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Poster Presentation 1-25
Solubility of Sugars and Oligomers in Hemicellulose Hydrolysis
Matthew Gray, Alvin O. Converse, and Charles E. Wyman
Thayer School of Engineering Dartmouth College 8000 Cummings Hall Hanover, New Hampshire 03755
Telephone: (603) 646-1211; Fax: (603) 646-2277 E-mail: Matthew.C.Gray@Dartmouth.edu
We have postulated that oligomer dissolution and solubility could play important roles during hemicellulose hydrolysis in biomass pretreatment. For this model, the dissolution rate should be proportional to the difference between the oligomer concentration in the bulk liquid and at the particle surface. At the saturation point, dissolution would depend on the rate of breakdown of oligomers. During reaction, the solubility limit of each oligomeric species is expected to rise with decreasing chain length (depolymerization) and be influenced by the concentrations of monomeric sugars, other oligomers, and other chemicals in the liquid. This research seeks to understand the solubility of hemicellulose sugar monomers and oligomers alone and in combinations and apply the insight gained to hydrolysis modeling. Because limited data are available in the literature, experimental solubility data are being developed for pure sugar monomers in the temperature range of 20 to 60˚C. In addition, new data are being obtained on the equilibrium concentrations of mixtures of various sugars and other compounds released during biomass hydrolysis (e.g., acetic acid) followed by solubility data for sugar oligomers alone and in combination with other compounds. UNIFAC and other statistical mechanics models are applied to predict equilibrium concentrations.
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