Rare-earth Y-type zeolite

Abstract

A rare-earth Y-zeolite used for preparing the cracking catalyst of petroleum hydrocarbon has 4-15 wt.% of rare-earth content, 2.45-2.458 nm of crystal cell contstant, 1000-1056 deg.C of differential thermal collapse temp, and 8.3-8.8 of Si / Al ratio. Its advantages are high activity and selectivity to heavy oil and coke, good hydrogen transfer activity, and high output rate of light oil.

Description

technical field [0001] The invention relates to a rare earth Y-type zeolite. Background technique [0002] FCC gasoline is the main component of motor gasoline. At present, FCC gasoline accounts for about 70% of motor gasoline in my country. In recent years, with the further improvement of environmental protection requirements, people's demand for catalytic cracking high-quality clean gasoline with low olefin and low sulfur content is also more urgent. However, the increasingly heavy catalytic cracking raw oil puts forward higher requirements for the catalytic cracking catalyst, that is, it is required not only to have higher activity, better selectivity and hydrogen transfer activity, but also to have higher hydrothermal stability. sex. [0003] Y-type zeolite, as the main active component of catalytic cracking catalyst, has gone through the following stages of development: [0004] NaY zeolite is inactive to acid or catalytic reaction, it is 4 + Exchange Na + After b...

AI Technical Summary

Problems solved by technology

[0007] In summary, although REY and REHY zeolites have high rare earth content, RE in REY 2 o 3 The content of 10-20% by weight, REHY in RE 2 o 3 The content is 6-14% by weight, which has high activity and hydrogen transfer activity, but the unit cell cannot shrink further, and the unit cell constant a 0 =2.468-2.470nm, the hydrothermal stability is poor, and its differential thermal collapse temperature is 900-980°C; on the contrary, USY zeolite has better unit cell shrinkage, a 0 = 2.445-2.450nm, good hydrothermal stability, differential thermal collapse temperature above 1000°C, but it is difficult to exchange rare earths in the crystal, and the content of rare earths is small

Moreover, the unit cells of the above two types of zeolites shrink greatly after aging due to different reasons, and the unit cell constant in the equilibrium state is only 2.425-2.428nm, so the hydrogen transfer activity loses quickly, and it is difficult to meet the requirements of new cracking catalysts for selective hydrogen transfer.

[0008] At present, when preparing the cracking catalyst, the ultra-stable Y zeolite with rare earth ion exchange has to be used, that is, the ultra-stable Y zeolite containing rare earth (REUSY's RE 2 o 3 The content is generally about 3% by weight) and REHY zeolite (RE 2 o 3 The content is generally 6-14% by weight) and REY zeolite (RE) containing high rare earth content 2 o 3 The content is generally 10-20% by weight) are matched with each other and mixed in different proportions. Although the activity level of the catalyst has been improved, REHY and REY itself have poor hydrothermal stability, which will make the thermal and hydrothermal stability of the catalyst Deterioration, the catalyst is easy to deactivate during the operation of the device, which is manifested by low balancer activity and poor coke selectivity

And if the amount of REUSY is increased, the zeolite in the catalyst will be increased from the conventional 30-35% to 40%, or even higher 45%, which will undoubtedly greatly increase the production cost

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