Highly efficient post-combustion CO2 capture by low-temperature steam-aided vacuum swing adsorption using a novel polyamine-based solid sorbent

Abstract

A novel amine-based solid sorbent was prepared for CO2 capture, and the CO2 adsorption characteristics were evaluated for simulated flue gas. Furthermore, CO2 capture tests using a lab-scale three-column fixed-bed system were performed. A novel amine compound was synthesized by attaching hindered functional groups to the terminal primary amino groups of a polyamine, followed by impregnation into pelletized mesoporous MSU-F silica. This novel amine-impregnated solid sorbent overcame the problem of limited CO2 diffusion and exhibited extremely high regenerability even at low temperatures. Lab-scale CO2 capture tests suggested that operation conditions such as temperature, cycle time, rinsing time, flow rate, and regeneration method directly affected CO2 capture performance. In particular, direct low-temperature steam stripping desorption drastically enhanced CO2 capture performance. Steam-aided vacuum swing adsorption (SA-VSA) process was feasible for our amine-based solid sorbent and enabled the recovery of CO2 with high purity (>98%) and recovery rate (>93%). The regeneration heat calculated from the amount of recovered CO2 and the amount of supplied steam was considerably lower (1.47 GJ/t-CO2) than that of liquid amine solvents and other amine-based solid sorbents.