Selective hydrogenation method of crude isopentene

Abstract

The invention relates to a hydrogenation method of crude isopentene. The method comprises the following step: carrying out hydrogenation reaction on a crude isopentene distillate material through a fixed bed catalyst bed in the presence of a CO-H2 gas mixture. The volume liquid hourly space velocity is controlled at 4.0-12.0 hr<1>, the system pressure is controlled at 0.5-2.0MPa, and the reactant feed temperature is controlled at 30-80 DEG C. In the crude isopentene distillate material, the feed mol ratio of hydrogen to crude isopentene distillate is (1-1.5):1 on the basis of isoprene, and the volume percent of CO in the CO-hydrogen gas mixture is 0.0005-0.0020%. The catalyst is a spherical Pd / Al2O3 supported catalyst of which the particle size is 3-5mm, and the weight percent of Pd in the catalyst is 0.25-0.32%. The hydrogenation process can convert isoprene in the crude isopentene distillate into isopentene and effectively inhibit the isomerization reaction of 1-pentylene on the premise of keeping other hydrogenation conditions unchanged, thereby enhancing the content of the 1-pentylene in the hydrogenated crude isopentene.

Description

Technical field [0001] The present invention relates to a method for selective hydrogenation of crude isoamylene, in particular to the separation of crude isoamylene fractions containing conjugated diolefins in CO and H 2 Pass Pd / Al in the presence of mixed gas 2 O 3 The catalyst bed is hydrogenated to convert isoprene into isoamylene and effectively inhibit the isomerization reaction of 1-pentene. Background technique [0002] In the process of naphtha steam cracking to produce ethylene, a considerable amount of carbon five fractions are by-produced. At present, the most valuable comprehensive utilization of carbon five fractions is to separate and obtain the piperylene and isoprene by physical methods. Olefins and dicyclopentadiene, these three diolefins are widely used in fine chemicals and isoprene rubber fields. The composition of the C5 fraction is quite complicated. In the separation of diolefins, a part of the C5 materials containing C5 monoolefins and alkanes must be sep...

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Problems solved by technology

At present, in addition to the production of isoamylene from the crude isoamylene fraction, 1-pentene, which can be used as a raw material for the production of high-efficiency, low-toxicity, and spectrally active fungicide propiconazole, has not been separated and utilized. The main reason is that in the crude isoamylene During the selective hydrogenation process of the fraction, the hydrogenation of isoprene is accompanied by the hydroisomerization of 1-pentene into trans-2-pentene, so that the crude isopentene fraction after hydrogenation The content of 1-pentene in the medium is significantly reduced, and the energy consumption of separating 1-pentene is too high

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