Partial Simultaneous Saccharification and Fermentation at High Solids Loadings of Alkaline-pretreated Miscanthus for Bioethanol Production

Abstract

In this study, alkaline pretreatment at a bench scale (15-L capacity) was performed to obtain a higher solid residue for the SSF (simultaneous saccharification and fermentation) of Miscanthus sacchariflorus "GoedaeUksae 1" (GU) under the following conditions: 1 M NaOH concentration, 150 °C, and 60 min residence time. Compositional analysis and scanning electron microscope analysis revealed the pretreatment to be highly effective for achieving delignification and morphological changes. Spiral impellers were used for the rapid liquefaction of pretreated GU into slurry, and no additional nutrients were added to the fermentation mixture to reduce overall process costs. The SSF was subsequently conducted in a laboratory-scale fermenter (5-L capacity) for 108 to 120 h with 12% and 16% glucan containing pretreated GU. Consequently, 62.8 g/L and 81.1 g/L of ethanol were obtained. Based on these data, the theoretical ethanol yields from 1 kg of GU (dry weight base) were estimated at 164.6 to 171.1 g/L.

Life cycle assessment of ethanol production from miscanthus: A comparison of production pathways at two European sites

“…As lignin adheres to enzymes and renders them ineffective, the amount of lignin in enzymatic hydrolysis can be a decisive factor (X. Zhao, Zhang, & Liu, ). A substantial lignin removal, as commonly given in alkaline pretreatments, could allow lower enzyme dosage and thereby contribute to substantial reductions in enzyme‐related impacts for DAH (Cha et al, ; Chang & Holtzapple, ). In addition, impacts related to enzyme production could be reduced by replacing the carbon source (cornstarch glucose in the present study) with sugar cane molasses or lignocellulosic materials.…”