EP2044376A2 - Procédé et dispositif pour liquéfier un courant d'hydrocarbures - Google Patents

Procédé et dispositif pour liquéfier un courant d'hydrocarbures

Info

Publication number
EP2044376A2
EP2044376A2 EP07787727A EP07787727A EP2044376A2 EP 2044376 A2 EP2044376 A2 EP 2044376A2 EP 07787727 A EP07787727 A EP 07787727A EP 07787727 A EP07787727 A EP 07787727A EP 2044376 A2 EP2044376 A2 EP 2044376A2
Authority
EP
European Patent Office
Prior art keywords
refrigerant
stream
cooled
cooling stage
heat exchanger
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP07787727A
Other languages
German (de)
English (en)
Inventor
Marco Dick Jager
Robert Klein Nagelvoort
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shell Internationale Research Maatschappij BV
Original Assignee
Shell Internationale Research Maatschappij BV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shell Internationale Research Maatschappij BV filed Critical Shell Internationale Research Maatschappij BV
Priority to EP07787727A priority Critical patent/EP2044376A2/fr
Publication of EP2044376A2 publication Critical patent/EP2044376A2/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • 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.
    • F25J1/0292—Refrigerant compression by cold or cryogenic suction of the refrigerant gas
    • 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"
    • F25J1/0042—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 liquid expansion with extraction of work
    • 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
    • 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
    • F25J1/0055—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 originating from an incorporated cascade
    • 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
    • F25J1/0057—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 after expansion of the liquid refrigerant stream with extraction of work
    • 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
    • F25J1/0211—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 multi-component refrigerant [MCR] fluid in a closed vapor compression cycle
    • F25J1/0214—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 multi-component refrigerant [MCR] fluid in a closed vapor compression cycle as a dual level refrigeration cascade with at least one MCR cycle
    • 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
    • F25J1/0211—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 multi-component refrigerant [MCR] fluid in a closed vapor compression cycle
    • F25J1/0217—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 multi-component refrigerant [MCR] fluid in a closed vapor compression cycle as at least a three level refrigeration cascade with at least one MCR cycle
    • 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.
    • F25J1/0281—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc. characterised by the type of prime driver, e.g. hot gas expander
    • 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.
    • F25J1/0281—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc. characterised by the type of prime driver, e.g. hot gas expander
    • F25J1/0283—Gas turbine as the prime mechanical driver
    • 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
    • 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.
    • F25J1/0291—Refrigerant compression by combined gas compression and liquid pumping
    • 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
    • F25J2220/62—Separating low boiling components, e.g. He, H2, N2, Air

