Hydrodynamics behavior and mass transfer performance of gas–liquid two-phase flow in the honeycomb fractal microreactor

Abstract

The gas–liquid two-phase flow and mass transfer performance in the honeycomb fractal reactor with equal diameter were visually investigated. The effects of operating conditions on flow pattern, fluid distribution and mass transfer coefficient were studied. The intrinsic dependence of mass transfer coefficient on fluid uniformity was revealed. Four flow patterns were observed in this work: non-breakup flow, symmetrical flow, unobvious asymmetrical flow, and obvious asymmetrical flow. It was found that the fluid distribution was mainly influenced by the downstream feedback of the channel. The bubble uniformity relies dramatically on the bubble breakup, pressure fluctuations, and downstream feedback. A relatively uniform bubble distribution could be obtained at partial symmetrical flow and unobvious asymmetrical flow. The mass transfer could be greatly enhanced in the case of excellent fluid distribution and uniform bubble size, conversely, the mass transfer coefficient would decrease. The increasing leakage flow and internal circulation inside the liquid are conducive to mass transfer performance. Additionally, the honeycomb fractal reactor with variable diameter was designed based on Murray's law and its comprehensive performance was compared with the fractal reactor with equal diameter, which could provide a theoretical basis for the design and optimization of the fractal microreactor.