The Experts below are selected from a list of 8313 Experts worldwide ranked by ideXlab platform
Moonyong Lee - One of the best experts on this subject based on the ideXlab platform.
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Gas–liquid dual-expander natural gas Liquefaction Process with confirmation of biogeography-based energy and cost savings
Applied Thermal Engineering, 2020Co-Authors: Muhammad Abdul Qyyum, Kinza Qadeer, Ashfaq Ahmad, Moonyong LeeAbstract:Abstract The use of nitrogen (N2) expander-based Liquefaction Processes is prevalent in offshore sites for the production of floating liquefied natural gas. It is safe, has simple operability, and has portable design with a small deck space requirement. However, the high operating cost that mainly accounts for the shaft work requirement in the compression units of the refrigeration cycle, is still a major ongoing issue associated with nitrogen expander Liquefaction Processes. This high operating cost increases the total annualized costs of the N2 expander Liquefaction technology, and this ultimately reduces its global competitiveness of the Process. Recent developments in expansion devices pave the way toward the handling of gas–liquid (two-phase) refrigerant in an isentropic manner instead of an isenthalpic one. This study presents the propane-nitrogen two-phase dual expander Liquefaction Process for offshore applications. A bio-inspired strategy named “biogeography” is used to confirm the overall energy savings with minimal total annualized costs. The results show that the proposed Liquefaction technology gives 36.6% operating cost savings, and this confirms a 16.5% saving in total annualized costs compared with the conventional nitrogen dual gas-phase expander Liquefaction Process. This study is an extension of our previous study “Innovative propane-nitrogen two-phase expander refrigeration cycle for energy-efficient and low-global warming potential LNG production”.
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energy optimization for single mixed refrigerant natural gas Liquefaction Process using the metaheuristic vortex search algorithm
Applied Thermal Engineering, 2018Co-Authors: Wahid Ali, Muhammad Abdul Qyyum, Kinza Qadee, Moonyong LeeAbstract:Abstract A metaheuristic vortex search algorithm was investigated for the optimization of a single mixed refrigerant (SMR) natural gas Liquefaction Process. The optimal design of a natural gas Liquefaction Processes involves multivariable non-linear thermodynamic interactions, which lead to exergy destruction and contribute to Process irreversibility. As key decision variables, the optimal values of mixed refrigerant flow rates and Process operating pressures were determined in the vortex pattern corresponding to the minimum required energy. In addition, the rigorous SMR Process was simulated using Aspen Hysys® software and the resulting model was connected with the vortex search optimization algorithm coded in MATLAB. The optimal operating conditions found by the vortex search algorithm significantly reduced the required energy of the single mixed refrigerant Process by ≤41.5% and improved the coefficient of performance by ≤32.8% in comparison with the base case. The vortex search algorithm was also compared with other well-proven optimization algorithms, such as genetic and particle swarm optimization algorithms, and was found to exhibit a superior performance over these existing approaches.
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feasibility study of environmental relative humidity through the thermodynamic effects on the performance of natural gas Liquefaction Process
Applied Thermal Engineering, 2018Co-Authors: Muhammad Abdul Qyyum, Wahid Ali, Arif Hussain, Le Quang Minh, Alireza Bahadori, Moonyong LeeAbstract:Abstract This study examined the thermodynamic effects of relative humidity (RH) on the performance of the natural gas Liquefaction Process. A single mixed refrigerant (SMR) Liquefaction Process was chosen for this study because of its simplicity and compactness. In addition, it is considered the most promising Process for the liquefied natural gas (LNG) floating production, storage and offloading (FPSO) unit. The SMR Process was optimized using a modified coordinate descent methodology, which resulted in 13.6% energy savings. Subsequently, an interface between commercial software Aspen Hysys® and MS-Excel VBA was carried out to study the effects of RH. The results showed that RH has pronounced effects on the performance of the LNG cycle by affecting the enthalpy balance around the air coolers, which ultimately affects the overall compression power, LNG exchanger performance, and other design and operational parameters. Furthermore, when the RH was increased from 0% to 95%, the UA value (product of overall heat transfer coefficient and heat transfer area) of the air coolers and the overall compression power decreased and increased linearly, respectively. Moreover, the heat transfer coefficient of the LNG cryogenic exchanger increased as a 4th order polynomial function in terms of the log-mean enthalpy difference. The results can provide insight into the selection of the appropriate design and operational parameters for the LNG plants associated with the regions of low or high relative humidity.
