WorldWideScience

Sample records for biomass gas steam

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

    Directory of Open Access Journals (Sweden)

    V. Sednin

    2014-09-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    Full text: The aim of this work has been undertaken as part of the design of continuous hydrogen production using the high temperature steam reforming process. The steady-state test condition was carried out using syngas from biomass pyrolysis, whilst operating at high temperatures between 600 and 1200 degree Celsius. The main reformer operating parameters (e.g. temperature, resident time and steam to biomass ratio (S/B)) have been examined in order to optimize the performance of the reformer. The operating temperature is a key factor in determining the extent to which hydrogen production is increased at higher temperatures (900 -1200 degree Celsius) whilst maintaining the same as resident time and S/B ratio. The effects of exhaust gas composition on heating value were also investigated. The steam reforming process produced methane (CH4) and ethylene (C2H4) between 600 to 800 degree Celsius and enhanced production ethane (C2H6) at 700 degree Celsius. However carbon monoxide (CO) emission was slightly increased for higher temperatures all conditions. The results show that the use of biomass pyrolysis gas can produce higher hydrogen production from high temperature steam reforming. In addition the increasing reformer efficiency needs to be optimized for different operating conditions. (author)

  4. Biomass Steam Gasification with In-Situ CO2 Capture for Enriched Hydrogen Gas Production: A Reaction Kinetics Modelling Approach

    Directory of Open Access Journals (Sweden)

    Mohamed Ibrahim Abdul Mutalib

    2010-08-01

    Full Text Available Due to energy and environmental issues, hydrogen has become a more attractive clean fuel. Furthermore, there is high interest in producing hydrogen from biomass with a view to sustainability. The thermochemical process for hydrogen production, i.e. gasification, is the focus of this work. This paper discusses the mathematical modeling of hydrogen production process via biomass steam gasification with calcium oxide as sorbent in a gasifier. A modelling framework consisting of kinetics models for char gasification, methanation, Boudouard, methane reforming, water gas shift and carbonation reactions to represent the gasification and CO2 adsorption in the gasifier, is developed and implemented in MATLAB. The scope of the work includes an investigation of the influence of the temperature, steam/biomass ratio and sorbent/biomass ratio on the amount of hydrogen produced, product gas compositions and carbon conversion. The importance of different reactions involved in the process is also discussed. It is observed that hydrogen production and carbon conversion increase with increasing temperature and steam/biomass ratio. The model predicts a maximum hydrogen mole fraction in the product gas of 0.81 occurring at 950 K, steam/biomass ratio of 3.0 and sorbent/biomass ratio of 1.0. In addition, at sorbent/biomass ratio of 1.52, purity of H2 can be increased to 0.98 mole fraction with all CO2 present in the system adsorbed.

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

    Directory of Open Access Journals (Sweden)

    A. Sordi

    2009-03-01

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

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

    Directory of Open Access Journals (Sweden)

    A. Sordi

    2009-12-01

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

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

    International Nuclear Information System (INIS)

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

  8. AGAPUTE - Advanced gas purification technologies for co-gasification of coal, refinery by-products, biomass & waste, targeted to clean power produced from gas & steam turbine generator sets and fuel cells. FINAL REPORT

    OpenAIRE

    Di Donato, Antonello; Puigjaner Corbella, Lluís; Velo García, Enrique; Nougués, José María; Pérez Fortes, María del Mar; Bojarski, Aarón David

    2010-01-01

    Informe Final del Projecte ECSC RFC-CR-04006: AGAPUTE - Advanced gas purification technologies for co-gasification of coal, refinery by-products, biomass & waste, targeted to clean power produced from gas & steam turbine generator sets and fuel cells

  9. Biomass steam gasification with in-situ CO{sub 2} capture for enriched hydrogen gas production: a reaction kinetics modelling approach

    Energy Technology Data Exchange (ETDEWEB)

    Abrar Inayat, A.; Ahmad, M. M.; Yusup, S.; Mutalib, M. I. A. [Department of Chemical Engineering, Universiti Teknologi Petronas, Bandar Seri Iskandar, 31750 Tronoh (Malaysia)

    2010-08-15

    Due to energy and environmental issues, hydrogen has become a more attractive clean fuel. Furthermore, there is high interest in producing hydrogen from biomass with a view to sustainability. The thermochemical process for hydrogen production, i.e. gasification, is the focus of this work. This paper discusses the mathematical modeling of hydrogen production process via biomass steam gasification with calcium oxide as sorbent in a gasifier. A modelling framework consisting of kinetics models for char gasification, methanation, Boudouard, methane reforming, water gas shift and carbonation reactions to represent the gasification and CO{sub 2} adsorption in the gasifier, is developed and implemented in MATLAB. The scope of the work includes an investigation of the influence of the temperature, steam/biomass ratio and sorbent/biomass ratio on the amount of hydrogen produced, product gas compositions and carbon conversion. The importance of different reactions involved in the process is also discussed. It is observed that hydrogen production and carbon conversion increase with increasing temperature and steam/biomass ratio. The model predicts a maximum hydrogen mole fraction in the product gas of 0.81 occurring at 950 K, steam/biomass ratio of 3.0 and sorbent/biomass ratio of 1.0. In addition, at sorbent/biomass ratio of 1.52, purity of H{sub 2} can be increased to 0.98 mole fraction with all CO{sub 2} present in the system adsorbed. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

    Sterzinger, G J [Economics, Environment and Regulation, Washington, DC (United States)

    1994-05-01

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

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

    International Nuclear Information System (INIS)

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

  12. Steam boiler for biomass

    OpenAIRE

    Knichal, Jaroslav

    2008-01-01

    At present, people already fully aware of how expensive it is energy dependence on fossil fuels. Trying to reduce this dependence goes hand in hand with environmental limits, which restrict the production of dangerous compounds. Biomass is a fuel that does not create large amounts of sulfur and carbon dioxide generated during combustion is in a closed cycle. Different types of biomass have different calorific value, and therefore different demands on the quantity needed to produce MWh. It is ...

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

    International Nuclear Information System (INIS)

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

  14. 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

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

    Science.gov (United States)

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

    2014-10-01

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

  16. Steam gasification of plant biomass using molten carbonate salts

    International Nuclear Information System (INIS)

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

  17. Integrated vacuum absorption steam cycle gas separation

    Science.gov (United States)

    Chen, Shiaguo; Lu, Yonggi; Rostam-Abadi, Massoud

    2011-11-22

    Methods and systems for separating a targeted gas from a gas stream emitted from a power plant. The gas stream is brought into contact with an absorption solution to preferentially absorb the targeted gas to be separated from the gas stream so that an absorbed gas is present within the absorption solution. This provides a gas-rich solution, which is introduced into a stripper. Low pressure exhaust steam from a low pressure steam turbine of the power plant is injected into the stripper with the gas-rich solution. The absorbed gas from the gas-rich solution is stripped in the stripper using the injected low pressure steam to provide a gas stream containing the targeted gas. The stripper is at or near vacuum. Water vapor in a gas stream from the stripper is condensed in a condenser operating at a pressure lower than the stripper to concentrate the targeted gas. Condensed water is separated from the concentrated targeted gas.

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

    Science.gov (United States)

    Petrakopoulou, F.; Sanz, J.

    2014-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-08-01

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Alevanau, Aliaksandr

    2010-10-15

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

  3. 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. PMID:24880809

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  5. Biomass to hydrogen via fast pyrolysis and catalytic steam reforming

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-09-01

    Fast pyrolysis of biomass results in a pyrolytic oil which is a mixture of (a) carbohydrate-derived acids, aldehydes and polyols, (b) lignin-derived substituted phenolics, and (c) extractives-derived terpenoids and fatty acids. The conversion of this pyrolysis oil into H{sub 2} and CO{sub 2} is thermodynamically favored under appropriate steam reforming conditions. Our efforts have focused in understanding the catalysis of steam reforming which will lead to a successful process at reasonable steam/carbon ratios arid process severities. The experimental work, carried out at the laboratory and bench scale levels, has centered on the performance of Ni-based catalysts using model compounds as prototypes of the oxygenates present in the pyrolysis oil. Steam reforming of acetic acid, hydroxyacetaldehyde, furfural and syringol has been proven to proceed rapidly within a reasonable range of severities. Time-on-stream studies are now underway using a fixed bed barometric pressure reactor to ascertain the durability of the catalysts and thus substantiate the scientific and technical feasibility of the catalytic reforming option. Economic analyses are being carried out in parallel to determine the opportunity zones for the combined fast pyrolysis/steam reforming approach. A discussion on the current state of the project is presented.

  6. Biomass combustion gas turbine CHP

    Energy Technology Data Exchange (ETDEWEB)

    Pritchard, D.

    2002-07-01

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Balegedde Ramachandran, P.

    2013-01-01

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

  9. Gas Heated Steam Reformer Modelling

    OpenAIRE

    Wesenberg, Margrete Hånes

    2006-01-01

    Conversion of natural gas is becoming increasingly relevant in the future as the world energy market will demand cleaner fuels, cleaner production of fuels and better utilization of the large, remote, and still undiscovered gas reserves in the world. The refining of the natural gas to synthetic gasoline, diesel and future energy fuels such as methanol and hydrogen is a solution for making the most of these gas reserves.The intermediate process step in gas refining, the synthesis gas productio...

  10. Exergoeconomic analysis of small-scale biomass steam cogeneration

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

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

    International Nuclear Information System (INIS)

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

  12. To the application of steam-gas circuits for saturated-steam turbine plants

    International Nuclear Information System (INIS)

    Different thermal schemes of duel-circuit NPPs with saturated-steam turbine plants, operating in steam-gas cycle were analyzed. Analytical dependences for evaluating change of NPP efficiency in result of steam-gas circuit introduction were obtained. It was concluded that energy indices of plants grew in result of using circuits with higher initial temperature and decreasing temperature of external air

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-01

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

  14. Produce synthesis gas by steam reforming natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Marsch, H.D.; Herbort, H.J.

    1982-06-01

    For production of synthesis gas from natural gas the steam reforming process is still the most economical. It generates synthesis gas for ammonia and methanol production as well as hydrogen, oxo gas and town gas. After desulfurization, the natural gas is mixed with steam and fed to the reforming furnace where decomposition of hydrocarbons takes place in the presence of a nickel-containing catalyst. Synthesis gas that must be free of CO and CO/sub 2/ is further treated in a CO shift conversion, a CO/sub 2/ scrubbing unit and a methanation unit. The discussion covers the following topics - reforming furnace; the outlet manifold system; secondary reformer; reformed gas cooling. Many design details of equipment used are given.

  15. Third steam-gas plant in Slovakia

    International Nuclear Information System (INIS)

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

  16. Catalytic destruction of tar in biomass derived producer gas

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

    2009-10-15

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

  19. Catalytic cracking of tar in biomass pyrolysis gas in the presence of calcined dolomite

    International Nuclear Information System (INIS)

    The possibility of decreasing the tar content of the fuel gas obtained by biomass pyrolysis was studied. Pyrolysis of mixed hardwood chips was carried out in a laboratory-scale cracking reactor using a dolomite catalyst, which showed a high catalytic activity. The effects of reaction variables such as temperature, and amount of catalyst and steam, were studied. The overall effect of the dolomite is to increase the gas yield by decreasing the tar yield. The dolomite and the steam used seem to affect the amount of naphthalene produced. By adjusting both the amounts of catalyst and steam, the amounts of naphthalene (13 mg/kg of dry biomass) and tar (164 mg/kg) were decreased significantly. The yields of hydrogen, CO and CO2 depended on the steam to biomass weight ratio in the range of 0 to 0.6 kg/kg. 18 refs., 8 figs., 5 tabs

  20. Biomass/coal steam co-gasification integrated with in-situ CO2 capture

    International Nuclear Information System (INIS)

    Addressing recent environmental regulations on fossil fuel power systems and both biomass fuel supply and coal greenhouse gas issues, biomass/coal co-gasification could provide a feasible transition solution for power plants. In the quest for an even more sustainable process, steam co-gasification of switchgrass and coal was integrated with in-situ CO2 capture, with limestone as the bed material and sorbent. Five gasification/carbonation (at <700 °C) and calcination (at >850 °C) cycles were performed in an atmospheric pilot scale bubbling fluidized bed reactor. Hydrogen production was enhanced significantly (∼22%) due to partial adsorption of CO2 by the CaO sorbent, shifting the gasification reactions forward, consistent with Le Châtelier's principle. Tar yield measurements showed that reducing the gasification temperature could be achieved without experiencing higher tar yield, indicating that the lime has a catalytic effect. The sorbent particles decayed and lost their calcium utilization efficiency in the course of cycling due to sintering. The co-existence of three types of solids (biomass, coal, lime) with different particle properties led to bed segregation. An equilibrium model was found to be useful in design of lime-enhanced gasification systems. - Highlights: • Biomass/coal steam co-gasification was integrated with in-situ CO2 capture. • 5 gasification/carbonation (<700 °C) and calcination (>850 °C) cycles were performed. • Lime-enhanced co-gasification enhanced hydrogen production significantly (∼22%). • CaO decayed as an absorbent of CO2 due to sintering and some was lost by attrition. • Equilibrium models are useful in design of lime-enhanced gasification systems

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

    International Nuclear Information System (INIS)

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

  2. Catalytic steam gasification of biomass for a sustainable hydrogen future: influence of catalyst composition

    OpenAIRE

    Wu, C.; Wang, Z.; Wang, L.; J. Huang; Williams, PT

    2014-01-01

    Hydrogen is regarded as a clean energy for fuelling the future. Hydrogen will be the energy carrier from other resources such as hydropower, wind, solar and biomass. Producing hydrogen from gasification of biomass wastes, particularly in the presence of steam, represents a promising route to produce this clean and CO2-neutral fuel. The steam pyrolysis-gasification ofbiomass (wood sawdust) was carried out with various nickel-based catalysts for hydrogen production in a two-stage fixed bed reac...

  3. Numerical Analysis on Transient of Steam-gas Pressurizer

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-05-01

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

  5. Gas--steam turbine combined cycle power plants

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.

    1978-10-01

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

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

    OpenAIRE

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

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

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

    International Nuclear Information System (INIS)

    Highlights: • ECR technique was proposed to convert biomass gasification tar model compounds. • Electric current enhanced the reforming efficiency remarkably. • The highest toluene conversion reached 99.9%. • Ni–CeO2/γ-Al2O3 exhibited good stability during the ECR performance. - Abstract: Electrochemical catalytic reforming (ECR) technique, known as electric current enhanced catalytic reforming technique, was proposed to convert the biomass gasification tar into syngas. In this study, Ni–CeO2/γ-Al2O3 catalyst was prepared, and toluene was employed as the major feedstock for ECR experiments using a fixed-bed lab-scale setup where thermal electrons could be generated and provided to the catalyst. Several factors, including the electric current intensity, reaction temperature and steam/carbon (S/C) ratio, were investigated to reveal their effects on the conversion of toluene as well as the composition of the gas products. Moreover, toluene, two other tar model compounds (benzene and 1-methylnaphthalene) and real tar (tar-containing wastewater) were subjected to the long period catalytic stability tests. All the used catalysts were analyzed to determine their carbon contents. The results indicated that the presence of electric current enhanced the catalytic performance remarkably. The toluene conversion reached 99.9% under the electric current of 4 A, catalytic temperature of 800 °C and S/C ratio of 3. Stable conversion performances of benzene, 1-methylnaphthalene and tar-containing wastewater were also observed in the ECR process. H2 and CO were the major gas products, while CO2 and CH4 were the minor ones. Due to the promising capability, the ECR technique deserves further investigation and application for efficient tar conversion

  10. steam power plants re powering with gas turbine review

    International Nuclear Information System (INIS)

    Re powering faith gas turbine means integration of new gas turbine in existing power plant. Such integration yield higher efficiencies lower operating and maintenance costs and reduction in pollution emission. This paper summarizes the results of a feasibility study that inquired the possibilities of such integration in Israel Electric Corporation - IEC's existing steam power plants (oil fired)

  11. Greenhouse gas balances of biomass energy systems

    International Nuclear Information System (INIS)

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

  12. SMALL SCALE BIOMASS FUELED GAS TURBINE ENGINE

    Science.gov (United States)

    A new generation of small scale (less than 20 MWe) biomass fueled, power plants are being developed based on a gas turbine (Brayton cycle) prime mover. These power plants are expected to increase the efficiency and lower the cost of generating power from fuels such as wood. The n...

  13. Development of Ni-Based Catalysts for Steam Reforming of Tar Derived from Biomass Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Dalin LI; Yoshinao NAKAGAWA; Keiichi TOMISHIGE

    2012-01-01

    Nickel catalysts are effective for the steam reforming of tar derived from biomass pyrolysis,but the improvement is needed in terms of activity,stability,suppression of coke deposition and aggregation,and regeneration.Our recent development of Ni-based catalysts for the steam reforming of tar is reviewed including the modification with CeO2 (or MnO),trace Pt,and MgO.The role of additives such as CeO2,MnO,Pt,and MgO is also discussed.

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

    Directory of Open Access Journals (Sweden)

    Maha M. Ibrahim

    2010-02-01

    Full Text Available The isolation of cellulose from different lignocellulosic biomass sources such as corn cob, banana plant, cotton stalk, and cotton gin waste, was studied using a steam explosion technology as a pre-treatment process for different times followed by alkaline peroxide bleaching. The agricultural residues were steam-exploded at 220 ºC for 1-4 min for the corn cob, 2 and 4 min for the banana plant, 3-5 min for the cotton gin waste, and for 5 min for the cotton stalk. The steamed fibers were water extracted followed by alkali extraction and finally peroxide bleaching to yield cellulose with different degrees of crystallinity. The degree of polymerization of the cellulose fraction ranged from 167.4 to 1615.7. Longer residence time of the steam explosion led to an increase in cellulose crystallinity. The ten isolated cellulose samples were further characterized by SEM, FT-IR, and thermal analysis. Four lignin preparations were also obtained from steam-exploded corn cob, banana plant, cotton stalk, and cotton gin waste after alkali treatment. The SEM micrographs of the lignin showed different morphological structure for the different agricultural residues. The FT-IR and TGA analyses showed that the steam pre-treatment led to an extensive cleavage of ether bonds, condensation reactions, and some demethylation of aromatic methoxyl groups in the lignin structure. The thermal stabilities of the isolated lignins were different for different agricultural residues.

  15. LIQUID BIO-FUEL PRODUCTION FROM NON-FOOD BIOMASS VIA HIGH TEMPERATURE STEAM ELECTROLYSIS

    Energy Technology Data Exchange (ETDEWEB)

    G. L. Hawkes; J. E. O' Brien; M. G. McKellar

    2011-11-01

    Bio-Syntrolysis is a hybrid energy process that enables production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), bio-syntrolysis has the potential to provide a significant alternative petroleum source that could reduce US dependence on imported oil. Combining hydrogen from HTSE with CO from an oxygen-blown biomass gasifier yields syngas to be used as a feedstock for synthesis of liquid transportation fuels via a Fischer-Tropsch process. Conversion of syngas to liquid hydrocarbon fuels, using a biomass-based carbon source, expands the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-blown biomass gasifier. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon monoxide and hydrogen). Assuming the thermal efficiency of the power

  16. Adding gas from biomass to the gas grid

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    fuel passing unburned through the combustion. Measurements of the slip of the producer gas fuel components CO and CH4 showed that these are of similar order. When the environmental effect of the emissions is discussed, unburned hydrocarbons in the form of methane is a strong greenhouse gas (21 times......High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. CO emissions from engines operating on biomass producer gases are high, especially at very lean conditions where...... higher than CO2) while CO only indirectly through photochemical reactions is involved in the production of the greenhouse gas ozone....

  18. Biomass Gasification and High Temperature Gas Cleaning

    Czech Academy of Sciences Publication Activity Database

    Hejdová, Petra; Solich, M.; Vosecký, Martin; Malecha, J.; Koutský, B.; Punčochář, Miroslav; Skoblia, Sergej

    -: -, 2005, s. 221-224. ISBN 80-8073-382-1. [New Trends in Technology Systems Operation'05. Prešov (SK), 20.11.2005-21.11.2005] R&D Projects: GA ČR(CZ) GA104/04/0829 Institutional research plan: CEZ:AV0Z40720504 Keywords : biomass and waste * gasification * hot gas cleaning Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  19. 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.

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

    DEFF Research Database (Denmark)

    Toor, Saqib; Rosendahl, Lasse; Hoffmann, Jessica;

    2013-01-01

    With the ever rising demand for more energy and the limited availability of depleted world resources, many are beginning to look for alternatives to fossil fuels. Liquid biofuel, in particular, is of key interest to decrease our dependency on fuels produced from imported petroleum. Biomass pre-treatment...... of different pretreatment methods are known to enhance the digestibility of lingo-cellulosic biomass by affecting these limiting factors. Some of them are: milling, thermal pretreatment with steam or hot water, acid pre-treatment and alkaline pre-treatment. This chapter will focus on one of the more...... promising technologies; thermal pre-treatment with steam. The Norwegian company CAMBI developed a process for treatment of sludge from waste water treatment plants, and the idea was based on the experience that cooking sludge under pressure at temperature from 150oC to 180oC improved the digestibility and...

  1. Supercritical steam cycles and biomass integrated gasification combined cycles for sugarcane mills

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrini, Luiz Felipe; Burbano, Juan Carlos [Laboratory of Environmental and Thermal Engineering, Polytechnic School - University of Sao Paulo, Av. Prof. Luciano Gualberto, 1289 Cidade Universitaria, CEP: 05508-900, Sao Paulo, SP (Brazil); de Oliveira Junior, Silvio [Mechanical Engineering Faculty, Technological University of Pereira, Pereira (Colombia)

    2010-02-15

    Back in 1970s and 1980s, cogeneration plants in sugarcane mills were primarily designed to consume all bagasse, and produce steam and electricity to the process. The plants used medium pressure steam boilers (21 bar and 300 C) and backpressure steam turbines. Some plants needed also an additional fuel, as the boilers were very inefficient. In those times, sugarcane bagasse did not have an economic value, and it was considered a problem by most mills. During the 1990s and the beginning of the 2000s, sugarcane industry faced an open market perspective, thus, there was a great necessity to reduce costs in the production processes. In addition, the economic value of by-products (bagasse, molasses, etc.) increased, and there was a possibility of selling electricity to the grid. This new scenario led to a search for more advanced cogeneration systems, based mainly on higher steam parameters (40-80 bar and 400-500 C). In the future, some authors suggest that biomass integrated gasification combined cycles are the best alternative to cogeneration plants in sugarcane mills. These systems might attain 35-40% efficiency for the power conversion. However, supercritical steam cycles might also attain these efficiency values, what makes them an alternative to gasification-based systems. This paper presents a comparative thermoeconomic study of these systems for sugarcane mills. The configurations studied are based on real systems that could be adapted to biomass use. Different steam consumptions in the process are considered, in order to better integrate these configurations in the mill. (author)

  2. A modelling approach for the assessment of an air-dryer economic feasibility for small-scale biomass steam boilers

    OpenAIRE

    De Fusco, Lucio; Jeanmart, Hervé; Blondeau, Julien

    2015-01-01

    Fuel drying is an energetically and economically expensive pretreatment process, which may not be worth the investment in the case of small-scale generation plants. This paper presents an investigation on the air dryer feasibility to enhance the operation of biomass steam boiler. In the proposed approach, the external drying technology using preheated air and the biomass steam production system is modelled in terms of energy and an economical analysis. A focus is given to the system size infl...

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

    International Nuclear Information System (INIS)

    In this paper, the greenhouse gas and energy balances of the production and use for space heating of substitute natural gas from biomass (bio-SNG) for space heat are analysed. These balances are compared to the use of natural gas and solid biomass as wood chips to provide the same service. The reduction of the greenhouse gas emissions (CO2-eq.) – carbon dioxide, methane and nitrous oxide – and of the fossil primary energy use is investigated in a life cycle assessment (LCA). This assessment was performed for nine systems for bio-SNG; three types of gasification technologies (O2-blown entrained flow, O2-blown circulating fluidised bed and air–steam indirect gasification) with three different types of feedstock (forest residues, miscanthus and short rotation forestry). The greenhouse gas analysis shows that forest residues using the air–steam indirect gasification technology result in the lowest greenhouse gas emissions (in CO2-eq. 32 kg MWh−1 of heat output). This combination results in 80% reduction of greenhouse gas emissions when compared to natural gas and a 29% reduction of greenhouse gases if the forest residues were converted to wood chips and combusted. The gasification technologies O2-blown entrained flow and O2-blown circulating fluidised bed gasification have higher greenhouse gas emissions that range between in CO2-eq. 41 to 75 kg MWh−1 of heat output depending on the feedstock. When comparing feedstocks in the bio-SNG systems, miscanthus had the highest greenhouse gas emissions bio-SNG systems producing in CO2-eq. 57–75 kg MWh−1 of heat output. Energy analysis shows that the total primary energy use is higher for bio-SNG systems (1.59–2.13 MWh MWh−1 of heat output) than for the reference systems (in 1.37–1.51 MWh MWh−1 of heat output). However, with bio-SNG the fossil primary energy consumption is reduced compared to natural gas. For example, fossil primary energy use is reduced by 92% when air–steam indirect gasification

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  5. Combining the nuclear power plant steam cycle with gas turbines

    International Nuclear Information System (INIS)

    Nuclear steam power plants (NPP) are characterized by low efficiency, compared to steam power plants using fossil fuels. This is due to the relatively low temperature and pressure-throttling conditions of the NPP compared to those using fossil fuel. The light water pressurized water reactor (LW PWR) commercially known as AP600 was suggested for Kuwait cogeneration power desalting plant (CPDP). It has 600 MW nominal power capacity and 33% overall efficiency. Meanwhile, the Kuwaiti Ministry of Electricity and Water (MEW) installed plenty of gas turbines (GTs) to cover the drastic increase in the peak electrical load during the summer season. Combining some of these GTs with the AP600 can increase the capacity and efficiency of the combined plant, compared to either the GT open cycle or the NPP separate plants. This paper investigates the feasibility of utilizing the hot gases leaving the GT to superheat the steam leaving the steam generator of the AP600 NPP, as well as heating the feed water returning to the steam generator of the NPP condenser. This drastically increases the power output and the efficiency of the NPP. Detailed modifications to the NPP power cycle and the resulting enhancement of its performance are presented.

  6. Yangzi Petrochemical Company Uses Natural Gas to Supplement Steam Cracker Fuel Gas

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ A major energy conservation and retrofitting project-ap-plication of natural gas as supplementary fuel for steam crackers has been successfully put into operation starting April 30, 2008 at the SINOPEC Yangzi Petrochemical Company.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  8. Highly efficient electricity generation from biomass by integration and hybridization with combined cycle gas turbine (CCGT) plants for natural gas

    International Nuclear Information System (INIS)

    Integration/co-firing with existing fossil fuel plants could give near term highly efficient and low cost power production from biomass. This paper presents a techno-economical analysis on options for integrating biomass thermal conversion (optimized for local resources ∝50 MWth) with existing CCGT (combined cycle gas turbine) power plants (800-1400 MWth). Options include hybrid combined cycles (HCC), indirect gasification of biomass and simple cycle biomass steam plants which are simulated using the software Ebsilon Professional and Aspen Plus. Levelized cost of electricity (LCoE) is calculated with cost functions derived from power plant data. Results show that the integrated HCC configurations (fully-fired) show a significantly higher efficiency (40-41%, LHV (lower heating value)) than a stand-alone steam plant (35.5%); roughly half of the efficiency (2.4% points) is due to more efficient fuel drying. Because of higher investment costs, HCC options have cost advantages over stand-alone options at high biomass fuel prices (>25 EUR/MWh) or low discount rates (<5%). Gasification options show even higher efficiency (46-50%), and the lowest LCoE for the options studied for fuel costs exceeding 10 EUR/MWh. It can be concluded that clear efficiency improvements and possible cost reductions can be reached by integration of biomass with CCGT power plants compared to stand-alone plants. (author)

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  10. Synthesis gas production from various biomass feedstocks

    Directory of Open Access Journals (Sweden)

    Juan A. Conesa

    2013-10-01

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

  11. Comparative Exergoeconomic Analyses of Gas Turbine Steam Injection Cycles with and without Fogging Inlet Cooling

    OpenAIRE

    Hassan Athari; Saeed Soltani; Marc A. Rosen; Seyed Mohammad Seyed Mahmoudi; Tatiana Morosuk

    2015-01-01

    The results are reported of exergoeconomic analyses of a simple gas turbine cycle without a fogging system (SGT), a simple steam injection gas turbine cycle (STIG), and a steam injection gas turbine cycle with inlet fogging cooler (FSTIG). The results show that (1) a gas-turbine cycle with steam injection and simultaneous cooling has a higher power output than the other considered cycle; (2) at maximum energy efficiency conditions the gas turbine has the highest exergy efficiency of the cycle...

  12. 140 g H{sub 2}/kg biomass d.a.f. by a CO-shift reactor downstream from a FB biomass gasifier and a catalytic steam reformer

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-04-15

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

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

    Directory of Open Access Journals (Sweden)

    Oakey John

    2004-01-01

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

  14. Steam reforming of toluene as model compound of biomass pyrolysis tar for hydrogen

    International Nuclear Information System (INIS)

    Steam reforming of tar during biomass pyrolysis for hydrogen will not only avoid frequent equipment shutdown for maintenance and repair but also increase hydrogen yield. In this paper, the effects of temperature and steam/carbon molar ration on steam reforming of toluene as model compound of tar was studied by simulation of thermodynamic equilibrium and experiments using Ni/cordierite catalyst in a fixed bed reactor. The results of thermodynamic simulations indicate that the S/C molar ratio of 2 and the temperature range from 1023 K to 1173 K provide favorable operating conditions for steam reforming of toluene in order to get high hydrogen productivity. These operating parameters were adopted in the experiments using Ni/cordierite catalyst in a fixed bed reactor. H2 content remains about 66 mol% and slightly varies with the increasing temperature. Conversion efficiency of toluene increases with temperature, reaching 94.1% at 1173 K. The simulation was improved in order to be closer to experimental results. It is found that only a very small amount of toluene did not participate in the reaction. In the aromatic hydrocarbons of reactive system, benzene and naphthalene were the main products and the proportion of naphthalene decreases with increasing temperature while that of benzene increases.

  15. Topping gas turbines improve steam power plant efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Lezuo, A. (Siemens AG, Erlangen (Germany, F.R.). KWU Group)

    An interesting option for improving the efficiency and output of an existing conventional steam power plant is to convert it into a combined steam-and-gas cycle power plant by adding a topping gas turbine. The investment involved is relatively low, the payback period is short, and the low specific fuel consumption makes it possible to save on overall running costs. At the same time, the amount of residue for disposal and also pollutant emissions are drastically reduced. This article describes the configuration of a fully-fired combined-cycle power plant and discusses thermodynamic design and efficiency, operational aspects, emissions and residues and investment and economic viability. Both coal-fired and gas or oil-fired steam power plants can be converted by adding a topping cycle and the investment cost is about 20% of the cost of a new plant with the same output rating as the plant to be converted. Conversion reduces pollutant emission and residues produced (SO{sub 2}, NO{sub x}, CO{sub 2}, dust, ash, gypsum, waste heat). 4 figs.

  16. High effective synthesis gas production by steam hydrocarbon conversion

    International Nuclear Information System (INIS)

    Synthesis gas production by steam hydrocarbon conversion underlies of the series processes as hydrogen, methanol, dimethyl ether, ammonia, petrol, etc. It is known that the stage of synthesis gas production takes 70% of capital and operation costs of total final product production. Synthesis gas production is complicated, expansive and power-consuming process. Traditionally the process of steam hydrocarbon conversion is carried out in the tubular reformers and shift reactors over a nickel catalyst. The heat supply required for endothermic reaction is carried out by fuel gases through the walls of the reaction tubes at the expense of fuel gas burned in the inter-tubular space or at the expense of a part of the hydrocarbons to be burned inside the reactor above the catalyst bed combined with oxygen or air. The using 'FAST ENGINEERING' design of catalytic reactors, heat exchanger and mass-transfer apparatuses for synthesis gas production enables to decrease too much capital investment, energy consumption as well as to solve environment problems. 'FAST ENGINEERING' catalytic reactor design is compact, provides optimal temperature conditions for carry out catalytic process, effective heat supply (remove) to (from) the reaction zone, an opportunity of using the most active fine-grained catalyst keeping low pressure drop in the granular bed and wide range of loads, pressures and temperatures for a catalytic process. Compact 'FAST ENGINEERING' heat exchanger design provides low pressure drop, an opportunity to carry out the heat exchanging process in wide range of temperatures (from minus 269 till 1100 C), pressures and loads of heat exchange mediums, has maximum specific surface for heat exchanging in volume unit of cylindrical apparatus. They could be used as air-cooled apparatus, evaporator, condenser, etc. The using 'FAST ENGINEERING' catalytic reactors and heat exchanger apparatuses for synthesis gas production by steam or steam and carbon-dioxide natural gas

  17. A study of oxy-coal combustion with steam addition and biomass blending by thermogravimetric analysis

    OpenAIRE

    Gil Matellanes, María Victoria; Riaza Benito, Juan; Álvarez González, Lucía; Pevida García, Covadonga; Pis Martínez, José Juan; Rubiera González, Fernando

    2011-01-01

    The thermal characteristics of pulverized coal have been studied under oxy-fuel combustion conditions using non-isothermal thermogravimetric analysis (TG). The atmospheres used were 21%O2/79%N2, 21%O2/79%CO2, 30%O2/70%O2, and 35%O2/65%CO2. Coal blends of coal with 10 and 20% of biomass were also studied under these atmospheres. The addition of 10 and 20% of steam was evaluated for the oxy-fuel combustion atmospheres with 21 and 30% of O2 in order to study the effect of the wet recirculation o...

  18. BIOMASS COMBUSTION IN GAS-TURBINE-BASED SYSTEMS

    Science.gov (United States)

    The paper gives results of a comparative evaluation of a range of biomass power generation systems. he objective was to identify systems most suitable for unique properties of biomass. he characteristics of biomass fuels were reviewed, and the performance of several gas-turbine-b...

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    . However, high costs for both oxygen supply equipment and operation are significant challenges for the commercial implementation of this technology. Mixed ionic and electronic conducting (MIEC) membranes can be used for oxygen separation from air at a lower energy consumption compared to cryogenic...... distillation, especially for small to medium scale plants. This paper examines different configurations for oxygen production using MIEC membranes where the oxygen partial pressure difference is achieved by creating a vacuum on the permeate side, compressing the air on the feed side or a combination of the two....... The two configurations demonstrating the highest efficiency are then thermally integrated into an oxygen– steam biomass gasification plant. The energy demand for oxygen production and the membrane area required for a 6 MWth biomass plant are calculated for different operating conditions. Increasing...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  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. Power Plants, Steam and Gas Turbines WebQuest

    OpenAIRE

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

    2012-01-01

    A WebQuest is an Internet-based and inquiry-oriented learning activity. The aim of this work is to outline the creation of a WebQuest entitled “Power Generation Plants: Steam and Gas Turbines.” This is one of the topics covered in the course “Thermodynamics and Heat Transfer,” which is offered in the second year of Mechanical Engineering at the Defense University Center at the Naval Academy in Vigo, Spain. While participating in the activity, students will be divided into groups of no more th...

  4. Steam reforming of sunflower oil for hydrogen gas production

    OpenAIRE

    Dupont V.

    2007-01-01

    Methods of current hydrogen production for the petroleum refinery industry as well as future technologies under research and development in preparation for a global hydrogen-based economy are briefly reviewed. The advantages of biomass and of liquid biofuels, including vegetable oils as fuel sources in the sustainable production of hydrogen gas are then presented. The bulk of this lecture is thereafter concerned with the thermo-chemical means of hydrogen production which are suitable to the c...

  5. Initial study on steam reformer of high-temperature gas-cooled reactor powered steam methane reforming hydrogen production system

    International Nuclear Information System (INIS)

    Based on one-dimension quasi-homogeneous phase model, a dynamic model for single-tube steam reformer of high-temperature gas-cooled reactor was presented, and computer program was developed. Steady state calculation and analysis were performed for the steam reformer design by Japan Atomic Energy Research Institute. The results show that heat loss at the entrance of helium influences the steam reformer performance remarkably, and reaction velocity is not main factor influencing the performance. The steady state calculation results fit well with experiment results. (authors)

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

    International Nuclear Information System (INIS)

    Electricity generation from fossil fuels has become a focal point of energy and climate change policies due to its central role in modern economics and its leading contribution to greenhouse gas emissions. Carbon capture and sequestration (CCS) is regarded by the International Energy Agency as an essential part of the technology portfolio for carbon mitigation, as it can significantly reduce CO2 emissions while ensuring electricity generation from fossil fuel power plants. This paper studies the retrofit of natural gas combined cycles (NGCCs) with an amine-based post-combustion carbon capture system. NGCCs with differently rated capacities were analysed under the assumptions that the heat requirement of the capture system was provided via a steam extraction upstream of the low-pressure steam turbine or by an auxiliary unit that was able to reduce the power plant derating related to the energy needs of the CCS system. Different types of auxiliary units were investigated based on power plant size, including a gas turbine cogeneration plant and a supplementary firing unit or boiler fed by natural gas or biomass. Energy and economic analyses were performed in order to evaluate the impact of type and layout of retrofit option on energy, environmental and economic performance of NGCCs with the CCS system. - Highlights: • Steam-gas power plants with an amine-based CO2 capture unit are examined. • The study concerns three combined cycles with different capacity and plant layout. • Several options to fulfil the heat requirement of the CCS system are explored. • Steam extraction significantly reduces the capacity of steam-gas power plant. • An auxiliary combined heat and power unit allows to reduce power plant derating

  7. An Experimental Investigation of Hydrogen Production from Biomass

    Institute of Scientific and Technical Information of China (English)

    吕鹏梅; 常杰; 付严; 王铁军; 陈勇; 祝京旭

    2003-01-01

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

  8. Engineering analysis of biomass gasifier product gas cleaning technology

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-08-01

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

  9. Numerical Study on Combustion Features of Gasified Biomass Gas

    OpenAIRE

    Zhang, Xiaoxiang

    2015-01-01

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

  10. Sorption enhanced steam reforming of biomass-derived compounds: process and material

    Energy Technology Data Exchange (ETDEWEB)

    He, Li

    2010-07-01

    An attempt has been made to develop a flexible system to produce very pure H{sub 2} with high efficiency from renewable bio-based recourses. First, such model compounds as ethanol, glycerol, sorbitol and glucose, have been tested for H{sub 2} production via sorption enhanced steam reforming (SESR) over Co-Ni/hydrotalcite-like (HTls) derived catalyst and CaO-based CO{sub 2} acceptor. The experimental results show that all of feedstocks, even heavy feedstocks, were able to offer high H{sub 2} purity (97.3approx99.1%) and yield at low steam to carbon (S/C = 1.3approx6) ratio in comparison to the corresponding steam reforming process. In addition, the studied system also presents encouraging potential for improvement of energy efficiency. Chemical looping combustion (CLC) was coupled to the cyclic multi-step SESR process to assist the acceptor regeneration by using multifunctional Pd/Co-Ni/HTls catalyst. With coupling of CLC to SESR, H{sub 2} concentration in the gas effluent of the SESR reactions was still higher than 95 mol% on a dry basis. The assembled CLC-SESR process has inherent high efficiency in H{sub 2} production. (Author)

  11. Kinetic study of wood biomass co-firing with gas

    International Nuclear Information System (INIS)

    The main aim of this study is to develop and optimise the wood biomass (wood granules) and gas (propane) co-firing technology, by replacing fossil fuel with a renewable energy source, enhancing and stabilising the wood biomass burnout, reducing at the same time carbon emissions from the combined combustion process. (authors)

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

    Directory of Open Access Journals (Sweden)

    Erik Dahlquist

    2013-07-01

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

  13. 16 CFR Appendix G6 to Part 305 - Boilers-Gas (Steam)

    Science.gov (United States)

    2010-01-01

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

  14. 16 CFR Appendix G5 to Part 305 - Boilers-Gas (Except Steam)

    Science.gov (United States)

    2010-01-01

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

  15. Peculiar Features of Nuclear Power and Steam and Gas Plant of Thermal Power Station

    OpenAIRE

    I. A. Bokoun

    2014-01-01

    The paper reveals peculiar features concerning of power generation at a nuclear power station and a steam and gas plant of a thermal power station. According to technical and economical indices a nuclear power station is at a disadvantage in relation to a steam and gas plant of a thermal power station.

  16. Compatibility of gas turbine materials with steam cooling

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

  18. Biomass and Natural Gas Hybrid Combined Cycles

    OpenAIRE

    Petrov, Miroslav

    2003-01-01

    Biomass is one of the main natural resources in Sweden.Increased utilisation of biomass for energy purposes incombined heat and power (CHP) plants can help the country meetits nuclear phase-out commitment. The present low-CO2 emissioncharacteristics of the Swedish electricity production system(governed by hydropower and nuclear power) can be retained onlyby expansion of biofuels in the CHP sector. Domestic Swedishbiomass resources are vast and renewable, but not infinite.They should be utilis...

  19. Status of external firing of biomass in gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Bram, S.; De Ruyck, J.; Novak Zdravkovic, A.

    2005-02-15

    Dry biomass can be used as a fuel for gas turbines in different ways: it can be gasified or pyrolysed for internal combustion or it can be used as an external heat source. This heat source can be used to replace the combustor, to preheat the combustion air, or eventually to feed a primary reformer to yield hydrogen for the gas turbine. The present paper discusses the use of biomass as on external heat source from both a technical and an economic point of view. Past, present, and future projects are discussed. Possibilities range from cogeneration with microturbines where the biomass can cover a major part of the primary energy, to combined cycle plants where biomass can replace a small percentage of the natural gas. A microturbine EFGT project under construction is disclosed. (Author)

  20. Biomass Gas Cleanup Using a Therminator

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-06

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

  1. SELECTION OF RUSSIAN STEAM TURBINES FOR THE VIETNAMESE COMBINED GASSTEAM PLANT. THE INFLUENCE OF THE EFFICIENCY OF HIGH-PRESSURE CYLINDER OF STEAM TURBINE K-300-240-2 ON THE POWER OF A GAS-STEAM PLANT IN VIETNAM

    Directory of Open Access Journals (Sweden)

    Pham A. H.

    2015-06-01

    Full Text Available The article looks at the current state of energy in Vietnam and the selection of new Russian steam turbines for operation in combined gas-steam plant in Vietnam. The calculated results of thermal performance scheme 3x1 with combined gas-steam plant 1090 MW based on the Russian steam turbines K-330-240-2 and on the steam turbines TS2A40 Mitsubishi (station PhuMy-1, Vietnam. It also looks at the influence of the efficiency of high-pressure cylinders of Russian steam turbine K-330-240-2 on the efficiency and power of a gas-steam plant 3x1 with 1090 MW, increasing the efficiency of high-pressure cylinder of steam turbine through the use of honeycomb seals in flow part

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

    Directory of Open Access Journals (Sweden)

    Galashov Nikolay

    2016-01-01

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

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

    Science.gov (United States)

    Galashov, Nikolay; Tsibulskii, Svjatoslav; Matveev, Aleksandr; Masjuk, Vladimir

    2016-02-01

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

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

    International Nuclear Information System (INIS)

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

  5. Thermo-economic process model for thermochemical production of Synthetic Natural Gas (SNG) from lignocellulosic biomass

    Energy Technology Data Exchange (ETDEWEB)

    Gassner, Martin; Marechal, Francois [Industrial Energy Systems Laboratory, Ecole Polytechnique Federale de Lausanne Station postale 9, CH-1015 Lausanne (Switzerland)

    2009-11-15

    A detailed thermo-economic model considering different technological alternatives for thermochemical production of Synthetic Natural Gas (SNG) from lignocellulosic biomass is presented. First, candidate technology for processes based on biomass gasification and subsequent methanation is discussed and assembled in a general superstructure. Both energetic and economic models for biomass drying with air or steam, thermal pretreatment by torrefaction or pyrolysis, indirectly and directly heated gasification, methane synthesis and carbon dioxide removal by physical absorption, pressure swing adsorption and polymeric membranes are then developed. Performance computations for the different process steps and some exemplary technology scenarios of integrated plants are carried out, and overall energy and exergy efficiencies in the range of 69-76% and 63-69%, respectively, are assessed. For these scenarios, the production cost of SNG including the investment depreciation is estimated to 76-107 EUR MWh{sup -1}{sub SNG} for a plant capacity of 20 MW{sub th,biomass}, whereas 59-97 EUR MWh{sup -1}{sub SNG} might be reached at scales of 150 MW{sub th,biomass} and above. Based on this work, a future thermo-economic optimisation will allow for determining the most promising options for the polygeneration of fuel, power and heat. (author)

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

    International Nuclear Information System (INIS)

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

  7. Technical and economic analysis of steam-injected gas-turbine cogeneration

    Science.gov (United States)

    Larson, Eric D.; Williams, Robert H.

