Study on a novel process for CO2compression and liquefaction integrated with the refrigeration process

Abstract

SUMMARY In order to transport and store the captured CO2 from coal-fired power plants, it is necessary to compress and liquefy CO2 first. However, the power consumption of conventional process is enormous. In this paper, a novel process for CO2 compression and liquefaction based on the analysis of the power consumption of traditional method is proposed. The new process integrates the refrigeration process driven by the lower level heat from the coal-fired power plant. This paper analyzes and compares the energy consumptions of conventional process and new process for CO2 compression and liquefaction. The research result indicates that, when CO2 needs to be compressed and liquefied and an abundant low quality heat is available, the new process has obvious superiority in lowering the energy consumption. The new process for CO2 compression and liquation integrated with the exhaust heat powered refrigeration can greatly reduce the work consumption of CO2 compression and liquefaction. The refrigeration temperature has great effects both on the coefficient of performance of refrigeration process and work consumption of compressors. The refrigeration temperature can be selected by optimization. Using refrigerator with double stages of evaporation can further reduce the amount of the extracted steam and lower the total energy consumption for CO2 compression and liquation. Recovering the cool energy of CO2 is beneficial to the reduction of the total work consumption. The achievements obtained from this paper will provide a useful reference for CO2 compression and liquefaction with the lower energy consumption. Copyright © 2012 John Wiley & Sons, Ltd.