Advanced exergy analysis of the modified process of natural gas cryogenic helium extraction

Abstract

Conventional exergy analysis can only quantitatively analyse the exergy destruction of devices, while advanced exergy analysis can obtain the detailed distribution of the exergy destruction. For analysing the energy consumption of equipment in the process of cryogenic helium extraction, advanced exergy analysis was performed on a modified process for natural gas helium extraction. The analysis results show that the largest part of most equipment exergy destruction is endogenous exergy destruction; the equipment that has the largest exergy destruction in the process is the cold box, followed by the compressor. The exergy destruction of compression equipment is similar, but the exergy destruction of different heat exchange equipment is different. Sensitivity analysis shows that in order to minimise the unavoidable exergy destruction of the column, the recommended feed pressure of the primary concentration column is 3,200, and the recommended feed temperature of the cryogenic separator before the secondary concentration column is -150. [Received: January 18, 2022; Accepted: June 14, 2022]