Comparative Evaluation of 11 Industrial Hemp Varieties as Potential Energy Crops

Industrial hemp (IH) has been a commodity crop grown in United States for various applications and is getting increasing interest due to recent legal amendments and new incentives towards hemp related research. Despite existing applications in hemp derived fiber and oil products, IH can be a potential energy crop for biofuels and bioproducts. However, technical uncertainty and economic feasibility remains a challenge for hemp cultivation. This study aims to combine agronomy, laboratory, and economic analysis approaches to evaluate and compare the potential of eleven IH varieties grown in Kentucky. Based on the agronomic data, the per hectare stem biomass yield for fiber only varieties ranged from 2933 kg to 8340 kg, while for the dual variety it ranged from 3582 kg to 7665 kg. The biomass yield of IH stem alone was at a similar level to the other energy crops such as switchgrass and sorghum. The eleven IH varieties underwent dilute acid pretreatment followed by enzymatic hydrolysis and fermentation to evaluate the ethanol production. The highest ethanol yield of 91.1 gallons /dry ton hemp stems was observed from Futura 75, while the lowest ethanol yield of 70.6 gallons /dry ton hemp stems was obtained in Codimone. In addition to the hemp stems, field trial for the dual variety also showed a grain yield of 1082 kg/ha for Bialobrzeskie, whereas Santhica 27 obtained a grain yield of 554 kg/ha. Lastly, cost analyses were conducted to compare the economics of IH based biofuels production, combined with sensitivity analysis on scenarios to coproduce fiber, grain, and biofuels. These collective evaluations illustrate that IH has significant potential to become a promising regional commodity crop for boosting bio-economy.