Mordenite/SAPO-34 composite molecular sieve amination catalyst and method for preparing same

Abstract

The invention discloses a mordenite / SAPO-34 composite molecular sieve amination catalyst and a method for preparing the same. The amination catalyst comprises the following raw materials by weight percent: 75-90% of mordenite / SAPO-34 composite molecular sieve, 5-15% of titanium oxide, and 5-10% of alumina binder. The mordenite with the ratio of SiO2 to Al2O3 being 20-80 in the mordenite / SAPO-34 composite molecular sieve accounts for 50-80% of the total weight of the mordenite / SAPO-3 composite molecular sieve, and the SAPO-34 molecular sieve accounts for 20-60% of the total weight of the mordenite / SAPO-3composite molecular sieve. The method for preparing the mordenite / SAPO-34 composite molecular sieve amination catalyst comprises the following steps of: mixing an aluminum source, a phosphorus source, a silicon source and a template agent, adding the mordenite, putting the materials in a high-pressure kettle, and crystallizing to obtain the mordenite / SAPO-34 composite molecular sieve, mixing the mordenite / SAPO-34 composite molecular sieve, the titanium oxide and the alumina uniformly, pressing and moulding, and sintering at 450 DEG C for 8 hours to obtain the amination catalyst.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a mordenite / SAPO-34 composite molecular sieve amination catalyst and a preparation method thereof. Background technique [0002] Ethyleneamine is a general term for compounds including ethylenediamine, piperazine, triethylenediamine, aminoethylpiperazine and diethylenetriamine. Usually, ethanolamine and ammonia are used as raw materials to carry out amination reaction to synthesize ethyleneamine in the presence of an amination catalyst. [0003] The preparation of the amination catalyst is generally obtained by modifying a single mordenite or HZSM-5. US Patent (US5731449) discloses a zeolite catalyst treated with alkali solution to synthesize triethylenediamine and piperazine from amides. Soak ZSM-5 with NaOH aqueous solution to convert it into NaZSM-5, and then use NH 4+ The aqueous solution is ion-exchanged and converted into NH 4 ZSM-5, and finally ge...

AI Technical Summary

Problems solved by technology

Due to the low selectivity of the catalyst, more by-products are generated, and the total selectivity is generally lower than 70%.

[0005] In the prior art, the amination reaction raw materials are ethanolamine and liquid ammonia, and the reaction products are ethylenediamine, piperazine, triethylenediamine, aminoethylpiperazine, diethylenetriamine, etc., and the reactants and products are strong Alkaline substances are easy to adsorb and difficult to desorb on various acidic sites of modified zeolite molecular sieve catalysts, and are easy to further react to form various alkaline coking compounds, which block the catalyst pores and cover the active sites of the catalyst, so there is low temperature activity Not high, and the problem of fast coking when the temperature is high

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