Low-pressure packed-bed gas phase conversion of glycerol to acetol

This article describes the investigations carried out on the vapor-phase hydrogenolysis of glycerol to acetol over a copper-chromite catalyst in a packed bed flow reactor. The effects of reaction method (liquid-phase vs. vapor-phase mode), vapor-phase reaction with gas feed. reaction temperature, catalyst loading, and hydrogen feed rate were studied to arrive at optimum conditions. Operating the reactor ill vapor-phase mode dramatically reduced the amount of undesired by-product formation, and thereby increased the overall yield of acetol and propylene glycol. The optimum reaction temperature is near 220 degrees C. Higher hydrogen feed rates increased propylene glycol selectivity. The proposed production scheme has application for production of both acetol and propylene glycol from the crude glycerol that contains various soluble salts. (C) 2008 American Institute of Chemical Engineers.