EP1895254A1 - Method for starting up a plant for the liquefaction of a hydrocarbon stream - Google Patents

Method for starting up a plant for the liquefaction of a hydrocarbon stream Download PDF

Info

Publication number
EP1895254A1
EP1895254A1 EP06119677A EP06119677A EP1895254A1 EP 1895254 A1 EP1895254 A1 EP 1895254A1 EP 06119677 A EP06119677 A EP 06119677A EP 06119677 A EP06119677 A EP 06119677A EP 1895254 A1 EP1895254 A1 EP 1895254A1
Authority
EP
European Patent Office
Prior art keywords
plant
liquefied
stream
liquefaction
hydrocarbon stream
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Withdrawn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
EP06119677A
Other languages
German (de)
French (fr)
Inventor
Bruce Michael Mariott
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 EP06119677A priority Critical patent/EP1895254A1/en
Publication of EP1895254A1 publication Critical patent/EP1895254A1/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/0002Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the fluid to be liquefied
    • F25J1/0022Hydrocarbons, e.g. natural gas
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02Processes 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
    • F25J1/0228Coupling of the liquefaction unit to other units or processes, so-called integrated processes
    • F25J1/0229Integration with a unit for using hydrocarbons, e.g. consuming hydrocarbons as feed stock
    • F25J1/023Integration with a unit for using hydrocarbons, e.g. consuming hydrocarbons as feed stock for the combustion as fuels, i.e. integration with the fuel gas system
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02Processes 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
    • F25J1/0243Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0244Operation; Control and regulation; Instrumentation
    • F25J1/0245Different modes, i.e. 'runs', of operation; Process control
    • F25J1/0247Different modes, i.e. 'runs', of operation; Process control start-up of the process
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02Processes 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
    • F25J1/0243Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0279Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
    • F25J1/0281Compression 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
    • F25J1/0283Gas turbine as the prime mechanical driver
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2210/00Processes characterised by the type or other details of the feed stream
    • F25J2210/62Liquefied natural gas [LNG]; Natural gas liquids [NGL]; Liquefied petroleum gas [LPG]

