Method for preparing NaY molecular sieve with high aluminum-silicon ratio

Abstract

The invention relates to a method for preparing a NaY molecular sieve with a high aluminum-silicon ratio, which comprises the following steps of: mixing a silicon source, an aluminum source and deionized water, uniformly mixing two guide agents in different molar ratios, water glass, acidic aluminum salt and sodium aluminate solution in a molar ratio of gel materials to prepare two gels, and crystallizing respectively, wherein the molar ratio of the gel materials is (1.0-6.5)Na2O:Al2O3:(5.0-18)SiO2:(100-280)H2O, and Al2O3 in the guide agents accounts for 0.01 to 15 percent of the total weightof Al2O3; uniformly mixing the two gels in a mass ratio of 1:(0.1-10) to prepare a mixed gel; and crystallizing the prepared mixed gel at the temperature of between 80 and 120 DEG C for 2 to 50 hoursto prepare the NaY molecular sieve. Compared with the prior art, the method has the advantages that: the NaY molecular sieve with the high aluminum-silicon ratio can be prepared in shorter time underthe condition of the same feeding molar ratio.

Description

technical field [0001] The invention relates to a preparation method of NaY molecular sieve with high silicon-aluminum ratio (silicon-aluminum ratio≥6.0). Background technique [0002] Y-type molecular sieve with faujasite crystal structure is the main active component of industrial FCC catalysts. Its crystallinity, silicon-aluminum ratio, pore structure and acid distribution directly affect the cracking activity and selectivity of molecular sieves and the product distribution of cracking reactions. Wait. [0003] In 1972, the United States GRACE company first proposed in the patent USP3,639,099 to use the crystallization directing agent method to synthesize NaY molecular sieves. This method is to first prepare the composition as [0004] (15~17)Na 2 O:Al 2 o 3 :(14~16)SiO 2 :(285~357)H 2 O, the directing agent slurry whose crystal nucleus particle size is generally less than 0.05 microns, and then the directing agent is mixed with water glass, sodium aluminate, acidic...

AI Technical Summary

Problems solved by technology

[0016] In short, although the existing technologies for preparing NaY molecular sieves with high silicon-aluminum ratio can effectively increase the silicon-aluminum ratio of the product, there are problems such as insufficient increase in silicon-aluminum ratio, long crystallization time, complicated process flow, or low utilization rate of silicon sources, etc. Disadvantages, still need further technical progress