CO2 capture in a miniaturized annular rotating device with countercurrent flow

Microdevices are becoming a hot technology for process intensification of CO2 capture. However, most microdevices are limited to a small handling capacity, low volume gas to liquid ratio, and cocurrent flow mode. In this context, we proposed a miniaturized annular rotating device (m-ARD), which has a high handling capacity, can be employed for high volume ratios of gas to liquid, and utilizes a countercurrent flow mode. Variables were investigated to determine the flow characteristic, absorption efficiency of CO2, and volume mass transfer coefficient. The gas hold-up and specific surface area in the m-ARD were up to 43.8 % and 1000 m2/m3, and low pressure drop was observed. Notably, the optimal volume gas to liquid phase ratio, absorption efficiency of CO2, and overall volumetric mass transfer coefficient were close to 200 %, 100 %, and 0.53 s-1, respectively. Furthermore, two dimensionless equations were built to predict the volumetric mass transfer coefficient and gas hold-up. In addition, the contributions of the specific surface area and mass transfer coefficient for enhancing CO2 absorption were discussed, respectively. This work provides a prospective device for enhancing CO2 capture and other gas-liquid separation and reaction processes.