| Levulinic acid is the direct hydrolysis of biomass resources, which is an important product. Large quantities of renewable resources could produce to mass the levulinic acid, which has become a new biomass～based platform chemical and be used to to produce various high value～added products.Its molecules have a carbonyl, a carboxyl group,a methyl and two methylene, which has good physical and chemical properties.Levulinic acid could occur esterification, substitution, and the neutralization reaction, which be used to mainly pesticides,perfume, light industry and other industrial areas.At present, it is the preparation of biomass hydrolysis levulinic acid process, and the sulfuric acid is more used to catalyst. But it is the process has greater corrosion of equipment, and environmental pollution. Therefore, it is the development of new green hydrolysis which become a top priority.Accordingly, this paper usesd a extremtly low acid hydrolysis of biomass with the rice husk It is study to hydrolysis at a extrememtly low acid, and on this basis, the rice husk conversion levulinic acid conditions and dynamics are explored, So it is provide a threretical reference about biomass to preparation of levulinic acid with extremetly low acid.The reason why rice husk as raw material, it is because China is a major rice producing countries, and the rice husk has a very rich resources, but it is particularly low utilization, the majority of rice husk were abandoned in vain, The rice husk as a raw material in order to get the attention of staff to so that it "turning waste into wealth."First of all,in the acid concentration of 0.1%,the temperature range of 160～260℃,the cellulose in the extremtly low acid to the degradation study. The results showed that:the rice husk with a extremtly low acid in the degradation of temperature there are two phases, two phases were consistent with the different kinetic models. Analysis by two linear regression equations:at 160℃～200℃, the linear regression equation was:,y=-3.4773+2.9019 x.at 220℃～260℃,the reaction of the linear regression equation:y=-3.0196+2.4472 x Further, it is the extremtly low acid concentration of 0.1% sulfuric acid in the water environment,and it is using self-designed high pressure reaction vessel.In the range of 200～280℃,it is respectively of temperature, time, liquid to solid ratio, mesh and other factors on levulinic acid yield. The results showed that the rice husk particle size on the yield of levulinic acid which has little effect, other four factors have significant effect, and it has been optimized conditions were:reaction temperature 240℃,0.1% sulfuric acid concentration, liquid to solid ratio of 32:1, reaction time 30min. Under this condition, the rice husk was 32.09% in the conversion of cellulose.Thirdly, on this basis, it is through the instrument of rice husk residue on the response to a comparative analysis of raw materials, firstly by scanning electron microscopy (SEM) morphology of the hydrolysis residues were compared, and combined with X-ray diffraction (XRD) and thermal gravimetric analysis, and the rice husk with before and after reaction by the change were discussed, it is in order to reveal the rice husk hydrolysis to provide the basis for the mechanism with the extremtly low acid.Finally, it is the mechanism of hydrolysis of the liquid phase experimental analysis, it obtained under the conditions of rice husk of the model about liquid from the solid phase with extremtly low acid.
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