Adsorptive cyclic purification process for CO 2 mixtures captured from coal power plants

CO 2 capture technology combined with bulk separation and purification processes has become an attractive alternative to reduce capture costs. Furthermore, the required purity in the application for CO 2 conversion and utilization is more stringent than that required from a captured CO 2 mixture for geological storage. In this study, an adsorptive cyclic purification process was developed to upgrade a CO 2 /N 2 mixture captured from greenhouse gas emission plants as a feasibility study for a second capture unit or captured CO 2 purifier. To purify 90% CO 2 with balance N 2 as a captured gas mixture, two‐bed pressure swing adsorption and pressure vacuum swing adsorption (PVSA) processes using activated carbon were experimentally and theoretically studied at adsorption pressures of 250–650 kPa and a fixed vacuum pressure of 50 kPa. CO 2 with higher than 95% purity was produced with more than 89% recovery. However, a four‐bed PVSA process could successfully produce CO 2 with greater than 98% purity and 90% recovery. © 2016 American Institute of Chemical Engineers AIChE J , 63: 1051–1063, 2017