    1985-11-01

    Industrial cogeneration is gaining popularity as an energy and money saving alternative to separate steam and electricity generation. Among cogeneration technologies, gas-turbine systems are attractive largely because of their lower capital cost and high thermodynamic efficiency. However, at industrial plants where steam and electricity loads vary daily, seasonally, or unpredictably, the economics of conventional gas turbines are often unfavorable due to low capacity utilization. Steam-injected gas-turbine cogeneration overcomes the part-load problem by providing for excess steam to be injected back into the turbine to raise electrical output and generating efficiency. Under provisions of the Public Utilities Regulatory Policies Act, any excess electricity can be sold to the local grid at the prevailing avoided cost of electricity. Steam-injected gas-turbine cogeneration can result in a consistently high rate of return on investment over a wide range of variation in process steam loads. Moreover, this technology can also give rise to greater annual electricity production and fuel savings per unit of process steam generated, compared to simple-cycle cogeneration, making the technology attractive from the perspective of society, as well as that of the user. Steam-injected gas-turbines may soon find applications in electric utility base-load generation, as well, since it appears that electrical generating efficiencies in excess of 50% can be obtained from turbines producing of the order of 100 MW of electricity at a fully-installed capital cost as low as 500/kW.

  8. A comparison between exergetic and economic criteria for optimizing the heat recovery steam generators of gas-steam power plants

    International Nuclear Information System (INIS)

    CCGT (Combined-cycle gas turbines) are gaining an increasingly important role in power generation thanks to their high thermal efficiency, low installed cost and ready availability. Increasing natural gas prices, the optimization of CCGT operating parameters is becoming a topic of growing interest. In this paper two different methodologies for optimizing CCGTs are compared. The first aims to minimize the cost per unit of electricity generated, the second to minimize an objective function based on exergoeconomic principles accounting for the costs related with thermodynamic inefficiencies. Optimization results have been obtained considering different CCGT configurations, with single or multi-pressure HRSG (heat recovery steam generators), and varying the gas turbine technology, fuel price and plant capacity factor. A modular approach has been adopted to design a highly effective and flexible HRSG layout, in terms of number of pressure levels and arrangement of heat exchange sections along the flue gas path, together with the corresponding energy, exergy and cost balances, using an “interaction matrix”, with nodes between elementary components and towards the surrounding environment. - Highlights: • Two methods for optimizing the HRSG of gas-steam power plants are compared. • Decision variables are HRSG operating parameters and heat exchange sections layout. • Gas-steam power plants with single or multi-pressure HRSG are optimized. • Results of exergoeconomic optimization differ from those of COE minimization. • COE minimization allows to establish a proper ranking of CCGT configurations

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

  10. Thermodynamics of gas and steam-blast eruptions

    Science.gov (United States)

    Mastin, L.G.

    1995-01-01

    Eruptions of gas or steam and non-juvenile debris are common in volcanic and hydrothermal areas. From reports of non-juvenile eruptions or eruptive sequences world-wide, at least three types (or end-members) can be identified: (1) those involving rock and liquid water initially at boiling-point temperatures ('boiling-point eruptions'); (2) those powered by gas (primarily water vapor) at initial temperatures approaching magmatic ('gas eruptions'); and (3) those caused by rapid mixing of hot rock and ground- or surface water ('mixing eruptions'). For these eruption types, the mechanical energy released, final temperatures, liquid water contents and maximum theoretical velocities are compared by assuming that the erupting mixtures of rock and fluid thermally equilibrate, then decompress isentropically from initial, near-surface pressure (???10 MPa) to atmospheric pressure. Maximum mechanical energy release is by far greatest for gas eruptions (??????1.3 MJ/kg of fluid-rock mixture)-about one-half that of an equivalent mass of gunpowder and one-fourth that of TNT. It is somewhat less for mixing eruptions (??????0.4 MJ/kg), and least for boiling-point eruptions (??????0.25 MJ/kg). The final water contents of crupted boiling-point mixtures are usually high, producing wet, sloppy deposits. Final erupted mixtures from gas eruptions are nearly always dry, whereas those from mixing eruptions vary from wet to dry. If all the enthalpy released in the eruptions were converted to kinetic energy, the final velocity (vmax) of these mixtures could range up to 670 m/s for boiling-point eruptions and 1820 m/s for gas eruptions (highest for high initial pressure and mass fractions of rock (mr) near zero). For mixing eruptions, vmax ranges up to 1150 m/s. All observed eruption velocities are less than 400 m/s, largely because (1) most solid material is expelled when mr is high, hence vmax is low; (2) observations are made of large blocks the velocities of which may be less than the

  11. Biomass energy: Sustainable solution for greenhouse gas emission

    Science.gov (United States)

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

    2012-06-01

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

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

    OpenAIRE

    John Oakey; Nigel Simms; Paul Kilgallon

    2004-01-01

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

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

    OpenAIRE

    Arif, Muhammad Jalil

    2013-01-01

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

  14. Comparative Exergoeconomic Analyses of Gas Turbine Steam Injection Cycles with and without Fogging Inlet Cooling

    Directory of Open Access Journals (Sweden)

    Hassan Athari

    2015-09-01

    Full Text Available The results are reported of exergoeconomic analyses of a simple gas turbine cycle without a fogging system (SGT, a simple steam injection gas turbine cycle (STIG, and a steam injection gas turbine cycle with inlet fogging cooler (FSTIG. The results show that (1 a gas-turbine cycle with steam injection and simultaneous cooling has a higher power output than the other considered cycle; (2 at maximum energy efficiency conditions the gas turbine has the highest exergy efficiency of the cycle components and the lowest value of exergy efficiency is calculated for the fog cooler, where the mixing of air and water at greatly different temperatures causes the high exergy destruction; and (3 utilization of the fogging cooler in the steam injection cycle increases the exergy destruction in the combustion chamber. Furthermore, the simple gas turbine cycle is found to be more economic as its relative cost difference, total unit product cost, and exergoeconomic factors are less than those for the two other configurations. However, its efficiency and net power output are notably lower than for the gas turbine with steam injection and/or fog cooling. The total unit product cost is highest for the simple gas turbine with steam injection.

  15. Kinetic model on coke oven gas with steam reforming

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jia-yuan; ZHOU Jie-min; YAN Hong-jie

    2008-01-01

    The effects of factors such as the molar ratio of H2O to CH4 (n(H2O)/n(CH4)), methane conversion temperature and time on methane conversion rate were investigated to build kinetic model for reforming of coke-oven gas with steam. The results of experiments show that the optimal conditions for methane conversion are that the molar ratio of H2O to CH4 varies from 1.1 to 1.3and the conversion temperature varies from 1 223 to 1 273 K. The methane conversion rate is more than 95% when the molar ratio ofH2O to CH4 is 1.2, the conversion temperature is above 1 223 K and the conversion time is longer than 0.75 s. Kinetic model of methane conversion was proposed. All results demonstrate that the calculated values by the kinetic model accord with the experimental data well, and the error is less than 1.5%.

  16. Power Plants, Steam and Gas Turbines WebQuest

    Directory of Open Access Journals (Sweden)

    Carlos Ulloa

    2012-10-01

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

  17. Numerical Investigation on Transient Behavior of Steam-gas Pressurizer in Integral PWR

    International Nuclear Information System (INIS)

    The steam-gas pressurizer incorporated in the integral reactors such as REX-10 or AST-500 maintains certain content of noncondensable gas to provide the system pressure in primary circuit and the subcooling at core outlet. With steam and nitrogen gas as the gaseous mixture in upper volume, it pursues the progress in the passive feature of reactor, excluding active equipment. The presence of noncondensable gas, however, requires a new mathematical model to predict transient behavior of steam-gas pressurizer. A dynamic model for steam-gas pressurizer is proposed in this study. It is two-region nonequilibrium model whereby pressurizer volume is separated into two distinct regions by an interface, i.e. gaseous mixture and liquid, with each establishing its own thermodynamic state. Mass and energy equations are applied to the three components; steam, nitrogen and liquid water. Physical phenomena to be modeled include surge (SU), rainout (RO), flashing (FL), inter-region heat and mass transfer (ITR), wall condensation (WC). The mathematical model is numerically solved by iterative computing to calculate the pressure with respect to time. The dynamic response of the steam-gas pressurizer in a transient is simulated

  18. Improving the Transient Performance of the Gas Turbine by Steam Injection during Frequency Dips

    OpenAIRE

    Ali Ghaffari; Saeed Bahrami; Marcus Thern

    2013-01-01

    Single-shaft gas turbines are sensitive to frequency changes which might affect the grid stability during large frequency drops. This paper presents a new control system that uses steam injection as an auxiliary input to improve the transient performance of the gas turbine during frequency drops. Steam injection is beneficial because it reduces the peak temperature in the combustion chamber and augments the output power by increasing the mass flow through the turbine. The use of this auxiliar...

  19. Thermodynamic analyses of an externally fired gas turbine combined cycle integrated with a biomass gasification plant

    International Nuclear Information System (INIS)

    Highlights: • A gas turbine combined cycle with gasified biomass external firing is analyzed. • Thermodynamic analysis considers first and second law analyses. • Thermal efficiency peaks at an optimum cycle pressure ratio (about 9). • Three sets of operating parameters are considered in a detailed case study. • One of three cases is more efficient from first or second law viewpoints. - Abstract: Thermodynamic analyses of an externally fired gas turbine combined cycle integrated with a biomass gasification plant, using energy and exergy approaches, are reported for a proposed configuration. Paper is taken to be the fuel and the thermodynamic performance and sizing of the plant is examined for various values of cycle pressure ratio (7–12), gas turbine inlet temperature (1200–1400 K) and heat exchanger cold-end temperature difference (245–275 K). Depending on the gas turbine inlet temperature and heat exchanger cold-end temperature difference, the system overall energy efficiency is observed to attain a maximum at a particular pressure ratio. For a given pressure ratio, the energy efficiency increases with gas turbine inlet temperature and decreases with heat exchanger cold-end temperature difference. An increase in pressure ratio results in a decrease of air flow rate and an increase of steam flow rates. These flow rates are attributable to the size of combined cycle plant. Raising the gas turbine inlet temperature reduces the air flow rate. The performance of a 1 MW plant is investigated with various operating parameters to obtain component ratings and biomass feed rates. Exergy efficiencies of cycle components are examined along with the major thermodynamic irreversibilities

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

    OpenAIRE

    Trane-Restrup, Rasmus; Jensen, Anker Degn; Dahl, Søren

    2013-01-01

    Bio-oil is a liquid produced by pyrolysis of biomass and its main advantage compared with biomass is an up to ten times higher energy density. This entails lower transportation costs associated with the utilization of biomass for production of energy and fuels. Nevertheless, the bio-oil has a low heating value and high content of oxygen, which makes it unsuited for direct utilization in engines. One prospective technology for upgrading of bio-oil is steam reforming(SR), which can be used to p...

  1. Liquefied synthetic natural gas from woody biomass. Investigation of cryogenic technique for gas upgrading

    OpenAIRE

    Garcia Jarque, Sílvia; Birgen, Cansu

    2012-01-01

    Biomass-based liquefied natural gas (bio-LNG) is very valuable renewable fuel as it has high energy density and transportability. Bio-LNG requires liquefaction of the synthetic natural gas (bio-SNG). Cryogenic technology is a promising option for integration of the gas upgrading and liquefaction streams with the main biomass gasification and methane synthesis plant. This thesis investigates the feasibility of this technology for future commercial bio-SNG production plants based on indirect ga...

  2. DEVELOPMENT OF A NANO-Ni-La-Fe/Al2O3 CATALYST TO BE USED FOR SYN-GAS PRODUCTION AND TAR REMOVAL AFTER BIOMASS GASIFICATION

    Directory of Open Access Journals (Sweden)

    Jianfen Li

    2009-11-01

    Full Text Available The objective of this study was to develop a supported tri-metallic catalyst (nano-Ni-La-Fe/γ-Al2O3 for tar removal in biomass steam gasification, to significantly enhance the quality of the produced gas. For this purpose, the supported tri-metallic catalysts were prepared by a deposition-precipitation (DP method. Different analytical approaches were used to characterize the synthesized catalysts. The results showed that the prepared tri-metallic catalysts had an egg-shell structure with a specific surface area of 214.7 m2/g. The activity of the catalysts for gas production and tar removal in the process of biomass gasification was also investigated using a bench-scale combined fixed bed reactor. The experiments indicated that the tar yield after adding catalyst was reduced significantly and the efficiency of tar removal reached 99% for the biomass steam gasification at 800oC, while the gas yield after adding catalysts increased markedly and less coke was found over the catalyst. Meanwhile, the compositions of gas products before and after adding catalyst in the process also changed significantly; in particular, the content of hydrogen in catalytic steam gasification was improved by over 10 vol%. Therefore, using the prepared tri-metallic catalyst in biomass gasification can significantly improve the quality of the produced gas and efficiently eliminate the tar generation, preventing coke deposition on the catalyst surfaces, thus demonstrating a long lifetime of the catalyst.

  3. Effect of Gas/Steam Turbine Inlet Temperatures on Combined Cycle Having Air Transpiration Cooled Gas Turbine

    Science.gov (United States)

    Kumar, S.; Singh, O.

    2012-10-01

    Worldwide efforts are being made for further improving the gas/steam combined cycle performance by having better blade cooling technology in topping cycle and enhanced heat recovery in bottoming cycle. The scope of improvement is possible through turbines having higher turbine inlet temperatures (TITs) of both gas turbine and steam turbine. Literature review shows that a combined cycle with transpiration cooled gas turbine has not been analyzed with varying gas/steam TITs. In view of above the present study has been undertaken for thermodynamic study of gas/steam combined cycle with respect to variation in TIT in both topping and bottoming cycles, for air transpiration cooled gas turbine. The performance of combined cycle with dual pressure heat recovery steam generator has been evaluated for different cycle pressure ratios (CPRs) varying from 11 to 23 and the selection diagrams presented for TIT varying from 1,600 to 1,900 K. Both the cycle efficiency and specific work increase with TIT for each pressure ratio. For each TIT there exists an optimum pressure ratio for cycle efficiency and specific work. For the CPR of 23 the best cycle performance is seen at a TIT of 1,900 K for maximum steam temperature of 570 °C, which gives the cycle efficiency of 60.9 % with net specific work of 909 kJ/kg.

  4. Exergetic optimization of single level combined gas-steam power plants considering different objective functions

    Energy Technology Data Exchange (ETDEWEB)

    Bracco, Stefano [Department of Turbomachinery, Energy Systems and Transportation, University of Genova, Via Montallegro 1, 16145 Genova (Italy); Siri, Silvia [Department of Communications, Computer and Systems Science, University of Genova, Via Opera Pia 13, 16145 Genova (Italy)

    2010-12-15

    Combined cycle power plants have been studied in this paper with the aim of optimizing the heat recovery steam generator using a first and second law approach. To this end, a mathematical model has been developed for determining the optimal steam pressure in a one pressure level heat recovery steam generator, considering that the gas turbine is known. Different objective functions have been analysed in this study, some of which refer only to the exergy balance of the heat recovery steam generator while others involve the whole bottoming cycle. Some constraints for the operating parameters of the power plant have also been taken into account, regarding for instance the steam quality at the turbine outlet and the steam turbine blade height. Some numerical results have been reported in the paper, comparing the different objective functions for heat recovery steam generators coupled with several gas turbines; the developed parametric analysis has been performed in order to evaluate the influence of some parameters on both the heat recovery steam generator and the whole bottoming cycle. (author)

  5. Influence of reservoir parameters and steam rate on SAGD process in a reservoir with gas cap

    Energy Technology Data Exchange (ETDEWEB)

    Barillas, J.L.M.; Dutra, T.V.Jr. [Rio Grande do Norte Federal Univ., Natal (Brazil). Dept. of Chemical Engineering; Mata, W. [Rio Grande do Norte Federal Univ., Natal (Brazil). Dept. of Electrical Engineering

    2008-07-01

    The process of steam injection in heavy oil reservoirs involves heating the reservoir to reduce oil viscosity and increase oil-phase mobility. Steam assisted gravity drainage is one of the most promising thermal recovery methods that has been used in countries such as Canada, the United States and Venezuela, but not in Brazil. This study verified if the process could be applied in Brazilian reservoirs. In particular, a reservoir with northeast Brazilian characteristics was studied in a homogeneous model with a gas cap. The STARS software from CMG was used for all cases. The steam requirement was optimized based on an economical study in which a simplified calculation for net present value (NPV) was obtained. The calculation depended on factors such as cumulative oil, steam injected volume, steam/oil cost ratio, net production cost and, oil price and internal return rate. This function made it possible to perform a steam optimization for different systems with maximal NPV. It was determined that optimal steam rate depends on reservoir characteristics. The thickness of the gas cap was found to have little influence on oil recovery. It was concluded that the optimal steam injection rate can be determined for maximal NPV depending on the physical characteristics of the reservoir. 9 refs., 3 tabs., 10 figs.

  6. Properties of synthetic gas produced by plasma gasification of biomass

    Czech Academy of Sciences Publication Activity Database

    Hlína, Michal; Hrabovský, Milan; Konrád, Miloš; Kopecký, Vladimír; Kavka, Tetyana; Lorcet, H.

    Greifswald: INP Greifswald, 2010, s. 452-455. ISBN 0-9539105-4-7. [International Conference on Gas Discharges and Their Applications (GD 2010)/18th./. Greifswald (DE), 05.09.2010-10.09.2010] R&D Projects: GA ČR GA202/08/1084; GA MŠk MEB020814 Institutional research plan: CEZ:AV0Z20430508 Keywords : Plasma * Gerdien arc * gasification * biomass Subject RIV: BL - Plasma and Gas Discharge Physics

  7. Assessment of steam-injected gas turbine systems and their potential application

    Science.gov (United States)

    Stochl, R. J.

    1982-01-01

    Results were arrived at by utilizing and expanding on information presented in the literature. The results were analyzed and compared with those for simple gas turbine and combined cycles for both utility power generation and industrial cogeneration applications. The efficiency and specific power of simple gas turbine cycles can be increased as much as 30 and 50 percent, respectively, by the injection of steam into the combustor. Steam-injected gas turbines appear to be economically competitive with both simple gas turbine and combined cycles for small, clean-fuel-fired utility power generation and industrial cogeneration applications. For large powerplants with integrated coal gasifiers, the economic advantages appear to be marginal.

  8. Thermo-economic analysis of a solid oxide fuel cell and steam injected gas turbine plant integrated with woodchips gasification

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Rokni, Masoud

    2014-01-01

    This paper presents a thermo-economic analysis of an integrated biogas-fueled solid oxide fuel cell (SOFC) system for electric power generation. Basic plant layout consists of a gasification plant (GP), an SOFC and a retrofitted steam-injected gas turbine (STIG). Different system configurations and......% respectively which are significantly greater than conventional 10 MWe plants fed by biomass. Thermo-economic analysis provides an average cost of electricity for best performing layouts close to 6.4 and 9.4 c€/kWe which is competitive within the market. A sensitivity analysis of the influence of SOFC stack...... simulations are presented and investigated. A parallel analysis for simpler power plants, combining GP, SOFC, and hybrid gas turbine (GT) is carried out to obtain a reference point for thermodynamic results. Thermodynamic analysis shows energetic and exergetic efficiencies for optimized plant above 53% and 43...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    Highlights: • Innovation in gasifier design. • Integration of pyrolysis and steam gasification processes. • Energy saving, improvement of gasifier efficiency, syngas and hydrogen yield. • Overall investigation on gasification parameters. • Optimization conditions of integration of pyrolysis and gasification process. - Abstract: Fuel production from agro-waste has become an interesting alternative for energy generation due to energy policies and greater understanding of the importance of green energy. This research was carried out in a lab-scale gasifier and coconut shell was used as feedstock in the integrated process. In order to acquire the optimum condition of syngas production, the effect of the reaction temperature, equivalence ratio (ER) and steam/biomass (S/B) ratio was investigated. Under the optimized condition, H2 and syngas yield achieved to 83.3 g/kg feedstock and 485.9 g/kg feedstock respectively, while LHV of produced gases achieved to 12.54 MJ/N m3

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

  14. Feasibility Study on Steam and Gas Push with Dual Horizontal Wells in a Moderate-Depth Heavy Oil Reservoir

    OpenAIRE

    Jie Fan; Xiangfang Li; Tianjie Qin

    2016-01-01

    Non-condensable gas (NCG) with steam co-injection makes steam assisted gravity drainage less energy-intensive as well as reduces greenhouse gas emission and water consumption. Numerous studies have shown that the technology called steam and gas push (SAGP) is feasible for heavy oil and bitumen. However, most of these studies have focused on shallow heavy oil reservoirs and only a few works have investigated moderate-depth heavy oil reservoirs. In this study, laboratory experiments...

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

    International Nuclear Information System (INIS)

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

  16. Effect of steam addition on cycle performance of simple and recuperated gas turbines

    Science.gov (United States)

    Boyle, R. J.

    1979-01-01

    Results are presented for the cycle efficiency and specific power of simple and recuperated gas turbine cycles in which steam is generated and used to increase turbine flow. Calculations showed significant improvements in cycle efficiency and specific power by adding steam. The calculations were made using component efficiencies and loss assumptions typical of stationary powerplants. These results are presented for a range of operating temperatures and pressures. Relative heat exchanger size and the water use rate are also examined.

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-15

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

  19. QUALITY ENHANCEMENT OF PRODUCER GAS FROM CASSAVA RHIZOME USING HIGH TEMPERATURE AIR-STEAM DOWNDRAFT GASIFICATION

    Directory of Open Access Journals (Sweden)

    Worapot Ngamchompoo

    2013-01-01

    Full Text Available High Temperature Air-Steam Gasification (HTAG was performed on a bench-scale downdraft gasifier. A cassava rhizome was used as feedstock for the gasification. Air and steam were utilized as the gasifying agents. The objectives in this study were to study the potential of HTAG technology applied with a downdraft gasifier to improve producer gas quality in terms of Higher Heating Value (HHV and lower tar content. The results were compared with conventional air-steam gasification (without preheating. The results were that the HHV of the producer gas from the HTAG process at 900°C improved by as much as 5.1 MJ/Nm3 (at S/B ratio = 0.3, while the air-steam gasification, HTAG at 300°C and HTAG at 600°C couldonly obtain a HHV of 3.8 MJ/Nm3 (at S/B = 0.4, 4.2 MJ/Nm3 (at S/B = 0.1 and4.8 MJ/Nm3 (at S/B = 0.2, respectively. In addition, tar content in the producer gas of the HTAG process at 900°C had the lowest value (95 mg/m3 which could be used as fuel in an internal combustion engine. While the minimum tar content of the air-steam gasification was 320 mg/m3. In the HTAG process at 900°C, the maximum Cold Gas Efficiency (CGE was 65%, which was slightly lower than the CGE of air-steam gasification (69%. However, in the HTAG process at 300, 600 and 900°C the maximum Hot Gas Efficiency (HGE increased 33% (from 72 to 96%, 25 (from 72 to 90% and 7 (from 72 to 77%, respectively; when compared with air-steam gasification.

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

    International Nuclear Information System (INIS)

    In order to quantitatively analyze the performance of the helium-heated reformer used in steam methane reforming hydrogen production system connected with high temperature gas cooled reactor, a dynamic model has been set up based on one-dimension quasi-homogeneous phase model. And a computer program is development. Model verification is performed under steady state using test results of Japan Atomic Energy Institute. The steady state calculation results fit well with the experiment results. Reaction velocity is not the main factor influencing the performance. Reformer tube with finned central tube improves the performance remarkably comparing with smooth central tube. (authors)

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

    DEFF Research Database (Denmark)

    Løj, Lusi Hindiyarti

    2007-01-01

    Gas Phase Sulfur, Chlorine and Alkali Metal Chemistry in Biomass Combustion Concern about aerosols formation, deposits, corrosion, and gaseous emissions during biomass combustion, especially straw, continues to be a driving force for investigation on S, Cl, K-containing species under combustions...... uncertainties. In the present work, the detailed kinetic model for gas phase sulfur, chlorine, alkali metal, and their interaction has been updated. The K/O/H/Cl chemistry, S chemistry, and their interaction can reasonably predict a range of experimental data. In general, understanding of the interaction...... sulfur chemistry important for the SO2/SO3 ratio under combustion conditions has been updated. The uncertainties of the important rate constants have been minimized. Modeling predictions with a revised reaction mechanism for SO2/SO3 chemistry are in a good agreement with a range of experimental data from...

  2. Minimizing the formation of coke and methane on Co nanoparticles in steam reforming of biomass-derived oxygenates

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junming; Mei, Donghai; Karim, Ayman M.; Datye, Abhaya K.; Wang, Yong

    2013-06-01

    Fundamental understanding and control of chemical transformations are essential to the development of technically feasible and economically viable catalytic processes for efficient conversion of biomass to fuels and chemicals. Using an integrated experimental and theoretical approach, we report high hydrogen selectivity and catalyst durability of acetone steam reforming (ASR) on inert carbon supported Co nanoparticles. The observed catalytic performance is further elucidated on the basis of comprehensive first-principles calculations. Instead of being considered as an undesired intermediate prone for catalyst deactivation during bioethanol steam reforming (ESR), acetone is suggested as a key and desired intermediate in proposed two-stage ESR process that leads to high hydrogen selectivity and low methane formation on Co-based catalysts. The significance of the present work also sheds a light on controlling the chemical transformations of key intermediates in biomass conversion such as ketones. We gratefully acknowledge the financial support from U. S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, and the Laboratory directed research and development (LDRD) project of Pacific Northwest National Laboratory (PNNL). Computing time was granted by the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). The EMSL is a U.S. DOE national scientific user facility located at PNNL, and sponsored by the U.S. DOE’s Office of Biological and Environmental Research.

  3. Kinetics study on biomass pyrolysis for fuel gas production

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Kinetic knowledge is of great importance in achieving good control of the pyrolysis and gasification process and optimising system design. An overall kinetic pyrolysis scheme is therefore addressed here. The kinetic modelling incorporates the following basic steps: the degradation of the virgin biomass materials into primary products (tar, gas and semi-char), the decomposition of primary tar into secondary products and the continuous interaction between primary gas and char. The last step is disregarded completely by models in the literature. Analysis and comparison of predicted results from different kinetic schemes and experimental data on our fixed bed pyrolyser yielded very positive evidence to support our kinetic scheme.

  4. Kinetics study on biomass pyrolysis for fuel gas production

    Institute of Scientific and Technical Information of China (English)

    陈冠益; 方梦祥; ANDRIES,J.; 骆仲泱; SPLIETHOFF,H.; 岑可法

    2003-01-01

    Kinetic knowledge is of great importance in achieving good control of the pyrolysis and gasification process and optimising system design. An overall kinetic pyrolysis scheme is therefore addressed here. The ki-netic modelling incorporates the following basic steps: the degradation of the virgin biomass materials into pri-mary products ( tar, gas and semi-char), the decomposition of primary tar into secondary products and the continuous interaction between primary gas and char. The last step is disregarded completely by models in the literature. Analysis and comparison of predicted results from different kinetic schemes and experimental data on our fixed bed pyrolyser yielded very positive evidence to support our kinetic scheme.

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

    International Nuclear Information System (INIS)

    This paper reviews the materials technology aspects of steam generators for HTGRs which feature a graphite-moderated, uranium-thorium, all-ceramic core and utilizes high-pressure helium as the primary coolant. The steam generators are exposed to gas-side temperatures approaching 7600C and produce superheated steam at 5380C and 16.5 MPa (2400 psi). The prototype Peach Bottom I 40-MW(e) HTGR was operated for 1349 EFPD over 7 years. Examination after decommissioning of the U-tube steam generators and other components showed the steam generators to be in very satisfactory condition. The 330-MW(e) Fort St. Vrain HTGR, now in the final stages of startup, has achieved 70% power and generated more than 1.5 x 106 MWh of electricity. The steam generators in this reactor are once-through units of helical configuration, requiring a number of new materials factors including creep-fatigue and water chemistry control. Current designs of larger HTGRs also feature steam generators of helical once-through design. Materials issues that are important in these designs include detailed consideration of time-dependent behavior of both base metals and welds, as required by current American Society of Mechanical Engineers (ASME) Code rules, evaluation of bimetallic weld behavior, evaluation of the properties of large forgings, etc

  6. A high-temperature gas-and-steam turbine plant operating on combined fuel

    Science.gov (United States)

    Klimenko, A. V.; Milman, O. O.; Shifrin, B. A.

    2015-11-01

    A high-temperature gas-steam turbine plant (GSTP) for ultrasupercritical steam conditions is proposed based on an analysis of prospects for the development of power engineering around the world and in Russia up to 2040. The performance indicators of a GSTP using steam from a coal-fired boiler with a temperature of 560-620°C with its superheating to 1000-1500°C by firing natural gas with oxygen in a mixingtype steam superheater are analyzed. The thermal process circuit and design of a GSTP for a capacity of 25 MW with the high- and intermediate-pressure high-temperature parts with the total efficiency equal to 51.7% and the natural gas utilization efficiency equal to 64-68% are developed. The principles of designing and the design arrangement of a 300 MW GSTP are developed. The effect of economic parameters (the level and ratio of prices for solid fuel and gas, and capital investments) on the net cost of electric energy is determined. The net cost of electric energy produced by the GSTP is lower than that produced by modern combined-cycle power plants in a wide variation range of these parameters. The components of a high-temperature GSTP the development of which determines the main features of such installations are pointed out: a chamber for combusting natural gas and oxygen in a mixture with steam, a vacuum device for condensing steam with a high content of nondensables, and a control system. The possibility of using domestically available gas turbine technologies for developing the GSTP's intermediate-pressure high-temperature part is pointed out. In regard of its environmental characteristics, the GSTP is more advantageous as compared with modern condensing power plants: it allows a flow of concentrated carbon dioxide to be obtained at its outlet, which can be reclaimed; in addition, this plant requires half as much consumption of fresh water.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  8. Development and Application of Advanced Models for Steam Hydrogasification: Process Design and Economic Evaluation

    OpenAIRE

    Lu, Xiaoming

    2012-01-01

    This thesis is aimed at the process development, design, modeling and optimization of synthetic fuels, power and Substitute Natural Gas (SNG) production from coal and biomass with economic analysis based on steam hydrogasification technology. The steam hydrogasification is a thermochemical process to convert carbonaceous materials into methane-rich gas in the Steam Hydrogasification Reactor (SHR) at high hydrogen and steam environment. The methane could be either converted into syngas in the ...

  9. Hydrogen-rich gas production via CaO sorption-enhanced steam gasification of rice husk: a modelling study.

    Science.gov (United States)

    Beheshti, Sayyed Mohsen; Ghassemi, Hojat; Shahsavan-Markadeh, Rasoul; Fremaux, Sylvain

    2015-01-01

    Gasification is a thermochemical process in which solid or liquid fuels are transformed into synthesis gas through partial oxidation. In this paper, a kinetic model of rice husk gasification has been developed, which is interesting for the applications of the syngas produced. It is a zero-dimensional, steady-state model based on global reaction kinetic, empirical correlation of pyrolysis and is capable of predicting hydrogen yield in the presence of sorbent CaO. The model can also be used as a useful tool to investigate the influence of process parameters including steam/biomass ratio, CaO/fuel ratio (CaO/Fuel), and gasification temperature on hydrogen efficiency, CO2 capture ratio (CCR), and average carbonation conversion (Save). Similar to hydrogen formation, CCR also increases with increasing CaO/Fuel, but an opposite trend is exhibited in Save. Model predictions were compared with available data from the literature, which showed fairly good agreement. PMID:25403373

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.; Hart, R.; Lazic, L. [SNC-Lavlin Nuclear Inc. (Canada)

    2009-07-01

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

  12. Comparison of performance of the integrated gas and steam cycle (IGSC) with the combined cycle (CC)

    International Nuclear Information System (INIS)

    The clear advantages of the gas turbine engine are making it the engine of the future in electric power generation. Some combined cycle power plants are breaking the 60% efficiency barrier. One of the key technologies for such high thermal efficiency is steam cooling.In the integrated gas and steam cycle (IGSC), part of the steam generated in the heat recovery boiler (HRB) is used in the gas turbine as the cooling medium instead of air, whereas the other part is used as process steam. In the analysis, the compressor pressure ratio rc and the turbine inlet temperature were considered the main variables. A computer program was specially tailored to carry out calculations and evaluate performance over a wide range of operating conditions including the design point.Performance results show that, when the cooling air is disregarded, the combined cycle (CC) produces 7% more power than IGSC, whereas the latter outperforms the CC by about 6% in SFCov and 12% in ηov.However, when 5% cooling air is considered, the IGSC outperforms the CC by 2%, 12% and 20%, respectively (in points).Moreover, considerable saving in capital cost is achieved by dispensing with the steam turbine, condenser and cooling tower needed by the CC. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Alevanau, Aliaksandr

    2010-01-01

    Among the latest achievements in gasification technology, one may list the development of a method to preheat gasification agents using switched ceramic honey combs. The best output from this technology is achieved with use of water steam as a gasification agent, which is heated up to 1600 °C. The application of these temperatures with steam as a gasification agent provides a cleaner syngas (no nitrogen from air, cracked tars) and the ash melts into easily utilised glass-like sludge. High hyd...

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

    Energy Technology Data Exchange (ETDEWEB)

    Griselin, Nicolas

    2000-11-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  18. Optical Absorption Spectroscopy for Gas Analysis in Biomass Gasification

    DEFF Research Database (Denmark)

    Grosch, Helge

    Biomass gasication as a source of heat, power and chemical feedstock needs monitoring of the gas species to improve the performance and gas quality, deepen the understanding of the process and to be able to control the emission of hazardous compounds. Major species, like H2, CO and CO2, can already...... be determined with sucient precision. However, minor species, like organic, aromatic, sulfur- and nitrogen-containing compounds, still cause problems in down-stream equipment and are harmful for health and environment. As a result, many different approaches for applications have been proposed to...... and aromatic compounds were determined in laboratory experiments. By means of the laboratory results and spectroscopic databases,the concentrations of the major gas species and the aromatic compounds phenol and naphthalene were determined in extraction and in-situ measurements....

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

    International Nuclear Information System (INIS)

    In gas cooled reactors with graphitic primary circuit structures - such as HTR, AGR or Magnox - the water ingress is an event of great safety concern. Water or steam entering the primary circuit react with the hot graphite and carbon-oxide and hydrogen are produced. As the most important initiating event a leak in a steam generator must be taken into account. From the safety point of view as well as for availability reasons it is necessary to construct reliable boilers. Thus the occurrence of a boiler leak should be a rare event. In the context of a probabilistic safety study for an HTR-Project much effort was invested to get information about the frequency and the size distribution of tube failures in steam generators of gas cooled reactors. The main data base was the boiler tube failure statistics of United Kingdom gas cooled reactors. The data were selected and applied to a modern HTR steam generator design. A review of the data showed that the failure frequency is not connected with the load level (pressures, temperatures) or with the geometric size of the heating surface of the boiler. Design, construction, fabrication, examination and operation conditions have the greatest influence an the failure frequency but they are practically not to be quantified. The typical leak develops from smallest size. By erosion effects of the entering water or steam it is enlarged to perhaps some mm2, then usually it is detected by moisture monitors. Sudden tube breaks were not reported in the investigated period. As a rule boiler leaks in gas cooled reactors are much more, rare then leaks in steam generators of light water reactors and fossil fired boilers. (author)

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    heat from the exhaust gas is utilised for drying and pyrolysis of the biomass in the gasification system, and the engine directly controls the load of the gasifier. Two different control approaches have been applied and investigated: one where the flow rate of the producer gas is fixed and the engine...... conditions when compared to the current regulation for CO emissions. Measurements of the PAH showed that there were no detectable PAH in exhaust gas from the engine when it is operated on producer gas. The emissions of aldehydes were measured to be significantly lower for producer gas operation than for...

  1. High-temperature gas-cooled-reactor steam-methane reformer design

    International Nuclear Information System (INIS)

    The concept of the long distance transportation of process heat energy from a High Temperature Gas Cooled Reactor (HTGR) heat source, based on the steam reforming reaction, is currently being evaluated as an energy source/application for use early in the 21st century. The steam-methane reforming reaction is an endothermic reaction at temperatures approximately 7000C and higher, which produces hydrogen, carbon monoxide and carbon dioxide. The heat of the reaction products can then be released, after being pumped to industrial site users, in a methanation process producing superheated steam and methane which is then returned to the reactor plant site. In this application the steam reforming reaction temperatures are produced by the heat energy from the core of the HTGR through forced convection of the primary or secondary helium circuit to the catalytic chemical reactor (steam reformer). This paper summarizes the design of a helium heated steam reformer utilized in conjunction with a 1170 MW(t) intermediate loop, 8500C reactor outlet temperature, HTGR process heat plant concept. This paper also discusses various design considerations leading to the mechanical design features, the thermochemical performance, materials selection and the structural design analysis

  2. REFINEMENT OF PRODUCER GAS GENERATED FROM BIOMASS GASIFIER

    Directory of Open Access Journals (Sweden)

    L. KUMARARAJA

    2016-01-01

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

  3. Steam boiler for fytomass

    OpenAIRE

    Baláš, Jiří

    2008-01-01

    The purpose of this Diploma Thesis was the construction design of the steam boiler for fytomass. For the specified parameters of biomass have been gradually implemented stoichiometric calculations of which are further based calculation of enthalpies of combustion gas. In the next part have been dealt with heat balance of the boiler, the efficiency of the boiler, recirculation of exhaust gases and the temperature of the combustion gases in outlet from fire. Thereinafter, the proposal of partic...

  4. Automation of steam generator services at public service electric ampersand gas

    International Nuclear Information System (INIS)

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

  5. The combined operation of nuclear and coal fired gas and steam turbine power plants

    International Nuclear Information System (INIS)

    The combined operation of LWR nuclear power plants and hard coal fired gas and steam turbine plants with carbon dioxide removal systems allows optimum seasonal load matching to be achieved in an electricity supply regime largely free from CO2 and based on uranium and coal. The basic idea is this: In periods of low load (the summer months), part of the electricity generated by an LWR is converted electrolytically into hydrogen and oxygen, the oxygen being stored in underground caverns and the hydrogen being added to the methane in the natural gas system. In periods of high load (the winter months), the stored oxygen is used for coal gas evaporation in the gas and steam power plant, whose efficiency is raised by the absence of the air separation system. (orig.)

  6. Open-Cycle Gas Turbine/Steam Turbine Combined Cycles with synthetic fuels from coal

    Science.gov (United States)

    Shah, R. P.; Corman, J. C.

    1977-01-01

    The Open-Cycle Gas Turbine/Steam Turbine Combined Cycle can be an effective energy conversion system for converting coal to electricity. The intermediate step in this energy conversion process is to convert the coal into a fuel acceptable to a gas turbine. This can be accomplished by producing a synthetic gas or liquid, and by removing, in the fuel conversion step, the elements in the fuel that would be harmful to the environment if combusted. In this paper, two open-cycle gas turbine combined systems are evaluated: one employing an integrated low-Btu gasifier, and one utilizing a semi-clean liquid fuel. A consistent technical/economic information base is developed for these two systems, and is compared with a reference steam plant burning coal directly in a conventional furnace.

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

    International Nuclear Information System (INIS)

    Utilizing large amounts of animal waste as a source of renewable energy has the potential to reduce its disposal problems and associated pollution issues. Gasification characteristics of the manure compost make it possible for low temperature gasification. In this paper, an energy efficient approach to hydrogen-rich syngas from manure compost is represented at relatively low temperature, around 600 oC, in a continuous-feeding fluidized bed reactor. The effects of catalyst performance, reactor temperature, steam, and reaction type on gas yield, gas composition, and carbon conversion efficiency are discussed. The Ni-Al2O3 catalyst simultaneously promotes tar cracking and steam reforming. Higher temperature contributes to higher gas yield and carbon conversion. The steam introduction increases hydrogen yield, by steam reforming and water-gas shift reaction. Two-stage gasification is also tried, showing the advantage of better catalyst utilization and enhancing the catalytic reactions to some extent.

  8. Thermal Plasma Gasification of Biomass for Fuel Gas Production

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, Milan; Hlína, Michal; Konrád, Miloš; Kopecký, Vladimír; Kavka, Tetyana; Chumak, Oleksiy; Mašláni, Alan

    2009-01-01

    Roč. 13, č. 3-4 (2009), s. 299-313. ISSN 1093-3611 R&D Projects: GA ČR GA202/08/1084 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal plasma * plasma gasification * syngas * biomass Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.333, year: 2009 http://www.begellhouse.com/journals/57d172397126f956,5cbc272245f24168,0ac09d02537962cf.html

  9. The potential for biomass to mitigate greenhouse gas emissions in the Northeastern US. Northeast Regional Biomass Program

    Energy Technology Data Exchange (ETDEWEB)

    Bernow, S.S.; Gurney, K.; Prince, G.; Cyr, M.

    1992-04-01

    This study, for the Northeast Regional Biomass Program (NRBP) of the Coalition of Northeast Governors (CONEG), evaluates the potential for local, state and regional biomass policies to contribute to an overall energy/biomass strategy for the reduction of greenhouse gas releases in the Northeastern United States. Biomass is a conditionally renewable resource that can play a dual role: by reducing emissions of greenhouse gases in meeting our energy needs; and by removing carbon from the atmosphere and sequestering it in standing biomass stocks and long-lived products. In this study we examine the contribution of biomass to the energy system in the Northeast and to the region`s net releases of carbon dioxide and methane, and project these releases over three decades, given a continuation of current trends and policies. We then compare this Reference Case with three alternative scenarios, assuming successively more aggressive efforts to reduce greenhouse gas emissions through strategic implementation of energy efficiency and biomass resources. Finally, we identify and examine policy options for expanding the role of biomass in the region`s energy and greenhouse gas mitigation strategies.

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

    Energy Technology Data Exchange (ETDEWEB)

    Noergaard Hansson, A.