Definitions

  • the present invention relates to a method and apparatus for liquefying a hydrocarbon stream, particularly but not exclusively natural gas.
  • LNG liquefied natural gas
  • US 6,105,389A shows a method and device for liquefying natural gas using a compressed coolant mixture which is sub-cooled, expanded and vapourized, followed by a second cooling stage to liquefy the natural gas.
  • first cooling stage fractions of the first coolant mixture are expanded by expansion valves to cool the coolant mixture.
  • expansion valves are isenthalpic, so that the work which is available from the expansion of a fluid such as a coolant as it is let down in pressure in such a valve, is essentially lost.
  • the present invention provides a method of liquefying a hydrocarbon stream such as natural gas from a feed stream, the method at least comprising the steps of: (a) circulating a first refrigerant stream in a first refrigerant circuit;
  • step (e) passing the cooled hydrocarbon stream through a second cooling stage against a second refrigerant stream to provide a liquefied hydrocarbon stream; wherein at least one expander is an expansion turbine whose work energy created in step (c) is used in the first refrigerant circuit.
  • the near isentropic expansion of any gas to a lower pressure reduces the internal energy out of the gas during the expansion, and produces at least a part of this energy as useful work.
  • This work energy can then be transferred and usefully employed elsewhere in the liquefying method, process and/or apparatus, such as to help drive another unit or device or part thereof, such as a compressor, pump, or electric generator.
  • the hydrocarbon stream may be any suitable gas stream to be liquefied, but is usually a natural gas stream obtained from natural gas or petroleum reservoirs.
  • the natural gas stream may also be obtained from another source, also including a synthetic source such as a Fischer-Tropsch process.
  • the natural gas stream is comprised substantially of methane.
  • the feed stream comprises at least 60 mol% methane, more preferably at least 80 mol% methane.
  • the natural gas may contain varying amounts of hydrocarbons heavier than methane such as ethane, propane, butanes and pentanes, as well as some aromatic hydrocarbons.
  • the natural gas stream may also contain non-hydrocarbons such as H2O, N2, CO2, H2S and other sulphur compounds, and the like.
  • the feed stream containing the natural gas may be pre-treated before use.
  • This pre-treatment may comprise reduction and/or removal of undesired components such as CO2 and H2S or other steps such as early cooling, pre-pressurizing or the like. As these steps are well known to the person skilled in the art, they are not further discussed here.
  • feed stream as used herein relates to any hydrocarbon-containing composition usually containing a large amount of methane.
  • natural gas contained various amounts of ethane, propane and heavier hydrocarbons.
  • the composition varies depending upon the type and location of the gas.
  • Hydrocarbons heavier than methane generally need to be removed from natural gas for several reasons, such as having different freezing or liquefaction temperatures that may cause them to block parts of a methane liquefaction plant.
  • C2-4 hydrocarbons can be used as a source of natural gas liquids .
  • feed stream also includes a composition prior to any treatment, such treatment including cleaning, dehydration and/or scrubbing, as well as any composition having been partly, substantially or wholly treated for the reduction and/or removal of one or more compounds or substances, including but not limited to sulfur, sulfur compounds, carbon dioxide, water, and C2+ hydrocarbons.
  • expander includes any unit, device or apparatus able to reduce the pressure in a stream. This includes valves as well as expansion turbines, and also includes one or two-phase expanders. Where at least one expander of the heat exchangers of the first cooling stage is an expansion turbine, one or more other expanders may be valves. Preferably, all of the heat exchangers of the first cooling stage are expansion turbines .
  • the first cooling stage of the present invention is intended to reduce the temperature of the cooled hydrocarbon stream to below 0 0 C, usually in the range - 20 0 C to -70 0 C. Such a cooling stage is sometimes also termed a y pre-cooling' stage.
  • the second cooling stage is preferably separate from the first cooling stage. That is, the second cooling stage comprises one or more separate heat exchangers using a second refrigerant circulating in a second refrigerant circuit, although the refrigerant of the second refrigerant stream may also pass through at least one heat exchanger of the first cooling stage, preferably all the heat exchangers of the first cooling stage.
  • the first refrigerant circuit comprises one or more ambient coolers prior to the first heat exchanger.
  • the created work energy is used to increase the pressure of the first refrigerant stream prior to the first heat exchanger.
  • One example of this is to use the work energy to drive one or more pumps circulating the first refrigerant stream.
