Liquid-liquid equilibrium of aqueous systems containing protic ionic liquids to fractionation of lignin

Abstract

Biorefinery has attracted the attention of scientists in the last years due to the crescent interest in biofuels and high-value-added and renewable products. In this kind of industrial complex, the biomass needs to be separated into rich fractions of its compounds (cellulose, hemicellulose, and lignin), and, afterward, its fractions may be potentially converted into biomaterials, biofuels, and renewable products of great economical and financial interest. Among the mentioned components, lignin is the least susceptible to chemical modifications, the least applied to produce fine chemicals and poorly commercialized. In this context, has been proposed the use of protic ionic liquids (PILs) as significant media and solvents to the fractionation of lignin. Therefore, the objective of this project is to synthesize a series of PILs produced from pyrrolidinium and carboxylic acids and determines the physical and chemical properties of these solvents. Besides, the fractionation of lignin will be evaluated using liquid-liquid equilibrium (LLE) of aqueous systems containing PILs. Finally, the lignin samples recovered will be characterized using techniques such as NMR, GPC, and FT-IR, and applications of these samples will be proposed. (AU)