    2009-07-01

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

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

    International Nuclear Information System (INIS)

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

  12. The economics of biomass for power and greenhouse gas reduction

    Science.gov (United States)

    Cameron, Jay Brooker

    The power cost and optimum plant size for power plants using straw fuel in western Canada was determined. The optimum size for agricultural residues is 450 MW (the largest single biomass unit judged feasible in this study), and the power cost is 50.30 MWh-1. If a larger biomass boiler could be built, the optiμm project size for straw would be 628 MW. For a market power price of 40 MWh-1 the cost of the GHG credit generated by a straw-fired plant is 11 tonne-1 CO2. Straw was evaluated as a possible supplement to the primary coal fuel at the Genesee power station in order to reduce the greenhouse gas (GHG) emissions intensity. Cofiring straw at the Genesee power station does not compete favorably with other GHG abatement technologies, even the lowest cost option is estimated at 22 tonne-1 CO2. The cost of transporting wood chips by truck and by pipeline as a water slurry is determined. The pipeline would be economical at large capacity (>0.5 M dry tonnes per year for a one way pipeline, and >1.25 M dry tonnes per year for a two way pipeline that returns the carrier fluid to the pipeline inlet), and at medium to long distances (>75 km (one way) and >470 km (two way) at a capacity of 2 M dry tonnes per year). Pipelining was determined to be unsuitable for combustion applications. Pipeline transport of corn is evaluated against a range of truck transport costs. At 20% solids, pipeline transport of corn stover costs less than trucking at capacities in excess of 1.4 M dry tonnes/yr when compared to a mid range of truck transport. Pipelining of corn stover gives the opportunity to conduct simultaneous transport and saccharification (STS) but would require a source of waste heat at the pipeline inlet in order to be economical. Transport of corn stover in multiple pipelines offers the opportunity to develop a large ethanol fermentation plant, avoiding some of the diseconomies of scale that arise from smaller plants whose capacities are limited by issues of truck congestion

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

    International Nuclear Information System (INIS)

    Green biogas seems to be an interesting option to make the Dutch economy, with a large share of gas in the energy system, more sustainable. Biomass that is used as feedstock for biogas can also be deployed for the production of Electricity, biodiesel, bio-ethanol, bio-plastics, bio-chemical products and even bio-steel. This memo compares the main characteristics of biomass uses for production of gas with alternative uses in other sectors. The comparison shows that wet biomass flows in particular (e.g. manure and KGW) are suitable for conversion in biogas. This leads to a potential of 1 to 1.5 billion Nm3 of gas in 2020. Gasification of dry biomass may also become interesting in the future. However, this fuel is subjected to fierce competition with the electricity sector, which can use solid biomass for combustion purposes. Moreover, the steel, chemical and transport sector may also be able to use the feedstock in time.

  14. Steam generators and heat exchangers for gas-cooled reactors. Background and status in Switzerland

    International Nuclear Information System (INIS)

    The Swiss company Sulzer Brothers Ltd. built its first nuclear steam generator in 1961 for a CO2-cooled prototype reactor. Since then the Company has been involved in the planning, development and manufacture of steam generators for gas-cooled reactors, in particular for the French Magnox reactor program. In 1980 Sulzer delivered the 6-module steam generator for the German High Temperature Reactor Prototype THTR-300. The production of hardware was continuously accompanied and supported by extensive research and development activities. Experimental programs comprised thermohydraulic investigations related to the primary gas-side as well as to the secondary side and its two-phase-flow stability. In the area of high temperature materials thermal cycling tests were performed to analyse the fatigue of bimetallic welds under severe transients. Low cycle creep fatigue damage in tube bends and the wear and fretting characteristics of protective coatings on the helium side of hot tubes were investigated. Fabrication experiments for large helical heat exchangers served to extrapolate known manufacturing technology to commercial size HTGR units. In the frame of international GCR programs Switzerland participated in the Gas Breeder Reactor Association and the High Temperature Helium Turbine Project. For these projects Sulzer designed and developed steam generators, recuperators and primary coolers

  15. Thermodynamic analysis for heat recovery steam generation of cogeneration gas turbine cycle with reheat

    Energy Technology Data Exchange (ETDEWEB)

    Mosafa, A.H. [Islamic Azad Univ., Bonab (Iran, Islamic Republic of); Mahmoudi, S.M.S.; Farshi, L.G. [Tabriz Univ., Tabriz (Iran, Islamic Republic of). Faculty of Mechanical Engineering

    2008-07-01

    Much attention has been given to reheat gas turbine cycles in recent years due to their high exhaust gas temperature and the possibility of using that waste heat in a steam generation system. In this study, a heat recovery steam generator (HRSG) was analyzed as an appliance for transferring heat between exhaust gases and water. Design parameters were optimized. The results showed that a decrease in the pinch point temperature difference resulted in an increase in both energetic and exergetic efficiency. As process steam pressure increased, exergetic efficiency increased significantly but energetic efficiency decreased. These efficiencies were less affected by variation in final temperature difference. However decreasing the final temperature difference resulted in an increase in the steam's mass flow rate. Therefore, in order to design an optimal HRSG in a combined system such as cogeneration gas turbine cycle with reheat, a proper value of parameters must be chosen depending on the demand for heat or power. 15 refs., 2 tabs., 14 figs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wise, D. L; Wentworth, R. L

    1978-05-30

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

  17. Non-contacting shaft seals for gas and steam turbines

    OpenAIRE

    Aubry, James R.; Gillepsie, David

    2012-01-01

    Improvements upon current gas turbine sealing technology performance are essential for decreasing specific fuel consumption to meet stringent future efficiency targets. The clearances between rotating and static components of a gas turbine, which need to be sealed, vary over a flight cycle. Hence, a seal which can passively maintain an optimum clearance, whilst preventing contact between itself and the rotor, is extremely desirable. Various configurations of a Rolls Royce (RR) seal concep...

  18. Leak locating in Bruce NGS-A steam generators using gas tracer techniques

    International Nuclear Information System (INIS)

    In 1981, Ontario Hydro requested development of a leak locating technique capable of locating a 0.5 kg.h-1 heavy water leak within 72 h of access to the steam generator head. A gas tracer technique has been developed to the point where it can now be used in the station to locate such leaks. The technique consists of pressurizing the shell side to 450 kPa with a sulfur hexafluoride air mixture and sampling on the tube side. To speed up the search, a multi-tube sampler is used to sniff a number of tubes simultaneously. The technique as proposed requires a man to enter the steam generator head, but can be adapted for use from outside the steam generator head. The development equipment and procedures required to complete a search are described

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

    International Nuclear Information System (INIS)

    This research investigates experimentally local heat transfer from condensation in the presence of noncondensable gases inside a vertical tube. Using a novel experimental apparatus for accurately measuring local heat fluxes, an extensive data base has been obtained for the condensation of pure steam, steam-air mixtures and steam-helium mixtures. Three different correlations, implementing the degradation factor method, diffusion layer theory, and mass transfer conductance model, are presented. The correlation using the simple degradation factor method has been shown to give satisfactory engineering accuracy. However, this method is based on very simplified arguments that do not fully represent the complex physical phenomena involved. Based on diffusion layer theory and a mass transfer conductance model, more physically based correlations were developed for the heat transfer of vapor-gas side. The total heat transfer coefficient predicted by the correlations from these two mechanistic models are in close agreement with experimental values. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-01

    This research investigates experimentally local heat transfer from condensation in the presence of noncondensable gases inside a vertical tube. Using a novel experimental apparatus for accurately measuring local heat fluxes, an extensive data base has been obtained for the condensation of pure steam, steam-air mixtures and steam-helium mixtures. Three different correlations, implementing the degradation factor method, diffusion layer theory, and mass transfer conductance model, are presented. The correlation using the simple degradation factor method has been shown to give satisfactory engineering accuracy. However, this method is based on very simplified arguments that do not fully represent the complex physical phenomena involved. Based on diffusion layer theory and a mass transfer conductance model, more physically based correlations were developed for the heat transfer of vapor-gas side. The total heat transfer coefficient predicted by the correlations from these two mechanistic models are in close agreement with experimental values. (orig.) 24 refs.

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

    Directory of Open Access Journals (Sweden)

    Vincenzo Naso

    2013-07-01

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

  2. Fuel ethanol production using nuclear-plant steam

    International Nuclear Information System (INIS)

    In the United States, the production of fuel ethanol from corn for cars and light trucks has increased from about 6 billion liters per year in 2000 to 19 billion liters per year in 2006. A third of the world's liquid fuel demands could ultimately be obtained from biomass. The production of fuel ethanol from biomass requires large quantities of steam. For a large ethanol plant producing 380 million liters of fuel ethanol from corn per year, about 80 MW(t) of 1-MPa (∼180 deg. C) steam is required. Within several decades, the steam demand for ethanol plants in the United States is projected to be tens of gigawatts, with the worldwide demand being several times larger. This market may become the largest market for cogeneration of steam from nuclear electric power plants. There are strong incentives to use steam from nuclear power plants to meet this requirement. The cost of low-pressure steam from nuclear power plants is less than that of natural gas, which is now used to make steam in corn-to-ethanol plants. Steam from nuclear power plants reduces greenhouse gases compared with steam produced from fossil fuels. While ethanol is now produced from sugarcane and corn, the next-generation ethanol plants will use more abundant cellulose feedstocks. It is planned that these plants will burn the lignin in the cellulosic feedstocks to provide the required steam. Lignin is the primary non-sugar-based component in cellulosic biomass that can not be converted to ethanol. Low-cost steam from nuclear plants creates the option of converting the lignin to other liquid fuels and thus increase the liquid fuel production per unit of biomass. Because liquid fuel production from biomass is ultimately limited by the availability of biomass, steam from nuclear plants can ultimately increase the total liquid fuels produced from biomass. (author)

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

    International Nuclear Information System (INIS)

    Biomass fast pyrolysis (BFP) is a promising pre-treatment technology for converting biomass to transport fuel and in the future also for high-grade chemicals. BFP can be integrated with a municipal combined heat and power (CHP) plant. This paper shows the influence of BFP integration on a CHP plant's main parameters and its effect on the energetic and environmental performance of the connected district heating network. The work comprises full- and part-load operation of a CHP plant integrated with BFP and steam drying. It also evaluates different usage alternatives for the BFP products (char and oil). The results show that the integration is possible and strongly beneficial regarding energetic and environmental performance. Offering the possibility to provide lower district heating loads, the operation hours of the plant can be increased by up to 57%. The BFP products should be sold rather than applied for internal use as this increases the district heating network's primary energy efficiency the most. With this integration strategy future CHP plants can provide valuable products at high efficiency and also can help to mitigate global CO2 emissions. - Highlights: • Part load simulation of a cogeneration plant integrated with biomas fast pyrolysis. • Analysis of energetic and environmental performance. • Assessment of different uses of the pyrolysis products

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-05-15

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

  5. High-temperature entrained flow gasification of biomass

    DEFF Research Database (Denmark)

    Qin, Ke; Lin, Weigang; Jensen, Peter Arendt;

    2012-01-01

    Biomass (wood and straw) gasification has been studied in a laboratory scale atmospheric pressure entrained flow reactor. Effects of reaction temperature, steam/carbon molar ratio, excess air ratio, and biomass type on the solid, liquid and gas products were investigated. The biomass was completely...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    The integration of steam bottoming cycles on oil and gas platforms is currently regarded as the most promising option for improving the performance of these energy-intensive systems. In this paper, a North Sea platform is taken as case study, and a systematic analysis of its energy requirements is...... cooling utility, and (iv) the weight limitations on the platform are quantitatively assessed. The results illustrate the benefits of converting the gas turbine process into a combined cycle, since the fuel gas consumption and the total CO2-emissions can be reduced by more than 15 %. Using the cooling...

  7. Biomass to hydrogen-rich syngas via catalytic steam gasification of bio-oil/biochar slurry.

    Science.gov (United States)

    Chen, Guanyi; Yao, Jingang; Liu, Jing; Yan, Beibei; Shan, Rui

    2015-12-01

    The catalytic steam gasification of bio-oil/biochar slurry (bioslurry) for hydrogen-rich syngas production was investigated in a fixed-bed reactor using LaXFeO3 (X=Ce, Mg, K) perovskite-type catalysts. The effects of elemental substitution in LaFeO3, temperature, water to carbon molar ratio (WCMR) and bioslurry weight hourly space velocity (WbHSV) were examined. The results showed that La0.8Ce0.2FeO3 gave the best performance among the prepared catalysts and had better catalytic activity and stability than the commercial 14 wt.% Ni/Al2O3. The deactivation caused by carbon deposition and sintering was significantly depressed in the case of La0.8Ce0.2FeO3 catalyst. Both higher temperature and lower WbHSV contributed to more H2 yield. The optimal WCMR was found to be 2, and excessive introducing of steam reduced hydrogen yield. The La0.8Ce0.2FeO3 catalyst gave a maximum H2 yield of 82.01% with carbon conversion of 65.57% under the optimum operating conditions (temperature=800°C, WCMR=2 and WbHSV=15.36h(-1)). PMID:26378962

  8. Improving the Transient Performance of the Gas Turbine by Steam Injection during Frequency Dips

    Directory of Open Access Journals (Sweden)

    Ali Ghaffari

    2013-10-01

    Full Text Available Single-shaft gas turbines are sensitive to frequency changes which might affect the grid stability during large frequency drops. This paper presents a new control system that uses steam injection as an auxiliary input to improve the transient performance of the gas turbine during frequency drops. Steam injection is beneficial because it reduces the peak temperature in the combustion chamber and augments the output power by increasing the mass flow through the turbine. The use of this auxiliary input is based on the event-based control approach. It means that during the frequency drop, the controller exploits the steam injection to help the main control loop recover the frequency and when the frequency reaches its predefined value, the system will return to its normal operation. The performance of the proposed control algorithm is investigated under different scenarios and the results show that the application of steam injection improves the performance of the regular control algorithm significantly, especially near full load condition.

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

    Directory of Open Access Journals (Sweden)

    Martin Lisý

    2015-12-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    Rapidly growing demand for gas turbines promotes research on their performance improvement and reducing their exhaust pollutants. Even small increments in net power or thermal efficiency and small changes in pollutant emissions have become significant concerns for both new designs and cycle modifications. To fulfill these requirements an accurate performance evaluation method which enables to see the effects on the exhaust gas composition is an important necessity. To fill this gap, a thermo-ecologic performance evaluation approach for gas turbine cycles with chemical equilibrium approximation which enables performance and environmental aspects to be considered simultaneously, is presented in this work. Steam injection is an effective modification to boost power and limit NOx emissions for gas turbine systems. Steam injection also increases thermal efficiency so less fuel is burnt to maintain the same power output. Because of its performance related and environmental advantages, presented approach is applied on the steam injected gas turbine cycle and a precise multi-criterion optimization is carried out for varying steam injection, as well as equivalence and pressure ratios. Irreversibilities and pressure losses are also considered. Effects of each parameter on the net work and thermal efficiency as well as non-equilibrium NOx and CO emissions are demonstrated. Precision improvement of the presented thermo-ecological model is shown and two main concerns; constant turbine inlet condition for higher net work output and constant net work output condition for lower fuel consumption are compared. - Highlights: • A thermodynamically precise performance estimation tool for GT cycles is presented. • STIG application is provided to show its flexibility for any GT cycle and diluents. • Constant TIT and net work output conditions have been compared and discussed. • The model provides results to evaluate economic and environmental aspects together. • It provides a

  12. Performance Assessment and Optimization of Biomass Steam Turbine Power Plants by Data Envelopment Analysis

    OpenAIRE

    Nattanin Ueasin; Anupong Wongchai; Sakkarin Nonthapot

    2015-01-01

    As rice husk is abundantly natural resource in Thailand, it has been used as the biomass energy resource in the stream turbine power plants, in particular to very small power producers (VSPPs). The VSPPs’ plants produced by rice husk is generally found in many regions of Thailand, however its performance efficiency and optimization has never been assessed at any level. This study aimed to fulfill this gap by adopting the method of data envelopment analysis (DEA) to relatively measure the perf...

  13. Parametric performance analysis of steam-injected gas turbine with a thermionic-energy-converter-lined combustor

    Science.gov (United States)

    Choo, Y. K.; Burns, R. K.

    1982-01-01

    The performance of steam-injected gas turbines having combustors lined with thermionic energy converters (STIG/TEC systems) was analyzed and compared with that of two baseline systems; a steam-injected gas turbine (without a TEC-lined combustor) and a conventional combined gas turbine/steam turbine cycle. Common gas turbine parameters were assumed for all of the systems. Two configurations of the STIG/TEC system were investigated. In both cases, steam produced in an exhaust-heat-recovery boiler cools the TEC collectors. It is then injected into the gas combustion stream and expanded through the gas turbine. The STIG/TEC system combines the advantage of gas turbine steam injection with the conversion of high-temperature combustion heat by TEC's. The addition of TEC's to the baseline steam-injected gas turbine improves both its efficiency and specific power. Depending on system configuration and design parameters, the STIG/TEC system can also achieve higher efficiency and specific power than the baseline combined cycle.

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

    Energy Technology Data Exchange (ETDEWEB)

    David Liscinsky

    2002-10-20

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

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

    Directory of Open Access Journals (Sweden)

    P V Aravind

    2012-07-01

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

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

    International Nuclear Information System (INIS)

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

  17. Development of biomass as an alternative fuel for gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Hamrick, J T [Aerospace Research Corp., Roanoke, VA (USA)

    1991-04-01

    A program to develop biomass as an alternative fuel for gas turbines was started at Aerospace Research Corporation in 1980. The research culminated in construction and installation of a power generation system using an Allison T-56 gas turbine at Red Boiling Springs, Tennessee. The system has been successfully operated with delivery of power to the Tennessee Valley Authority (TVA). Emissions from the system meet or exceed EPA requirements. No erosion of the turbine has been detected in over 760 hours of operation, 106 of which were on line generating power for the TVA. It was necessary to limit the turbine inlet temperature to 1450{degrees}F to control the rate of ash deposition on the turbine blades and stators and facilitate periodic cleaning of these components. Results of tests by researchers at Battelle Memorial Institute -- Columbus Division, give promise that deposits on the turbine blades, which must be periodically removed with milled walnut hulls, can be eliminated with addition of lime to the fuel. Operational problems, which are centered primarily around the feed system and engine configuration, have been adequately identified and can be corrected in an upgraded design. The system is now ready for development of a commercial version. The US Department of Energy (DOE) provided support only for the evaluation of wood as an alternative fuel for gas turbines. However, the system appears to have high potential for integration into a hybrid system for the production of ethanol from sorghum or sugar cane. 7 refs., 23 figs., 18 tabs.

  18. Emissions and Furnace Gas Temperature for Electricity Generation Via Co-Firing of Coal and Biomass

    OpenAIRE

    Shoaib Mehmood; Bale Reddy; Marc Rosen

    2015-01-01

    The emissions of carbon dioxide and nitrogen and sulphur oxides for electricity generation with coal and biomass co-firing are investigated and the furnace gas temperature assessed. The study uses simulation and considers fuel combinations based on two coals (bituminous coal, lignite) and four types of biomass (rice husk, sawdust, chicken litter, refused derived fuel). With increasing biomass, net CO2 emissions are seen to decline significantly for all types of selected biomass, while gross c...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  1. Technical and Economical Analysis of Regulation Methods for Intermediate Steam Over-Heating in Gas and Fuel Oil Boilers

    OpenAIRE

    V. I. Nazarov; E. V. Vakulich

    2014-01-01

    Various methods for temperature regulation of intermediate steam over-heating have been investigated. The most economical method, namely, smoke gas recirculation with regular water sprinkling from ПВД-8 drain has been selected in the paper.

  2. ABOUT THE MAINTENANCE OF THE RADIAL AND AXIAL SHAFT BEARINGS FROM PROPULSION PLANT WITH GAS AND STEAM TURBINES

    Directory of Open Access Journals (Sweden)

    ION ADRIAN GIRBA

    2016-06-01

    Full Text Available The paper presents the main rules imposed by classification societies for design the shaft for propulsion plant with gas and steam turbines. It also analyzes the main maintenance activities to ensure their safe operation.

  3. Feasibility Study on Steam and Gas Push with Dual Horizontal Wells in a Moderate-Depth Heavy Oil Reservoir

    Directory of Open Access Journals (Sweden)

    Jie Fan

    2016-02-01

    Full Text Available Non-condensable gas (NCG with steam co-injection makes steam assisted gravity drainage less energy-intensive as well as reduces greenhouse gas emission and water consumption. Numerous studies have shown that the technology called steam and gas push (SAGP is feasible for heavy oil and bitumen. However, most of these studies have focused on shallow heavy oil reservoirs and only a few works have investigated moderate-depth heavy oil reservoirs. In this study, laboratory experiments and numerical simulations were conducted to study shape change, steam chamber expansion, and temperature change after co-injecting NCG with steam into an actual moderate-depth heavy oil reservoir. Results showed that after co-injecting NCG with steam, the transverse expansion rate of the steam chamber accelerated, vertical expansion slowed down, thermal utilization increased, and oil–steam ratio improved. In addition, the injection parameters of SAGP were also optimized via numerical simulation, which indicated that SAGP could effectively improve development effect and recovery for moderate-depth heavy oil reservoirs.

  4. Experimental evaluation of energy efficiency in a gas-heated self-contained steam jacketed kettle

    International Nuclear Information System (INIS)

    Gas Technological Development Center (CDT de GAS) has developed a new gas-heated self-contained steam jacketed kettle as a solution for temperature-controlled cooking of pulp fruit in the Colombian traditional candy-making industry. This initiative seeks to contribute to the promotion of natural gas as a cleaner and more efficient alternative to traditional fuels such as wood and coal in the Andean countries. Prototype follows the operational and safety rules provided by international and local standards: ASTM-F1602, ASME (section VIII, division 1), and NTC-4082. This paper presents the methodology, experimental setup and results obtained during the performance tests for heating efficiency evaluation of the kettle, according to the ASTM-F1785 standard, and the estimation of measurement uncertainty according to GUM method. The heating efficiency rate for this new prototype is higher to the convectional and commercial models of gas heated self-contained steam jacketed kettle. The results showed a heating efficiency of 63.83% ± 1.66% (k=2), whereas the emission of CO and NOX in stack gases was under the regulate limits for natural gas equipment

  5. Thermo-economic analysis of a solid oxide fuel cell and steam injected gas turbine plant integrated with woodchips gasification

    International Nuclear Information System (INIS)

    This paper presents a thermo-economic analysis of an integrated biogas-fueled solid oxide fuel cell (SOFC) system for electric power generation. Basic plant layout consists of a gasification plant (GP), an SOFC and a retrofitted steam-injected gas turbine (STIG). Different system configurations and simulations are presented and investigated. A parallel analysis for simpler power plants, combining GP, SOFC, and hybrid gas turbine (GT) is carried out to obtain a reference point for thermodynamic results. Thermodynamic analysis shows energetic and exergetic efficiencies for optimized plant above 53% and 43% respectively which are significantly greater than conventional 10 MWe plants fed by biomass. Thermo-economic analysis provides an average cost of electricity for best performing layouts close to 6.4 and 9.4 c€/kWe which is competitive within the market. A sensitivity analysis of the influence of SOFC stack cost on the generation cost is also presented. In order to discuss the investment cost, an economic analysis has been carried out and main parameters such as Net Present Value (NPV), internal rate of return (IRR) and Time of Return of Investment (TIR) are calculated and discussed. - Highlights: • We model 14 different integrated syngas fueled SOFC systems targeting a power of 10 MWe. • Different STIG configurations are integrated with the SOFC plant. • Biomass gasification is integrated with the STIG and SOFC plants. • The best performing layouts achieve energy efficiencies in the range of 48.5–53.8%. • The thermo-economic analysis provides a minimum generation costs of 6.38 c€/kW h

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

    Science.gov (United States)

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

    2016-01-01

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

  7. Combined gas-steam power stations with pressurized fluidized bed combustion (PFBC) of coal

    Energy Technology Data Exchange (ETDEWEB)

    Grzegorczyk, W. (Energoprojekt, Warsaw (Poland))

    1990-11-01

    Presents pressurized fluidized bed combustion (PFBC) of coal that combines fluidized bed combustion with two-agent gas-steam circulation. PFBC permits clean combustion of coal with low calorific value and high ash and sulfur content. The ABB company offered a block for the Pruszkow power plant in Poland. Specifications of the block are given as: thermal power in fuel 430 MW and electrical power 175 MW. The boiler, gas turbine and turbine set are described. Technical and economic indices are given. The supplier attests that the emission values of 70 mg sulfur dioxide per MJ and 120 mg of nitrogen dioxide will not be exceeded under normal conditions.

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-09-01

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

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

    International Nuclear Information System (INIS)

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

  11. Methanol production from steel-work off-gases and biomass based synthesis gas

    International Nuclear Information System (INIS)

    Highlights: • The integration of a methanol synthesis process in steel plants increases the gas utilization efficiency. • Methanol produced by off-gases from steelmaking combined with biomass show competitive production costs versus petrol. • The integration of a methanol synthesis process in steel plants may reduce the specific CO2-emissions of the plant. - Abstract: Off-gases generated during steelmaking are to a large extent used as fuels in process units within the plant. The surplus gases are commonly supplied to a plant for combined heat and power production. The main objective of this study has been to techno-economically investigate the feasibility of an innovative way of producing methanol from these off-gases, thereby upgrading the economic value of the gases. Cases analyzed have included both off-gases only and mixes with synthesis gas, based on 300 MWth of biomass. The SSAB steel plant in the town of Luleå, Sweden has been used as a basis. The studied biomass gasification technology is based on a fluidized-bed gasification technology, where the production capacity is determined from case to case coupled to the heat production required to satisfy the local district heating demand. Critical factors are the integration of the gases with availability to the synthesis unit, to balance the steam system of the biorefinery and to meet the district heat demand of Luleå. The annual production potential of methanol, the overall energy efficiency, the methanol production cost and the environmental effect have been assessed for each case. Depending on case, in the range of 102,000–287,000 ton of methanol can be produced per year at production costs in the range of 0.80–1.1 EUR per liter petrol equivalent at assumed conditions. The overall energy efficiency of the plant increases in all the cases, up to nearly 14%-units on an annual average, due to a more effective utilization of the off-gases. The main conclusion is that integrating methanol production

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

    International Nuclear Information System (INIS)

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

  13. Experimental study on application of high temperature reactor excess heat in the process of coal and biomass co-gasification to hydrogen-rich gas

    International Nuclear Information System (INIS)

    The paper presents the results of the experimental study on the simulated application of HTR (High Temperature Reactor) excess heat in the process of allothermal co-gasification of coal and biomass. The laboratory scale installation with a fixed bed gasifier and auxiliary gasification agents pre-heating system, simulating the utilization of the HTR excess heat, were applied in the study. Steam and oxygen were the gasification media employed, and the process was focused on hydrogen-rich gas production. The results of the co-gasification of fuel blends of various biomass content at 800 °C and in various system configurations proved that the application of the simulated HTR excess heat in pre-heating of the gasification agents leads to the increase in the gaseous product yield. Furthermore, the HCA (Hierarchical Clustering Analysis) employed in the experimental data analysis revealed that the gasification of fuel blends of 20 and 40%w/w of biomass content results in higher volumes of the total gas, hydrogen, carbon monoxide and carbon dioxide than gasification of fuel blends of higher biomass content. - Highlights: • Simulated utilization of HTR excess heat in co-gasification of coal and biomass. • Assessment of three system configurations in terms of hydrogen production. • Application of the HCA in the experimental data set analysis. • Variation in gas components volume and content with fuel blend composition

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

    International Nuclear Information System (INIS)

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

  15. Improved yield parameters in catalytic steam gasification of forestry residue; optimizing biomass feed rate and catalyst type

    Energy Technology Data Exchange (ETDEWEB)

    Corujo, Andrea; Yerman, Luis; Arizaga, Beatriz; Brusoni, Mariana; Castiglioni, Jorge [Laboratorio de Fisicoquimica de Superficies, DETEMA Facultad de Quimica, Universidad de la Republica, Gral. Flores 2124, CC 1157, 11800-Montevideo (Uruguay)

    2010-12-15

    The catalytic gasification (900 C) of forestry industry residue (Eucalyptus saligna) was laboratory-studied. Biomass feed rate and type and amount of catalyst were assayed for their effect on the gasified product composition and the overall energy yield of the gasification reaction. The use of a calcined dolomite catalyst resulted in a combustible gas mixture of adequate calorific power (10.65 MJ m{sup -3}) for use as fuel, but neither the product gas composition nor the energy yield varied significantly with widely different amounts of the catalyst (2 g and 20 g). The use of NiO-loaded calcined dolomite catalysts did not affect the product gas composition significantly but led to a 30% increase in the total product gas volume and to a reduction in the rate of tar and char formation. The catalyst loaded with the smallest amount of NiO studied (0.4 wt%. Ni/Dol) led to the highest energy yield (21.50 MJ kg{sup -1} on a dry-wood basis) based on the use of the gasified product as fuel. The gasified product was found to have an adequate H{sub 2}/CO molar ratio and H{sub 2} content for use as synthesis gas source and partial source of H{sub 2}. (author)

  16. Entrained Flow Gasification of Biomass

    DEFF Research Database (Denmark)

    Qin, Ke

    The present Ph. D. thesis describes experimental and modeling investigations on entrained flow gasification of biomass and an experimental investigation on entrained flow cogasification of biomass and coal. A review of the current knowledge of biomass entrained flow gasification is presented....... Biomass gasification experiments were performed in a laboratory-scale atmospheric pressure entrained flow reactor with the aim to investigate the effects of operating parameters and biomass types on syngas products. A wide range of operating parameters was involved: reactor temperature, steam/carbon ratio......, excess air ratio, oxygen concentration, feeder gas flow, and residence time. Wood, straw, and lignin were used as biomass fuels. In general, the carbon conversion was higher than 90 % in the biomass gasification experiments conducted at high temperatures (> 1200 °C). The biomass carbon that was not...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    Highlights: • The energy demand of a North Sea platform is systematically analysed. • The integration of steam bottoming cycles is investigated, considering energy, economic and environmental criteria. • The fuel gas consumption and total CO2-emissions can be reduced by more than 15%. - Abstract: The integration of steam bottoming cycles on oil and gas platforms is currently regarded as the most promising option for improving the performance of these energy-intensive systems. In this paper, a North Sea platform is taken as case study, and a systematic analysis of its energy requirements is conducted. The site-scale integration of steam networks is evaluated, based on thermodynamic, economic and environmental performance indicators. The penalties induced by operational restrictions such as (i) the use of a heat transfer loop, (ii) the demand for a heat buffer, (iii) the selection of a specific cooling utility, and (iv) the weight limitations on the platform are quantitatively assessed. The results illustrate the benefits of converting the gas turbine process into a combined cycle, since the fuel gas consumption and the total CO2-emissions can be reduced by more than 15%. Using the cooling water from the processing plant reveals to be more profitable than using seawater, as the additional pumping power outweighs the benefit of using a cooling medium at a temperature of about 8 °C lower. This study highlights thereby the importance of analysing energy savings and recovery options at the scale of the entire platform, rather than at the level of the utility plant solely

  19. Model performance of a biomass-fueled power station with variable furnace exit gas temperature to control fouling deposition

    Science.gov (United States)

    Yomogida, David Edwin

    A major problem associated with the utilization of any biomass fuel in direct-combustion energy production is fouling (ash deposition on boiler surfaces) and the related issue of slagging, resulting from transformations among the inorganic constituents of the fuel. These deposits reduce heat transfer from the fire- to water-side, reducing power plant efficiency and necessitating the design of more tolerant heat exchange equipment. Wood: currently serves as the major source of fuel in biomass conversion to energy because of its more general availability, and it suffers less from fouling and slagging than many other biomass fuels such as rice straw. To reduce fouling severity, furnace exit gas temperature (FEGT) may be decreased to solidify ash ahead of superheaters and other heat exchanger equipment. Thermal and economic computer models of a direct-combustion Rankine cycle power plant were developed to predict the impact of variable FEGT and overall heat transfer coefficient on power plant efficiency and economy. No attempt was made to model the fire-side processes leading to the formation of fouling deposits. A base case: operational and economic profile of a biomass power plant was established, and models, were executed using these parameters, approximating a power plant efficiency of 19.9% and a cost of electricity (COE) of 0.0636 kWh-1 (including capital costs). If no capital, costs are included, then COE is 0.0205 kWh-1. Sensitivity analyses were performed on power plant efficiency and COE. Changes in FEGT through variable excess air resulted in substantial sensitivity in power plant efficiency (plant efficiency of 21.4% for FEGT of 1030°C (5% excess air) and 18.7% for 924°C (55% excess air)). Plant efficiency was determined to be moderately sensitive to changes in overall heat transfer coefficient on the secondary superheater (18.7% for no heat transfer through secondary superheater and 19.9% for base case heat transfer). Fouling scenarios showed that FEGT

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Kinya Sakanishi

    2012-05-01

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

  2. [Flue gas desulfurization by a novel biomass activated carbon].

    Science.gov (United States)

    Liu, Jie-Ling; Tang, Zheng-Guang; Chen, Jie; Jiang, Wen-Ju; Jiang, Xia

    2013-04-01

    A novel biomass columnar activated carbon was prepared from walnut shell and pyrolusite was added as a catalyst. The activated carbon prepared was used for flue gas desulphurization in a fixed-bed reactor with 16 g of activated carbon. The impact of operating parameters such as SO2 inlet concentration, space velocity, bed temperature, moisture content and O2 concentration on the desulfurization efficiency of activated carbon was investigated. The results showed that both the breakthrough sulfur capacity and breakthrough time of activated carbon decreased with the increase of SO2 inlet concentration within the range of 0.1% -0.3%. The breakthrough sulfur capacity deceased with the increase of space velocity, with optimal space velocity of 600 h(-1). The optimal bed temperature was 80 degrees C, and the desulfurization efficiency can be reduced if the temperature continue to increase. The presence of moisture and oxygen greatly promoted the adsorption of SO2 onto the activated carbon. The best moisture content was 10%. When the oxygen concentrations were between 10% and 13%, the desulfurization performance of activated carbon was the highest. Under the optimal operating conditions, the sulfur capacity of activated carbon was 252 mg x g(-1), and the breakthrough time was up to 26 h when the SO2 inlet concentration was 0.2%. PMID:23798152

  3. Emissions and Furnace Gas Temperature for Electricity Generation Via Co-Firing of Coal and Biomass

    Directory of Open Access Journals (Sweden)

    Shoaib Mehmood

    2015-12-01

    Full Text Available The emissions of carbon dioxide and nitrogen and sulphur oxides for electricity generation with coal and biomass co-firing are investigated and the furnace gas temperature assessed. The study uses simulation and considers fuel combinations based on two coals (bituminous coal, lignite and four types of biomass (rice husk, sawdust, chicken litter, refused derived fuel. With increasing biomass, net CO2 emissions are seen to decline significantly for all types of selected biomass, while gross carbon dioxide emissions increase for all blends except bituminous coal/refuse derived fuel, lignite/chicken litter and lignite/refuse derived fuel. The reductions in emissions of nitrogen and sulphur oxides are dependent on the contents of nitrogen and sulphur in the biomass. The results also show for all fuel combinations that increasing the biomass proportion decreases the furnace exit gas temperature.

  4. Steam Reforming of Dimethyl Ether by Gliding Arc Gas Discharge Plasma for Hydrogen Production

    Institute of Scientific and Technical Information of China (English)

    王保伟; 孙启梅; 吕一军; 杨美琳; 闫文娟

    2014-01-01

    Gliding arc gas discharge plasma was used for the generation of hydrogen from steam reforming of di-methyl ether (DME). A systemic procedure was employed to determine the suitable experimental conditions. It was found that DME conversion first increased up to the maximum and then decreased slightly with the increase of added water and air. The increase of total feed gas flow rate resulted in the decrease of DME conversion and hy-drogen yield, but hydrogen energy consumption dropped down to the lowest as total feed gas flow rate increased to 76 ml·min-1. Larger electrode gap and higher discharge voltage were advantageous. Electrode shape had an impor-tant effect on the conversion of DME and production of H2. Among the five electrodes, electrode 2# with valid length of 55 mm and the radian of 34 degrees of the top electrode section was the best option, which enhanced ob-viously the conversion of DME.

  5. Biomass-to-electricity: analysis and optimization of the complete pathway steam explosion--enzymatic hydrolysis--anaerobic digestion with ICE vs SOFC as biogas users.

    Science.gov (United States)

    Santarelli, M; Barra, S; Sagnelli, F; Zitella, P

    2012-11-01

    The paper deals with the energy analysis and optimization of a complete biomass-to-electricity energy pathway, starting from raw biomass towards the production of renewable electricity. The first step (biomass-to-biogas) is based on a real pilot plant located in Environment Park S.p.A. (Torino, Italy) with three main steps ((1) impregnation; (2) steam explosion; (3) enzymatic hydrolysis), completed by a two-step anaerobic fermentation. In the second step (biogas-to-electricity), the paper considers two technologies: internal combustion engines and a stack of solid oxide fuel cells. First, the complete pathway has been modeled and validated through experimental data. After, the model has been used for an analysis and optimization of the complete thermo-chemical and biological process, with the objective function of maximization of the energy balance at minimum consumption. The comparison between ICE and SOFC shows the better performance of the integrated plants based on SOFC. PMID:22940353

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

    International Nuclear Information System (INIS)

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

  7. Reactivity Effect Of Steam / Water Ingress in Generation-IV Gas-Cooled Fast Reactor Core

    International Nuclear Information System (INIS)

    This paper presents a static neutronic calculational study of steam/water ingress into a Gas-cooled Fast Reactor (GFR Generation IV) core performed by using three Monte-Carlo codes, namely SERPENT version 1.1-16, KENO-VI module of the SCALE, MCNPX version 2.7.0, and different modern nuclear data libraries, i.e. JEFF-3.1, JEFF-3.1.1 and ENDF/B-VII. The analysis was performed for a wide range of water/steam densities [0 – 1.0 g/cm3] within the core and the neutronic parameters were compared between the different codes and libraries. The obtained results demonstrate that this accidental event would result in a large negative reactivity insertion. The main reason of such core behaviour was found to be an increased neutron absorption rate in the cladding liner made of refractory metals (W and Re) due to the neutron spectrum thermalisation resulting from the steam/water ingress. (author)

  8. Structure interaction due to thermal bowing of shrouds in steam generator of gas-cooled reactor

    International Nuclear Information System (INIS)

    The design of the gas-cooled reactor steam generators includes a tube bundle support plate system which restrains and supports the helical tubes in the steam generator. The support system consists of an array of radially oriented, perforated plates through which the helical tube coils are wound. These support plates have tabs on their edges which fit into vertical slots in the inner and outer shrouds. When the helical tube bundle and support plates are installed in the steam generator, they most likely cannot fit evenly between the inner and outer shrouds. This imperfection leads to different gaps between two extreme sides of the tube bundle and the shrouds. With different gaps through the tube bundle height, the helium flow experiences different cooling effects from the tube bundle. Hence, the temperature distribution in the shrouds will be non-uniform circumferentially since their surrounding helium flow temperatures are varied. These non-uniform temperatures in the shrouds result in the phenomenon of thermal bowing of shrouds

  9. Safety aspect of high temperature nuclear reactor application for natural gas steam reforming

    International Nuclear Information System (INIS)

    An assessment of the safety aspect of high temperature nuclear reactor application for natural gas steam reforming has been carried out. The basic safety aspect associated with nuclear coupling to chemical process is to prevent the release of radioactive materials to the environment and or the chemical process. In utilizing nuclear heat for chemical process, intermediate heat exchanger (IHX) is used as an interface that separates nuclear and non nuclear zones. IHX is helium-helium heat exchanger in which the primary helium (905oC) coming out from the reactor, and transfer its heat to the secondary helium gas (890oC). To prevent possible release of radioactive materials from nuclear zone, balanced pressure is applied. The pressure of chemical process (4.5 MPa) is designed to be higher than the pressure of secondary helium (4.1 MPa) or primary helium (4 MPa). The design of balance pressure and the use of IHX cause some inferior condition of the nuclear heated reformer since the lower temperature (~800oC) reaches catalyst tube of reformer. This condition gives impact on lower thermal efficiency (~50%) compared to the fossil-fuelled plant (80-85%). Some modification in design and operation, such as: selecting the bayonet type of reformer equipped with orifice baffle, and enhancing heat utilization, can improve the lack of condition and are capable to increase the thermal efficiency of nuclear heated natural gas steam reformer to reach about 78%. (author)

  10. The Analysis of Initial Parameters of Steam in the Combined-Cycle Plant with High Temperature Gas Turbine

    Directory of Open Access Journals (Sweden)

    Uvarov Artem

    2015-01-01

    Full Text Available Presents the results of studying the influence of initial steam parameters on the thermal efficiency of double-circuit combined-cycle plant based on a powerful high-temperature gas turbines of the last generation. The advantages of double-circuit combined-cycle plant without reheat in comparison with more complex schemes. Found optimal thermal efficiency values of initial parameters of steam.

  11. Impact study on the use of biomass-derived fuels in gas turbines for power generation

    Energy Technology Data Exchange (ETDEWEB)

    Moses, C A; Bernstein, H [Southwest Research Inst., San Antonio, TX (United States)

    1994-01-01

    This report evaluates the properties of fuels derived from biomass, both gaseous and liquid, against the fuel requirements of gas turbine systems for gernating electrical power. The report attempts to be quantitative rather than merely qualitative to establish the significant variations in the properties of biomass fuels from those of conventional fuels. Three general categories are covered: performance, durability, and storage and handling.

  12. Wet scrubbing of biomass producer gas tars using vegetable oil

    Science.gov (United States)

    Bhoi, Prakashbhai Ramabhai

    The overall aims of this research study were to generate novel design data and to develop an equilibrium stage-based thermodynamic model of a vegetable oil based wet scrubbing system for the removal of model tar compounds (benzene, toluene and ethylbenzene) found in biomass producer gas. The specific objectives were to design, fabricate and evaluate a vegetable oil based wet scrubbing system and to optimize the design and operating variables; i.e., packed bed height, vegetable oil type, solvent temperature, and solvent flow rate. The experimental wet packed bed scrubbing system includes a liquid distributor specifically designed to distribute a high viscous vegetable oil uniformly and a mixing section, which was designed to generate a desired concentration of tar compounds in a simulated air stream. A method and calibration protocol of gas chromatography/mass spectroscopy was developed to quantify tar compounds. Experimental data were analyzed statistically using analysis of variance (ANOVA) procedure. Statistical analysis showed that both soybean and canola oils are potential solvents, providing comparable removal efficiency of tar compounds. The experimental height equivalent to a theoretical plate (HETP) was determined as 0.11 m for vegetable oil based scrubbing system. Packed bed height and solvent temperature had highly significant effect (p0.05) effect on the removal of model tar compounds. The packing specific constants, Ch and CP,0, for the Billet and Schultes pressure drop correlation were determined as 2.52 and 2.93, respectively. The equilibrium stage based thermodynamic model predicted the removal efficiency of model tar compounds in the range of 1-6%, 1-4% and 1-2% of experimental data for benzene, toluene and ethylbenzene, respectively, for the solvent temperature of 30° C. The NRTL-PR property model and UNIFAC for estimating binary interaction parameters are recommended for modeling absorption of tar compounds in vegetable oils. Bench scale

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

    DEFF Research Database (Denmark)

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

    The technical requirements and the economical assessment of converting commercial diesel engine gen-sets into high compression spark ignition operation on biomass producer gas have been investigated. Assessments showed that for a 200 kWe gen-set there would be a financial benefit of approximately...... this specific biomass producer gas. The results showed an increase in the electrical efficiency from 30% to 34% when the compression ratio was increased....

