NOVELTY - Converting carbohydrates from lignocellulosic biomass to ethanol, comprises cutting the biomass, steaming the biomass, squeezing the biomass, adding mineral acid to the biomass, adjusting moisture content of the acidified biomass, pretreating (3) the biomass in vessel, purging the biomass components, submitting to explosive decompression, extracting the pretreated biomass, heating the liquid stream, hydrolyzing (7) the solids stream, combining the hydrolyzed solids stream with the liquid stream, co-fermenting hexose and pentose sugars in the stream to ethanol, and distilling (9) the ethanol.    USE - The process is useful for converting carbohydrates from lignocellulosic biomass to ethanol (claimed), which is useful in fuel. The ethanol is distillated and dehydrated to create a high-octane fuel which is a substitute for gasoline.    ADVANTAGE - The process provides the maximum extraction yield of glucose and xylose from the feedstock to form ethanol in an economical manner. The process is simple, rapid and environmentally friendly. The ethanol has improved sustainability and reduces greenhouse gas emissions.    DETAILED DESCRIPTION - Converting carbohydrates from lignocellulosic biomass to ethanol, comprises (a) cutting the biomass to a prescribed size, (b) steaming the sized biomass at atmospheric pressure, (c) squeezing the steamed biomass for removing a first liquid stream and generating squeezed biomass, (d) adding mineral or organic acid (0.5-0.9 wt.%) to the squeezed biomass on an incoming biomass dry matter basis, to obtain acidified biomass, (e) adjusting a moisture content of the acidified biomass to 50-80 wt.% of water, (f) pretreating (3) the acidified biomass in a continuous treatment vessel by steam treatment under pressure, at a preselected pretreatment temperature for a preselected pretreatment time and at a preselected pretreatment pressure that depends on the feedstock used, (g) continuously purging from the treatment vessel under pressure volatile components generated by the pressurized steam treatment and liquid condensate formed in the vessel and containing soluble biomass components, (h) submitting to explosive decompression the biomass exiting the continuous pre-treatment vessel prior to or after the washing step, (i) extracting the pre-treated biomass with water to recover a cellulose rich solids stream and a liquid stream, (k) heating the liquid stream for simultaneously concentrating the liquid stream and removing inhibitory compounds by evaporation of volatile components, to obtain a concentrated liquid stream containing acetic acid (6 gpl), where the evaporation being carried out at pressure and temperature conditions comprise (i) under vacuum at a temperature of 70-85 degrees C, and at 50-250 mbar, and/or under pressure of 5-35 psig, (l) optionally further hydrolyzing xylo-oligosaccharides in the liquid stream before, during or after the concentrating step, (m) hydrolyzing (7) the solids stream with a mixture of cellulases and hemicellulases to obtain a hydrolyzed solids stream, (n) combining the hydrolyzed solids stream with the concentrated liquid stream to obtain a combined hydrolysate stream, (o) co-fermenting hexose and pentose sugars in the combined hydrolysate stream to ethanol, and (p) distilling (9) the ethanol from the fermentation broth to recover ethanol and a de-ethanolized slurry.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the continuous process.    Controlling moisture content of the biomass (1)    Pretreating continuous steam explosion (3)    Washing (4)    Hydrolyzing with enzymes (7)    Distilling. (9)