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CN-121990865-A - Norbornene production process

CN121990865ACN 121990865 ACN121990865 ACN 121990865ACN-121990865-A

Abstract

The invention provides a production process of norbornene, which belongs to the technical field of norbornene synthesis, and comprises the steps of feeding dicyclopentadiene solution and ethylene into a first radial tubular reactor for reaction, wherein the reaction temperature is 200-280 ℃, the reaction pressure is 4-10MPa, the residence time of the dicyclopentadiene solution and the ethylene is 0.1-2h, feeding materials into a second radial tubular reactor for reaction, the reaction temperature is 160-260 ℃, the reaction pressure is 4-10MPa, the residence time is 0.1-1h, separating gas from liquid, rectifying and separating to obtain norbornene, and filling inert fillers into the first radial tubular reactor and the second radial tubular reactor. The invention realizes the intensified mixing and mass transfer, shortens the time of the process flow, reduces the process severity, has milder reaction conditions and reduces the operation cost.

Inventors

  • LI JIN
  • LU XU
  • LIU SHI
  • LI WENBING
  • LI CHUANXI
  • ZHU DEZHAO
  • SHAO SHIBO
  • WEI XIAOHUI
  • ZHANG KUNYU

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241108

Claims (10)

  1. 1. A process for producing norbornene, comprising the steps of: s1, feeding dicyclopentadiene solution and ethylene into a first radial tubular reactor for reaction, wherein the reaction temperature is 200-280 ℃, the reaction pressure is 4-10MPa, and the residence time of the dicyclopentadiene solution and the ethylene is 0.1-2h; S2, feeding the materials into a second radial tubular reactor for reaction, wherein the reaction temperature is 160-260 ℃, the reaction pressure is 4-10MPa, and the residence time is 0.1-1h; S3, carrying out gas-liquid separation and rectification separation on the materials to obtain norbornene; wherein inert filler is filled in the first radial tubular reactor and the second radial tubular reactor.
  2. 2. The process according to claim 1, wherein the ratio of the height to the diameter of the first radial tubular reactor to the height to diameter of the second radial tubular reactor is (5-20): 1.
  3. 3. The process according to claim 1, wherein the reaction temperature in S1 is 200-260 ℃, the reaction pressure is 4-8MPa, and the residence time is 0.2-1.8h.
  4. 4. The process according to claim 1, wherein the reaction temperature in S2 is 160-230 ℃, the reaction pressure is 4-8MPa, and the residence time is 0.3-1.5h.
  5. 5. The production process according to claim 1, wherein the inert filler comprises one or more of raschig ring filler, inert porcelain balls, stepped ring filler, corrugated filler, saddle filler.
  6. 6. The process according to any one of claims 2 to 5, wherein the dicyclopentadiene solution comprises dicyclopentadiene in an amount of 10 to 80% by mass, and the balance is an inert solvent.
  7. 7. The process according to claim 6, wherein the inert solvent comprises one or more of an alkane-based inert solvent, a fluoride-based solvent, an ester-based inert solvent, a carbonyl-based solvent, and a chloride-based solvent.
  8. 8. The process according to claim 7, wherein the mass ratio of dicyclopentadiene solution to ethylene is (5-20): 1.
  9. 9. The process according to claim 1, wherein the conditions for the separation by distillation include a reflux ratio of 1 to 10, a column top temperature of 0 to 40 ℃ and a column pressure of normal pressure.
  10. 10. The process of claim 1 further comprising premixing the dicyclopentadiene solution and ethylene prior to feeding the dicyclopentadiene solution to the first radial tubular reactor.

