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Kyu-yeul Lee - One of the best experts on this subject based on the ideXlab platform.
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Optimal Liquefaction process cycle considering simplicity and efficiency for LNG FPSO at FEED stage
Computers and Chemical Engineering, 2014Co-Authors: Jihyun Hwang, Kyu-yeul LeeAbstract:In this paper, the offshore selection criteria for the optimal Liquefaction process system are studied to contribute to the future FEED engineering for the liquefied natural gas (LNG) floating, production, storage, and offloading (LNG FPSO) Liquefaction process system.From the foregoing, it is clear that offshore Liquefaction plants have process requirements different from those of the traditional onshore Liquefaction plants. While thermodynamic efficiency is the key technical process selection criterion for large onshore Liquefaction plants, the high-efficiency pre-cooled mixed refrigerant and optimized cascade plants that dominate the onshore LNG installations are unlikely to meet the diverse technical and safety needs of offshore Liquefaction facilities. Offshore Liquefaction technology developers are rightly focusing on process simplicity, low weight, small footprint, and other criteria. The key criteria that influence process selection and plant optimization for the offshore Liquefaction cycle lead to some trade-offs and compromises between efficiency and simplicity. In addition, other criteria for offshore Liquefaction cycles should also be considered, such as flexibility, safety, vessel motion, refrigerant storage hazard, proven technology, simplicity of operation, ease of start-up/shutdown, and capital cost.First of all, this paper proposes a generic mixed refrigerant (MR) Liquefaction cycle based on four configuration strategies. The 27 feasible MR Liquefaction cycles from such generic MR Liquefaction cycle are configured for optimal synthesis. From the 27 MR Liquefaction cycles, the top 10 are selected based on the minimum amount of power required for the compressors. Then, one MR Liquefaction cycle is selected based on simplicity among the 10 MR process cycles, and this is called a "potential MR Liquefaction cycle.". Second, three additional offshore Liquefaction cycles - DMR for SHELL LNG FPSO, C3MR for onshore projects, and the dual N2expander for FLEX LNG FPSO - are considered for comparison with the potential MR Liquefaction cycle for the selection of the optimal offshore Liquefaction cycle.Such four cycles are compared based on simplicity, efficiency, and other criteria. Therefore, the optimal operating conditions for each cycle with four LNG capacities (4.0, 3.0, 2.0, and 1.0 MTPA) are calculated with the minimum amount of power required for the compressors. Then the preliminary equipment module layout for the four cycles are designed as multi-deck instead of single-deck, and this equipment module layout should be optimized to reduce the area occupied by the topside equipment at the FEED stage. In this paper, the connectivity cost, the construction cost proportional to the deck area, and the distance of the main cryogenic heat exchanger (MCHE) and separators from the centerline of the hull are considered objective functions to be minimized. Moreover, the constraints are proposed to ensure the safety and considering the deck penetration of the long equipment across several decks. Considering the above, mathematical models were formulated for them. For example, the potential MR Liquefaction cycle has a mathematical model consisting of 257 unknowns, 193 equality constraints, and 330 inequality constraints. The preliminary optimal equipment module layouts with four LNG capacities (4.0, 3.0, 2.0, and 1.0 MTPA) are then obtained using mixed-integer nonlinear programming (MINLP).Based on the above optimal operating conditions and equipment module layouts for the four potential offshore Liquefaction cycles, trade-offs between simplicity and efficiency are performed for actual offshore application, and finally, the potential MR Liquefaction cycle is selected for the optimal Liquefaction cycle for LNG FPSO. © 2014.