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

    Science.gov (United States)

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

  15. Design and Performance Experiments of Biomass Briquette Chain Steam Boiler%生物质成型燃料链条蒸汽锅炉的设计和性能试验

    Institute of Scientific and Technical Information of China (English)

    王鹏晓; 刘圣勇; 夏许宁; 翟万里; 管泽运; 刘霞

    2016-01-01

    根据生物质成型燃料挥发分含量高、固定碳含量低和灰渣熔融性强的特点,设计了工作压力1.25 MPa、额定出口蒸汽温度194℃的链条蒸汽锅炉.该锅炉拥有独特的多拱炉膛结构和二次风配风系统,实现生物质成型燃料的气相多段燃烧和固相低强度燃烧,提高燃烧稳定性.试验表明:该锅炉的热效率达82.79%,烟气中颗粒物、二氧化硫、氮氧化物等污染物排放浓度均低于锅炉大气污染物排放标准的限值,锅炉具有良好的热效率和环保效益.%According to high volatile content,low fixed carbon content and low ash melting of biomass briquette, the chain-steam boiler with working pressure of 1.25 MPa and rated outlet steam temperature of 194℃is designed. This boiler has special multi-arch furnace structure and air distribution systems,which achieves biomass briquette's gas multi-segment combustion and the low intensity combustion of solid phase,improving combustion stability. The test results show that thermal efficiency of the boiler reaches to 82.79%,and the pollutant emission concentration of flue gas is lower than the boiler air pollutant emission standards limits. The boiler has a good thermal efficiency and environmental benefits.

  16. Basic characteristics of heat-exchanger type steam reformer heated by high temperature helium gas, (2)

    International Nuclear Information System (INIS)

    A computer simulation model has been developed to analyze the basic characteristics of heat-exchanger type steam-methane reformer which is the key component to produce hydrogen using the nuclear process heat from high temperature gas cooled reactor. This model is based on the one-dimensional one taking account of heat transfer and reaction kinetics. In the previous report, the analytical model and the solution procedure have been described, and an example of calculation result has been shown compared with the experimental data in reference. This report describes simulation results of the dependencies of the characteristic quantities such as heat flux, reaction rates and hydrogen production rate in reformer tube on selected parameters, namely, the operating conditions (inlet gas temperatures, pressure and flow rates), the activities of the catalyst, the heat transfer rate and the dimensions of reaction tube. (author)

  17. The potential for biomass to mitigate greenhouse gas emissions in the Northeastern US

    Energy Technology Data Exchange (ETDEWEB)

    Bernow, S.S.; Gurney, K.; Prince, G.; Cyr, M.

    1992-04-01

    This study, for the Northeast Regional Biomass Program (NRBP) of the Coalition of Northeast Governors (CONEG), evaluates the potential for local, state and regional biomass policies to contribute to an overall energy/biomass strategy for the reduction of greenhouse gas releases in the Northeastern United States. Biomass is a conditionally renewable resource that can play a dual role: by reducing emissions of greenhouse gases in meeting our energy needs; and by removing carbon from the atmosphere and sequestering it in standing biomass stocks and long-lived products. In this study we examine the contribution of biomass to the energy system in the Northeast and to the region's net releases of carbon dioxide and methane, and project these releases over three decades, given a continuation of current trends and policies. We then compare this Reference Case with three alternative scenarios, assuming successively more aggressive efforts to reduce greenhouse gas emissions through strategic implementation of energy efficiency and biomass resources. Finally, we identify and examine policy options for expanding the role of biomass in the region's energy and greenhouse gas mitigation strategies.

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

    International Nuclear Information System (INIS)

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

  19. Small-scale power/heat production based on biomass

    International Nuclear Information System (INIS)

    Conventional energy production from biomass is most often used to produce steam, hot water or air heating. According to this conference paper, the maximum electric output is obtained in processes based on gasification of biomass in combined gas turbine/steam turbine systems. The efficiency increases with increasing plant size. Production cost decreases with increasing plant size. However, large plants producing 20 MW electric also produce 30 MW heat energy which must be utilized if the total efficiency is to be large. There is a potential for small systems (3 - 5 kw electric) for decentralized power/heat production. The paper surveys in brief various technologies for small-scale power/heat plants based on biomass: steam turbine, steam engine, gas turbine, Stirling engine, diesel engine/gas engine. 9 refs., 5 figs

  20. Comparative Analysis of a Power Plant Comprising One Gas and One Steam Turbine with respect to Two Types of Inspection

    Directory of Open Access Journals (Sweden)

    Dalip Singh

    2014-06-01

    Full Text Available Comparative analysis between two models is made with respect to two types of inspection in the present paper. The two models (Model 1 and Model 2 considered are on a gas turbine power plant comprising one gas turbine and one steam turbine with the difference in the type of inspection. Model 1 considers the scheduled inspection whereas random inspection is considered in Model 2. Initially, both the units i.e. the gas turbine as well as the steam turbine are operating. On failure of the gas turbine, system goes to down state, whereas on failure of the steam turbine, the system may be kept in the up state with only gas turbine working if the buyer of the power so generated is ready to pay higher amount or otherwise put to down state. When only the gas turbine is operative and the steam turbine is failed, this type of working of the system is called working in the Single Cycle; whereas when both the units are operative then it is called the Combined Cycle. Expressions for various measures of system effectiveness and cost-benefit analysis for Model 1 were obtained by [1] but with no computational work. Here the computational work has been done for Model 1 and with interesting conclusions. Also, this model has been compared with the model wherein the random inspection is carried out. System is analyzed by making use of semi - Markov processes and regenerative point technique.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

    The Laboratory for Thermal Power Engineering of the Delft University of Technology is participating in an EU-funded, international R + D project which is designed to aid European industry in addressing issues regarding pressurised combustion of biomass-derived, low calorific flue fuel gas. The objects of the project are: To design, manufacture and test a pressurised, high temperature gas turbine combustor for biomass derived LCV fuel gas; to develop a steady-state and dynamic model describing a combustor using biomass-derived, low calorific value fuel gases; to gather reliable experimental data on the steady-state and dynamic characteristics of the combustor; to study the steady-state and dynamic plant behaviour using a plant layout wich incorporates a model of a gas turbine suitable for operation on low calorific value fuel gas. (orig)

  2. Dependence of the boiler flue gas losses on humidity of wood biomass

    Directory of Open Access Journals (Sweden)

    Dzurenda Ladislav

    2015-12-01

    Full Text Available The paper analyzes the influence of humidity of combusted wood biomass on the flue gas losses. A mathematical relation between flue gas losses of the boiler on wood biomass humidity is presented as well as temperature of flue gas emitted from the boiler into the atmosphere. The limits of model application for the humidity of wood biomass falls into the interval 10–60% whereas the range of temperatures of flue gases emitted from the boiler to the atmosphere is 120–200 °C. The influence of the humidity of wood biomass has an adverse effect on increasing the extent of the boiler flue gas losses and thus inefficiency of the heat production. The increase of the wood biomass humidity from the value of 10% to 60% with the outlet temperature of flue gases from the boiler 120 °C causes an increase in flue gas loss of the boiler from the value 8.37% to 12.43%, similarly the increase of flue gas loss by 200 °C from 15.19% to 22.55%, or the increase of the flue gas loss by 7.36%.

  3. Dependence of the boiler flue gas losses on humidity of wood biomass

    Science.gov (United States)

    Dzurenda, Ladislav; Banski, Adrián

    2015-12-01

    The paper analyzes the influence of humidity of combusted wood biomass on the flue gas losses. A mathematical relation between flue gas losses of the boiler on wood biomass humidity is presented as well as temperature of flue gas emitted from the boiler into the atmosphere. The limits of model application for the humidity of wood biomass falls into the interval 10-60% whereas the range of temperatures of flue gases emitted from the boiler to the atmosphere is 120-200 °C. The influence of the humidity of wood biomass has an adverse effect on increasing the extent of the boiler flue gas losses and thus inefficiency of the heat production. The increase of the wood biomass humidity from the value of 10% to 60% with the outlet temperature of flue gases from the boiler 120 °C causes an increase in flue gas loss of the boiler from the value 8.37% to 12.43%, similarly the increase of flue gas loss by 200 °C from 15.19% to 22.55%, or the increase of the flue gas loss by 7.36%.

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

    International Nuclear Information System (INIS)

    Advanced Gas Cooled Reactors (AGRS) employ once-through steam Generators of unique design to provide steam at approximately 530 degrees C and 155 bar to steam turbines of similar design to those of fossil plants. The steam generators are highly compact, and have either a serpentine or helical tube geometry. The tubes are heated on the outside by hot C02 gas, and steam is generated on the inside of the tubes. Each individual steam generator tube consists of a carbon steel feed and primary economiser section, a 9%Cr steel secondary economiser, evaporator and primary superheater, and a Type 316L austenitic stainless steel secondary superheater, all within a single tube pass. The multi-material nature of the individual tube passes, the need to maintain specific thermohydraulic conditions within the different material sections, and the difficulties of steam generator inspection and repair, have required extensive corrosion-chemistry test programmes to ensure waterside corrosion does not present a challenge to their integrity. A major part of these programmes has been the use of a full scale steam generator test facility capable of simulating all aspects of the waterside conditions which exist in the plant. This facility has been used to address a wide variety of possible plant drainage/degradation processes. These include; single- and two-phase flow accelerated corrosion of carbon steel, superheat margins requirements and the stress-corrosion behaviour of the austenitic superheaters, on-load corrosion of the evaporator materials, and iron transport and oxide deposition behaviour. The paper outlines a number of these, and indicates how they have been of value in helping to maintain reliable operation of the plant. (author)

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

    International Nuclear Information System (INIS)

    This paper describes the experimental and analytical investigations of the gas-side heat transfer and flow characteristics of steam generators in the AGR stations carried out by CERL. The majority of the experimental work on heat transfer and flow characteristics of close-packed tube arrangements in cross-flow of gases is carried out in a pressurised heat exchanger rig. The rig is operated on-line by a dedicated PDP 11/40 computer over the range of Reynolds number 104 to 3x105. Atmospheric wind tunnels employing either small or large scale models of the specific sections of steam generators are used for a variety of supplementary and development studies. Various measurements techniques and, in particular, LDA and hot wire anemometry employed in these studies are described. The more important aspects of various investigations are illustrated by typical results. In order to ensure the efficient operation and integrity of steam generators under asymmetric boundary conditions a MIX suite of 2-dimensional codes has been developed. The codes calculate the gas and water/steam flow and temperature distributions in each channel of the steam generator taking into account thermal mixing in the gas as it passes through the generator. Application of the MIX codes to the solution of various operational problems is illustrated by typical examples and the continuing exercise of validating the codes against plant operational data is discussed. (author)

  6. Thermodynamic analysis of a tri-generation system based on micro-gas turbine with a steam ejector refrigeration system

    International Nuclear Information System (INIS)

    In the present work, performance of new configuration of Micro-gas turbine cogeneration and tri-generation systems, with a steam ejector refrigeration system and Heat recovery Steam Generator (HRSG) are studied. A micro-gas turbine cycle produces 200 KW power and exhaust gases of this micro-gas turbine are recovered in an HRSG. The main part of saturated steam in HRSG is used through a steam ejector refrigeration system to produce cooling in summer. In winter, this part of saturated steam is used to produce heating. In the first part of this paper, performance evaluation of this system with respect to Energy Utilization Factor (EUF), Fuel Energy Saving Ratio (FESR), thermal efficiency, pinch point temperature difference, net power to evaporator cooling load and power to heat ratio is carried out. It has been shown that by using the present cogeneration system, one can save fuel consumption from about 23% in summer up to 33% in winter in comparison with separate generation of heating, cooling and electricity. In the second part of this paper, exergy analysis of the system has been done. It has been shown that combustion chamber; HRSG and heat exchanger are recognized as the largest sources of exergy losses respectively.

  7. Removal of ammonia from producer gas in biomass gasification: integration of gasification optimisation and hot catalytic gas cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Hongrapipat, Janjira; Saw, Woei-Lean; Pang, Shusheng [University of Canterbury, Department of Chemical and Process Engineering, Christchurch (New Zealand)

    2012-12-15

    Ammonia (NH{sub 3}) is one of the main contaminants in the biomass gasification producer gas, which is undesirable in downstream applications, and thus must be removed. When the producer gas is used in integrated gasification combined cycle (IGCC) technology, NH{sub 3} is the main precursor of nitrogen oxides (NO{sub x}) formed in gas turbine, whereas in Fischer-Tropsch synthesis and in integrated gasification fuel cell (IGFC) technology, the NH{sub 3} gas poisons the catalysts employed. This paper presents a critical review on the recent development in the understanding of the NH{sub 3} formation in biomass gasification process and in the NH{sub 3} gas cleaning technologies. The NH{sub 3} gas concentration in the producer gas can firstly be reduced by the primary measures taken in the gasification process by operation optimisation and using in-bed catalytic materials. Further removal of the NH{sub 3} gas can be implemented by the secondary measures introduced in the post-gasification gas-cleaning process. Focus is given on the catalytic gas cleaning in the secondary measures and its advantages are analysed including energy efficiency, impacts on environment and recyclability of the catalyst. Based on the review, the most effective cleaning process is proposed with integration of both the primary and the secondary measures for application in a biomass gasification process. (orig.)

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

    International Nuclear Information System (INIS)

    The conventional biomass pyrolysis/gasification process for production of medium heating value gas for industrial or civil applications faces two disadvantages, i.e. low gas productivity and the accompanying corrosion of downstream equipment caused by the high content of tar vapour contained in the gas phase. The objective of this paper is to overcome these disadvantages, and therefore, the effects of the operating parameters on biomass pyrolysis are investigated in a laboratory setup based on the principle of keeping the heating value of the gas almost unchanged. The studied parameters include reaction temperature, residence time of volatile phase in the reactor, physico-chemical pretreatment of biomass particles, heating rate of the external heating furnace and improvement of the heat and mass transfer ability of the pyrolysis reactor. The running temperature of a separate cracking reactor and the geometrical configuration of the pyrolysis reactor are also studied. However, due to time limits, different types of catalysts are not used in this work to determine their positive influences on biomass pyrolysis behaviour. The results indicate that product gas production from biomass pyrolysis is sensitive to the operating parameters mentioned above, and the product gas heating value is high, up to 13-15 MJ/N m3

  9. Thermodynamic analysis of gassteam combined cycle with carbon dioxide (CO2 emissions saving

    Directory of Open Access Journals (Sweden)

    Alka Gupta, Om Prakash, S.K. Shukla

    2011-03-01

    Full Text Available In this paper, cogeneration or combined heat and power (CHP cycle has been analyzed in order to improve the efficiency of the gassteam combined cycle and utilization of waste heat. The efficiency of the combined cycle is improved by decreasing the compressor inlet temperature (CIT and increasing the turbine inlet temperature (TIT. It is observed that the cycle offers the advantage of making efficient use of the energy available in the fuel and in turn, eliminate some portion of pollution associated with the power generation. The study also reveals that if this cycle is being employed for cogeneration, there is a significant saving (11.60% in the amount of Carbon dioxide (CO2 emitted by the coal-fired thermal power plants.

  10. Optimization of heat recovery steam generators for combined cycle gas turbine power plants

    Energy Technology Data Exchange (ETDEWEB)

    Valdes, M. [Universidad Politecnica de Madrid (Spain). Departamento de Ingenieria Energetica y Fluidomecanica; Rapun, J.L. [IBERDROLA Ingenieria y Consultoria, Madrid (Spain)

    2001-08-01

    The heat recovery steam generator (HRSG) is one of the few components of combined cycle gas turbine power plants tailored for each specific application. Any change in its design would directly affect all the variables of the cycle and therefore the availability of tools for its optimization is of the greatest relevance. This paper presents a method for the optimization of the HRSG based on the application of influence coefficients. The influence coefficients are a useful mathematical tool in design optimization problems. They are obtained after solving the equations of the system through the Newton-Raphson method. The main advantage of the proposed method is that it permits a better understanding of the influence of the design parameters on the cycle performance. The study of the optimization of the distribution of the boiler area between its different components is presented as an example of the proposed technique. (author)

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

    Science.gov (United States)

    Nainiger, J. J.

    1978-01-01

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

  12. Technical and Economical Analysis of Regulation Methods for Intermediate Steam Over-Heating in Gas and Fuel Oil Boilers

    Directory of Open Access Journals (Sweden)

    V. I. Nazarov

    2014-06-01

    Full Text Available Various methods for temperature regulation of intermediate steam over-heating have been investigated. The most economical method, namely, smoke gas recirculation with regular water sprinkling from ПВД-8 drain has been selected in the paper.

  13. Determination of Fuel Consumption Indexes of Co-generation Combined Cycle Steam and Gas Units with unfired waste heat boilers

    OpenAIRE

    S. A. Kachan; V. I. Filazafovich; A. N. Dubravenski

    2014-01-01

    The paper presents the developed methodology and the results of determination of fuel consumption indexes of co-generation combined cycle steam and gas units (PGU) with unfired waste heat boilers apply to PGU-230 of 3-d co-generation power plant ofMinsk. 

  14. Determination of Fuel Consumption Indexes of Co-generation Combined Cycle Steam and Gas Units with unfired waste heat boilers

    Directory of Open Access Journals (Sweden)

    S. A. Kachan

    2014-07-01

    Full Text Available The paper presents the developed methodology and the results of determination of fuel consumption indexes of co-generation combined cycle steam and gas units (PGU with unfired waste heat boilers apply to PGU-230 of 3-d co-generation power plant ofMinsk. 

  15. Analysis of Indirectly Fired Gas Turbine for Wet Biomass Fuels Based on commercial micro gas turbine data

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Qvale, Einar Bjørn

    2002-01-01

    The results of a study of a novel gas turbine configuration is being presented. In this power plant, an Indirectly Fired Gas Turbine (IFGT), is being fueled with very wet biomass. The exhaust gas is being used to dry the biomass, but instead of striving to recover as much as possible of the thermal...... turbines. The study shows that the novel configuration, in which an IFGT and a drying unit have been combined, has considerable merit, in that its performance exceeds that of the currently available methods converting wet biomass to electric power by a factor of five. The configuration also has clear...... energy, which has been the practice up to now, the low temperature exhaust gases after having served as drying agent, are lead out into the environment; a simple change of process integration that has a profound effect on the performance. Four different cycles have been studied. These are the Simple IFGT...

  16. Opportunities for Green Gas. Competition of Green Gas with other Biomass Options; Kansen voor Groen Gas. Concurrentie Groen Gas met andere biomassa opties

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-04-15

    Green biogas seems to be an interesting option to make the Dutch economy, with a large share of gas in the energy system, more sustainable. Biomass that is used as feedstock for biogas can also be deployed for the production of Electricity, biodiesel, bio-ethanol, bio-plastics, bio-chemical products and even bio-steel. This memo compares the main characteristics of biomass uses for production of gas with alternative uses in other sectors. The comparison shows that wet biomass flows in particular (e.g. manure and KGW) are suitable for conversion in biogas. This leads to a potential of 1 to 1.5 billion Nm{sup 3} of gas in 2020. Gasification of dry biomass may also become interesting in the future. However, this fuel is subjected to fierce competition with the electricity sector, which can use solid biomass for combustion purposes. Moreover, the steel, chemical and transport sector may also be able to use the feedstock in time. [Dutch] Groen biogas lijkt een interessante optie om de Nederlandse economie met veel gas in de energievoorziening te verduurzamen. Biomassa dat als grondstof voor biogas dient kan echter ook ingezet worden voor productie van elektriciteit, biodiesel, bio-ethanol, bioplastics, biochemie en zelfs biostaal. In deze notitie zijn de kenmerken van biomassagebruiken voor het maken van gas vergeleken met de mogelijkheden in andere sectoren. Uit deze vergelijking blijkt dat met name natte biomassastromen (bijvoorbeeld mest en GFT) geschikt zijn voor conversie in biogas. Dat levert een potentieel op van 1 tot 1,5 miljard Nm{sup 3} gas in 2020. Het zou kunnen dat ook vergassing van droge biomassa op termijn interessant wordt. Voor deze grondstof is er echter een stevige competitie met de elektriciteitssector die vaste biomassa via verbranding kan gebruiken. Verder kunnen op termijn ook de staal-, chemie- en transportsector deze grondstof gebruiken.

  17. Thermodynamic optimization of several (heat recovery steam generator) HRSG configurations for a range of exhaust gas temperatures

    International Nuclear Information System (INIS)

    Design optimization of a (heat recovery steam generator) HRSG is essential due to its direct impact on large power generation combined cycles. This study is aimed at giving a thermodynamic comparison between the optimums of three configurations of HRSG operating at exhaust gas temperature (TOT) from 350 °C to 650 °C. The optimization results, using PSO (Particle Swarm Optimization) method, show that adding another pressure level allows achieving a higher pressure at the inlet of high pressure turbine, producing more steam quantities, destroying less exergy and finally producing more specific work independently of TOT. For a given value of 600 °C representative of TOT of recent gas turbines, an addition of a pressure level is shown to increase the specific work of about 17 kJ/kg, representing a benefit of about 10% for the steam cycle, whereas a third pressure level results in 8 kJ/kg increase in the specific work, corresponding to 4% in the steam cycle. - Highlights: • Three types of HRSG are optimized and compared between them for several TOT values. • Adding a pressure level leads to thermodynamic performance enhancement whatever TOT. • Adding a pressure level permits reaching higher optimal pressures whatever TOT value. • Adding a pressure level permits producing more steam quantities. • Superheater effectiveness tends to its highest possible value except for high TOTs

  18. Steam Turbines

    Science.gov (United States)

    1981-01-01

    Turbonetics Energy, Inc.'s steam turbines are used as power generating systems in the oil and gas, chemical, pharmaceuticals, metals and mining, and pulp and paper industries. The Turbonetics line benefited from use of NASA research data on radial inflow steam turbines and from company contact with personnel of Lewis Research Center, also use of Lewis-developed computer programs to determine performance characteristics of turbines.

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

    International Nuclear Information System (INIS)

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

  20. Synthesis gas from biomass for fuels and chemicals

    International Nuclear Information System (INIS)

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

  1. Approaches to greenhouse gas accounting methods for biomass carbon

    International Nuclear Information System (INIS)

    This investigation examines different approaches for the GHG flux accounting of activities within a tight boundary of biomass C cycling, with scope limited to exclude all other aspects of the lifecycle. Alternative approaches are examined that a) account for all emissions including biogenic CO2 cycling – the biogenic method; b) account for the quantity of C that is moved to and maintained in the non-atmospheric pool – the stock method; and c) assume that the net balance of C taken up by biomass is neutral over the short-term and hence there is no requirement to include this C in the calculation – the simplified method. This investigation demonstrates the inaccuracies in both emissions forecasting and abatement calculations that result from the use of the simplified method, which is commonly accepted for use. It has been found that the stock method is the most accurate and appropriate approach for use in calculating GHG inventories, however short-comings of this approach emerge when applied to abatement projects, as it does not account for the increase in biogenic CO2 emissions that are generated when non-CO2 GHG emissions in the business-as-usual case are offset. Therefore the biogenic method or a modified version of the stock method should be used to accurately estimate GHG emissions abatement achieved by a project. This investigation uses both the derivation of methodology equations from first principles and worked examples to explore the fundamental differences in the alternative approaches. Examples are developed for three project scenarios including; landfill, combustion and slow-pyrolysis (biochar) of biomass. -- Highlights: • Different approaches can be taken to account for the GHG emissions from biomass. • Simplification of GHG accounting methods is useful, however, can lead to inaccuracies. • Approaches used currently are often inadequate for practises that store carbon. • Accounting methods for emissions forecasting can be inadequate for

  2. Influence of steam injection through exhaust heat recovery on the design performance of solid oxide fuel cell . gas turbine hybrid systems

    International Nuclear Information System (INIS)

    This study analyzed the influence of steam injection on the performance of hybrid systems combining a solid oxide fuel cell and a gas turbine. Two different configurations (pressurized system and ambient pressure system) were examined and the effects of injecting steam, generated by recovering heat from the exhaust gas, on system performances were compared. Performance variations according to the design of different turbine inlet temperatures were examined. Two representative gas turbine pressure ratios were used. Without steam injection, the pressurized system generally exhibits higher system efficiency than the ambient pressure system. The steam injection augments gas turbine power, thus increasing the power capacity of the hybrid system. The power boost effect due to the steam injection is generally greater in the relatively higher pressure ratio design in both the pressurized and ambient pressure systems. The effect of the steam injection on system efficiency varies depending on system configurations and design conditions. The pressurized system hardly takes advantage of the steam injection in terms of system efficiency. On the other hand, the steam injection contributes to the efficiency improvement of the ambient pressure system in some design conditions. In particular, a higher pressure ratio provides a better chance of efficiency increase due to the steam injection

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

    International Nuclear Information System (INIS)

    The European Union (EU) energy policy has three targets: supply security, development of a competitive energy sector and environmental sustainability. The EU countries have issued so-called National Renewable Energy Action Plans (NREAP) for increased renewable energy generation. Biomass is stipulated to account for 56% of renewable energy generation by 2020, corresponding to an increase in bioenergy generation from 2.4 × 109 GJ in 2005 to 5.7 × 109 GJ in 2020. There is uncertainty about the amounts of biomass available in the EU, and import challenges policy targets on supply security and sustainability. We address issues about how, from a technical point of view, the EU may deploy its biomass resources to reduce greenhouse gas (GHG) emissions from energy consumption. We investigate if deployment patterns depend on resource availability and technological development. In situations with adequate biomass availability the analysis suggests that liquid fuel production should be based on agricultural residues. Electricity production should be based on forest residues and other woody biomass and heat production on forest and agricultural residues. Improved conversion technologies implicitly relax the strain on biomass resources and improve supply security. - Highlights: • Optimal allocation of biomass to energy is analysed conceptually for the EU by 2020. • Allocation is influenced not only by GHG performance, also by resource availability. • Surplus biomass could be allocated to electricity generation to reduce GHG emissions

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

    Energy Technology Data Exchange (ETDEWEB)

    Staalenheim, Annika; Henderson, Pamela

    2011-02-15

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

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

    International Nuclear Information System (INIS)

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

  6. Experimental Research on Heterogeneous N2O Decomposition with Ash and Biomass Gasification Gas

    Directory of Open Access Journals (Sweden)

    Wu Qin

    2011-11-01

    Full Text Available In this paper, the promoting effects of ash and biomass gas reburning on N2O decomposition were investigated based on a fluidized bed reactor, with the assessment of the influence of O2 on N2O decomposition with circulating ashes. Experimental results show that different metal oxides contained in ash play distinct roles in the process of N2O decomposition with biomass gas reburning. Compared with other components in ash, CaO is proven to be very active and has the greatest promoting impact on N2O decomposition. It is also found that O2, even in small amounts, can weaken the promoting effect of ash on N2O decomposition by using biomass gas reburning.

  7. Experimental Research on Heterogeneous N2O Decomposition with Ash and Biomass Gasification Gas

    OpenAIRE

    Wu Qin; Qiang Lu; Changqing Dong; Xiaoying Hu; Yongping Yang; Junjiao Zhang

    2011-01-01

    In this paper, the promoting effects of ash and biomass gas reburning on N2O decomposition were investigated based on a fluidized bed reactor, with the assessment of the influence of O2 on N2O decomposition with circulating ashes. Experimental results show that different metal oxides contained in ash play distinct roles in the process of N2O decomposition with biomass gas reburning. Compared with other components in ash, CaO is proven to be very active and has the greatest promoting impact on...

  8. Experimental Research on Heterogeneous N 2 O Decomposition with Ash and Biomass Gasification Gas

    OpenAIRE

    Junjiao Zhang; Yongping Yang; Xiaoying Hu; Changqing Dong; Qiang Lu; Wu Qin

    2011-01-01

    In this paper, the promoting effects of ash and biomass gas reburning on N 2 O decomposition were investigated based on a fluidized bed reactor, with the assessment of the influence of O 2 on N 2 O decomposition with circulating ashes. Experimental results show that different metal oxides contained in ash play distinct roles in the process of N 2 O decomposition with biomass gas reburning. Compared with other components in ash, CaO is proven to be very active and has the greatest promoting im...

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

    International Nuclear Information System (INIS)

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

  10. Optical Absorption Spectroscopy for Gas Analysis in Biomass Gasification

    OpenAIRE

    Grosch, Helge; Fateev, Alexander; Clausen, Sønnik

    2014-01-01

    Forgasning af biomasse er en bæredygtigt kilde til produktion af varme, el og kemiske råstoffer. Forgasningsgassens hovedkomponenter, såsom H2, CO, CO2og CH4, kan måles med den fornødne præcision. Det kniber til gengæld med at måle sporgasserne, såsom organiske, aromatiske, svovl- og kvælstofholdigekomponenter, som dels kan volde problemer i de systemer der aftager forgasningsgassen og dels være skadelige for helbred og miljøet. I dette arbejde er der udviklet en optisk metode til direkte kon...

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

    OpenAIRE

    Vincenzo Naso; Andrea Micangeli; Mario Sisinni; Enrico Bocci; Andrea Di Carlo

    2013-01-01

    The aim of this work was the evaluation of the catalytic steam reforming of a gaseous fuel obtained by steam biomass gasification to convert topping atmosphere residue (TAR) and CH4 and to produce pure H2 by means of a CO2 sorbent. This experimental work deals with the demonstration of the practical feasibility of such concepts, using a real woodgas obtained from fluidized bed steam gasification of hazelnut shells. This study evaluates the use of a commercial Ni catalyst and calcined dolomite...

  12. Hydrogen-Rich Gas Production by Sorption Enhanced Steam Reforming of Woodgas Containing TAR over a Commercial Ni Catalyst and Calcined Dolomite as CO 2 Sorbent

    OpenAIRE

    Mario Sisinni; Andrea Di Carlo; Enrico Bocci; Andrea Micangeli; Vincenzo Naso

    2013-01-01

    The aim of this work was the evaluation of the catalytic steam reforming of a gaseous fuel obtained by steam biomass gasification to convert topping atmosphere residue (TAR) and CH 4 and to produce pure H 2 by means of a CO 2 sorbent. This experimental work deals with the demonstration of the practical feasibility of such concepts, using a real woodgas obtained from fluidized bed steam gasification of hazelnut shells. This study evaluates the use of a commercial Ni catalyst and calcined dolom...

  13. Intrinsic reactivity of biomass-derived char under steam gasification conditions. Potential of wood ash as catalyst.

    NARCIS (Netherlands)

    Nanou, Pavlina; Gutierrez Murillo, Hector E.; Swaaij, van Wim P.M.; Rossum, van Guus; Kersten, Sascha R.A.

    2013-01-01

    The influence of ash on the steam gasification rate of pine wood derived char particles in the temperature range 600–800 °C is investigated. Ash derived from pine wood or specific ash components were added to the pine-wood (before pyrolysis) or to the produced char (after pyrolysis) via physical mix

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Long Nguyen

    2014-11-01

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

  16. Coupling-in of outside steam and de-coupling of process steam at the Moerdijk Gas and Steam Plant in The Netherlands; Fremddampfeinkopplung und Prozessdampfauskopplung in der GUD-Anlage Moerdijk/Niederlande

    Energy Technology Data Exchange (ETDEWEB)

    Toebes, J. von; Beker, M. [N.V. Elektriciteits-Produktiemaatschappij Zuid-Nederland, Eindhoven (Netherlands)

    1998-09-01

    Following a construction time of 2 1/2 years, the three V64-3 turbines at the Moerdijk Gas und Steam Plant in The Netherlands were put into operation. Both the technical concept and also the construction and phased commissioning of the power station with coupling-in of high pressure steam from a refuse incineration plant and decoupling of intermediate pressure steam to a neighbouring chemical works have proved to be successful. Operating experience accumulated to date has shown that heat consumption as well as pollution emissions have met guarantee values but availability has not yet fulfilled expectations. (orig.) [Deutsch] Nach einer Bauzeit von 2 1/2 Jahren wurden im Jahre 1996 die drei V64.3-Turbinen der GuD-Anlage Moerdijk/Niederlande in Betrieb genommen. Sowohl das technische Konzept als auch der Bau und die phasenweise Inbetriebsetzung des Kraftwerks mit HD-Dampfeinkopplung aus einer Muellverbrennungsanlage und MD-Dampfauskopplung nach einem benachbarten Chemiewerk hat sich als erfolgreich erwiesen. Die bisherigen Betriebserfahrungen haben gezeigt, dass der Waermeverbrauch wie auch die Schadstoffemissionen die Garantiewerte erfuellen, die Verfuegbarkeit die Erwartungen jedoch noch nicht erfuellt hat. (orig.)

  17. Off-design analysis of a gas turbine powerplant augmented by steam injection using various fuels

    Science.gov (United States)

    Stochl, R. J.

    1980-01-01

    Results are compared using coal derived low and intermediate heating valve fuel gases and a conventional distillate. The results indicate that steam injection provides substantial increases in both power and efficiency within the available compressor surge margin. The results also indicate that these performance gains are relatively insensitive as to the type of fuel. Also, in a cogeneration application, steam injection could provide some degree of flexibility by varying the split between power and process steam.

  18. Dynamics of once-through steam generator control for a nuclear power plant with a gas cooled reactor

    International Nuclear Information System (INIS)

    Studied is the mathematical model of once-through steam generator for power plant with high-temperature gas cooled reactor. The objective of the work is: determination of dynamic performances of the plant, investigation of the primary and secondary circuit interconnections, choice of rational structure for the plant automatic control systems. The analogue computers are used for realization of the mathematical model. The block diagram of the above model and the plant control system schemes both for uncontrolled and controlled load are presented. The studies have shown that steam generators for high-temperature gas cooled plants possess low time lag. There is the interconnection between the coolant parameters for the primary and secondary circuits and so small variations in the plant regime give rise to considerable and quick deviations in vapor parameters. Such peculiarities of steam generators require an application of quick-operating control system. Investigations of control circuits showed that if at small load variations (up to 20 %) permissible fluctuations of cold gas temperature constitute 30 deg C, the operation of the plant with uncontrolled temperature of cold gas is possible

  19. Thermodynamic Analysis of a Power Plant Integrated with Fogging Inlet Cooling and a Biomass Gasification

    Directory of Open Access Journals (Sweden)

    Hassan Athari

    2015-01-01

    Full Text Available Biomass energy and especially biofuels produced by biomass gasification are clean and renewable options for power plants. Also, on hot days the performance of gas turbines decreases substantially, a problem that can be mitigated by fog cooling. In the present paper, a biomass-integrated fogging steam injected gas turbine cycle is analyzed with energy and exergy methods. It is observed that (1 increasing the compressor pressure ratio raises the air flow rate in the plant but reduces the biomass flow rate; (2 increasing the gas turbine inlet temperature decreases the air and biomass flow rates; (3 increasing the compressor pressure ratio raises the energy and exergy efficiencies, especially at lower pressure ratios; (4 increasing the gas turbine inlet temperature raises both efficiencies; and (5 overspray increases the energy efficiency and net cycle power slightly. The gas turbine exhibits the highest exergy efficiency of the cycle components and the combustor the lowest. A comparison of the cycle with similar cycles fired by natural gas and differently configured cycles fueled by biomass shows that the cycle with natural gas firing has an energy efficiency 18 percentage points above the biomass fired cycle, and that steam injection increases the energy efficiency about five percentage points relative to the cycle without steam injection. Also, the influence of steam injection on energy efficiency is more significant than fog cooling.

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

    OpenAIRE

    Ahrenfeldt, Jesper; Foged, Esben Vendelbo; Strand, Rune; Henriksen, Ulrik Birk

    2010-01-01

    The technical requirements and the economical assessment of converting commercial diesel engine gen-sets into high compression spark ignition operation on biomass producer gas have been investigated. Assessments showed that for a 200 kWe gen-set there would be a financial benefit of approximately 600.000 DKK corresponding to a reduction of 60% in investment costs compared to the price of a conventional gas engine gen-set. Experimental investigations have been conducted on two identical small ...

  1. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification

    Science.gov (United States)

    Yan, Fang; Xu, Kaili; Yao, Xiwen; Li, Yang

    2016-01-01

    Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA) is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie) analysis was proposed by mapping bow-tie analysis into Bayesian network (BN). Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures. PMID:27463975

  2. Properties of hybrid gas-water torch used for gasification of biomass

    Czech Academy of Sciences Publication Activity Database

    Kavka, Tetyana; Mašláni, Alan; Kopecký, Vladimír; Hrabovský, Milan

    Heilbronn: Institute of Space Propulsion, German Aerospace Center, 2010. s. 29-29. ISBN N. [International Workshop and Exhibition on Plasma Assisted Combustion/6th./. 13.09.2010-15.09.2010, Heilbronn] Institutional research plan: CEZ:AV0Z20430508 Keywords : DC arc plasma torch * gasification of biomass Subject RIV: BL - Plasma and Gas Discharge Physics

  3. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification.

    Science.gov (United States)

    Yan, Fang; Xu, Kaili; Yao, Xiwen; Li, Yang

    2016-01-01

    Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA) is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie) analysis was proposed by mapping bow-tie analysis into Bayesian network (BN). Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures. PMID:27463975

  4. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification.

    Directory of Open Access Journals (Sweden)

    Fang Yan

    Full Text Available Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie analysis was proposed by mapping bow-tie analysis into Bayesian network (BN. Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-15

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

  6. Thermodynamic Analysis of a Power Plant Integrated with Fogging Inlet Cooling and a Biomass Gasification

    OpenAIRE

    Hassan Athari; Saeed Soltani; Marc A. Rosen; Seyed Mohammad Seyed Mahmoudi; Tatiana Morosuk

    2015-01-01

    Biomass energy and especially biofuels produced by biomass gasification are clean and renewable options for power plants. Also, on hot days the performance of gas turbines decreases substantially, a problem that can be mitigated by fog cooling. In the present paper, a biomass-integrated fogging steam injected gas turbine cycle is analyzed with energy and exergy methods. It is observed that (1) increasing the compressor pressure ratio raises the air flow rate in the plant but reduces the bioma...

  7. Failure analysis of austenitic stainless steel tubes in a gas fired steam heater

    International Nuclear Information System (INIS)

    Highlights: ► 304H stainless steel is more susceptible to caustic SCC compared to SA335 alloy steel. ► Caustic attacks the protective layer of stainless steel superheater tubes. ► Sigma phase formation at the weld zone causes crack initiation in fired heater tubes. -- Abstract: Carryover of caustic soda (NaOH) in the steam path caused catastrophic failure of superheater 304H stainless steel tubes in a gas fired heater and led to an unexpected shutdown after just 5 months of continuous service following the start of production. The cause of the failure was studied, with a focus on the effect of caustic embrittlement on stress corrosion cracking (SCC). The cracks were examined at the seam weld, heat affected zone (HAZ), and U-bend areas. Hardness was measured for the base metal, HAZ, and weld metal, and microstructures were examined using optical microscopy and scanning electron microscopy (SEM). Crack initiation is attributed to gouging on the precipitated carbide at the HAZ and also the formation of sigma phase in the weld metal, as shown by energy dispersive X-ray (EDX) analysis. In addition, cracking was propagated by caustic embrittlement because of residual stresses and hammering. Finally, the characteristic feature of fracture was illustrated by SEM fractography, and consists mostly of intergranular SCC and some quasi-cleavage transgranular.

  8. Thermodynamic and kinetic model of reforming coke-oven gas with steam

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiayuan; Zhang, Xiaohui; Chen, Zhuo; Li, Li [School of Energy Science and Engineering, Central South University, Changsha, 932 South Lushan Rd, Hunan 410083 (China)

    2010-07-15

    The experiments of reforming the methane of coke-oven gas with steam were performed. The effects of the thermodynamic factors, such as the H{sub 2}O/CH{sub 4} ratio, the conversion temperature (T) of methane and the reaction time (t), on the methane conversion rate have been investigated. The experimental results show that the H{sub 2}O/CH{sub 4} ratio within the range of 1.1-1.3 and the temperature 1223-1273 K are the reasonable thermodynamic conditions for methane conversion. A methane conversion of more than 95% can be achieved when the H{sub 2}O/CH{sub 4} ratio is 1.2, the conversion temperature is above 1223 K and the conversion time is up to 15 s respectively. In additional, kinetic data of different reaction conditions were measured, and a dynamic model of methane conversion was proposed and verified. All results demonstrated that the results of the dynamic models agree well with the experiments, of which the deviation is less than 1.5%. (author)

  9. Thermodynamic and kinetic model of reforming coke-oven gas with steam

    International Nuclear Information System (INIS)

    The experiments of reforming the methane of coke-oven gas with steam were performed. The effects of the thermodynamic factors, such as the H2O/CH4 ratio, the conversion temperature (T) of methane and the reaction time (t), on the methane conversion rate have been investigated. The experimental results show that the H2O/CH4 ratio within the range of 1.1-1.3 and the temperature 1223-1273 K are the reasonable thermodynamic conditions for methane conversion. A methane conversion of more than 95% can be achieved when the H2O/CH4 ratio is 1.2, the conversion temperature is above 1223 K and the conversion time is up to 15 s respectively. In additional, kinetic data of different reaction conditions were measured, and a dynamic model of methane conversion was proposed and verified. All results demonstrated that the results of the dynamic models agree well with the experiments, of which the deviation is less than 1.5%.

  10. Synthetic Gas Production by Biomass/Oil Partial Oxidation

    Czech Academy of Sciences Publication Activity Database

    Hanika, Jiří; Lederer, J.; Tukač, V.; Veselý, Václav; Kovač, D.

    Bratislava: AXIMA Graphics Design and Printing Services, 2012 - (Markoš, J.), s. 217 ISBN 978-80-89475-04-9. [International Conference of Slovak Society of Chemical Engineering /39./. Tatranské Matliare (SK), 21.05.2012-25.05.2012] R&D Projects: GA TA ČR TE01020080; GA MPO 2A-2TP1/024 Institutional support: RVO:67985858 Keywords : synthetic gas * bio mass * partialoxidation Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  11. Prospects for biogenic natural gas. Pt. I. Production from wet and dry biomass; Perspektiven fuer Bio-Erdgas. T. I.. Bereitstellung aus nasser und trockener Biomasse

    Energy Technology Data Exchange (ETDEWEB)

    Leible, Ludwig; Kaelber, Stefan; Kappler, Gunnar [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (DE). Inst. fuer Technikfolgenabschaetzung und Systemanalyse (ITAS); Eltrop, Ludger; Stenull, Maria [Stuttgart Univ. (DE). Inst. fuer Energiewirtschaft und Rationelle Energieanwendung (IER); Lansche, Jens [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Agrartechnik; Poboss, Norman [Stuttgart Univ. (DE). Inst. fuer Feuerungs- und Kraftwerkstechnik (IFK); Stuermer, Bernd; Kelm, Tobias [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany); Koeppel, Wolfgang [Deutsche Vereinigung des Gas- und Wasserfaches e.V. (DVGW), Forschungsstelle am Engler-Bunte-Institut (EBI), Karlsruhe (Germany)

    2012-07-01

    Biogenic natural gas offers as substitute for natural gas (SNG) various opportunities for different types of biomass for a more efficient handling and energy use in the power, heat and fuel sector. Part I of this publication deals with techno-economic aspects of SNG production based on biogas and thermo-chemically produced gas. Associated GHG emissions are discussed as well. Part II focuses on the utilization of biogenic natural gas for heat, power and fuel production. A comparison with fossil natural gas and the direct use of biogas or thermo-chemically produced gas is included. (orig.)

