Moving bed adsorption process with internal heat integration for carbon dioxide capture

A moving bed adsorption (MBA) process with heat integration is proposed as a potentially viable post-combustion process for the capture of CO2 from large-scale CO2-emitting plants. The proposed process consists of an adsorption bed and two desorption beds through which the adsorbent particles continuously circulate. The adsorbent particles and the flue gas flow in opposite directions in the adsorption bed, which is operated at low temperature and atmospheric pressure. The adsorbents discharged from the adsorption bed are transferred to a desorption bed operated at a high temperature and 1 atm, then transferred to another desorption bed operated at a high temperature and in a vacuum, and returned to the adsorption bed. A heat integration scheme in which the thermal energy removed from the adsorption bed is reused in the desorption beds was designed. After a numerical model of the proposed process was developed, the effects of the model parameters and operating conditions on the performance and behavior of the process were investigated. The proposed MBA process with the heat integration scheme was estimated to produce CO2 with a purity of over 97% and a recovery of over 80% while the recovered energy from the adsorber can provide up to 54.4% of the regeneration energy.