CO2 Capture in a Miniaturized Annular Rotating Device with Countercurrent Flow

•A m-ARD operated at high-phase-ratio of gas to liquid and countercurrent flow mode is proposed.•The contribution of mass transfer coefficient and specific surface area for enhancing CO2 absorption are discussed.•The maximum η and kLa are up to 99.3 % and 0.53 s−1, respectively.•When the volume ratio gas to liquid is 200, η is still higher than 80 %.