Catalyst for selectively producing propene by methanol or dimethyl ether and preparation method thereof

Abstract

The invention relates to a catalyst for selectively producing propene by methanol or dimethyl ether and a preparation method thereof. The catalyst is a compound molecular sieve of SAPO-11 and H-ZSM-5, wherein the mass fraction of the H-ZSM-5 is 18-70 percent. The preparation method is characterized by comprising the following steps of: firstly, dissolving raw material pseudo-boehmite into mixed liquid of dissolvent and phosphate according to a certain mole proportion of Sio2:Al2O3:P2O5:dissolvent: template agent, and stirring for 1-2hat room temperature; secondly, adding raw material silica sol, then stirring for 1-2h at the room temperature , adding a H-ZSM-5 molecular sieve, stirring for 1-2h at the room temperature , adding the template agent and stirring for 1-2h at the room temperature; and thirdly, crystallizing the stirred mixture for 48-72h at the temperature of 170-200 DEG C, filtering, washing and drying a product for 10-12h , then raising the temperature to 500-600 DEG C with the velocity of 2 DEG C / min, and roasting for 4-8h to prepare preparing the propene at constant temperature. By using the catalyst, under the set evaluation condition, the conversion rate of the methanol or the dimethyl ether is 100 percent, the single pass selectivity of the product propene can reach up to 57.6 percent, the ratio of the propene to ethane is 8.73, the product selectivity of C1 is lower than 1.3 percent, the selectivity of C2=-C4= is 80.4 percent, and the catalyst also has favorable stability.

Description

technical field [0001] The invention relates to a catalyst for selectively producing propylene from methanol or dimethyl ether and a preparation method thereof. Background technique [0002] With the rise of crude oil prices, the catalyst and process of methanol to olefins (MTO) from coal / natural gas have been developed rapidly. It is expected to provide a beneficial complement to steam cracking and catalytic cracking to produce olefins routes. A variety of microporous molecular sieves, non-molecular sieves and other catalyst materials have been used in the study of the MTO process, relatively more reported are silicon aluminum molecular sieve (ZSM-5) and silicon aluminum phosphorus molecular sieve (SAPO-34) (M. Microp. Mesop. Mater., 1999, 29, 3-48). When the MTO process of UOP Hydro Company produces ethylene in the maximum amount, the yields of ethylene, propylene, and butene are 46%, 30%, and 9% respectively, and the remaining by-products are 15%. The MTP process of L...

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Problems solved by technology

[0004] One of the purposes of the present invention is to provide a catalyst for the selective production of propylene from methanol or dimethyl ether, which can improve the selectivity of the product propylene and the stability of the catalyst in view of the low selectivity of single-pass propylene in the existing MTO technology;

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