Low-cost Removal of Dissolved Solids and Fermentation Inhibitors for Cellulosic Ethanol

While significant progress has been made in the conversion of cellulosic biomass to fuel ethanol, it has not yet been commercialized on a wide-scale because a number of important technical problems remain unsolved. If these challenges can be overcome, cellulosic ethanol is much more promising as a renewable bio-fuel than corn ethanol because it produces a much greater net greenhouse gas (GHG) emission reduction, as well as higher net fossil fuel displacement, and most importantly, has much lower feedstock costs. With improved technologies for conversion of cellulosic biomass it could be possible to convert forest biomass into fuel ethanol. Forestry wastes as well as dedicated forest crops and herbaceous crops (switchgrass) represent the largest potential feedstock sources of lignocellulosic biomass in the United States. One of the important unresolved problems in the overall woody biomass production process is that there is still no cheep and effective way to remove the fermentation inhibitors and dissolved solids made during the pretreatment steps. These separations account for more than 20% of the cost of the ethanol product. TDA Research has identified a new separation method that could simultaneously remove both dissolved solids and fermentation inhibitors at a significantly reduced cost. This project will demonstrate the technical performance of this separation method and estimate the cost savings over existing technologies.