  • the use of work energy from one or more expansion turbines in a first cooling stage is particularly advantageous where the temperature of the associated refrigerant stream is not intended to be significantly low, such as -50 ° C or -100 ° C, prior to expansion.
  • the increase in temperature in the refrigerant stream caused by its passage through one or more pumps, (where its increase in pressure causes an increase in temperature) can be more easily extracted by the use of one or more ambient coolers such as water and/or air coolers known in the art.
  • ambient coolers to reduce the temperature of a refrigerant stream intended to cool a hydrocarbon stream to a much lower temperature, such as below -100 0 C, would be clearly insufficient .
  • the present invention is particularly advantageous where the work energy provided by each expansion turbine is used in a first cooling or pre- cooling stage, as no additional cooling is required in a first refrigerant circuit which already involves one or more ambient coolers prior to the heat exchanger (s) .
  • the work energy or exergy created, or at least minimum energy wastage in the overall method of liquefaction.
  • the first cooling stage comprises two or three heat exchangers, and preferably, each heat exchanger has an associated expansion turbine through which at least a part of the first cooled refrigerant stream passes to provide an expanded cooled first refrigerant stream to its respective heat exchanger.
  • the present invention provides apparatus for liquefying a hydrocarbon stream such as natural gas stream from a feed stream, the apparatus at least comprising: a first refrigerant circuit circulating a first refrigerant stream; a first cooling stage having one or more heat exchangers to receive the first refrigerant stream and to provide a cooled first refrigerant stream; one or more expanders to expand at least a part of the cooled first refrigerant stream to provide one or more expanded first refrigerant streams, at least one expander being an expansion turbine whose work energy created by the expansion is used in the first refrigerant circuit; the or each heat exchanger having a first inlet to pass the feed stream thereinto, and a second inlet to pass the or at least one of the expanded first refrigerant streams thereinto to cool the feed stream and so provide a cooled hydrocarbon stream; and a second cooling stage comprising one or more heat exchangers arranged to receive the cooled hydrocarbon stream from the first cooling stage and to provide a
  • Figure 1 is a general scheme of a liquefying process according to one embodiment of the present invention.
  • Figure 1 shows a general scheme for a liquefying a hydrocarbon stream such as natural gas . It shows an initial feed stream containing natural gas 10, which feed stream may be pre-treated to separate out at least some heavier hydrocarbons and impurities such as carbon dioxide, nitrogen, helium, water, sulfur and sulfur compounds, including but not limited to acid gases.
  • the feed stream 10 passes through a first cooling stage 100 using a first refrigerant being cycled in a first cooling refrigerant circuit 110, thereby obtaining a cooled hydrocarbon stream 40b.
  • the first refrigerant may be any suitable component or, preferably, a mixture thereof, including one or more, preferably two or more, of nitrogen, methane, ethane, ethylene, propane, propylene, butane, pentane, etc.
  • the feed stream 10 passes into a first heat exchanger 14a through inlet 32a and passes therethrough as line 73a. Meanwhile, the first refrigerant passes into the first heat exchanger 14a through inlet 36a and passes through the first heat exchanger 14a as line 71a. In this way, the first refrigerant line 71a is also cooled in the first heat exchanger 14a. Outflowing the first heat exchanger 14a through outlet 38a is a cooled first refrigerant stream 20a.
  • a suitable divider (not shown), such as split piping, there is created first and second fractions or parts 21a, 21b respectively of the cooled first refrigerant stream 20a.
  • the first part 21a is directed towards a first expansion turbine 12a, which expands the first cooled first refrigerant fraction in a near isentropic manner to provide an expanded cooled first refrigerant stream 30a.
  • the expanded stream 30a has an internal energy that is lower than the internal energy of stream 21a.
  • the difference in energy can be used as work, e.g. to drive a unit or device in the first refrigerant circuit 110.
  • the energy provided by the first expansion turbine 12a is used to drive a first pump 28a which is part of the first refrigeration circuit 110, and whose function is described hereinafter.
  • the ratio of the first and second parts 21a, 21b of the cooled first refrigerant stream 20a in Figure 1 can be any suitable ratio known in the art.
  • the first cooling stage 100 has two heat exchangers 14a, 14b, and uses a mixed refrigerant
  • an example ratio for two pressure levels is 35/65.
  • An example of possible pressure levels in the heat exchangers 14a, 14b is 8 bar for a high pressure exchanger and 3 bar for a low pressure exchanger.