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enhancement of single mixed refrigerant natural gas Liquefaction Process through Process knowledge inspired optimization and modification
Applied Thermal Engineering, 2017Co-Authors: Tram Ngoc Pham, Sanggyu Lee, Nguye Van Duc Long, Moonyong LeeAbstract:Abstract This study examined the enhancement of the single mixed refrigerant (SMR) natural gas Liquefaction Process. The effects of the main parameters, such as mixed refrigerant (MR) composition and operating pressures on the compression energy requirement were investigated. A Process knowledge inspired decision-making method was exploited for liquefied natural gas Process optimization. The results showed that the proposed optimization methodology is simple and effective in determining the optimal operating conditions and could save up to 30.6% in terms of the compressor duty compared to the base case. In addition, the proposed optimization methodology provides Process understanding, which is essential to Process engineers. Another benefit of the proposed methodology is that it can be applied to any MR Liquefaction cycle. The use of heavier refrigerants, such as isobutane and isopentane, and the addition of a NG compressor were examined to improve the energy efficiency of the SMR Process. The effect of the intercooler outlet temperature on energy saving was also considered. The synergistic effects of those modifications on improving the performance of the Liquefaction Process were investigated.
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a novel vortex tube based n2 expander Liquefaction Process for enhancing the energy efficiency of natural gas Liquefaction
E3S Web of Conferences, 2017Co-Authors: Muhammad Abdul Qyyum, Wahid Ali, Feng Wei, Arif Hussai, Oh Sehee, Moonyong LeeAbstract:This research work unfolds a simple, safe, and environment-friendly energy efficient novel vortex tube-based natural gas Liquefaction Process (LNG). A vortex tube was introduced to the popular N 2 -expander Liquefaction Process to enhance the Liquefaction efficiency. The Process structure and condition were modified and optimized to take a potential advantage of the vortex tube on the natural gas Liquefaction cycle. Two commercial simulators ANSYS® and Aspen HYSYS® were used to investigate the application of vortex tube in the refrigeration cycle of LNG Process. The Computational fluid dynamics (CFD) model was used to simulate the vortex tube with nitrogen (N 2 ) as a working fluid. Subsequently, the results of the CFD model were embedded in the Aspen HYSYS® to validate the proposed LNG Liquefaction Process. The proposed natural gas Liquefaction Process was optimized using the knowledge-based optimization (KBO) approach. The overall energy consumption was chosen as an objective function for optimization. The performance of the proposed Liquefaction Process was compared with the conventional N 2 -expander Liquefaction Process. The vortex tube-based LNG Process showed a significant improvement of energy efficiency by 20% in comparison with the conventional N 2 -expander Liquefaction Process. This high energy efficiency was mainly due to the isentropic expansion of the vortex tube. It turned out that the high energy efficiency of vortex tube-based Process is totally dependent on the refrigerant cold fraction, operating conditions as well as refrigerant cycle configurations.
Muhammad Abdul Qyyum - One of the best experts on this subject based on the ideXlab platform.