  12. Identification of Carbon Deposits on the Nickel-Based Catalyst Used for the Steam Reforming of Biomass Tar at 500 °C

    Czech Academy of Sciences Publication Activity Database

    Vosecký, Martin; Skoblia, Sergej; Jirátová, Květa; Kameníková, Petra; Pohořelý, Michael; Punčochář, Miroslav

    Jerusalem: -, 2009, s. 419. ISBN N. [EuropaCat IX: "Catalysis for Sustainable World". Salamanca (ES), 30.08.2009-04.09.2009] R&D Projects: GA ČR(CZ) GA104/07/0977 Institutional research plan: CEZ:AV0Z40720504 Keywords : carbon deposits * biomass gasification gas * analysis Subject RIV: CC - Organic Chemistry http://www.certh.gr/577CC7CC.en.aspx

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-28

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Huffman, Gerald

    2012-12-31

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

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

    International Nuclear Information System (INIS)

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

  16. Evaluation of Steam and Gas-flow for APR1400 IRWST using GOTHIC 6.1b

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mun Soo; Lee, Suk Ho; Kim, Han Gon [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2009-05-15

    The In-Containment Refueling Water Storage Tank (IRWST) of APR1400 is installed at the bottom of the containment building to promote the plant safety functions during an accident. This design feature brings about uncertainty factors that may necessitate improvement or revision of the conventional prediction of temperature and pressure of the containment building in the event of an accident. The hot steam that is released from a RCS break enters the IRWST through four Pressure Relief Dampers (PRDs). The steam is expected to be condensed with water stored in the IRWST, in which water is colder than the incoming steam. The purpose of this study is to investigate the influence of IRWST and PRDs on back pressure and temperature in APR1400 containment by utilizing a containment code: GOTHIC 6.1b (Generation of Thermal-Hydraulic Information for Containments). For this purpose, a multi-compartment and detailed three-dimensional model was developed to predict the steam and gas flow-rate in IRWST.

  17. Investigation of effect of variation of cycle parameters on thermodynamic performance of gas-steam combined cycle

    International Nuclear Information System (INIS)

    The paper deals with second law thermodynamic analysis of a basic gas turbine based gas-steam combined cycle. The article investigates the effect of variation of cycle parameters on rational efficiency and component-wise non-dimensionalised exergy destruction of the plant. Component-wise inefficiencies of the combined cycle have been quantified with the objective to pin-point the major sources of exergy destruction. The parameter that affects cycle performance most is the TIT (turbine inlet temperature). TIT should be kept on the higher side, because at lower values, the exergy destruction is higher. The summation of total exergy destruction of all components in percentage terms is lower (44.88%) at TIT of 1800 K and rp,c = 23, as compared to that at TIT = 1700 K. The sum total of rational efficiency of gas turbine and steam turbine is found to be higher (54.91%) at TIT = 1800 K and rp,c = 23, as compared to that at TIT = 1700 K. Compressor pressure ratio also affects the exergy performance. The sum total of exergy destruction of all components of the combined cycle plant is lower (44.17%) at higher value of compressor pressure ratio (23) and TIT = 1700 K, as compared to that at compressor pressure ratio (16). Also exergy destruction is minimized with the adoption of multi-pressure-reheat steam generator configuration. -- Research highlights: →Adoption of higher value of TIT leads to the reduction in exergy destruction. →Rational efficiency of cycle is around 54%. →Exergy destruction is minimized by the adoption of multi-pressure-reheat steam cycle.

  18. A Medium-Scale 50 MW fuel Biomass Gasification Based Bio-SNG Plant: A Developed Gas Cleaning Process

    OpenAIRE

    Ramiar Sadegh-Vaziri; Marko Amovic; Rolf Ljunggren; Klas Engvall

    2015-01-01

    Natural gas is becoming increasingly important as a primary energy source. A suitable replacement for fossil natural gas is bio-SNG, produced by biomass gasification, followed by methanation. A major challenge is efficient gas cleaning processes for removal of sulfur compounds and other impurities. The present study focuses on development of a gas cleaning step for a product gas produced in a 50 MW fuel gasification system. The developed gas cleaning washing process is basically a modificatio...

  19. A Medium-Scale 50 MWfuel Biomass Gasification Based Bio-SNG Plant: A Developed Gas Cleaning Process

    OpenAIRE

    Ramiar Sadegh-Vaziri; Marko Amovic; Rolf Ljunggren; Klas Engvall

    2015-01-01

    Natural gas is becoming increasingly important as a primary energy source. A suitable replacement for fossil natural gas is bio-SNG, produced by biomass gasification, followed by methanation. A major challenge is efficient gas cleaning processes for removal of sulfur compounds and other impurities. The present study focuses on development of a gas cleaning step for a product gas produced in a 50 MWfuel gasification system. The developed gas cleaning washing process is basically a modificatio...

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

    Directory of Open Access Journals (Sweden)

    Masoud Rokni

    2016-05-01

    Full Text Available Repowering is a process for transforming an old power plant for greater capacity and/or higher efficiency. As a consequence, the repowered plant is characterized by higher power output and less specific CO2 emissions. Usually, repowering is performed by adding one or more gas turbines into an existing steam cycle which was built decades ago. Thus, traditional repowering results in combined cycles (CC. High temperature fuel cells (such as solid oxide fuel cell (SOFC could also be used as a topping cycle, achieving even higher global plant efficiency and even lower specific CO2 emissions. Decreasing the operating temperature in a SOFC allows the use of less complex materials and construction methods, consequently reducing plant and the electricity costs. A lower working temperature makes it also suitable for topping an existing steam cycle, instead of gas turbines. This is also the target of this study, repowering of an existing power plant with SOFC as well as gas turbines. Different repowering strategies are studied here, repowering with one gas turbine with and without supplementary firing, repowering with two gas turbines with and without supplementary firing and finally repowering using SOFC. Plant performances and CO2 emissions are compared for the suggested repowered plants.

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

    Energy Technology Data Exchange (ETDEWEB)

    Stemmler, Michael

    2010-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-15

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

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

    International Nuclear Information System (INIS)

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO2equiv if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

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

    International Nuclear Information System (INIS)

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

  5. Hydrogen rich gas from oil palm biomass as a potential source of renewable energy in Malaysia

    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); Taufiq-Yap, Y.H. [Centre of Excellence for Catalysis Science and Technology and Department of Chemistry, Faculty of Science, University Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2011-02-15

    Oil palm is one of the major economic crops in many countries. Malaysia alone produces about 47% of the world's palm oil supply and can be considered as the world's largest producer and exporter of palm oil. Malaysia also generates huge quantity of oil palm biomass including oil palm trunks, oil palm fronds, empty fruit bunches (EFB), shells and fibers as waste from palm oil fruit harvest and oil extraction processing. At present there is a continuously increasing interest in the utilization of oil palm biomass as a source of clean energy. One of the major interests is hydrogen from oil palm biomass. Hydrogen from biomass is a clean and efficient energy source and is expected to take a significant role in future energy demand due to the raw material availability. This paper presents a review which focuses on different types of thermo-chemical processes for conversion of oil palm biomass to hydrogen rich gas. This paper offers a concise and up-to-date scenario of the present status of oil palm industry in contributing towards sustainable and renewable energy. (author)

  6. Calibration and performance of the PFR steam - generating unit gas-space hydrogen detection system at high hydrogen partial pressures

    International Nuclear Information System (INIS)

    The PFR secondary circuit hydrogen detection system was calibrated at levels up to 20% hydrogen in argon, in order to follow quantitatively the hydrogen build-up as a consequence of small gas-space evaporator steam/water to sodium leaks. This is a pre-requisite for determining steam/water to sodium leak rates. Experiments conducted over the temperature range 388 - 530 0C show that the response of the nickel permeation membrane is non-linear, even at hundreds of volume parts per million H2 in Ar. Good correlation between experimental results and permeation theory (based on Ficks laws) was obtained, after correcting where necessary for the non-linear katharometer response. These thermal conductivity detectors tend to read lower than absolute above about 0.5% H2 in Ar. (author)

  7. Steam Generator Component Model in a Combined Cycle of Power Conversion Unit for Very High Temperature Gas-Cooled Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Chang H; Han, James; Barner, Robert; Sherman, Steven R

    2007-06-01

    The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP), Very High Temperature Gas-Cooled Reactor (VHTR) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility, early designs are expected to be dual-purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor, electrical generation and hydrogen production is under way. A combined cycle is considered as one of the power conversion units to be coupled to the very high-temperature gas-cooled reactor (VHTR). The combined cycle configuration consists of a Brayton top cycle coupled to a Rankine bottoming cycle by means of a steam generator. A detailed sizing and pressure drop model of a steam generator is not available in the HYSYS processes code. Therefore a four region model was developed for implementation into HYSYS. The focus of this study was the validation of a HYSYS steam generator model of two phase flow correlations. The correlations calculated the size and heat exchange of the steam generator. To assess the model, those calculations were input into a RELAP5 model and its results were compared with HYSYS results. The comparison showed many differences in parameters such as the heat transfer coefficients and revealed the different methods used by the codes. Despite differences in approach, the overall results of heat transfer were in good agreement.

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

    International Nuclear Information System (INIS)

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

  9. Design and materials of a large scale gas generator for the steam gasification of coal using nuclear heat

    International Nuclear Information System (INIS)

    For the gasification of coal, energy in the form of electricity and steam is needed as well as process heat. In conventional gasification processes, e.g., Lurgi, Winkler, and Koppers-Totzek, this energy is generated by the combustion of about 40 - 50% of the feed coal. An equivalent amount of coal can consequently be saved or converted into gas if electricity, steam, and especially process heat, are made available from a high-temperature nuclear reactor (HTR). The nuclear heat from the HTR is used directly as process heat. In view of the almost double-specific gas yield compared with conventional gasification the approach here has three major advantages: 1. saving of available coal reserves; 2. reduction of specific coal emissions; 3. lower gas production costs compared to conventional gasification. Helium is used as heat carrier in the primary HTR circuit and heated up to 9500C. The heat is transferred via a heat exchanger to a secondary circuit which also uses helium as the operating medium. This paper describes function and design of the gas generator, its main components, the materials especially selected for the high temperature heat exchanger and the experience with a pilot plant gasifier

  10. Feasibility analysis of co-fired combined-cycles using biomass-derived gas and natural gas

    International Nuclear Information System (INIS)

    This paper reports the feasibility analysis of co-fired combined cycles (biomass-derived gas + natural gas) based on the gasification of sugarcane residues (bagasse and trash). Performance results are based on simulation of co-fired combined cycles. Feasibility analysis is based on estimates of the capital costs and O and M costs for such cycles, taking into account current and middle term costs of BIG-CC technology (both considering scaling and learning effects). A deep reduction of the investments regarding the gasification island and auxiliaries is a key point to make BIG-CC competitive in the electricity market, and the required learning can be reached with co-fired BIG-CC systems. Besides alleviation of technical problems related to gas turbine operation with biomass-derived gas, co-fired BIG-CC units can operate with relative flexibility regarding the fuel mix. The construction of 10-15 short- to medium-size gasification islands would be enough to induce important cost reductions due to learning effects. As long as the investment on the gasification island is reduced, and depending on the price ratio of natural gas and biomass, pure BIG-CC plants could achieve a reasonable level of feasibility regarding other options of electricity production. In the short run there is no advantage for co-fired combined cycles regarding the costs of reduction of carbon dioxide emissions, but in the middle run both co-fired and pure BIG-CC power plants can be a better option than capture and storage of CO2

  11. Catalytic conversion of biomass-derived synthesis gas to liquid fuels

    OpenAIRE

    Suárez París, Rodrigo

    2016-01-01

    Climate change is one of the biggest global threats of the 21st century. Fossil fuels constitute by far the most important energy source for transportation and the different governments are starting to take action to promote the use of cleaner fuels. Biomass-derived fuels are a promising alternative for diversifying fuel sources, reducing fossil fuel dependency and abating greenhouse gas emissions. The research interest has quickly shifted from first-generation biofuels, obtained from food co...

  12. Thermal plasma gasification of organic waste and biomass for fuel gas production

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, Milan

    Patras : University of Patras Plasma Technology Lab, 2008. s. 3-3. ISBN N. [Biennial European Plasma Conference HTTP-10/10th./. 07.07.2008-11.07.2008, Patras] R&D Projects: GA ČR GA202/08/1084 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal plasma * biomass * gasification Subject RIV: BL - Plasma and Gas Discharge Physics

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

    OpenAIRE

    Kalina, Jacek

    2011-01-01

    Abstract The paper theoretically investigates the performance of a distributed generation plant made up of gasifier, Internal Combustion Engine (ICE) and Organic Rankine Cycle (ORC) machine as a bottoming unit. The system can be used for maximization of electricity production from biomass in the case where there is no heat demand for cogeneration plant. To analyze the performance of the gasifier a model based on the thermodynamic equilibrium approach is used. Performance of the gas...

  14. Thermal plasma gasification of organic waste and biomass for fuel gas production

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, Milan

    Patras: University of Patras Plasma Technology Lab, 2008. s. 3-3. ISBN N. [Biennial European Plasma Conference HTTP-10/10th./. 07.07.2008-11.07.2008, Patras] R&D Projects: GA ČR GA202/08/1084 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal plasma * biomass * gasification Subject RIV: BL - Plasma and Gas Discharge Physics

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-15

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

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

    International Nuclear Information System (INIS)

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

  17. Experimental study of simulating high pressure steam-water to-phase flow with sulfur hexafluoride gas and ethyl alcohol liquid

    International Nuclear Information System (INIS)

    Mist flow appears in various industrial plants and machines; nuclear power plants, chemical plants, heat exchangers, steam turbines, and so on. Behaviors of droplet have effects on heat and mass transfer process on them. As for a steam generator of a nuclear power plant, mist flow appears at primary and secondary separator. These apparatus separates steam and droplet. Droplet erodes steam turbine blade and gives it too much damage. In order to prevent it, we must clarify the behavior of droplet; i.e. diameter and its distribution. Clarification of droplet behavior at actual pressure and temperature of a steam generator is very difficult and it costs too much and takes long time to develop a steam generator. It is needed, therefore, to develop a new experimental method. One of the best ways is to use alternate fluids of which properties as same as that of high pressure and high temperature steam-water system. We have developed the new experimental method and simulated actual pressure steam-water two phase flow using Sulfur Hexafluoride gas and ethyl alcohol liquid two-phase flow at low pressures and atmospheric temperature. The specific objectives of this study are to: (1) simulate easily a high pressure and high temperature steam-water system by using alternative fluids; (2) confirm that Sulfur Hexafluoride and ethyl alcohol system at atmospheric temperature and low pressure is able to simulate steam-water system. For measuring drop diameter, the laser diffraction technique was applied. Further, the photographs of the droplets were taken by the video camera. The drop diameter decreased as increasing gas velocity and it was found that drop diameter was about 100∼200μm under the simulation condition of 6MPa and 280 .deg. C

  18. 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.)

  19. Biomass boilers

    OpenAIRE

    Nahodil, Jiří

    2011-01-01

    Bachelor’s thesis deals with the use of biomass for heating houses and apartment houses. The first part is dedicated to biomass. Here are mentioned the possibility of energy recovery, treatment and transformation of biomass into a form suitable for burning, its properties and combustion process itself. The second part is devoted to biomass boilers, their separation and description. The last section compares the specific biomass boiler with a boiler to natural gas, particularly from an economi...

  20. 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.)

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

    Directory of Open Access Journals (Sweden)

    Mr. Akhilesh Kumar

    2014-10-01

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

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

    International Nuclear Information System (INIS)

    Highlights: • Production emissions dominate transportation and processing emissions. • Choice of feedstock, geographic location and prior land use drive emissions profile. • Within scenarios, emissions variability is driven by uncertainty in yields. • Favorable scenarios maximize carbon storage from direct land-use change. • Similarly, biomass production should attempt to minimize indirect land-use change. -- Abstract: Many policies in the United States, at both the federal and state levels, encourage the adoption of renewable energy from biomass. Though largely motivated by a desire to reduce greenhouse gas emissions, these policies do not explicitly identify scenarios in which the use of biomass will produce the greatest benefits. We have modeled “farm-to-hopper” emissions associated with seven biomass feedstocks, under a wide variety of scenarios and production choices, to characterize the uncertainty in emissions. We demonstrate that only a handful of factors have a significant impact on life cycle emissions: choice of feedstock, geographic location, prior land use, and time dynamics. Within a given production scenario, the remaining variability in emissions is driven by uncertainty in feedstock yields and the release rate of N2O into the atmosphere from nitrogen fertilizers. With few exceptions, transport and processing choices have relatively little impact on total emissions. These results illustrate the key decisions that will determine the success of biomass programs in reducing the emissions profile of energy production, and our publicly available model provides a useful tool for identifying the most beneficial production scenarios. While model data and results are restricted to biomass production in the contiguous United States, we provide qualitative guidance for identifying favorable production scenarios that should be applicable in other regions

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

    International Nuclear Information System (INIS)

    Highlights: • The paper presents integrated catalytic adsorption (ICA) steam gasification for H2 yield. • Effects of adsorbent to biomass, biomass particle size and fluidization velocity on H2 yield are examined. • The present study produces higher H2 yield as compared to that obtained in literatures. • The ICA provides enhancement of H2 yield as compared to independent catalytic and CO2 adsorption gasification systems. - Abstract: The present study investigates the integrated catalytic adsorption (ICA) steam gasification of palm kernel shell for hydrogen production in a pilot scale atmospheric fluidized bed gasifier. The biomass steam gasification is performed in the presence of an adsorbent and a catalyst in the system. The effect of adsorbent to biomass (A/B) ratio (0.5–1.5 wt/wt), fluidization velocity (0.15–0.26 m/s) and biomass particle size (0.355–2.0 mm) are studied at temperature of 675 °C, steam to biomass (S/B) ratio of 2.0 (wt/wt) and biomass to catalyst ratio of 0.1 (wt/wt). Hydrogen composition and yield, total gas yield, and lower product gas heating values (LHVgas) increases with increasing A/B ratio, while particle size has no significant effect on hydrogen composition and yield, total gas and char yield, gasification and carbon conversion efficiency. However, gas heating values increased with increasing biomass particle size which is due to presence of high methane content in product gas. Meanwhile, medium fluidization velocity of 0.21 m/s favoured hydrogen composition and yield. The results showed that the maximum hydrogen composition and yield of 84.62 vol% and 91.11 g H2/kg biomass are observed at A/B ratio of 1.5, S/B ratio of 2.0, catalyst to biomass ratio of 0.1 and temperature of 675 °C. The product gas heating values are observed in the range of 10.92–17.02 MJ/N m3. Gasification and carbon conversion efficiency are observed in the range of 25.66–42.95% and 20.61–41.95%, respectively. These lower efficiencies are due

  4. Analysis of a feasible polygeneration system for power and methanol production taking natural gas and biomass as materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hongqiang [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100080 (China); College of Civil Engineering, Hunan University, Changsha 410082 (China); Hong, Hui; Jin, Hongguang; Cai, Ruixian [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100080 (China)

    2010-09-15

    Co-utilization of natural gas and biomass is a successful way to make efficient use of them for chemical production and power generation, for biomass is rich in carbon while natural gas is rich in hydrogen. The present paper therefore proposes a new polygeneration system taking biomass and natural gas as materials for methanol production and power generation. The new polygeneration system can achieve the optimal ratio of H{sub 2} to CO for methanol production by adjusting input ratio of natural gas to biomass without any energy penalty. Thus, the suggested system can eliminate CO to H{sub 2} shift process and CO{sub 2} remove process, which can avoid material and energy destruction; however, those processes are otherwise necessary in individual biomass to methanol plant. Moreover, the new system eliminates the CO{sub 2} addition process; however, the addition of CO{sub 2} is necessary in individual natural gas to methanol plant, which causes extra energy penalty. This system combined chemical production and power generation together, in order to achieve the cascaded utilization of chemical and physical energy of natural gas and biomass. In a further way, we investigated the key processes, to maximize the utilization of energy and improve system performance. A thermo-chemical process taking biomass and natural gas as co-feedstock is compared with the systems that only taking either biomass or natural gas as resource for methanol production and power generation. The evaluation and calculation of the systems are carried out by help of Aspen Plus process simulator. The evaluation results indicate that, the new polygeneration system can reduce materials input at least 9% compared with individual systems with same output. In a further way, the effect of natural gas to biomass feed ratio on system performance is also investigated. The research results show that, the proposed polygeneration system would be expected to realize efficient utilization of biomass and natural

  5. Phenols and lignin: Key players in reducing enzymatic hydrolysis yields of steam-pretreated biomass in presence of laccase.

    Science.gov (United States)

    Oliva-Taravilla, Alfredo; Tomás-Pejó, Elia; Demuez, Marie; González-Fernández, Cristina; Ballesteros, Mercedes

    2016-01-20

    Phenols are known as inhibitors for cellulases and fermentative microorganisms in bioethanol production processes. The addition of laccases removes the phenolic compounds and subsequently reduces the lag phase of the fermentative microorganism. However, the application of laccases diminishes glucose release during the enzymatic hydrolysis. In this study a model cellulosic substrate (Sigmacell) together with lignin extract, whole steam-pretreated wheat straw (slurry) and its water insoluble solid fraction (WIS) were subjected to enzymatic hydrolysis to evaluate the effects of laccase treatment in presence of lignin and phenols. The presence of laccase in enzymatic hydrolysis of Sigmacell with lignin extract reduced glucose yield by 37% compared with assays without laccase. Furthermore, this reduction was even more marked in presence of phenols (55% reduction). Interestingly, when hydrolyzing WIS, the addition of phenols coupled with laccase treatment did not show a reduction when compared with only laccase addition. This fact suggests the key role of lignin in the hydrolysis inhibition since in WIS the ratio cellulase per gram of lignin was much lower than in Sigmacell experiments. Finally, the lower cellobiose and xylose recoveries point out that phenolic oligomers formed by laccase oxidation play important roles in the inhibition of endoglucanases, cellobiohydrolases and xylanases. To conclude, the proportion of lignin and the composition of phenols are key players in the inhibition of cellulases when the enzymatic hydrolysis is combined with laccases detoxification. PMID:26684987

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

    Energy Technology Data Exchange (ETDEWEB)

    Nexant Inc.

    2006-05-01

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

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

    OpenAIRE

    Sallevelt, Johan Leonard Hendrik Pieter

    2015-01-01

    The combustion of liquid biofuels in gas turbines is an efficient way of generating heat and power from biomass. Gas turbines play a major role in the global energy supply and are suitable for a wide range of applications. However, biofuels generally have different properties compared to conventional fossil fuels. This can lead to various problems in case biofuels are directly used in existing installations. This thesis aims to provide better insight into the combustion of biomass-derived pyr...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2016-01-01

    existing steam cycle which was built decades ago. Thus, traditional repowering results in combined cycles (CC). High temperature fuel cells (such as solid oxide fuel cell (SOFC)) could also be used as a topping cycle, achieving even higher global plant efficiency and even lower specific CO2 emissions......Repowering is a process for transforming an old power plant for greater capacity and/or higher efficiency. As a consequence, the repowered plant is characterized by higher power output and less specific CO2 emissions. Usually, repowering is performed by adding one or more gas turbines into an...... using SOFC. Plant performances and CO2 emissions are compared for the suggested repowered plants....

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

    International Nuclear Information System (INIS)

    Thermodynamic analysis of performance of steam methane reforming hydrogen production system connected with High-Temperature Gas-Cooled Reactor is presented, which provides a framework for further detailed research. Complete reaction model and equilibrium reaction model were developed. System efficiency and hydrogen output variation related to process parameters were researched. Limit value of performance index and optimum process parameter were determined. The comparison of equilibrium reaction model prediction to experimental data shows that the equilibrium reaction model is appropriate for preliminary analysis for the system. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

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

    International Nuclear Information System (INIS)

    This paper presents an exergy analysis of SNG production via indirect gasification of various biomass feedstock, including virgin (woody) biomass as well as waste biomass (municipal solid waste and sludge). In indirect gasification heat needed for endothermic gasification reactions is produced by burning char in a separate combustion section of the gasifier and subsequently the heat is transferred to the gasification section. The advantages of indirect gasification are no syngas dilution with nitrogen and no external heat source required. The production process involves several process units, including biomass gasification, syngas cooler, cleaning and compression, methanation reactors and SNG conditioning. The process is simulated with a computer model using the flow-sheeting program Aspen Plus. The exergy analysis is performed for various operating conditions such as gasifier pressure, methanation pressure and temperature. The largest internal exergy losses occur in the gasifier followed by methanation and SNG conditioning. It is shown that exergetic efficiency of biomass-to-SNG process for woody biomass is higher than that for waste biomass. The exergetic efficiency for all biomass feedstock increases with gasification pressure, whereas the effects of methanation pressure and temperature are opposite for treated wood and waste biomass.

  14. Volumetric combustion of torrefied biomass for large percentage biomass co-firing up to 100% fuel switch

    OpenAIRE

    Li, Jun

    2014-01-01

    The co-firing of biomass and coal plays an important role in increasing the biomass power capacity and reducing greenhouse gas (GHG) emissions. The challenges of the large percentage biomass co-firing (over 20% on energy basis) in existing pulverized coal boilers are keeping the same steam parameters and having a high boiler efficiency and a stable operating. The primary goal of this thesis is to develop a combustion concept for coal-fired boilers to enablea large percentage of biomass co-fir...

  15. The reactivity effects of steam ingress into the core of gas-cooled fast reactors

    International Nuclear Information System (INIS)

    Steam ingress reactivity effect is caused by steam ingress into the core of GCFRs through coolant channels from the secondary coolant system during a hypothetical accident. This reactivity effect in GCFR can be considered one of the most important safety-related physics parameters as is the sodium void reactivity effect in LMFBR. The steam ingress reactivity effects have been studied for 300 MWe and 1000 MWe GCFR designed at General Atomics in US., taking account of the influences of fuel burnup, fuel temperature and the presence of control rods. The calculations have been made basing on the exact perturbation theory in R-Z geometry together with JAERI-Fast 25 group constants set Version 2. In addition, to assess the uncertainties associated with the data and methods, some detailed investigations have been made on the influences of heterogeneous arrangement of fuel pins in a subassembly, and of differences in nuclear data and their processing methods to produce group constants. And also the measurements of the concerned reactivity effects at ZPR-9 have been analysed to understand our predicting accuracy. From this study, the following conclusions were drawn: (1) In the cold clean state at low fuel temperature with no control rods present, the steam ingress reactivity effect is most positive for 1000 MWe GCFR at BOL but is negative for 300 MWe GCFR. The positive reactivity effect increases as the steam density increases. (2) The presence of control rods in the core significantly reduces the large positive reactivity effect for 1000 MWe GCFR mentioned above. (author)

  16. Design and simulation of a small polygeneration plant cofiring biomass and natural gas in a dual combustion micro gas turbine (BIO_MGT)

    OpenAIRE

    Riccio, G.; Chiaramonti D.

    2009-01-01

    The operation and performances of an innovative small scale polygeneration system (BIO_MGT), which combines biomass and natural gas in a micro gas turbine, has been simulated in the present work by means of a thermodynamic matching analysis. The BIO_MGT unit matches an externally fired cycle with a commercial Micro Gas Turbine (MGT, 100 kWe). A significant share of the total energy input (w70%) is supplied by solid biomass: the remaining is provided by natural gas. The system i...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

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

  18. Greenhouse gas emissions from forest, land use and biomass burning in Tanzania

    International Nuclear Information System (INIS)

    Carbon dioxide (CO2) and methane (CH4) gases are the main contributors to the greenhouse effect that consequently results in global warming. This paper examines the sources and sinks of these gases from/to forest, land use and biomass burning and their likely contribution to climate change using IPCC/OECD methodology. Emissions have been calculated in mass units of carbon and nitrogen Emissions and uptake have been summed for each gas and the emissions converted to full molecular weights. Mismanagement of forests and land misuse have contributed much to greenhouse gas emissions in Tanzania. For example, cultivation methods, forest clearing, burning of savannah grass and indiscriminate logging (non-sustainable logging) have contributed significantly to greenhouse gas emissions. These categories contribute more than 90% of total CO2 emissions. However, the study shows that shifting cultivation, savannah burning and forest clearing for conversion to permanent crop land and pasture are the main contributors

  19. The Use of Aerosol Optical Depth in Estimating Trace Gas Emissions from Biomass Burning Plumes

    Science.gov (United States)

    Jones, N.; Paton-Walsh, C.; Wilson, S.; Meier, A.; Deutscher, N.; Griffith, D.; Murcray, F.

    2003-12-01

    We have observed significant correlations between aerosol optical depth (AOD) at 500 nm and column amounts of a number of biomass burning indicators (carbon monoxide, hydrogen cyanide, formaldehyde and ammonia) in bushfire smoke plumes over SE Australia during the 2001/2002 and 2002/2003 fire seasons from remote sensing measurements. The Department of Chemistry, University of Wollongong, operates a high resolution Fourier Transform Spectrometer (FTS), in the city of Wollongong, approximately 80 km south of Sydney. During the recent bushfires we collected over 1500 solar FTIR spectra directly through the smoke over Wollongong. The total column amounts of the biomass burning indicators were calculated using the profile retrieval software package SFIT2. Using the same solar beam, a small grating spectrometer equipped with a 2048 pixel CCD detector array, was used to calculate simultaneous aerosol optical depths. This dataset is therefore unique in its temporal sampling, location to active fires, and range of simultaneously measured constituents. There are several important applications of the AOD to gas column correlation. The estimation of global emissions from biomass burning currently has very large associated uncertainties. The use of visible radiances measured by satellites, and hence AOD, could significantly reduce these uncertainties by giving a direct estimate of global emissions of gases from biomass burning through application of the AOD to gas correlation. On a more local level, satellite-derived aerosol optical depth maps could be inverted to infer approximate concentration levels of smoke-related pollutants at the ground and in the lower troposphere, and thus can be used to determine the nature of any significant health impacts.

  20. Modeling the kinetics of methane conversion in steam reforming process of coke-oven gas based on experimental data

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jia-yuan; ZHOU Jie-min

    2007-01-01

    Steam-reforming is an effective approach for upgrading methane and hydrocarbon of coke-oven gas into CO and H2, but the kinetic behavior needs more study. We investigated the conversion of methane in coke-oven gas by steam reforming process in an electric tubular flow at 14 kPa with temperature varying from 500℃ to 950℃, and developed a kenetic model for , ignoring the effects of adsorption and diffusion. The optimal dynamic conditions for methane conversion 14 kPa are as follows: the ratio of the amount of water to the amount of methane is from 1.1 to 1.3; the reaction temperature is from 1 223 K to 1 273 K. The methane conversion rate is larger than 95% when the ratio of the amount of water to the amount of methane is 1.2 at a temperature above 1 223 K with the residence time up to 0.75 s.

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Abdulkareem, A.S.

    2005-01-01

    Our life is completely dependent on a reliable and adequate supply of energy. In other to reduce dependence on fossil fuels, the use of animal dung in producing a renewable alternative source of energy has been proved using cow dung. This work is aimed at produced and refined bio - gas from animal dung by reduces the H2S and CO2 content of bio - gas in other to improved the quality of the bio - gas to be used as an alternative to the petroleum based produces in use now. The sample of gas prod...

  3. Power generation from a 7700C heat source by means of a main steam cycle, a topping closed gas cycle and an ammonia bottoming cycle

    International Nuclear Information System (INIS)

    For power generap)on, steam cycles make an efficient use of medium temperature heat sources. They can be adapted to dry cooling, higher power ratings and output increase in winter by addition of an ammonia bottoming cycle. Active development is carried out in this field by ''Electricite de France''. It is shown that a satisfactory result, for heat sources of about 770 C, is obtained with a topping glosed gas cycle of moderate power rating, rejecting its waste heat into the main steam cygle. Attention has to be paid to the gas turbine cycle waste heat recovery and to the coupling of the gas turbine and steam cycles. This concept drastically reduces the importance of new technology components. 17 refs

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

    Science.gov (United States)

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

    1976-01-01

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

  5. Neutronic analysis of water-steam injection accidents for generation 4 gas-cooled fast reactors - 201

    International Nuclear Information System (INIS)

    The present paper is addressing the static neutronic analysis, and a code-to-code validation, of water-steam injection accidents for three different Gas-cooled Fast Reactor (GFR) core designs. It is assumed that this type of accident can occur as consequence of either the rupture of a pipe in the main steam generator or a leak in the decay heat removal heat exchanger. The analysis is focused on fast-spectrum, helium-cooled systems currently being developed and investigated in the context of the Generation IV International Forum (GIF) and the 6. Framework Program of the European Union. More specifically, two 2400 MWth GFR cores and a small-size 50 MWth GFR demonstrator have been analyzed and systematically compared for a large range of water-steam densities from 0 (dry core) to 250 kg/m3 within the core. The neutronic analysis was performed using both the deterministic system code ERANOS-2.1 and the Monte Carlo method MCNPX-2.5 code, in association with modern nuclear data libraries, i.e. JEF-2.2 and ERALIB1 (adjusted library) for ERANOS, and JEF-2.2 for MCNPX. First, simulations were performed based on cell models and then with whole core representation, in order to ease the code-to-code comparison. Based on the core analysis, the keff-value for the two GFR core designs is seen to first increase with the water-steam density, and then, beyond 40-100 kg/m3, to decrease monotonically. On the contrary, for ETDR, the keff-value increases throughout the analyzed water-steam density range. Globally, a good agreement is obtained between the deterministic and stochastic results, the discrepancy being in the range of a few hundreds of pcm. Additional investigations have been conducted on effects such as the neutron spectrum softening, leakage reduction and the contribution of structural materials. It has been observed that non-conventional materials, such as tungsten, play a major role and help counteract the positive reactivity effect. Finally, the analysis has shown the

  6. 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)

  7. Biomass & Natural Gas Based Hydrogen Fuel For Gas Turbine (Power Generation)

    Science.gov (United States)

    Significant progress has been made by major power generation equipment manufacturers in the development of market applications for hydrogen fuel use in gas turbines in recent years. Development of a new application using gas turbines for significant reduction of power plant CO2 e...

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

    Energy Technology Data Exchange (ETDEWEB)

    Waldner, M. H.

    2007-07-01

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

  9. Thermoeconomic modeling and parametric study of hybrid SOFC-gas turbine-steam turbine power plants ranging from 1.5 to 10 MWe

    Science.gov (United States)

    Arsalis, Alexandros

    Detailed thermodynamic, kinetic, geometric, and cost models are developed, implemented, and validated for the synthesis/design and operational analysis of hybrid SOFC-gas turbine-steam turbine systems ranging in size from 1.5 to 10 MWe. The fuel cell model used in this research work is based on a tubular Siemens-Westinghouse-type SOFC, which is integrated with a gas turbine and a heat recovery steam generator (HRSG) integrated in turn with a steam turbine cycle. The current work considers the possible benefits of using the exhaust gases in a HRSG in order to produce steam which drives a steam turbine for additional power output. Four different steam turbine cycles are considered in this research work: a single-pressure, a dual-pressure, a triple pressure, and a triple pressure with reheat. The models have been developed to function both at design (full load) and off-design (partial load) conditions. In addition, different solid oxide fuel cell sizes are examined to assure a proper selection of SOFC size based on efficiency or cost. The thermoeconomic analysis includes cost functions developed specifically for the different system and component sizes (capacities) analyzed. A parametric study is used to determine the most viable system/component syntheses/designs based on maximizing total system efficiency or minimizing total system life cycle cost.

  10. Thermal plasma generated in gas-water torch and its utilization for gasification of biomass

    Czech Academy of Sciences Publication Activity Database

    Kavka, Tetyana; Hrabovský, Milan; Konrád, Miloš; Mašláni, Alan

    Bratislava, Slovensko : Comenius University Press, 2007 - (Matúška, J.; Matejčík, Š.; Skalný, J.). s. 197-198 ISBN 978-80-89186-13-6. [Symposium on Application of Plasma Processes/16th./. 20.1.2007-25.1.2007, Podbanske] R&D Projects: GA ČR(CZ) 202/05/0669 Institutional research plan: CEZ:AV0Z20430508 Source of funding: V - iné verejné zdroje Keywords : Thermal plasma jet * gasification * biomass Subject RIV: BL - Plasma and Gas Discharge Physics http:// neon .dpp.fmph.uniba.sk/sapp/

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

    NARCIS (Netherlands)

    Sallevelt, Johan Leonard Hendrik Pieter

    2015-01-01

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

  12. Evaluation of Various Solid Biomass Fuels Using Thermal Analysis and Gas Emission Tests

    Directory of Open Access Journals (Sweden)

    Hiroshi Koseki

    2011-04-01

    Full Text Available Various recently proposed biomass fuels are reviewed from the point of view of their safety. Many biomass materials are proposed for use as fuels, such as refuse derived fuel (RDF, wood chips, coal-wood mixtures, etc. However, these fuels have high energy potentials and can cause fires and explosions. We have experienced many such incidents. It is very difficult to extinguish fires in huge piles of biomass fuel or storage facilities. Here current studies on heat generation for these materials and proposed evaluation methods for these new developing materials in Japan are introduced, which are consistent with measurements using highly sensitive calorimeters such as C80, or TAM, and gas emission tests. The highly sensitive calorimeters can detect small heat generation between room temperature and 80 °C, due to fermentation or other causes. This heat generation sometimes initiates real fires, and also produces combustible gases which can explode if fuel is stored in silos or indoor storage facilities.

  13. Biomass energy conversion: conventional and advanced technologies

    International Nuclear Information System (INIS)

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

  14. Production of a gas rich in hydrogen from gasification of biomass

    International Nuclear Information System (INIS)

    The gasification consists in a thermal transformation of a strong fuel (coal, peat, wood...) in presence of a sparkling compound (O2, air, CO, steam of water...). The goal of this transformation is generally to convert the strong in view of the obtaining of a combustible sparkling mixture. She/it distinguishes herself/itself therefore of the pyrolysis, thermal operation taking place in the absence of gas reacting with the strong follows a partial oxidation of pyrolysis products in presence of oxygen or air to a temperature of 600 to 1.000 C. One gets a gas satisfying the CO, of the CO2, of the H2.... The generated gas is a fuel that can be used then in furnaces or purified and used in turbines to room of combustion and batteries to fuels. This transformation puts in game a set of thermochemical mechanisms, pyrolysis, oxidation and reduction, greatly coupled, that condition the working of a gasification process and whose optimization imposes the technological constraints of which some are only raised partially at this day. (authors)

  15. ALTENER - Biomass event in Finland

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

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

    International Nuclear Information System (INIS)

    Life cycle inventory models of greenhouse gas emissions from biofuel production have become tightly integrated into government mandates and other policies to encourage biofuel production. Current models do not include life cycle impacts of biomass storage or reflect current literature on emissions from soil and biomass decomposition. In this study, the GREET model framework was used to determine net greenhouse gas emissions during ethanol production from corn and switchgrass via three biomass storage systems: wet ensiling of whole corn, and indoor and outdoor dry bale storage of corn stover and switchgrass. Dry matter losses during storage were estimated from the literature and used to modify GREET inventory analysis. Results showed that biomass stability is a key parameter affecting fuel production per farmed hectare and life cycle greenhouse gas emissions. Corn silage may generate 5358 L/ha of ethanol at 26.5 g CO2 eq/MJ, relative to 5654 L/ha at 52.3 g CO2 eq/MJ from combined corn stover and conventional grain corn ethanol production, or 3919 L/ha at 21.3 g CO2 eq/MJ from switchgrass. Dry matter losses can increase net emissions by 3–25% (ensiling), 5–53% (bales outdoors), or 1–12% (bales indoors), decreasing the net GHG reduction of ethanol over gasoline by up to 10.9%. Greater understanding of biomass storage losses and greenhouse gas fluxes during storage is necessary to accurately assess biomass storage options to ensure that the design of biomass supply logistics systems meet GHG reduction mandates for biofuel production. -- Highlights: ► Analyzed the impact of biomass loss during storage. ► Probable dry matter losses strongly depend on storage method and infrastructure. ► Assessed impact of storage losses on LCA for cellulosic ethanol production. ► Storage losses increase GHG emissions by 1–53% depending upon storage conditions.

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Jorge E. Preciado

    2012-11-01

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

  20. Effect of a condensation utilizer on the operation of steam and hot-water gas-fired boilers

    Science.gov (United States)

    Ionkin, I. L.; Ragutkin, A. V.; Roslyakov, P. V.; Supranov, V. M.; Zaichenko, M. N.; Luning, B.

    2015-05-01

    Various designs for condensation utilizers of the low-grade heat of furnace gases that are constructed based on an open-type heat exchanger are considered. Computational investigations are carried out for the effect of the condensation utilizer with tempering and moistening of air on the operation of steam and hot-water boilers burning natural gas. The investigations are performed based on the predeveloped adequate calculating models of the steam and hot-water boilers in a Boiler Designer program complex. Investigation results for TGM-96B and PTVM-120 boilers are given. The enhancement of the operation efficiency of the condensation utilizer can be attained using a design with tempering and moistening of air supplied to combustion that results in an insignificant increase in the temperature of waste gases. This has no effect on the total operation efficiency of the boiler and the condenser unit, because additional losses with waste gases are compensated owing to the operation of the last. The tempering and moistening of air provide a substantial decrease in the temperature in the zone of active combustion and shortening the nitrogen oxide emission. The computational investigations show that the premoistening of air supplied to combustion makes the technical and economic efficiency of boilers operating with the Condensation Utilizer no worse.

  1. Techno-economic study of a heat pump enhanced flue gas heat recovery for biomass boilers

    International Nuclear Information System (INIS)

    An active condensation system for the heat recovery of biomass boilers is evaluated. The active condensation system utilizes the flue gas enthalpy exiting the boiler by combining a quench and a compression heat pump. The system is modelled by mass and energy balances. This study evaluates the operating costs, primary energy efficiency and greenhouse gas emissions on an Austrian data basis for four test cases. Two pellet boilers (10 kW and 100 kW) and two wood chip boilers (100 kW and 10 MW) are considered. The economic analysis shows a decrease in operating costs between 2% and 13%. Meanwhile the primary energy efficiency is increased by 3–21%. The greenhouse gas emissions in CO2 equivalents are calculated to 15.3–27.9 kg MWh−1 based on an Austrian electricity mix. The payback time is evaluated on a net present value (NPV) method, showing a payback time of 2–12 years for the 10 MW wood chip test case. - Highlights: • A heat pump was studied to recover both sensible and latent heat of the flue gas. • The economic analysis shows a decrease in operating costs between 2% and 13%. • For a 10 MW wood chip boiler a payback time of 2–12 years was estimated

  2. Demonstration of a steam jet scrubber off-gas system and the burner efficiency of a mixed incinerator facility

    International Nuclear Information System (INIS)

    A full-scale incinerator system, the Consolidated Incineration Facility (CIF), is being designed to process solid and liquid low-level radioactive, mixed, and RCRA hazardous waste. This facility will consist of a rotary kiln, secondary combustion chamber (SCC), and a wet of-gas system. A prototype steam jet scrubber wastewater will be immobilized in a cement matrix after assumptions for the CIF. The scrubber wastewater will be immobilized in a cement matrix after the blowdown has been concentrated to a maximum solids concentration in a cross-flow filtration system. A sintered metal inertial filter system has been successfully tested. Burner efficiency was tested in a high intensity vortex burner, which destroyed the hazardous waste streams tested. These tests are detailed by the authors

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

    Directory of Open Access Journals (Sweden)

    Barari Bamdad

    2012-01-01

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

  4. Optimisation of environmental gas cleaning routes for solid wastes cogeneration systems Part I - Analysis of waste incineration steam cycle

    International Nuclear Information System (INIS)

    Research of advanced technologies for energy generation contemplates a series of alternatives that are introduced both in the investigation of new energy sources and in the improvement and/or development of new components and systems. Even though significant reductions are observed in the amount of emissions, the proposed alternatives require the use of exhaust gases cleaning systems. The results of environmental analyses based on two configurations proposed for urban waste incineration are presented in this paper; the annexation of integer (Boolean) variables to the environomic model makes it possible to define the best gas cleaning routes based on exergetic cost minimisation criteria. In this first part, the results for steam cogeneration system analysis associated with the incineration of municipal solid wastes (MSW) is presented

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Terry Brown; Jeffrey Morris; Patrick Richards; Joel Mason

    2010-09-30

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

  7. The methods and tools for system analysis of surface heat exchangers of steam-gas turbine and oil-electrical energy installations

    OpenAIRE

    ГАНЖА, А. Н.; Марченко, Н. А.