  • the expanded stream 30a is recycled into the first heat exchanger 14a at or near the top thereof, and as the expanded stream 30a passes downwardly through the heat exchanger 14a and vapourises, it provides cooling to the lines in the first heat exchanger 14a carrying the feed stream 10 (line 73a) and the first refrigerant (line 71a), as is known in the art. This provides a cooled hydrocarbon stream 40a.
  • vapourized first refrigerant can be collected and outflowed via outlet 42a from the first heat exchanger 14a as a first vapour exit stream 90a at or near its bottom end, and passed to the first compressor 22 for recompression and circulation in the first refrigerant circuit 110.
  • the first refrigerant stream passes through outlet 38b at or near the top of the second heat exchanger 14b as a further cooled first refrigerant stream 20b, and it is expanded through a second expansion turbine 12b to provide a second expanded first refrigerant stream 30b, which can then be passed back into the second heat exchanger 14b via inlet 44b for downward passage therethrough.
  • the second expanded stream 30b passes downwardly though the second heat exchanger 14b, it provides cooling to the lines of hydrocarbon stream (line 73b) and first refrigerant (line 71b) passing up through the second heat exchanger 14b in a manner known in the art.
  • the second expanded refrigerant stream 30b is vapourized during its passage downwardly through the second heat exchanger 14b, and can be collected through outlet 42b as a second vapour exit stream 90b which passes to the first compressor 22 for recompression and circulation in the first refrigeration circuit 110.
  • the second expanded stream 30b is expanded by the second expansion turbine 12b in a near isentropic manner, and the difference in energy between the pre-expanded stream 20b and the post-expanded stream 30b can also be used as work in the first refrigeration circuit 110.
  • the first refrigerant collected from the first and second heat exchangers 14a, 14b is compressed by compressor 22 to provide a compressed stream 95, and cooled by a water and/or air cooler 26 to provide a re-condensed stream 70 for reentry into the heat exchangers 14a, 14b.
  • a water and/or air cooler 26 To assist circulation of the re-condensed first refrigerant stream 70, it is passed consecutively through the first and second pumps 28b, 28a to provide a pumped stream 70a prior to a final ambient cooler 29, which may comprise one or more ambient coolers such as water and/or air coolers, to provide a cooled pumped stream 70b ready for re-use in the heat exchangers 14a, 14b..
  • Pumps are common in refrigerant circuits, but still require to be driven, i.e. energy input. Moreover, they also increase the temperature of a stream passing therethrough as it is pressurised. In the present invention, it is particularly advantageous to drive or work the pumps 28a, 28b by using the work energy created by the close or neighbouring expansion turbines 12a, 12b.
  • the work energy of the expansion turbines 12a, 12b can be transferred to the associated pumps 28a, 28b through any mechanical linkage that interconnects them, such as a common shaft.
  • the temperature of the re-condensed stream 70 is typically 40 0 C to 60 0 C, for example 50 0 C.
  • Each pump in a first refrigerant circuit can raise the temperature of a re-condensed stream by a few degrees Celsius, so that for the arrangement shown in Figure 1 based on a hot climate, a typical temperature for the pumped stream 70a can be for example 53 0 C to 56 0 C.
  • One or more ambient coolers such as the ambient cooler 29 shown in Figure 1 can then reduce the temperature of the pumped stream 70a by 10 to 20 0 C, so that a typical temperature for the cooled pumped stream 70b is 40 0 C.
  • the temperatures of these streams may be 10 to 20 0 C lower, but the increased temperature effect of the pumps is the same.
  • the drive for one or both of the pumps 28a, 28b may be partly, substantially or wholly provided by the work energy from the expansion turbines 12a, 12b. In this way, the external energy requirement of the first refrigerant circuit 110 is reduced, thereby making it more efficient.
  • the further cooled first refrigerant stream 20b could have been split to provide a further line of first refrigerant to pass therethrough, and so forth for any further heat exchangers, until the last heat exchanger recycles all the first refrigerant as shown in Figure 1 for stream 20b.
  • the hydrocarbon stream exits the second heat exchanger 14b through outlet 34b as a cooled hydrocarbon stream 40b.
  • Each expansion turbine 12a, 12b allows the expansion of the first refrigerant to be near isentropic, which improves the efficiency of the first refrigeration circuit 110. That is, the internal energy of streams 30a, 30b is lowered, which benefits the efficiency of the process. Moreover, a lower internal energy, e.g. lower entropy, of the recycled first refrigerant stream equates to a cooler refrigerant temperature, such that the recycled refrigerant streams provide better cooling to the heat exchangers, and/or less work for the refrigerant compressor ( s ) to recompress the refrigerant.
  • the first cooling stage 100 cools the feed stream 10 to below 0 0 C, such as between -20 0 C and - 70 0 C, preferably either between -20 0 C and -35°C, or between -40 0 C and -70 0 C, generally depending on the type of first cooling stage process.
