Hydrogenolysis of glycerol

Abstract

The purpose of this research was to achieved selective hydrogenolysis of glycerol to 1,2-PDO (1,2-propanediol). Hydrogenolysis of glycerol was investigated in batch and trickle flow fixed bed continuous reactors. Raney catalysts and carbon supported precious catalysts were tested in the batch reactor. Ru/C and oxide-supported catalysts were tested in a continuous reactor. Parametric studies were performed and kinetics parameters were estimated with Raney copper catalyst in a batch reactor and with Cu/Al2O3 in a continuous reactor. The network of glycerol hydrogenolysis was studied on Cu/Al2O3. Cu/Al2O3 was investigated in the continuous reactor. Preparation methods, Cu loading and Cu catalyst support effects were studied. Catalyst characterization was performed to find out the factors that affected catalyst performance. Cu/Al2O3 catalyst was further modified by adding small amounts of Co and Ni to enhance the activity. The factors that affect the catalyst deactivation were also investigated. Raney Cu in the batch reactor and Cu/Al2O3 in the continuous reactor were the catalysts most selective to 1,2-PDO for glycerol hydrogenolysis. Cu catalyst on Al2O3 support of 18 wt % Cu loading prepared by co-precipitation method with ammonia is the most efficient catalyst for glycerol hydrogenolysis to 1,2-PDO. Catalyst characterization shows that the Cu/Al2O3 activity is related to the active Cu surface area on alumina support and the selectivity to 1,2-PDO is constant for the Cu/Al2O3 with different Cu surface area. Small amounts of Ni or Co improve the Cu/Al2O3 activity. The most effective deactivation factor for Cu/Al2O3 is coking or oxygenates on the spent catalyst.