Experimental Study On Cellulose Hydrothermal Decomposition To Produce 5-hydroxymethyl-furaldehyde

5-hydroxymethyl-furaldehyde (5-HMF) which was obtained from glucose or fructose dehydration reaction is a specific medicament, which is effective on the preventment of neurodegenerative diseases and cognitive impairment.In this paper, the reaction conditions, reaction mechanisms and reaction kinetics of cellulose decomposition to product 5-HMF in Hot-Temperature-Water/Carbon Dioxide (HTW/CO2) binary system were studied.Firstly, cellulose decomposition to product 5-HMF in HTW was studied. The results indicated that cellulose could be decomposed in HTW even without any catalyze. The yield of 5-HMF was increased and the residence time was shortened slightly after adding of CO2 in HTW, the results of cellulose decomposition in HTW/CO2 binary system showed that CO2 could accelerate cellulose decomposition reaction when compared with cellulose decomposition in HTW. Secondly, the optimal conditions of cellulose decomposition in HTW/CO2 binary system were as follows:CO2 mol fraction, temperature, residence time and pressure were XCO2=5.0%, 523.15K, 7.25Mpa and 30min respectively, under which conditions the yield reached 16.19%. Cellulose decomposition in HTW/CO2 binary system is preferable to cellulose decomposition in HTW. Thirdly, to characterize the reaction mechanism and reaction pathways of cellulose degradation in HTW/CO2 binary system, key compounds which were intermediates of cellulose degradation, were identified through GC-MS. The chemical reaction pathways of cellulose decomposition in HTW/CO2 were identified.As addition, reaction kinetics of cellulose decomposition in HTW and HTW/CO2 binary systems were studied. The results indicated that cellulose decomposition in HTW and HTW/CO2 binary systems were first-order reaction. The kinetics formulas and reaction activation energies for cellulose decomposition in HTW and HTW/CO2 binary systems were gained respectively. The results of cellulose decomposition in HTW and HTW/CO2 binary systems showed that with the adding of CO2 could increase the apparent reaction rate constant and decrease the reaction activation energy. Reaction...