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International audience; Fractionation of lignocellulose is a fundamental step in the valorization of cellulose, hemicelluloses, and lignin to produce various sustainable fuels, materials and chemicals. Strong alkaline fractionation is one of the most applied processes since the paper industry has been using it for more than a century, and the mineral acid fractionation process is currently the most applied for the production of cellulosic ethanol. However, in the last decade, mild alkaline fractionation has been becoming increasingly widespread in the frame of cellulosic ethanol biorefineries. It leads to the solubilization of hemicelluloses and lignin at various extent depending on the conditions of the extraction, whereas the cellulose remains insoluble. Some studies showed that the cellulose saccharification and fermentation into ethanol gave higher yields than the mineral acid fractionation process. Besides, contrary to the acid fractionation process, the mild alkaline fractionation process does not hydrolyze the sugar polymers, which can be of interest for different applications. Lignocellulosic mild alkaline extracts contain hemicelluloses, lignin oligomers, phenolic monomers, acetic acid, and inorganic salts. In order to optimize the economic efficiency of the biorefineries using a mild alkaline fractionation process, the purification of the alkaline extract to valorize its different components is of major importance. This review details the conditions used for the mild alkaline fractionation process and the purification techniques that have been carried out on the obtained hydrolysates, with a focus on the yields and purities of the different compounds.

Fractionation of lignocellulose is a fundamental step in the valorization of cellulose, hemicelluloses, and lignin to produce various sustainable fuels, materials and chemicals. Strong alkaline fractionation is one of the most applied processes since the paper industry has been using it for more than a century, and the mineral acid fractionation process is currently the most applied for the production of cellulosic ethanol. However, in the last decade, mild alkaline fractionation has been becoming increasingly widespread in the frame of cellulosic ethanol biorefineries. It leads to the solubilization of hemicelluloses and lignin at various extent depending on the conditions of the extraction, whereas the cellulose remains insoluble. Some studies showed that the cellulose saccharification and fermentation into ethanol gave higher yields than the mineral acid fractionation process. Besides, contrary to the acid fractionation process, the mild alkaline fractionation process does not hydrolyze the sugar polymers, which can be of interest for different applications. Lignocellulosic mild alkaline extracts contain hemicelluloses, lignin oligomers, phenolic monomers, acetic acid, and inorganic salts. In order to optimize the economic efficiency of the biorefineries using a mild alkaline fractionation process, the purification of the alkaline extract to valorize its different components is of major importance. This review details the conditions used for the mild alkaline fractionation process and the purification techniques that have been carried out on the obtained hydrolysates, with a focus on the yields and purities of the different compounds.

PROBLEM TO BE SOLVED: To provide a method for reducing or preventing the proliferation of bacteria or fungi to materials based on lignocellulose material, especially wooden pieces or sawdust. SOLUTION: In the method, the lignocellulose material, such as the wooden pieces or the sawdust, is processed with a chemical agent containing a hydrocarbon chain, which is selected from mixed carboxylic anhydrides and is suitable for securing to graft a plurality of hydrocarbon chains onto the material by covalent bonding.

The chemical modification of wood with mixed anhydrides with aim to improve its properties has been investigated. Unsymmetrical acetic-fatty anhydrides were obtained after reaction between acetic anhydride and a fatty acid and two consecutive equilibrated reactions were put in evidence, yielding at equilibrium also a fatty anhydride in low proportion. Cellulose and Scots pine sawdust were treated by mixed anhydride mixtures and yielded lowly substituted mixed esters with different acetyl/fatty acyl ratios. The hydrophobicity of the esters, measured by water vapor sorption, was correlated to the total DS whereas the contact angle depended only on the fatty acyl substitution and was reached even at very low degree of substitution (DS=3.10-4). The treatment of wood blocks resulted in high dimensional stability (Anti-swelling efficiency ASE of 90%) and depended on the total grafting whatever was the acyl group grafted. Mechanical properties of the treated wood were found to be preserved

Utilisation d'un matériau à base de matières lignocellulosiques, notamment une pièce de bois ou de la sciure de bois, soumis à un procédé de traitement chimique desdites matières lignocellulosiques consistant à soumettre lesdites matières à un traitement par un agent chimique comportant des chaînes hydrocarbonées, cet agent étant choisi parmi les anhydrides carboxyliques mixtes, ledit agent étant adapté pour assurer un greffage par liaison covalente d'une pluralité de chaînes hydrocarbonées sur lesdites matières, comme matériau résistant aux insectes xylophages.

