when this technology will be commercialized, it could easily be adopted to the production of hydrogen. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-01

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

  8. Advanced biomass gasification for high-efficiency power. Final activity report of BiGPower Project

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Kurkela, M. (eds.)

    2009-11-15

    The BiGPower project was related to the development of 2nd generation high-efficiency biomass-to-electricity technologies, which have the potential to meet the targets of cost effective electricity production from wide range of biomass and waste fuels in size ranges typical to locally available feedstock sources (below 100 MW{sub e}). This project was designed to create the fundamental and technical basis for successful future industrial developments and demonstration projects aiming to commercial breakthrough by 2010-2020. This overall aim was approached by carrying out in pre-competitive manner well-focused R and D activities on the key bottlenecks of advanced biomass gasification power systems. Three promising European gasification technologies in this target size range were selected to form the basis for the development: 1) air-blow novel fixed-bed gasifier for size range of 0.5-5 MWe, 2) steam gasification in a dual-fluidisedbed gasifier for 5-50 MWe and 3) air-blown pressurised fluidised-bed gasification technology for 5-100 MWe. In all biomass gasification processes, the product gas contains several types of gas contaminants, which have to be efficiently removed before utilising the gas in advanced power systems. The key technical solutions developed in the BiGPower project were: a) high-temperature catalytic removal of tars and ammonia by new catalytic methods, and b) development of innovative low cost gas filtration. Three most potential power production cycle alternatives were examined and developed: 1) gas engines, 2) molten carbonate fuel cells (MCFC) and 3) the simplified Integrated Gasification Combined Cycle (IGCC) process. The performance and techno-economic feasibility of these advanced gasification-topower concepts were examined by carrying out case studies in different European Union. (orig.)

  9. Coal gasification by indirect heating in a single moving bed reactor: Process development & simulation

    Directory of Open Access Journals (Sweden)

    Junaid Akhlas

    2015-10-01

    Full Text Available In this work, the development and simulation of a new coal gasification process with indirect heat supply is performed. In this way, the need of pure oxygen production as in a conventional gasification process is avoided. The feasibility and energetic self-sufficiency of the proposed processes are addressed. To avoid the need of Air Separation Unit, the heat required by gasification reactions is supplied by the combustion flue gases, and transferred to the reacting mixture through a bayonet heat exchanger installed inside the gasifier. Two alternatives for the flue gas generation have been investigated and compared. The proposed processes are modeled using chemical kinetics validated on experimental gasification data by means of a standard process simulator (Aspen PlusTM, integrated with a spreadsheet for the modeling of a special type of heat exchanger. Simulation results are presented and discussed for proposed integrated process schemes. It is shown that they do not need external energy supply and ensure overall efficiencies comparable to conventional processes while producing syngas with lower content of carbon dioxide.

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

    Energy Technology Data Exchange (ETDEWEB)

    Song, W.

    2003-12-15

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

  11. Fates and roles of alkali and alkaline earth metal species during the pyrolysis and gasification of a Victorian lignite

    Energy Technology Data Exchange (ETDEWEB)

    Mody, D.; Wu, H.; Li, C. [Monash University, Vic. (Australia). CRC for Clean Power from Lignite, Dept. of Chemical Engineering

    2000-07-01

    The transformation of alkali and alkaline earth metal (AAEM) species in a Victorian lignite during the pyrolysis and subsequent gasification in CO{sub 2} was studied in a novel quartz fluidised-bed reactor. Lignite samples prepared by physically adding NaCl and ion-exchanging Na{sup +} and Ca{sup ++} into the lignite were used to investigate the effects of chemical forms and valency of the AAEM species in the substrate lignite on their transformation during pyrolysis and gasification. Carboxyl-bound Na was found to be less volatile than Na present as NaCl, but more volatile than carboxyl-bound Ca during pyrolysis at temperatures between 400 and 900{sup o}C. However, the carboxyl-bound Na was volatilised to a much greater extent than the carboxyl-bound Ca in the same lignite during pyrolysis. It was seen that the loading of NaCl into the lignite did not significantly affect the char reactivity in the fluidised-bed reactor at 900{sup o}C.

  12. Power generation based on biomass by combined fermentation and gasification--a new concept derived from experiments and modelling.

    Science.gov (United States)

    Methling, Torsten; Armbrust, Nina; Haitz, Thilo; Speidel, Michael; Poboss, Norman; Braun-Unkhoff, Marina; Dieter, Heiko; Kempter-Regel, Brigitte; Kraaij, Gerard; Schliessmann, Ursula; Sterr, Yasemin; Wörner, Antje; Hirth, Thomas; Riedel, Uwe; Scheffknecht, Günter

    2014-10-01

    A new concept is proposed for combined fermentation (two-stage high-load fermenter) and gasification (two-stage fluidised bed gasifier with CO2 separation) of sewage sludge and wood, and the subsequent utilisation of the biogenic gases in a hybrid power plant, consisting of a solid oxide fuel cell and a gas turbine. The development and optimisation of the important processes of the new concept (fermentation, gasification, utilisation) are reported in detail. For the gas production, process parameters were experimentally and numerically investigated to achieve high conversion rates of biomass. For the product gas utilisation, important combustion properties (laminar flame speed, ignition delay time) were analysed numerically to evaluate machinery operation (reliability, emissions). Furthermore, the coupling of the processes was numerically analysed and optimised by means of integration of heat and mass flows. The high, simulated electrical efficiency of 42% including the conversion of raw biomass is promising for future power generation by biomass.

  13. Principles of a novel multistage circulating fluidized bed reactor for biomass gasification

    NARCIS (Netherlands)

    Kersten, Sascha R.A.; Prins, Wolter; Drift, van der Bram; Swaaij, van Wim P.M.

    2003-01-01

    In this paper a novel multistage circulating fluidized bed reactor has been introduced. The riser of this multistage circulating fluidized bed consists of several segments (seven in the base-case design) in series each built-up out of two opposite cones. Due to the specific shape, a fluidized bed ar

  14. Experimental and Modeling Investigation of Coal Gasification in a Fluidized Bed Reactor

    Institute of Scientific and Technical Information of China (English)

    CuiLin; ShenYouting; 等

    1996-01-01

    This paper presents a new approach to study the process of coal gasification.Non-linear programming techniques are used to determine the value of the model parameters that depends on coal species and experimental conditions and thus minimize the difference between experimental results and model predictions.Model predictions being in good agreement with the experimental results show that this method of combining model with experiment is effective for modeling complex processes.

  15. Soil application of ash produced by low-temperature fluidized bed gasification: effects on soil nutrient dynamics and crop response

    DEFF Research Database (Denmark)

    Müller-Stöver, Dorette Sophie; Ahrenfeldt, Jesper; Holm, Jens Kai

    2012-01-01

    Recycling of residual products of bioenergy conversion processes is important for adding value to the technologies and as a potential beneficial soil fertility amendment. In this study, two different ash materials originating from low temperature circulating fluidized bed (LT-CFB) gasification...... of either wheat straw (SA) or residue fibers mainly from citrus peels (CP) were tested regarding their potential to be used as fertilizer on agricultural soils. A soil incubation study, a greenhouse experiment with barley and faba bean, and an accompanying outdoor experiment with maize were carried out...... to investigate the effects of the ashes on soil microbiological and chemical properties and on the response of the three crops. The ash treatments were compared with a control treatment that received only nitrogen, magnesium, and sulphur (CO) and a fully fertilized control (COPK). Soil microbial parameters were...

  16. Optimization of a Bubbling Fluidized Bed Plant for Low-Temperature Gasification of Biomass

    Directory of Open Access Journals (Sweden)

    María Pilar González-Vázquez

    2017-03-01

    Full Text Available Investigation into clean energies has been focused on finding an alternative to fossil fuels in order to reduce global warming while at the same time satisfying the world’s energy needs. Biomass gasification is seen as a promising thermochemical conversion technology as it allows useful gaseous products to be obtained from low-energy-density solid fuels. Air–steam mixtures are the most commonly used gasification agents. The gasification performances of several biomass samples and their mixtures were compared. One softwood (pine and one hardwood (chestnut, their torrefied counterparts, and other Spanish-based biomass wastes such as almond shell, olive stone, grape and olive pomaces or cocoa shell were tested, and their behaviors at several different stoichiometric ratios (SR and steam/air ratios (S/A were compared. The optimum SR was found to be in the 0.2–0.3 range for S/A = 75/25. At these conditions a syngas stream with 35% of H2 + CO and a gas yield of 2 L gas/g fuel were obtained, which represents a cold-gas efficiency of almost 50%. The torrefaction process does not significantly affect the quality of the product syngas. Some of the obtained chars were analyzed to assess their use as precursors for catalysts, combustion fuel or for agricultural purposes such as soil amendment.

  17. In bed and downstream hot gas desulphurization during solid fuel gasification: A review

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Xiangmei; de Jong, Wiebren; Pal, Ranadeep; Verkooijen, Adrian H.M. [Faculty of Mechanical, Maritime and Materials Engineering, Process and Energy Department, Energy Technology Section, Delft University of Technology, Leeghwaterstraat 44, 2628 CA, Delft (Netherlands)

    2010-08-15

    Syngas produced by gasification process of biomass fuels is an environmental friendly alternative to conventional petrochemical fuels for the production of electricity, hydrogen, synthetic transportation biofuels and other chemicals. However, the advanced utilization of syngas is significantly limited due to the contaminants which can seriously deactivate the catalysts used for downstream reaction such as steam reforming methane, Fischer-Tropsch synthesis and corrosion of downstream equipments such as a gas turbine. Among the contaminants, sulphur compounds produced in the gasification process, which are mainly H{sub 2}S with small amounts of COS, CS{sub 2} and thiophenes depending on process conditions, must be removed. For biomass feedstock advances are required in the cleanup technologies and processes to upgrade the raw product gas with minimal impact on the overall process efficiency. Hot gas desulphurization (HGD) can improve the overall thermal efficiency due to the elimination of fuel gas cooling and associated heat exchangers. With this aim, the present review paper highlights currently developed methods used for desulphurization of hot gas produced from gasification process of solid fuels. The methods presented here are for both in situ and downstream sulphur capture. Also, the attention is paid to the regeneration of the used materials. In situ sulphur capture is mainly done by using calcium-based sorbents such as limestone and dolomite, whereas downstream sulphur capture is mainly focused on the use of regenerable single, mixed, and supported metal oxides. A comparison is indicated at the end to show the sulphur loading of various materials. (author)

  18. Transformation of chlorine in NaCl-loaded Victorian brown coal during the gasification in steam

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu; Mohammad Asadullah; Rosalie Hocking; LIN Jian-ying; LI Chun-zhu

    2012-01-01

    This study is to examine the changes in Cl volatilizations and chemical forms in NaCl-loaded Victorian brown coal during gasification in steam at 800 ℃ using Cl K-edge X-ray absorption near-edge structure (XANES) spectroscopy.The char samples were prepared in a novel one-stage fluidised-bed/fixed-bed quartz reactor at a fast heating rate.The samples were then collected and sealed in an argon-filled bag in order to minimise possible oxidation of char and Cl by air prior to analysis by XANES.Char-steam reactions were found to significantly affect the transformation of Cl,including the possible formation of chlorine-containing organic structures.On the other hand,volatile-char interactions during the gasificauon appeared to enhance the Cl retention and prevent the formation of organic chlorine compounds in chars.

  19. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer

    DEFF Research Database (Denmark)

    Thomsen, Tobias Pape; Hauggaard-Nielsen, Henrik; Gøbel, Benny

    2017-01-01

    to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottomashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded thatLT-CFB gasification and co-gasification is a highly effective way to purify...

  20. Gasification system

    Science.gov (United States)

    Haldipur, Gaurang B.; Anderson, Richard G.; Cherish, Peter

    1983-01-01

    A method and system for injecting coal and process fluids into a fluidized bed gasification reactor. Three concentric tubes extend vertically upward into the fluidized bed. Coal particulates in a transport gas are injected through an inner tube, and an oxygen rich mixture of oxygen and steam are injected through an inner annulus about the inner tube. A gaseous medium relatively lean in oxygen content, such as steam, is injected through an annulus surrounding the inner annulus.

  1. High temperature solid oxide fuel cell integrated with novel allothermal biomass gasification. Part I: Modelling and feasibility study

    Science.gov (United States)

    Panopoulos, K. D.; Fryda, L. E.; Karl, J.; Poulou, S.; Kakaras, E.

    Biomass gasification derived fuel gas is a renewable fuel that can be used by high temperature fuel cells. In this two-part work an attempt is made to investigate the integration of a near atmospheric pressure solid oxide fuel cell (SOFC) with a novel allothermal biomass steam gasification process into a combined heat and power (CHP) system of less than MW e nominal output range. Heat for steam gasification is supplied from SOFC depleted fuel into a fluidised bed combustor via high temperature sodium heat pipes. The integrated system model was built in Aspen Plus™ simulation software and is described in detail. Part I investigates the feasibility and critical aspects of the system based on modelling results. A low gasification steam to biomass ratio (STBR = 0.6) is used to avoid excess heat demands and to allow effective H 2S high temperature removal. Water vapour is added prior to the anode to avoid carbon deposition. The SOFC off gases adequately provide gasification heat when fuel utilisation factors are f = 0.7 and current density 2500 A m -2 the electrical efficiency is estimated at 36% while thermal efficiency at 14%. An exergy analysis is presented in Part II.

  2. DEVELOPMENT OF PRESSURIZED CIRCULATIONG FLUIDIZED BED PARTIAL GASIFICATION MODULE(PGM)

    Energy Technology Data Exchange (ETDEWEB)

    Archie Robertson

    2003-04-17

    Foster Wheeler Power Group, Inc. is working under US Department of Energy contract No. DE-FC26-00NT40972 to develop a partial gasification module (PGM) that represents a critical element of several potential coal-fired Vision 21 plants. When utilized for electrical power generation, these plants will operate with efficiencies greater than 60% and produce near zero emissions of traditional stack gas pollutants. The new process partially gasifies coal at elevated pressure producing a coal-derived syngas and a char residue. The syngas can be used to fuel the most advanced power producing equipment such as solid oxide fuel cells or gas turbines, or processed to produce clean liquid fuels or chemicals for industrial users. The char residue is not wasted; it can also be used to generate electricity by fueling boilers that drive the most advanced ultra-supercritical pressure steam turbines. The amount of syngas and char produced by the PGM can be tailored to fit the production objectives of the overall plant, i.e., power generation, clean liquid fuel production, chemicals production, etc. Hence, PGM is a robust building block that offers all the advantages of coal gasification but in a more user-friendly form; it is also fuel flexible in that it can use alternative fuels such as biomass, sewerage sludge, etc. This report describes the work performed during the January 1--March 31, 2003 time period.

  3. Application of fluidised particles as turbulence promoters in ultrafiltration Improvement of flux and rejection

    NARCIS (Netherlands)

    Noordman, TR; de Jonge, A; Wesselingh, JA; Bel, W; Dekker, M; Ter Voorde, E; Grijpma, SD

    2002-01-01

    To prevent fouling of ultrafiltration membranes during processing of protein solutions, a high degree of turbulence should be introduced in the feed solution, keeping the energy consumption as low as possible. For this purpose, the application of fluidised beds at the upstream side of the membrane c

  4. Development of a bi-equilibrium model for biomass gasification in a downdraft bed reactor.

    Science.gov (United States)

    Biagini, Enrico; Barontini, Federica; Tognotti, Leonardo

    2016-02-01

    This work proposes a simple and accurate tool for predicting the main parameters of biomass gasification (syngas composition, heating value, flow rate), suitable for process study and system analysis. A multizonal model based on non-stoichiometric equilibrium models and a repartition factor, simulating the bypass of pyrolysis products through the oxidant zone, was developed. The results of tests with different feedstocks (corn cobs, wood pellets, rice husks and vine pruning) in a demonstrative downdraft gasifier (350kW) were used for validation. The average discrepancy between model and experimental results was up to 8 times less than the one with the simple equilibrium model. The repartition factor was successfully related to the operating conditions and characteristics of the biomass to simulate different conditions of the gasifier (variation in potentiality, densification and mixing of feedstock) and analyze the model sensitivity.

  5. Direct Causticizing for Black Liquor Gasification in a Circulating Fluidized Bed

    Energy Technology Data Exchange (ETDEWEB)

    Scott Sinquefield; Xiaoyan Zeng, Alan Ball

    2010-03-02

    Gasification of black liquor (BLG) has distinct advantages over direct combustion in Tomlinson recovery boilers. In this project we seek to resolve causticizing issues in order to make pressurized BLG even more efficient and cost-effective. One advantage of BLG is that the inherent partial separation of sulfur and sodium during gasification lends itself to the use of proven high yield variants to conventional kraft pulping which require just such a separation. Processes such as polysulfide, split sulfidity, ASAQ, and MSSAQ can increase pulp yield from 1% to 10% over conventional kraft but require varying degrees of sulfur/sodium separation, which requires additional [and costly] processing in a conventional Tomlinson recovery process. However during gasification, the sulfur is partitioned between the gas and smelt phases, while the sodium all leaves in the smelt; thus creating the opportunity to produce sulfur-rich and sulfur-lean white liquors for specialty pulping processes. A second major incentive of BLG is the production of a combustible product gas, rich in H2 and CO. This product gas (a.k.a. “syngas”) can be used in gas turbines for combined cycle power generation (which is twice as efficient as the steam cycle alone), or it can be used as a precursor to form liquid fuels, such as dimethyl ether or Fischer Tropsh diesel. There is drawback to BLG, which has the potential to become a third major incentive if this work is successful. The causticizing load is greater for gasification of black liquor than for combustion in a Tomlinson boiler. So implementing BLG in an existing mill would require costly increases to the causticizing capacity. In situ causticizing [within the gasifier] would handle the entire causticizing load and therefore eliminate the lime cycle entirely. Previous work by the author and others has shown that titanate direct causticizing (i.e. in situ) works quite well for high-temperature BLG (950°C), but was limited to pressures below

  6. On-line measurement of raw gas elemental composition in fluidized bed biomass steam gasification

    Energy Technology Data Exchange (ETDEWEB)

    Neves, D. [Dept. of Environment and Planning, Centre of Environmental and Marine Studies, Univ. of Aveiro, Campus Universitario de Santiago, Aveiro (Portugal); Dept. of Energy and Environment, Chalmers Univ. of Technology, Goeteborg (Sweden); Thunman, H.; Larsson, A.; Seemann, M. [Dept. of Energy and Environment, Chalmers Univ. of Technology, Goeteborg (Sweden); Tarelho, L.; Matos, A. [Dept. of Environment and Planning, Centre of Environmental and Marine Studies, Univ. of Aveiro, Campus Universitario de Santiago, Aveiro (Portugal)

    2012-11-01

    At the present stage of technology development pursuing to achieve unattended gasification processes, the available methods to determine the CHON composition of raw gas involve a great deal of laboratory tasks, making it unpractical, time-consuming and costly. For instance, there are available analyzers to measure the chemical composition of dry raw gas but offline methods are used to determine the liquids (organic compounds + water). An alternative that is investigated in this work is to convert the raw gas first into simple product species that are easily analyzed. The straightforward way to achieve this is to burn the gas with proper amount of oxygen to assure quantitative conversion into CO{sub 2}, H{sub 2}O and N{sub 2}. This method is demonstrated here by monitoring the CHON composition of raw gas with high temporal resolution from Chalmers 2MW{sub th} FB gasifier.

  7. 生物质鼓泡流化床和循环流化床气化对比试验%Comparison of Bubbling Fluidized Bed and Circulating Fluidized Bed in Gasification of Biomass

    Institute of Scientific and Technical Information of China (English)

    范晓旭; 贤建伟; 初雷哲; 杨立国

    2011-01-01

    在内径为φ0.2 m、高6 m的流化床装置上,利用两种不同粒径的石英砂,分别进行了高速鼓泡流化床(BFB)和循环流化床(CFB)的冷态压力分布试验和热态气化试验.结果表明:冷态试验中,鼓泡流化床压力分布主要集中在底部的密相区,循环流化床压力分布更趋均匀.热态稳定气化阶段,循环流化床轴向温差只有40℃,气化的燃气热值、碳转化率和气化效率均高于鼓泡流化床.%The results from biomass gasification in a pilot-scale (6m tall × 0. 2 m internal diameter) air-blown circulating fluidized bed gasifier was tested and compared with bubbling fluidized bed gasifier. The results showed that the diameters of bed material in bubbling fluidized bed and circulating fluidized bed were different. The bubbling fluidized bed had a dense zone and bed material was homogeneous distribution in circulating fluidized bed. The temperature of the circulating fluidized bed was more uniform than bubbling fluidized bed. The carbon conversion rate, gasification efficiency and low gas heat value of circulating fluidized bed were larger than that of bubbling fluidized bed gasifier.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  9. Coffee parchment in fluidisation

    Directory of Open Access Journals (Sweden)

    Elkin Mauricio López Fontal

    2010-07-01

    Full Text Available All coffee is harvested as cherry grains which are then crushed and extracted traditionally or by applying the Becolsub method. Once the coffee parchment obtained has been washed, it is naturally or mechanically dried. Static dryers are the most used mechanical dryers, generally producing lack of uniformity in the grain’s final humidity content which must range from 10% to 12% b.h. Drying by fluidization was used in the present research work; this turns a solid particle bed into a suspended and expanded mass, possessing many of the properties of a liquid. A 5,000 g capacity prototype was designed and constructed in which coffee was dried at three air drying temperatures: 42°C, 46°C and 49°C; drying time lasted 6 to 8 hours. Good uniformity in final grain humidity content was obtained, differences being less than 0.86%. As well as the grain test, a control cup test was used, finding that the product presented good organoleptic qualities.

  10. PFB air gasification of biomass. Investigation of product formation and problematic issues related to ammonia, tar and alkali

    Energy Technology Data Exchange (ETDEWEB)

    Padban, Nader

    2000-09-01

    Fluidised bed thermal gasification of biomass is an effective route that results in 100 % conversion of the fuel. In contrast to chemical, enzymatic or anaerobic methods of biomass treatment, the thermal conversion leaves no contaminated residue after the process. The product gas evolved within thermal conversion can be used in several applications such as: fuel for gas turbines, combustion engines and fuel cells, and raw material for production of chemicals and synthetic liquid fuels. This thesis treats a part of the experimental data from two different gasifiers: a 90 kW{sub th} pressurised fluidised bubbling bed gasifier at Lund University and a 18 MW{sub th} circulating fluidised bed gasifier integrated with gas turbine (IGCC) in Vaernamo. A series of parallel and consecutive chemical reactions is involved in thermal gasification, giving origin to formation of a variety of products. These products can be classified within three major groups: gases, tars and oils, and char. The proportion of these categories of species in the final product is a matter of the gasifier design and the process parameters. The thesis addresses the technical and theoretical aspects of the biomass thermochemical conversion and presents a new approach in describing the gasification reactions. There is an evidence of fuel effect on the characteristics of the final products: a mixture of plastic waste (polyethylene) and biomass results in higher concentration of linear hydrocarbons in the gas than gasification of pure biomass. Mixing the biomass with textile waste (containing aromatic structure) results in a high degree of formation of aromatic compounds and light tars. Three topic questions within biomass gasification, namely: tar, NO{sub x} and alkali are discussed in the thesis. The experimental results show that gasification at high ER or high temperature decreases the total amount of the tars and simultaneously reduces the contents of the oxygenated and alkyl-substituted poly

  11. About the gasification of untreated scrap and waste wood in fluidized bed reactor for use in decentralized gas engine-cogeneration plants; Zur Vergasung von Rest- und Abfallholz in Wirbelschichtreaktoren fuer dezentrale Energieversorgungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Tepper, H.

    2005-10-20

    This dissertation examines the thermochemical conversion (gasification) of untreated scrap and waste wood in combustible gases for use in decentralized gas engine-cogeneration plants of low output (1 to 10 MW fuel power). A general section goes into the basics of the energetic utilization of solid biomass, the subprocesses of thermochemical conversion being described in more detail. Special attention is given to the processes and state of the art of biomass gasification in decentralized plants. A theoretical section analyzes the gasification models for solid biomass presented in the literature. Based on this analysis, a simplified kinetic model is derived for the gasification of untreated scrap and waste wood with air in bubbling fluidized bed reactors. It includes a fluid mechanic analysis of the fluidized bed based on HILLIGARDT, an empirical pyrolysis model and a global kinetic approach to the main chemical reaction taken from the literature. An experimental section describes the tests of the gasification of forest scrap wood in a semi-industrial fluidized bed gasification test plant with 150 kW fuel power and presents the significant test results. The gasification model derived is applied to check the test plant's standard settings and compare them with measured values. Furthermore, the model is employed to explain basic reaction paths and zones and to perform concluding parameter simulations. (orig.)

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

    Science.gov (United States)

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

    2012-04-01

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

  13. Flow behavior inside a novel rotating fluidized bed for solar gasification of biomass

    Science.gov (United States)

    Lu, Zhao; Jafarian, Mehdi; Chinnici, Alfonso; Arjomandi, Maziar; Nathan, Graham J.

    2017-06-01

    The present paper reports a numerical investigation of the iso-thermal flow field and particle deposition onto the reactor window of a novel concept of Rotating Fluidized Bed Solar Reactor (RFBSR) and their sensitivity to reactor inner diameter. The RFBSR differs from conventional fluidized bed solar reactors in that it relies on the centrifugal force generated through rotation to counteract the drag force produced by the fluidizing gas on the particles. A three dimensional Computational Fluid Dynamics (CFD) model of the RFBSR was developed and combined with a Lagrangian particle tracking model to investigate the flow velocity components at various locations and particle concentration onto the window surface. The CFD model was partially verified by comparing its predictions with the published experimental measurements in a rotating porous cylindrical vessel with a radially injected flow. It was found that the Baseline Reynold Stress Model (RSM BSL) produces more agreeable predictions with the experimental measurements than Re-Normalization Group (RNG) k-ɛ and k-ω Shear Stress Transport (SST) models. Also, it was found that for the reactor configurations investigated here, reducing the reactor diameter has the effects of increasing the core axial flow velocity and particle deposition onto the window. The results presented assist in developing an understanding of the operation of the RFBSR.

  14. Biomass staged-gasification characteristics in high-temperature entrained-flow bed%生物质高温气流床分级气化特性

    Institute of Scientific and Technical Information of China (English)

    陈超; 周劲松; 项阳阳; 顾珊; 骆仲泱

    2015-01-01

    为了满足生物质间接液化中对合成气组成的要求,特别是H2与CO体积比要达到1.0~2.0,采用生物质低温热解炉结合高温气流床的生物质分级气化系统,研究气流床分级气化方式对生物质气化合成气的影响.针对温度、一次气化时间等因素,研究合成气组分、H2与CO体积比、碳转化率、气化效率以及焦油质量浓度等方面的变化情况.结果表明,生物质分级气化和温度的升高均能够提高 H2与CO体积比.生物质分级气化系统的最佳工况是一次气化时间为0.6 s ,当气化温度为1100℃时,此时气化效果最好,气化效率达到75%,H2与CO体积比可达1.22,碳转化率达到96.3%.分级气化合成气中焦油质量浓度比传统气化明显减少,从5.46 g/m3降低到了50 mg/m3.%The raw material requirements for the indirect liquefaction of biomass are strict .The volume ratio of H2 to CO must be greater than or equal to 1 .0~2 .0 .The effect on biomass gasification syngas in staged‐gasification of biomass was analyzed .Biomass staged‐gasification system contained low temperature biomass pyrolysis furnace and high temperature entrained‐flow bed . Influence factors were studied including gasification temperature and first gasification time . T he result investigation contained composition of syngas ,volume ratio of H2 to CO ,carbon conversion ratio ,gasification efficiency and tar mass concentration . Results show that staged‐gasification and increasing temperature can enhance the volume ratio of H2 to CO .The optimum condition of staged gasification was the first gasification time at 0 .6 s and gasification temperature at 1 100 ℃ . The result was best in the conditions . Gasification efficiency was up to 75% ,the volume ratio of H2 to CO reached the maximum at 1 .22 ,and carbon conversion was up to 96 .3% .The tar mass concentration was decreased from 5 .46 g/m3 to 50 mg/m3 .

  15. Hydrodynamics of Biomass Gasification in a Dual Chamber Circulating Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    Wahyu Haifa

    2016-01-01

    Full Text Available This paper presents work on hydrodynamics of several types of biomass mixture in a dual chamber circulating fluidized bed. In designing the CFBreactornecessary to know the distribution of solid particles radially and axially influenced by fluidizing gas velocity, particle size, solid circulation flux, reactor diameter and height of the reactor. These factors will affect pressure drop along the riser of the reaction chamber. Pressure drop is an important factor in the study of hydrodynamics of particle flow. The pressure drop was measured using mathematical model compared to experimental results done on a cold mode. Since it was found that both results were consistent which means that the model can be used to predict the operating parameters of CFB design.

  16. Sewage sludge gasification in fluidized bed: influence of temperature and the stoichiometric relation; Gasificacion de fangos de depuradora en lecho fluidizado: influencia de la temperatura y de la relacion estequiometrica

    Energy Technology Data Exchange (ETDEWEB)

    Manya, J.J.; Gonzalo, A.; Sanchez, J.L.; Arauzo, J. [Universidad de Zaragoza, Aragon (Spain). Inst. de Investigacion en Ingenieria. Grupo de Procesos Termoquimicos; Rocha, J.D. [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico (NIPE); Mesa Perez, J.M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Agricola (FEAGRI)

    2004-07-01

    The gasification of a dry granular sewage sludge has been experimentally studied. The gasification was carried out in a bench scale BFB facility, operated at steady state. The attention was focused on the presence of tar in the produced gas which affect the process efficiency and give negative drawbacks in the utilization in motors. The influence of two operating variables (bed temperature and equivalence ratio) on the gasification performances has been explored. Results show that the composition of produced gas is quite dependent of the variables analyzed. However, the results of tar yield show an unexpected behaviour. (author)

  17. Hydrogen production from biomass over steam gasification

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, R.; Potetz, A.; Hofbauer, H. [Vienna Univ. of Technology (Austria). Inst. of Chemical Engineering; Weber, G. [Bioenergy 2020+, Guessing (Austria)

    2010-12-30

    Renewable hydrogen is one option for a clean energy carrier in the future. There were several research programs in the past, to produce hydrogen on a renewable basis by electrolysis, direct conversion of water or by gasification of biomass. None of these options were developed to a stage, that they could be used on a commercial basis. At the moment almost all hydrogen is produced from fossil fuels and one main consumer of hydrogen are refineries. So a good option to demonstrate the production of renewable hydrogen and bring it later into the market is over refineries. The most economic option to produce renewable hydrogen at the moment is over gasification of biomass. In Austria an indirect gasification system was developed and is demonstrated in Guessing, Austria. The biomass CHP Guessing uses the allothermal steam dual fluidised bed gasifier and produces a high grade product gas, which is used at the moment for the CHP in a gas engine. As there is no nitrogen in the product gas and high hydrogen content, this gas can be also used as synthesis gas or for production of hydrogen. The main aim of this paper is to present the experimental and simulation work to convert biomass into renewable hydrogen. The product gas of the indirect gasification system is mainly hydrogen, carbon monoxide, carbon dioxide and methane. Within the ERA-Net project ''OptiBtLGas'' the reforming of methane and the CO-shift reaction was investigated to convert all hydrocarbons and carbon monoxide to hydrogen. On basis of the experimental results the mass- and energy balances of a commercial 100 MW fuel input plant was done. Here 3 different cases of complexity of the overall plant were simulated. The first case was without reforming and CO-shift, only by hydrogen separation. The second case was by including steam - reforming and afterwards separation of hydrogen. The third case includes hydrocarbon reforming, CO-shift and hydrogen separation. In all cases the off-gases (CO

  18. Hydrogen-rich gas production by steam gasification of char from biomass fast pyrolysis in a fixed-bed reactor: influence of temperature and steam on hydrogen yield and syngas composition.

