REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

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

2004-10-01

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

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

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

2005-01-01

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

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

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

2005-04-01

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

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang

2005-07-01

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

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr.; Alireza Rezaie

2004-04-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-12-31

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

Simulation of an integrated gasification combined cycle with chemical-looping combustion and carbon dioxide sequestration

International Nuclear Information System (INIS)

Jiménez Álvaro, Ángel; López Paniagua, Ignacio; González Fernández, Celina; Rodríguez Martín, Javier; Nieto Carlier, Rafael

2015-01-01

Highlights: • A chemical-looping combustion based integrated gasification combined cycle is simulated. • The energetic performance of the plant is analyzed. • Different hydrogen-content synthesis gases are under study. • Energy savings accounting carbon dioxide sequestration and storage are quantified. • A notable increase on thermal efficiency up to 7% is found. - Abstract: Chemical-looping combustion is an interesting technique that makes it possible to integrate power generation from fuels combustion and sequestration of carbon dioxide without energy penalty. In addition, the combustion chemical reaction occurs with a lower irreversibility compared to a conventional combustion, leading to attain a somewhat higher overall thermal efficiency in gas turbine systems. This paper provides results about the energetic performance of an integrated gasification combined cycle power plant based on chemical-looping combustion of synthesis gas. A real understanding of the behavior of this concept of power plant implies a complete thermodynamic analysis, involving several interrelated aspects as the integration of energy flows between the gasifier and the combined cycle, the restrictions in relation with heat balances and chemical equilibrium in reactors and the performance of the gas turbines and the downstream steam cycle. An accurate thermodynamic modeling is required for the optimization of several design parameters. Simulations to evaluate the energetic efficiency of this chemical-looping-combustion based power plant under diverse working conditions have been carried out, and a comparison with a conventional integrated gasification power plant with precombustion capture of carbon dioxide has been made. Two different synthesis gas compositions have been tried to check its influence on the results. The energy saved in carbon capture and storage is found to be significant and even notable, inducing an improvement of the overall power plant thermal efficiency of

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Jun Wei

2005-03-01

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

High performance integrated solar combined cycles with minimum modifications to the combined cycle power plant design

International Nuclear Information System (INIS)

Manente, Giovanni

2016-01-01

Highlights: • Off-design model of a 390 MW_e three pressure combined cycle developed and validated. • The off-design model is used to evaluate different hybridization schemes with solar. • Power boosting and fuel saving with different design modifications are considered. • Maximum solar share of total electricity is only 1% with the existing equipment. • The maximum incremental solar radiation-to-electrical efficiency approaches 29%. - Abstract: The integration of solar energy into natural gas combined cycles has been successfully demonstrated in several integrated solar combined cycles since the beginning of this decade in many countries. There are many motivations that drive investments on integrated solar combined cycles which are primarily the repowering of existing power plants, the compliance with more severe environmental laws on emissions and the mitigation of risks associated with large solar projects. Integrated solar combined cycles are usually developed as brownfield facilities by retrofitting existing natural gas combined cycles and keeping the existing equipment to minimize costs. In this work a detailed off-design model of a 390 MW_e three pressure level natural gas combined cycle is built to evaluate different integration schemes of solar energy which either keep the equipment of the combined cycle unchanged or include new equipment (steam turbine, heat recovery steam generator). Both power boosting and fuel saving operation strategies are analyzed in the search for the highest annual efficiency and solar share. Results show that the maximum incremental power output from solar at design solar irradiance is limited to 19 MW_e without modifications to the existing equipment. Higher values are attainable only including a larger steam turbine. High solar radiation-to-electrical efficiencies in the range 24–29% can be achieved in the integrated solar combined cycle depending on solar share and extension of tube banks in the heat recovery

Tunable Diode Laser Sensors to Monitor Temperature and Gas Composition in High-Temperature Coal Gasifiers

Energy Technology Data Exchange (ETDEWEB)

Hanson, Ronald [Stanford Univ., CA (United States); Whitty, Kevin [Univ. of Utah, Salt Lake City, UT (United States)

2014-12-01

The integrated gasification combined cycle (IGCC) when combined with carbon capture and storage can be one of the cleanest methods of extracting energy from coal. Control of coal and biomass gasification processes to accommodate the changing character of input-fuel streams is required for practical implementation of integrated gasification combined-cycle (IGCC) technologies. Therefore a fast time-response sensor is needed for real-time monitoring of the composition and ideally the heating value of the synthesis gas (here called syngas) as it exits the gasifier. The goal of this project was the design, construction, and demonstration an in situ laserabsorption sensor to monitor multiple species in the syngas output from practical-scale coal gasifiers. This project investigated the hypothesis of using laser absorption sensing in particulateladen syngas. Absorption transitions were selected with design rules to optimize signal strength while minimizing interference from other species. Successful in situ measurements in the dusty, high-pressure syngas flow were enabled by Stanford’s normalized and scanned wavelength modulation strategy. A prototype sensor for CO, CH4, CO2, and H2O was refined with experiments conducted in the laboratory at Stanford University, a pilot-scale at the University of Utah, and an engineering-scale gasifier at DoE’s National Center for Carbon Capture with the demonstration of a prototype sensor with technical readiness level 6 in the 2014 measurement campaign.

Carbon exergy tax applied to biomass integrated gasification combined cycle in sugarcane industry

International Nuclear Information System (INIS)

Fonseca Filho, Valdi Freire da; Matelli, José Alexandre; Perrella Balestieri, José Antonio

2016-01-01

The development of technologies based on energy renewable sources is increasing worldwide in order to diversify the energy mix and satisfy the rigorous environmental legislation and international agreements to reduce pollutant emission. Considering specific characteristics of biofuels available in Brazil, studies regarding such technologies should be carried out aiming energy mix diversification. Several technologies for power generation from biomass have been presented in the technical literature, and plants with BIGCC (biomass integrated gasification combined cycle) emerge as a major technological innovation. By obtaining a fuel rich in hydrogen from solid biomass gasification, BIGCC presents higher overall process efficiency than direct burning of the solid fuel in conventional boilers. The objective of this paper is to develop a thermodynamic and chemical equilibrium model of a BIGCC configuration for sugarcane bagasse. The model embodies exergetic cost and CO_2 emission analyses through the method of CET (carbon exergy tax). An exergetic penalty comparison between the BIGCC technology (with and without CO_2 capture and sequestration), a natural gas combined cycle and the traditional steam cycle of sugarcane sector is then presented. It is verified that the BIGCC configuration with CO_2 capture and sequestration presents technical and environmental advantages when compared to traditional technology. - Highlights: • We compared thermal cycles with the exergetic carbon exergy tax. • Thermal cycles with and without carbon capture and sequestration were considered. • Burned and gasified sugarcane bagasse was assumed as renewable fuel. • Exergetic carbon penalty tax was imposed to all studied configurations. • BIGCC with carbon sequestration revealed to be advantageous.

The potential for control of carbon dioxide emissions from integrated gasification/combined-cycle systems

Energy Technology Data Exchange (ETDEWEB)

Livengood, C.D.; Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.; Berry, G.F.

1994-06-01

Initiatives to limit carbon dioxide (CO{sub 2}) emissions have drawn considerable interest to integrated gasification/combined-cycle (IGCC) power generation, a process that reduces CO{sub 2} production through efficient fuel used is amenable to CO{sub 2} capture. This paper presents a comparison of energy systems that encompass fuel supply, an IGCC system, CO{sub 2} recovery using commercial technologies, CO{sub 2} transport by pipeline, and land-based sequestering in geological reservoirs. The intent is to evaluate the energy-efficiency impacts of controlling CO{sub 2} in such systems and to provide the CO{sub 2} budget, or an to equivalent CO{sub 2}`` budget, associated with each of the individual energy-cycle steps. The value used for the ``equivalent CO{sub 2}`` budget is 1 kg/kWh CO{sub 2}. The base case for the comparison is a 457-MW IGCC system that uses an air-blown Kellogg-Rust-Westinghouse (KRW) agglomerating fluidized-bed gasifier, Illinois No. 6 bituminous coal, and in-bed sulfur removal. Mining, preparation, and transportation of the coal and limestone result in a net system electric power production of 454 MW with a 0.835 kg/kwh CO{sub 2} release rate. For comparison, the gasifier output is taken through a water-gas shift to convert CO to CO{sub 2} and then processed in a glycol-based absorber unit to recover CO{sub 2} Prior to the combustion turbine. A 500-km pipeline then transports the CO{sub 2} for geological sequestering. The net electric power production for the system with CO{sub 2} recovery is 381 MW with a 0.156 kg/kwh CO{sub 2} release rate.

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

Directory of Open Access Journals (Sweden)

Ping Wang

2013-02-01

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

Corrosion behavior of Haynes registered 230 registered nickel-based super-alloys for integrated coal gasification combined cycle syngas plants. A plant exposure study

International Nuclear Information System (INIS)

Lee, Sungkyu; Lee, Jieun; Kang, Suk-Hwan; Lee, Seung-Jong; Yun, Yongseung; Kim, Min Jung

2015-01-01

The corrosion behavior of commercially available Haynes registered 230 registered nickel-based alloy samples was investigated by exposure to coal-gasifying integrated coal gasification combined cycle pilot plant facilities affiliated with the Institute for Advanced Engineering (2.005 MPa and 160-300 C). The morphological and microstructural analyses of the exposed samples were conducted using scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis on the external surface of the recovered corrosion test samples to obtain information of the corrosion scale. These analyses based on the pre- and post-exposure corrosion test samples combined with thermodynamic Ellingham-Pourbaix stability diagrams provided preliminary insight into the mechanism of the observed corrosion behavior prevailing in the piping materials that connected the particulate removal unit and water scrubber of the integrated coal gasification combined cycle pilot plant. Uniform material wastage was observed after 46 hours of operation, and a preliminary corrosion mechanism was suggested: the observed material waste and corrosion behavior of the Haynes registered 230 registered nickel-based alloy samples cut off from the coal syngas integrated coal gasification combined cycle plant were explained by the formation of discontinuous (complex) oxide phases and subsequent chlorine-induced active oxidation under the predominantly reducing environment encountered. This contribution continues the already published studies of the Fe-Ni-Cr-Co alloy Haynes registered 556 registered .

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

CSIR Research Space (South Africa)

Engelbrecht, AD

2010-08-31

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

Study of ammonia removal from coal-gasified fuel

Energy Technology Data Exchange (ETDEWEB)

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

1998-07-01

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

Second stage gasifier in staged gasification and integrated process

Science.gov (United States)

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

2015-10-06

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-05-15

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

Modeling work of a small scale gasifier/SOFC CHP system

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-01

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

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Corrosion behavior of Haynes {sup registered} 230 {sup registered} nickel-based super-alloys for integrated coal gasification combined cycle syngas plants. A plant exposure study

Energy Technology Data Exchange (ETDEWEB)

Lee, Sungkyu; Lee, Jieun; Kang, Suk-Hwan; Lee, Seung-Jong; Yun, Yongseung [Institute for Advanced Engineering (IAE), Gyeonggi-do (Korea, Republic of). Plant Engineering Center; Kim, Min Jung [Sungkyunkwan Univ, Gyeonggi-do (Korea, Republic of). Advanced Materials Technology Research Center

2015-07-01

The corrosion behavior of commercially available Haynes {sup registered} 230 {sup registered} nickel-based alloy samples was investigated by exposure to coal-gasifying integrated coal gasification combined cycle pilot plant facilities affiliated with the Institute for Advanced Engineering (2.005 MPa and 160-300 C). The morphological and microstructural analyses of the exposed samples were conducted using scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis on the external surface of the recovered corrosion test samples to obtain information of the corrosion scale. These analyses based on the pre- and post-exposure corrosion test samples combined with thermodynamic Ellingham-Pourbaix stability diagrams provided preliminary insight into the mechanism of the observed corrosion behavior prevailing in the piping materials that connected the particulate removal unit and water scrubber of the integrated coal gasification combined cycle pilot plant. Uniform material wastage was observed after 46 hours of operation, and a preliminary corrosion mechanism was suggested: the observed material waste and corrosion behavior of the Haynes {sup registered} 230 {sup registered} nickel-based alloy samples cut off from the coal syngas integrated coal gasification combined cycle plant were explained by the formation of discontinuous (complex) oxide phases and subsequent chlorine-induced active oxidation under the predominantly reducing environment encountered. This contribution continues the already published studies of the Fe-Ni-Cr-Co alloy Haynes {sup registered} 556 {sup registered}.

Economic optimization of the combined cycle integrated with multi-product gasification system

International Nuclear Information System (INIS)

Liszka, M.; Ziebik, A.

2009-01-01

The system taken into consideration consists of the Corex unit, combined cycle power plant and air separation unit (ASU). The Corex process (trademark of Siemens-VAI) is one of technologies for cokeless hot metal production. Coal is gasified by oxygen in the hot metal environment. The excess gas can be used out of installation. It has been assumed that the Corex export gas is fired in combined cycle. The gas turbine (GT) structure was assumed as a fixed simple cycle while the heat recovery steam generator (HRSG) and steam turbine arrangements are free for optimization. The examples of independent variables selected for optimization are number of HRSG pressure levels, GT pressure ratio, minimal temperature differences in HRSG, flow rate of compressed air form GT compressor to ASU. Finally, 16 independent variables have been qualified for optimization. The synthesis optimization is based on the superstructure method. The economic net present value (NPV) has been chosen as the objective function. All power plant facilities have been modeled on the GateCycle software. The off-design models include, among others, the GT blade cooling and HRSG heat transfer coefficient analyses. Two optimization methods - genetic algorithm and Powells conjugate directions have been coupled in one hybrid procedure. The whole optimization analysis has been repeated several times for different price scenarios on the coal, iron and electricity markets

Fossil fuel savings, carbon emission reduction and economic attractiveness of medium-scale integrated biomass gasification combined cycle cogeneration plants

Directory of Open Access Journals (Sweden)

Kalina Jacek

2012-01-01

Full Text Available The paper theoretically investigates the system made up of fluidized bed gasifier, SGT-100 gas turbine and bottoming steam cycle. Different configurations of the combined cycle plant are examined. A comparison is made between systems with producer gas (PG and natural gas (NG fired turbine. Supplementary firing of the PG in a heat recovery steam generator is also taken into account. The performance of the gas turbine is investigated using in-house built Engineering Equation Solver model. Steam cycle is modeled using GateCycleTM simulation software. The results are compared in terms of electric energy generation efficiency, CO2 emission and fossil fuel energy savings. Finally there is performed an economic analysis of a sample project. The results show relatively good performance in the both alternative configurations at different rates of supplementary firing. Furthermore, positive values of economic indices were obtained. [Acknowledgements. This work was carried out within the frame of research project no. N N513 004036, titled: Analysis and optimization of distributed energy conversion plants integrated with gasification of biomass. The project is financed by the Polish Ministry of Science.

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-01

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

Thermodynamic and economic analysis on geothermal integrated combined-cycle power plants

International Nuclear Information System (INIS)

Bettocchi, R.; Cantore, G.; Negri di Montenegro, G.; Gadda, E.

1992-01-01

This paper considers geothermal integrated power plants obtained matching a geothermal plant with, a two pressure level combined plant. The purpose of the paper is the evaluation of thermodynamic and economic aspects on geothermal integrated combined-cycle power plant and a comparison with conventional solutions. The results show that the integrated combined plant power is greater than the sum of combined cycle and geothermal plant powers considered separately and that the integrated plant can offer economic benefits reaching the 16% of the total capital required

Thermodynamic analysis and conceptual design for partial coal gasification air preheating coal-fired combined cycle

Science.gov (United States)

Xu, Yue; Wu, Yining; Deng, Shimin; Wei, Shirang

2004-02-01

The partial coal gasification air pre-heating coal-fired combined cycle (PGACC) is a cleaning coal power system, which integrates the coal gasification technology, circulating fluidized bed technology, and combined cycle technology. It has high efficiency and simple construction, and is a new selection of the cleaning coal power systems. A thermodynamic analysis of the PGACC is carried out. The effects of coal gasifying rate, pre-heating air temperature, and coal gas temperature on the performances of the power system are studied. In order to repower the power plant rated 100 MW by using the PGACC, a conceptual design is suggested. The computational results show that the PGACC is feasible for modernizing the old steam power plants and building the new cleaning power plants.

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

International Nuclear Information System (INIS)

Kalina, Jacek

2011-01-01

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

Pre-Combustion Carbondioxide Capture in Integrated Gasification Combined Cycles

Directory of Open Access Journals (Sweden)

M. Zeki YILMAZOĞLU

2010-02-01

Full Text Available Thermal power plants have a significant place big proportion in the production of electric energy. Thermal power plants are the systems which converts heat energy to mechanical energy and also mechanical energy to electrical energy. Heat energy is obtained from combustion process and as a result of this, some harmful emissions, like CO2, which are the reason for global warming, are released to atmosphere. The contribution of carbondioxide to global warming has been exposed by the previous researchs. Due to this fact, clean energy technologies are growing rapidly all around the world. Coal is generally used in power plants and when compared to other fossil energy sources unit electricity production cost is less than others. When reserve rate is taken into account, coal may be converted to energy in a more efficient and cleaner way. The aim for using the clean coal technologies are to eradicate the harmful emissions of coal and to store the carbondioxide, orginated from combustion, in different forms. In line with this aim, carbondioxide may be captured by either pre-combustion, by O2/CO2 recycling combustion systems or by post combustion. The integrated gasification combined cycles (IGCC are available in pre-combustion capture systems, whereas in O2/CO2 recycling combustion systems there are ultrasuper critical boiler technologies and finally flue gas washing systems by amines exists in post combustion systems. In this study, a pre-combustion CO2 capture process via oxygen blown gasifiers is compared with a conventional power plant in terms of CO2 emissions. Captured carbondioxide quantity has been presented as a result of the calculations made throughout the study.

Evaluation of advanced coal gasification combined-cycle systems under uncertainty

International Nuclear Information System (INIS)

Frey, H.C.; Rubin, E.S.

1992-01-01

Advanced integrated gasification combined cycle (IGCC) systems have not been commercially demonstrated, and uncertainties remain regarding their commercial-scale performance and cost. Therefore, a probabilistic evaluation method has been developed and applied to explicitly consider these uncertainties. The insights afforded by this method are illustrated for an IGCC design featuring a fixed-bed gasifier and a hot gas cleanup system. Detailed case studies are conducted to characterize uncertainties in key measures of process performance and cost, evaluate design trade-offs under uncertainty, identify research priorities, evaluate the potential benefits of additional research, compare results for different uncertainty assumptions, and compare the advanced IGCC system to a conventional system under uncertainty. The implications of probabilistic results for research planning and technology selection are discussed in this paper

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

Energy Technology Data Exchange (ETDEWEB)

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

2000-07-01

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

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.

High temperature corrosion in gasifiers

Directory of Open Access Journals (Sweden)

Bakker Wate

2004-01-01

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

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.

Optimised heat recovery steam generators for integrated solar combined cycle plants

Science.gov (United States)

Peterseim, Jürgen H.; Huschka, Karsten

2017-06-01

The cost of concentrating solar power (CSP) plants is decreasing but, due to the cost differences and the currently limited value of energy storage, implementation of new facilities is still slow compared to photovoltaic systems. One recognized option to lower cost instantly is the hybridization of CSP with other energy sources, such as natural gas or biomass. Various references exist for the combination of CSP with natural gas in combined cycle plants, also known as Integrated Solar Combined Cycle (ISCC) plants. One problem with current ISCC concepts is the so called ISCC crisis, which occurs when CSP is not contributing and cycle efficiency falls below efficiency levels of solely natural gas only fired combined cycle plants. This paper analyses current ISCC concepts and compares them with two optimised designs. The comparison is based on a Kuraymat type ISCC plant and shows that cycle optimization enables a net capacity increase of 1.4% and additional daily generation of up to 7.9%. The specific investment of the optimised Integrated Solar Combined Cycle plant results in a 0.4% cost increase, which is below the additional net capacity and daily generation increase.

Thermodynamic evaluation of CHP (combined heat and power) plants integrated with installations of coal gasification

International Nuclear Information System (INIS)

Ziębik, Andrzej; Malik, Tomasz; Liszka, Marcin

2015-01-01

Integration of a CHP steam plant with an installation of coal gasification and gas turbine leads to an IGCC-CHP (integrated gasification combined cycle-combined heat and power). Two installations of coal gasification have been analyzed, i.e. pressurized entrained flow gasifier – case 1 and pressurized fluidized bed gasifier with CO_2 recirculation – case 2. Basing on the results of mathematical modelling of an IGCC-CHP plant, the algorithms of calculating typical energy indices have been derived. The following energy indices are considered, i.e. coefficient of heat performance and relative savings of chemical energy of fuels. The results of coefficients of heat performance are contained between 1.87 and 2.37. Values exceeding 1 are thermodynamically justified because the idea of cogeneration of heat and electricity based on combining cycles of the heat engine and heat pump the efficiency of which exceeds 1. Higher values concerning waste heat replace more thermodynamically effective sources of heat in CHP plants. Relative savings of the chemical energy of fuels are similar in both cases of IGCC-CHP plants and are contained between the lower value of the CHP (combined heat and power) plants fuelled with coal and higher value of CHP plants fired with natural gas. - Highlights: • Energy savings of fuel is an adequate measure of cogeneration. • Relative energy savings of IGCC-CHP is near the result of a gas and steam CHP. • COHP (coefficient of heat performance) can help to divide fuel between heat fluxes. • Higher values of COHP in the case of waste heat recovery result from the lower thermal parameters.

CANMET Gasifier Liner Coupon Material Test Report

Energy Technology Data Exchange (ETDEWEB)

Mark Fitzsimmons; Dave Grimmett; Bryan McEnerney

2007-01-31

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-09-30

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

Life cycle assessment of a biomass gasification combined-cycle power system

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-01

The potential environmental benefits from biomass power are numerous. However, biomass power may also have some negative effects on the environment. Although the environmental benefits and drawbacks of biomass power have been debated for some time, the total significance has not been assessed. This study serves to answer some of the questions most often raised in regard to biomass power: What are the net CO{sub 2} emissions? What is the energy balance of the integrated system? Which substances are emitted at the highest rates? What parts of the system are responsible for these emissions? To provide answers to these questions, a life cycle assessment (LCA) of a hypothetical biomass power plant located in the Midwest United States was performed. LCA is an analytical tool for quantifying the emissions, resource consumption, and energy use, collectively known as environmental stressors, that are associated with converting a raw material to a final product. Performed in conjunction with a technoeconomic feasibility study, the total economic and environmental benefits and drawbacks of a process can be quantified. This study complements a technoeconomic analysis of the same process, reported in Craig and Mann (1996) and updated here. The process studied is based on the concept of power Generation in a biomass integrated gasification combined cycle (BIGCC) plant. Broadly speaking, the overall system consists of biomass production, its transportation to the power plant, electricity generation, and any upstream processes required for system operation. The biomass is assumed to be supplied to the plant as wood chips from a biomass plantation, which would produce energy crops in a manner similar to the way food and fiber crops are produced today. Transportation of the biomass and other materials is by both rail and truck. The IGCC plant is sized at 113 MW, and integrates an indirectly-heated gasifier with an industrial gas turbine and steam cycle. 63 refs., 34 figs., 32 tabs.

Life cycle assessment of a biomass gasification combined-cycle power system

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-01

The potential environmental benefits from biomass power are numerous. However, biomass power may also have some negative effects on the environment. Although the environmental benefits and drawbacks of biomass power have been debated for some time, the total significance has not been assessed. This study serves to answer some of the questions most often raised in regard to biomass power: What are the net CO{sub 2} emissions? What is the energy balance of the integrated system? Which substances are emitted at the highest rates? What parts of the system are responsible for these emissions? To provide answers to these questions, a life cycle assessment (LCA) of a hypothetical biomass power plant located in the Midwest United States was performed. LCA is an analytical tool for quantifying the emissions, resource consumption, and energy use, collectively known as environmental stressors, that are associated with converting a raw material to a final product. Performed in conjunction with a t echnoeconomic feasibility study, the total economic and environmental benefits and drawbacks of a process can be quantified. This study complements a technoeconomic analysis of the same process, reported in Craig and Mann (1996) and updated here. The process studied is based on the concept of power Generation in a biomass integrated gasification combined cycle (BIGCC) plant. Broadly speaking, the overall system consists of biomass production, its transportation to the power plant, electricity generation, and any upstream processes required for system operation. The biomass is assumed to be supplied to the plant as wood chips from a biomass plantation, which would produce energy crops in a manner similar to the way food and fiber crops are produced today. Transportation of the biomass and other materials is by both rail and truck. The IGCC plant is sized at 113 MW, and integrates an indirectly-heated gasifier with an industrial gas turbine and steam cycle. 63 refs., 34 figs., 32 tabs.

The role of policy instruments for promoting combined heat and power production with low CO2 emissions in district heating systems

International Nuclear Information System (INIS)

Marbe, A.; Harvey, S.

2005-01-01

Policy instruments clearly influence the choice of production technologies and fuels in large energy systems, including district heating networks. Current Swedish policy instruments aim at promoting the use of biofuel in district heating systems, and at promoting electric power generation from renewable energy sources. However, there is increasing pressure to harmonize energy policy instruments within the EU. In addition, natural gas based combined cycle technology has emerged as the technology of choice in the power generation sector in the EU. This study aims at exploring the role of policy instruments for promoting the use of low CO 2 emissions fuels in high performance combined heat and power systems in the district heating sector. The paper presents the results of a case study for a Swedish district heating network where new large size natural gas combined cycle (NGCC) combined heat and power (CHP) is being built. Given the aim of current Swedish energy policy, it is assumed that it could be of interest in the future to integrate a biofuel gasifier to the CHP plant and co-fire the gasified biofuel in the gas turbine unit, thereby reducing usage of fossil fuel. The goals of the study are to evaluate which policy instruments promote construction of the planned NGCC CHP unit, the technical performance of an integrated biofuelled pressurized gasifier with or without dryer on plant site, and which combination of policy instruments promote integration of a biofuel gasifier to the planned CHP unit. The power plant simulation program GateCycle was used for plant performance evaluation. The results show that current Swedish energy policy instruments favour investing in the NGCC CHP unit. The corresponding cost of electricity (COE) from the NGCC CHP unit is estimated at 253 SEK MWh -1 , which is lower than the reference power price of 284 SEK MWh -1 . Investing in the NGCC CHP unit is also shown to be attractive if a CO 2 trading system is implemented. If the value of

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Investigation of thermodynamic performances for two solar-biomass hybrid combined cycle power generation systems

International Nuclear Information System (INIS)

Liu, Qibin; Bai, Zhang; Wang, Xiaohe; Lei, Jing; Jin, Hongguang

2016-01-01

Highlights: • Two solar-biomass hybrid combined cycle power generation systems are proposed. • The characters of the two proposed systems are compared. • The on-design and off-design properties of the system are numerically investigated. • The favorable performances of thermochemical hybrid routine are validated. - Abstract: Two solar-biomass hybrid combined cycle power generation systems are proposed in this work. The first system employs the thermochemical hybrid routine, in which the biomass gasification is driven by the concentrated solar energy, and the gasified syngas as a solar fuel is utilized in a combined cycle for generating power. The second system adopts the thermal integration concept, and the solar energy is directly used to heat the compressed air in the topping Brayton cycle. The thermodynamic performances of the developed systems are investigated under the on-design and off-design conditions. The advantages of the hybrid utilization technical mode are demonstrated. The solar energy can be converted and stored into the chemical fuel by the solar-biomass gasification, with the net solar-to-fuel efficiency of 61.23% and the net solar share of 19.01% under the specific gasification temperature of 1150 K. Meanwhile, the proposed system with the solar thermochemical routine shows more favorable behaviors, the annual system overall energy efficiency and the solar-to-electric efficiency reach to 29.36% and 18.49%, while the with thermal integration concept of 28.03% and 15.13%, respectively. The comparison work introduces a promising approach for the efficient utilization of the abundant solar and biomass resources in the western China, and realizes the mitigation of CO_2 emission.

Technical comparison between Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) power plants

Energy Technology Data Exchange (ETDEWEB)

Ortiz, Pablo Andres Silva; Venturini, Osvaldo Jose; Lora, Electo Eduardo Silva [Federal University of Itajuba - UNIFEI, MG (Brazil). Excellence Group in Thermal Power and Distributed Generation - NEST], e-mails: osvaldo@unifei.edu.br, electo@unifei.edu.br

2010-07-01

Among the emerging clean coal technologies for power generation, Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) systems are receiving considerable attention as a potentially attractive option to reduce the emissions of greenhouse gases (GHG). The main reason is because these systems has high efficiency and low emissions in comparison with traditional power generation plants. Currently in IGCC and NGCC systems at demonstration stage is been considered to implement CCS technology. CO{sub 2} emissions can be avoided in a gasification-based power plant because by transferring almost all carbon compounds to CO{sub 2} through the water gas shift (WGS) reaction, then removing the CO{sub 2} before it is diluted in the combustion stage. The aim of this study is to compare the technical performance of an IGCC system that uses Brazilian coal and petroleum coke as fuel with a NGCC system, with the same fixed output power of 450 MW. The first section of this paper presents the plant configurations of IGCC systems. The following section presents an analysis of NGCC technology. (author)

The market outlook for integrated gasification combined cycle technology

International Nuclear Information System (INIS)

MacGregor, P.R.; Maslak, C.E.; Stoll, H.G.

1991-01-01

Integrated gasification combined cycle (IGCC) technology was developed in the 1970s and is now competitive with other coal fired technologies. Because it is a new technology, IGCC technology developments are continuing at a rapid pace and the trend in decreasing capital costs is similar to the same trend seen during the early decades of simple cycle gas turbines. Consequently, IGCC technology is expected to be even more economical during the mid and late 1990s than it is today. The objective of this paper is to provide an examination of the basic economic principles of IGCC technology and to illustrate the extent to which this technology is a viable least-cost generation addition technology. Moreover, key reliability and emissions issues are addressed in relation to the technology alternatives. This paper is organized to first review the IGCC technology and to contrast its reliability, emission, performance and cost data with the three key commercially proven technologies: simple cycle combustion turbines, combined cycle plants, and coal-fired steam plants. Economic screening curves are used to illustrate the need for a balanced generation expansion mix of technologies. The regional market opportunity for coal fueled technology orders in the US from 1992 through 2005 is presented

Combined cycle power plant with integrated low temperature heat (LOTHECO)

International Nuclear Information System (INIS)

Kakaras, E.; Doukelis, A.; Leithner, R.; Aronis, N.

2004-01-01

The major driver to enhance the efficiency of the simple gas turbine cycle has been the increase in process conditions through advancements in materials and cooling methods. Thermodynamic cycle developments or cycle integration are among the possible ways to further enhance performance. The current paper presents the possibilities and advantages from the LOTHECO natural gas-fired combined cycle concept. In the LOTHECO cycle, low-temperature waste heat or solar heat is used for the evaporation of injected water droplets in the compressed air entering the gas turbine's combustion chamber. Following a description of this innovative cycle, its advantages are demonstrated by comparison between different gas turbine power generation systems for small and large-scale applications, including thermodynamic and economic analysis. A commercial gas turbine (ALSTOM GT10C) has been selected and computed with the heat mass balance program ENBIPRO. The results from the energy analysis are presented and the features of each concept are discussed. In addition, the exergy analysis provides information on the irreversibilities of each process and suggested improvements. Finally, the economic analysis reveals that the combined cycle plant with a heavy-duty gas turbine is the most efficient and economic way to produce electricity at base load. However, on a smaller scale, innovative designs, such as the LOTHECO concept, are required to reach the same level of performance at feasible costs

Thermochemical equilibrium modelling of a gasifying process

International Nuclear Information System (INIS)

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

2007-01-01

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

Alternative ORC bottoming cycles FOR combined cycle power plants

International Nuclear Information System (INIS)

Chacartegui, R.; Sanchez, D.; Munoz, J.M.; Sanchez, T.

2009-01-01

In this work, low temperature Organic Rankine Cycles are studied as bottoming cycle in medium and large scale combined cycle power plants. The analysis aims to show the interest of using these alternative cycles with high efficiency heavy duty gas turbines, for example recuperative gas turbines with lower gas turbine exhaust temperatures than in conventional combined cycle gas turbines. The following organic fluids have been considered: R113, R245, isobutene, toluene, cyclohexane and isopentane. Competitive results have been obtained for toluene and cyclohexane ORC combined cycles, with reasonably high global efficiencies. The paper is structured in four main parts. A review of combined cycle and ORC cycle technologies is presented, followed by a thermodynamic analysis of combined cycles with commercial gas turbines and ORC low temperature bottoming cycles. Then, a parametric optimization of an ORC combined cycle plant is performed in order to achieve a better integration between these two technologies. Finally, some economic considerations related to the use of ORC in combined cycles are discussed.

The reliability of integrated gasification combined cycle (IGCC) power generation units

Energy Technology Data Exchange (ETDEWEB)

Higman, C.; DellaVilla, S.; Steele, B. [Syngas Consultants Ltd. (United Kingdom)

2006-07-01

This paper presents two interlinked projects aimed at supporting the improvement of integrated gasification combined cycle (IGCC) reliability. The one project comprises the extension of SPS's existing ORAP (Operational Reliability Analysis Program) reliability, availability and maintainability (RAM) tracking technology from its existing base in natural gas open and combined cycle operations into IGCC. The other project is using the extended ORAP database to evaluate performance data from existing plants. The initial work has concentrated on evaluating public domain data on the performance of gasification based power and chemical plants. This is being followed up by plant interviews in some 20 plants to verify and expand the database on current performance. 23 refs., 8 figs., 2 tabs.

Integrated gasification combined cycle for acid rain control

Energy Technology Data Exchange (ETDEWEB)

Simbeck, D.R.; Dickenson, R.L.

1986-10-01

The role of integrated coal gasification combined-cycle power plants in the abatement of emission of SO/sub 2/ and NO/sub 2/ which lead to acid rain is discussed. The economics of this IGCC approach are assessed for a nominal 500 MW plant size. Phased construction of IGCC plants is recommended as a means of reducing SO/sub 2/ and NO/sub x/ emissions noting that high-sulfur coals could continue to be used. It is also noted that phased construction IGCC is the only acid rain control technology that greatly reduces NO/sub x/. 17 references.

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

International Nuclear Information System (INIS)

Sterzinger, G.J.

1994-05-01

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

Comparison of Different Technologies for Integrated Solar Combined Cycles: Analysis of Concentrating Technology and Solar Integration

Directory of Open Access Journals (Sweden)

Antonio Rovira

2018-04-01

Full Text Available This paper compares the annual performance of Integrated Solar Combined Cycles (ISCCs using different solar concentration technologies: parabolic trough collectors (PTC, linear Fresnel reflectors (LFR and central tower receiver (CT. Each solar technology (i.e. PTC, LFR and CT is proposed to integrate solar energy into the combined cycle in two different ways. The first one is based on the use of solar energy to evaporate water of the steam cycle by means of direct steam generation (DSG, increasing the steam production of the high pressure level of the steam generator. The other one is based on the use of solar energy to preheat the pressurized air at the exit of the gas turbine compressor before it is introduced in the combustion chamber, reducing the fuel consumption. Results show that ISCC with DSG increases the yearly production while solar air heating reduces it due to the incremental pressure drop. However, air heating allows significantly higher solar-to-electricity efficiencies and lower heat rates. Regarding the solar technologies, PTC provides the best thermal results.

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Integrated Sensing and Controls for Coal Gasification - Development of Model-Based Controls for GE's Gasifier and Syngas Cooler

Energy Technology Data Exchange (ETDEWEB)

Aditya Kumar

2010-12-30

This report summarizes the achievements and final results of this program. The objective of this program is to develop a comprehensive systems approach to integrated design of sensing and control systems for an Integrated Gasification Combined Cycle (IGCC) plant, using advanced model-based techniques. In particular, this program is focused on the model-based sensing and control system design for the core gasification section of an IGCC plant. The overall approach consists of (i) developing a first-principles physics-based dynamic model of the gasification section, (ii) performing model-reduction where needed to derive low-order models suitable for controls analysis and design, (iii) developing a sensing system solution combining online sensors with model-based estimation for important process variables not measured directly, and (iv) optimizing the steady-state and transient operation of the plant for normal operation as well as for startup using model predictive controls (MPC). Initially, available process unit models were implemented in a common platform using Matlab/Simulink{reg_sign}, and appropriate model reduction and model updates were performed to obtain the overall gasification section dynamic model. Also, a set of sensor packages were developed through extensive lab testing and implemented in the Tampa Electric Company IGCC plant at Polk power station in 2009, to measure temperature and strain in the radiant syngas cooler (RSC). Plant operation data was also used to validate the overall gasification section model. The overall dynamic model was then used to develop a sensing solution including a set of online sensors coupled with model-based estimation using nonlinear extended Kalman filter (EKF). Its performance in terms of estimating key unmeasured variables like gasifier temperature, carbon conversion, etc., was studied through extensive simulations in the presence sensing errors (noise and bias) and modeling errors (e.g. unknown gasifier kinetics, RSC

Modeling and simulation of syngas purification and power generation in integrated gasification combined cycle (IGCS)

Energy Technology Data Exchange (ETDEWEB)

Mehmood, N; Zaman, Z U; Mehran, M T [National Development, Islamabad (Pakistan)

2011-07-01

Integrated Gasification Combined Cycle (IGCC) is one of the most promising technologies for power generation; The environmental benefits and the higher energy conversion efficiency distinguish it from traditional coal generation technologies. This work presents a structured and validated conceptual model of purification of coal gas produced during the Underground Coal Gasification (UCG) of coal containing high sulfur contents. Gas cleaning operations for CO/sub 2/, H/sub 2/S and moisture removal have been modeled in steady and dynamic state. The power generation from combined cycle is also modeled. The model has been developed using Aspen HYSYS and Aspen Plus simulation software. Predicted results of clean gas composition and generated power present a good agreement with industrial data and efficiency parameters. This study is aimed at obtaining optimal assessment of an integrated gasification combined cycle (IGCC) power plant configurations. (author)

Modeling and simulation of syngas purification and power generation in integrated gasification combined cycle (IGCS)

International Nuclear Information System (INIS)

Mehmood, N.; Zaman, Z.U.; Mehran, M.T.

