DEVELOPMENT OF IONIC LIQUID TECHNOLOGIES FOR THE INTEGRATION OF PRE-TREATMENT, FRACTIONATION, EXTRACTION, HYDROLYSIS AND CONVERSION OF BIOMASS IN THE FRAME OF THE BIOREFINERY CONCEPT

摘要

Two innovative strategies for biomass valorization with ionic liquids (ILs) were approached in thisrnwork. A first strategy was based on a three-step fractionation of lignocellulosic biomass into cellulose, hemicellulosernand lignin assisted by 1-ethyl-3-methylimidazolium acetate ([emim][OAc]). Simultaneously, this IL allowed furtherrnvalorization by extraction of high value added phenolic compounds from biomass during the process. Purification ofrnvanillin, tricin, p-hydroxybenzaldehyde, syringaldehyde, p-coumaric and vanillic acids from IL was accomplishedrnusing polymeric resins and supercritical CO_2. The second strategy was focused on the ability of acidic Ils, such as 1-rnbutyl-3-methylimidazolium hydrogen sulfate ([bmim][HSO_4]) and 1-ethyl-3-methylimidazolium hydrogen sulfatern([emim][HSO_4]), to hydrolyze and to convert selectively hemicellulose into reducing sugars and furans. In thisrnscenario, depending on specific properties of Ils, such as basicity and acidity, biomass is physically and chemicallyrnaltered allowing the integration of biomass pre-treatment, fractionation, hydrolysis and conversion processes tornproduce desired compounds.