Processing of lignocellulosic biomass

A process for treating lignocellulosic biomass to produce organic chemicals, the process comprising:

• (a) subjecting the lignocellulosic biomass to a first hydrolysis at a temperature no higher than 250° C. to hydrolyse hemicellulose, to form a liquid component comprising the products of hemicellulose hydrolysis in solution, and a solid component comprising cellulose and lignin;
• (b) then subjecting the solid component to a second hydrolysis at a temperature above 350° C., so as to hydrolyse cellulose and vaporise the resulting products of cellulose hydrolysis;
• and
• (c) then condensing the resulting vapours to form an aqueous solution containing the products of cellulose hydrolysis,
• wherein, after the first hydrolysis and before the second hydrolysis, the process also comprises a plurality of first washing steps, wherein during each of the plurality of first washing steps, the solid component is washed with the aqueous solution containing the products of cellulose hydrolysis, to separate the said liquid component from the solid component and produce a resultant aqueous sugar solution comprising the products of hemicellulose hydrolysis and the products of cellulose hydrolysis, the process further comprising a second washing step subsequent to the plurality of first washing steps, in which the solid component is washed using demineralized water to remove residual sugars produced by washing the solid component with the aqueous solution containing the products of cellulose hydrolysis in the first washing steps,
• wherein the volume of water used in the second washing step is less than the volume of the aqueous solution containing the products of cellulose hydrolysis and that was used for each of the plurality of first washing steps.