    Science.gov (United States)

    Yan, Feng; Luo, Si-yi; Hu, Zhi-quan; Xiao, Bo; Cheng, Gong

    2010-07-01

    Steam gasification experiments of biomass char were carried out in a fixed-bed reactor. The experiments were completed at bed temperature of 600-850 degrees C, a steam flow rate of 0-0.357 g/min/g of biomass char, and a reaction time of 15min. The aim of this study is to determine the effects of bed temperature and steam flow rate on syngas yield and its compositions. The results showed that both high gasification temperature and introduction of proper steam led to higher yield of dry gas and higher carbon conversion efficiency. However, excessive steam reduced gas yield and carbon conversion efficiency. The maximum dry gas yield was obtained at the gasification temperature of 850 degrees C and steam flow rate of 0.165 g/min/g biomass char.

  19. CFB gasification of biomass residues for co-combustion in large utility boilers studies on ash control and gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Moilanen, A.; Nieminen, M. [VTT Energy, Espoo (Finland)

    1999-07-01

    The woody residues of mechanical and chemical wood industry as well as other high-grade woody biofuels can be co-combusted with coal in existing fluidised- bed boilers or even in pulverised combustors without major problems. On the other hand, extensive full-scale test programmes carried out with straw in Denmark and with various agrobiofuels in the United States have clearly shown the limitations of this type of co-combustion methods. Many potential biomass feedstocks, such as straw, have a problematic ash melting behaviour, which causes sintering and fouling problems in combustors. Straw and many fast-growing energy crops as well as industrial and municipal waste fuels often contain high amounts of chlorine and alkali metals, which have a tendency to cause severe corrosion problems in coal-fired boilers. This problem can be assumed to be more severe in the modern plants where supercritical steam values are utilised. Perhaps the most critical factor controlling possibilities for direct co-firing of these problematic biofuels in large PC boilers is the usability of coal ash for cement industry and construction purposes. Demolition wood waste is another example of a locally important renewable feedstock, which is difficult to be introduced into ordinary coal-based combustion plants due to the relatively high content of heavy metals (Zn,Pb, Cd) and chlorine. In principle, there are three main technical solutions to avoid sintering, corrosion and ash problems in co-utilisation of problematic biofuels in large coal-fired power plants: Construction of a smaller separate boiler with low steam values for the biofuels and superheating the steam of the biomass boiler in the coal-fired boiler. Production of pyrolysis oils from the biomass, and Gasification of biomass and combustion of cleaned product gas in the boiler. The concept based on gasification has several advantages over the other alternatives. First of all the gasification reactor, bubbling or circulating fluidised-bed

  20. Numerical Simulation of Biomass Gasification in a Fluidized Bed%流化床中生物质气化的数值模拟

    Institute of Scientific and Technical Information of China (English)

    李乾军; 潘效军; 张东平; 蒋斌

    2011-01-01

    基于欧拉多相流模型,自编化学反应子模型,通过建立生物质流化床气化动力学模型,对某实验室规模的流化床生物质气化炉进行了数值模拟,研究了蒸汽与生物质的质量比(mS/mB)、生物质粒径对产气组分、蒸汽分解率等的影响.结果表明:mS/mB增大,H2体积分数先上升后保持不变,而CO和CH4的体积分数先下降后几乎不变,蒸汽分解率下降;生物质粒径减小有利于气化过程,使CO和H2的体积分数明显上升;计算结果和试验结果基本吻合,表明基于欧拉多相流的动力学模型能对流化床中生物质的气化进行比较准确的模拟.%Based on Euler multiphase flow models and self-developed chemical reaction models,the dynamical model of biomass gasification in a fluidized bed was set up,with which numerical simulation was carried out to biomass gasification in a lab-scale biomass fluidized bed,so as to study the effect of mass ratio of steam and biomass(mS/mB) and biomass particle size on the gas composition and steam decomposition rate.Results show that with the rise of mS/mB,the volume fraction of H2 rises firstly and then remains unchanged,and that of CO and CH4 decreases firstly and then gets stable,while the steam decomposition rate drops gradually.The reduction of biomass particle size is in favor of the gasification process,which makes the volume fraction of CO and H2 rise.Simulation results basically agree with that of experiments,indicating that the dynamical model based on Euler multiphase flow can be used to simulate the biomass gasification in fluidized bed.

  1. Cold test with a benchtop set-up for fluidized bed reactor using quartz sand to simulate gasification of coal cokes by concentrated solar radiation

    Science.gov (United States)

    Gokon, Nobuyuki; Tanabe, Tomoaki; Shimizu, Tadaaki; Kodama, Tatsuya

    2016-05-01

    The impacts of internal circulation of a mixture of coal-coke particles and quartz sand on the fluidization state in a fluidized bed reactor are investigated by a cold test with a benchtop set-up in order to design 10-30 kWth scale prototype windowed fluidized-bed reactor. Firstly, a basic relationship between pressure loss of inlet gas and gas velocity was experimentally examined using quartz sand with different particle sizes by a small-scale quartz tube with a distributor at ambient pressure and temperature. Based on the results, an appropriate particle range of quartz sand and layer height/layer diameter ratio (L/D ratio) was determined for a design of the fluidized bed reactor. Secondly, a windowed reactor mock-up was designed and fabricated for solar coke gasification using quartz sand as a bed material. The pressure loss between the inlet and outlet gases was examined, and descending cokes and sand particles on the sidewall of the reactor was observed in the reactor mock-up. The moving velocity and distance of descending particles/sands from the top to bottom of fluidized bed were measured by the visual observation of the colored tracer particles on outside wall of the reactor.

  2. Co-gasification of biosolids with biomass: Thermogravimetric analysis and pilot scale study in a bubbling fluidized bed reactor.

    Science.gov (United States)

    Yu, Ming Ming; Masnadi, Mohammad S; Grace, John R; Bi, Xiaotao T; Lim, C Jim; Li, Yonghua

    2015-01-01

    This work studied the feasibility of co-gasification of biosolids with biomass as a means of disposal with energy recovery. The kinetics study at 800°C showed that biomass, such as switchgrass, could catalyze the reactions because switchgrass ash contained a high proportion of potassium, an excellent catalyst for gasification. However, biosolids could also inhibit gasification due to interaction between biomass alkali/alkaline earth metals and biosolids clay minerals. In the pilot scale experiments, increasing the proportion of biosolids in the feedstock affected gasification performance negatively. Syngas yield and char conversion decreased from 1.38 to 0.47m(3)/kg and 82-36% respectively as the biosolids proportion in the fuel increased from 0% to 100%. Over the same range, the tar content increased from 10.3 to 200g/m(3), while the ammonia concentration increased from 1660 to 19,200ppmv. No more than 25% biosolids in the fuel feed is recommended to maintain a reasonable gasification.

  3. Utilisation of wood waste and REF with a new fixed-bed gasification method.; Puujaetteiden ja REF-polttoaineiden hyoedyntaeminen uuden kiinteaekerroskaasutusmenetelmaen avulla

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

    Energy use of wood waste from wood-processing industries and of recovered fuels (REF) applying novel fixed-bed gasification technology in the size class of 3 - 15 MW will be developed. Data on the suitability of various fuels and mixtures for NOVEL gasifiers, on the capacity of the gasifier, on impurities in product gas, and on gas cleaning technology will be created for investment plans of enterprises participating in the project. The tests of development work will be carried out in a 400 kW pilot plant of VTT Energy with the following fuels: plywood waste, demolition wood, REF3, sludge/peat/wood mixtures and moist bark. The aim is a) to assess the suitability of various wood wastes and mixtures for gasification, b) to study the suitability of the Novel gasification method for REF3 and sludge/wood/ peat mixtures, c) to determine the impurity contents in the product gas (i.a., particulates, alkali/heavy metals, chlorine, tars, nitrogen compounds) during gasification cycles of different fuels, and d) to design and price a cleaning concept that meets the emission standards of waste incineration. The final target is the technical readiness for demonstration projects. The research project comprises three main tasks: 1. Experiments with wood wastes and a reference run with peat: Two-three pilot test runs will be carried out with wood wastes from participating enterprises, i.a., waste wood from plywood and furniture industries, and moist bark. The plywood waste contains sodium-rich resin, which has caused sintering and deposit problems in fluidized-bed and grate boilers. It is neither possible to use bark or light wood wastes from carpentry and furniture industries in conventional updraft gasifiers. A reference test run with sod peat as fuel will also be carried out to compare the results of Novel gasification with experiences obtained at the existing Bioneer gasification plants. 2. Experiments with REF and with sludge/peat mixture: Two-three pilot test runs with REF and

  4. Co-gasification of biomass and plastics: pyrolysis kinetics studies, experiments on 100 kW dual fluidized bed pilot plant and development of thermodynamic equilibrium model and balances.

    Science.gov (United States)

    Narobe, M; Golob, J; Klinar, D; Francetič, V; Likozar, B

    2014-06-01

    Thermo-gravimetric analysis (TGA) of volatilization reaction kinetics for 50 wt.% mixtures of plastics (PE) and biomass (wood pellets) as well as for 100 wt.% plastics was conducted to predict decomposition times at 850°C and 900°C using iso-conversional model method. For mixtures, agreement with residence time of dual fluidized bed (DFB) reactor, treated as continuous stirred-tank reactor (CSTR), was obtained at large conversions. Mono-gasification of plastics and its co-gasification with biomass were performed in DFB pilot plant, using olivine as heterogeneous catalyst and heat transfer agent. It was found that co-gasification led to successful thermochemical conversion of plastics as opposed to mono-gasification. Unknown flow rates were determined applying nonlinear regression to energy and mass balances acknowledging combustion fuel, air, steam, feedstock, but also exiting char, tar, steam and other components in DFB gasification unit. Water-gas shift equilibrium and methanol synthesis requirements were incorporated into gasification model, based on measurements.

  5. Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 1: Process performance and gas product characterization

    DEFF Research Database (Denmark)

    Thomsen, Tobias Pape; Sárossy, Zsuzsa; Gøbel, Benny

    2017-01-01

    process is characterized with respect to process stability, process performance and gas product characteristics. All experimental campaigns were conducted at maximum temperatures below 750°C, with air equivalence ratios around 0.12 and with pure silica sand as start-up bed material. A total of 8600kg...... substantially, hot gas efficiencies of around 90% could be achieved for all MSS fuel types....

  6. Fluidized Bed Gasification as a Mature And Reliable Technology for the Production of Bio-Syngas and Applied in the Production of Liquid Transportation Fuels—A Review

    Directory of Open Access Journals (Sweden)

    Adrian H.M. Verkooijen

    2011-03-01

    Full Text Available Biomass is one of the renewable and potentially sustainable energy sources and has many possible applications varying from heat generation to the production of advanced secondary energy carriers. The latter option would allow mobile services like the transportation sector to reduce its dependency on the fossil fuel supply. This article reviews the state-of-the-art of the fluidization technology applied for the gasification of biomass aimed at the production of gas for subsequent synthesis of the liquid energy carriers via, e.g., the Fischer-Tropsch process. It discusses the advantages of the gasification technology over combustion, considers the size of the conversion plant in view of the local biomass availability, assesses the pros and cons of different gasifier types in view of the application of the product gas. Subsequently the article focuses on the fluidized bed technology to discuss the main process parameters and their influence on the product composition and the operability of the gasifier. Finally a synthesis process (FT is introduced shortly to illustrate the necessary gas cleaning steps in view of the purity requirements for the FT feed gas.

  7. Fluidized-bed gasification of biomass: Conversion of fine carabon particles in the freeboard; Biomassevergasung in der Wirbelschicht: Umsatz von feinen Kohlenstoffpartikeln im Freeboard

    Energy Technology Data Exchange (ETDEWEB)

    Miccio, F. [Ist. Ricerche sulla Combustione-CNR, Napoli (Italy); Moersch, O.; Spliethoff, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen

    1998-09-01

    The conversion of carbon particles in gasification processes was investigated in a fluidized-bed reactor of the Institute of Chemical Engineering and Steam Boiler Technology of Stuttgart University. This reactor is heated electrically to process temperature, and freeboard coal particles can be sampled using an isokinetic probe. The fuel used in the experiments consisted of beech wood chips. The temperature and air rating, i.e. the main parameters of the process, were varied in order to investigate their influence on product gas quality and carbon conversion. The conversion rate is influenced to a significant extent by grain disintegration and discharge of carbon particles. In gasification conditions, a further conversion process takes place in the freeboard. (orig.) [Deutsch] In dieser Arbeit wird die Umsetzung von Kohlenstoffpartikeln unter Vergasungsbedingungen untersucht. Die Versuche wurden an einem Wirbelschichtreaktor des Instituts fuer Verfahrenstechnik und Dampfkesselwesen der Universitaet Stuttgart durchgefuehrt. Dieser Reaktor wird elektrisch auf Prozesstemperatur beheizt. Mit Hilfe einer isokinetischen Sonde koennen Proben von Kohlenstoffpartikeln im Freeboard genommen werden. Als Brennstoff wurden zerkleinerte Buchenholz-Hackschnitzel eingesetzt. Variiert wurden als Hauptparameter des Prozesses Temperatur und Luftzahl. Untersucht wurde der Einfluss dieser Parameter auf die Qualitaet des Produktgases und die Umsetzung des Kohlenstoffes. Kornzersetzungs- und Austragsvorgaenge von Kohlenstoffpartikeln spielen eine wichtige Rolle fuer den Kohlenstoffumsatz. Unter Vergasungsbedingungen findet im Freeboard eine weitere Umsetzung der Partikel statt. (orig.)

  8. Steam gasification of wood biomass in a fluidized biocatalytic system bed gasifier: A model development and validation using experiment and Boubaker Polynomials Expansion Scheme BPES

    Directory of Open Access Journals (Sweden)

    Luigi Vecchione

    2015-07-01

    Full Text Available One of the most important issues in biomass biocatalytic gasification is the correct prediction of gasification products, with particular attention to the Topping Atmosphere Residues (TARs. In this work, performedwithin the European 7FP UNIfHY project, we develops and validate experimentally a model which is able of predicting the outputs,including TARs, of a steam-fluidized bed biomass gasifier. Pine wood was chosen as biomass feedstock: the products obtained in pyrolysis tests are the relevant model input. Hydrodynamics and chemical properties of the reacting system are considered: the hydrodynamic approach is based on the two phase theory of fluidization, meanwhile the chemical model is based on the kinetic equations for the heterogeneous and homogenous reactions. The derived differentials equations for the gasifier at steady state were implemented MATLAB. Solution was consecutively carried out using the Boubaker Polynomials Expansion Scheme by varying steam/biomass ratio (0.5-1 and operating temperature (750-850°C.The comparison between models and experimental results showed that the model is able of predicting gas mole fractions and production rate including most of the representative TARs compounds

  9. Advanced development of a pressurized ash agglomerating fluidized-bed coal gasification system: Phase 2, Final report, May 1, 1983-July 31, 1984

    Energy Technology Data Exchange (ETDEWEB)

    None

    1987-09-15

    KRW Energy Systems Inc. is engaged in the development of a pressurized, fluidized-bed, gasification process at its Waltz Mill Site in Madison, Pennsylvania. The overall objective of the program is to demonstrate the viability of the KRW process for the environmentally acceptable production of low- and medium-Btu fuel gas from a variety of fossilized, carbonaceous feedstocks for electrical power generation, substitute natural gas, chemical feedstocks, and industrial fuels. This report covers Phase II of the contract period (May 1, 1983 to July 31, 1984) and is a continuation of the work performed in 1983 and reported in the Phase I final report, FE-19122-30. Included is work performed in fiscal 1983 to 1984 on PDU testing, process analysis, cold flow scaleup facility, process and component engineering and design, and laboratory support studies.

  10. Design, fabrication, operation and Aspen simulation of oil shale pyrolysis and biomass gasification process using a moving bed downdraft reactor

    Science.gov (United States)

    Golpour, Hassan

    Energy is the major facilitator of the modern life. Every developed and developing economy requires access to advanced sources of energy to support its growth and prosperity. Declining worldwide crude oil reserves and increasing energy needs has focused attention on developing existing unconventional fossil fuels like oil shale and renewable resources such as biomass. Sustainable, renewable and reliable resources of domestically produced biomass comparing to wind and solar energy is a sensible motivation to establish a small-scale power plant using biomass as feed to supply electricity demand and heat for rural development. The work in Paper I focuses on the possibility of water pollution from spent oil shale which should be studied before any significant commercial production is attempted. In Paper II, the proposed Aspen models for oil shale pyrolysis is to identify the key process parameters for the reactor and optimize the rate of production of syncrude from oil shale. The work in Paper III focuses on (1) Design and operation of a vertical downdraft reactor, (2) Establishing an optimum operating methodology and parameters to maximize syngas production through process testing. Finally in Paper IV, a proposed Aspen model for biomass gasification simulates a real biomass gasification system discussed in Paper III.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hoteit, A

    2006-06-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Boelle, A.

    1997-02-17

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

  13. Technical and economical optimization of wood gasification in a circulating fluidized bed. Final report; Technische und wirtschaftliche Optimierung der Vergasung von Holz in der zirkulierenden Wirbelschicht. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Ising, M.; Unger, C.; Heunemann, F.; Dinkelbach, L.

    2002-12-01

    The project's objective was the optimization of a novel process for high efficient combined heat and power production from solid biomass. The processed air blown wood gasification in a pilot scale circulating fluidized bed was added by a catalytic tar reformer which would yield a tar-free gas quality suitable for IC-engine operation. Major efforts were taken for technical improvement of the tar reformer, especially concerning temperature control and cleaning devices which is important for keeping constantly a high activity. Pure natural timber did not yield chemical deactivation at the catalyst whereas the gasification of waste wood yielded decreasing activity which could be partly reversed by special measures taken. Further optimization of the process considered a better automation and improvement of the engine's flue gas emissions. Also a detailed economic consideration and evaluation of the entire process has been carried out. As a result the novel process should have economic advantages compared with conventional technology. (orig.) [German] Gegenstand des Vorhabens war die Weiterentwicklung eines Verfahrens zur effizienteren Strom- und Waermegewinnung aus festen Biobrennstoffen. Durch luftgeblasene Vergasung von Holz im Pilotmassstab in einer zirkulierenden Wirbelschicht und anschliessender katalytischer Teerspaltung konnte ein niederkalorisches Brenngas erzeugt werden, welches zum Betrieb eines Motoren-Blockheizkraftwerks geeignet war. Im Rahmen der Verfahrensoptimierung wurde der katalytische Teer-Reformer, insbesondere in Bezug auf Temperaturfuehrung und die zum Aktivitaetserhalt wichtige Abreinigungsvorrichtung, verbessert. Bei der Vergasung von Naturholz wurde keine chemische Desaktivierung festgestellt. Beim Altholzeinsatz wurde ein ueberwiegend reversibler Aktivitaetsverlust verzeichnet und begruendet. Geeignete Gegenmassnahmen wurden untersucht und beschrieben. Weitere Optimierungen betrafen die Anlagensteuerungstechnik im Hinblick auf die

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

    Science.gov (United States)

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

    2016-03-01

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

  15. Gasification trends

    Energy Technology Data Exchange (ETDEWEB)

    Simbeck, D.R.; Dickenson, R.L.; Karp, A.D. [SFA Pacific, Inc., Mountain View, CA (United States)

    1997-05-01

    The traditional use of gasification for high value chemicals will continue where fuel prices make gasification more competitive than steam methane reforming. However, oil companies already have the essentials--expertise, fuels, and financing--to be a dominant force in the new world of competitive energy markets. Refinery-based gasification therefore can be expected to proliferate as deregulation of electric power generation promotes the efficiency and economic advantages of cogeneration and trigeneration. The greatest market potential for gasification in the future is electric power generation. In traditional electric utility applications, the efficiency and overall economics of coal gasification may be only marginally superior to those of well-designed, coal-fired steam cycles having state-of-the-art emission controls. Offsetting gasification`s environmental and efficiency advantages in such applications are concerns about capital cost and the need for chemical process expertise. However, power industry deregulation and competition are likely to diminish the importance of large, new central power plants, while imparting increased value to gasification`s strategic advantages, which include: Gasification`s superior environmental performance, particularly in the area of solid wastes; gasification`s superior ability to exploit high-efficiency combustion turbine-based opportunities for combined-cycle and especially cogeneration applications; gasification`s superior ability to exploit a range of fuels--from natural gas and opportunity fuels in the near-to-intermediate term to coal in the longer term, when natural gas prices escalate; and gasification`s superior market economics and flexibility to create and profit from combined power and synthesis gas chemical applications.

  16. Drying with a pulsed-fluidized bed, a new technology which reduces the costs of drying; Le sechoir a lit fluidise pulse, une nouvelle technologie qui diminue les couts de sechage

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M.G.; Kudra, T.; Platon, R. [Natural Resources Canada, Varennes, PQ (Canada). Energy Diversification Research Laboratory

    1999-09-01

    Drying refers to the removal of water from solid materials and tends to cover processes such as filtration, heat removal of humidity and even sublimation. It is probably the most energy intensive operation in industry, consuming nearly 8.4% of all the energy used by Canadian industry. This datum applies to a vast gamut of technologies and techniques for drying products in the form of solid particles, pastes, slurries or solutions. The CANMET Energy Diversification Laboratory developed a new type of dryer for the dewatering of solid particles: the pulsed-fluidized bed dryer. The new technology is described as well as its performance and advantages. In the course of the last four years, the laboratory transferred Polish technology and modified it for high temperature operation. The laboratory obtained a patent for the modified technology and negotiated a licence with Barr-Rosin Inc. for the manufacturing and commercialization of pulsed-fluidized bed dryers. Given the numerous advantages of the technology, and economic and technical planning, the laboratory foresees a vast gamut of uses for the future. 3 refs.

  17. An integrated process for hydrogen-rich gas production from cotton stalks: The simultaneous gasification of pyrolysis gases and char in an entrained flow bed reactor.

    Science.gov (United States)

    Chen, Zhiyuan; Zhang, Suping; Chen, Zhenqi; Ding, Ding

    2015-12-01

    An integrated process (pyrolysis, gas-solid simultaneous gasification and catalytic steam reforming) was utilized to produce hydrogen-rich gas from cotton stalks. The simultaneous conversion of the pyrolysis products (char and pyrolysis gases) was emphatically investigated using an entrained flow bed reactor. More carbon of char is converted into hydrogen-rich gas in the simultaneous conversion process and the carbon conversion is increased from 78.84% to 92.06% compared with the two stages process (pyrolysis and catalytic steam reforming). The distribution of tar components is also changed in this process. The polycyclic aromatic compounds (PACs) of tar are converted into low-ring compounds or even chain compounds due to the catalysis of char. In addition, the carbon deposition yield over NiO/MgO catalyst in the steam reforming process is approximately 4 times higher without the simultaneous process. The potential H2 yield increases from 47.71 to 78.19g/kg cotton stalks due to the simultaneous conversion process.

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

    Science.gov (United States)

    Yan, Linbo; He, Boshu

    2017-07-01

    A clean power generation system was built based on the steam co-gasification of biomass and coal in a quadruple fluidized bed gasifier. The chemical looping with oxygen uncoupling technology was used to supply oxygen for the calciner. The solid oxide fuel cell and the steam turbine were combined to generate power. The calcium looping and mineral carbonation were used for CO2 capture and sequestration. The aim of this work was to study the characteristics of this system. The effects of key operation parameters on the system total energy efficiency (ŋten), total exergy efficiency (ŋtex) and carbon sequestration rate (Rcs) were detected. The energy and exergy balance calculations were implemented and the corresponding Sankey and Grassmann diagrams were drawn. It was found that the maximum energy and exergy losses occurred in the steam turbine. The system ŋten and ŋtex could be ∼50% and ∼47%, and Rcs could be over unit. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Advanced treatment of biologically pretreated coal gasification wastewater using a novel anoxic moving bed biofilm reactor (ANMBBR)-biological aerated filter (BAF) system.

    Science.gov (United States)

    Zhuang, Haifeng; Han, Hongjun; Jia, Shengyong; Zhao, Qian; Hou, Baolin

    2014-04-01

    A novel system integrating anoxic moving bed biofilm reactor (ANMBBR) and biological aerated filter (BAF) with short-cut biological nitrogen removal (SBNR) process was investigated as advanced treatment of real biologically pretreated coal gasification wastewater (CGW). The results showed the system had efficient capacity of degradation of pollutants especially nitrogen removal. The best performance was obtained at hydraulic residence times of 12h and nitrite recycling ratios of 200%. The removal efficiencies of COD, total organic carbon, NH4(+)-N, total phenols and total nitrogen (TN) were 74.6%, 70.0%, 85.0%, 92.7% and 72.3%, the corresponding effluent concentrations were 35.1, 18.0, 4.8, 2.2 and 13.6mg/L, respectively. Compared with traditional A(2)/O process, the system had high performance of NH4(+)-N and TN removal, especially under the high toxic loading. Moreover, ANMBBR played a key role in eliminating toxicity and degrading refractory compounds, which was beneficial to improve biodegradability of raw wastewater for SBNR process.

  20. Underground gasification for steeply dipping coal beds. Phase I report: feasibility study and program plan, September 30, 1977--February 28, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1978-05-01

    The first phase of the DOE project for gasification of steeply dipping coal beds consisted of site selection activities, a concept feasibility study and program planning. A test site was selected at North Knobs near Rawlins, Wyoming. This site has the best potential for a successful first UCG-SDB test. Analysis of the concept suggests air emission and aquifer degradation as possible areas of environmental impact. A monitoring plan has been established to determine the environmental effect of the tests. The detailed technical approach for the project is being developed based on present DOE field experiences and previous Russian work. Emphasis will be on resolving technical areas where the DOE experience is not transferrable (i.e., process modeling, well configuration, and installation). Using a proprietary cost estimating model, the parameters of greatest sensitivity were product gas quality, gas leakage, and yield of product gas per unit volume of injection air. A facility and equipment design was established for cost projection and to serve as a basis for detailed design work during the second phase. A cost analysis of the project indicated that the original costs projections still hold but that the spending curve will require revision.

  1. Gasification techniques and fluidized-bed gasification of biomass - ways of optimising combustion and energy utilisation. Vergasungstechniken und Wirbelschichtvergasung von Biomasse - Wege zur Optimierung der Verbrennung und der Energienutzung

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, W. (Wamsler Umwelttechnik, Muenchen (Germany))

    1994-01-01

    To date, electricity can only be generated from biomass via steam production. There are no gasification techniques available for generating electricity from biomass at an industrial scale. The paper describes the current stage of development and two possible applications of a gasification technique whose attractivity lies not only in direct electricity production and utilisation of residual heat (block-type thermal power station). The gasification is also a way of compensating the drawbacks of solid fuel combustion compared with gas combustion. (orig./EF)

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

    Energy Technology Data Exchange (ETDEWEB)

    Begis, J.; Balzer, G.

    1997-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Desroches-Ducarne, E.

    1997-09-30

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-01-01

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

  5. Effect of heating style on gasification process of pilot scale bubble fluidized bed%升温方式对中试鼓泡流化床气化过程的影响

    Institute of Scientific and Technical Information of China (English)

    李晓伟; 刘建坤; 王贵路; 李明鹤; 郑磊; 叶仁文; 张大雷

    2015-01-01

    In order to study the heat process characteristics of pilot scale bubbing fluidized bed, by using the self heating pilot scale bubbling fluidized bed reactor of 50 kg/h in capacity, with sawdust as raw material, the experimental study on air gasification were conducted. At present, the externally heating for the fluidized bed startup was widely used in bench scale experiment. It had the advantages of rapidly raising of temperature, accurate control, etc., but the equipment was complex and difficult for maintenance, and was higher energy cost, especially, the externally heating was quite different with that for practical utilization. It is not helpful for find out the reaction characteristics so that the guiding for practical utilization was weakened. For solving the problem, using the pilot scale fluidized bed reactor as experimental device which is self heated, continuously fed and operated, air gasification experiment study on 3 temperature raising modes were conducted. Three temperature raising modes, which were sawdust combustion heating, sawdust/charcoal mixture combustion heating and charcoal combustion heating, were adopted respectively. The influence of different temperature raising ways on gasification temperature, tar content, the minimum fluidization velocity and gas quality in the process of gasification has been studied. The results showed that the heating effect of charcoal combustion was more ideal, and its heat value of charcoal was up to 32 MJ/kg, thus the heat released was much larger than that of sawdust. It provided more heat for bed heating process. In the preheating process, the warming up process was faster in the first hour, along with the increase of bed height, the heat storage in the bed material was also increased, and the heating rate was steady. It took 2.5 h for the gasification reactor to reach the reaction temperature. Due to the complexity for adding bed material and charcoal in the reactor, the optimization on the feeding device

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

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, Roger; Rogbeck, Jan; Suer, Pascal

    2004-01-01

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

  7. Gasificación con aire en lecho fluidizado de los residuos sólidos del proceso industrial de la naranja//Air gasification in fluidized bed of solid residue the orange industrial process

    Directory of Open Access Journals (Sweden)

    Leonardo Aguiar-Trujillo

    2012-12-01

    Full Text Available La industria procesadora de la naranja genera elevados volúmenes de residuos sólidos. Este residuo se ha utilizado en la alimentación animal y en procesos bioquímicos; pero no se ha aprovechado a través de la gasificación. El objetivo del trabajo fue determinar el aporte energético por medio del proceso de gasificación, realizándose estudios de los residuos sólidos de naranja, utilizando aire en reactor de lecho fluidizado burbujeante (variando la temperatura de gasificación, relación estequiométrica y altura del lecho. En el proceso se utilizó un diseño de experimento factorial completo de 2k, valorando la influencia de las variables independientes y sus interacciones en las respuestas, con un grado de significación del 95 %. Se obtuvieron los parámetros para efectuar el proceso de gasificación de los residuos sólidos de naranja, obteniendo un gas de bajo poder calórico, próximo a 5046 kJ/m3N, demostrando sus cualidades para su aprovechamiento energético.Palabras claves: gasificación con aire, lecho fluidizado, residuo de naranja._______________________________________________________________________________AbstractThe orange industrial process generates high volumes of solid residue. This residue has been used as complement in the animal feeding and biochemical processes; but it has not taken advantage through of the gasification process. The objective of the work was to determine the energy contribution by means ofthe gasification process, were carried out studies of the orange solid residue, using air in reactor of bubbling fluidized bed (varying the gasification temperature, air ratio and bed height. In the process a design of complete factorial experiment of 2k, was used, valuing the influence of the independent variables and its interactions in the answers, using a confidence level of 95 %. Were obtained the parameters to make the process of gasification of the orange solid residue, obtaining a gas of lower heating

  8. Preliminary experimental study of bituminous coal gasification on dual fluidized beds%烟煤在双流化床中气化特性初步实验研究

    Institute of Scientific and Technical Information of China (English)

    武小军; 范晓旭; 陈文义; 初雷哲

    2012-01-01

    利用一套高3m的双流化床煤气化实验系统,以烟煤为燃料进行了气化初步实验研究.烟煤在气化炉中进行热解气化,生成的半焦经下返料器送入燃烧炉进行燃烧,通过高温循环灰携带能量供给气化炉.通过调整气化炉内料层高度改变燃料在气化炉内的停留时间,从而影响气化效果,料层高度可以通过气化炉内压差进行监测.烟煤气化达到稳定工况时,燃烧炉和气化炉的温度和压差基本保持稳定.燃气热值为5.53 MJ/m3,尚未达到中热值标准,原因在于实验装置规模较小导致散热损失较大,同时返料器以空气为返料风降低了燃气品质.%Gasification experiments on bituminous coal were made in an experimental system of dual fluidized beds with 3 m in height. Gasifier was used for coal pyrolysis/gasification. Semicarbon was sent into burner for combustion by U-valve. Energy for gasification was carried by high temperature cycle ash. Status of gasification can be influenced by residence time of fuel which can be changed by adjusting the bed material level in gasifier. Differential pressures in gasifier were used for analyzed the bed material level. The temperature and differential pressure in gasifier and burner maintained stability when gasification condition operated steadily. The calorific value of gas was 5.53 MJ/Nm3 and didn't reach the standard of medium heat value. The cause is that the heat loss is bigger in small size and gas quality was decreased by the air which is used as return wind.

