Performance of a membrane bioreactor for enzymatic transesterification: Characterization and comparison with a batch stirred tank reactor

A membrane bioreactor containing cutinase microencapsulated in reversed mic elles of AOT/isooctane was used to perform the alcoholysis of butyl acetate with hexanol. The membrane used was a tubular ceramic membrane with a cut- off of 15,000 Da, Membrane characterization involved two parts: structure d efinition and operational properties. The former included membrane imaging to define the average membrane pore size. With the values obtained, charact erization proceeded through the prediction of permeability and number of po res. The separation properties of the membrane were evaluated with the dete rmination of rejection coefficients, based on transmission experiments, for all system components, including the substrates, products and the biocatal yst. The performance of the membrane bioreactor (MBR) was compared with the results obtained in a batch stirred tank reactor (BSTR) using the normaliz ed residence time concept. The MBR operated as a differential reactor as th eoretical treatment of experimental data demonstrated.