Definitions

  • the present invention relates to a method for starting up a plant for the liquefaction of a hydrocarbon stream such as natural gas.
  • the present invention is especially directed to starting up a new plant.
  • natural gas can be stored and transported over long distances more readily as a liquid than in gaseous form, because it occupies a smaller volume and does not need to be stored at high pressures.
  • the starting-up of a plant for the liquefaction of a hydrocarbon stream, such as an LNG (Liquefied Natural Gas) plant may take a considerable amount of time as the various elements need to be purged and cooled down to the desired operating temperatures.
  • LNG Liquefied Natural Gas
  • a problem of the above known method for starting up the plant is that it takes a considerable amount of time; as can be learned form the above presentation, the starting up of an LNG plant may easily take more than 6 months. The above problem is even more pertinent if no on-spec fuel gas is available.
  • a further problem of the above method is that in the process of starting up of the plant fuel gas that is available during the starting up is used for firing a gas turbine for driving one or more compressors in the refrigerant cycles.
  • a disadvantage is that this fuel gas being available during the starting up may not be on-spec for the gas turbine.
  • the gas turbine is only started up after some fuel gas becomes available to the plant, resulting in a significant loss of time.
  • One or more of the above or other objects are achieved according to the present invention by providing a method for starting up a plant, preferably a new plant, for the liquefaction of a hydrocarbon feed stream such as natural gas, wherein a liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is used.
  • a further advantage of the present invention is that the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may have a more desired composition than the fuel gas that is available during the starting up of the plant.
  • An even further advantage of the present invention is that equipment and piping systems being situated at the more downstream side of the plant may be started up at an earlier moment, i.e. well before the finalization of the start-up of the upstream elements of the liquefaction plant and even before any hydrocarbon feed stream to be liquefied is present.
  • starting up includes the restarting up of an already existing plant as well as the starting up of a new plant.
  • starting up is not limited to activities performed for cooling down the plant, but also includes the commissioning of a plant, i.e. the activities performed after equipment of the plant has been installed but before the plant is cooled down or before a hydrocarbon feed stream is introduced for actual production of a liquefied hydrocarbon product and fuel gases. This commissioning may e.g. include testing, purging and drying out the various equipment and piping systems. In this respect also reference is made to the activities as mentioned under "Milestones" in the above-mentioned GasTech 2000 article.
  • the hydrocarbon feed stream to be liquefied may be any suitable hydrocarbon-containing 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 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 H 2 O, N 2 , CO 2 , H 2 S and other sulphur compounds, and the like.
  • the feed stream containing the natural gas may be pre-treated before liquefaction.
  • This pretreatment may comprise removal of undesired components such as CO 2 and H 2 S, or other steps such as pre-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.
  • the liquefaction plant to be started up may be one of various line-ups, without being limited to a specific line-up. As the person skilled readily understands how to liquefy a hydrocarbon stream, this is not further discussed here in full detail.
  • the plant may e.g.
  • NGL natural gas liquids
  • the liquefied natural gas may be further processed, if desired.
  • a liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is meant that an already existing liquefied hydrocarbon stream is used that has not been liquefied in the plant being started up but that has previously been liquefied in a different liquefaction plant.
  • the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may have been produced in a nearby liquefaction train that has already been started up.
  • usually the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant will have been produced in a remote location and shipped or otherwise transported to the location where the plant to be started up is located.
  • the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is preferably obtained from an offloading LNG carrier vessel.
  • the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be stored temporarily in a storage tank before it is used in the plant to be started up, e.g. in a storage tank at an LNG import terminal. If desired, the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be even be stored temporarily in the storage tank forming part of the plant to be started up (i.e. the storage tank wherein the liquefied hydrocarbon stream produced in the plant to be started up will be stored).
  • the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be used in various ways during the starting up of the liquefaction plant.
  • At least a part of the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is vaporized and subsequently used as a fuel gas in the plant.
  • the fuel gas may be used e.g. to commission fuel gas systems, for power generation of any gas turbines in the plant, to commission electrical distribution systems, to fire heaters, etc.
  • the fuel gas is used for firing a gas turbine of the plant, in particular for driving a compressor, preferably a compressor forming part of a refrigerant cycle used for cooling at least a part of the hydrocarbon feed stream to be liquefied in the plant being started up.
  • At least a part of the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is used for providing electric power to the plant.
  • At least a part of the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be vaporized and subsequently used as a commissioning gas in the plant, e.g. in a hydrocarbon purge process train, to dry out a mercury removal bed, to regenerate molecular sieves, to test refrigerant compressors, etc.
  • At least a part of the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is introduced into the plant, in particular for cooling down the plant.
