Preparation method and application of modified HZSM-5 molecular sieve catalyst

Abstract

The invention provides a preparation method of a modified HZSM-5 molecular sieve catalyst. The method includes the following steps that firstly, a nano aggregate HZSM-5 molecular sieve, pseudo-boehmite, nitric acid, water, methyl cellulose, polyethylene glycol and tween are evenly mixed in the mass ratio of 1:(0.1-0.5):(0.02-0.08):(0.2-0.8):(0.005-0.05):(0.002-0.008):(0.002-0.008), extruded and formed, drying, bar breaking and calcination are conducted, and a catalyst precursor is obtained; secondly, the catalyst precursor is soaked in a mixed solution containing a proper amount of magnesium nitrate and zinc nitrate or a mixed solution containing calcium nitrate and zinc nitrate, dried and calcinated to obtain the modified HZSM-5 molecular sieve catalyst, wherein the massic volume ratio of the catalyst precursor to the mixed solution is 100:(1-5) (g / L). When a catalyst in the method is applied in a reaction for preparing gasoline with methyl alcohol as the raw material or methyl alcohol and naphtha as mixed raw materials, the methyl alcohol conversion rate and the oil product yield can be increased, the content of durene is remarkably reduced, and the octane number of the gasoline is increased. Methyl alcohol and naphtha serve as the raw materials to synthesize the gasoline, the heat exchange process is optimized, and the octane number of naphtha and the gasoline yield are increased.

Description

technical field [0001] The invention belongs to the field of catalyst preparation, and in particular relates to a preparation method and application of a modified HZSM-5 molecular sieve catalyst. Background technique [0002] With the rapid development of the world economy, the human demand for energy is increasing. my country is a country rich in coal, short of gas, and oil-poor. The oil reserves are about 3 billion tons, accounting for only 2.4% of the world's oil volume. . Therefore, at present, most of the oil consumed in my country comes from foreign imports, and the dependence on foreign countries is relatively high. The development of technologies for non-oil resource sources of gasoline is in line with my country's national conditions. Methanol-to-gasoline (MTG) uses coal, synthesis gas, etc. as raw materials to produce high-octane gasoline, and consumes a large amount of methanol in the process, which can not only solve the problem of oversupply of methanol products...

AI Technical Summary

Problems solved by technology

However, durene content is still high and gasoline octane is low

[0007] Finished gasoline generally requires the content of durene to be less than 2%. If the content of durene in gasoline is too high, it will crystallize in the gasifier when the engine is started at low temperature and form precipitates to block the oil circuit, which is not good for the operation of the automobile engine; secondly, its combustion Afterwards, carcinogen benzene will be produced, which will increase carbon dioxide emissions and directly affect human health.

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