A kind of synthetic method of low-cost sapo-34 molecular sieve

Abstract

The invention discloses a synthesis method of low-cost SAPO-34 molecular sieve, which comprises the following steps: 1) soaking aluminum hydroxide powder in sodium hydroxide solution; 2) soaking the soaked aluminum hydroxide solid phase in sodium citrate , sodium pyrophosphate aqueous solution, then sequentially add sodium carbonate, propylene glycol and β-cyclodextrin in the solution, the solution is heated up to 50-60 ℃ and kept for more than 30min, then filtered and dried; 3) the solid obtained in step 2) Phase and water are added to the orthophosphoric acid solution to obtain a mixture, and the mixture is placed in an autoclave to heat and react to obtain a reaction product; 4) Add a silicon source, an organic amine template agent and water to the reaction product for dynamic crystallization, and cool and filter after the crystallization is completed , washed, dried, and roasted to obtain SAPO‑34 molecular sieves. The preparation method of the present invention is an improvement to the prior art. While improving the catalytic activity of the SAPO-34 molecular sieve MTO reaction, the service life of the molecular sieve is improved. Reduce costs.

Description

technical field [0001] The invention belongs to the technical field of molecular sieves, in particular to a method for synthesizing low-cost SAPO-34 molecular sieves. Background technique [0002] The successful operation of the methanol-to-low-carbon olefins (MTO) industrial plant has promoted the development of my country's "coal instead of oil" energy strategy, and greatly supplemented my country's demand for low-carbon olefins. In recent years, the MTO industry has developed rapidly in our country, and the preparation of catalyst, which is the key technology of MTO, has also developed accordingly. Among them, SAPO-34 molecular sieve has a small and uniform pore size, a large specific surface area, and moderate acidity, and has shown good activity and low-carbon olefin selectivity in the MTO catalytic reaction, becoming the preferred catalyst activity. components. SAPO-34 molecular sieve is one of the representatives of silicoaluminophosphate molecular sieves composed o...

AI Technical Summary

Problems solved by technology

However, these treatment methods have limited improvement on the comprehensive performance of molecular sieves, and in most cases only one aspect of the performance of molecular sieves is considered. For example, the method of improving the catalytic activity of molecular sieves often reduces its service life, resulting in higher use costs of SAPO-34 molecular sieves.

Images