The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Emmanouil Kakaras - One of the best experts on this subject based on the ideXlab platform.
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modelling of substitute natural gas production via combined Gasification and power to fuel
Renewable Energy, 2019Co-Authors: Emmanouil Kakaras, Efthymia Ioanna Koytsoumpa, Sotirios KarellasAbstract:Abstract The combination of water electrolysis and solid fuel Gasification offers the substitution of Air Separation Unit, the reduction or elimination of water gas shift catalytic system and acid gas removal technology. Subsequently, the direct utilisation of CO2, which otherwise would be emitted during production and its conversion to valuable fuels in combination with energy storage are achieved. Steam Gasification and steam-Oxygen Gasification in different operating conditions and scales are combined with electrolysers with the aim to define optimum efficiencies towards SNG production and reduction of direct CO2 emissions. Modelling and comparison of 6 different cases for steam and steam-Oxygen Gasification process, gas cleaning and conditioning technologies focusing on tar removal, activated carbon, water gas shift, and acid gas removal technologies with potassium carbonate and MDEA are investigated. Capture ratios are balanced with and without water gas shift reactor according to the requirements of SNG synthesis. The efficiency of Gasification and power to SNG ranges between 57.67% and 63.43% for the optimum cases with low pressure steam/Oxygen Gasification and electrolysers sized according to Oxygen demand and according to the oversized electrolysers case respectively. The overall energy conversion resulted in an energy conversion efficiency of 72.83% and 73.51% with the production of steam.
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An evaluation of Substitute natural gas production from different coal Gasification processes based on modeling
Energy, 2012Co-Authors: Sotirios Karellas, K.d. Panopoulos, G. Panousis, A. Rigas, Jürgen Karl, Emmanouil KakarasAbstract:Abstract Coal and lignite will play a significant role in the future energy production. However, the technical options for the reduction of CO2 emissions will define the extent of their share in the future energy mix. The production of synthetic or substitute natural gas (SNG) from solid fossil fuels seems to be a very attractive process: coal and lignite can be upgraded into a methane rich gas which can be transported and further used in high efficient power systems coupled with CO2 sequestration technologies. The aim of this paper is to present a modeling analysis comparison between substitute natural gas production from coal by means of allothermal steam Gasification and autothermal Oxygen Gasification. In order to produce SNG from syngas several unit operations are required such as syngas cooling, cleaning, potential compression and, of course, methanation reactors. Finally the gas which is produced has to be conditioned i.e. removal of unwanted species, such as CO2 etc. The heat recovered from the overall process is utilized by a steam cycle, producing power. These processes were modeled with the computer software IPSEpro™. An energetic and exergetic analysis of the coal to SNG processes have been realized and compared.
Efthymia Ioanna Koytsoumpa - One of the best experts on this subject based on the ideXlab platform.
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modelling of substitute natural gas production via combined Gasification and power to fuel
Renewable Energy, 2019Co-Authors: Emmanouil Kakaras, Efthymia Ioanna Koytsoumpa, Sotirios KarellasAbstract:Abstract The combination of water electrolysis and solid fuel Gasification offers the substitution of Air Separation Unit, the reduction or elimination of water gas shift catalytic system and acid gas removal technology. Subsequently, the direct utilisation of CO2, which otherwise would be emitted during production and its conversion to valuable fuels in combination with energy storage are achieved. Steam Gasification and steam-Oxygen Gasification in different operating conditions and scales are combined with electrolysers with the aim to define optimum efficiencies towards SNG production and reduction of direct CO2 emissions. Modelling and comparison of 6 different cases for steam and steam-Oxygen Gasification process, gas cleaning and conditioning technologies focusing on tar removal, activated carbon, water gas shift, and acid gas removal technologies with potassium carbonate and MDEA are investigated. Capture ratios are balanced with and without water gas shift reactor according to the requirements of SNG synthesis. The efficiency of Gasification and power to SNG ranges between 57.67% and 63.43% for the optimum cases with low pressure steam/Oxygen Gasification and electrolysers sized according to Oxygen demand and according to the oversized electrolysers case respectively. The overall energy conversion resulted in an energy conversion efficiency of 72.83% and 73.51% with the production of steam.
