(544h) A Fundamental Study of Cellulose Hydrolysis in Super Acidic Molten Salt Hydrate Media

Finding green and economical media for the dissolution and hydrolysis of cellulosic biomass has become a great challenge. Molten salt hydrates (MSH) and other ionic liquids are emerging as potential alternatives to strong acid and thermal treatment previously used in the hydrolysis of cellulose. Depolymerization of cellulosic biomass in MSH has resulted in high glucose yields at low acid and temperature conditions^[1]. However, our understanding of this promising medium is limited.

In the present work, we studied the effect of different salt concentrations in the overall system acidity and in the rate of hydrolysis of glucose dimers. To understand the effect of the salts in the acidity, we use thermodynamic modeling to predict the H⁺ activity and the concentration of relevant species in solution. We then correlated the predicted proton activities with the experimentally measured reaction rates (via HPLC) to elucidate the effect of proton source in the hydrolysis of the glucose dimers. Furthermore, to validate the model predictions, we developed a spectroscopic method of estimating proton activity in super acidic media and more specifically in the acidified lithium bromide molten hydrate system.

1. Deng, W., Kennedy, J. R., Tsilomelekis, G., Zheng, W., and Nikolakis, V. “Cellulose Hydrolysis in Acidified LiBr Molten Salt Hydrate Media” Industrial & Engineering Chemistry Research no. 54 (2015): 5226–5236. doi:10.1021/acs.iecr.5b00757, Available at http://pubs.acs.org/doi/pdf/10.1021/acs.iecr.5b00757