Cellulose hydrolysis in an enzymatic membrane reactor: fouling mechanism

Enzymatic Membrane Reactor (EMR) was applied to overcome drawback from batch cellulose hydrolysis such as inability of reusing the enzyme and product inhibition which leads to low product yield. However, the major problem of EMR is membrane fouling. Therefore, the membrane fouling mechanisms in EMR was investigated using Hermia’s pore blocking model. In this study, fed batch cellulose hydrolysis in EMR was carried out for 72 hours. The hydrolysate was filtered using polyethersulfone (PES) membrane at 24 hours interval and the flux of permeate was recorded. The cellulose hydrolysis has successfully converted more than 80% of the substrate into reducing sugar in EMR, which is approximately 20% more in batch hydrolysis. The product inhibition was minimized when there was glucose removal in EMR. The flux was analysed and the result showed that the membrane fouling was controlled by cake filtration mechanism. The larger size of substrate and enzyme than the membrane pore size blocked the membrane pore and eventually cause the development of cake layer.