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Gas–liquid dual-expander natural gas Liquefaction Process with confirmation of biogeography-based energy and cost savings
Applied Thermal Engineering, 2020Co-Authors: Muhammad Abdul Qyyum, Kinza Qadeer, Ashfaq Ahmad, Moonyong LeeAbstract:Abstract The use of nitrogen (N2) expander-based Liquefaction Processes is prevalent in offshore sites for the production of floating liquefied natural gas. It is safe, has simple operability, and has portable design with a small deck space requirement. However, the high operating cost that mainly accounts for the shaft work requirement in the compression units of the refrigeration cycle, is still a major ongoing issue associated with nitrogen expander Liquefaction Processes. This high operating cost increases the total annualized costs of the N2 expander Liquefaction technology, and this ultimately reduces its global competitiveness of the Process. Recent developments in expansion devices pave the way toward the handling of gas–liquid (two-phase) refrigerant in an isentropic manner instead of an isenthalpic one. This study presents the propane-nitrogen two-phase dual expander Liquefaction Process for offshore applications. A bio-inspired strategy named “biogeography” is used to confirm the overall energy savings with minimal total annualized costs. The results show that the proposed Liquefaction technology gives 36.6% operating cost savings, and this confirms a 16.5% saving in total annualized costs compared with the conventional nitrogen dual gas-phase expander Liquefaction Process. This study is an extension of our previous study “Innovative propane-nitrogen two-phase expander refrigeration cycle for energy-efficient and low-global warming potential LNG production”.
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An innovative vortex-tube turbo-expander refrigeration cycle for performance enhancement of nitrogen-based natural-gas Liquefaction Process
Applied Thermal Engineering, 2018Co-Authors: Muhammad Abdul Qyyum, Arif Hussain, Adnan Aslam NoonAbstract:Abstract Liquefied natural gas (LNG) has attracted global attention as a more ecological energy source when compared to other fossil fuels. The nitrogen (N2) expander Liquefaction is the most green and safe Process among the different types of commercial natural gas Liquefaction Processes, but its relatively low energy efficiency is a major issue. To solve this issue, an energy-efficient, safe, and simple refrigeration cycle was proposed to improve the energy efficiency of the N2 based natural-gas Liquefaction Process. In the proposed refrigeration cycle, vortex tube as an expansion device was integrated with turbo-expander in order to reduce the overall required energy for LNG production. A well-known commercial simulator Aspen Hysys® v9 was employed for modeling and analysis of proposed LNG Process. The hybrid vortex-tube turbo-expander LNG Process resulted in the specific energy requirement of 0.5900 kWh/kg LNG. Furthermore, the energy efficiency of the proposed LNG Process was also compared with previous N2 expander-based LNG Processes. The results demonstrated that the proposed hybrid configuration saved up to 68.5% (depending on feed composition and conditions) in terms of the overall specific energy requirement in comparison with previous studies.
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energy optimization for single mixed refrigerant natural gas Liquefaction Process using the metaheuristic vortex search algorithm
Applied Thermal Engineering, 2018Co-Authors: Wahid Ali, Muhammad Abdul Qyyum, Kinza Qadee, Moonyong LeeAbstract:Abstract A metaheuristic vortex search algorithm was investigated for the optimization of a single mixed refrigerant (SMR) natural gas Liquefaction Process. The optimal design of a natural gas Liquefaction Processes involves multivariable non-linear thermodynamic interactions, which lead to exergy destruction and contribute to Process irreversibility. As key decision variables, the optimal values of mixed refrigerant flow rates and Process operating pressures were determined in the vortex pattern corresponding to the minimum required energy. In addition, the rigorous SMR Process was simulated using Aspen Hysys® software and the resulting model was connected with the vortex search optimization algorithm coded in MATLAB. The optimal operating conditions found by the vortex search algorithm significantly reduced the required energy of the single mixed refrigerant Process by ≤41.5% and improved the coefficient of performance by ≤32.8% in comparison with the base case. The vortex search algorithm was also compared with other well-proven optimization algorithms, such as genetic and particle swarm optimization algorithms, and was found to exhibit a superior performance over these existing approaches.
