(714b) Evaluation of Industrial Hemp Varieties As Potential Biomass Feedstock for Biofuels and Bioproducts

Authors: 
Shi, J., University of Kentucky
Li, W., University of Kentucky
Das, L., University of Kentucky
Ray, A. E., Idaho National Laboratory
Hu, H., Idaho National Laboratory
Li, C., Idaho National Laboratory
Williams, D. W., University of Kentucky
Industrial hemp is an annual herbaceous crop historically grown for fiber in the U.S. and worldwide. Despite existing applications of industrial hemp based fiber and oil products, hemp-based biofuels and bioproducts represent a new potential application area. Several key questions still remain for the technical and economic feasibility of using hemp as a bioenergy crop. Furthermore, it is necessary to screen industrial hemp species and process conditions while aiming at maximized production of biofuel and bioproducts. Hence, this study takes combined agronomy, laboratory, and economic analysis approaches to evaluate industrial hemp in comparison with other biomass feedstocks e.g. kenaf, switchgrass and biomass sorghum. Several industrial hemp varieties, currently widely cultivated in North America, Europe and Asia, were evaluated. Experimental results show an ethanol yield of 85-100 gallons /dry ton hemp stems using dilute alkali or acid pretreatment, enzymatic hydrolysis and fermentation, which is comparable to the other three tested feedstocks. Agronomy data suggest that the per hectare yield of industrial hemp stem alone was at a similar level to the other energy crops such as switchgrass and sorghum; while the hemp plants may require reduced inputs. Field trial also showed that ~1200 kg/ha hemp grain can be harvested in addition to stems. A preliminary cost analysis indicates that industrial hemp could generate higher per hectare gross profit than the other crops if both hemp grains and biofuels from hemp stem were counted. These combined evaluation results demonstrate that industrial hemp has great potential to become a promising regional commodity crop for producing both biofuels and value-added products.