Journal of Membrane Science, Vol.444, 285-317, 2013
Membrane processes in biorefinery applications
The 1st generation of biofuels stemming from sugar cane, rape or corn is commercially established today and holds a considerable market share as a drop-in fuel. However, due to interference with the food chain, the ethical discussion on 'fuel or food' has originated. Therefore, current research focuses on the utilization of lignocellulosic materials as a bio-renewable feedstock. Simultaneously several biomass-based processes were developed over the past decade suggesting scenarios from a classic biofuel plant to a new biorefinery concept which produces for instance polymers which were previous fossil resources based. The growth of bio resource based chemicals, functional monomers as well as fuels leads to an increased demand for new separation processes. This review highlights the role of membrane separations within current and future biofuel and biorefinery scenarios. Membrane processes reviewed are for instance pervaporation for alcohol recovery and ultrafiltration of canola oil, as well as new developments such as the ultrafiltration/nanofiltration of lignin in a solvent-based lignocellulose conversion process or the recovery of amino acids via electrodialysis. The membrane processes are classically categorized as concentration-driven membrane processes, pressure-driven membrane processes, electrical-driven membrane processes and prospective membrane processes. It follows the transition of a classic biofuel production plant to a new sophisticated biorefinery. The review closes with a reflection of membrane-based downstream processes required in a biorefinery transforming cellulose into an itaconic acid. (C) 2013 Elsevier B.V. All rights reserved.