2011-01-01

Integrated Gasification Combined Cycle (IGCC) is one of the most promising technologies for power generation; The environmental benefits and the higher energy conversion efficiency distinguish it from traditional coal generation technologies. This work presents a structured and validated conceptual model of purification of coal gas produced during the Underground Coal Gasification (UCG) of coal containing high sulfur contents. Gas cleaning operations for CO/sub 2/, H/sub 2/S and moisture removal have been modeled in steady and dynamic state. The power generation from combined cycle is also modeled. The model has been developed using Aspen HYSYS and Aspen Plus simulation software. Predicted results of clean gas composition and generated power present a good agreement with industrial data and efficiency parameters. This study is aimed at obtaining optimal assessment of an integrated gasification combined cycle (IGCC) power plant configurations. (author)

Modelling the low-tar BIG gasification concept[Biomass Integrated gasification

Energy Technology Data Exchange (ETDEWEB)

Andersen, Lars; Elmegaard, B.; Qvale, B.; Henriksen, Ulrrik [Technical univ. of Denmark (Denmark); Bentzen, J.D.; Hummelshoej, R. [COWI A/S (Denmark)

2007-07-01

A low-tar, high-efficient biomass gasification concept for medium- to large-scale power plants has been designed. The concept is named 'Low-Tar BIG' (BIG = Biomass Integrated Gasification). The concept is based on separate pyrolysis and gasification units. The volatile gases from the pyrolysis (containing tar) are partially oxidised in a separate chamber, and hereby the tar content is dramatically reduced. Thus, the investment, and running cost of a gas cleaning system can be reduced, and the reliability can be increased. Both pyrolysis and gasification chamber are bubbling fluid beds, fluidised with steam. For moist fuels, the gasifier can be integrated with a steam drying process, where the produced steam is used in the pyrolysis/gasification chamber. In this paper, mathematical models and results from initial tests of a laboratory Low-Tar BIG gasifier are presented. Two types of models are presented: 1. The gasifier-dryer applied in different power plant systems: Gas engine, Simple cycle gas turbine, Recuperated gas turbine and Integrated Gasification and Combined Cycle (IGCC). The paper determines the differences in efficiency of these systems and shows that the gasifier will be applicable for very different fuels with different moisture contents, depending on the system. 2. A thermodynamic Low-Tar BIG model. This model is based on mass and heat balance between four reactors: Pyrolysis, partial oxidation, gasification, gas-solid mixer. The paper describes the results from this study and compares the results to actual laboratory tests. The study shows, that the Low-Tar BIG process can use very wet fuels (up to 65-70% moist) and still produce heat and power with a remarkable high electric efficiency. Hereby the process offers the unique combination of large scale gasification and low-cost gas cleaning and use of low-cost fuels which very likely is the necessary combination that will lead to a breakthrough of gasification technology. (au)

Analysis of energetic and exergetic efficiency, and environmental benefits of biomass integrated gasification combined cycle technology.

Science.gov (United States)

Mínguez, María; Jiménez, Angel; Rodríguez, Javier; González, Celina; López, Ignacio; Nieto, Rafael

2013-04-01

The problem of the high carbon dioxide emissions linked to power generation makes necessary active research on the use of biofuels in gas turbine systems as a promising alternative to fossil fuels. Gasification of biomass waste is particularly of interest in obtaining a fuel to be run in gas turbines, as it is an efficient biomass-to-biofuel conversion process, and an integration into a combined cycle power plant leads to a high performance with regard to energetic efficiency. The goal of this study was to carry out an energetic, exergetic and environmental analysis of the behaviour of an integrated gasification combined cycle (IGCC) plant fuelled with different kinds of biomass waste by means of simulations. A preliminary economic study is also included. Although a technological development in gasification technology is necessary, the results of simulations indicate a high technical and environmental interest in the use of biomass integrated gasification combined cycle (BioIGCC) systems for large-scale power generation from biomass waste.

Coal Integrated Gasification Fuel Cell System Study

Energy Technology Data Exchange (ETDEWEB)

Chellappa Balan; Debashis Dey; Sukru-Alper Eker; Max Peter; Pavel Sokolov; Greg Wotzak

2004-01-31

This study analyzes the performance and economics of power generation systems based on Solid Oxide Fuel Cell (SOFC) technology and fueled by gasified coal. System concepts that integrate a coal gasifier with a SOFC, a gas turbine, and a steam turbine were developed and analyzed for plant sizes in excess of 200 MW. Two alternative integration configurations were selected with projected system efficiency of over 53% on a HHV basis, or about 10 percentage points higher than that of the state-of-the-art Integrated Gasification Combined Cycle (IGCC) systems. The initial cost of both selected configurations was found to be comparable with the IGCC system costs at approximately $1700/kW. An absorption-based CO2 isolation scheme was developed, and its penalty on the system performance and cost was estimated to be less approximately 2.7% and $370/kW. Technology gaps and required engineering development efforts were identified and evaluated.

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

Directory of Open Access Journals (Sweden)

Jai-Houng Leu

2010-01-01

Full Text Available Biomass is the largest renewable energy source in the world. Its importance grows gradually in the future energy market. Since most biomass sources are low in energy density and are widespread in space, small-scale biomass conversion system is therefore more competitive than a large stand-alone conversion plant. The current study proposes a small-scale solid biomass power system to explore the viability of direct coupling of an updraft fixed bed gasifier with a Stirling engine. The modified updraft fixed bed gasifier employs an embedded combustor inside the gasifier to fully combust the synthetic gas generated by the gasifier. The flue gas produced by the synthetic gas combustion inside the combustion tube is piped directly to the heater head of the Stirling engine. The engine will then extract and convert the heat contained in the flue gas into electricity automatically. Output depends on heat input. And, the heat input is proportional to the flow rate and temperature of the flue gas. The preliminary study of the proposed direct coupling of an updraft gasifier with a 25 kW Stirling engine demonstrates that full power output could be produced by the current system. It could be found from the current investigation that no auxiliary fuel is required to operate the current system smoothly. The proposed technology and units could be considered as a viable solid biomass power system.

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

Science.gov (United States)

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

2012-12-01

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

Effect of reverse Boudouard reaction catalyst on the performance of solid oxide carbon fuel cells integrated with a dry gasifier

International Nuclear Information System (INIS)

Kim, Sun-Kyung; Mehran, Muhammad Taqi; Mushtaq, Usman; Lim, Tak-Hyoung; Lee, Jong-Won; Lee, Seung-Bok; Park, Seok-Joo; Song, Rak-Hyun

2016-01-01

Highlights: • The addition of K_2CO_3 catalyst in carbon fuel improves the performance of SO-CFC. • Thermal and electrochemical analyses done to elucidate the catalytic enhancement. • Material characterization of SO-CFC performed after long-term degradation test. - Abstract: A solid oxide carbon fuel cell (SO-CFC) integrated with a dry gasifier was operated on activated carbon fuel and the effect of adding a reverse Boudouard gasification catalyst on the performance and long-term operation characteristics of the SO-CFC was investigated. The reactivity of the carbon fuels for the Boudouard gasification reaction was analyzed by a thermal analysis at various operating conditions. The SO-CFC was then operated on gasified fuel gas consisting of CO_2 and CO obtained from the integrated dry gasifier. The SO-CFC operated on activated carbon fuel with 5 wt.% K_2CO_3 achieved a maximum power density of 202, 262, and 271 mW/cm"2 at 750, 800, and 850 °C, respectively; the SO-CFC fueled with activated carbon fuel without a catalyst meanwhile yielded maximum power density of 168 mW/cm"2 at 850 °C. By using electrochemical impedance spectroscopy, the effect of adding the catalyst on the gasification products and subsequently on the performance of the SO-CFC was studied. A long-term degradation test was conducted by continuously operating the SO-CFC at 50 mA/cm"2 for 518 h at 750 °C. During the long-term degradation test, the average degradation rate of the SO-CFC was found to be 183 mV/kh. The post-mortem SEM and XRD analyses of the SO-CFC after the long-term test revealed the presence of carbon deposits and oxidation of Ni at the anode, causing a relatively higher degree of degradation in the SO-CFC integrated with the dry gasifier during the long-term operation. The addition of the K_2CO_3 based dry gasification catalyst significantly enhances the performance of the SO-CFC integrated with dry gasification, but during long-term operation, the degradation rate is found

Integrated gasification combined-cycle research development and demonstration activities in the US

Energy Technology Data Exchange (ETDEWEB)

Ness, H.M.; Brdar, R.D.

1996-09-01

The United States Department of Energy (DOE)`s Office of Fossil Energy, Morgantown Energy Technology Center, is managing a research development and demonstration (RD&D) program that supports the commercialization of integrated gasification combined-cycle (IGCC) advanced power systems. This overview briefly describes the supporting RD&D activities and the IGCC projects selected for demonstration in the Clean Coal Technology (CCT) Program.

Integrated gasification gas combined cycle plant with membrane reactors: Technological and economical analysis

International Nuclear Information System (INIS)

Amelio, Mario; Morrone, Pietropaolo; Gallucci, Fausto; Basile, Angelo

2007-01-01

In the present work, the capture and storage of carbon dioxide from the fossil fuel power plant have been considered. The main objective was to analyze the thermodynamic performances and the technological aspects of two integrated gasification gas combined cycle plants (IGCC), as well as to give a forecast of the investment costs for the plants and the resulting energy consumptions. The first plant considered is an IGCC* plant (integrated gasification gas combined cycle plant with traditional shift reactors) characterized by the traditional water gas shift reactors and a CO 2 physical adsorption system followed by the power section. The second one is an IGCC M plant (integrated gasification gas combined cycle plant with membrane reactor) where the coal thermal input is the same as the first one, but the traditional shift reactors and the physical adsorption unit are replaced by catalytic palladium membrane reactors (CMR). In the present work, a mono-dimensional computational model of the membrane reactor was proposed to simulate and evaluate the capability of the IGCC M plant to capture carbon dioxide. The energetic performances, efficiency and net power of the IGCC* and IGCC M plants were, thus, compared, assuming as standard a traditional IGCC plant without carbon dioxide capture. The economical aspects of the three plants were compared through an economical analysis. Since the IGCC* and IGCC M plants have additional costs related to the capture and disposal of the carbon dioxide, a Carbon Tax (adopted in some countries like Sweden) proportional to the number of kilograms of carbon dioxide released in the environment was assumed. According to the economical analysis, the IGCC M plant proved to be more convenient than the IGCC* one

Integrated operation and management system for a 700MW combined cycle power plant

Energy Technology Data Exchange (ETDEWEB)

Shiroumaru, I. (Yanai Power Plant Construction Office, Chugoku Electric Power Co., Inc., 1575-5 Yanai-Miyamoto-Shiohama, Yanai-shi, Yamaguchi-ken (JP)); Iwamiya, T. (Omika Works, Hitachi, Ltd., 5-2-1 Omika-cho, Hitachi-shi, Ibaraki-ken (JP)); Fukai, M. (Hitachi Works, Hitachi, Ltd., 3-1-1 Saiwai-cho, Hitachi-shi, Ibaraki-ken (JP))

1992-03-01

Yanai Power Plant of the Chugoku Electric Power Co., Inc. (Yamaguchi Pref., Japan) is in the process of constructing a 1400MW state-of-the-art combined cycle power plant. The first phase, a 350MW power plant, started operation on a commercial basis in November, 1990. This power plant has achieved high efficiency and high operability, major features of a combined cycle power plant. The integrated operation and management system of the power plant takes care of operation, maintenance, control of general business, etc., and was built using the latest computer and digital control and communication technologies. This paper reports that it is expected that this system will enhance efficient operation and management for the power plant.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Transportation fuel production from gasified biomass integrated with a pulp and paper mill - Part B: Analysis of economic performance and greenhouse gas emissions

International Nuclear Information System (INIS)

Isaksson, Johan; Jansson, Mikael; Åsblad, Anders; Berntsson, Thore

2016-01-01

This paper presents a comparison between four gasification-based biorefineries integrated with a pulp and paper mill. It is a continuation of 'Transportation fuel production from gasified biomass integrated with a pulp and paper mill - Part A: Heat integration and system performance'. Synthesis into methanol, Fischer-Tropsch crude or synthetic natural gas, or electricity generation in a gas turbine combined cycle, were evaluated. The concepts were assessed in terms of GHG (greenhouse gas) emissions and economic performance. Net annual profits were positive for all biofuel cases for an annuity factor of 0.1 in the year 2030; however, the results are sensitive to biofuel selling prices and CO_2_,_e_q charge. Additionally, GHG emissions from grid electricity are highly influential on the results since all biofuel processes require external power. Credits for stored CO_2 might be necessary for processes to be competitive, i.e. storage of separated CO_2 from the syngas conditioning has an important role to play. Without CO_2 storage, the gas turbine case is better than, or equal to, biofuels regarding GHG emissions. Efficiency measures at the host mill prior to heat integration of a gasification process are beneficial from the perspective of GHG emissions, while having a negative impact on the economy. - Highlights: • Biomass gasification integrated with a pulp and paper mill was evaluated. • Greenhouse gas emission consequences and economic performance were assessed. • CCS has an important role to play, both in terms of emissions and economy. • Green electricity production is competitive compared to biofuel production in terms of GHG. • All biofuel cases are profitable in 2030 with assumed level of future policy instruments.

Performance and operational economics estimates for a coal gasification combined-cycle cogeneration powerplant

Science.gov (United States)

Nainiger, J. J.; Burns, R. K.; Easley, A. J.

1982-01-01

A performance and operational economics analysis is presented for an integrated-gasifier, combined-cycle (IGCC) system to meet the steam and baseload electrical requirements. The effect of time variations in steam and electrial requirements is included. The amount and timing of electricity purchases from sales to the electric utility are determined. The resulting expenses for purchased electricity and revenues from electricity sales are estimated by using an assumed utility rate structure model. Cogeneration results for a range of potential IGCC cogeneration system sizes are compared with the fuel consumption and costs of natural gas and electricity to meet requirements without cogeneration. The results indicate that an IGCC cogeneration system could save about 10 percent of the total fuel energy presently required to supply steam and electrical requirements without cogeneration. Also for the assumed future fuel and electricity prices, an annual operating cost savings of 21 percent to 26 percent could be achieved with such a cogeneration system. An analysis of the effects of electricity price, fuel price, and system availability indicates that the IGCC cogeneration system has a good potential for economical operation over a wide range in these assumptions.

Thermodynamic analysis of a novel integrated solar combined cycle

International Nuclear Information System (INIS)

Li, Yuanyuan; Yang, Yongping

2014-01-01

Highlights: • A novel ISCC scheme with two-stage DSG fields has been proposed and analyzed. • HRSG and steam turbine working parameters have been optimized to match the solar integration. • New scheme exhibits higher solar shares in the power output and solar-to-electricity efficiency. • Thermodynamic performances between new and reference systems have been investigated and compared. - Abstract: Integrated solar combined cycle (ISCC) systems have become more and more popular due to their high fuel and solar energy utilization efficiencies. Conventional ISCC systems with direct steam generation (DSG) have only one-stage solar input. A novel ISCC with DSG system has been proposed and analyzed in this paper. The new system consists two-stage solar input, which would significantly increase solar share in the total power output. Moreover, how and where solar energy is input into ISCC system would have impact on the solar and system overall efficiencies, which have been analyzed in the paper. It has been found that using solar heat to supply latent heat for vaporization of feedwater would be superior to that to be used for sensible heating purposes (e.g. Superheating steam). The study shows that: (1) producing both the high- and low-pressure saturated steam in the DSG trough collector could be an efficient way to improve process and system performance; (2) for a given live steam pressure, the optimum secondary and reheat steam conditions could be matched to reach the highest system thermal efficiency and net solar-to-electricity efficiency; (3) the net solar-to-electricity efficiency could reach up to 30% in the novel two-stage ISCC system, higher than that in the one-stage ISCC power plant; (4) compared with the conventional combined cycle gas turbine (CCGT) power system, lower stack temperature could be achieved, owing to the elimination of the approach-temperature-difference constraint, resulting in better thermal match in the heat recovery steam generator

Technical and economic assessment of the integrated solar combined cycle power plants in Iran

International Nuclear Information System (INIS)

Soltani Hosseini, M.; Hosseini, R.; Valizadeh, G.H.

2002-01-01

Thermal efficiency, capacity factor, environmental considerations, investment cost, fuel and O and M costs are the main parameters for technical and economic assessment of solar power plants. This analysis has shown that the Integrated Solar Combined Cycle System with 67 MW e solar field(ISCCS-67) is the most suitable plan for the first solar power plant in Iran. The Levelized Energy Costs of combined cycle and ISCCS-67 power plants would be equal if 49 million dollars of ISCCS-67 capital cost supplied by the international environmental organizations such as Global Environmental Facilities and World Bank. This study shows that an ISCCS-67 saves 59 million dollars in fuel consumption and reduces about 2.4 million ton in CO 2 emission during 30 years operating period. Increasing of steam turbine capacity by 50%, and 4% improvement in overall efficiency are other advantages of iSCCS-67 power plant. The LEC of ISCCS-67 is 10% and so 33% lower than the combined cycle and gas turbine, respectively, at the same capacity factor with consideration of environmental costs

OUT Success Stories: Biomass Gasifiers

International Nuclear Information System (INIS)

Jones, J.

2000-01-01

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

An evaluation of the performance of an integrated solar combined cycle plant provided with air-linear parabolic collectors

International Nuclear Information System (INIS)

Amelio, Mario; Ferraro, Vittorio; Marinelli, Valerio; Summaria, Antonio

2014-01-01

An evaluation of the performance of an innovative solar system integrated in a combined cycle plant is presented, in which the heat transfer fluid flowing in linear parabolic collectors is the same oxidant air that is introduced into the combustion chamber of the plant. This peculiarity allows a great simplification of the plant. There is a 22% saving of fossil fuel results in design conditions and 15.5% on an annual basis, when the plant works at nominal volumetric flow rate in the daily hours. The net average year efficiency is 60.9% against the value of 51.4% of a reference combined cycle plant without solar integration. Moreover, an economic evaluation of the plant is carried out, which shows that the extra-cost of the solar part is recovered in about 5 years. - Highlights: • A model to calculate an innovative ISCCS (Integrated solar Combined Cycle Systems) solar plant is presented. • The plant uses air as heat transfer fluid as well as oxidant in the combustor. • The plant presents a very high thermodynamic efficiency. • The plant is very simple in comparison with existing ISCCS

Development and Testing of Prototype Commercial Gasifier Sensor

Energy Technology Data Exchange (ETDEWEB)

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

2015-01-31

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

TASK 3: PILOT PLANT GASIFIER TESTING

Energy Technology Data Exchange (ETDEWEB)

Fusselman, Steve

2015-11-01

Aerojet Rocketdyne (AR) has developed an innovative gasifier concept incorporating advanced technologies in ultra-dense phase dry feed system, rapid mix injector, and advanced component cooling to significantly improve gasifier performance, life, and cost compared to commercially available state-of-the-art systems. Design, fabrication and initial testing of the pilot plant compact gasifier was completed in 2011 by a development team led by AR. Findings from this initial test program, as well as subsequent gasifier design and pilot plant testing by AR, identified a number of technical aspects to address prior to advancing into a demonstration-scale gasifier design. Key among these were an evaluation of gasifier ability to handle thermal environments with highly reactive coals; ability to handle high ash content, high ash fusion temperature coals with reliable slag discharge; and to develop an understanding of residual properties pertaining to gasification kinetics as carbon conversion approaches 99%. The gasifier did demonstrate the ability to withstand the thermal environments of highly reactive Powder River Basin coal, while achieving high carbon conversion in < 0.15 seconds residence time. Continuous operation with the high ash fusion temperature Xinyuan coal was demonstrated in long duration testing, validating suitability of outlet design as well as downstream slag discharge systems. Surface area and porosity data were obtained for the Xinyuan and Xinjing coals for carbon conversion ranging from 85% to 97%, and showed a pronounced downward trend in surface area per unit mass carbon as conversion increased. Injector faceplate measurements showed no incremental loss of material over the course of these experiments, validating the commercially traceable design approach and supportive of long injector life goals. Hybrid testing of PRB and natural gas was successfully completed over a wide range of natural gas feed content, providing test data to anchor predictions

Dynamic Modeling and Plantwide Control of a Hybrid Power and Chemical Plant: An Integrated Gasification Combined Cycle Coupled with a Methanol Plant

Science.gov (United States)

Robinson, Patrick J.

Gasification has been used in industry on a relatively limited scale for many years, but it is emerging as the premier unit operation in the energy and chemical industries. The switch from expensive and insecure petroleum to solid hydrocarbon sources (coal and biomass) is occurring due to the vast amount of domestic solid resources, national security and global warming issues. Gasification (or partial oxidation) is a vital component of "clean coal" technology. Sulfur and nitrogen emissions can be reduced, overall energy efficiency is increased and carbon dioxide recovery and sequestration are facilitated. Gasification units in an electric power generation plant produce a fuel gas for driving combustion turbines. Gasification units in a chemical plant generate synthesis gas, which can be used to produce a wide spectrum of chemical products. Future plants are predicted to be hybrid power/chemical plants with gasification as the key unit operation. The coupling of an Integrated Gasification Combined Cycle (IGCC) with a methanol plant can handle swings in power demand by diverting hydrogen gas from a combustion turbine and synthesis gas from the gasifier to a methanol plant for the production of an easily-stored, hydrogen-consuming liquid product. An additional control degree of freedom is provided with this hybrid plant, fundamentally improving the controllability of the process. The idea is to base-load the gasifier and use the more responsive gas-phase units to handle disturbances. During the summer days, power demand can fluctuate up to 50% over a 12-hour period. The winter provides a different problem where spikes of power demand can go up 15% within the hour. The following dissertation develops a hybrid IGCC / methanol plant model, validates the steady-state results with a National Energy Technical Laboratory study, and tests a proposed control structure to handle these significant disturbances. All modeling was performed in the widely used chemical process

Carbon behavior in the cyclic operation of dry desulfurization process for oxy-fuel integrated gasification combined cycle power generation

International Nuclear Information System (INIS)

Kobayashi, Makoto; Akiho, Hiroyuki

2016-01-01

Highlights: • Power plant with semi-closed gas turbine and O_2–CO_2 coal gasifier was studied. • Dry gas sulfur removal sorbent was improved for durability to carbon deposition. • The improved sorbent showed very low amount of deposited carbon during operation. • The sorbent is regenerable to be used repeatedly in the cyclic operation. • The sorbent exhibited high sulfur-removal performance in the cyclic operation. - Abstract: The dry sulfur-removal process is essential to provide suitable syngas treatment for the oxy-fuel integrated gasification combined cycle power generation plant. It is required that the dry sulfur-removal process to be durable to the carbon deposition due to syngas containing high concentration of carbon monoxide in addition to achieve sufficient performance for sulfur removal. Zinc ferrite sorbent is the most promising candidate for the dry sulfur-removal process. The sorbent was improved to enhance durability to the carbon deposition by modifying preparation. The improved sorbent was prepared from sulfates as the raw materials of zinc ferrite, while the former sorbent was using nitrates as the raw materials. The improved sorbent as well as the former sorbent were evaluated on the performance and carbon deposition tendency in oxy-fuel syngas condition in a fixed bed reactor at elevated pressure and temperature. The results expressed that the improved sorbent has higher desulfurization performance and durability to carbon deposition in the condition expected for cyclic operation of the sulfur-removal process in comparison with the former sorbent. The improved sorbent possessed the superior desulfurization performance as well as the capability for inhibit carbon deposition in the oxy-fuel syngas conditions. The results confirmed the enhanced feasibility of the dry sulfur-removal process by utilizing the improved sorbent.

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.

Real Time Flame Monitoring of Gasifier and Injectors

Energy Technology Data Exchange (ETDEWEB)

Zelepouga, Serguei; Saveliev, Alexei

2011-12-31

This project is a multistage effort with the final goal to develop a practical and reliable nonintrusive gasifier injector monitor to assess burner wear and need for replacement. The project team included the National Energy Technology Laboratory (NETL), Gas Technology Institute (GTI), North Carolina State University, and ConocoPhillips. This report presents the results of the sensor development and testing initially at GTI combustion laboratory with natural gas flames, then at the Canada Energy Technology Center (CANMET), Canada in the atmospheric coal combustor as well as in the pilot scale pressurized entrained flow gasifier, and finally the sensor capabilities were demonstrated at the Pratt and Whitney Rocketdyne (PWR) Gasifier and the Wabash River Repowering plant located in West Terre Haute, IN. The initial tests demonstrated that GTI gasifier sensor technology was capable of detecting shape and rich/lean properties of natural gas air/oxygen enriched air flames. The following testing at the Vertical Combustor Research Facility (VCRF) was a logical transition step from the atmospheric natural gas flames to pressurized coal gasification environment. The results of testing with atmospheric coal flames showed that light emitted by excited OH* and CH* radicals in coal/air flames can be detected and quantified. The maximum emission intensities of OH*, CH*, and black body (char combustion) occur at different axial positions along the flame length. Therefore, the excitation rates of CH* and OH* are distinct at different stages of coal combustion and can be utilized to identify and characterize processes which occur during coal combustion such as devolatilization, char heating and burning. To accomplish the goals set for Tasks 4 and 5, GTI utilized the CANMET Pressurized Entrained Flow Gasifier (PEFG). The testing parameters of the PEFG were selected to simulate optimum gasifier operation as well as gasifier conditions normally resulting from improper operation or

Simulation of the biomass updraft gasifier

Energy Technology Data Exchange (ETDEWEB)

Teislev, B.

2006-07-15

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

Down-flow moving-bed gasifier with catalyst recycle

Science.gov (United States)

Halow, John S.

1999-01-01

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

Commissioning an Engineering Scale Coal Gasifier

Energy Technology Data Exchange (ETDEWEB)

Reid, Douglas J.; Bearden, Mark D.; Cabe, James E.

2010-07-01

This report explains the development, commissioning, and testing of an engineering scale slagging coal gasifier at PNNL. The initial objective of this project was to commission the gasifier with zero safety incidents. The commissioning work was primarily an empirical study that required an engineering design approach. After bringing the gasifier on-line, tests were conducted to assess the impact of various operating parameters on the synthesis gas (syngas) product composition. The long-term intent of this project is to produce syngas product for use by internal Pacific Northwest National Laboratory (PNNL) researchers in catalyst, materials, and instrumentation development. Future work on the project will focus on improving the reliability and performance of the gasifier, with a goal of continuous operation for greater than 4 hours using coal feedstock. In addition, alternate designs that allow for increased flexibility regarding the fuel sources that can be used for syngas production is desired. Continued modifications to the fuel feed system will be pursued to address these goals. Alternative feed mechanisms such as a coal/methanol slurry are being considered.

Condensate from a two-stage gasifier

DEFF Research Database (Denmark)

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

2000-01-01

Condensate, produced when gas from downdraft biomass gasifier is cooled, contains organic compounds that inhibit nitrifiers. Treatment with activated carbon removes most of the organics and makes the condensate far less inhibitory. The condensate from an optimised two-stage gasifier is so clean...... that the organic compounds and the inhibition effect are very low even before treatment with activated carbon. The moderate inhibition effect relates to a high content of ammonia in the condensate. The nitrifiers become tolerant to the condensate after a few weeks of exposure. The level of organic compounds...... and the level of inhibition are so low that condensate from the optimised two-stage gasifier can be led to the public sewer....

Numerical investigation of slag formation in an entrained-flow gasifier

Science.gov (United States)

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

2018-05-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-07-01

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

Biomass Gasifier for Computer Simulation; Biomassa foergasare foer Computer Simulation

Energy Technology Data Exchange (ETDEWEB)

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

2011-08-15

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

Dry syngas purification process for coal gas produced in oxy-fuel type integrated gasification combined cycle power generation with carbon dioxide capturing feature.

Science.gov (United States)

Kobayashi, Makoto; Akiho, Hiroyuki

2017-12-01

Electricity production from coal fuel with minimizing efficiency penalty for the carbon dioxide abatement will bring us sustainable and compatible energy utilization. One of the promising options is oxy-fuel type Integrated Gasification Combined Cycle (oxy-fuel IGCC) power generation that is estimated to achieve thermal efficiency of 44% at lower heating value (LHV) base and provide compressed carbon dioxide (CO 2 ) with concentration of 93 vol%. The proper operation of the plant is established by introducing dry syngas cleaning processes to control halide and sulfur compounds satisfying tolerate contaminants level of gas turbine. To realize the dry process, the bench scale test facility was planned to demonstrate the first-ever halide and sulfur removal with fixed bed reactor using actual syngas from O 2 -CO 2 blown gasifier for the oxy-fuel IGCC power generation. Design parameter for the test facility was required for the candidate sorbents for halide removal and sulfur removal. Breakthrough test was performed on two kinds of halide sorbents at accelerated condition and on honeycomb desulfurization sorbent at varied space velocity condition. The results for the both sorbents for halide and sulfur exhibited sufficient removal within the satisfactory short depth of sorbent bed, as well as superior bed conversion of the impurity removal reaction. These performance evaluation of the candidate sorbents of halide and sulfur removal provided rational and affordable design parameters for the bench scale test facility to demonstrate the dry syngas cleaning process for oxy-fuel IGCC system as the scaled up step of process development. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

African Journals Online (AJOL)

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

Simulation of the biomass updraft gasifier

Energy Technology Data Exchange (ETDEWEB)

Teislev, B.

2006-07-15

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

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Improved Gasifier Availability with Bed Material and Additives

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-15

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

Performance evaluation of open core gasifier on multi-fuels

Energy Technology Data Exchange (ETDEWEB)

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

2006-06-15

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

Thermodynamics of the CO2–Absorption/Desorption Section in the Integrated Gasifying Combined cycle — II. Analysis

Directory of Open Access Journals (Sweden)

Jaroslav KOZACZKA

2012-06-01

Full Text Available The thermodynamic analysis of the absorption/desorption section of the ICGC–cycle has been presented using the Second Law with special emphasis on the thermodynamic effectivity concept and usability for complex systems investigations. Essential problems have been discussed based on the classical bibliographical items on the subject. Numerical calculations have been accomplished using results obtained in the first part, which contained absorption and desorption modeling approach oriented onto thermodynamic analyzes. Additionally the special properties of dilute solutions, especially the CO2/water system, have been presented and the problem of the solute chemical concentration exergy change suggested.

Low-Chrome/Chrome Free Refractories for Slagging Gasifiers

International Nuclear Information System (INIS)

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

2007-01-01

Gasifiers are containment vessels used to react carbon-containing materials with oxygen and water, producing syngas (CO and H2) that is used in chemical and power production. It is also a potential source of H2 in a future hydrogen economy. Air cooled slagging gasifiers are one type of gasifier, operating at temperatures from 1275-1575 C and at pressures of 400 psi or higher. They typically use coal or petroleum coke as the carbon source, materials which contain ash impurities that liquefy at the gasification temperatures, producing liquid slag in quantities of 100 or more tons/day, depending on the carbon fed rate and the percent ash present in the feedstock. The molten slag is corrosive to refractory linings, causing chemical dissolution and spalling. The refractory lining is composed of chrome oxide, alumina, and zirconia; and is replaced every 3-24 months. Gasifier users would like greater on-line availability and reliability of gasifier liners, something that has impacted gasifier acceptance by industry. Research is underway at NETL to improve refractory service life and to develop a no-chrome or low-chrome oxide alternative refractory liner. Over 250 samples of no- or low-chrome oxide compositions have been evaluated for slag interactions by cup testing; with potential candidates for further studies including those with ZrO2, Al2O3, and MgO materials. The development of improved liner materials is necessary if technologies such as IGCC and DOE's Near Zero Emissions Advanced Fossil Fuel Power Plant are to be successful and move forward in the marketplace

Recovery of flue gas energy in heat-integrated gasification combined cycle (IGCC) power plants using the contact economizer system

CSIR Research Space (South Africa)

Madzivhandila, VA

2011-03-01

Full Text Available (flue gas) stream of a heat-integrated gasification combined cycle (IGCC) design of the Elcogas plant adopted from previous studies. The underlying support for this idea was the direct relationship between efficiency of the IGCC and the boiler feedwater...

Results from tests of a Stirling engine and wood chips gasifier plant

DEFF Research Database (Denmark)

Carlsen, Henrik; Bovin, Jonas Kabell; Werling, J.

2002-01-01

The combination of thermal gasification and a Stirling engine is an interesting concept for use in small Combined Heat and Power (CHP) plants based on biomass, because the need for gas cleaning is eliminated and problems with fouling of the Stirling engine heater are considerably reduced....... Furthermore, the overall electric efficiency of the system can be improved. At the Technical University of Denmark a small CHP plant based on a Stirling engine and an updraft gasifier has been developed and tested successfully. The advantages of updraft gasifiers are the simplicity and that the amount...... of the Stirling engine reduces the problems with tar to a minor problem in the design of the burner. The Stirling engine, which has an electric power output of 35 kW, is specifically designed for utilisation of fuels with a content of particles. The gas burner for the engine is designed for low specific energy...

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-07-01

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

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

Transportation fuel production from gasified biomass integrated with a pulp and paper mill – Part A: Heat integration and system performance

International Nuclear Information System (INIS)

Isaksson, Johan; Jansson, Mikael; Åsblad, Anders; Berntsson, Thore

2016-01-01

Production of transportation fuels from biorefineries via biomass gasification has been suggested as a way of introducing renewable alternatives in the transportation system with an aim to reduce greenhouse gas emissions to the atmosphere. By co-locating gasification-based processes within heat demanding industries, excess heat from the gasification process can replace fossil or renewable fuels. The objective of this study was to compare the heat integration potential of four different gasification-based biorefinery concepts with a chemical pulp and paper mill. The results showed that the choice of end-product which was either methanol, Fischer-Tropsch crude, synthetic natural gas or electricity, can have significant impact on the heat integration potential with a pulp and paper mill and that the heat saving measures implemented in the mill in connection to integration of a gasification process can increase the biomass resource efficiency by up to 3%-points. Heat saving measures can reduce the necessary biomass input to the biorefinery by 50% if the sizing constraint is to replace the bark boiler with excess heat from the biorefinery. A large integrated gasification process with excess steam utilisation in a condensing turbine was beneficial only if grid electricity is produced at below 30% electrical efficiency. - Highlights: • Biomass gasification integrated with a pulp and paper mill. • Different sizing constraints of integrated biofuel production. • The biofuel product largely influence the heat integration potential. • An oversized gasifier for increased power production could be favourable.

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

DEFF Research Database (Denmark)

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

2006-01-01

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

Process for electrochemically gasifying coal using electromagnetism

Science.gov (United States)

Botts, Thomas E.; Powell, James R.

1987-01-01

A process for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution.

Aspen Plus simulation of biomass integrated gasification combined cycle systems at corn ethanol plants

International Nuclear Information System (INIS)

Zheng, Huixiao; Kaliyan, Nalladurai; Morey, R. Vance

2013-01-01

Biomass integrated gasification combined cycle (BIGCC) systems and natural gas combined cycle (NGCC) systems are employed to provide heat and electricity to a 0.19 hm 3 y −1 (50 million gallon per year) corn ethanol plant using different fuels (syrup and corn stover, corn stover alone, and natural gas). Aspen Plus simulations of BIGCC/NGCC systems are performed to study effects of different fuels, gas turbine compression pressure, dryers (steam tube or superheated steam) for biomass fuels and ethanol co-products, and steam tube dryer exhaust treatment methods. The goal is to maximize electricity generation while meeting process heat needs of the plant. At fuel input rates of 110 MW, BIGCC systems with steam tube dryers provide 20–25 MW of power to the grid with system thermal efficiencies (net power generated plus process heat rate divided by fuel input rate) of 69–74%. NGCC systems with steam tube dryers provide 26–30 MW of power to the grid with system thermal efficiencies of 74–78%. BIGCC systems with superheated steam dryers provide 20–22 MW of power to the grid with system thermal efficiencies of 53–56%. The life-cycle greenhouse gas (GHG) emission reduction for conventional corn ethanol compared to gasoline is 39% for process heat with natural gas (grid electricity), 117% for BIGCC with syrup and corn stover fuel, 124% for BIGCC with corn stover fuel, and 93% for NGCC with natural gas fuel. These GHG emission estimates do not include indirect land use change effects. -- Highlights: •BIGCC and natural gas combined cycle systems at corn ethanol plants are simulated. •The best performance results in 25–30 MW power to grid. •The best performance results in 74–78% system thermal efficiencies. •GHG reduction for corn ethanol with BIGCC systems compared to gasoline is over 100%

The History and Promise of Combined Cycle Engines for Access to Space Applications

Science.gov (United States)

Clark, Casie

2010-01-01

For the summer of 2010, I have been working in the Aerodynamics and Propulsion Branch at NASA Dryden Flight Research Center studying combined-cycle engines, a high speed propulsion concept. Combined cycle engines integrate multiple propulsion systems into a single engine capable of running in multiple modes. These different modes allow the engine to be extremely versatile and efficient in varied flight conditions. The two most common types of combined cycle engines are Rocket-Based Combined Cycle (RBCC) and Turbine Based Combined Cycle (TBCC). The RBCC essentially combines a rocket and ramjet engine, while the TBCC integrates a turbojet and ramjet1. These two engines are able to switch between different propulsion modes to achieve maximum performance. Extensive conceptual and ground test studies of RBCC engines have been undertaken; however, an RBCC engine has never, to my knowledge, been demonstrated in flight. RBCC engines are of particular interest because they could potentially power a reusable launch vehicle (RLV) into space. The TBCC has been flight tested and shown to be effective at reaching supersonic speeds, most notably in the SR-71 Blackbird2.

