The Studies On Catalysts Using For Conversation Of Monosaccharide To 5-Hydroxymethylfurfural

With the rapid development of the economy, the energy requirements are gradually increasing in social life. Currently, our energy supply depends mainly on the non-renewable fossil resources such as coal, oil, natural gas. We will face a serious energy crisis in the future with continuous consumption of these resources. In order to solve this problem, seeking renewable resource to replace fossil fuels has become a research focus. Biomass resources are abundant in nature as renewable resource, and 5-hydroxymethyl furfural(HMF) can be synthesized by the dehydration reaction of monosaccharide and then used to synthesize useful compounds or new polymer materials. Becaues of its high application value, it was praised as the bridge connecting petrochemical and carbohydrate chemistry. Therefore, preparation of HMF through carbohydrate transformation has become a research focus in recent years.The main subject of the study was the catalyst preparation to select a high activity catalyst system. The main research contents are as follows:(1) The effects of the additives type and amount on the yield of HMF were studied using AlCl3 as a catalyst. The results showed that NH4 Br can effectively promote the catalytic activity of AlCl3-NH4 Br system. NH4 Br can show its promotion effects only when AlCl3 was existence. In addition, the solvent type, reaction temperature and reaction time were optimized in the study. The yield of HMF reached 47% under the optimization conditions. In addition, NH4 Br can effectively promote the catalytic activity of CrCl3-NH4 Br and SnCl4-NH4 Br system.(2) With AlCl3 as a catalyst,the effects of the NH4Br-NaBr promoter system were examined for the conversion of glucose to HMF. The results showed that the combination of 0.08 M NH4Br and 0.32 M NaBr could effectively promote the catalytic system. In addition, the amount of promoter and other factors were investigated in detail. The yield of HMF is 54% under optimum conditions.(3) With the Phosphotungstic acid(PWA) as the active ingredient, PWA/meso-SiO2 catalysts were synthesized by one-step condensation method, PWA/SiO2 catalysts were prepared by impregnation of SiO2 with PWA. Both of them were evaluated as catalysts for the dehydration of fructose to prepare HMF. The results showed that PWA/meso-SiO2 has better catalytic activity. With PWA/meso-SiO2 as the catalysts, the yield of HMF could be up to 83%. In addition, the catalytic activity remained 71% after repeating for five cycles, indicating PWA/meso-SiO2 has a better stability.(4) AlPO catalyst have been synthesized from Al(NO3)3 and H3PO4 in the presence of citric acid. The AlPO were evaluated as catalyst for the conversation of glucose to prepare HMF. The effect of P/Al(n:n), reaction temperature, reaction time, catalyst concentration and the Glucose quality were investigated in detail. The results showed that With 10wt% catalyst of AlP1.0O(P/Al=1:1,n:n) and 10 ml DMSO as solvent, HMF yield could up to 35% while react at 150℃ for 5h.