GLYCEROL HYDROGENOLYSIS TO 1,2- PROPANEDIOL WITH IN SITU HYDROGEN PRODUCED FROM METHANOL STEAM REFORMING

摘要

Converting glycerol, the by-product of the biodiesel process, into value-added products will add to the economics for biodiesel production. 1,2-propanediol (1,2-PD) is an important commodity chemical and it can be produced via dehydration of glycerol into acetol followed by hydrogenation of acetol into 1,2-PD. The conventional glycerol hydrogenolysis reaction is carried out in a batch reactor under hydrogen pressure up to 10MPa. The high hydrogen pressure incurs significant cost due to the transportation and storage of gaseous hydrogen. In addition, the high pressure hydrogen in the storage tanks and reactors can cause safety problems due to potential leakage and explosion on contact with air. To overcome the drawbacks of using high pressure hydrogen, formic acid and isopropanol [1] as sources of in situ hydrogen have been reported. However, the use of methanol as a hydrogen source has received little attention. Recently a new process using in situ hydrogen produced from methanol steam reforming for the hydrogenolysis of glycerol [2, 3] have been reported . Methanol is often used in stoichiometric excess for biodiesel production. Due to the solubility of glycerol in methanol, crude glycerol from biodiesel production will contain significant quantities of methanol. This paper will describe glycerol hydrogenolysis using in situ hydrogen produced from methanol steam reforming with Cu/ZnO/Al2O3 catalysts prepared via different preparation methods. The effect of Ni on the catalyst activity and selectivity has also been studied.