    2010-01-01

    The methods and tools for system analysis of heat-exchange equipments of steam-gas turbine and oil-electrical energy installations are developed. The methodic and dependences can use for solution of optimization tasks. The apparatus effectiveness depending on surface composition and generalized parameters that reflects of heat-transfer rates, relation of heat carrier expense, operational and technological factors are investigated.

  8. Local heat transfer coefficients for forced-convection condensation of steam in a vertical tube in the presence of a noncondensable gas

    International Nuclear Information System (INIS)

    An experimental investigation has been conducted to determine the local condensation heat transfer coefficient (HTC) of steam in the presence of air or helium flowing downward inside a 46-mm-i.d. vertical tube. The gas-steam mixture flow rate was measured with a calibrated vortex flowmeter before it entered the 2.54-m-long test condenser. Cooling water flow rate in an annulus around the tube was measure with a calibrated rotameter. Temperatures of the cooling water, the gas-steam mixture, and the tube inside and outside surfaces were measured at 0.3-m intervals in the test condenser. Inlet and exit pressures and temperatures of the gas-steam mixture and of the cooling water were also measured. The local heat flux was obtained from the slope of the coolant axial temperature profile and the coolant mass flow rate. It was found that for the same mass fraction of the noncondensable gas, compared with air, helium has a more inhibiting effect on the heat transfer, but for the same molar ratio, air was found to be more inhibiting. An application where there is important is the proposed advanced passive boiling water reactor design (Simplified Boiling Water Reactor), which utilizes the isolation condenser as a main component of the passive containment cooling system (PCCS)

  9. Biogas from lignocellulosic biomass

    Energy Technology Data Exchange (ETDEWEB)

    Berglund Odhner, Peter; Schabbauer, Anna [Grontmij AB, Stockholm (Sweden); Sarvari Horvath, Ilona; Mohseni Kabir, Maryam [Hoegskolan i Boraas, Boraas (Sweden)

    2012-01-15

    Grontmij AB has cooperated with the University of Boraas to evaluate the technological and economical possibilities for biogas production from substrates containing lignocellulose, such as forest residues, straw and paper. The state of knowledge regarding biogas production from cellulosic biomass has been summarized. The research in the field has been described, especially focusing on pretreatment methods and their results on increased gas yields. An investigation concerning commercially available pretreatment methods and the cost of these technologies has been performed. An economic evaluation of biogas production from lignocellulosic materials has provided answers to questions regarding the profitability of these processes. Pretreatment with steam explosion was economically evaluated for three feedstocks - wood, straw and paper - and a combination of steam explosion and addition of NaOH for paper. The presented costs pertain to costs for the pretreatment step as it, in this study, was assumed that the pretreatment would be added to an existing plant and the lignocellulosic substrates would be part of a co-digestion process. The results of the investigation indicate that it is difficult to provide a positive net result when comparing the cost of pretreatment versus the gas yield (value) for two of the feedstocks - forest residues and straw. This is mainly due to the high cost of the raw material. For forest residues the steam pretreatment cost exceeded the gas yield by over 50 %, mainly due to the high cost of the raw material. For straw, the production cost was similar to the value of the gas. Paper showed the best economic result. The gas yield (value) for paper exceeded the pretreatment cost by 15 %, which makes it interesting to study paper further.

  10. Thermochemical gas production from biomass - pyrolysis and gasification. Papers of a seminar organized by the Energy Research Project Manager in cooperation with the German Society for Technical Collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Gehrmann, J. (ed.)

    1981-11-01

    A collection of papers are presented which were given on November 12 and 13, 1981 at the Juelich Nuclear Research Institute. The topics include pyrolysis and vaporization from biomass, gas fuel production from biomass, energy production from biomass, and various concepts on energy supply and systems. Papers are accompanied by diagrams and illustrations.

  11. Steam Bottoming Cycles for the W20V34SG Gas Engine

    OpenAIRE

    Petrov, Miroslav

    2006-01-01

    Modern internal combustion engines fired with natural gas offer comparatively low installation costs, long life, good efficiency characteristics, and show reliable performance in power applications. Additional positive features such as short delivery times, quick start-up, and retained high efficiency at part-loads have made gas engines the preferred choice for many small- to medium-scale power plants. Wärtsilä’s gas engine portfolio offers several well-proven engine models optimised for stat...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-01

    The main constituents rendering the engine use of gas produced from biomass are the tar content of the gases (condensing hydrocarbons), which cause problems for pipings, nozzles, and control of combustion. Purification methods, based on catalytic cracking of tars are investigated in the research in order to eliminate these problems. The target of the project is to demonstrate the developed gasification/gas purification process with engine test using PDU-scale equipment. Impurities of biomasses and biomass wastes (alkalis, chlorine, heavy metals), and the ash melting properties restrict in many cases the combined utilisation of biomasses and coal in power plant boilers. The second main task of this research is to investigate the removal of the problematic gas and ash components from the product gas. The sufficient degree of purification should be achieved by as simple and as cheap purification methods as possible. The main tasks of the first year of the project were (a) determination of the dimensioning characteristics of ambient pressure PDU scale cell-catalyst reactor (tests with laboratory-scale equipment), designing and construction of the reactor, (b) to investigate the operation of a cell-catalyst in purification of pre-cracked down-draft gasification gas, (c) acquisition of dimensioning data for dolomite-cracker based on fluidized bed principle, and (d) gasification of the Dutch building demolition waste and Danish straw, and the purification tests with the gases

  13. Thermodynamic analysis of biomass gasification with CO2 recycle for synthesis gas production

    International Nuclear Information System (INIS)

    Highlights: • Cold gas efficiency does not take system energy into account, another factor is proposed. • Recycled CO2 improves efficiency and CO2 per syngas production at some operating conditions. • Optimum CO2/C is around 0.1–0.2 for pressurized and low temperature gasification. - Abstract: Thermodynamic analysis of biomass gasification with recycled CO2 was investigated in this work to determine optimum operation mode and CO2/C ratio. Gasification System Efficiency (GSE), which takes into account the energy demand in the system, and CO2 emission per syngas production (CO2/Sg) were calculated to evaluate the performance of the gasification system. Considering the production of syngas at a H2/CO ratio of 1.5, it was revealed that indirect gasification using biomass as fuel is the most efficient and environmental-friendly operation mode. The recycled CO2 proves to increase syngas production. However, when considering the additional energy demand required for processing the CO2 recycle, it was demonstrated that there are only some ranges of operating conditions (high pressure and low temperature) which offer the benefit of the CO2 recycle. The optimum CO2/C was reported to be around 0.1–0.2 for pressurized and low temperature gasification

  14. Biomass torrefaction mill

    Science.gov (United States)

    Sprouse, Kenneth M.

    2016-05-17

    A biomass torrefaction system includes a mill which receives a raw biomass feedstock and operates at temperatures above 400 F (204 C) to generate a dusty flue gas which contains a milled biomass product.

  15. Integrated biomass utilization system developments (Kyoto-Bio-Cycle Project) and the effects of greenhouse gas reduction

    International Nuclear Information System (INIS)

    Full text: The biomass available in Kyoto City located in urban area of Japan was estimated to be 2.02x106 t-wet/ yr (0.14x106 k liter/ yr oil equivalent), of which waste paper, waste timber, waste food, unused forest wood from the surrounding mountains and sewage sludge account for the largest amounts on an energy basis. These types of biomass can contribute to utilize for the reduction of fossil fuel consumption and for the reduction of greenhouse gas (GHG) emission. Therefore we started the Kyoto-Bio-Cycle Project (FY 2007-2009), which is the demonstration of renewable energy conversion technologies from the biomass. Specifically, we aimed for the greening of necessary materials such as methanol and the cyclic use of byproducts, with the bio diesel fuel production from used cooking oil (5 k liter-methyl ester/ day) as the core activity. Two technologies are being developed as part of the project. One is gasification and methanol synthesis to synthesize methanol with the pyrolytic gas generated from woody biomass. The other is high efficiency bio gasification that treats waste food, waste paper, and waste glycerin. This technology can improve the production rate of biogas and reduce the residue through the introduction of 80 degree Celsius-hyper-thermophilic hydrolysis in the 55 degree Celsius-thermophilic anaerobic fermentation process. These systems can produce 4 types of renewable energy such as bio diesel fuel, biogas, electricity and heat. And we conducted the life-cycle system analysis of GHG reduction effect for the demonstrating technologies, additionally we examined an optimum method of biomass utilization in the future low-carbon-society. As a result, the method that produces the liquid fuel (methanol, Ft oil) from dry biomass (waste timber, etc.) and the biogas from wet biomass (waste food, etc.) can reduce GHG emission highly at present and in the future, compared with the current direct combustion of biomass for the power generation. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Tsimpanogiannis, Ioannis N.; Yortsos, Yanis C.

    2002-06-11

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

  17. Hydrogen-based power generation from bioethanol steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Tasnadi-Asztalos, Zs., E-mail: tazsolt@chem.ubbcluj.ro; Cormos, C. C., E-mail: cormos@chem.ubbcluj.ro; Agachi, P. S. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos, Postal code: 400028, Cluj-Napoca (Romania)

    2015-12-23

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO{sub 2} emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  18. Hydrogen-based power generation from bioethanol steam reforming

    Science.gov (United States)

    Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

    2015-12-01

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

  19. Hydrogen-based power generation from bioethanol steam reforming

    International Nuclear Information System (INIS)

    This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint

  20. Reducing life cycle greenhouse gas emissions of corn ethanol by integrating biomass to produce heat and power at ethanol plants

    International Nuclear Information System (INIS)

    A life-cycle assessment (LCA) of corn ethanol was conducted to determine the reduction in the life-cycle greenhouse gas (GHG) emissions for corn ethanol compared to gasoline by integrating biomass fuels to replace fossil fuels (natural gas and grid electricity) in a U.S. Midwest dry-grind corn ethanol plant producing 0.19 hm3 y-1 of denatured ethanol. The biomass fuels studied are corn stover and ethanol co-products [dried distillers grains with solubles (DDGS), and syrup (solubles portion of DDGS)]. The biomass conversion technologies/systems considered are process heat (PH) only systems, combined heat and power (CHP) systems, and biomass integrated gasification combined cycle (BIGCC) systems. The life-cycle GHG emission reduction for corn ethanol compared to gasoline is 38.9% for PH with natural gas, 57.7% for PH with corn stover, 79.1% for CHP with corn stover, 78.2% for IGCC with natural gas, 119.0% for BIGCC with corn stover, and 111.4% for BIGCC with syrup and stover. These GHG emission estimates do not include indirect land use change effects. GHG emission reductions for CHP, IGCC, and BIGCC include power sent to the grid which replaces electricity from coal. BIGCC results in greater reductions in GHG emissions than IGCC with natural gas because biomass is substituted for fossil fuels. In addition, underground sequestration of CO2 gas from the ethanol plant's fermentation tank could further reduce the life-cycle GHG emission for corn ethanol by 32% compared to gasoline.

  1. Technical and economic analyses of a hydrogen-fed gas turbine with steam injection and co-generation

    International Nuclear Information System (INIS)

    Enel has been working on a hydrogen programme dealing with both hydrogen production and uses. The first phase deals with a hydrogen-fed, gas turbine-based co-generative cycle, in which steam injection in the gas turbine itself is adopted in order to couple high process efficiencies with very low nitrous oxide emissions. This paper presents the main results of the co-generative cycle thermodynamic analysis and focuses on the plant economic evaluations under different economic and regulatory scenarios. Results show that hydrogen can be used very effectively in this kind of plant, where electricity efficiency can reach 40% and global co-generation efficiencies can also exceed 90% in relatively small-scale power plants. However, the very high specific investment costs associated with small plants require promotion policies to be applied in order to allow profitable investments. In the future, this kind of plant could provide densely populated areas with electricity and heat with no additional side-effects on the environment. (author)

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

    Science.gov (United States)

    Siriwardane, Ranjani V; Fisher, II, James C

    2013-12-31

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

  3. Flash pyrolysis at high temperature of ligno-cellulosic biomass and its components - production of synthesis gas; Pyrolyse flash a haute temperature de la biomasse ligno-cellulosique et de ses composes - production de gaz de synthese

    Energy Technology Data Exchange (ETDEWEB)

    Couhert, C

    2007-11-15

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

  4. Biomass and leaf-level gas exchange characteristics of three African savanna C4 grass species under optimum growth conditions

    NARCIS (Netherlands)

    Mantlana, K.B.; Veenendaal, E.M.; Arneth, A.; Grispen, V.; Bonyongo, C.M.; Heitkönig, I.M.A.; Lloyd, J.

    2009-01-01

    C4 savanna grass species, Digitaria eriantha, Eragrostis lehmanniana and Panicum repens, were grown under optimum growth conditions with the aim of characterizing their above- and below-ground biomass allocation and the response of their gas exchange to changes in light intensity, CO2 concentration

  5. The use of flue gas for the growth of microalgal biomass

    International Nuclear Information System (INIS)

    Capture and utilization of carbon dioxide (CO2) by microalgae is a promising technology to help reduce emissions from fossil fuel-fired power plants. Microalgae are of particular interest because of their rapid growth rates and tolerance to varying environmental conditions. Laboratory work is directed toward investigating the effects of simulated flue gas on microalgae, while engineering studies have focused on the economics of the technology. One strain of a green algae, Monoraphidium minutum, has shown excellent tolerance and growth when exposed to simulated flue gas which meets the requirements of the 1990 Clean Air Act Amendments (1990 CAAA). Biomass concentrations of ∼2g/L have been measured in batch culture. Several other microalgae have also shown tolerance to simulated flue gas; however, the growth of these strains is not equivalent to that observed for M. minutum. Coupling the production of biodiesel or other microalgae-derived commodity chemicals with the use of flue gas carbon dioxide is potentially a zero-cost method of reducing the amount of carbon dioxide contributed to the atmosphere by fossil fuel-fired power plants. We have identified two major biological performance parameters which can provide sufficient improvement in this technology to render it cost-competitive with other existing COx mitigation technologies. These are algal growth rate and lipid content. An updated economic analysis shows that growth rate is the more important of the two, and should be the focus of near term research activities. The long term goal of achieving zero cost will require other, non-biological, improvements in the process

  6. The use of flue gas for the growth of microalgal biomass

    Energy Technology Data Exchange (ETDEWEB)

    Zeiler, K.G.; Kadam, K.L.; Heacox, D.A. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1995-11-01

    Capture and utilization of carbon dioxide (CO{sub 2}) by microalgae is a promising technology to help reduce emissions from fossil fuel-fired power plants. Microalgae are of particular interest because of their rapid growth rates and tolerance to varying environmental conditions. Laboratory work is directed toward investigating the effects of simulated flue gas on microalgae, while engineering studies have focused on the economics of the technology. One strain of a green algae, Monoraphidium minutum, has shown excellent tolerance and growth when exposed to simulated flue gas which meets the requirements of the 1990 Clean Air Act Amendments (1990 CAAA). Biomass concentrations of {similar_to}2g/L have been measured in batch culture. Several other microalgae have also shown tolerance to simulated flue gas; however, the growth of these strains is not equivalent to that observed for M. minutum. Coupling the production of biodiesel or other microalgae-derived commodity chemicals with the use of flue gas carbon dioxide is potentially a zero-cost method of reducing the amount of carbon dioxide contributed to the atmosphere by fossil fuel-fired power plants. We have identified two major biological performance parameters which can provide sufficient improvement in this technology to render it cost-competitive with other existing CO{sub x} mitigation technologies. These are algal growth rate and lipid content. An updated economic analysis shows that growth rate is the more important of the two, and should be the focus of near term research activities. The long term goal of achieving zero cost will require other, non-biological, improvements in the process.

  7. Explosiveness of mist/steam/air or mist/gas/air mixtures

    International Nuclear Information System (INIS)

    The accidental release of a pressurized gas or liquid not only may lead to an explosive gas- or vapour-cloud, but even more may form a mist/gas/air-cloud (hybrid mixture cloud) and so risk analysis is faced with the question, if such hybrid mixtures may give rise to higher flame speeds and consequently higher explosion pressurizes and more severe damages than gas- or vapour-clouds of comparable turbulence and fuel concentration. This question is dealt with by measuring the flame velocities of test mixtures (octanol mist, propan gas and air) in a 1,7 m3 vessel; the turbulence, the concentration of gaseous and liquid fuel and the mean drop size of the liquid phase are investigated as influencing parameters. Concerning the generation of the mist component the results indicate, that explosive mist/air-mixtures of moderate (e.g. atmospheric) turbulence are instable with respect to droplet-coagulation and so - due to the rapid sedimentation of large coagulated droplets - the spreading of explosive mist-air-mixtures under atmospheric turbulence will be rather limited. (orig./RW)

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

    International Nuclear Information System (INIS)

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

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

    DEFF Research Database (Denmark)

    Bang-Møller, Christian; Rokni, Masoud

    2010-01-01

    A system level modelling study of three combined heat and power systems based on biomass gasification is presented. Product gas is converted in a micro gas turbine (MGT) in the first system, in a solid oxide fuel cell (SOFC) in the second system and in a combined SOFC–MGT arrangement in the third...... University of Denmark. The SOFC converts the syngas more efficiently than the MGT, which is reflected by the energetic electrical efficiency of the gasifier and MGT system in opposition to the gasifier and SOFC configuration – η_el = 28.1% versus η_el = 36.4%. By combining the SOFC and MGT, the unconverted...... syngas from the SOFC is utilised in the MGT to produce more power and the SOFC is pressurised, which improves the efficiency to as much as η_el = 50.3%. Variation of the different operating conditions reveals an optimum for the chosen pressure ratio with respect to the resulting electrical efficiency...

  10. Gas Transfer Controls Carbon Limitation During Biomass Production by Marine Microalgae.

    Science.gov (United States)

    Tamburic, Bojan; Evenhuis, Christian R; Suggett, David J; Larkum, Anthony W D; Raven, John A; Ralph, Peter J

    2015-08-24

    This study presents the first in-depth analysis of CO2 limitation on the biomass productivity of the biofuel candidate marine microalga Nannochloropsis oculata. Net photosynthesis decreased by 60% from 125 to 50 μmol O2 L(-1)h(-1) over a 12 h light cycle as a direct result of carbon limitation. Continuous dissolved O2 and pH measurements were used to develop a detailed diurnal mechanism for the interaction between photosynthesis, gas exchange and carbonate chemistry in the photo-bioreactor. Gas exchange determined the degree of carbon limitation experienced by the algae. Carbon limitation was confirmed by delivering more CO2 , which increased net photosynthesis back to its steady-state maximum. This study highlights the importance of maintaining replete carbon concentrations in photo-bioreactors and other culturing facilities, either by constant pH operation or preferably by designing a feedback loop based on the dissolved O2 concentration. PMID:26212226

  11. At last, an affordable commercial boiler that burns wet biomass as cleanly as oil and gas

    International Nuclear Information System (INIS)

    Over the past 16 years, Northern Light Research and Development has built 11 highly efficient and clean burning biomass combustion systems. Official emissions testing, by Bonneville/EPA, of a residential-size prototype showed that green wood can be burned as cleanly as gas and oil. Particulate emissions were 0.228 grams per hour, 1/33rd of the 1990 EPA non-catalytic woodstove laboratory emissions standard (using well-seasoned lumber), 1/65th of the average state-of-the-art catalytic woodstove emissions in recent field studies, and 1/3 of the cleanest pellet burner yet tested. This particulate emissions level is 0.0076 grains/dry standard cubic foot, one quarter of Washington's stringent Best Available Control Technology standard, which is attainable with present systems only by installing expensive cyclone separators, bag-house filters, and electrostatic precipitators. The prototype described above was tested with no stack clean-up equipment, electric fans or controls. In the same test, carbon monoxide emissions over a two hour test period were four parts per million, which is 1/7500th of the Federal Auto Emissions standard, 1/100th of the gas industry's standard for 'CO-Free Combustion,' and 1/2 of the EPA's standard for acceptable 24 hours indoor air quality

  12. 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.

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

    OpenAIRE

    Park, Chan Seung; Norbeck, Joseph N.

    2008-01-01

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

  14. Thermodynamic Analyses of Biomass Gasification Integrated Externally Fired, Post-Firing and Dual-Fuel Combined Cycles

    Directory of Open Access Journals (Sweden)

    Saeed Soltani

    2015-01-01

    Full Text Available In the present work, the results are reported of the energy and exergy analyses of three biomass-related processes for electricity generation: the biomass gasification integrated externally fired combined cycle, the biomass gasification integrated dual-fuel combined cycle, and the biomass gasification integrated post-firing combined cycle. The energy efficiency for the biomass gasification integrated post-firing combined cycle is 3% to 6% points higher than for the other cycles. Although the efficiency of the externally fired biomass combined cycle is the lowest, it has an advantage in that it only uses biomass. The energy and exergy efficiencies are maximized for the three configurations at particular values of compressor pressure ratios, and increase with gas turbine inlet temperature. As pressure ratio increases, the mass of air per mass of steam decreases for the biomass gasification integrated post-firing combined cycle, but the pressure ratio has little influence on the ratio of mass of air per mass of steam for the other cycles. The gas turbine exergy efficiency is the highest for the three configurations. The combustion chamber for the dual-fuel cycle exhibits the highest exergy efficiency and that for the post-firing cycle the lowest. Another benefit of the biomass gasification integrated externally fired combined cycle is that it exhibits the highest air preheater and heat recovery steam generator exergy efficiencies.

  15. Modelling the impact of biomass burning on atmospheric aerosol and greenhouse gas abundances

    International Nuclear Information System (INIS)

    Full text: Biomass burning (BB) emissions contribute significantly to the atmospheric composition in the domains of global green-house and reactive gases and frequently dominate aerosols and regional air quality. Due to its high variability on all time scales from hours to years, these emissions can often not be described with static inventories, but need to be derived from satellite-based fire observations of each individual situation. The global GEMS systems use several versions of the BB emission inventory GFEDv2 as baseline. In addition, a dedicated fire assimilation systems based on the Fire Radiative Power (FRP) from SEVIRI, which EUMETSAT is currently developing, has been implemented for the aerosol and greenhouse gas in the African and Southern European domain. By comparing different model and assimilation runs, we show that BB emission input is significant for both types of runs in the aerosol and greenhouse gas monitoring systems. A temporal resolution of the BB emissions of about a week appears sufficient for the greenhouse gas monitoring in GEMs, while the aerosol monitoring requires a temporal resolution of hours. The latter requirement can be generalized for reactive gases and regional air quality. A case study of the forest fires ravaging Greece in August 2008 demonstrates the capability of real-time monitoring and forecasting of large fire plumes in the future GMES atmospheric service. Complementary developments of fire assimilation systems based on observations by further fire observation from geostationary and polar orbiting platforms indicate a the development path to a truly global and real-time fire assimilation system. (author)

  16. Auto-thermal reforming of biomass raw fuel gas to syngas in a novel reformer: Promotion of hot-electron

    International Nuclear Information System (INIS)

    Highlights: • A novel reformer with porous ceramic tube circled by electric wire was designed. • The temperature uniformities along diameter and axial direction were measured. • The auto-thermal reforming of model and real biomass fuel gas was performed. • The hot electron promoted biomass fuel gas elimination mechanism was proposed. - Abstract: A novel reformer with porous ceramic oxygen distribution tube circled by electric wire for inspiring hot electron was designed for auto-thermal reforming of biomass raw fuel gas to produce syngas (H2 + CO). The temperature of auto-thermal reformer was nearly uniform due to the excellent performance of partial oxygenation reaction in the reformer with porous ceramic tube for oxygen partitioning. The hot-electron inspired by electric wire promoted the cracking of biomass tar to form radical species, which were converted effectively to syngas over nickel based catalyst. The hot-electron also played an essential role in decreasing coke deposition on the surface of nickel based catalyst, which prolonged the lifetime of the reforming catalyst

  17. Technoeconomic assessment of biomass to energy

    International Nuclear Information System (INIS)

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

  18. Exergy analysis and optimization of a biomass gasification, solid oxide fuel cell and micro gas turbine hybrid system

    DEFF Research Database (Denmark)

    Bang-Møller, Christian; Rokni, Masoud; Elmegaard, Brian

    2011-01-01

    A hybrid plant producing combined heat and power (CHP) from biomass by use of a two-stage gasification concept, solid oxide fuel cells (SOFC) and a micro gas turbine was considered for optimization. The hybrid plant represents a sustainable and efficient alternative to conventional decentralized...... CHP plants. A clean product gas was produced by the demonstrated two-stage gasifier, thus only simple gas conditioning was necessary prior to the SOFC stack. The plant was investigated by thermodynamic modeling combining zero-dimensional component models into complete system-level models. Energy and...

  19. Use of Coke Oven Gas during shutdown period of Direct Reduced Iron Plant for Steam Generation: Experimentation and Optimization

    Directory of Open Access Journals (Sweden)

    Harish C. Dalai

    2015-11-01

    Full Text Available Development of any country is largely based on its magnitude of industrial growth. Steel industries in India took a leading role in the world after mid-sixties. During the last five decades, the steel industries all over the world made considerable developments in new methods for reducing iron ore directly to metallic iron for use as commercial scrap substitute in the manufacture of steels. BSL has been producing steel and other products over last two decades and the above process is used in BSL for one decade. Direct reduction is a process, which extracts high metallic solid iron by removing oxygen from iron ore or any other iron oxides without passing through molten stage, i.e. solid state reduction. The product, so formed is known as directly reduced tron (DRI or Sponge Iron. Due to shortage of raw material or any other problem in DRI sections, the DRI section undergoes a temporary short down. During the shutdown period the equipments tend to be idle. To keep the equipment ready for operation as well as to maintain the plants economy an alternate methodology is used in this research. Various operations are: CO gas from Coke Oven, DRI, Steam Generation, and Power Generation.

  20. Influence of the heat recovery steam generator design parameters on the thermoeconomic performances of combined cycle gas turbine power plants

    Energy Technology Data Exchange (ETDEWEB)

    Valdes, Manuel; Rovira, Antonio; Duran, Ma Dolores [Universidad Politecnica de Madrid, Dept. de Ingenieria Energetica y Fluidomecanica, Madrid (Spain)

    2004-07-01

    This paper proposes a methodology to identify the most relevant design parameters that impact on the thermal efficiency and the economic results of combined cycle gas turbine power plants. The analysis focuses on the heat recovery steam generator (HRSG) design and more specifically on those operating parameters that have a direct influence on the economic results of the power plant. These results are obtained both at full and part load conditions using a dedicated code capable of simulating a wide number of different plant configurations. Two different thermoeconomic models aimed to select the best design point are proposed and compared: the first one analyzes the generating cost of the energy while the second one analyzes the annual cash flow of the plant. Their objective is to determine whether an increase in the investment in order to improve the thermal efficiency is worthwhile from an economic point of view. Both models and the different HRSG configurations analysed are compared in the results section. Some parametric analysis show how the design parameters might be varied in order to improve the power plant efficiency or the economic results. (Author)

  1. A simplified Probabilistic Safety Assesment of a Steam-Methane Reforming Hydrogen Production Plant coupled to a High-Temperature Gas Cooled Nuclear Reactor

    OpenAIRE

    Nelson Edelstein, Pamela; Flores Flores, Alain; Francois Lacouture, Juan Luis

    2005-01-01

    A Probabilistic Safety Assessment (PSA) is being developed for a steam-methane reforming hydrogen production plant linked to a High-Temperature Gas Cooled Nuclear Reactor (HTGR). This work is based on the Japan Atomic Energy Research Institute’s (JAERI) High Temperature Test Reactor (HTTR) prototype in Japan. This study has two major objectives: calculate the risk to onsite and offsite individuals, and calculate the frequency of different types of damage to the complex. A simplified HAZOP...

  2. Interaction between hydroxypropyl methylcellulose and biphasic calcium phosphate after steam sterilisation: capillary gas chromatography studies.

    OpenAIRE

    Bourges, Xavier; Schmitt, Michel; Amouriq, Yves; Daculsi, Guy; Legeay, Gilbert; Pierre WEISS

    2001-01-01

    The purpose of this study was to check the chemical stability of an injectable bone substitute (IBS) composed of a 50/50 w/w mixture of a 2.92% hydroxypropyl methylcellulose (HPMC) solution in deionised water containing biphasic calcium phosphate (BCP) granules (60% hydroxyapatite/40% β-tricalcium phosphate w/w). After separation of the organic and mineral phases, capillary gas chromatography (GC) was used to study the possible modification of HPMC due to the contact with BCP granules followi...

  3. Compact conversion of natural gas and biomass to DME in microstructured reactors

    Energy Technology Data Exchange (ETDEWEB)

    Myrstad, Rune

    2010-07-01

    Efficient production of easily distributable fuel from natural gas or biomass in the small-to-medium scale calls for a more compact and efficient process than using conventional technology. Microstructured reactors have improved heat and mass transfer properties which make them suitable for process intensified production of liquid fuel from synthesis gas and demonstration plants using such technology are announced. Dimethyl ether (DME) can be used as an intermediate in the production of several industrial chemicals and DME is also used as an aerosol propellant because of its environmentally benign properties. Since DME has high cetane number and is considered as an ultra-clean fuel with reduced NO{sub x}, SO{sub x}, and PM emissions, DME has emerged as a substitute for auto diesel fuel and bio-DME is one of the most promising second-generation biofuels. DME can be prepared in a one-step process from synthesis gas, which is thermodynamically and economically favourable to the two step process consisting of methanol synthesis followed by dehydration of methanol to DME. As the direct process is strongly exothermic, the reaction heat has to be effectively removed from the reaction system in order to maintain a safe and economic operational mode. Direct DME synthesis possesses a high volumetric heat production rate and hence the temperature control is a main challenge. Besides this, parameters such as syngas composition, pressure, contact time and catalytic system affect the conversion and yield. In this work direct DME synthesis from syngas in a microstructured packed bed reactor was demonstrated to operate at practically isothermal conditions. The performance of the catalyst was enhanced by elimination of the undesired phenomena related to the exothermic process, such as hot spot formation and side reactions. The influence of process parameters on methanol selectivity and DME productivity was studied. The highest CO conversion was achieved by a H{sub 2}-rich syngas at

  4. Experimental study of simulating high pressure steam-water two-phase flow with sulfur hexafluoride gas and ethyl alcohol liquid (droplets behavior of downward mist flow)

    International Nuclear Information System (INIS)

    The full text follows. Mist flow appears in various industrial plants and machines; nuclear power plants, chemical plants, heat exchangers, steam turbines, and so on. Behaviors of droplet have effects on heat and mass transfer process on them. As for nuclear power plants, droplet diameters of downward mist flow have an important effect on peak-clad-temperature (PCT) at loss of coolant accidents (LOCA). Reliability of two-fluid model computer codes to predict gas-liquid two-phase flow relies on the experimental database. We simulated actual pressure steam-water two-phase flow using Sulfur Hexafluoride gas and ethyl alcohol liquid two-phase flow at low pressures. The specific objectives of this study are to: (1) simulate easily a high pressure and high temperature steam-water system by using alternative fluids; (2) clarify the diameter of droplet which does not break up any more (stable droplet diameter) in the blow down phenomenon of LOCA; (3) extend the downward mist flow database to lower liquid-to-gas density ratio. We carried out the experiment of downward mist flow with two kinds of fluids: Sulfur Hexafluoride (SF6) and ethyl alcohol (C2H5OH) as gas and liquid phase, respectively. Those fluids can simulate a high pressure and temperature steam-water system of 6 MPa, and 550 K at the condition of the lower pressure and atmospheric temperature (0.5 MPa and 300 K, respectively). The physical properties of SF6 and C2H5OH are as same as steam-water system. The density ratio and surface tension, which affect on the diameter of droplet, of SF6 / C2H5OH at 0.5 MPa and 300 K is about 30 and 2.1 10-2 N/m, respectively. SF6 is widely used in electronic equipment as insulating gas. It stays in the same chemical state under the condition of atmospheric temperature and chemical decomposition due to thermal energy is not developed below 770 K. Experimental conditions of superficial gas and liquid velocities were 1.5 m/s-10 m/s and 0.01 m/s-0.03 m/s, respectively. The system

  5. Control strategy of gas-steam combined cycle units%燃气-蒸汽联合循环机组控制策略分析

    Institute of Scientific and Technical Information of China (English)

    靳允立; 於国良

    2015-01-01

    In order to provide principles and basis for design of coordinated control system (CCS)for gas-steam combined cycle units,the characteristics of control strategy of an actual gas-steam combined cycle u-nit was analyzed.The results show that,the fast response to unit load demand should be executed by gas turbine,and the steam turbine load only follows the variation of exhaust gas parameters of the gas turbine. After the coordinated control system was put into service,the gas turbine load controller,to which the co-ordinated control loop provides load set point,still needs to be placed in control loop of the gas turbine side.The main steam pressure is regulated by both the steam turbine governing valve and the bypass sys-tem which should be always put into automatic operation.Correction of power and fuel quantity of primary frequency regulation can be realized independently by the gas turbine load control loop.To meet the stress margin requirements of heat recovery boilers and steam turbines,the CCS should regulate the set point of exhaust gas temperature of the gas turbine.The inlet guide vane (IGV)regulation ought to have preced-ence over fuel regulation in controlling the exhaust gas temperature of the gas turbine.%对某燃气-蒸汽联合循环机组的联合循环协调控制策略特点进行了分析,以为该类机组协调控制系统设计提供原则和依据。结果表明:联合循环机组对负荷指令的快速响应应由燃气轮机(燃机)实现,蒸汽轮机仅随燃机排气参数的变化应做相应的负荷改变;协调控制方式投入时,燃机负荷控制器仍应置于燃机侧控制回路,协调控制仅提供负荷设定值;主蒸汽压力由蒸汽轮机调节阀和旁路系统共同控制;可由燃机负荷控制回路独立实现一次调频的功率和燃料量修正;为了满足余热锅炉、汽轮机应力裕度要求,协调控制应对燃机排气温度设定进行干预调节;压气机进口导叶(IGV)在

  6. Exploring the assumed invariance of implied emission factors for forest biomass in greenhouse gas inventories

    International Nuclear Information System (INIS)

    Reviews of each nation's annual greenhouse gas inventory submissions including forestland are part of the ongoing reporting process of the United Nations Framework Convention on Climate Change. Goals of these reviews include improving quality and consistency within and among reports. One method of facilitating comparisons is the use of a standard index such as an implied emission factor (IEF), which for forest biomass indicates net rate of carbon emission or sequestration per area. Guidance on the use of IEFs in reviews is limited, but there is an expectation that values should be relatively constant both over time and across spatial scales. To address this hypothesis, we examine IEFs over time, derived from U.S. forests at plot-, state-, and national-levels. Results show that at increasingly aggregated levels, relative heterogeneity decreases but can still be substantial. A net increase in U.S. whole-forest IEFs over time is consistent with results from temperate forests of nations in the European Community. IEFs are better viewed as a distribution of values rather than one constant value principally because of sensitivities to productivity, disturbance, and land use change, which can all vary considerably across a nation's forest land.

  7. Overview of biomass conversion technologies

    International Nuclear Information System (INIS)

    A large part of the biomass is used for non-commercial purposes and mostly for cooking and heating, but the use is not sustainable, because it destroys soil-nutrients, causes indoor and outdoor pollution, adds to greenhouse gases, and results in health problems. Commercial use of biomass includes household fuelwood in industrialized countries and bio-char (charcoal) and firewood in urban and industrial areas in developing countries. The most efficient way of biomass utilization is through gasification, in which the gas produced by biomass gasification can either be used to generate power in an ordinary steam-cycle or be converted into motor fuel. In the latter case, there are two alternatives, namely, the synthesis of methanol and methanol-based motor fuels, or Fischer-Tropsch hydrocarbon synthesis. This paper deals with the technological overview of the state-of-the-art key biomass-conversion technologies that can play an important role in the future. The conversion routes for production of Heat, power and transportation fuel have been summarized in this paper, viz. combustion, gasification, pyrolysis, digestion, fermentation and extraction. (author)

  8. Densified biomass can cost-effectively mitigate greenhouse gas emissions and address energy security in thermal applications.

    Science.gov (United States)

    Wilson, Thomas O; McNeal, Frederick M; Spatari, Sabrina; G Abler, David; Adler, Paul R

    2012-01-17

    Regional supplies of biomass are currently being evaluated as feedstocks in energy applications to meet renewable portfolio (RPS) and low carbon fuel standards. We investigate the life cycle greenhouse gas (GHG) emissions and associated abatement costs resulting from using densified switchgrass for thermal and electrical energy. In contrast to the large and positive abatement costs for using biomass in electricity generation ($149/Mg CO(2)e) due to the low cost of coal and high feedstock and power plant operation costs, abatement costs for replacing fuel oil with biomass in thermal applications are large and negative (-$52 to -$92/Mg CO(2)e), resulting in cost savings. Replacing fuel oil with biomass in thermal applications results in least cost reductions compared to replacing coal in electricity generation, an alternative that has gained attention due to RPS legislation and the centralized production model most often considered in U.S. policy. Our estimates indicate a more than doubling of liquid fuel displacement when switchgrass is substituted for fuel oil as opposed to gasoline, suggesting that, in certain U.S. locations, such as the northeast, densified biomass would help to significantly decarbonize energy supply with regionally sourced feedstock, while also reducing imported oil. On the basis of supply projections from the recently released Billion Ton Report, there will be enough sustainably harvested biomass available in the northeast by 2022 to offset the entirety of heating oil demand in the same region. This will save NE consumers between $2.3 and $3.9 billion annually. Diverting the same resource to electricity generation would cost the region $7.7 billion per year. While there is great need for finding low carbon substitutes for coal power and liquid transportation fuels in the U.S., we argue that in certain regions it makes cost- (and GHG mitigation-) effective sense to phase out liquid heating fuels with locally produced biomass first. PMID

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

    International Nuclear Information System (INIS)

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

  10. Greenhouse gas balances and new business opportunities for biomass-based transportation fuels and agro biomass; Liikenteen biopolttoaineiden ja peltoenergian kasvihuonekaasutaseet ja uudet liiketoimintakonseptit

    Energy Technology Data Exchange (ETDEWEB)

    Tuula Maekinen, T.; Soimakallio, S.; Paappanen, T. [VTT, Espoo (Finland); Pahkala, K. [MTT Agrifood Research Finland, Jokioinen (Finland); Mikkola, H. [MTT, Agrifood Research Finland, Vihti (Finland)

    2006-12-19

    The aim of the project was to assess greenhouse gas balances and greenhouse gas reduction costs for biomass-based fuels used in transportation and combined heat and power production (CHP). New business opportunities were identified, and business plans for commercialisation of the most cost-effective technologies through research, development and demonstration were presented. Both the commercial technologies and the technologies under development were assessed. The main options were barley-based ethanol, biodiesel (RME), forest residue and reed canary grass-derived synthetic fuels, and forestry residues and reed canary grass as a fuel for CHP production. The whole utilisation chain from the fuel production to the end se was evaluated. The results indicated that e.g. the production and use of barley- based ethanol or rape seed-based biodiesel does not necessarily reduce greenhouse gas emissions, but can on the contrary increase the greenhouse gas emissions compared to fossil-based reference fuels. However, absolute emissions can be reduced by optimising cultivation and production chains, e.g. by utilisation straw in energy production. The second generation biofuels produced using forestry residues or reed canary grass as a raw material seems to be significantly more favourable in reducing greenhouse gases cost- effectively. (orig.)

  11. Energy Characterization and Gasification of Biomass Derived by Hazelnut Cultivation: Analysis of Produced Syngas by Gas Chromatography

    Directory of Open Access Journals (Sweden)

    D. Monarca

    2012-01-01

    Full Text Available Modern agriculture is an extremely energy intensive process. However, high agricultural productivities and the growth of green revolution has been possible only by large amount of energy inputs, especially those coming from fossil fuels. These energy resources have not been able to provide an economically viable solution for agricultural applications. Biomass energy-based systems had been extensively used for transportation and on farm systems during World War II: the most common and reliable solution was wood or biomass gasification. The latter means incomplete combustion of biomass resulting in production of combustible gases which mostly consist of carbon monoxide (CO, hydrogen (H2 and traces of methane (CH4. This mixture is called syngas, which can be successfully used to run internal combustion engines (both compression and spark ignition or as substitute for furnace oil in direct heat applications. The aim of the present paper is to help the experimentation of innovative plants for electric power production using agro-forest biomass derived by hazelnut cultivations. An additional purpose is to point out a connection among the chemical and physical properties of the outgoing syngas by biomass characterization and gas-chromatography analysis.

  12. Effect of Flue Gas on Microalgae Population and Study the Heavy Metals Accumulation in Biomass from Power Plant System

    Directory of Open Access Journals (Sweden)

    Mahendraperumal Guruvaiah

    2014-06-01

    Full Text Available Microalgae have high photosynthetic efficiency that can fix CO2 from the flue gas directly without any upstream CO2 separation, and concomitantly produce biomass for biofuel applications. These gases, both untreated and treated into current discharge standards, contain CO2, N2, H2O, O2, NOx, SOx, CxHy, CO, particulate matter, halogen acids and heavy metals. Microalgae population studies were conducted in a batch mode experiments at Power plant site of Chamois, Missouri. The experiments were conducted in different period (June to December 2011 of time. This study evaluated the effect of several heavy metals that are present in flue gases on the algae, focusing on the growth and accumulation of lipids in the algae that can be converted to biodiesel. The genus Scenedesmus presented the greatest richness of species and number of counted individuals in the flue gas ponds compare than non flue gas treatment ponds. Among the diatomaceae the genus Navicula sp, Nitizchia sp and Synedra sp. presented the next subdominant richness in the ponds. The last results of counted green algae Ulothrix sp and Coelastrum sp were least number of cells reported in these ponds. The heavy metal-contaminated in flue gas and also enter into the microalgae biomass population. Comparative studies were carried out by flue gas and control system of open ponds. Control system of microalgae population was represented in less amount of heavy metals compare than flue gas ponds.

  13. Evaluation of Various Solid Biomass Fuels Using Thermal Analysis and Gas Emission Tests

    OpenAIRE

    Hiroshi Koseki

    2011-01-01

    Various recently proposed biomass fuels are reviewed from the point of view of their safety. Many biomass materials are proposed for use as fuels, such as refuse derived fuel (RDF), wood chips, coal-wood mixtures, etc . However, these fuels have high energy potentials and can cause fires and explosions. We have experienced many such incidents. It is very difficult to extinguish fires in huge piles of biomass fuel or storage facilities. Here current studies on heat generation for these materia...

  14. Biomass Gasification Behavior in an Entrained Flow Reactor: Gas Product Distribution and Soot Formation

    DEFF Research Database (Denmark)

    Qin, Ke; Jensen, Peter Arendt; Lin, Weigang;

    2012-01-01

    Biomass gasification and pyrolysis were studied in a laboratory-scale atmospheric pressure entrained flow reactor. Effects of operating parameters and biomass types on the syngas composition were investigated. In general, the carbon conversion during biomass gasification was higher than 90% at th...... increased both the H2 and CO yields. Wood, straw, and dried 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....

  15. Rupture of a high pressure gas or steam pipe in a tunnel: A preliminary investigation of the jet thrust exerted on a tunnel barrier

    International Nuclear Information System (INIS)

    On power plant, if a high pressure pipe containing high temperature gas or steam were to rupture, sensitive equipment necessary for safety shutdown of the plant could possibly be incapacitated if exposed to the subsequent high temperature environment. In many plant configurations the high pressure pipework is contained in tunnels where it is possible to construct barriers which isolate one section of the plant from another, thereby restricting the spread of the high temperature fluid/air mixture. This paper describes a preliminary experimental investigation of the magnitude of the thrust likely to be exerted on such barriers by a gas jet issuing from the failed pipe. (orig.)

