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A Study on the Optimal Process Design of Cryogenic Air Separation Unit for Oxy-Fuel Combustion

순산소 연소를 위한 초저온 공기분리장치의 최적공정 설계 연구

  • Choi, Hyeung-Chul (Daesung Cryogenic Research Institute, Daesung Industrial Gases Co., Ltd.) ;
  • Moon, Hung-Man (Daesung Cryogenic Research Institute, Daesung Industrial Gases Co., Ltd.) ;
  • Cho, Jung-ho (Department of Chemical Engineering, University of Kongju)
  • 최형철 (대성산업가스(주) 초저온연구소) ;
  • 문흥만 (대성산업가스(주) 초저온연구소) ;
  • 조정호 (공주대학교 화학공학부)
  • Received : 2018.07.11
  • Accepted : 2018.08.14
  • Published : 2018.10.01

Abstract

In order to solve the global warming and reduce greenhouse gas emissions, it has been developed the $CO_2$ capture technology by oxy-fuel combustion. But there is a problem that the economic efficiency is low because the oxygen production cost is high. ASU (Air Separation Unit) is known to be most suitable method for producing large capacity of oxygen (>2,000 tpd). But most of them are optimized for high purity (>99.5%) oxygen production. If the ASU process is optimized for low purity(90~97%) oxygen producing, it is possible to reduce the production cost of oxygen by improving the process efficiency. In this study, the process analysis and comparative evaluation was conducted for developing large capacity ASU for oxy-fuel combustion. The process efficiency was evaluated by calculating the recovery rate and power consumption according to the oxygen purity using the AspenHysys. As a result, it confirmed that the optimal purity of oxygen for oxyfuel combustion is 95%, and the power consumption can be reduced by process optimization to 12~18%.

Keywords

Oxy-fuel combustion;Oxygen;Cryogenic;Air separation;ASU

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