NOVELTY - Lignocellulosic biomass (100) is treated by mixing lignocellulosic biomass with ionic liquid for a sufficient temperature and time to swell lignocellulosic biomass without dissolution of lignocellulosic biomass in ionic liquid and performing mild alkaline treatment (400) on swelled lignocellulosic biomass to separate lignin from cellulose and hemicellulose.    USE - Treatment of lignocellulosic biomass for enhanced production of sugars and lignin.    ADVANTAGE - Resulting biomass is easily fractionated and amenable to efficient and rapid enzymatic hydrolysis or acid hydrolysis and catalytic conversion to valuable products, such as sugars, fuels, and chemicals, with high recovery of enzymes used in hydrolysis.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) conversion of carbohydrates of lignocellulosic biomass to sugars which involves mixing lignocellulosic biomass in ionic liquid to swell but not dissolve the biomass, applying radio frequency (RF) heating (200) to lignocellulosic biomass to heat to a target temperature range, applying ultrasonics, electromagnetic (EM), convective, and/or conductive heating to lignocellulosic biomass to maintain lignocellulosic biomass at target temperature of 50-220 degrees C, washing (300) treated lignocellulosic biomass, subjecting lignocellulosic biomass to mild alkaline treatment to release lignin from cellulosic components, washing treated lignocellulosic biomass, recovering lignin, cellulose, and hemicellulose, and hydrolyzing cellulose and hemicellulose to yield sugars;    (2) treatment of lignocellulosic biomass which involves incubating biomass in a sufficient amount of ionic liquid for a sufficient time and temperature to swell lignocellulosic biomass without dissolution of lignocellulosic biomass, applying RF heating to lignocellulosic biomass to heat to a target temperature range, applying ultrasonic heating to lignocellulosic biomass to maintain the biomass at target temperature range, washing pretreated lignocellulosic biomass, subjecting lignocellulosic biomass to mild alkaline treatment to release lignin from the cellulosic components, washing treated lignocellulosic biomass with liquid non-solvent for cellulose that is miscible with water and the ionic liquid, recovering lignin, cellulose, and hemicellulose, and contacting washed treated lignocellulosic biomass with aqueous buffer containing enzymes capable of hydrolyzing cellulose and hemicellulose to produce sugars;    (3) acid hydrolysis of biomass which involves reducing biomass in size, preferably to particles of 0.1-20 mm in size, incubating biomass in a sufficient amount of ionic liquid for a sufficient time and temperature to swell without dissolution of lignocellulosic biomass, treating biomass under mild alkaline treatment to separate lignin from cellulose and hemicellulose, separating cellulosic, hemicellulosic, and lignin streams, recovering lignin, adding acid to each of cellulosic and hemicellulosic streams to lower pH below 7, preferably adding catalyst, heating cellulosic and hemicellulosic streams to heat to 150-200 degrees C for 15-360 minutes, and recovering chemicals;    (4) conversion of carbohydrates of lignocellulosic biomass to sugars which involves mixing lignocellulosic biomass in ionic liquid to swell but not dissolve, applying ultrasonics, EM, preferably RF, convective, and/or conductive heating to lignocellulosic biomass to heat to 50-220 degrees C, washing treated lignocellulosic biomass, subjecting lignocellulosic biomass to mild alkaline treatment to release lignin from cellulosic components, washing treated lignocellulosic biomass, recovering lignin, cellulose, and hemicellulose, separating lignin, cellulose, and hemicellulose, hydrolyzing cellulose to yield sugars, and hydrolyzing hemicellulose to yield sugars; and    (5) treatment of lignocellulosic biomass which involves incubating biomass in a sufficient amount of ionic liquid for a sufficient time and temperature to swell lignocellulosic biomass without dissolution, applying RF heating and/or ultrasonic heating to lignocellulosic biomass to maintain at a target temperature range, washing pretreated lignocellulosic biomass, subjecting to mild alkaline treatment to release lignin from cellulosic components, washing with liquid non-solvent for cellulose that is miscible with water and the ionic liquid, recovering lignin, cellulose, and hemicellulose, separating lignin, cellulose, and hemicellulose, hydrolyzing cellulose to yield sugars, and hydrolyzing hemicellulose to yield sugars.    DESCRIPTION OF DRAWING(S) - The drawing shows a flow diagram of the method for processing biomass.    Biomass (100)    Heating process (200)    Solvent washing (300)    Mild alkaline treatment (400)    Hydrolysis of cellulose/hemicellulose stream (500)