WO2018004701A1 - Configurations and methods for small scale lng production - Google Patents
Configurations and methods for small scale lng production Download PDFInfo
- Publication number
- WO2018004701A1 WO2018004701A1 PCT/US2016/040954 US2016040954W WO2018004701A1 WO 2018004701 A1 WO2018004701 A1 WO 2018004701A1 US 2016040954 W US2016040954 W US 2016040954W WO 2018004701 A1 WO2018004701 A1 WO 2018004701A1
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- Prior art keywords
- pressure
- heat exchanger
- stream
- refrigerant stream
- refrigerant
- Prior art date
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- 238000000034 method Methods 0.000 title claims description 43
- 238000004519 manufacturing process Methods 0.000 title description 7
- 239000003507 refrigerant Substances 0.000 claims abstract description 160
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 98
- 238000005057 refrigeration Methods 0.000 claims abstract description 83
- 239000003345 natural gas Substances 0.000 claims abstract description 46
- 238000011144 upstream manufacturing Methods 0.000 claims description 3
- 239000003949 liquefied natural gas Substances 0.000 description 146
- 239000007789 gas Substances 0.000 description 61
- 238000003860 storage Methods 0.000 description 40
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 20
- 230000032258 transport Effects 0.000 description 15
- 229910052757 nitrogen Inorganic materials 0.000 description 11
- 230000006835 compression Effects 0.000 description 10
- 238000007906 compression Methods 0.000 description 10
- 229930195733 hydrocarbon Natural products 0.000 description 10
- 150000002430 hydrocarbons Chemical class 0.000 description 10
- 239000004215 Carbon black (E152) Substances 0.000 description 9
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 8
- 238000013461 design Methods 0.000 description 7
- 239000000446 fuel Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 230000018044 dehydration Effects 0.000 description 4
- 238000006297 dehydration reaction Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 239000001294 propane Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 239000003245 coal Substances 0.000 description 3
- 239000002131 composite material Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000004172 nitrogen cycle Methods 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 2
- 125000003277 amino group Chemical group 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 239000010779 crude oil Substances 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 238000002203 pretreatment Methods 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 239000013589 supplement Substances 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000779 depleting effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 239000003502 gasoline Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 239000000463 material Substances 0.000 description 1
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- 239000002808 molecular sieve Substances 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000000135 prohibitive effect Effects 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/0002—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the fluid to be liquefied
- F25J1/0022—Hydrocarbons, e.g. natural gas
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
- F25J1/0032—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration"
- F25J1/004—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration" by flash gas recovery
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
- F25J1/0047—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle
- F25J1/005—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle by expansion of a gaseous refrigerant stream with extraction of work
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
- F25J1/0047—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle
- F25J1/0052—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle by vaporising a liquid refrigerant stream
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/006—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the refrigerant fluid used
- F25J1/007—Primary atmospheric gases, mixtures thereof
- F25J1/0072—Nitrogen
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0203—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a single-component refrigerant [SCR] fluid in a closed vapor compression cycle
- F25J1/0208—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a single-component refrigerant [SCR] fluid in a closed vapor compression cycle in combination with an internal quasi-closed refrigeration loop, e.g. with deep flash recycle loop
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
- F25J1/0244—Operation; Control and regulation; Instrumentation
- F25J1/0245—Different modes, i.e. 'runs', of operation; Process control
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
- F25J1/0257—Construction and layout of liquefaction equipments, e.g. valves, machines
- F25J1/0275—Construction and layout of liquefaction equipments, e.g. valves, machines adapted for special use of the liquefaction unit, e.g. portable or transportable devices
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
- F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
- F25J1/0285—Combination of different types of drivers mechanically coupled to the same refrigerant compressor, possibly split on multiple compressor casings
- F25J1/0288—Combination of different types of drivers mechanically coupled to the same refrigerant compressor, possibly split on multiple compressor casings using work extraction by mechanical coupling of compression and expansion of the refrigerant, so-called companders
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J5/00—Arrangements of cold exchangers or cold accumulators in separation or liquefaction plants
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2210/00—Processes characterised by the type or other details of the feed stream
- F25J2210/60—Natural gas or synthetic natural gas [SNG]
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2220/00—Processes or apparatus involving steps for the removal of impurities
- F25J2220/60—Separating impurities from natural gas, e.g. mercury, cyclic hydrocarbons
- F25J2220/66—Separating acid gases, e.g. CO2, SO2, H2S or RSH
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2220/00—Processes or apparatus involving steps for the removal of impurities
- F25J2220/60—Separating impurities from natural gas, e.g. mercury, cyclic hydrocarbons
- F25J2220/68—Separating water or hydrates
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
- F25J2230/60—Processes or apparatus involving steps for increasing the pressure of gaseous process streams the fluid being hydrocarbons or a mixture of hydrocarbons
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2240/00—Processes or apparatus involving steps for expanding of process streams
- F25J2240/40—Expansion without extracting work, i.e. isenthalpic throttling, e.g. JT valve, regulating valve or venturi, or isentropic nozzle, e.g. Laval
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2245/00—Processes or apparatus involving steps for recycling of process streams
- F25J2245/90—Processes or apparatus involving steps for recycling of process streams the recycled stream being boil-off gas from storage
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2270/00—Refrigeration techniques used
- F25J2270/14—External refrigeration with work-producing gas expansion loop
- F25J2270/16—External refrigeration with work-producing gas expansion loop with mutliple gas expansion loops of the same refrigerant
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
- F25J2290/12—Particular process parameters like pressure, temperature, ratios
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
- F25J2290/60—Details about pipelines, i.e. network, for feed or product distribution
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
- F25J2290/62—Details of storing a fluid in a tank
Definitions
- CNG CNG is more common than LNG as a transportation fuel, mainly due to the cost of high liquefaction and the lack of infrastructure to support LNG fueling facilities.
- LNG can be used to replace diesel and is presently used in many heavy duty vehicles, including refuse haulers, grocery delivery trucks, transit buses, and coal miner lifters.
- small to mid-scale LNG plants must be constructed close to both pipelines and LNG consumers, as long distance transfer of LNG is costly and therefore often not economical.
