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CN-122010668-A - Production method of high-purity cyclopentene

CN122010668ACN 122010668 ACN122010668 ACN 122010668ACN-122010668-A

Abstract

The invention provides a production method of high-purity cyclopentene, and belongs to the technical field of olefin production. The invention adopts the method that the crude cyclopentene raw material rich in cyclopentene, cyclopentane and 1, 2-pentadiene is mixed with hydrogen and then introduced into an adiabatic bubbling bed reactor for selective hydrogenation reaction, and the catalyst is modified Pd/Al 2 O 3 . The hydrogenation reaction liquid is subjected to light component removal and refining to obtain a high-purity cyclopentene product with the content of more than 99.9 percent and the content of 1, 2-pentadiene of less than 10ppm, which meets the monomer requirement of producing cyclopentene rubber.

Inventors

  • CHEN FENG

Assignees

  • 铜陵贝斯美科技有限公司

Dates

Publication Date
20260512
Application Date
20260312

Claims (5)

  1. 1. A production method of high-purity cyclopentene is characterized by mixing a crude cyclopentene raw material rich in cyclopentene, cyclopentane and 0.001-0.30% of 1, 2-pentadiene with hydrogen, introducing the mixture into an adiabatic bubbling bed reactor for selective hydrogenation reaction, wherein the molar feed ratio of the hydrogen to diolefin in the raw material is 60-180:1, the volume airspeed is 0.5-3.0 hr -1 , the reaction pressure is 8-15 bar, the reaction temperature is 40-60 ℃, and the hydrogenation reaction liquid is subjected to light removal and refining to obtain a high-purity cyclopentene product.
  2. 2. The method for producing high-purity cyclopentene according to claim 1, wherein the molar feed ratio of hydrogen to diolefin in the material in step 1 is 90-150:1.
  3. 3. The method for producing high-purity cyclopentene according to claim 2, wherein in step 1, the volume space velocity is 1.0 to 2.0hr -1 , the reaction pressure is 10 to 12 bar, and the reaction temperature is 50 to 55 ℃.
  4. 4. The method for producing high-purity cyclopentene according to claim 1, wherein the catalyst for the selective hydrogenation reaction is Pd/Al 2 O 3 , pd is an active component, al 2 O 3 is a carrier, and the Pd loading amount is 0.30-0.35%.
  5. 5. The method for producing high purity cyclopentene according to claim 4, wherein Pd/Al 2 O 3 catalyst is added with rare earth oxide for acid-base fine adjustment.

Description

Production method of high-purity cyclopentene Technical Field The invention relates to the technical field of cyclopentene production, in particular to a production method of high-purity cyclopentene. Background Cyclopentene (hereinafter referred to as CPE) is an important intermediate for fine chemical products, and can be used as a raw material for producing high-added-value medicines and perfume intermediates such as cyclopentanol, cyclopentanone, bromopentane, chlorocyclopentane, cyclopentanoic acid and the like, and also as an important monomer for polycycloolefin high-molecular polymers and a raw material for producing special electronic chemicals. Cyclopentene is mainly present in the carbon five fraction of catalytic cracking gasoline or the carbon five fraction of ethylene byproduct produced by naphtha cracking, and because the carbon five materials contain a plurality of compounds with very similar boiling points, high-purity cyclopentene products with the content of more than 99.9% cannot be produced by adopting a conventional rectification method. The current alternative method is to depolymerize dicyclopentadiene (hereinafter referred to as DCPD) to cyclopentadiene (hereinafter referred to as CPD), and then obtain cyclopentene by selective hydrogenation and rectification. In general, with suitable hydrogenation catalysts and process conditions, the cyclopentadiene conversion during hydrogenation can reach about 99.5% and the cyclopentene selectivity about 97%. There is a small amount of cyclopentadiene, cyclopentene and a small amount of cyclopentane which is the serial hydrogenation product remaining in the hydrogenation product. Since the boiling points of cyclopentadiene, cyclopentene and cyclopentane are very close, 41.50 ℃, 44.23 ℃ and 49.25 ℃ respectively, the difficulty of obtaining high-purity cyclopentene products by rectification is great. U.S. patent No. 6153804a describes a process for producing cyclopentane or (and) cyclopentene from a partially hydrocracked gasoline by fractional distillation. The scheme is that a low boiling point carbon five fraction is firstly extracted from the top of a first rectifying tower, a heavy component containing six carbons or more is extracted from the tower bottom, a fraction containing at least 40% of cyclopentane and cyclopentene is extracted from the side line and is sent to a hydrogenation reactor to convert olefin into alkane, the hydrogenation product is sent to a second rectifying tower, a mixture of n-pentane and isopentane is separated from the top of the tower, and the tower bottom liquid is sent to a third rectifying tower to obtain cyclopentane, or the fraction containing at least 40% of cyclopentane and cyclopentene is directly subjected to rectification separation to obtain cyclopentene and cyclopentane. U.S. patent No. 6264799B1 proposes a process for producing cyclopentane or (and) cyclopentene. The scheme is that the hydrogenated carbon five fraction is rectified in a first rectifying tower, the carbon five fraction with low boiling point is separated from the top of the tower, the tower bottom fraction is sent to a second rectifying tower, and cyclopentene is separated from the top of the tower. The method mainly obtains cyclopentene through selective hydrogenation and rectification separation processes, but the separation of mono-olefin with the boiling point very close to that of cyclopentene is involved, so that the energy consumption is high, the content of the obtained cyclopentene is only about 99.5%, the downstream chemical utilization is affected, and particularly the requirement that the monomer content of the polycyclopentene rubber is more than 99.9% and the content of 1, 2-pentadiene is less than 10ppm can not be met. Cyclopentene having a content of 99.9% or more and 1, 2-pentadiene of 10ppm or less is a key monomer for producing cyclopentene rubber, and more than 10ppm of 1, 2-pentadiene in cyclopentene leads to rapid deactivation of the polymerization catalyst. The cyclopentene rubber is a novel elastomer having a "linear structure" and a "all-terminal modification", and has a linear structure, a low glass transition temperature of about-110 ℃, excellent flexibility even at low temperatures, and an improved affinity with silica and carbon black due to all-terminal modification, so that the cyclopentene rubber has overwhelmingly low fuel consumption, and further exhibits a low temperature characteristic more excellent than conventional rubber in low temperature characteristic evaluation at-40 ℃, and the cyclopentene rubber can be reconverted into cyclopentene by a closed loop process of catalytic depolymerization, and the recovery rate exceeds 90%. Disclosure of Invention Aiming at the technical problem that the existing cyclopentene production process cannot meet the purity requirement, the invention provides a production method of high-purity cyclopentene, which takes crude cyclopentene as a raw material, and the c