Catalyst for synthesizing pyridine using microsphere type high-silicon ZSM-5 molecular sieve as carrier and preparation method thereof

Abstract

The invention provides a pyridine synthesis catalyst which takes microspherical high-silicon ZSM-5 molecular sieve as a carrier and a preparation method thereof. The preparation method adopts hydroxides of silicon source, aluminium source, alkali metal or alkaline earth metal, tetrapropylammonium bromide or tetrapropylammonium hydroxide and water as raw materials for preparing slurry, silicon-aluminum microspheres with the diameter of 30 to 200 um are obtained by spray drying and shaping, then the silicon-aluminum microspheres are arranged in organic amine steam, and the microspherical high-silicon ZSM-5 molecular sieve is obtained by washing, drying and calcination after the hydrothermal synthesis and the crystallization. The microspherical high-silicon ZSM-5 molecular sieve is taken as the carrier, one or more Pb, Sn and Zn elements is / are taken as main agents of active components, VIII family transition elements, IV family transition elements or / and alkaline earth metal elements are taken as auxiliary agents of the active components, wherein, the molar ratio of the total auxiliary agent to the total main agents is 0: 1 to 1: 1, the weight ratio of the active components and the carrier is 0.01 to 0.2; the carrier is impregnated in solution containing active components, and the catalyst of the invention is obtained by drying, calcination and activation, etc. As the synthesis process of the microspherical high-silicon ZSM-5 molecular sieve carrier which is used by the catalyst is shaped, the secondary shaping is unnecessary; at the same time, the catalyst can avoid the impact of a binding agent, thereby having better activity in applications. The yield of pyridine can achieve 77 percent and the total yield of pyridine derivatives can achieve 90 percent under the actionof the catalyst. The catalyst of the invention is especially applicable to the fluidized bed catalytic process.

Description

technical field [0001] The invention relates to a catalyst used in the production of pyridine and a preparation method thereof, in particular to a pyridine synthesis catalyst with a microspherical high-silicon ZSM-5 molecular sieve as a carrier and a preparation method thereof. Background technique [0002] Pyridine and its derivatives are widely used in medicine, pesticide and other fields, as well as rubber industry, surfactant, dye industry and so on. [0003] The early production of pyridine was mainly extracted from the by-products of coal coking. This method has low yield and poor purity of the product. With the continuous increase of demand, people have developed a number of synthetic process routes, such as aldehyde (ketone) ammonia method, unsaturated hydrocarbon method, side chain alkylation method, cyanamide method, etc., wherein aldehyde (ketone) ammonia method The process route is the most mature. Aldehyde (ketone) ammonia method is to produce pyridine and its...

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Problems solved by technology

[0010] The purpose of the present invention is to overcome the problems of low yield and many by-products of existing catalysts, and provide a kind of microspherical high-silicon ZSM-5 molecular sieve that can improve the yield of pyridine and picoline and reduce high-boiling point by-products. Supported Catalysts for Pyridine Synthesis

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