Effect Of Manufacture Process On Hydrothermal Stability Of FCC Catalyst

Catalytic cracking is an important process of heavy oil conversion to light fractions and the catalytic cracking catalyst is the key factor for the development of FCC process.The microporous surface of FCC catalyst is the site of catalytic cracking reaction;however,the reaction conditions of catalytic cracking in actual production will break the microporous structure.Currently,it is difficult to acquire the characterization of porous material,and there is little study reports on variation characteristics of pore structure and its influence on the reaction performance of catalytic cracking.Thus,it has a very important significance to associate the micropore surface area after the hydrothermal aging of FCC catalyst,with the reaction performance of FCC catalyst.In this paper,through a lot of experiments,the corresponding characterization and performance evaluation,the evaluation conditions to reflect the hydrothermal stability property of micropore structure of the zeolites are figured out,the existing evaluation method of the hydrothermal stability property of catalyst pore structure is verified,lots of influence brought to the pore structure of the finished product by the manufacturing process of zeolites and the process of catalyst components mixing into gel,is investigated.With this,the better understanding of the impact of the various factors is obtained,the conditions of the manufacturing process are optimized and industrial production is carried out.Through the experiments,the conditions when the zeolites structure partially collapses,are identified and taken as the evaluation criterion to reflect the hydrothermal stability property of the zeolites.In the process of zeolites modification,we investigate the influence of various factors on the quality of zeolites during first exchange,the first roasting,and the second exchange.The result shows,if La₂O₃ content in the zeolites is high,Na₂O content is low,the hydrothermal stability of the zeolites is good,and the effect of Na₂O content on the hydrothermal stability of zeolites is bigger than that of La₂O₃.The design experiments show that in the analysis process of the hydrothermal aging treatment of catalyst and sampling of the surface area of catalyst,the location of the aging sample in the aging device and the randomness of sampling have no obvious effect on the analysis of the micropore surface area.By means of orthogonal test the impact of the raw material of catalyst components mixing into gel and the process condition,on the micropore surface area of the catalyst after aging,is investigated and the result shows that the zeolites quality,ratio of matrix and binder,ratio of acid to aluminum,acidification time,temperature ratio and calcinations temperature have the different degree of influence on the hydrothermal stability of FCC catalyst.With those findings,the conditions of optimizing the process of catalyst production are gained and industrial production of FCC catalyst is carried out with the stable hydrothermal quality.