  9. Volatilisation and catalytic effects of alkali and alkaline earth metallic species during the pyrolysis and gasification of Victorian brown coal. Part IV. Catalytic effects of NaCl and ion-exchangeable Na in coal on char reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Dimple Mody Quyn; Hongwei Wu; Jun-ichiro Hayashi; Chun-Zhu Li, [Monash University, Monash, Vic. (Australia). CRC for Clean Power from Lignite, Department of Chemical Engineering

    2003-03-01

    The purpose of this study is to investigate the catalytic effects of Na as NaCl or as sodium carboxylates ( COONa) in Victorian brown coal on the char reactivity. A Na-exchanged coal and a set of NaCl-loaded coal samples prepared from a Loy Yang brown coal were pyrolysed in a fluidised-bed/fixed-bed reactor and in a thermogravimetric analyser (TGA). The reactivities of the chars were measured in air at 400{sup o}C using the TGA. The experimental data indicate that the Na in coal as NaCl and as sodium carboxylates ( COONa) had very different catalytic effects on the char reactivity. It is the chemical form and dispersion of Na in char, not in coal, that govern the catalytic effects of Na. For the Na-form (Na-exchanged) coal, the char reactivity increased with increasing pyrolysis temperature from 500 to 700{sup o}C and then decreased with pyrolysis temperature from 700 to 900{sup o}C. The increase in reactivity with pyrolysis temperature (500 700{sup o}C) is mainly due to the changes in the relative distribution of Na in the char matrix and on the pore surface. For the NaCl-loaded coals, when Cl was released during pyrolysis or gasification, the Na originally present in coal as NaCl showed good catalytic effects for the char gasification. Otherwise, Cl would combine with Na in the char to form NaCl during gasification, preventing Na from becoming an active catalyst. Controlling the pyrolysis conditions to favour the release of Cl can be a promising way to transform NaCl in coal into an active catalyst for char gasification. 38 refs., 5 figs.

  10. Technoeconomical evaluation of black liquor gasification processes; Teknisk ekonomisk utvaerdering av svartlutfoergasningsprocesser

    Energy Technology Data Exchange (ETDEWEB)

    Warnqvist, Bjoern; Delin, Lennart [AaF-IPK AB, Stockholm (Sweden); Theliander, Hans; Nohlgren, Ingrid [Luleaa Tekniska Universitet (Sweden). Chemical Engineering Design

    2000-06-01

    Black liquor gasification processes have been studied as an alternative to conventional chemical recovery with recovery boiler/steam turbine. Energy balances and investment costs have been calculated/estimated for four gasification processes in a model mill for 1000 ADt/d bleached kraft market pulp (according to the KAM-Mistra program, i.e. a mill with the best available technology). The original four alternatives studied were: (1) Pressurised entrained-flow high temperature gasifier (950 deg C) with smelt formation. Quencher and gas/liquor production (cf. Chemrec) with high temperature gas turbine, waste heat boiler and steam turbine; (2) Ditto with combined cycle with pressurised steam boiler and gas turbine (moderate gas turbine temperature); (3) Pressurised gasification in a fluidised bed (700 deg C) in a combined cycle with pressurised steam boiler and gas turbine; (4) Pressurised gasification in a fluidised bed with titanate for direct causticising (850-900 deg C) in a combined cycle with pressurised steam boiler and gas turbine. All systems have a bark boiler (falling bark) and steam central. All but the last system also have conventional causticising and lime kiln. All systems also have a condensing turbine to absorb the net surplus of steam that both the conventional recovery and the gasification systems produce. After the completion of the original study, a more detailed description of the Chemrec concept has been made available to us. An alternative that more closely resembles the Chemrec process has therefore been added. A more detailed description of the ABB system has not been available, but this system has also been recalculated for the same type of gas turbine that is used in the Chemrec case. We have also added the alternative that the biomass fuel is gasified and used in a combined cycle. We have furthermore added calculations with the new alternatives implemented in a hypothetical integrated mill with a need for external fuel. The development of

  11. Availability of P and K in ash from thermal gasification of animal manure

    Energy Technology Data Exchange (ETDEWEB)

    Rubaek, G.H.; Soerensen, Peter [Danish Inst. of Agricultural Sciences, Dept. of Agroecology, Tjele (Denmark); Stoholm, P. [Danish Fluid Bed Technology (Denmark)

    2006-08-15

    In areas like Denmark where the livestock density is regulated on the basis of manure N content, surplus phosphorus is becoming a key environmental problem, which has to be solved in order to avoid increasing P losses to surface waters in the future. Combustion of animal manure or its solid fraction and the subsequent export of the ash to nutrient-poor areas could be a solution. However, combustion is difficult due to fouling and corrosion problems, and the ash will only be marketable if the fertiliser value of the remaining P and K is acceptable and if the content of contaminants (heavy metals) is sufficiently low. A combined fast pyrolysis and char gasification technique for treatment of biomass has been developed where organic material such as manure is processed in a fluidised bed reactor at temperatures and around 700 deg. C. After simple separation of a fine textured ash, the cleaned gas is suitable for combustion in a separate unit for energy production. One advantage of this technique is that the temperature can be finely controlled, and temperatures exceeding the melting point of e.g. potassium chloride can be avoided. The low and well-controlled temperature probably also prevents severe reductions in the availability of nutrients in the ash. However, the availability of P and K in the ash remains to be thoroughly tested. (au)

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

    African Journals Online (AJOL)

    2012-02-01

    Feb 1, 2012 ... 40 to 320 mg N·ℓ-1 led to a stable nitrification performance with high nitrite accumulation .... Additionally, in order to evaluate the impact of organic load ...... CHEN YJ, ZHANG ZJ and LI ZR (2006) Study on nitrification char-.

  13. Reactive Gas Solids Flow in Circulating Fluidised Beds

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  14. Fluidised bed combustion of two species of energy crops

    OpenAIRE

    Abelha, Pedro; Franco, Carlos; Lopes, M. Helena; Gulyurtlu, Ibrahim; Cabrita,Isabel

    2009-01-01

    The use of biomass fuels for energy production through combustion has a growing application worldwide mainly for two reasons: first, the utilization of biomass for energy contributes to mitigate emission of green house gases; second, its use decreases the dependence of imported fossil fuels in Europe. The objective of this work was to study the combustion behaviour of two endogenous biomass species: cardoon (cynara cardunculus) and arundo (arundo donax), which were specially produced in energ...

  15. Chemical Processes Related to Combustion in Fluidised Bed

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-12-01

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

  16. 基于流化床热解的中药渣两段气化基础研究%Fundamental study on Chinese herb residue pyrolysis and gasification by combining fluidized bed and fixed bed

    Institute of Scientific and Technical Information of China (English)

    汪印; 刘殊远; 任明威; 许光文

    2013-01-01

    The tar and char from a fluidized bed Chinese herb residue (CHR) pyrolysis were cracked and gasified in a fixed char bed. The change in chemical species of tar before and after passing through a fixed char bed was analyzed. The results show that increasing the residence time of tar and pyrolysis gas in the char bed from 0 s to 0.95 s causes a significant decrease in the chemical species containing -OH, C-H, C-O, C = O and C=C groups, but leads to an obvious increase in the aromatic species. Introducing steam into the char bed results in the formation of more species containing aromatic rings, C-O and -OH groups, while adding the oxygen to the atmosphere increases the amount of aromatic components but has little effect on the amount of species containing -OH, C-H, C = O, C = C and C-O. Both steam and oxygen are effective to remove tar from the gasification gas, but the effect of steam is relatively weaker. Introducing steam together with oxygen will have a rather higher tar removal efficiency, and the tar in the producer gas can be ignored.%以中药渣为原料,研究了流化床热解和固定床半焦催化/重整焦油及半焦气化的特性,特别是对固定床重整前后焦油中组分的变化进行了分析.结果表明,随着热解气体在固定床半焦中停留时间从0s延长到0.95 s,焦油中-OH、C-H、C-O、C=O和C=C官能团的含量显著减少,芳香类物质含量明显增加;向固定床中加入水蒸气后,焦油中芳香类、C-O和羟基-OH官能团的含量增加;而加入氧气后,焦油中羟基-OH、C-H、羰基C=O、C=C和C-O官能团物质含量变化不大,但芳烃类物质明显增多.虽然向固定床中加入水蒸气或氧气均能降低焦油含量,但水蒸气的作用稍弱,两者联合对焦油脱除和半焦气化效果更好,生成的燃气中基本不含焦油.

  17. 串行流化床生物质气化合成二甲醚的模拟%Simulation of DME Synthesis from Biomass Gasification in Interconnected Fluidized Beds

    Institute of Scientific and Technical Information of China (English)

    江宏玲; 肖军; 沈来宏

    2012-01-01

    Taking the rice straw as an object of study,a simulation model for synthesis of dimethyl ether(DME) from biomass gasification in interconnected fluidized beds was established using Aspen Plus software,so as to analyze how following factors influence the synthesis process,such as the gasification temperature,steam/biomass(mS/mB) mass ratio,synthesis temperature and pressure,absorption tower operating pressure and the absorbent/DME(nA/nD) flow ratio,ect.Results show that for the purpose of direct DME synthesis from biomass gasification in interconnected fluidized beds using steam gasification technology,it is suggested that relevant parameters be set as follows: gasification temperature at 750 ℃,mS/mB=0.3,and DME systhesis temperature and pressure respectively at 260 ℃ and 4 MPa;if water is taken as the absorbent,the absorption tower operating pressure is proposed to be within 3-4 MPa with an nA/nD ratio of 0.5.Under above optimal conditions,the DME yield may reach 6.1 mol per kg biomass.%以稻秸秆为研究对象,利用Aspen Plus软件建立了串行流化床生物质气化制取合成气合成二甲醚(DME)的模型,研究了不同气化温度、水蒸气与生物质的质量比(mS/mB)、DME合成温度、合成压力、吸收塔操作压力及吸收剂与DME的配比(nA/nD)对合成工艺的影响.结果表明:对于采用串行流化床生物质水蒸气气化技术制取DME的一步法合成系统,建议气化温度取750℃左右,mS/mB取0.3,DME合成温度取260℃,合成压力取4MPa,用水作吸收剂,吸收塔的操作压力控制在3~4MPa,nA/nD取0.5;在此工况下,1kg生物质(干燥基)所能产生的二甲醚物质的量约为6.1mol.

  18. Biomass gasification with oxygen and steam in a fluidized bed gasifier%生物质流化床氧气-水蒸气气化实验研究

    Institute of Scientific and Technical Information of China (English)

    苏德仁; 刘华财; 周肇秋; 阴秀丽; 吴创之

    2012-01-01

    The characteristics of biomass gasification with oxygen-steam mixtures in a fluidized bed are studied in this paper. The effects of feedstock, equivalence ratio (ER), steam to biomass ratio (S/B), gasification temperature, secondary oxygen supply and bed materials on gasification performance were investigated. The results showed that higher C and H content of feedstock was more favorable for higher H2 and CO content and lower tar content of fuel gas. The H2 content increased with gasification temperature and reached its maximum at ER=0.27 and S/B = 0.6. Higher gasification temperature (>840℃) also contributed to higher CO content. The introduction of secondary flow upper the feedstock inlet with a second flow ratio of 15% improved the gas quality significantly, and more tar was reduced as the secondary flow inlet move upward the gasifier. Dolomite and limestone performed better than olivine on cracking tar and increasing H2 content, but resulted in higher ash content.%在小型流化床气化装置上进行了氧气-水蒸气气化实验,考察了原料、当量比、水蒸气配比、温度、二次风和床料对气化特性的影响.结果表明,原料中C和H含量越高,气化气中H2和CO含量越高,焦油含量越低;当量比为0.27和水蒸气配比为0.6时,H2含量达到最大值;温度的升高可提高H2含量,在840℃以上,可提高CO含量;二次风从进料口偏上且二次风比率为15%通入,气体组分变化较明显,二次风通入点位置越高,焦油含量降低幅度越大;白云石和石灰石裂解焦油和提高H2含量的活性高于橄榄石,但同时明显提高了气体中的灰分含量.

  19. Fluid-Bed Testing of Greatpoint Energy's Direct Oxygen Injection Catalytic Gasification Process for Synthetic Natural Gas and Hydrogen Coproduction Year 6 - Activity 1.14 - Development of a National Center for Hydrogen Technology

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, Michael; Henderson, Ann

    2012-04-01

    The GreatPoint Energy (GPE) concept for producing synthetic natural gas and hydrogen from coal involves the catalytic gasification of coal and carbon. GPE’s technology “refines” coal by employing a novel catalyst to “crack” the carbon bonds and transform the coal into cleanburning methane (natural gas) and hydrogen. The GPE mild “catalytic” gasifier design and operating conditions result in reactor components that are less expensive and produce pipeline-grade methane and relatively high purity hydrogen. The system operates extremely efficiently on very low cost carbon sources such as lignites, subbituminous coals, tar sands, petcoke, and petroleum residual oil. In addition, GPE’s catalytic coal gasification process eliminates troublesome ash removal and slagging problems, reduces maintenance requirements, and increases thermal efficiency, significantly reducing the size of the air separation plant (a system that alone accounts for 20% of the capital cost of most gasification systems) in the catalytic gasification process. Energy & Environmental Research Center (EERC) pilot-scale gasification facilities were used to demonstrate how coal and catalyst are fed into a fluid-bed reactor with pressurized steam and a small amount of oxygen to “fluidize” the mixture and ensure constant contact between the catalyst and the carbon particles. In this environment, the catalyst facilitates multiple chemical reactions between the carbon and the steam on the surface of the coal. These reactions generate a mixture of predominantly methane, hydrogen, and carbon dioxide. Product gases from the process are sent to a gas-cleaning system where CO{sub 2} and other contaminants are removed. In a full-scale system, catalyst would be recovered from the bottom of the gasifier and recycled back into the fluid-bed reactor. The by-products (such as sulfur, nitrogen, and CO{sub 2}) would be captured and could be sold to the chemicals and petroleum industries, resulting in

  20. Fluid-Bed Testing of Greatpoint Energy's Direct Oxygen Injection Catalytic Gasification Process for Synthetic Natural Gas and Hydrogen Coproduction Year 6 - Activity 1.14 - Development of a National Center for Hydrogen Technology

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, Michael; Henderson, Ann

    2012-04-01

    The GreatPoint Energy (GPE) concept for producing synthetic natural gas and hydrogen from coal involves the catalytic gasification of coal and carbon. GPE’s technology “refines” coal by employing a novel catalyst to “crack” the carbon bonds and transform the coal into cleanburning methane (natural gas) and hydrogen. The GPE mild “catalytic” gasifier design and operating conditions result in reactor components that are less expensive and produce pipeline-grade methane and relatively high purity hydrogen. The system operates extremely efficiently on very low cost carbon sources such as lignites, subbituminous coals, tar sands, petcoke, and petroleum residual oil. In addition, GPE’s catalytic coal gasification process eliminates troublesome ash removal and slagging problems, reduces maintenance requirements, and increases thermal efficiency, significantly reducing the size of the air separation plant (a system that alone accounts for 20% of the capital cost of most gasification systems) in the catalytic gasification process. Energy & Environmental Research Center (EERC) pilot-scale gasification facilities were used to demonstrate how coal and catalyst are fed into a fluid-bed reactor with pressurized steam and a small amount of oxygen to “fluidize” the mixture and ensure constant contact between the catalyst and the carbon particles. In this environment, the catalyst facilitates multiple chemical reactions between the carbon and the steam on the surface of the coal. These reactions generate a mixture of predominantly methane, hydrogen, and carbon dioxide. Product gases from the process are sent to a gas-cleaning system where CO{sub 2} and other contaminants are removed. In a full-scale system, catalyst would be recovered from the bottom of the gasifier and recycled back into the fluid-bed reactor. The by-products (such as sulfur, nitrogen, and CO{sub 2}) would be captured and could be sold to the chemicals and petroleum industries, resulting in

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

  2. Experimental investigation of wood chip gasification using downdraft fixed bed gasifier%基于下吸式固定床的木片气化试验

    Institute of Scientific and Technical Information of China (English)

    马中青; 叶结旺; 赵超; 孙庆丰; 张齐生

    2016-01-01

    Gasification is a thermo-chemical process to convert carbonaceous materials into gaseous products which could be used as a fuel in engines for power generation or in boiler for heat supply. This paper investigated the effect of equivalence ratio (ER) on the gasification performance in terms of the temperature in the gasifier, the composition distribution of the producer gas, and the tar content in the producer gas using a lab-scale downdraft fixed bed gasifier fed by Pinus sylvestris wood chips. In addition, the characteristics of gasification byproducts, namely bio-char and bio-tar, were analyzed. The proximate and ultimate analysis, the surface morphology, the surface area, and the pore size distribution of wood charcoal were obtained by the scanning electron microscopy (SEM) and the Brunauer-Emmett-Teller (BET) method. The components of light tar and heavy tar were obtained by the gas chromatography-mass spectrometry (GC-MS). The results showed that the optimal ER was 0.251 with the maximum LHV of producer gas (4.55 MJ/Nm3 along with CO of 17.47%, H2 of 14.67%, CO2 of 12.43%, and CH4 of 2.12%), a minimum tar content of 350 mg/Nm3, and a maximum cold gas efficiency of 65.46%. The charcoal was a porous material with a high heating value of 28.17 MJ/kg and a high BET surface area 342 m2/g which could potentially be feedstock for the production of briquettes fuel and activated carbon. The light tar was mainly composed of phenols (36.75%), acetic acid (22.14%) and ketones (13.73%). After refining and dilution, the light tar could be a potential substance to produce plant growth regulator. The heavy tar was mainly composed of heterocyclic aromatics (59.98%), light aromatics (1 ring) (4.71%) and light polycyclic aromatic hydrocarbons (2-3 ring) (16.48%). The heavy tar could be a potential feedstock for aromatic chemicals production.%樟子松木材是中国一种重要的生物质能源原料,通过气化技术可将其转化为高热值生物燃气,用于内燃

  3. Gasification combined cycle power generation - process alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Kurkela, E.; Korhonen, M.

    1988-01-01

    Interest in Integrated Gasification Combined Cycle (IGCC) power plants has recently increased also in Finland. The IGCC systems offer the potential of superior efficiency and environmental performance over conventional pulverized coal or peat fired boilers. Potential applications are both large-scale electricity production from coal and medium-scale combined heat and electricity production. In the latter case, the gasification process should also be applicable to peat and wood. Several IGCC processes have been developed in USA and in Europe. These processes differ from each other in many respects. Nearest to commercialization are processes, which employ oxygen gasification and cold gas cleanup. The Cool Water plant, which was brought into operation in 1984 in USA, has demonstrated the feasibility of an IGCC system using Texaco entrained-bed gasifier. Several pressurized fluidized-bed and fixed-bed gasification processes have also reached a pilot or demonstration stage with a wide variety of coals from lignite to hard coal. Pressurized fluidized-bed gasification of peat (Rheinbraun-HTW-process) will also be demonstrated at the peat ammonia plant of Kemira Oy, which will be commissioned in 1988 in Oulu, Finland. Oxygen gasification and cold gas cleanup are, however, economically viable only in large-scale applications. Technology is being developed to simplify the IGCC system, in order to reduce its capital costs and increase its efficiency. Air gasification combined with ho gas cleanup seems to have a great potential of improving the competitiveness of the IGCC system.

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

    Directory of Open Access Journals (Sweden)

    Moni Mohamad Nazmi Zaidi

    2014-07-01

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

  5. Modeling and comparative assessment of bubbling fluidized bed gasification system for syngas production - a gateway for a cleaner future in Pakistan.

    Science.gov (United States)

    Shehzad, Areeb; Bashir, Mohammed J K; Horttanainen, Mika; Manttari, Mika; Havukainen, Jouni; Abbas, Ghulam

    2017-06-19

    The present study explores the potential of MSW gasification for exergy analysis and has been recently given a premier attention in a region like Pakistan where the urbanization is rapidly growing and resources are few. The plant capacity was set at 50 MW based on reference data available and the total exergetic efficiency was recorded to be 31.5 MW. The largest irreversibility distribution appears in the gasifier followed by methanation unit and CO2 capture. The effect of process temperature, equivalence ratio and MSW moisture content was explored for inspecting the variations in syngas composition, lower heating value, carbon conversion efficiency and cold gas efficiency. Special attention of the paper is paid to the comparative assessment of MSW gasification products in four regions, namely Pakistan, USA, UAE and Thailand. This extended study gave an insight into the spectrum of socioeconomic conditions with varying MSW compositions in order to explain the effect of MSW composition variance on the gasification products.

  6. Iron-based materials as tar cracking catalyst in waste gasification

    Energy Technology Data Exchange (ETDEWEB)

    Nordgreen, Thomas

    2011-07-01

    The treatment of municipal solid waste (MSW) in Sweden has changed during the past decades due to national legislation and European Union directives. The former landfills have more or less been abandoned in favour of material recycling and waste incineration. On a yearly basis approximately 2.2 million tonnes waste are incinerated in Sweden with heat recovery and to some extent also with electricity generation, though at a low efficiency. It is desirable to alter this utilisation and instead employ MSW as fuel in a fluid bed gasification process. Then electrical energy may be produced at a much higher efficiency. However, MSW contain about 1 % chlorine in the form of ordinary table salt (NaCl) from food scraps. This implies that the tar cracking catalyst, dolomite, which is normally employed in gasification, will suffer from poisoning if applied under such conditions. Then the tar cracking capacity will be reduced or vanish completely with time. Consequently, an alternative catalyst, more resistant to chlorine, is needed. Preliminary research at KTH has indicated that iron in its metallic state may possess tar cracking ability. With this information at hand and participating in the project 'Energy from Waste' an experimental campaign was launched. Numerous experiments were conducted using iron as tar cracking catalyst. First iron sinter pellets from LKAB were employed. They were reduced in situ with a stream of hydrogen before they were applied. Later iron-based granules from Hoeganaes AB were tested. These materials were delivered in the metallic state. In all tests the KTH atmospheric fluidised bed gasifier with a secondary catalytic reactor housing the catalytic material was deployed. Mostly, the applied fuel was birch. The results show that metallic iron possesses an intrinsic ability, almost in the range of dolomite, to crack tars. Calculations indicate that iron may be more resistant to chlorine than dolomite. The exploration of metallic iron

  7. Application and development status of coal gasification technology in China

    Institute of Scientific and Technical Information of China (English)

    BU Xue-peng; XU Zhen-gang

    2004-01-01

    Introduced the application and development status of coal gasification technology in China. The most widely used coal gasification technology in China is the atmospheric fixed-bed gasifier, its total number is about 9 000. About 30 pressurized fixed-bed gasifiers are in operation, and more than 10 atmospheric fluidized-bed gasifiers were used. There are 13 Texaco entrained-flow bed gasifiers are under operation,10 Texaco and 11 Shell gasifiers that are being installed or imported. About 10 underground gasifiers are under running now. The present R&D of coal gasification technologies are to improve the operation and controlling level of fixed-bed gasification technology, and developing or demonstration of fluidized-bed and entrained-flow bed gasifiers.

  8. Reaction kinetics study of coal catalytic gasification in lab scale fixed bed reactor%小型固定床煤催化气化动力学研究

    Institute of Scientific and Technical Information of China (English)

    高攀; 顾松园; 钟思青; 金永明; 曹勇

    2015-01-01

    K2CO3 catalytic gasification of Neimeng brown coal was studied in a fixed bed reactor. The effects of catalyst loading, temperature, gasification agents, such as H2O and H2, and partial pressure of H2O on the carbon conversion and reaction rate were investigated. The results showed that K2CO3 could accelerated the rate of coal-steam gasification obviously, and the carbon conversion reached 70% with the addition of only 10% K2CO3 by mass at 700℃, while H2 inhibited the coal-steam gasification seriously. A kinetic reaction equation was proposed based on an n order and Langmuir-Hinshewood expression by evaluating the carbon conversion behavior. The gasification activity significantly increased with steam partial pressure. In the n order expression, the order nwas 0.87 and the activation energy was 169.2kJ/mol, and, in the L-H expression, the activation energy was 121.9kJ/mol.%以K2CO3和内蒙褐煤为研究对象,在小型固定床上考察了催化剂负载量、温度,氢气以及水蒸气分压对碳转化率和气化反应速率的影响。结果表明,K2CO3对煤焦-水蒸气气化反应有明显的催化作用,700℃,当添加10%的K2CO3,碳的转化率为70%,氢气的含量对煤焦-水蒸气的反应有明显的抑制作用,并采用n级速率方程和Langmuir-Hinshelwood速率方程考察了水蒸气分压的影响,分压提高,煤焦-水蒸气气化反应活性提高,采用n级速率方程得到煤-水蒸气气化反应级数为0.87,活化能为169.2kJ/mol;采用L-H方程得到活化能为121.9kJ/mol。

  9. GASIFICATION FOR DISTRIBUTED GENERATION

    Energy Technology Data Exchange (ETDEWEB)

    Ronald C. Timpe; Michael D. Mann; Darren D. Schmidt

    2000-05-01

    evaluated through reactivity and product composition were carried out on thermogravimetric analysis (TGA) equipment. These tests were evaluated and then followed by bench-scale studies at 1123 K using an integrated bench-scale fluidized-bed gasifier (IBG) which can be operated in the semicontinuous batch mode. Products from tests were solid (ash), liquid (tar), and gas. Tar was separated on an open chromatographic column. Analysis of the gas product was carried out using on-line Fourier transform infrared spectroscopy (FT-IR). For selected tests, gas was collected periodically and analyzed using a refinery gas analyzer GC (gas chromatograph). The solid product was not extensively analyzed. This report is a part of a search into emerging gasification technologies that can provide power under 30 MW in a distributed generation setting. Larger-scale gasification has been used commercially for more than 50 years to produce clean synthesis gas for the refining, chemical, and power industries, and it is probable that scaled-down applications for use in remote areas will become viable. The appendix to this report contains a list, description, and sources of currently available gasification technologies that could be or are being commercially applied for distributed generation. This list was gathered from current sources and provides information about the supplier, the relative size range, and the status of the technology.

  10. Biomass gasification and energy production

    Energy Technology Data Exchange (ETDEWEB)

    Mahinpey, N.; Nikoo, M.B. [Regina Univ., SK (Canada). Faculty of Engineering

    2007-07-01

    The ASPEN PLUS simulation program was used to model an atmospheric fluidized bed biomass gasifier. The aim of the study was develop a simulation capable of accurately predicting steady state performance of the gasifier in relation to hydrodynamics and reaction kinetics. The influences of feed decomposition, volatile reactions, gas gasification and gas-solid separation were considered through modularized ASPEN PLUS models. The ASPEN PLUS yield reactor was used to simulate biomass feed decomposition. A separation column model was used to separate volatile materials and solids. Experimental data from a pine biomass gasification experiment conducted in a laboratory-scale fluidized bed gasifier was used to validate the simulation results. Good agreement was shown for gas composition, although carbon dioxide (CO{sub 2}) rates were slightly underestimated. The study also demonstrated that higher temperatures improved the gasification process and carbon conversion. The optimized gasification process produced more carbon monoxide (CO) and less CO{sub 2}. The introduction of lower temperature steam to the gasification process increased tar output. It was concluded that the conversion efficiency increased when the equivalence ratio was increased. 7 refs., 1 tab., 12 figs.

  11. Influence of gas environment on reactions between sodium and silicon minerals during gasification of low-rank coal

    Energy Technology Data Exchange (ETDEWEB)

    Kosminski, A.; Agnew, J.B. [Department of Chemical Engineering, University of Adelaide, South Australia, 5005 (Australia); Ross, D.P. [Department of Chemical Engineering, Tokyo University of Agriculture and Technology, BASE, Nakamachi 2-24-16 Koganei, Tokyo, 184-8588 (Japan)

    2006-11-15

    Thermodynamic equilibrium calculations were performed to determine the possible compositions and conditions for formation of potential liquid phases responsible for fluidised bed agglomeration during gasification of a high-sulphur low-rank coal from South Australia. The coals from this region of Australia are typically characterised by containing high levels of sodium, silica and sulphur. The transformation behaviour of the form of sodium present in coal, as either a carboxylate forming part of the coal organic matter or as soluble salt (NaCl) and its reaction with silicon compounds (silica or kaolin) is presented. The influence of temperature and gas atmosphere on equilibrium composition was evaluated. Thermodynamic equilibrium calculations show that the distribution of sodium among the produced species will depend on the form of sodium in the coal, the gas atmosphere and the forms in which silicon is present in the coal. Steam was found to have the most significant effect causing a lowering of the sodium carbonate melting point temperature. (author)

  12. Reformation and Summarization for Capacity Enlargement of Gasification Plant with Wet Gas Flow Bed%湿法气流床气化装置扩能改造小结

    Institute of Scientific and Technical Information of China (English)

    朱春鹏; 张光瑞; 任军哲; 徐宏伟; 罗进成; 马浚杰

    2014-01-01

    针对湿法气流床气化装置因工艺配置和关键设备的设计缺陷而长期低负荷运行的问题,提出了制浆系统、气化系统和灰水系统的扩能改造措施。结果表明,扩能改造完成后,装置整体运行平稳,产能提高了20%以上。%In allusion to problem that the gasification plant with wet gas flow bed was operated in the long term under low load due to the design de-fects of process configuration and key equipment, measures for enlarging capacity and reformation were proposed for slurry preparation system, gasification system and grey water system. Result indicates that after capacity enlargement and reformation finished, plant runs placidly as a whole, production capaci-ty is increased by more than 20%.

  13. Catalytic gasification of biomass

    Science.gov (United States)

    Robertus, R. J.; Mudge, L. K.; Sealock, L. J., Jr.; Mitchell, D. H.; Weber, S. L.

