Bubble Diameter, Mass Transfer, and Bioreaction of Dynamic Membrane-Stirred Reactors

Abstract

The gas–liquid mass transfer of reactors is the focus of intensifying biochemical engineering. Hence, this paper develops a dynamic membrane-stirred reactor to increase the gas–liquid mass transfer efficiency (k L a) and improve bioreactions. Dynamic membrane coupling mixing and aeration form uniform microbubbles to intensify gas–liquid mass transfer. The optimal pore diameter and blade angle of the dynamic membrane are 10 μm and 45°, respectively, providing more uniform microbubbles, better gas–liquid mixing performance, higher gas holdup, and better k L a. Compared with the traditional stirred reactor, the dynamic membrane-stirred reactor reduces the energy consumption by 50% and improves biomass and enzyme activity. The maximum dry cell weight is 30.13 g·L–1, and the maximum specific cell growth rate is 0.38 h–1, 48.9% higher and 31% higher than the traditional reactor. To sum up, the unique structure of a dynamic membrane-stirred reactor effectively reduces the bubble diameter and improves k L a and the bioreaction process.