(29b) Characterization, Fractionation, Separation and Hydro ysate Toxicity Reduction on Fermentation Of C5 and C6 Sugars Derived From Lignocellulosic Biomass

Biomass pretreatment is necessary to reduce the calcitrance  of lignocellulosic feedstocks to enzyme saccharification and to allow the liberation of soluble sugars (C5 and C6) from the plant cell wall. However, pretreatment can also release undesirable compounds into the hydrolysate that can inhibit the growth and product yields of fermentation organisms. It is critical to understand and characterize the toxicity effects of fermentation hydrolysate to devise optimal pretreatment and down stream inhibitor sequestering process, that maximizes cellulosic sugar recovery, conversion and enhance productivity of the test organisms .

Sweetwater Energy have a proprietary modular pretreatment system for extracting sugars from biomass. We conducted systematic study to characterize  the key inhibitors and toxic molecules  in the hydrolysate that the necessary parameters to reduce and eliminate these inhibitors  around hydrolysate toxicity in various the dilute acid pretreated feedstocks . Initial results and the outline of the strategy directed toward further refining the cellulosic sugars using membranes  and ion exchange resins and its combination would be presented. In addition,  the problems and the prospects of establishing a cost effect integrated down stream separation  technology that  renders the cellulosic sugar mixtures of C5 and C6 syrups and make them emendable to the next stage of fermentation will be highlighted.