    1981-12-01

    Methane and methanol synthesis gas can be produced by steam gasification of biomass in the presence of appropriate catalysts. This concept is to use catalysts in a fluidized bed reactor which is heated indirectly. The objective is to determine the technical and economic feasibility of the concept. Technically the concept has been demonstrated on a 50 lb per hr scale. Potential advantages over conventional processes include: no oxygen plant is needed, little tar is produced so gas and water treatment are simplified, and yields and efficiencies are greater than obtained by conventional gasification. Economic studies for a plant processing 2000 T/per day dry wood show that the cost of methanol from wood by catalytic gasification is competitive with the current price of methanol. Similar studies show the cost of methane from wood is competitive with projected future costs of synthetic natural gas. When the plant capacity is decreased to 200 T per day dry wood, neither product is very attractive in today's market.

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

    OpenAIRE

    Moni Mohamad Nazmi Zaidi; Sulaiman Shaharin Anwar; Hassan Suhaimi

    2014-01-01

    Oil palm frond (OPF) has been successfully gasified to produce syngas and has since deemed as a potential source of biomass fuel in Malaysia. However, if OPF is to be utilized as a main fuel for industrial-scale firing/gasification plant, interruption in fuel supply may occur due to numerous reasons, for instance inefficient fuel processing and ineffective transportation. A secondary supporting solid fuel is therefore necessary as a partial component to the main fuel in such cases, where the ...

  15. Hydrolysis, acidification and methanogenesis during low-temperature anaerobic digestion of dilute dairy wastewater in an inverted fluidised bioreactor.

    Science.gov (United States)

    Bialek, Katarzyna; Cysneiros, Denise; O'Flaherty, Vincent

    2014-10-01

    The application of low-temperature (10 °C) anaerobic digestion (LtAD) for the treatment of complex dairy-based wastewater in an inverted fluidised bed (IFB) reactor was investigated. Inadequate mixing intensity provoked poor hydrolysis of the substrate (mostly protein), which resulted in low chemical oxygen demand (COD) removal efficiency throughout the trial, averaging ~69 % at the best operational period. Overgrowth of the attached biomass to the support particles (Extendospheres) induced bed stratification by provoking agglutination of the particles and supporting their washout by sedimentation, which contributed to unstable bioprocess performance at the organic loading rates (OLRs) between 0.5 and 5 kg COD m(-3) day(-1). An applied OLR above 2 kg COD m(-3) day(-1) additionally promoted acidification and strongly influenced the microbial composition and dynamics. Hydrogenotrophic methanogens appeared to be the mostly affected group by the Extendospheres particle washout as a decrease in their abundance was observed by quantitative PCR analysis towards the end of the trial, although the specific methanogenic activity and maximum substrate utilisation rate on H2/CO2 indicated high metabolic activity and preference towards hydrogenotrophic methanogenesis of the reactor biomass at this stage. The bacterial community in the bioreactor monitored via denaturing gradient gel electrophoresis (DGGE) also suggested an influence of OLR stress on bacterial community structure and population dynamics. The data presented in this work can provide useful information in future optimisation of fluidised reactors intended for digestion of complex industrial wastewaters during LtAD.

  16. LIEKKI 2 - Combustion and gasification research programme 1993- 1998. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M. [ed.

    1998-12-31

    expenditure of FIM 227 million have resulted in individual valuable results in abundance. Based on these results conclusions have been made and new understanding of the combustion process has been obtained. One example of tangible results is the elucidation of the mechanisms governing the formation of nitrous oxide (laughing gas). Much effort was invested in this topic because of the threats it presented to the Finnish fluidised bed technology. The control of this emission is no longer considered a problem

  17. Gasification : petcoke gasification for products

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, R. [GE Energy, Houston, TX (United States)

    2009-07-01

    Gasification is a partial oxidation process that can convert any hydrocarbon into carbon monoxide and hydrogen (syngas). This presentation discussed integrated coking and gasification to address today's refining challenges. Several case studies were presented. General Electric Energy's quench gasification process was also discussed with particular reference to key characteristics such as its simplicity, low cost, efficiency, reliability and flexibility. Other advantages of the process include its entrained flow, slagging, slurry feed and short residence time. Petcoke was discussed as a suitable gasifier feed. Converting petcoke to hydrogen, steam, and power was also presented. The challenges ahead include the piling up of millions of tons of petcoke; emissions rules shrinking the coke segment; shortage of expensive natural gas; increased needs of hydrogen, steam, and power; plant and fuel level emissions mandates; and reducing the carbon dioxide footprint of oil sands. These challenges may result in excess coke and a hydrogen deficit. The presentation concluded by bringing attention to GE Energy's leadership in gasification technology and an alliance between GE Energy and Schlumberger. figs.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    A mathematical model was developed for batch top-spray fluid bed coating processes based on Ronsse et al. [2007a.b. Combined population balance and thermodynamic modelling of the batch top-spray fluidised bed coating process. Part I-model development and validation. journal of Food Engineering 78......, 296-307; Combined population balance and thermodynamic modelling of the batch top-spray fluidised bed coating process. Part II-model and process analysis. journal of Food Engineering 78, 308-322]. The model is based on one-dimensional discretisation of the fluid bed into a number of well-mixed control...

  19. Porous-based rheological model for tissue fluidisation

    Science.gov (United States)

    Asadipour, N.; Trepat, X.; Muñoz, J. J.

    2016-11-01

    It has been experimentally observed that cells exhibit a fluidisation process when subjected to a transient stretch, with an eventual recovery of the mechanical properties upon removal of the applied deformation. This fluidisation process is characterised by a decrease of the storage modulus and an increase of the phase angle. We propose a rheological model which is able to reproduce this combined mechanical response. The model is described in the context of continua and adapted to a cell-centred particle system that simulates cell-cell interactions. Mechanical equilibrium is coupled with two evolution laws: (i) one for the reference configuration, and (ii) another for the porosity or polymer density. The first law depends on the actual strain of the tissue, while the second assumes different remodelling rates during porosity increase and decrease. The theory is implemented on a particle based model and tested on a stretching experiment. The numerical results agree with the experimental measurements for different stretching magnitudes.

  20. Apparatus for solar coal gasification

    Science.gov (United States)

    Gregg, D.W.

    Apparatus for using focused solar radiation to gasify coal and other carbonaceous materials is described. Incident solar radiation is focused from an array of heliostats onto a tower-mounted secondary mirror which redirects the focused solar radiation down through a window onto the surface of a vertically-moving bed of coal, or a fluidized bed of coal, contained within a gasification reactor. The reactor is designed to minimize contact between the window and solids in the reactor. Steam introduced into the gasification reactor reacts with the heated coal to produce gas consisting mainly of carbon monoxide and hydrogen, commonly called synthesis gas, which can be converted to methane, methanol, gasoline, and other useful products. One of the novel features of the invention is the generation of process steam at the rear surface of the secondary mirror.

  1. Chemical-looping gasification of biomass in a 10k Wth interconnected fluidized bed reactor using Fe2 O3/Al2 O3 oxygen carrier

    Institute of Scientific and Technical Information of China (English)

    HUSEYIN Sozen; WEI Guo-qiang; LI Hai-bin; HE Fang; HUANG Zhen

    2014-01-01

    The aim of this research is to design and operate a 10 kW hot chemical-looping gasification ( CLG) unit using Fe2 O3/Al2 O3 as an oxygen carrier and saw dust as a fuel. The effect of the operation temperature on gas composition in the air reactor and the fuel reactor, and the carbon conversion of biomass to CO2 and CO in the fuel reactor have been experimentally studied. A total 60 h run has been obtained with the same batch of oxygen carrier of iron oxide supported with alumina. The results show that CO and H2 concentrations are increased with increasing temperature in the fuel reactor. It is also found that with increasing fuel reactor temperature, both the amount of residual char in the fuel reactor and CO2 concentration of the exit gas from the air reactor are degreased. Carbon conversion rate and gasification efficiency are increased by increasing temperature and H2 production at 870 ℃reaches the highest rate. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET-surface area tests have been used to characterize fresh and reacted oxygen carrier particles. The results display that the oxygen carrier activity is not declined and the specific surface area of the oxygen carrier particles is not decreased significantly.

  2. 国内干粉气流床煤气化技术的工程化应用现状与展望%Present Engineering Application Situation and Prospect for Coal Gasification Technology of Dry Powder Gas Flow Bed in China

    Institute of Scientific and Technical Information of China (English)

    赵涛

    2013-01-01

      Author has reviewed the progresses for coal gasification technologies of Shell and GSP dry powder gas flow bed , imported by China, as well as self-developed HT-L, WHG etc.; has analyzed the presently industrialized application situation of the various kinds of pulverized coal gasification tech -nologies in China; has supposed some problems to be solved in the developing process of the gasification technologies of dry powder gas flow bed ; has pros-pected the engineering application foreground for the pulverized coal gasification technology.%  回顾了我国引进壳牌和 GSP 干粉气流床煤气化技术以及自主开发 HT -L、WHG 等煤气化技术的历程;分析了国内各种粉煤气化技术的工业化应用现状;提出了干粉气流床气化技术发展过程中需要解决的若干问题;展望了粉煤气化技术的工程化应用的前景。

  3. Co-gasification of sewage sludge and woody biomass in a fixed-bed downdraft gasifier: toxicity assessment of solid residues.

    Science.gov (United States)

    Rong, Le; Maneerung, Thawatchai; Ng, Jingwen Charmaine; Neoh, Koon Gee; Bay, Boon Huat; Tong, Yen Wah; Dai, Yanjun; Wang, Chi-Hwa

    2015-02-01

    As the demand for fossil fuels and biofuels increases, the volume of ash generated will correspondingly increase. Even though ash disposal is now strictly regulated in many countries, the increasing volume of ash puts pressure on landfill sites with regard to cost, capacity and maintenance. In addition, the probability of environmental pollution from leakage of bottom ash leachate also increases. The main aim of this research is to investigate the toxicity of bottom ash, which is an unavoidable solid residue arising from biomass gasification, on human cells in vitro. Two human cell lines i.e. HepG2 (liver cell) and MRC-5 (lung fibroblast) were used to study the toxicity of the bottom ash as the toxins in the bottom ash may enter blood circulation by drinking the contaminated water or eating the food grown in bottom ash-contaminated water/soil and the toxic compounds may be carried all over the human body including to important organs such as lung, liver, kidney, and heart. It was found that the bottom ash extract has a high basicity (pH = 9.8-12.2) and a high ionic strength, due to the presence of alkali and alkaline earth metals e.g. K, Na, Ca and Mg. Moreover, it also contains concentrations of heavy metals (e.g. Zn, Co, Cu, Fe, Mn, Ni and Mo) and non-toxic organic compounds. Although human beings require these trace elements, excessive levels can be damaging to the body. From the analyses of cell viability (using MTS assay) and morphology (using fluorescence microscope), the high toxicity of the gasification bottom ash extract could be related to effects of high ionic strength, heavy metals or a combination of these two effects. Therefore, our results suggest that the improper disposal of the bottom ash wastes arising from gasification can create potential risks to human health and, thus, it has become a matter of urgency to find alternative options for the disposal of bottom ash wastes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Biomass Gasification — Primary Methods for Eliminating Tar

    Directory of Open Access Journals (Sweden)

    Martin Lisý

    2012-01-01

    Full Text Available This present paper deals with primary methods for reducing tar in biomass gasification, namely by feeding a natural catalyst into a fluidized bed. This method is verified using an experimental pilot plant.

  5. 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)

  6. Progress in the field of underground gasification. Report on the 3rd symposium on underground gasification in California

    Energy Technology Data Exchange (ETDEWEB)

    Beckervordersandforth, C.P. (Technische Hochschule Aachen (Germany, F.R.). Lehrstuhl und Inst. fuer Eisenhuettenkunde)

    1978-06-01

    The underground gasification programme in the USA is described. The individual concepts within the ERDA (linked vertical well process, packed bed concept, long wall generator concept, steeply dipping beds), essentially differentiate from each other in the method in which the natural permeability of the coal is increased. Projects not within ERDA (Texas utilities project (brown coal gasification), Texas AM-project and Alberta Research Council project) arepresented briefly.

  7. 顶部点火上吸式固定床中农业废弃物气化特性分析%Gasification property of agriculture wastes in an updraft fixed bed gasifier with top-lit ignition

    Institute of Scientific and Technical Information of China (English)

    张世红; 李相鹏; 何广昌; 杨海平; 王贤华; 陈汉平

    2013-01-01

      为了了解在固定床气化炉中生物质的气化特性和炉内温度演变规律,该研究采用顶部点火上吸式(top-lit up draft,简称TLUD)固定床气化炉研究了农业废弃物的气化行为,重点考察了不同空气流量下炉内温度分布、燃气成分和热值的变化规律,探讨了生物质气化过程机理。结果表明,气化过程明显分为2个阶段,即挥发份的析出和焦炭的缓慢气化。整个气化过程中燃气的热值可稳定维持在3 MJ/m3以上,温度场的演变过程与波传递具有相似性,花生壳和稻壳的最佳空气当量比分别为0.31和0.35,且其燃气中焦油含量很低,分别为0.25、0.49 g/m3。该研究为TLUD固定床气化炉的设计和运行提供了有益的参考。%The gasification behavior of agriculture waste was investigated using a Top-lit Up Draft (TLUD) fixed-bed gasifier system which consists of four subsystems (gasifier reaction system, temperature monitor system, tar sampling system, and gas measurement system), in an attempt to find out the influence of air flow on the gasifier’s temperature distribution, gas component, and heating value, and discuss the gasification mechanism of biomass. In the study, peanut shells and rice husks were chosen as experiment material. The reactor is made fromФ219 mm×6 mm stainless steel pipe with length of 800 mm. After the reactor filled up with sample materials (about 3.5 kg), a certain amount of air (range from 2.5 m3/h to 4.0 m3/h) was pumped in at the bottom, and the sample was lit at the top. The temperature was then tested by a temperature monitoring system, and the gas product was detected by a Gasboard-3100P-type multi-component portable infrared gas analyzer (Quartet Photoelectric Technology Co., Ltd. Wuhan, China), and the tar was collected by a tar sampling system. From the results of the investigation, the gasification process lasted about 100 min, and was divided into two stages. First

  8. Method of reducing CO in combustion plant, particularly in fluidized bed combustion plant. Verfahren zur Reduzierung von CO bei Verbrennungsanlagen, insbesondere bei Wirbelbettfeuerungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Hoelter, H.; Igelbuescher, H.; Gresch, H.; Dewert, H.

    1989-05-10

    The invention describes a method of reducing the development of CO in combustion plant, particularly fluidised combustion plant, characterised in that the air is introduced in a heated condition at the points where increased CO concentrations are measured, the air being heated in tube bundles, these tube bundles being formed in such a manner as to cause an impact precipitative effect in the form of an impact precipitative arrangement at the proportioned fuel input of fluidised bed combustion plant.

  9. Mathematical model for the gasification of coal under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Biba, V.; Macak, J.; Kloss, E.; Malecha, J.

    1978-01-01

    A mathematical model for the the high-pressure gasification of solid fuels in the charged layer is presented which permits the quantitative description of the the static behavior of the generator. Deals with the parameters of reaction kinetics and of the transfer of matter and energy which are necessary for developing the model of a fixed-bed reactor. To obtain a practical model, simplifications are needed which concern the gasification, degasification, and drying processes. They are dealt with individually. For calculating the concentration and temperature profiles for the solid and gas phases along the gasification bed height, a system of differential equations was obtained which was supplemented by some algebraic equations.

  10. Estudio mecánico e hidrodinámico de un reactor de gasificación de lecho fluidizado. // Mechanic and hydrodynamic study of a fluidized bed gasification reactor.

    Directory of Open Access Journals (Sweden)

    W. Rosales

    2008-01-01

    Full Text Available Se realizó una simulación mediante Elementos Finitos y CFD de un prototipo de gasificador experimental a partir de unageometría propuesta. Se abordan aspectos termomecánicos, al calcularse las deformaciones originadas en el equipo,producto de su peso, en las condiciones de emplazamiento y la carga térmica a la que se somete. También se considera elflujo multifásico gas-sólido presente en el lecho fluidizado, se determina el rango de presiones y velocidades de trabajo deldispositivo, y se estudia la evolución del flujo. Para ello se utiliza el modelo de fuerza de arrastre y presión de sólido deGidaspow, así como los criterios de velocidad mínima de fluidización de Wen & Yu y Kunii & Levenspiel.Palabras claves: Gasificación, lecho fluidizado, CFD, FEM, flujo multifásico.______________________________________________________________________________Abstract.A Finite Element and CFD simulations were conducted to a prototype of experimental gasifier, starting from a proposedgeometry. Thermomechanic aspects are briefed, calculating the reactor deformation, due to its weight and the thermic load.The gas-solid multiphase flow, present on the fluidized bed was also considered, the working range for the pressure andvelocity fields were determined and the flow evolution was studied. The drag force and solid pressure models byGidaspow, and the minimum fluidization velocity criteria, by Wen & Yu and Kunii & Levenspiel were used.Key words: gasification, fluidized bed, CFD, Finite Element, Multiphase Flow.

  11. Studies in Three Phase Gas-Liquid Fluidised Systems

    Science.gov (United States)

    Awofisayo, Joyce Ololade

    1992-01-01

    Available from UMI in association with The British Library. The work is a logical continuation of research started at Aston some years ago when studies were conducted on fermentations in bubble columns. The present work highlights typical design and operating problems that could arise in such systems as waste water, chemical, biochemical and petroleum operations involving three-phase, gas-liquid -solid fluidisation; such systems are in increasing use. It is believed that this is one of few studies concerned with "true" three-phase, gas-liquid-solid fluidised systems, and that this work will contribute significantly to closing some of the gaps in knowledge in this area. The research work was experimentally based and involved studies of the hydrodynamic parameters, phase holdups (gas and solid), particle mixing and segregation, and phase flow dynamics (flow regime and circulation patterns). The studies have focused particularly on the solid behaviour and the influence of properties of solids present on the above parameters in three-phase, gas-liquid-solid fluidised systems containing single particle components and those containing binary and ternary mixtures of particles. All particles were near spherical in shape and two particle sizes and total concentration levels were used. Experiments were carried out in two- and three-dimensional bubble columns. Quantitative results are presented in graphical form and are supported by qualitative results from visual studies which are also shown as schematic diagrams and in photographic form. Gas and solid holdup results are compared for air-water containing single, binary and ternary component particle mixtures. It should be noted that the criteria for selection of the materials used are very important if true three-phase fluidisation is to be achieved: this is very evident when comparing the results with those in the literature. The fluid flow and circulation patterns observed were assessed for validation of the generally

  12. A breakthrough in coal gasification technology

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Tearning up with engineers of the Jincheng Anthracite Mining Group in north China's Shanxi Province, CAS researchers have successfully carried out a 1.0MPa, long-period (up to 72 hours) high-pressure test on a semi- industrial platform of pressurized ash agglomerating fluidized bed (AFB) coal gasification.

  13. Mathematical Modelling of Coal Gasification Processes

    Science.gov (United States)

    Sundararajan, T.; Raghavan, V.; Ajilkumar, A.; Vijay Kumar, K.

    2017-07-01

    Coal is by far the most commonly employed fuel for electrical power generation around the world. While combustion could be the route for coal utilization for high grade coals, gasification becomes the preferred process for low grade coals having higher composition of volatiles or ash. Indian coals suffer from high ash content-nearly 50% by weight in some cases. Instead of transporting such high ash coals, it is more energy efficient to gasify the coal and transport the product syngas. Integrated Gasification Combined Cycle (IGCC) plants and Underground Gasification of coal have become attractive technologies for the best utilization of high ash coals. Gasification could be achieved in fixed beds, fluidized beds and entrained beds; faster rates of gasification are possible in fluidized beds and entrained flow systems, because of the small particle sizes and higher gas velocities. The media employed for gasification could involve air/oxygen and steam. Use of oxygen will yield relatively higher calorific value syngas because of the absence of nitrogen. Sequestration of the carbon dioxide after the combustion of the syngas is also easier, if oxygen is used for gasification. Addition of steam can increase hydrogen yield in the syngas and thereby increase the calorific value also. Gasification in the presence of suitable catalysts can increase the composition of methane in the product gas. Several competing heterogenous and homogenous reactions occur during coal major heterogenous reaction pathways, while interactions between carbon monoxide, oxygen, hydrogen, water vapour, methane and carbon dioxide result in several simultaneous gas-phase (homogenous) reactions. The overall product composition of the coal gasification process depends on the input reactant composition, particle size and type of gasifier, and pressure and temperature of the gasifier. The use of catalysts can also selectively change the product composition. At IIT Madras, over the last one decade, both

  14. Biomass gasification, stage 2 LTH. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bjerle, I.; Chambert, L.; Hallgren, A.; Hellgren, R.; Johansson, Anders; Mirazovic, M.; Maartensson, R.; Padban, N.; Ye Zhicheng [comps.] [Lund Univ. (Sweden). Dept. of Chemical Engineering II

    1996-11-01

    This report presents the final report of the first phase of a project dealing with a comprehensive investigation on pressurized biomass gasification. The intention with the project first phase was firstly to design, install and to take in operation a PCFB biomass gasifier. A thorough feasibility study was made during the first half year including extensive calculations on an internal circulating fluidized bed concept. The experimental phase was intended to study pressurized gasification up to 2.5 MPa (N{sub 2}, air) at temperatures in the interval 850-950 deg C. The more specific experimental objective was to examine the impact from various process conditions on the product formation as well as on the function of the different systems. The technical concept has been able to offer novel approaches regarding biomass feeding and PCFB gasification. The first gasification test run was made in December 1993 after almost 18 months of installation work. Extensive work was made during 1994 and the first half of 1995 to find the balance of the PCFB gasifier. It turned out to be very difficult to find operating parameters such that gave a stable circulation of the bed material during gasification mode. Apparently, the produced gas partly changed the pressure profile over the riser which in turn gave unstable operation. After a comprehensive investigation involving more than 100 hours of tests runs it was decided to leave the circulating bed concept and focus on bubbling bed operations. The test rig is currently operating as a bubbling bed gasifier. 4 refs, 24 figs, 6 tabs

  15. Pyrolysis and Gasification

    DEFF Research Database (Denmark)

    Astrup, Thomas; Bilitewski, B.

    2011-01-01

    Pyrolysis and gasification include processes that thermally convert carbonaceous materials into products such as gas, char, coke, ash, and tar. Overall, pyrolysis generates products like gas, tar, and char, while gasification converts the carboncontaining materials (e.g. the outputs from pyrolysis......) into a mainly gaseous output. The specific output composition and relative amounts of the outputs greatly depend on the input fuel and the overall process configuration. Although pyrolysis processes in many cases also occur in gasification (however prior to the gasification processes), the overall technology...... may often be described as gasification only. Pyrolysis, however, can also be employed without proceeding with gasification. Gasification is by no means a novel process; in the 19th century so-called ‘town gas’ was produced by the gasification of coal and for example used for illumination purposes...

  16. Convection and segregation in fluidised granular systems exposed to two-dimensional vibration

    Science.gov (United States)

    Windows-Yule, C. R. K.

    2016-03-01

    Convection and segregation in granular systems not only provide a rich phenomenology of scientifically interesting behaviours but are also crucial to numerous ‘real-world’ processes ranging from important and widely used industrial procedures to potentially cataclysmic geophysical phenomena. Simple, small-scale experimental or simulated test systems are often employed by researchers in order to gain an understanding of the fundamental physics underlying the behaviours of granular media. Such systems have been the subject of extensive research over several decades, with numerous system geometries and manners of producing excitation explored. Energy is commonly provided to granular assemblies through the application of vibration—the simplicity of the dynamical systems produced and the high degree of control afforded over their behaviour make vibrated granular beds a valuable canonical system by which to explore a diverse range of phenomena. Although a wide variety of vibrated systems have been explored in the existing literature, the vast majority are exposed to vibration along only a single spatial direction. In this paper, we study highly fluidised systems subjected to strong, multi-directional driving, providing a first insight into the dynamics and behaviours of these systems which may potentially hold valuable new information relevant to important industrial and natural processes. With a particular focus on the processes of convection and segregation, we analyse the various states and phase transitions exhibited by our system, detailing a number of previously unobserved dynamical phenomena and system states.

  17. Considerations on coal gasification

    Science.gov (United States)

    Franzen, J. E.

    1978-01-01

    Commercial processes for the gasification of coal with oxygen are discussed. The Koppers-Totzek process for the gasification of coal dust entrained in a stream of gasifying agents is described in particular detail. The outlook for future applications of coal gasification is presented.

  18. Gasification performance of switchgrass pretreated with torrefaction and densification

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Shankar Tumuluru; Various

    2014-08-01

    The purpose of this study was to investigate gasification performance of four switchgrass pretreatments (torrefaction at 230 and 270 °C, densification, and combined torrefaction and densification) and three gasification temperatures (700, 800 and 900 °C). Gasification was performed in a fixed-bed externally heated reactor with air as an oxidizing agent. Switchgrass pretreatment and gasification temperature had significant effects on gasification performance such as gas yields, syngas lower heating value (LHV), and carbon conversion and cold gas efficiencies. With an increase in the gasification temperature, yields of H2 and CO, syngas LHV, and gasifier efficiencies increased whereas CH4, CO2 and N2 yields decreased. Among all switchgrass pretreatments, gasification performance of switchgrass with combined torrefaction and densification was the best followed by that of densified, raw and torrefied switchgrass. Gasification of combined torrefied and densified switchgrass resulted in the highest yields of H2 (0.03 kg/kg biomass) and CO (0.72 kg/kg biomass), highest syngas LHV (5.08 MJ m-3), CCE (92.53%), and CGE (68.40%) at the gasification temperature of 900 °C.

  19. CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Yaw D. Yeboah; Dr. Yong Xu; Dr. Atul Sheth; Dr. Pradeep Agrawal

    2001-12-01

    The Gas Research Institute (GRI) estimates that by the year 2010, 40% or more of U.S. gas supply will be provided by supplements including substitute natural gas (SNG) from coal. These supplements must be cost competitive with other energy sources. The first generation technologies for coal gasification e.g. the Lurgi Pressure Gasification Process and the relatively newer technologies e.g. the KBW (Westinghouse) Ash Agglomerating Fluidized-Bed, U-Gas Ash Agglomerating Fluidized-Bed, British Gas Corporation/Lurgi Slagging Gasifier, Texaco Moving-Bed Gasifier, and Dow and Shell Gasification Processes, have several disadvantages. These disadvantages include high severities of gasification conditions, low methane production, high oxygen consumption, inability to handle caking coals, and unattractive economics. Another problem encountered in catalytic coal gasification is deactivation of hydroxide forms of alkali and alkaline earth metal catalysts by oxides of carbon (CO{sub x}). To seek solutions to these problems, a team consisting of Clark Atlanta University (CAU, a Historically Black College and University, HBCU), the University of Tennessee Space Institute (UTSI) and Georgia Institute of Technology (Georgia Tech) proposed to identify suitable low melting eutectic salt mixtures for improved coal gasification. The research objectives of this project were to: Identify appropriate eutectic salt mixture catalysts for coal gasification; Assess agglomeration tendency of catalyzed coal; Evaluate various catalyst impregnation techniques to improve initial catalyst dispersion; Determine catalyst dispersion at high carbon conversion levels; Evaluate effects of major process variables (such as temperature, system pressure, etc.) on coal gasification; Evaluate the recovery, regeneration and recycle of the spent catalysts; and Conduct an analysis and modeling of the gasification process to provide better understanding of the fundamental mechanisms and kinetics of the process.

  20. EMERY BIOMASS GASIFICATION POWER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin Phillips; Scott Hassett; Harry Gatley

    2002-11-27

    Emery Recycling Corporation (now Emery Energy Company, LLC) evaluated the technical and economical feasibility of the Emery Biomass Gasification Power System (EBGPS). The gasifier technology is owned and being developed by Emery. The Emery Gasifier for this project was an oxygen-blown, pressurized, non-slagging gasification process that novelly integrates both fixed-bed and entrained-flow gasification processes into a single vessel. This unique internal geometry of the gasifier vessel will allow for tar and oil destruction within the gasifier. Additionally, the use of novel syngas cleaning processes using sorbents is proposed with the potential to displace traditional amine-based and other syngas cleaning processes. The work scope within this project included: one-dimensional gasifier modeling, overall plant process modeling (ASPEN), feedstock assessment, additional analyses on the proposed syngas cleaning process, plant cost estimating, and, market analysis to determine overall feasibility and applicability of the technology for further development and commercial deployment opportunities. Additionally, the project included the development of a detailed technology development roadmap necessary to commercialize the Emery Gasification technology. Process modeling was used to evaluate both combined cycle and solid oxide fuel cell power configurations. Ten (10) cases were evaluated in an ASPEN model wherein nine (9) cases were IGCC configurations with fuel-to-electricity efficiencies ranging from 38-42% and one (1) case was an IGFC solid oxide case where 53.5% overall plant efficiency was projected. The cost of electricity was determined to be very competitive at scales from 35-71 MWe. Market analysis of feedstock availability showed numerous market opportunities for commercial deployment of the technology with modular capabilities for various plant sizes based on feedstock availability and power demand.

  1. Gasification of secondary fuels in a circulating fluidized bed for energetic use in cement production; Vergasung von Sekundaerbrennstoffen in der zirkulierenden Wirbelschicht zur energetischen Nutzung fuer die Zementherstellung

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, J.; Gafron, B. [Lurgi Umwelt GmbH, Frankfurt am Main (Germany); Scur, P.; Wirthwein, R. [Ruedersdorfer Zement GmbH (Germany)

    1998-09-01

    Ruedersforf cement factory was commissioned a century ago as one of the first in Germany. After the plant was taken over by Readymix AG, a comprehensive sanitation concept was carried through. The plant has a production capacity of 8000 t/d of cement clinkers which are produced in a new kiln with a capacity of 6000 t/d and two modernized kilns each with a capacity of 1000 t/d. Reduction of energy consumption was the main goal of modernisation, with fuel gas generation in a circulating fluidized bed as a key element. The unit provides 40 % of the energy consumed by the clinker production process and is also used for selective ash production up to 25 t/h. The ash is used as a raw material for cement production. (orig./SR) [Deutsch] Bereits vor 100 Jahren wurde eine der ersten Zementfabriken in Deutschland am Standort Ruedersdorf in Betrieb genommen. Zum Erhalt der Wettbewerbsfaehigkeit wurde nach der Uebernahme des Werkes Ruedersdorf durch die Readymix AG ein umfangreiches Sanierungskonzept in die Wege geleitet. Bei einer Produktionskapazitaet von ca. 8 000 t Klinker pro Tag werden eine neue Ofenanlage mit einer Kapazitaet von 6 000 t/Tag sowie 2 sanierte kleine Anlagen zu je 1000 t/Tag betrieben. In der neuen Ofenanlage werden alle Moeglichkeiten genutzt, den Energiebedarf fuer die Klinkerproduktion zu senken. Eine wesentliche neue innovative Komponente ist dabei eine Brenngaserzeugung in einer Zirkulierenden Wirbelschicht, ueber die im folgenden berichtet werden soll. Die Anlage kann bis zu 40% des Energiebedarfes des Zementprozesses liefern. Weiterhin wird mit der ZWS eine gezielte Ascheproduktion, bis zu 25 t/h, betrieben. Diese Aschen sind Teil der Rohstoffrezeptur an der Rohmuehle. (orig./SR)

  2. The technical and economic feasibility of Cynara cardunculus L. gasification

    OpenAIRE

    Gómez García, Alberto

    2013-01-01

    This PhD Thesis analyses the technical and economic feasibility of the gasification of one of the most promising energy crops in terms of biomass yield and plantation costs: Cynara cardunculus L. (cynara). The aim of this analysis is to assess the bioenergy production via fluidized bed gasification (FBG) and the ulterior treatment of the synthesis gas (syngas) produced in the FBG reactor to adequate it to end-use applications such as gas turbines and internal combustion engines. To achieve th...