A novel nuclear combined power and cooling system integrating high temperature gas-cooled reactor with ammonia–water cycle

International Nuclear Information System (INIS)

Luo, Chending; Zhao, Fuqiang; Zhang, Na

2014-01-01

Highlights: • We propose a novel nuclear ammonia–water power and cooling cogeneration system. • The high temperature reactor is inherently safe, with exhaust heat fully recovered. • The thermal performances are improved compared with nuclear combined cycle. • The base case attains an energy efficiency of 69.9% and exergy efficiency of 72.5%. • Energy conservation and emission reduction are achieved in this cogeneration way. - Abstract: A nuclear ammonia–water power and refrigeration cogeneration system (NAPR) has been proposed and analyzed in this paper. It consists of a closed high temperature gas-cooled reactor (HTGR) topping Brayton cycle and a modified ammonia water power/refrigeration combined bottoming cycle (APR). The HTGR is an inherently safe reactor, and thus could be stable, flexible and suitable for various energy supply situation, and its exhaust heat is fully recovered by the mixture of ammonia and water in the bottoming cycle. To reduce exergy losses and enhance outputs, the ammonia concentrations of the bottoming cycle working fluid are optimized in both power and refrigeration processes. With the HTGR of 200 MW thermal capacity and 900 °C/70 bar reactor-core-outlet helium, the system achieves 88.8 MW net electrical output and 9.27 MW refrigeration capacity, and also attains an energy efficiency of 69.9% and exergy efficiency of 72.5%, which are higher by 5.3%-points and 2.6%-points as compared with the nuclear combined cycle (NCC, like a conventional gas/steam power-only combined cycle while the topping cycle is a closed HTGR Brayton cycle) with the same nuclear energy input. Compared with conventional separate power and refrigeration generation systems, the fossil fuel saving (based on CH 4 ) and CO 2 emission reduction of base-case NAPR could reach ∼9.66 × 10 4 t/y and ∼26.6 × 10 4 t/y, respectively. The system integration accomplishes the safe and high-efficiency utilization of nuclear energy by power and refrigeration

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

International Nuclear Information System (INIS)

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

2009-01-01

In this study, we utilize some experimental data taken from the literature, especially on the air blown gasification characteristics of six different biomass fuels, namely almond shell (ASF), walnut pruning (WPF), rice straw (RSF), whole tree wood chips (WWF), sludge (SLF) and non-recyclable waste paper (NPF) for hydrogen production from an integrated gasifier-boiler power system. Then, we undertake an exergy analysis of this integrated system and assess its performance through energy and exergy efficiencies. The exergy content values calculated for the biomass fuels range from 15.89 to 22.07 MJ/kg. The stack gas is examined at cyclone out, and the hydrogen concentrations determined change between 7 and 18 (%v/v) for NPF and ASF. Furthermore, the system considered is studied in terms of irreversibility and improvement potential rates. These rate values change from 6.82 to 43.11 kW for irreversibility and 6.01 to 41.24 kW for improvement potential, respectively. The exergy efficiencies of the system are calculated as 4.33 to 11.89%. Finally, we consider N and NH 3 contents of the six biomass fuels and their stack gas compositions. (author)

A rice husk gasifier for paddy drying

International Nuclear Information System (INIS)

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

2013-01-01

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

Performance and Characteristics of a Cyclone Gasifier for Gasification of Sawdust

Science.gov (United States)

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

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

Exergy analysis of parabolic trough solar collectors integrated with combined steam and organic Rankine cycles

International Nuclear Information System (INIS)

Al-Sulaiman, Fahad A.

2014-01-01

Highlights: • As the solar irradiation increases, the exergetic efficiency increases. • The R134a combined cycle has best exergetic performance, 26%. • The R600a combined cycle has the lowest exergetic efficiency, 20%. • The main source of exergy destruction is the solar collector. • There is an exergetic improvement potential of 75% in the systems considered. - Abstract: In this paper, detailed exergy analysis of selected thermal power systems driven by parabolic trough solar collectors (PTSCs) is presented. The power is produced using either a steam Rankine cycle (SRC) or a combined cycle, in which the SRC is the topping cycle and an organic Rankine cycle (ORC) is the bottoming cycle. Seven refrigerants for the ORC were examined: R134a, R152a, R290, R407c, R600, R600a, and ammonia. Key exergetic parameters were examined: exergetic efficiency, exergy destruction rate, fuel depletion ratio, irreversibility ratio, and improvement potential. For all the cases considered it was revealed that as the solar irradiation increases, the exergetic efficiency increases. Among the combined cycles examined, the R134a combined cycle demonstrates the best exergetic performance with a maximum exergetic efficiency of 26% followed by the R152a combined cycle with an exergetic efficiency of 25%. Alternatively, the R600a combined cycle has the lowest exergetic efficiency, 20–21%. This study reveals that the main source of exergy destruction is the solar collector where more than 50% of inlet exergy is destructed, or in other words more than 70% of the total destructed exergy. In addition, more than 13% of the inlet exergy is destructed in the evaporator which is equivalent to around 19% of the destructed exergy. Finally, this study reveals that there is an exergetic improvement potential of 75% in the systems considered

CHP from Updraft Gasifier and Stirling Engine

DEFF Research Database (Denmark)

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

2002-01-01

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

Scaling up biomass gasifier use: an application-specific approach

International Nuclear Information System (INIS)

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

2006-01-01

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

Process modelling and techno-economic analysis of natural gas combined cycle integrated with calcium looping

Directory of Open Access Journals (Sweden)

Erans María

2016-01-01

Full Text Available Calcium looping (CaL is promising for large-scale CO2 capture in the power generation and industrial sectors due to the cheap sorbent used and the relatively low energy penalties achieved with this process. Because of the high operating temperatures the heat utilisation is a major advantage of the process, since a significant amount of power can be generated from it. However, this increases its complexity and capital costs. Therefore, not only the energy efficiency performance is important for these cycles, but also the capital costs must be taken into account, i.e. techno-economic analyses are required in order to determine which parameters and configurations are optimal to enhance technology viability in different integration scenarios. In this study the integration scenarios of CaL cycles and natural gas combined cycles (NGCC are explored. The process models of the NGCC and CaL capture plant are developed to explore the most promising scenarios for NGCC-CaL integration with regards to efficiency penalties. Two scenarios are analysed in detail, and show that the system with heat recovery steam generator (HRSG before and after the capture plant exhibited better performance of 49.1% efficiency compared with that of 45.7% when only one HRSG is located after the capture plant. However, the techno-economic analyses showed that the more energy efficient case, with two HRSGs, implies relatively higher cost of electricity (COE, 44.1€/MWh, when compared to that of the reference plant system (33.1€/MWh. The predicted cost of CO2 avoided for the case with two HRSGS is 29.3 €/ton CO2.

Development Activities on Airbreathing Combined Cycle Engines

Science.gov (United States)

McArthur, J. Craig; Lyles, Garry (Technical Monitor)

2000-01-01

Contents include the following: Advanced reusable transportation(ART); aerojet and rocketdyne tests, RBCC focused concept flowpaths,fabricate flight weigh, test select components, document ART project, Istar (Integrated system test of an airbreathing rocket); combined cycle propulsion testbed;hydrocarbon demonstrator tracebility; Istar engine system and vehicle system closure study; and Istar project planning.

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

Directory of Open Access Journals (Sweden)

Franco Cotana

2014-08-01

Full Text Available The Biomass Research Centre, section of CIRIAF, has recently developed a biomass boiler (300 kW thermal powered, fed by the poultry manure collected in a nearby livestock. All the thermal requirements of the livestock will be covered by the heat produced by gas combustion in the gasifier boiler. Within the activities carried out by the research project ENERPOLL (Energy Valorization of Poultry Manure in a Thermal Power Plant, funded by the Italian Ministry of Agriculture and Forestry, this paper aims at studying an upgrade version of the existing thermal plant, investigating and analyzing the possible applications for electricity production recovering the exceeding thermal energy. A comparison of Organic Rankine Cycle turbines and Stirling engines, to produce electricity from gasified poultry waste, is proposed, evaluating technical and economic parameters, considering actual incentives on renewable produced electricity.

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

African Journals Online (AJOL)

user

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

Optimum gas turbine cycle for combined cycle power plant

International Nuclear Information System (INIS)

Polyzakis, A.L.; Koroneos, C.; Xydis, G.

2008-01-01

The gas turbine based power plant is characterized by its relatively low capital cost compared with the steam power plant. It has environmental advantages and short construction lead time. However, conventional industrial engines have lower efficiencies, especially at part load. One of the technologies adopted nowadays for efficiency improvement is the 'combined cycle'. The combined cycle technology is now well established and offers superior efficiency to any of the competing gas turbine based systems that are likely to be available in the medium term for large scale power generation applications. This paper has as objective the optimization of a combined cycle power plant describing and comparing four different gas turbine cycles: simple cycle, intercooled cycle, reheated cycle and intercooled and reheated cycle. The proposed combined cycle plant would produce 300 MW of power (200 MW from the gas turbine and 100 MW from the steam turbine). The results showed that the reheated gas turbine is the most desirable overall, mainly because of its high turbine exhaust gas temperature and resulting high thermal efficiency of the bottoming steam cycle. The optimal gas turbine (GT) cycle will lead to a more efficient combined cycle power plant (CCPP), and this will result in great savings. The initial approach adopted is to investigate independently the four theoretically possible configurations of the gas plant. On the basis of combining these with a single pressure Rankine cycle, the optimum gas scheme is found. Once the gas turbine is selected, the next step is to investigate the impact of the steam cycle design and parameters on the overall performance of the plant, in order to choose the combined cycle offering the best fit with the objectives of the work as depicted above. Each alterative cycle was studied, aiming to find the best option from the standpoint of overall efficiency, installation and operational costs, maintainability and reliability for a combined power

Thermodynamic analysis of engineering solutions aimed at raising the efficiency of integrated gasification combined cycle

Science.gov (United States)

Gordeev, S. I.; Bogatova, T. F.; Ryzhkov, A. F.

2017-11-01

Raising the efficiency and environmental friendliness of electric power generation from coal is the aim of numerous research groups today. The traditional approach based on the steam power cycle has reached its efficiency limit, prompted by materials development and maneuverability performance. The rival approach based on the combined cycle is also drawing nearer to its efficiency limit. However, there is a reserve for efficiency increase of the integrated gasification combined cycle, which has the energy efficiency at the level of modern steam-turbine power units. The limit of increase in efficiency is the efficiency of NGCC. One of the main problems of the IGCC is higher costs of receiving and preparing fuel gas for GTU. It would be reasonable to decrease the necessary amount of fuel gas in the power unit to minimize the costs. The effect can be reached by raising of the heat value of fuel gas, its heat content and the heat content of cycle air. On the example of the process flowsheet of the IGCC with a power of 500 MW, running on Kuznetsk bituminous coal, by means of software Thermoflex, the influence of the developed technical solutions on the efficiency of the power plant is considered. It is received that rise in steam-air blast temperature to 900°C leads to an increase in conversion efficiency up to 84.2%. An increase in temperature levels of fuel gas clean-up to 900°C leads to an increase in the IGCC efficiency gross/net by 3.42%. Cycle air heating reduces the need for fuel gas by 40% and raises the IGCC efficiency gross/net by 0.85-1.22%. The offered solutions for IGCC allow to exceed net efficiency of analogous plants by 1.8-2.3%.

Test of pyrolysis gasifier stoves in two institutional kitchens in Uganda

DEFF Research Database (Denmark)

Wendelbo, Pall; Nielsen, Per Sieverts

1998-01-01

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

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Thermo-economic assessment of the integration of steam cycles on offshore platforms

DEFF Research Database (Denmark)

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

2014-01-01

thermodynamic and economic performance indicators. The results illustrate the benefits of converting the gas turbines into a combined cycle. Using seawater results in smaller power generation and greater CO2-emissions than using process water, as the additional power generation in the combined cycle......The integration of steam bottoming cycles on oil platforms is often seen as a possible route to mitigate the CO2-emissions offshore. In this paper, a North Sea platform and its energy requirements are systematically analysed. The site-scale integration of steam networks is assessed by using...... is compensated by the significant pumping demand. This work emphasises that energy improvement efforts should be analysed at the scale of the overall site and not solely at the level of the combined cycle....

Handbook of biomass downdraft gasifier engine systems

Energy Technology Data Exchange (ETDEWEB)

Reed, T B; Das, A

1988-03-01

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

Catalytic combustion of gasified waste - Experimental part. Final report

Energy Technology Data Exchange (ETDEWEB)

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

2003-08-01

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

Performance analysis of an Integrated Solar Combined Cycle using Direct Steam Generation in parabolic trough collectors

International Nuclear Information System (INIS)

Montes, M.J.; Rovira, A.; Munoz, M.; Martinez-Val, J.M.

2011-01-01

Highlights: → Solar hybridization improves the performance of CCGT in a very hot and dry weather. → The scheme analyzed is a DSG parabolic trough field coupled to the Rankine cycle. → An annual simulation has been carried out for two locations: Almeria and Las Vegas. → Economical analysis shows that this scheme is a cheaper way to exploit solar energy. → For that, solar hybridization must be limited to a small fraction of the CCGT power. - Abstract: The contribution of solar thermal power to improve the performance of gas-fired combined cycles in very hot and dry environmental conditions is analyzed in this work, in order to assess the potential of this technique, and to feature Direct Steam Generation (DSG) as a well suited candidate for achieving very good results in this quest. The particular Integrated Solar Combined Cycle (ISCC) power plant proposed consists of a DSG parabolic trough field coupled to the bottoming steam cycle of a Combined Cycle Gas Turbine (CCGT) power plant. For this analysis, the solar thermal power plant performs in a solar dispatching mode: the gas turbine always operates at full load, only depending on ambient conditions, whereas the steam turbine is somewhat boosted to accommodate the thermal hybridization from the solar field. Although the analysis is aimed to studying such complementary effects in the widest perspective, two relevant examples are given, corresponding to two well-known sites: Almeria (Spain), with a mediterranean climate, and Las Vegas (USA), with a hot and dry climate. The annual simulations show that, although the conventional CCGT power plant works worse in Las Vegas, owing to the higher temperatures, the ISCC system operates better in Las Vegas than in Almeria, because of solar hybridization is especially well coupled to the CCGT power plant in the frequent days with great solar radiation and high temperatures in Las Vegas. The complementary effect will be clearly seen in these cases, because the thermal

Valuing flexibility: The case of an Integrated Gasification Combined Cycle power plant

International Nuclear Information System (INIS)

Abadie, Luis M.; Chamorro, Jose M.

2008-01-01

In this paper we analyze the choice between two technologies for producing electricity. In particular, the firm has to decide whether and when to invest either in a Natural Gas Combined Cycle (NGCC) power plant or in an Integrated Gasification Combined Cycle (IGCC) power plant, which may burn either coal or natural gas. Instead of assuming that fuel prices follow standard geometric Brownian motions, here they are assumed to show mean reversion, specifically to follow an inhomogeneous geometric Brownian motion. First we consider the opportunity to invest in a NGCC power plant. We derive the optimal investment rule as a function of natural gas price and the remaining life of the right to invest. In addition, the analytical solution for a perpetual option to invest is obtained. Then we turn to the IGCC power plant. We analyse the valuation of an operating plant when there are switching costs between modes of operation, and the choice of the best operation mode. This serves as an input to evaluate the option to invest in this plant. Finally we derive the value of an opportunity to invest either in a NGCC or IGCC power plant, i.e. to choose between an inflexible and a flexible technology, respectively. Depending on the opportunity's time to maturity, we derive the pairs of coal and gas prices for which it is optimal to invest in NGCC, in IGCC, or simply not to invest. Numerical computations involve the use of one- and two-dimensional binomial lattices that support a mean-reverting process for coal and gas prices. Basic parameter values are taken from an actual IGCC power plant currently in operation. Sensitivity of some results with respect to the underlying stochastic process for fuel price is also checked

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

Directory of Open Access Journals (Sweden)

Kamil Dino Adem

2017-01-01

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

Slagging gasifier refractories. A new pathway to longer refractory life

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-01

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

Energy, exergy and economic assessments of a novel integrated biomass based multigeneration energy system with hydrogen production and LNG regasification cycle

International Nuclear Information System (INIS)

Taheri, M.H.; Mosaffa, A.H.; Farshi, L. Garousi

2017-01-01

In this work, a novel integrated biomass based multigeneration energy system is presented and investigated for power, cooling and hydrogen production. The proposed system consists of a combination of biomass integrated gasifier-gas turbine cycle, a Rankine cycle, a cascade organic Rankine cycle, an absorption refrigeration system and a PEM to produce hydrogen. This system uses cold energy of LNG as a thermal sink. Comprehensive thermodynamic and economic analyses as well as an optimization are performed. The effects of operating parameters on thermodynamic performance and total cost rate are investigated for overall system and subsystems. The results show that the fuel mass flow rate is the dominant factor affecting the variation of energy efficiency and total cost rate. An increase in fuel mass flow rate from 4 kg s"−"1 to 10 kg s"−"1 leads to a decrease of 8.5% and an increase of 122.8% overall energy efficiency and total cost rate, respectively. Also, the largest increase in exergy efficiency occurs when gas turbine inlet temperature increases. The results of optimization showed that the highest net power output, mass flow rate of natural gas delivered to city and the flue gas temperature discharged to the environment are obtained for the exergy efficiency optimal design. - Highlights: • A novel multigeneration system is investigated and optimized thermodynamically and economically. • This system is proposed for power, cooling and hydrogen production. • Proposed system uses LNG cold energy thermal sink that can generate power after vaporization. • The effects of operating parameters on energy and exergy efficiencies and total cost rate are investigated. • An optimization is applied based on the energy, exergy and economic viewpoints.

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

OpenAIRE

Kuhe, Aondoyila; Aliyu, Samuel Jacob

2015-01-01

In this paper, gasification potential of biomass residue was investigated using a laboratory scale throatless downdraft gasifier. Experimental results of groundnut shell was gasified in the throatless downdraft gasifier to produce a clean gas with a calorific value of around 5.92 MJ/Nm3 and a combustible fraction of 45% v/v. Low moisture (8.6%) and ash content (3.19%) are the main advantages of groundnut shells for gasification. It is suggested that gasification of shell waste products is a ...

Model predictive control system and method for integrated gasification combined cycle power generation

Science.gov (United States)

Kumar, Aditya; Shi, Ruijie; Kumar, Rajeeva; Dokucu, Mustafa

2013-04-09

Control system and method for controlling an integrated gasification combined cycle (IGCC) plant are provided. The system may include a controller coupled to a dynamic model of the plant to process a prediction of plant performance and determine a control strategy for the IGCC plant over a time horizon subject to plant constraints. The control strategy may include control functionality to meet a tracking objective and control functionality to meet an optimization objective. The control strategy may be configured to prioritize the tracking objective over the optimization objective based on a coordinate transformation, such as an orthogonal or quasi-orthogonal projection. A plurality of plant control knobs may be set in accordance with the control strategy to generate a sequence of coordinated multivariable control inputs to meet the tracking objective and the optimization objective subject to the prioritization resulting from the coordinate transformation.

Small scale combined woodgas power plant

International Nuclear Information System (INIS)

Gulbis, V.

2003-01-01

As a first attempt to introduce biomass gasification technology in Latvia at the Faculty of Engineering of Latvia University of Agriculture an integral small scale combined heat and power (CHP) system based on a used Russian-made diesel-alternator set with electrical output 100 kWe was developed. The diesel is converted to dual fuel gas engine, using producer gas as the main fuel and gas oil as pilot fuel. To get sufficiently clean (tar content ≤ 250 mg/m 3 ) woodgas for using in IC engine a downdraft type of gasifier was chosen designed and constructed on the IMBERT gasifier principles. The test runs of the first experimental model showed that the engine does not develop expected power because of high resistance of gasifier and gas cleaning system does not work sufficiently enough. There was rather high level of tar content in woodgas because the temperature in the reduction zone was low. Calculations were carried out and new technological scheme of gasification system was worked out, introducing innovative ideas aimed on improving the working parameters (author)

A moving-bed gasifier with internal recycle of pyrolysis gas

NARCIS (Netherlands)

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

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

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Exergetic optimisation of a production process of Fischer-Tropsch fuels from biomass

NARCIS (Netherlands)

Prins, M.J.; Ptasinski, K.J.; Janssen, F.J.J.G.

2005-01-01

An exergy analysis of Biomass Integrated Gasification-Fischer–Tropsch process is presented. The process combines an air-blown, atmospheric gasifier, using sawdust as feedstock, with a Fischer–Tropsch reactor and a steam-Rankine cycle for electricity generation from the Fischer–Tropsch tail gas.

Artificial neural network models for biomass gasification in fluidized bed gasifiers

DEFF Research Database (Denmark)

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

2013-01-01

Artificial neural networks (ANNs) have been applied for modeling biomass gasification process in fluidized bed reactors. Two architectures of ANNs models are presented; one for circulating fluidized bed gasifiers (CFB) and the other for bubbling fluidized bed gasifiers (BFB). Both models determine...

Emission characterization for a down draft gasifier

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

Modelling the low-tar BIG process; Modellering af low-tar BIG processen

Energy Technology Data Exchange (ETDEWEB)

Andersen, Lars Henrik

2002-09-15

This report describes the possibilities of integrating a biomass gasifier in a combined heat and power plant. The purpose of the study is, among others, to see if the gasification technology can challenge existing heat and power production methods. A research programme dealing with the construction of a low far gasifier (LT-BIG), which easily can be scaled to large gasification plants, is in progress. This report also contains a model formulation and implementation for this suggested low tar gasifier. All the models are created by the use of the energy simulation tool DNA. For some cases it has been necessary to develop new components or to alter existing components in DNA. Three different systems are considered; Gas Engine, Simple Cycle Gas Turbine and Combined Cycle. When biomass with and lower heating value of 19 MJ/kg and a moisture content of 50% is employed the subsequent results and designs are achieved: 1) The Engine plant utilizes the hot flue-gas to dry the biomass, but has difficulties taking advantage of the potential energy from the cooling of the syngas. An engine with a net electric efficiency of 40% at full load is computed to convert 38,5% of the energy content in the biomass to electricity. 2) The Simple Cycle Gas Turbine plant has good potential for integration with a gasifier. It dries the biomass by means of the flue-gas and recuperates the energy from the hot syngas to preheat the pressurised gas before it enters the combustion chamber. With an isentropic efficiency of 89% and a pressure ratio of 20, an electric efficiency of 38% is computed. 3) The Combined Cycle plant almost reach a computed efficiency of 45%. It utilises the cooling of the hot syngas to produce extra steam for the cycle, which results in a very steady efficiency, even when the moisture content of the fuel is changed. A grand parametric and sensitivity study of the LT-BIG model is carried out. The study includes estimates of the air demand for the gasifier and the partial

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

Directory of Open Access Journals (Sweden)

Aondoyila Kuhe

2015-07-01

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

Model Predictive Control of Integrated Gasification Combined Cycle Power Plants

Energy Technology Data Exchange (ETDEWEB)

B. Wayne Bequette; Priyadarshi Mahapatra

2010-08-31

The primary project objectives were to understand how the process design of an integrated gasification combined cycle (IGCC) power plant affects the dynamic operability and controllability of the process. Steady-state and dynamic simulation models were developed to predict the process behavior during typical transients that occur in plant operation. Advanced control strategies were developed to improve the ability of the process to follow changes in the power load demand, and to improve performance during transitions between power levels. Another objective of the proposed work was to educate graduate and undergraduate students in the application of process systems and control to coal technology. Educational materials were developed for use in engineering courses to further broaden this exposure to many students. ASPENTECH software was used to perform steady-state and dynamic simulations of an IGCC power plant. Linear systems analysis techniques were used to assess the steady-state and dynamic operability of the power plant under various plant operating conditions. Model predictive control (MPC) strategies were developed to improve the dynamic operation of the power plants. MATLAB and SIMULINK software were used for systems analysis and control system design, and the SIMULINK functionality in ASPEN DYNAMICS was used to test the control strategies on the simulated process. Project funds were used to support a Ph.D. student to receive education and training in coal technology and the application of modeling and simulation techniques.

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

A Philippines gasifier case study

International Nuclear Information System (INIS)

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

1991-01-01

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

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

DEFF Research Database (Denmark)

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

2017-01-01

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

Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Combined cycle performance

DEFF Research Database (Denmark)

Haglind, Fredrik

2011-01-01

The part-load performance of combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry gas turbines on the part-load efficiency for combined...... cycles used for ship propulsion. Moreover, the paper is aimed at developing methodologies and deriving models for part-load simulations suitable for energy system analysis of various components within combined cycle power plants. Two different gas turbine configurations are studied, a two-shaft aero......-derivative configuration and a single-shaft industrial configuration. The results suggest that by the use of variable geometry gas turbines, the combined cycle part-load performance can be improved. In order to minimise the voyage fuel consumption, a combined cycle featuring two-shaft gas turbines with VAN control...

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 9: Closed-cycle MHD. [energy conversion efficiency of electric power plants using magnetohydrodynamics

Science.gov (United States)

Tsu, T. C.

1976-01-01

A closed-cycle MHD system for an electric power plant was studied. It consists of 3 interlocking loops, an external heating loop, a closed-cycle cesium seeded argon nonequilibrium ionization MHD loop, and a steam bottomer. A MHD duct maximum temperature of 2366 K (3800 F), a pressure of 0.939 MPa (9.27 atm) and a Mach number of 0.9 are found to give a topping cycle efficiency of 59.3%; however when combined with an integrated gasifier and optimistic steam bottomer the coal to bus bar efficiency drops to 45.5%. A 1978 K (3100 F) cycle has an efficiency of 55.1% and a power plant efficiency of 42.2%. The high cost of the external heating loop components results in a cost of electricity of 21.41 mills/MJ (77.07 mills/kWh) for the high temperature system and 19.0 mills/MJ (68.5 mills/kWh) for the lower temperature system. It is, therefore, thought that this cycle may be more applicable to internally heated systems such as some futuristic high temperature gas cooled reactor.

Wabash River Coal Gasification Combined Cycle Repowering Project: Clean Coal Technology Program

International Nuclear Information System (INIS)

1993-05-01

The proposed project would result in a combined-cycle power plant with lower emissions and higher efficiency than most existing coal-fired power plants of comparable size. The net plant heat rate (energy content of the fuel input per useable electrical generation output; i.e., Btu/kilowatt hour) for the new repowered unit would be a 21% improvement over the existing unit, while reducing SO 2 emissions by greater than 90% and limiting NO x emissions by greater than 85% over that produced by conventional coal-fired boilers. The technology, which relies on gasified coal, is capable of producing as much as 25% more electricity from a given amount of coal than today's conventional coal-burning methods. Besides having the positive environmental benefit of producing less pollutants per unit of power generated, the higher overall efficiency of the proposed CGCC project encourages greater utilization to meet base load requirements in order to realize the associated economic benefits. This greater utilization (i.e., increased capacity factor) of a cleaner operating plant has global environmental benefits in that it is likely that such power would replace power currently being produced by less efficient plants emitting a greater volume of pollutants per unit of power generated

Catalytic Combustion of Gasified Waste

Energy Technology Data Exchange (ETDEWEB)

Kusar, Henrik

2003-09-01

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

Method and system to estimate variables in an integrated gasification combined cycle (IGCC) plant

Science.gov (United States)

Kumar, Aditya; Shi, Ruijie; Dokucu, Mustafa

2013-09-17

System and method to estimate variables in an integrated gasification combined cycle (IGCC) plant are provided. The system includes a sensor suite to measure respective plant input and output variables. An extended Kalman filter (EKF) receives sensed plant input variables and includes a dynamic model to generate a plurality of plant state estimates and a covariance matrix for the state estimates. A preemptive-constraining processor is configured to preemptively constrain the state estimates and covariance matrix to be free of constraint violations. A measurement-correction processor may be configured to correct constrained state estimates and a constrained covariance matrix based on processing of sensed plant output variables. The measurement-correction processor is coupled to update the dynamic model with corrected state estimates and a corrected covariance matrix. The updated dynamic model may be configured to estimate values for at least one plant variable not originally sensed by the sensor suite.

Sampling/classification of gasifier particulates

International Nuclear Information System (INIS)

Wegrzyn, J.

1984-01-01

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

Bifuel coal-gas combined cycles

International Nuclear Information System (INIS)

Chmielniak, Tadeusz; Kotowicz, Janusz; Lyczko, Jacek

1997-01-01

This paper describes basic ways of realization of bi fuel cool-gas combined cycles. The criterion of classification of the systems specification is a joint of the gas pail with the steam part: a) The gas turbine flue gases are introduced into the steam boiler combustion chamber (the serial, hot wind box). b) Bypass of the beat exchangers at the steam turbine unit and/or the steam boiler, by use the waste heat exchangers, or waste boiler at the gas turbine unit (the parallel-coupled). c) The mixed, it's a combination of the two upper. The analysis of the parallel system has been specially presented. In derived formulas for the total efficiency of the bi fuel parallel combined cycle balance equations have been used. This formulas can be used for planning new combined cycle power plants and for modernization existing steam power plants. It was made a discussion about influence of the ratio the gas and the steam turbine electric power on the cycle efficiency in care of the full and the part load of the bi fuel combined cycle power plant. The various systems of the joint of the gas part with the steam part have been examined. The selected results of the calculations have been attached. The models and the numerical simulations have been based on data from the existing steam power plants and real gas turbine units. (Author)

A novel syngas-fired hybrid heating source for solar-thermal applications: Energy and exergy analysis

International Nuclear Information System (INIS)

Pramanik, Santanu; Ravikrishna, R.V.

2016-01-01

Highlights: • Biomass-derived syngas as a hybrid energy source for solar thermal power plants. • A novel combustor concept using rich-catalytic and MILD combustion technologies. • Hybrid energy source for a solar-driven supercritical CO 2 -based Brayton cycle. • Comprehensive energetic and exergetic analysis of the combined system. - Abstract: A hybrid heating source using biomass-derived syngas is proposed to enable continuous operation of standalone solar thermal power generation plants. A novel, two-stage, low temperature combustion system is proposed that has the potential to provide stable combustion of syngas with near-zero NO x emissions. The hybrid heating system consists of a downdraft gasifier, a two-stage combustion system, and other auxiliaries. When integrated with a solar cycle, the entire system can be referred to as the integrated gasification solar combined cycle (IGSCC). The supercritical CO 2 Brayton cycle (SCO 2 ) is selected for the solar cycle due to its high efficiency. The thermodynamic performance evaluation of the individual unit and the combined system has been conducted from both energy and exergy considerations. The effect of parameters such as gasification temperature, biomass moisture content, equivalence ratio, and pressure ratio is studied. The efficiency of the IGSCC exhibited a non-monotonic behavior. A maximum thermal efficiency of 36.5% was achieved at an overall equivalence ratio of 0.22 and pressure ratio of 2.75 when the gasifier was operating at T g = 1073 K with biomass containing 20% moisture. The efficiency increased to 40.8% when dry biomass was gasified at a temperature of 973 K. The exergy analysis revealed that the maximum exergy destruction occurred in the gasification system, followed by the combustion system, SCO 2 cycle, and regenerator. The exergy analysis also showed that 8.72% of the total exergy is lost in the exhaust; however, this can be utilized for drying of the biomass.

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

Science.gov (United States)

Grindley, Thomas

1989-01-01

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

Integrated gasification and Cu-Cl cycle for trigeneration of hydrogen, steam and electricity

Energy Technology Data Exchange (ETDEWEB)

Aghahosseini, S; Dincer, I; Naterer, G F [University of Ontario, Oshawa, ON (Canada). Institute of Technology

2011-02-15

This paper develops and analyzes an integrated process model of an Integrated Gasification Combined Cycle (IGCC) and a thermochemical copper-chlorine (Cu-Cl) cycle for trigeneration of hydrogen, steam and electricity. The process model is developed with Aspen HYSYS software. By using oxygen instead of air for the gasification process, where oxygen is provided by the integrated Cu-Cl cycle, it is found that the hydrogen content of produced syngas increases by about 20%, due to improvement of the gasification combustion efficiency and reduction of syngas NOx emissions. Moreover, about 60% of external heat required for the integrated Cu-Cl cycle can be provided by the IGCC plant, with minor modifications of the steam cycle, and a slight decrease of IGCC overall efficiency. Integration of gasification and thermochemical hydrogen production can provide significant improvements in the overall hydrogen, steam and electricity output, when compared against the processes each operating separately and independently of each other.

Critical review of the first-law efficiency in different power combined cycle architectures

International Nuclear Information System (INIS)

Iglesias Garcia, Steven; Ferreiro Garcia, Ramon; Carbia Carril, Jose; Iglesias Garcia, Denis

2017-01-01

Highlights: • The adiabatic expansion based TC can improve the energy efficiency of CCs. • A revolutionary TC can be a starting point to develop high-performance CCs. • A theoretical thermal efficiency of 83.7% was reached in a Nuclear Power Plant using a TC as bottoming cycle. - Abstract: This critical review explores the potential of an innovative trilateral thermodynamic cycle used to transform low-grade heat into mechanical work and compares its performance with relevant traditional thermodynamic cycles in combined cycles. The aim of this work is to show that combined cycles use traditional low efficiency power cycles in their bottoming cycle, and to evaluate theoretically the implementation of alternative power bottoming cycles. Different types of combined cycles have been reviewed, highlighting their relevant characteristics. The efficiencies of power plants using combined cycles are reviewed and compared. The relevance of researching thermodynamic cycles for combined cycle applications is that a vast amount of heat energy is available at negligible cost in the bottoming cycle of a combined cycle, with the drawback that existing thermal cycles cannot make efficient use of such available low temperature heat due to their low efficiency. The first-law efficiency is used as a parameter to compare and suggest improvements in the combined cycles (CCs) reviewed. The analysis shows that trilateral cycles using closed processes are by far the most efficient published thermal cycles for combined cycles to transform low-grade heat into mechanical work. An innovative trilateral bottoming cycle is proposed to show that the application of non-traditional power cycles can increase significantly the first-law efficiency of CCs. The highest first-law efficiencies achieved are: 85.55% in a CC using LNG cool, 73.82% for a transport vehicle CC, 74.40% in a marine CC, 83.07% in a CC for nuclear power plants, 73.82% in a CC using Brayton and Rankine cycles, 78.31% in a CC

Studies of a Combined-Cycle Engine

OpenAIRE

苅田, 丈士; KANDA, Takeshi

2003-01-01

For a Single-Stage-to-Orbit (SSTO) aerospace plane (Fig.1), several engines will be necessary to reach orbit. The combined-cycle engine incorporates several operational modes in a single engine. Study of the combined cycle engine has a long history, and several kinds of such engines have been proposed and studied. When several engines are mounted on a vehicle, each engine of the system will show a performance higher than that of the combined cycle engine. However, during the operation of one ...

Cogeneration based on gasified biomass - a comparison of concepts

Energy Technology Data Exchange (ETDEWEB)

Olsson, Fredrik

1999-01-01

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

Modelling of a downdraft gasifier fed by agricultural residues

International Nuclear Information System (INIS)

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

2012-01-01

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

The R.D.F. gasifier of Florentine area

Energy Technology Data Exchange (ETDEWEB)

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

1993-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-05-01

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

High Performance Gasification with the Two-Stage Gasifier

DEFF Research Database (Denmark)

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

2002-01-01

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

Research report for fiscal 1998. Basic research for promoting joint implementation, etc. (conversion of old coal-fired thermoelectric power plants in Poland into combined cycle plants); 1998 nendo chosa hokokusho. Poland sekitan karyoku hatsudensho (kyushiki) combined cycle eno tenkan

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

A project is discussed for modernization for energy efficiency enhancement and greenhouse gas reduction. The most effective way to reduce greenhouse gas in Poland is to totally replace the existing coal-fired power plants with natural gas combined cycle plants. Under this project, however, natural gas-fired power generation and integrated coal/brown coal gasification combined cycle power generation are both subjected to study. This is because the power plant modernization project is closely related to the fate of coal/brown coal industries which constitute the important industrial department of Poland. As for the earning rate of the project in case of natural gas-fired combined cycle power generation, the rate will be 13.2% even at the Kaweczyn station which is the highest in earning rate, and this fails to satisfy the project conditions. If integrated coal/brown gasification combined cycle power generation is chosen, the rate will be still lower. When the cost for greenhouse gas reduction is taken up, the Konin station exhibits the lowest of 9 dollars/tCO2, and the others 15-17 dollars/tCO2. When coal gas combined cycle is employed, the cost will be 3-4 times higher. (NEDO)

Combined-cycle plants

International Nuclear Information System (INIS)

Valenti, M.