- Such small to mid-scale LNG plants should be designed to produce 0.2 mtpy to 2.0 mtpy (million tonnes per year).
- such small to mid-scale LNG plants must be simple in design, easy to operate, and sufficiently robust to support an unmanned operation. Still further, it would be desirable to integrate liquefaction with LNG truck fueling operations to allow for even greater delivery flexibility.
- U.S. Pat. No. 5,755,1 14 to Foglietta teaches a hybrid liquefaction cycle which includes a closed loop propane refrigeration cycle and a turboexpander cycle. Compared to other liquefaction processes, the liquefaction process has been simplified, but is still unsuitable and/or economically unattractive for small to mid-scale LNG plants.
- U.S. Pat. No. 7,673,476 to Whitesell discloses a compact and modular liquefaction system that requires no external refrigeration. The system uses gas expansion by recycling feed gas to generate cooling. While this design is relatively compact, operation of the recycle system is complicated, and the use of hydrocarbon gas for cooling remains a safety concern.
- an LNG plant comprises a cold box comprising a plurality of heat exchanger passes and a refrigeration unit comprising a closed refrigeration cycle.
- the cold box is fluidly coupled with the refrigeration unit, and the cold box is configured to receive a natural gas feed stream and produce LNG from the feed stream using a refrigeration content from the refrigeration unit.
- the refrigeration unit comprises a first compressor unit configured to compress a refrigerant to produce a compressed refrigerant at a first pressure, a first heat exchanger pass of the plurality of heat exchanger passes that is configured to pass the compressed refrigerant through the cold box to cool the compressed refrigerant, a splitter configured to separate the cooled, compressed refrigerant into a first portion and a second portion, a first expander configured to receive the first portion from the splitter and expand the first portion to a second pressure, a second expander configured to receive the second portion from the splitter and expand the second portion to a third pressure, a second heat exchanger pass of the plurality of heat exchanger passes configured to pass the first portion at the second pressure through the cold box, a third heat exchanger pass of the plurality of heat exchanger passes configured to pass the second portion at the third pressure through the cold box to provide at least a portion of the refrigeration content in the cold box, at least one second compressor that is configured to receive the second portion downstream of the third heat exchanger pass and compress the second
- an LNG plant comprises a cold box comprising a heat exchanger that has a plurality of heat exchanger passes and a refrigeration unit fluidly coupled with the plurality of heat exchanger passes.
- the refrigeration unit is configured to provide a first refrigerant stream to a first heat exchanger pass of the plurality of heat exchanger passes at a first pressure, a second refrigerant stream to a second heat exchanger pass of the plurality of heat exchanger passes, and a third refrigerant stream to a third heat exchanger pass of the plurality of heat exchanger passes.
- the second refrigerant stream comprises a first portion of the first refrigerant stream downstream of the first heat exchanger pass, and the second refrigerant stream is at a second pressure.
- the third refrigerant stream comprises a second portion of the first refrigerant stream downstream of the first heat exchanger pass, and the third refrigerant stream is at a third pressure.
- the second pressure and the third pressure are both below the first pressure.
- the cold box is configured to receive a natural gas feed stream and produce LNG from the natural gas feed stream using a refrigeration content from the refrigeration unit in the plurality of heat exchanger passes.
- a method of generating LNG from a natural gas feed comprises passing a first refrigerant stream through a first heat exchanger pass of a plurality of heat exchanger passes in a cold box at a first pressure, separating the first refrigerant stream into a second refrigerant stream and a third refrigerant stream downstream of the cold box, passing the second refrigerant stream through a second heat exchanger pass of the plurality of heat exchanger passes at a second pressure, passing the third refrigerant stream through a third heat exchanger pass of the plurality of heat exchanger passes, passing a natural gas feed stream through at least a fourth heat exchanger pass of the plurality of heat exchanger passes, and liquefying at least a portion of the natural gas stream in the cold box using a refrigeration content provided by at least one of the second refrigerant stream or the third refrigerant stream to form an LNG stream.
- the third refrigerant stream is at a third pressure, and the second pressure and the third pressure are both below the first
- Figure 1 is one exemplary configuration according to an embodiment using a nitrogen cycle.
- Figure 2 is another exemplary configuration according to an embodiment using a nitrogen cycle with an integrated LNG loading.
- Figure 3 is an exemplary graph illustrating the close temperature approach of the heat composite curves between the feed gas and the refrigeration circuit of Figure 2.
- component or feature may,” “can,” “could,” “should,” “would,” “preferably,” “possibly,” “typically,” “optionally,” “for example,” “often,” or “might” (or other such language) be included or have a characteristic, that particular component or feature is not required to be included or to have the characteristic. Such component or feature may be optionally included in some embodiments, or it may be excluded.
- the systems and methods described herein are directed to natural gas liquefaction and LNG (liquefied natural gas) truck loading, and especially use of gas expansion processes for small to mid-scale LNG plants and integration of natural gas liquefaction with an LNG truck loading facility.
- a small to mid-scale LNG plant can be integrated with an LNG truck loading facility in a simple and cost-effective manner.
- the small to mid-scale LNG plant can have a capacity of typically about 0.2 mtpy to about 0.7 mtpy, typically between about 0.7 mtpy to about 1.5 mtpy, and most typically between about 1.5 mtpy to about 2.5 mtpy of LNG by liquefaction of appropriate quantities of feed gas.
- the contemplated process may also be suitable for producing LNG below about 0.1 mtpy.
- the refrigeration process uses a non-hydrocarbon refrigerant (e.g., nitrogen, air, etc.) in a compression expansion cycle to so avoid the safety issues commonly associated with a hydrocarbon refrigeration system.
- a non-hydrocarbon refrigerant e.g., nitrogen, air, etc.
- natural gas e.g. , delivered from a pipeline
- natural gas can be liquefied in a cold box using a gas expansion cycle that employs a two-stage compressor to so produce at least two pressure level gases.
