Industrial & Engineering Chemistry Research, Vol.55, No.9, 2527-2533, 2016
Vapor-Phase Hydrogenolysis of Glycerol to 1,2-Propanediol over Cu/AL(2)O(3) Catalyst at Ambient Hydrogen Pressure
In this paper, we report that the hydrogenolysis of glycerol can be carried out at atmospheric pressure and low temperature with high selectivity to 1,2-propanediol (1,2-PDO) over reduced copper catalyst. The vapor-phase reaction was carried out over the copper-based catalysts supported on alumina at ambient pressure, and the effects of temperature, space time, and H-2 molar fraction in the feed were analyzed. The textural and structural characteristics of the catalysts with increasing copper loading were determined by N-2 sorptometry (BET), inductively coupled plasma-atomic spectroscopy (ICP-AES), powder X-ray diffraction (PXRD), temperature-programmed reduction (TPR), and N2O chemisorption (metallic area). On the basis of both characterization and activity results, it was possible to conclude that the hydrogenolysis of glycerol to 1,2-propanediol in vapor phase at atmospheric pressure over copper-based catalysts, is a structure sensitive reaction. Activity results suggests that the most probable pathway for the glycerol conversion into 1,2-propanediol under the employed conditions is glycerol is dehydration to hydroxyacetone (acetol), followed by its hydrogenation into 1,2-propanediol. Complete glycerol conversion and a selectivity of 60% to 1,2-propanediol was achieved, using a catalyst with 15 wt % CuO at 200 degrees C, H-2 molar fraction of 61%, and atmospheric pressure.