Study On The Decomposition Of Biomass Resource To 5-hydroxymethylfurfural In An Catalyst-extraction Biphasic System Of Ionic Liquid/organic Solvent

Now,a lot of researchers are devoting themselves to the study on 5-hydroxymethylfurfural(5-HMF),which can derive a number of downstream products.So far,most of the 5-HMF is prepared by monosaccharide,but many forefront investigations put emphasis on decomposition of cellulose to 5-HMF.It has some shortcomings,such as the productions of decomposition of cellulose to 5-HMF are complicated,more side reactions and not easy to separate 5-HMF from reaction system resulting in low yield.The text studied the decomposition of cellulose to 5-HMF in an ionic liquid / organic solvent biphasic system.The contents of the text are as followings:Firstly,it determined the optimum conditions in an ionic liquid / organic solvent(methylbenzene)biphasic system: ionic liquid: organic solvent = 1:10:44,amount of catalyst CrCl3 was 6.8mol%,reaction temperature was 130 °C,reaction time was 180 min.The yield of 5-HMF was 55.4%,and the yield of TRS was 27.3%,under the condition.At the same time,the re-utilization of the ionic liquid /organic solvent(methylbenzene)biphasic system was also studied,the results were indicated that the structure of ionic liquid was still stable throughout after the reaction,it could be recycled and applied to the next reaction.The re-utilization process of the biphasic system was studied: the 5-HMF and organic solvent(methylbenzene)were obtained after the concentration and drying of upper liquid,the organic solvent was re-utilized.The catalyst CrCl3,TRS and ionic liquid were obtained after the centrifugation of lower liquid,they could be re-utilized to the next reaction.Secondly,the kinetics study of the decomposition of microcrystalline cellulose to 5-HMF in an ionic liquid/organic solvent(methylbenzene)biphasic system was investigated,the results indicated that the decomposition constant of cellulose and the decomposition constant of glucose were related to the concentration of products,therefore,they were all first order reactions.The decomposition constants of cellulose and glucose were increased with increased temperature,increased time,increased catalyst,increased ionic liquid and increased organic solvent.The organic solvent could offer a higher degree of the increase of the decomposition constants of cellulose and glucose than the catalyst and ionic liquid.Comparison with other reaction systems,it found that heating ways had significant impact on the decomposition of cellulose to 5-HMF,microwave heating could enhance the solubility of cellulose in ionic liquid,resulting in the reaction temperature reduction and the reaction time reduction.Finally,the decomposition of microcrystalline cellulose to 5-HMF in an ionic liquid/organic solvent(ethyl butyrate)biphasic system was investigated,it determined the optimum conditions in the system: ionic liquid: organic solvent=1:4.0,reaction temperature was 130 °C,reaction time was 3h.The yield of 5-HMF was 40.29%,and the yield of TRS was 41.7%,under the condition.It found that the ionic liquid could be re-utilized after the investigation of the reaction system re-utilization.The re-utilization process of the biphasic system was also studied.In the last,the text studied the comparison of the methylbenzene system and ethyl butyrate system.