Patent Grant
10514166
Flare stacks are gas combustion devices used in the oil refinery, chemical processing, and natural gas procurement industries for burning off flammable gases released during processing and procurement. During processing and procurement, combustible or natural gases can build up and be routed to a pressure release valve. When the pressure reaches a particular limit, or is otherwise opened via manual control, the gas travels through the piping in the stack to a flame located at the flare tip or the pilot light. Upon contact with the open flame, the gas will flare.
The gases that are flared tend to be waste gas, although it is possible that natural gases are flared when they cannot be recaptured and used during the refinery process. Gas flaring is important because it prevents natural and waste gases from escaping into the environment. Allowing these gases to simply escape into the environment risks harming the atmosphere (such as by methane gas, which is a greenhouse gas), or possibly poisoning nearby wildlife (such as by a sulfur-based gas). Flare stacks, therefore, play an important part in the refinery process.
The present invention provides, among other things, methods and systems to address the problem of a flare tip extinguishing during routine use, for example methods and systems that ensure a flame is burning at the flare tip of a flare stack, or otherwise act as a back-up to ensure that a flame can be lit, should the normal lighting mechanism fail. Further, the present invention encompasses the recognition that operating flare stacks at colder temperatures can be problematic. For example, in cold weather environments, it is possible that wind could extinguish the flame, and cold weather may seize certain mechanisms used to re-light the flame.
Accordingly, the present disclosure provides, among other things, methods and systems for burning combustible waste gas using a pyrophoric liquid. In some embodiments, such methods and systems are useful in cold temperature conditions, such as −20° C., or −40° C. Using a pyrophoric liquid as a source of flame for the flare stack can avoid the pitfalls associated with known flare stacks.
In some embodiments, the present disclosure provides a method of burning a combustible waste gas, the method comprising:
In some embodiments, the present disclosure provides a flare ignition system comprising:
In some embodiments, the present disclosure provides a flare ignition system comprising:
In some embodiments, the present disclosure provides a method comprising the steps of:
In some embodiments, the present disclosure provides a method of igniting a stream of combustible waste gas, the method comprising
In some embodiments, the present disclosure provides a method of igniting a stream of combustible waste gas, the method comprising
Definitions
The term “pyrophoric liquid,” as used herein, refers to liquids that have the potential to spontaneously ignite upon exposure to oxygen (e.g., air) at temperatures of 55° C. or below (e.g., 0° C. or below, −20° C. or below, or −40° C. or below). Some pyrophoric liquids can also ignite upon exposure to water. Exemplary pyrophoric liquids include, but are not limited to, organometallics of main group metals, (e.g., aluminum, gallium, indium, zinc, and cadmium), organoboranes, and organolithiums. Suitable pyrophoric liquids useful in the methods and systems described herein include, but are not limited to alkylaluminum (e.g., triethylaluminum), alkyllithium, alkenyllithium, aryllithium, alkynyllithium, alkylzinc, and alkylborane (e.g., triethylborane).
The term “alkyl,” as used herein, means an unbranched or branched chain, saturated, monovalent hydrocarbon residue containing 1 to 10 carbon atoms (“C1-C10”). Suitable alkyl groups include, without limitation, methyl, ethyl, n- and iso-propyl, n-, sec-, iso- and tert-butyl, neopentyl, and the like.
The term “alkenyl,” as used herein, means a monovalent straight or branched chain group of, unless otherwise specified, from 2 to 10 carbon atoms (“C2-C10”) containing one or more carbon-carbon double bonds. Suitable alkenyl groups include, without limitation, ethenyl, propenyl, butenyl, pentenyl, hexenyl, and the like.
The term “alkynyl,” as used herein, means a monovalent straight or branched chain group from 2 to 10 carbon atoms (“C2-C10”) containing at least one carbon-carbon triple bond. Suitable alkynyl groups include, without limitation, ethynyl, propynyl, butynyl, pentynyl, hexynyl, and the like.
The term “aryl,” as used herein, means monocyclic and bicyclic ring systems having a total of six to fourteen ring members, wherein at least one ring in the system is aromatic. The term “aryl” may be used interchangeably with the term “aryl ring”. In certain embodiments, “aryl” refers to an aromatic ring system which includes, but not limited to, phenyl, biphenyl, naphthyl, anthracyl, and the like, which may bear one or more substituents. Also included within the scope of the term “aryl”, as it is used herein, is a group in which an aromatic ring is fused to one or more non-aromatic rings, such as indanyl, phthalimidyl, naphthimidyl, phenanthridinyl, or tetrahydronaphthyl, and the like.
The term “combustible gas,” or “combustible waste gas,” as used herein, refers to any gas that, when mixed with oxygen (e.g., air) and contacted with a flame, will ignite. Exemplary combustible gases include methane, pentane, propane, butane, hydrogen, and hydrogen sulfide.
