A kind of equipment and preparation method for preparing low-sodium high-silicon-aluminum ratio Y-type molecular sieve

Abstract

The invention discloses equipment for preparing Y type molecular sieve with low sodium and a high silica-alumina ratio and a preparation method. The equipment comprises a reactor (1), a first feed passage (2), a discharge passage (4), a second feed channel (3), a mixing device (8), reaction assemblies (7), a heating device (9), a gas-solid separation device (5) and a heat storage device (10), wherein the reactor (1) comprises at least one reaction assembly (7) distributed in the reactor (1) uniformly, and each reaction assembly (7) comprises at least one fluidized bed. When used for preparing the molecular sieve, the equipment has the advantages of short operation process, small sewage amount, low production cost, good reaction controllability, high reaction degree, low sodium content of a product, high silica-alumina ratio, adjustable silica-alumina ratio and uniform product property, causes no ammonia-nitrogen pollution and can perform large-scale continuous automatic operation.

Description

technical field [0001] The invention relates to the technical field of molecular sieve modification, in particular to the technical field of Y-type molecular sieves with low sodium and high silicon-aluminum ratio. Background technique [0002] As we all know, reducing the sodium content and alumina center density of Y-type molecular sieves and increasing the silicon-aluminum ratio are beneficial to improving the chemical stability and hydrothermal stability of molecular sieves, improving the life of catalysts with molecular sieves as active components, and reducing hydrogen transfer. Activity, reduce coke formation. Therefore, how to obtain low-sodium and high-silicon-aluminum ratio Y-type molecular sieves with short process and low emission is very important to improve the stability of molecular sieves and catalyst performance, reduce environmental pollution, and reduce manufacturing costs. [0003] Since NaY molecular sieves do not exhibit acidity, in order to produce sol...

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Problems solved by technology

However, in this method, the concentration of molecular sieve in the reactor is high, the bed density is higher, and the molecular sieve is in a dense phase state with silicon tetrachloride in the pipeline, and the mass transfer and heat transfer effect is poor, which will cause different properties of the product; another On the one hand, the gas phase of the contact reaction is pure silicon tetrachloride gas, which is not diluted by the carrier gas, and the high concentration of silicon tetrachloride directly contacts with the molecular sieve particles, and the strong dealumination and silicon supplementation reaction will greatly damage the crystal form, resulting in molecular sieve The structural collapse is serious, the crystallinity of the product is greatly reduced, and the large amount of heat released is also prone to local overheating; the installation of the rotating device of the inclined tubular reactor and the molecular sieve conveying device in the reactor also increase the equipment manufacturing cost and construction difficulty, and After silicon tetrachloride reacts with lye in the absorption tower, it is directly discharged as wastewater, which will increase the burden of sewage treatment and cause great damage to the environment.

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