阅读说明：本技术 用于溶液聚合方法的金属茂催化剂进料系统 (Metallocene catalyst feed system for solution polymerization process ) 是由 V·R·埃斯瓦兰 J·L·雷米尔斯 K·C·加洛维 于 2019-01-22 设计创作，主要内容包括：用于溶液聚合的方法和系统。所述方法可以包括形成基本上由至少一种催化剂和工艺溶剂组成的第一混合物料流,和形成基本上由至少一种活化剂和工艺溶剂组成的第二混合物料流。可以将所述第一混合物料流和所述第二混合物料流分别地供给至少一个包含一种或多种溶解在所述工艺溶剂中的单体的反应区,其中可以在所述至少一个反应区内在所述催化剂、活化剂和工艺溶剂的存在下使所述至少一种单体聚合制备聚合物产物。(Methods and systems for solution polymerization. The method may include forming a first mixture stream consisting essentially of at least one catalyst and a process solvent, and forming a second mixture stream consisting essentially of at least one activator and a process solvent. The first mixture stream and the second mixture stream may be separately fed to at least one reaction zone comprising one or more monomers dissolved in the process solvent, wherein the at least one monomer may be polymerized in the presence of the catalyst, activator, and process solvent within the at least one reaction zone to produce a polymer product.)

1. A process for solution polymerization comprising:

forming a first mixture stream consisting essentially of at least one catalyst and a process solvent;

forming a second mixture stream consisting essentially of at least one activator and a process solvent;

separately supplying the first mixture stream and the second mixture stream to at least one reaction zone comprising one or more monomers dissolved in the process solvent;

polymerizing said at least one monomer in the presence of said catalyst, activator and process solvent in said at least one reaction zone; and

recovering the polymer.

2. The process of claim 1, wherein the first mixture stream consists essentially of the at least one catalyst, the process solvent, and one or more olefins.

3. The process of any of the preceding claims, wherein the second mixture stream consists essentially of the at least one activator, the process solvent, and one or more olefins.

4. The process of claim 1, wherein only one of the first mixture stream and the second mixture stream, but not both streams, further comprises one or more olefins.

5. The process of any of the preceding claims, wherein the reaction zone comprises at least one spiral heat exchanger disposed therein.

6. The method of any of the above claims, wherein recovering the polymer comprises separating the second effluent stream into a product stream comprising polymer substantially free of solvent and a recycle stream comprising the process solvent and unreacted monomer, wherein the polymer is substantially free of the process solvent.

7. The method of any of the preceding claims, wherein the monomer comprises one or more C₂-C₄₀An olefin.

8. The method of claim 7, wherein the one or more C' s₂-C₄₀The olefin is selected from the group consisting of ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, and dodecene.

9. The method of any of the preceding claims, wherein the polymer comprises polyethylene, polypropylene, or copolymers thereof.

10. The method of any of the preceding claims, wherein the polymer is an ethylene polymer or a propylene polymer, or a copolymer thereof.

11. The method of any of the preceding claims, wherein the polymer comprises one or more C₂-C₂₀A comonomer.

12. The method of claim 11, wherein the one or more C' s₂-C₂₀The comonomer is selected from the group consisting of ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, and dodecene.

13. A process for solution polymerization comprising:

forming a first mixture stream consisting essentially of at least one catalyst and a process solvent;

forming a second mixture stream consisting essentially of at least one activator and a process solvent;

separately supplying the first mixture stream and the second mixture stream to at least one reaction zone comprising one or more monomers dissolved in the process solvent;

polymerizing said at least one monomer in the presence of said catalyst, activator and process solvent in said at least one reaction zone to obtain a first effluent stream comprising a solution of polymer dissolved in said process solvent;

cooling the first effluent stream in at least one spiral heat exchanger to produce a second effluent stream, wherein the first effluent stream flows through the at least one spiral heat exchanger in a cross-flow direction relative to the coils of the at least one spiral heat exchanger; and

recovering the polymer.

14. The process of claim 13, wherein recovering said polymer comprises separating said second effluent stream into a product stream comprising polymer substantially free of solvent and a recycle stream comprising said process solvent and unreacted monomer, wherein said polymer is substantially free of said process solvent.

15. The process of claims 13-14, wherein the first mixture stream consists essentially of the at least one catalyst, the process solvent, and the one or more olefins, and wherein the second mixture stream consists essentially of the at least one activator, the process solvent, and the one or more olefins.

16. The process of claims 13-15, wherein only one of the first mixture stream and the second mixture stream, but not both streams, further comprises one or more olefins.

