A process for production of C5 and C6 sugar enriched syrups from lignocellulosic biomass and fermentation products therefrom is described. A lignocellulosic biomass is treated with acetic acid with washing thereof with a C.sub.1-C.sub.2 acid-miscible organic solvent, (e.g., ethyl acetate). A soluble hemicellulose and lignin enriched fraction is obtained separately from a cellulose pulp enriched fraction and lignin is removed from the soluble hemicellulose fraction. The soluble hemicellulose and lignin enriched fraction is subjected to liquid/liquid separation to obtain an aqueous phase enriched in C5 sugars and C6 sugars and reduced in content of acetic acid. The syrup is suitable for fermentation. The process also produces fractions of organic-insoluble lignin, organic-soluble lignin, and acetate salts.
STATEMENT OF FEDERAL SPONSORED RESEARCH
 This invention was made with government support under department of Energy Grant No: DE-EE0002870. The federal government has certain rights in this invention.