Recovery of carbon dioxide from stack gas by piston-driven ultra-rapid PSA.

Abstract

Application of piston-driven ultra-rapid pressure swing adsorption (URPSA) to CO2 recovery from a stack gas was investigated by using a model stack gas. Specific objectives of this work are to experimentally achieve high capacity CO2, reduction and to elucidate the effects of moisture contained in the stack gas on CO2 recovery by the URPSA using hydrophilic and hydrophobic zeolites. Also, CO2 recovery using URPSA was investigated by numerical simulations on the basis of a simplified mathematical model.CO2 recovery from a model stack gas is successfully demonstrated by piston-driven ultra-rapid PSA. The moisture contained in a model stack gas was accumulated in hydrophilic zeolite and drastically reduced CO2 adsorption capacity. However, since the effects of accumulation of H2O are negligibly small in the case of hydrophobic zeolite, hydrophobic zeolite should be employed for this purpose. The production capacity of the URPSA was about one order of magnitude higher than those of conventional PSAs. Still, the performance of CO2 recovery of the URPSA was low. It is known that decreasing the pressure drop of the adsorbent and optimizing the sequence control are needed to improve the efficiency. Numerical simulations using a simplified mathematical model were successful, and the model developed will be useful for further investigations.