Fluidized bed methods for making polymers

• US 6,759,489 B1
• Filed: 05/20/2003
• Issued: 07/06/2004
• Est. Priority Date: 05/20/2003
• Status: Expired due to Fees

• Current Assignee: Eastern Petrochemical Company Limited
• Original Assignee: Eastern Petrochemical Company Limited
• Inventors: Turkistani, Nabil M.
• Primary Examiner(s): TESKIN, FRED M
• Application Number:
  US10/441,379
• Time in Patent Office: 413 Days
• Field of Search: 526/59, 526/61, 526/67, 526/68, 526/348.5, 526/348.6
• US Class Current: 526/68
• CPC Class Codes: C08F 2/34 Polymerisation in gaseous state
• CPC Class Codes: C08F 210/08 Butenes
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 2500/18 Bulk density

Abstract

The invention relates to continuous gas fluidized bed methods for making a polymer featuring a condensing agent in a recycle stream; and also to methods for monitoring and providing continuity in a gas fluidized bed method for making a polymer featuring a condensing agent in a recycle stream. Certain ranges of Δρ, in some cases combined with certain ranges of values for A_n, can be used to find and define desirable operating states, i.e., the “steady state,” “alert state,” “corrective action state,” “continuity impairment state” and/or “Δρ alarm state,” for the gas fluidized bed reactor polymerization method (where Δρ, A_n and the particular states are disclosed herein).

Claims

1. A continuous gas fluidized bed method for making a polymer featuring a condensing agent in a recycle stream comprising:

continuously passing a gaseous stream comprising monomer and the condensing agent through a fluidized bed in a reaction zone having a controlled reactor bed temperature, a lower fluidized bed density, an upper fluidized bed density and a plurality of measuring site_n temperatures, in the presence of catalyst;

withdrawing from the reaction zone polymer product and a stream comprising unreacted gases;

recycling the stream into the reaction zone with sufficient additional monomer to replace monomer polymerized and withdrawn as polymer product;

cooling the recycle stream to condense a portion thereof and form a liquid-containing mixture having a recycle stream dew point temperature, a reactor inlet temperature and comprising from about 17.5% to about 70% liquid by weight based on the total weight of the cooled recycle stream wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 5°

C.; and

introducing the mixture into the reaction zone wherein the liquid in the mixture is vaporized;

wherein Δ

ρ

satisfies the condition 0 kg/m³≦

Δ

ρ

<

70 kg/m³ and, when Δ

ρ

≧

10 kg/m³, simultaneously, at least a critical number of A_n satisfy the condition 0.25≦

A_n<

0.8; and

wherein Δ

ρ

is equal to the (lower fluidized bed density) minus the (upper fluidized bed density) and $A_n=\frac{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{measuring}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\mathrm{site}}_n<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{inlet}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}.$

2. The continuous gas fluidized bed method of claim 1, wherein the polymer is a polyolefin.

3. The continuous gas fluidized bed method of claim 2, wherein the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

4. The continuous gas fluidized bed method of claim 2, wherein the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

5. The continuous gas fluidized bed method of claim 2, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

6. The continuous gas fluidized bed method of claim 5, wherein the controlled reactor bed temperature is from about 105°

C. to about 110°

C.

7. The continuous gas fluidized bed method of claim 2, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

8. The continuous gas fluidized bed method of claim 7, wherein the controlled reactor bed temperature is from about 80°

C. to about 90°

C.

9. The continuous gas fluidized bed method of claim 2, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

10. The continuous gas fluidized bed method of claim 2, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

11. The continuous gas fluidized bed method of claim 2, wherein the monomer is propylene.

12. The continuous gas fluidized bed method of claim 2, wherein the monomers are propylene and butene-1.

13. The continuous gas fluidized bed method of claim 2, wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 10°

C.