Description

Norbornene production process Technical Field The invention relates to the technical field of norbornene synthesis, in particular to a norbornene production process. Background Norbornene, english name Norbornene, NB for short, chemical name is bicyclo [2.2.1] -2-heptene, molecular formula C7H10, white transparent crystallization at normal temperature, easy sublimation and high combustibility. Norbornene is industrially synthesized from ethylene and cyclopentadiene (cyclopentadiene, CPD) via Diels-Alder reaction. Wherein, CPD mainly comes from dicyclopentadiene (dicyclopentadiene, DCPD) thermal decomposition products separated from C5 fractions which are byproducts in the process of preparing ethylene by naphtha pyrolysis, has abundant sources and low price, and is beneficial to promoting the comprehensive utilization of the C5 fractions. The norbornene product is mainly used for synthesizing the cycloolefin copolymer COC and the cycloolefin polymer COP, and is used for preparing the high-energy liquid fuel in a small amount. Since the efficient synthesis of norbornene is highly dependent on uniform mixing and mass and heat transfer between raw materials, further reaction is sufficient. The prior norbornene synthesis technology has a great deal of designs in the aspects of mixing and enhancing mass and heat transfer, but the defects and the shortcomings of more side reactions and poorer main reaction selectivity still exist. Therefore, how to design a reactor for synthesizing norbornene is very critical to skillfully reduce side reactions and improve the selectivity of main reactions. Chinese patent application CN1284052a proposes a process and a reactor for the production of norbornene, comprising a device for injecting reactants, by dispersing substantially completely liquid DCPD or a liquid DCPD-CPD mixture under the reaction conditions by means of ethylene in the supercritical state, two concentric tubes being used as injection devices for transporting the reactants through the bottom of the reactor, the two concentric tubes extending axially along a portion of the height of the reactor, the DCPD or DCPD-CPD mixture coming from a central tube, the ethylene coming from the annular space between the two concentric tubes, the top of the system constituting a zone of intense mixing of the reactants, the bottom of the reactor constituting a zone of turbulence of the crude norbornene produced, the crude norbornene produced being evolved through the bottom of the reactor. The technology has a general strengthening effect on mass and heat transfer, and ethylene in a supercritical state is required to be dispersed. The Chinese patent application CN102249839A proposes a method for preparing norbornene in a loop reactor, which comprises the steps of firstly carrying out preheating decomposition on dicyclopentadiene in a heat exchanger to partially or completely decompose the dicyclopentadiene into cyclopentadiene, then conveying the cyclopentadiene into a loop reaction, introducing ethylene into the loop reaction to react to obtain the norbornene, wherein the reaction temperature is 180-300 ℃, the outlet pressure is 5-30MPa, the molar ratio of the ethylene to the dicyclopentadiene is 1-20:1, and the circulation ratio is 100-300:1. The Chinese patent application CN105585397A proposes a method for synthesizing vinyl norbornene by using a multi-side line feeding tubular reactor, wherein the multi-side line feeding tubular reactor is divided into a plurality of reaction sections, a feed port is arranged at the front section of each reaction section, the front end of the first reaction section is a main line feed port, and the rest is side line feed ports. Chinese patent application CN105481625A proposes a method for preparing NB from DCPD and ethylene, which uses p-tert-butylcatechol as polymerization inhibitor and methyl isobutyl ketone (MIBK) as solvent, and synthesizes norbornene by a two-pot serial process. In the technical scheme provided by the application, the reaction pressure is 7-11MPa, the molar ratio of ethylene to dicyclopentadiene is 10-50:1, and the residence time of the reactants is distributed widely, so that the polymer is accumulated in the kettle along with the extension of the reaction period. Chinese patent application CN103664470a proposes a method for preparing norbornene, which adopts a process of a first kettle type reactor and a second tubular type reactor, by mixing DCPD, ethylene and solvent in the kettle type reactor, wherein DCPD is partially decomposed into CPD, and then the mixture is introduced into the kettle type reactor for reaction, and finally, norbornene with higher yield and purity is obtained by separation and purification. The patent application utilizes the advantages of the kettle type reactor and the tubular reactor to a certain extent, but does not effectively utilize the reaction of the kettle type reactor, only uses the kettle type reactor as a decomposing device of DCP