NOVELTY - Producing carbohydrate-enriched biomass (M1) involves a) providing lignocellulosic biomass having lignin; b) suspending the biomass in organic solvent solution containing water and at least one sulfide salt under alkaline conditions by biomass-solvent suspension is formed; c) heating the biomass-solvent suspension at 100-220 degrees C for 5 minutes to 5 hours where lignin is fragmented and is dissolved in the suspension; and d) filtering free liquid by the dissolved lignin is removed and readily carbohydrate-enriched biomass is produced.    USE - For producing carbohydrate-enriched biomass (claimed).    ADVANTAGE - The use of sulfides in the lignocellulosic biomass pretreatment process enhances lignin fragmentation and increases the selectivity of lignin extraction with respect to carbohydrate, producing carbohydrate-enriched biomass that is highly susceptible to enzymatic saccharification. The method provides cost-effective process to obtain carbohydrate-enriched biomass for enzymatic saccharification. Such biomass then, produces very high yields of fermentable sugars (glucose, as well as xylose) for their bioconversion to value-added chemicals and fuels.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for method of simultaneous fragmentation and selective extraction of lignin from lignocellulosic biomass to produced lignin-free biomass (M2) involving a1) providing 1) lignocellulosic biomass; 2) multi-component organic solvent solution containing 40-70% ethanol in water; 3) at least one sulfide salt; and 4) at least one alkylamine under alkaline conditions; b1) contacting the biomass with the multi-component solvent solution of a1) where solvent-biomass mixture is produced; c1) placing the solvent-biomass mixture in a sealed pressure vessel by the mixture of b1) is heated 100-220 degrees C for 5 minutes to 5 hours where lignin is fragmented and dissolved in the solvent; d1) removing the dissolved lignin of c1) by filtration; and e1) washing the residual biomass with organic solvent, where lignin-free biomass is produced.