Hydrolyse physico-chimique et biologique de la biomasse ligno-cellulosique pour la production de bio-éthanol de deuxième génération

Different industrial operations of plants cause frequently the formation of considerable amounts waste lignocellulosic named biomass wastes. The aim of this study is the valorization of this biomass by producing second-generation bioethanol, this is an optimal valorisation type "biorefinery" for the production of fermentable simple sugars with high added value. In the first process which is the chemical hydrolysis, the biomass was depolymerized by a steam treatment. Then, treatment with sulfuric acid was carried out to saccharification and release of simple sugars. In order to reduce phenolic compounds, the substrate was decanted and filtered and then treated with calcium dihydroxide. Meanwhile, in a second process which is the enzymatic hydrolysis the biomass was pretreated by steam explosion to make all these compounds accessible to enzymatic hydrolysis. The preparation of enzyme was obtained from the supernatant of culture medium of strain Trichoderma reesei. In addition, techniques and variable chemical and biological hydrolysis (temperature, pressure, time, concentration and conditions of detoxification and enzyme production) have been optimized. In conclusion, this work has helped to develop a biotechnological process to value the solid biomass in the order decrease costs and add socio-economic value to this waste. [PUBLICATION ABSTRACT]