14. The continuous gas fluidized bed method of claim 13, wherein the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

15. The continuous gas fluidized bed method of claim 13, wherein the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

16. The continuous gas fluidized bed method of claim 13, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

17. The continuous gas fluidized bed method of claim 16, wherein the controlled reactor bed temperature is from about 105°

C. to about 110°

C.

18. The continuous gas fluidized bed method of claim 13, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

19. The continuous gas fluidized bed method of claim 18, wherein the controlled reactor bed temperature is from about 80°

C. to about 90°

C.

20. The continuous gas fluidized bed method of claim 13, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

21. The continuous gas fluidized bed method of claim 13, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

22. The continuous gas fluidized bed method of claim 13, wherein the monomer is propylene.

23. The continuous gas fluidized bed method of claim 13, wherein the monomers are propylene and butene-1.

24. The continuous gas fluidized bed method of claim 2, wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 15°

C.

25. The continuous gas fluidized bed method of claim 24, wherein the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

26. The continuous gas fluidized bed method of claim 24, wherein the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

27. The continuous gas fluidized bed method of claim 24, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

28. The continuous gas fluidized bed method of claim 27, wherein the controlled reactor bed temperature is from about 105°

C. to about 110°

C.

29. The continuous gas fluidized bed method of claim 24, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

30. The continuous gas fluidized bed method of claim 29, wherein the controlled reactor bed temperature is from about 80°

C. to about 90°

C.

31. The continuous gas fluidized bed method of claim 24, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

32. The continuous gas fluidized bed method of claim 24, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

33. The continuous gas fluidized bed method of claim 24, wherein the monomer is propylene.

34. The continuous gas fluidized bed method of claim 24, wherein the monomers are propylene and butene-1.

35. A continuous gas fluidized bed method for making a polymer featuring a condensing agent in a recycle stream comprising:

continuously passing a gaseous stream comprising monomer and the condensing agent through a fluidized bed in a reaction zone having a controlled reactor bed temperature, a lower fluidized bed density, an upper fluidized bed density and a plurality of measuring site_n temperatures, in the presence of catalyst;

withdrawing from the reaction zone polymer product and a stream comprising unreacted gases;

recycling the stream into the reaction zone with sufficient additional monomer to replace monomer polymerized and withdrawn as polymer product;

cooling the recycle stream to condense a portion thereof and form a liquid-containing mixture having a recycle stream dew point temperature, a reactor inlet temperature and comprising from about 17.5% to about 70% liquid by weight based on the total weight of the cooled recycle stream wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 5°

C.; and

introducing the mixture into the reaction zone wherein the liquid in the mixture is vaporized;

wherein, simultaneously, Δ

ρ

satisfies the condition 10 kg/m³≦

Δ

ρ

<

30 kg/m³ and at least a critical number of A_n satisfy the condition 0.25≦

A_n<

0.55; and

wherein Δ

ρ

is equal to the (lower fluidized bed density) minus the (upper fluidized bed density) and $A_n=\frac{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{measuring}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\mathrm{site}}_n<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{inlet}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}.$

36. The continuous gas fluidized bed method of claim 35, wherein the polymer is a polyolefin.

37. The continuous gas fluidized bed method of claim 36, wherein the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

38. The continuous gas fluidized bed method of claim 36, wherein the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

39. The continuous gas fluidized bed method of claim 36, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

40. The continuous gas fluidized bed method of claim 36, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

41. The continuous gas fluidized bed method of claim 36, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

42. The continuous gas fluidized bed method of claim 36, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

43. The continuous gas fluidized bed method of claim 36, wherein the monomer is propylene.

44. The continuous gas fluidized bed method of claim 36, wherein the monomers are propylene and butene-1.

45. The continuous gas fluidized bed method of claim 36, wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 10°

C.