1991-01-01

This paper reports that as tougher emissions standards take hold throughout the industrialized world, manufacturers such as GE, Siemens, Foster Wheeler, and Asea Brown Boveri are designing advanced combined-cycle equipment that offers improved environmental performance without sacrificing power efficiency

Lignite chemical conversion in an indirect heat rotary kiln gasifier

Directory of Open Access Journals (Sweden)

Hatzilyberis Kostas S.

2006-01-01

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

Combined Heat and Power: Coal-Fired Air Turbine (CAT)-Cycle Plant

International Nuclear Information System (INIS)

Lee Recca

1999-01-01

By combining an integrated system with a gas turbine, coal-fired air turbine cycle technology can produce energy at an efficiency rate of over 40%, with capital and operating costs below those of competing conventional systems. Read this fact sheet to discover the additional benefits of this exciting new technology

Experimental and computational studies on a gasifier based stove

International Nuclear Information System (INIS)

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

2012-01-01

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

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

Science.gov (United States)

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

2018-01-01

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

The integrity management cycle as a business process

Energy Technology Data Exchange (ETDEWEB)

Ackhurst, Trent B.; Peverelli, Romina P. [PIMS - Pipeline Integrity Management Specialists of London Ltd. (United Kingdom).

2009-07-01

It is a best-practice Oil and Gas pipeline integrity and reliability technique to apply integrity management cycles. This is conforms to the business principles of continuous improvement. This paper examines the integrity management cycle - both goals and objectives and subsequent component steps - from a business perspective. Traits that businesses require, to glean maximum benefit from such a cycle, are highlighted. A case study focuses upon an integrity and reliability process developed to apply to pipeline operators. installations. This is compared and contrasted to the pipeline integrity management cycle to underline both cycles. consistency with the principles of continuous improvement. (author)

Integrated Metrics for Improving the Life Cycle Approach to Assessing Product System Sustainability

Directory of Open Access Journals (Sweden)

Wesley Ingwersen

2014-03-01

Full Text Available Life cycle approaches are critical for identifying and reducing environmental burdens of products. While these methods can indicate potential environmental impacts of a product, current Life Cycle Assessment (LCA methods fail to integrate the multiple impacts of a system into unified measures of social, economic or environmental performance related to sustainability. Integrated metrics that combine multiple aspects of system performance based on a common scientific or economic principle have proven to be valuable for sustainability evaluation. In this work, we propose methods of adapting four integrated metrics for use with LCAs of product systems: ecological footprint, emergy, green net value added, and Fisher information. These metrics provide information on the full product system in land, energy, monetary equivalents, and as a unitless information index; each bundled with one or more indicators for reporting. When used together and for relative comparison, integrated metrics provide a broader coverage of sustainability aspects from multiple theoretical perspectives that is more likely to illuminate potential issues than individual impact indicators. These integrated metrics are recommended for use in combination with traditional indicators used in LCA. Future work will test and demonstrate the value of using these integrated metrics and combinations to assess product system sustainability.

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

Science.gov (United States)

Grindley, T.

1988-04-05

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-10-01

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

Thermodynamic Model for Updraft Gasifier with External Recirculation of Pyrolysis Gas

Directory of Open Access Journals (Sweden)

Fajri Vidian

2016-01-01

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

Evaluation of 450-MWe BGL GCC power plants fueled with Pittsburgh No. 8 coal

International Nuclear Information System (INIS)

Pechtl, P.A.; Chen, T.P.; Thompson, B.H.; Greil, C.F.; Niermann, S.E.; Jandrisevits, M.

1992-11-01

In this study, a conceptual design and cost estimate were developed for a nominal 450 MW integrated gasification combined cycle plant using the British Gas/Lurgi slagging gasification process. The present study is a design update of a previous study (EPRI Report AP-6011). The major design improvements incorporated include use of the latest GE 7F gas turbine rating, integrating the air separation plant with gas turbine, use of fuel gas saturation for NO x control, use of treated gasifier waste water as makeup water for the fuel gas saturation, and several process changes in the acid gas removal and sulfur recovery areas. Alternate design options for feeding the excess coal fines to the gasifier, treating the gasifier waste water, and the use of conventional air separation without integration with gas turbine were evaluated. The design improvements incorporated were found to increase significantly the overall plant efficiency and reduce the cost reported in the previous study. The various design options evaluated were found to have significant impacts on the plant efficiency but negligible impacts on the cost of electricity

Hybrid Combined Cycles with Biomass and Waste Fired Bottoming Cycle - a Literature Study

Energy Technology Data Exchange (ETDEWEB)

Petrov, Miroslav P.

2002-02-01

Biomass is one of the main natural resources in Sweden. The present low-CO{sub 2} emission characteristics of the Swedish electricity production system (hydro and nuclear) can be retained only by expansion of biofuel applications for energy purposes. Domestic Swedish biomass resources are vast and renewable, but not infinite. They must be utilized as efficiently as possible, in order to make sure that they meet the conditions for sustainability in the future. Application of efficient power generation cycles at low costs is essential for meeting this challenge. This applies also to municipal solid waste incineration with energy extraction, which should be preferred to its dumping in landfills. Hybrid dual-fuel combined cycle units are a simple and affordable way to increase the electric efficiency of biofuel energy utilization, without big investments, uncertainties or loss of reliability arising from complicated technologies. Configurations of such power cycles are very flexible and reliable. Their potential for high electric efficiency in condensing mode, high total efficiency in combined heat and power mode and unrivalled load flexibility is explored in this project. The present report is a literature study that concentrates on certain biomass utilization technologies, in particular the design and performance of hybrid combined cycle power units of various configurations, with gas turbines and internal combustion engines as topping cycles. An overview of published literature and general development trends on the relevant topic is presented. The study is extended to encompass a short overview of biomass utilization as an energy source (focusing on Sweden), history of combined cycles development with reference especially to combined cycles with supplementary firing and coal-fired hybrid combined cycles, repowering of old steam units into hybrid ones and combined cycles for internal combustion engines. The hybrid combined cycle concept for municipal solid waste

Thermodynamic assessment of impact of inlet air cooling techniques on gas turbine and combined cycle performance

International Nuclear Information System (INIS)

Mohapatra, Alok Ku; Sanjay

2014-01-01

The article is focused on the comparison of impact of two different methods of inlet air cooling (vapor compression and vapor absorption cooling) integrated to a cooled gas turbine based combined cycle plant. Air-film cooling has been adopted as the cooling technique for gas turbine blades. A parametric study of the effect of compressor pressure ratio, compressor inlet temperature (T i , C ), turbine inlet temperature (T i , T ), ambient relative humidity and ambient temperature on performance parameters of plant has been carried out. Optimum T i , T corresponding to maximum plant efficiency of combined cycle increases by 100 °C due to the integration of inlet air cooling. It has been observed that vapor compression cooling improves the efficiency of gas turbine cycle by 4.88% and work output by 14.77%. In case of vapor absorption cooling an improvement of 17.2% in gas cycle work output and 9.47% in gas cycle efficiency has been observed. For combined cycle configuration, however, vapor compression cooling should be preferred over absorption cooling in terms of higher plant performance. The optimum value of compressor inlet temperature has been observed to be 20 °C for the chosen set of conditions for both the inlet air cooling schemes. - Highlights: • Inlet air cooling improves performance of cooled gas turbine based combined cycle. • Vapor compression inlet air cooling is superior to vapor absorption inlet cooling. • For every turbine inlet temperature, there exists an optimum pressure ratio. • The optimum compressor inlet temperature is found to be 293 K

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Thermodynamic analysis of an integrated gasification solid oxide fuel cell plant combined with an organic Rankine cycle

DEFF Research Database (Denmark)

Pierobon, Leonardo; Rokni, Masoud; Larsen, Ulrik

2013-01-01

into a fixed bed gasification plant to produce syngas which fuels the combined solid oxide fuel cells e organic Rankine cycle system to produce electricity. More than a hundred fluids are considered as possible alternative for the organic cycle using non-ideal equations of state (or state-of-the-art equations......A 100 kWe hybrid plant consisting of gasification system, solid oxide fuel cells and organic Rankine cycle is presented. The nominal power is selected based on cultivation area requirement. For the considered output a land of around 0.5 km2 needs to be utilized. Woodchips are introduced...... achieved by simple and double stage organic Rankine cycle plants and around the same efficiency of a combined gasification, solid oxide fuel cells and micro gas turbine plant. © 2013 Elsevier Ltd. All rights reserved....

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

Science.gov (United States)

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

2012-04-01

The feasibility and operation performance of the gasification of rice straw in an atmospheric fluidized-bed gasifier was studied. The gasification was carried out between 700 and 850 °C. The stoichiometric air-fuel ratio (A/F) for rice straw was 4.28 and air supplied was 7-25% of that necessary for stoichiometric combustion. Mass and power balances, tar concentration, produced gas composition, gas phase ammonia, chloride and potassium concentrations, agglomeration tendencies and gas efficiencies were assessed. Agglomeration was avoided by replacing the normal alumina-silicate bed by a mixture of alumina-silicate sand and MgO. It was shown that it is possible to produce high quality syngas from the gasification of rice straw. Under the experimental conditions used, the higher heating value (HHV) of the produced gas reached 5.1 MJ Nm(-3), the hot gas efficiency 61% and the cold gas efficiency 52%. The obtained results prove that rice straw may be used as fuel for close-coupled boiler-gasifier systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Straw Gasification in a Two-Stage Gasifier

DEFF Research Database (Denmark)

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

2002-01-01

- and to maintain a high fuel reactivity, a mixture of phosphorus acid, calcium hydroxide, molasses and water was mixed into the ground pellets. Following the gasifier was running continuously for more than 50 hours as planned. Several tar, gas and particle measurements were carried out during the test, and the ash...

Parametric-based thermodynamic analysis of organic Rankine cycle as bottoming cycle for combined-cycle power plant

International Nuclear Information System (INIS)

Qureshi, S.; Memon, A.G.; Abbasi, A.F.

2017-01-01

In Pakistan, the thermal efficiency of the power plants is low because of a huge share of fuel energy is dumped into the atmosphere as waste heat. The ORC (Organic Rankine Cycle) has been revealed as one of the promising technologies to recover waste heat to enhance the thermal efficiency of the power plant. In current work, ORC is proposed as a second bottoming cycle for existing CCPP (Combined Cycle Power Plant). In order to assess the efficiency of the plant, a thermodynamic model is developed in the ESS (Engineering Equation Solver) software. The developed model is used for parametric analysis to assess the effects of various operating parameters on the system performance. The analysis of results shows that the integration of ORC system with existing CCPP system enhances the overall power output in the range of 150.5-154.58 MW with 0.24-5% enhancement in the efficiency depending on the operating conditions. During the parametric analysis of ORC, it is observed that inlet pressure of the turbine shows a significant effect on the performance of the system as compared to other operating parameters. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2000-07-01

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

WABASH RIVER INTEGRATED METHANOL AND POWER PRODUCTION FROM CLEAN COAL TECHNOLOGIES (IMPPCCT)

Energy Technology Data Exchange (ETDEWEB)

Doug Strickland; Albert Tsang

2002-10-14

gas is used to fuel a combustion turbine generator whose exhaust is integrated with a heat recovery steam generator to drive a refurbished steam turbine generator. The gasifier uses technology initially developed by The Dow Chemical Company (the Destec Gasification Process), and now offered commercially by Global Energy, Inc., as the E-GAS{trademark} technology. In a joint effort with the U.S. Department of Energy, working under a Cooperative Agreement Award from the ''Early Entrance Coproduction Plant'' (EECP) initiative, the GEC and an Industrial Consortia are investigating the application of synthesis gas from the E-GAS{trademark} technology to a coproduction environment to enhance the efficiency and productivity of solid fuel gasification combined cycle power plants. The objectives of this effort are to determine the feasibility of an EECP located at a specific site which produces some combination of electric power (or heat), fuels, and/or chemicals from synthesis gas derived from coal, or, coal in combination with some other carbonaceous feedstock. The project's intended result is to provide the necessary technical, economic, and environmental information that will be needed to move the EECP forward to detailed design, construction, and operation by industry.

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

Directory of Open Access Journals (Sweden)

Jinsu Kim

2018-04-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-12-15

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

Estimate for interstage water injection in air compressor incorporated into gas-turbine cycles and combined power plants cycles

Science.gov (United States)

Kler, A. M.; Zakharov, Yu. B.; Potanina, Yu. M.

2017-05-01

The objects of study are the gas turbine (GT) plant and combined cycle power plant (CCPP) with opportunity for injection between the stages of air compressor. The objective of this paper is technical and economy optimization calculations for these classes of plants with water interstage injection. The integrated development environment "System of machine building program" was a tool for creating the mathematic models for these classes of power plants. Optimization calculations with the criterion of minimum for specific capital investment as a function of the unit efficiency have been carried out. For a gas-turbine plant, the economic gain from water injection exists for entire range of power efficiency. For the combined cycle plant, the economic benefit was observed only for a certain range of plant's power efficiency.

Dual Pressure versus Hybrid Recuperation in an Integrated Solid Oxide Fuel Cell Cycle – Steam Cycle

DEFF Research Database (Denmark)

Rokni, Masoud

2014-01-01

A SOFC (solid oxide fuel cell) cycle running on natural gas was integrated with a ST (steam turbine) cycle. The fuel is desulfurized and pre-reformed before entering the SOFC. A burner was used to combust the remaining fuel after the SOFC stacks. The off-gases from the burner were used to produce...... pressure configuration steam cycle combined with SOFC cycle (SOFC-ST) was new and has not been studied previously. In each of the configuration, a hybrid recuperator was used to recovery the remaining energy of the off-gases after the HRSG. Thus, four different plants system setups were compared to each...... other to reveal the most superior concept with respect to plant efficiency and power. It was found that in order to increase the plant efficiency considerably, it was enough to use a single pressure with a hybrid recuperator instead of a dual pressure Rankine cycle....

Decomposition of tar in gas from updraft gasifier by thermal cracking

DEFF Research Database (Denmark)

Brandt, Peder; Henriksen, Ulrik Birk

2000-01-01

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

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

Science.gov (United States)

Vakalis, Stergios; Patuzzi, Francesco; Baratieri, Marco

2016-04-01

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

Effective energy management by combining gas turbine cycles and forward osmosis desalination process

International Nuclear Information System (INIS)

Park, Min Young; Shin, Serin; Kim, Eung Soo

2015-01-01

Highlights: • Innovative gas turbine system and FO integrated system was proposed. • The feasibility of the integrated system was analyzed thermodynamically. • GOR of the FO–gas turbine system is 17% higher than those of MED and MSF. • Waste heat utilization of the suggested system is 85.7%. • Water production capacity of the suggested system is 3.5 times higher than the MSF–gas turbine system. - Abstract: In the recent years, attempts to improve the thermal efficiency of the gas turbine cycles have been made. In order to enhance the energy management of the gas turbine cycle, a new integration concept has been proposed; integration of gas turbine cycle and forward osmosis desalination process. The combination of the gas turbine cycle and the forward osmosis (FO) desalination process basically implies the coupling of the waste heat from the gas turbine cycle to the draw solute recovery system in the FO process which is the most energy consuming part of the whole FO process. By doing this, a strong system that is capable of producing water and electricity with very little waste heat can be achieved. The feasibility of this newly proposed system was analyzed using UNISIM program and the OLI property package. For the analysis, the thermolytic draw solutes which has been suggested by other research groups have been selected and studied. Sensitivity analysis was conducted on the integration system in order to understand and identify the key parameters of the integrated system. And the integrated system was further evaluated by comparing the gain output ratio (GOR) values with the conventional desalination technologies such as multi stage flash (MSF) and multi effect distillation (MED). The suggested integrated system was calculated to have a GOR of 14.8, while the MSF and MED when integrated to the gas turbine cycle showed GOR value of 12. It should also be noted that the energy utilization of the suggested integrated system is significantly higher by 27

Analysis of a combined Rankine-vapour-compression refrigeration cycle

International Nuclear Information System (INIS)

Aphornratana, Satha; Sriveerakul, Thanarath

2010-01-01

This paper describes a theoretical analysis of a heat-powered refrigeration cycle, a combined Rankine-vapour-compression refrigeration cycle. This refrigeration cycle combines an Organic Rankine Cycle and a vapour-compression cycle. The cycle can be powered by low grade thermal energy as low as 60 deg. C and can produce cooling temperature as low as -10 deg. C. In the analysis, two combined Rankine-vapour-compression refrigeration cycles were investigated: the system with R22 and the system with R134a. Calculated COP values between 0.1 and 0.6 of both the systems were found.

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

NARCIS (Netherlands)

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

2012-01-01

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

Exergy analysis and optimisation of a marine molten carbonate fuel cell system in simple and combined cycle configuration

International Nuclear Information System (INIS)

Dimopoulos, George G.; Stefanatos, Iason C.; Kakalis, Nikolaos M.P.

2016-01-01

Highlights: • Process modelling and optimisation of an integrated marine MCFC system. • Component-level and spatially distributed exergy analysis and balances. • Optimal simple cycle MCFC system with 45.5% overall exergy efficiency. • Optimal combined cycle MCFC system with 60% overall exergy efficiency. • Combined cycle MCFC system yields 30% CO_2 relative emissions reduction. - Abstract: In this paper we present the exergy analysis and design optimisation of an integrated molten carbonate fuel cell (MCFC) system for marine applications, considering waste heat recovery options for additional power production. High temperature fuel cells are attractive solutions for marine energy systems, as they can significantly reduce gaseous emissions, increase efficiency and facilitate the introduction of more environmentally-friendly fuels, like LNG and biofuels. We consider an already installed MCFC system onboard a sea-going vessel, which has many tightly integrated sub-systems and components: fuel delivery and pre-reforming, internal reforming sections, electrochemical conversion, catalytic burner, air supply and high temperature exhaust gas. The high temperature exhaust gasses offer significant potential for heat recovery that can be directed into both covering the system’s auxiliary heat requirements and power production. Therefore, an integrated systems approach is employed to accurately identify the true sources of losses in the various components and to optimise the overall system with respect to its energy efficiency, taking into account the various trade-offs and subject to several constraints. Here, we present a four-step approach: a. dynamic process models development of simple and combined-cycle MCFC system; b. MCFC components and system models calibration via onboard MCFC measurements; c. exergy analysis, and d. optimisation of the simple and combined-cycle systems with respect to their exergetic performance. Our methodology is based on the

Sulfate reduction in an entrained-flow black liquor gasifier

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-01-15

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

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

International Nuclear Information System (INIS)

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

1994-01-01

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

Combined Cycle Power Generation Employing Pressure Gain Combustion

Energy Technology Data Exchange (ETDEWEB)

Holley, Adam [United Technologies Corporation, East Hartford, CT (United States). Research Center

2017-05-15

The Phase I program assessed the potential benefit of applying pressure gain combustion (PGC) technology to a natural gas combined cycle power plant. A conceptual design of the PGC integrated gas turbine was generated which was simulated in a detailed system modeling tool. The PGC integrated system was 1.93% more efficient, produced 3.09% more power, and reduced COE by 0.58%. Since the PGC system used had the same fuel flow rate as the baseline system, it also reduced CO₂ emissions by 3.09%. The PGC system did produce more NOx than standard systems, but even with the performanceand cost penalties associated with the cleanup system it is better in every measure. This technology benefits all of DOE’s stated program goals to improve plant efficiency, reduce CO₂ production, and reduce COE.

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-01-01

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

Performance comparison of two low-CO2 emission solar/methanol hybrid combined cycle power systems

International Nuclear Information System (INIS)

Li, Yuanyuan; Zhang, Na; Lior, Noam

2015-01-01

Highlights: • Two novel solar hybrid combined cycle systems have been proposed and analyzed. • The power systems integrate solar-driven thermo-chemical conversion and CO 2 capture. • Exergy efficiency of about 55% and specific CO 2 emissions of 34 g/kW h are predicted. • Systems CO 2 emissions are 36.8% lower compared to a combined cycle with CO 2 capture. • The fossil fuel demand is ∼30% lower with a solar share of ∼20%. - Abstract: Two novel hybrid combined cycle power systems that use solar heat and methanol, and integrate CO 2 capture, are proposed and analyzed, one based on solar-driven methanol decomposition and the other on solar-driven methanol reforming. The high methanol conversion rates at relatively low temperatures offer the advantage of using the solar heat at only 200–300 °C to drive the syngas production by endothermic methanol conversions and its conversion to chemical energy. Pre-combustion decarbonization is employed to produce CO 2 -free fuel from the fully converted syngas, which is then burned to produce heat at the high temperature for power generation in the proposed advanced combined cycle systems. To improve efficiency, the systems’ configurations were based on the principle of cascade use of multiple heat sources of different temperatures. The thermodynamic performance of the hybrid power systems at its design point is simulated and evaluated. The results show that the hybrid systems can attain an exergy efficiency of about 55%, and specific CO 2 emissions as low as 34 g/kW h. Compared to a gas/steam combined cycle with flue gas CO 2 capture, the proposed solar-assisted system CO 2 emissions are 36.8% lower, and a fossil fuel saving ratio of ∼30% is achievable with a solar thermal share of ∼20%. The system integration predicts high efficiency conversion of solar heat and low-energy-penalty CO 2 capture, with the additional advantage that solar heat is at relatively low temperature where its collection is cheaper and

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

Science.gov (United States)

Iliuta, Ion; Leclerc, Arnaud; Larachi, Faïçal

2010-05-01

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

Study of combined cycle engine for aerospace plane

OpenAIRE

苅田, 丈士; KANDA, Takeshi; 工藤, 賢司; KUDO, Kenji

2002-01-01

At the Ramjet Propulsion Research Center, the scramjet engine for an aerospace plane has been studied. Other engines are required for the plane to go into orbit. Recently, a combined cycle engine including scramjet mode has been also studied to complete the engine system for the plane. The scramjet and the combined cycle engine are most effective with application to the Single-Stage-to-Orbit (SSTO) aerospace plane, as shown in Figure 1. Recent activity on the combined cycle engine and the SST...

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

Energy Technology Data Exchange (ETDEWEB)

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

2005-07-01

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

GEOSS Water Cycle Integrator

Science.gov (United States)

Koike, Toshio; Lawford, Richard; Cripe, Douglas

2013-04-01

It is critically important to recognize and co-manage the fundamental linkages across the water-dependent domains; land use, including deforestation; ecosystem services; and food-, energy- and health-securities. Sharing coordinated, comprehensive and sustained observations and information for sound decision-making is a first step; however, to take full advantage of these opportunities, we need to develop an effective collaboration mechanism for working together across different disciplines, sectors and agencies, and thereby gain a holistic view of the continuity between environmentally sustainable development, climate change adaptation and enhanced resilience. To promote effective multi-sectoral, interdisciplinary collaboration based on coordinated and integrated efforts, the intergovernmental Group on Earth Observations (GEO) is implementing the Global Earth Observation System of Systems (GEOSS). A component of GEOSS now under development is the "GEOSS Water Cycle Integrator (WCI)", which integrates Earth observations, modeling, data and information, management systems and education systems. GEOSS/WCI sets up "work benches" by which partners can share data, information and applications in an interoperable way, exchange knowledge and experiences, deepen mutual understanding and work together effectively to ultimately respond to issues of both mitigation and adaptation. (A work bench is a virtual geographical or phenomenological space where experts and managers collaborate to use information to address a problem within that space). GEOSS/WCI enhances the coordination of efforts to strengthen individual, institutional and infrastructure capacities, especially for effective interdisciplinary coordination and integration. GEO has established the GEOSS Asian Water Cycle Initiative (AWCI) and GEOSS African Water Cycle Coordination Initiative (AfWCCI). Through regional, inter-disciplinary, multi-sectoral integration and inter-agency coordination in Asia and Africa, GEOSS

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

International Nuclear Information System (INIS)

Peascoe, RA

2001-01-01

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

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Performance study of a combined cycle power plant with integral gasification; Estudio del desempeno de una planta de potencia de ciclo combinado con gasificacion integral

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Rocha, Jose Clemente

2007-04-15

At world-wide level, in the last decade the interest has been increased in the use of petroleum coke as fuel in the clean generation of energy applying the gasification technology. This interest is mainly due to the increment the production of petroleum coke as a result of processing larger volumes of crude processed in the refineries and to the increment in the yield of products with high added value, such as turbo-fuel or diesel, among others. With the new reconfiguration of the Mexican refinery of Cd. Madero and Cadereyta and soon with the completion of the reconfiguration of the Minatitlan, Veracruz refinery, larger amounts of coke will be produced, with the possibility of using it, by means of the appropriate gasification technology, to produce a clean synthetic gas (gasl) with the appropriate energy characteristic to be used as fuel in a combined cycle existing in Mexico. In Mexico the possibilities of generation of electrical energy from the utilization of petroleum coke have been considered departing from the use of petroleum coke using the gasification technology or using fluidized bed steam generators as is the case of the power plant TEG in Taquin, San Luis Potosi. Such is the fact, that at the moment PEMEX Refinacion, has completed the project of constructing in Tuxpan, Veracruz a crude processing refinery of Mayan crude with a high sulfur content and next to the Tuxpan Power Plant, being contemplated the possibility of applying the concept of combined cycle with integrated gasification (CCGI); with this infrastructure it will be possible to consume the coke generated by the Mexican refineries. The expected electrical generation is of 500 MW, of which 100 MW will be for own consumption of the refinery and 400 MW free to cover the electrical energy demand within the North East and Center Zone of the country. The petroleum coke derived from the refineries of the country can be used for the clean generation of electricity by means of its gasification and

Process integrated modelling for steelmaking Life Cycle Inventory analysis

International Nuclear Information System (INIS)

Iosif, Ana-Maria; Hanrot, Francois; Ablitzer, Denis

2008-01-01

During recent years, strict environmental regulations have been implemented by governments for the steelmaking industry in order to reduce their environmental impact. In the frame of the ULCOS project, we have developed a new methodological framework which combines the process integrated modelling approach with Life Cycle Assessment (LCA) method in order to carry out the Life Cycle Inventory of steelmaking. In the current paper, this new concept has been applied to the sinter plant which is the most polluting steelmaking process. It has been shown that this approach is a powerful tool to make the collection of data easier, to save time and to provide reliable information concerning the environmental diagnostic of the steelmaking processes

Improving bioethanol production from sugarcane: evaluation of distillation, thermal integration and cogeneration systems

International Nuclear Information System (INIS)

Dias, Marina O.S.; Modesto, Marcelo; Ensinas, Adriano V.; Nebra, Silvia A.; Filho, Rubens Maciel; Rossell, Carlos E.V.

2011-01-01

Demand for bioethanol has grown considerably over the last years. Even though Brazil has been producing ethanol from sugarcane on a large scale for decades, this industry is characterized by low energy efficiency, using a large fraction of the bagasse produced as fuel in the cogeneration system to supply the process energy requirements. The possibility of selling surplus electricity to the grid or using surplus bagasse as raw material of other processes has motivated investments on more efficient cogeneration systems and process thermal integration. In this work simulations of an autonomous distillery were carried out, along with utilities demand optimization using Pinch Analysis concepts. Different cogeneration systems were analyzed: a traditional Rankine Cycle, with steam of high temperature and pressure (80 bar, 510 o C) and back pressure and condensing steam turbines configuration, and a BIGCC (Biomass Integrated Gasification Combined Cycle), comprised by a gas turbine set operating with biomass gas produced in a gasifier that uses sugarcane bagasse as raw material. Thermoeconomic analyses determining exergy-based costs of electricity and ethanol for both cases were carried out. The main objective is to show the impact that these process improvements can produce in industrial systems, compared to the current situation.

First image from a combined positron emission tomography and field-cycled MRI system.

Science.gov (United States)

Bindseil, Geron A; Gilbert, Kyle M; Scholl, Timothy J; Handler, William B; Chronik, Blaine A

2011-07-01

Combining positron emission tomography and MRI modalities typically requires using either conventional MRI with a MR-compatible positron emission tomography system or a modified MR system with conventional positron emission tomography. A feature of field-cycled MRI is that all magnetic fields can be turned off rapidly, enabling the use of conventional positron emission tomography detectors based on photomultiplier tubes. In this demonstration, two photomultiplier tube-based positron emission tomography detectors were integrated with a field-cycled MRI system (0.3 T/4 MHz) by placing them into a 9-cm axial gap. A positron emission tomography-MRI phantom consisting of a triangular arrangement of positron-emitting point sources embedded in an onion was imaged in a repeating interleaved sequence of ∼1 sec MRI then 1 sec positron emission tomography. The first multimodality images from the combined positron emission tomography and field-cycled MRI system show no additional artifacts due to interaction between the systems and demonstrate the potential of this approach to combining positron emission tomography and MRI. Copyright © 2010 Wiley-Liss, Inc.

NOVEL GAS CLEANING/CONDITIONING FOR INTEGRATED GASIFICATION COMBINED CYCLE

Energy Technology Data Exchange (ETDEWEB)

Dennis A. Horazak; Richard A. Newby; Eugene E. Smeltzer; Rachid B. Slimane; P. Vann Bush; James L. Aderhold Jr; Bruce G. Bryan

2005-12-01

Development efforts have been underway for decades to replace dry-gas cleaning technology with humid-gas cleaning technology that would maintain the water vapor content in the raw gas by conducting cleaning at sufficiently high temperature to avoid water vapor condensation and would thus significantly simplify the plant and improve its thermal efficiency. Siemens Power Generation, Inc. conducted a program with the Gas Technology Institute (GTI) to develop a Novel Gas Cleaning process that uses a new type of gas-sorbent contactor, the ''filter-reactor''. The Filter-Reactor Novel Gas Cleaning process described and evaluated here is in its early stages of development and this evaluation is classified as conceptual. The commercial evaluations have been coupled with integrated Process Development Unit testing performed at a GTI coal gasifier test facility to demonstrate, at sub-scale the process performance capabilities. The commercial evaluations and Process Development Unit test results are presented in Volumes 1 and 2 of this report, respectively. Two gas cleaning applications with significantly differing gas cleaning requirements were considered in the evaluation: IGCC power generation, and Methanol Synthesis with electric power co-production. For the IGCC power generation application, two sets of gas cleaning requirements were applied, one representing the most stringent ''current'' gas cleaning requirements, and a second set representing possible, very stringent ''future'' gas cleaning requirements. Current gas cleaning requirements were used for Methanol Synthesis in the evaluation because these cleaning requirements represent the most stringent of cleaning requirements and the most challenging for the Filter-Reactor Novel Gas Cleaning process. The scope of the evaluation for each application was: (1) Select the configuration for the Filter-Reactor Novel Gas Cleaning Process, the arrangement of the

Highlights from a Mach 4 Experimental Demonstration of Inlet Mode Transition for Turbine-Based Combined Cycle Hypersonic Propulsion

Science.gov (United States)

Foster, Lancert E.; Saunders, John D., Jr.; Sanders, Bobby W.; Weir, Lois J.

2012-01-01

NASA is focused on technologies for combined cycle, air-breathing propulsion systems to enable reusable launch systems for access to space. Turbine Based Combined Cycle (TBCC) propulsion systems offer specific impulse (Isp) improvements over rocket-based propulsion systems in the subsonic takeoff and return mission segments along with improved safety. Among the most critical TBCC enabling technologies are: 1) mode transition from the low speed propulsion system to the high speed propulsion system, 2) high Mach turbine engine development and 3) innovative turbine based combined cycle integration. To address these challenges, NASA initiated an experimental mode transition task including analytical methods to assess the state-of-the-art of propulsion system performance and design codes. One effort has been the Combined-Cycle Engine Large Scale Inlet Mode Transition Experiment (CCE-LIMX) which is a fully integrated TBCC propulsion system with flowpath sizing consistent with previous NASA and DoD proposed Hypersonic experimental flight test plans. This experiment was tested in the NASA GRC 10 by 10-Foot Supersonic Wind Tunnel (SWT) Facility. The goal of this activity is to address key hypersonic combined-cycle engine issues including: (1) dual integrated inlet operability and performance issues-unstart constraints, distortion constraints, bleed requirements, and controls, (2) mode-transition sequence elements caused by switching between the turbine and the ramjet/scramjet flowpaths (imposed variable geometry requirements), and (3) turbine engine transients (and associated time scales) during transition. Testing of the initial inlet and dynamic characterization phases were completed and smooth mode transition was demonstrated. A database focused on a Mach 4 transition speed with limited off-design elements was developed and will serve to guide future TBCC system studies and to validate higher level analyses.

Fluid Dynamics of Pressurized, Entrained Coal Gasifiers

International Nuclear Information System (INIS)

1997-01-01

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

Airbreathing combined cycle engine systems

Science.gov (United States)

Rohde, John

1992-01-01

The Air Force and NASA share a common interest in developing advanced propulsion systems for commercial and military aerospace vehicles which require efficient acceleration and cruise operation in the Mach 4 to 6 flight regime. The principle engine of interest is the turboramjet; however, other combined cycles such as the turboscramjet, air turborocket, supercharged ejector ramjet, ejector ramjet, and air liquefaction based propulsion are also of interest. Over the past months careful planning and program implementation have resulted in a number of development efforts that will lead to a broad technology base for those combined cycle propulsion systems. Individual development programs are underway in thermal management, controls materials, endothermic hydrocarbon fuels, air intake systems, nozzle exhaust systems, gas turbines and ramjet ramburners.

Generating power at high efficiency combined cycle technology for sustainable energy production

CERN Document Server

Jeffs, E

2008-01-01

Combined cycle technology is used to generate power at one of the highest levels of efficiency of conventional power plants. It does this through primary generation from a gas turbine coupled with secondary generation from a steam turbine powered by primary exhaust heat. Generating power at high efficiency thoroughly charts the development and implementation of this technology in power plants and looks to the future of the technology, noting the advantages of the most important technical features - including gas turbines, steam generator, combined heat and power and integrated gasification com

Oxygen blast furnace and combined cycle (OBF-CC) - an efficient iron-making and power generation process

International Nuclear Information System (INIS)

Jianwei, Y.; Guolong, S.; Cunjiang, K.; Tianjun, Y.

2003-01-01

A new iron and power generating process, oxygen blast furnace and combined cycle (OBF-CC), is presented. In order to support the opinion, the features of the oxygen blast furnace and integrated coal gasification and combined cycle (IGCC) are summarized. The relation between the blasting parameters and the output gas quantity, as well as caloric value is calculated based on mass and energy balance. Analysis and calculation indicate that the OBF-CC will be an efficient iron-making and power generation process with higher energy efficiency and less pollution

Comparison of Heat Transfer Fluid and Direct Steam Generation technologies for Integrated Solar Combined Cycles

International Nuclear Information System (INIS)

Rovira, Antonio; Montes, María José; Varela, Fernando; Gil, Mónica

2013-01-01

At present time and in the medium term, Solar Thermal Power Plants are going to share scenario with conventional energy generation technologies, like fossil and nuclear. In such a context, Integrated Solar Combined Cycles (ISCCs) may be an interesting choice since integrated designs may lead to a very efficient use of the solar and fossil resources. In this work, different ISCC configurations including a solar field based on parabolic trough collectors and working with the so-called Heat Transfer Fluid (HTF) and Direct Steam Generation (DSG) technologies are compared. For each technology, four layouts have been studied: one in which solar heat is used to evaporate part of the high pressure steam of a bottoming Rankine cycle with two pressure levels, another that incorporates a preheating section to the previous layout, the third one that includes superheating instead of preheating and the last one including both preheating and superheating in addition to the evaporation. The analysis is made with the aim of finding out which of the different layouts reaches the best performance. For that purpose, three types of comparisons have been performed. The first one assesses the benefits of including a solar steam production fixed at 50 MW th . The second one compares the configurations with a standardised solar field size instead of a fixed solar steam production. Finally, the last one consists on an even more homogeneous comparison considering the same steam generator size for all the configurations as well as standardised solar fields. The configurations are studied by mean of exergy analyses. Several figures of merit are used to correctly assess the configurations. Results reveal that the only-evaporative DSG configuration becomes the best choice, since it benefits of both low irreversibility at the heat recovery steam generator and high thermal efficiency in the solar field. Highlights: ► ISCC configurations with DSG and HTF technologies are compared. ► Four

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

Directory of Open Access Journals (Sweden)

Liu Sheng

2013-01-01

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

Developments in modelling and simulation of coal gasification

Energy Technology Data Exchange (ETDEWEB)

NONE

2014-02-01

In recent years, the considerable increase in the price of crude oil and natural gas and concerns about their security of supply focused attention on whether fuel for power production and feedstocks for the chemical industry could be obtained from the gasification of coal. The need to reduce greenhouse gas emissions has enhanced the prospects of power generation from Integrated Gasification Combined Cycle (IGCC) plant. However, the higher capital costs and concerns about reliability and availability of IGCC plant have limited their market penetration. The coal gasifier has been a significant source of operational issues. A thorough understanding of the processes occurring in a gasifier is essential both for addressing existing causes of gasifier unavailability and improving designs for the future. Many complex processes take place in a gasifier and developing models of gasifiers results in a greater insight into these processes. Computational models in conjunction with plant data can be used to evaluate gasifier operation, solve operational problems, probe new designs and provide performance data for commercial scale-up. This report has surveyed models which are currently available for modelling gasifiers. The report contains a brief description of the three types of gasifiers which are most commonly used. The models available for each type of gasifier are considered. Insight gained by modelling has advanced the design of gasifiers and can improve gasifier performance. In some cases, the results have been compared with plant data and it has been possible to choose model inputs to give reasonable fit with the measured data. However, there are fewer examples where modelling has directly solved operational problems.

