Total flare gas recovery system

Patent metadata

Field	Value
Publication number	US-2022357034-A1
Application number	US-202117316138-A
Country	US
Kind code	A1
Filing date	May 10, 2021
Priority date	May 10, 2021
Publication date	Nov 10, 2022
Grant date	—

Abstract

Flare gas is recovered by varying a number of ejector legs that depends on a flare gas flowrate. The ejector legs include ejectors piped in parallel, each ejector has a flare gas inlet and a motive fluid inlet. Flare gas and motive fluid is provided to ejectors by selectively opening or closing valves. The number of ejector legs online is varied to accommodate the amount of flare gas. The controller is also programmed to direct signals to actuators attached to the valves to open or close the valves, or to change the capacity of the ejector legs so they can handle changing flowrates of the flare gas. Included is a flare gas storage system with vessels made with flexible material, when flare gas is evacuated from the vessels, pressure in the vessels is maintained by compressing the vessels with an external force.

First claim

What is claimed is:

1 . A processing facility comprising:
a source of flare gas; a flare gas recovery system; and a flare gas storage system made up of flare gas storage units that each comprise an outer shell made from a flexible material that is supported on a resilient member to define a vessel.

2 . The facility of claim 1 , the flare gas storage units each further comprise a pressure system that is selectively changeable between an extended configuration and a retracted configuration, and when in the extended configuration the vessel is in a compressed configuration.

3 . The facility of claim 2 , wherein the pressure system comprises an arm, a platen mounted on an end of the arm and that is in contact with an end of the vessel, and an actuator that when selectively energized the arm and platen are urged into compressive engagement with the vessel and the vessel and resilient member are reconfigured into a compressed configuration.

4 . The facility of claim 1 , wherein the resilient member comprises a helical spring.

5 . The facility of claim 1 , wherein the flexible material defines a barrier to flare gas and forms a cavity in which flare gas is stored.

6 . The facility of claim 2 , further comprising a pressure sensor in pressure communication with an inside of the vessel and that is in communication with the pressure system.

7 . The facility of claim 6 , wherein the pressure system is controlled based on pressure sensed inside the vessel.

8 . The facility of claim 1 , wherein the flare gas storage units are arranged in parallel, the flare gas storage system further comprising a piping circuit, wherein the flare gas storage units are in selective communication with the source of flare gas through the piping circuit.

9 . The facility of claim 7 , wherein the piping circuit comprises fluid line, fluid leads, and valves in the lines and leads, and wherein the valves are selectively opened and closes to provide communication to the flare gas storage units.

10 . The facility of claim 1 , wherein the flare gas recovery system comprises a piping circuit comprising legs of tubulars piped in parallel that are selectively online, an ejector in each of the legs and where a one of the ejectors has a design flowrate that is approximately equal to an anticipated minimum flowrate of the flare gas, each ejector comprising, a low pressure inlet in selective communication with a source of the flare gas, a high pressure inlet in selective communication with a source of motive fluid, and a mixing portion where flare gas and motive fluid form a combination and a controller system for bringing a quantity of the legs online that have a cumulative capacity that is at least as great as a measured flowrate of the flare gas.

11 . A method of operating a processing facility comprising:
receiving an amount of flare gas from a flare gas source; using a flare gas recovery system to direct the flare gas to a vessel in a flare gas storage system; storing the flare gas in the vessel; and compressing the vessel to remove the flare gas from the vessel.

12 . The method of claim 11 wherein the step of compressing the vessel is controlled based on pressure inside the vessel.

13 . The method of claim 11 , wherein the step of compressing the vessel comprises applying an axial force to an end of the vessel, the method further comprising removing the axial force and allowing the vessel to automatically change from a compressed configuration to an extended configuration.

14 . The method of claim 11 further comprising directing another amount of flare gas into the vessel.

15 . The method of claim 11 , wherein the vessel comprises a first vessel, the method further comprising storing the flare gas in multiple vessels, and wherein the vessels are piped in parallel.

16 . The method of claim 15 , further comprising selectively directing flare gas to less than all of the vessels by maintaining valves in a closed configuration, wherein the valves are in a piping circuit that provides fluid communication to the vessels from the source of the flare gas.

17 . The method of claim 1 further comprising obtaining a flowrate of the flow of flare gas, directing the flow of the flare gas to a piping circuit comprising a plurality of ejector legs piped in parallel, comparing the flowrate of the flow of flare gas with flow capacities of the ejector legs; identifying a particular one or ones of the ejector legs having a cumulative capacity to adequately handle the flow of the flare gas; directing a flow of a motive fluid to the piping circuit to motive fluid inlets of ejectors in the particular one or ones of the ejector legs; and directing the flow of flare gas to suction inlets of the ejectors in the particular one or ones of the ejector legs.

Assignees

• Saudi Arabian Oil Co

Inventors

• Salu Samusideen Adewale
• Soliman Mohamed Ahmed
• Ansari Nisar Ahmad

Classifications

• F23G2207/102

  for pressure · CPC title

• F23G2207/20

  Waste supply · CPC title

• F23G7/08 Primary

  using flares, e.g. in stacks · CPC title

• F23G2900/70601

  Temporary storage means, e.g. buffers for accumulating fumes or gases, between treatment stages · CPC title

• F23G5/50

  Control or safety arrangements · CPC title