Catalytic Conversion Of Monosaccharides And Cotton Pulp Into 5-Hydroxymethylfurfural

5-hydroxymethylfurfural (HMF) is a very potential biomass-based platform chemical. HMF is currently receiving a great deal of attention. HMF can be converted to many derivatives because of HMF molecules containing hydroxymethyl and formyl-type groups. HMF generated from the carbohydrates is hot issue in current research. To sum up, choosing a suitable reaction system and using efficient selective catalysts are the main directions of research. The conversion of carbohydrates into HMF has been widely investigated in water, organic solvents, biphasic system, sub/supercritical system, and ion liquid. The conversion was catalyzed by mineral acids, organic acids, and solid acids. Solid catalysts and ionic liquids are advantageous. Solid acid catalyst was suitably selected according to good thermal stability, ease of recycling, environmental protection. Hence, Sn-Beta and Sn-MCM-41 was synthesized by different methods, and used for the one -pot synthesis of HMF in biphasic system containing THF/H2O or 2-MeTHF/H2O. The detailed optimization of process parameters and catalyst recycling are presented. Finally, the conversion of Cotton pulp into HMF with co-metal chlorides has investigated in ion liquid.In this study, the conversion of glucose and cotton pulp into HMF was inverstigated in experimental condition:(1)We studied on the one-pot conversion of glucose into HMF using Sn-Beta and dilute hydrochloric acid as catalysts in THF/H2O system. This part was mainly aimed at obtaining a maxium HMF yield. Using Sn-Beta and dilute hydrochloric aicd as catalysts is significantly improving the HMF yield. The best HMF yield of 53.0% was obtained at 190℃ for 70 min, and glucose was catalyzed by Sn-Beta and dilute HCl in THF/H2O (v/v,3/1). Further, when cellulose was used as feed, the HMF yield was over 20%.(2)We studied on the one-pot conversion of glucose into HMF using Sn-MCM-41 and dilute acid as catalysts in 2-MeTHF/H2O system. This part was mainly aimed at obtaining a maxium HMF yield. The detailed optimization of process parameters and catalyst reusability were also presented. The best HMF yield of 53.3%was obtained at 180℃ for 30 min, and glucose was catalyzed by Sn-MCM-41 and dilute H2SO4 in 2-MeTHF/H2O (v/v,3/1).(3)We systematically studied on direact synthesis of HMF by one-pot conversion of cotton pulp in ion liquid with co-metal chlorides as catalysts. The detailed optimization of process parameters was also presented. All of the data collected explained the suitability of ion liquid [Emim]Cl as reaction media and the catalytic activity of co-metal chlorides (CrCl3-ZrOCl2) for the conversion of cotton pulp into HMF. The best HMF yield of 55.9% was obtained at 120℃ for 8 h. This research data could accelerate the synthesis of HMF by biomass dehydration in the furture.