Membrane separation: An essential component for a wood-based biorefinery

The separation and purification platform chemicals from the wood extracts for a wood-based biorefinery were discussed. When wood was subjected to hot-water extraction, extractives, hemicelluloses and other components leached out into the extraction liquor. Up to 25% woody biomass can be leached out while the wood chips still remain rigid and maintains traditional utilities. The wood extracts can be fractionated for platform chemicals such as monomeric sugars, acetic acid, and methanol. Membrane units can be employed to accomplish the separation and concentration tasks. The permeate flow rate increased with increasing pressure drop and decreased with increasing extract concentration. Compared with evaporation concentration, membrane systems can significantly improve the energy efficiency. This is an abstract of a paper presented at the AIChE Annual Meeting (Salt Lake City, UT 11/4-9/2007).