The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Ahmed F Ghoniem - One of the best experts on this subject based on the ideXlab platform.
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Modeling the slag layer in solid Fuel Gasification and combustion -- Two-way coupling with CFD
Fuel, 2012Co-Authors: Sze Zheng Yong, Ahmed F GhoniemAbstract:Abstract A steady-state model has been developed to describe the flow and heat transfer characteristics of slag that takes into consideration the contribution of the momentum of captured particles and the possibility of slag resolidification along the walls. The model also incorporates a criterion for particle capture or rebound. Captured particles flow with the local slag average velocity. Some of these particles may contain combustibles and they continue to burn at a different rate. To take this into account, a wall consumption submodel is proposed to predict a correction factor for the porous char consumption models. The slag flow model, along with the particle capture and consumption submodels are two-way coupled with a Computational Fluid Dynamics (CFD) of coal combustion, resulting in changing the discrete phase and temperature boundary conditions of the bulk flow simulations. The coupled CFD simulation shows that the wall traps about 56% of the coal particles fed to the combustor, while the wall temperature and heat flux to the wall are not significantly affected by the inclusion of a slag layer.
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Modeling the slag layer in solid Fuel Gasification and combustion -- Formulation and sensitivity analysis
Fuel, 2012Co-Authors: Sze Zheng Yong, Marco Gazzino, Ahmed F GhoniemAbstract:Abstract A steady-state model has been developed to describe the flow and heat transfer characteristics of the slag layer in solid Fuel Gasification and combustion. The model incorporates a number of sub-models including one for particle capture, and takes into consideration the temperature and composition dependent properties of slag, the contribution of momentum of captured particles and the possibility of slag resolidification. An equally important issue is the interaction of the particles colliding with the slag layer. High inertia particles tend to rebound whereas slower particles are trapped in the slag layer. Since only trapped particles are relevant to the slag layer build-up, a particle capture criterion for colliding particles is introduced. The model predicts the local thickness of the molten and the solid slag layers, the average slag velocity, the temperature distribution across the layer and the heat flux to the coolant, taking into account the influence of molten and resolidified slag layers coating the combustor or reactor wall.
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Reduced Order Modeling of Entrained Flow Solid Fuel Gasification
Proceedings of the Asme International Mechanical Engineering Congress and Exposition, 2009Co-Authors: Rory F D Monaghan, Simcha L Singer, Mayank Kumar, Cheng Zhang, Ahmed F GhoniemAbstract:Reduced order models that accurately predict the operation of entrained flow gasifiers as components within integrated Gasification combined cycle (IGCC) or polygeneration plants are essential for greater commercialization of Gasification-based energy systems. A reduced order model, implemented in Aspen Custom Modeler, for entrained flow gasifiers that incorporates mixing and recirculation, rigorously calculated char properties, drying and devolatilization, chemical kinetics, simplified fluid dynamics, heat transfer, slag behavior and syngas cooling is presented. The model structure and submodels are described. Results are presented for the steady-state simulation of a two-metric-tonne-per-day (2 tpd) laboratory-scale Mitsubishi Heavy Industries (MHI) gasifier, fed by two different types of coal. Improvements over the state-of-the-art for reduced order modeling include the ability to incorporate realistic flow conditions and hence predict the gasifier internal and external temperature profiles, the ability to easily interface the model with plant-wide flowsheet models, and the flexibility to apply the same model to a variety of entrained flow gasifier designs. Model validation shows satisfactory agreement with measured values and computational fluid dynamics (CFD) results for syngas temperature profiles, syngas composition, carbon conversion, char flow rate, syngas heating value and cold gas efficiency. Analysis of the results shows the accuracy of the reduced order model to be similar to that of more detailed models that incorporate CFD. Next steps include the activation of pollutant chemistry and slag submodels, application of the reduced order model to other gasifier designs, parameter studies and uncertainty analysis of unknown and/or assumed physical and modeling parameters, and activation of dynamic simulation capability.
Su Shiung Lam - One of the best experts on this subject based on the ideXlab platform.
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Gasification of refuse-derived Fuel from municipal solid waste for energy production: a review.