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 7: Metal vapor Rankine topping-steam bottoming cycles. [energy conversion efficiency in electric power plants

Science.gov (United States)

Deegan, P. B.

1976-01-01

Adding a metal vapor Rankine topper to a steam cycle was studied as a way to increase the mean temperature at which heat is added to the cycle to raise the efficiency of an electric power plant. Potassium and cesium topping fluids were considered. Pressurized fluidized bed or pressurized (with an integrated low-Btu gasifier) boilers were assumed. Included in the cycles was a pressurizing gas turbine with its associated recuperator, and a gas economizer and feedwater heater. One of the ternary systems studied shows plant efficiency of 42.3% with a plant capitalization of $66.7/kW and a cost of electricity of 8.19 mills/MJ (29.5 mills/kWh).

Process integration of organic Rankine cycle

International Nuclear Information System (INIS)

Desai, Nishith B.; Bandyopadhyay, Santanu

2009-01-01

An organic Rankine cycle (ORC) uses an organic fluid as a working medium within a Rankine cycle power plant. ORC offers advantages over conventional Rankine cycle with water as the working medium, as ORC generates shaft-work from low to medium temperature heat sources with higher thermodynamic efficiency. The dry and the isentropic fluids are most preferred working fluid for the ORC. The basic ORC can be modified by incorporating both regeneration and turbine bleeding to improve its thermal efficiency. In this paper, 16 different organic fluids have been analyzed as a working medium for the basic as well as modified ORCs. A methodology is also proposed for appropriate integration and optimization of an ORC as a cogeneration process with the background process to generate shaft-work. It has been illustrated that the choice of cycle configuration for appropriate integration with the background process depends on the heat rejection profile of the background process (i.e., the shape of the below pinch portion of the process grand composite curve). The benefits of integrating ORC with the background process and the applicability of the proposed methodology have been demonstrated through illustrative examples.

Dynamic modeling of IGCC power plants

International Nuclear Information System (INIS)

Casella, F.; Colonna, P.

2012-01-01

Integrated Gasification Combined Cycle (IGCC) power plants are an effective option to reduce emissions and implement carbon-dioxide sequestration. The combination of a very complex fuel-processing plant and a combined cycle power station leads to challenging problems as far as dynamic operation is concerned. Dynamic performance is extremely relevant because recent developments in the electricity market push toward an ever more flexible and varying operation of power plants. A dynamic model of the entire system and models of its sub-systems are indispensable tools in order to perform computer simulations aimed at process and control design. This paper presents the development of the lumped-parameters dynamic model of an entrained-flow gasifier, with special emphasis on the modeling approach. The model is implemented into software by means of the Modelica language and validated by comparison with one set of data related to the steady operation of the gasifier of the Buggenum power station in the Netherlands. Furthermore, in order to demonstrate the potential of the proposed modeling approach and the use of simulation for control design purposes, a complete model of an exemplary IGCC power plant, including its control system, has been developed, by re-using existing models of combined cycle plant components; the results of a load dispatch ramp simulation are presented and shortly discussed. - Highlights: ► The acausal dynamic model of an entrained gasifier has been developed. ► The model can be used to perform system optimization and control studies. ► The model has been validated using field data. ► Model use is illustrated with an example showing the transient of an IGCC plant.

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

Directory of Open Access Journals (Sweden)

Dhaundiyal Alok

2016-03-01

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

Performance analysis of solar parabolic trough collectors driven combined supercritical CO2 and organic Rankine cycle

Directory of Open Access Journals (Sweden)

Harwinder Singh

2018-06-01

Full Text Available In this paper, attempts have been made on the detailed energy and exergy analysis of solar parabolic trough collectors (SPTCs driven combined power plant. The combination of supercritical CO2 (SCO2 cycle and organic Rankine cycle (ORC integrated with SPTCs has been used to produce power, in which SCO2 cycle and ORC are arranged as a topping and bottoming cycle. Five organic working fluids like R134a, R1234yf, R407c, R1234ze, and R245fa were selected for a low temperature bottoming ORC. Five key exergetic parameters such as exergetic efficiency, exergy destruction rate, fuel depletion ratio, irreversibility ratio, and improvement potential were also examined. It was revealed that exergetic and thermal efficiency of all the combined cycles enhances as the direct normal irradiance increases from 0.5 kW/m2 to 0.95 kW/m2. As can be seen, R407c combined cycle has the maximum exergetic as well as thermal efficiency which is around 78.07% at 0.95 kW/m2 and 43.49% at 0.95 kW/m2, respectively. Alternatively, the R134a and R245fa combined cycle yields less promising results with the marginal difference in their performance. As inferred from the study that SCO2 turbine and evaporator has a certain amount of exergy destruction which is around 9.72% and 8.54% of the inlet exergy, and almost 38.10% of the total exergy destruction in case of R407c combined cycle. Moreover, the maximum amount of exergy destructed by the solar collector field which is more than 25% of the solar inlet exergy and around 54% of the total destructed exergy. Finally, this study concludes that R407c combined cycle has a minimum fuel depletion ratio of 0.2583 for a solar collector and possess the highest power output of 3740 kW. Keywords: Supercritical CO2cycle, Organic Rankine cycle, Exergetic performance, SPTCs, Organic fluids

Gasification and combined cycles: Present situation and future prospects

International Nuclear Information System (INIS)

Brustia, G.F.; Bressan, L.; Domenichini, R.

1992-01-01

The gasification of coal and/or residual fuels from refineries together with the use of combined cycle power generation systems represents a technically and economically feasible method for the conversion of poor quality fossil fuels into electric power. The conversion is accomplished with maximum respect for the severest environmental normatives. In addition, foreseen technical improvements for components and plant systems are expected to heighten the marketing potential of gasification/combined cycle power plants. After Italy's moratorium on nuclear energy, the passing eras of conventional fossil fuel and then combined cycle power plants, the need for highly competitive industrial production technologies and the urgency of nation-wide energy conservation appear to be ushering in the new era of gasification with combined cycles

Parametric Investigation and Thermoeconomic Optimization of a Combined Cycle for Recovering the Waste Heat from Nuclear Closed Brayton Cycle

Directory of Open Access Journals (Sweden)

Lihuang Luo

2016-01-01

Full Text Available A combined cycle that combines AWM cycle with a nuclear closed Brayton cycle is proposed to recover the waste heat rejected from the precooler of a nuclear closed Brayton cycle in this paper. The detailed thermodynamic and economic analyses are carried out for the combined cycle. The effects of several important parameters, such as the absorber pressure, the turbine inlet pressure, the turbine inlet temperature, the ammonia mass fraction, and the ambient temperature, are investigated. The combined cycle performance is also optimized based on a multiobjective function. Compared with the closed Brayton cycle, the optimized power output and overall efficiency of the combined cycle are higher by 2.41% and 2.43%, respectively. The optimized LEC of the combined cycle is 0.73% lower than that of the closed Brayton cycle.

Thermodynamic investigation of an integrated gasification plant with solid oxide fuel cell and steam cycles

Energy Technology Data Exchange (ETDEWEB)

Rokni, Masoud [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Mechanical Engineering, Thermal Energy System

2012-07-01

A gasification plant is integrated on the top of a solid oxide fuel cell (SOFC) cycle, while a steam turbine (ST) cycle is used as a bottoming cycle for the SOFC plant. The gasification plant was fueled by woodchips to produce biogas and the SOFC stacks were fired with biogas. The produced gas was rather clean for feeding to the SOFC stacks after a simple cleaning step. Because all the fuel cannot be burned in the SOFC stacks, a burner was used to combust the remaining fuel. The off-gases from the burner were then used to produce steam for the bottoming steam cycle in a heat recovery steam generator (HRSG). The steam cycle was modeled with a simple single pressure level. In addition, a hybrid recuperator was used to recover more energy from the HRSG and send it back to the SOFC cycle. Thus two different configurations were investigated to study the plants characteristic. Such system integration configurations are completely novel and have not been studied elsewhere. Plant efficiencies of 56% were achieved under normal operation which was considerably higher than the IGCC (Integrated Gasification Combined Cycle) in which a gasification plant is integrated with a gas turbine and a steam turbine. Furthermore, it is shown that under certain operating conditions, plant efficiency of about 62 is also possible to achieve. (orig.)

Combined rankine and vapor compression cycles

Science.gov (United States)

Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

2005-04-19

An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

Effects of syngas type on the operation and performance of a gas turbine in integrated gasification combined cycle

International Nuclear Information System (INIS)

Kim, Young Sik; Lee, Jong Jun; Kim, Tong Seop; Sohn, Jeong L.

2011-01-01

Research highlights: → The effect of firing syngas in a gas turbine designed for natural gas was investigated. → A full off-design analysis was performed for a wide syngas heating value range. → Restrictions on compressor surge margin and turbine metal temperature were considered. -- Abstract: We investigated the effects of firing syngas in a gas turbine designed for natural gas. Four different syngases were evaluated as fuels for a gas turbine in the integrated gasification combined cycle (IGCC). A full off-design analysis of the gas turbine was performed. Without any restrictions on gas turbine operation, as the heating value of the syngas decreases, a greater net system power output and efficiency is possible due to the increased turbine mass flow. However, the gas turbine is more vulnerable to compressor surge and the blade metal becomes more overheated. These two problems can be mitigated by reductions in two parameters: the firing temperature and the nitrogen flow to the combustor. With the restrictions on surge margin and metal temperature, the net system performance decreases compared to the cases without restrictions, especially in the surge margin control range. The net power outputs of all syngas cases converge to a similar level as the degree of integration approaches zero. The difference in net power output between unrestricted and restricted operation increases as the fuel heating value decreases. The optimal integration degree, which shows the greatest net system power output and efficiency, increases with decreasing syngas heating value.

Effects of syngas type on the operation and performance of a gas turbine in integrated gasification combined cycle

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Sik; Lee, Jong Jun [Graduate School, Inha University, Incheon 402-751 (Korea, Republic of); Kim, Tong Seop, E-mail: kts@inha.ac.k [Dept. of Mechanical Engineering, Inha University, Incheon 402-751 (Korea, Republic of); Sohn, Jeong L. [Center for Next Generation Heat Exchangers, Busan 618-230 (Korea, Republic of)

2011-05-15

Research highlights: {yields} The effect of firing syngas in a gas turbine designed for natural gas was investigated. {yields} A full off-design analysis was performed for a wide syngas heating value range. {yields} Restrictions on compressor surge margin and turbine metal temperature were considered. -- Abstract: We investigated the effects of firing syngas in a gas turbine designed for natural gas. Four different syngases were evaluated as fuels for a gas turbine in the integrated gasification combined cycle (IGCC). A full off-design analysis of the gas turbine was performed. Without any restrictions on gas turbine operation, as the heating value of the syngas decreases, a greater net system power output and efficiency is possible due to the increased turbine mass flow. However, the gas turbine is more vulnerable to compressor surge and the blade metal becomes more overheated. These two problems can be mitigated by reductions in two parameters: the firing temperature and the nitrogen flow to the combustor. With the restrictions on surge margin and metal temperature, the net system performance decreases compared to the cases without restrictions, especially in the surge margin control range. The net power outputs of all syngas cases converge to a similar level as the degree of integration approaches zero. The difference in net power output between unrestricted and restricted operation increases as the fuel heating value decreases. The optimal integration degree, which shows the greatest net system power output and efficiency, increases with decreasing syngas heating value.

Low CO2-emissions hybrid solar combined-cycle power system with methane membrane reforming

International Nuclear Information System (INIS)

Li, Yuanyuan; Zhang, Na; Cai, Ruixian

2013-01-01

Based on the principle of cascade utilization of multiple energy resources, a gas-steam combined cycle power system integrated with solar thermo-chemical fuel conversion and CO 2 capture has been proposed and analyzed. The collected solar heat at 550 °C drives the endothermic methane reforming and is converted to the produced syngas chemical exergy, and then released as high-temperature thermal energy via combustion for power generation, achieving its high-efficiency heat-power conversion. The reforming reaction is integrated with a hydrogen separation membrane, which continuously withdraws hydrogen from the reaction zone and enables nearly full methane conversion. The CO 2 enriched gas being concentrated in the retentate zone is collected and processed with pre-combustion decarbonization. The system is thermodynamically simulated using the ASPEN PLUS code. The results show that with 91% CO 2 captured, the specific CO 2 emission is 25 g/kWh. An exergy efficiency of 58% and thermal efficiency of 51.6% can be obtained. A fossil fuel saving ratio of 31.2% is achievable with a solar thermal share of 28.2%, and the net solar-to-electricity efficiency based on the gross solar heat incident on the collector is about 36.4% compared with the same gas-steam combined cycle system with an equal CO 2 removal ratio obtained by post-combustion decarbonization. - Highlights: ► A solar-assisted hybrid combined cycle power system has been proposed and analyzed. ► The system integrates power generation with solar-driven reforming and CO 2 capture. ► solar heat upgrading and high-efficiency heat-to-power conversion are achieved. ► membrane reforming enables high CH 4 conversion and pre-combustion CO 2 capture. ► The system thermodynamic performances have been investigated and compared

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

DEFF Research Database (Denmark)

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

2003-01-01

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

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

Science.gov (United States)

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

2011-05-01

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

Progress and status of the integral fast reactor (IFR) fuel cycle development

International Nuclear Information System (INIS)

Till, C.E.; Chang, Y.I.

1993-01-01

The Integral Fast Reactor (IFR) fuel cycle holds promise for substantial improvements in economics, diversion-resistance, and waste management. This paper discusses technical features of the IFR fuel cycle, its technical progress, the development status, and the future plans and directions. The Integral Fast Reactor (IFR) fuel cycle, is based on the use of a metallic fuel alloy (U-Pu-Zr) that permits use of an innovative method for processing of spent fuel. This method, a combination of pyrometallurgical and electrochemical processes, has been termed pyroprocessing. It offers the advantages of a simple, compact processing system and limited volumes of stabilized high-level wastes. This translates to an economically viable system that is likely to receive favorable public response, particularly when combined with the other attributes of the Integral Fast Reactor. Substantial progress has been made in the development of the IFR pyroprocessing method. A comprehensive demonstration of the process will soon begin at the Argonne National Laboratory Idaho site, using spent fuel from the EBR-II reactor. An important advantage of the IFR is its ability to recycle fuel in the process of power generation, extending fuel resources by a considerable amount and assuring the continued viability of nuclear power stations by reducing dependence on external fuel supplies. Pyroprocessing is the means whereby the recycle process is accomplished. It can also be applied to the recovery of fuel constituents from spent fuel generated in the process of operation of conventional light water reactor power plants, offering the means to recover the valuable fuel resources remaining in that material

Wabash River Integrated Methanol and Power Production from Clean Coal Technologies (IMPPCCT)

Energy Technology Data Exchange (ETDEWEB)

Conocophillips

2007-09-30

The Wabash River Integrated Methanol and Power Production from Clean Coal Technologies (IMPPCCT) project was established to evaluate integrated electrical power generation and methanol production through clean coal technologies. The project was under the leadership of ConocoPhillips Company (COP), after it acquired Gasification Engineering Corporation (GEC) and the E-Gas gasification technology from Global Energy Inc. in July 2003. The project has completed both Phase 1 and Phase 2 of development. The two project phases include the following: (1) Feasibility study and conceptual design for an integrated demonstration facility at SG Solutions LLC (SGS), previously the Wabash River Energy Limited, Gasification Facility located in West Terre Haute, Indiana, and for a fence-line commercial embodiment plant (CEP) operated at the Dow Chemical Company or Dow Corning Corporation chemical plant locations. (2) Research, development, and testing (RD&T) to define any technology gaps or critical design and integration issues. Phase 1 of this project was supported by a multi-industry team consisting of Air Products and Chemicals, Inc., The Dow Chemical Company, Dow Corning Corporation, Methanex Corporation, and Siemens Westinghouse Power Corporation, while Phase 2 was supported by Gas Technology Institute, TDA Research Inc., and Nucon International, Inc. The SGS integrated gasification combined cycle (IGCC) facility was designed, constructed, and operated under a project selected and co-funded under the Round IV of the United States Department of Energy's (DOE's) Clean Coal Technology Program. In this project, coal and/or other carbonaceous fuel feedstocks are gasified in an oxygen-blown, entrained-flow gasifier with continuous slag removal and a dry particulate removal system. The resulting product synthesis gas (syngas) is used to fuel a combustion turbine generator whose exhaust is integrated with a heat recovery steam generator to drive a refurbished steam turbine

Integrated corporate structure life cycle management modeling and organization

OpenAIRE

Naumenko, M.; Morozova, L.

2011-01-01

Integrated business structure presented as complementary pool of its participants skills. The methodical approach to integrated business structure life cycle modeling proposed. Recommendations of enterprises life cycles stages correlate are submitted.

CANDU combined cycles featuring gas-turbine engines

International Nuclear Information System (INIS)

Vecchiarelli, J.; Choy, E.; Peryoga, Y.; Aryono, N.A.

1998-01-01

In the present study, a power-plant analysis is conducted to evaluate the thermodynamic merit of various CANDU combined cycles in which continuously operating gas-turbine engines are employed as a source of class IV power restoration. It is proposed to utilize gas turbines in future CANDU power plants, for sites (such as Indonesia) where natural gas or other combustible fuels are abundant. The primary objective is to eliminate the standby diesel-generators (which serve as a backup supply of class III power) since they are nonproductive and expensive. In the proposed concept, the gas turbines would: (1) normally operate on a continuous basis and (2) serve as a reliable backup supply of class IV power (the Gentilly-2 nuclear power plant uses standby gas turbines for this purpose). The backup class IV power enables the plant to operate in poison-prevent mode until normal class IV power is restored. This feature is particularly beneficial to countries with relatively small and less stable grids. Thermodynamically, the advantage of the proposed concept is twofold. Firstly, the operation of the gas-turbine engines would directly increase the net (electrical) power output and the overall thermal efficiency of a CANDU power plant. Secondly, the hot exhaust gases from the gas turbines could be employed to heat water in the CANDU Balance Of Plant (BOP) and therefore improve the thermodynamic performance of the BOP. This may be accomplished via several different combined-cycle configurations, with no impact on the current CANDU Nuclear Steam Supply System (NSSS) full-power operating conditions when each gas turbine is at maximum power. For instance, the hot exhaust gases may be employed for feedwater preheating and steam reheating and/or superheating; heat exchange could be accomplished in a heat recovery steam generator, as in conventional gas-turbine combined-cycle plants. The commercially available GateCycle power plant analysis program was applied to conduct a

A Combined High and Low Cycle Fatigue Model for Life Prediction of Turbine Blades

Directory of Open Access Journals (Sweden)

Shun-Peng Zhu

2017-06-01

Full Text Available Combined high and low cycle fatigue (CCF generally induces the failure of aircraft gas turbine attachments. Based on the aero-engine load spectrum, accurate assessment of fatigue damage due to the interaction of high cycle fatigue (HCF resulting from high frequency vibrations and low cycle fatigue (LCF from ground-air-ground engine cycles is of critical importance for ensuring structural integrity of engine components, like turbine blades. In this paper, the influence of combined damage accumulation on the expected CCF life are investigated for turbine blades. The CCF behavior of a turbine blade is usually studied by testing with four load-controlled parameters, including high cycle stress amplitude and frequency, and low cycle stress amplitude and frequency. According to this, a new damage accumulation model is proposed based on Miner’s rule to consider the coupled damage due to HCF-LCF interaction by introducing the four load parameters. Five experimental datasets of turbine blade alloys and turbine blades were introduced for model validation and comparison between the proposed Miner, Manson-Halford, and Trufyakov-Kovalchuk models. Results show that the proposed model provides more accurate predictions than others with lower mean and standard deviation values of model prediction errors.

Maximisation of Combined Cycle Power Plant Efficiency

Directory of Open Access Journals (Sweden)

Janusz Kotowicz

2015-12-01

Full Text Available The paper presents concepts for increasing the efficiency of a modern combined cycle power plant. Improvement of gas turbine performance indicators as well as recovering heat from the air cooling the gas turbine’s flow system enable reaching gross electrical efficiencies of around 65%. Analyses for a wide range of compressor pressure ratios were performed. Operating characteristics were developed for the analysed combined cycle plant, for different types of open air cooling arrangements of the gas turbine’s expander: convective, transpiration and film.

Diagnostic system for combine cycle power plant

International Nuclear Information System (INIS)

Shimizu, Yujiro; Nomura, Masumi; Tanaka, Satoshi; Ito, Ryoji; Kita, Yoshiyuki

2000-01-01

We developed the Diagnostic System for Combined Cycle Power Plant which enables inexperienced operators as well as experienced operators to cope with abnormal conditions of Combined Cycle Power Plant. The features of this system are the Estimate of Emergency Level for Operation and the Prediction of Subsequent Abnormality, adding to the Diagnosis of Cause and the Operation Guidance. Moreover in this system, Diagnosis of Cause was improved by using our original method and support screens can be displayed for educational means in normal condition as well. (Authors)

A comparison of advanced heat recovery power cycles in a combined cycle for large ships

International Nuclear Information System (INIS)

Larsen, Ulrik; Sigthorsson, Oskar; Haglind, Fredrik

2014-01-01

Strong motivation exists within the marine sector to reduce fuel expenses and to comply with ever stricter emission regulations. Heat recovery can address both of these issues. The ORC (organic Rankine cycle), the Kalina cycle and the steam Rankine cycle have received the majority of the focus in the literature. In the present work we compare these cycles in a combined cycle application with a large marine two-stroke diesel engine. We present an evaluation of the efficiency and the environmental impact, safety concerns and practical aspects of each of the cycles. A previously validated numerical engine model is combined with a turbocharger model and bottoming cycle models written in Matlab. Genetic algorithm optimisation results suggest that the Kalina cycle possess no significant advantages compared to the ORC or the steam cycle. While contributing to very high efficiencies, the organic working fluids possess high global warming potentials and hazard levels. It is concluded that the ORC has the greatest potential for increasing the fuel efficiency, and the combined cycle offers very high thermal efficiency. While being less efficient, the steam cycle has the advantages of being well proven, harmless to the environment as well as being less hazardous in comparison. - Highlights: • We compare steam, ORC (organic Rankine cycle) and Kalina cycles for waste heat recovery in marine engines. • We evaluate the efficiency and important qualitative differences. • The Kalina cycle presents no apparent advantages. • The steam cycle is well known, harmless and has a high efficiency. • The ORC has the highest efficiency but also important drawbacks

Parametric analysis and optimization for a combined power and refrigeration cycle

International Nuclear Information System (INIS)

Wang Jiangfeng; Dai Yiping; Gao Lin

2008-01-01

A combined power and refrigeration cycle is proposed, which combines the Rankine cycle and the absorption refrigeration cycle. This combined cycle uses a binary ammonia-water mixture as the working fluid and produces both power output and refrigeration output simultaneously with only one heat source. A parametric analysis is conducted to evaluate the effects of thermodynamic parameters on the performance of the combined cycle. It is shown that heat source temperature, environment temperature, refrigeration temperature, turbine inlet pressure, turbine inlet temperature, and basic solution ammonia concentration have significant effects on the net power output, refrigeration output and exergy efficiency of the combined cycle. A parameter optimization is achieved by means of genetic algorithm to reach the maximum exergy efficiency. The optimized exergy efficiency is 43.06% under the given condition

Business Cycle Synchronization and Regional Integration

OpenAIRE

Fiess, Norbert

2007-01-01

Deeper trade integration between Central America and the United States, as envisaged under the Central American Free Trade Agreement, is likely to lead to closer links between Central American and U.S. business cycles. This article assesses the degree of business cycle synchronization between Central America and the United States—relevant not only for a better understanding of the influence of important trading partners on the business cycle fluctuations in the domestic economy but for evalua...

Heat Integration of the Water-Gas Shift Reaction System for Carbon Sequestration Ready IGCC Process with Chemical Looping

Energy Technology Data Exchange (ETDEWEB)

Juan M. Salazara; Stephen E. Zitney; Urmila M. Diwekara

2010-01-01

Integrated gasification combined cycle (IGCC) technology has been considered as an important alternative for efficient power systems that can reduce fuel consumption and CO2 emissions. One of the technological schemes combines water-gas shift reaction and chemical-looping combustion as post gasification techniques in order to produce sequestration-ready CO2 and potentially reduce the size of the gas turbine. However, these schemes have not been energetically integrated and process synthesis techniques can be applied to obtain an optimal flowsheet. This work studies the heat exchange network synthesis (HENS) for the water-gas shift reaction train employing a set of alternative designs provided by Aspen energy analyzer (AEA) and combined in a process superstructure that was simulated in Aspen Plus (AP). This approach allows a rigorous evaluation of the alternative designs and their combinations avoiding all the AEA simplifications (linearized models of heat exchangers). A CAPE-OPEN compliant capability which makes use of a MINLP algorithm for sequential modular simulators was employed to obtain a heat exchange network that provided a cost of energy that was 27% lower than the base case. Highly influential parameters for the pos gasification technologies (i.e. CO/steam ratio, gasifier temperature and pressure) were calculated to obtain the minimum cost of energy while chemical looping parameters (oxidation and reduction temperature) were ensured to be satisfied.

Thermodynamic performance optimization of a combined power/cooling cycle

International Nuclear Information System (INIS)

Pouraghaie, M.; Atashkari, K.; Besarati, S.M.; Nariman-zadeh, N.

2010-01-01

A combined thermal power and cooling cycle has already been proposed in which thermal energy is used to produce work and to generate a sub-ambient temperature stream that is suitable for cooling applications. The cycle uses ammonia-water mixture as working fluid and is a combination of a Rankine cycle and absorption cycle. The very high ammonia vapor concentration, exiting turbine under certain operating conditions, can provide power output as well as refrigeration. In this paper, the goal is to employ multi-objective algorithms for Pareto approach optimization of thermodynamic performance of the cycle. It has been carried out by varying the selected design variables, namely, turbine inlet pressure (P h ), superheater temperature (T superheat ) and condenser temperature (T condensor ). The important conflicting thermodynamic objective functions that have been considered in this study are turbine work (w T ), cooling capacity (q cool ) and thermal efficiency (η th ) of the cycle. It is shown that some interesting and important relationships among optimal objective functions and decision variables involved in the combined cycle can be discovered consequently. Such important relationships as useful optimal design principles would have not been obtained without the use of a multi-objective optimization approach.

Analysis and performance assessment of a new solar-based multigeneration system integrated with ammonia fuel cell and solid oxide fuel cell-gas turbine combined cycle

Science.gov (United States)

Siddiqui, Osamah; Dincer, Ibrahim

2017-12-01

In the present study, a new solar-based multigeneration system integrated with an ammonia fuel cell and solid oxide fuel cell-gas turbine combined cycle to produce electricity, hydrogen, cooling and hot water is developed for analysis and performance assessment. In this regard, thermodynamic analyses and modeling through both energy and exergy approaches are employed to assess and evaluate the overall system performance. Various parametric studies are conducted to study the effects of varying system parameters and operating conditions on the energy and exergy efficiencies. The results of this study show that the overall multigeneration system energy efficiency is obtained as 39.1% while the overall system exergy efficiency is calculated as 38.7%, respectively. The performance of this multigeneration system results in an increase of 19.3% in energy efficiency as compared to single generation system. Furthermore, the exergy efficiency of the multigeneration system is 17.8% higher than the single generation system. Moreover, both energy and exergy efficiencies of the solid oxide fuel cell-gas turbine combined cycle are determined as 68.5% and 55.9% respectively.

A combined cycle utilizing LNG and low-temperature solar energy

International Nuclear Information System (INIS)

Rao, Wen-Ji; Zhao, Liang-Ju; Liu, Chao; Zhang, Mo-Geng

2013-01-01

This paper has proposed a combined cycle, in which low-temperature solar energy and cold energy of liquefied natural gas (LNG) can be effectively utilized together. Comparative analysis based on a same net work output between the proposed combined cycle and separated solar ORC and LNG vapor system has been done. The results show that, for the combined cycle, a decrease of nearly 82.2% on the area of solar collector is obtained and the area of heat exchanger decreases by 31.7%. Moreover, exergy efficiency is higher than both two separated systems. This work has also dealt with the thermodynamic analyses for the proposed cycle. The results show that R143a followed by propane and propene emerges as most suitable fluid. Moreover, with a regenerator added in the cycle, performance improvement is obtained for the reduction on area of solar collector and increase on system efficiency and exergy efficiency. -- Highlights: • A combined cycle utilizing low-temperature solar energy and LNG together is proposed. • Five objection functions are used to decide the best working fluids. • Cycle with a regenerator has good performance

Parametric analysis for a new combined power and ejector-absorption refrigeration cycle

International Nuclear Information System (INIS)

Wang Jiangfeng; Dai Yiping; Zhang Taiyong; Ma Shaolin

2009-01-01

A new combined power and ejector-absorption refrigeration cycle is proposed, which combines the Rankine cycle and the ejector-absorption refrigeration cycle, and could produce both power output and refrigeration output simultaneously. This combined cycle, which originates from the cycle proposed by authors previously, introduces an ejector between the rectifier and the condenser, and provides a performance improvement without greatly increasing the complexity of the system. A parametric analysis is conducted to evaluate the effects of the key thermodynamic parameters on the cycle performance. It is shown that heat source temperature, condenser temperature, evaporator temperature, turbine inlet pressure, turbine inlet temperature, and basic solution ammonia concentration have significant effects on the net power output, refrigeration output and exergy efficiency of the combined cycle. It is evident that the ejector can improve the performance of the combined cycle proposed by authors previously.

Particle Distribution in a Fixed Bed Down Draft Wood Gasifier

DEFF Research Database (Denmark)

Hindsgaul, Claus

2005-01-01

Char particle samples were collected from six distances above the grate in a fixed bed of a down draft biomass gasifier. Each sample was separated into twelve size fractions by screening through standard sieves in order to determine the local particle size distribution. The ash contents of each...

Advanced modeling and simulation of integrated gasification combined cycle power plants with CO2-capture

International Nuclear Information System (INIS)

Rieger, Mathias

2014-01-01

The objective of this thesis is to provide an extensive description of the correlations in some of the most crucial sub-processes for hard coal fired IGCC with carbon capture (CC-IGCC). For this purpose, process simulation models are developed for four industrial gasification processes, the CO-shift cycle, the acid gas removal unit, the sulfur recovery process, the gas turbine, the water-/steam cycle and the air separation unit (ASU). Process simulations clarify the influence of certain boundary conditions on plant operation, performance and economics. Based on that, a comparative benchmark of CC-IGCC concepts is conducted. Furthermore, the influence of integration between the gas turbine and the ASU is analyzed in detail. The generated findings are used to develop an advanced plant configuration with improved economics. Nevertheless, IGCC power plants with carbon capture are not found to be an economically efficient power generation technology at present day boundary conditions.

Optimization of Biomass-Fuelled Combined Cooling, Heating and Power (CCHP Systems Integrated with Subcritical or Transcritical Organic Rankine Cycles (ORCs

Directory of Open Access Journals (Sweden)

Daniel Maraver

2014-04-01

Full Text Available This work is focused on the thermodynamic optimization of Organic Rankine Cycles (ORCs, coupled with absorption or adsorption cooling units, for combined cooling heating and power (CCHP generation from biomass combustion. Results were obtained by modelling with the main aim of providing optimization guidelines for the operating conditions of these types of systems, specifically the subcritical or transcritical ORC, when integrated in a CCHP system to supply typical heating and cooling demands in the tertiary sector. The thermodynamic approach was complemented, to avoid its possible limitations, by the technological constraints of the expander, the heat exchangers and the pump of the ORC. The working fluids considered are: n-pentane, n-heptane, octamethyltrisiloxane, toluene and dodecamethylcyclohexasiloxane. In addition, the energy and environmental performance of the different optimal CCHP plants was investigated. The optimal plant from the energy and environmental point of view is the one integrated by a toluene recuperative ORC, although it is limited to a development with a turbine type expander. Also, the trigeneration plant could be developed in an energy and environmental efficient way with an n-pentane recuperative ORC and a volumetric type expander.

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-11-01

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

Biomass Gasification Combined Cycle

Energy Technology Data Exchange (ETDEWEB)

Judith A. Kieffer

2000-07-01

Gasification combined cycle continues to represent an important defining technology area for the forest products industry. The ''Forest Products Gasification Initiative'', organized under the Industry's Agenda 2020 technology vision and supported by the DOE ''Industries of the Future'' program, is well positioned to guide these technologies to commercial success within a five-to ten-year timeframe given supportive federal budgets and public policy. Commercial success will result in significant environmental and renewable energy goals that are shared by the Industry and the Nation. The Battelle/FERCO LIVG technology, which is the technology of choice for the application reported here, remains of high interest due to characteristics that make it well suited for integration with the infrastructure of a pulp production facility. The capital cost, operating economics and long-term demonstration of this technology area key input to future economically sustainable projects and must be verified by the 200 BDT/day demonstration facility currently operating in Burlington, Vermont. The New Bern application that was the initial objective of this project is not currently economically viable and will not be implemented at this time due to several changes at and around the mill which have occurred since the inception of the project in 1995. The analysis shows that for this technology, and likely other gasification technologies as well, the first few installations will require unique circumstances, or supportive public policies, or both to attract host sites and investors.

Integrated fuel-cycle models for fast breeder reactors

International Nuclear Information System (INIS)

Ott, K.O.; Maudlin, P.J.

1981-01-01

Breeder-reactor fuel-cycle analysis can be divided into four different areas or categories. The first category concerns questions about the spatial variation of the fuel composition for single loading intervals. Questions of the variations in the fuel composition over several cycles represent a second category. Third, there is a need for a determination of the breeding capability of the reactor. The fourth category concerns the investigation of breeding and long-term fuel logistics. Two fuel-cycle models used to answer questions in the third and fourth area are presented. The space- and time-dependent actinide balance, coupled with criticality and fuel-management constraints, is the basis for both the Discontinuous Integrated Fuel-Cycle Model and the Continuous Integrated Fuel-Cycle Model. The results of the continuous model are compared with results obtained from detailed two-dimensional space and multigroup depletion calculations. The continuous model yields nearly the same results as the detailed calculation, and this is with a comparatively insignificant fraction of the computational effort needed for the detailed calculation. Thus, the integrated model presented is an accurate tool for answering questions concerning reactor breeding capability and long-term fuel logistics. (author)

Wabash Valley Integrated Gasification Combined Cycle, Coal to Fischer Tropsch Jet Fuel Conversion Study

Energy Technology Data Exchange (ETDEWEB)

Shah, Jayesh [Lummus Technology Inc., Bloomfield, NJ (United States); Hess, Fernando [Lummus Technology Inc., Bloomfield, NJ (United States); Horzen, Wessel van [Lummus Technology Inc., Bloomfield, NJ (United States); Williams, Daniel [Lummus Technology Inc., Bloomfield, NJ (United States); Peevor, Andy [JM Davy, London (United Kingdom); Dyer, Andy [JM Davy, London (United Kingdom); Frankel, Louis [Canonsburgh, PA (United States)

2016-06-01

This reports examines the feasibility of converting the existing Wabash Integrated Gasification Combined Cycle (IGCC) plant into a liquid fuel facility, with the goal of maximizing jet fuel production. The fuels produced are required to be in compliance with Section 526 of the Energy Independence and Security Act of 2007 (EISA 2007 §526) lifecycle greenhouse gas (GHG) emissions requirements, so lifecycle GHG emissions from the fuel must be equal to or better than conventional fuels. Retrofitting an existing gasification facility reduces the technical risk and capital costs associated with a coal to liquids project, leading to a higher probability of implementation and more competitive liquid fuel prices. The existing combustion turbine will continue to operate on low cost natural gas and low carbon fuel gas from the gasification facility. The gasification technology utilized at Wabash is the E-Gas™ Technology and has been in commercial operation since 1995. In order to minimize capital costs, the study maximizes reuse of existing equipment with minimal modifications. Plant data and process models were used to develop process data for downstream units. Process modeling was utilized for the syngas conditioning, acid gas removal, CO₂ compression and utility units. Syngas conversion to Fischer Tropsch (FT) liquids and upgrading of the liquids was modeled and designed by Johnson Matthey Davy Technologies (JM Davy). In order to maintain the GHG emission profile below that of conventional fuels, the CO₂ from the process must be captured and exported for sequestration or enhanced oil recovery. In addition the power utilized for the plant’s auxiliary loads had to be supplied by a low carbon fuel source. Since the process produces a fuel gas with sufficient energy content to power the plant’s loads, this fuel gas was converted to hydrogen and exported to the existing gas turbine for low carbon power production. Utilizing low carbon fuel gas and

Energy Conversion Alternatives Study (ECAS)

Science.gov (United States)

1977-01-01

ECAS compared various advanced energy conversion systems that can use coal or coal-derived fuels for baseload electric power generation. It was conducted in two phases. Phase 1 consisted of parametric studies. From these results, 11 concepts were selected for further study in Phase 2. For each of the Phase 2 systems and a common set of ground rules, performance, cost, environmental intrusion, and natural resource requirements were estimated. In addition, the contractors defined the state of the associated technology, identified the advances required, prepared preliminary research and development plans, and assessed other factors that would affect the implementation of each type of powerplant. The systems studied in Phase 2 include steam systems with atmospheric- and pressurized-fluidized-bed boilers; combined cycle gas turbine/steam systems with integrated gasifiers or fired by a semiclean, coal derived fuel; a potassium/steam system with a pressurized-fluidized-bed boiler; a closed-cycle gas turbine/organic system with a high-temperature, atmospheric-fluidized-bed furnace; a direct-coal-fired, open- cycle magnetohydrodynamic/steam system; and a molten-carbonate fuel cell/steam system with an integrated gasifier. The sensitivity of the results to changes in the ground rules and the impact of uncertainties in capital cost estimates were also examined.

