초록
<P><B>Abstract</B></P> <P>The combined effect of anions of ionic liquids (IL) and anti-solvents on pre-treatment and dissolution mechanisms of biomass are not well studied. To reveal the above effect, three different ionic liquids composed with fixed cation ([EMIM]<SUP>+</SUP>) but varied anions were studied for Miscanthus dissolution. Results showed that [EMIM]<SUP>+</SUP>[Ac]<SUP>–</SUP> was very good in altering the cellulose structure and crystallinity followed by enzymatic digestibility with a sugar yield of 0.98 (g/g of cellulose). The IL [EMIM]<SUP>+</SUP>[HSO<SUB>4</SUB>]<SUP>–</SUP> was very efficient to remove lignin and partially solubilize hemicellulose, however, the sugar yield was low (0.43 g/g of cellulose) compared with [EMIM]<SUP>+</SUP>[MeSO<SUB>3</SUB>]<SUP>–</SUP> and even the untreated Miscanthus. The regenerated biomass with water-acetone mixture (1:1 v/v) as anti-solvent resulted in higher glucose yield. The hydrogen bond basicity (<I>β</I> value) correlated well with cellulose crystallinity, lignin removal, and glucose yield.</P> <P><B>Highlights</B></P> <P> <UL> <LI> [EMIM]<SUP>+</SUP>[Ac]<SUP>–</SUP> drastically decreased the cellulose crystallinity of Miscanthus. </LI> <LI> [EMIM]<SUP>+</SUP>[HSO<SUB>4</SUB>]<SUP>–</SUP> solubilized almost entire amount of lignin present in Miscanthus. </LI> <LI> Enzymatic digestibility is very high for [EMIM]<SUP>+</SUP>[Ac]<SUP>–</SUP> pretreated biomass. </LI> <LI> Glucose yield increased with water-acetone mixture (1:1 v/v) as anti-solvent. </LI> <LI> <I>β</I> value related well with crystallinity index, lignin removal and glucose yield. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>