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feasibility study of environmental relative humidity through the thermodynamic effects on the performance of natural gas Liquefaction Process
Applied Thermal Engineering, 2018Co-Authors: Muhammad Abdul Qyyum, Wahid Ali, Arif Hussain, Le Quang Minh, Alireza Bahadori, Moonyong LeeAbstract:Abstract This study examined the thermodynamic effects of relative humidity (RH) on the performance of the natural gas Liquefaction Process. A single mixed refrigerant (SMR) Liquefaction Process was chosen for this study because of its simplicity and compactness. In addition, it is considered the most promising Process for the liquefied natural gas (LNG) floating production, storage and offloading (FPSO) unit. The SMR Process was optimized using a modified coordinate descent methodology, which resulted in 13.6% energy savings. Subsequently, an interface between commercial software Aspen Hysys® and MS-Excel VBA was carried out to study the effects of RH. The results showed that RH has pronounced effects on the performance of the LNG cycle by affecting the enthalpy balance around the air coolers, which ultimately affects the overall compression power, LNG exchanger performance, and other design and operational parameters. Furthermore, when the RH was increased from 0% to 95%, the UA value (product of overall heat transfer coefficient and heat transfer area) of the air coolers and the overall compression power decreased and increased linearly, respectively. Moreover, the heat transfer coefficient of the LNG cryogenic exchanger increased as a 4th order polynomial function in terms of the log-mean enthalpy difference. The results can provide insight into the selection of the appropriate design and operational parameters for the LNG plants associated with the regions of low or high relative humidity.
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a novel vortex tube based n2 expander Liquefaction Process for enhancing the energy efficiency of natural gas Liquefaction
E3S Web of Conferences, 2017Co-Authors: Muhammad Abdul Qyyum, Wahid Ali, Feng Wei, Arif Hussai, Oh Sehee, Moonyong LeeAbstract:This research work unfolds a simple, safe, and environment-friendly energy efficient novel vortex tube-based natural gas Liquefaction Process (LNG). A vortex tube was introduced to the popular N 2 -expander Liquefaction Process to enhance the Liquefaction efficiency. The Process structure and condition were modified and optimized to take a potential advantage of the vortex tube on the natural gas Liquefaction cycle. Two commercial simulators ANSYS® and Aspen HYSYS® were used to investigate the application of vortex tube in the refrigeration cycle of LNG Process. The Computational fluid dynamics (CFD) model was used to simulate the vortex tube with nitrogen (N 2 ) as a working fluid. Subsequently, the results of the CFD model were embedded in the Aspen HYSYS® to validate the proposed LNG Liquefaction Process. The proposed natural gas Liquefaction Process was optimized using the knowledge-based optimization (KBO) approach. The overall energy consumption was chosen as an objective function for optimization. The performance of the proposed Liquefaction Process was compared with the conventional N 2 -expander Liquefaction Process. The vortex tube-based LNG Process showed a significant improvement of energy efficiency by 20% in comparison with the conventional N 2 -expander Liquefaction Process. This high energy efficiency was mainly due to the isentropic expansion of the vortex tube. It turned out that the high energy efficiency of vortex tube-based Process is totally dependent on the refrigerant cold fraction, operating conditions as well as refrigerant cycle configurations.
Dongil Shi - One of the best experts on this subject based on the ideXlab platform.
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effects of varying the ambient temperature on the performance of a single mixed refrigerant Liquefaction Process
Journal of Natural Gas Science and Engineering, 2016Co-Authors: Kyungtae Park, Dongil ShiAbstract:Abstract This paper presents the optimal design and operational solutions for a single mixed refrigerant Liquefaction Process under varying ambient temperatures. Given that the ambient temperature can affect the performance of air coolers and gas turbines, the correlation between changes in the ambient temperature and the performance of a single mixed refrigerant Liquefaction Process should be investigated. A simulation model and a mathematical model were devised and linked to find the optimal design and operational solutions for a single mixed refrigerant Liquefaction Process, and the particle swarm optimization method was adopted for used with the mathematical model. The results of this study can provide insight about taking advantage of low ambient temperatures for Process engineers associated with LNG Liquefaction plants.
Robert C. Brown - One of the best experts on this subject based on the ideXlab platform.