  16. Study of gas product generation out of solid biomass under the effect of temperature and ionizing radiation

    International Nuclear Information System (INIS)

    Full text: Biomass is an efficient renewable energy source. There are different types of biomass almost in all regions of the world and in each of them their conversion into energy and fuel can be adjusted. Recently the interest to obtain liquid and gaseous products out of wood raw materials by the method of pyrolysis has risen. Hemicellulose is firstly exposed to thermal destruction in the temperature range of 170-260 C degree, then follows the decomposition of cellulose (240-350 C degree) and lignin (280-500 C degree). The given work is dedicated to radiation-thermochemical conversion of the components of solid biomass of hardwood (oak, beech) and softwood (pine). The radiolysis process of solid biomass is complicated and multiform. The radiation effect on the mechanism of solid biomass conversion has not been investigated sufficiently. All products generated during radiolysis process can be divided into three main groups: decomposition and destruction products; hydrocarbon molecules; internal conversion products in which hydrocarbon chain of the generated composition contains as many carbon atoms as the chain of the initial composition. The opportunity of generating gaseous hydrocarbons at different temperature and absorbed dose has been revealed and the degree of conversion of solid biomass has been determined. It has been established that the generation of H2, CO, CO2 gases and C1-C7 hydrocarbons is detected in the composition of the radiation decomposition products of solid biomass. It has been ascertained in the dose range of D≤10 kGy ( D=0.48 Gy/sec., τ=5 hours) the value of gas generation is increasing, furthermore the growth of dose D≥10 kGy results in saturation. Thermal and radiation-thermal dependence of the conversion degree of solid biomass has been simultaneously studied. Kinetic dependence shows that gas generation processes at the temperature of 300 and 350 is increasing. In accordance with these temperature ranges the conversion degree of

  17. Experimental investigation of condensation and mixing during venting of a steam / non-condensable gas mixture into a pressure suppression pool

    International Nuclear Information System (INIS)

    Experiments have been performed in the LINX facility to investigate condensation and mixing phenomena in pressure Suppression Pools (SPs), in the context of the European Simplified Boiling Water Reactor (ESBWR) study. As a contribution to the TEPSS project of the 4th European Framework Programme, eight medium-scale, separate-effect tests were carried out in which constant steam/air flow rates were injected below the surface of a two-metre diameter water pool, maintained at constant pressure, through a large downward vent. The vessel pressure was regulated, the pool temperature rising until equilibrium conditions with the incoming gas were reached. The SP temperature distribution was measured, as well as the inlet and outlet gas flow rates, and the overall condensation rate was estimated using mass and heat balances. The test matrix was based on steam mass floret and air mass fraction of the injected gas, the vent immersion depth, and the vessel pressure. Overall, the condensation was shown to be efficient for all tests performed, even for high non-condensable gas concentrations of the injected gas. Thermal stratification above the vent outlet was shown to be moderate. The tests performed allowed a better understanding to be gained of the mechanisms of condensation and mixing in the SP and Wetwell, and results were incorporated into an ORACLE database, to be used for further model development. (authors)

  18. The impact of contaminated biomass for the formation of emission in the combustion process of producer gas in the cogeneration unit

    Science.gov (United States)

    Kočanová, Slávka; Lukáč, Ladislav; Széplaky, Dávid; Lazić, Ladislav

    2014-08-01

    The paper presents the measurement result to the equipment designed for utilization contaminated biomass with segregated waste. Presented technology gasification of segregated waste together with biomass shows the optimization process of converting solid fuel to gas and its energy utilization in the cogeneration unit.

  19. Modelling of a Biomass Gasification Plant Feeding a Hybrid Solid Oxide Fuel Cell and Micro Gas Turbine System

    DEFF Research Database (Denmark)

    Bang-Møller, Christian; Rokni, Masoud

    2009-01-01

    A system level modelling study on two combined heat and power (CHP) systems both based on biomass gasification. One system converts the product gas in a solid oxide fuel cell (SOFC) and the other in a combined SOFC and micro gas turbine (MGT) arrangement. An electrochemical model of the SOFC has...... been developed and calibrated against published data from Topsoe Fuel Cells A/S (TOFC) and Risø National Laboratory. The modelled gasifier is based on an up scaled version of the demonstrated low tar gasifier, Viking, situated at the Technical University of Denmark. The MGT utilizes the unconverted...

  20. Optimization of radial systems with biomass fueled gas engine from a metaheuristic and probabilistic point of view

    International Nuclear Information System (INIS)

    Highlights: ► Loads and distributed generation production are modeled as random variables. ► Distribution system with biomass fueled gas engines. ► Random nature of lower heat value of biomass and load. ► The Cornish–Fisher expansion is used for approximating quantiles of a random variable. ► Computational cost is low enough than that required for Monte Carlo simulation. - Abstract: This paper shows that the technical constraints must be considered in radial distribution networks, where the voltage regulation is one of the primary problems to be dealt in distributed generation systems based on biomass fueled engine. Loads and distributed generation production are modeled as random variables. Results prove that the proposed method can be applied for the keeping of voltages within desired limits at all load buses of a distribution system with biomass fueled gas engines. To evaluate the performance of this distribution system, this paper has developed a probabilistic model that takes into account the random nature of lower heat value of biomass and load. The Cornish–Fisher expansion is used for approximating quantiles of a random variable. This work introduces a hybrid method that utilizes a new optimization method based on swarm intelligence and probabilistic radial load flow. It is demonstrated the reduction in computation time achieved by the more efficient probabilistic load flow in comparison to Monte Carlo simulation. Acceptable solutions are reached in a smaller number of iterations. Therefore, convergence is more rapidly attained and computational cost is significantly lower than that required for Monte Carlo methods.

  1. Process for purifying geothermal steam

    Science.gov (United States)

    Li, C.T.

    Steam containing hydrogen sulfide is purified and sulfur recovered by passing the steam through a reactor packed with activated carbon in the presence of a stoichiometric amount of oxygen which oxidizes the hydrogen sulfide to elemental sulfur which is adsorbed on the bed. The carbon can be recycled after the sulfur has been recovered by vacuum distillation, inert gas entrainment or solvent extraction. The process is suitable for the purification of steam from geothermal sources which may also contain other noncondensable gases.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-01-01

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

  3. Exergy analysis and optimization of a biomass gasification, solid oxide fuel cell and micro gas turbine hybrid system

    International Nuclear Information System (INIS)

    A hybrid plant producing combined heat and power (CHP) from biomass by use of a two-stage gasification concept, solid oxide fuel cells (SOFC) and a micro gas turbine was considered for optimization. The hybrid plant represents a sustainable and efficient alternative to conventional decentralized CHP plants. A clean product gas was produced by the demonstrated two-stage gasifier, thus only simple gas conditioning was necessary prior to the SOFC stack. The plant was investigated by thermodynamic modeling combining zero-dimensional component models into complete system-level models. Energy and exergy analyses were applied. Focus in this optimization study was heat management, and the optimization efforts resulted in a substantial gain of approximately 6% in the electrical efficiency of the plant. The optimized hybrid plant produced approximately 290 kWe at an electrical efficiency of 58.2% based on lower heating value (LHV). -- Highlights: → Combined two-stage gasification, solid oxide fuel cells and gas turbine technology. → Hybrid plant for efficient decentralized power and heat production from biomass. → Through modeling, energy and exergy analyses reveal inefficiencies. → Optimization efforts for increased plant efficiency. → Electrical efficiency reached 58% (LHV) producing 290 kW electricity.

  4. Design and simulation of a small polygeneration plant cofiring biomass and natural gas in a dual combustion micro gas turbine (BIOMGT)

    International Nuclear Information System (INIS)

    The operation and performances of an innovative small scale polygeneration system (BIOMGT), which combines biomass and natural gas in a micro gas turbine, has been simulated in the present work by means of a thermodynamic matching analysis. The BIOMGT unit matches an externally fired cycle with a commercial Micro Gas Turbine (MGT, 100 kWe). A significant share of the total energy input (∼70%) is supplied by solid biomass: the remaining is provided by natural gas. The system is therefore characterised by a dual combustion system. The configuration of the plant has been conceived so to require only minor modifications to conventional MGTs and biomass furnaces available on the market. This paper describes the design of the proposed bioenergy plant as well as the structure and the application of the in-house developed simulation model AMOS which has been used as computer-aid design tool. The design activity compared various plant schemes available from literature or past research works. The thermodynamic matching analysis of the selected configuration was then carried out, with the aim to verify compressor and turbine working points and to compare these with those typical of the MGT working under standard natural gas conditions. The steady-state matching analysis was based on the performance maps (i.e. characteristic lines) of each component. The design specifications and operating range for main and sub-components were defined, and the BIOMGT performance maps were computed. Results showed that both the turbine as well as the compressor will work within the acceptable limits, and plant performances have also been calculated at part load conditions.

  5. Design and simulation of a small polygeneration plant cofiring biomass and natural gas in a dual combustion micro gas turbine (BIO{sub M}GT)

    Energy Technology Data Exchange (ETDEWEB)

    Riccio, G.; Chiaramonti, D. [Energetics Department ' ' S. Stecco' ' , Faculty of Mechanical Engineering, University of Florence, Via S. Marta 3, I-50139 Florence (Italy)

    2009-11-15

    The operation and performances of an innovative small scale polygeneration system (BIO{sub M}GT), which combines biomass and natural gas in a micro gas turbine, has been simulated in the present work by means of a thermodynamic matching analysis. The BIO{sub M}GT unit matches an externally fired cycle with a commercial Micro Gas Turbine (MGT, 100 kWe). A significant share of the total energy input ({proportional_to}70%) is supplied by solid biomass: the remaining is provided by natural gas. The system is therefore characterised by a dual combustion system. The configuration of the plant has been conceived so to require only minor modifications to conventional MGTs and biomass furnaces available on the market. This paper describes the design of the proposed bioenergy plant as well as the structure and the application of the in-house developed simulation model AMOS which has been used as computer-aid design tool. The design activity compared various plant schemes available from literature or past research works. The thermodynamic matching analysis of the selected configuration was then carried out, with the aim to verify compressor and turbine working points and to compare these with those typical of the MGT working under standard natural gas conditions. The steady-state matching analysis was based on the performance maps (i.e. characteristic lines) of each component. The design specifications and operating range for main and sub-components were defined, and the BIO{sub M}GT performance maps were computed. Results showed that both the turbine as well as the compressor will work within the acceptable limits, and plant performances have also been calculated at part load conditions. (author)

  6. Design and simulation of a small polygeneration plant cofiring biomass and natural gas in a dual combustion micro gas turbine (BIOMGT)

    International Nuclear Information System (INIS)

    The operation and performances of an innovative small scale polygeneration system (BIOMGT), which combines biomass and natural gas in a micro gas turbine, has been simulated in the present work by means of a thermodynamic matching analysis. The BIOMGT unit matches an externally fired cycle with a commercial Micro Gas Turbine (MGT, 100 kWe). A significant share of the total energy input (∝70%) is supplied by solid biomass: the remaining is provided by natural gas. The system is therefore characterised by a dual combustion system. The configuration of the plant has been conceived so to require only minor modifications to conventional MGTs and biomass furnaces available on the market. This paper describes the design of the proposed bioenergy plant as well as the structure and the application of the in-house developed simulation model AMOS which has been used as computer-aid design tool. The design activity compared various plant schemes available from literature or past research works. The thermodynamic matching analysis of the selected configuration was then carried out, with the aim to verify compressor and turbine working points and to compare these with those typical of the MGT working under standard natural gas conditions. The steady-state matching analysis was based on the performance maps (i.e. characteristic lines) of each component. The design specifications and operating range for main and sub-components were defined, and the BIOMGT performance maps were computed. Results showed that both the turbine as well as the compressor will work within the acceptable limits, and plant performances have also been calculated at part load conditions. (author)

  7. Use of California biomass in the production of transportation-fuel oxygenates: Estimates for reduction in CO2 emissions and greenhouse gas potential on a life cycle basis

    International Nuclear Information System (INIS)

    A set of environmental flows associated with two disposal options for thee types of California biomass - forest biomass, rice straw, chaparral - over their life cycles were studied, the emphasis being on energy consumption and greenhouse gas emissions. The two options studied were: producing ethyl-tertiary-butyl ether (ETBE) from biomass and biomass burning, and producing methyl-tertiary-butyl ether (MTBE) from natural gas. Results showed a lower (by 40 to 50 per cent) greenhouse effect impact, lower net values for carbon dioxide and fossil fuel energy consumption, and higher net values for renewable energy consumption for the ETBE option. Based on these results, the deployment of the biomass-to-ethanol ETBE option is recommended as the one that contributes most to the reduction of GHG emissions. 12 refs., 2 tabs., 5 figs

  8. A Medium-Scale 50 MWfuel Biomass Gasification Based Bio-SNG Plant: A Developed Gas Cleaning Process

    Directory of Open Access Journals (Sweden)

    Ramiar Sadegh-Vaziri

    2015-06-01

    Full Text Available Natural gas is becoming increasingly important as a primary energy source. A suitable replacement for fossil natural gas is bio-SNG, produced by biomass gasification, followed by methanation. A major challenge is efficient gas cleaning processes for removal of sulfur compounds and other impurities. The present study focuses on development of a gas cleaning step for a product gas produced in a 50 MWfuel gasification system. The developed gas cleaning washing process is basically a modification of the Rectisol process. Several different process configurations were evaluated using Aspen plus, including PC-SAFT for the thermodynamic modeling. The developed configuration takes advantage of only one methanol wash column, compared to two columns in a conventional Rectisol process. Results from modeling show the ability of the proposed configuration to remove impurities to a sufficiently low concentrations - almost zero concentration for H2S, CS2, HCl, NH3 and HCN, and approximately 0.01 mg/Nm3 for COS. These levels are acceptable for further upgrading of the gas in a methanation process. Simultaneously, up to 92% of the original CO2 is preserved in the final cleaned syngas stream. No process integration or economic consideration was performed within the scope of the present study, but will be investigated in future projects to improve the overall process.

  9. Process steam production from cotton gin trash

    Energy Technology Data Exchange (ETDEWEB)

    LePori, W.A.; Carney, D.B.; Lalk, T.R.; Anthony, R.G.

    1981-01-01

    A steam producing system based on fluidized-bed gasification of biomass materials is discussed. Limited experimental results are discussed and show that steam has been produced at rates of 334.3 kg/hr. (737 lbs/hr.) with 2.8 kg of stream produced for each kilogram of cotton gin trash (2.8 lb/lb.). ref.

  10. Biomass energy

    International Nuclear Information System (INIS)

    Bioenergy systems can provide an energy supply that is environmentally sound and sustainable, although, like all energy systems, they have an environmental impact. The impact often depends more on the way the whole system is managed than on the fuel or on the conversion technology. The authors first describe traditional biomass systems: combustion and deforestation; health impact; charcoal conversion; and agricultural residues. A discussion of modern biomass systems follows: biogas; producer gas; alcohol fuels; modern wood fuel resources; and modern biomass combustion. The issue of bioenergy and the environment (land use; air pollution; water; socioeconomic impacts) and a discussion of sustainable bioenergy use complete the paper. 53 refs., 9 figs., 14 tabs

  11. Component testing of a ground based gas turbine steam cooled rich-burn primary zone combustor for emissions control of nitrogeneous fuels

    Science.gov (United States)

    Schultz, D. F.

    1986-01-01

    This effort summarizes the work performed on a steam cooled, rich-burn primary zone, variable geometry combustor designed for combustion of nitrogeneous fuels such as heavy oils or synthetic crude oils. The steam cooling was employed to determine its feasibility and assess its usefulness as part of a ground based gas turbine bottoming cycle. Variable combustor geometry was employed to demonstrate its ability to control primary and secondary zone equivalence ratios and overall pressure drop. Both concepts proved to be highly successful in achieving their desired objectives. The steam cooling reduced peak liner temperatures to less than 800 K. This low temperature offers the potential of both long life and reduced use of strategic materials for liner fabrication. These degrees of variable geometry were successfully employed to control air flow distribution within the combustor. A variable blade angle axial flow air swirler was used to control primary zone air flow, while the secondary and tertiary zone air flows were controlled by rotating bands which regulated air flow to the secondary zone quench holes and the dilutions holes respectively.

  12. The study on water ingress mass in the steam generator heat-exchange tube rupture accident of modular high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    The steam generator heat-exchange tube rupture (SGTR) accident is an important and particular accident which will result in water ingress to the primary loop of reactor. Water ingress will result in chemical reaction of graphite fuel and structure with water, which may cause overpressure due to generation of explosive gaseous in large quantity. The study on the water ingress accident is significant for the verification of the inherent characteristics of high temperature gas-cooled reactor. The previous research shows that the amount of water ingress mass is the dominant key factor on the severity of the accident consequence. The 200 MWe high temperature gas-cooled reactor (HTR-PM), which is the first modular pebble-bed high temperature gas-cooled reactor in China designed by the Institute of Nuclear and New Energy Technology of Tsinghua University, is selected to be analyzed in this paper. The different DBA accident scenarios of double-ended break of single heat-exchange tube are simulated respectively by the thermal-hydraulic analysis code RETRAN-02. The results show the water ingress mass through the broken heat-exchange tube is related to the break location. The amount of water ingress mass is affected obviously by the capacity of the emptier system. With the balance of safety and economical efficiency, the amount of water ingress mass from the secondary side of steam generator into the primary coolant loop will be reduced by increasing properly the diameter of the draining lines. (authors)

  13. Studying the characteristics of a 5 kW power installation on solid-oxide fuel cells with steam reforming of natural gas

    Science.gov (United States)

    Munts, V. A.; Volkova, Yu. V.; Plotnikov, N. S.; Dubinin, A. M.; Tuponogov, V. G.; Chernishev, V. A.

    2015-11-01

    The results from tests of a 5 kW power plant on solid-oxide fuel cells (SOFCs), in which natural gas is used as fuel, are presented. The installation's process circuit, the test procedure, and the analysis of the obtained results are described. The characteristics of the power plant developed by the Ural Industrial Company are investigated in four steady-state modes of its operation: with the SOFC nominal power capacity utilized by 40% (2 kW), 60% (3 kW), 90% (4.5 kW) and 110% (5.4 kW) (the peaking mode). The electrical and thermodynamic efficiencies are calculated for all operating modes, and the most efficient mode, in which the electrical efficiency reached almost 70%, is determined. The air excess coefficient and heat loss with flue gases q 2 are determined, and it is revealed that the heat loss q 5 decreases from 40 to 25% with increasing the load. Thermal balances are drawn up for the following components of the system the reformer, the SOFC battery, the catalytic burner for afterburning anode gases, the heat exchanger for heating the cathode air and the mixture of natural gas and steam, and the actual fuel utilization rates in the electrochemical generator are calculated. An equation for the resulting natural gas steam reforming reaction was obtained based on the results from calculating the equilibrium composition of reforming products for the achieved temperatures at the reformer outlet t 3.

  14. Impact of Contaminants Present in Coal-Biomass Derived Synthesis Gas on Water-gas Shift and Fischer-Tropsch Synthesis Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Alptekin, Gokhan [TDA Research, Inc., Wheat Ridge, CO (United States)

    2013-02-15

    Co-gasification of biomass and coal in large-scale, Integrated Gasification Combined Cycle (IGCC) plants increases the efficiency and reduces the environmental impact of making synthesis gas ("syngas") that can be used in Coal-Biomass-to-Liquids (CBTL) processes for producing transportation fuels. However, the water-gas shift (WGS) and Fischer-Tropsch synthesis (FTS) catalysts used in these processes may be poisoned by multiple contaminants found in coal-biomass derived syngas; sulfur species, trace toxic metals, halides, nitrogen species, the vapors of alkali metals and their salts (e.g., KCl and NaCl), ammonia, and phosphorous. Thus, it is essential to develop a fundamental understanding of poisoning/inhibition mechanisms before investing in the development of any costly mitigation technologies. We therefore investigated the impact of potential contaminants (H2S, NH3, HCN, AsH3, PH3, HCl, NaCl, KCl, AS3, NH4NO3, NH4OH, KNO3, HBr, HF, and HNO3) on the performance and lifetime of commercially available and generic (prepared in-house) WGS and FT catalysts.

  15. Effect of partial replacement of diesel or biodiesel with gas from biomass gasification in a diesel engine

    International Nuclear Information System (INIS)

    The injected diesel fuel used in a diesel engine was partially replaced with biomass-derived gas through the intake port, and the effect on performance and pollutant emissions was studied. The experimental work was carried out in a supercharged, common-rail injection, single-cylinder diesel engine by replacing diesel fuel up to 20% (by energy), keeping constant the engine power. Three engine loads (60, 90, 105 Nm), three different EGR (exhaust gas recirculation) ratios (0, 7.5, 15%) and two intake temperatures (45, 60 °C) were tested. Finally, some of the tested conditions were selected to replace diesel injection fuel with biodiesel injection. Although the brake thermal efficiency was decreased and hydrocarbons and carbon monoxide emissions increased with increasing fuel replacement, particulate emissions decreased significantly and NOx emissions decreased slightly at all loads and EGR ratios. Thermodynamic diagnostic results showed higher premixed ratio and lower combustion duration for increasing diesel fuel replacement. High EGR ratios improved both engine performance and emissions, especially when intake temperature was increased, which suggest removing EGR cooling when diesel fuel is replaced. Finally, when biodiesel was used instead of diesel fuel, the gas replacement improved the efficiency and reduced the hydrocarbon, carbon monoxide and particulate emissions. - Highlights: • Replacing injected fuel with gas permits an efficient valorization of waste biomass. • Inlet gas was inefficiently burned after the end of liquid fuel injection. • Engine parameters were combined to simultaneously reduce particle and NOx emissions. • Hot EGR (exhaust gas recirculation) and biodiesel injection are proposed to improve efficiency and emissions

  16. 硫磺尾气焚烧炉蒸汽过热器失效分析%Failure Analysis of Steam Superheater in Sulphur Tail Gas Incinerator

    Institute of Scientific and Technical Information of China (English)

    姜伟

    2012-01-01

    针对硫磺尾气焚烧炉蒸汽过热器的泄漏问题,结合其实际运行情况,从宏观和微观两方面分析了失效原因,提出了处理措施,取得了较好的效果.%The leakage cause of sulphur tail gas incinerator steam superheater was analyzed through macro and micro-examinations. And measures were taken on the basis of the failure analysis. Result showed that the measures had good effect.

  17. CHP Gorzow - first Polish gas-steam CHP with GT8C turbine; EC Gorzow SA - pierwsza w Polsce elektrocieplownia gazowo-parowa z turbina GT8C

    Energy Technology Data Exchange (ETDEWEB)

    Woloncewicz, Z. [Elektrocieplownia Gorzow S.A., Gorzow Wielkopolski, (Poland); Rudny, S. [Energoprojekt Gliwice S.A., Gliwice (Poland); Wronkowski, H.; Dzierzgowski, J. [ABB Zamech Ltd., Elblag, (Poland)

    1996-06-01

    Combined-cycle power plant Gorzow generates heat and electric power for the needs of Gorzow Wielkopolski town and local industry. Old part of the plant with 4 coal-fired units will be replaced by gas-steam CHP in 1998. The basic technical data of CHP are given and GT8C turbine is described. The consequences for environment such as elimination of dust as well as substantial abatement of SO{sub 2} and NO{sub x} emission are stressed. A way of noise abatement is also presented. 7 figs.

  18. A Geothermal Energy Supported Gas-steam Cogeneration Unit as a Possible Replacement for the Old Part of a Municipal CHP Plant (TEKO

    Directory of Open Access Journals (Sweden)

    L. Böszörményi

    2001-01-01

    Full Text Available The need for more intensive utilization of local renewable energy sources is indisputable. Under the current economic circumstances their competitiveness in comparison with fossil fuels is rather low, if we do not take into account environmental considerations. Integrating geothermal sources into combined heat and power production in a municipal CHP plant would be an excellent solution to this problem. This concept could lead to an innovative type of power plant - a gas-steam cycle based, geothermal energy supported cogeneration unit.

  19. Estimating greenhouse gas abatement potential of biomass crops in Scotland under various management options

    International Nuclear Information System (INIS)

    Bioenergy crops are one of the renewable energy options available to decarbonise the energy sector in Scotland and help to achieve the overall planned target of 80% reduction in greenhouse gas (GHG) emissions by 2050. A process-based model for poplar and willow developed for simulating the effect of different environmental and management options on growth and biomass yield was used to estimate the GHG abatement potential (GHG-AP) under different crop management options in Scotland. The model results of annual wood yield did not show a strong relation with any of the environmental factors except that of initial soil organic carbon (SOC) content. Increasing plant density and decreasing harvest frequency increased GHG-AP. Application of N-fertilizers at a rate of 50–100 kg N ha−1 resulted in the buildup of carbon in soils with less than 180 Mg C ha−1. However, in soils with greater SOC contents, annual emissions resulting from N fertilizer application were greater than the carbon saving through marginal increases in wood yield and SOC changes. The best management scenario in terms of economic and environmental objectives depends on identifying an optimum plant density based on the site specific conditions with a fertilizer application of 20–100 kg ha−1 y−1 and a five year harvest interval. Even under the best economic scenarios, SRC willow and poplar have a GHG-AP ranging from 9.9 to 11.6 and 8.8–10.0 Mg CO2 eq. ha−1 y−1, respectively. Under the best environmental scenarios this range increases to 10.5- 13.2 and 9–11.1 Mg CO2 eq. ha−1 y−1 for willow and poplar, respectively. -- Highlights: ► A process model for willow and poplar was used to estimate the GHG-AP in Scotland. ► Increasing plant density and decreasing harvest frequency increased GHG-AP. ► The best crop management is to use 20–100 kg N ha−1 y−1 and 5 year harvest interval. ► GHG-AP range from 8.8 to 11.6 Mg CO2 eq. ha−1 y−1 under the best economic scenarios.

  20. Suppression pool testing at the SIET labs (2). Steam chugging investigation under the presence of non-condensable gas in a vertical opened pipe

    International Nuclear Information System (INIS)

    Chugging of steam direct contact condensation is a well-known phenomenon and one of the most studied in connection to steam direct contact condensation in the suppression chamber of nuclear power plants. Chugging occurs at small mass flux, low water temperatures and large pipe diameters and is characterized by a strong bubble implosion and cyclic behavior. In the past, chugging has been mainly studied in relation to the high pressure load it exerts on the pool structures, in particular during the late stage of a loss of coolant accident. The focus of the present experimental investigation is to comprehend the effects of air on the bubble growth and implosion. Such conditions are of main interest after the reactor pressure vessel failure during a severe accident progression. In the performed experiment a relatively large diameter steel pipe (0.2 m) was employed with two different steam mass flow rates, respectively 30 and 100 g/s and air mass flow rate varying up to 8 g/s. The water temperature has been measured at sixteen locations in the pool at four different elevations and a high speed camera has been employed to visualize the bubble growth and implosion. It has been found that the presence of noncondensable gas, also in a relatively small amount, can significantly decrease the strength of the bubble implosion and the subsequent effects on the structures. Nevertheless the presence of noncondensable maintains the oscillatory behavior of the steam-water interface, which characterizes the chugging phenomenon, so that large water mixing occurs within the pool. The present study aims to drive the creation of generic physical models to be used in both lumped parameters severe accident codes and detailed CFD simulations. (author)

  1. Process for treating biomass

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Timothy J; Teymouri, Farzaneh

    2015-11-04

    This invention is directed to a process for treating biomass. The biomass is treated with a biomass swelling agent within the vessel to swell or rupture at least a portion of the biomass. A portion of the swelling agent is removed from a first end of the vessel following the treatment. Then steam is introduced into a second end of the vessel different from the first end to further remove swelling agent from the vessel in such a manner that the swelling agent exits the vessel at a relatively low water content.

  2. Process for treating biomass

    Science.gov (United States)

    Campbell, Timothy J.; Teymouri, Farzaneh

    2015-08-11

    This invention is directed to a process for treating biomass. The biomass is treated with a biomass swelling agent within the vessel to swell or rupture at least a portion of the biomass. A portion of the swelling agent is removed from a first end of the vessel following the treatment. Then steam is introduced into a second end of the vessel different from the first end to further remove swelling agent from the vessel in such a manner that the swelling agent exits the vessel at a relatively low water content.

  3. Catalytic pyrolysis of biomass: Effects of pyrolysis temperature, sweeping gas flow rate and MgO catalyst

    International Nuclear Information System (INIS)

    Cotton seed, as a biomass source, is pyrolysed in a tubular fixed-bed reactor under various sweeping gas (N2) flow rates at different pyrolysis temperatures. In the non-catalytic work, the maximum bio-oil yield was attained as 48.30% at 550 oC with a sweeping gas flow rate of 200 mL min-1. At the optimum conditions, catalytic pyrolysis of biomass samples was performed with various amounts of MgO catalyst (5, 10, 15, and 20 wt.% of raw material). Catalyst addition decreased the quantity of bio-oil yet increased the quality of bio-oil in terms of calorific value, hydrocarbon distribution and removal of oxygenated groups. It was observed that increasing the amount of catalyst used, decreased the oil yields while increased the gas and char yields. Bio-oils obtained at the optimum conditions were separated into aliphatic, aromatic and polar sub-fractions. After the application of column chromatography, bio-oils were subjected into elemental, FT-IR and 1H NMR analyses. Aliphatic sub-fractions of bio-oils were analyzed by GC-MS. It was deduced that the fuel obtained via catalytic pyrolysis mainly consisted of lower weight hydrocarbons in the diesel range. Finally, obtained results were compared with petroleum fractions and evaluated as a potential source for liquid fuels.

  4. Thermodynamic analyses of a biomass integrated fired combined cycle

    International Nuclear Information System (INIS)

    A biomass integrated fired combined cycle (BIFCC) is proposed and examined with energy and exergy analyses. A focal point is the biomass gasification process, for which four different biomasses are examined. The fuel in the bottoming cycle is a biomass while the topping cycle fuel is natural gas. The analyses consider a range of compressor pressure ratios (6–24), gas turbine inlet temperatures (1300–1500 K), heat recovery steam generator (HRSG) inlet temperatures (840–940 K) and molar natural gas to biomass ratios (0.05–1.50). The energy efficiency is compared when the cycle uses natural gas, or natural gas and biomass (of various kinds). The efficiency is seen to be maximized at an optimum pressure ratio, which depends on the gas turbine and HRSG inlet temperatures. Increasing the gas turbine and decreasing the HRSG inlet temperatures leads to in an increase in energy and exergy efficiencies for the cycle. The performance of an 80-MW capacity plant is investigated for three cases, with optimum pressure ratios and various operating parameters. The most advantageous performance among the three cases, for which the energy and exergy efficiencies are 53.16 and 48.39% respectively, is achieved when the turbine inlet temperature is 1500 K, the HRSG inlet temperature is 840 K and the compressor pressure ratio is 14. -- Highlights: • A gas turbine combined cycle with gasified biomass firing is analyzed. • Thermodynamic analysis considers first and second law analyses. • Thermal efficiency peaks at an optimum cycle pressure ratio (about 10–14). • Three sets of operating parameters are considered in a detailed case study. • One of three cases is more efficient from energy and exergy viewpoints

  5. BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

    Energy Technology Data Exchange (ETDEWEB)

    Jay R. Gunderson; Bruce C. Folkedahl; Darren D. Schmidt; Greg F. Weber; Christopher J. Zygarlicke

    2002-05-01

    The Energy & Environmental Research Center (EERC) is conducting a project to examine the fundamental issues limiting the use of biomass in small industrial steam/power systems in order to increase the future use of this valuable domestic resource. Specifically, the EERC is attempting to elucidate the ash-related problems--grate clinkering and heat exchange surface fouling--associated with cofiring coal and biomass in grate-fired systems. Utilization of biomass in stoker boilers designed for coal can be a cause of concern for boiler operators. Boilers that were designed for low-volatile fuels with lower reactivities can experience damaging fouling when switched to higher-volatile and more reactive lower-rank fuels, such as when cofiring biomass. Higher heat release rates at the grate can cause more clinkering or slagging at the grate because of higher temperatures. Combustion and loss of volatile matter can start too early with biomass fuels compared to design fuel, vaporizing alkali and chlorides which then condense on rear walls and heat exchange tube banks in the convective pass of the boiler, causing noticeable increases in fouling. In addition, stoker-fired boilers that switch to biomass blends may encounter new chemical species such as potassium sulfates and various chlorides in combination with different flue gas temperatures because of changes in fuel heating value, which can adversely affect ash deposition behavior.

  6. Biomass Thermochemical Conversion Program. 1983 Annual report

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-08-01

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

  7. Hydrogen Production From Crude Bio-oil and Biomass Char by Electrochemical Catalytic Reforming

    Institute of Scientific and Technical Information of China (English)

    Xing-long Li; Shen Ning; Li-xia Yuan; Quan-xin Li

    2011-01-01

    We reports an efficient approach for production of hydrogen from crude bio-oil and biomass char in the dual fixed-bed system by using the electrochemical catalytic reforming method.The maximal absolute hydrogen yield reached 110.9 g H2/kg dry biomass.The product gas was a mixed gas containing 72%H2,26%CO2,1.9%CO,and a trace amount of CH4.It was observed that adding biomass char (a by-product of pyrolysis of biomass) could remarkably increase the absolute H2 yield (about 20%-50%).The higher reforming temperature could enhance the steam reforming reaction of organic compounds in crude bio-oil and the reaction of CO and H2O.In addition,the CuZn-Al2O3 catalyst in the water-gas shift bed could also increase the absolute H2 yield via shifting CO to CO2.

  8. Experiments about the integrity of BWR relief pipes in postulated radiolysis gas combustion. Scenario No.2. Minor steam leakages without any lowering of the water level

    International Nuclear Information System (INIS)

    The experiments described in this article were performed to study this comprehensive radiolysis gas scenario: - The relief pipe is filled completely with radiolysis gas (2H2+O2). - After opening of the S and R valve, the radiolysis gas is compressed adiabatically by the incoming steam without mixing. - Roughly at the point of peak pressure in the relief pipe (20 bar) the radiolysis gas ignites. This dynamic scenario was studied in steady-state model experiments with a test pipe which corresponds to the relief pipes installed in KKP-1 in terms of materials, dimensions, and manufacturing control. The initial conditions and boundary conditions of the experiments were conservative. In the course of the tests, the maximum dynamic strain and the residual plastic deformation of the test pipe were measured via the transient detonation load. The maximum dynamic strain measured was 0.75%, the maximum residual plastic strain reached 0.15%. The pipe suffered no other deformation above and beyond this slight plastic strain. The radiolysis gas detonation was simulated very well numerically. Using the calculated pressure loads in a structural dynamics model also showed good agreement with the measured maximum dynamic pipe strains. In this way, the experimental findings were confirmed theoretically. The experiments and the calculations showed that postulated radiolysis gas reactions during pressure relief cannot jeopardize the integrity of the relief pipe. (orig.)

  9. Economic assessment of solar and conventional biomass gasification technologies: Financial and policy implications under feedstock and product gas price uncertainty

    International Nuclear Information System (INIS)

    Four configurations of a novel solar-heated biomass gasification facility and one configuration of conventional biomass gasification are analyzed through financial and policy scenarios. The purpose of this study is to determine the potential financial position for varying configurations of a novel technology, as compared to the current state-of-the-art gasification technology. Through the use of project finance and policy scenario development, we assess the baseline breakeven syngas price (normalized against natural gas prices and based upon annual feedstock consumption), the sensitivity of major cost components for the novel facilities, and the implications of policy levers on the economic feasibility of the solar facilities. Findings show that certain solar configurations may compete with conventional facilities on a straightforward economic basis. However, with renewable energy policy levers in place the solar technologies become increasingly attractive options. - Highlights: • We model four solar and one conventional biomass gasification systems. • We assess economic feasibility of these systems with and without policy incentives. • Solar facilities compete with the conventional system in certain scenarios. • Feedstock costs are the largest contributor to system cost sensitivity. • Policy incentives create an economically favorable scenario for solar facilities

  10. Aspen Plus simulation of biomass integrated gasification combined cycle systems at corn ethanol plants

    International Nuclear Information System (INIS)

    Biomass integrated gasification combined cycle (BIGCC) systems and natural gas combined cycle (NGCC) systems are employed to provide heat and electricity to a 0.19 hm3 y−1 (50 million gallon per year) corn ethanol plant using different fuels (syrup and corn stover, corn stover alone, and natural gas). Aspen Plus simulations of BIGCC/NGCC systems are performed to study effects of different fuels, gas turbine compression pressure, dryers (steam tube or superheated steam) for biomass fuels and ethanol co-products, and steam tube dryer exhaust treatment methods. The goal is to maximize electricity generation while meeting process heat needs of the plant. At fuel input rates of 110 MW, BIGCC systems with steam tube dryers provide 20–25 MW of power to the grid with system thermal efficiencies (net power generated plus process heat rate divided by fuel input rate) of 69–74%. NGCC systems with steam tube dryers provide 26–30 MW of power to the grid with system thermal efficiencies of 74–78%. BIGCC systems with superheated steam dryers provide 20–22 MW of power to the grid with system thermal efficiencies of 53–56%. The life-cycle greenhouse gas (GHG) emission reduction for conventional corn ethanol compared to gasoline is 39% for process heat with natural gas (grid electricity), 117% for BIGCC with syrup and corn stover fuel, 124% for BIGCC with corn stover fuel, and 93% for NGCC with natural gas fuel. These GHG emission estimates do not include indirect land use change effects. -- Highlights: •BIGCC and natural gas combined cycle systems at corn ethanol plants are simulated. •The best performance results in 25–30 MW power to grid. •The best performance results in 74–78% system thermal efficiencies. •GHG reduction for corn ethanol with BIGCC systems compared to gasoline is over 100%

  11. Design principles of an integrated natural gas steam reformer for stationary PEMFC systems; Auslegungsprinzipien eines integrierten Erdgas-Dampfreformers fuer stationaere PEM-Brennstoffzellen-Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Grosser, K.

    2006-09-05

    The function, efficiency and economic efficiency of fuel cell systems are defined by various influencing factors, especially in the case of hydrogen production by steam reforming of natural gas. The dissertation describes the design of integrated natural gas steam reformers for PEM fuel cell systems in the electric power range of 1- 10 kW; the influencing factors of the process are investigated and weighted. Design principles are derived from which optimum operating parameters can be defined and which can be used for designing a multitude of components. [German] Die Funktionsfaehigkeit, der Wirkungsgrad und die Wirtschaftlichkeit von Brennstoffzellen-Systemen werden insbesondere bei der Wasserstofferzeugung durch Erdgas-Dampfreformierung durch verschiedene Einflussfaktoren bestimmt. In dieser Dissertation werden die Methodik der Auslegung integrierter Erdgas-Dampfreformer fuer PEM-Brennstoffzellen-Systeme im elektrischen Leistungsbereich von 1-10 kW beschrieben und die prozessbestimmenden Einflussfaktoren untersucht und gewichtet. Daraus werden Auslegungsprinzipien abgeleitet, mit denen sich die optimalen Betriebsparameter ermitteln lassen und die zur konstruktiven Gestaltung einer Vielzahl von Anlagenteilen genutzt werden koennen.

  12. A simulation study on the torrefied biomass gasification

    International Nuclear Information System (INIS)

    Highlights: • Equilibrium model for raw and torrefied biomass with thermodynamic analysis. • Experimental pyrolysis yields including tar as inputs to the model. • Equivalence ratio had the most pronounced effect on the model outcomes. • Torrefied biomass gave higher H2 and CO contents and energy and exergy efficiencies. • Torrefaction mass yields affect the gasification process efficiency. - Abstract: Many studies have evaluated biomass behavior in a gasification process. Similar studies with torrefied biomass are needed to evaluate the improvements in biomass properties with torrefaction. This forms the basis of this study. A two-stage biomass gasification model is presented by using Aspen Plus as the simulation and modeling tool. The model included the minimization of the Gibbs free energy of the produced gas to achieve chemical equilibrium in the process, constrained by mass and energy balances for the system. Air and steam were used as the oxidizing agent in the process that uses both untreated and torrefied biomass as feedstocks. Three process parameters, equivalence ratio (ER), Gibbs reactor temperature and steam-to-biomass ratio (SBR), were studied. 27 cases were included in the analysis by operating the system below the carbon deposition boundary with all carbon in gaseous form in the product gas. Product gas composition in the form of hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4) and nitrogen (N2) was analyzed together with cold gas energy and exergy efficiencies for all the cases. Overall, mole fractions of H2, CO, CO2 and N2 were between 0.23–0.40, 0.22–0.42, 0.01–0.09 and 0.14–0.36 for torrefied wood and 0.21–0.40, 0.17–0.34, 0.03–0.09 and 0.15–0.37 for untreated wood, respectively. Similarly, cold gas energy and exergy efficiencies were between 76.1–97.9% and 68.3–85.8% for torrefied wood and 67.9–91.0% and 60.7–79.4% for untreated wood, respectively. Torrefied biomass has higher H2 and CO

  13. The effects of location, feedstock availability, and supply-chain logistics on the greenhouse gas emissions of forest-biomass energy utilization in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Jappinen, E,

    2013-11-01

    Forest biomass represents a geographically distributed feedstock, and geographical location affects the greenhouse gas (GHG) performance of a given forest-bioenergy system in several ways. For example, biomass availability, forest operations, transportation possibilities and the distances involved, biomass end-use possibilities, fossil reference systems, and forest carbon balances all depend to some extent on location. The overall objective of this thesis was to assess the GHG emissions derived from supply and energy-utilization chains of forest biomass in Finland, with a specific focus on the effect of location in relation to forest biomass's availability and the transportation possibilities. Biomass availability and transportation-network assessments were conducted through utilization of geographical information system methods, and the GHG emissions were assessed by means of lifecycle assessment. The thesis is based on four papers in which forest biomass supply on industrial scale was assessed. The feedstocks assessed in this thesis include harvesting residues, smalldiameter energy wood and stumps. The principal implication of the findings in this thesis is that in Finland, the location and availability of biomass in the proximity of a given energyutilization or energy-conversion plant is not a decisive factor in supply-chain GHG emissions or the possible GHG savings to be achieved with forest-biomass energy use. Therefore, for the greatest GHG reductions with limited forest-biomass resources, energy utilization of forest biomass in Finland should be directed to the locations where most GHG savings are achieved through replacement of fossil fuels. Furthermore, one should prioritize the types of forest biomass with the lowest direct supply-chain GHG emissions (e.g., from transport and comminution) and the lowest indirect ones (in particular, soil carbon-stock losses), regardless of location. In this respect, the best combination is to use harvesting residues

  14. Basic petrochemicals from natural gas, coal and biomass: energy use and CO2 emissions

    NARCIS (Netherlands)

    Ren, T.; Patel, M.K.

    2009-01-01

    While high-value basic petrochemicals (HVCs) are mostly produced through conventional naphtha and ethane-based process routes, it is also possible to produce them through coal and biomass-based routes. In this paper, we compared these routes in terms of energy use and CO2 emissions per ton of HVCs.

  15. CO2 removal from municipal waste incinerator flue gas and biomass production by microalgae

    Czech Academy of Sciences Publication Activity Database

    Doušková, Irena; Doucha, Jiří; Novák, P.; Umysová, Dáša; Vítová, Milada; Zachleder, Vilém

    České Budějovice: Scientific Pedagogical Publishing,, 2008, s. 35-37. ISBN 80-85645-58-0. [Biotechnology 2008. České Budějovice (CZ), 13.02.2008-14.02.2008] Institutional research plan: CEZ:AV0Z50200510 Keywords : microalgae * biomass * bioremediation Subject RIV: EE - Microbiology, Virology

  16. The mathematical description of the gasification process of woody biomass in installations with a plasma heat source for producing synthesis gas

    Science.gov (United States)

    Sadrtdinov, A. R.; Safin, R. G.; Gerasimov, M. K.; Petrov, V. I.; Gilfanov, K. K.

