Bubble dynamics and mass transfer enhancement in split-and-recombine (SAR) microreactor with rapid chemical reaction

In this study, a split-and-recombine (SAR) microreactor which is composed of convergent-divergent arc channel and rectangular obstacles was designed, and its enhancement characteristics in gas-liquid rapid chemical ab-sorption system were explored. In the SAR microreactor, the deformation, splitting, stretching and breakup of bubbles are monitored by a high-speed camera. Accordingly, the bubble velocity pulsation caused by SAR structure is analyzed. The squeezing mechanism for bubble breakup located on the front surface of the obstacle is revealed. Two breakup patterns, namely complete and partial breakup, are observed, and the mass transfer performance is highly related to them. The mass transfer enhancement factor (E-ka) of SAR structure increases with gas/liquid flow rate in complete breakup pattern while decreases in partial breakup pattern. The increase of gas-liquid flow rates and the number of SAR units, or slower reaction rate strengthens the velocity fluctuation and bubble breakup, resulting in an increase in E-ka, with a maximum value of 2.74. Overall, the SAR micro-reactor performs comparable to Corning Advanced Flow Reactor in term of mass transfer energy efficiency. This work guides the application of SAR microreactor in rapid gas-liquid chemical reaction system.

Automated summary

In this study, a split-and-recombine (SAR) microreactor composed of convergent-divergent arc channel and rectangular obstacles was designed and its enhancement characteristics in a gas-liquid rapid chemical absorption system were explored. The study found that the SAR structure caused bubble velocity pulsation and revealed the squeezing mechanism for bubble breakup. Different breakup patterns had an influence on the mass transfer performance.