Two-stage process and system for forming high viscosity polyalphaolefins
A final polymer product is formed using a two-stage process and system. In the first stage, a catalyst system is used to polymerize an alpha-olefin monomer to form an effluent. In the second stage, additional alpha-olefin monomer is supplied and is polymerized in the presence of the effluent from the first stage. The second stage produces the final polymer product, which may have a lower molecular weight and viscosity than the polymer formed in the first stage. The final polymer product may be used as a base stock for lubricant compositions.
1. A process for forming a final polymer product comprising:
(a) polymerizing a first olefin monomer in a first reaction zone in the presence of a catalyst system comprising a catalyst to form an effluent comprising a first polymer having a first viscosity and activated catalyst; and
(b) polymerizing a second olefin monomer in a second reaction zone in the presence of the first polymer and the catalyst to form the final polymer product having a second viscosity,
wherein the first polymer has a weight average molecular weight of from 500 to 10,000 and the final polymer product has a weight average molecular weight of from 500 to 8,000 and the final polymer product has a kinematic viscosity at 100° C. of from 20-1000 cSt.
2. The process of claim 1 , further comprising the step of:
(c) directing the first effluent or a portion thereof from the first reaction zone to the second reaction zone.
3. The process of claim 1 , wherein the first olefin monomer and the second olefin monomer comprise alpha-olefin monomers having from 2 to 20 carbon atoms.
4. The process of claim 1 , wherein the first olefin monomer and the second olefin monomer comprise 1-decene.
5. The process of claim 1 , wherein the first olefin monomer is the same as the second olefin monomer.
6. The process of claim 1 , further comprising the step of:
(d) loading a seed composition to the first reaction zone to activate the catalyst.
7. The process of claim 6 , further comprising the step of polymerizing at least a portion of the first polymer in the second reaction zone in the presence of the activated catalyst.
8. The process of claim 1 , wherein the second olefin monomer is only polymerized in the presence of the catalyst system in the effluent without the addition of a separate catalyst system.
9. A process for forming a final polymer product comprising:
(a) polymerizing a first olefin monomer in a first reaction zone in the presence of a catalyst system comprising a catalyst to form an effluent comprising a first polymer having a first viscosity and activated catalyst; and
(b) polymerizing a second olefin monomer in a second reaction zone in the presence of the first polymer and the catalyst to form the final polymer product having a second viscosity,
wherein the first polymer has a weight average molecular weight of from 4,000 to 10,000 and the final polymer product has a weight average molecular weight of from 2,500 to 9,000 and the final polymer product has a kinematic viscosity at 100° C. of from 70 to 140 cSt.
10. The process of claim 1 , wherein the final polymer product has a weight average molecular weight that is at least 50% less than the first polymer.
11. The process of claim 1 , wherein first polymer has a kinematic viscosity at 100° C. of from 20 to 500 cSt.
12. The process of claim 1 , wherein final polymer product has a kinematic viscosity at 100° C. of from 20 to 60 cSt.
13. The process of claim 1 , wherein the final polymer product has a kinematic viscosity at 100° C. of from 70 to 140 cSt.
14. The process of claim 1 , wherein the first viscosity is greater than the second viscosity.
15. The process of claim 1 , wherein the first viscosity is substantially equal to the second viscosity.
16. The process of claim 1 , wherein the molar ratio of the first olefin monomer to the second olefin monomer is from 4:1 to 1:4.
17. The process of claim 1 , wherein the first reaction zone is heated to a first temperature of from 25 to 45° C.
18. The process of claim 1 , wherein the second reaction zone is heated to a second temperature of from 30 to 55° C.
19. The process of claim 1 , wherein the residence time in the first reaction zone is from 1 to 15 hrs.
20. The process of claim 1 , wherein the residence time in the second reaction zone is from 0.25 to 7 hrs.
21. The process of claim 1 , wherein the ratio of the residence time in the first reaction zone to the residence time in the second reaction zone is from 1:4 to 4:1.
22. The process of claim 1 , wherein the catalyst system comprises an alkyl-halide and an alkyl-aluminum.
23. The process of claim 1 , wherein the catalyst system comprises isobutyl bromide and triethylaluminum.
24. The process of claim 1 , wherein the process is a continuous process.
25. The process of claim 9 , further comprising the step of:
(c) directing the first effluent or a portion thereof from the first reaction zone to the second reaction zone.
26. The process of claim 9 , wherein the first olefin monomer and the second olefin monomer comprise alpha-olefin monomers having from 2 to 20 carbon atoms.
27. The process of claim 9 , wherein the first olefin monomer and the second olefin monomer comprise 1-decene.
28. The process of claim 9 , wherein the first olefin monomer is the same as the second olefin monomer.
29. The process of claim 9 , further comprising the step of:
(d) loading a seed composition to the first reaction zone to activate the catalyst.
30. The process of claim 9 , further comprising the step of polymerizing at least a portion of the first polymer in the second reaction zone in the presence of the activated catalyst.
31. The process of claim 9 , wherein the second olefin monomer is only polymerized in the presence of the catalyst system in the effluent without the addition of a separate catalyst system.
32. The process of claim 9 , wherein the catalyst system comprises an alkyl-halide and an alkyl-aluminum.