Filtration-Based Separations in the Biorefinery

Abstract

Biorefinery processes can be divided into three sections. The first consists of pretreatment where biomass is rendered amenable to biochemical conversions using enzymes or acids. The second section consists of separation and purifications of different pretreatment output streams. Compounds that are toxic to fermentation microbes and inhibitors for enzyme activities are removed. In addition, some useful products such as lignin may be removed. The final stage is the downstream conversion of the liquors and biomass into fuel or polymeric products by fermentation or other processes. This chapter focuses on the development of filtration processes for the separation of solid phase from the liquids of the various streams encountered in the biorefinery. It reviews some basic principles of filtration, including dead-end and tangential-flow filtration. Experimental results of filtration studies carried out on hardwood hydrolyzates have been presented. Cake filtration may be applied to recover either of the solid or liquid phases.