Method for synthesizing silicon aluminum orthophosphate molecular sieve using white bole

Abstract

The invention relates to a method of molecular sieve catalyst synthesis using the kaolin for the synthesis of silicon aluminum phosphate molecular sieve, belonging to the technical field of the preparation of the catalyst materials. The invention is characterized in utilizing the low-cost kaolin as materials. Through (1) roasting the kaolin in the high temperature to gain the crystal aluminum sources and silicon sources; (2) mixing the kaolin with the phosphorus sources and the template agent with the deionized water, processing hydro-thermal crystallization, and roasting and activating the products after washing and drying, the catalyst of the silicon aluminum phosphate molecular sieve can be gained. The structure of the silicon aluminum phosphate molecular sieve is CHA or the intergrowth of CHA and AEI. The invention has the advantages of smaller or lamellar structure molecular sieve gains of the prepared catalyst, which can be used for the process of making olefin from the oxygenic compounds like the limited diffuse alcohol ether to gain the good activity of reaction and the product selectivity, and further the directly application of the catalyst carried by the kaolin micro sphere into fluidized bed reactor.

Description

technical field [0001] The invention belongs to the technical field of catalyst material preparation, and in particular relates to a method for synthesizing silicoaluminophosphate molecular sieves by using kaolin to synthesize molecular sieve catalysts. Background technique [0002] The silicoaluminophosphate (SAPO) molecular sieve contains [SiO 2 ], [AlO 2 ] and [PO 2 ] Three-dimensional microporous crystal framework structure of corner-sharing tetrahedral units. Among them, the small-pore SAPO-34 molecular sieve is a silicoaluminophosphate molecular sieve developed by the United States Union Carbide Corporation in 1984. The pore channel of its eight-membered ring is only 0.38nm. This molecular sieve has a structure similar to chabazite (CHA), and can be used in Adsorbents, catalysts and catalyst supports, etc. The small pores of SAPO-34 molecular sieve make isobutene and C with larger molecular dynamic diameter 5 The above hydrocarbons cannot pass through, so it has a...

AI Technical Summary

Problems solved by technology

Nano-molecular sieves have a large external area and short and regular channels, which are conducive to the diffusion of target product olefins. Therefore, their reactivity and olefin selectivity are superior to conventional molecular sieves. However, the problem of nano-molecular sieves is poor hydrothermal stability. its further application