Delignification of Miscanthus by Extraction

Removal of lignin from miscanthus liberates cellulose and hemicellulose for hydrolysis to obtain sugars that can subsequently be fermented to ethanol or butanol. Extraction of lignin from raw miscanthus at 70°C is feasible when the extracting solvent contains a base (Ethylenediamine, EDA) mixed with an organic solvent or a mildly hydrophobic ionic liquid. A 50–50 (by weight) mixture of EDA and ethylene glycol removes 75% of the lignin from raw miscanthus when the weight ratio of solvent to miscanthus is 10:1. At the same ratio of solvent to miscanthus, a 10–90 (by weight) mixture of EDA and ionic liquid, 1-ethyl-3-methylimidazolium tosylate ([Emim][Ts]) removes 60% of the lignin. These results suggest that it may be possible to delignify miscanthus by extraction at moderate temperature and atmospheric pressure.