  3. Coal Chemical Gasification Process Schedule Control%煤气化工艺研究

    Institute of Scientific and Technical Information of China (English)

    李振

    2015-01-01

    介绍了Lurgi炉固定床加压气化、Texaco水煤浆加压气化、Shell 煤气化工艺和 GSP 粉煤气化工艺4种煤气化工艺,阐述了Shell 煤气化工艺和 GSP 粉煤气化工艺的工艺流程,并对其进行了技术分析。%Introduces the Lurgi fixed bed gasification furnace,Texaco coal-water slurry gasification,Shell coal gasifica-tion Process,GSP coal gasification process four kinds of coal gasification process,and which elaborates technical character-istics and process of coal gasification process control of Shell coal gasification process and GSP process.

  4. High Performance Gasification with the Two-Stage Gasifier

    DEFF Research Database (Denmark)

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

    2002-01-01

    Based on more than 15 years of research and practical experience, the Technical University of Denmark (DTU) and COWI Consulting Engineers and Planners AS present the two-stage gasification process, a concept for high efficiency gasification of biomass producing negligible amounts of tars. In the ......Based on more than 15 years of research and practical experience, the Technical University of Denmark (DTU) and COWI Consulting Engineers and Planners AS present the two-stage gasification process, a concept for high efficiency gasification of biomass producing negligible amounts of tars....... In the two-stage gasification concept, the pyrolysis and the gasification processes are physical separated. The volatiles from the pyrolysis are partially oxidized, and the hot gases are used as gasification medium to gasify the char. Hot gases from the gasifier and a combustion unit can be used for drying...... a cold gas efficiency exceeding 90% is obtained. In the original design of the two-stage gasification process, the pyrolysis unit consists of a screw conveyor with external heating, and the char unit is a fixed bed gasifier. This design is well proven during more than 1000 hours of testing with various...

  5. Biomass utilization for the process of gasification

    Directory of Open Access Journals (Sweden)

    Josef Spěvák

    2008-01-01

    Full Text Available Biomass as one of the renewable resources of energy has bright future in utilization, especially in obtaining various forms of energy (heat, electrical energy, gas.According to the conception of energy policy of the Czech Republic and according to the fulfillment of the indicators of renewable resources using until the year 2010, the research of thermophysical characteristics of biofuels was realized.There were acquired considerable amount of results by combustion and gasification process on the basis of three-year project „Biomass energy parameters.” By means of combustion and gasification tests of various (biomass fuels were acquired the results which were not published so far.Acquired results are published in the fuel sheets, which are divided into four parts. They consist of information on fuel composition, ash composition, testing conditions and measurand overview. Measurements were realized for the process of combustion, fluidized-bed gasification and fixed-bed gasification. Following fuels were tested: Acacia, Pine, Birch, Beech, Spruce, Poplar, Willow, Rape, Amaranth, Corn, Flax, Wheat, Safflower, Mallow, and Sorrel.

  6. Gasification of Woody Biomass.

    Science.gov (United States)

    Dai, Jianjun; Saayman, Jean; Grace, John R; Ellis, Naoko

    2015-01-01

    Interest in biomass to produce heat, power, liquid fuels, hydrogen, and value-added chemicals with reduced greenhouse gas emissions is increasing worldwide. Gasification is becoming a promising technology for biomass utilization with a positive environmental impact. This review focuses specifically on woody biomass gasification and recent advances in the field. The physical properties, chemical structure, and composition of biomass greatly affect gasification performance, pretreatment, and handling. Primary and secondary catalysts are of key importance to improve the conversion and cracking of tars, and lime-enhanced gasification advantageously combines CO2 capture with gasification. These topics are covered here, including the reaction mechanisms and biomass characterization. Experimental research and industrial experience are investigated to elucidate concepts, processes, and characteristics of woody biomass gasification and to identify challenges.

  7. Biomass Oxygen Enriched-steam Gasification in an Atmospheric Fluidized Bed for Syngas Production%生物质流化床富氧-水蒸气气化制备合成气研究

    Institute of Scientific and Technical Information of China (English)

    苏德仁; 周肇秋; 谢建军; 朗林; 阴秀丽; 吴创之

    2011-01-01

    Biomass gasification with steam-oxygen enriched air in an atmospheric fluidized bed gasifier was studied. The gasifier was 9 m high with the bed diameter of 0. 5 m. Sawdust with different moisture contents was used as feedstock, and it was fed into the gasifier at flow rates of 180 ~ 270 kg/h. The effects of equivalence ratio, steam to biomass ratio, secondary flow ratio and feedstock moisture on the bed temperature, gas compositions, tar content, lower heating values, gas yield, carbon conversion efficiency and cold gas efficiency were investigated. The results showed under the operating conditions of ER is 0. 25 ~ 0. 27 and S/B = 0. 4, the following syngas was obtained: H2 content of 28. 7% , H2/CO ratio of 0.94, low heating value of 9.9 MJ/m3, cold gas efficiency was more than 75% , carbon conversion efficiency was more than 97% ; a second flow ratio of 25% at the ER of 0. 29 can significantly reduce the tar content to 49 mg/m , but hardly improve the quality of the gas produced; the rise of the feedstock moisture content caused a significant increase in CO2 content and a reduction in H2 and CO contents, and the moisture content is expected not to exceed 20% .%使用不同含水率的木粉为原料,以180~270 kg/h的进料速度在内径0.5 m、高9 m的常压流化床气化炉上进行了富氧-水蒸气气化制备合成气实验.考察了当量比、水蒸气配比、二次风以及原料含水率对气化温度、燃气组分、低位热值、气体产率、气化效率和碳转化率等参数的影响.结果显示:当量比为0.25~0.27之间,水蒸气配比0.4时,H:含量最高可达28.7%,H2/CO为0.94,燃气热值9.9 MJ/m3,气化效率大于75%,碳转化率大于97%;提高二次风比率可明显降低焦油含量,在总当量比0.29、二次风比率25%时焦油含量为49 ms/m3;原料水分增加,气体质量下降,含水率以不超过20%为宜.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-01

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

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

    NARCIS (Netherlands)

    Siedlecki, M.

    2011-01-01

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

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

    NARCIS (Netherlands)

    Siedlecki, M.

    2011-01-01

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

  11. Radiative Gasification Apparatus

    Data.gov (United States)

    Federal Laboratory Consortium — This apparatus, developed at EL, determines gasification rate (mass loss rate) of a horizontally oriented specimen exposed in a nitrogen environment to a controlled...

  12. Pyrolysis and Gasification

    DEFF Research Database (Denmark)

    Astrup, Thomas; Bilitewski, B.

    2011-01-01

    Pyrolysis and gasification include processes that thermally convert carbonaceous materials into products such as gas, char, coke, ash, and tar. Overall, pyrolysis generates products like gas, tar, and char, while gasification converts the carboncontaining materials (e.g. the outputs from pyrolysis....... Today gasification is used within a range of applications, the most important of which are conversion of coal into syngas for use as chemical feedstock or energy production; but also gasification of biomass and waste is gaining significant interest as emerging technologies for sustainable energy. From...

  13. Gasification-based biomass

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-01-18

    The gasification-based biomass section of the Renewable Energy Technology Characterizations describes the technical and economic status of this emerging renewable energy option for electricity supply.

  14. International Seminar on Gasification 2008

    Energy Technology Data Exchange (ETDEWEB)

    Held, Joergen (ed.)

    2008-11-15

    results in a product gas free of nitrogen and hence suitable for production of biomethane. The concept has been proven at the Guessing plant using a slip-stream but still we are awaiting the first commercial plant that produce biomethane suitable as vehicle fuel or for grid injection. Several demonstration projects are related to air-blown gasification and CHP production. The two-stage Viking gasifier developed at Technical University of Denmark produces a gas with low tar content (<5 mg/Nm3) suitable for combined heat and power production where a gas engine is used for the electricity production. The 70 kW{sub th} pilot plant has an electric efficiency of 25 %. With a scale-up to 0.2-2 MW{sub e} and improved internal heat recovery an electric efficiency of >37 % is expected. In Skive, Denmark, biomass gasification in a 20 MW{sub th} gasifier based on technology developed at GTI, USA and commercialized by Carbona, Finland is demonstrated. The total investment cost is 30 million Euro. Expected pay-back time is approx. 10 years. The project is delayed and the official opening is planned to April 2009. The delay reflects the inherent uncertainty related to large-scale demonstration of new technology. There are several other demonstrations related to biomass gasification and gas cleaning on their way and the field of gasification seems to experience a renaissance. Gas engines utilizing gasified biomass are commercially available. GE Jenbacher has installed gas engines in many biomass gasification plants in Europe. The accumulated hours of operation for the gas engines well exceed 100,000 hours. The plants with installed gas engines span over different gasification technologies (e.g. fixed bed - updraft, fixed bed - down draft and indirect gasification) and different gas compositions with lower heating values ranging from 5.4 MJ/Nm3 to 10.5 MJ/Nm3. High CO content in the gas results in high CO emissions from the gas engine which calls for exhaust gas after-treatment. To avoid

  15. International Seminar on Gasification 2008

    Energy Technology Data Exchange (ETDEWEB)

    Held, Joergen (ed.)

    2008-11-15

    results in a product gas free of nitrogen and hence suitable for production of biomethane. The concept has been proven at the Guessing plant using a slip-stream but still we are awaiting the first commercial plant that produce biomethane suitable as vehicle fuel or for grid injection. Several demonstration projects are related to air-blown gasification and CHP production. The two-stage Viking gasifier developed at Technical University of Denmark produces a gas with low tar content (<5 mg/Nm3) suitable for combined heat and power production where a gas engine is used for the electricity production. The 70 kW{sub th} pilot plant has an electric efficiency of 25 %. With a scale-up to 0.2-2 MW{sub e} and improved internal heat recovery an electric efficiency of >37 % is expected. In Skive, Denmark, biomass gasification in a 20 MW{sub th} gasifier based on technology developed at GTI, USA and commercialized by Carbona, Finland is demonstrated. The total investment cost is 30 million Euro. Expected pay-back time is approx. 10 years. The project is delayed and the official opening is planned to April 2009. The delay reflects the inherent uncertainty related to large-scale demonstration of new technology. There are several other demonstrations related to biomass gasification and gas cleaning on their way and the field of gasification seems to experience a renaissance. Gas engines utilizing gasified biomass are commercially available. GE Jenbacher has installed gas engines in many biomass gasification plants in Europe. The accumulated hours of operation for the gas engines well exceed 100,000 hours. The plants with installed gas engines span over different gasification technologies (e.g. fixed bed - updraft, fixed bed - down draft and indirect gasification) and different gas compositions with lower heating values ranging from 5.4 MJ/Nm3 to 10.5 MJ/Nm3. High CO content in the gas results in high CO emissions from the gas engine which calls for exhaust gas after-treatment. To avoid

  16. Combined heat and power production based on gas turbine operation with biomass by gasification or powder firing; Kraftvaermeproduktion baserad paa gasturbindrift med biobraensle genom foergasning alternativt pulvereldning

    Energy Technology Data Exchange (ETDEWEB)

    Marbe, Aasa; Colmsjoe, Linda

    2006-12-15

    Combined heat and power (CHP) technique is relatively less extended in the Swedish energy system. There is a production of 56,2 TWh in district heating meanwhile only 7,6 TWh electricity comes from CHP. This only corresponds to 6 % of all electricity produced in Sweden (132 TWh). Based on the existing district heating system the amount of electricity produced in CHP-plants could rise from today 7,6 to 20 TWh. The Swedish government has decided to reduce the amount of CO{sub 2} released to atmosphere with 4 % by the year 2012. Furthermore there is a government decision that the nuclear power in a long time perspective will be phased out, so the amount of biofuelled heat and power plants has a huge potential to increase. To be competitive, the technique is to be efficient; hence the amount electricity produced should be as high as possible. Gasification of biofuel where the gas is used in a combined-cycle provides a higher efficiency compared to the traditional steam-cycle technique. To increase the electrical efficiency, an alternative method such as integration of a gas turbine with combustion of powder shape bio fuel in an external combustion chamber could be used. The concept is known as PFBC- technique in which the coal powder is combusted in a pressurised fluidised bed, the warm flue gases are cleaned up and expanded in a gas turbine. The objectives of this project have been to investigate the technical and economical conditions for gasification of bio fuel and for powder combustion in gas turbine for production of heat and power in different districts heat systems. Respectively technique has been studied in two different cases, Boraas Energi AB and ENA Energi AB. In Boraas the existing CHP-plant has been replaced by a bio fuelled gasification plant (IGCC) meanwhile at ENA Energi the existing CHP-plant has been complemented white a powder fuelled (bio) gas turbine. The task group for this report are decision makers of Energy Companies and the report will help

  17. An evaluation of char reactivity and ash properties in biomass gasification. Fundamental processes in biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Holst Soerensen, L.; Fjellerup, J.; Henriksen, U.; Moilanen, A.; Kurkela, E.; Winther, E.

    2000-09-01

    This work focus on the connection between char reactivity, ash agglomeration and sintering and the gas composition in the turbid environment in a circulating fluidized bed gasification process, where biomass is gasified, with focus on straw gasification. The model approach intends to combine equilibrium calculation programming of complex multicomponent-multiphase systems involving gas, solid and liquid solutions of salts and silicates with the concept of catalytic effects in fuel reactivity. Char gasification reactivity and ash characteristics have been tested experimentally in a bench scale fluidized bed, in different thermal balances and in high-temperature light-microscope equipment. Ten different Danish straw samples and some artificial samples and catalysts were tested. It was found that the most important difference between the straw behaviour, that seems to determine the reactivity and the sintering tendency, were the calculated solid bed mol-ratio, {gamma}{sub {kappa}}=SiO{sub 2}/K{sub 2}O. We suggest that a fuel has high agglomeration tendency if 2<{gamma}{kappa}<15 and very high agglomeration tendency if 3<{gamma}{kappa}<5. It has also been found that a number of additives if properly added are effective for the prevention of agglomeration and sintering of straw ash. A literature survey study on tar cracking from biomass gasification has been performed. (au)

  18. Gasification Product Improvement Facility (GPIF). Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The gasifier selected for development under this contract is an innovative and patented hybrid technology which combines the best features of both fixed-bed and fluidized-bed types. PyGas{trademark}, meaning Pyrolysis Gasification, is well suited for integration into advanced power cycles such as IGCC. It is also well matched to hot gas clean-up technologies currently in development. Unlike other gasification technologies, PyGas can be designed into both large and small scale systems. It is expected that partial repowering with PyGas could be done at a cost of electricity of only 2.78 cents/kWh, more economical than natural gas repowering. It is extremely unfortunate that Government funding for such a noble cause is becoming reduced to the point where current contracts must be canceled. The Gasification Product Improvement Facility (GPIF) project was initiated to provide a test facility to support early commercialization of advanced fixed-bed coal gasification technology at a cost approaching $1,000 per kilowatt for electric power generation applications. The project was to include an innovative, advanced, air-blown, pressurized, fixed-bed, dry-bottom gasifier and a follow-on hot metal oxide gas desulfurization sub-system. To help defray the cost of testing materials, the facility was to be located at a nearby utility coal fired generating site. The patented PyGas{trademark} technology was selected via a competitive bidding process as the candidate which best fit overall DOE objectives. The paper describes the accomplishments to date.

  19. Model-based prediction of fluid bed state in full-scale drinking water pellet softening reactors

    NARCIS (Netherlands)

    Kramer, O.; Jobse, M.A.; Baars, E.T.; van der Helm, A.W.C.; Colin, M.G.; Kors, L...J...; van Vugt, W.H.

    2015-01-01

    Softening at drinking water treatment plants is often realised by fluidised bed pellet reactors. Generally, sand is used as seeding material and pellets are produced as a by-product. To improve to sustainability, research has been carried out to replace the seeding material by re-using grained and s

  20. Conceptual design report -- Gasification Product Improvement Facility (GPIF)

    Energy Technology Data Exchange (ETDEWEB)

    Sadowski, R.S.; Skinner, W.H.; House, L.S.; Duck, R.R. [CRS Sirrine Engineers, Inc., Greenville, SC (United States); Lisauskas, R.A.; Dixit, V.J. [Riley Stoker Corp., Worcester, MA (United States); Morgan, M.E.; Johnson, S.A. [PSI Technology Co., Andover, MA (United States). PowerServe Div.; Boni, A.A. [PSI-Environmental Instruments Corp., Andover, MA (United States)

    1994-09-01

    The problems heretofore with coal gasification and IGCC concepts have been their high cost and historical poor performance of fixed-bed gasifiers, particularly on caking coals. The Gasification Product Improvement Facility (GPIF) project is being developed to solve these problems through the development of a novel coal gasification invention which incorporates pyrolysis (carbonization) with gasification (fixed-bed). It employs a pyrolyzer (carbonizer) to avoid sticky coal agglomeration caused in the conventional process of gradually heating coal through the 400 F to 900 F range. In so doing, the coal is rapidly heated sufficiently such that the coal tar exists in gaseous form rather than as a liquid. Gaseous tars are then thermally cracked prior to the completion of the gasification process. During the subsequent endothermic gasification reactions, volatilized alkali can become chemically bound to aluminosilicates in (or added to) the ash. To reduce NH{sub 3} and HCN from fuel born nitrogen, steam injection is minimized, and residual nitrogen compounds are partially chemically reduced in the cracking stage in the upper gasifier region. Assuming testing confirms successful deployment of all these integrated processes, future IGCC applications will be much simplified, require significantly less mechanical components, and will likely achieve the $1,000/kWe commercialized system cost goal of the GPIF project. This report describes the process and its operation, design of the plant and equipment, site requirements, and the cost and schedule. 23 refs., 45 figs., 23 tabs.

  1. Gasification biochar as a valuable by-product for carbon sequestration and soil amendment

    DEFF Research Database (Denmark)

    Hansen, Veronika; Müller-Stöver, Dorette Sophie; Ahrenfeldt, Jesper

    2015-01-01

    Thermal gasification of various biomass residues is a promising technology for combining bioenergy production with soil fertility management through the application of the resulting biochar as soil amendment. In this study, we investigated gasification biochar (GB) materials originating from two...... major global biomass fuels: straw gasification biochar (SGB) and wood gasification biochar (WGB), produced by a Low Temperature Circulating Fluidized Bed gasifier (LT-CFB) and a TwoStage gasifier, respectively, optimized for energy conversion. Stability of carbon in GB against microbial degradation...

  2. A Study of Solid Particles Feeding Tehnic by Fluidization Une technique d'alimentation en particules solides par fluidisation

    Directory of Open Access Journals (Sweden)

    Dolignier J.-C.

    2006-12-01

    Full Text Available The study of heterogeneous reactions in a drop tube furnace, at a laboratory scale, needs a continuous feeding and dispersing technic to yield mass flow rates as low as 1 g/h. In the present work, a solution based on fluidization, is proposed. A mixture of lime and sand is fluidized at a superficial velocity higher than the free fall velocity of the lime particles which are therefore carried over by the fluidizing gas stream out of the bed. The effects of various parameters such as the particles diameter, the lime content in the solid mixture, the height of the fluidized bed and the gas fluidizing velocity, on the flow have been investigated. The operating conditions leading to the obtention of a constant solid rate have been optimized. A simple method of evaluating the mass of the evacuated and dispersed lime particles have been developed, and satisfactory results were obtained. L'étude des réactions hétérogènes dans un four à chute à l'échelle du laboratoire nécessite l'utilisation d'une technique d'alimentation et de dispersion afin de débiter des masses de solides autour de 1 g/h. Dans ce présent travail, une technique basée sur la fluidisation est proposée. Un mélange de chaux et de sable est fluidisé à une vitesse superficielle plus élevée que la vitesse terminale de chute des particules de chaux, qui par conséquent sont transportées hors du lit. L'influence des divers paramètres tels que le diamètre des particules, le pourcentage de chaux dans le mélange, la hauteur du lit et la vitesse de fluidisation du gaz sur l'écoulement ont été étudiés. Les conditions opératoires permettant d'obtenir des débits de solides constants ont été optimisées. Une méthode relativement simple permettant d'évaluer la quantité de solide évacuée a été développée et des résultats satisfaisants ont été obtenus.

  3. Integrated hot fuel gas cleaning for advanced gasification combined cycle process

    Energy Technology Data Exchange (ETDEWEB)

    Nieminen, M.; Kangasmaa, K.; Laatikainen, J.; Staahlberg, P.; Kurkela, E. [VTT Energy, Espoo (Finland). Gasification and Advanced Combustion

    1996-12-01

    The fate of halogens in pressurised fluidized-bed gasification and hot gas filtration is determined. Potential halogen removal sorbents, suitable for integrated hot gas cleaning, are screened and some selected sorbents are tested in bench scale. Finally, halogen removal results are verified using the PDU-scale pressurised fluidized-bed gasification and integrated hot gas cleaning facilities of VTT. The project is part of the JOULE II Extension programme of the European Union. (author)

  4. 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.

  5. High Pressure Biomass Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Pradeep K [Georgia Tech Research Corporation, Atlanta, GA (United States)

    2016-07-29

    According to the Billion Ton Report, the U.S. has a large supply of biomass available that can supplement fossil fuels for producing chemicals and transportation fuels. Agricultural waste, forest residue, and energy crops offer potential benefits: renewable feedstock, zero to low CO2 emissions depending on the specific source, and domestic supply availability. Biomass can be converted into chemicals and fuels using one of several approaches: (i) biological platform converts corn into ethanol by using depolymerization of cellulose to form sugars followed by fermentation, (ii) low-temperature pyrolysis to obtain bio-oils which must be treated to reduce oxygen content via HDO hydrodeoxygenation), and (iii) high temperature pyrolysis to produce syngas (CO + H2). This last approach consists of producing syngas using the thermal platform which can be used to produce a variety of chemicals and fuels. The goal of this project was to develop an improved understanding of the gasification of biomass at high pressure conditions and how various gasification parameters might affect the gasification behavior. Since most downstream applications of synags conversion (e.g., alcohol synthesis, Fischer-Tropsch synthesis etc) involve utilizing high pressure catalytic processes, there is an interest in carrying out the biomass gasification at high pressure which can potentially reduce the gasifier size and subsequent downstream cleaning processes. It is traditionally accepted that high pressure should increase the gasification rates (kinetic effect). There is also precedence from coal gasification literature from the 1970s that high pressure gasification would be a beneficial route to consider. Traditional approach of using thermogravimetric analyzer (TGA) or high-pressure themogravimetric analyzer (PTGA) worked well in understanding the gasification kinetics of coal gasification which was useful in designing high pressure coal gasification processes. However

  6. Integrated bioenergy conversion concepts for small scale gasification power systems

    Science.gov (United States)

    Aldas, Rizaldo Elauria

    Thermal and biological gasification are promising technologies for addressing the emerging concerns in biomass-based renewable energy, environmental protection and waste management. However, technical barriers such as feedstock quality limitations, tars, and high NOx emissions from biogas fueled engines impact their full utilization and make them suffer at the small scale from the need to purify the raw gas for most downstream processes, including power generation other than direct boiler use. The two separate gasification technologies may be integrated to better address the issues of power generation and waste management and to complement some of each technologies' limitations. This research project investigated the technical feasibility of an integrated thermal and biological gasification concept for parameters critical to appropriately matching an anaerobic digester with a biomass gasifier. Specific studies investigated the thermal gasification characteristics of selected feedstocks in four fixed-bed gasification experiments: (1) updraft gasification of rice hull, (2) indirect-heated gasification of rice hull, (3) updraft gasification of Athel wood, and (4) downdraft gasification of Athel and Eucalyptus woods. The effects of tars and other components of producer gas on anaerobic digestion at mesophilic temperature of 36°C and the biodegradation potentials and soil carbon mineralization of gasification tars during short-term aerobic incubation at 27.5°C were also examined. Experiments brought out the ranges in performance and quality and quantity of gasification products under different operating conditions and showed that within the conditions considered in the study, these gasification products did not adversely impact the overall digester performance. Short-term aerobic incubation demonstrated variable impacts on carbon mineralization depending on tar and soil conditions. Although tars exhibited low biodegradation indices, degradation may be improved if the

  7. Development program to support industrial coal gasification. Quarterly report 1

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-01-15

    The Development Program to Support Industrial Coal Gasification is on schedule. The efforts have centered on collecting background information and data, planning, and getting the experimental program underway. The three principal objectives in Task I-A were accomplished. The technical literature was reviewed, the coals and binders to be employed were selected, and tests and testing equipment to be used in evaluating agglomerates were developed. The entire Erie Mining facility design was reviewed and a large portion of the fluidized-bed coal gasification plant design was completed. Much of the work in Task I will be experimental. Wafer-briquette and roll-briquette screening tests will be performed. In Task II, work on the fluidized-bed gasification plant design will be completed and work on a plant design involving entrained-flow gasifiers will be initiated.

  8. Gasification - Status and technology

    Energy Technology Data Exchange (ETDEWEB)

    Held, Joergen

    2012-06-15

    In this report gasification and gas cleaning techniques for biomass are treated. The main reason for gasifying biomass is to refine the fuel to make it suitable for efficient CHP production, as vehicle fuel or in industrial processes. The focus is on production of synthesis gas that can be used for production of vehicle fuel and for CHP production. Depending on application different types of gasifiers, gasification techniques and process parameters are of interest. Two gasification techniques have been identified as suitable for syngas generation, mainly due to the fact that they allow the production of a nitrogen free gas out of the gasifier; Indirect gasification and pressurized oxygen-blown gasification For CHP production there are no restrictions on the gas composition in terms of nitrogen and here air-blown gasification is of interest as well. The main challenge when it comes to gas cleaning is related to sulphur and tars. There are different concepts and alternatives to handle sulphur and tars. Some of them are based on conventional techniques with well-proven components that are commercially available while others, more advantageous solutions, still need further development.

  9. Biomass integrated CFB gasification combined cycle plants

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-01-01

    This paper presents an overview on the Lurgi-Circulating Fluidized Bed technology (CFB). CFB units are state of the art and have proven their capability of converting biomass, waste or coal into power and/or steam. CFB reactors are in commercial operation for reduction processes and for combustion and gasification of solid fuels. In this paper reduction processes are not considered. The fact, that world-wide over 80 CFB combustion plants using Lurgi technology are commercially operating proves that this technology is well accepted. Lurgi's CFB gasification technology is at present applied in two industrial plants. It is the key process for the advanced biomass or waste utilisation plants. The paper focuses on CFB fuel gas production for combined cycle plants (IGCC) and for cofiring into existing boiler plants. 5 refs., 4 figs.

  10. Biomass integrated CFB gasification combined cycle plants

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

    This paper presents an overview on the Lurgi-Circulating Fluidized Bed technology (CFB). CFB units are state of the art and have proven their capability of converting biomass, waste or coal into power and/or steam. CFB reactors are in commercial operation for reduction processes and for combustion and gasification of solid fuels. In this paper reduction processes are not considered. The fact, that world-wide over 80 CFB combustion plants using Lurgi technology are commercially operating proves that this technology is well accepted. Lurgi`s CFB gasification technology is at present applied in two industrial plants. It is the key process for the advanced biomass or waste utilisation plants. The paper focuses on CFB fuel gas production for combined cycle plants (IGCC) and for cofiring into existing boiler plants. 5 refs., 4 figs.

  11. Study on pyrolysis and gasification of wood in MSW

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to develop municipal solid waste(MSW) pyrolysis/gasification and melting technology with low emission and high efficiency, it was planed that all the main components in MSW and some typical kinds of MSW were pyrolyzed/gasified to propose an expert system for raw MSW. In this paper, wood, which was a prevalent component in MSW, was pyrolyzed and gasified in fluidized-bed reactors at different apparent excess air ratios (EARs), temperatures and fluidizing velocities. For pyrolysis, with temperature increasing from 400℃ to 700℃, the yield of pyrolysis char decreased while that of pyrolysis gas increased (in this paper respectively from 28% to 20% and from 10% to 35%), and when temperature was 500℃, the yield of pyrolysis tar reached the highest,up to 38% in this paper. It was the optimum for gasification when temperature was 600℃ and apparent EAR was 0.4. Under the experimental conditions of this paper, gasification efficiency achieved 73%, lower heat value(LHV) reached 5800 kJ/(Nm3) and yield of syngas was 2.01 Nm3/kg. Lower fluidizing velocity was useful to upgrade gasification efficiency and LHV of syngas for wood gasification. Based on the results, the reactive courses and mechanism were analyzed respectively for wood pyrolysis and gasification.

  12. Integrated coal gasification combined cycle

    Science.gov (United States)

    Richards, P. C.; Wijffels, J.-B.; Zuideveld, P. L.

    Features of the integrated coal gasification combined cycle power plants are described against the backdrop of the development and first commercial application of the shell coal gasification process. Focus is on the efficiency and excellent environmental performance of the integrated coal gasification combined power plants. Current IGCC projects are given together with an outline of some of the options for integrating coal gasification with combined cycles and also other applications of synthesis gas.

  13. Gasification Plant Cost and Performance Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Samuel Tam; Alan Nizamoff; Sheldon Kramer; Scott Olson; Francis Lau; Mike Roberts; David Stopek; Robert Zabransky; Jeffrey Hoffmann; Erik Shuster; Nelson Zhan

    2005-05-01

    As part of an ongoing effort of the U.S. Department of Energy (DOE) to investigate the feasibility of gasification on a broader level, Nexant, Inc. was contracted to perform a comprehensive study to provide a set of gasification alternatives for consideration by the DOE. Nexant completed the first two tasks (Tasks 1 and 2) of the ''Gasification Plant Cost and Performance Optimization Study'' for the DOE's National Energy Technology Laboratory (NETL) in 2003. These tasks evaluated the use of the E-GAS{trademark} gasification technology (now owned by ConocoPhillips) for the production of power either alone or with polygeneration of industrial grade steam, fuel gas, hydrocarbon liquids, or hydrogen. NETL expanded this effort in Task 3 to evaluate Gas Technology Institute's (GTI) fluidized bed U-GAS{reg_sign} gasifier. The Task 3 study had three main objectives. The first was to examine the application of the gasifier at an industrial application in upstate New York using a Southeastern Ohio coal. The second was to investigate the GTI gasifier in a stand-alone lignite-fueled IGCC power plant application, sited in North Dakota. The final goal was to train NETL personnel in the methods of process design and systems analysis. These objectives were divided into five subtasks. Subtasks 3.2 through 3.4 covered the technical analyses for the different design cases. Subtask 3.1 covered management activities, and Subtask 3.5 covered reporting. Conceptual designs were developed for several coal gasification facilities based on the fluidized bed U-GAS{reg_sign} gasifier. Subtask 3.2 developed two base case designs for industrial combined heat and power facilities using Southeastern Ohio coal that will be located at an upstate New York location. One base case design used an air-blown gasifier, and the other used an oxygen-blown gasifier in order to evaluate their relative economics. Subtask 3.3 developed an advanced design for an air

  14. Gasification from waste organic materials

    Directory of Open Access Journals (Sweden)

    Santiago Ramírez Rubio

    2011-08-01

    Full Text Available This article describes the fixed bed biomass gasifier operation designed and built by the Clean Development Mechanisms and Energy Management research group, the gasifier equipment and the measurement system. The experiment involved agro-industrial residues (biomass such wood chips, coconut shell, cocoa and coffee husk; some temperatures along the bed, its pressure, inlet air flow and the percentage of carbon monoxide and carbon dioxide in the syngas composition were measured. The test results showed that a fuel gas was being obtained which was suitable for use with an internal combustion engine for generating electricity because more carbon monoxide than carbon dioxide was being obtained during several parts of the operation. The gasification experimentation revealed that a gasifier having these characteristics should be ideal for bringing energy to areas where it is hard to obtain it (such as many rural sites in Latin-America or other places where large amounts of agro-industrial wastes are produced. Temperatures of around 1,000°C were obtained in the combustion zone, generating a syngas having more than 20% carbon monoxide in its composition, thereby leading to obtaining combustible gas.

