Reaction Rates for the Partial Dehydration of Glucose to Organic Acids in Solid-Acid,Molecular-Sieving Catalyst Powders

Molecular-sieving catalysts have the potential to promote the production of oxygenated hydrocarbons from glucose. A kinetic model for the partial dehydration of glucose to organic acids by micro- and mesoporous aluminosilicate catalysts was developed. Kinetic parameters were estimated from glucose conversion and product yield versus time data at 150°C for HY-zeolite, aluminum-pillared montmorillonite, MCM-20 and MCM-41 catalyst powders of 0·5 mmol H⁺ g⁻¹ solid-acid activity. Rate constants for the partial dehydration of glucose to 5-hydroxymethylfurfural (HMF) and the rehydration and cleavage of HMF to formic acid and 4-oxopentanoic acid were maximized at catalyst pore diameters of 10–30 Å. The final organic acid product yields were low, less than 60% of theoretical for formic acid and 10% of theoretical for 4-oxopentanoic acid, due to significant coke formation. © 1997 SCI.