Catalytic Dehydration-Hydrogenation of Glycerol to 1,2-Propylene Glycol at Ambient Hydrogen Pressure

The novel technology for synthesis of 1,2-propylene glycol by dehydration-hydrogenation of glycerol at ambient hydrogen pressure was reported. Dehydration of glycerol to acetol was catalyzed by Cu/Al(2)O(3) catalyst. A 86% selectivity for acetol was achieved at 220 degrees C and ambient hydrogen pressure. The effects of copper loading, reaction temperature, and reaction atmosphere on the catalyst performance were studied. Raney Ni catalyst showed excellent catalytic performance in the hydrogenation of acetol to 1,2-propylene glycol. The selectivity for 1,2-propylene glycol was more than 99% at 120 degrees C and ambient hydrogen pressure, and no appreciable change in the activity was observed over the Raney Ni catalyst after 5 h of time-on-stream. The influence of reaction conditions on the conversion and selectivity was also investigated in the hydrogenation of acetol.