• Clean Technology
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• v.22 no.4
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• pp.225-231
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• 2016

In this study, modeling and optimization study have been performed to obtain $1,524.58kg\;h^{-1}$ of a solidified NaCl by evaporating a 21.0 wt% of NaCl aqueous solution in order to reduce the steam consumption from $3,139kg\;h^{-1}$ to $496kg\;h^{-1}$ using a two-stage evaporation and a vapor recompression processes. Aspen Plus release 8.8 at AspenTech was utilized for the modeling of two stage evaporation process and PRO/II with PROVISION release 9.4 at Schneider Electric was also used for the simulation of two-stage vapor recompression process with an inter-cooler. For the simulation of the evaporation process containing NaCl aqueous solution, Aspen Plus release 8.8 at AspenTech Inc. was utilized and for the modeling of vapor recompression process PRO/II with PROVISION release at Schneider Electric Inc. For the vapor recompression process, single stage compression and two-stage compression system was compared.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.11a
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• pp.165-170
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• 1999

기계적 증기재압축(Mechanical Vapor Recompression) 시스템은 증기를 압축하여 압력을 올리면 온도가 상승하는 원리를 이용한 것으로서 시스템의 최종 증발관에서 발생한 저온의 증발증기를 전량 증기압축기로 압축ㆍ승온하여 자신의 최초 증발관의 가열 열원으로 재사용 하는 방식이다. 따라서 이 사이클에 필요한 보충열원은 가열측과 증발측과의 온도상승분 만큼만 증기의 포화온도를 올리면 되므로 에너지절약 효과가 매우 크다.(중략)

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.11
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• pp.434-443
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• 2016

The evaporation of water from an aqueous solution is widely used in the food, desalination, pulp, and chemical industries. Usually, a large amount of energy is consumed in the evaporation process to boil off water due to atmospheric pressure. As a way of improving the energy efficiency of the evaporation process, the combination of multiple effect evaporation and thermal vapor recompression has been proposed and has become a successful technique. In this study, 4 multiple-effect falling film type evaporators for sugar solution are designed and the energy efficiency of the system is analyzed in response to the selection of the steam ejector position. Energy efficiency is increased and vapor is more compressed in the steam ejector as the Thermal Vapor Recompression (TVR) is arranged in the rear part of the evaporator system. A simplified 0-dimensional evaporator model is developed using non-linear equations derived from mass balances, energy balances, and heat transfer equations. Steam economy is calculated to compare the evaporation performance of the 4 proposed evaporators. The entrainment ratio, compression ratio, and expansion ratio are computed to check the ejector performance.

• Environmental engineer
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• s.137
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• pp.16-19
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• 1998

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2000.04a
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• pp.243-248
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• 2000

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.23 no.5
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• pp.403-413
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• 1994

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.245-249
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• 2013

The depropanizing, debutanizing and deisobutanizing fractionation steps of processing natural gas liquids were improved through studying complex distillation arrangements, including the double dividing wall column arrangement (DDWC), the sequence including a dividing wall column (DWC) and a bottom DWC (BDWC), and the sequence including a DWC and a BDWC with top vapor recompression heat pump. These arrangements offer benefits by decreasing reboiler and condenser power consumption. Reducing the number of columns and their diameters can potentially reduce construction costs. The result also showed that operating cost could be reduced most significantly through novel combinations of internal and external heat integration: bottom dividing wall columns employing a top vapor recompression heat pump.

• KEPCO Journal on Electric Power and Energy
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• v.4 no.1
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• pp.33-38
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• 2018

This study applied upgrades to the processes of a 10 MW wet amine $CO_2$ capture pilot plant and conducted performance evaluation. The 10 MW $CO_2$ Capture Pilot Plant is a facility that applies 1/50 of the combustion flue gas produced from a 500 MW coal-fired power plant, and is capable of capturing up to 200 tons of $CO_2$. This study aimed to quantitatively measure efficiency improvements of post-combustion $CO_2$ capture facilities resulting from process upgrades to propose reliable data for the first time in Korea. The key components of the process upgrades involve absorber intercooling, lean/rich amine exchanger efficiency improvements, reboiler steam TVR (Thermal Vapor Recompression), and lean amine MVR (Mechanical Vapor Recompression). The components were sequentially applied to test the energy reduction effect of each component. In addition, the performance evaluation was conducted with the absorber $CO_2$ removal efficiency maintained at the performance evaluation standard value proposed by the IEA-GHG ($CO_2$ removal rate: 90%). The absorbent used in the study was the highly efficient KoSol-5 that was developed by KEPCO (Korea Electric Power Corporation). From the performance evaluation results, it was found that the steam consumption (regeneration energy) for the regeneration of the absorbent decreased by $0.38GJ/tonCO_2$ after applying the process upgrades: from $2.93GJ/ton\;CO_2$ to $2.55GJ/tonCO_2$. This study confirmed the excellent performance of the post-combustion wet $CO_2$ capture process developed by KEPCO Research Institute (KEPRI) within KEPCO, and the process upgrades validated in this study are expected to substantially reduce $CO_2$ capture costs when applied in demonstration $CO_2$ capture plants.

• Journal of the Korean Institute of Gas
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• v.20 no.1
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• pp.1-6
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• 2016

In order to reduce the anthropogenic emission of greenhouse gases, CCS technology has emerged as the most promising and practical solution. Among CCS technology, post-combustion $CO_2$ capture is known as the most mature and effective process to remove $CO_2$ from power plant, but its energy consumption for chemical solvent regeneration still remains as an obstacle for commercialization. In this study, a process alternative integrating $CO_2$ capture with compression process is proposed which not only reduces the amount of thermal energy required for solvent regeneration but also produces $CO_2$ at an elevated pressure.

• Journal of Hydrogen and New Energy
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• v.34 no.2
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• pp.226-233
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• 2023

In this study, we compared the performance of several refrigeration cycles using different refrigerants and utilizing the cold heat of liquefied natural gas (LNG) for the liquefaction of carbon dioxide. The final conditions for the liquefied CO₂ were set to -20℃ and 20 bar. The refrigerants used included R404a, ammonia, propane, and propylene using a vapor recompression refrigeration cycle. For the refrigeration cycle, the CO₂ at room temperature and pressure was compressed in a two-stage compression process with an intermediate cooling stage using a refrigeration unit. To compare with the liquefaction process using refrigeration, we compressed the CO₂ to 8 bar in a single compression stage and cooled it to around -50℃ using the cold heat of the LNG before liquefying it. Results showed that using ammonia as the refrigerant required the least amount of compressor power for the liquefaction process, and the heat transfer area of the evaporator was the smallest when using propylene as the refrigerant. Using the cold heat of LNG instead of refrigeration using R404a resulted in approximately 69% less energy consumption.