High-pressure polymerization process of ethylenically unsaturated monomers

Patent metadata

Field	Value
Publication number	US-10562986-B2
Application number	US-201716099996-A
Country	US
Kind code	B2
Filing date	May 9, 2017
Priority date	May 10, 2016
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

A process for polymerizing or copolymerizing ethylenically unsaturated monomers at pressures in the range of from 110 MPa to 500 MPa in a production line comprising a continuously operated polymerization reactor, wherein the process comprises monitoring the surrounding of the production line with respect to an occurrence of a leakage of monomers or of reaction mixture by an IR point detector arrangement of at least three groups of IR point detectors which are capable of detecting hydrocarbons and the groups of IR point detectors are operating according to a voting logic and starting automatically an emergency pressure release program when a group of IR point detectors of the IR point detector arrangement detects the presence of hydrocarbons.

First claim

What is claimed is:

1. A process for polymerizing or copolymerizing one or more ethylenically unsaturated monomers at temperatures from 100° C. to 350° C. and pressures in the range of from 110 MPa to 500 MPa in a continuously operated polymerization reactor,
wherein the polymerization is carried out in a production line in which the monomers are brought to the polymerization pressure by one or more compressors in a sequence of compression stages in which the compressed gas mixture is cooled after each compression stage by a compression stage cooler, the compressed monomers are optionally passed through a pre-heater or a pre-cooler and transferred into the polymerization reactor which is optionally cooled by cooling jackets, a reaction mixture obtained by the polymerization is leaving the reactor through a pressure control valve and optionally cooled by a post reactor cooler, the reaction mixture is separated into polymeric and gaseous components in two or more stages, where the gaseous components separated off in a first stage at an absolute pressure of from 15 MPa to 50 MPa are recycled to the one or more compressors via a high-pressure gas recycle line, and the gaseous components separated off in a second stage at an absolute pressure in the range of from 0.1 to 0.5 MPa are recycled to the first stage of the sequence of compression stages via a low-pressure gas recycle line, and the polymeric components obtained by the polymerization are transformed into pellets, the process comprising
monitoring the surrounding of the production line with respect to an occurrence of a leakage of monomers or of reaction mixture by an IR point detector arrangement of at least three groups of IR point detectors which are capable of detecting hydrocarbons and the groups of IR point detectors are operating according to a voting logic, and
starting automatically an emergency pressure release program when a group of IR point detectors of the IR point detector arrangement detects the presence of hydrocarbons.

2. The process of claim 1 , wherein the polymerization reactor and optionally further parts of the production line are installed within a protective enclosure and the area within the protective enclosure is monitored by the IR point detector arrangement or a part of the IR point detector arrangement.

3. The process of claim 1 , wherein the monitoring of the surrounding of the production line is carried out by a combination of the IR point detector arrangement and one or more IR open path detectors which are capable of detecting hydrocarbons, and an emergency pressure release program is automatically started when a group of IR point detectors of the IR point detector arrangement or an IR open path detector detects the presence of hydrocarbons.

4. The process of claim 1 , wherein the IR point detector arrangement is combined with one or more groups of IR open path detectors which are capable of detecting hydrocarbons and the groups of IR open path are operating according to a voting logic, and an emergency pressure release program is automatically started when a group of IR point detectors of the IR point detector arrangement or a group of IR open path detectors detects the presence of hydrocarbons.

5. The process of claim 1 , wherein the IR point detector arrangement is combined with one or more ultrasonic detectors.

6. The process of claim 5 , wherein an emergency pressure release program is automatically started when a group of IR point detectors of the IR point detector arrangement detects the presence of hydrocarbons or an ultrasonic detector detects a gas leak.

7. The process of claim 1 , wherein at least one of the compression stage coolers, the cooling jackets of the polymerization reactor, the post reactor cooler or a cooler within the high-pressure gas recycle line is cooled by a cooling medium and additionally at least one of the cooling media which cool the compression stage coolers, the cooling jackets of the polymerization reactor, the post reactor cooler or the cooler within the high-pressure gas recycle line is monitored with respect to an occurrence of a leakage of monomers or of reaction mixture into the cooling medium.

8. The process of claim 7 , wherein air is passed through the cooling medium, which is monitored with respect to an occurrence of a leakage of monomers or of reaction mixture into the cooling medium, and thereafter conveyed to an IR point detector capable of detecting hydrocarbons.

9. The process of claim 8 , wherein an emergency pressure release program is automatically started when a group of IR point detectors of the IR point detector arrangement or the IR point detector monitoring the air passed through the cooling medium detects the presence of hydrocarbons.

10. The process of claim 1 , wherein at least one of the pre-heater or pre-cooler, the polymerization reactor and the post reactor cooler is composed of tubes of a length from 5 m to 25 m which are flanged together, either directly or via bends, thereby forming flanges between two tubes or between a tube and a bend, and the flanges are covered by a chimney construction, and the air exiting the chimney construction is monitored with respect to the hydrocarbons concentration by one or more IR open path detectors or by an IR point detector which is supplied with air exiting the chimney construction.

11. The process of claim 10 , wherein the polymerization reactor is a tubular reactor or a reactor cascade comprising a tubular reactor and the production line comprises a pre-heater and a post reactor cooler, and the pre-heater, the polymerization reactor and the post reactor cooler are composed of the tubes of a length from 5 m to 25 m which are flanged together, either directly or via bends, and the flanges are covered by a chimney construction, and air is conveyed through the chimney construction, and the air exiting the chimney construction is monitored with respect to the hydrocarbon concentration.

12. The process of claim 10 , wherein an emergency pressure release program is automatically started when a group of IR point detectors of the IR point detector arrangement or an IR open path detector monitoring the air exiting the chimney construction or the IR point detector monitoring the air exiting the chimney construction detects the presence of hydrocarbons.

13. The process of claim 1 , wherein the pressure control valve is installed within a housing and the air within the housing is monitored with respect to the hydrocarbon concentration by an IR point detector which is supplied with air from within the housing by an aspiration line.

14. The process of claim 2 , wherein a water based deluge system is started automatically in parallel with the emergency pressure release program and the water based deluge system provides droplets of a diameter in the range from 25 μm to 20 mm to the area within the protective enclosure when a leakage of monomers or of reaction mixture is detected and the droplets are provided with a minimum flow rate of 10 L/min per m 2 of the area within the protective enclosure.

15. The process of claim 2 , wherein a steam based deluge system is started automatically in parallel with the emergency pressure release program.

16. The process of claim 2 , wherein a water based deluge system and a steam based deluge system are started automatically in parallel with the emergency pressure release program and the water based deluge system provides droplets of a diameter in a range from 25 μm to 20 mm to the area within the protective enclosure when a leakage of monomers or reaction mixture is detected and the droplets are provided w

Assignees

• Basell Polyolefine Gmbh

Inventors

• Gonioukh Andrei
• Herrmann Thomas
• Littmann Dieter
• Finette Andre-Armand
• Wolfram Sven

Classifications

• B01J19/1812

  Tubular reactors · CPC title

• C08F2/01 Primary

  characterised by special features of the polymerisation apparatus used · CPC title

• C08F2/34 Primary

  Polymerisation in gaseous state · CPC title

• B01J2208/00548

  Flow · CPC title

• B01J2208/00539

  Pressure · CPC title