Cellulose Hydrolysis in Acidified LiBr Molten Salt Hydrate Media

Abstract

We screened nine acidified molten salt hydrates (solutions with water to salt molar ratio equal or less than the coordination number of the cation) as reaction media for cellulose hydrolysis, and we found that cellulose can be efficiently hydrolyzed in LiBr acidified MSH under mild conditions (>90% yield to water-soluble products in 0.05 M H2SO4 at 85 °C for 30 min). The effect of various factors (temperature as well as acid and initial cellulose concentrations) on the kinetics of hydrolysis reaction was also investigated. At the lowest temperatures examined (70 and 85 °C) low amounts of degradation products have been observed, and glucose appears to be in equilibrium with its dimers and possibly other oligomers. Higher temperatures (100–115 °C) enhanced the formation of degradation products (organic acids and humins). Analysis of the kinetic data indicate that hydrolysis rates are first order in cellulose and in H2SO4 concentration, and the initial hydrolysis rates have an apparent activation energy ∼123...