  • each heat exchanger of a multi-stage first cooling stage 100 involves a different first refrigerant pressure.
  • the expanded refrigerant from each pressure stage could be compressed in one or more compressors, for example, using different compressors for different refrigerant entry pressures .
  • the feed stream does not pass through all the heat exchangers of the first cooling stage, but may only pass through one or more of said heat exchangers.
  • the feed stream 10 could pass through the second heat exchanger 14b only to achieve the required cooling of the first cooling stage 100.
  • the final cooled hydrocarbon stream 40b from the second heat exchanger 14b is then sent to a second cooling stage 200 using a second refrigerant, preferably a mixed refrigerant as hereinbefore described, circulating in a second refrigerant circuit 80.
  • a second refrigerant preferably a mixed refrigerant as hereinbefore described
  • cooled hydrocarbon stream 40b and the second refrigerant circuit 80 in and through the second cooling stage 200.
  • Such arrangements are known in the art. These can involve one or more cooling stages, optionally at different pressure levels, and optionally within one vessel such as a cryogenic heat exchanger.
  • the second cooling stage 200 may reduce the temperature of the cooled hydrocarbon stream 40b to provide a liquefied hydrocarbon stream 60 at a temperature of about or lower than -130 0 C.
  • the second refrigerant circuit 80 passes the vapourised second refrigerant exit stream 50a through two second compressors 52 driven by a driver 54, and a water and/or air cooler 56. After the cooler 56, the condensing second refrigerant can pass through the heat exchangers 14a, 14b of the first cooling stage 100 as line 75a, 75b, to provide a cooler, liquefied second refrigerant stream 50 for use in the second cooling stage 200.
  • the second refrigerant is at least partly cooled by the first cooling stage 100.
  • This arrangement simplifies the method of liquefying a hydrocarbon feed stream such as natural gas by combining a portion of the cooling duty of the first cooling stage of the feed stream with an equivalent portion of the cooling of the second refrigerant using the same equipment, rather than the second refrigeration circuit 200 requiring other heat exchangers to sufficiently cool the second refrigerant for use in the second cooling stage 200. This therefore reduces the level of apparatus and equipment needed, and reduces the capital and running costs for the process shown in Figure 1.
  • Additional cooling of the feed stream, cooled and/or liquefied hydrocarbon stream and/or the refrigerant ( s ) could be provided by one or more other refrigerants or refrigerant cycles in addition to cooling by the first and second cooling stages, optionally being connected with another part of the method and/or apparatus for liquefying a hydrocarbon stream as described herein.
  • the liquefied stream 60 could then undergo a third cooling stage (not shown), preferably sub-cooling.
  • Sub-cooling can be provided by passing the liquefied stream through one or more stages using one or more sub-cooling heat exchangers.
  • the or each heat exchanger of the sub-cooling would preferably be supplied with cooling by a mixed (third) refrigerant.
  • Additional cooling of the liquefied stream and/or the sub-cooling refrigerant could be provided by one or more other refrigerants or refrigerant circuits, optionally being connected with another part of the method and/or apparatus for liquefying a hydrocarbon stream as described herein.
  • the liquefied natural gas may be further processed, if desired.
  • the obtained LNG may be depressurized by means of a Joule-Thomson valve or by means of a cryogenic turbo- expander .
  • Table 1 gives an overview of the power requirements in three cases. Table 1
  • the specific power of a liquefaction process is defined as the refrigerant compressor power (in KW) required by the process, divided by the quantity (in tpd) of liquefied hydrocarbon stream (for example LNG) provided.
  • Case 1 relates to the power required to drive the compressor of a refrigeration circuit for a first or pre- cooling stage of a liquid natural gas liquefaction system involving two heat exchangers, and using expansion valves as described in US 6,105,389A.
  • Case 2 is the power required to drive the compressor 22 in the liquefying process shown in Figure 1 as described above, but without any pumps 28a, 28b.
  • Case 3 is the power required to drive the compressor 22 in Figure 1 wherein the first refrigerant circuit 110 includes the pumps 28a, 28b as shown.
  • Case 2 the power requirement for Case 2 is lower than that for Case 1, such that the use of expansion turbines has reduced the power required to recompress the first refrigerant in the first refrigerant circuit 110. Less compression pressure is required as the expanded first refrigerant (after passing through the expansion turbines) has a lower energy, and is therefore cooler, than by use of expansion valves.
  • Case 3 introduces the pumps 28a, 28b driven by the work output of the expansion turbines 12a, 12b.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Separation By Low-Temperature Treatments (AREA)