    2016-04-01

    The article presents the scheme of processing of plant biomass in the gasification installation with a plasma heat source to produce synthesis gas suitable for chemical industry. The analyzed physical picture of raw materials' recycling process underlies a mathematical description of the process set out in the form of the basic differential equations with boundary conditions. The received mathematical description allows calculating of the main parameters of equipment for biomass recycling and to determine the optimal modes of its operation.

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

    OpenAIRE

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

    2012-01-01

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

  18. Study of the effect of noncondensable gas on heat transfer phenomena in horizontal steam generator of pactel facility with CATHARE2 V1.5a

    International Nuclear Information System (INIS)

    Lappeenranta University of Technology (LTKK) and VTT Energy carried out a series of preliminary tests in 1999 to study the behavior of noncondensable (NC) gases in VVER geometry. The tests aimed at studying the effect of NC gases on system thermal-hydraulics and on heat transfer in a horizontal steam generator (HSG). The system behavior can be affected by hydrogen produced in the core in case of a severe accident, by nitrogen from hydro-accumulators released into the primary circuit in case of a loss-of-coolant accident (LOCA) and more generally by any NC gas in all cases where cooling is ensured by natural circulation. A secondary objective of the tests - the first series of tests ever performed with NC gas with PACTEL - was to find out, if the instrumentation of PACTEL was adequate for this type of tests and if it was functioning properly. This paper presents the measured and calculated (CATHARE code version V15a mod 2.1) results of the test NCg-l. It was carried out in natural circulation (one loop in operation) and at about 50 % of primary mass inventory. Compressed air, simulating nitrogen gas was injected in the vertical part of the hot leg below the HSG. Clearly, the initial conditions in calculation and test are quite different. Before NC gas injection, the system is probably in a two-phase mode. At the measured inventory, the calculation predicts single-phase vapor mode. However, CATHARE predicts some qualitative trends of the test: (1) primary pressure increase after each air injection, and (2) existence of passive zones in steam generator tubes. Some quantitative disagreements have to be better understood by investigating the reasons for differences in the initial state: power level, heat losses, coolant repartition and flow rate in the primary circuit, uncertainty of measured pressures and temperatures, improvement of the CATHARE nodalization. The possible occurrence of reverse flow in some steam generator tubes must be also studied in more detail

  19. Steamed over SAGD

    International Nuclear Information System (INIS)

    Gulf Canada Resources asked the Alberta Energy and Utilities Board (AEUB) to suspend natural gas production by other producers on Gulf's Surmount lease, a huge pool of oilsands, because they were testing a new technology developed by the Alberta Energy Department called SAGD (steam assisted gravity drainage). SAGD recovers bitumen from oilsands through the use of a pair of horizontal wells, placed one above the other. Steam is injected into the upper well, heating and thinning the bitumen which then drains down to the producing well which pumps it to the surface. While drilling the wells, Gulf had noticed pressure variations which they believe are due to gas production. They claim that the reservoir must be free of outside influences while they test combinations of steam pressure, temperature and volume for optimal productivity. The six gas producers in the area claim that their gas production is not affecting Gulf's oilsands reserves. If the suspension takes place, the AEUB could order Gulf to compensate the gas producers for lost production. 1 fig

  20. Controlling of biomass dryers; Styrning av biobraensletorkar

    Energy Technology Data Exchange (ETDEWEB)

    Axby, F. [Sycon Energikonsult AB (Sweden)

    1999-05-01

    When drying biomass it is important to dry the goods sufficiently but not too much and that the moisture is uniform. In rotating dryers there are often problems to keep the moisture uniform. Parameters as moisture of incoming goods, temperature and gas and goods flow influence the drying result. The background to the idea in this project is to use the principle that Niro uses in their steam dryers. In steam dryers the superheating in the last cell is controlling the dryer. Applied on rotary dryers with flue gas as drying gas the humidity of the flue gas is measured. The purpose of this project is to find a connection between the humidity in the flue gas and the moisture in the biomass. The humidity and the temperature of the flue gas is used in a transfer function to prognosticate the moisture in the biomass. The project is executed at the Sydkraft Vaerme fuel manufacturing plant in Vaernamo. The dryer in the plant is a rotating drum dryer with flue gas from a biomass fired furnace as drying medium. Today the temperature gas is controlling the biomass flow to the dryer. The moisture of the biomass that is fed to the dryer is 50-60 % by weight and is dried to 12 {+-} 3 % by weight (the figures is valid for one middle fraction). The used method is to find the delay of time that corresponds to the best correlation between humidity versus moisture and temperature and moisture. When the time delays are found, parameters in a transfer function is adjusted so that the calculated values agree with the measured. At the experiments a number of parameters were registered but only temperature and humidity of the gas were used for the transfer function. The humidity was measured with a capacitive humidity sensor and the temperature was measured with a PT100-sensor. The moisture was measured by drying in an oven for 12 hours at 105 deg C. The measurements were conducted with the controlling equipment turned on. To minimise the influence of the controlling the measurements was

  1. Steam turbine

    OpenAIRE

    Vališ, Petr

    2010-01-01

    The master´s thesis concentrates on a project of steam turbine with controlled extraction points destined for a communal waste incineration plant. First, there the history of devices using steam as a moving medium is introduced and than follows the description of computing program, where the calculation was running. The master´s thesis subject consists in the thermodynamic project of turbine vaning, in basic project of gearbox including the check calculations and in technical economic compari...

  2. Hydrogen production from high-moisture content biomass in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Antal, M.J. Jr.; Adschiri, T.; Ekbom, T. [Univ. of Hawaii, Honolulu, HI (United States)] [and others

    1996-10-01

    Most hydrogen is produced by steam reforming methane at elevated pressures. The goal of this research is to develop commercial processes for the catalytic steam reforming of biomass and other organic wastes at high pressures. This approach avoids the high cost of gas compression and takes advantage of the unique properties of water at high pressures. Prior to this year the authors reported the ability of carbon to catalyze the decomposition of biomass and related model compounds in supercritical water. The product gas consists of hydrogen, carbon dioxide, carbon monoxide, methane, and traces of higher hydrocarbons. During the past year the authors have: (a) developed a method to extend the catalyst life, (b) begun studies of the role of the shift reaction, (c) completed studies of carbon dioxide absorption from the product effluent by high pressure water, (d) measured the rate of carbon catalyst gasification in supercritical water, (e) discovered the pumpability of oil-biomass slurries, and (f) completed the design and begun fabrication of a flow reactor that will steam reform whole biomass feedstocks (i.e. sewage sludge) and produce a hydrogen rich synthesis gas at very high pressure (>22 MPa).

  3. Biomass Gasification - Process analysis and dimensioning aspects for downdraft units and gas cleaning lines

    OpenAIRE

    Stoppiello, Giovanni

    2010-01-01

    In such territories where food production is mostly scattered in several small / medium size or even domestic farms, a lot of heterogeneous residues are produced yearly, since farmers usually carry out different activities in their properties. The amount and composition of farm residues, therefore, widely change during year, according to the single production process periodically achieved. Coupling high efficiency micro-cogeneration energy units with easy handling biomass conversion equipm...

  4. Energy and greenhouse gas balance of decentralized energy supply systems based on organic agricultural biomass

    OpenAIRE

    Kimming, Marie

    2011-01-01

    More and more farms apply organic production methods to reduce their environmental impact, but currently even organic farms are mainly using fossil fuels. Technologies available today or in the near future make it possible to produce heat, electricity and fuels from agricultural residues or woody biomass. The agricultural sector can thereby contribute to the fulfillment of climate goals and energy security without reducing the output of food products. The thesis describes and assesses possibl...

  5. Green House Gas Control and Agricultural Biomass for Sustainable Animal Agriculture in Developing Countries

    OpenAIRE

    Takahashi, J.

    2010-01-01

    Important green house gases (GHG) attributed to animal agriculture are methane (CH4) and nitrous oxide (N2O), though carbon dioxide (CO2) contributes almost half of total greenhouse effect. Rumen CH4 production in an enteric fermentation can be accounted as the biggest anthropogenic source. Some of prebiotics and probiotics have been innovated to mitigate rumen CH4 emission. The possible use of agricultural biomass consisted of non-edible parts of crop plants such as cellulose and hemi cellul...

  6. Hydrogen Production via Synthetic Gas by Biomass/Oil Partial Oxidation

    Czech Academy of Sciences Publication Activity Database

    Hanika, Jiří; Lederer, J.; Tukač, V.; Veselý, Václav; Kováč, D.

    176-177, - (2011), s. 286-290. ISSN 1385-8947. [International Conference on Chemical Reactors CHEMREACTOR-19 /19./. Vienna, 05.09.2010-09.09.2010] R&D Projects: GA MPO 2A-2TP1/024 Institutional research plan: CEZ:AV0Z40720504 Keywords : hydrogen * biomass * partial oxidation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.461, year: 2011

  7. Large-scale analysis of GHG (greenhouse gas) reduction by means of biomass co-firing at country-scale: Application to the Spanish case

    International Nuclear Information System (INIS)

    The knowledge of the potentially achievable reduction of greenhouse gas (GHG) emissions by biomass co-firing is a powerful tool in supporting decision makers when it comes to undertaking energy planning. The main goal of this work was to develop a methodology by which significant biomass co-firing potentials and subsequent reduced GHG emissions, could be obtained at large territories. This methodology has been applied to Spain. It has been found that agricultural and forestry residual biomass feedstocks, available within 100 km of coal-fired power plants (CPP), currently total up to 75.8 PJth/yr. If energy crop feedstocks are included, this quantity increases up to 91.1 PJth/yr. However, the utilisation of biomass in CPPs is constrained by technical limitations. Taking into account these restrictions, biomass could be co-fired to generate up to 7.7% of electricity produced in CPPs (42.1 PJth/yr of biomass). A life cycle assessment has been performed to all the processes involved. The results indicate that up to 87 tCO2eq can be reduced by utilising 1 TJth of biomass replacing coal. The combination of these figures points out that biomass co-firing could contribute to mitigating 3.4 MtCO2eq in Spain annually. This value equates to almost 1% of its total GHG emissions.

  8. Green House Gas Control and Agricultural Biomass for Sustainable Animal Agriculture in Developing Countries

    Directory of Open Access Journals (Sweden)

    J Takahashi

    2010-06-01

    Full Text Available Important green house gases (GHG attributed to animal agriculture are methane (CH4 and nitrous oxide (N2O, though carbon dioxide (CO2 contributes almost half of total greenhouse effect. Rumen CH4 production in an enteric fermentation can be accounted as the biggest anthropogenic source. Some of prebiotics and probiotics have been innovated to mitigate rumen CH4 emission. The possible use of agricultural biomass consisted of non-edible parts of crop plants such as cellulose and hemi cellulose and animal wastes was proposed as a renewable energy and nitrogen sources. The ammonia stripping from digested slurry of animal manure in biogas plant applied three options of nitrogen recycling to mitigate nitrous oxide emission. In the first option of the ammonia stripping, the effect of ammonolysis on feed value of cellulose biomass was evaluated on digestibility, energy metabolism and protein utilization. Saccharification of the NH3 treated cellulose biomass was confirmed in strictly anaerobic incubation with rumen cellulolytic bacteria, Ruminoccous flavefaciens, to produce bio-ethanol as the second option of ammonia stripping. In an attempt of NH3 fuel cell, the reformed hydrogen from the NH3 stripped from 20 liter of digested slurry in thermophilic biogas plant could generate 0.12 W electricity with proton exchange membrane fuel cell (PEM as the third option.

  9. Effects of hydrothermal treatment of sewage sludge on pyrolysis and steam gasification

    International Nuclear Information System (INIS)

    Highlights: • Hydrothermal treatment (HT) is energy efficient and increases fuel energy density. • Pyrolysis and steam gasification were performed with sewage sludge before/after HT. • Product gases resembled those from wood chips, particularly at high temperature. • HT increases sludge lignin content, possibly enhancing methane yield of product gas. • HT can improve sewage sludge for use as an alternative to biomass and fossil fuels. - Abstract: Hydrothermal treatment is a promising option for pretreatment drying of organic waste, due to its low energy consumption and contribution to increasing fuel energy density. In this study, the characteristics of hydrothermally treated sewage sludge were investigated, and pyrolysis and steam gasification were performed with the sludge before and after hydrothermal treatment. The overall composition of product gases from treated sludge was similar to that obtained from steam gasification of wood chips, particularly under high-temperature conditions. In addition, the increase in lignin content of sewage sludge following hydrothermal treatment could help enhance methane yield in product gas during pyrolysis and steam gasification. The findings suggest that hydrothermal treatment is an appropriate method for improving sewage sludge for use as an alternative to biomass and fossil fuels

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-15

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

  11. Spatial effects of aboveground biomass on soil ecological parameters and trace gas fluxes in a savannah ecosystem of Mount Kilimanjaro

    Science.gov (United States)

    Becker, Joscha; Gütlein, Adrian; Sierra Cornejo, Natalia; Kiese, Ralf; Hertel, Dietrich; Kuzyakov, Yakov

    2015-04-01

    The savannah biome is a hotspot for biodiversity and wildlife conservation in Africa and recently got in the focus of research on carbon sequestration. Savannah ecosystems are under strong pressure from climate and land-use change, especially around populous areas like the Mt. Kilimanjaro region. Savannah vegetation in this area consists of grassland with isolated trees and is therefore characterized by high spatial variation of canopy cover, aboveground biomass and root structure. Canopy structure is known to affect microclimate, throughfall and evapotranspiration and thereby controls soil moisture conditions. Consequently, the canopy structure is a major regulator for soil ecological parameters and soil-atmospheric trace gas exchange (CO2, N2O, CH4) in water limited environments. The spatial distribution of these parameters and the connection between above and belowground processes are important to understand and predict ecosystem changes and estimate its vulnerability. Our objective was to determine trends and changes of soil parameters and relate their spatial variability to the vegetation structure. We chose three trees from each of the two most dominant species (Acacia nilotica and Balanites aegyptiaca) in our research area. For each tree, we selected transects with nine sampling points of the same relative distances to the stem. Distances were calculated in relation to the crown radius. At these each sampling point a soil core was taken and separated in 0-10 cm and 10-30 cm depth. We measured soil carbon (C) and nitrogen (N) storage, microbial biomass carbon C and N, soil respiration as well as root biomass and -density, soil temperature and soil water content. Each tree was characterized by crown spread, leaf area index and basal area. Preliminary results show that C and N stocks decreased about 50% with depth independently of distance to the tree. Soil water content under the tree crown increased with depth while it decreased under grass cover. Microbial

  12. Economic and Technical Assessment of Wood Biomass Fuel Gasification for Industrial Gas Production

    Energy Technology Data Exchange (ETDEWEB)

    Anastasia M. Gribik; Ronald E. Mizia; Harry Gatley; Benjamin Phillips

    2007-09-01

    This project addresses both the technical and economic feasibility of replacing industrial gas in lime kilns with synthesis gas from the gasification of hog fuel. The technical assessment includes a materials evaluation, processing equipment needs, and suitability of the heat content of the synthesis gas as a replacement for industrial gas. The economic assessment includes estimations for capital, construction, operating, maintenance, and management costs for the reference plant. To perform these assessments, detailed models of the gasification and lime kiln processes were developed using Aspen Plus. The material and energy balance outputs from the Aspen Plus model were used as inputs to both the material and economic evaluations.

  13. Nitrogen fertilization of switchgrass increases biomass yield and improves net greenhouse gas balance in northern Michigan, U.S.A

    International Nuclear Information System (INIS)

    Nitrogen (N) fertilization can increase bioenergy crop production; however, fertilizer production and application can contribute to greenhouse gas (GHG) emissions, potentially undermining the GHG benefits of bioenergy crops. The objective of this study was to evaluate the effects of N fertilization on GHG emissions and biomass production of switchgrass bioenergy crop, in northern Michigan. Nitrogen fertilization treatments included 0 kg ha-1 (control), 56 kg ha-1 (low) and 112 kg ha-1 (high) of N applied as urea. Soil fluxes of CO2, N2O and CH4 were measured every two weeks using static chambers. Indirect GHG emissions associated with field activities, manufacturing and transport of fertilizer and pesticides were derived from the literature. Switchgrass aboveground biomass yield was evaluated at the end of the growing season. Nitrogen fertilization contributed little to soil GHG emissions; relative to the control, there were additional global warming potential of 0.7 Mg ha-1 y-1 and 1.5 Mg ha-1 y-1 as CO2 equivalents (CO2eq), calculated using the IPCC values, in the low and high N fertilization treatments, respectively. However, N fertilization greatly stimulated CO2 uptake by switchgrass, resulting in 1.5- and 2.5-fold increases in biomass yield in the low and high N fertilization treatments, respectively. Nitrogen amendments improved the net GHG benefits by 2.6 Mg ha-1 y-1 and 9.4 Mg ha-1 y-1 as CO2eq relative to the control. Results suggest that N fertilization of switchgrass in this region could reduce (15-50%) the land base needed for bioenergy production and decrease pressure on land for food and forage crop production. -- Highlights: → We examine the effects of N fertilization of switchgrass on GHG emissions. → Effects of N fertilization on biomass production of switchgrass bioenergy crop. → N fertilization contributed little to greenhouse gas emissions. → N fertilization greatly stimulated CO2 uptake by the switchgrass. → N fertilization of

  14. INTEGRATED PYROLYSIS COMBINED CYCLE BIOMASS POWER SYSTEM CONCEPT DEFINITION

    Energy Technology Data Exchange (ETDEWEB)

    Eric Sandvig; Gary Walling; Robert C. Brown; Ryan Pletka; Desmond Radlein; Warren Johnson

    2003-03-01

    Advanced power systems based on integrated gasification/combined cycles (IGCC) are often presented as a solution to the present shortcomings of biomass as fuel. Although IGCC has been technically demonstrated at full scale, it has not been adopted for commercial power generation. Part of the reason for this situation is the continuing low price for coal. However, another significant barrier to IGCC is the high level of integration of this technology: the gas output from the gasifier must be perfectly matched to the energy demand of the gas turbine cycle. We are developing an alternative to IGCC for biomass power: the integrated (fast) pyrolysis/ combined cycle (IPCC). In this system solid biomass is converted into liquid rather than gaseous fuel. This liquid fuel, called bio-oil, is a mixture of oxygenated organic compounds and water that serves as fuel for a gas turbine topping cycle. Waste heat from the gas turbine provides thermal energy to the steam turbine bottoming cycle. Advantages of the biomass-fueled IPCC system include: combined cycle efficiency exceeding 37 percent efficiency for a system as small as 7.6 MW{sub e}; absence of high pressure thermal reactors; decoupling of fuel processing and power generation; and opportunities for recovering value-added products from the bio-oil. This report provides a technical overview of the system including pyrolyzer design, fuel clean-up strategies, pyrolysate condenser design, opportunities for recovering pyrolysis byproducts, gas turbine cycle design, and Rankine steam cycle. The report also reviews the potential biomass fuel supply in Iowa, provide and economic analysis, and present a summery of benefits from the proposed system.

  15. INTEGRATED PYROLYSIS COMBINED CYCLE BIOMASS POWER SYSTEM CONCEPT DEFINITION

    International Nuclear Information System (INIS)

    Advanced power systems based on integrated gasification/combined cycles (IGCC) are often presented as a solution to the present shortcomings of biomass as fuel. Although IGCC has been technically demonstrated at full scale, it has not been adopted for commercial power generation. Part of the reason for this situation is the continuing low price for coal. However, another significant barrier to IGCC is the high level of integration of this technology: the gas output from the gasifier must be perfectly matched to the energy demand of the gas turbine cycle. We are developing an alternative to IGCC for biomass power: the integrated (fast) pyrolysis/ combined cycle (IPCC). In this system solid biomass is converted into liquid rather than gaseous fuel. This liquid fuel, called bio-oil, is a mixture of oxygenated organic compounds and water that serves as fuel for a gas turbine topping cycle. Waste heat from the gas turbine provides thermal energy to the steam turbine bottoming cycle. Advantages of the biomass-fueled IPCC system include: combined cycle efficiency exceeding 37 percent efficiency for a system as small as 7.6 MWe; absence of high pressure thermal reactors; decoupling of fuel processing and power generation; and opportunities for recovering value-added products from the bio-oil. This report provides a technical overview of the system including pyrolyzer design, fuel clean-up strategies, pyrolysate condenser design, opportunities for recovering pyrolysis byproducts, gas turbine cycle design, and Rankine steam cycle. The report also reviews the potential biomass fuel supply in Iowa, provide and economic analysis, and present a summery of benefits from the proposed system

  16. Utilization of high CO2 content formation gas for steam and electricity generation; Aprovechamiento del gas de formacion con alto contenido de CO2 para generacion de vapor y electricidad

    Energy Technology Data Exchange (ETDEWEB)

    Villagomez, Paul; Lamino, Marcelo; Jacome, Jose; Pastor, Santiago [EcuadorTLC, Quito (Ecuador). Grupo PETROBRAS

    2008-07-01

    Ecuador TLC SA, as part of the PETROBRAS Group, respecting its mission to act safe, cost-effectiveness, social and environmental responsibility, currently operates an oil production project in the Ecuatorian Amazon, known as Block 18. In Block 18, the process of gas burning is response for launch approximately 10 MMSCF of the gas associated with 77% CO2 in the environment. For this reason it was built a centralized power generation plants (PGE), of 17.38 MW, taking advantage of the gas with 77% CO2 from boilers to burn it, using it as a source of heat in a combined cycle steam turbines, generating electricity. This project is environmentally efficient with reduced emissions of CO2 and as reducing fuel costs to zero. The results of CO2 reduction is a corporate goal of PETROBRAS and this project will contribute to reducing CO2 emissions by approximately 400,000 Ton over the life of the project.

  17. A growth inhibitory model with SO(x) influenced effective growth rate for estimation of algal biomass concentration under flue gas atmosphere.

    Science.gov (United States)

    Ronda, Srinivasa Reddy; Kethineni, Chandrika; Parupudi, Lakshmi Chandrika Pavani; Thunuguntla, Venkata Bala Sai Chaitanya; Vemula, Sandeep; Settaluri, Vijaya Saradhi; Allu, Prasada Rao; Grande, Suresh Kumar; Sharma, Suraj; Kandala, Chari Venkatakrishna

    2014-01-01

    A theoretical model for the prediction of biomass concentration under rice husk flue gas emission has been developed. The growth inhibitory model (GIM) considers the CO2 mass transfer rate, the critical SOx concentration and its role in pH-based inter-conversion of bicarbonate. The calibration and subsequent validation of the growth profile of Nannochloropsis limnetica at 2% and 10% (v/v) CO2 showed that the predicted values were consistent with the measured values, with r(2) being 0.96 and 0.98, respectively, and pphoto-bioreactors treated with flue gas in the generation of biomass feed stock for biofuel production. PMID:24300846

  18. Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup, and Oxygen Separation Equipment; Task 9: Mixed Alcohols From Syngas -- State of Technology

    Energy Technology Data Exchange (ETDEWEB)

    Nexant Inc.

    2006-05-01

    This deliverable is for Task 9, Mixed Alcohols from Syngas: State of Technology, as part of National Renewable Energy Laboratory (NREL) Award ACO-5-44027, ''Equipment Design and Cost Estimation for Small Modular Biomass Systems, Synthesis Gas Cleanup and Oxygen Separation Equipment''. Task 9 supplements the work previously done by NREL in the mixed alcohols section of the 2003 technical report Preliminary Screening--Technical and Economic Assessment of Synthesis Gas to Fuels and Chemicals with Emphasis on the Potential for Biomass-Derived Syngas.

  19. Purificación y acondicionamiento del gas de gasificación de biomasa

    OpenAIRE

    Ruiz, E.; Sánchez, J. M.

    2014-01-01

    [EN] The biomass gasification process produces a gas susceptible of use in boilers, engines, gas turbine and steam turbine (combined cycle), fuel cells and chemical synthesis. Nevertheless it is necessary a previous gas purification and conditioning step with the objective of eliminating contaminants at levels sufficiently low to comply with environmental regulations and with the tolerance of gas conversion systems, adjusting the CO/H2 ratio and improving the qualit...

  20. Investigations of heat supply of a low-capacity natural gas steam reformer; Untersuchungen zur Waermeversorgung eines Erdgas-Dampf-Reformers kleiner Leistung

    Energy Technology Data Exchange (ETDEWEB)

    Gardemann, Ulrich

    2010-07-21

    The author investigated the heat supply of a natural gas steam reformer in a fuel cell heating system for hydrogen production. Heat is normally supplied by a burner which together with the air supply system, sensors and control system makes up the burner system. Aspects like the general function in specific operating conditions, pollutant emissions and reformer efficiency were investigated theoretically and practically. The dissertation starts by describing the technological fundamentals of the fuel cell technology, hydrogen production technology and combustion technology. The focus was on the PEM fuel cell and on steam reforming; both technologies are considered promising options for fuel cell heating systems and resulted in specific requirements on the burner system. For an objective assessment of emissions, emission units were converted from volumetric into fuel energy related. A conversion tool was developed according to VDI 4660. Further, an emission assessment concept for fuel cell heating systems was developed which uses the fuel energy related emission unit mg/kWh and enables accurate assessment of the burner and the whole fuel cell system in terms of pollutant emissions. (orig.)

  1. 1982 annual report: Biomass Thermochemical Conversion Program

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-01-01

    This report provides a brief overview of the Thermochemical Conversion Program's activities and major accomplishments during fiscal year 1982. The objective of the Biomass Thermochemical Conversion Program is to generate scientific data and fundamental biomass converison process information that, in the long term, could lead to establishment of cost effective processes for conversion of biomass resources into clean fuels and petrochemical substitutes. The goal of the program is to improve the data base for biomass conversion by investigating the fundamental aspects of conversion technologies and exploring those parameters which are critical to these conversion processes. To achieve this objective and goal, the Thermochemical Conversion Program is sponsoring high-risk, long-term research with high payoff potential which industry is not currently sponsoring, nor is likely to support. Thermochemical conversion processes employ elevated temperatures to convert biomass materials into energy. Process examples include: combustion to produce heat, steam, electricity, direct mechanical power; gasification to produce fuel gas or synthesis gases for the production of methanol and hydrocarbon fuels; direct liquefaction to produce heavy oils or distillates; and pyrolysis to produce a mixture of oils, fuel gases, and char. A bibliography of publications for 1982 is included.

  2. Preparation of Hydrogen through Catalytic Steam Reforming of Bio-oil

    Institute of Scientific and Technical Information of China (English)

    吴层; 颜涌捷; 李庭琛; 亓伟

    2007-01-01

    Hydrogen was prepared via catalytic steam reforming of bio-oil which was obtained from fast pyrolysis of biomass in a fluidized bed reactor. Influential factors including temperature, weight hourly space velocity (WHSV) of bio-oil, mass ratio of steam to bio-oil (S/B) as well as catalyst type on hydrogen selectivity and other desirable gas products were investigated. Based on hydrogen in stoichiometric potential and carbon balance in gaseous phase and feed, hydrogen yield and carbon selectivity were examined. The experimental results show that higher temperature favors the hydrogen selectivity by H2 mole fraction in gaseous products stream and it plays an important role in hydrogen yield and carbon selectivity. Higher hydrogen selectivity and yield, and carbon selectivity were obtained at lower bio-oil WHSV. In catalytic steam reforming system a maximum steam concentration value exists, at which hydrogen selectivity and yield, and carbon selectivity keep constant. Through experiments, preferential operation conditions were obtained as follows: temperature 800~850℃, bio-oil WHSV below 3.0 h-1, and mass ratio of steam to bio-oil 10~12. The performance tests indicate that Ni-based catalysts are optional, especially Ni/a-Al2O3 effective in the steam reforming process.

  3. Thermodynamic approach to biomass gasification

    International Nuclear Information System (INIS)

    The document presents an approach of biomass transformation in presence of steam, hydrogen or oxygen. Calculation results based on thermodynamic equilibrium are discussed. The objective of gasification techniques is to increase the gas content in CO and H2. The maximum content in these gases is obtained when thermodynamic equilibrium is approached. Any optimisation action of a process. will, thus, tend to approach thermodynamic equilibrium conditions. On the other hand, such calculations can be used to determine the conditions which lead to an increase in the production of CO and H2. An objective is also to determine transformation enthalpies that are an important input for process calculations. Various existing processes are assessed, and associated thermodynamic limitations are evidenced. (author)

  4. CFD analysis of combustion of natural gas and syngas from biomass pyrolysis in the combustion chamber of a micro gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Fantozzi, Francesco; Laranci, Paolo; D' Alessandro, Bruno [University of Perugia (DII/UNIPG) (Italy). Dept. of Industrial Engineering], Emails: fanto@unipg.it, paolo.laranci@unipg.it, dalessandro@bio-net.it

    2009-07-01

    Micro gas turbines (MGT) can be profitably used for the production of distributed energy (DE), with the possibility to use gaseous fuels with low BTU derived from biomass or waste through the pyrolysis or gasification processes. These synthesis gases (SG) show significant differences with respect to natural gas (NG), in terms of composition, calorific value, content of hydrogen, tar and particulate matter content; such differences can be turn into problems of ignition, instability burning, difficulties in controlling the emissions and fouling. CFD analysis of the combustion process is an essential tool for identifying the main critical arising in using these gases, in order to modify existing geometries and to develop new generation of combustor for use with low BTU gases. This paper describes the activities of experimental and numerical analysis carried out to study the combustion process occurring inside an existing annular Rich-Quench-Lean (RQL) Combustion Chamber (CC) of a 80 kW MGT. In the paper some results of a CFD study of the combustion process performed with an original developed chemical models are reported in terms of temperature and velocity distributions inside the CC and in terms of compositions of turbine inlet gas and of its thermodynamic parameters (mass flow, temperature, pressure). An evaluation of pollutant emissions of CO, CO{sub 2} and NOx and a comparison with the available experimental data relating to the case of combustion of NG is also provided in the paper. Moreover, the carried out investigation concerns the case of operation with a SG fuel derived from biomass in an Integrated Pyrolysis Regenerated Plant (IPRP). (author)

  5. Characterization of products obtained from pyrolysis and steam gasification of wood waste, RDF, and RPF.

    Science.gov (United States)

    Hwang, In-Hee; Kobayashi, Jun; Kawamoto, Katsuya

    2014-02-01

    Pyrolysis and steam gasification of woody biomass chip (WBC) obtained from construction and demolition wastes, refuse-derived fuel (RDF), and refuse paper and plastic fuel (RPF) were performed at various temperatures using a lab-scale instrument. The gas, liquid, and solid products were examined to determine their generation amounts, properties, and the carbon balance between raw material and products. The amount of product gas and its hydrogen concentration showed a considerable difference depending on pyrolysis and steam gasification at higher temperature. The reaction of steam and solid product, char, contributed to an increase in gas amount and hydrogen concentration. The amount of liquid products generated greatly depended on temperature rather than pyrolysis or steam gasification. The compositions of liquid product varied relying on raw materials used at 500°C but the polycyclic aromatic hydrocarbons became the major compounds at 900°C irrespective of the raw materials used. Almost fixed carbon (FC) of raw materials remained as solid products under pyrolysis condition whereas FC started to decompose at 700°C under steam gasification condition. For WBC, both char utilization by pyrolysis at low temperature (500°C) and syngas recovery by steam gasification at higher temperature (900°C) might be practical options. From the results of carbon balance of RDF and RPF, it was confirmed that the carbon conversion to liquid products conspicuously increased as the amount of plastic increased in the raw material. To recover feedstock from RPF, pyrolysis for oil recovery at low temperature (500°C) might be one of viable options. Steam gasification at 900°C could be an option but the method of tar reforming (e.g. catalyst utilization) should be considered. PMID:24246576

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

    International Nuclear Information System (INIS)

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

  7. Biomass IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Salo, K.; Keraenen, H. [Enviropower Inc., Espoo (Finland)

    1996-12-31

    Enviropower Inc. is developing a modern power plant concept based on pressurised fluidized-bed gasification and gas turbine combined cycle (IGCC). The process is capable of maximising the electricity production with a variety of solid fuels - different biomass and coal types - mixed or separately. The development work is conducted on many levels. These and demonstration efforts are highlighted in this article. The feasibility of a pressurised gasification based processes compared to competing technologies in different applications is discussed. The potential of power production from biomass is also reviewed. (orig.) 4 refs.

  8. RELAP5 post-test analyses of OECD/NEA ROSA project experiments on steam generator depressurization with or without non-condensable gas inflow

    International Nuclear Information System (INIS)

    Two LSTF experiments were conducted for OECD/NEA ROSA Project simulating PWR 0.5% cold leg small break LOCA. Steam generator (SG) secondary-side depressurization was performed by fully opening the relief valves at 10 minutes after a safety injection signal with or without non-condensable gas (air) inflow from accumulator tanks with total failure of high pressure injection system. Further assumptions were made to conduct enhanced SG depressurization by fully opening the safety valves when the primary pressure decreased to 2 MPa and no actuation of low pressure injection system, both to well observe natural circulation (NC) phenomena at low pressures. The primary depressurization rate decreased when non-condensable gas started to enter primary loops because of degradation in the condensation heat transfer in SG U-tubes, while two-phase flow NC has continued even after non-condensable gas inflow. Asymmetric NC behaviors appeared between two loops due probably to different number of forward flow SG U-tubes which would have been under influences of non-condensable gas. Post-test analyses by using JAEA-modified RELAP5/MOD3.2.1.2 code indicated that the code has remaining problems in propor prediction of the primary loop flow rate and SG U-tube liquid level behaviors especially after non-condensable gas inflow. The improvement of the condensation heat transfer model under non-condensable gas mixture condition and the SG U-tube model may be necessary for correct analysis of the LSTF SG depressurization transient. (author)

  9. Life cycle assessment of fuels for district heating: A comparison of waste incineration, biomass- and natural gas combustion

    International Nuclear Information System (INIS)

    The aim of this consequential life cycle assessment (LCA) is to compare district heating based on waste incineration with combustion of biomass or natural gas. The study comprises two options for energy recovery (combined heat and power (CHP) or heat only), two alternatives for external, marginal electricity generation (fossil lean or intense), and two alternatives for the alternative waste management (landfill disposal or material recovery). A secondary objective was to test a combination of dynamic energy system modelling and LCA by combining the concept of complex marginal electricity production in a static, environmental systems analysis. Furthermore, we wanted to increase the methodological knowledge about how waste can be environmentally compared to other fuels in district-heat production. The results indicate that combustion of biofuel in a CHP is environmentally favourable and robust with respect to the avoided type of electricity and waste management. Waste incineration is often (but not always) the preferable choice when incineration substitutes landfill disposal of waste. It is however, never the best choice (and often the worst) when incineration substitutes recycling. A natural gas fired CHP is an alternative of interest if marginal electricity has a high fossil content. However, if the marginal electricity is mainly based on non-fossil sources, natural gas is in general worse than biofuels

  10. Particulate and trace gas emissions from large biomass fires in North America

    International Nuclear Information System (INIS)

    In this chapter the authors describe the results of airborne studies of smokes from 17 biomass fuel fires, including 14 prescribed fires and 3 wildfires, burned primarily in the temperature zone of North America between 34 degree and 49 degree N latitude. The prescribed fires were in forested lands and logging debris and varied in areas burned from 10 to 700 hectares (ha) (over a few hours). One of the wildfires ultimately consumed 20,000 h a and burned over a period of weeks. The larger fires produced towering columns of smoke and capping water clouds. As an indication of scale, the prescribed fires were visible only as small features in meteorological satellite imagery, but one of the wildfires studied produced a persistent, visible plume more than 1,000 kilometers (km) long. The studies have focused on factors that could impact global climate through alteration of the earth's radiation balance. These include emissions of trace gases and smoke particles from biomass burning, the optical properties of the smoke, and the interaction of the smoke particles with clouds

  11. Evaluation of reduced kinetics in simulation of gasified biomass gas combustion

    OpenAIRE

    ZHANG, Xiaoxiang; Jayasuriya, Jeevan; Fakhraie, Reza; Fransson, Torsten

    2013-01-01

    It is essentially important to use appropriate chemical kinetic models in the simulation process of gas turbine combustion. To integrate the detailed kinetics into complex combustion simulations has proven to be a computationally expensive task with tens to thousands of elementary reaction steps. It has been suggested that an appropriate simplified kinetics which are computationally efficient could be used instead. Therefore reduced kinetics are often used in CFD simulation of gas turbine com...

  12. Film condensation of steam flowing downward on a tier of horizontal cylinders at different inclination angles in the presence of a non-condensable gas

    Science.gov (United States)

    Ramadan, Abdulghani; Yamali, Cemil

    2013-12-01

    The problem of forced laminar film condensation of steam flowing downward a tier of horizontal cylinders is investigated numerically. The effects of free stream non-condensable gas, air concentration (m1,∞), free stream velocity (Reynolds number), cylinder diameter, and angle of inclination on the condensation heat transfer are analyzed. Two flow arrangements, inline and staggered, are analyzed and investigated. The mathematical model takes into account the effect of staggering of the cylinders and how condensation is affected at the lower cylinders when condensate does not fall on to the center line of the cylinders. Condensation heat transfer results are available in ranges from (U∞ = 1 - 30 m/s) for free stream velocity, (m1,∞ = 0.01 -0.8) for free stream air mass fraction and (D = 12.7 -50.8 mm) for cylinder diameter. Results show that; a remarked reduction in the vapor side heat transfer coefficient is noticed. This results from the presence of small amounts of free stream air mass fractions in the steam-air mixture and increase in the cylinder diameter. On the other hand, it increases by increasing the free stream velocity (Reynolds number). Average heat transfer coefficient at the middle and the bottom cylinders increases by increasing the angle of inclination, whereas, no significant change is observed for that of the upper cylinder. Down the bank, a rapid decrease in the vapor side heat transfer coefficient is noticed. It may be resulted from the combined effects of inundation, decrease in the vapor velocity and increase in the non-condensable gas (air) at the bottom cylinders in the bank.

  13. Investigations on catalyzed steam gasification of biomass. Appendix A: Feasibility study of methane production via catalytic gasification of 2000 tons of wood per day

    Science.gov (United States)

    Mudge, L. K.; Weber, S. L.; Michell, D. H.; Sealock, L. J., Jr.; Robertus, R. J.

    1981-01-01

    The plant is designed to process 2000 tons per day of dry wood to SNG. Plant production is 21.6 MM scfd of SNG with a HHV of 956 Btu per scf. All process and support facilities necessary to convert wood to SNG are included. The plant location is Newport, Oregon. The capital cost for the plant is $95,115,000 September, 1980 basis. Gas production costs which allow for return on capital were calculated for various wood prices for both utility and private investor financing.

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

    International Nuclear Information System (INIS)

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

  15. Response of mat conditions and flakeboard properties to steam- injection variables

    OpenAIRE

    Johnson, Stephen E.

    1990-01-01

    Mat conditions of temperature and gas pressure were measured in three locations for one conventional and four steam-injection press schedules used in the laboratory scale manufacture of aspen (Populus grandidentata and Populus tremuloides) flakeboard. Two resins, phenol formaldehyde and polymeric MDI, were used. Steam-injection press schedules varied from low steam input to high steam input by adjusting steam pressure, steam time, and the density range for steam-inject...

  16. Enhancing the production of biomethane : A comparison between GoBiGas process and new process of combining anaerobic digestion and biomass gasification

    OpenAIRE

    Mehmood, Daheem

    2016-01-01

    In recent years, there is a rapid growing interest in the use of biomethane for the transport sector. A new method of combining anaerobic digestion and biomass gasification is proposed.The feasibility study shows that more biomethane can be produced; resulting in an increase in the revenue compared to individual biogas plants. The GoBiGas project,which is initiated by Göteborg Energi, adopted another method based on gasification, water gas shift and methanation to enable biomethane production...

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

    Science.gov (United States)

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

  18. Bridging gaps in bioenergy: Deploying system analysis to investigate potential biomass supply, demand and greenhouse gas mitigation scenarios from a national, European and global perspective

    NARCIS (Netherlands)

    Hoefnagels, E.T.A.

    2014-01-01

    In transition towards a sustainable energy system with deep reductions in greenhouse gas (GHG) emissions and reduced consumption of fossil fuels, substitution of fossil energy carriers with biomass is considered one of the most important options. In the last decade, fossil energy and GHG mitigation

  19. Dynamic simulation analyzes expanded refinery steam system

    Energy Technology Data Exchange (ETDEWEB)

    Gandhi, S.L.; Graham, J.; Duffield, M.A.; Cortes, R.M. [M.W. Kellogg Co., Houston, TX (United States)

    1995-11-01

    There is a rising demand for more-stable process operations with increasing facility modernization and automation. This requires steam system controls that provide effective and stable responses to operational disturbances. Today it is possible to use dynamic simulation analysis for designing steam systems. The main objectives were to: develop a high-fidelity dynamic simulation model of the steam system and its associated controls; develop dynamic system responses to major plant disturbances; and assist in designing new control strategies and modifying existing controls to minimize the impact of plant upsets on system performance. The steam system for this project included two power plant supplying steam and power and a steam pipe network comprising three levels of steam with stream flows to and from process units spread over several square kilometers. Whether the steam system and its controls would respond effectively to major operational upsets, such as boiler, steam turbogenerator or process gas compressor trips, or a steep increase in steam demand, can only be determined from evaluating dynamic responses to these incidents. The model consisted of about 5,000 equations, 1,000 parameters and data items, and was used for evaluating steam system responses to various operational upset scenarios. The responses were used to identify limitations of the as designed control system. The model also proved to be an effective tool for verifying adequacy of the proposed recommendations. These included modifications to control valve letdown stations, steam turbogenerator governor controls and the boiler master-pressure controller.

  20. Airborne measurements of trace gas and aerosol particle emissions from biomass burning in Amazonia

    Directory of Open Access Journals (Sweden)

    P. Guyon

    2005-05-01

    Full Text Available As part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall, and Climate 2002 campaign, we studied the emission of carbon monoxide (CO, carbon dioxide (CO2, and aerosol particles from Amazonian deforestation fires using an instrumented aircraft. Emission ratios for aerosol number (CN relative to CO (ERCN/CO fell in the range 14–32 cm-3 ppb-1 for most of the time, in agreement with values usually found from tropical savanna fires. The number of particles emitted per amount biomass burned was found to be dependant on the fire condition (combustion efficiency. Variability in the ERCN/CO between fires was similar to the variability caused by variations in combustion behavior within each individual fire. This was confirmed by observations of CO-to-CO2 emission ratios (ERCO/CO2, which stretched across the same wide range of values for individual fires as for all the fires observed during the sampling campaign, indicating that flaming and smoldering phases are present simultaneously in deforestation fires. Emission factors (EF for CO and aerosol particles were computed and a correction was applied for the residual smoldering combustion (RSC fraction of emissions that are not sampled by the aircraft. The correction, previously unpublished for tropical deforestation fires, suggested an EF about one and a half to twice as large for these species. Vertical transport of biomass-burning plumes from the boundary layer (BL to the cloud detrainment layer (CDL and the free troposphere (FT was found to be a very common phenomenon. We observed a 20% loss in particle number as a result of this vertical transport and subsequent cloud processing, attributable to in-cloud coagulation. This small loss fraction suggests that this mode of transport is very efficient in terms of particle numbers and occurs mostly via non