(415c) Membrane Separation: An Essential Component For A Wood-Based Biorefinery

Starting from a wood-based biorefinery, this paper discusses the separation and purification platform chemicals from the wood extracts. When wood is subject to hot-water extraction, extractives, hemicelluloses and other components leach 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. It has been found that the permeate flow rate increase with increasing pressure drop and decreases with increasing extract concentration. Besides using membrane units as a fractionation device, they can be employed to concentrate the sugar / chemical stream as well. As compared with evaporation concentration, membrane systems can significantly improve the energy efficiency.