LIGNO-CELLULOSIC BIOMASS TREATMENT PROCESS.

The invention relates to a method for treating lignocellulosic biomass comprising at least the following steps: a) a step of conditioning the biomass comprising at least one grinding so as to obtain particles of crushed biomass having a size of at most 300mm b) a step of washing said particles with liquid water or an acid liquor， at a temperature of 10-95 ° C， preferably at atmospheric pressure， c) a step of separating the used washing water from the washed biomass particles to obtain a separated lignocellulosic substrate having 15-70% dry matter， d) a step of impregnating said substrate with an acid liquor so as to obtain an impregnated substrate having a pH of 0.1 to 3， e) a step of solid / liquid separation of the lignocellulosic substrate so as to obtain a lignocellulosic substrate having a rate of dry matter between 15% by weight and 70% by weight and a liquid effluent; f) a step of pretreatment of the impregnated lignocellulosic substrate resulting from step e).