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Correction: Tetrahydrofuran-based two-step solvent Liquefaction Process for production of lignocellulosic sugars
Reaction Chemistry & Engineering, 2020Co-Authors: Arpa Ghosh, Martin R. Haverly, Jake K. Lindstrom, Patrick A. Johnston, Robert C. BrownAbstract:Correction for ‘Tetrahydrofuran-based two-step solvent Liquefaction Process for production of lignocellulosic sugars’ by Arpa Ghosh et al., React. Chem. Eng., 2020, DOI: 10.1039/d0re00192a.
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Tetrahydrofuran-based two-step solvent Liquefaction Process for production of lignocellulosic sugars
Reaction Chemistry & Engineering, 2020Co-Authors: Arpa Ghosh, Martin R. Haverly, Jake K. Lindstrom, Patrick A. Johnston, Robert C. BrownAbstract:Large-scale production of biofuels and chemicals will require cost-effective, sustainable, and rapid deconstruction of woody biomass into its constituent sugars. Here, we introduce a novel two-step Liquefaction Process for producing fermentable sugars from red oak using a mixture of tetrahydrofuran (THF), water and dilute sulfuric acid. THF promotes acid-catalyzed solubilization of lignin and hemicellulose in biomass achieving 61% lignin extraction and 64% xylose recovery in a mild pretreatment step. The pretreatment opens the structure of biomass through delignification and produces a cellulose-rich biomass, which is readily solubilized at low temperature giving 65% total sugar yields in a subsequent Liquefaction Process employing the same solvent mixture. This Process achieves competitive sugar yields at high volumetric productivity compared to conventional saccharification methods. THF, which can be derived from renewable resources, has several benefits as solvent including ease of recovery from the sugar solution and relatively low toxicity and cost.
Go Bong Choi - One of the best experts on this subject based on the ideXlab platform.
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optimal design and operating condition of boil off co2 re Liquefaction Process considering seawater temperature variation and compressor discharge temperature limit
Chemical Engineering Research & Design, 2017Co-Authors: Go Bong ChoiAbstract:Abstract Low-temperature liquid CO2 could boil off during ship transportation because of the heat ingress from the surroundings to inside the tank, which causes the tank pressure to increase. To maintain the operating pressure range of the tank, the re-Liquefaction Process is indispensable. Three design alternatives to the re-Liquefaction Process using boil-off CO2 as a refrigerant are proposed and compared. A systematic procedure to find the optimal design of CO2 re-Liquefaction is provided considering operational constraints such as the cooling water temperature and compressor discharge temperature. The optimal operating conditions of the proposed Processes are determined by solving nonlinear programming. The compressor power consumption as the operation energy for the CO2 re-Liquefaction ranges from 60 to 120 kW/t CO2 given the operational constraints. As the seawater temperature is lower and the discharge temperature limit is higher, the proposed Alternative 2 design consumes less power than the other designs.
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Optimal Design and Operating Conditions of the CO2 Liquefaction Process, Considering Variations in Cooling Water Temperature
Industrial & Engineering Chemistry Research, 2015Co-Authors: Seok Goo Lee, Go Bong Choi, Jong Min LeeAbstract:Ship transportation of liquid CO2 is now considered as an alternative transport option to pipelines, in the absence of any suitable onshore storage locations. The compressors for a Liquefaction Process in the transport chain account for a significant portion of the total energy consumption. The temperature of seawater as an intercooling medium has a very significant effect on the energy consumption of the multistage compressors. Although several studies for the optimal design and operation of Liquefaction Process have been proposed, they do not consider the seasonal and locational variations in the cooling water temperature; therefore, further improvement in the energy efficiency in the CO2 Liquefaction Process is necessary. In this study, the variations in the operational energy and other operational issues of the CO2 Liquefaction Process, according to the actual seawater temperature in the range of 5–30 °C was investigated. Moreover, the optimal discharge pressure of the final stage compressor before th...