Abstract

L'invention concerne un procédé pour liquéfier un courant d'hydrocarbure tel que le gaz naturel provenant d'un courant d'alimentation (10), le procédé comprenant au moins les étapes consistant à : (a) faire circuler un premier courant de réfrigérant (70) dans un premier circuit de réfrigérant (110); (b) refroidir le premier courant de réfrigérant (70) dans un ou plusieurs échangeurs de chaleur (14) d'un premier stade de refroidissement (100) pour fournir un premier courant de réfrigérant refroidi (20); (c) faire passer au moins une partie du premier courant de réfrigérant refroidi (20) à travers un ou plusieurs dispositifs d'expansion pour fournir un ou plusieurs premiers courants de réfrigérant refroidis expansés (30); (d) faire passer au moins l'un des premiers courants de réfrigérant refroidis expansés (30) et le courant d'alimentation (10) à travers l'un ou plusieurs des premiers échangeur de chaleur (14) pour fournir un courant d'hydrocarbure refroidi (40); (e) faire passer le courant d'hydrocarbure refroidi (40) à travers un second stade de refroidissement (200) à l'encontre d'un second courant de réfrigérant (50) pour fournir un courant d'hydrocarbure liquéfié (60); dans ce procédé, au moins un dispositif d'expansion est une turbine d'expansion (12) dont l'énergie de travail créée à l'étape (c) est utilisée dans le premier circuit de réfrigérant (110).
EP07787727A 2006-07-21 2007-07-19 Procédé et dispositif pour liquéfier un courant d'hydrocarbures Withdrawn EP2044376A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP07787727A EP2044376A2 (fr) 2006-07-21 2007-07-19 Procédé et dispositif pour liquéfier un courant d'hydrocarbures

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP06117663 2006-07-21
PCT/EP2007/057469 WO2008009721A2 (fr) 2006-07-21 2007-07-19 Procédé et appareil pour liquéfier un courant d'hydrocarbure
EP07787727A EP2044376A2 (fr) 2006-07-21 2007-07-19 Procédé et dispositif pour liquéfier un courant d'hydrocarbures

Publications (1)

Publication Number Publication Date
EP2044376A2 true EP2044376A2 (fr) 2009-04-08

Family

ID=37591545

Family Applications (1)

Application Number Title Priority Date Filing Date
EP07787727A Withdrawn EP2044376A2 (fr) 2006-07-21 2007-07-19 Procédé et dispositif pour liquéfier un courant d'hydrocarbures

Country Status (6)

Country Link
US (1) US20100011808A1 (fr)
EP (1) EP2044376A2 (fr)
JP (1) JP2009544923A (fr)
AU (1) AU2007275118B2 (fr)
RU (1) RU2434190C2 (fr)
WO (1) WO2008009721A2 (fr)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011000900A2 (fr) 2009-07-03 2011-01-06 Shell Internationale Research Maatschappij B.V. Procédé et appareil de production d'un flux hydrocarboné refroidi
KR101637334B1 (ko) * 2010-04-30 2016-07-08 대우조선해양 주식회사 천연가스 액화방법 및 장치
FR2980564A1 (fr) * 2011-09-23 2013-03-29 Air Liquide Procede et installation de refrigeration
EP2972028B1 (fr) * 2013-03-15 2020-01-22 Chart Energy & Chemicals, Inc. Procédé et système réfrigérant mixte
US11428463B2 (en) 2013-03-15 2022-08-30 Chart Energy & Chemicals, Inc. Mixed refrigerant system and method
US11408673B2 (en) 2013-03-15 2022-08-09 Chart Energy & Chemicals, Inc. Mixed refrigerant system and method
GB2512360B (en) 2013-03-27 2015-08-05 Highview Entpr Ltd Method and apparatus in a cryogenic liquefaction process
ITFI20130076A1 (it) * 2013-04-04 2014-10-05 Nuovo Pignone Srl "integrally-geared compressors for precooling in lng applications"
CN103234326B (zh) * 2013-05-02 2015-11-25 中国海洋石油总公司 应用于基荷型天然气液化工厂的双混合冷剂液化系统
JP6578665B2 (ja) * 2015-02-10 2019-09-25 セイコーエプソン株式会社 液体吐出装置及び液体吐出装置の制御方法
US10852059B2 (en) * 2017-09-28 2020-12-01 Air Products And Chemicals, Inc. Multiple pressure mixed refrigerant cooling system
RU2715277C1 (ru) * 2019-05-22 2020-02-26 Акционерное общество "Военно-промышленная корпорация "Научно-производственное объединение машиностроения" Цифровая система управления пиротехническими средствами
WO2024096757A1 (fr) * 2022-11-02 2024-05-10 Gasanova Olesya Igorevna Procédé de liquéfaction de gaz naturel

