Purification and Concentration of Wood Extracts By Membrane Filtration

Ultrafiltration and nanofiltration were applied to remove impurities and increase sugar concentrations of wood extracts and/or hydrolysates. A series of samples have been taken to determine the change of compositions in both the retentate and the permeate flows. By analyzing 1D and 2D NMR results, we were able to find the constitution of each component and thus draw a set of concentration curves to see how they changed during the process. The results showed that membrane filtration is an effective mean to remove inhibitors from the stream. A mathematical model based on solution-diffusion model has been developed to explain the mechanism and then simulate the process.