Process Analysis And Product Control Of Glucose Hydrogenolysis To Low Carbon Glycols Over Ni-W₂C/AC Catalyst

Conversion of biomass resources instead of fossil fuel to valuable chemicals is significant for sustainable chemical industry. Conversion of glucose to ethylene glycol (EG) and 1,2-propanediol (1,2-PG) attracts attention of many researchers. N1-W2C/AC is an efficient catalyst used in the conversion of glucose, which leads to a high yield of EG. However, some problems like the low concentrated glucose solution and coking restrict the industry application of the process. Our previous work showed the pathways of glucose hydrogenolysis over N1-W2C/AC, this paper would have a research on the process of glucose hydrogenolysis.In this paper, thermodynamic analysis of reactions involved in the glucose hydrogenolysi has been studied. The unknown product was analyzed by LC-MS and TOF-MS. The product distribution was regulated and controlled. The main results and conclusions are as follows:1. Hydrogenation of fructose was favor for the formation of sorbitol than glucose hydrogenation. The formation rate of EG and 1,2-PG were respectively restricted by hydrogenation of glycolaldehyde and hydroxyacetone. The easily dehydration reaction of glucose and fructose leaded to the formation of 5-HMF. Hydrogenation favored the low temperature, while the dehydration and hydrogenolysis favored the high temperature.2. An HPLC method was established to determine the content of products in glucose hydrogenolysis. The molecular formula of the unknown product was C5H6O3 and it was probably derived from the conversion of glucose.3. The addition of inorganic base could promote the isomerization of glucose to fructose which leads to more C3 and C6 products. Solvent effect existed in glucose hydrogenolysis, a higher dissolving capacity for glucose was in favor for the formation of EG. OH" dissociated from the solvent was beneficial to yield C3 products.4. Reaction pathway of glucose hydrogenolysis can be controlled by changing reaction conditions such as reaction temperature and glucose concentration, which leads to more target product. A low concentration reactant and high temperature make for the retro-aldol reaction of glucose, while concentrated reactant and low temperature benefit the hydrogenation reaction, more catalyst can inhibit the coking with concentrated reactant.