Purification process for preparing C4 materials for isobutene by C4 linear chain olefin skeleton isomerism

Abstract

The invention relates to a purification process for producing C4 materials in an oil refinery, which comprises the following steps in any order to produce the C4 materials in the oil refinery: a, passing through a fibrous membrane reactor taking alkaline solution as working solution; b, passing through refined desulfurization reactor with a refined desulfurizer; c, passing through a hydrogenationbutadiene removal reactor with a noble metal selective hydrogenation catalyst; d, passing through an arsenic and phosphorus removal reactor with an arsenic and phosphorus removal agent; e, passing through a dechlorinating reactor with a dechlorinating agent; and f, passing through an oxygen-containing and nitrogen-containing compound removal reactor with oxygen-containing and nitrogen-containing compounds. After being purified by the process, the C4 materials etherified in the oil refinery can meet the requirements of the process for producing the isobutene by the butylene isomerism and catalysts.

Description

technical field [0001] The invention relates to a purification technology for low-carbon olefins in the field of petrochemicals, in particular to a purification process for C4 materials produced in Shanshan refineries for isobutene production from straight-chain C4-olefins. Background technique [0002] About 70w% of gasoline in China comes from catalytic cracking (FCC) gasoline, and catalytic gasoline has high sulfur content and low alkane number. Therefore, the current FCC gasoline needs desulfurization and addition of methyl tert-butyl ether (MTBE) to meet high gasoline standards. MTBE) to reduce the sulfur content in gasoline and increase the octane number of gasoline, the production of MTBE is very important to increase the octane number of gasoline in China. Most of the nearly 200 refineries currently have MTBE production units. [0003] The production of MTBE is the etherification of isobutene and methanol under the action of a catalyst to generate MTBE. The isobuten...

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Problems solved by technology

[0007] The existence of propylene, isobutylene, C5 and components above C5 in the C4 raw material will easily deactivate the coke of the heterogeneous catalyst, and the above components will polymerize or crack carbon deposits on the catalyst; Deactivation, so it must be removed before isomerization; sulfur is easily adsorbed on the active center of the isomerization catalyst, causing partial poisoning of the isomerization catalyst, and sulfur is also easy to deactivate the butadiene (BD) hydrogenation catalyst, so the material is required The total sulfur in the medium is less than 1ppm; organic oxides include organic alcohols, ketones, acids, esters, ethers, etc., such as methanol, dimethyl ether, methyl ethyl ketone, tert-butanol, etc., which are easy to poison the regeneration of isomerization catalysts. If the concentration exceeds the standard, the heterogeneous catalyst will be quickly deactivated and the selectivity will be worse, but it can be regenerated; organic nitrogen compounds such as acetonitrile and propionitrile, etc., can permanently poison the heterogeneous catalyst, because the heterogeneous catalyst is a strongly acidic molecular sieve. Alkaline substances are easy to neutralize the acid center of the catalyst; metal compounds and iron, arsenic and lead cause permanent poisoning of the catalyst, iron comes from corrosion in the pipeline reactor, arsenic and lead are brought from the C4 material; halogen, especially chlorine in the raw material Can poison isomerization catalyst regeneration and must also be removed

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