High silicon Y-type zeolite containing rare-earth and its preparing method

Abstract

A rare-earth-containing high-silicon Y-type zeolite, the zeolite contains rare earths, is characterized in that the silicon-aluminum ratio of the zeolite is 5-30, the initial unit cell constant is 2.430-2.465 nanometers, and the balance unit cell constant and the initial unit cell constant The ratio is at least 0.985. The zeolite has the characteristics of small initial unit cell constant and large equilibrium unit cell constant. It has high structural stability and hydrothermal stability. The cracking catalyst containing this zeolite is not easy to deactivate. The choice of gasoline, diesel oil, dry gas and coke Good sex.

Description

technical field [0001] The present invention relates to a Y-type zeolite and a preparation method thereof, and more particularly relates to a rare earth-containing high-silicon Y-type zeolite and a preparation method thereof. Background technique [0002] Since US3293192 proposed the hydrothermal dealumination method to prepare high-silicon Y-type zeolite, the preparation of high-silicon Y-type zeolite by hydrothermal method has been widely used. US3,442,715 discloses dealuminated Y zeolite (DAY), US3,449,070 discloses ultrastable Y zeolite (USY), US4,51,694 and US4,401,556 disclose ultrastable hydrophobic Y zeolite and so on. [0003] Introducing rare earths into high-silicon Y-type zeolite to prepare rare-earth-containing high-silicon Y-type zeolite is a way to improve the activity and hydrothermal stability of high-silicon Y-type zeolite. [0004] Rare earth-containing high-silicon Y-type zeolite can be prepared by subjecting NaY zeolite to s...

AI Technical Summary

Problems solved by technology

The formation of a large number of dense lumps makes the contact between silicon tetrachloride gas and zeolite solid extremely uneven. Less contact, or even contact with silicon tetrachloride gas, also makes the hydrothermal stability of the rare earth-containing high-silicon Y-type zeolite product not good, and the initial unit cell is not easy to shrink, and the equilibrium unit cell constant is low Shortcomings

The formation of a large number of dense lumps also causes the formed lumps to stick to the walls of the reactor causing product loss and the need to clean the walls

[0008] Moreover, the method for preparing high-silicon Y-type zeolite by adopting the existing gas-phase extraction of aluminum and supplementing silicon, the zeolite solid particles in the zeolite solid particle bed layer are static and cannot move, and the mass transfer and heat transfer properties of the zeolite solid particles are relatively poor, while The process of gas-phase extraction of aluminum and silicon supplementation is an exothermic reaction, the heat is not easy to spread rapidly, and it is easy to produce local overheating, resulting in a large reaction temperature gradient in the fixed bed, making the reaction between zeolite solid particles and silicon tetrachloride gas uneven , which also makes the hydrothermal stability of the obtained rare earth-containing high-silicon Y-type zeolite product not good

[0009] In addition, the high silicon Y-type zeolite is prepared by using the existing method of gas-phase extraction of aluminum to supplement silicon. Since the zeolite solid particles are a static fixed bed, fillers must be filled at both ends, which causes the inconvenience of disassembling the zeolite solid particles. , it is also necessary to separate the zeolite solid particles from the filler, which is not only labor-intensive, but also the transportation of zeolite solid particles and unloading from the reaction equipment is not easy to automate

And because zeolite is an ultrafine powder, when the zeolite solid is transported and unloaded from the reaction equipment, it is easy to pollute the environment and damage the health of the operators.

[0010] It is also because the zeolite solid particles in the existing gas-phase extraction method for aluminum supplementation is a static fixed bed, and the gas that reacts with the zeolite solid particles must be a flowing gas that carries silicon tetrachloride. Another disadvantage of the silicon method is that the amount of silicon tetrachloride and the gas carrying silicon tetrachloride and the waste gas generated by the reaction is very large.

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