Research Project Summary Information
Membrane Filtration for Separating Sugars for Fermentation into Bioethanol and/or Other Products from Hydrolyzates of Sugar Maple(ST9701-1)
SUNY - ESF
Separation of hemicelluloses from wood hydrolyzates is an important step in the production of ethanol from wood. Ceramic membranes such as those developed by Corning, Inc. can be used at higher temperatures and more corrosive environments than other membranes. They also foul less easily than polymeric membranes. These process conditions are all inherent to the wood sugar extraction process.
The goal of this project was to assess the feasibility of using Corning membranes in State University of New York College of Environmental Science and Forestry (SUNY ESF)’s biorefinery process.
Hemicelluloses are currently burned for heat at paper mills. Better separation could lead to higher-value uses such as ethanol. Furthermore, the removal of these compounds from wood pulp could lead to more energy efficient papermaking at Kraft paper mills. This project used membranes at flow rates of less than 10 gallons/minute. Later stages will scale up to 100 gallons/minute, which is suitable for a pilot demonstration.
Work included: 1) setting up the membrane unit that is on loan from Corning; 2) measuring the physical characteristics of wood sugar extracts; 3) filtering the extracts with a variety of filters; 4) analyzing results and creating a model; and, 5) using the model to predict the performance of larger units. Sugar maple wood chips were pre-extracted using hot water according to a process developed at ESF. Ceramic membrane filters supplied by Hilliard Corporation were used to separate and concentrate the wood hydrolyzates. Ceramic microfilters of two different pore sizes were used. Cross-flow permeation fluxes were determined for varying transmembrane pressures. Rather large declines in the initial (clean membrane) fluxes were observed to occur on a time scale of 60-120 min. indicating extensive membrane fouling. The flux decline was accentuated by higher transmembrane pressures, slower cross-flow velocity or larger membrane pore size. The permeate flux decreased exponentially with time in all cases, suggesting that pore blocking is the dominant fouling mechanism, at least in the initial stages. Particulates dispersed in the extracts were removed successfully, as indicated by large reductions in the turbidity of the permeates. It was possible to clean the membranes by first back-flushing with deionized water, followed by alkali soaking and rinsing.
SUNY - ESF
1 Forestry Dr
Syracuse, NY 13210
SUNY College of Environmental Science an
Indigenous/Renewable Energy Resources
NYSERDA Contact Information
R&D - Environment & Energy Res