Cellulose-solvent-based lignocellulose fractionation with modest reaction conditions and reagent cycling

A process for fractionating lignocellulosic biomass, the process comprising:

• (i) providing lignocellulosic biomass with an amount of hemicellulose present in the biomass in its native form;
• (ii) providing a first solvent and combining with the lignocellulosic biomass, wherein the first solvent dissolves at least some of the cellulose present in the lignocellulosic biomass;
• (iii) providing a second solvent and combining with the material from step (ii), wherein at least some of the cellulose that is dissolved by the first solvent in step (ii) precipitates out of the liquid phase;
• (iv) providing a third solvent and combining with the material from step (iii), and then separating a black liquor and substantially solid phase;
• and
• (v) providing a fourth solvent and combining with the substantially solid phase from step (iv), and then separating the solid phase comprising cellulose, and a light liquor comprising hemicellulose, and no xylose or xylose as a minor constituent.