Hydrogenolysis of glycerol to propylene glycol using heterogeneous catalysts in basic aqueous solutions

The efficient catalytic conversion of glycerol, the main by-product from the bio-diesel production, into valuable chemicals, can contribute to the promotion of bio-diesel utilization from economic and environmental points of view. Glycerol can be hydrogenated to propylene glycol using copper chromite catalyst with high yield and conversion under mild reaction conditions (20 bar, 200 °C, 8 h) and basic aqueous solutions. The effect of the added base type was discussed in this paper and the results indicated that different influences of alkali bases on the activity might be associated with the size of the metal cations. The highest conversion of glycerol and the highest selectivity to 1,2-propanediol were observed in presence of LiOH, whose additions proved to be effective.