- the so produced gases are then cooled and expanded to a lower pressure to thereby generate refrigeration prior to mixing in a heat exchanger as a single gas stream that is then fed to the compressors that are driven by the expanders.
- the expander cycle can use nitrogen that is inherently safe to operate and more reliable than conventional mixed refrigerant processes while the nitrogen expander cycle can be of low pressure or high pressure design to match the feed gas composition and pressure with power consumption per unit of LNG produced of about 320 to about 425 kW/ton.
- the LNG loading facility has a pressure control system that uses high pressure feed gas as a motive force to move the LNG product from an LNG storage tank to an LNG truck while boil-off vapors from the LNG truck are recovered in the liquefaction plant.
- a small to mid-scale LNG plant can have an integrated loading terminal, wherein the plant includes a cold box with a closed refrigeration cycle (preferably a two stage expander refrigeration system, operating with a non-hydrocarbon refrigerant) to so provide refrigeration content to a natural gas feed at a temperature sufficient to produce LNG from the natural gas feed.
- a closed refrigeration cycle preferably a two stage expander refrigeration system, operating with a non-hydrocarbon refrigerant
- an LNG storage tank is thermally coupled to the refrigeration cycle to receive and store the LNG, and that a first boil off vapor line provides a first boil off vapor from an LNG transporter to the cold box, and from the cold box to the LNG storage tank, while a second boil off vapor line provides a second boil off vapor from the LNG storage tank to the cold box, and from the cold box to the natural gas feed.
- a compressor compresses at least one of the first and second boil off vapors, and/or a differential pressure controller maintains a predetermined pressure differential (e.g. , 5-200 psi, more typically 10-50 psi) between the LNG storage tank and the LNG transporter.
- a predetermined pressure differential e.g. , 5-200 psi, more typically 10-50 psi
- LNG from the storage tank is unloaded from the top of the storage tank using an internal pipe in the storage tank, which eliminates the potential hazards of LNG spillage of the LNG tank inventory typically used in commonly used tank configurations.
- a method of liquefying natural gas and loading the LNG to an LNG transporter will include a step of liquefying natural gas feed in a cold box using a closed refrigeration cycle, and feeding the LNG to an LNG storage tank.
- a first boil off vapor from an LNG transporter is cooled and compressed and used as a motive force to deliver LNG from the LNG storage tank to the LNG transporter.
- a second boil off vapor from the LNG storage tank can be cooled and compressed and moved from the cold box to the natural gas feed.
- the step of liquefying a natural gas feed can be performed using a two stage closed refrigeration cycle, typically using a non-hydrocarbon refrigerant, such as nitrogen.
- FIG. 1 illustrates an embodiment of a LNG liquefaction system 100.
- Feed gas stream 102 can be supplied to the small scale LNG liquefaction plant.
- the feed gas stream can comprise primarily light hydrocarbons, such as methane and ethane. Minor amounts of various other gases, including inert gases such as nitrogen, argon and the like, can also be present.
- the feed gas stream can be treated in a gas treatment unit that typically includes an amine unit and a dehydration unit for removal of C02 and water, forming a dry and substantially C02 free gas stream.
- the feed gas stream may have a temperature of between about 50 °F and 200 °F and a pressure of between about 100 psia and 700 psia.
- the feed gas stream 102 can enter the cold box 151 , which can comprise a plurality of heat exchanger passes 152, 153, 154, and 155. While four heat exchanger passes are shown in Figure 1 , more than four heat exchanger passes or less than four heat exchanger passes can also be used with the system 100.
- the feed gas can be chilled by nitrogen refrigeration in heat exchanger pass 152 and form a sub-cooled LNG stream 103, which can then be let down in pressure in a downstream JT valve forming a flashed LNG stream.
- the flashed vapor can be returned to the liquefaction unit and the resulting liquid LNG can be stored in a LNG storage tank, as described in more detail herein.
- the refrigeration for the cold box 151 can be provided by the closed refrigeration cycle.
- the closed refrigeration cycle can comprise a two-stage liquefaction cycle using a high-pressure refrigerant cycle, typically operating at pressures greater than about 1,000 psia.
- stream 126 from compressor 150 can be discharged at a pressure between about 400 psia and 600 psia to feed the compressor unit 160, which compresses the refrigerant gas to greater than about 1 ,000 psia (e.g., greater than 1,100 psia, greater than 1,200 psia, or greater than 1 ,300 psia) to form stream 128.
- the compressor unit 160 may generally have an upper compression limit of around 1 ,500 psia, though the stream 126 may not be compressed to this limit in most configurations.
- the compressor unit 160 can comprise single-stage or multistage compressors, optionally with intercoolers.
- the compressor discharge can be cooled in cooler 164 to form stream 129, which can be further cooled in the cold box 151 in exchanger pass 155 to between -10 °F and about -50 °F forming stream 130.
- Stream 130 can be split into two portions: streams 130a and 130b.
- the molar ratio of the two streams can be divided into any suitable amounts, which can be based on the feed gas composition and/or the pressure.
- the two streams 130a and 130b can be split at a molar ratio of stream 130a to stream 130 of between about 0.5 and about 0.75, or between about 0.6 and about 0.7, or at about 0.68.
- Stream 130a can be expanded in expander 170 to between about 20% and about 50%, or between about 30% and about 45%, or between about 35% and about 42% of the original pressure on an absolute pressure scale to form stream 179 that passes through heat exchanger pass
- Stream 179 can cool the feed gas stream 102 and the high-pressure refrigerant stream 129 in the cold box 151. Stream 179 can pass out of the cold box 151 as stream 132.
- Stream 130b can be expanded in expander 180 to between about 3% and about 20%, or between about 4% and about 15%, or between about 5% and about 10%, or between about 7% and about 9% of the original pressure on an absolute pressure scale to form stream 127 that passes through heat exchanger pass
- Stream 127 can be used to cool the feed gas and the high-pressure refrigerant in the cold box 151.
- Stream 127 can pass out of the cold box 151 as stream 121 , which can then be compressed by compressor 150 to a pressure substantially the same as the pressure of stream 179, and stream 121 can then be mixed with stream 132 to form stream 120 as feed to the compressor 160.