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

    Directory of Open Access Journals (Sweden)

    Antonescu Nicolae

    2014-06-01

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

  16. Fluidised Bed Microencapsulation of Ascorbic Acid: Effectiveness of Protection under Simulated Tropical Storage Conditions

    Science.gov (United States)

    2012-01-01

    of food science and technology and food chemistry , with particular interests in food fortification, microencapsulation, product development and food...and immune status, plays a fundamental role in ensuring that Australian Defence Force (ADF) personnel are operationally ready (Forbes-Ewan, 2009...International Dairy Journal 20(4): 292-302. Department of Defence. 2008a. Australian Defence Force Food Specifications and Scales of Issue: SUPMAN

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

    CSIR Research Space (South Africa)

    Baloyi, J

    2016-07-01

    Full Text Available In the study the comparison of irreversibilities was done when the wall condition of the combustor was changed from adiabatic to negative heat flux, for incoming air temperature of 400 K. The reactant mixture of solid pitch pine wood fuel and air...

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

    CSIR Research Space (South Africa)

    Baloyi, J

    2015-07-01

    Full Text Available The focus of the world is the reduction of greenhouse gases like carbon dioxide, which contribute to the global warming currently experienced. Since most of the carbon dioxide emitted into the atmosphere is from fossil fuel combustion, alternative...

  19. The fluid dynamics of a downer fluidised bed using a cluster-based approach (CBA

    Directory of Open Access Journals (Sweden)

    Germán González Silva

    2010-05-01

    Full Text Available The fluid dynamics of a downer reactor were numerically resolved by adapting a mathematical conservation model. The mathematical model was based on the solid and fluid properties and physical characteristics using a cluster-based approach (CBA. Comparing the numerical results to the experimental data found in the literature indicated that the mathematical model could satisfactorily predict the experimental data. The mathematical simulation determined that there were three fluid dynamic areas in the downer reactor which were characterized by accelerated, slowed-down and fully-developed flow. The fully developed flow area in the downer decreased with increased gas surface speed keeping solid flux constant.

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

    CSIR Research Space (South Africa)

    Hadley, TD

    2005-01-01

    Full Text Available capture to reduce the sulphur dioxide off-gas content. Additionally, work has been conducted on a number of sulphur bearing ores. More recently attention has been placed on the oxidative and reductive roasting of ilmenite to affect the downstream recovery...

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

    CSIR Research Space (South Africa)

    North, BC

    2005-11-01

    Full Text Available multi-national food company based in Estcourt, Kwa-Zulu Natal, South Africa. Two design requirements emerged from the clients needs: Additional plant steam and disposal of 12 t/h of coffee grounds sludge containing up to 87% water. The dual purpose...

  2. Experimental study on MSW gasification and melting technology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to develop municipal solid waste (MSW) gasification and melting technology, two preliminary experiments and a principle integrated experiment were fulfilled respectively. The gasification characteristics of MSW are studied at 500-750℃ when equivalence ratio (ER) was 0.2-0.5 using a fluidized-bed gasifier. When temperature was 550-700℃ and ER was 0.2-0.4, low heat value (LHV) of syngas reaches 4000-12000 kJ/Nm3. The melting characteristics of fly ash were investigated at 1100-1460℃ using a fixed-bed furnace. It was proved that over 99.9% of dioxins could be decomposed and most heavy-metals could be solidified when temperature was 1100-1300℃. The principle integrated experiment was carried out in a fluidized-bed gasification and swirl-melting system. MSW was gasified efficiently at 550-650℃, swirl-melting furnace maintains at 1200-1300℃ stably and over 95% of fly ash could be caught by the swirl-melting furnace. The results provided much practical experience and basic data to develop MSW gasification and melting technology.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Whitty

    2003-12-01

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

  4. Synergistic combination of biomass torrefaction and co-gasification: Reactivity studies.

    Science.gov (United States)

    Zhang, Yan; Geng, Ping; Liu, Rui

    2017-09-01

    Two typical biomass feedstocks obtained from woody wastes and agricultural residues were torrefied or mildly pyrolized in a fixed-bed reactor. Effects of the torrefaction conditions on product distributions, compositional and energetic properties of the solid products, char gasification reactivity, and co-gasification behavior between coal and torrefied solids were systematically investigated. Torrefaction pretreatment produced high quality bio-solids with not only increased energy density, but also concentrated alkali and alkaline earth metals (AAEM). As a consequence of greater retention of catalytic elements in the solid products, the chars derived from torrefied biomass exhibited a faster conversion than those derived from raw biomass during CO2 gasification. Furthermore, co-gasification of coal/torrefied biomass blends exhibited stronger synergy compared to the coal/raw biomass blends. The results and insights provided by this study filled a gap in understanding synergy during co-gasification of coal and torrefied biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. 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

  6. Gasification of black liquor

    Science.gov (United States)

    Kohl, Arthur L.

    1987-07-28

    A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediatley above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone.

  7. Downdraft gasification of pellets made of wood, palm-oil residues respective bagasse: Experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Erlich, Catharina; Fransson, Torsten H. [Department of Energy Technology, School of Industrial Technology and Management (ITM), Royal Institute of Technology (KTH), 100 44 Stockholm (Sweden)

    2011-03-15

    The downdraft gasification technology has an increased interest among researchers worldwide due to the possibility to produce mechanical and electrical power from biomass in small-scale to an affordable price. The research is generally focused on improvement of the performance and optimizing of a certain gasifier, on testing different fuels, on increasing the user-friendliness of the gasifier and on finding other uses for the product gas than in an IC-engine, for example liquid fuel production. The main objective with the gasification tests presented here is to further contribute in the field by studying the impact of the char bed properties such as char bed porosity and pressure drop on the gasification performance as well as the impact of fuel particle size and composition on the gasification process in one and the same gasifier. In addition, there is very little gasification data available in literature of ''before disregarded'' fuels such as sugar cane bagasse from sugar/alcohol production and empty fruit bunch (EFB) from the palm-oil production. By pelletizing these residues, it is possible to introduce them into downdraft gasification technology which has been done in this study. The results show that one and the same reactor can be used for a variety of fuels in pellet form, but at varying air-fuel ratios, temperature levels, gas compositions and lower heating values. Gasification of wood pellets results in a richer producer gas while EFB pellets give a poorer one with higher contents of non-combustible compounds. In this gasification study, there is almost linear relation between the air-fuel ratio and the cold-gas efficiency for the studied fuels: Higher air-fuel ratios result in better efficiency. The pressure drop in the char bed is higher for more reactive fuels, which in turn is caused by low porosity char beds. (author)

  8. EXPERIMENTAL STUDY ON BIO-OIL PYROLYSIS/GASIFICATION

    Directory of Open Access Journals (Sweden)

    Mou Zhang

    2010-02-01

    Full Text Available This study aims to understand the mechanism of bio-oil gasification and the influence of operating parameters on the properties of the gas products. Firstly, the pyrolysis/gasification of bio-oil was performed using a thermogravimetric analyzer (TGA. The evaporation of gas products from bio-oil were measured on-line with coupled Fourier Transform Infrared Spectroscopy (FTIR. The main gas products were CO, CO2, CH4, H2O, and light hydrocarbons, etc. Organics mainly evolved out at lower temperature (100-200°C, while the cracking of heavy hydrocarbon components took place at higher temperature (>200°C. Simultaneously, the gasification behavior of bio-oil was investigated in a fixed bed gasification reactor under different temperature and residence time. The gas product evolving was checked using micro-gas chromatography. It was observed that the yield of CO and H2 increased with increasing gasification temperature above 600°C, and the maximum value was obtained at 800°C. Prolonging the residence time was not favorable for the upgrading of syngas quality.

  9. Investigation of polycyclic aromatic hydrocarbons from coal gasification.

    Science.gov (United States)

    Zhou, Hong-cang; Jin, Bao-sheng; Zhong, Zhao-ping; Huang, Ya-ji; Xiao, Rui; Li, Da-ji

    2005-01-01

    The hazardous organic pollutants generated from coal gasification, such as polycyclic aromatic hydrocarbons(PAHs), are highly mutagenic and carcinogenic. More researchers have paid particular attention to them. Using air and steam as gasification medium, the experiments of three kinds of coals were carried out in a bench-scale atmospheric fluidized bed gasifier. The contents of the 16 PAHs specified by US EPA in raw coal, slag, bag house coke, cyclone coke and gas were measured by HPLC to study the contents of PAHs in raw coal and the effects of the inherent characters of coals on the formation and release of PAHs in coal gasification. The experimental results showed that the distributions of PAHs in the gasified products are similar to raw coals and the total-PAHs content in coal gasification is higher than in raw coal(except Coal C). The total-PAHs contents increase and then decrease with the rise of fixed carbon and sulfur of coal while there has an opposite variation when volatile matters content increase. The quantities of PAHs reduce with the increase of ash content or the drop of heating value during coal gasification.

  10. Tar Management and Recycling in Biomass Gasification and Syngas Purification

    Science.gov (United States)

    McCaffrey, Zach

    Removal of tars is critical to the design and operation of biomass gasification systems as most syngas utilization processing equipment (e.g. internal combustion engines, gas turbines, fuel cells, and liquid fuel synthesis reactors) have a low tolerance for tar. Capturing and disposal of tar is expensive due to equipment costs, high hazardous waste disposal costs where direct uses cannot be found, and system energy losses incurred. Water scrubbing is an existing technique commonly used in gasification plants to remove contaminants and tar; however using water as the absorbent is non-ideal as tar compounds have low or no water solubility. Hydrophobic solvents can improve scrubber performance and this study evaluated tar solubility in selected solvents using slip-streams of untreated syngas from a laboratory fluidized bed reactor operated on almond composite feedstock using both air and steam gasification. Tar solubility was compared with Hansen's solubility theory to examine the extent to which the tar removal can be predicted. As collection of tar without utilization leads to a hazardous waste problem, the study investigated the effects of recycling tars back into the gasifier for destruction. Prior to experiments conducted on tar capture and recycle, characterizations of the air and steam gasification of the almond composite mix were made. This work aims to provide a better understanding of tar collection and solvent selection for wet scrubbers, and to provide information for designing improved tar management systems for biomass gasification.

  11. Gaseous fuels production from dried sewage sludge via air gasification.

    Science.gov (United States)

    Werle, Sebastian; Dudziak, Mariusz

    2014-07-01

    Gasification is a perspective alternative method of dried sewage sludge thermal treatment. For the purpose of experimental investigations, a laboratory fixed-bed gasifier installation was designed and built. Two sewage sludge (SS) feedstocks, taken from two typical Polish wastewater treatment systems, were analysed: SS1, from a mechanical-biological wastewater treatment system with anaerobic stabilization (fermentation) and high temperature drying; and (SS2) from a mechanical-biological-chemical wastewater treatment system with fermentation and low temperature drying. The gasification results show that greater oxygen content in sewage sludge has a strong influence on the properties of the produced gas. Increasing the air flow caused a decrease in the heating value of the produced gas. Higher hydrogen content in the sewage sludge (from SS1) affected the produced gas composition, which was characterized by high concentrations of combustible components. In the case of the SS1 gasification, ash, charcoal, and tar were produced as byproducts. In the case of SS2 gasification, only ash and tar were produced. SS1 and solid byproducts from its gasification (ash and charcoal) were characterized by lower toxicity in comparison to SS2. However, in all analysed cases, tar samples were toxic.

  12. Investigation of polycyclic aromatic hydrocarbons from coal gasification

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hong-cang; JIN Bao-sheng; ZHONG Zhao-ping; HUANG Ya-ji; XIAO Rui; LI Da-ji

    2005-01-01

    The hazardous organic pollutants generated from coal gasification, such as polycyclic aromatic hydrocarbons(PAHs), are highly mutagenic and carcinogenic. More researchers have paid particular attention to them. Using air and steam as gasification medium, the experiments of three kinds of coals were carried out in a bench-scale atmospheric fluidized bed gasifier. The contents of the 16 PAHs specified by US EPA in raw coal, slag, bag house coke, cyclone coke and gas were measured by HPLC to study the contents of PAHs in raw coal and the effects of the inherent characters of coals on the formation and release of PAHs in coal gasification. The experimental results showed that the distributions of PAHs in the gasified products are similar to raw coals and the total-PAHs content in coal gasification is higher than in raw coal(except Coal C). The total-PAHs contents increase and then decrease with the rise of fixed carbon and sulfur of coal while there has an opposite variation when volatile matters content increase. The quantities of PAHs reduce with the increase of ash content or the drop of heating value during coal gasification.

  13. Release of fuel-bound nitrogen during biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, J.; Masutani, S.M.; Ishimura, D.M.; Turn, S.Q.; Kinoshita, C.M.

    2000-03-01

    Gasification of four biomass feedstocks (leucaena, sawdust, bagasse, and banagrass) with significantly different fuel-bound nitrogen (FBN) content was investigated to determine the effects of operational parameters and nitrogen content of biomass on the partitioning of FBN among nitrogenous gas species. Experiments were performed using a bench-scale, indirectly heated, fluidized-bed gasifier. Data were obtained over a range of temperatures and equivalence ratios representative of commercial biomass gasification processes. An assay of all major nitrogenous components in the gasification products was performed for the first time, providing a clear accounting of the evolution of FBN. Important findings of this research include the following: (1) NH{sub 3} and N{sub 2} are the dominant species evolved from fuel nitrogen during biomass gasification; >90% of FBN in feedstock is converted to NH{sub 3} and N{sub 2}; (2) relative levels of NH{sub 3} and N{sub 2} are determined by thermochemical reactions in the gasifier; these reactions are affected strongly by temperature; (3) N{sub 2} appears to be primarily produced through the conversion of NH{sub 3} in the gas phase; (4) the structural formula and content of fuel nitrogen in biomass feedstock significantly affect the formation and evolution of nitrogen species during biomass gasification.

  14. Improvement of biomass char-CO{sub 2} gasification reactivity using microwave irradiation and natural catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Lahijani, Pooya, E-mail: pooya.lahijani@gmail.com [Biomass and Bioenergy Laboratory, School of Mechanical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Mohammadi, Maedeh, E-mail: m.mohammadi@nit.ac.ir [Faculty of Chemical Engineering, Babol Noushirvani University of Technology, 47148 Babol (Iran, Islamic Republic of); Zainal, Zainal Alimuddin, E-mail: mezainal@eng.usm.my [Biomass and Bioenergy Laboratory, School of Mechanical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Mohamed, Abdul Rahman, E-mail: chrahman@usm.my [Low Carbon Economy (LCE) Research Group, School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-03-20

    Highlights: • We study microwave-induced gasification of EFB ash-loaded biomass char with CO{sub 2}. • Synergistic effect of microwave and catalyst resulted in CO{sub 2} conversion of 93%. • Gasification of pristine char using conventional heating gives CO{sub 2} conversion of 58%. • E{sub a} of 74 and 247 kJ/mol were obtained for microwave and conventional CO{sub 2} gasification. - Abstract: In char-CO{sub 2} gasification, the highly endothermic nature of the Boudouard reaction (CO{sub 2} (g) + C (s) ↔ 2CO (g)) dictates use of very high temperatures to shift the equilibrium towards CO production. In this study, such high temperature (750–900 °C) was provided by microwave irradiation. A microwave heating system was developed to perform the gasification tests by passing CO{sub 2} through a packed bed of oil palm shell (OPS) char. In order to speed up the microwave-induced CO{sub 2} gasification, ash of palm empty fruit bunch (EFB) was used as natural catalyst (rich in potassium) and incorporated into the skeleton of the OPS char. The synergistic effect of microwave and catalyst concluded to very encouraging results, where a CO{sub 2} conversion of 93% was achieved at 900 °C, within 60 min microwave gasification. In comparison, CO{sub 2} conversion in thermal gasification (conventional heating) of pristine OPS char was only 58% under the same operating condition.

  15. Combustion, pyrolysis, gasification, and liquefaction of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Reed, T.B.

    1980-09-01

    All the products now obtained from oil can be provided by thermal conversion of the solid fuels biomass and coal. As a feedstock, biomass has many advantages over coal and has the potential to supply up to 20% of US energy by the year 2000 and significant amounts of energy for other countries. However, it is imperative that in producing biomass for energy we practice careful land use. Combustion is the simplest method of producing heat from biomass, using either the traditional fixed-bed combustion on a grate or the fluidized-bed and suspended combustion techniques now being developed. Pyrolysis of biomass is a particularly attractive process if all three products - gas, wood tars, and charcoal - can be used. Gasification of biomass with air is perhaps the most flexible and best-developed process for conversion of biomass to fuel today, yielding a low energy gas that can be burned in existing gas/oil boilers or in engines. Oxygen gasification yields a gas with higher energy content that can be used in pipelines or to fire turbines. In addition, this gas can be used for producing methanol, ammonia, or gasoline by indirect liquefaction. Fast pyrolysis of biomass produces a gas rich in ethylene that can be used to make alcohols or gasoline. Finally, treatment of biomass with high pressure hydrogen can yield liquid fuels through direct liquefaction.

  16. An advanced coal gasification desulfurization process

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Rehmat, A. (Institute of Gas Technology, Chicago, IL (USA)); Leppin, D. (Gas Research Inst., Chicago, IL (USA)); Banerjee, D.D. (Center for Research on Sulfur in Coal, Carterville, IL (USA))

    1990-01-01

    The Institute of Gas Technology (IGT) is in the process of developing an advanced coal gasification desulfurization process in which a calcium-based sorbent such as limestone or dolomite is injected into the fluidized-bed gasifier with coal to achieve in-bed desulfurization of coal as it is converted into clean fuel gas. The reactions involving calcium-based sorbents takes place in two steps. In the first step, the desulfurization reaction takes place between hydrogen sulfide and calcium oxide in the reducing zone of the reactor to produce calcium sulfide. The latter subsequently reacts with oxygen in the oxidizing zone of the reactor to produce calcium sulfate which can be safely disposed of along with the coal ash. This process will reduce the capital requirement for coal gasification plants and provide cost effective alternatives to scrubbers for industrial and utility use of high-sulfur coal. This paper addresses the basic research being conducted at IGT to confirm the viability of this process. 9 refs., 3 figs., 1 tab.

  17. Combustion, pyrolysis, gasification, and liquefaction of biomas

    Science.gov (United States)

    Reed, T. B.

    1980-09-01

    The advantages of biomass as a feedstock are examined and biomass conversion techniques are described. Combustion is the simplest method of producing heat from biomass, using either the traditional fixed bed combustion on a grate or the fluidized bed and suspended combustion techniques now being developed. Pyrolysis of biomass is a particularly attractive process if all three products gas, wood tars, and charcoal can be used. Gasification of biomass with air is perhaps the most flexible and best developed process for conversion of biomass to fuel, yielding a low energy gas that can be burned in existing gas/oil boilers or in engines. Oxygen gasification yields a gas with higher energy content that can be used in pipelines or to fire turbines. In addition, this gas can be used for producing methanol, ammonia, or gasoline by indirect liquefaction. Fast pyrolysis of biomass produces a gas rich in ethylene that can be used to make alcohols or gasoline. Finally, treatment of biomass with high pressure hydrogen can yield liquid fuels through direct liquefaction.

  18. Research on low emission MSW gasification and melting system

    Institute of Scientific and Technical Information of China (English)

    XIAO Gang; NI Mingjiang; CHI Yong; JIN Yuqi; ZHANG Jiaquan; MIAO Qi; CEN Kefa

    2007-01-01

    In order to eliminate secondary pollution caused by municipal solid waste (MSW) incineration,a MSW gasification and melting process is proposed.The process is expected to reduce the emission of pollutants,especially heavy-metals and dioxins.In this paper,the combustible components of MSW and simulated MSW were gasified in a lab-scale fluidized bed at 400℃-700℃ when the excess air ratio (ER) was between 0.2 and 0.8.The experimental results indicated that the MSW could be gasified effectively in a fluidized bed at approximately 600℃-700℃ when excess air ratio was 0.2-0.4.The melting characteristics of two typical fly ash samples from MSW incinerators were investigated.The results indicated that fly ash of pure MSW incineration could be melted at approximately 1,300℃ and that of MSW and coal co-combustion could be melted at approximately 1,400℃.When temperature was over 1,100℃,more than 99.9% of the dioxins could be decomposed and most of the heavy-metals could be solidified in the slag.Based on the above experiments,two feasible MSW gasification and melting processes were proposed for low calorific value MSW:(1) sieved MSW gasification and melting system,which was based on an idea of multi-recycle;(2) gasification and melting scheme of MSW adding coal as assistant fuel.

  19. Entrained Flow Gasification of Biomass

    DEFF Research Database (Denmark)

    Qin, Ke

    concentration, larger feeder gas flow, and longer residence time. Wood, straw, and lignin had similar gasification behavior except with regard to soot formation. The soot yield was lowest during straw gasification possibly because of its high potassium content. The equilibrium product compositions under...... from straw gasification had quite low content of soot while high contents of volatilizable KCl and K2SO4, and thereby appeared as irregular crystals (> 100 nm). During lignin gasification, the filter sample mainly consisted of soot and nonvolatilizable inorganic matter. The parent wood particles...... the wood soot with respect to both oxidation and CO2 gasification. Besides, the wood soot produced at higher temperature was more reactive than the soot produced at lower temperature. Biomass and coal co-gasification experiments were performed in the same entrained flow reactor. The effect of mixing ratio...

  20. Underground gasification of coal

    Energy Technology Data Exchange (ETDEWEB)

    Koranda, J.

    1986-11-01

    A brief history is given of research in Czechoslovakia, which took 3 main factors into account: environmental protection, geological situation and need to produce gas for use both within the plant and elsewhere. In order to assess economic viability, model studies were performed on following mines: Podlesice (North Bohemia), Vatovce (South Slovakia), Syrenov (East Moravia), Zukovsky Hrbet (Ostrava-Karvina), Stonovska (Ostrava-Karvina) and Merkur (North Bohemia). Figures given in tabular form show that underground gasification at these sites would be cheaper than importing natural gas. Problems are discussed associated with underground gasification and it is concluded that research must be conducted into drilling techniques, drill design, methods of cutting through coal seam between shafts, underground generator design, methods of gasifying several seams with one shaft and methods of dealing with residual pillars.

  1. Expanded bed adsorption as a primary recovery step for the isolation of the insulin precursor MI3 process development and scale up.

    Science.gov (United States)

    Brixius, Peter; Mollerup, Inger; Jensen, Ole Elvang; Halfar, Markus; Thömmes, Jörg; Kula, Maria-Regina

    2006-01-05

    Expanded bed adsorption (EBA) was evaluated for the isolation of the human insulin precursor MI3, expressed and secreted by the yeast Saccharomyces cerevisiae. The isoelectric point of the insulin precursor (pH 5.3) makes cation exchange a prime candidate for direct adsorption. In order to find a suitable window of operation for the process the adsorption equilibrium was analysed in a wide range of operating conditions (pH and conductivity) and for three different stationary phases. The same array of operating conditions was examined with regard to stable fluidisation of the adsorbents in S. cerevisiae suspensions. Interactions of the yeast with the fluidised stationary phase were investigated by a pulse response technique and the hydrodynamics of the fluidised bed under process conditions by residence time distribution analysis. The case study demonstrates that by parallel examination of product binding and fluidisation quality a window of operation can be found. Analysis of the binding kinetics by breakthrough experiments and modelling led to the definition of a set of operating conditions, which yield a compromise between optimal use of the equilibrium capacity provided by the adsorbent and high throughput required for an industrial separation. After initial experiments on the bench scale the protocol was transferred successfully to pilot scale demonstrating the design of a reliable operation.

  2. Fuel Flexibility in Gasification

    Energy Technology Data Exchange (ETDEWEB)

    McLendon, T. Robert; Pineault, Richard L.; Richardson, Steven W.; Rockey, John M.; Beer, Stephen K. (U.S. DOE National Energy Technology Laboratory); Lui, Alain P.; Batton, William A. (Parsons Infrastructure and Technology Group, Inc.)

    2001-11-06

    In order to increase efficiencies of carbonizers, operation at high pressures is needed. In addition, waste biomass fuels of opportunity can be used to offset fossil fuel use. The National Energy Technology Laboratory (NETL) Fluidized Bed Gasifier/Combustor (FBG/C) was used to gasify coal and mixtures of coal and biomass (sawdust) at 425 psig. The purpose of the testing program was to generate steady state operating data for modeling efforts of carbonizers. A test program was completed with a matrix of parameters varied one at a time in order to avoid second order interactions. Variables were: coal feed rate, pressure, and varying mixtures of sawdust and coal types. Coal types were Montana Rosebud subbituminous and Pittsburgh No. 8 bituminous. The sawdust was sanding waste from a furniture manufacturer in upstate New York. Coal was sieved from -14 to +60 mesh and sawdust was sieved to -14 mesh. The FBG/C operates at a nominal 425 psig, but pressures can be lowered. For the tests reported it was operated as a jetting, fluidized bed, ash-agglomerating gasifier. Preheated air and steam are injected into the center of the bottom along with the solid feed that is conveyed with cool air. Fairly stable reactor internal flow patterns develop and temperatures stabilize (with some fluctuations) when steady state is reached. At nominal conditions the solids residence time in the reactor is on the order of 1.5 to 2 hours, so changes in feed types can require on the order of hours to equilibrate. Changes in operating conditions (e.g. feed rate) usually require much less time. The operating periods of interest for these tests were only the steady state periods, so transient conditions were not monitored as closely. The test matrix first established a base case of operations to which single parameter changes in conditions could be compared. The base case used Montana Rosebud at a coal feed rate of 70 lbm/hr at 425 psig. The coal sawdust mixtures are reported as percent by weight

  3. Biomass Gasification Combined Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Judith A. Kieffer

    2000-07-01

    Gasification combined cycle continues to represent an important defining technology area for the forest products industry. The ''Forest Products Gasification Initiative'', organized under the Industry's Agenda 2020 technology vision and supported by the DOE ''Industries of the Future'' program, is well positioned to guide these technologies to commercial success within a five-to ten-year timeframe given supportive federal budgets and public policy. Commercial success will result in significant environmental and renewable energy goals that are shared by the Industry and the Nation. The Battelle/FERCO LIVG technology, which is the technology of choice for the application reported here, remains of high interest due to characteristics that make it well suited for integration with the infrastructure of a pulp production facility. The capital cost, operating economics and long-term demonstration of this technology area key input to future economically sustainable projects and must be verified by the 200 BDT/day demonstration facility currently operating in Burlington, Vermont. The New Bern application that was the initial objective of this project is not currently economically viable and will not be implemented at this time due to several changes at and around the mill which have occurred since the inception of the project in 1995. The analysis shows that for this technology, and likely other gasification technologies as well, the first few installations will require unique circumstances, or supportive public policies, or both to attract host sites and investors.

  4. Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Whitty

    2007-06-30

    University of Utah's project entitled 'Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer' (DOE Cooperative Agreement DE-FC26-02NT41490) was developed in response to a solicitation released by the U.S. Department of Energy in December 2001, requesting proposals for projects targeted towards black liquor/biomass gasification technology support research and development. Specifically, the solicitation was seeking projects that would provide technical support for Department of Energy supported black liquor and biomass gasification demonstration projects under development at the time.

  5. Guideline for safe and eco-friendly biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Vos, J.; Knoef, H. (BTG biomass technology group, Enschede (Netherlands)); Hauth, M. (Graz Univ. of Technology. Institute of Thermal Engineering, Graz (Austria)) (and others)

    2009-11-15

    The objective of the Gasification Guide project is to accelerate the market penetration of small-scale biomass gasification systems (< 5 MW fuel power) by the development of a Guideline and Software Tool to facilitate risk assessment of HSE aspects. The Guideline may also be applied in retrofitting or converting old thermal plants in the Eastern European countries - with rich biomass recourses - to new gasification plants. The objective of this document is to guide key target groups identifying potential hazards and make a proper risk assessment. The software tool is an additional aid in the risk assessment. This guideline is intended to be a training tool and a resource for workers and employers to safely design, fabricate, construct, operate and maintain small-scale biomass gasification facilities. The Guideline is applicable with the following constraints: 1) The maximum scale of the gasification plant was agreed to be about 1 MW{sub e}. The reason is that large companies do have normally their safety rules in place; 2) This means in principle only fixed bed gasifier designs. However, most parts are also valid to other designs and even other thermal conversion processes; 3) The use of contaminated biomass is beyond the scope of this Guideline. The Guideline contains five major chapters; Chapter 2 briefly describes the gasification technology in general. Chapter 3 gives an overview of major legal framework issues on plant permission and operation. The legal frame is changing and the description is based on the situation by the end of 2007. Chapter 4 explains the theory behind the risk assessment method and risk reduction measures. Chapter 5 is the heart of the Guideline and gives practical examples of good design, operation and maintenance principles. The practical examples and feedback have been received throughout the project and the description is based on mid-2009. Chapter 6 describes the best techniques currently available for emission abatement which are

  6. Biomass Gasification - A synthesis of technical barriers and current research issues for deployment at large scale

    Energy Technology Data Exchange (ETDEWEB)

    Heyne, Stefan [Chalmers Univ. of Technology, Gothenburg (Sweden); Liliedahl, Truls [KTH, Royal Inst. of Technology, Stockholm (Sweden); Marklund, Magnus [Energy Technology Centre, Piteaa (Sweden)

    2013-09-01

    Thermal gasification at large scale for cogeneration of power and heat and/or production of fuels and materials is a main pathway for a sustainable deployment of biomass resources. However, so far no such full scale production exists and biomass gasification projects remain at the pilot or demonstration scale. This report focuses on the key critical technology challenges for the large-scale deployment of the following biomass-based gasification concepts: Direct Fluidized Bed Gasification (FBG), Entrained Flow Gasification (EFG) and indirect Dual Fluidized Bed Gasification (DFBG). The main content in this report is based on responses from a number of experts in biomass gasification obtained from a questionnaire. The survey was composed of a number of more or less specific questions on technical barriers as to the three gasification concepts considered. For formalising the questionnaire, the concept of Technology Readiness Level (TRL 1-9) was used for grading the level of technical maturity of the different sub-processes within the three generic biomass gasification technologies. For direct fluidized bed gasification (FBG) it is mentioned that the technology is already available at commercial scale as air-blown technology and thus that air-blown FBG gasification may be reckoned a mature technology. The remaining technical challenge is the conversion to operation on oxygen with the final goal of producing chemicals or transport fuels. Tar reduction, in particular, and gas cleaning and upgrading in general are by far the most frequently named technical issues considered problematic. Other important aspects are problems that may occur when operating on low-grade fuels - i.e. low-cost fuels. These problems include bed agglomeration/ash sintering as well as alkali fouling. Even the preparation and feeding of these low-grade fuels tend to be problematic and require further development to be used on a commercial scale. Furthermore, efficient char conversion is mentioned by

  7. Control of nitrogen oxides in pressurised bed systems

    Energy Technology Data Exchange (ETDEWEB)

    Minchener, A.J.; Kelsall, G.J. (British Coal Corp., Stoke Orchard (UK). Coal Research Establishment)

    1990-01-01

    This study assesses the effects of a wide range of operating parameters on NO {sub x} formation and evaluates techniques for reduction of NO {sub x} emissions from pressurised fluidised bed combustion (PFBC) systems. The level of excess air is shown to be the dominant parameter, although fluidisation conditions may also be important, as may the bed temperature. In terms of the overall PFBC combined cycle, staging at the bed surface gives the best results, since some 65% reduction in NO{sub x} levels can be achieved without adverse effects on the off-gas temperature or combustor performance. Studies of the use of ammonia injection have been undertaken in parallel with the staged combustion trials. The effectiveness of this technique is strongly dependent on injection location, on gas temperature and on the composition of the gas/solid streams. The implications for a commercial plant are that while staged combustion may be effective for full-load conditions, at part-load ammonia injection may be a better technique for NO{sub x} control.