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optimal design of Liquefaction cycles of liquefied natural gas floating production storage and offloading unit considering optimal synthesis
Industrial & Engineering Chemistry Research, 2013Co-Authors: Jihyun Hwang, Namkug Ku, Myungil Roh, Kyu-yeul LeeAbstract:The Liquefaction process is regarded as primary among all topside systems in liquefied natural gas floating, production, storage, and offloading (LNG FPSO) applications. The Liquefaction process, which typically accounts for 70% of the capital cost of topside process systems and 30 to 40% of the overall cost of LNG FPSO plants, condenses separated and pretreated natural gas into LNG. The volume of liquid occupies about 1/600 the volume of the natural gas. The cycles in the Liquefaction process use seven main types of equipment: compressor, seawater cooler, expansion valve, heat exchanger, phase separator, tee, and common header. Different types of Liquefaction cycles are determined according to their respective synthesis and optimized operating conditions. This study proposes a generic Liquefaction model to represent various types of Liquefaction cycles. Twenty-seven feasible Liquefaction configurations derived from the generic model are selected to perform the most effective synthesis for the optimizatio...
Jihyun Hwang - One of the best experts on this subject based on the ideXlab platform.
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Optimal Liquefaction process cycle considering simplicity and efficiency for LNG FPSO at FEED stage
Computers and Chemical Engineering, 2014Co-Authors: Jihyun Hwang, Kyu-yeul LeeAbstract:In this paper, the offshore selection criteria for the optimal Liquefaction process system are studied to contribute to the future FEED engineering for the liquefied natural gas (LNG) floating, production, storage, and offloading (LNG FPSO) Liquefaction process system.From the foregoing, it is clear that offshore Liquefaction plants have process requirements different from those of the traditional onshore Liquefaction plants. While thermodynamic efficiency is the key technical process selection criterion for large onshore Liquefaction plants, the high-efficiency pre-cooled mixed refrigerant and optimized cascade plants that dominate the onshore LNG installations are unlikely to meet the diverse technical and safety needs of offshore Liquefaction facilities. Offshore Liquefaction technology developers are rightly focusing on process simplicity, low weight, small footprint, and other criteria. The key criteria that influence process selection and plant optimization for the offshore Liquefaction cycle lead to some trade-offs and compromises between efficiency and simplicity. In addition, other criteria for offshore Liquefaction cycles should also be considered, such as flexibility, safety, vessel motion, refrigerant storage hazard, proven technology, simplicity of operation, ease of start-up/shutdown, and capital cost.First of all, this paper proposes a generic mixed refrigerant (MR) Liquefaction cycle based on four configuration strategies. The 27 feasible MR Liquefaction cycles from such generic MR Liquefaction cycle are configured for optimal synthesis. From the 27 MR Liquefaction cycles, the top 10 are selected based on the minimum amount of power required for the compressors. Then, one MR Liquefaction cycle is selected based on simplicity among the 10 MR process cycles, and this is called a "potential MR Liquefaction cycle.". Second, three additional offshore Liquefaction cycles - DMR for SHELL LNG FPSO, C3MR for onshore projects, and the dual N2expander for FLEX LNG FPSO - are considered for comparison with the potential MR Liquefaction cycle for the selection of the optimal offshore Liquefaction cycle.Such four cycles are compared based on simplicity, efficiency, and other criteria. Therefore, the optimal operating conditions for each cycle with four LNG capacities (4.0, 3.0, 2.0, and 1.0 MTPA) are calculated with the minimum amount of power required for the compressors. Then the preliminary equipment module layout for the four cycles are designed as multi-deck instead of single-deck, and this equipment module layout should be optimized to reduce the area occupied by the topside equipment at the FEED stage. In this paper, the connectivity cost, the construction cost proportional to the deck area, and the distance of the main cryogenic heat exchanger (MCHE) and separators from the centerline of the hull are considered objective functions to be minimized. Moreover, the constraints are proposed to ensure the safety and considering the deck penetration of the long equipment across several decks. Considering the above, mathematical models were formulated for them. For example, the potential MR Liquefaction cycle has a mathematical model consisting of 257 unknowns, 193 equality constraints, and 330 inequality constraints. The preliminary optimal equipment module layouts with four LNG capacities (4.0, 3.0, 2.0, and 1.0 MTPA) are then obtained using mixed-integer nonlinear programming (MINLP).Based on the above optimal operating conditions and equipment module layouts for the four potential offshore Liquefaction cycles, trade-offs between simplicity and efficiency are performed for actual offshore application, and finally, the potential MR Liquefaction cycle is selected for the optimal Liquefaction cycle for LNG FPSO. © 2014.
