Steam-assisted temperature swing adsorption for carbon capture integrated with heat pump

Abstract

Carbon capture, utilization and storage (CCUS) is considered as a promising technology to effectively mitigate CO2 emissions. Currently process design on CCUS is mainly focused on temperature swing adsorption (TSA) process and steam purge technology has the advantages of direct heat exchange and reduced carbon dioxide concentration in regeneration step. The paper initially proposes a steam-assisted temperature swing adsorption (S-TSA) process for carbon capture, in which heat pump plays a role to provide the driving force of desorption. The performance of the integrated system is evaluated in terms of feed, purge and cooling gas flowrates and evaporation and flash temperature. Results show that when the feed gas flowrates increase from 44 NL·min−1 to 56 NL·min−1, CO2 purity increases from 90.24% to 90.89% and recovery rate decreases from 95.88% to 85.72%. Heat and power consumption of the integrated system increase significantly with the rise of purge flowrates. If the waste heat inside the carbon capture system is utilized, the heat consumption can be reduced by a maximum of 14.91% at flash temperature of 75 °C. The significance of each flowrate and temperature to simulation results is analyzed through the orthogonal design and multivariate analysis of variance. It shows that performance of the integrated system is significantly influenced by feed flowrate and flash temperature, and cooling flowrate has the minimal impact. It demonstrates that the feed flowrate and desorption temperature should be given priority when choosing appropriate operating conditions for a real carbon capture system.