A preparing method of 2-methyl-2-butene

Abstract

The invention relates to a preparing method of 2-methyl-2-butene. The method comprises following steps of: 1) feeding a raffinate C5 raw material into a first-section fixed-bed reactor, with the middle of the first-section fixed-bed reactor being filled with a ZSM-5 sodium type aluminosilicate crystal molecular sieve, and allowing n-pentene in the raffinate C5 to be isomerized into isopentene; 2) feeding the reaction materials obtained in the step 1) into a second-section fixed bed isomerization reactor and isomerizing 2-methyl-1-butene into 2-methyl-2-butene; 3) feeding the reaction materials in the step 2) into a rectifying tower for rectification, discharging 3-methyl-1-butene, n-pentane, isopentane, a small amount of unreacted 1-pentene, 2-methyl-1-butene, and other components from the tower top, and obtaining unreacted 2-pentene, 2-methyl-2-butene and a small amount of n-pentane and heavy components from the tower bottom; 4) feeding the tower bottom material obtained in the step 3) into a rectifying tower for continuous rectification, obtaining n-pentane and 2-pentene from the tower top, and obtaining 2-methyl-2-butene and a small amount of heavy components from the tower bottom; and 5) feeding the materials discharged from the tower top in the step 4) to a feeding port of a first-section isomerization reactor, mixing with a fresh raffinate C5 raw material, and feeding the mixture to the first-section isomerization reactor. Compared with the prior art, the method has advantages of high reaction yields, good anti-coking performance, long catalyst service lifetime, and the like.

Description

technical field [0001] The invention relates to a method for preparing 2-methyl-2-butene, in particular to the preparation of 2-methyl-2-butene by isomerization in a fixed-bed reactor using n-pentene in the raffinate C5 as raw material Methods. . Background technique [0002] The by-product of oil cracking to ethylene production is a considerable amount of C5 fractions, which account for 10% of the ethylene production. The comprehensive utilization of C5 fractions is an important way to improve the economic benefits of ethylene. At present, the comprehensive utilization of C5 fractions is mainly the separation of C5 fractions to obtain chemical intermediates of isoprene, dicyclopentadiene, piperylene diolefins and isopentene, which are widely used in the fields of polymers and fine chemicals . The residual C5 material from diolefins and isopentene after extraction and separation accounts for about 10% to 15% of the C5 fraction raw material. The five components of raffina...

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Problems solved by technology

Journal of Cataiysis (1999, 187, 202-208) reported that H-ZSM-5 molecular sieve was used as a catalyst, the molar ratio of silicon to aluminum was 59, the reaction temperature was 290°C, WHSV=2kg / (kg.h), and the reaction pressure was 0.5 atmospheres, 1 -Amylene conversion is approximately 100%, isoamylene (the sum of 2-methyl-1-butene and 2-methyl-2-butene) reaction per pass yield is 40%, but the catalyst in the technical scheme shorter lifespan

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