Production of fiberboards from shives collected after continuous fiber mechanical extraction from oleaginous flax

In this study, fiberboards were produced from shives collected after continuous fiber mechanical extraction from oleaginous flax straw. Fiberboards were produced through thermo-pressing, and their mechanical and thermomechanical properties were studied, as well as their water resistance. The influence of two pretreatments for shives and lignin addition was investigated on the different properties. Boards obtained were all cohesive hardboards. The optimal board was obtained from fibers extruded from the shives and without addition of any supplementary lignin amount. Looking at its characteristics and standard NF EN 312, the latter perfectly complied with the requirements for type P1 boards, i.e., boards for general uses in dry conditions

Twin-Screw Extrusion: a key technology for the biorefinery

International audienceFor more than 30 years, the Laboratory of Agro-industrial Chemistry (LCA) develops an ambitious and multi-scale research topic on the use of twin-screw extrusion (TSE) for the processing of biomass for non-food applications. This chapter will give an overview of past and present projects, discussing specific operating conditions and their consequences on biopolymer native organization. For the production of agro-materials, compounding processes have been designed and in some cases industrialized integrating specific targeted actions such as the plasticization of primary cell-walls (sugar beet, tobacco), the "fusion" of storage polymers (starch, oilseed proteins) and/or the destructuring of secondary cell-walls (lignocellulosic fibers). For the pretreatment of lignocellulosic fibers, the conjugated use of chemicals is also discussed. Those processes have also been coupled with biodegradable polyester blending (involving compatibilization with acid citric) and compounding. In integrated biorefining processes, TSE may also be used simultaneously as a continuous liquid-solid extractor through mechanical pressing or solvent extraction, for extracting oil, polysaccharides, proteins, polyphenols or hydroxycinnamic acids and as a pre-treatment of the fibrous raffinate. This is especially efficient for the processing of oilseed crops and the production of binderless fiberboards or to prepare technical fibers for composite applications. This has been widely demonstrated on sunflower, jatropha or more recently coriander. Finally, in the bioenergy field, a specific pretreatment process for the production of bioethanol from lignocellulosic feedstock has been developed and is actually in the up-scaling phase. Integrating the use of enzymes in a one-step TSE, this process has been called "bioextrusion"