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2471567B1 (fr) * 1979-12-12 1986-11-28 Technip Cie Procede et systeme de refrigeration d'un fluide a refroidir a basse temperature
US4541852A (en) * 1984-02-13 1985-09-17 Air Products And Chemicals, Inc. Deep flash LNG cycle
US4970867A (en) * 1989-08-21 1990-11-20 Air Products And Chemicals, Inc. Liquefaction of natural gas using process-loaded expanders
JP3563143B2 (ja) * 1995-02-14 2004-09-08 千代田化工建設株式会社 天然ガス液化プラントのコンプレッサ駆動装置
US5537827A (en) * 1995-06-07 1996-07-23 Low; William R. Method for liquefaction of natural gas
EP0862717B1 (fr) * 1995-10-05 2003-03-12 BHP Petroleum Pty. Ltd. Procede de liquefaction
FR2778232B1 (fr) * 1998-04-29 2000-06-02 Inst Francais Du Petrole Procede et dispositif de liquefaction d'un gaz naturel sans separation de phases sur les melanges refrigerants
TW477890B (en) * 1998-05-21 2002-03-01 Shell Int Research Method of liquefying a stream enriched in methane
US6119479A (en) * 1998-12-09 2000-09-19 Air Products And Chemicals, Inc. Dual mixed refrigerant cycle for gas liquefaction
US6347532B1 (en) * 1999-10-12 2002-02-19 Air Products And Chemicals, Inc. Gas liquefaction process with partial condensation of mixed refrigerant at intermediate temperatures
US6412302B1 (en) * 2001-03-06 2002-07-02 Abb Lummus Global, Inc. - Randall Division LNG production using dual independent expander refrigeration cycles
DE10355935A1 (de) * 2003-11-29 2005-06-30 Linde Ag Verfahren zum Verflüssigen eines Kohlenwasserstoff-reichen Stromes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2008009721A3 *

Also Published As

Publication number Publication date
RU2434190C2 (ru) 2011-11-20
WO2008009721A3 (fr) 2008-11-27
AU2007275118B2 (en) 2010-08-12
WO2008009721A2 (fr) 2008-01-24
US20100011808A1 (en) 2010-01-21
JP2009544923A (ja) 2009-12-17
AU2007275118A1 (en) 2008-01-24
RU2009106092A (ru) 2010-08-27

Similar Documents

Publication Publication Date Title
AU2007275118B2 (en) Method and apparatus for liquefying a hydrocarbon stream
AU2008208879B2 (en) Method and apparatus for cooling a hydrocarbon stream
AU2007286291B2 (en) Method and apparatus for cooling a hydrocarbon stream
US6751985B2 (en) Process for producing a pressurized liquefied gas product by cooling and expansion of a gas stream in the supercritical state
AU2019268173B2 (en) Multiple pressure mixed refrigerant cooling process and system
RU2443952C2 (ru) Способ и устройство для сжижения потока углеводородов
EP2041507A2 (fr) Procédé et dispositif pour refroidir un courant d'hydrocarbures
WO2008020044A2 (fr) Procédé et appareil de liquéfaction d'un courant d'alimentation contenant des hydrocarbures
JP6702919B2 (ja) 混合冷媒冷却プロセスおよびシステム
WO2007135062A2 (fr) Procédé et appareil pour traiter un courant d'hydrocarbures
AU2007310940B2 (en) Method and apparatus for liquefying hydrocarbon streams
US11624555B2 (en) Method and system for cooling a hydrocarbon stream
EP3489594A1 (fr) Procédé et système de refroidissement d'un flux d'hydrocarbure

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20081218

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20150203