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-09-30

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

Comparative performance analysis of combined-cycle pulse detonation turbofan engines (PDTEs

Directory of Open Access Journals (Sweden)

Sudip Bhattrai

2013-09-01

Full Text Available Combined-cycle pulse detonation engines are promising contenders for hypersonic propulsion systems. In the present study, design and propulsive performance analysis of combined-cycle pulse detonation turbofan engines (PDTEs is presented. Analysis is done with respect to Mach number at two consecutive modes of operation: (1 Combined-cycle PDTE using a pulse detonation afterburner mode (PDA-mode and (2 combined-cycle PDTE in pulse detonation ramjet engine mode (PDRE-mode. The performance of combined-cycle PDTEs is compared with baseline afterburning turbofan and ramjet engines. The comparison of afterburning modes is done for Mach numbers from 0 to 3 at 15.24 km altitude conditions, while that of pulse detonation ramjet engine (PDRE is done for Mach 1.5 to Mach 6 at 18.3 km altitude conditions. The analysis shows that the propulsive performance of a turbine engine can be greatly improved by replacing the conventional afterburner with a pulse detonation afterburner (PDA. The PDRE also outperforms its ramjet counterpart at all flight conditions considered herein. The gains obtained are outstanding for both the combined-cycle PDTE modes compared to baseline turbofan and ramjet engines.

Effects of upgrading systems on energy conversion efficiency of a gasifier - fuel cell - gas turbine power plant

International Nuclear Information System (INIS)

Pedrazzi, Simone; Allesina, Giulio; Tartarini, Paolo

2016-01-01

Highlights: • An advanced gasifier-SOFC-MGT system is modeled. • An overall electrical efficiency of 32.81% is reached. • Influence of all the sub-system modeled on the power plant efficiency is discussed. • Compression storage of syngas is taken into account. - Abstract: This work focuses on a DG-SOFC-MGT (downdraft gasifier - solid oxide fuel cell - micro gas turbine) power plant for electrical energy production and investigates two possible performance-upgrading systems: polyphenylene oxide (PPO) membrane and zeolite filters. The first is used to produce oxygen-enriched air used in the reactor, while the latter separates the CO_2 content from the syngas. In order to prevent power plant shutdowns during the gasifier reactor scheduled maintenance, the system is equipped with a gas storage tank. The generation unit consists of a SOFC-MGT system characterized by higher electrical efficiency when compared to conventional power production technology (IC engines, ORC and EFGT). Poplar wood chips with 10% of total moisture are used as feedstock. Four different combinations with and without PPO and zeolite filtrations are simulated and discussed. One-year energy and power simulation were used as basis for comparison between all the cases analyzed. The modeling of the gasification reactions gives results consistent with literature about oxygen-enriched processes. Results showed that the highest electrical efficiency obtained is 32.81%. This value is reached by the power plant equipped only with PPO membrane filtration. Contrary to the PPO filtering, zeolite filtration does not increase the SOFC-MGT unit performance while it affects the energy balance with high auxiliary electrical consumption. This solution can be considered valuable only for future work coupling a CO_2 sequestration system to the power plant.

Technical evaluation of biomass gasification technology integrated with combined cycle using bagasse as fuel; Avaliacao tecnica da tecnologia de gaseificacao de biomassa integrada a ciclos combinados utilizando bagaco como combustivel

Energy Technology Data Exchange (ETDEWEB)

Ortiz, Pablo Silva; Venturini, Osvaldo Jose; Lora, Electo Silva [Universidade Federal de Itajuba (NEST/UNIFEI), MG (Brazil). Nucleo de Excelencia em Geracao Termeletrica e Distribuida], email: pablo.silvaortiz@gmail.com; Campo, Andres Perez [Universidade Automona de Bucaramanga (UNAB) (Colombia). Fac. de Engenharia Fisico- Mecanica, Engenharia em Energia

2010-07-01

Biomass Integrated Gasification Combined Cycle (BIGCC) was identified as an advanced technology with potential to be competitive for electricity generation. The BIGCC technology uses biomass and the sub products of some industrial sectors processing, like sugar cane, as feedstock. The current Brazilian energy matrix is mainly based on renewable generation sources, making it important to assess these gasification technologies in the production of sugar, ethanol and electricity. In this work, a technical evaluation of the technologies incorporated in BIGCC power plants is done: the gasification process and the combined cycle power plant. On the other hand, the generated costs of these systems are analyzed, and the potential for implementation in Brazil plants from sugar cane bagasse is studied, in which a 10% increase in efficiency is obtained. (author)

Integrated methanol synthesis

International Nuclear Information System (INIS)

Jaeger, W.

1982-01-01

This invention concerns a plant for methanol manufacture from gasified coal, particularly using nuclear power. In order to reduce the cost of the hydrogen circuits, the methanol synthesis is integrated in the coal gasification plant. The coal used is gasified with hydration by means of hydrogen and the crude gas emerging, after cooling and separating the carbon dioxide and hydrogen sulphide, is mixed with the synthetic gas leaving the methane cracking furnace. This mixture is taken to the methanol synthesis and more than 90% is converted into methanol in one pass. The gas mixture remaning after condensation and separation of methanol is decomposed into three fractions in low temperature gas decomposition with a high proportion of unconverted carbon monoxide. The flow of methane is taken to the cracking furnace with steam, the flow of hydrogen is taken to the hydrating coal gasifier, and the flow of carbon monoxide is taken to the methanol synthesis. The heat required for cracking the methane can either be provided by a nuclear reactor or by the coke left after hydrating gasification. (orig./RB) [de

Novel integrated gasification combined cycles with a carbon dioxide recovery option

Energy Technology Data Exchange (ETDEWEB)

Lawton, J.

1997-08-01

Two novel combined cycle configurations offering potential to reduce the cost of electricity from coal-fired IGCCs were investigated - one based on the use of flue gas recycling with heat recovery to the recycled stream, the other, aimed at removing carbon dioxide, using flue gas recycle and heat recovery but with oxygen as the oxidant in the gas turbine. The investigation included the use of fuels other than coal. It was found that gasification efficiency was increased by use of a coal/Orimulsion slurry. Flue gas recycling at 1 bar for the industrial gas turbine offered a gain of about 0.4 percentage points. In a standard IGCC the industrial gas turbine showed an advantage of 1.5 percentage points over the aero-derived machine. The least cost electricity with CO{sub 2} removal was achieved using an oxygen-fed industrial gas turbine with flue gas recycling and recovery. Several recommendations are made for further studies to reduce costs of electricity production. 11 refs., 3 figs., 5 tabs., 1 app.

Combined compressed air storage-low BTU coal gasification power plant

Science.gov (United States)

Kartsounes, George T.; Sather, Norman F.

1979-01-01

An electrical generating power plant includes a Compressed Air Energy Storage System (CAES) fueled with low BTU coal gas generated in a continuously operating high pressure coal gasifier system. This system is used in coordination with a continuously operating main power generating plant to store excess power generated during off-peak hours from the power generating plant, and to return the stored energy as peak power to the power generating plant when needed. The excess coal gas which is produced by the coal gasifier during off-peak hours is stored in a coal gas reservoir. During peak hours the stored coal gas is combined with the output of the coal gasifier to fuel the gas turbines and ultimately supply electrical power to the base power plant.

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

Directory of Open Access Journals (Sweden)

Adi Surjosatyo

2014-01-01

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

Exergy analysis of a combined power and cooling cycle

International Nuclear Information System (INIS)

Fontalvo, Armando; Pinzon, Horacio; Duarte, Jorge; Bula, Antonio; Quiroga, Arturo Gonzalez; Padilla, Ricardo Vasquez

2013-01-01

This paper presents a comprehensive exergy analysis of a combined power and cooling cycle which combines a Rankine and absorption refrigeration cycle by using ammonia–water mixture as working fluid. A thermodynamic model was developed in Matlab ® to find out the effect of pressure ratio, ammonia mass fraction at the absorber and turbine efficiency on the total exergy destruction of the cycle. The contribution of each cycle component on the total exergy destruction was also determined. The results showed that total exergy destruction decreases when pressure ratio increases, and reaches a maximum at x ≈ 0.5, when ammonia mass fraction is varied at absorber. Also, it was found that the absorber, the boiler and the turbine had the major contribution to the total exergy destruction of the cycle, and the increase of the turbine efficiency reduces the total exergy destruction. The effect of rectification cooling source (external and internal) on the cycle output was investigated, and the results showed that internal rectification cooling reduces the total exergy destruction of the cycle. Finally, the effect of the presence or absence of the superheater after the rectification process was determined and it was obtained that the superheated condition reduces the exergy destruction of the cycle at high turbine efficiency values. Highlights: • A parametric exergy analysis of a combined power and cooling cycle is performed. • Two scenarios for rectifier cooling (internal and external) were studied. • Internal cooling source is more exergetic efficient than external cooling source. • The absorber and boiler have the largest total exergy destruction. • Our results show that the superheater reduces the exergy destruction of the cycle

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-12-31

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

Combined Turbine and Cycle Optimization for Organic Rankine Cycle Power Systems—Part A

DEFF Research Database (Denmark)

Meroni, Andrea; La Seta, Angelo; Andreasen, Jesper Graa

2016-01-01

Axial-flow turbines represent a well-established technology for a wide variety of power generation systems. Compactness, flexibility, reliability and high efficiency have been key factors for the extensive use of axial turbines in conventional power plants and, in the last decades, in organic...... Rankine cycle power systems. In this two-part paper, an overall cycle model and a model of an axial turbine were combined in order to provide a comprehensive preliminary design of the organic Rankine cycle unit, taking into account both cycle and turbine optimal designs. Part A presents the preliminary...

Air bottoming cycle, an alternative to combined cycles. Final report

Energy Technology Data Exchange (ETDEWEB)

Kaikko, J. [Royal Inst. of Techn., Stockholm (Sweden). Dept. of Energy Technology

2001-10-01

In this work, the idea of Air Bottoming Cycle (ABC) has been studied. The objectives for the work have been to establish an understanding of the concept for power and heat generation as well as to find - if possible - feasible concepts for future use in the Swedish energy system. Combined cycle in power generation is an established technology. In the conventional combined cycle, a gas turbine works as a topping cycle together with the steam (Rankine) bottoming cycle. In the ABC the steam bottoming cycle is replaced with a gas turbine (Brayton) bottoming cycle having air as a working fluid. The two gas turbines are thermally connected over a gas-to-gas heat exchanger. This concept promises savings in weight and cost, as well as operating benefits, compared to the Rankine bottoming technology. The ABC has been modelled using a heat balance program, and a parametric study for the concept optimisation as well as for off-design analysis has been performed. Performance of the ABC has been compared to other, established technologies. A preliminary economic evaluation has been made. As a result of the study, it is clarified that the Rankine bottoming cycle with steam remains superior to the ABC as regards electrical efficiency in the medium and large power scale. For small-scale applications (<10 MW{sub e}) where the thermodynamic advantage of the Rankine cycle is not dominating any longer and its economy is burdened by the heavy investment structure, the ABC becomes the better alternative for energy utilisation. A preliminary economic evaluation shows that (at energy prices autumn 2000) the ABC is at the same level as the comparable small-scale cogeneration installations. Due to high power-to-heat ratio however, higher electricity prices will favour the ABC. One interesting feature of the ABC is that about 50% of the dissipated low-value heat from the cycle is carried by clean (sterile) air at the temperature around 200 deg C. This air can be utilised for space heating or

Energetic analysis of a syngas-fueled chemical-looping combustion combined cycle with integration of carbon dioxide sequestration

International Nuclear Information System (INIS)

Jiménez Álvaro, Ángel; Paniagua, Ignacio López; Fernández, Celina González; Carlier, Rafael Nieto; Martín, Javier Rodríguez

2014-01-01

Chemical-looping combustion for power generation has significant advantages over conventional combustion. Mainly, it allows an integration of CO 2 capture in the power plant without energy penalty; secondly, a less exergy destruction in the combustion chemical transformation is achieved, leading to a greater overall thermal efficiency. Most efforts have been devoted to systems based on methane as a fuel, although other systems for alternative fuels have can be proposed. This paper focus on the study of the energetic performance of this concept of combustion in a gas turbine combined cycle when synthesis gas is used as fuel. After optimization of some thermodynamic parameters of the cycle, the power plant performance is evaluated under diverse working conditions and compared to a conventional gas turbine system. Energy savings related with CO 2 capture and storage have been quantified. The overall efficiency increase is found to be significant, reaching values of around 5% (even more in some cases). In order to analyze the influence of syngas composition on the results, different H 2 -content fuels are considered. In a context of real urgency to reduce green house gas emissions, this work is intended to contribute to the conceptual development of highly efficient alternative power generation systems. - Highlights: • Analysis of the energetic performance of a CLC (chemical-looping combustion) gas turbine system is done. • Syngas as fuel and iron oxides as oxygen carrier are considered. • Different H 2 -content syngas are under study. • Energy savings accounting CO 2 sequestration and storage are quantified. • A significant increase on thermal efficiency of about 5–6% is found

Thermodynamic analysis of heat recovery steam generator in combined cycle power plant

Directory of Open Access Journals (Sweden)

Ravi Kumar Naradasu

2007-01-01

Full Text Available Combined cycle power plants play an important role in the present energy sector. The main challenge in designing a combined cycle power plant is proper utilization of gas turbine exhaust heat in the steam cycle in order to achieve optimum steam turbine output. Most of the combined cycle developers focused on the gas turbine output and neglected the role of the heat recovery steam generator which strongly affects the overall performance of the combined cycle power plant. The present paper is aimed at optimal utilization of the flue gas recovery heat with different heat recovery steam generator configurations of single pressure and dual pressure. The combined cycle efficiency with different heat recovery steam generator configurations have been analyzed parametrically by using first law and second law of thermodynamics. It is observed that in the dual cycle high pressure steam turbine pressure must be high and low pressure steam turbine pressure must be low for better heat recovery from heat recovery steam generator.

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 8: Open-cycle MHD. [energy conversion efficiency and design analysis of electric power plants employing magnetohydrodynamics

Science.gov (United States)

Hoover, D. Q.

1976-01-01

Electric power plant costs and efficiencies are presented for three basic open-cycle MHD systems: (1) direct coal fired system, (2) a system with a separately fired air heater, and (3) a system burning low-Btu gas from an integrated gasifier. Power plant designs were developed corresponding to the basic cases with variation of major parameters for which major system components were sized and costed. Flow diagrams describing each design are presented. A discussion of the limitations of each design is made within the framework of the assumptions made.

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Gas fired combined cycle plant in Singapore: energy use, GWP and cost-a life cycle approach

International Nuclear Information System (INIS)

Kannan, R.; Leong, K.C.; Osman, Ramli; Ho, H.K.; Tso, C.P.

2005-01-01

A life cycle assessment was performed to quantify the non-renewable (fossil) energy use and global warming potential (GWP) in electricity generation from a typical gas fired combined cycle power plant in Singapore. The cost of electricity generation was estimated using a life cycle cost analysis (LCCA) tool. The life cycle assessment (LCA) of a 367.5 MW gas fired combined cycle power plant operating in Singapore revealed that hidden processes consume about 8% additional energy in addition to the fuel embedded energy, and the hidden GWP is about 18%. The natural gas consumed during the operational phase accounted for 82% of the life cycle cost of electricity generation. An empirical relation between plant efficiency and life cycle energy use and GWP in addition to a scenario for electricity cost with varying gas prices and plant efficiency have been established

Computer simulation of a downdraft wood gasifier for tea drying

Energy Technology Data Exchange (ETDEWEB)

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

2003-10-01

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

Integration Research on Gas Turbine and Tunnel Kiln Combined System

Science.gov (United States)

Shi, Hefei; Ma, Liangdong; Liu, Mingsheng

2018-04-01

Through the integrated modeling of gas turbine and tunnel kiln combined system, a thermodynamic calculation method of combined system is put forward, and the combined system operation parameters are obtained. By this method, the optimization of the combined system is analyzed and the optimal configuration of the gas turbine is calculated. At the same time, the thermal efficiency of the combined system is analyzed, and the heat distribution and thermal efficiency of the system before and after the improvement are explained. Taking the 1500 kg/h ceramic production as an example, pointed out that if the tunnel kiln has a gas turbine with a power of 342 kw. The amount of electricity of the combined system that produced per unit volume of the fuel which consumes more than it used to will be 7.19 kwh, the system thermal efficiency will reach 57.49%, which higher than the individual gas turbine’s cycle thermal efficiency 20% at least.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

MHD Integrated Topping Cycle Project

Energy Technology Data Exchange (ETDEWEB)

1992-01-01

The overall objective of the project is to design and construct prototypical hardware for an integrated MHD topping cycle, and conduct long duration proof-of-concept tests of integrated system at the US DOE Component Development and Integration Facility in Butte, Montana. The results of the long duration tests will augment the existing engineering design data base on MHD power train reliability, availability, maintainability, and performance, and will serve as a basis for scaling up the topping cycle design to the next level of development, an early commercial scale power plant retrofit. The components of the MHD power train to be designed, fabricated, and tested include: A slagging coal combustor with a rated capacity of 50 MW thermal input, capable of operation with an Eastern (Illinois {number sign}6) or Western (Montana Rosebud) coal, a segmented supersonic nozzle, a supersonic MHD channel capable of generating at least 1.5 MW of electrical power, a segmented supersonic diffuser section to interface the channel with existing facility quench and exhaust systems, a complete set of current control circuits for local diagonal current control along the channel, and a set of current consolidation circuits to interface the channel with the existing facility inverter.

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.

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Air bottoming cycle, an alternative to combined cycles. Final report

Energy Technology Data Exchange (ETDEWEB)

Kaikko, J. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Energy Technology

2002-02-01

In this work, the idea of Air Bottoming Cycle (ABC) has been studied. The objectives for the work have been to establish an understanding of the concept for power and heat generation as well as to find - if possible - feasible concepts for future use in the Swedish energy system. Combined cycle in power generation is an established technology. In the conventional combined cycle, a gas turbine works as a topping cycle together with the steam (Rankine) bottoming cycle. In the ABC the steam bottoming cycle is replaced with a gas turbine (Brayton) bottoming cycle having air as a working fluid. The two gas turbines are thermally connected over a gas-to-gas heat exchanger. This concept promises savings in weight and cost, as well as operating benefits, compared to the Rankine bottoming technology. The ABC has been modelled using a heat balance program, and a parametric study for the concept optimisation as well as for off-design analysis has been performed. Performance of the ABC has been compared to other, established technologies. A preliminary economic evaluation has been made. As a result of the study, it is clarified that the Rankine bottoming cycle with steam remains superior to the ABC as regards electrical efficiency in the medium and large power scale. For small-scale applications (<10 MW{sub e}) where the thermodynamic advantage of the Rankine cycle is not dominating any longer and its economy is burdened by the heavy investment structure, the ABC becomes the better alternative for energy utilisation. A preliminary economic evaluation shows that (at energy prices autumn 2000) the ABC is at the same level as the comparable small-scale cogeneration installations. Due to high power-to-heat ratio however, higher electricity prices will favour the ABC. One interesting feature of the ABC is that about 50% of the dissipated low-value heat from the cycle is carried by clean (sterile) air at the temperature around 200 deg C. This air can be utilised for space heating or

[Tampa Electric Company IGCC project]. 1996 DOE annual technical report, January--December 1996

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

Tampa Electric Company`s Polk Power Station Unit 1 (PPS-1) Integrated Gasification Combined Cycle (IGCC) demonstration project uses a Texaco pressurized, oxygen-blown, entrained-flow coal gasifier to convert approximately 2,000 tons per day of coal to syngas. The gasification plant is coupled with a combined cycle power block to produce a net 250 MW electrical power output. Coal is slurried in water, combined with 95% pure oxygen from an air separation unit, and sent to the gasifier to produce a high temperature, high pressure, medium-Btu syngas with a heat content of about 250 BTUs/cf (HHV). The syngas then flows through a high temperature heat recovery unit which cools the syngas prior to its entering the cleanup systems. Molten coal ash flows from the bottom of the high temperature heat recovery unit into a water-filled quench chamber where it solidifies into a marketable slag by-product. Approximately 10% of the raw, hot syngas at 900 F is designed to pass through an intermittently moving bed of metal-oxide sorbent which removes sulfur-bearing compounds from the syngas. PPS-1 will be the first unit in the world to demonstrate this advanced metal oxide hot gas desulfurization technology on a commercial unit. The emphasis during 1996 centered around start-up activities.

Simulation of a combined-cycle engine

Science.gov (United States)

Vangerpen, Jon

1991-01-01

A FORTRAN computer program was developed to simulate the performance of combined-cycle engines. These engines combine features of both gas turbines and reciprocating engines. The computer program can simulate both design point and off-design operation. Widely varying engine configurations can be evaluated for their power, performance, and efficiency as well as the influence of altitude and air speed. Although the program was developed to simulate aircraft engines, it can be used with equal success for stationary and automative applications.

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

Science.gov (United States)

Sweeney, Daniel Joseph

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

Sampling of contaminants from product gases of biomass gasifiers

Energy Technology Data Exchange (ETDEWEB)

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

1998-12-01

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

Technical And Economical FACTIBILITY To Apply A Combined Cycle

International Nuclear Information System (INIS)

Hernández Rangel, Elybe

2017-01-01

In the state of Falcon specifically in the peninsula of Paraguaná, there are two electric plants; GENEVAPCA and CADAFE. These companies are in charge of providing electrical power to the population, which is being affected by the increment of the population, plus the touristic development of the tax free zone. This reasons cause the systematic ration of the electrical power that as a consequence causes electrical interruptions for a long period of time. Due to this electrical plants can not cover the demand in its totality, there must be created alternative for usage of the electricity which would increment its production. The following thesis has an objective to analyze the technical and economical factibility to apply a combined cycle, with the purpose of increasing the electrical power supply and obtain a better thermodynamically performance. Such project was elaborated in four phases. The first phase contemplated the data collection related to the subject, obtaining important information to select the best option of the combined cycle. In the Second phase was executed the termination of the thermodynamically and energetically properties of the combined cycle, comparing the efficient of the simple cycle with the cycle mention before. As final phase, the project’s economical rentability was estimated for possible installation. (author)

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

International Nuclear Information System (INIS)

Wang, Li-Qun; Chen, Zhao-Sheng

2013-01-01

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

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

NARCIS (Netherlands)

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

2011-01-01

This paper made a modest attempt for designing a sustainable model for financial viability of biomass gasifier power projects for enhancing electricity access in India and other developing countries. For long term sustainability of distributed generation projects in remote rural areas, viability

Thermodynamic Modeling for Open Combined Regenerative Brayton and Inverse Brayton Cycles with Regeneration before the Inverse Cycle

Directory of Open Access Journals (Sweden)

Lingen Chen

2012-01-01

Full Text Available A thermodynamic model of an open combined regenerative Brayton and inverse Brayton cycles with regeneration before the inverse cycle is established in this paper by using thermodynamic optimization theory. The flow processes of the working fluid with the pressure drops and the size constraint of the real power plant are modeled. There are 13 flow resistances encountered by the working fluid stream for the cycle model. Four of these, the friction through the blades and vanes of the compressors and the turbines, are related to the isentropic efficiencies. The remaining nine flow resistances are always present because of the changes in flow cross-section at the compressor inlet of the top cycle, regenerator inlet and outlet, combustion chamber inlet and outlet, turbine outlet of the top cycle, turbine outlet of the bottom cycle, heat exchanger inlet, and compressor inlet of the bottom cycle. These resistances associated with the flow through various cross-sectional areas are derived as functions of the compressor inlet relative pressure drop of the top cycle, and control the air flow rate, the net power output and the thermal efficiency. The analytical formulae about the power output, efficiency and other coefficients are derived with 13 pressure drop losses. It is found that the combined cycle with regenerator can reach higher thermal efficiency but smaller power output than those of the base combined cycle at small compressor inlet relative pressure drop of the top cycle.

Effective Integration of Life Cycle Engineering in Education

NARCIS (Netherlands)

Oude Luttikhuis, Ellen; Toxopeus, Marten E.; Lutters, Diederick

2015-01-01

In practice, applying life cycle engineering in product design and development requires an integrated approach, because of the many stakeholders and variables (e.g. cost, environmental impact, energy, safety, quality) involved in a complete product life cycle. In educating young engineers, the same

Optimum design and thermodynamic analysis of a gas turbine and ORC combined cycle with recuperators

International Nuclear Information System (INIS)

Cao, Yue; Gao, Yike; Zheng, Ya; Dai, Yiping

2016-01-01

Highlights: • A GT-ORC combined cycle with recuperators was designed. • The effect of the ORC turbine inlet pressure on the combined cycle was examined. • Toluene was a more suitable working fluid for the GT-ORC combined cycle. • The GT-ORC combined cycle performed better than the GT-Rankine combined cycle. • The sensitivity analysis to the ambient temperature was completed. - Abstract: Gas turbines are widely used in distributed power generation because of their high efficiency, low pollution and low operational cost. To further utilize the waste heat from gas turbines, an organic Rankine cycle (ORC) was proposed as the bottoming cycle for gas turbines in this paper. Two recuperators were coupled with the combined cycle to increase the thermal efficiency, and aromatics were chosen as the working fluid for the bottoming cycle. This paper focused on the optimum design and thermodynamic analysis of the gas turbine and ORC (GT-ORC) combined cycle. Results showed that the net power and thermal efficiency of the ORC increased with the ORC turbine inlet pressure and achieved optimum values at a specific pressure based on the optimum criteria. Furthermore, compared with the GT-Rankine combined cycle, the GT-ORC combined cycle had better thermodynamic performance. Toluene was a more suitable working fluid for the GT-ORC combined cycle. Moreover, ambient temperature sensitivity simulations concluded that the GT-ORC combined cycle had a maximum thermal efficiency and the combined cycle net power was mainly determined by the topping gas turbine cycle.

Advanced modeling and simulation of integrated gasification combined cycle power plants with CO{sub 2}-capture

Energy Technology Data Exchange (ETDEWEB)

Rieger, Mathias

2014-04-17

The objective of this thesis is to provide an extensive description of the correlations in some of the most crucial sub-processes for hard coal fired IGCC with carbon capture (CC-IGCC). For this purpose, process simulation models are developed for four industrial gasification processes, the CO-shift cycle, the acid gas removal unit, the sulfur recovery process, the gas turbine, the water-/steam cycle and the air separation unit (ASU). Process simulations clarify the influence of certain boundary conditions on plant operation, performance and economics. Based on that, a comparative benchmark of CC-IGCC concepts is conducted. Furthermore, the influence of integration between the gas turbine and the ASU is analyzed in detail. The generated findings are used to develop an advanced plant configuration with improved economics. Nevertheless, IGCC power plants with carbon capture are not found to be an economically efficient power generation technology at present day boundary conditions.

Combined cycle versus one thousand diesel power plants: pollutant emissions, ecological efficiency and economic analysis

International Nuclear Information System (INIS)

Silveira, Jose Luz; de Carvalho, Joao Andrade; de Castro Villela, Iraides Aparecida

2007-01-01

The increase in the use of natural gas in Brazil has stimulated public and private sectors to analyse the possibility of using combined cycle systems for generation of electrical energy. Gas turbine combined cycle power plants are becoming increasingly common due to their high efficiency, short lead times, and ability to meet environmental standards. Power is produced in a generator linked directly to the gas turbine. The gas turbine exhaust gases are sent to a heat recovery steam generator to produce superheated steam that can be used in a steam turbine to produce additional power. In this paper a comparative study between a 1000 MW combined cycle power plant and 1000kW diesel power plant is presented. In first step, the energetic situation in Brazil, the needs of the electric sector modification and the needs of demand management and integrated means planning are clarified. In another step the characteristics of large and small thermoelectric power plants that use natural gas and diesel fuel, respectively, are presented. The ecological efficiency levels of each type of power plant is considered in the discussion, presenting the emissions of particulate material, sulphur dioxide (SO 2 ), carbon dioxide (CO 2 ) and nitrogen oxides (NO x ). (author)

Life cycle tools combined with multi-criteria and participatory methods for agricultural sustainability: Insights from a systematic and critical review.

Science.gov (United States)

De Luca, Anna Irene; Iofrida, Nathalie; Leskinen, Pekka; Stillitano, Teodora; Falcone, Giacomo; Strano, Alfio; Gulisano, Giovanni

2017-10-01

Life cycle (LC) methodologies have attracted a great interest in agricultural sustainability assessments, even if, at the same time, they have sometimes been criticized for making unrealistic assumptions and subjective choices. To cope with these weaknesses, Multi-Criteria Decision Analysis (MCDA) and/or participatory methods can be used to balance and integrate different sustainability dimensions. The purpose of this study is to highlight how life cycle approaches were combined with MCDA and participatory methods to address agricultural sustainability in the published scientific literature. A systematic and critical review was developed, highlighting the following features: which multi-criterial and/or participatory methods have been associated with LC tools; how they have been integrated or complemented (methodological relationships); the intensity of the involvement of stakeholders (degree of participation); and which synergies have been achieved by combining the methods. The main typology of integration was represented by multi-criterial frameworks integrating LC evaluations. LC tools can provide MCDA studies with local and global information on how to reduce negative impacts and avoid burden shifts, while MCDA methods can help LC practitioners deal with subjective assumptions in an objective way, to take into consideration actors' values and to overcome trade-offs among the different dimensions of sustainability. Considerations concerning the further development of Life Cycle Sustainability Assessment (LCSA) have been identified as well. Copyright © 2017 Elsevier B.V. All rights reserved.

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

International Nuclear Information System (INIS)

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

1997-01-01

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

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

Science.gov (United States)

Boravelli, Sai Chandra Teja

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

Numerical simulation of coal gasification process using the modifying Watanabe - Otaka model.

Energy Technology Data Exchange (ETDEWEB)

T. Papadopoulos; M. Losurdo; H. Spliethoff

2009-07-01

High-pressure entrained flow coal gasification is becoming increasingly important particularly in the development of Integrated Coal Gasification Combined Cycle (IGCC) technology for the production of electricity. However, there is a lack of knowledge worldwide for the gasification process and more especially for the chemical reactions (reactions rates) that take place under high pressure and temperature. Therefore a gasifier has been designed and is being built at the Institute for Energy Systems (Lehrstuhl fuer Energisysteme - LES) at the Technische Universitaet Muenchen (TUM). This gasifier is an entrained flow gasifier and has the advantage that it can operate to very high conditions of pressure and temperature, up to 50 bar pressure and 1800{sup o}C temperature. In an ongoing project, a great variety of experiments are planned to determine chemical reactions rates at high pressure conditions. In addition to the experimental work, CFD numerical simulations of pulverized coal gasification are being performed. The aim is to use numerical investigations for preliminary assessment of the facility. The goal is to develop a gasification model suitable for high pressure and condition tailored on the experiments to be used in CFD computations to predict chemical reactions, the heat transfer and the turbulence inside the gasifier. 9 refs., 2 figs., 2 tabs.

A combined thermodynamic cycle used for waste heat recovery of internal combustion engine

International Nuclear Information System (INIS)

He, Maogang; Zhang, Xinxin; Zeng, Ke; Gao, Ke

2011-01-01

In this paper, we present a steady-state experiment, energy balance and exergy analysis of exhaust gas in order to improve the recovery of the waste heat of an internal combustion engine (ICE). Considering the different characteristics of the waste heat of exhaust gas, cooling water, and lubricant, a combined thermodynamic cycle for waste heat recovery of ICE is proposed. This combined thermodynamic cycle consists of two cycles: the organic Rankine cycle (ORC), for recovering the waste heat of lubricant and high-temperature exhaust gas, and the Kalina cycle, for recovering the waste heat of low-temperature cooling water. Based on Peng–Robinson (PR) equation of state (EOS), the thermodynamic parameters in the high-temperature ORC were calculated and determined via an in-house computer program. Suitable working fluids used in high-temperature ORC are proposed and the performance of this combined thermodynamic cycle is analyzed. Compared with the traditional cycle configuration, more waste heat can be recovered by the combined cycle introduced in this paper. -- Highlights: ► We study the energy balance of fuel in internal combustion engine. ► Heat recovery effect of exhaust gas is good when ICE is at a high-load condition. ► We propose a new combined thermodynamic cycle for waste heat of ICE. ► The combined cycle has a higher recovery efficiency than previous configurations.

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Optimization of the triple-pressure combined cycle power plant

Directory of Open Access Journals (Sweden)

Alus Muammer

2012-01-01

Full Text Available The aim of this work was to develop a new system for optimization of parameters for combined cycle power plants (CCGTs with triple-pressure heat recovery steam generator (HRSG. Thermodynamic and thermoeconomic optimizations were carried out. The objective of the thermodynamic optimization is to enhance the efficiency of the CCGTs and to maximize the power production in the steam cycle (steam turbine gross power. Improvement of the efficiency of the CCGT plants is achieved through optimization of the operating parameters: temperature difference between the gas and steam (pinch point P.P. and the steam pressure in the HRSG. The objective of the thermoeconomic optimization is to minimize the production costs per unit of the generated electricity. Defining the optimal P.P. was the first step in the optimization procedure. Then, through the developed optimization process, other optimal operating parameters (steam pressure and condenser pressure were identified. The developed system was demonstrated for the case of a 282 MW CCGT power plant with a typical design for commercial combined cycle power plants. The optimized combined cycle was compared with the regular CCGT plant.

A comparison of advanced heat recovery power cycles in a combined cycle for large ships

DEFF Research Database (Denmark)

Larsen, Ulrik; Sigthorsson, Oskar; Haglind, Fredrik

2014-01-01

Strong motivation exists within the marine sector to reduce fuel expenses and to comply with ever stricter emission regulations. Heat recovery can address both of these issues. The ORC (organic Rankine cycle), the Kalina cycle and the steam Rankine cycle have received the majority of the focus...... fluids possess high global warming potentials and hazard levels. It is concluded that the ORC has the greatest potential for increasing the fuel efficiency, and the combined cycle offers very high thermal efficiency. While being less efficient, the steam cycle has the advantages of being well proven...

Cost and operational acceptability improvements to gasifiers

Energy Technology Data Exchange (ETDEWEB)

Connor, A.

2003-07-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Thermodynamic assessment of a wind turbine based combined cycle

International Nuclear Information System (INIS)

Rabbani, M.; Dincer, I.; Naterer, G.F.

2012-01-01

Combined cycles use the exhaust gases released from a Gas Turbine (GT). Approximately 30–40% of the turbine shaft work is typically used to drive the Compressor. The present study analyzes a system that couples a Wind Turbine (WT) with a combined cycle. It demonstrates how a WT can be used to supply power to the Compressor in the GT cycle and pump fluid through a reheat Rankine cycle, in order to increase the overall power output. Three different configurations are discussed, namely high penetration, low penetration and wind power addition. In the case of a low electricity demand and high penetration configuration, extra wind power is used to compress air which can then be used in the low penetration configuration. During a high load demand, all the wind power is used to drive the pump and compressor and if required additional compressed air is supplied by a storage unit. The analysis shows that increasing the combustion temperature reduces the critical velocity and mass flow rate. Increases in wind speed reduce both energy and exergy efficiency of the overall system. -- Highlights: ► This study analyzes a system that couples a wind turbine with a combined power generation cycle. ► Surplus wind power is used to compress air, which is then stored and used at a later time. ► Increasing the pressure ratio will reduce the work ratio between the Rankine and Brayton cycles. ► A higher combustion temperature will increase the net work output, as well as the system energy and exergy efficiencies.

System studies on Biofuel production via Integrated Biomass Gasification

Energy Technology Data Exchange (ETDEWEB)

Andersson, Jim; Lundgren, Joakim [Luleaa Univ. of Technology Bio4Energy, Luleaa (Sweden); Malek, Laura; Hulteberg, Christian [Lund Univ., Lund (Sweden); Pettersson, Karin [Chalmers Univ. of Technology, Goeteborg (Sweden); Wetterlund, Elisabeth [Linkoeping Univ. Linkoeping (Sweden)

2013-09-01

A large number of national and international techno-economic studies on industrially integrated gasifiers for production of biofuels have been published during the recent years. These studies comprise different types of gasifiers (fluidized bed, indirect and entrained flow) integrated in different industries for the production of various types of chemicals and transportation fuels (SNG, FT-products, methanol, DME etc.) The results are often used for techno-economic comparisons between different biorefinery concepts. One relatively common observation is that even if the applied technology and the produced biofuel are the same, the results of the techno-economic studies may differ significantly. The main objective of this project has been to perform a comprehensive review of publications regarding industrially integrated biomass gasifiers for motor fuel production. The purposes have been to identify and highlight the main reasons why similar studies differ considerably and to prepare a basis for fair techno-economic comparisons. Another objective has been to identify possible lack of industrial integration studies that may be of interest to carry out in a second phase of the project. Around 40 national and international reports and articles have been analysed and reviewed. The majority of the studies concern gasifiers installed in chemical pulp and paper mills where black liquor gasification is the dominating technology. District heating systems are also well represented. Only a few studies have been found with mechanical pulp and paper mills, steel industries and the oil refineries as case basis. Other industries have rarely, or not at all, been considered for industrial integration studies. Surprisingly, no studies regarding integration of biomass gasification neither in saw mills nor in wood pellet production industry have been found. In the published economic evaluations, it has been found that there is a large number of studies containing both integration and

Modeling of a Large-Scale High Temperature Regenerative Sulfur Removal Process

DEFF Research Database (Denmark)

Konttinen, Jukka T.; Johnsson, Jan Erik

1999-01-01

model that does not account for bed hydrodynamics. The pilot-scale test run results, obtained in the test runs of the sulfur removal process with real coal gasifier gas, have been used for parameter estimation. The validity of the reactor model for commercial-scale design applications is discussed.......Regenerable mixed metal oxide sorbents are prime candidates for the removal of hydrogen sulfide from hot gasifier gas in the simplified integrated gasification combined cycle (IGCC) process. As part of the regenerative sulfur removal process development, reactor models are needed for scale......-up. Steady-state kinetic reactor models are needed for reactor sizing, and dynamic models can be used for process control design and operator training. The regenerative sulfur removal process to be studied in this paper consists of two side-by-side fluidized bed reactors operating at temperatures of 400...

