Use of Filter Aids to Improve the Filterability of Enzymatically Hydrolyzed Biomass Suspensions

Filter aids are used in challenging filtration applications, such as the deliquoring of biomass suspensions and separation of fine particles from liquids. Organic filter aids, typically composed of cellulose, may be the preferred option in the case of bioprocesses because their energy content can be recovered together with the primary filter cake. In this study, a laboratory-scale pressure filter was used in order to investigate the effect of various filter aids on the filtration of an enzymatically hydrolyzed biomass suspension. Various organic and inorganic filter aids were used in two modes: as a body feed and as a precoat. According to the results, the average specific resistance of the cakes could be best reduced using the body feed mode. Filter aids also helped to reduce the moisture content of the cakes and to increase the corresponding filtration capacities. Additionally, a process scheme enabling utilization of the solids was proposed.