High-silicon ZSM-5 molecular sieve and preparation method and application thereof

Abstract

The invention relates to the field of methanol-to-olefin catalysts, discloses a high-silicon ZSM-5 molecular sieve and a preparation method and application thereof, in particular to a preparation method of the high-silicon ZSM-5 molecular sieve. The preparation method comprises the following steps: mixing a solid silicon source, an aluminum source, a ZSM-5 molecular sieve seed crystal, a template, an alkali, urea and water uniformly in sequence, and carrying out aging and hydro-thermal synthesis crystallization, wherein urea is added in the stage of uniformly mixing the raw materials, the liquid silicon source is SiO2, the aluminum source is Al2O3, and the mixing ratio of the raw materials meets that the molar ratio of the solid silicon source, the aluminum source, the template, the alkali, the urea to the water is 1: (0.001 to 0.01): (0.025 to 0.25): (0.02 to 0.2): (0.3 to 4): (2 to 50), and the weight ratio of the ZSM-5 molecular sieve seed crystal to SiO2 in the solid silicon source is (1 to 10): 100. The invention also relates to the high-silicon ZSM-5 molecular sieve prepared by the invention and application thereof. When the prepared flaky high-silicon ZSM-5 molecular sieve is used for reactions for catalyzing methanol to propylene and / or butane, the selectivity of C3 and / or C4 olefin products is improved.

Description

technical field [0001] The invention relates to the field of molecular sieves used as catalysts for conversion of organic oxygen-containing compounds, such as methanol and / or dimethyl ether to olefins, in particular to a high-silicon ZSM-5 molecular sieve and its preparation method and application. Background technique [0002] Coal or natural gas is used as raw material to synthesize methanol through synthesis gas, and low-carbon olefins can be produced from methanol with high efficiency. A new raw material route has been found for olefin production, which will greatly alleviate the energy crisis caused by oil and natural gas resources. Propylene is an important organic chemical raw material. With the rapid growth of demand for polypropylene and other derivatives, the demand for raw material propylene is also increasing year by year. C4Hs, as the main component of liquefied gas, have been consumed as civil fuels for a long time. The chemical utilization rate of carbon four...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a high-silicon ZSM-5 molecular sieve and its preparation in order to overcome the defects of low single-pot yield, difficult filtration of molecular sieves and low selectivity of methanol-to-olefins catalysts in the preparation process of molecular sieves in the prior art Methods and Applications

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