- the use of two expanded refrigerant flow paths through the cold box 151 may allow for a more efficient cooling in some instances.
- the two lower pressure streams passing through separate heat exchanger passes through the cold box 151 can have a relative pressure ratio of between about 10: 1 and about 2: 1, between about 7:1 and about 3 :1 , or between about 5: 1 and about 4:1 , each as a ratio of the higher pressure refrigerant stream 179 to lower pressure refrigerant stream 127 on an absolute pressure scale.
- the closed refrigeration cycle can comprise a cold box having multiple heat exchanger passes, including a plurality of heat exchanger passes for the refrigerant and at least one heat exchanger pass for the natural gas feed stream.
- the refrigeration unit is fluid coupled to the cold box and the plurality of heat exchanger passes to provide the refrigerant and refrigeration content for forming LNG from the natural gas feed stream in the cold box.
- the refrigeration unit is configured to provide at least a first refrigerant stream to a first heat exchanger pass of the plurality of heat exchanger passes.
- the first refrigerant stream can be at a first pressure, which can be a relatively high pressure after being compressed in compressor unit 160.
- the refrigeration unit is also configured to provide a second refrigerant stream to a second heat exchanger pass in the cold box.
- the second refrigerant stream can be a portion of the compressed refrigerant stream resulting from splitting the compressed refrigerant stream downstream of the first heat exchanger pass.
- the second refrigerant stream can be expanded (e.g., using an expander) such that the second refrigerant stream can be at a second pressure that is lower than the compressed pressure at the entrance to the second heat exchanger pass.
- the refrigeration unit can also provide a third refrigerant stream to a third heat exchanger pass.
- the third refrigerant stream can be the remaining portion of the compressed refrigerant stream resulting from splitting the compressed refrigerant stream downstream of the first heat exchanger pass.
- the third refrigerant stream can be expanded (e.g., using an expander) such that the third refrigerant stream is at a third pressure that is lower than the second pressure at the entrance to the third heat exchanger pass.
- the second and/or third heat exchanger passes can provide the refrigeration content within the cold box.
- the resulting refrigeration content can then be used to form the LNG from the natural gas in the natural gas feed stream with power consumption per unit of LNG produced of about 320 kW/ton to about 425 kW/ton.
- FIG. 2 illustrates another embodiment of an LNG production system 200.
- the refrigeration unit of Figure 2 is similar to the refrigeration unit of the system 100 illustrated in Figure 1, and the differences will be described in more detail with reference to Figure 2.
- the feed gas stream 201 can be supplied to the LNG liquefaction plant at any suitable flow rate, temperature, and pressure.
- the feed gas stream can be the same or similar to the feed gas stream 102 described with respect to Figure 1 , including the composition, pressure, and temperature.
- the feed gas stream 201 can be delivered at a flow rate of about 1.7 MMscfd, at a temperature of about 100°F, and at a pressure of about 453 psia.
- the feed gas stream can have a composition comprising about 1.0 mol% N 2 , about 0.1 mol% C0 2 , about 96.5 mol% methane, about 2 mol% ethane, and about 0.5 mol% propane and heavier components.
- the feed gas can be treated in a gas treatment unit 241 that can include an amine unit and/or a dehydration unit (e.g., a molecular sieve dehydration unit) for the removal of C0 2 and water, forming a substantially dry and C0 2 free gas stream 202.
- a gas treatment unit 241 can include an amine unit and/or a dehydration unit (e.g., a molecular sieve dehydration unit) for the removal of C0 2 and water, forming a substantially dry and C0 2 free gas stream 202.
- the dried gas stream 202 can be combined with a recycle gas stream 21 1, as described in more detail herein, and can enter the cold box 251 , which typically comprises a plurality of heat exchanger passes, 152, 153, 154, 155, and 156.
- the feed gas 102 can be chilled by nitrogen refrigeration in heat exchanger pass 152 to form a sub-cooled stream 203 and can then be let down in pressure in Joule-Thomson valve 271 to form stream 204.
- the sub-cooled stream can be cooled to about -223 °F, and the flashed liquid downstream of the JT valve 271 can be at about -227 °F.
- the flashed liquid can be stored in storage tank 265, which can operate at a pressure above atmospheric, e.g., between about 20 psia and 100 psi, or at about 60 psia.
- the flashed gas stream 208 can be recovered by recycling the gas in stream 208 back to the exchanger pass 156 via valve 270. As the gas in stream 208 is in equilibrium with the liquid in the storage tank 265, the gas can have a temperature less than that of the other streams in the cold box 151. The refrigeration content of this recycle stream can be recovered in the cold box 151.
- the flashed stream from the storage tank 265 can be heated in the cold box 151.
- the stream 210 can exit the cold box 151 and be compressed by compressor 268 to a pressure at or above the feed gas pressure to form stream 211 prior to mixing with feed gas stream 102.
- the two-stage nitrogen liquefaction cycle can also be configured using a high- pressure nitrogen cycle, typically operating at above 1,000 psia (e.g., at or above about 1 ,100 psia, 1 ,200 psia, 1 ,300 psia, etc.) as described above with respect to Figure 1. Nitrogen or air can be used in this cycle as long as the gas is dry. The hydrocarbon content is monitored as known in the art to detect any leakages, and the unit can immediately shut down during emergency.
- the refrigeration cycle shown in Figure 2 is similar to the refrigeration cycle shown in Figure 1 except that the compressor unit 160 shown in Figure 1 can comprise a two-stage compressor as shown in Figure 2. Further, the compressor unit 150 that compresses a portion of the refrigerant stream can comprise a two-stage compression, where the two-stage compression can be mechanically coupled to the parallel expanders 170, 180 as shown in Figure 1.
- feed gas is chilled and at least partially liquefied by the refrigeration cycle in the exchanger pass 152 to form a sub-cooled stream 103.
- the sub-cooled stream can be at about -238 °F, which can then be let down in pressure in the JT valve 271 to form stream 204 that passes to the storage tank 265 as described above.
