Bioethanol production from dedicated energy crops and residues in Arkansas, USA

Globally, one of the major technologic goals is to achieve cost-effective lignocellulosic ethanol production from biomass feedstocks. Lignocellulosic biomass of four dedicated energy crops [giant reed (Arundo donax L.), elephantgrass (Pennisetum purpureum (Schumach), Miscanthus × giganteus (Illinois clone), and (clone Q42641) {hybrid of Miscanthus sinensis Anderss. and Miscanthus sacchariflorus (Maxim)}, Hack. called giant miscanthus, and sugarcane clone US 84-1028 (Saccharum L. spp. hybrid)] and residues from two crops [soybean (Glycine max (L.) Merr.) litter and rice (Oryza sativa L.) husk] were tested for bioethanol production using cellulose solvent-based lignocellulose fractionation (CSLF) pretreatment and enzymatic (cellulase) hydrolysis. Giant miscanthus (Illinois), giant reed, giant miscanthus (Q42641), elephantgrass, and sugarcane all yielded higher amount of glucose on a biomass dry weight basis (0.290-0.331 g/g), than did rice husk (0.181 g/g) and soybean litter (0.186 g/g). To reduce the capital investment for energy consumption in fermentation, we used a self-flocculating yeast strain (SPSC01) to ferment the lignocellulosic biomass hydrolysates. Bioethanol production was ∼0.1 g/g in dedicated energy crops and less in two crop residues. These methods and data can help to develop a cost-effective downstream process for bioethanol production.