Claims
- 1. A process for stopping an olefin polymerisation which is carried out in a low pressure gas phase reactor, which process comprises introducing an effective quantity of deactiving agent into the reactor characterised in that the olefin polymerisation is carried out using a chromium oxide catalyst and in that the deactivating agent is selected from the group consisting of oxygen, ammonia, water and carbon monoxide and is introduced over a relatively short period of time.
- 2. A process according to claim 1, characterised in that the quantity of the deactivating agent introduced is from 1 to 10 times the minimum quantity necessary for stopping the olefin polymerisation.
- 3. A process according to claim 2, characterised in that the quantity of the deactivating agent introduced is in the range from 2 to 3 times the minimum quantity necessary for stopping the olefin polymerisation.
- 4. A process according to claim 1, characterised in that the deactivating agent is oxygen and is introduced in a quantity in the range from 2 to 80 g per kilogram of catalyst.
- 5. A process according to claim 1, characterised in that the deactivating agent is water and is introduced in a quantity in the range from 10 to 80 g per kilogram of catalyst.
- 6. A process according to claim 1, characterised in that the deactivating agent is carbon monoxide and is introduced in a quantity in the range from 3 to 130 g per kilogram of catalyst.
- 7. A process according to claim 1, characterised in that the feeding of catalyst into the reactor is discontinued.
- 8. A process according to claim 1, characterised in that the feeding of olefin into the reactor is discontinued.
- 9. A process according to claim 1, characterised in that the introduction of an organometallic compound into the reactor is stopped.
- 10. A process according to claim 1, characterised in that the introduction of the deactivating agent into the reactor is performed over a period shorter than 5 minutes.
- 11. A process according to claim 1, characterised in that the reactor is a fluidised bed reactor.
- 12. A process according to claim 11, characterised in that the catalyst is in the form of a prepolymer.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9010281 |
Aug 1990 |
FRX |
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Parent Case Info
This application is a continuation-in-part of application Ser. No. 07/733,343 filed on Jul. 22, 1991, now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (1)
Number |
Date |
Country |
116917 |
Aug 1984 |
EPX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
733343 |
Jul 1991 |
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