Processes for producing cellulose pulp, sugars, and co-products from lignocellulosic biomass

A process for co-producing corrugated medium pulp or paper pulp as well as hemicellulosic sugars from biomass, said process comprising:

• (a) providing lignocellulosic biomass comprising cellulose, hemicellulose, and lignin;
• (b) digesting said biomass in the presence of steam and/or hot water to extract at least a portion of said hemicellulose into a liquid phase, thereby generating extracted solids, wherein step (b) does not include a chemical pulping method;
• (c) separating at least some of said liquid phase from said extracted solids;
• (d) washing said extracted solids with water at a washing pH of about 7 or less, thereby generating a liquid wash filtrate and washed solids;
• (e) separating at least some of said liquid wash filtrate from said washed solids;
• (f) refining said washed solids at a refining pH of 4 to 6.5, thereby generating corrugated medium pulp or paper pulp;
• and
• (g) hydrolyzing said hemicellulose contained in said liquid phase and/or in said liquid wash filtrate, in the presence of a hydrolysis catalyst, to generate hemicellulosic sugars,
• wherein step (c) is performed prior to step (d), wherein said liquid phase separated in step (c) and said liquid wash filtrate are separately processed and not later combined.