The Research Of Preparation And Application Of Catalyst For Oil Catalytic Cracking

In this paper,firstly,the synthesis and the application in catalytic cracking of zeolite ZSM-5 are investigated.Secondly,The influences of Alkali treatment in zeolite ZSM-5 is researched.Finally on the basis of experiments,the parameters are optimized,and the reaction mechanism is explored according to the existing theories.The main findings are as follows:(1)Synthesis zeolite ZSM-5 and performance in oil catalytic cracking are investigated.The result shows that the optimization of synthesis is 12h aging time,60h crystallization time,170?crystallization temperature and the result of related catalytic cracking is liquid conversion rate 26.6%,deoxidizing rate 95.7%and acid value 1.24 mgKOH·g-1.According to the analysis of products,products are mainly composed of benzene and benzene homologues,the number of carbon atoms in C6-C10.The benzene,toluene and o-xylene and p-xylene,is 10.02%,20.52%,14.45%and 10.02%respectively.(2)Preparation and performance of hierarchical zeolite ZSM-5 treated by alkali treatment in catalytic cracking oil are researched.The result shows that the optimal alkali concentration is 1.0mol/LNa2CO3,and the alkalescent solution hardly affected the specific surface area,the crystal structure was hardly destroyed,at the same time,the creation of mesopores in the zeolite offers a better platform for reactions,so that the transformation rate of liquid reached 62.36%in 500?.All kinds of alkali treatment zeolite ZSM-5 can play well in 500? and 12.21h-1.It can conclude that the reaction proceed smoothly depend on the crystal structure and specific surface area.And there may be some small differences in reactions among zeolites because of the differences in crystal structure and specific surface area.According to the analysis of products,the product fractionated between room temperature to 100 ? is composed by olefins and aromatics,and product fractionated between 100 ? to 200 ? is composed by aromatic hydrocarbons and aromatic hydrocarbons.(3)The reaction of Jatropha Curcasl oil catalytic cracking is optimized and the reaction mechanism is investigated.The result shows that the optimal catalytic cracking process conditions of temperature is 500?,the quality of the space velocity is 4.54h-1,and transformation rate of liquid is 29.60%,the acid value is 0.71mgKOH·g-1,kinematic viscosity is 0.73 mPa·s,density is 874.4 mg·m-3.According to the analysis of products,the product of general distribution is given priority to with the product of C6-C10,content is the highest for toluene(26.42%),followed by a relatively high content of compound for benzene,ethyl benzene,xylene and o-xylene,respectively 9.62%,7.25%,17.29%and 6.83%of the total.Through analyzing the composition of raw material and product compositions,hydrogen transfer reaction,catalytic cracking reaction and aromatics isomerization reaction were happened,at the same time ester group and carboxyl deoxygenate oxygen changed into CO2 and H2O.Product composition is complicated,giving priority to light hydrocarbon,and contains some product which didn't effected by catalyst.