Abstract: The invention relates to a process for the simultaneous extraction of lignin and silica from lignocellulosic plant material, characterized in that it comprises the steps of: a) fractionating the lignocellulosic plant material in the presence of an acid solution, so as to obtain a solid fraction comprising cellulose, residual lignin and silica; b) extracting simultaneously lignin and silica from the solid fraction obtained in step a) with a basic solution, at a pH between 10 and 13 and at a temperature between 70° C. and 90° C., so as to obtain a liquid phase comprising lignin and silica, and a solid phase; c) separating the liquid phase and of the solid phase obtained in step b), d) coprecipitating a mixture of lignin and silica comprised in the liquid phase, at a pH between 5 and 6.

Abstract: A lignin-phenol-formaldehyde resin, which is obtained by polycondensation of formaldehyde, phenol and lignin in the presence of a basic or acidic catalyst, is characterized in that the lignin is a lignin that is not chemically modified at the available functional groups. This lignin has a low molecular mass and includes available functional groups chosen from the group including aliphatic hydroxyls and phenolic hydroxyls. The degree of substitution by weight of phenol with the lignin is between 50% and 60%. The weight proportion of the lignin and of phenol in the resin is equal to the weight proportion of phenol in a lignin-free phenol-formaldehyde (PF) resin.

Abstract: A process for producing bioethanol includes the steps of pretreatment (consisting in destructuring the lignocellulosic vegetable raw material by placing it in the presence of a mixture containing formic acid, acetic acid and water, then in separating cellulose), of enzymatic hydrolysis and of alcoholic fermentation, characterized in that it includes, prior to the enzymatic hydrolysis, a step of partial elimination of the lignins so as to obtain a residual overall level of lignins (T), expressed as percentage by weight, which is non-zero and which is included in a range determined by a lower limit, and an upper limit Bsup, respectively equal to 0.30% and 4%. In order to obtain conditions of acidification before the enzymatic hydrolysis step, the process includes a step for re-acidification of the mixture, which is carried out with an acid, or of a mixture of acids, of determined pKa, and preferably with weak organic.

Abstract: A method for pretreating plant starting material for the purpose of producing bioethanol and/or sugar via a common chamber (12), is characterized in that: —during one period, the plant material (MP), introduced into the common pretreatment chamber, is a lignocellulosic plant starting material, whose pretreatment is aimed at separating the cellulose, the hemicelluloses and the lignins so as to obtain a pretreated plant material that can be hydrolyzed and fermented for the production of bioethanol; —during another period, the plant material (MP), introduced into the common pretreatment chamber, is a sacchariferous plant starting material, whose pretreatment is aimed at extracting therefrom, by diffusion, a sugar juice for the production of sugar and/or of bioethanol.

Abstract: A process for pretreating a lignocellulosic plant raw material in order to obtain a pretreated material that is capable of being hydrolyzed and fermented for the production of bioethanol, includes the following successive steps: (i) destructuring the lignocellulosic plant raw material by placing it in the presence of a mixture containing formic acid and water, at a reaction temperature between 95° C. and 110° C.; (ii) then, at atmospheric pressure and prior to any hydrolysis then fermentation action, separating: on the one hand, the solid phase, mainly composed of the cellulose, constituting a first co-substrate, capable of then being hydrolyzed and fermented for the production of bioethanol; and on the other hand, the liquid phase, containing, in particular in aqueous solution, the formic acid, the lignins, and the hemicelluloses, constituting a second co-substrate, capable of then being hydrolyzed and fermented for the production of bioethanol.