The Doping Of Perovskite Catalyst And Its Catalytic Pyrolysis Lignin To Prepare The Oxygenation

In nature,the waste of resources is ubiquitous,lignin is one of the serious situations,a lot of lignin is burned by the most simplest and inefficientest way,not only the utilization is low,but also it has a great impact on the environment,so how to utilise lignin effectively is the key question,it is the only renewable biomass resources that produces aromatic compounds by lignin,therefore,through the chemical method to extract phenolic compounds from lignin and convert the phenolic compounds into the aromatic compounds and it is one of the most effective methods for realizing the high quality and resource using of lignin.Catalyst is the most important in the chemical methods,a efficient catalyst has a great role for promoting the chemical reaction,therefore,in this paper,the main content of research is the bagasse lignin as raw materialas well as using CaCO₃ and SrCO₃ to dope the perovskite catalyst LaTi_0.2Fe_0.8O₃ to prepare a series of La_x Ca_1-x-x Ti_0.2Fe_0.8O₃ and La_x Sr_1-xTi_0.2Fe_0.8O₃ catalyst,then utilising the MIEC oxides catalyst of doping modification to selectively catalytic oxidation lignin to prepare the aromatic base compounds,the lignin and catalyst are characterized through SEM,XRD,FTIR,etc.and analyzed its molecular structure,crystal structure and morphology,and inspecting the influence of temperature,proportion,and the pore structure of catalyst for reaction,and finally characterizing analysis and testing the liquid products by GC-MS,the catalytic pyrolysis of lignin is carried out by fixed bed reactor,and the performance of catalyst is evaluated.the results show that:（1）LaTi_0.2Fe_0.8O₃ catalytic lignin under 600℃,add 300 orders graphite with a theoretical value of 0.0500 g,and its catalytic cracking effect is best,out of the liquid products is faster and more.（2）The prepared composite oxide catalyst has a good perovskite phase,which is obtained by XRD.the peaks of La_0.2Sr_0.8Ti_0.2Fe_0.8O₃,La_0.8Ca_0.2Ti_0.2Fe_0.8O₃ are the best,and the crystal structure of La_0.2Sr_0.8Ti_0.2Fe_0.8O₃ and La_0.8Ca_0.2Ti_0.2Fe_0.8O₃ is the most stable,and the catalytic effect will be the best.（3）the SEM showed that granules of the composite oxide La_0.2Sr_0.8Ti_0.2Fe_0.8O₃and La_0.8Ca_0.2Ti_0.2Fe_0.8O₃ is complete,and there is almost no reunion,the surface area is relatively larger and suitable for the occurrence of catalytic reaction.（4）in the process of catalyst for catalytic oxidation lignin,the best portion of reaction is 3:1 and the reaction temperature is 600℃,under the optimum reaction conditions,the gas phase products,liquid phase products and solid phase products are respectly 0.6613 g,0.9594 g and 1.8651 g,the yield of liquid products is 27.94%,a total of six categories products,they are respectly benzene,phenol,base class guaiac wood,lilacs base class,phenyl alkyl ether,catechol classes.（5）added graphite as the Pore-forming agent in the compound oxides of La_xSr_1-x-x Ti_0.2Fe_0.8O₃ and La_x Ca_1-xTi_0.2Fe_0.8O₃ series.in the case of La_xSr_1-x-x Ti_0.2Fe_0.8O₃,when X=0.4 and the temperature is 311.7℃,the effect of adding graphite of 300 orders is the best,while in the case of La_xCa_1-xTi_0.2Fe_0.8O₃,when X=0.2 and temperature is 474.3℃,the effect of adding graphite of 500 orders is optimal.（6）after the reaction,the morphology and crystal shape of the catalyst do not change significantly,indicating that the catalyst has good activity and stability.