T. M. Bogacheva - One of the best experts on this subject based on the ideXlab platform.
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Synthesis gas from coal
Thermal Engineering, 2002Co-Authors: T. M. Bogacheva, B. A. Kol'chuginAbstract:A concept for producing artificial gaseous fuel from coal is presented. Results of an experimental investigation of steam-Oxygen Gasification of Kuznetsk lean coal on a test facility that converts 5 kg/h of coal are presented.
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Modeling of the Transformation of Sulfur Compounds in Oxygen Gasification of Coal Dust
Combustion Explosion and Shock Waves, 2001Co-Authors: G. Ya. Gerasimov, T. M. BogachevaAbstract:It is shown that, owing to the presence of a large amount of Ca and Fe in the mineral part of a fuel, it is possible to substantially reduce the sulfur content in the gaseous phase and, hence, improve ecological indexes of the process under the following conditions: the content of O_2 is close to the stoichiometric value for fuel Gasification, the temperature is ≈(1600–1800) K, and the pressure is ≈ 10 atm or higher.
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Thermodynamic Analysis of the Process of Formation of Sulfur Compounds in Oxygen Gasification of Coal
Journal of Engineering Physics and Thermophysics, 2001Co-Authors: G. Ya. Gerasimov, T. M. BogachevaAbstract:A thermodynamic approach to the description of the behavior of the system fuel–oxidizer in Oxygen Gasification of coal is used to reveal the main mechanisms of the process of capture of sulfur by the mineral part of the coal and to determine the fundamental possibility of the process for coals from different coal fields.
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Gasification of pulverized coal fuel at atmospheric pressure
Solid Fuel Chemistry, 2001Co-Authors: T. M. Bogacheva, G. Ya. Gerasimov, B. A. Kolchugin, A. A. Kniga, V. N. Proskurin, A. S. SamoilovAbstract:This paper presents the results of an experimental investigation of the process of Oxygen Gasification of Kuznetsk coal of grade T at atmospheric pressure in a bench installation with a capacity of up to 5 kg/hr with respect to coal. The experimental results are comparable with the data of numerical simulation.
Robert C. Brown - One of the best experts on this subject based on the ideXlab platform.
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steam Oxygen Gasification system for the production of clean syngas from switchgrass
Fuel, 2015Co-Authors: Karl M. Broer, Patrick J. Woolcock, Patrick A. Johnston, Robert C. BrownAbstract:Abstract A pilot-scale 25 kg/h fluidized bed, Oxygen/steam blown gasifier and syngas cleaning system was developed to convert switchgrass into clean syngas. The system is rated for operation at gage pressures up to 1 bar. The reactor vessel incorporated a novel guard heating system to simulate near-adiabatic operation of large commercial-scale gasifiers, and was effective for Gasification temperatures up to 900 °C. After removing particulate from the gas stream via cyclones, a warm-gas cleaning operation based on oil scrubbing was used to remove tars. Sulfur compounds were removed via solid-phase adsorption. Ammonia was removed by water scrubbing. Baseline Gasification tests with steam and Oxygen were conducted at equivalence ratios (ER) between 0.21 and 0.38 using switchgrass as fuel. Measurements on the raw and cleaned syngas included permanent gas composition, C2 hydrocarbons, water, heavy and light tars, Gasification residues (char and ash), hydrogen sulfide (H2S), carbonyl sulfide (COS), carbon disulfide (CS2), ammonia (NH3), and the first reported measurements of hydrogen cyanide (HCN) for Oxygen/steam blown Gasification. Heavy tars were removed with high efficiency by the method employed, although more difficult to remove light tars reduced overall tar removal efficiency to less than 80%. The sulfur scrubbing system demonstrated 99.9% removal efficiency, resulting in less than 200 ppb of H2S in the cleaned gas. The NH3 scrubbing system also accomplished greater than 99.9% removal efficiency, resulting in final NH3 concentrations of less than 1 ppm.
