(629ak) Selective Oxidation of Glycerol to Dihydroxyacetone In a Trickle-Bed Reactor

The economic viability of biodiesel production can be enhanced by conversion of the primary byproduct glycerol to the higher value chemical dihydroxyacetone (DHA).  This can be accomplished by selective oxidation of the secondary hydroxyl group of glycerol by using a 3%Pt, 0.6%Bi on activated carbon catalyst, which has achieved high yield (>40%) in a semi-batch reactor [1].  To increase production, a trickle-bed reactor has been developed with cocurrent downflow of oxygen and aqueous glycerol.  Feed solution pH and concentration as well as reactor temperature and pressure have been optimized.  The impact of gas and liquid flowrates on yield has also been investigated, with additional consideration given to the influence of the complex hydrodynamics of trickle bed reactors.  The development of a continuous-flow process for conversion of glycerol to DHA bolsters the economic capability of biodiesel production, while additionally providing insight into the behavior of trickle-bed reactors.

[1] Hu, W., Knight, D., Lowry, B., Varma, A. Selective Oxidation of Glycerol to Dihydroxyacetone over Pt-Bi/C Catalyst:  Optimization of Catalyst and Reaction Conditions. Ind. Eng. Chem. Res. 2010, 49 (21), 10876-10882.