Flare Ignition Systems
In some embodiments, the present disclosure provides methods and systems for burning combustible waste gas using a pyrophoric liquid. Accordingly, in some embodiments, the present disclosure provides a flare ignition system comprising:
In some embodiments, the at least one pyrophoric liquid comprises at least one of an alkylaluminum, an alkyllithium, an alkenyllithium, an aryllithium, an alkynyllithium, an alkylzinc, and an alkylborane. In some embodiments the at least one pyrophoric liquid comprises at least one of an alkylaluminum and an alkylborane. In some embodiments, the at least one pyrophoric liquid comprises triethylaluminum, triethylborane, or a combination thereof. In some embodiments, the at least one pyrophoric liquid comprises a mixture of triethylaluminum and triethylborane.
For example, as seen in
The flare ignition system 100 in
In some embodiments, as also seen in
In some embodiments, a detector 130 is configured to monitor a flame at a flare tip 125. In certain embodiments, a detector 130 monitors the flame via a thermocouple sensor capable of measuring temperature, an infrared sensor capable of measuring infrared radiation, a closed circuit television monitoring the flame, an ultraviolet sensor capable of measuring ultraviolet radiation, a flame ionization detector capable of measuring organic species in a gas stream, or any combination of thereof. In some embodiments, a detector 130 comprises a thermocouple sensor capable of measuring temperature. In some embodiments, a detector 130 comprises an infrared sensor capable of measuring infrared radiation. A detector 130, measuring a change in temperature or a change in infrared radiation, will send a signal to a control valve 115, thereby causing an injection system 120 to pump or otherwise cause the release of pyrophoric liquid from a pyrophoric liquid storage unit 110 to a flare tip 125.
In some embodiments, the present disclosure provides a flare ignition system comprising:
Pyrophoric liquid can be housed in a pyrophoric liquid storage unit (not pictured) and pumped into a flame front generator 305 via an injection system 315. Upon exposure of pyrophoric liquid to oxygen or air with a flame front generator 305, a flame can be ignited, and travel to a flare tip 325.
Similar to the exemplary embodiment rendered in
It should be noted that, while the flare ignition system of
In some embodiments, a detector 425 is configured to monitor either a pilot burner 410 (when present) or a flare tip 415. Similar to the configuration illustrated in
In some embodiments, flare ignition systems described herein do not comprise a sparking mechanism.
In some embodiments, the present disclosure provides a flare stack comprising any of the flare ignition systems described herein.
In some embodiments, the present disclosure provides flare ignition systems configured to operate at a temperature of 0° C. or less. In some embodiments, a flare ignition system is configured to operate at a temperature of −20° C. or less. In some embodiments, the flare ignition system is configured to operate at a temperature of −40° C. or less.
Methods of Disposing of Waste Gas
The present disclosure also provides methods of disposing of waste gas through the use of pyrophoric liquids. Accordingly, in some embodiments, the present disclosure provides a method of burning a combustible waste gas, the method comprising
In some embodiments, the present disclosure provides a method comprising the steps of:
In some embodiments, the present disclosure provides a method of igniting a stream of combustible waste gas, the method comprising:
In some embodiments, the present disclosure provides a method of igniting a stream of combustible waste gas, the method comprising:
The foregoing has been a description of certain non-limiting embodiments of the invention. Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
It is contemplated that systems, devices, methods, and processes of the claimed invention encompass variations and adaptations developed using information from the embodiments described herein. Adaptation and/or modification of the systems, devices, methods, and processes described herein may be performed by those of ordinary skill in the relevant art.
Throughout the description, where articles, devices, and systems are described as having, including, or comprising specific components, or where processes and methods are described as having, including, or comprising specific steps, it is contemplated that, additionally, there are articles, devices, and systems of the present invention that consist essentially of, or consist of, the recited components, and that there are processes and methods according to the present invention that consist essentially of, or consist of, the recited processing steps.
It should be understood that the order of steps or order for performing certain action is immaterial so long as the invention remains operable. Moreover, two or more steps or actions may be conducted simultaneously.
It is contemplated that systems, devices, methods, and processes of the claimed invention encompass variations and adaptations developed using information from the embodiments described herein. Adaptation and/or modification of the systems, devices, methods, and processes described herein may be performed by those of ordinary skill in the relevant art.
Throughout the description, where articles, devices, and systems are described as having, including, or comprising specific components, or where processes and methods are described as having, including, or comprising specific steps, it is contemplated that, additionally, there are articles, devices, and systems of the present invention that consist essentially of, or consist of, the recited components, and that there are processes and methods according to the present invention that consist essentially of, or consist of, the recited processing steps.
It should be understood that the order of steps or order for performing certain action is immaterial so long as the invention remains operable. Moreover, two or more steps or actions may be conducted simultaneously.
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| 20190063743 A1 | Feb 2019 | US |
