(738d) Reaction Mechanism and Kinetics of Maleic Acid for Altering the Selectivity of Glucose Dehydration and Degradation

Zhang, X., Purdue University
Mosier, N. S., Purdue University

5-hydroxymethyfurfural (HMF) and levulinic acid are platform chemicals for producing a variety of fuels and polymers.  However, undesirable humic substances can be generated in a substantial amounts, lowering the yields of desired products. We report the use of hydrochloric acid and maleic acid separately and mixed with a Lewis acid (AlCl3) to catalyze the process of glucose isomerization, dehydration, and hydrolysis. Analysis of results between 130 and 180 oC were used to develop a kinetic model for the glucose conversion to HMF and levulinic acid by these selected catalysts. Preliminary results show that after 6 minutes at 180oC maleic acid combined with AlCl3 generated only 50% of total humins compared to hydrochloric acid combined with AlCl3. We report an analysis of this shift in selectivity of the reaction toward levulinate and describe possible mechanisms for interactions between maleic/maleate and the reactants and intermediates.