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Autothermal Gasification
The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Stéphane Abanades – One of the best experts on this subject based on the ideXlab platform.
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dynamic simulation and control of solar biomass Gasification for hydrogen rich syngas production during allothermal and hybrid solar Autothermal operation
International Journal of Hydrogen Energy, 2020Co-Authors: Houssame Boujjat, Sylvain Rodat, Giberto Mitsuyoshi Yuki, Stéphane AbanadesAbstract:Abstract Solar biomass steam Gasification using concentrated sunlight offers an efficient means of storing intermittent solar energy into renewable solar fuels while upgrading the carbonaceous feedstock. Such solar-driven (allothermal) processes have demonstrated the ability and the effectiveness for the production of high quality hydrogen-rich syngas, but they suffer from inherent barriers related to the variability of solar energy caused by cloud passages and shut off at night. The concept of hybrid solar/Autothermal Gasification appears promising to meet the requirement for stable and continuous operation under fluctuating or intermittent solar irradiation. To date, dynamic modelling to simulate coupled solar/combustion heating and steam Gasification using real solar irradiation data has never been proposed and could be used to predict the annual performance of large-scale solar Gasification plants. In this study, a dynamic mathematical model of a scaled-up solar Gasification reactor was developed. The model was composed of a system of differential equations that were derived from unsteady mass and energy conservation equations. After an experimental validation step with the results from a lab-scale solar reactor, the dynamic model was applied at large scale to determine the reactor temperature and syngas production evolution during continuous day and night operation in both solar-only (allothermal) and hybrid solar/Autothermal modes. Different reactants feeding management strategies were proposed and compared with the aim of achieving enhanced syngas productivity and optimized use of solar energy during solar-aided steam Gasification. It was shown that the hybrid mode with partial oxy-combustion of the feedstock and dynamic feeding control results in the most stable process operation upon fluctuating solar power input, while ensuring continuous production of H2 and CO at night and during cloudy periods.
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Solar-hybrid Thermochemical Gasification of Wood Particles and Solid Recovered Fuel in a Continuously-Fed Prototype Reactor
Energies, 2020Co-Authors: Houssame Boujjat, Sylvain Rodat, Stéphane AbanadesAbstract:Solar thermochemical Gasification is a promising solution for the clean production of low-emission synthetic fuels. It offers the possibility to upgrade various biomasses and waste feedstocks and further provides an efficient way to sustainably store solar energy into high-value and energy-intensive chemical fuels. In this work, a novel continuously-fed solar steam gasifier was studied using beechwood and solid recovered fuels (SRF) particles. Solar-only and hybrid solar/Autothermal Gasification experiments were performed at high temperatures to assess the performance of the reactor and its flexibility in converting various types of feedstocks. The hybrid operation was considered to increase the solar reactor temperature when the solar power input is not sufficient thanks to partial feedstock oxy-combustion. The hybrid solar process is thus a sustainable alternative option outperforming the conventional Gasification processes for syngas production. Wood and waste particles solar conversion was successfully achieved, yielding high-quality syngas and suitable reactor performance, with Cold Gas Efficiencies (CGE) up to 1.04 and 1.13 respectively during the allothermal operation. The hybrid process allowed operating with a lower solar power input, but the H 2 and CO yields noticeably declined. SRF Gasification experiments suffered furthermore from ash melting/agglomeration issues and injection instabilities that undermined the continuity of the process. This study demonstrated the solar reactor flexibility in converting both biomass and waste feedstocks into syngas performed in continuous feeding operation. The experimental outcomes showed the feasibility of operating the reactor in both allothermal (solar-only) and hybrid allothermal/Autothermal (combined solar and oxy-combustion heating) for continuous syngas production with high yields and energy conversion efficiencies.
