Gas-liquid distribution and mass transfer of CO2 absorption into sodium glycinate aqueous solution in parallel multi-channel microreactor

Abstract

The flow, gas-liquid distribution and mass transfer of CO2 absorption into sodium glycinate aqueous solution in microreactor with parallel multi-channel were investigated by using high-speed camera. The effects of the gas and liquid flow rates and the sodium glycinate concentration on gas-liquid distribution, CO2 absorption efficiency and volumetric mass transfer coefficient were studied. The increase of gas flow rate could aggravate the non-uniformity of gas-liquid distribution in the channels, while the increase of liquid flow rate or sodium glycinate concentration could weaken the non-uniformity of gas-liquid distribution in the channels. The absorption efficiency of CO2 increases firstly and then decreases with the increase of gas flow rate, and increases with the increase of liquid flow rate or the sodium glycinate concentration. The volumetric mass transfer coefficient of liquid side increases with increasing gas flow rate, liquid flow rate or liquid concentration. Within the experimental range, the average standard deviation of gas-liquid distribution in each channel is 5.6%, and the average liquid side volumetric mass transfer coefficient in parallel multi-channel microreactor is slightly lower than that in a single microchannel under the same conditions, indicating that the multi-channel microreactor used in this work has good distribution and mass transfer performance.