Vapour Phase Hydrogenolysis of Glycerol over NaY-Zeolite Supported Ru Catalysts for Targeted Selectivity towards 1,2-Propanediol

Biodiesel waste (glycerol) valorization has been gaining interest currently due to the unique structural characteristic of the compound to be processed into many valuable commodities. The current study is focused on the catalytic hydrogenolysis of glycerol to 1,2-propanediol over Ru supported on NaY-Zeolite catalyst via a sustainable route. The catalysts with variable Ru loading (1-5wt%) synthesized by wetness impregnation method were tested for the selective hydrogenolysis of glycerol in a continuous fixed bed reactor at atmospheric pressure and moderate temperatures (160-240 °C). The physicochemical properties of the catalytic materials have been characterized by FTIR, XRD and SEM-EDX techniques. It was observed that the synthesized catalyst remained stable and retained the high crystallinity upon increasing Ru loading and the stretching vibrations of the silica-alumina structure exhibited no difference before and after metal impregnation. Reaction parametric studies performed to compare the effect of calcination and reaction temperature on the catalytic performance during glycerol hydrogenolysis suggested that calcined catalyst has better activity towards glycerol conversion as compared to that of the uncalcined catalyst. Optimization of other reaction parameters such as metal loading, catalyst weight, glycerol concentration, glycerol flow rate as well as hydrogen flow rate is expected to elevate the selectivity towards 1,2-propanediol to a greater extent.