The Low temperature CFB gasifier

DEFF Research Database (Denmark)

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

2003-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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

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

DEFF Research Database (Denmark)

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

2003-01-01

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

Preliminary analysis of combined cycle of modular high-temperature gas cooled reactor

International Nuclear Information System (INIS)

Baogang, Z.; Xiaoyong, Y.; Jie, W.; Gang, Z.; Qian, S.

2015-01-01

Modular high-temperature gas cooled reactor (HTGR) is known as one of the most advanced nuclear reactors because of its inherent safety and high efficiency. The power conversion system of HTGR can be steam turbine based on Rankine cycle or gas turbine based on Brayton cycle respectively. The steam turbine system is mature and the gas turbine system has high efficiency but under development. The Brayton-Rankine combined cycle is an effective way to further promote the efficiency. This paper investigated the performance of combined cycle from the viewpoint of thermodynamics. The effect of non-dimensional parameters on combined cycle’s efficiency, such as temperature ratio, compression ratio, efficiency of compressor, efficiency of turbine, was analyzed. Furthermore, the optimal parameters to achieve highest efficiency was also given by this analysis under engineering constraints. The conclusions could be helpful to the design and development of combined cycle of HTGR. (author)

Next-generation coal utilization technology development study. Environmentally-friendly coal combustion technology; topping cycles; Sekitan riyo jisedai gijutsu kaihatsu chosa. Kankyo chowagata sekitan nensho gijutsu bun`ya (topping nensho gijutsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

As a realistic measure to reduce environmental pollutants emitted from coal-fueled boilers, a developmental study was conducted of high-efficient combustion systems. In fiscal 1994, four types of topping cycles which are different in system structure and gasifier type were selected, and topping cycles assuming a 300MW-class power plant were trially designed. Further, an evaluation of adaptability of these systems was made, and an selection of the optimum system for the early development was made among the systems. As a result, the evaluation was obtained that `a system using air blown gasifier` is most suitable for conducting the next-stage research. In the element test on the topping combustion technology, collection was made of data of desulfurization activity, desulfurization oxidation mechanism and alkali metal behavior at the laboratory level, data of temperatures and gas concentration distribution in coal gasification, data of simulation of the gasifier reaction, and the other data. 262 figs., 66 tabs.

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

Science.gov (United States)

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

2018-03-12

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

Energy and exergy analysis of a closed Brayton cycle-based combined cycle for solar power tower plants

International Nuclear Information System (INIS)

Zare, V.; Hasanzadeh, M.

2016-01-01

Highlights: • A novel combined cycle is proposed for solar power tower plants. • The effects of solar subsystem and power cycle parameters are examined. • The proposed combined cycle yields exergy efficiencies of higher than 70%. • For the overall power plant exergy efficiencies of higher than 30% is achievable. - Abstract: Concentrating Solar Power (CSP) technology offers an interesting potential for future power generation and research on CSP systems of all types, particularly those with central receiver system (CRS) has been attracting a lot of attention recently. Today, these power plants cannot compete with the conventional power generation systems in terms of Levelized Cost of Electricity (LCOE) and if a competitive LCOE is to be reached, employing an efficient thermodynamic power cycle is deemed essential. In the present work, a novel combined cycle is proposed for power generation from solar power towers. The proposed system consists of a closed Brayton cycle, which uses helium as the working fluid, and two organic Rankine cycles which are employed to recover the waste heat of the Brayton cycle. The system is thermodynamically assessed from both the first and second law viewpoints. A parametric study is conducted to examine the effects of key operating parameters (including solar subsystem and power cycle parameters) on the overall power plant performance. The results indicate that exergy efficiencies of higher than 30% are achieved for the overall power plant. Also, according to the results, the power cycle proposed in this work has a better performance than the other investigated Rankine and supercritical CO_2 systems operating under similar conditions, for these types of solar power plants.

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

DEFF Research Database (Denmark)

Narayan, Vikas

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

Hybrid solar central receiver for combined cycle power plant

Science.gov (United States)

Bharathan, Desikan; Bohn, Mark S.; Williams, Thomas A.

1995-01-01

A hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production.

Integration of the military and civilian nuclear fuel cycles in Russia

International Nuclear Information System (INIS)

Bukharin, O.

1994-01-01

This paper describes the close integration of the civil and military nuclear fuel cycles in Russia. Individual processing facilities, as well as the flow of nuclear material, are described as they existed in the 1980s and as they exist today. The end of the Cold War and the breakup of the Soviet Union weakened the ties between the two nuclear fuel cycles, but did not separate them. Separation of the military and civilian nuclear fuel cycles would facilitate Russia's integration into the world's nuclear fuel cycle and its participation in international non-proliferation regimes

Modeling of a combined cycle power plant

International Nuclear Information System (INIS)

Faridah Mohamad Idris

2001-01-01

The combined cycle power plant is a non-linear, closed loop system, which consists of high-pressure (HP) superheater, HP evaporator, HP economizer, low-pressure (LP) evaporator, HP drum, HP deaerator, condenser, HP and LP steam turbine and gas turbine. The two types of turbines in the plant for example the gas turbine and the HP and LP steam turbines operate concurrently to generate power to the plant. The exhaust gas which originate from the combustion chamber drives the gas turbine, after which it flows into the heat recovery steam generator (HRSG) to generate superheated steam to be used in driving the HP and LP steam turbines. In this thesis, the combined cycle power plant is modeled at component level using the physical method. Assuming that there is delay in transport, except for the gas turbine system, the mass and heat balances are applied on the components of the plant to derive the governing equations of the components. These time dependent equations, which are of first order differential types, are then solved for the mass and enthalpy of the components. The solutions were simulated using Matlab Simulink using measured plant data. Where necessary there is no plant data available, approximated data were used. The generalized regression neural networks are also used to generate extra sets of simulation data for the HRSG system. Comparisons of the simulation results with its corresponding plant data showed good agreements between the two and indicated that the models developed for the components could be used to represent the combined cycle power plant under study. (author)

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

Directory of Open Access Journals (Sweden)

Maj Izabella

2017-01-01

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

Rocket Based Combined Cycle (RBCC) engine inlet

Science.gov (United States)

2004-01-01

Pictured is a component of the Rocket Based Combined Cycle (RBCC) engine. This engine was designed to ultimately serve as the near term basis for Two Stage to Orbit (TSTO) air breathing propulsion systems and ultimately a Single Stage to Orbit (SSTO) air breathing propulsion system.

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

Science.gov (United States)

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

2009-09-01

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

Historical Business Cycles and Market Integration: Evidence from Comovement

NARCIS (Netherlands)

Uebele, Martin

2009-01-01

This thesis addresses historical business cycles and market integration in Europe and America in the 19th and 20th centuries. For the analysis of historical business cycles, the widely used methodology of historical national accounting is complemented with a dynamic factor model that allows for

Gasification integrated to combined cycles; Gasificacion integrada a ciclos combinados

Energy Technology Data Exchange (ETDEWEB)

Fernandez M, Manuel F; Alcaraz C, Agustin M [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2001-07-01

The mineral coal is one of the most abundant fuels in the planet, but it has important amounts of sulfur and ashes that make difficult their use. On the other hand, many countries at the present time prevent to use the fuel oil as combustible with conventional technologies due to the metal and sulfur contents. Finally, in the new schemes of oil refinement it is anticipated to use the coking to take advantage of the barrel bottoms. The remainder product of this process, known as refinery coke, has a low commercial value, a high calorific power and high sulfur content and metals. The gasification has been developed in the last the two decades, in the highly industrialized countries, as an alternative for the efficient and clean generation of electricity from dirty fuels, as well as for obtaining certain fuels in places where access to petroleum is not available, but to the coal. This technology fulfills the strictest regulations of the world in what polluting emissions refers and it is the only solution, next to the fluidized beds, for the problems that present some fuels that are difficult to burn with conventional technologies, as the mineral coal, the petroleum coke and even the liquid remainders of the refinement. With base in the former, it is possible to think about the integration of this technology to a combined cycle plant for the generation of electricity or to a refinery generating steam, electrical energy, hydrogen and other consumables at a competitive cost, in such a way that the problems of handling and storage of the remainders are solved; on the other hand the use of the primary power resources in the country is maximized. [Spanish] El carbon mineral es uno de los combustibles mas abundantes en el planeta, pero posee cantidades importantes de azufre y cenizas que dificultan su utilizacion. Por otra parte, muchos paises en la actualidad impiden utilizar el combustoleo como combustible para tecnologias convencionales debido a los contenidos de azufre y

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Integral benchmarks with reference to thorium fuel cycle

International Nuclear Information System (INIS)

Ganesan, S.

2003-01-01

This is a power point presentation about the Indian participation in the CRP 'Evaluated Data for the Thorium-Uranium fuel cycle'. The plans and scope of the Indian participation are to provide selected integral experimental benchmarks for nuclear data validation, including Indian Thorium burn up benchmarks, post-irradiation examination studies, comparison of basic evaluated data files and analysis of selected benchmarks for Th-U fuel cycle

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-11-30

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

A Thermodynamic Analysis of Two Competing Mid-Sized Oxyfuel Combustion Combined Cycles

Directory of Open Access Journals (Sweden)

Egill Thorbergsson

2016-01-01

Full Text Available A comparative analysis of two mid-sized oxyfuel combustion combined cycles is performed. The two cycles are the semiclosed oxyfuel combustion combined cycle (SCOC-CC and the Graz cycle. In addition, a reference cycle was established as the basis for the analysis of the oxyfuel combustion cycles. A parametric study was conducted where the pressure ratio and the turbine entry temperature were varied. The layout and the design of the SCOC-CC are considerably simpler than the Graz cycle while it achieves the same net efficiency as the Graz cycle. The fact that the efficiencies for the two cycles are close to identical differs from previously reported work. Earlier studies have reported around a 3% points advantage in efficiency for the Graz cycle, which is attributed to the use of a second bottoming cycle. This additional feature is omitted to make the two cycles more comparable in terms of complexity. The Graz cycle has substantially lower pressure ratio at the optimum efficiency and has much higher power density for the gas turbine than both the reference cycle and the SCOC-CC.

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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

Comparison between externally fired gas turbine and gasifier-gas turbine system for the olive oil industry

International Nuclear Information System (INIS)

Vera, D.; Jurado, F.; Mena, B. de; Schories, G.

2011-01-01

The olive oil industry generates during the extraction process several solid wastes as olive tree leaves and prunings, exhausted pomace and olive pits. These renewable wastes could be used for power and heat applications. The aim of this paper is to compare the performance of two small-scale CHP systems: a gasification- gas turbine system and an EFGT (externally fired gas turbine system). For this reason, several parameters have been calculated: generated heat and power, electric and overall efficiencies, biomass consumption, exergy efficiency, optimum pressure ratio, etc. These systems provide 30 kW e and about 60kW th . Simulation results show that the electrical and overall efficiencies achieved in EFGT system (19.1% and 59.3%, respectively) are significantly higher than those obtained in the gasification plant (12.3% and 45.4%). The proposed CHP systems have been modeled using Cycle-Tempo ® software. -- Highlights: ► Comparison between externally fired gas turbine and gasifier-gas turbine system. ► Olive oil industry generates several solid wastes as olive tree leaves and prunings. ► Thermodynamic parameters have been calculated. ► Systems have been modeled using Cycle-Tempo ® software. ► Simulation results show electrical and overall efficiencies achieved in the systems.

A combined gas cooled nuclear reactor and fuel cell cycle

Science.gov (United States)

Palmer, David J.

Rising oil costs, global warming, national security concerns, economic concerns and escalating energy demands are forcing the engineering communities to explore methods to address these concerns. It is the intention of this thesis to offer a proposal for a novel design of a combined cycle, an advanced nuclear helium reactor/solid oxide fuel cell (SOFC) plant that will help to mitigate some of the above concerns. Moreover, the adoption of this proposal may help to reinvigorate the Nuclear Power industry while providing a practical method to foster the development of a hydrogen economy. Specifically, this thesis concentrates on the importance of the U.S. Nuclear Navy adopting this novel design for its nuclear electric vessels of the future with discussion on efficiency and thermodynamic performance characteristics related to the combined cycle. Thus, the goals and objectives are to develop an innovative combined cycle that provides a solution to the stated concerns and show that it provides superior performance. In order to show performance, it is necessary to develop a rigorous thermodynamic model and computer program to analyze the SOFC in relation with the overall cycle. A large increase in efficiency over the conventional pressurized water reactor cycle is realized. Both sides of the cycle achieve higher efficiencies at partial loads which is extremely important as most naval vessels operate at partial loads as well as the fact that traditional gas turbines operating alone have poor performance at reduced speeds. Furthermore, each side of the cycle provides important benefits to the other side. The high temperature exhaust from the overall exothermic reaction of the fuel cell provides heat for the reheater allowing for an overall increase in power on the nuclear side of the cycle. Likewise, the high temperature helium exiting the nuclear reactor provides a controllable method to stabilize the fuel cell at an optimal temperature band even during transients helping

Computational Fluid Dynamics Analysis Method Developed for Rocket-Based Combined Cycle Engine Inlet

Science.gov (United States)

1997-01-01

Renewed interest in hypersonic propulsion systems has led to research programs investigating combined cycle engines that are designed to operate efficiently across the flight regime. The Rocket-Based Combined Cycle Engine is a propulsion system under development at the NASA Lewis Research Center. This engine integrates a high specific impulse, low thrust-to-weight, airbreathing engine with a low-impulse, high thrust-to-weight rocket. From takeoff to Mach 2.5, the engine operates as an air-augmented rocket. At Mach 2.5, the engine becomes a dual-mode ramjet; and beyond Mach 8, the rocket is turned back on. One Rocket-Based Combined Cycle Engine variation known as the "Strut-Jet" concept is being investigated jointly by NASA Lewis, the U.S. Air Force, Gencorp Aerojet, General Applied Science Labs (GASL), and Lockheed Martin Corporation. Work thus far has included wind tunnel experiments and computational fluid dynamics (CFD) investigations with the NPARC code. The CFD method was initiated by modeling the geometry of the Strut-Jet with the GRIDGEN structured grid generator. Grids representing a subscale inlet model and the full-scale demonstrator geometry were constructed. These grids modeled one-half of the symmetric inlet flow path, including the precompression plate, diverter, center duct, side duct, and combustor. After the grid generation, full Navier-Stokes flow simulations were conducted with the NPARC Navier-Stokes code. The Chien low-Reynolds-number k-e turbulence model was employed to simulate the high-speed turbulent flow. Finally, the CFD solutions were postprocessed with a Fortran code. This code provided wall static pressure distributions, pitot pressure distributions, mass flow rates, and internal drag. These results were compared with experimental data from a subscale inlet test for code validation; then they were used to help evaluate the demonstrator engine net thrust.

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

NARCIS (Netherlands)

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

1979-01-01

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

The United States of America and the People`s Republic of China experts report on integrated gasification combined-cycle technology (IGCC)

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-01

A report written by the leading US and Chinese experts in Integrated Gasification Combined Cycle (IGCC) power plants, intended for high level decision makers, may greatly accelerate the development of an IGCC demonstration project in the People`s Republic of China (PRC). The potential market for IGCC systems in China and the competitiveness of IGCC technology with other clean coal options for China have been analyzed in the report. Such information will be useful not only to the Chinese government but also to US vendors and companies. The goal of this report is to analyze the energy supply structure of China, China`s energy and environmental protection demand, and the potential market in China in order to make a justified and reasonable assessment on feasibility of the transfer of US Clean Coal Technologies to China. The Expert Report was developed and written by the joint US/PRC IGCC experts and will be presented to the State Planning Commission (SPC) by the President of the CAS to ensure consideration of the importance of IGCC for future PRC power production.

Comparison of Engine Cycle Codes for Rocket-Based Combined Cycle Engines

Science.gov (United States)

Waltrup, Paul J.; Auslender, Aaron H.; Bradford, John E.; Carreiro, Louis R.; Gettinger, Christopher; Komar, D. R.; McDonald, J.; Snyder, Christopher A.

2002-01-01

This paper summarizes the results from a one day workshop on Rocket-Based Combined Cycle (RBCC) Engine Cycle Codes held in Monterey CA in November of 2000 at the 2000 JANNAF JPM with the authors as primary participants. The objectives of the workshop were to discuss and compare the merits of existing Rocket-Based Combined Cycle (RBCC) engine cycle codes being used by government and industry to predict RBCC engine performance and interpret experimental results. These merits included physical and chemical modeling, accuracy and user friendliness. The ultimate purpose of the workshop was to identify the best codes for analyzing RBCC engines and to document any potential shortcomings, not to demonstrate the merits or deficiencies of any particular engine design. Five cases representative of the operating regimes of typical RBCC engines were used as the basis of these comparisons. These included Mach 0 sea level static and Mach 1.0 and Mach 2.5 Air-Augmented-Rocket (AAR), Mach 4 subsonic combustion ramjet or dual-mode scramjet, and Mach 8 scramjet operating modes. Specification of a generic RBCC engine geometry and concomitant component operating efficiencies, bypass ratios, fuel/oxidizer/air equivalence ratios and flight dynamic pressures were provided. The engine included an air inlet, isolator duct, axial rocket motor/injector, axial wall fuel injectors, diverging combustor, and exit nozzle. Gaseous hydrogen was used as the fuel with the rocket portion of the system using a gaseous H2/O2 propellant system to avoid cryogenic issues. The results of the workshop, even after post-workshop adjudication of differences, were surprising. They showed that the codes predicted essentially the same performance at the Mach 0 and I conditions, but progressively diverged from a common value (for example, for fuel specific impulse, Isp) as the flight Mach number increased, with the largest differences at Mach 8. The example cases and results are compared and discussed in this paper.

Rocket Based Combined Cycle (RBCC) Engine

Science.gov (United States)

2004-01-01

Pictured is an artist's concept of the Rocket Based Combined Cycle (RBCC) launch. The RBCC's overall objective is to provide a technology test bed to investigate critical technologies associated with opperational usage of these engines. The program will focus on near term technologies that can be leveraged to ultimately serve as the near term basis for Two Stage to Orbit (TSTO) air breathing propulsions systems and ultimately a Single Stage To Orbit (SSTO) air breathing propulsion system.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Integration of photovoltaic and concentrated solar thermal technologies for H2 production by the hybrid sulfur cycle

Science.gov (United States)

Liberatore, Raffaele; Ferrara, Mariarosaria; Lanchi, Michela; Turchetti, Luca

2017-06-01

It is widely agreed that hydrogen used as energy carrier and/or storage media may significantly contribute in the reduction of emissions, especially if produced by renewable energy sources. The Hybrid Sulfur (HyS) cycle is considered as one of the most promising processes to produce hydrogen through the water-splitting process. The FP7 project SOL2HY2 (Solar to Hydrogen Hybrid Cycles) investigates innovative material and process solutions for the use of solar heat and power in the HyS process. A significant part of the SOL2HY2 project is devoted to the analysis and optimization of the integration of the solar and chemical (hydrogen production) plants. In this context, this work investigates the possibility to integrate different solar technologies, namely photovoltaic, solar central receiver and solar troughs, to optimize their use in the HyS cycle for a green hydrogen production, both in the open and closed process configurations. The analysis carried out accounts for different combinations of geographical location and plant sizing criteria. The use of a sulfur burner, which can serve both as thermal backup and SO2 source for the open cycle, is also considered.

Efficiency tests on the pyrolysis gasifier stove Peko Pe

DEFF Research Database (Denmark)

Nielsen, Per Sieverts

1996-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-12-31

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

Adoption and use of a semi-gasifier cooking and water heating stove and fuel intervention in the Tibetan Plateau, China

Science.gov (United States)

Clark, S.; Carter, E.; Shan, M.; Ni, K.; Niu, H.; Tseng, J. T. W.; Pattanayak, S. K.; Jeuland, M.; Schauer, J. J.; Ezzati, M.; Wiedinmyer, C.; Yang, X.; Baumgartner, J.

2017-07-01

Improved cookstoves and fuels, such as advanced gasifier stoves, carry the promise of improving health outcomes, preserving local environments, and reducing climate-forcing air pollutants. However, low adoption and use of these stoves in many settings has limited their benefits. We aimed to improve the understanding of improved stove use by describing the patterns and predictors of adoption of a semi-gasifier stove and processed biomass fuel intervention in southwestern China. Of 113 intervention homes interviewed, 79% of homes tried the stove, and the majority of these (92%) continued using it 5-10 months later. One to five months after intervention, the average proportion of days that the semi-gasifier stove was in use was modest (40.4% [95% CI 34.3-46.6]), and further declined over 13 months. Homes that received the stove in the first batch used it more frequently (67.2% [95% CI 42.1-92.3] days in use) than homes that received it in the second batch (29.3% [95% CI 13.8-44.5] days in use), likely because of stove quality and user training. Household stove use was positively associated with reported cooking needs and negatively associated with age of the main cook, household socioeconomic status, and the availability of substitute cleaner-burning stoves. Our results show that even a carefully engineered, multi-purpose semi-gasifier stove and fuel intervention contributed modestly to overall household energy use in rural China.

Thermodynamic analysis of combined cycle under design/off-design conditions for its efficient design and operation

International Nuclear Information System (INIS)

Zhang, Guoqiang; Zheng, Jiongzhi; Xie, Angjun; Yang, Yongping; Liu, Wenyi

2016-01-01

Highlights: • Based on the PG9351FA gas turbine, two gas-steam combined cycles are redesigned. • Analysis of detailed off-design characteristics of the combined cycle main parts. • Suggestions for improving design and operation performance of the combined cycle. • Higher design efficiency has higher off-design efficiency in general PR range. • High pressure ratio combined cycles possess good off-design performance. - Abstract: To achieve a highly efficient design and operation of combined cycles, this study analyzed in detail the off-design characteristics of the main components of three combined cycles with different compressor pressure ratios (PRs) based on real units. The off-design model of combined cycle was built consisting of a compressor, a combustor, a gas turbine, and a heat recovery steam generator (HRSG). The PG9351FA unit is selected as the benchmark unit, on the basis of which the compressor is redesigned with two different PRs. Then, the design/off-design characteristics of the three units with different design PRs and the interactive relations between topping and bottoming cycles are analyzed with the same turbine inlet temperature (TIT). The results show that the off-design characteristics of the topping cycle affect dramatically the combined cycle performance. The variation range of the exergy efficiency of the topping cycle for the three units is between 11.9% and 12.4% under the design/off-design conditions. This range is larger than that of the bottoming cycle (between 9.2% and 9.5%). The HRSG can effectively recycle the heat/heat exergy of the gas turbine exhaust. Comparison among the three units shows that for a traditional gas-steam combined cycle, a high design efficiency results in a high off-design efficiency in the usual PR range. The combined cycle design efficiency of higher pressure ratio is almost equal to that of the PG9351FA, but its off-design efficiency is higher (maximum 0.42%) and the specific power decreases. As for

Process for gasifying fuels with the recovery of rich gases

Energy Technology Data Exchange (ETDEWEB)

Jahns, F

1921-04-10

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

Space-Charge Simulation of Integrable Rapid Cycling Synchrotron

Energy Technology Data Exchange (ETDEWEB)

Eldred, Jeffery [Fermilab; Valishev, Alexander [Fermilab

2017-05-01

Integrable optics is an innovation in particle accelerator design that enables strong nonlinear focusing without generating parametric resonances. We use a Synergia space-charge simulation to investigate the application of integrable optics to a high-intensity hadron ring that could replace the Fermilab Booster. We find that incorporating integrability into the design suppresses the beam halo generated by a mismatched KV beam. Our integrable rapid cycling synchrotron (iRCS) design includes other features of modern ring design such as low momentum compaction factor and harmonically canceling sextupoles. Experimental tests of high-intensity beams in integrable lattices will take place over the next several years at the Fermilab Integrable Optics Test Accelerator (IOTA) and the University of Maryland Electron Ring (UMER).

Exergy analysis, parametric analysis and optimization for a novel combined power and ejector refrigeration cycle

International Nuclear Information System (INIS)

Dai Yiping; Wang Jiangfeng; Gao Lin

2009-01-01

A new combined power and refrigeration cycle is proposed, which combines the Rankine cycle and the ejector refrigeration cycle. This combined cycle produces both power output and refrigeration output simultaneously. It can be driven by the flue gas of gas turbine or engine, solar energy, geothermal energy and industrial waste heats. An exergy analysis is performed to guide the thermodynamic improvement for this cycle. And a parametric analysis is conducted to evaluate the effects of the key thermodynamic parameters on the performance of the combined cycle. In addition, a parameter optimization is achieved by means of genetic algorithm to reach the maximum exergy efficiency. The results show that the biggest exergy loss due to the irreversibility occurs in heat addition processes, and the ejector causes the next largest exergy loss. It is also shown that the turbine inlet pressure, the turbine back pressure, the condenser temperature and the evaporator temperature have significant effects on the turbine power output, refrigeration output and exergy efficiency of the combined cycle. The optimized exergy efficiency is 27.10% under the given condition.

Semantic Data Integration and Ontology Use within the Global Earth Observation System of Systems (GEOSS) Global Water Cycle Data Integration System

Science.gov (United States)

Pozzi, W.; Fekete, B.; Piasecki, M.; McGuinness, D.; Fox, P.; Lawford, R.; Vorosmarty, C.; Houser, P.; Imam, B.

2008-12-01

The inadequacies of water cycle observations for monitoring long-term changes in the global water system, as well as their feedback into the climate system, poses a major constraint on sustainable development of water resources and improvement of water management practices. Hence, The Group on Earth Observations (GEO) has established Task WA-08-01, "Integration of in situ and satellite data for water cycle monitoring," an integrative initiative combining different types of satellite and in situ observations related to key variables of the water cycle with model outputs for improved accuracy and global coverage. This presentation proposes development of the Rapid, Integrated Monitoring System for the Water Cycle (Global-RIMS)--already employed by the GEO Global Terrestrial Network for Hydrology (GTN-H)--as either one of the main components or linked with the Asian system to constitute the modeling system of GEOSS for water cycle monitoring. We further propose expanded, augmented capability to run multiple grids to embrace some of the heterogeneous methods and formats of the Earth Science, Hydrology, and Hydraulic Engineering communities. Different methodologies are employed by the Earth Science (land surface modeling), the Hydrological (GIS), and the Hydraulic Engineering Communities; with each community employing models that require different input data. Data will be routed as input variables to the models through web services, allowing satellite and in situ data to be integrated together within the modeling framework. Semantic data integration will provide the automation to enable this system to operate in near-real-time. Multiple data collections for ground water, precipitation, soil moisture satellite data, such as SMAP, and lake data will require multiple low level ontologies, and an upper level ontology will permit user-friendly water management knowledge to be synthesized. These ontologies will have to have overlapping terms mapped and linked together. so

Numerical simulation of divergent rocket-based-combined-cycle performances under the flight condition of Mach 3

Science.gov (United States)

Cui, Peng; Xu, WanWu; Li, Qinglian

2018-01-01

Currently, the upper operating limit of the turbine engine is Mach 2+, and the lower limit of the dual-mode scramjet is Mach 4. Therefore no single power systems can operate within the range between Mach 2 + and Mach 4. By using ejector rockets, Rocket-based-combined-cycle can work well in the above scope. As the key component of Rocket-based-combined-cycle, the ejector rocket has significant influence on Rocket-based-combined-cycle performance. Research on the influence of rocket parameters on Rocket-based-combined-cycle in the speed range of Mach 2 + to Mach 4 is scarce. In the present study, influences of Mach number and total pressure of the ejector rocket on Rocket-based-combined-cycle were analyzed numerically. Due to the significant effects of the flight conditions and the Rocket-based-combined-cycle configuration on Rocket-based-combined-cycle performances, flight altitude, flight Mach number, and divergence ratio were also considered. The simulation results indicate that matching lower altitude with higher flight Mach numbers can increase Rocket-based-combined-cycle thrust. For another thing, with an increase of the divergent ratio, the effect of the divergent configuration will strengthen and there is a limit on the divergent ratio. When the divergent ratio is greater than the limit, the effect of divergent configuration will gradually exceed that of combustion on supersonic flows. Further increases in the divergent ratio will decrease Rocket-based-combined-cycle thrust.

Integration of the Mini-Sulfide Sulfite Anthraquinone (MSS-AQ) Pulping Process and Black Liquor Gasification in a Pulp Mill

Energy Technology Data Exchange (ETDEWEB)

Hasan Jameel, North Carolina State University; Adrianna Kirkman, North Carolina State University; Ravi Chandran,Thermochem Recovery International Brian Turk Research Triangle Institute; Brian Green, Research Triangle Institute

2010-01-27

As many of the recovery boilers and other pieces of large capital equipment of U.S. pulp mills are nearing the end of their useful life, the pulp and paper industry will soon need to make long-term investments in new technologies. The ability to install integrated, complete systems that are highly efficient will impact the industry’s energy use for decades to come. Developing a process for these new systems is key to the adoption of state-of-the-art technologies in the Forest Products industry. This project defined an integrated process model that combines mini-sulfide sulfite anthraquinone (MSS-AQ) pulping and black liquor gasification with a proprietary desulfurization process developed by the Research Triangle Institute. Black liquor gasification is an emerging technology that enables the use of MSS-AQ pulping, which results in higher yield, lower bleaching cost, lower sulfur emissions, and the elimination of causticization requirements. The recently developed gas cleanup/absorber technology can clean the product gas to a state suitable for use in a gas turbine and also regenerate the pulping chemicals needed to for the MSS-AQ pulping process. The combination of three advanced technologies into an integrated design will enable the pulping industry to achieve a new level of efficiency, environmental performance, and cost savings. Because the three technologies are complimentary, their adoption as a streamlined package will ensure their ability to deliver maximum energy and cost savings benefits. The process models developed by this project will enable the successful integration of new technologies into the next generation of chemical pulping mills. When compared to the Kraft reference pulp, the MSS-AQ procedures produced pulps with a 10-15 % yield benefit and the ISO brightness was 1.5-2 times greater. The pulp refined little easier and had a slightly lower apparent sheet density (In both the cases). At similar levels of tear index the MSS-AQ pulps also

Combined Turbine and Cycle Optimization for Organic Rankine Cycle Power Systems—Part B

DEFF Research Database (Denmark)

La Seta, Angelo; Meroni, Andrea; Andreasen, Jesper Graa

2016-01-01

Organic Rankine cycle (ORC) power systems have recently emerged as promising solutions for waste heat recovery in low- and medium-size power plants. Their performance and economic feasibility strongly depend on the expander. The design process and efficiency estimation are particularly challenging...... due to the peculiar physical properties of the working fluid and the gas-dynamic phenomena occurring in the machine. Unlike steam Rankine and Brayton engines, organic Rankine cycle expanders combine small enthalpy drops with large expansion ratios. These features yield turbine designs with few highly...... is the preliminary design of an organic Rankine cycle turbogenerator to increase the overall energy efficiency of an offshore platform. For an increase in expander pressure ratio from 10 to 35, the results indicate up to 10% point reduction in expander performance. This corresponds to a relative reduction in net...

Theoretical analysis of a combined power and ejector refrigeration cycle using zeotropic mixture

International Nuclear Information System (INIS)

Yang, Xingyang; Zhao, Li; Li, Hailong; Yu, Zhixin

2015-01-01

Highlights: • A combined power and refrigeration cycle using zeotropic mixture is analyzed. • The cycle performances with different mixture compositions are compared. • Both exergy and parametric analysis of the combined cycle are conducted. - Abstract: A theoretical study on a combined power and ejector refrigeration cycle using zeotropic mixture isobutane/pentane is carried out. The performances of different mixture compositions are compared. An exergy analysis is conducted for the cycle. The result reveals that most exergy destruction happens in the ejector, where more than 40% exergy is lost. The heat exchange in generator causes the second largest exergy loss, larger than 28%. As the mass fraction of isobutane changes ranges from 100% to 0%, the relative exergy destruction of each component is also changing. And mixture isobutane/pentane (50/50) has the maximum exergy efficiency of 7.83%. The parametric analysis of generator temperature, condenser temperature and evaporator temperature for all the mixtures shows that, all these three thermodynamic parameters have a strong effect on the cycle performance.

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

International Nuclear Information System (INIS)

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

2013-01-01

The existing biomass gasifier systems have several technical challenges, which need to be addressed. They are reduction of impurities in the gas, increasing the reliability of the system, easy in operation and maintenance. It is also essential to have a simple design of gasifier system for power generation, which can work even in remote locations. A dual fired downdraft gasifier system was designed to produce clean gas from biomass fuel, used for electricity generation. This system is proposed to overcome a number of technical challenges. The system is equipped with dry gas cleaning and indirect gas cooling equipment. The dry gas cleaning system completely eliminates wet scrubbers that require large quantities of water. It also helps to do away with the disposal issues with the polluted water. With the improved gasifier system, the tar level in the raw gas is less than 100 mg Nm −3 .Cold gas efficiency has improved to 89% by complete gasification of biomass and recycling of waste heat into the reactor. Several parameters, which are considered in the design and development of the reactors, are presented in detail with their performance indicators. - Highlights: • Hot air injection in dual fired reactor reduces the tar content to less than 100 mg Nm −3 . • In clean gas the tar content is 35 mg Nm −3 and the dust content is nil. • The specific gasification rate is 2.8 Nm 3 kg −1 of fuel wood and cold gas efficiency is 89.7%. • CV of the gas: 5.3 MJ Nm −3 , SFC: 1.1 kg kWh −1 and wood to power efficiency: 21%. • Cold gas efficiency is improved by optimizing the reactor's design and recycling the waste heat from hot gas

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Exergetic Analysis of a Novel Solar Cooling System for Combined Cycle Power Plants

Directory of Open Access Journals (Sweden)

Francesco Calise

2016-09-01

Full Text Available This paper presents a detailed exergetic analysis of a novel high-temperature Solar Assisted Combined Cycle (SACC power plant. The system includes a solar field consisting of innovative high-temperature flat plate evacuated solar thermal collectors, a double stage LiBr-H2O absorption chiller, pumps, heat exchangers, storage tanks, mixers, diverters, controllers and a simple single-pressure Combined Cycle (CC power plant. Here, a high temperature solar cooling system is coupled with a conventional combined cycle, in order to pre-cool gas turbine inlet air in order to enhance system efficiency and electrical capacity. In this paper, the system is analyzed from an exergetic point of view, on the basis of an energy-economic model presented in a recent work, where the obtained main results show that SACC exhibits a higher electrical production and efficiency with respect to the conventional CC. The system performance is evaluated by a dynamic simulation, where detailed simulation models are implemented for all the components included in the system. In addition, for all the components and for the system as whole, energy and exergy balances are implemented in order to calculate the magnitude of the irreversibilities within the system. In fact, exergy analysis is used in order to assess: exergy destructions and exergetic efficiencies. Such parameters are used in order to evaluate the magnitude of the irreversibilities in the system and to identify the sources of such irreversibilities. Exergetic efficiencies and exergy destructions are dynamically calculated for the 1-year operation of the system. Similarly, exergetic results are also integrated on weekly and yearly bases in order to evaluate the corresponding irreversibilities. The results showed that the components of the Joule cycle (combustor, turbine and compressor are the major sources of irreversibilities. System overall exergetic efficiency was around 48%. Average weekly solar collector

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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

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.)

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-01

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

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

Science.gov (United States)

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

Thermodynamic analyses of solar thermal gasification of coal for hybrid solar-fossil power and fuel production

International Nuclear Information System (INIS)

Ng, Yi Cheng; Lipiński, Wojciech

2012-01-01

Thermodynamic analyses are performed for solar thermal steam and dry gasification of coal. The selected types of coal are anthracite, bituminous, lignite and peat. Two model conversion paths are considered for each combination of the gasifying agent and the coal type: production of the synthesis gas with its subsequent use in a combined cycle power plant to generate power, and production of the synthesis gas with its subsequent use to produce gasoline via the Fischer–Tropsch synthesis. Replacement of a coal-fired 35% efficient Rankine cycle power plant and a combustion-based integrated gasification combined cycle power plant by a solar-based integrated gasification combined cycle power plant leads to the reduction in specific carbon dioxide emissions by at least 47% and 27%, respectively. Replacement of a conventional gasoline production process via coal gasification and a subsequent Fischer–Tropsch synthesis with gasoline production via solar thermal coal gasification with a subsequent Fischer–Tropsch synthesis leads to the reduction in specific carbon dioxide emissions by at least 39%. -- Highlights: ► Thermodynamic analyses for steam and dry gasification of coal are presented. ► Hybrid solar-fossil paths to power and fuels are compared to those using only combustion. ► Hybrid power production can reduce specific CO 2 emissions by more than 27%. ► Hybrid fuel production can reduce specific CO 2 emissions by more than 39%.

