SSZ -13 molecular sieve preparing method

Abstract

The invention discloses a SSZ -13 molecular sieve preparing method comprising the steps of (1) evenly mixing and putting N,N,N- trimethyl adamantane ammonium hydroxide and crystal growth agent into high-pressure reaction kettle, then adding silicon source, aluminium source and water successively into it and obtaining initial gel after mixing; (2) crystallizing the initial gel obtained in step (1) under 155-175oC for 17-72 hours and obtaining crystallized product; (3) centrifugalizing the crystallized product obtained in step (2) to obtain filter cake and filtrate, washing the obtained filter cake by deionized water to pH 7-8, then drying it for 10-13 hours under 100-120oC to obtain the SSZ -13 molecular sieve; the SSZ -13 molecular sieve preparing method in the invention may realize the free modulation for partical size of SSZ -13 molecular sieve from 0. 3-17Mum through adding crystal growth agent; the addition of crystal growth agent in the invention makes more even dispersion of molecular sieve crystal.

Description

technical field [0001] The invention relates to the technical field of molecular sieves, in particular to a preparation method of SSZ-13 molecular sieves. Background technique [0002] SSZ-13 molecular sieve has an ellipsoidal cage with an eight-membered ring structure and a three-dimensional intersecting channel structure, and its specific surface area can reach up to 700m 2 / g, because of its exchangeable cations and surface proton acid centers, it is often used as an adsorbent or catalyst, but the template commonly used in the synthesis of SSZ-13 molecular sieves is N,N,N-trimethyladamantane hydrogen Ammonium oxide SDA is expensive, which seriously restricts its industrialization process. The synthesis cost of SSZ-13 molecular sieve is the main factor restricting the industrial production of SSZ-13 molecular sieve. For molecular sieves, particle size is a very important quality index. Usually, small particle size molecular sieves have relatively high reactivity due to th...

AI Technical Summary

Problems solved by technology

[0003] At present, the main method to reduce the synthesis cost of SSZ-13 molecular sieve is to reduce the use of N,N,N-trimethyladamantyl ammonium hydroxide. The common method is to find a suitable template to replace SDA, such as organic template tetraethyl Ammonium hydroxide can partially or completely replace SDA to synthesize pure phase SSZ-13 molecular sieve, but the SSZ-13 molecular sieve synthesized by this method has poor crystal form and uneven particle size, which seriously affects the catalytic performance of molecular sieve

Images