46. The continuous gas fluidized bed method of claim 45, wherein the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

47. The continuous gas fluidized bed method of claim 45, wherein the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

48. The continuous gas fluidized bed method of claim 45, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

49. The continuous gas fluidized bed method of claim 45, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

50. The continuous gas fluidized bed method of claim 45, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

51. The continuous gas fluidized bed method of claim 45, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

52. The continuous gas fluidized bed method of claim 45, wherein the monomer is propylene.

53. The continuous gas fluidized bed method of claim 45, wherein the monomers are propylene and butene-1.

54. The continuous gas fluidized bed method of claim 36, wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 15°

C.

55. The continuous gas fluidized bed method of claim 54, wherein the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

56. The continuous gas fluidized bed method of claim 54, wherein the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

57. The continuous gas fluidized bed method of claim 54, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

58. The continuous gas fluidized bed method of claim 54, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

59. The continuous gas fluidized bed method of claim 54, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

60. The continuous gas fluidized bed method of claim 54, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

61. The continuous gas fluidized bed method of claim 54, wherein the monomer is propylene.

62. The continuous gas fluidized bed method of claim 54, wherein the monomers are propylene and butene-1.

63. A continuous gas fluidized bed method for making a polymer featuring a condensing agent in a recycle stream comprising:

continuously passing a gaseous stream comprising monomer and the condensing agent through a fluidized bed in a reaction zone having a controlled reactor bed temperature, a lower fluidized bed density, an upper fluidized bed density and a plurality of measuring site_n temperatures, in the presence of catalyst;

withdrawing from the reaction zone polymer product and a stream comprising unreacted gases;

recycling the stream into the reaction zone with sufficient additional monomer to replace monomer polymerized and withdrawn as polymer product;

cooling the recycle stream to condense a portion thereof and form a liquid-containing mixture having a recycle stream dew point temperature, a reactor inlet temperature and comprising from about 17.5% to about 70% liquid by weight based on the total weight of the cooled recycle stream wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 5°

C.; and

introducing the mixture into the reaction zone wherein the liquid in the mixture is vaporized;

wherein, simultaneously, Δ

ρ

satisfies the condition 30 kg/m³≦

Δ

ρ

<

40 kg/m³ and at least a critical number of A_n satisfy the condition 0.55≦

A_n<

0.6; and

wherein Δ

ρ

is equal to the (lower fluidized bed density) minus the (upper fluidized bed density) and $A_n=\frac{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{measuring}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\mathrm{site}}_n<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{inlet}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}.$

64. The continuous gas fluidized bed method of claim 63, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

65. The continuous gas fluidized bed method of claim 63, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

66. The continuous gas fluidized bed method of claim 63, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

67. The continuous gas fluidized bed method of claim 63, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

68. The continuous gas fluidized bed method of claim 63, wherein the monomer is propylene.

69. The continuous gas fluidized bed method of claim 63, wherein the monomers are propylene and butene-1.

70. A continuous gas fluidized bed method for making a polymer featuring a condensing agent in a recycle stream comprising:

continuously passing a gaseous stream comprising monomer and the condensing agent through a fluidized bed in a reaction zone having a controlled reactor bed temperature, a lower fluidized bed density, an upper fluidized bed density and a plurality of measuring site_n temperatures, in the presence of catalyst;

withdrawing from the reaction zone polymer product and a stream comprising unreacted gases;

recycling the stream into the reaction zone with sufficient additional monomer to replace monomer polymerized and withdrawn as polymer product;

cooling the recycle stream to condense a portion thereof and form a liquid-containing mixture having a recycle stream dew point temperature, a reactor inlet temperature and comprising from about 17.5% to about 70% liquid by weight based on the total weight of the cooled recycle stream wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 5°

C.; and

introducing the mixture into the reaction zone wherein the liquid in the mixture is vaporized;

wherein, simultaneously, Δ

ρ

satisfies the condition 40 kg/m³≦

Δ

ρ

<

50 kg/m³ and at least a critical number of A_n satisfy the condition 0.6≦

A_n<

0.7; and

wherein Δ

ρ

is equal to the (lower fluidized bed density) minus the (upper fluidized bed density) and $A_n=\frac{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{measuring}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\mathrm{site}}_n<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{inlet}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}.$