- stream 226 from compressor 260 which can optionally be mechanically coupled to the expander 259, can be discharged, and optionally cooled in ambient cooler 212, prior to being combined with stream 132 to form the feed to the compressor unit.
- the stream 226 can be compressed to about 507 psia prior to being combined with stream 132.
- the compressor unit can comprise a two-stage refrigerant compressor unit comprising compressor 261 and compressor 262 with an intercooler 263.
- stream 120 can be compressed in compressor 261, the compressed stream 22 can pass to the intercooler 263, and the cooled, compressed stream 223 can then pass to the second-stage compressor 262.
- the compressor unit can compress the refrigerant to a high pressure above 1,000 psi, or another of the other pressures disclosed herein.
- the compressed refrigerant stream 128 can be cooled in an ambient cooler 164 to form stream 129.
- the ambient cooler 164 can comprise any suitable heat exchanger to cool the compressed refrigerant such as an air exchanger, water exchanger, or the like.
- Stream 129 can pass from the ambient cooler 164 to the cold box 151 and pass through heat exchanger pass 155 to cool the high pressure refrigerant stream and form stream 130.
- the refrigerant in stream 129 can be cooled to form stream 130 at about -30°F.
- Stream 130 can then be split into two portions including stream 130a and 130b.
- the molar ratio of the two streams can be divided into any suitable amounts (e.g., as disclosed with respect to Figure 1), which can be based on the feed gas composition and/or the pressure.
- the two streams 130a and 130b can be split at any of the molar ratios described with respect to Figure 1.
- Stream 130a can be expanded in expander 257 to form stream 179.
- the expander 257 can be the same or similar to the expander 170 described with respect to Figure 1.
- the expander can expand stream 130a according to any of the pressure ranges described with respect to Figure 1.
- stream 130a can be expanded from about 1282 psia to about 508 psia, which is a ratio of about 40%.
- the expansion of stream 130a in the expander 257 can result in the formation of stream 179, which can be passed back to the cold box 151 in heat exchanger pass 153.
- the expansion of stream 130a can result in stream 179 having a temperature of about - 126°F.
- Stream 179 can be used to cool the feed gas stream 102 and the high-pressure nitrogen steam 129 in heat exchanger pass 153 to form stream 132.
- stream 132 can leave the cold box 151 at about 507 psia and about 94°F.
- Stream 130b can be expanded in expander 259 to form stream 127.
- the expander 159 can be the same or similar to the expander 180 described with respect to Figure 1.
- the expander 159 can expand stream 130b according to any of the pressure ranges described with respect to Figure 1. Further, the relative pressure ratios of the two expanded streams to each other and relative to the high pressure stream can fall within any of the ranges described with respect to Figure 1.
- stream 130b can be expanded from about 1282 psia to about 110 psia using expander 259, which results in stream 127 have a pressure that is about 8.5% of the pressure of stream 130b.
- the expansion can result in stream 127 having a lower temperature, for example, about -242°F.
- Stream 127 can then be used to cool the feed gas 102 and the high pressure refrigerant stream in heat exchanger pass 154.
- the low pressure stream 121 can then be compressed prior to being combined with stream 132.
- the stream 121 can be compressed by compressor 258, pass through line 233, and be compressed by a second-stage compressor 260 to compress the portion of the refrigerant to a pressure at or above the pressure in stream 132.
- the compression of the stream 121 can be carried out in a two-stage compression using compressors 258, 260 arranged in series.
- stream 121 can be compressed in compressors 258, 260 to about 508 psia, so that the stream 121 can be combined with stream 132 to form stream 120 as the feed to the refrigerant compressors 261 , 262.
- the expansion and compression cycles can be mechanically coupled.
- the expanders used to expand streams 130a and 130b can be mechanically coupled to the compressors for the low-pressure stream 121 leaving heat exchanger pass 154.
- the expander 257 can be mechanically coupled to compressor 258, and the expander 259 can be mechanically coupled to compressor 260.
- This type of configuration can be used to reduce the overall compression energy requirements.
- Figure 3 illustrates a heat composite curve showing the temperature approaches between the feed gas and the refrigeration circuit according to the system described with respect to Figure 2. This composite heat curve demonstrates the efficiency in achieving the natural gas liquefaction of the system described herein.
- LNG can be transferred from the LNG storage tank 265 to LNG transport 267 via streams 205, 206 and loading hose 266 by pressure differential, thereby allowing filling operation without the use of an LNG pump.
- LNG can be transferred from a top outlet nozzle 298 using an internal pipe 299 inside the storage tank 265.
- Flow controller 282 can be adjusted as necessary to deliver the flow quantity to the LNG transport 267.
- the level control 297 can reduce or stop flow in stream 205 at a predetermined low level.
- the LNG storage tank 265 can be configured with a capacity of between about 10,000 gallons and about 50,000 gallons, or about 30,000 gallons, which is sufficient to load at least two LNG transports 267, such as LNG trucks, each with 10,000 gallons capacity.
- the valve 270 is closed, and the valve 269 is open, allowing boil-off vapor stream 207 to be vented from the LNG transport 267 to the cold box 151 as stream 209.
- Valve 269 can control the LNG transport vapor header at about 50 psig using the pressure controller 281 , the lower pressure set- point of the LNG transport 267. With these valves operating in tandem, the boil-off vapors during loading are recovered, and venting to atmosphere is avoided.
- the boil-off vapors can be at a lower temperature than the streams in the cold box 151 , and routing these boil- off vapors back to the cold box 151 can allow the refrigerant content of the boil-off vapors to be recovered in the cold box 151.
- valve 284 can be opened to provide high pressure gas in stream 285 to the storage tank 265.
- a pressure differential controller 288 and a pressure controller 283 can be used to control the flow rate of the LNG to the LNG transport 267.
- the pressure differential can be set at about 10 psi or higher, depending on the distance between the storage tank 265 and the LNG transport 267.
- the LNG loading rate can be varied from about 250 GPM to about 500 GPM using the flow controller 282. In general, the differential pressure can be increased to increase the loading rate. Therefore, it should be appreciated that LNG pumping is not necessary, and the loading system size and cost can be significantly reduced.
