Computational Fluid Dynamics of Rectangular Monolith Reactor vs. Packed-Bed Column for Sorption-Enhanced Water-Gas Shift

Sorption-enhanced water-gas shift (SEWGS) process is very attractive for an energy efficient pre-combustion CO2 capture, as it enables direct conversion of syngas into separate streams of H-2 and CO2 at high temperatures and pressures. Using advanced computational fluid dynamics (CFD) methods, quantitative performance differences were assessed for rectangular channel monolith structures versus regular packed-bed structures when used for pre-combustion CO2 capture. Published data of breakthrough capacities at different pressures for CO2 and H2O were used to validate a multicomponent adsorption isotherm. A COMSOL 1D model was developed to describe CO2 adsorption in a fixed-bed reactor, filled with adsorbent pellets, to confirm the accuracy of the results compared to the existing studies, after which a 2D model was built simulating the adsorption step of a SEWGS process inside of a monolith reactor channel. Model predictions display an increase in productivity of adsorption in the case of monolith structures versus conventional packed-bed columns. Results will be used to improve the performance of experimental monolith structures undergoing SEWGS.