  8. Fundamental studies of catalytic gasification

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, H.; Somorjai, G.A.

    1991-06-01

    The major purpose of this project was to finding catalysts which will permit steam gasification of carbonaceous material at reasonable rates and at lower temperatures than currently practiced. This quarter, experiments with steam gasification of graphite were performed. Catalysts studied were potassium, calcium, and nickel oxides. Reaction kinetics are discussed. 28 refs., 34 figs., 8 tabs.

  9. Experimental investigation on the changes in bed properties of a ...

    African Journals Online (AJOL)

    Experimental investigation on the changes in bed properties of a downdraft biomass gasifier. ... pressure measurements, physical observation, sampling of bed particles, ... char properties viz., weight, volume, density and volatile matter content along ... Specific gasification rate for wood pieces was found to be 75 kg h-1 m-2 ...

  10. Straw Gasification in a Two-Stage Gasifier

    DEFF Research Database (Denmark)

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

    2002-01-01

    Additive-prepared straw pellets were gasified in the 100 kW two-stage gasifier at The Department of Mechanical Engineering of the Technical University of Denmark (DTU). The fixed bed temperature range was 800-1000°C. In order to avoid bed sintering, as observed earlier with straw gasification...... residues were examined after the test. No agglomeration or sintering was observed in the ash residues. The tar content was measured both by solid phase amino adsorption (SPA) method and cold trapping (Petersen method). Both showed low tar contents (~42 mg/Nm3 without gas cleaning). The particle content...

  11. Experimental Study on Coal Multi-generation in Dual Fluidized Beds

    Institute of Scientific and Technical Information of China (English)

    Fan Xiaoxu; Lu Qinggang; Na Yongjie; Liu Qi

    2007-01-01

    An atmospheric test system of dual fluidized beds for coal multi-generation was built. One bubbling fluidized bed is for gasification and a circulating fluidized bed for combustion. The two beds are combined with two valves:one valve to send high temperature ash from combustion bed to the gasification bed and another valve to send char and ash from gasification bed to combustion bed. Experiments on Shenhua coal multi-generation were made at temperatures from 1112 K to 1191 K in the dual fluidized beds. The temperatures of the combustor are stable and the char combustion efficiency is about 98%. Increasing air/coal ratio to the fluidized bed leads to the increase of temperature and gasification efficiency. The maximum gasification efficiency is 36.7% and the calorific value of fuel gas is 10.7 MJ/Nm3. The tar yield in this work is 1.5%, much lower than that of pyrolysis.Carbon conversion efficiency to fuel gas and flue gas is about 90%.

  12. Thermodynamic Analysis of an Integrated Gasification Solid Oxide Fuel Cell Plant with a Kalina Cycle

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Rokni, Masoud

    2015-01-01

    A hybrid plant that consists of a gasification system, Solid Oxide Fuel Cells (SOFC) and a Simple Kalina Cycle (SKC) is investigated. Woodchips are introduced into a fixed bed gasification plant to produce syngas, which is then fed into an integrated SOFC-SKC plant to produce electricity. The pre......-treated fuel then enters the anode side of the SOFC. Complete fuel oxidation is ensured in a burner by off-gases exiting the SOFC stacks. Off-gases are utilized as heat source for a SKC where a mixture of ammonia and water is expanded in a turbine to produce additional electric power. Thus, a triple novel...... system based on a gasification plant, a SOFC plant and a SKC plant is presented and investigated. The system is called IGSKC (Integrated Gasification SOFC Simple Kalina Cycle). The system layout is studied, and the optimal ammonia-water mole fraction is selected. An electrical efficiency of 58...

  13. Behaviors of Char Gasification Based on Two-stage Gasifier of Biomass

    Science.gov (United States)

    Taniguchi, Miki; Sasauchi, Kenichi; Ahn, Chulju; Ito, Yusuke; Hayashi, Toshiaki; Akamatsu, Fumiteru

    In order to develop a small-scale gasifier in which biomass can be converted to energy with high efficiency, we planed a gasification process that consists of two parts: pyrolysis part (rotary kiln) and gasification part (downdraft gasifier). We performed fundamental experiments on gasification part and discussed the apropriate conditions such as air supply location, air ratio, air temperature and hearth load. The following results was found: 1) the air supply into the char bed is more effective than that into the gas phase, 2) we can have the maximum cold gas efficiency of 80% on the following conditions: air supply location: char layer, air temperature: 20°C, air ratio: 0.2. 3) As air temperature is higher, the cold gas efficiency is larger. As for the hearth load, the cold gas efficiency becomes higher and reaches the constant level. It is expected from the results that high temperature in the char layer is effective on the char gasification.

  14. Municipal Solid Waste Gasification with Solid Oxide Fuel Cells and Stirling Engine

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    . The gasification process is usually based on an atmospheric - pressure circulating fluidized bed gasifier coupled to a tar - crac king vessel. Syngas can be used as fuel in different kind of power plant such as gas turbine cycle, steam cycle, combined cycle, internal and external combustion engine and Solid Oxide...... studied to optimize the plant efficiency in terms of operating conditions. Compared with modern waste incinerators with heat recovery, the gasification process integrated with SOFC and Stirling engine permits an increase in electricity output up of 50%, which means that the solid waste gasification...... Fuel Cell (SOFC). In the present study, a MSW gasification plant int egrated with SOFC is combined with a Stirling engine to recover the energy of the off - gases from the topping SOFC cycle. Detailed plant design is proposed and thermodynamic analysis is performed. Relevant parameters have been...

  15. Municipal Solid Waste Gasification with Solid Oxide Fuel Cells and Stirling Engine

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    studied to optimize the plant efficiency in terms of operating conditions. Compared with modern waste incinerators with heat recovery, the gasification process integrated with SOFC and Stirling engine permits an increase in electricity output up of 50%, which means that the solid waste gasification...... storage in landfills and devote these spaces to other human activities. It is also important to point out that this kind of renewable energy suffers significantly less availabilit y which characterizes other type o f renewable energy sources such as in wind and solar energy. In a gasification process....... The gasification process is usually based on an atmospheric - pressure circulating fluidized bed gasifier coupled to a tar - crac king vessel. Syngas can be used as fuel in different kind of power plant such as gas turbine cycle, steam cycle, combined cycle, internal and external combustion engine and Solid Oxide...

  16. Catalytic gasification of biomass (Miscanthus) enhanced by CO2 sorption.

    Science.gov (United States)

    Zamboni, I; Debal, M; Matt, M; Girods, P; Kiennemann, A; Rogaume, Y; Courson, C

    2016-11-01

    The main objective of this work concerns the coupling of biomass gasification reaction and CO2 sorption. The study shows the feasibility to promote biomass steam gasification in a dense fluidized bed reactor with CO2 sorption to enhance tar removal and hydrogen production. It also proves the efficiency of CaO-Ca12Al14O33/olivine bi-functional materials to reduce heavy tar production. Experiments have been carried out in a fluidized bed gasifier using steam as the fluidizing medium to improve hydrogen production. Bed materials consisting of CaO-based oxide for CO2 sorption (CaO-Ca12Al14O33) deposited on olivine for tar reduction were synthesized, their structural and textural properties were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), and temperature-programmed reduction (TPR) methods, and the determination of their sorption capacity and stability analyzed by thermogravimetric analysis (TGA). It appears that this CaO-Ca12Al14O33/olivine sorbent/catalyst presents a good CO2 sorption stability (for seven cycles of carbonation/decarbonation). Compared to olivine and Fe/olivine in a fixed bed reactor for steam reforming of toluene chosen as tar model compound, it shows a better hydrogen production rate and a lower CO2 selectivity due to its sorption on the CaO phase. In the biomass steam gasification, the use of CaO-Ca12Al14O33/olivine as bed material at 700 °C leads to a higher H2 production than olivine at 800 °C thanks to CO2 sorption. Similar tar concentration and lighter tar production (analyzed by HPLC/UV) are observed. At 700 °C, sorbent addition allows to halve tar content and to eliminate the heaviest tars.

  17. Gasification Performance of a Top-Lit Updraft Cook Stove

    Directory of Open Access Journals (Sweden)

    Yogesh Mehta

    2017-10-01

    Full Text Available This paper reports on an experimental study of a top-lit updraft cook stove with a focus on gasification. The reactor is operated with primary air only. The performance is studied for a variation in the primary airflow, as well as reactor geometry. Temperature in the reactor, air flow rate, fuel consumption rate, and producer gas composition were measured. From the measurements the superficial velocity, pyrolysis front velocity, peak bed temperature, air fuel ratio, heating value of the producer gas, and gasification rate were calculated. The results show that the producer gas energy content was maximized at a superficial velocity of 9 cm/s. The percent char remaining at the end of gasification decreased with increasing combustion chamber diameter. For a fixed superficial velocity, the gasification rate and producer gas energy content were found to scale linearly with diameter. The energy content of the producer gas was maximized at an air fuel (AF ratio of 1.8 regardless of the diameter.

  18. 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.

  19. Catalytic Hydrothermal Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Douglas C.

    2015-05-31

    The term “hydrothermal” used here refers to the processing of biomass in water slurries at elevated temperature and pressure to facilitate the chemical conversion of the organic structures in biomass into useful fuels. The process is meant to provide a means for treating wet biomass materials without drying and to access ionic reaction conditions by maintaining a liquid water processing medium. Typical hydrothermal processing conditions are 523-647K of temperature and operating pressures from 4-22 MPa of pressure. The temperature is sufficient to initiate pyrolytic mechanisms in the biopolymers while the pressure is sufficient to maintain a liquid water processing phase. Hydrothermal gasification is accomplished at the upper end of the process temperature range. It can be considered an extension of the hydrothermal liquefaction mechanisms that begin at the lowest hydrothermal conditions with subsequent decomposition of biopolymer fragments formed in liquefaction to smaller molecules and eventually to gas. Typically, hydrothermal gasification requires an active catalyst to accomplish reasonable rates of gas formation from biomass.

  20. Exergetic analysis of coal gasification processes

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, P.; Conger, W.L.

    1980-12-01

    In this study, the efficiency and economics of the Synthane Gasification process are evaluated and discussed. The efficiency of the Synthane process was determined using the exergy analysis (availability) approach to process evaluation. The exergy analysis utilizes both the first and second laws of thermodynamics to determine the efficiency of a process, and is very useful in determining the causes of inefficiency. In order to accurately apply the exergy analysis, it is essential that the absolute enthalpy and entropy values of each stream be determined. In this study, methods for predicting the enthalpy and entropy of coal, char, tar, and ash, as a function of temperature and material composition previously developed were used. A computer simulation of the Synthane process was developed which allowed for the effect of changes in plant operating parameters on both the efficiency and economics. The simulation included a three-section model of the Synthane fluidized bed gasifier.

  1. Pulsed combustion process for black liquor gasification

    Energy Technology Data Exchange (ETDEWEB)

    Durai-Swamy, K.; Mansour, M.N.; Warren, D.W.

    1991-02-01

    The objective of this project is to test an energy efficient, innovative black liquor recovery system on an industrial scale. In the MTCI recovery process, black liquor is sprayed directly onto a bed of sodium carbonate solids which is fluidized by steam. Direct contact of the black liquor with hot bed solids promotes high rates of heating and pyrolysis. Residual carbon, which forms as a deposit on the particle surface, is then gasified by reaction with steam. Heat is supplied from pulse combustor resonance tubes which are immersed within the fluid bed. A portion of the gasifier product gas is returned to the pulse combustors to provide the energy requirements of the reactor. Oxidized sulfur species are partially reduced by reaction with the gasifier products, principally carbon monoxide and hydrogen. The reduced sulfur decomposed to solid sodium carbonate and gaseous hydrogen sulfide (H{sub 2}S). Sodium values are recovered by discharging a dry sodium carbonate product from the gasifier. MTCI's indirectly heated gasification technology for black liquor recovery also relies on the scrubbing of H{sub 2}S for product gases to regenerate green liquor for reuse in the mill circuit. Due to concerns relative to the efficiency of sulfur recovery in the MTCI integrated process, an experimental investigation was undertaken to establish performance and design data for this portion of the system.

  2. PHYSICO-CHEMICAL PROPERTIES OF THE SOLID AND LIQUID WASTE PRODUCTS FROM THE HEAVY METAL CONTAMINATED ENERGY CROPS GASIFICATION PROCESS

    Directory of Open Access Journals (Sweden)

    Sebastian Werle

    2017-02-01

    Full Text Available The paper presents the results of basic physico-chemical properties of solid (ash and liquid (tar waste products of the gasification process of the heavy metal contaminated energy crops. The gasification process has carried out in a laboratory fixed bed reactor. Three types of energy crops: Miscanthus x giganteus, Sida hermaphrodita and Spartina Pectinata were used. The experimental plots were established on heavy metal contaminated arable land located in Bytom (southern part of Poland, Silesian Voivodship.

  3. A thermo fluid dynamic model of wood particle gasification- and combustion processes

    Directory of Open Access Journals (Sweden)

    G Boiger

    2016-09-01

    Full Text Available In order to qualitatively understand and evaluate the thermo- fluid dynamic situation within a wood gasification reactor, a 1D particle model has been created. The presented tool accounts for the highly in- stationary, kinetic- and thermo chemical effects, leading to partial gasification and combustion of a wood particle embedded within a packed bed collective. It considers the fluid- dynamic situation within the changing porous bulk structure of the packed bed, its impact on species- and heat transition mechanisms, the energy- and mass balances of wood, coal, pyrolysis-gas, wood- gas and off- gas phases, the thermodynamics of locally developing gasification- and combustion reaction equilibria, as well as the presence of the chemical species hydrogen, water, carbon (di- oxide, methane, oxygen, solid carbon and gaseous, longer chain hydrocarbons from pyrolysis. Model results can be shown to yield very good, qualitative agreement with measurements, found in literature.

  4. Gasification of high ash, high ash fusion temperature bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  5. Gasification of high ash, high ash fusion temperature bituminous coals

    Science.gov (United States)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  6. Catalytic hot gas cleaning of gasification gas

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1997-12-31

    The aim of this work was to study the catalytic cleaning of gasification gas from tars and ammonia. In addition, factors influencing catalytic activity in industrial applications were studied, as well as the effects of different operation conditions and limits. Also the catalytic reactions of tar and ammonia with gasification gas components were studied. The activities of different catalyst materials were measured with laboratory-scale reactors fed by slip streams taken from updraft and fluid bed gasifiers. Carbonate rocks and nickel catalysts proved to be active tar decomposing catalysts. Ammonia decomposition was in turn facilitated by nickel catalysts and iron materials like iron sinter and iron dolomite. Temperatures over 850 deg C were required at 2000{sup -1} space velocity at ambient pressure to achieve almost complete conversions. During catalytic reactions H{sub 2} and CO were formed and H{sub 2}O was consumed in addition to decomposing hydrocarbons and ammonia. Equilibrium gas composition was almost achieved with nickel catalysts at 900 deg C. No deactivation by H{sub 2}S or carbon took place in these conditions. Catalyst blocking by particulates was avoided by using a monolith type of catalyst. The apparent first order kinetic parameters were determined for the most active materials. The activities of dolomite, nickel catalyst and reference materials were measured in different gas atmospheres using laboratory apparatus. This consisted of nitrogen carrier, toluene as tar model compound, ammonia and one of the components H{sub 2}, H{sub 2}O, CO, CO{sub 2}, CO{sub 2}+H{sub 2}O or CO+CO{sub 2}. Also synthetic gasification gas was used. With the dolomite and nickel catalyst the highest toluene decomposition rates were measured with CO{sub 2} and H{sub 2}O. In gasification gas, however, the rate was retarded due to inhibition by reaction products (CO, H{sub 2}, CO{sub 2}). Tar decomposition over dolomite was modelled by benzene reactions with CO{sub 2}, H

  7. Entrained Flow Gasification of Biomass

    DEFF Research Database (Denmark)

    Qin, Ke

    of different fuels on syngas products was investigated at 1400 °C with steam addition. The yields of residual particulates (char and/or soot) decreased with increasing straw fraction during straw/wood co-gasification and with increasing biomass fraction (straw or wood) during biomass/coal co......, char-gas and soot-gas reactions, detailed gas-phase reactions, and mass and heat transfer. The model could reasonable predict the yields of syngas products obtained in the biomass gasification experiments. Moreover, the simulation results suggest that the soot can be completely converted and thereby......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...

  8. Effects of coal combustion and gasification upon lung structure and function. Quarterly progress report

    Energy Technology Data Exchange (ETDEWEB)

    Hinton, Dr., David E.

    1980-12-12

    The effects on lungs of emissions from fluidized-bed combustion and coal gasification on man are being studied by inhalation experiments and intratracheal administration of fly ash to hamsters. The hamsters are sacrificed at 1, 3, 6, 9 and 30 days and the lungs examined by methods which are described. (LTN)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  10. Coal gasification and occupational health.

    Science.gov (United States)

    Young, R J; McKay, W J; Evans, J M

    1978-12-01

    Identification and prevention of health effects due to occupational exposures in coal gasification processes requires a basic knowledge of the technological process by which gasification proceeds. This paper presents an overview of the technology and a rational approach to health hazard identification based upon the concept of the unit operation specific micro environment. A final section is devoted to summarizing current research efforts being carried out under the aegis of the National Institute for Occupational Safety and Health.

  11. Combustion in fluidized bed reactors; Verbrennung in Wirbelschichtreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Thome-Kozmiensky, Karl J. [vivis CONSULT GmbH, Nietwerder (Germany)

    2013-03-01

    Since the first application for the coal gasification, the fluidized bed technology has passed an impressive development. Nowadays, the fluidized bed technology is utilized at chemical processes, drying and cooling, gasification, combustion and purification of exhaust gas. In the firing technology, the fluidized technology initially has been proved in the combustion of very high ash coal and sewage sludge. Recently, the fluidized bed technology also is applied in the drying of sewage sludge, combustion of domestic waste - as in Japan and Sweden - as well as in the gasification and combustion of substitute fuels, biomass - wood pellets, wood chips, straw, cocoa shells and so forth - and residues from the paper manufacturing - such as in Germany and Austria. Under this aspect, the author of the contribution under consideration reports on the combustion of sewage sludge, substitute fuels and biomass.

  12. Co-combustion and gasification of various biomasses

    Energy Technology Data Exchange (ETDEWEB)

    Mutanen, K. [A. Ahlstrom Corporation, Varkaus (Finland). Ahlstrom Pyropower

    1996-12-31

    During the last twenty years the development of fluidized bed combustion and gasification technology has made it possible to increase significantly utilisation of various biomasses in power and heat generation. The forerunner was the pulp and paper industry that has an adequate biomass fuel supply and energy demand on site. Later on municipalities and even utilities have seen biomass as a potential fuel. The range of available biomasses includes wood-based fuels and wastes like bark, wood chips, and saw dust, agricultural wastes like straw, olive waste and rice husk, sludges from paper mills and de-inking plants, other wastes like municipal sludges, waste paper and RDF. Recently new environmental regulations and taxation of fossil fuels have further increased interest in the use of biomasses in energy generation. However, in many cases available quantities and/or qualities of biomasses are not adequate for only biomass-based energy generation in an economic sense. On the other hand plant owners want to maintain a high level of fuel flexibility and fuel supply security. In some cases disposing by burning is the only feasible way to handle certain wastes. In many cases the only way to fulfil these targets and utilize the energy is to apply co-combustion or gasification of different fuels and wastes. Due to the fact that fluidized bed combustion technology offers a very high fuel flexibility and high combustion efficiency with low emissions it has become the dominating technology in co-combustion applications. This presentation will present Alhstrom`s experiences in co-combustion of biomasses in bubbling beds and Ahlstrom Pyroflow circulating fluidized beds based on about 200 operating references worldwide. CFB gasification will also be discussed 9 refs.

  13. Coal gasification vessel

    Science.gov (United States)

    Loo, Billy W.

    1982-01-01

    A vessel system (10) comprises an outer shell (14) of carbon fibers held in a binder, a coolant circulation mechanism (16) and control mechanism (42) and an inner shell (46) comprised of a refractory material and is of light weight and capable of withstanding the extreme temperature and pressure environment of, for example, a coal gasification process. The control mechanism (42) can be computer controlled and can be used to monitor and modulate the coolant which is provided through the circulation mechanism (16) for cooling and protecting the carbon fiber and outer shell (14). The control mechanism (42) is also used to locate any isolated hot spots which may occur through the local disintegration of the inner refractory shell (46).

  14. Bed Bugs

    Science.gov (United States)

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

  15. Experimental investigations of biomass gasification with carbon-dioxide

    Science.gov (United States)

    Sircar, Indraneel

    A sustainable energy cycle may include enhanced utilization of solar energy and atmospheric CO2 to produce biomass and enhanced utilization of exhaust CO2 from power plants for synthetic gas production. The reaction of carbon with CO2 is potentially one of the important processes in a future sustainable carbon cycle. Reactions involving carbon and CO2 are also relevant to the chemical process and metal industries. Biomass char has been recognized as a present and future alternative to fossil-fuels for energy production and fuel synthesis. Therefore, biomass char gasification with CO2 recycling is proposed as a sustainable and carbon-neutral energy technology. Biomass char is a complex porous solid and its gasification involves heat and mass transfer processes within pores of multiple sizes from nanometer to millimeter scales. These processes are coupled with heterogeneous chemistry at the internal and external surfaces. Rates for the heterogeneous carbon gasification reactions are affected by inorganic content of the char. Furthermore, pore structure of the char develops with conversion and influences apparent gasification rates. Effective modeling of the gasification reactions has relied on the best available understanding of diffusion processes and kinetic rate property constants from state of the art experiments. Improvement of the influences of inorganic composition, and process parameters, such as pressure and temperature on the gasification reaction rates has been a continuous process. Economic viability of gasification relies on use of optimum catalysts. These aspects of the current status of gasification technologies have motivated the work reported in this dissertation. The reactions between biomass chars and CO2 are investigated to determine the effects of temperature and pressure on the reaction rates for large char particles of relevance to practical gasification technologies. An experimental apparatus consisting of a high-pressure fixed-bed reactor

  16. Efficient gasification of wet biomass residue to produce middle caloric gas

    Institute of Scientific and Technical Information of China (English)

    Guangwen Xu; Takahiro Murakami; Toshiyuki Suda; Hidehisa Tani; Yutaka Mito

    2008-01-01

    Various process residues represent a kind of biomass resource already concentrated but containing water as much as 60 wt.%.These materials are generally treated as waste or simply combusted directly to generate heat.Recently,we attempted to convert them into middle caloric gas to substitute for natural gas,as a chemical or a high-rank gaseous fuel for advanced combustion utilities.Such conversion is implemented through dual fluidized bed gasification (DFBG).Concerning the high water content of the fuels,DFBG was suggested to accomplish either with high-efficiency fuel drying in advance or direct decoupling of fuel drying/pyrolysis from char gasification and tar/hydrocarbon reforming.Along with fuel drying,calcium-based catalyst can be impregnated into the fuel,without much additional cost,to increase the fuel's gasification reactivity and to reduce tar formation.This article reports the Ca impregnation method and its resulting effects on gasification reactivity and tar suppression ability.Meanwhile,the principle of directly gasifying wet fuel with decoupled dual fluidized bed gasification (D-DFBG) is also highlighted.

  17. Effect of pulsation on black liquor gasification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Zinn, B.T.; Jagoda, J.; Jeong, H.; Kushari, A.; Rosen, L.J.

    1998-12-01

    Pyrolysis is an endothermic process. The heat of reaction is provided either by partial combustion of the waste or by heat transfer from an external combustion process. In one proposed system black liquor is pyrolized in a fluidized bed to which heat is added through a series of pulse combustor tail pipes submerged in the bed material. This system appears promising because of the relatively high heat transfer in pulse combustors and in fluidized beds. Other advantages of pulse combustors are discussed elsewhere. The process is, however, only economically viable if a part of the pyrolysis products can be used to fire the pulse combustors. The overall goals of this study were to determine: (1) which is the limiting heat transfer rate in the process of transferring heat from the hot combustion products to the pipe, through the pipe, from the tail pipe to the bed and through the bed; i.e., whether increased heat transfer within the pulse combustor will significantly increase the overall heat transfer rate; (2) whether the heat transfer benefits of the pulse combustor can be utilized while maintaining the temperature in the bed within the narrow temperature range required by the process without generating hot spots in the bed; and (3) whether the fuel gas produced during the gasification process can be used to efficiently fire the pulse combustor.

  18. Hydrogen production from lignocellulosic biomass by two-step gasification method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In-Gu [Korea Institute of Energy Research (Korea, Republic of)

    2010-07-01

    Hydrogen can be produced from woody biomass by conventional gasification methods such as partial oxidation or steam gasification. Since these methods produce gas products with low content of hydrogen as well as high content of tar from gasification reactors, posttreatment processes including tar cracker and water-gas shift reaction process are usually necessary for obtaining clean hydrogen-rich gas from woody biomass. In this work, a twostep gasification method was experimentally studied as an alternative to the conventional methods. The first step of the gasification is the fast pyrolysis of biomass to obtain liquid-phase product (bio-oil) and the second step is to gasify the bio-oil to hydrogen-rich gas in supercritical water. The fast pyrolysis of woody biomass was carried out using a bench-scale fluidized-bed reactor. The gasification of bio-oil in supercritical water was performed using a continuous-flow reactor packed with catalyst. The effect of major reaction conditions such as temperature and catalyst on hydrogen yield will be discussed. (orig.)

  19. Assessment of coal gasification/hot gas cleanup based advanced gas turbine systems

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-01

    The major objectives of the joint SCS/DOE study of air-blown gasification power plants with hot gas cleanup are to: (1) Evaluate various power plant configurations to determine if an air-blown gasification-based power plant with hot gas cleanup can compete against pulverized coal with flue gas desulfurization for baseload expansion at Georgia Power Company's Plant Wansley; (2) determine if air-blown gasification with hot gas cleanup is more cost effective than oxygen-blown IGCC with cold gas cleanup; (3) perform Second-Law/Thermoeconomic Analysis of air-blown IGCC with hot gas cleanup and oxygen-blown IGCC with cold gas cleanup; (4) compare cost, performance, and reliability of IGCC based on industrial gas turbines and ISTIG power island configurations based on aeroderivative gas turbines; (5) compare cost, performance, and reliability of large (400 MW) and small (100 to 200 MW) gasification power plants; and (6) compare cost, performance, and reliability of air-blown gasification power plants using fluidized-bed gasifiers to air-blown IGCC using transport gasification and pressurized combustion.

  20. Technology Assessment Report: Aqueous Sludge Gasification Technologies

    Science.gov (United States)

    The study reveals that sludge gasification is a potentially suitable alternative to conventional sludge handling and disposal methods. However, very few commercial operations are in existence. The limited pilot, demonstration or commercial application of gasification technology t...

  1. Ash behaviour in fluidized bed gasification and combustion: release of harmful trace elements and the behavior of alkalis; Tuhkan muuntuminen leijukerroskaasutuksessa ja -poltossa: Haitallisten hivenmetallien vapautuminen ja alkalien kaeyttaeytyminen

    Energy Technology Data Exchange (ETDEWEB)

    Kauppinen, E.; Valmari, T. [VTT Chemical Technology, Espoo (Finland)

    1997-10-01

    During 1996 the behaviour of alkaline metals (K and Na) during circulating fluidized bed combustion of forest residue was studied in a real-scale plant using aerosol measurement instruments (filters, impactor, DMA). Prior to heat exchangers (850 deg C) the ash mass-concentration was 1.0 - 1.3 g/Nm{sup 3} with 1 % of ash forming constituents as vapours. At least 98 % of sulphur, over 90 % of sodium and over 80 % of potassium were found in particulate phase prior to heat exchangers. On the other hand, at least 80 % of the chlorine was in vapour phase. 98 % of the ash was in coarse (> 0.3 {mu}m) particles. Coarse ash particles had an irregular surface structure often consisting of fine primary particles. The remaining 2 % was observed in fine particles of about 0.1 {mu}m. Both rounded and cornered (suggesting crystal structure) fine particles were found. The fine particles were composed of alkali chlorides and sulphates, mainly of KCl. About 80 % of the ash on mass basis was deposited onto heat exchanger surfaces when soot-blowing was not carried out. Practically all of the particles larger than 10 {mu}m were deposited. The deposition was less significant for smaller particles. The fine particle concentration before and after the heat exchangers was the same within the experimental inaccuracy. The deposited fraction of potassium, sodium and sulphur was about the same than that of the total ash: However, the deposition of chlorine was much lower since the chlorine content was low in the coarse particles that were deposited most effectively. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Francis Lau

    2002-12-01

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

  3. Environmental benefits of underground coal gasification.

    Science.gov (United States)

    Liu, Shu-qin; Liu, Jun-hua; Yu, Li

    2002-04-01

    Environmental benefits of underground coal gasification are evaluated. The results showed that through underground coal gasification, gangue discharge is eliminated, sulfur emission is reduced, and the amount of ash, mercury, and tar discharge are decreased. Moreover, effect of underground gasification on underground water is analyzed and CO2 disposal method is put forward.

  4. Environmental benefits of underground coal gasification

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Environmental benefits of underground coal gasification are evaluated. The results showed that through underground coal gasification,gangue discharge is eliminated, sulfur emission is reduced, and the amount of ash, mercury, and tar discharge are decreased. Moreover, effect of underground gasification on underground water is analyzed and CO2 disposal method is put forward.