71. The continuous gas fluidized bed method of claim 70, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

72. The continuous gas fluidized bed method of claim 70, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

73. The continuous gas fluidized bed method of claim 70, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

74. The continuous gas fluidized bed method of claim 70, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

75. The continuous gas fluidized bed method of claim 70, wherein the monomer is propylene.

76. The continuous gas fluidized bed method of claim 70, wherein the monomers are propylene and butene-1.

77. A continuous gas fluidized bed method for making a polymer featuring a condensing agent in a recycle stream comprising:

continuously passing a gaseous stream comprising monomer and the condensing agent through a fluidized bed in a reaction zone having a controlled reactor bed temperature, a lower fluidized bed density, an upper fluidized bed density and a plurality of measuring site_n temperatures, in the presence of catalyst;

withdrawing from the reaction zone polymer product and a stream comprising unreacted gases;

recycling the stream into the reaction zone with sufficient additional monomer to replace monomer polymerized and withdrawn as polymer product;

cooling the recycle stream to condense a portion thereof and form a liquid-containing mixture having a recycle stream dew point temperature, a reactor inlet temperature and comprising from about 17.5% to about 70% liquid by weight based on the total weight of the cooled recycle stream wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 5°

C.; and

introducing the mixture into the reaction zone wherein the liquid in the mixture is vaporized;

wherein, simultaneously, Δ

ρ

satisfies the condition 50 kg/m³≦

Δ

ρ

<

70 kg/m³ and at least a critical number of A_n satisfy the condition 0.7≦

A_n<

0.8; and

wherein Δ

ρ

is equal to the (lower fluidized bed density) minus the (upper fluidized bed density) and $A_n=\frac{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{measuring}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\mathrm{site}}_n<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{inlet}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}.$

78. The continuous gas fluidized bed method of claim 77, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.80% liquid by weight based on the total weight of the cooled recycle stream.

79. The continuous gas fluidized bed method of claim 77, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

80. The continuous gas fluidized bed method of claim 77, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

81. The continuous gas fluidized bed method of claim 77, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

82. The continuous gas fluidized bed method of claim 77, wherein the monomer is propylene.

83. The continuous gas fluidized bed method of claim 77, wherein the monomers are propylene and butene-1.

84. A continuous gas fluidized bed method for making a polymer featuring a condensing agent in a recycle stream comprising:

continuously passing a gaseous stream comprising monomer and the condensing agent through a fluidized bed in a reaction zone having a controlled reactor bed temperature, a lower fluidized bed density, an upper fluidized bed density and a plurality of measuring site_n temperatures, in the presence of catalyst;

withdrawing from the reaction zone polymer product and a stream comprising unreacted gases;

recycling the stream into the reaction zone with sufficient additional monomer to replace monomer polymerized and withdrawn as polymer product;

cooling the recycle stream to condense a portion thereof and form a liquid-containing mixture having a recycle stream dew point temperature, a reactor inlet temperature and comprising from about 17.5% to about 70% liquid by weight based on the total weight of the cooled recycle stream wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 5°

C.; and

introducing the mixture into the reaction zone wherein the liquid in the mixture is vaporized;

wherein Δ

ρ

satisfies the condition 0 kg/m³≦

Δ

ρ

<

10 kg/m³ and wherein Δ

ρ

is equal to the (lower fluidized bed density) minus the (upper fluidized bed density).

