Catalytic Conversion Of Carbohydrates To Diols

Nowadays, the price of petrochemical products increased rapidly with the shortage of fossil resources. Diols, as petrochemical downstream products, were in short supply. It becomes more and more essential to find an alternative route to produce propylene glycol and ethylene glycol from renewable resources. In recent years, a potential route of converting natural resources to high valuable chemicals and fuels, such as diols, has attracted intensive attentions because it can solve the shortage of diols, provide a route to explore the renewable resources and achieve the sustainable development of human society. In this thesis, we used carbohydrates as raw materials to produce diols using the concept of green catalytic conversion.In our study, a series of Ni catalysts were prepared through incipient wet impregnation methods, and the effects of different Ni catalysts and different reaction conditions were tested in this work. GC、GC-MS、TOF、IC were used to distinguish and quantify the products. We got a general cognition of the process of glucose hydrogenolysis. We summarized the shortcomings of glucose using as a reactant andfound a catalytic system with a high concentration of sorbitol and Mo-Raney Ni catalyst was choosen to catalyze sorbitol to diols with a high glycol yield. The factors affecting the sorbitol hydrogenolysis reaction such as the amount of basic promoter and catalyst, sorbitol concentration, hydrogen pressure, temperature and reaction time, were optimized in our work. With the lots of experiments, we found that single metal Ni catalysts showed a high hydrogenation activity, but with little activity of C-C cleavage. The results also showed that Mo species is helpful to convert sorbitol into glycols and it may act as an accelerant in the reaction. The results showed that the selectivity of1,2-PD raised when basic promoter was introduced to this system. Mo-Raney Ni can give a glycol yield of64.7%with a optimum reaction condition. The reusability of Mo-Raney Ni showed that catalyst was stable in our experiment system and could be reused at least5times...