Assessment of Arundo donax (giant reed) as feedstock for conversion to ethanol

The focus of this study was to assess the feasibility of using giant reed (Arundo donax) for bioethanol production via pretreatment, enzymatic hydrolysis, and fermentation. Sugar and ethanol yields from giant reed were compared with those from hybrid poplar, a well-regarded woody biomass feedstock. Low (L), medium (M), and high (H) severity steam pretreatment conditions were applied to giant reed to select the set of conditions that would allow recovery of the maximum amount of sugars in hydrolysable and fermentable form. Simultaneous saccharification and fermentation (SSF) of the combined water insoluble and water soluble fractions from steam pretreated giant reed at the L severity condition of 190°C, 5 min, and 3% SO2 provided the highest ethanol yield − 79% of the theoretical maximum, which corresponds to 0.179 L ethanol/kg of raw material (based on six carbon sugars). Hybrid poplar pretreated at 200°C, 5 min, 3% SO2 produced 0.205 L ethanol/kg raw material after SSF, corresponding to 80% of the theoretical maximum ethanol yield (based on six carbon sugars). Giant reed appears to be a good alternative for biorefineries using poplar or similar hardwood feedstocks.