Influence of collection method on the sugar and ethanol processing characteristics

The impact of collection method on the characteristics of sugar and ethanol processing was studied. Corn stover fractions were separated by hand and analyzed for glucan, xylan, acid soluble lignin, acid insoluble lignin, and ash composition. The stover fractions were pretreated with either 0, 0.4, or 0.8% NaOH for 2 hr at room temperature, washed, autoclaved and saccharified. In addition, acid pretreated samples underwent simultaneous saccharification and fermentation (SSF) to ethanol. The two pretreatments produced similar trends with cobs, husks, and leaves responding best to the pretreatments, the tops of stalks responding slightly less, and the bottom of the stalks responding the least. Corn husks pretreated with 0.8% NaOH released over 90% of the available glucan, while only 45% of the glucan was produced from identically treated stalk bottoms. Estimates of the theoretical ethanol yield using acid pretreatment followed by SSF corresponded to 63 (standard error of 11.5%) for husks and 37% (standard error of 1.2%) for stalk bottoms. This suggests that integration of biomass collection systems to remove sustainable feedstocks could be integrated with the processes within a biorefinery to minimize overall ethanol production costs. This is an abstract of a paper presented at the 2007 AIChE Annual Meeting (Salt Lake City, UT 11/4-9/2007).