Flare elimination process and methods of use
Rich natural gas is first compressed, then ambient air cooled and separated into lean natural gas, NGL and water. Hydrate formation during decompression of the lean gas is precluded by either heating the lean natural gas or mixing the lean natural gas with methanol or other additive before depressurization. Similarly, hydrate formation in the NGL is also precluded by either heating the NGL or mixing the NGL with methanol or other additive before depressurization. The NGL is conditioned for storage and transport in common propane tanks by a stabilizer or two-phase separator. The lean natural gas can be used for internal combustion, liquefied natural gas, compressed natural gas or liquid fuel processing.
1. A flare elimination system comprising:
at least one separator fluidly connected downstream of an ambient air cooler and adapted to receive a compression fluid including a residue gas, natural gas liquid (NGL), and water and to separate the residue gas, the NGL, and the water into separate flows;
an NGL upgrader disposed downstream of said at least one separator receiving the NGL, configured to remove a stabilizer gas from a top of said NGL upgrader and a hydrocarbon liquid from a bottom of said NGL upgrader;
wherein the cooler is disposed upstream of said at least one separator, configured to cool said compressor fluid and deliver cooled compressor fluid to the at least one separator;
a first heat exchanger disposed downstream of said at least one separator receiving residue gas on a cold side of said first heat exchanger from said at least one separator and receiving the compression fluid on a hot side of said first heat exchanger;
a first valve disposed downstream of said first heat exchanger receiving the residue gas from said first heat exchanger;
a second heat exchanger disposed downstream of said at least one separator receiving the NGL on a cold side of said second heat exchanger from said at least one separator and receiving the compression fluid on a hot side of said second heat exchanger; and
a second valve disposed downstream of said second heat exchanger receiving the NGL from said second heat exchanger.
2. A flare elimination system of claim 1 , wherein the at least one separator is a three-phase separator.
3. A flare elimination system of claim 1 , wherein the at least one separator includes a set of two two-phase separators.
4. A flare elimination system of claim 1 , wherein a heating medium other than compression fluid flows through one or more of said heat exchangers, whereby compression fluid bypasses said heat exchangers.
5. A flare elimination system of claim 1 , further comprising a third heat exchanger configured to receive the hydrocarbon liquid on a cold side of said third heat exchanger from the bottom of said NGL upgrader, return a vaporized hydrocarbon to said NGL upgrader, deliver a stabilized NGL via an NGL product conduit, and receive the compression fluid on a hot side of said third heat exchanger.
6. A flare elimination system of claim 5 , wherein the compression fluid is coupled sequentially to said third heat exchanger, then said first heat exchanger, then said second heat exchanger, and then said cooler.
7. A flare elimination system of claim 5 , wherein heating medium is delivered sequentially to said second heat exchanger before said first and third heat exchangers.
8. A flare elimination system of claim 5 , wherein heating medium is delivered sequentially to said first heat exchanger before said second and third heat exchangers.
9. A flare elimination system of claim 5 , wherein heating medium is delivered in parallel to two of said heat exchangers.
10. A flare elimination system of claim 5 , wherein heating medium is delivered in parallel to three of said heat exchangers.
11. A flare elimination system of claim 1 , wherein said NGL upgrader is a stabilizer.
12. A flare elimination system of claim 1 , wherein said NGL upgrader is a two-phase separator.
13. A flare elimination system of claim 1 , wherein said stabilizer gas is not recycled to a compressor.
14. A flare elimination system of claim 1 , wherein said residue gas does not flow through a heat exchanger.