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optimal design of Liquefaction cycles of liquefied natural gas floating production storage and offloading unit considering optimal synthesis
Industrial & Engineering Chemistry Research, 2013Co-Authors: Jihyun Hwang, Namkug Ku, Myungil Roh, Kyu-yeul LeeAbstract:The Liquefaction process is regarded as primary among all topside systems in liquefied natural gas floating, production, storage, and offloading (LNG FPSO) applications. The Liquefaction process, which typically accounts for 70% of the capital cost of topside process systems and 30 to 40% of the overall cost of LNG FPSO plants, condenses separated and pretreated natural gas into LNG. The volume of liquid occupies about 1/600 the volume of the natural gas. The cycles in the Liquefaction process use seven main types of equipment: compressor, seawater cooler, expansion valve, heat exchanger, phase separator, tee, and common header. Different types of Liquefaction cycles are determined according to their respective synthesis and optimized operating conditions. This study proposes a generic Liquefaction model to represent various types of Liquefaction cycles. Twenty-seven feasible Liquefaction configurations derived from the generic model are selected to perform the most effective synthesis for the optimizatio...
Mohamed Gadalla - One of the best experts on this subject based on the ideXlab platform.
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Economics of hydrogen production and Liquefaction by geothermal energy
International Journal of Hydrogen Energy, 2020Co-Authors: Ceyhun Yilmaz, Mehmet Kanoglu, Ali Bolatturk, Mohamed GadallaAbstract:Abstract Seven models are considered for the production and Liquefaction of hydrogen by geothermal energy. In these models, we use electrolysis and high-temperature steam electrolysis processes for hydrogen production, a binary power plant for geothermal power production, and a pre-cooled Linde–Hampson cycle for hydrogen Liquefaction. Also, an absorption cooling system is used for the pre-cooling of hydrogen before the Liquefaction process. A methodology is developed for the economic analysis of the models. It is estimated that the cost of hydrogen production and Liquefaction ranges between 0.979 $/kg H2 and 2.615 $/kg H2 depending on the model. The effect of geothermal water temperature on the cost of hydrogen production and Liquefaction is investigated. The results show that the cost of hydrogen production and Liquefaction decreases as the geothermal water temperature increases. Also, capital costs for the models involving hydrogen Liquefaction are greater than those for the models involving hydrogen production only.
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Economics of hydrogen production and Liquefaction by geothermal energy
International Journal of Hydrogen Energy, 2012Co-Authors: Ceyhun Yilmaz, Mehmet Kanoglu, Ali Bolatturk, Mohamed GadallaAbstract:Seven models are considered for the production and Liquefaction of hydrogen by geothermal energy. In these models, we use electrolysis and high-temperature steam electrolysis processes for hydrogen production, a binary power plant for geothermal power production, and a pre-cooled Linde-Hampson cycle for hydrogen Liquefaction. Also, an absorption cooling system is used for the pre-cooling of hydrogen before the Liquefaction process. A methodology is developed for the economic analysis of the models. It is estimated that the cost of hydrogen production and Liquefaction ranges between 0.979 $/kg H2and 2.615 $/kg H2depending on the model. The effect of geothermal water temperature on the cost of hydrogen production and Liquefaction is investigated. The results show that the cost of hydrogen production and Liquefaction decreases as the geothermal water temperature increases. Also, capital costs for the models involving hydrogen Liquefaction are greater than those for the models involving hydrogen production only. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Ceyhun Yilmaz - One of the best experts on this subject based on the ideXlab platform.
