Investigation On Solid Acid Catalysts For Hexose Dehydration To 5-hydroxymethylfurfural

Biomass is a renewable resource that is cheap and readily available to replace fossil resources.Conversion of biomass feedstock to energy and chemicals for human development has been a hot topic in the past decade.5-Hydroxymethylfurfural is an important platform compound that can be transformed from biomass.It can be converted into a variety of high value-added compounds for use in energy,plastics,western medicine,fine chemicals and other fields.In this dissertation,novel solid acid catalysts were designed for conversion of biomass-derived glucose and fructose to 5-hydroxymethylfurfural(5-HMF).In this dissertation,the metal chloride-loaded carbon sulfonic acids CBSA-CuCl2,CBSA-AlCl3,CBSA-ZnCl2,and CBSA-FeCl3 were prepared by impregnation method using carbon sulfonic acid as carrier.The solid acid catalysts of this series have both L and B acids.They catalyzed dehydration of fructose to 5-HMF,and CBSA-CuCl2 showed the best catalytic activity.At the reaction conditions of temperature 180?,time 30 min,fructose dosage 0.5 g,solvent 1-methyl-2-pyrrolidone 10 mL,and catalyst dosage 0.1 g,the yield of 5-HMF reached 91.30%.Catalytic activities of bamboo-charcoal supported bimetallic chloride solid acid catalysts in the dehydration of glucose to 5-HMF were then studied.The results showed that excellent catalytic activity of BC-NiCl2-ZnCl2 was obtained when the reaction temperature was 180?,reaction time was 90 min,amount of catalyst was 0.1 g,ratio of water to methylpyrrolidone was l:19.Yield of 5-HMF reached 40.80%.Finally,alumina and bamboo charcoal sulfonic acid were used as catalysts for glucose dehydration to 5-HMF,and the co-catalysis of the two was studied.The results showed that catalytic activity of the two better than that of a single catalyst.Alumina was a good catalyst for glucose isomerization to fructose,and bamboo charcoal sulphonic acid was a good catalyst for catalyzing the dehydration of fructose.In the co-catalyst reaction systems,isomeric fructose can be promptly converted into the target product 5-HMF by bamboo charcoal sulphonic acid,so that the reaction conversion rate and selectivity of HMF can be increased greatly.At a reaction temperature of 180 ? and a reaction time of 2h,the yield of 5-HMF reached 52.52%.