Enhancement effect and mechanism of gas-liquid mass transfer by baffles embedded in the microchannel

• Published in: Chemical engineering science Vol. 201; pp. 264 - 273
• Main Authors: Yin, Yaran, Zhu, Chunying, Fu, Taotao, Ma, Youguang, Wang, Kai, Luo, Guangsheng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 29.06.2019
• Subjects: Baffle; Enhancement factor; Gas-liquid two-phase; Mass transfer enhancement; Microchannel; Mass transfer enhancement; Enhancement factor; Gas-liquid two-phase; Microchannel; Baffle
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2019.02.039

[Display omitted] •Mass transfer intensification was achieved by embedding baffles in microchannels.•Mass transfer of CO2 into MEA/[Bmim][BF4] aqueous solution was studied in baffled microchannels.•kLa in baffled microchannels could be increased by 50% with a maximum increase in Δp of 0.3 kPa or 20%. The enhancement of gas-liquid mass transfer by baffles embedded in a microchannel was investigated experimentally for CO2 absorption into monoethanolamine/1-butyl-3-methylimidazolium tetrafluoroborate (MEA/[Bmim][BF4]) aqueous solutions. The influences of baffle size on mass transfer rate and pressure drop were studied through varying the MEA/[Bmim][BF4] concentration ratio, gas-liquid flow rate and blockage ratio. Experimental results showed that the proper baffle configuration could improve effectively gas-liquid mass transfer performance. Although the pressure drop of the baffled microchannel has slight increase (the maximum growth 0.3 kPa, or 20% in relative term) in comparison with the unobstructed microchannel, it is acceptable for industrial application. Under lower MEA/[Bmim][BF4] concentration ratios, higher two-phase flow rates and blockage ratios, the mass transfer enhancement is more pronounced and the enhancement factor could reach to 1.5. A new empirical correlation of enhancement factor is proposed with good predictive performance.