- contemplated methods and plants presented herein may have any capacity, it should be appreciated that such plants and methods are especially suitable for a small to mid-scale LNG plant having capacity of typically between 0.2 to 0.7 mtpy (million tonnes per year), more typically between 0.7 to 1.5 mtpy, and most typically between 1.5 to 2.5 mtpy of LNG production by liquefaction of appropriate quantities of feed gas. Consequently, contemplated plants and methods may be implemented at any location where substantial quantities of natural gas are available, and especially preferred locations include gas producing wells, gasification plants (e.g., coal and other carbonaceous materials), and at decentralized locations using gas from a natural gas pipeline.
- gasification plants e.g., coal and other carbonaceous materials
- pre-treatment units include dehydration units, acid gas removal units, etc.
- dPC differential pressure controller
- the dPC is preferably implemented as a control device with a CPU, and may therefore be configured as a suitably-programmed personal computer or programmable logic controller.
- the dPC is configured such that the dPC controls operation of control valves to thereby maintain a predetermined pressure differential between the storage tank and the tank in the LNG transport vessel using pressure sensors and valves as is well known in the art.
- control may be achieved by regulating pressure and/or flow volume of compressed boil-off vapor from the compressor outlet en route to the storage tank, by regulating pressure and/or flow volume of boil-off vapor from the tank in the LNG transport vessel, and/or by regulating pressure and/or flow volume of LNG from the storage tank to the tank in the LNG transport vessel.
- the differential pressure controller will be configured to allow liquefaction operation concurrent with filling operation of the LNG transporter. Therefore, feeding of the natural gas to the liquefaction unit is done in a continuous manner. However, discontinuous feeding and liquefaction is also contemplated.
- the storage tank may be modified in a manner such that LNG for export from the storage tank is drawn from a lower portion of the storage tank (e.g., sump or other location, typically below the center of gravity of the tank) through the vapor space of the tank to the filling line/loading hose, thereby avoiding problems associated with filling ports at the lower portion of the storage tank.
- the tank will include an internal fill pipe that terminates at an upper portion of the tank to so allow connecting the internal fill pipe to a filling line/loading hose.
- an LNG plant comprises a cold box comprising a plurality of heat exchanger passes; and a refrigeration unit comprising a closed refrigeration cycle, wherein the cold box is fluidly coupled with the refrigeration unit, wherein the cold box is configured to receive a natural gas feed stream and produce LNG from the feed stream using a refrigeration content from the refrigeration unit, wherein the refrigeration unit comprises: a first compressor unit configured to compress a refrigerant to produce a compressed refrigerant at a first pressure; a first heat exchanger pass of the plurality of heat exchanger passes, wherein the first heat exchanger pass is configured to pass the compressed refrigerant through the cold box to cool the compressed refrigerant; a splitter configured to separate the cooled, compressed refrigerant into a first portion and a second portion; a first expander configured to receive the first portion from the splitter and expand the first portion to a second pressure, wherein the second
- a second aspect can include the LNG plant of the first aspect, wherein the first compressor unit comprises a plurality of compressors arranged in series and an intercooler disposed between consecutive compressors.
- a third aspect can include the LNG plant of the first or second aspects, wherein the at least one second compressor comprises a plurality of second compressors, and wherein at least one second compressor of the plurality of second compressors is mechanically coupled to the first expander or the second expander.
- a fourth aspect can include the LNG plant of any of the first to third aspects, wherein the second pressure is between about 20% and about 50% of the first pressure on an absolute scale.
- a fifth aspect can include the LNG plant of any of the first to fourth aspects, wherein the third pressure is between about 3% and about 20% of the first pressure on an absolute scale.
- a sixth aspect can include the LNG plant of any of the first to fifth aspects, further comprising a heat exchanger fluidly coupled between the first compressor and the first heat exchanger pass, wherein the heat exchanger is configured to cool the compressed refrigerant prior to the compressed refrigerant passing to the first heat exchanger pass.
- an LNG plant comprises a cold box comprising a heat exchanger, wherein the heat exchanger comprises a plurality of heat exchanger passes; a refrigeration unit fluidly coupled with the plurality of heat exchanger passes, wherein the refrigeration unit is configured to provide: a first refrigerant stream to a first heat exchanger pass of the plurality of heat exchanger passes, wherein the first refrigerant stream is at a first pressure; a second refrigerant stream to a second heat exchanger pass of the plurality of heat exchanger passes, wherein the second refrigerant stream comprises a first portion of the first refrigerant stream downstream of the first heat exchanger pass, and wherein the second refrigerant stream is at a second pressure; and a third refrigerant stream to a third heat exchanger pass of the plurality of heat exchanger passes, wherein the third refrigerant stream comprises a second portion of the first refrigerant stream downstream of the first heat exchanger pass, and wherein the third refrigerant stream is
- An eighth aspect can include the LNG plant of the seventh aspect, wherein the first pressure is between about 1,000 psia and 2,000 psia.
- a ninth aspect can include the LNG plant of the seventh or eighth aspect, wherein the second pressure is between about 20% and about 50% of the first pressure on an absolute scale.
- a tenth aspect can include the LNG plant of any of the seventh to ninth aspects, wherein the third pressure is between about 3% and about 20% of the first pressure on an absolute scale.
- An eleventh aspect can include the LNG plant of any of the seventh to tenth aspects, wherein a ratio of the second pressure to the third pressure is between about 10:1 and about 2: 1.
- a twelfth aspect can include the LNG plant of any of the seventh to eleventh aspects, wherein a molar ratio of a flowrate of the second refrigerant stream to a flowrate of the first refrigerant stream is between about 0.5 and about 0.75.
- a thirteenth aspect can include the LNG plant of any of the seventh to twelfth aspects, wherein the refrigeration unit is configured to provide the LNG at an energy of between about 320 kW/ton and about 425 kW/ton.
