Slurry phase polymerisation process
View Patent ↗A process comprising polymerising in a loop reactor of continuous tubular construction an olefin monomer optionally together with an olefin comonomer in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the internal diameter of at least 50% of the total length of the reactor is at least 700 millimeters and the solids concentration in the reactor is at least 20 volume % is disclosed.
1. A process comprising polymerising in a loop reactor of continuous tubular construction an olefin monomer, optionally together with an olefin comonomer, in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent, wherein the internal diameter of at least 50% of the total length of the reactor is at least 700 millimeters and the solids concentration in the reactor is at least 20 volume % and wherein the process takes place in a reactor system that comprises more than one loop reactor connected in series or in parallel.
2. A process as claimed in claim 1 wherein the solids concentration in the reactor is in the range 25-35 volume %.
3. A process as claimed in claim 1 wherein the internal diameter of at least 50% of the total length of the reactor is over 750 millimeters.
4. A process as claimed in claim 1 wherein the internal diameter of at least 70% of the total length of the reactor is over 700 millimeters.
5. A process as claimed in claim 4 wherein the internal diameter of at least 85% of the total length of the reactor is over 700 millimeters.
6. A process as claimed in claim 1 wherein the Froude number is maintained below 30.
7. A process as claimed in claim 1 for the production of multimodal polymers.
8. A process as claimed in claim 1 comprising at least two reactors in series.
9. A process as claimed in claim 8 in which hydrogen is maintained at between 0-0.1 vol % in at least one reactor in the series to manufacture high molecular weight components and at between 0.5-2.4 vol % in at least one reactor in the series to manufacture low molecular weight components.
10. A process as claimed in claim 1 wherein a polymer of molecular weight less than 50kDaltons is produced.
11. A process as claimed in claim 1 wherein a polymer of molecular weight greater than 200 kDaltons is produced.
12. A process as claimed in claim 9 wherein a polymer of molecular weight less than 50 kDaltons is produced.
13. A process as claimed in claim 9 wherein a polymer of molecular weight greater than 200 kDaltons is produced.
14. A process as claimed in claim 1 wherein the catalyst is a Ziegler catalyst.
15. A process as claimed in claim 1 wherein the catalyst is a metallocene catalyst.
16. A process as claimed in claim 1 wherein the catalyst is an inorganic supported chromium oxide catalyst.
17. A loop reactor of a continuous tubular construction having at least 2 horizontal sections and at least 2 vertical sections wherein the internal diameter of at least 50% of the total length of the reactor is over 750 millimeters and wherein the loop reactor is part of a reactor system that comprises more than one loop reactor connected in series.
18. A loop reactor as claimed in claim 17 wherein the internal diameter of at least 70% of the total length of the reactor is at over 750 millimeters.
19. A loop reactor as claimed in claim 17 wherein the internal diameter of at least 85% of the total length of the reactor is over 750 millimeters.
20. A loop reactor as claimed in claim 17 wherein the ratio of reactor length to internal diameter is less than 500.
21. A loop reactor as claimed in claim 20 wherein the ratio of reactor length to internal diameter is less than 250.
22. A loop reactor as claimed in claim 17 wherein the reactor size is over 20 m 3 .
23. A loop reactor as claimed in claim 22 wherein the reactor size is in the range 100-175 m 3 .