System and method for seal flush

Patent metadata

Field	Value
Publication number	US-9776158-B2
Application number	US-201615093304-A
Country	US
Kind code	B2
Filing date	Apr 7, 2016
Priority date	Oct 31, 2012
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

Techniques are provided for seal flush systems. A system may include a reactor circulation pump configured to circulate a slurry through a polymerization reactor. The slurry may include an olefin monomer, a catalyst, and a diluent. The system may also include a catalyst-inhibiting additive system configured to supply a catalyst-inhibiting additive to a seal of the reactor circulation pump and a seal flush system configured to generate a seal flush mixture and supply the seal flush mixture to the seal of the reactor circulation pump.

First claim

What is claimed is:

1. A system, comprising:
one or more automation controllers configured to:
receive a first input indicative of a demand for a catalyst-inhibiting additive;
deliver a first output in response to the first input to adjust a flow of the catalyst-inhibiting additive to be delivered to a seal of a reactor circulation pump;
receive a second input indicative of a demand for a seal flush mixture; and
deliver a second output in response to the second input to adjust a flow of the seal flush mixture to be delivered to the seal of the reactor circulation pump.

2. The system of claim 1 , wherein the one or more automation controllers are configured to:
receive a third input indicative of a demand for a seal flush; and
deliver a third output in response to the third input to adjust a flow of the seal flush to be combined with the catalyst-inhibiting additive to generate the seal flush mixture.

3. The system of claim 2 , wherein the third output comprises a control signal to an actuator of a seal flush control valve, or a control signal to an actuator of a seal flush pump, or any combination thereof.

4. The system of claim 1 , wherein the first output comprises a control signal to an actuator of a catalyst-inhibiting control valve, or a control signal to an actuator of a catalyst-inhibiting pump, or any combination thereof.

5. The system of claim 1 , wherein the second output comprises a control signal to an actuator of a seal flush mixture control valve, or a control signal to an actuator of a seal flush mixture pump, or any combination thereof.

6. The system of claim 1 , wherein the catalyst-inhibiting additive is an antistatic agent, a catalyst poison, a catalyst inhibitor, an electron donor, a stereoregulator, a temper agent, a modifier, an adjuvant, a kill agent, an alcohol, water, or a moderation system chemical, or any combination thereof.

7. The system of claim 1 , wherein first input indicative of the demand for the catalyst-inhibiting additive comprises an actual flow rate of the catalyst-inhibiting additive.

8. The system of claim 7 , wherein the one or more automation controllers are configured to compare the actual flow rate of the catalyst-inhibiting additive to a predetermined flow rate of the catalyst-inhibiting additive, and wherein the one or more automation controllers are configured to deliver the first output based at least on the comparison between the actual flow rate of the catalyst-inhibiting additive and the predetermined flow rate of the catalyst-inhibiting additive.

9. The system of claim 1 , wherein the first input indicative of the demand for the catalyst-inhibiting additive comprises a concentration of the catalyst-inhibiting additive in the seal flush mixture, or a temperature of the seal of the reactor circulation pump, or both.

10. The system of claim 9 , wherein the one or more automation controllers are configured to deliver the first output based at least on the concentration of the catalyst-inhibiting additive in the seal flush mixture, or the temperature of the seal of the reactor circulation pump, or both.

11. A system for generating a polyolefin, comprising:
a polymerization reactor configured to subject an olefin monomer, a catalyst, and a diluent to polymerization conditions to generate the polyolefin;
a reactor circulation pump configured to direct the olefin monomer, the catalyst, and the diluent through the polymerization reactor;
a catalyst-inhibiting additive system configured to supply a catalyst-inhibiting additive to a seal of the reactor circulation pump;
a seal flush system configured to supply a seal flush mixture to the seal of the reactor circulation pump;
one or more automation controllers configured to control the catalyst-inhibiting additive system, or the seal flush system, or both; and
an effluent treatment system downstream from the polymerization reactor and configured to separate particles of the polyolefin from unreacted olefin monomer, unreacted catalyst, and the diluent.

12. The system of claim 11 , wherein the seal flush mixture is configured to reduce a polymerization rate of the olefin monomer while in contact with the seal of the reactor circulation pump.

13. The system of claim 12 , wherein the seal flush system is configured to pass the seal flush mixture over accumulated materials, flush out the accumulated materials, and remove heat from the seal of the reactor circulation pump.

14. The system of claim 11 , wherein the reactor circulation pump comprises an in-line axial flow pump having a propeller disposed within the polymerization reactor.

15. The system of claim 11 , wherein the catalyst-inhibiting additive system and the seal flush system are separate from one another such that a flow of the catalyst-inhibiting additive is independent from a flow of the seal flush mixture.

16. The system of claim 11 , wherein the catalyst-inhibiting additive system comprises a supply line configured to transfer the catalyst-inhibiting additive to a mixture supply line of the seal flush system, wherein the mixture supply line is configured to transfer the seal flush mixture to the seal.

17. A method, comprising:
circulating an olefin monomer, a catalyst, and a diluent through a polymerization reactor using a reactor circulation pump;
subjecting the olefin monomer, the catalyst, and the diluent to polymerization conditions to form particles of polyolefin;
supplying a catalyst-inhibiting additive to a seal of the reactor circulation pump using one or more automation controllers; and
supplying a seal flush mixture to the seal of the reactor circulation pump using the one or more automation controllers.

18. The method of claim 17 , wherein supplying the catalyst-inhibiting additive to the seal of the reactor circulation pump and supplying the seal flush mixture to the seal of the reactor circulation pump comprises mixing the catalyst-inhibiting additive and a seal flush to form the seal flush mixture.

19. The method of claim 17 , comprising extracting reactor effluent from the polymerization reactor, and separating the particles of the polyolefin from the reactor effluent.

20. The method of claim 17 , comprising inhibiting polymerization at the seal of the reactor circulation pump using at least the catalyst-inhibiting additive.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Nguyen Thanh
• Hottovy John D

Classifications

• B01J2219/00252

  Formation of deposits other than coke · CPC title

• C08F2/01

  characterised by special features of the polymerisation apparatus used · CPC title

• F04D29/708

  specially for liquid pumps · CPC title

• B01J19/2455

  provoking a loop type movement of the reactants (tubular loop-type reactors B01J19/2435; loop reactors having moving elements inside B01J19/1868) · CPC title

• B01J2219/00006

  Large-scale industrial plants · CPC title