National audience; The aim of this study was to investigate two new complementary and independent possible uses of animal meal. The lipidic fraction was used as biodiesel or biolubricant and the defatted residue or the raw meal was considered as raw material for polymer preparation. All the studies were led following the alimentary general direction quality rules. High flow extraction tools and rapid analysis methods of major and minor components were developed. This resulted in animal meal characterisation and allowed us to choose the chemical transformation strategy. Conversion of the lipidic fraction, based on an acyl-transfer reaction, gave free fatty acids directly transformed into fatty acid esters well known for biofuel applications. In the future such specific technology could be used to decontaminate animal meal during its transformation. In addition, the raw animal meal or the defatted meal was used to synthesise polymers. Animal biopolymer structure was broken by thermomechanical treatment (liquefaction) to produce new monomeric units. Animal meal liquefaction with phenol provided promising results. This polymer synthesis would be a great way to add value to large amounts of animal meal.; L’objectif des travaux est d’étudier la faisabilité de nouvelles voies d’élimination et de valorisation des farines animales. Nous abordons ici l’étude de deux voies de valorisation complémentaires et indépendantes : d’une part, la valorisation de la fraction lipidique en « biocarburant » et « biolubrifiant » et, d’autre part, celle du résidu délipidé ou de l’ensemble de la matrice dans la fabrication de matériaux polymères. Dans un premier temps, les études développées se proposent de mettre en oeuvre un suivi qualité selon les recommandations de la Direction Générale de l’Alimentation. Ensuite, l’étude de la mise en oeuvre d’outils d’extraction à haut débit et de méthodes rapides de caractérisation des constituants majeurs et mineurs a pour but de caractériser la matrice « farines animales ». La connaissance de la composition de la matrice a gouverné l’orientation de la stratégie de transformation de la fraction lipidique axée sur les études de transfert d’acyles. Elle permet d’obtenir des acides gras à partir des lipides extraits, puis de les utiliser pour synthétiser des esters gras simples. En perspective, nous proposons d’associer cette méthodologie à des technologies spécifiques qui permettront d’envisager la décontamination des farines animales lors de leur transformation. La deuxième partie des travaux consiste à utiliser les farines animales ainsi que les farines obtenues après extraction des lipides comme matières premières dans le cadre d’une étude de faisabilité concernant de nouveaux matériaux polymères. Il s’agit de procéder à la déstructuration thermochimique des macromolécules animales (susceptible de dégrader l’agent pathogène) dans le but de les réduire à l’état de monomères destinés à participer à la synthèse d’un nouveau polymère. Les essais de liquéfaction de cette matrice en présence de phénol ont donné des résultats encourageants. La fabrication de matériaux polymères constituerait une voie de valorisation permettant d’écouler de grandes quantités de farines animales.

National audience; L’objectif des travaux est d’étudier la faisabilité de nouvelles voies d’élimination et de valorisation des farines animales. Nous abordons ici l’étude de deux voies de valorisation complémentaires et indépendantes: d’une part, la valorisation de la fraction lipidique en «biocarburant» et «biolubrifiant» et, d’autre part, celle du résidu délipidé ou de l’ensemble de la matrice dans la fabrication de matériaux polymères. Dans un premier temps, les études développées se proposent de mettre en oeuvre un suivi qualité selon les recommandations de la Direction Générale de l’Alimentation. Ensuite, l’étude de la mise en oeuvre d’outils d’extraction à haut débit et de méthodes rapides de caractérisation des constituants majeurs et mineurs a pour but de caractériser la matrice «farines animales». La connaissance de la composition de la matrice a gouverné l’orientation de la stratégie de transformation de la fraction lipidique axée sur les études de transfert d’acyles. Elle permet d’obtenir des acides gras à partir des lipides extraits, puis de les utiliser pour synthétiser des esters gras simples. En perspective, nous proposons d’associer cette méthodologie à des technologies spécifiques qui permettront d’envisager la décontamination des farines animales lors de leur transformation. La deuxième partie des travaux consiste à utiliser les farines animales ainsi que les farines obtenues après extraction des lipides comme matières premières dans le cadre d’une étude de faisabilité concernant de nouveaux matériaux polymères. Il s’agit de procéder à la déstructuration thermochimique des macromolécules animales (susceptible de dégrader l’agent pathogène) dans le but de les réduire à l’état de monomères destinés à participer à la synthèse d’un nouveau polymère. Les essais de liquéfaction de cette matrice en présence de phénol ont donné des résultats encourageants. La fabrication de matériaux polymères constituerait une voie de valorisation permettant d’écouler de grandes quantités de farines animales.

High-pressure molding at an elevated temperature was investigated as a potential technique for performing the esterification of octanoic acid and octanoic anhydride on cellulose and miscanthus. Emulsion, solvent exchange, and high-pressure homogenizer pretreatments were performed on the reactants in order to improve liquid-solid contacts. After pretreatment, cellulose or miscanthus and octanoic acid or octanoic anhydride were molded at 220 MPa and an elevated temperature. The mechanical properties of the resulting compressed materials were measured, and the material was then ground and washed; the water drop angle was measured, and IR analysis was performed, as well as an accurate measure of the degree of substitution. The esterification reaction was confirmed, the water properties of the grafted cellulose were modified, and the mechanical properties of the modified materials were altered. From this pioneering work, a better understanding of the effect of the molding process on the reaction and production of water-resistant compressed cellulose materials was developed.