Polymerisation process
Polymerization process for the polymerization of monomer in a polymerization system having at least one component attached thereto which component is flushed with a flush medium which enters the polymerization system. Initially, the component is flushed with a first flush medium, and subsequently the component is flushed with a second flush medium.
1. A process for the polymerisation of monomer in a polymerisation system having at least one component attached thereto which is flushed with a flush medium which enters the polymerisation system, wherein initially said component is flushed with a first flush medium, and subsequently said component is flushed with a second flush medium which second flush medium differs in composition from the first flush medium, the flow of flush medium being used to keep polymer and/or polymer reaction medium away from the component, wherein the polymerisation system is a slurry phase polymerisation system.
2. A process according to claim 1 wherein the at least one component is selected from seals, pressure relief valves, withdrawal lines, inlet lines, and instrument tappings.
3. A process according to claim 2 wherein the instrument tapping is a pressure tapping.
4. A process according to claim 1 wherein there are multiple components attached to the polymerisation system and which are flushed with a flush medium which enters the polymerisation system.
5. A process according to claim 1 wherein downstream recycle lines in the polymerisation system have components which are flushed.
6. A process according to claim 1 wherein downstream degassing steps in the polymerisation system have compressors with seals or filters which are flushed.
7. A process according to claim 1 wherein the at least one component is attached on a polymerisation reactor and is selected from pressure relief valves, withdrawal lines, inlet lines, and instrument tappings.
8. A process according to claim 7 wherein stand-by or unused withdrawal and inlet lines are maintained with a manual or control valve closed and the stagnant zone between the reactor and the valve is flushed.
9. A process according to claim 1 wherein one of the first and second flush mediums comprises an inert medium, and the other comprises one or more non-inert components.
10. A process according to claim 1 wherein the first and second flush mediums are first and second flush gases.
11. A process according to claim 1 which is applied during process start-up, shut-down or a process upset.
12. A process according to claim 1 which is a polymerisation system for polymerisation of an olefin monomer in one or more slurry loop reactors.
13. A process for the polymerisation of monomer in a polymerisation system having at least one component attached thereto which is flushed with a flush medium which enters the polymerisation system, wherein initially said component is flushed with a first flush medium, and subsequently said component is flushed with a second flush medium which second flush medium differs in composition from the first flush medium, the flow of flush medium being used to keep polymer and/or polymer reaction medium away from the component, wherein the at least one component is attached on a polymerisation reactor is selected from pressure relief valves, withdrawal lines, inlet lines, and instrument tappings, and wherein stand-by or unused withdrawal and inlet lines are maintained with a manual or control valve closed and the stagnant zone between the reactor and the valve is flushed.
14. A process according to claim 13 wherein there are multiple components attached to the polymerisation system and which are flushed with a flush medium which enters the polymerisation system.
15. A process according to claim 13 wherein one of the first and second flush mediums comprises an inert medium, and the other comprises one or more non-inert components.
16. A process according to claim 13 wherein the polymerisation system is a gas phase polymerisation system.
17. A process according to claim 16 wherein the polymerisation system is a fluidized bed gas phase polymerisation system.
18. A process according to claim 13 wherein the first and second flush systems are first and second flush gases.
19. A process according to claim 13 which is applied during process start-up, shut-down or a process upset.
20. A process according to claim 13 wherein the polymerisation system is a slurry phase polymerisation system.
21. A process according to claim 20 which is a polymerisation system for polymerisation of an olefin monomer in one or more slurry loop reactors.