- a method of generating LNG from a natural gas feed comprises passing a first refrigerant stream through a first heat exchanger pass of a plurality of heat exchanger passes in a cold box, wherein the first refrigerant stream is at a first pressure; separating the first refrigerant stream into a second refrigerant stream and a third refrigerant stream downstream of the cold box; passing the second refrigerant stream through a second heat exchanger pass of the plurality of heat exchanger passes, wherein the second refrigerant stream is at a second pressure; passing the third refrigerant stream through a third heat exchanger pass of the plurality of heat exchanger passes, wherein the third refrigerant stream is at a third pressure, wherein the second pressure and the third pressure are both below the first pressure; passing a natural gas feed stream through at least a fourth heat exchanger pass of the plurality of heat exchanger passes; and liquefying at least a portion of the natural gas stream in the cold box using
- a fifteenth aspect can include the method of the fourteenth aspect, further comprising combining the second refrigerant stream and the third refrigerant stream downstream of the cold box to form a recycle stream; and compressing the recycle stream to form the first refrigerant stream.
- a sixteenth aspect can include the method of the fifteenth aspect, wherein compressing the recycle stream comprises compressing the recycle stream in a two-stage compressor.
- a seventeenth aspect can include the method of the fifteenth or sixteenth aspect, further comprising expanding the second refrigerant stream to the second pressure in a first expander; expanding the third refrigerant stream to the third pressure in a second expander, wherein the second pressure is between about 20% and about 50% of the first pressure on an absolute scale; and compressing the third refrigerant stream prior to combining the second refrigerant stream and the third refrigerant stream.
- An eighteenth aspect can include the method of the seventeenth aspect, wherein at least one of the first expander or the second expander is coupled to a compressor, wherein compressing the third refrigerant stream prior to combining the second refrigerant stream and the third refrigerant stream comprises using the compressor to compress the third refrigeration stream.
- a nineteenth aspect can include the method of any of the fourteenth to eighteenth aspects, wherein the second pressure is between about 20% and about 50% of the first pressure on an absolute scale.
- a twentieth aspect can include the method of any of the fourteenth to nineteenth aspects, wherein the third pressure is between about 3% and about 20% of the first pressure on an absolute scale.
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BR112018077326A BR112018077326A2 (en) | 2016-07-01 | 2016-07-05 | Configurations and Methods for Small-Scale LNG Production |
AU2016412662A AU2016412662A1 (en) | 2016-07-01 | 2016-07-05 | Configurations and methods for small scale LNG production |
MX2018015551A MX2018015551A (en) | 2016-07-01 | 2016-07-05 | Configurations and methods for small scale lng production. |
CN201680087367.9A CN109661535B (en) | 2016-07-01 | 2016-07-05 | Configurations and methods for small scale LNG production |
CA3027483A CA3027483C (en) | 2016-07-01 | 2016-07-05 | Configurations and methods for small scale lng production |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11112173B2 (en) | 2016-07-01 | 2021-09-07 | Fluor Technologies Corporation | Configurations and methods for small scale LNG production |
EP3904815A1 (en) * | 2020-04-30 | 2021-11-03 | Air Products And Chemicals, Inc. | Process for enhanced closed-circuit cooling system |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10788261B2 (en) * | 2018-04-27 | 2020-09-29 | Air Products And Chemicals, Inc. | Method and system for cooling a hydrocarbon stream using a gas phase refrigerant |
GB2580927A (en) * | 2019-01-30 | 2020-08-05 | Linde Ag | Method and filling device for filling a transport tank |
US11465093B2 (en) * | 2019-08-19 | 2022-10-11 | Exxonmobil Upstream Research Company | Compliant composite heat exchangers |
WO2022093762A1 (en) * | 2020-10-26 | 2022-05-05 | JTurbo Engineering & Technology, LLC | Methods and configurations for lng liquefaction |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100146971A1 (en) * | 2007-05-30 | 2010-06-17 | Fluor Technologies Corporation | LNG Regasification And Power Generation |
US20110056238A1 (en) * | 2008-04-11 | 2011-03-10 | Fluor Technologies Corporation | Methods and Configurations of Boil-off Gas Handling in LNG Regasification Terminals |
WO2012016166A1 (en) * | 2010-07-29 | 2012-02-02 | Fluor Technologies Corporation | Configurations and methods for small scale lng production |
US20130340475A1 (en) * | 2012-06-20 | 2013-12-26 | Battelle Energy Alliance, Llc | Natural gas liquefaction employing independent refrigerant path |
US20140260415A1 (en) * | 2013-03-15 | 2014-09-18 | Chart Energy & Chemicals, Inc. | Mixed refrigerant system and method |
Family Cites Families (32)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2806688A (en) | 1954-02-23 | 1957-09-17 | Bumpers Inc | Resilient bumper |
US3690115A (en) | 1970-11-02 | 1972-09-12 | Phillips Petroleum Co | Controlling pressure in fluid transfer conduits |
US3792590A (en) | 1970-12-21 | 1974-02-19 | Airco Inc | Liquefaction of natural gas |
US3797514A (en) | 1972-06-27 | 1974-03-19 | Gulf Research Development Co | Automated filler and lever controller for liquid nitrogen |
US5036671A (en) | 1990-02-06 | 1991-08-06 | Liquid Air Engineering Company | Method of liquefying natural gas |
