Direct Catalytic Conversion Of Glucose Into Low Carbon Glycols Over Modified NiB Amorphous Alloy Catalysts

With the depletion of fossil energy and the deterioration of the earth’s environment, biomass, one of the major clean energy resources, has been considered to have great potential for use as an alternative feedstock to petroleum in the production of clean energy and renewable chemicals. Hydrogenolysis of glucose into valuable chemicals such as ethylene and propylene glycols, an alternative technology for conversion of biomass into valuable chemicals, is a promising green process.The effect of the components of NiB based amorphous alloy has been investigated on its physical, chemical properties and catalytic performance in hydrogenolysis of glucose into ethylene and propylene glycols. The results indicated that tungsten modified NiB amorphous alloy catalyst (NiWB) presented the best catalytic performance. Meanwhile, the catalyst preparation parameters for NiWB catalyst and reaction parameters in hydrogenolysis of glucose were optimized. Moreover, NiWB catalyst was successfully supported on activated carbon (AC) and exhibited good performance. The main results and conclusions are as follows:(1) The composition of amorphous alloy catalyst has significant effects on the catalytic hydrogenolysis of glucose. Tungsten was coupled into the microstructure of NiB amorphous alloy and increased the B content in the amorphous alloy catalyst NiWB, showing doubled activity in glucose hydrogenolysis. The NiWB catalyst was believed to be an promising catalyst for ethylene glycol and1,2-propylene glycol production from glucose.(2) The effect of catalyst preparation parameters of NiWB on its physical, chemical properties and catalytic performance were systematically studied. The optimized parameters were W/Ni=0.1, NaBH4/Ni=3, and reductant adding rate1.2mL/min, under which the NiWB catalyst showed best performance with100%glucose conversion, ethylene glycol yield37.0%,1,2-propylene glycol yield11.3%and sorbitol yield25.0%.(3) The yield of ethylene glycol increased from37.0%to60.0%when semi-continous feeding method was employed in the batch reactor. Moreover, the reaction parameters of semi-continous feeding-batch reaction system were optimized as4MPa initial H2pressure,5mL/min feeding rate of glucose solution,220℃and reaction time of40min.100.0%glucose conversion with ethylene glycol yield62.3%,1,2-propylene glycol yield11.0%and sorbitol yield6.4%were obtained.