Catalytic cracking aid for producing isomerized low-carbon olefins and its preparation method and application

Abstract

The invention relates to a catalytic cracking aid for producing isomeric low-carbon olefins and its preparation method and application. On a dry basis, the catalytic cracking aid for producing isomeric low-carbon olefins, based on the total weight of the catalytic cracking aid, includes: 15 to 45% by weight of alkali-modified ZSM-5 molecular sieve; 1 to 20% by weight % of mesoporous ZSM‑5 molecular sieve; 1 to 10% by weight of beta zeolite; 3 to 25% by weight of P 2 O 5 ; 3 to 25% by weight of inorganic oxides; and the balance clay. The catalytic cracking aid of the present invention that produces high amounts of isomeric low-carbon olefins can promote the shape-selective isomerization cracking reaction of gasoline components above C8 in catalytically cracked gasoline, and can simultaneously increase the yields of propylene, isobutylene and isoamylene, and improve liquefaction. The propylene content in the gas increment (Δpropylene / Δliquefied gas) is increased and high-octane gasoline is co-produced.

Description

technical field [0001] The present invention relates to a catalytic cracking additive capable of producing isomeric low-carbon olefins and its preparation method and application; it is applicable to the catalytic cracking of prolific propylene, isobutene and isopentene in a catalytic cracking process, and belongs to the field of petroleum refining process . Background technique [0002] With the rapid development of the petrochemical industry, the demand for propylene continues to grow. In 2013, the domestic demand for propylene was 17.1 million tons / year, and the output was about 14.6 million tons / year, showing a large gap between supply and demand. There are many technological schemes for producing propylene in the petrochemical process, such as traditional naphtha steam cracking method, metathesis reaction technology of ethylene and butene, butene disproportionation reaction (CN1618512A, CN1618515A), propane dehydrogenation technology (CN1073893A), Methanol to propylene...

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Problems solved by technology

[0020] The reason is that from the analysis of the catalytic cracking reaction principle, the secondary cracking of gasoline mainly occurs to increase the production of light olefins. The above-mentioned existing catalyst / auxiliary technology mainly cracks the C5-C7 components in gasoline, resulting in a large amount of C3-C4 components often generate a large amount of liquefied gas while increasing the production of propylene and butene, resulting in a low propylene content (Δpropylene / Δliquefied gas) in the liquefied gas increment, and sometimes reducing the isotropic gas in C5. Pentene

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