A modified molecular sieve for purifying olefins and a method for using it to remove oxygen-containing impurities in olefins

Abstract

The invention provides a modified molecular sieve for purifying olefins and a method for removing oxygen-containing impurities in olefins by using the modified molecular sieve. The modified molecular sieve is modified by metal-organic compounds, and the method includes: the olefin stream containing oxygen-containing impurities such as water, ether, aldehyde, ketone, alcohol, etc. passes through the molecular sieve bed layer modified by metal-organic compounds to obtain high-purity olefin stream. After the molecular sieve bed is saturated, the molecular sieve bed can be regenerated by purging with inert gas under high temperature conditions. The olefins purified by the method of the present invention, especially the isobutene, reach a high-purity standard and can be used in polymerization-level reactions and organic synthesis reactions.

Description

technical field [0001] The invention relates to a modified molecular sieve for purifying olefins and a method for removing oxygen-containing impurities in olefins by using the modified molecular sieve. Background technique [0002] The double bond groups in olefins have good reactivity, and can undergo addition reactions such as hydrogenation, halogenation, hydration, halogenation, hypohalogenation, sulfation, epoxidation, polymerization, etc., and can also be oxidized to cause double bond breaks , generating aldehydes, carboxylic acids, etc. [0003] Olefins are also the main chemical raw materials in industrial production. At present, the widely used bulk olefin chemical raw materials include ethylene, propylene, 1-butene, 2-butene, isobutene, etc. Due to the difference in production process, most olefin products contain Some oxygen-containing compounds, oxygen-containing compounds are mainly some water, ether, alcohol, ketone, aldehyde and other compounds. Although the p...

AI Technical Summary

Problems solved by technology

The above-mentioned patents use rectification to purify olefins, which consumes a lot of energy, and the purity of the obtained olefin products is low, generally below 99.9%. Trace oxygen-containing impurities have an impact on the downstream application of olefins, and often need to be processed through advanced purification processes

[0005] Chinese patent CN103495378A discloses a microsphere adsorbent with kaolin, alumina and submicron molecular sieve as components to remove trace amounts of methanol, dimethyl ether and propionaldehyde in olefin streams. Oxygen-containing impurities in olefins are The component content is treated from 10-200ppm to less than 1ppm. Chinese patent CN102942436A discloses a method for adsorbing trace amounts of methanol, dimethyl ether, MTBE, TBA, and water in isobutylene with molecular sieves modified by metal oxides. Oxygen compounds are reduced from less than 300ppm to 1-10ppm, but there is no mention of the adsorption effect on trace acetone, methyl ethyl ketone, etc.

The disadvantage of the above two patents is that the content of oxygen-containing impurities in the olefin raw material is required to be low, the total amount is below 300ppm, and the types of oxygen-containing impurities are less, and the adsorption effect on acetone, methyl ethyl ketone, etc. mentioned in this patent is not obvious

[0006] At present, the molecular sieve adsorption method can only treat olefins containing a small amount of oxygen-containing impurities, and cannot directly process olefins with a high content of oxygen-containing impurities into polymer-grade olefin monomers (generally, the total amount of oxygen-containing impurities is <30ppm), and it is necessary to seek A high-efficiency method for removing high-content oxygen-containing impurities in olefins, reducing the cost of olefin purification