US5322092A (en) | 1992-04-14 | 1994-06-21 | E. I. Du Pont De Nemours And Co. | System for transfering used refrigerant from multiple small recovery cylinders to large shipping cylinder |
JPH06159928A (en) | 1992-11-20 | 1994-06-07 | Chiyoda Corp | Liquefying method for natural gas |
US5755114A (en) | 1997-01-06 | 1998-05-26 | Abb Randall Corporation | Use of a turboexpander cycle in liquefied natural gas process |
DZ2535A1 (en) | 1997-06-20 | 2003-01-08 | Exxon Production Research Co | Advanced process for liquefying natural gas. |
US6237347B1 (en) | 1999-03-31 | 2001-05-29 | Exxonmobil Upstream Research Company | Method for loading pressurized liquefied natural gas into containers |
US8499569B2 (en) | 2004-09-13 | 2013-08-06 | Argent Marine Management, Inc. | System and process for transporting LNG by non-self-propelled marine LNG carrier |
JP4759571B2 (en) | 2004-12-16 | 2011-08-31 | フルオー・テクノロジーズ・コーポレイシヨン | Configurations and methods for LNG regasification and BTU control |
US7673476B2 (en) | 2005-03-28 | 2010-03-09 | Cambridge Cryogenics Technologies | Compact, modular method and apparatus for liquefying natural gas |
WO2006118458A2 (en) | 2005-05-04 | 2006-11-09 | Single Buoy Moorings Inc. | Large distance offshore lng export terminal with boil-off vapour collection and utilization capacities |
US7581411B2 (en) | 2006-05-08 | 2009-09-01 | Amcs Corporation | Equipment and process for liquefaction of LNG boiloff gas |
US7493778B2 (en) | 2006-08-11 | 2009-02-24 | Chicago Bridge & Iron Company | Boil-off gas condensing assembly for use with liquid storage tanks |
KR100835090B1 (en) | 2007-05-08 | 2008-06-03 | 대우조선해양 주식회사 | System and method for supplying fuel gas of lng carrier |
BRPI0813637B1 (en) | 2007-07-09 | 2019-07-09 | Lng Technology Pty Ltd | PROCESS AND SYSTEM FOR PRODUCTION OF LIQUID NATURAL GAS |
WO2009029140A1 (en) * | 2007-08-24 | 2009-03-05 | Exxonmobil Upstream Research Company | Natural gas liquefaction process |
WO2009057179A2 (en) | 2007-10-30 | 2009-05-07 | G.P.T. S.R.L. | Small-scale plant for production of liquified natural gas |
CN105423125B (en) | 2008-07-17 | 2018-03-20 | 氟石科技公司 | It is used for Waste Heat Recovery and the arrangements and methods of ambient air vaporizer in lng regas |
NO331740B1 (en) * | 2008-08-29 | 2012-03-12 | Hamworthy Gas Systems As | Method and system for optimized LNG production |
AU2009243512A1 (en) | 2008-12-05 | 2010-06-24 | Shell Internationale Research Maatschappij B.V. | Method of cooling a hydrocarbon stream and an apparatus therefor |
WO2011117655A2 (en) * | 2010-03-25 | 2011-09-29 | The University Of Manchester | Refrigeration process |
FR2977014B1 (en) * | 2011-06-24 | 2016-04-15 | Saipem Sa | PROCESS FOR THE LIQUEFACTION OF NATURAL GAS WITH A MIXTURE OF REFRIGERANT GAS. |
FR2977015B1 (en) * | 2011-06-24 | 2015-07-03 | Saipem Sa | METHOD FOR LIQUEFACTING NATURAL GAS WITH TRIPLE FIRM CIRCUIT OF REFRIGERATING GAS |
CN103998881B (en) * | 2011-10-21 | 2016-11-16 | 单浮标系泊有限公司 | The many nitrogen expansions technique produced for LNG |
NZ707810A (en) * | 2012-11-21 | 2016-05-27 | Shell Int Research | Method of treating a hydrocarbon stream comprising methane, and an apparatus therefor |
CN104807286B (en) * | 2014-10-31 | 2016-02-03 | 刘继福 | Recycle the nitrogen gas liquefaction system of LNG cold energy |
US11112173B2 (en) | 2016-07-01 | 2021-09-07 | Fluor Technologies Corporation | Configurations and methods for small scale LNG production |
US10605522B2 (en) | 2016-09-01 | 2020-03-31 | Fluor Technologies Corporation | Methods and configurations for LNG liquefaction |
US11461634B2 (en) | 2018-10-02 | 2022-10-04 | Adobe Inc. | Generating homogenous user embedding representations from heterogeneous user interaction data using a neural network |
-
2016
- 2016-07-01 US US15/201,070 patent/US11112173B2/en active Active
- 2016-07-05 CA CA3027483A patent/CA3027483C/en active Active
- 2016-07-05 CN CN201680087367.9A patent/CN109661535B/en not_active Expired - Fee Related
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- 2018-12-13 MX MX2023003745A patent/MX2023003745A/en unknown
-
2021
- 2021-07-12 US US17/373,249 patent/US20210341221A1/en not_active Abandoned
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100146971A1 (en) * | 2007-05-30 | 2010-06-17 | Fluor Technologies Corporation | LNG Regasification And Power Generation |
US20110056238A1 (en) * | 2008-04-11 | 2011-03-10 | Fluor Technologies Corporation | Methods and Configurations of Boil-off Gas Handling in LNG Regasification Terminals |
WO2012016166A1 (en) * | 2010-07-29 | 2012-02-02 | Fluor Technologies Corporation | Configurations and methods for small scale lng production |
US20130340475A1 (en) * | 2012-06-20 | 2013-12-26 | Battelle Energy Alliance, Llc | Natural gas liquefaction employing independent refrigerant path |
US20140260415A1 (en) * | 2013-03-15 | 2014-09-18 | Chart Energy & Chemicals, Inc. | Mixed refrigerant system and method |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11112173B2 (en) | 2016-07-01 | 2021-09-07 | Fluor Technologies Corporation | Configurations and methods for small scale LNG production |
EP3904815A1 (en) * | 2020-04-30 | 2021-11-03 | Air Products And Chemicals, Inc. | Process for enhanced closed-circuit cooling system |
US11639824B2 (en) | 2020-04-30 | 2023-05-02 | Air Products And Chemicals, Inc. | Process for enhanced closed-circuit cooling system |
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US20210341221A1 (en) | 2021-11-04 |
MX2023003745A (en) | 2023-04-24 |
CN109661535B (en) | 2022-03-01 |
BR112018077326A2 (en) | 2019-04-02 |
AU2016412662A1 (en) | 2019-01-17 |
US20180003429A1 (en) | 2018-01-04 |
US11112173B2 (en) | 2021-09-07 |
CA3027483A1 (en) | 2018-01-04 |
CA3027483C (en) | 2023-05-23 |
CN109661535A (en) | 2019-04-19 |
MX2018015551A (en) | 2019-12-18 |
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