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Experimental and numerical study of a directly irradiated hybrid solar/combustion spouted bed reactor for continuous steam Gasification of biomass
Energy, 2019Co-Authors: Houssame Boujjat, Sylvain Rodat, Srirat Chuayboon, Stéphane AbanadesAbstract:Abstract The concept of hybrid solar gasifiers is proposed to couple Autothermal Gasification with solar Gasification so as to meet the requirement for stable and continuous operation under intermittent or fluctuating solar irradiation. Solar process hybridization through partial oxy-combustion of the feedstock appears to be crucial because thermochemical processes are very sensitive to small solar energy input variations, and require permanent control of thermodynamic conditions to ensure fuel production quality. This work aims to study solar-hybridized steam Gasification of biomass in a novel directly-irradiated lab-scale reactor based on the principle of conical jet spouted beds. This concept was first numerically simulated to thoroughly analyze the reactor operation and to provide insights into the temperature distribution, fluid flow dynamics, reactive particle trajectories/conversion, gas species distribution and flame location inside the reactor. A two-phase flow model was developed including discrete phase model for the reactive biomass particles undergoing both combustion and pyro-Gasification, and coupled heat and mass transfer. Thereafter, solar-only and mixed solar-combustion experiments were carried out under real concentrated solar flux and the effects of process hybridization on syngas yield and reactor performance were investigated. The results confirmed that O2 feeding rate is a relevant variable to control the process temperature. Accordingly, a continuous operation of the solar reactor can be ensured with variable solar energy input.
Johann F. Görgens – One of the best experts on this subject based on the ideXlab platform.
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techno economic assessment of integrating methanol or fischer tropsch synthesis in a south african sugar mill
Bioresource Technology, 2015Co-Authors: Abdul M Petersen, Somayeh Farzad, Johann F. GörgensAbstract:Abstract This study considered an average-sized sugar mill in South Africa that crushes 300 wet tonnes per hour of cane, as a host for integrating methanol and Fischer–Tropsch synthesis, through Gasification of a combined flow of sugarcane trash and bagasse. Initially, it was shown that the conversion of biomass to syngas is preferably done by catalytic allothermal Gasification instead of catalytic Autothermal Gasification. Thereafter, conventional and advanced synthesis routes for both Methanol and Fischer–Tropsch products were simulated with Aspen Plus® software and compared by technical and economic feasibility. Advanced FT synthesis satisfied the overall energy demands, but was not economically viable for a private investment. Advanced methanol synthesis is also not viable for private investment since the internal rate of return was 21.1%, because it could not provide the steam that the sugar mill required. The conventional synthesis routes had less viability than the corresponding advanced synthesis routes.
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Techno-economic assessment of integrating methanol or Fischer–Tropsch synthesis in a South African sugar mill
Bioresource Technology, 2015Co-Authors: Abdul M Petersen, Somayeh Farzad, Johann F. GörgensAbstract:Abstract This study considered an average-sized sugar mill in South Africa that crushes 300 wet tonnes per hour of cane, as a host for integrating methanol and Fischer–Tropsch synthesis, through Gasification of a combined flow of sugarcane trash and bagasse. Initially, it was shown that the conversion of biomass to syngas is preferably done by catalytic allothermal Gasification instead of catalytic Autothermal Gasification. Thereafter, conventional and advanced synthesis routes for both Methanol and Fischer–Tropsch products were simulated with Aspen Plus® software and compared by technical and economic feasibility. Advanced FT synthesis satisfied the overall energy demands, but was not economically viable for a private investment. Advanced methanol synthesis is also not viable for private investment since the internal rate of return was 21.1%, because it could not provide the steam that the sugar mill required. The conventional synthesis routes had less viability than the corresponding advanced synthesis routes.
Houssame Boujjat – One of the best experts on this subject based on the ideXlab platform.