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Economics of hydrogen production and Liquefaction by geothermal energy
International Journal of Hydrogen Energy, 2020Co-Authors: Ceyhun Yilmaz, Mehmet Kanoglu, Ali Bolatturk, Mohamed GadallaAbstract:Abstract Seven models are considered for the production and Liquefaction of hydrogen by geothermal energy. In these models, we use electrolysis and high-temperature steam electrolysis processes for hydrogen production, a binary power plant for geothermal power production, and a pre-cooled Linde–Hampson cycle for hydrogen Liquefaction. Also, an absorption cooling system is used for the pre-cooling of hydrogen before the Liquefaction process. A methodology is developed for the economic analysis of the models. It is estimated that the cost of hydrogen production and Liquefaction ranges between 0.979 $/kg H2 and 2.615 $/kg H2 depending on the model. The effect of geothermal water temperature on the cost of hydrogen production and Liquefaction is investigated. The results show that the cost of hydrogen production and Liquefaction decreases as the geothermal water temperature increases. Also, capital costs for the models involving hydrogen Liquefaction are greater than those for the models involving hydrogen production only.
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Economics of hydrogen production and Liquefaction by geothermal energy
International Journal of Hydrogen Energy, 2012Co-Authors: Ceyhun Yilmaz, Mehmet Kanoglu, Ali Bolatturk, Mohamed GadallaAbstract:Seven models are considered for the production and Liquefaction of hydrogen by geothermal energy. In these models, we use electrolysis and high-temperature steam electrolysis processes for hydrogen production, a binary power plant for geothermal power production, and a pre-cooled Linde-Hampson cycle for hydrogen Liquefaction. Also, an absorption cooling system is used for the pre-cooling of hydrogen before the Liquefaction process. A methodology is developed for the economic analysis of the models. It is estimated that the cost of hydrogen production and Liquefaction ranges between 0.979 $/kg H2and 2.615 $/kg H2depending on the model. The effect of geothermal water temperature on the cost of hydrogen production and Liquefaction is investigated. The results show that the cost of hydrogen production and Liquefaction decreases as the geothermal water temperature increases. Also, capital costs for the models involving hydrogen Liquefaction are greater than those for the models involving hydrogen production only. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
H. Klein - One of the best experts on this subject based on the ideXlab platform.
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Process optimization for large-scale hydrogen Liquefaction
International Journal of Hydrogen Energy, 2017Co-Authors: U. Cardella, Johan Sundberg, L. De Decker, H. KleinAbstract:The investment in the hydrogen infrastructure for hydrogen mobility has lately seen a significant acceleration. The demand for energy and cost efficient hydrogen Liquefaction processes has also increased steadily. A significant scale-up in liquid hydrogen (LH2) production capacity from today's typical 5–10 metric tons per day (tpd) LH2is predicted for the next decade. For hydrogen Liquefaction, the future target for the specific energy consumption is set to 6 kWh per kg LH2and requires a reduction of up to 40% compared to conventional 5 tpd LH2liquefiers. Efficiency improvements, however, are limited by the required plant capital costs, technological risks and process complexity. The aim of this paper is the reduction of the specific costs for hydrogen Liquefaction, including plant capital and operating expenses, through process optimization. The paper outlines a novel approach to process development for large-scale hydrogen Liquefaction. The presented liquefier simulation and cost estimation model is coupled to a process optimizer with specific energy consumption and specific Liquefaction costs as objective functions. A design optimization is undertaken for newly developed hydrogen Liquefaction concepts, for plant capacities between 25 tpd and 100 tpd LH2with different precooling configurations and a sensitivity in the electricity costs. Compared to a 5 tpd LH2plant, the optimized specific Liquefaction costs for a 25 tpd LH2liquefier are reduced by about 50%. The high-pressure hydrogen cycle with a mixed-refrigerant precooling cycle is selected as preferred Liquefaction process for a cost-optimized 100 tpd LH2plant design. A specific energy consumption below 6 kWh per kg LH2can be achieved while reducing the specific Liquefaction costs by 67% compared to 5 tpd LH2plants. The cost targets for hydrogen refuelling and mobility can be reached with a liquid hydrogen distribution and the herewith presented cost-optimized large-scale Liquefaction plant concepts.