85. The continuous gas fluidized bed method of claim 84, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

86. The continuous gas fluidized bed method of claim 84, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

87. The continuous gas fluidized bed method of claim 84, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

88. The continuous gas fluidized bed method of claim 84, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

89. The continuous gas fluidized bed method of claim 84, wherein the monomer is propylene.

90. The continuous gas fluidized bed method of claim 84, wherein the monomers are propylene and butene-1.

91. A continuous gas fluidized bed method for making a polymer featuring a condensing agent in a recycle stream comprising:

continuously passing a gaseous stream comprising monomer and the condensing agent through a fluidized bed in a reaction zone having a controlled reactor bed temperature, a lower fluidized bed density, an upper fluidized bed density and a plurality of measuring site_n temperatures, in the presence of catalyst;

withdrawing from the reaction zone polymer product and a stream comprising unreacted gases;

recycling the stream into the reaction zone with sufficient additional monomer to replace monomer polymerized and withdrawn as polymer product;

cooling the recycle stream to condense a portion thereof and form a liquid-containing mixture having a recycle stream dew point temperature, a reactor inlet temperature and comprising from about 17.5% to about 70% liquid by weight based on the total weight of the cooled recycle stream wherein the difference between the controlled reactor bed temperature and the recycle stream dew point temperature of the mixture is greater than or equal to about 5°

C.; and

introducing the mixture into the reaction zone wherein the liquid in the mixture is vaporized;

wherein, simultaneously, Δ

ρ

satisfies the condition 10 kg/m³≦

Δ

ρ

<

70 kg/m³ and at least a critical number of A_n satisfy the condition 0.25≦

A_n<

0.8; and

wherein Δ

ρ

is equal to the (lower fluidized bed density) minus the (upper fluidized bed density) and $A_n=\frac{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{measuring}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\mathrm{site}}_n<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{inlet}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}.$

92. The continuous gas fluidized bed method of claim 91, wherein the monomer is ethylene, the controlled reactor bed temperature is from about 100°

C. to about 115°

C., and the liquid-containing mixture comprises at least about 21.8% liquid by weight based on the total weight of the cooled recycle stream.

93. The continuous gas fluidized bed method of claim 91, wherein the monomers are ethylene and butene-1, the controlled reactor bed temperature is from about 80°

C. to about 95°

C., and the liquid-containing mixture comprises from about 17.5% to about 40% liquid by weight based on the total weight of the cooled recycle stream.

94. The continuous gas fluidized bed method of claim 91, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 78°

C. to about 90°

C., and the liquid-containing mixture comprises at least about 17.5% liquid by weight based on the total weight of the cooled recycle stream.

95. The continuous gas fluidized bed method of claim 91, wherein the monomers are ethylene and hexene-1, the controlled reactor bed temperature is from about 100°

C. to about 110°

C., and the liquid-containing mixture comprises at least about 20% liquid by weight based on the total weight of the cooled recycle stream.

96. The continuous gas fluidized bed method of claim 91, wherein the monomer is propylene.

97. The continuous gas fluidized bed method of claim 91, wherein the monomers are propylene and butene-1.

98. A method for monitoring and providing continuity in a continuous gas fluidized bed method for making a polymer featuring a condensing agent in a recycle stream comprising:

monitoring the fluidized bed reaction zone, wherein the reaction zone has a controlled reactor bed temperature, a lower fluidized bed density, an upper fluidized bed density and a plurality of measuring site_n temperatures;

monitoring the recycle stream into the reaction zone wherein the stream has a reactor inlet temperature;

determining Δ

ρ and

comparing Δ

ρ

to at least one limit, wherein Δ

ρ

is equal to the (lower fluidized bed density) minus the (upper fluidized bed density); and

when Δ

ρ

≧

10 kg/m³, determining a plurality of A_n and comparing each A_n to a lower value and an upper value, wherein $A_n=\frac{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{measuring}<br><br>\text{\hspace{1em}<br><br>}<br><br>{\mathrm{site}}_n<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}{\left(\mathrm{controlled}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{bed}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)-<br><br>\text{\hspace{1em}<br><br>}<br><br>\left(\mathrm{reactor}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{inlet}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{temperature}\right)}.$

99. The method of claim 98, wherein there are 4 measuring site_n temperatures.

100. The method of claim 98, wherein there are 16 measuring site_n temperatures.