Catalyst for heavy oil catalytic cracking and preparation method thereof

Abstract

The invention discloses a cracking catalyst, which contains 10 to 50 weight percent of Y -shaped molecular sieve containing phosphorus and rare earth, 10 to 40 weight percent of an inorganic oxide adhesive and 10 to 70 weight percent of clay. In the Y-shaped molecular sieve containing the phosphorus and the rare earth, the content of rare earth oxide accounts for 12.0 to 16.0 weight percent, and P2O5 accounts for 0.5 to 7.0 weight percent; in a <31>P MAS NMR spectrum of the molecular sieve, peak areas of resonance signals of between -16 and -12 ppm and between -25 and -21 ppm as chemical displacements account for more than 85 percent of the total peak area; and in a <27> Al MAS NMR spectrum of the molecular sieve, the peak area of a resonance signal of between -2 and 2 ppm as the chemical displacement accounts for more than 20 percent of the total peak area. The Y-shaped molecular sieve containing the phosphorus and the rare earth can be obtained by the following steps: a NaY molecular sieve is contacted with an aqueous solution containing rare earth ions and an aqueous solution containing a phosphorus-aluminum modifying agent, then is subject to hydro-thermal treatment, and finally is contacted with an ammonium salt aqueous solution. The cracking catalyst is used for catalytic cracking reactions, and has strong cracking capability of heavy oil, high yield of gasoline, and strong anti-metallic contamination capability.

Description

technical field [0001] The invention relates to a hydrocarbon oil catalytic cracking catalyst. Background technique [0002] Catalytic cracking process is an important process of lightening heavy oil, and it is one of the main sources of economic benefits of each refinery. Due to limited resources, the feedstock for catalytic cracking has changed from traditional vacuum distillate oil to blended residue or pure residue feed. Residual oil not only contains macromolecular compounds such as colloid and asphaltene that are prone to coke, but also contains more heavy metals (such as nickel, vanadium, etc.). In the cracking reaction, metals such as nickel and vanadium are deposited on the catalyst, resulting in a decrease in catalyst activity. Especially for vanadium, vanadium in a high oxidation state has strong mobility in high-temperature hydrothermal environment, which seriously damages the structure of the active component molecular sieve in the catalyst, resulting in irrev...

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Problems solved by technology

[0022] The above patent documents have improved the utilization rate of rare earths by precipitating rare earths, but the unit cell constant is small after the ultra-stabilization treatment of molecular sieves.

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