Intensification of gas-liquid two-phase flow and mass transfer in microchannels by sudden expansions

• Published in: Chemical engineering science Vol. 229; p. 116040
• Main Authors: Zhang, Shizhe, Zhu, Chunying, Feng, Huisheng, Fu, Taotao, Ma, Youguang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 16.01.2021
• Subjects: Energy consumption; Gas-liquid mass transfer; Microchannel; Sudden expansion unit; Energy consumption; Gas-liquid mass transfer; Sudden expansion unit; Microchannel
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2020.116040

•kLa could increase up to 200% as increasing the number of sudden expansions.•Energy consumption and effective mass transfer enhancement efficiency were studied.•A new correlation with good predictive performance was proposed for predicting kLa. The intensification of mass transfer of CO2 absorption into [Bmim][BF4] aqueous solution by continuous sudden expansion units was investigated experimentally in microchannels. The influences of two-phase flow rates and the number of sudden expansion units on pressure drop and volumetric mass transfer coefficient were studied systematically. The results indicate that the sudden expansion structure could remarkably enhance gas-liquid mass transfer. The enhancement factor of mass transfer increases with increasing the number of sudden expansion units and gas-liquid flow rate ratio, while the pressure drop has only slight elevation. The effective mass transfer enhancement efficiency was assessed according to the energy consumption and enhancement factor, which could achieve from 1.2 to 2.4, showing excellent mass transfer intensification effect of the sudden expansion structure. Moreover, a new correlation was proposed for predicting liquid side volumetric mass transfer coefficient.