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dynamic simulation and control of solar biomass Gasification for hydrogen rich syngas production during allothermal and hybrid solar Autothermal operation
International Journal of Hydrogen Energy, 2020Co-Authors: Houssame Boujjat, Sylvain Rodat, Giberto Mitsuyoshi Yuki, Stéphane AbanadesAbstract:Abstract Solar biomass steam Gasification using concentrated sunlight offers an efficient means of storing intermittent solar energy into renewable solar fuels while upgrading the carbonaceous feedstock. Such solar-driven (allothermal) processes have demonstrated the ability and the effectiveness for the production of high quality hydrogen-rich syngas, but they suffer from inherent barriers related to the variability of solar energy caused by cloud passages and shut off at night. The concept of hybrid solar/Autothermal Gasification appears promising to meet the requirement for stable and continuous operation under fluctuating or intermittent solar irradiation. To date, dynamic modelling to simulate coupled solar/combustion heating and steam Gasification using real solar irradiation data has never been proposed and could be used to predict the annual performance of large-scale solar Gasification plants. In this study, a dynamic mathematical model of a scaled-up solar Gasification reactor was developed. The model was composed of a system of differential equations that were derived from unsteady mass and energy conservation equations. After an experimental validation step with the results from a lab-scale solar reactor, the dynamic model was applied at large scale to determine the reactor temperature and syngas production evolution during continuous day and night operation in both solar-only (allothermal) and hybrid solar/Autothermal modes. Different reactants feeding management strategies were proposed and compared with the aim of achieving enhanced syngas productivity and optimized use of solar energy during solar-aided steam Gasification. It was shown that the hybrid mode with partial oxy-combustion of the feedstock and dynamic feeding control results in the most stable process operation upon fluctuating solar power input, while ensuring continuous production of H2 and CO at night and during cloudy periods.
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Solar-hybrid Thermochemical Gasification of Wood Particles and Solid Recovered Fuel in a Continuously-Fed Prototype Reactor
Energies, 2020Co-Authors: Houssame Boujjat, Sylvain Rodat, Stéphane AbanadesAbstract:Solar thermochemical Gasification is a promising solution for the clean production of low-emission synthetic fuels. It offers the possibility to upgrade various biomasses and waste feedstocks and further provides an efficient way to sustainably store solar energy into high-value and energy-intensive chemical fuels. In this work, a novel continuously-fed solar steam gasifier was studied using beechwood and solid recovered fuels (SRF) particles. Solar-only and hybrid solar/Autothermal Gasification experiments were performed at high temperatures to assess the performance of the reactor and its flexibility in converting various types of feedstocks. The hybrid operation was considered to increase the solar reactor temperature when the solar power input is not sufficient thanks to partial feedstock oxy-combustion. The hybrid solar process is thus a sustainable alternative option outperforming the conventional Gasification processes for syngas production. Wood and waste particles solar conversion was successfully achieved, yielding high-quality syngas and suitable reactor performance, with Cold Gas Efficiencies (CGE) up to 1.04 and 1.13 respectively during the allothermal operation. The hybrid process allowed operating with a lower solar power input, but the H 2 and CO yields noticeably declined. SRF Gasification experiments suffered furthermore from ash melting/agglomeration issues and injection instabilities that undermined the continuity of the process. This study demonstrated the solar reactor flexibility in converting both biomass and waste feedstocks into syngas performed in continuous feeding operation. The experimental outcomes showed the feasibility of operating the reactor in both allothermal (solar-only) and hybrid allothermal/Autothermal (combined solar and oxy-combustion heating) for continuous syngas production with high yields and energy conversion efficiencies.
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Experimental and numerical study of a directly irradiated hybrid solar/combustion spouted bed reactor for continuous steam Gasification of biomass
Energy, 2019Co-Authors: Houssame Boujjat, Sylvain Rodat, Srirat Chuayboon, Stéphane AbanadesAbstract:Abstract The concept of hybrid solar gasifiers is proposed to couple Autothermal Gasification with solar Gasification so as to meet the requirement for stable and continuous operation under intermittent or fluctuating solar irradiation. Solar process hybridization through partial oxy-combustion of the feedstock appears to be crucial because thermochemical processes are very sensitive to small solar energy input variations, and require permanent control of thermodynamic conditions to ensure fuel production quality. This work aims to study solar-hybridized steam Gasification of biomass in a novel directly-irradiated lab-scale reactor based on the principle of conical jet spouted beds. This concept was first numerically simulated to thoroughly analyze the reactor operation and to provide insights into the temperature distribution, fluid flow dynamics, reactive particle trajectories/conversion, gas species distribution and flame location inside the reactor. A two-phase flow model was developed including discrete phase model for the reactive biomass particles undergoing both combustion and pyro-Gasification, and coupled heat and mass transfer. Thereafter, solar-only and mixed solar-combustion experiments were carried out under real concentrated solar flux and the effects of process hybridization on syngas yield and reactor performance were investigated. The results confirmed that O2 feeding rate is a relevant variable to control the process temperature. Accordingly, a continuous operation of the solar reactor can be ensured with variable solar energy input.