Mass transfer in gas-liquid flow in microchannels.

Experimental results on physical absorption of CO_2 into water in micro-contactors with a single and 16 parallel microchannels having hydraulic diameter of 667 μm were presented respectively.It was shown that the liquid side volumetric mass transfer coefficients increased dramatically with the increase of superficial liquid and gas velocities in single microchannel.Then correlations were proposed to depict the relationship between liquid side volumetric mass transfer coefficients and operational parameters.Compared with the conventional gas-liquid contactors, micro-contactors can provide at least one or two orders of magnitude higher liquid side volumetric mass transfer coefficients.Finally, the effect of two-phase flow distribution in parallel microchannels on the overall mass transfer performance was discussed, which revealed that specially designed inlet flow distribution areas of gas and liquid could guarantee high mass transfer rates in the subsequent microchannels.