Vertical integration in the nuclear fuel cycle

International Nuclear Information System (INIS)

Mommsen, J.T.

1977-01-01

Vertical integration in the nuclear fuel cycle and its contribution to market power of integrated fuel suppliers were studied. The industry subdivision analyzed is the uranium raw materials sector. The hypotheses demonstrated are that (1) this sector of the industry is trending toward vertical integration between production of uranium raw materials and the manufacture of nuclear fuel elements, and (2) this vertical integration confers upon integrated firms a significant market advantage over non-integrated fuel manufacturers. Under microeconomic concepts the rationale for vertical integration is the pursuit of efficiency, and it is beneficial because it increases physical output and decreases price. The Market Advantage Model developed is an arithmetical statement of the relative market power (in terms of price) between non-integrated nuclear fuel manufacturers and integrated raw material/fuel suppliers, based on the concept of the ''squeeze.'' In operation, the model compares net profit and return on sales of nuclear fuel elements between the competitors, under different price and cost circumstances. The model shows that, if integrated and non-integrated competitors sell their final product at identical prices, the non-integrated manufacturer returns a net profit only 17% of the integrated firm. Also, the integrated supplier can price his product 35% below the non-integrated producer's price and still return the same net profit. Vertical integration confers a definite market advantage to the integrated supplier, and the basic source of that advantage is the cost-price differential of the raw material, uranium

Energy storage technologies and hybrid architectures for specific diesel-driven rail duty cycles: Design and system integration aspects

International Nuclear Information System (INIS)

Meinert, M.; Prenleloup, P.; Schmid, S.; Palacin, R.

2015-01-01

Highlights: • We assessed integration of energy storage systems into hybrid system architectures. • We considered mechanical and electrical energy storage systems. • Potential of different combinations has been analyzed by standardized duty cycles. • Most promising are diesel-driven suburban, regional and shunting operations. • Double-layer capacitors and Lithium-ion batteries have the highest potential. - Abstract: The use of diesel-driven traction is an intrinsic part of the functioning of railway systems and it is expected to continue being so for the foreseeable future. The recent introduction of more restrictive greenhouse gas emission levels and other legislation aiming at the improvement of the environmental performance of railway systems has led to the need of exploring alternatives for cleaner diesel rolling stock. This paper focuses on assessing energy storage systems and the design of hybrid system architectures to determine their potential use in specific diesel-driven rail duty cycles. Hydrostatic accumulators, flywheels, Lithium-ion batteries and double-layer capacitors have been assessed and used to design hybrid system architectures. The potential of the different technology combinations has been analyzed using standardized duty cycles enhanced with gradient profiles related to suburban, regional and shunting operations. The results show that double-layer capacitors and Lithium-ion batteries have the highest potential to be successfully integrated into the system architecture of diesel-driven rail vehicles. Furthermore, the results also suggest that combining these two energy storage technologies into a single hybridisation package is a highly promising design that draws on their strengthens without any significant drawbacks.

Technical and environmental aspects of combined cycle power stations with integrated gasification (CCGI); Aspectos tecnicos y medioambientales de las centrales de ciclo combinado con gasificacion integrada (CCGI)

Energy Technology Data Exchange (ETDEWEB)

Beltran Mora, Hector Alejandro; Urias Romero, Francisco [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

2004-06-15

A description is presented of the operation of the Combined Cycle Power Stations with Integrated Gasification (CCGI) where the use of solid fuels (coal, vacuum residues, petroleum coke, and biomass) or liquids is possible in a thermal power station with the efficiency and many of the own environmental benefits of the combined cycles. The gasification process is analyzed, that is a thermo-chemical process by means of which a fuel that is in solid state or liquid becomes to the gaseous state by means of a partial oxidation and the obtained gas of this process is called synthesis gas (syngas, by its abbreviations in English) that is used in Combined Cycle Power Stations as a substitute for the natural gas. Also the other components of this type of power stations are shown, such as the air separating unit, and some of the modifications that are due to make to adapt a gas turbine so that it uses syngas, and the considerations of their integration with the air separating unit to optimize the operation of the plant are detailed. A comparison of efficiency values of power stations CCGI with the conventional carbon-electric and the power stations of combined cycle that use natural gas is also shown. Finally the emissions of pollutants of SO{sub 2}, NO{sub x} and CO{sub 2} are analyzed. The possibility of using fuels like petroleum coke and vacuum tower residues that are produced in the Cadereyta refinery is studied for the possible construction of a CCGI power station in Mexico. [Spanish] Se presenta la descripcion del funcionamiento de las centrales ciclo combinado con gasificacion integrada (CCGI) donde es posible el uso de combustibles solidos (carbon, residuos de vacio, coque de petroleo, biomasa) o liquidos en una central termica con la eficiencia y muchos de los beneficios ambientales propios de los ciclos combinados. Se analiza el proceso de gasificacion, que es un proceso termoquimico mediante el cual se convierte un combustible que se encuentra en estado solido o

Optimal integration of organic Rankine cycles with industrial processes

International Nuclear Information System (INIS)

Hipólito-Valencia, Brígido J.; Rubio-Castro, Eusiel; Ponce-Ortega, José M.; Serna-González, Medardo; Nápoles-Rivera, Fabricio; El-Halwagi, Mahmoud M.

2013-01-01

Highlights: • An optimization approach for heat integration is proposed. • A new general superstructure for heat integration is proposed. • Heat process streams are simultaneously integrated with an organic Rankine cycle. • Better results can be obtained respect to other previously reported methodologies. - Abstract: This paper presents a procedure for simultaneously handling the problem of optimal integration of regenerative organic Rankine cycles (ORCs) with overall processes. ORCs may allow the recovery of an important fraction of the low-temperature process excess heat (i.e., waste heat from industrial processes) in the form of mechanical energy. An integrated stagewise superstructure is proposed for representing the interconnections and interactions between the HEN and ORC for fixed data of process streams. Based on the integrated superstructure, the optimization problem is formulated as a mixed integer nonlinear programming problem to simultaneously account for the capital and operating costs including the revenue from the sale of the shaft power produced by the integrated system. The application of this method is illustrated with three example problems. Results show that the proposed procedure provides significantly better results than an earlier developed method for discovering optimal integrated systems using a sequential approach, due to the fact that it accounts simultaneously for the tradeoffs between the capital and operating costs as well as the sale of the produced energy. Also, the proposed method is an improvement over the previously reported methods for solving the synthesis problem of heat exchanger networks without the option of integration with an ORC (i.e., stand-alone heat exchanger networks)

CISCO - Combined Cycle with Integrated Sewage Sludge Combustion; Kombi-Anlage mit integrierter Klaerschlam-Verbrennung - CISCO (Combined Cycle with Integrated Sewage Sludge Combustion)

Energy Technology Data Exchange (ETDEWEB)

Vockrodt, S.; Leithner, R. [Technische Univ. Braunschweig (Germany). Inst. fuer Waerme- und Brennstofftechnik

2004-12-01

A new combined process is presented in which is sewage sludge is dried until it can be combusted, and the heat of combustion is used for sludge drying. (orig.) [German] Mit einer neuen Verfahrenskombination ist es moeglich, Klaerschlamm so weit zu trocknen, dass er verbrannt werden kann, wobei die Verbrennungswaerme zur Trocknung genutzt wird. (orig.)

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

DEFF Research Database (Denmark)

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

2014-01-01

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

Causticizing for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

Scott Sinquefeld; James Cantrell; Xiaoyan Zeng; Alan Ball; Jeff Empie

2009-01-07

The cost-benefit outlook of black liquor gasification (BLG) could be greatly improved if the smelt causticization step could be achieved in situ during the gasification step. Or, at a minimum, the increase in causticizing load associated with BLG could be mitigated. A number of chemistries have been proven successful during black liquor combustion. In this project, three in situ causticizing processes (titanate, manganate, and borate) were evaluated under conditions suitable for high temperature entrained flow BLG, and low temperature steam reforming of black liquor. The evaluation included both thermodynamic modeling and lab experimentation. Titanate and manganate were tested for complete direct causticizing (to thus eliminate the lime cycle), and borates were evaluated for partial causticizing (to mitigate the load increase associated with BLG). Criteria included high carbonate conversion, corresponding hydroxide recovery upon hydrolysis, non process element (NPE) removal, and economics. Of the six cases (three chemistries at two BLG conditions), only two were found to be industrially viable: titanates for complete causticizing during high temperature BLG, and borates for partial causticizing during high temperature BLG. These two cases were evaluated for integration into a gasification-based recovery island. The Larsen [28] BLG cost-benefit study was used as a reference case for economic forecasting (i.e. a 1500 tpd pulp mill using BLG and upgrading the lime cycle). By comparison, using the titanate direct causticizing process yielded a net present value (NPV) of $25M over the NPV of BLG with conventional lime cycle. Using the existing lime cycle plus borate autocausticizing for extra capacity yielded a NPV of $16M.

Energy-exergy analysis of compressor pressure ratio effects on thermodynamic performance of ammonia water combined cycle

International Nuclear Information System (INIS)

Mohtaram, Soheil; Chen, Wen; Zargar, T.; Lin, Ji

2017-01-01

Highlights: • Energy exergy analysis is conducted to find the effects of RP. • EES software is utilized to perform the detailed energy-exergy analyses. • Effects investigated through energy and exergy destruction, enthalpy, yields, etc. • Detailed results are reported showing the performance of gas and combined cycle. - Abstract: The purpose of this study is to investigate the effect of compressor pressure ratio (RP) on the thermodynamic performances of ammonia-water combined cycle through energy and exergy destruction, enthalpy temperature, yields, and flow velocity. The energy-exergy analysis is conducted on the ammonia water combined cycle and the Rankine cycle, respectively. Engineering Equation Solver (EES) software is utilized to perform the detailed analyses. Values and ratios regarding heat drop and exergy loss are presented in separate tables for different equipments. The results obtained by the energy-exergy analysis indicate that by increasing the pressure ratio compressor, exergy destruction of high-pressure compressors, intercooler, gas turbine and the special produced work of gas turbine cycle constantly increase and the exergy destruction of recuperator, in contrast, decreases continuously. In addition, the least amount of input fuel into the combined cycle is observed when the pressure ratio is no less than 7.5. Subsequently, the efficiency of the cycle in gas turbine and combined cycle is reduced because the fuel input into the combined cycle is increased.

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

Science.gov (United States)

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

2014-05-01

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

Combined Brayton-JT cycles with refrigerants for natural gas liquefaction

Science.gov (United States)

Chang, Ho-Myung; Park, Jae Hoon; Lee, Sanggyu; Choe, Kun Hyung

2012-06-01

Thermodynamic cycles for natural gas liquefaction with single-component refrigerants are investigated under a governmental project in Korea, aiming at new processes to meet the requirements on high efficiency, large capacity, and simple equipment. Based upon the optimization theory recently published by the present authors, it is proposed to replace the methane-JT cycle in conventional cascade process with a nitrogen-Brayton cycle. A variety of systems to combine nitrogen-Brayton, ethane-JT and propane-JT cycles are simulated with Aspen HYSYS and quantitatively compared in terms of thermodynamic efficiency, flow rate of refrigerants, and estimated size of heat exchangers. A specific Brayton-JT cycle is suggested with detailed thermodynamic data for further process development. The suggested cycle is expected to be more efficient and simpler than the existing cascade process, while still taking advantage of easy and robust operation with single-component refrigerants.

Integrated design strategy for product life-cycle management

Science.gov (United States)

Johnson, G. Patrick

2001-02-01

Two major trends suggest new considerations for environmentally conscious manufacturing (ECM) -- the continuation of dematerialization and the growing trend toward goods becoming services. A diversity of existing research could be integrated around those trends in ways that can enhance ECM. Major research-based achievements in information, computation, and communications systems, sophisticated and inexpensive sensing capabilities, highly automated and precise manufacturing technologies, and new materials continue to drive the phenomenon of dematerialization - the reduction of the material and energy content of per capita GDP. Knowledge is also growing about the sociology, economics, mathematics, management and organization of complex socio-economic systems. And that has driven a trend towards goods evolving into services. But even with these significant trends, the value of material, energy, information and human resources incorporated into the manufacture, use and disposal of modern products and services often far exceeds the benefits realized. Multi-disciplinary research integrating these drivers with advances in ECM concepts could be the basis for a new strategy of production. It is argued that a strategy of integrating information resources with physical and human resources over product life cycles, together with considering products as streams of service over time, could lead to significant economic payoff. That strategy leads to an overall design concept to minimize costs of all resources over the product life cycle to more fully capture benefits of all resources incorporated into modern products. It is possible by including life cycle monitoring, periodic component replacement, re-manufacture, salvage and human factor skill enhancement into initial design.

Integration between a thermophotovoltaic generator and an Organic Rankine Cycle

International Nuclear Information System (INIS)

De Pascale, Andrea; Ferrari, Claudio; Melino, Francesco; Morini, Mirko; Pinelli, Michele

2012-01-01

Highlights: ► A new energy system comprising a Thermo-Photo-Voltaic and Organic Rankine Cycle. ► An analytical model to calculate the performance of the system is introduced. ► The system shows promising results in terms of CHP performance. -- Abstract: The constant increase in energy need and the growing attention to the related environmental impact have given a boost to the development of new strategies in order to reduce the primary energy consumption and to improve its utilization. One of the possible strategies for achieving this aim is Combined Heat and Power (CHP) specially if coupled with the concept of on-site generation (also known as distributed generation). These approaches allow the reduction of fuel consumption and pollutant emissions and the increase of security in energy supply. This paper introduces the Thermophotovoltaic Organic Rankine Cycle Integrated System (TORCIS), an energy system integrating a ThermoPhotoVoltaic generator (TPV) and an Organic Rankine Cycle (ORC). This study represents the start-up of a research program which involves three research teams from IMEM – National Research Council, ENDIF – University of Ferrara and DIEM – University of Bologna. The aim of this research is the complete definition and the pre-prototyping characterization of this system covering all the unresolved issues in this field. More specifically, TPV is a system to convert the radiation emitted from an artificial heat source (i.e. the combustion of fuel) into electrical energy by the use of photovoltaic cells. In this system, the produced electrical power is strictly connected to the thermal one as their ratio is almost constant and cannot be changed without severe loss in performance. The coupling between TPV and ORC allows this limitation to be overcome by the realization of a CHP system which can be regulated with a large degree of freedom changing the ratio between the produced electrical and thermal power. In this study a thermodynamic

Combustion performance of cellulosic biomass in a gasifier-based cookstove

Science.gov (United States)

Sulaiman, Shaharin A.; Romli, Raffisyazana

2012-06-01

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

FY 1989 report on the results of the development of the entrained bed coal gasification power plant. Part 3. Fabrication/installation of pilot plant (Fabrication/installation drawings and fabrication/installation pictures - 1/2); 1989 nendo seika hokokusho. Funryusho sekitan gaska hatsuden plant kaihatsu - Sono 3. Pilot plant seisaku suetsuke hen (Seisaku suetsukezu oyobi seisaku suetsuke shashin) (1/2)

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-03-01

For the purpose of establishing the technology of the integrated coal gasification combined cycle power generation, the fabrication, installation work, etc. were conducted of a 200t/d entrained bed coal gasification pilot plant, and drawings of fabrication/installation in the FY 1989 were summarized. In fabrication/installation drawings, drawings of the following were included: layout of the total system and the yard, gasifier facilities (assembly drawing of the pressure part of gasifier, drawing of machinery arrangement of gasifier facilities, system diagram of raw coal receiving device, system diagram of pulverized coal feed equipment, system diagram of char feed equipment, etc.), gas refining facilities - dry desulfurizer (assembly drawing of desulfurizing agent carrying filter, assembly drawing of regeneration tower filter, structural drawing of SO{sub 2} reduction tower filter, assembly drawing of start-up heater, etc.), gas refining facilities - dry dust removal system (assembly drawing of No.1 dust separation filter, installation drawing of elevator, etc.), gas turbine facilities (cross section of gas turbine, front view of gas turbine, structural cross section of gas turbogenerator, etc.), actual-pressure/actual-size combustor test equipment (structural drawing of test stand, structural drawing of exhaust temperature reduction device, assembly/sectioned drawing of low-pressure air compressor, etc.) (NEDO)

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

Energy Technology Data Exchange (ETDEWEB)

1990-07-01

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

Outside-in control -Does plant cell wall integrity regulate cell cycle progression?

Science.gov (United States)

Gigli-Bisceglia, Nora; Hamann, Thorsten

2018-04-13

During recent years it has become accepted that plant cell walls are not inert objects surrounding all plant cells but are instead highly dynamic, plastic structures. They are involved in a large number of cell biological processes and contribute actively to plant growth, development and interaction with environment. Therefore, it is not surprising that cellular processes can control plant cell wall integrity while, simultaneously, cell wall integrity can influence cellular processes. In yeast and animal cells such a bi-directional relationship also exists between the yeast/animal extra-cellular matrices and the cell cycle. In yeast, the cell wall integrity maintenance mechanism and a dedicated plasmamembrane integrity checkpoint are mediating this relationship. Recent research has yielded insights into the mechanism controlling plant cell wall metabolism during cytokinesis. However, knowledge regarding putative regulatory pathways controlling adaptive modifications in plant cell cycle activity in response to changes in the state of the plant cell wall are not yet identified. In this review, we summarize similarities and differences in regulatory mechanisms coordinating extra cellular matrices and cell cycle activity in animal and yeast cells, discuss the available evidence supporting the existence of such a mechanism in plants and suggest that the plant cell wall integrity maintenance mechanism might also control cell cycle activity in plant cells. This article is protected by copyright. All rights reserved.

Reducing life cycle greenhouse gas emissions of corn ethanol by integrating biomass to produce heat and power at ethanol plants

International Nuclear Information System (INIS)

Kaliyan, Nalladurai; Morey, R. Vance; Tiffany, Douglas G.

2011-01-01

A life-cycle assessment (LCA) of corn ethanol was conducted to determine the reduction in the life-cycle greenhouse gas (GHG) emissions for corn ethanol compared to gasoline by integrating biomass fuels to replace fossil fuels (natural gas and grid electricity) in a U.S. Midwest dry-grind corn ethanol plant producing 0.19 hm 3 y -1 of denatured ethanol. The biomass fuels studied are corn stover and ethanol co-products [dried distillers grains with solubles (DDGS), and syrup (solubles portion of DDGS)]. The biomass conversion technologies/systems considered are process heat (PH) only systems, combined heat and power (CHP) systems, and biomass integrated gasification combined cycle (BIGCC) systems. The life-cycle GHG emission reduction for corn ethanol compared to gasoline is 38.9% for PH with natural gas, 57.7% for PH with corn stover, 79.1% for CHP with corn stover, 78.2% for IGCC with natural gas, 119.0% for BIGCC with corn stover, and 111.4% for BIGCC with syrup and stover. These GHG emission estimates do not include indirect land use change effects. GHG emission reductions for CHP, IGCC, and BIGCC include power sent to the grid which replaces electricity from coal. BIGCC results in greater reductions in GHG emissions than IGCC with natural gas because biomass is substituted for fossil fuels. In addition, underground sequestration of CO 2 gas from the ethanol plant's fermentation tank could further reduce the life-cycle GHG emission for corn ethanol by 32% compared to gasoline.

Sorting through the many total-energy-cycle pathways possible with early plug-in hybrids

International Nuclear Information System (INIS)

Gaines, L.; Burnham, A.; Rousseau, A.; Santini, D.

2008-01-01

Using the 'total energy cycle' methodology, we compare U.S. near term (to ∼2015) alternative pathways for converting energy to light-duty vehicle kilometers of travel (VKT) in plug-in hybrids (PHEVs), hybrids (HEVs), and conventional vehicles (CVs). For PHEVs, we present total energy-per-unit-of-VKT information two ways (1) energy from the grid during charge depletion (CD); (2) energy from stored on-board fossil fuel when charge sustaining (CS). We examine 'incremental sources of supply of liquid fuel such as (a) oil sands from Canada, (b) Fischer-Tropsch diesel via natural gas imported by LNG tanker, and (c) ethanol from cellulosic biomass. We compare such fuel pathways to various possible power converters producing electricity, including (i) new coal boilers, (ii) new integrated, gasified coal combined cycle (IGCC), (iii) existing natural gas fueled combined cycle (NGCC), (iv) existing natural gas combustion turbines, (v) wood-to-electricity, and (vi) wind/solar. We simulate a fuel cell HEV and also consider the possibility of a plug-in hybrid fuel cell vehicle (FCV). For the simulated FCV our results address the merits of converting some fuels to hydrogen to power the fuel cell vs. conversion of those same fuels to electricity to charge the PHEV battery. The investigation is confined to a U.S. compact sized car (i.e. a world passenger car). Where most other studies have focused on emissions (greenhouse gases and conventional air pollutants), this study focuses on identification of the pathway providing the most vehicle kilometers from each of five feedstocks examined. The GREET 1.7 fuel cycle model and the new GREET 2.7 vehicle cycle model were used as the foundation for this study. Total energy, energy by fuel type, total greenhouse gases (GHGs), volatile organic compounds (VOC), carbon monoxide (CO), nitrogen oxides (NO x ), fine particulate (PM2.5) and sulfur oxides (SO x ) values are presented. We also isolate the PHEV emissions contribution from varying k

The integral fast reactor fuel cycle

International Nuclear Information System (INIS)

Chang, Y.I.

1990-01-01

The liquid-metal reactor (LMR) has the potential to extend the uranium resource by a factor of 50 to 100 over current commercial light water reactors (LWRs). In the integral fast reactor (IFR) development program, the entire reactor system - reactor, fuel cycle, and waste process - is being developed and optimized at the same time as a single integral entity. A key feature of the IFR concept is the metallic fuel. The lead irradiation tests on the new U-Pu-Zr metallic fuel in the Experimental Breeder Reactor II have surpassed 185000 MWd/t burnup, and its high burnup capability has now been fully demonstrated. The metallic fuel also allows a radically improved fuel cycle technology. Pyroprocessing, which utilizes high temperatures and molten salt and molten metal solvents, can be advantageously utilized for processing metal fuels because the product is metal suitable for fabrication into new fuel elements. Direct production of a metal product avoids expensive and cumbersome chemical conversion steps that would result from use of the conventional Purex solvent extraction process. The key step in the IFR process is electrorefining, which provides for recovery of the valuable fuel constituents, uranium and plutonium, and for removal of fission products. A notable feature of the IFR process is that the actinide elements accompany plutonium through the process. This results in a major advantage in the high-level waste management

Gasification and co-gasification of biomass wastes: Effect of the biomass origin and the gasifier operating conditions

Energy Technology Data Exchange (ETDEWEB)

Lapuerta, Magin; Hernandez, Juan J.; Pazo, Amparo; Lopez, Julio [Universidad de Castilla-La Mancha, Escuela Tecnica Superior de Ingenieros Industriales (Edificio Politecnico), Avenida Camilo Jose Cela s/n. 13071 Ciudad Real (Spain)

2008-09-15

Air gasification of different biomass fuels, including forestry (pinus pinaster pruning) and agricultural (grapevine and olive tree pruning) wastes as well as industry wastes (sawdust and marc of grape), has been carried out in a circulating flow gasifier in order to evaluate the potential of using these types of biomass in the same equipment, thus providing higher operation flexibility and minimizing the effect of seasonal fuel supply variations. The potential of using biomass as an additional supporting fuel in coal fuelled power plants has also been evaluated through tests involving mixtures of biomass and coal-coke, the coke being a typical waste of oil companies. The effect of the main gasifier operating conditions, such as the relative biomass/air ratio and the reaction temperature, has been analysed to establish the conditions allowing higher gasification efficiency, carbon conversion and/or fuel constituents (CO, H{sub 2} and CH{sub 4}) concentration and production. Results of the work encourage the combined use of the different biomass fuels without significant modifications in the installation, although agricultural wastes (grapevine and olive pruning) could to lead to more efficient gasification processes. These latter wastes appear as interesting fuels to generate a producer gas to be used in internal combustion engines or gas turbines (high gasification efficiency and gas yield), while sawdust could be a very adequate fuel to produce a H{sub 2}-rich gas (with interest for fuel cells) due to its highest reactivity. The influence of the reaction temperature on the gasification characteristics was not as significant as that of the biomass/air ratio, although the H{sub 2} concentration increased with increasing temperature. (author)

Life cycle integrated thermoeconomic assessment method for energy conversion systems

International Nuclear Information System (INIS)

Kanbur, Baris Burak; Xiang, Liming; Dubey, Swapnil; Choo, Fook Hoong; Duan, Fei

2017-01-01

Highlights: • A new LCA integrated thermoeconomic approach is presented. • The new unit fuel cost is found 4.8 times higher than the classic method. • The new defined parameter increased the sustainability index by 67.1%. • The case studies are performed for countries with different CO 2 prices. - Abstract: Life cycle assessment (LCA) based thermoeconomic modelling has been applied for the evaluation of energy conversion systems since it provided more comprehensive and applicable assessment criteria. This study proposes an improved thermoeconomic method, named as life cycle integrated thermoeconomic assessment (LCiTA), which combines the LCA based enviroeconomic parameters in the production steps of the system components and fuel with the conventional thermoeconomic method for the energy conversion systems. A micro-cogeneration system is investigated and analyzed with the LCiTA method, the comparative studies show that the unit cost of fuel by using the LCiTA method is 3.8 times higher than the conventional thermoeconomic model. It is also realized that the enviroeconomic parameters during the operation of the system components do not have significant impacts on the system streams since the exergetic parameters are dominant in the thermoeconomic calculations. Moreover, the improved sustainability index is found roundly 67.2% higher than the previously defined sustainability index, suggesting that the enviroeconomic and thermoeconomic parameters decrease the impact of the exergy destruction in the sustainability index definition. To find the feasible operation conditions for the micro-cogeneration system, different assessment strategies are presented. Furthermore, a case study for Singapore is conducted to see the impact of the forecasted carbon dioxide prices on the thermoeconomic performance of the micro-cogeneration system.

Exergy analysis of a combined vapor power cycle and boiler flue gas driven double effect water–LiBr absorption refrigeration system

International Nuclear Information System (INIS)

Talukdar, K.; Gogoi, T.K.

2016-01-01

Highlights: • A combined vapor power and double effect water–LiBr absorption refrigeration system is proposed. • The flue gas of the power cycle boiler is the heat source for the double effect refrigeration system. • Energy and exergy analyses are performed to evaluate performance of the combined system. • Effect of high pressure generator temperature on combined system performance is highlighted. • Comparison is provided with a single effect absorption system integrated combined system. - Abstract: A combined vapor power cycle (PC) and double effect water–LiBr absorption refrigeration system (ARS) is proposed in this study. The boiler leaving flue gas of the PC is the heat source for the high pressure generator (HPG) of the double effect ARS. Exergy analysis of the proposed system is performed to show the performance variation of both the topping PC and the bottoming ARS with changing HPG temperature from 120 °C to 150 °C. Further the performance of double effect ARS integrated combined power and cooling system is compared with a similar system integrated with a single effect ARS. HPG temperature of the double effect ARS and generator temperature of the single effect ARS are considered as 120 °C and 80 °C respectively. Results show that the power and efficiency of the topping PC decreases with HPG temperature due to reduction in steam generation rate in the boiler. COP and exergy efficiency of the double effect ARS also reduces with increasing HPG temperature. The irreversible losses in the PC components decrease while the total irreversibility of the combined power and cooling system increases with HPG temperature due to increase in exergy loss with the HPG leaving flue gas and irreversibility of the ARS components. PC performance does not vary much due to replacement of the double effect ARS with the single effect ARS, however higher COP and exergy efficiency of the double effect system are achieved with much lower irreversible losses in the

Maximizing biofuel production in a thermochemical biorefinery by adding electrolytic hydrogen and by integrating torrefaction with entrained flow gasification

DEFF Research Database (Denmark)

Clausen, Lasse Røngaard

2015-01-01

double the biofuel production per biomass input by converting almost all of the carbon in the biomass feed to carbon stored in the biofuel product. Water or steam electrolysis can supply the hydrogen to the biorefinery and also the oxygen for the gasifier. This paper presents the design and thermodynamic...... analysis of two biorefineries integrating water electrolysis for the production of methanol. In both plants, torrefied woody biomass is supplied to an entrained flow gasifier, but in one of the plants, the torrefaction process occurs on-site, as it is integrated with the entrained flow gasification process....... The analysis shows that the biorefinery with integrated torrefaction has a higher biomass to methanol energy ratio (136% vs. 101%) as well as higher total energy efficiency (62% vs. 56%). By comparing with two identical biorefineries without electrolysis, it is concluded that the biorefinery with integrated...

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

Science.gov (United States)

Vakalis, S; Malamis, D; Moustakas, K

2018-06-15

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

Systems Analyses of Advanced Brayton Cycles

Energy Technology Data Exchange (ETDEWEB)

A.D. Rao; D.J. Francuz; J.D. Maclay; J. Brouwer; A. Verma; M. Li; G.S. Samuelsen

2008-09-30

The main objective is to identify and assess advanced improvements to the Brayton Cycle (such as but not limited to firing temperature, pressure ratio, combustion techniques, intercooling, fuel or combustion air augmentation, enhanced blade cooling schemes) that will lead to significant performance improvements in coal based power systems. This assessment is conducted in the context of conceptual design studies (systems studies) that advance state-of-art Brayton cycles and result in coal based efficiencies equivalent to 65% + on natural gas basis (LHV), or approximately an 8% reduction in heat rate of an IGCC plant utilizing the H class steam cooled gas turbine. H class gas turbines are commercially offered by General Electric and Mitsubishi for natural gas based combined cycle applications with 60% efficiency (LHV) and it is expected that such machine will be offered for syngas applications within the next 10 years. The studies are being sufficiently detailed so that third parties will be able to validate portions or all of the studies. The designs and system studies are based on plants for near zero emissions (including CO{sub 2}). Also included in this program is the performance evaluation of other advanced technologies such as advanced compression concepts and the fuel cell based combined cycle. The objective of the fuel cell based combined cycle task is to identify the desired performance characteristics and design basis for a gas turbine that will be integrated with an SOFC in Integrated Gasification Fuel Cell (IGFC) applications. The goal is the conceptualization of near zero emission (including CO{sub 2} capture) integrated gasification power plants producing electricity as the principle product. The capability of such plants to coproduce H{sub 2} is qualitatively addressed. Since a total systems solution is critical to establishing a plant configuration worthy of a comprehensive market interest, a baseline IGCC plant scheme is developed and used to study

Safeguards operations in the integral fast reactor fuel cycle

International Nuclear Information System (INIS)

Goff, K.M.; Benedict, R.W.; Brumbach, S.B.; Dickerman, C.E.; Tompot, R.W.

1994-01-01

Argonne National Laboratory is currently demonstrating the fuel cycle for the Integral Fast Reactor (IFR), an advanced reactor concept that takes advantage of the properties of metallic fuel and liquid metal cooling to offer significant improvements in reactor safety, operation, fuel-cycle economics, environmental protection, and safeguards. The IFR fuel cycle employs a pyrometallurgical process using molten salts and liquid metals to recover actinides from spent fuel. The safeguards aspects of the fuel cycle demonstration must be approved by the United States Department of Energy, but a further goal of the program is to develop a safeguards system that could gain acceptance from the Nuclear Regulatory Commission and International Atomic Energy Agency. This fuel cycle is described with emphasis on aspects that differ from aqueous reprocessing and on its improved safeguardability due to decreased attractiveness and diversion potential of all process streams, including the fuel product

Life cycle assessment of biofuels from an integrated Brazilian algae-sugarcane biorefinery

International Nuclear Information System (INIS)

Souza, Simone P.; Gopal, Anand R.; Seabra, Joaquim E.A.

2015-01-01

Sugarcane ethanol biorefineries in Brazil produce carbon dioxide, electricity and heat as byproducts. These are essential inputs for algae biodiesel production. In this paper, we assessed ethanol's life cycle greenhouse gas emissions and fossil energy use produced in an integrated sugarcane and algae biorefinery where biodiesel replaces petroleum diesel for all agricultural operations. Carbon dioxide from cane juice fermentation is used as the carbon source for algae cultivation, and sugarcane bagasse is the sole source of energy for the entire facility. Glycerin produced from the biodiesel plant is consumed by algae during the mixotrophic growth phase. We assessed the uncertainties through a detailed Monte-Carlo analysis. We found that this integrated system can improve both the life cycle greenhouse gas emissions and the fossil energy use of sugarcane ethanol by around 10% and 50%, respectively, compared to a traditional Brazilian sugarcane ethanol distillery. - Highlights: • A high diesel consumption is associated to the ethanol sugarcane life-cycle. • Sugarcane industry can provide sources of carbon and energy for the algae growing. • The sugarcane-algae integration can improve the ethanol life-cycle performance. • This integration is a promising pathway for the deployment of algae biodiesel. • There are still significant techno-economic barriers associated with algae biodiesel

Consequential environmental and economic life cycle assessment of green and gray stormwater infrastructures for combined sewer systems.

Science.gov (United States)

Wang, Ranran; Eckelman, Matthew J; Zimmerman, Julie B

2013-10-01

A consequential life cycle assessment (LCA) is conducted to evaluate the trade-offs between water quality improvements and the incremental climate, resource, and economic costs of implementing green (bioretention basin, green roof, and permeable pavement) versus gray (municipal separate stormwater sewer systems, MS4) alternatives of stormwater infrastructure expansions against a baseline combined sewer system with combined sewer overflows in a typical Northeast US watershed for typical, dry, and wet years. Results show that bioretention basins can achieve water quality improvement goals (e.g., mitigating freshwater eutrophication) for the least climate and economic costs of 61 kg CO2 eq. and $98 per kg P eq. reduction, respectively. MS4 demonstrates the minimum life cycle fossil energy use of 42 kg oil eq. per kg P eq. reduction. When integrated with the expansion in stormwater infrastructure, implementation of advanced wastewater treatment processes can further reduce the impact of stormwater runoff on aquatic environment at a minimal environmental cost (77 kg CO2 eq. per kg P eq. reduction), which provides support and valuable insights for the further development of integrated management of stormwater and wastewater. The consideration of critical model parameters (i.e., precipitation intensity, land imperviousness, and infrastructure life expectancy) highlighted the importance and implications of varying local conditions and infrastructure characteristics on the costs and benefits of stormwater management. Of particular note is that the impact of MS4 on the local aquatic environment is highly dependent on local runoff quality indicating that a combined system of green infrastructure prior to MS4 potentially provides a more cost-effective improvement to local water quality.

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

International Nuclear Information System (INIS)

Wilen, C.; Kurkela, E.

1997-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-12-31

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

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.

Exergy analysis for combined regenerative Brayton and inverse Brayton cycles

OpenAIRE

Zelong Zhang, Lingen Chen, Fengrui Sun

2012-01-01

This paper presents the study of exergy analysis of combined regenerative Brayton and inverse Brayton cycles. The analytical formulae of exergy loss and exergy efficiency are derived. The largest exergy loss location is determined. By taking the maximum exergy efficiency as the objective, the choice of bottom cycle pressure ratio is optimized by detailed numerical examples, and the corresponding optimal exergy efficiency is obtained. The influences of various parameters on the exergy efficien...

A combined thermodynamic cycle based on methanol dissociation for IC (internal combustion) engine exhaust heat recovery

International Nuclear Information System (INIS)

Fu, Jianqin; Liu, Jingping; Xu, Zhengxin; Ren, Chengqin; Deng, Banglin

2013-01-01

In this paper, a novel approach for exhaust heat recovery was proposed to improve IC (internal combustion) engine fuel efficiency and also to achieve the goal for direct usage of methanol as IC engine fuel. An open organic Rankine cycle system using methanol as working medium is coupled to IC engine exhaust pipe for exhaust heat recovery. In the bottom cycle, the working medium first undergoes dissociation and expansion processes, and is then directed back to IC engine as fuel. As the external bottom cycle and the IC engine main cycle are combined together, this scheme forms a combined thermodynamic cycle. Then, this concept was applied to a turbocharged engine, and the corresponding simulation models were built for both of the external bottom cycle and the IC engine main cycle. On this basis, the energy saving potential of this combined cycle was estimated by parametric analyses. Compared to the methanol vapor engine, IC engine in-cylinder efficiency has an increase of 1.4–2.1 percentage points under full load conditions, while the external bottom cycle can increase the fuel efficiency by 3.9–5.2 percentage points at the working pressure of 30 bar. The maximum improvement to the IC engine global fuel efficiency reaches 6.8 percentage points. - Highlights: • A combined thermodynamic cycle using methanol as working medium for IC engine exhaust heat recovery is proposed. • The external bottom cycle of exhaust heat recovery and IC engine working cycle are combined together. • IC engine fuel efficiency could be improved from both in-cylinder working cycle and external bottom cycle. • The maximum improvement to the IC engine global fuel efficiency reaches 6.8 percentage points at full load

Integrated hot fuel gas cleaning for advanced gasification combined cycle process