(129a) Bridging the Gap between Feedstock Growers and Users: A Study of Poplar Coppice Based Biorefinery

Authors: 
Dou, C., University of Washington
Gustafson, R., University of Washington
Bura, R., University of Washington
In the advanced biofuel industry, the land productivity is important to feedstock growers and the product yield of conversion process is important to biorefinery facilities. The crop productivities are often not positively correlated to their bioconversion yields. It is therefore critical to examine the sugar yield from a given feedstock and relate that to its productivity. In current study, the 2-year old poplar coppices, including one low-productive hybrid and one high-productive hybrid, were collected from two plantations. Through steam pretreatment and enzymatic hydrolysis, the bioconversion yields of low and high productive poplar hybrids were compared for both sites. Although they have the similar chemical composition, the low-productive hybrids had 9% to 19% higher sugar yields than the high-productive hybrids. This suggests that to evaluate the feedstocks and estimate the product yield, knowing the feedstock chemical composition is not enough. Biorefineries should conduct conversion trials to better understand the processing performance of feedstocks. Based on the findings, we investigated the economics from both perspectives of feedstock growers and users by examining a biorefinery with 700,000 dry tonne feedstock processing capacity.