Carbon dioxide capture in a HiGee reactor with packing featuring controllable cross-sectional area

Abstract

A rotating packed bed (RPB), as one of the typical HiGee reactors, has achieved extensive praise in CO2 capture fields. In this work, the novel mesh packings with controllable cross-sectional areas (CSAs) were applied to intensify the CO2 absorption process in an RPB, as well as combining with the blended aqueous amine solutions including diethylenetriamine (DETA) and piperazine (PZ). The gas pressure drop and CO2 absorption performance of various packings were investigated. Different operating conditions including rotational speed (400–2400 r/min), liquid flow rate (10–35 L/h), gas flow rate (900–2400 L/h), and CO2 molar fraction in gas inlet (2–12%) were considered. The results exhibited that the rise in gas pressure drop of concentric packing with constant CSA (CONC-9) relative to conventional coiled packing with increasing CSA (COII-9) was less than 10% on average. Meanwhile, the CO2 absorption efficiency of CONC-9 exceeded 17.1% on average than that of COII-9. For further comparison, the ratio of mass transfer coefficient to gas pressure drop in the wet RPB (KGa/△PW) was analyzed. The KGa/△PW of CONC-9 was 48.6% larger on average than that of COII-9. The average mass transfer coefficient and height of mass transfer unit of CONC-9 reached up to 16.7 kmol∙kPa−1∙m−3∙h−1 and 0.013 m, respectively. Overall, it is a viable way to adopt the packing with constant CSA to intensify the CO2 absorption in RPBs.