A Novel Sulfite Pretreatment Process (SPORL) for Efficient Biochemical Conversion Woody Biomass to Bioethanol

Woody biomass is a very important feedstock for the future bioeconomy for the rural US for its availability in large quantities, ease in storage, and low cost for transportation. However, woody biomass, especially softwood, is the most difficult to convert biochemically to fermentable sugars due to its strong physical integrity and chemical recalcitrance. The goal of this project is to develop a commercially deployable technology for woody biomass bioconversion to produce ethanol or specialty chemicals. The proposed technology, SPORL, showed superior performance in preliminary laboratory study to achieve over ninty percent softwood cellulose conversion to glucose in forty hours with normal enzyme dosage even when pretreatment is directly applied to wood chips without size reduction. The SPORL process can utilize existing technologies in the pulp and paper industry for commercialization, therefore it has low technological and environmental risks. With the continued decline of the US pulp and paper industry and shutting down many pulp and paper mills, many highly paid manufacturing jobs in rural US have being lost, which caused severe economic hardship and stress for rural US. The proposed technology can provide unlimited opportunities for those displaced people in rural pulp and paper mill towns to move into the biotechnology industry with a bright future. Furthermore, the proposed technology provides a viable avenue for value added utilization of underutilized forests and related resources, such as those from thinning of overpopulated forests. These underutilized forest resources have become a hazard and caused many catastrophic fires that have severely threatened the health of forest land and ecosystems in the last a couple of decades.