17. The method of claims 13-16, wherein the polymer is an ethylene polymer or a propylene polymer, or blends thereof, and the polymer comprises one or more C's selected from the group consisting of ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, and dodecene₂-C₂₀。

18. A process for solution polymerization comprising:

distributing a reactant feed comprising one or more monomers, a process solvent and optionally one or more comonomers into a first substream, a second substream, a first slipstream and a second slipstream;

forming a first mixture stream consisting essentially of at least one catalyst and the first sub-stream;

forming a second mixture stream consisting essentially of at least one activator and the second sub-stream;

mixing the first mixture stream with the first slip stream;

mixing the second mixture stream with the second slip stream;

feeding the resulting first mixture stream and the resulting second mixture stream separately to at least one reaction zone;

polymerizing at least one monomer and optionally one or more comonomers in the presence of the catalyst, activator and process solvent in the at least one reaction zone; and

the polymer is recovered.

19. The process of claim 18, wherein said first slipstream comprises less than 10 wt% of said first substream, and said second slipstream comprises less than 10 wt% of said second substream.

20. A system for solution polymerization, comprising:

a first inlet disposed on a reactor containing one or more reaction zones therein for injecting a mixture stream consisting essentially of at least one catalyst and a process solvent into at least one of the one or more reaction zones;

a second inlet disposed on the reactor for injecting a second mixture stream consisting essentially of at least one activator and process solvent into at least one of the one or more reaction zones; and

at least one spiral heat exchanger in fluid communication with the reactor, wherein a polymer effluent stream exiting the reactor flows through the at least one spiral heat exchanger in a cross-flow direction relative to the coils of the heat exchanger.

Technical Field

Embodiments described herein relate to olefin polymerization systems and methods. More specifically, embodiments described herein relate to solution polymerization for preparing olefin polymers.

Background

The Tubular Reactor (TR) may be defined as a conduit through which reactants, solvent and product flow while the polymerization reaction is in progress.A tubular reactor may be a loop reactor (L R) in which a portion of the product stream is recycled back to the reactor feed inlet, or a single pass reactor (once-through reactor) without such recycle.

In a loop reactor, the reactor feed is introduced into the recycle stream at a suitable location in the loop and the reactor product is withdrawn at a different location than the recycle stream. The mass ratio of the total recycle stream to the fresh feed stream may be from 0 (to mimic the performance of a Plug Flow Reactor (PFR)) to 15 and above (to mimic the performance of a CFSTR). Commercially practiced ratios are typically in the range of 0.5-10. The recycle ratio may also be expressed as the ratio of the total mass recycled in the loop divided by the mass flow rate of the effluent stream leaving the reactor loop.

When solution polymerization is conducted in a CFSTR, the catalyst and activator may be introduced into the reactor via separate injection nozzles or combined together and injected via a single nozzle. The catalyst and activator are typically dissolved or suspended in a solvent or carrier fluid, such as toluene, isohexane, mineral oil, and the like. Herein, the term "solvent" refers to "carrier fluid" or "mixture of carrier fluids" and may be used interchangeably therewith. The carrier fluid for the catalyst and activator may be the same or different than the carrier fluid for the reactants.

The catalyst and activator are sometimes added in the desired proportions to a suitable carrier fluid or fluid mixture to form a solid powder of a slurry or paste which is then introduced into the reactor. The catalyst and activator may be prepared in the same mixing tank using the same solvent to form a single solution. The catalyst solution may also be prepared separately from the activator solution. For example, the catalyst may be prepared in one solvent and the activator in a different solvent. Different dispersion media, such as mineral oils, or greases, or combinations thereof having a controlled viscosity may be used. The separate catalyst and activator solutions may then be mixed together in a manifold or injected into the reactor via separate nozzles prior to injection into the reactor. The catalyst solution and/or activator solution may be injected as a solution and otherwise as a slurry or dispersion depending on the solvent or dispersion medium desired.

A problem encountered with the above-described techniques is that the catalyst and/or activator flow rate is typically very low. When the catalyst and/or activator is prepared as a slurry or suspension, the insoluble particles tend to settle in the conduit or form small lumps as the concentration changes. Such changes lead to changes in the reaction rate, which is detrimental to the product quality. Particle deposition in tubing or pump assemblies can lead to flow disruptions, which in turn can disrupt production and/or alter product quality.

Accordingly, there remains a need for improved techniques for injecting catalysts and/or activators into solution polymerizations and improved systems for operating such solution polymerizations.

Disclosure of Invention