Experimental Study On Ligninization Of Magnetic Catalysts In Supercritical Methanol

Resource consumption of fossil fuels should take main responsibility to the global climate. And petrochemical products is the main supply of fossil fuels, it is because of petrochemical products limited that were forced to seek other alternatives. As a sustainable green raw materials,Biomass was used in the production of fuels and fine chemicals which can realize zero discharge of carbon. In order to search for renewable energy, international scholars are developing a series of more innovative chemical process will lignocellulosic biomass into fuel. In this paper, Based on the main composition of lignin biomass, analysis on the preparation of magnetic catalysts and their catalytic hydrogenation liquefaction of lignin in supercritical methanol.In this paper, the Fe3O4 was taked as magnetic carrier, the different Cu2+/M2+ ratio of Fe3O4@CuMAl-LDH (M=Mg、Zn、Ni、Mn) magnetic catalyst precursor was prepared by using the improved coprecipitation. Using X-ray diffractometer (XRD) and scanning electron microscope (SEM) analysis onthe structure characteristics of the preparation of the catalyst precursor.the catalyst precursor was calcined at 450℃ and 4h to obtain Fe3O4@CuO/MO/Al2O3(M= Mg, Zn, Ni, Mn) composite metal oxide catalyst. Study on the effects of the different M and various Cu2+/M2+ ratios catalyst hydrogenation liquefaction of lignin in supercritical methanol, so as to determine the best catalyst for Cu2+/Mn2+ = 1.5 Fe304@Cu0/Mn0/Al203 composite metal oxides. It turned out that the calcined under 450 ℃, the catalyst has excellent catalytic activity and stability, and compared with before roasting the magnetic properties is still quite good performance.Statistical experimental design method research was applied in supercritical methanol Fe3O4 @ CuO/MnO/Al2O3 catalytic liquefaction of lignin. In the study of statistical experimental design method, in view of the reaction temperature, reaction time, catalyst amount, material liquid than four factors to establish the 2k factorial design experiment and explore the factors and the interaction between various factors affect the lignin conversion.Results showed that the effect of lignin conversion is proportional to the relationship between reaction temperature and catalyst content, one of the biggest impact was reaction temperature, but the reaction time interacting with the material liquid is also more prominent.Aiming at the reaction time and material liquid than using response surface design lignin catalytic liquefaction curve model is established;Through the verification, the model has higher accuracy. In the study of statistical experimental design method, Through analysis of statistical of the various factors, lignin conversion can be obtained a maximum of 94.67% at the reaction temperature 360 ℃, catalyst 30 mg, reaction time 137.4 min, and liquid feed ratio 29.1.And make a preliminary analysis on the liquification product of lignin and its model, it is concluded that the origin and mechanism of the formation of different product components.