Preparation And Application Of Levulinic Acid From Rice Straw

With the rapid consumption of non-renewable resources, such as oil, gas and coal, the energy crisis and greenhouse gas pollution problem has been more serious, the utilization of renewable resources, instead of non-renewable ones, is attracting more and more attention worldwide. Biomass resource is vast in the nature reserves; the interested research is conversion of biomass recourse to useful compounds and biofuels recently. Levulinic acid (LA) can be prepared from biomass with large scale, high yield, and also it has and it has high reactive ability. Through salification, esterification, hydrogenation condensation oxidation and halogenations etc.LA can produce useful chemicals and new polymer materials, therefore levulinic acid can be used as a new platform chemical. In this paper levulinic acid is prepared by the hydrolysis of the rice straw. Double phenolic acid is then prepared by levulinic acid and phenol; finally double phenolic acid and epichlorohydrin are used to prepare epoxy resin.Levulinic acid is prepared by the acid hydrolysis of the rice straw though" two-step reaction". The effects of technological conditions of reaction time, temperatures, ratio of solid to liquid and sulfuric acid concentration on the yield of reducing sugar and levulinic acid are investigated respectively. The result shows that, in the reaction of acid hydrolysis, the best yield of reducing sugar is28.45%, under the optimal conditions of time35min, temperature220℃, ratio of solid to liquid1:15, sulfuric acid concentration6%; in the reaction of transforming, the best yield of levulinic acid is34.14%under the optimal conditions of time40min, temperature250℃.In the reaction of synthesis of double phenolic acid the effects of reaction temperature, reaction time, catalyst, assistant catalyst and ratio of phenol to levulinic acid were investigated by orthogonal test. The results showed that the reaction temperature of60℃, reaction time of50h,n(HCl):n(LA)=3:1, assistant catalyst of3ml, ratio of phenol to levulinic acid of3:1were found to be the best condition, and the best yield is73.51%.DPA-epoxy resin was prepared though the reaction of double phenolic acid and epichlorohydrin use the same method of BPA-epoxy resin. The structure and molecular weight distribution were characterized by FTIR, TGA and GPC. It indicated that the epoxy resin has been synthesized. The product samples were tested and showed better capabilities tensile intensity was3.59Mpa.