Study On Efficient And Environmentally Friendly Methods For Preparation Of Levulinic Acid

Levulinic acid(LA) is regarded recently as a new platform chemical because it can be prepared from biomass with large scale, high yield and low cost, and it has high reactive ability. Through salification, esterification, hydrogenation, condensation, oxidation and halogenation etc.,LA can produce useful chemicals and new polymer materials. As a part of " Study on efficient and environmentally friendly methods for preparation of levulinic acid", in this paper, a GC method for the analysis of LA in biomass decomposition products was established, in addition the kinetics and mechanism of hexose decomposition and the stability of LA in high temperature liquid water was studied.A rapid, direct GC method for the analysis of LA in biomass decomposition products was established. With benzoic acid as internal standard, good separation was achieved on FFAP column. A relative standard deviation of 0.78%(n=5) was found. The average recovery of the method for LA was 96.97%. The method proposed is fast and simple to practise. It is direct, accurate and reliable for the determination of LA in biomass decomposition products.Kinetics of hexose (fructose and glucose) decomposition in High Temperature Liquid Water (HTLW) was studied for temperature from 453.15K to 493.15K and pressure at lOMPa. From the results, hexose can decompose easily without acid catalysts, and with the increasing of temperature, the reaction rates increased sharply. The evaluated activation energy of fructose and glucose decomposition was 126.15 KJ /mol and 140.97KJ/mol, respectively. In addition, the effects of temperature and residence time on the yield distributions of main products were shown.Stability of LA in HTLW was studied for temperature from 533.15K to 573.15K and pressure at 11 MPa. The results showed that LA was quite stable in HTLW, andthe evaluated activation energy of LA decomposition was 127.38KJ/mol.The researches showed that the application of HTLW has a good potential in the field of biomass resource. With the application of HTLW, LA, a platform chemical, can be prepared from biomass with low cost, large scale and environment-friendly. Now study on kinetics and mechanism of biomass decomposition in HTLW has been done, and a lot of researches should be done to prepare LA efficiently and greenly.