Fundamentals of microscale bubbles in process engineering

Multiphase contact apparatuses are widely used in the chemical and biocatalytic process industry in which a gaseous reactant has to be supplied. The achievement of high mass transfer rates with regard to process efficiency is mostly challenging. In this work a novel aeration technique based on fine bubbles with diameters smaller 100 µm is experimentally analyzed, providing large interfacial areas for the mass transfer process. The experiments show the benefit of using fine bubbles by reaching significantly higher mass transfer rates compared to conventional aeration. Especially stirred tank reactors prove to be most suitable for fine bubble aeration. Finally, models are developed, describing the mass transfer characteristics at microscales.