A kind of chemical type hydrocracking catalyst and its preparation method

Abstract

The invention discloses a chemical type hydrocracking catalyst and a preparation method thereof. The chemical type hydrocracking catalyst comprises the following components calculated on the basis of the total weight of the catalyst: 55-85% of a carrier containing a modified Y-molecule sieve and 15-45% of a VIII-group and / or VIB-group metal on the basis of an oxide, wherein the carrier comprises 30-70% by mass of the modified Y-molecule sieve and the balance of amorphous silica-alumina and / or alumina; the specific surface area of the modified Y-molecule sieve is 500-800m<2> / g; the pore volume of the modified Y-molecule sieve is 0.3-0.8ml / g; the secondary pore volume of 2-7nm is greater than 40%, and is generally 50-60%; the infrared acid amount of the modified Y-molecule sieve is 0.5-1.2mmol / g; the content of Na2O is smaller than 0.15% by mass; the mole rataio of SiO2 / Al2O3 is 8-40; the lattice constant is 2.430-2.445; the relative crystallinity is greater than 80%. By adopting the chemical type hydrocracking catalyst, the quality of tail oil and the selectivity of heavy naphtha can be remarkably improved, and the stability of the catalyst can be remarkably improved.

Description

technical field [0001] The invention relates to a chemical type hydrocracking catalyst and a preparation method thereof, in particular to a hydrocracking catalyst rich in mesoporous structure, high silicon and high crystallinity modified Y molecular sieve and a preparation method thereof. Background technique [0002] Hydrocracking technology has the characteristics of strong adaptability to raw materials, great flexibility in production operations and product plans, and good product quality. It can directly convert various heavy and low-quality feedstocks into high-quality jet fuel, diesel, and lubricating oil base materials that are urgently needed by the market. As well as chemical naphtha and tail oil steam cracking raw materials for ethylene production, it has become one of the most important heavy oil deep processing processes in modern oil refining and petrochemical industries, and has been increasingly widely used at home and abroad. Due to the shortage of domestic c...

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Problems solved by technology

[0005] Chinese patent CN96120016.2 discloses a Y-type molecular sieve with high silicon crystallinity and its preparation method. 4 NaY is used as the reaction raw material. First, ammonium hexafluorosilicate is used to dealuminate silicon, then perform hydrothermal treatment, and finally treat with aluminum salt solution. The obtained Y molecular sieve maintains a high degree of crystallinity while being deeply dealuminated. However, The pore volume of the obtained modified Y molecular sieve should be low, which is not conducive to the contact and reaction of macromolecular reactants;

[0006] U.S. Patent No. 4,036,739 discloses a hydrocracking method, which discloses a method for modifying Y-type molecular sieves. At a temperature of 315 to 899 ° C, and at least 0.5 psi water vapor is contacted for a period of time to obtain modified Y The unit cell constant of the molecular sieve is 2.440~2.464nm; the treated Y molecular sieve is subjected to ammonium exchange to obtain an intermediate with a sodium content of less than 1%; then, a modified Y molecular sieve with a unit cell constant less than 2.440nm is obtained. The process is relatively harsh, so that the crystallinity of the obtained modified Y molecular sieve is severely damaged, and the crystallinity is low, which affects its performance

[0007] The existing Y-type molecular sieve modification technology has the problems of dealumination depth, silicon-aluminum ratio, secondary pore volume and crystallinity. When the dealumination depth increases, the silicon-aluminum ratio increases, and the secondary pore structure increases, the crystallinity tend to be more destructive; vice versa

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