  5. The assessment of sewage sludge gasification by-products toxicity by ecotoxicologial test.

    Science.gov (United States)

    Werle, Sebastian; Dudziak, Mariusz

    2015-08-01

    The process of gasification of sewage sludge generates by-products, which may be contaminated with toxic and hazardous substances, both organic and inorganic. It is therefore important to assess the environmental risk associated with this type of waste. The feasibility of using an ecotoxicological tests for this purpose was determined in the presented study. The applied tests contained indicator organisms belonging to various biological groups (bacteria, crustaceans, plants). The subject of the study were solid (ash, char) and liquid (tar) by-products generated during gasification (in a fixed bed reactor) of dried sewage sludge from various wastewater treatment systems. The tested samples were classified based on their toxic effect. The sensitivity of the indicator organisms to the tested material was determined. In-house procedures for the preparation for toxicity analysis of both sewage sludge and by-products generated during the gasification were presented. The scope of work also included the determination of the effect of selected process parameters (temperature, amount of gasifying agent) on the toxicity of gasification by-products depending on the sewage sludge source. It was shown that both the type of sewage sludge and the parameters of the gasification process affects the toxicity of the by-products of gasification. However, the results of toxicity studies also depend on the type of ecotoxicological test used, which is associated with a different sensitivity of the indicator organisms. Nevertheless, it may be concluded that the by-products formed during the gasification of the low toxicity sewage sludge can be regarded as non-toxic or low toxic. However, the results analysis of the gasification of the toxic sludge were not conclusive, which leads to further research needs in this area. © The Author(s) 2015.

  6. Survey of biomass gasification. Volume II. Principles of gasification

    Energy Technology Data Exchange (ETDEWEB)

    Reed, T.B. (comp.)

    1979-07-01

    Biomass can be converted by gasification into a clean-burning gaseous fuel that can be used to retrofit existing gas/oil boilers, to power engines, to generate electricity, and as a base for synthesis of methanol, gasoline, ammonia, or methane. This survey describes biomass gasification, associated technologies, and issues in three volumes. Volume I contains the synopsis and executive summary, giving highlights of the findings of the other volumes. In Volume II the technical background necessary for understanding the science, engineering, and commercialization of biomass is presented. In Volume III the present status of gasification processes is described in detail, followed by chapters on economics, gas conditioning, fuel synthesis, the institutional role to be played by the federal government, and recommendations for future research and development.

  7. Effect of Oxidizing Medium on Synthesis Gas Content at Solid Fuel Gasification

    Directory of Open Access Journals (Sweden)

    Korotkikh Alexander

    2016-01-01

    Full Text Available Solid fuel gasification is promising technology in sphere of clean energy. The synthesis gas content for air-blown fixed bed gasification may be defined using Gibbs free energy minimization procedure. The minimization procedure was realized via steepest descent method. The feed consisted of steam, air and coal at standard conditions. The temperature and gas content were calculated at different ratios of coal/steam/air. It was found that optimal syngas content resulted at component ratio of 1.0/0.5/2.2 with the ambient temperature of 1300 K and syngas heating power of 7.7 kJ/m3.

  8. 3rd international conference on coal gasification and liquefaction, University of Pittsburgh

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-01-01

    The third annual international conference on ''Coal Gasification and Liquefaction: What Needs to be Done Now'' was held at the University of Pittsburgh, Pittsburgh, PA on August 3-5, 1976. The majority of the papers dealt with coal gasification and liquefaction (often on the basis of process pilot plant experience) and on flue gas desulfurization by a variety of processes; fewer papers involved fluidized bed combustion, combined cycle power plants, coal desulfurization, government policy on environmental effects and on synthetic fuels, etc. Twenty-eight papers have been entered individually into EDB and ERA. (LTN)

  9. Clustering behavior of solid particles in two-dimensional liquid-solid fluidized-beds

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, the clustering behavior of solid particles in a two-dimensional (2D) liquid-solid fluidized-bed was studied by using the charge coupled devices (CCD) imaging measuring and processing technique and was characterized by fractal analysis. CCD images show that the distribution of solid particles in the 2D liquid-solid fluidised-bed is not uniform and self-organization behavior of solid particles was observed under the present experimental conditions. The solid particles move up in the 2D fluidized-bed in groups or clusters whose configurations are often in the form of horizontal strands. The box fractal dimension of the cluster images in the 2D liquid-solid fluidized-bed increases with the rising of solid holdup and reduces with the increment of solid particle diameter and superficial liquid velocity. At given solid holdup and solid particle size,the lighter particles show smaller fractal dimensions.

  10. The shell coal gasification process

    Energy Technology Data Exchange (ETDEWEB)

    Koenders, L.O.M.; Zuideveld, P.O. [Shell Internationale Petroleum Maatschappij B.V., The Hague (Netherlands)

    1995-12-01

    Future Integrated Coal Gasification Combined Cycle (ICGCC) power plants will have superior environmental performance and efficiency. The Shell Coal Gasification Process (SCGP) is a clean coal technology, which can convert a wide range of coals into clean syngas for high efficiency electricity generation in an ICGCC plant. SCGP flexibility has been demonstrated for high-rank bituminous coals to low rank lignites and petroleum coke, and the process is well suited for combined cycle power generation, resulting in efficiencies of 42 to 46% (LHV), depending on choice of coal and gas turbine efficiency. In the Netherlands, a 250 MWe coal gasification combined cycle plant based on Shell technology has been built by Demkolec, a development partnership of the Dutch Electricity Generating Board (N.V. Sep). The construction of the unit was completed end 1993 and is now followed by start-up and a 3 year demonstration period, after that the plant will be part of the Dutch electricity generating system.

  11. Diesel power plants based on biomass gasification. Final report

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

    The aim of the project was to assess the competitiveness and market potential of small-scale power plant concepts based on biomass gasification and on diesel/gas engines, and to study the effect of process parameters on the efficiency of the circulating fluidized-bed gasifier and on the formation of tarry impurities. Alternative diesel/gas engine power plant concepts based on gasification in scale 6-50 MW{sub e} were assessed. In the basic version, where the electricity is generated only by the a diesel/gas engine, the efficiency level of 37 % is achieved in power generation. When steam cycle is added to the process the efficiency of power generation increases to 44-48 %. The efficiencies achieved in the process are very high compared with those of biomass power plant processes on a commercial level or under development. The most significant potential of biomass-based power generation is made up by wastes of sugar industries in south and Central America and in Asia. There are also very extensive growth potentials of bioenergy use in the NAFTA countries (USA, Canada and Mexico) and in Europe. In Europe, the bioenergy use is expected to grow most sharply in Italy, Spain, Germany and Poland. Carbon conversion obtained in the gasifier was in the range of 99.0-99.9 % for sawdust and 96-98 % for forest residue chips. The tar content of the product gas 10-15 g/m- m{sup 3}{sub n}, for sawdust in the gasification temperature of 830-930 deg C and with sand as circulating fluid-bed. When dolomite was used as circulating fluid-bed, the tar contents were 2-3 g/m{sup 3}{sub n} at as low temperatures as 880-890 deg C. The tar content of gas can be reduced sharply by phasing of gasification air and by using catalytic circulating fluid-bed material Bioenergy Research Programme; LIEKKI 2 Research Programme. 26 refs., 40 figs.

  12. Biomass gasification with CHP production: A review of state of the art technology and near future perspectives

    Directory of Open Access Journals (Sweden)

    Jankes Goran G.

    2012-01-01

    Full Text Available This paper is a review of the state of the art of biomass gasification and the future of using biomass in Serbia and it presents researches within the project “The Development of a CHP Plant with Biomass Gasification”. The concept of downdraft demonstration unit coupled with gas engine is adopted. Downdraft fixed-bed gasification is generally favored for CHP, owing to the simple and reliable gasifiers and low content of tar and dust in produced gas. The composition and quantity of gas and the amount of air are defined by modeling biomass residues gasification process. The gas (290-400m3/h for 0.5- 0.7MW biomass input obtained by gasification at 800oC with air at atmospheric pressure contains 14% H2, 27% CO, 9% CO2, 2% CH4, and 48% N2, and its net heating value is 4.8-6 MJ/Nm3. The expected gasifier efficiency is up to 80%. The review of the work on biomass gasification has shown that the development of technology has reached the mature stage. There are CHP plants with biomass gasification operating as demonstration plants and several gasification demonstration units are successfully oriented to biofuel production. No attempt has been made here to address the economic feasibility of the system. Economics will be the part of a later work as firmer data are acquired.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

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

  16. Leaching From Biomass Gasification Residues

    DEFF Research Database (Denmark)

    Allegrini, Elisa; Boldrin, Alessio; Polletini, A.

    2011-01-01

    The aim of the present work is to attain an overall characterization of solid residues from biomass gasification. Besides the determination of chemical and physical properties, the work was focused on the study of leaching behaviour. Compliance and pH-dependence leaching tests coupled with geoche......The aim of the present work is to attain an overall characterization of solid residues from biomass gasification. Besides the determination of chemical and physical properties, the work was focused on the study of leaching behaviour. Compliance and pH-dependence leaching tests coupled...

  17. UTILIZATION OF LIGHTWEIGHT MATERIALS MADE FROM COAL GASIFICATION SLAGS

    Energy Technology Data Exchange (ETDEWEB)

    Vas Choudhry; Stephen Kwan; Steven R. Hadley

    2001-07-01

    The objective of the project entitled ''Utilization of Lightweight Materials Made from Coal Gasification Slags'' was to demonstrate the technical and economic viability of manufacturing low-unit-weight products from coal gasification slags which can be used as substitutes for conventional lightweight and ultra-lightweight aggregates. In Phase I, the technology developed by Praxis to produce lightweight aggregates from slag (termed SLA) was applied to produce a large batch (10 tons) of expanded slag using pilot direct-fired rotary kilns and a fluidized bed calciner. The expanded products were characterized using basic characterization and application-oriented tests. Phase II involved the demonstration and evaluation of the use of expanded slag aggregates to produce a number of end-use applications including lightweight roof tiles, lightweight precast products (e.g., masonry blocks), structural concrete, insulating concrete, loose fill insulation, and as a substitute for expanded perlite and vermiculite in horticultural applications. Prototypes of these end-use applications were made and tested with the assistance of commercial manufacturers. Finally, the economics of expanded slag production was determined and compared with the alternative of slag disposal. Production of value-added products from SLA has a significant potential to enhance the overall gasification process economics, especially when the avoided costs of disposal are considered.

  18. Co-gasification of coal/sewage sludge and gas turbine development

    Energy Technology Data Exchange (ETDEWEB)

    Kelsall, G.J.; Laughlin, K.; Davison, J.E.; Smith, M.A. [ed.] [British Coal Corporation, Stoke Orchard (United Kingdom). Coal Technology Development Division

    1995-12-31

    The project investigated the ability of the Air Blown Gasification Cycle (ABGC), formerly known as the British Coal Topping Cycle, to co-utilise coal and pelletised sewage sludge in the CTDU pressurised gasifier. The co-firing coal and pelletised sewage sludge in the CTDD pressurised gasifier did not have an adverse effect on the gasifier operability or process performance over the parameter range studied, provided that the carbon (in fuel) to oxygen (in fluidising air) input ratio was fixed. For all test conditions, sustained ash agglomeration-free operation was achieved. Tar levels were low and fines elutriation rates remained constant. The sulphur retention efficiency attained during co-gasification with limestone addition was high. This indicates that there may be scope for reducing sorbent requirements. Plant efficiencies for an IGCC plant co-firing straw and coal were predicted to decrease if lockoppers had to be used. However, it should be possibly to virtually eliminate this penalty if an advanced feeding system could be developed. The feeding of straw to an ABGC plant using lock hoppers should not incur a reduction in plant efficiency. The addition of sewage sludge to IGCC and ABGC plants was predicted to reduce the cost of electricity provided that the gate fee for sewage sludge was above 20 UK pounds per tonne. Two designs of turbine combustor based on the tubo-annual design principle were tested, burning both synthetic and coal/sewage sludge-derived fuel gases. Combustor performance was improved substantially by increasing the size of the flame-tube diameter from 82.5 mm to 125 mm, by increasing the residence time within the primary zone and by changing the combustor cooling approach to one which utilised a combination of film and impingement cooling. Emissions of CO and NO{sub x} were very low. 6 refs., 2 figs., 5 tabs.

  19. Calcination of limestone in a circulating fluidized bed with coal residues as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kaldin, B.V. (Kaldin BV, Koningsbosch (Netherlands))

    1993-01-01

    In April 1989 a plant was set up by NOVEM and Kaldin BV in which limestone was calcined in a fluidised bed using coal residues and fine-grained coal as fuels. This report describes the plants and discusses and compares the period in which coal residues were used and that in which fine grained coal was used. Emission levels, mass and energy balances and the product and its application in sand-lime bricks are discussed for each of the fuels. Other applications of the product are presented and the economic viability of the plant is discussed.

  20. Catalytic gasification of oil-extracted residue biomass of Botryococcus braunii.

    Science.gov (United States)

    Watanabe, Hideo; Li, Dalin; Nakagawa, Yoshinao; Tomishige, Keiichi; Watanabe, Makoto M

    2015-09-01

    Catalytic gasification of the oil-extracted residue biomass of Botryococcus braunii was demonstrated in a laboratory-scale continuous feeding dual bed reactor. Steam gasification at 1023 K over Ni-Fe/Mg/Al catalyst can completely reform tar derived from pyrolysis of the residue biomass into C1 gases and hydrogen, and has achieved 91%-C conversion to gaseous product (CO+CO2+CH4). Composition of product gas has higher contents of CO and H2 with their ratio (H2/CO) of around 2.4 which is slightly H2-rich syngas. Maximum hydrogen yield of 74.7 mmol g-biomass(-1) obtained in this work is much higher than that from gasification of other algal biomass reported in literature. The residue biomass of B. braunii can be a superior renewable source of syngas or hydrogen. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Developments in fluidized bed conversion of solid fuels

    Directory of Open Access Journals (Sweden)

    Leckner Bo

    2016-01-01

    Full Text Available A summary is given on the development of fluidized bed conversion (combustion and gasification of solid fuels. First, gasification is mentioned, following the line of development from the Winkler gasifier to recent designs. The combustors were initially bubbling beds, which were found unsuitable for combustion of coal because of various drawbacks, but they proved more useful for biomass where these drawbacks were absent. Instead, circulating fluidized bed boilers became the most important coal converters, whose design now is quite mature, and presently the increments in size and efficiency are the most important development tasks. The new modifications of these conversion devices are related to CO2 capture. Proposed methods with this purpose, involving fluidized bed, are single-reactor systems like oxy-fuel combustion, and dual-reactor systems, including also indirect biomass gasifiers.

  2. Pyrolysis and gasification-melting of automobile shredder residue.

    Science.gov (United States)

    Roh, Seon Ah; Kim, Woo Hyun; Yun, Jin Han; Min, Tae Jin; Kwak, Yeon Ho; Seo, Yong Chil

    2013-10-01

    Automobile shredder residue (ASR) from end-of-life vehicles (ELVs) in Korea has commonly been disposed of in landfills. Due to the growing number of scrapped cars and the decreasing availability of landfill space, effective technology for reducing ASR is needed. However ASR is a complex mixture, and finding an appropriate treatment is not easy on account of the harmful compounds in ASR. Therefore, research continues to seek an effective treatment technology. However most studies have thus far been performed in the laboratory, whereas few commercial and pilot studies have been performed. This paper studies the pyrolysis and gasification-melting of ASR. The pyrolyis characteristics have been analyzed in a thermogravimetric analyzer (TGA), a Lindberg furnace, and a fixed-bed pyrolyzer to study the fundamental characteristics of ASR thermal conversion. As a pilot study, shaft-type gasification-melting was performed. High-temperature gasification-melting was performed in a 5000 kg/day pilot system. The gas yield and syngas (H2 and CO) concentration increase when the reaction temperature increases. Gas with a high calorific value of more than 16,800 kJ/m3 was produced in the pyrolyzer. From the gasification-melting process, syngas of CO (30-40%) and H2(10-15%) was produced, with 5% CH4 produced as well. Slag generation was 17% of the initial ASR, with 5.8% metal content and 4% fly ash. The concentration of CO decreases, whereas the H2, CO2, and CH4 concentrations increase with an increase in the equivalence ratio (ER). The emission levels of dioxin and air pollution compounds except nitrogen oxides (NO(x)) were shown to satisfy Korean regulations.

  3. Calcium addition in straw gasification

    DEFF Research Database (Denmark)

    Risnes, H.; Fjellerup, Jan Søren; Henriksen, Ulrik Birk

    2003-01-01

    The present work focuses on the influence of calcium addition in gasification. The inorganic¿organic element interaction as well as the detailed inorganic¿inorganic elements interaction has been studied. The effect of calcium addition as calcium sugar/molasses solutions to straw significantly...

  4. BIMOMASS GASIFICATION PILOT PLANT STUDY

    Science.gov (United States)

    The report gives results of a gasification pilot program using two biomass feedstocks: bagasse pellets and wood chips. he object of the program was to determine the properties of biomass product gas and its suitability as a fuel for gas-turbine-based power generation cycles. he f...

  5. Biomass gasification in the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Van der Drift, A. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2013-07-15

    This reports summarizes the activities, industries, and plants on biomass gasification in the Netherlands. Most of the initiatives somehow relate to waste streams, rather than clean biomass, which may seem logic for a densely populated country as the Netherlands. Furthermore, there is an increasing interest for the production of SNG (Substitute Natural Gas) from biomass, both from governments and industry.

  6. Biomass waste gasification - can be the two stage process suitable for tar reduction and power generation?

    Science.gov (United States)

    Sulc, Jindřich; Stojdl, Jiří; Richter, Miroslav; Popelka, Jan; Svoboda, Karel; Smetana, Jiří; Vacek, Jiří; Skoblja, Siarhei; Buryan, Petr

    2012-04-01

    A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stage gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100-350 kW(th). The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950°C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar compound contents confirmed superiority of the two stage gasification system, drastic decrease of aromatic compounds with two and higher number of benzene rings by 1-2 orders. On the other hand the two stage gasification (with overall ER=0.71) led to substantial reduction of gas heating value (LHV=3.15 MJ/Nm(3)), elevation of gas volume and increase of nitrogen content in fuel gas. The increased temperature (>950°C) at the entrance to the char bed caused also substantial decrease of ammonia content in fuel gas. The char with higher content of ash leaving the

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

    CSIR Research Space (South Africa)

    Baloyi, J

    2014-06-01

    Full Text Available An analysis of irreversibilities generated due to combustion in an adiabatic combustor burning wood was conducted. This was done for a reactant mixture varying from a rich to a lean mixture. A non-adiabatic non-premixed combustion model of a...

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

    DEFF Research Database (Denmark)

    Hansen, Kim Granly

    implemented in the CFD code FLOTRACS-MP-3D. The decomposition reaction is studied in a 3D representation of a 0.254 m i.d. riser, which has been studied experimentally by Ouyang et al. (1993). Comparison between measured and simulated time-averaged ozone concentration at different elevations in the riser...... shows good agreement. The 3D representation of the reactor geometry gives better predictions of the radial variation in concentration than in a similar 2D simulation, Samuelsberg and Hjertager (1995). A parameter study is performed to investigate improvements in the predicted pressure drop profile. When...

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

    DEFF Research Database (Denmark)

    Hansen, Kim Granly

    shows good agreement. The 3D representation of the reactor geometry gives better predictions of the radial variation in concentration than in a similar 2D simulation, Samuelsberg and Hjertager (1995). A parameter study is performed to investigate improvements in the predicted pressure drop profile. When...... with experimental findings of both mass flux and pressure profile, but further improvements are proposed and investigated. A parameter study shows that mesh refinement, choice of particle diameter and choice of drag model are crucial when simulating FCC riser flow. The isothermal decomposition of ozone has been...... using two-fluid modeling to predict riser flows there have been difficulties in predicting the solids hold up in risers represented by the correct pressure drop profile. Mesh refinement has shown to improve the axial segregation of particles in the riser, but when simulating a riser with a large L...

  10. Beds, mattresses and cushions for pressure sore prevention and treatment.

    Science.gov (United States)

    Cullum, N; Deeks, J; Sheldon, T A; Song, F; Fletcher, A W

    2000-01-01

    To assess the effectiveness of pressure relieving beds, mattresses and cushions (support surfaces) in the prevention and treatment of pressure sores. Searches of 19 databases, hand searching of journals, conference proceedings, and bibliographies. Randomised controlled trials evaluating support surfaces for the prevention or treatment of pressure sores. There was no restriction on articles based on language or publication status. Data extraction and assessment of study quality was undertaken by two reviewers independently. Trials with similar patients, comparisons, and outcomes were pooled. Where pooling was inappropriate, trials are discussed in a narrative review. 29 RCTs of support surfaces for pressure sore prevention were identified. Some high specification foam mattresses were more effective than 'standard' hospital foam mattresses in moderate-high risk patients. Pressure relieving mattresses in the operating theatre reduced the incidence of pressure sores post-operatively. The relative merits of alternating and constant low pressure, and of the different alternating pressure devices are unclear. Seat cushions and simple, constant low-pressure devices have not been adequately evaluated. Limited evidence suggests that low air loss beds reduce the incidence of pressure sores in intensive care. 6 RCTs of support surfaces for pressure sore treatment were identified. There is good evidence that air-fluidised and low air loss beds improve healing rates. Seat cushions have not been adequately evaluated. 2 RCTs evaluated surfaces for both prevention and treatment in the same trial. PREVENTION - There is good evidence of the effectiveness of high specification foam over standard hospital foam, and pressure relief in the operating theatre. Treatment - There is good evidence of the effectiveness of air-fluidised and low air loss devices as treatments. Overall, however, it is impossible to determine the most effective surface for either prevention or treatment.

  11. Application of response surface methodology to assess the combined effect of operating variables on high-pressure coal gasification for H2-rich gas production

    OpenAIRE

    Fermoso Domínguez, Javier; Gil Matellanes, María Victoria; Arias Rozada, Borja; González Plaza, Marta; Pevida García, Covadonga; Pis Martínez, José Juan; Rubiera González, Fernando

    2010-01-01

    Coal gasification was performed by means of a high-pressure fixed bed gasifier fitted with a solids feeding system in continuous mode, using oxygen and steam as gasifying agents. The main aim of the paper was to assess the combined effects of the operating variables (temperature, oxygen and steam concentrations) on high-pressure coal gasification. To this end a face centered central composite design (FCCCD) based on response surface methodology (RSM) was used. The response variables studied w...

  12. Using potassium catalytic gasification to improve the performance of solid oxide direct carbon fuel cells: Experimental characterization and elementary reaction modeling

    OpenAIRE

    Yu, Xiankai; Shi, Yixiang; Wang, Hongjian; Cai, Ningsheng; Li, Chen; Ghoniem, Ahmed F

    2013-01-01

    The performance of a solid oxide electrolyte direct carbon fuel cell (SO-DCFC) is limited by the slow carbon gasification kinetics at the typical operating temperatures of cell: 650–850 °C. To overcome such limitation, potassium salt is used as a catalyst to speed up the dry carbon gasification reactions, increasing the power density by five-fold at 700–850 °C. The cell performance is shown to be sensitive to the bed temperature, emphasizing the role of gasification rates and that of CO produ...

  13. Non-catalytic co-gasification of sub-bituminous coal and biomass

    Science.gov (United States)

    Nyendu, Guevara Che

    Fluidization characteristics and co-gasification of pulverized sub-bituminous coal, hybrid poplar wood, corn stover, switchgrass, and their mixtures were investigated. Co-gasification studies were performed over temperature range from 700°C to 900°C in different media (N2, CO2, steam) using a bubbling fluidized bed reactor. In fluidization experiments, pressure drop (Delta P) observed for coal-biomass mixtures was higher than those of single coal and biomass bed materials in the complete fluidization regime. There was no systematic trend observed for minimum fluidization velocity ( Umf) with increasing biomass content. However, porosity at minimum fluidization (εmf) increased with increasing biomass content. Channeling effects were observed in biomass bed materials and coal bed with 40 wt.% and 50 wt.% biomass content at low gas flowrates. The effect of coal pressure overshoot reduced with increasing biomass content. Co-gasification of coal and corn stover mixtures showed minor interactions. Synergetic effects were observed with 10 wt.% corn stover. Coal mixed with corn stover formed agglomerates during co-gasification experiments and the effect was severe with increase in corn stover content and at 900°C. Syngas (H2 + CO) concentrations obtained using CO2 as co-gasification medium were higher (~78 vol.% at 700°C, ~87 vol.% at 800°C, ~93 vol.% at 900°C) than those obtained with N2 medium (~60 vol.% at 700°C, ~65 vol.% at 800°C, ~75 vol.% at 900°C). Experiments involving co-gasification of coal with poplar showed no synergetic effects. Experimental yields were identical to predicted yields. However, synergetic effects were observed on H2 production when steam was used as the co-gasification medium. Additionally, the presence of steam increased H2/CO ratio up to 2.5 with 10 wt.% hybrid poplar content. Overall, char and tar yields decreased with increasing temperature and increasing biomass content, which led to increase in product gas.

  14. Coal gasification. Quarterly report, April-June 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-04-01

    In DOE's program for the conversion of coal to gaseous fuels both high-and low-Btu gasification processes are being developed. High-Btu gas can be distributed economically to consumers in the same pipeline systems now used to carry natural gas. Low-Btu gas, the cheapest of the gaseous fuels produced from coal, can be used economically only on site, either for electric power generation or by industrial and petrochemical plants. High-Btu natural gas has a heating value of 950 to 1000 Btu per standard cubic foot, is composed essentially of methane, and contains virtually no sulfur, carbon monoxide, or free hydrogen. The conversion of coal to High-Btu gas requires a chemical and physical transformation of solid coal. Coals have widely differing chemical and physical properties, depending on where they are mined, and are difficult to process. Therefore, to develop the most suitable techniques for gasifying coal, DOE, together with the American Gas Association (AGA), is sponsoring the development of several advanced conversion processes. Although the basic coal-gasification chemical reactions are the same for each process, each of the processes under development have unique characteristics. A number of the processes for converting coal to high-Btu gas have reached the pilot plant Low-Btu gas, with a heating value of up to 350 Btu per standard cubic foot, is an economical fuel for industrial use as well as for power generation in combined gas-steam turbine power cycles. Because different low-Btu gasification processes are optimum for converting different types of coal, and because of the need to provide commercially acceptable processes at the earliest possible date, DOE is sponsoring the concurrent development of several basic types of gasifiers (fixed-bed, fluidized-bed, and entrained-flow).

  15. Chemical looping coal gasification with calcium ferrite and barium ferrite via solid--solid reactions

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardane, Ranjani [U.S. Department of Energy/NETL; Riley, Jarrett [Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States); Tian, Hanjing [West Virginia Univ., Morgantown, WV (United States); Richards, George [U.S. Department of Energy/NETL

    2016-01-01

    Coal gasification to produce synthesis gas by chemical looping was investigated with two oxygen carriers, barium ferrite (BaFe2O4) and calcium ferrite (CaFe2O4). Thermo-gravimetric analysis (TGA) and fixed-bed flow reactor data indicated that a solid–solid interaction occurred between oxygen carriers and coal to produce synthesis gas. Both thermodynamic analysis and experimental data indicated that BaFe2O4 and CaFe2O4 have high reactivity with coal but have a low reactivity with synthesis gas, which makes them very attractive for the coal gasification process. Adding steam increased the production of hydrogen (H2) and carbon monoxide (CO), but carbon dioxide (CO2) remained low because these oxygen carriers have minimal reactivity with H2 and CO. Therefore, the combined steam–oxygen carrier produced the highest quantity of synthesis gas. It appeared that neither the water–gas shift reaction nor the water splitting reaction promoted additional H2 formation with the oxygen carriers when steam was present. Wyodak coal, which is a sub-bituminous coal, had the best gasification yield with oxygen carrier–steam while Illinois #6 coal had the lowest. The rate of gasification and selectivity for synthesis gas production was significantly higher when these oxygen carriers were present during steam gasification of coal. The rates and synthesis gas yields during the temperature ramps of coal–steam with oxygen carriers were better than with gaseous oxygen.

  16. Hydrogen production from biomass gasification using biochar as a catalyst/support.

    Science.gov (United States)

    Yao, Dingding; Hu, Qiang; Wang, Daqian; Yang, Haiping; Wu, Chunfei; Wang, Xianhua; Chen, Hanping

    2016-09-01

    Biochar is a promising catalyst/support for biomass gasification. Hydrogen production from biomass steam gasification with biochar or Ni-based biochar has been investigated using a two stage fixed bed reactor. Commercial activated carbon was also studied as a comparison. Catalyst was prepared with an impregnation method and characterized by X-ray diffraction, specific surface and porosity analysis, X-ray fluorescence and scanning electron micrograph. The effects of gasification temperature, steam to biomass ratio, Ni loading and bio-char properties on catalyst activity in terms of hydrogen production were explored. The Ni/AC catalyst showed the best performance at gasification temperature of 800°C, S/B=4, Ni loading of 15wt.%. Texture and composition characterization of the catalysts suggested the interaction between volatiles and biochar promoted the reforming of pyrolysis volatiles. Cotton-char supported Ni exhibited the highest activity of H2 production (64.02vol.%, 92.08mgg(-1) biomass) from biomass gasification, while rice-char showed the lowest H2 production.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Buljit Buragohain, Sankar Chakma, Peeush Kumar, Pinakeswar Mahanta, Vijayanand S. Moholkar

    2013-01-01

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

  19. Bio-syngas production from agro-industrial biomass residues by steam gasification.

    Science.gov (United States)

    Pacioni, Tatiana Ramos; Soares, Diniara; Domenico, Michele Di; Rosa, Maria Fernanda; Moreira, Regina de Fátima Peralta Muniz; José, Humberto Jorge

    2016-12-01

    This study evaluated the steam gasification potential of three residues from Brazilian agro-industry by assessing their reaction kinetics and syngas production at temperatures from 650 to 850°C and a steam partial pressure range of 0.05 to 0.3bar. The transition temperature between kinetic control and diffusion control regimes was identified. Prior to the gasification tests, the raw biomasses, namely apple pomace, spent coffee grounds and sawdust, were pyrolyzed in a fixed-bed quartz tubular reactor under controlled conditions. Gasification tests were performed isothermally in a magnetic suspension thermobalance and the reaction products were analyzed by a gas chromatograph with TCD/FID detectors. According to the characterization results, the samples presented higher carbon and lower volatile matter contents than the biomasses. Nevertheless, all of the materials had high calorific value. Syngas production was influenced by both temperature and steam partial pressure. Higher concentrations of H2 and CO were found in the conversion range of 50-80% and higher concentrations of CO2 in conversions around 10%, for all the gasified biochars. The H2/CO decreased with increasing temperature, mainly in kinetic control regime, in the lower temperature range. The results indicate the gasification potential of Brazilian biomass residues and are an initial and important step in the development of gasification processes in Brazil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Co-gasification of coal and biomass: Synergy, characterization and reactivity of the residual char.

    Science.gov (United States)

    Hu, Junhao; Shao, Jingai; Yang, Haiping; Lin, Guiying; Chen, Yingquan; Wang, Xianhua; Zhang, Wennan; Chen, Hanping

    2017-11-01

    The synergy effect between coal and biomass in their co-gasification was studied in a vertical fixed bed reactor, and the physic-chemical structural characteristics and gasification reactivity of the residual char obtained from co-gasification were also investigated. The results shows that, conversion of the residual char and tar into gas is enhanced due to the synergy effect between coal and biomass. The physical structure of residual char shows more pore on coal char when more biomass is added in the co-gasification. The migration of inorganic elements between coal and biomass was found, the formation and competitive role of K2SiO3, KAlSiO4, and Ca3Al2(SiO4)3 is a mechanism behind the synergy. The graphization degree is enhanced but size of graphite crystallite in the residual char decreases with biomass blending ratio increasing. TGA results strongly suggest the big difference in the reactivity of chars derived from coal and biomass in spite of influence from co-gasification. Copyright © 2017 Elsevier Ltd. All rights reserved.