Simulation and energy consumption comparison of gas purification system based on elevated temperature pressure swing adsorption in ammonia synthetic system

Abstract

Elevated temperature pressure swing adsorption (ET-PSA) is a novel process for hydrogen purification. By operating steam rinse and purge at conditions beyond the dew point will significantly improve the recovery rate of the product gas. Moreover, since cooling and reheating processes are not needed in ET-PSA, the sensible heat of the incoming gas could also be preserved. In this study, a seven-column 5000 Nm3/h ET-PSA pilot scale model was designed for energy consumption analysis. Product H2 purity, recovery rate, product CO2 purity, CO2 capture rate, unit H2 purification energy consumption and unit CO2 capture energy consumption were set as the criteria for assessing the purification performance. Rinse pressure, rinse media, and desorption method were selected as variables during the design and optimisation of the ET-PSA process. Herein, a high process efficiency (99.98% product gas purity and 99.33% recovery) was achieved. These values increased by 5.38% and 4.44%, respectively, compared to the base case. Meanwhile, the CO2 capture energy consumption was reduced by 59.2 MJ/ton(CO2).