Investigation of Vapor – Liquid Equilibrium, Volumetric, Compressibility and Transport Properties of Some Aqueous Saccharides in Presence of Ionic Liquids

Lignocellulosic biomass is nontoxic and biodegradable source of saccharides that can beused for the production of fuels and chemicals [1, 2]. However due to their complex structure andlow solubility in conventional solvents, the effective conversion of these compounds faces withsome challanges [3]. To solve these problems, a new type of solvent referred to ionic liquid hasbeen proposed to use in biomass pretreatment process [4, 5]. In this work the salt effect resulted byaddition of ionic liquids to aqueous saccharide solutions is investigated. To achieve this goal,systematic studies have been made on ternary {saccharide + ionic liquid + water} system usingthe vapor-liquid equilibrium, density, speed of sound and viscosity data. To investigate ionicliquid-water and saccharide-water interactions, vapor pressure depression, osmotic and activitycoefficient data for the ionic liquids and saccharides in the binary solutions are used. To studysaccharide-ionic liquid interactions in ternary solutions, the activity coefficient of saccharides inpresence of ionic liquids, transfer Gibbs energies, pair and triplet interaction parameters, saltingconstants, standard partial molar volume (V(0 Φ)), partial molar isentropic compressibility (K(0 Φ)),hydration number (nH) , and viscosity B-coefficient (B) are used. The variety of ionic liquidsbased on imidazolium and pyridinium have been studied. In this article, the effect ofstereochemistry of sugar, cation (imidazolium or pyridinium), chain length and anion of ionicliquids on saccharide-ionic liquid interactions have been discussed.