Environmental chemistry letters, 2021Co-Authors: Yan Yang, Keey Liew, Arularasu Muthaliar Tamothran, Shin Ying Foong, Peter Nai Yuh Yek, Poh Wai Chia, Thuan Van Tran, Wanxi Peng, Su Shiung LamAbstract:Dwindling fossil Fuels and improper waste management are major challenges in the context of increasing population and industrialization, calling for new waste-to-energy sources. For instance, refuse-derived Fuels can be produced from transformation of municipal solid waste, which is forecasted to reach 2.6 billion metric tonnes in 2030. Gasification is a thermal-induced chemical reaction that produces gaseous Fuel such as hydrogen and syngas. Here, we review refuse-derived Fuel Gasification with focus on practices in various countries, recent progress in Gasification, Gasification modelling and economic analysis. We found that some countries that replace coal by refuse-derived Fuel reduce CO2 emission by 40%, and decrease the amount municipal solid waste being sent to landfill by more than 50%. The production cost of energy via refuse-derived Fuel Gasification is estimated at 0.05 USD/kWh. Co-Gasification by using two feedstocks appears more beneficial over conventional Gasification in terms of minimum tar formation and improved process efficiency.
Sze Zheng Yong - One of the best experts on this subject based on the ideXlab platform.
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Modeling the slag layer in solid Fuel Gasification and combustion -- Formulation and sensitivity analysis
Fuel, 2012Co-Authors: Sze Zheng Yong, Marco Gazzino, Ahmed F GhoniemAbstract:Abstract A steady-state model has been developed to describe the flow and heat transfer characteristics of the slag layer in solid Fuel Gasification and combustion. The model incorporates a number of sub-models including one for particle capture, and takes into consideration the temperature and composition dependent properties of slag, the contribution of momentum of captured particles and the possibility of slag resolidification. An equally important issue is the interaction of the particles colliding with the slag layer. High inertia particles tend to rebound whereas slower particles are trapped in the slag layer. Since only trapped particles are relevant to the slag layer build-up, a particle capture criterion for colliding particles is introduced. The model predicts the local thickness of the molten and the solid slag layers, the average slag velocity, the temperature distribution across the layer and the heat flux to the coolant, taking into account the influence of molten and resolidified slag layers coating the combustor or reactor wall.
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Modeling the slag layer in solid Fuel Gasification and combustion -- Two-way coupling with CFD
Fuel, 2012Co-Authors: Sze Zheng Yong, Ahmed F GhoniemAbstract:Abstract A steady-state model has been developed to describe the flow and heat transfer characteristics of slag that takes into consideration the contribution of the momentum of captured particles and the possibility of slag resolidification along the walls. The model also incorporates a criterion for particle capture or rebound. Captured particles flow with the local slag average velocity. Some of these particles may contain combustibles and they continue to burn at a different rate. To take this into account, a wall consumption submodel is proposed to predict a correction factor for the porous char consumption models. The slag flow model, along with the particle capture and consumption submodels are two-way coupled with a Computational Fluid Dynamics (CFD) of coal combustion, resulting in changing the discrete phase and temperature boundary conditions of the bulk flow simulations. The coupled CFD simulation shows that the wall traps about 56% of the coal particles fed to the combustor, while the wall temperature and heat flux to the wall are not significantly affected by the inclusion of a slag layer.
Yan Yang - One of the best experts on this subject based on the ideXlab platform.
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Gasification of refuse-derived Fuel from municipal solid waste for energy production: a review.
Environmental chemistry letters, 2021Co-Authors: Yan Yang, Keey Liew, Arularasu Muthaliar Tamothran, Shin Ying Foong, Peter Nai Yuh Yek, Poh Wai Chia, Thuan Van Tran, Wanxi Peng, Su Shiung LamAbstract:Dwindling fossil Fuels and improper waste management are major challenges in the context of increasing population and industrialization, calling for new waste-to-energy sources. For instance, refuse-derived Fuels can be produced from transformation of municipal solid waste, which is forecasted to reach 2.6 billion metric tonnes in 2030. Gasification is a thermal-induced chemical reaction that produces gaseous Fuel such as hydrogen and syngas. Here, we review refuse-derived Fuel Gasification with focus on practices in various countries, recent progress in Gasification, Gasification modelling and economic analysis. We found that some countries that replace coal by refuse-derived Fuel reduce CO2 emission by 40%, and decrease the amount municipal solid waste being sent to landfill by more than 50%. The production cost of energy via refuse-derived Fuel Gasification is estimated at 0.05 USD/kWh. Co-Gasification by using two feedstocks appears more beneficial over conventional Gasification in terms of minimum tar formation and improved process efficiency.
A. A. Salamov - One of the best experts on this subject based on the ideXlab platform.
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Thermal power stations with Fuel Gasification
Thermal Engineering, 2004Co-Authors: A. A. SalamovAbstract:Information is presented on steam-gas installations that use the intra-cycle Gasification of Fuel (coal, petroleum waste, wood, and other substances): their technical and economic indicators, their developmental experience, and the prospects for their use.
