Method for preparing cyclopentadiene through continuous depolymerization and rectification

A technology for cyclopentadiene and dicyclopentadiene, which is applied in the field of preparing high-purity cyclopentadiene by a liquid-phase indirect continuous depolymerization method, can solve the problems of difficult recovery of inert diluent heat-conducting oil, hindered equipment operation, etc. Low, easy-to-control, simple-to-equip effect

Inactive Publication Date: 2012-02-01
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Foreign patent (WO0236529A1) report, SAMAUNG company adopts liquid phase indirect depolymerization method, produces cyclopentadiene, depolymerization temperature 180~210 ℃, depolymerization rate 90%, adopts single polymerization inhibitor, but inert diluent (carrier heat conduction Oil) recovery is more difficult
At present, the liquid-phase indirect thermal depolymerization method mainly has coking or high polymers produced by olefin polymerization are brought into the carrier heat transfer oil, which hinders the long-term operation of the equipment.

Method used

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  • Method for preparing cyclopentadiene through continuous depolymerization and rectification

Examples

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Effect test

Embodiment 1

[0019] First, add pure heat transfer oil and composite polymerization inhibitor with a weight ratio of 1:0.005 to the thermal decomposer 2 and rectification reboiler 6, and then pass in nitrogen to replace the air in the system, heat the heat transfer oil to 270°C, and then pass the metering The pump adds crude dicyclopentadiene (83.5% by mass) from the bottom of the thermal decomposer to the thermal decomposer, contacts with high-temperature heat transfer oil, and controls the feed rate so that it stays in the thermal decomposer for 2.0S, dicyclopentadiene Diene gasification, depolymerized cyclopentadiene enters rectification column 3 for rectification, and the high-purity cyclopentadiene separated from the top of the tower enters collector 5 through condenser 4 (preserved at low temperature), and a small amount of uncracked cyclopentadiene Dicyclopentadiene and by-products are heated in the bottom reboiler 6 and rectified again. The composite inhibitor is a compound of hydro...

Embodiment 2

[0022] First, add pure heat transfer oil and composite polymerization inhibitor with a weight ratio of 1:0.008 to the thermal decomposer 2 and rectification reboiler 6, and then pass in nitrogen to replace the air in the system, heat the heat transfer oil to 280°C, and then pass the metering The pump adds crude dicyclopentadiene (83.5% by mass) from the bottom of the thermal decomposer to the thermal decomposer, contacts with high-temperature heat transfer oil, and controls the feed rate so that it stays in the thermal decomposer for 2.0S, dicyclopentadiene Diene gasification, depolymerized cyclopentadiene enters rectification column 3 for rectification, and the high-purity cyclopentadiene separated from the top of the tower enters collector 5 through condenser 4 (preserved at low temperature), and a small amount of uncracked cyclopentadiene Dicyclopentadiene and by-products are heated in the bottom reboiler 6 and rectified again. The complex polymerization inhibitor is a comp...

Embodiment 3

[0025] First, add pure heat transfer oil and composite polymerization inhibitor with a weight ratio of 1:0.01 to the thermal decomposer 2 and rectification reboiler 6, and then pass in nitrogen to replace the air in the system, heat the heat transfer oil to 280°C, and then pass the metering The pump adds crude dicyclopentadiene (92.7% by mass) from the bottom of the thermal decomposer to the thermal decomposer, contacts with high-temperature heat transfer oil, and controls the feed rate so that it stays in the thermal decomposer for 1.5S. Diene gasification, depolymerized cyclopentadiene enters rectification column 3 for rectification, and the high-purity cyclopentadiene separated from the top of the tower enters collector 5 through condenser 4 (preserved at low temperature), and a small amount of uncracked cyclopentadiene Dicyclopentadiene and by-products are heated in the bottom reboiler 6 and rectified again. The complex polymerization inhibitor is a compound of 4-tert-buty...

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Abstract

The invention relates to a method for preparing cyclopentadiene through continuous depolymerization and rectification. The method comprises steps that: under the protection of nitrogen, a composite polymerization inhibitor and pure heat conducting oil are added into a thermal decomposition apparatus according to a weight ratio of 0.005-0.01:1, and are heated to a depolymerization temperature of 270 to 300 DEG C; a crude product dicyclopentadiene is continuously and stably added into the thermal decomposition apparatus, a thermal depolymerization reaction time is 1.5 to 2s, and depolymerized cyclopentadiene is delivered into a rectification tower; cyclopentadiene separated from the tower top is delivered into a collecting device through a condenser; small amounts of dicyclopentadiene which is not decomposed, and by products are heated in a tower-bottom re-boiling apparatus, and are rectified again. According to the method, the composite polymerization inhibitor is a complex of an active immobile polymerization inhibitor, a heat sensitive polymerization inhibitor, and cupric salt, wherein a weight ratio of the three is 1:1:0.5-1. The method provided by the invention has advantages of simple equipment, high production capacity, and low coking. According to the invention, the raw material heat conducting oil and the equipment can be used for a long term.

Description

Technical field: [0001] The invention relates to a method for preparing cyclopentadiene through continuous depolymerization and rectification, and more specifically relates to a method for preparing high-purity cyclopentadiene by using a liquid-phase indirect continuous depolymerization method using polyester-grade dicyclopentadiene as a raw material. Background technique: [0002] Cyclopentadiene (CPD for short) is an important chemical intermediate with a wide range of uses and is a raw material for the synthesis of pesticides, plastics, and rubber. In recent years, the use of cyclopentadiene to hydrogenate cyclopentene to produce cyclopentene, and then to produce glutaraldehyde, cyclopentanone and other fine chemical products has attracted extensive attention from various countries. [0003] As far as the current technology is concerned, the production of cyclopentadiene mainly adopts the thermal depolymerization method of dicyclopentadiene, which is divided into liquid p...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C13/15C07C4/22
Inventor 程延华鲁荆林马明君张成业杨耀辉李丽萍
Owner PETROCHINA CO LTD
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