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Steam/Oxygen Gasification system for the production of clean syngas from switchgrass
Fuel, 2015Co-Authors: Karl M. Broer, Patrick J. Woolcock, Patrick A. Johnston, Robert C. BrownAbstract:Abstract A pilot-scale 25 kg/h fluidized bed, Oxygen/steam blown gasifier and syngas cleaning system was developed to convert switchgrass into clean syngas. The system is rated for operation at gage pressures up to 1 bar. The reactor vessel incorporated a novel guard heating system to simulate near-adiabatic operation of large commercial-scale gasifiers, and was effective for Gasification temperatures up to 900 °C. After removing particulate from the gas stream via cyclones, a warm-gas cleaning operation based on oil scrubbing was used to remove tars. Sulfur compounds were removed via solid-phase adsorption. Ammonia was removed by water scrubbing. Baseline Gasification tests with steam and Oxygen were conducted at equivalence ratios (ER) between 0.21 and 0.38 using switchgrass as fuel. Measurements on the raw and cleaned syngas included permanent gas composition, C2 hydrocarbons, water, heavy and light tars, Gasification residues (char and ash), hydrogen sulfide (H2S), carbonyl sulfide (COS), carbon disulfide (CS2), ammonia (NH3), and the first reported measurements of hydrogen cyanide (HCN) for Oxygen/steam blown Gasification. Heavy tars were removed with high efficiency by the method employed, although more difficult to remove light tars reduced overall tar removal efficiency to less than 80%. The sulfur scrubbing system demonstrated 99.9% removal efficiency, resulting in less than 200 ppb of H2S in the cleaned gas. The NH3 scrubbing system also accomplished greater than 99.9% removal efficiency, resulting in final NH3 concentrations of less than 1 ppm.
Ilkka Hiltunen - One of the best experts on this subject based on the ideXlab platform.
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Steam–Oxygen Gasification of forest residues and bark followed by hot gas filtration and catalytic reforming of tars: Results of an extended time test
Fuel Processing Technology, 2016Co-Authors: Esa Kurkela, Minna Kurkela, Ilkka HiltunenAbstract:Abstract Steam–Oxygen Gasification in a Circulating Fluidized-bed (CFB) reactor was developed for producing transportation fuels from different wood residues. This article presents the results of a two week test campaign, in which crushed forest residues and industrial bark mixture were used as the feedstocks. The aim of the work was to carry out extended time testing of the developed Gasification and hot gas cleaning process and to determine the fate of different gas contaminants and trace components of wood. In the test runs, wood fuels were gasified in the CFB reactor at a 0.2–0.25 MPa pressure using a mixture of steam and Oxygen as the Gasification agent. A mixture of sand and dolomite was used as the bed material in order to maintain stable fluidization and to catalyse in-situ tar decomposition before hot filtration. Raw gas was filtered at ca. 550 °C and the filtered gas was then led into a two-stage catalytic tar reformer. The gasifier performance and the concentrations of different gas contaminants were determined at four different operating variable set points during a total of 215 h of operation. The results for carbon conversion efficiency, raw gas composition and the fate of fuel nitrogen, chlorine and trace metals are presented in this paper. The concentrations of gas contaminants were determined after the ceramic filter unit and after the catalytic reformer. The conversion efficiencies for hydrocarbon gases, tars and ammonia in the reformer are also presented. The test run was carried out as a continuous operation without any interruptions or operational problems.
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steam Oxygen Gasification of forest residues and bark followed by hot gas filtration and catalytic reforming of tars results of an extended time test
Fuel Processing Technology, 2016Co-Authors: Esa Kurkela, Minna Kurkela, Ilkka HiltunenAbstract:Abstract Steam–Oxygen Gasification in a Circulating Fluidized-bed (CFB) reactor was developed for producing transportation fuels from different wood residues. This article presents the results of a two week test campaign, in which crushed forest residues and industrial bark mixture were used as the feedstocks. The aim of the work was to carry out extended time testing of the developed Gasification and hot gas cleaning process and to determine the fate of different gas contaminants and trace components of wood. In the test runs, wood fuels were gasified in the CFB reactor at a 0.2–0.25 MPa pressure using a mixture of steam and Oxygen as the Gasification agent. A mixture of sand and dolomite was used as the bed material in order to maintain stable fluidization and to catalyse in-situ tar decomposition before hot filtration. Raw gas was filtered at ca. 550 °C and the filtered gas was then led into a two-stage catalytic tar reformer. The gasifier performance and the concentrations of different gas contaminants were determined at four different operating variable set points during a total of 215 h of operation. The results for carbon conversion efficiency, raw gas composition and the fate of fuel nitrogen, chlorine and trace metals are presented in this paper. The concentrations of gas contaminants were determined after the ceramic filter unit and after the catalytic reformer. The conversion efficiencies for hydrocarbon gases, tars and ammonia in the reformer are also presented. The test run was carried out as a continuous operation without any interruptions or operational problems.