  • the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be introduced in e.g. the piping system and equipment of the plant.
  • the liquefied hydrocarbon that has been liquefied in a different liquefaction plant may be used to cool down the loading system, tanks and associated equipment and an end-flash system.
  • at least a part of the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be heat exchanged against a stream used in the plant to be started up.
  • the present invention provides a system for starting up a plant for the liquefaction of a hydrocarbon feed stream such as natural gas, the system at least comprising:
  • the system further comprises one or more of: a vaporizer connected to an outlet of the source for vaporizing at least a part of the liquefied hydrocarbon stream from said source; a gas turbine connected to an outlet of the vaporizer; etc.
  • FIG. 1 schematically shows a process scheme and system (generally indicated with reference no. 100) used during the starting up of a liquefaction plant 1 for the liquefaction of a hydrocarbon feed stream 10 such as natural gas.
  • the feed stream 10 may have been previously treated e.g. to remove propane and heavier hydrocarbons and/or other undesired components (such as H 2 O, N 2 , CO 2 and H 2 S) to a certain extent before the actual liquefaction takes place.
  • the system 100 comprises a liquefaction plant 1 for the liquefaction of a natural gas feed stream 10, a storage tank 5 for storing the liquefied natural gas (LNG) as produced during normal operation (i.e. after the plant 1 has been started up) and a separate source 4 (in casu a storage tank, e.g. at an LNG import terminal) of already existing LNG that has been previously produced in a separate plant (not shown).
  • LNG liquefied natural gas
  • the previously produced LNG may even be temporarily stored in the storage tank 5 forming part of the plant 1 to be started up as a result of which the tanks 4 and 5 may be one and the same.
  • the liquefaction plant 1 comprises a first heat exchanger 2 in which the feed stream 10 is heat exchanged against an evaporating refrigerant being cycled in a first refrigerant cycle 6.
  • the first refrigerant cycle comprises a compressor 8 for recompressing refrigerant stream 40 being evaporated in the first heat exchanger 2 and a cooler 9 such as an air or water cooler for cooling the compressed stream 50. After cooling in the cooler 9 the refrigerant is recycled as stream 60 to the first heat exchanger 2 in which it is again evaporated to remove heat from the feed stream 10.
  • the first heat exchanger 2 has an inlet 21 for the feed stream 10 and an outlet 22 for cooled stream 20.
  • the cooled stream 20 is passed to the inlet 31 of a second heat exchanger 3 in which during normal operation the actual liquefaction will take place.
  • the cooled stream 20 is heat exchanged in second heat exchanger 3 against an evaporating refrigerant being cycled in a second refrigerant cycle 7.
  • the second refrigerant cycle 7 comprises a compressor 11 for recompressing refrigerant stream 70 being evaporated in the second heat exchanger 3 and a cooler 12 such as an air or water cooler for cooling the compressed stream 80. After cooling in the cooler 12 the refrigerant is recycled as stream 90 to the second heat exchanger 3 in which it is again evaporated to remove heat from the cooled stream 20.
  • a liquefied stream 30 is removed at the outlet 32 of the second heat exchanger 3 and passed to a storage tank 5. If desired, more than the two refrigerant cycles 6, 7 may be present.
  • the compressor 8 of the first refrigerant cycle 6 is driven by a gas turbine 13 that is fired using LNG taken (as stream 110) from the separate source 4 (at outlet 41) after it has been vaporized in vaporizer 15.
  • the vaporized stream is passed on as stream 120 to the gas turbine 13.
  • Reference number 130 indicates that the gas turbine can be mechanically connected to the compressor 8.
  • stream 110 may - alternatively or in addition - be used for firing a gas turbine (not shown), e.g. for driving the compressor 11 in the second refrigerant cycle 7.
  • liquefied stream 110 will be taken from the separate source 4 to assist in the starting up of the plant 1.
  • At least a part of the liquefied hydrocarbon stream 110 may be vaporized in vaporizer 15 and subsequently used as a fuel gas in the plant 1.
  • the fuel gas may be used e.g. to commission fuel gas systems, for power generation of any gas turbines in the plant, to commission electrical distribution systems, to fire heaters, etc.
  • the fuel gas is passed on as stream 120 and used for firing the gas turbine 13 for driving the compressor 8 forming part of the refrigerant cycle 6 used for cooling at least a part of the hydrocarbon feed stream 10.
  • At least a part of the liquefied hydrocarbon stream 110 may also be used for providing electric power to the plant 1.
  • the liquefied hydrocarbon stream 110 may be vaporized in the vaporizer 15 and subsequently used as a commissioning gas in the plant 1, e.g. in a hydrocarbon purge process train, to dry out a mercury removal bed, to regenerate molecular sieves, to test refrigerant compressors, etc.
  • the liquefied hydrocarbon stream 110 may be introduced into the plant 1, in particular for cooling down the plant 1.
  • the liquefied hydrocarbon stream 110 may be introduced in e.g. the piping system and equipment of the plant.
  • the liquefied hydrocarbon stream 110 may be used to cool down the loading system, piping systems (such as lines 10, 20 and 30), tanks (such as tank 5) and associated equipment and an end-flash system.
  • each heat exchanger may comprise a train of heat exchangers.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Separation By Low-Temperature Treatments (AREA)

Abstract

The present invention relates to a method for starting up a plant (1), preferably a new plant, for the liquefaction of a hydrocarbon feed stream (10) such as natural gas, wherein a liquefied hydrocarbon stream (110) that has been liquefied in a different liquefaction plant is used.
At least a part of the liquefied hydrocarbon stream (110) that has been liquefied in a different liquefaction plant may be vaporized (15) and subsequently used as a fuel gas (120) or a commissioning gas in the plant (1).
Further, at least a part of the liquefied hydrocarbon stream (110) that has been liquefied in a different liquefaction plant may be introduced into the plant (1), in particular for cooling down the plant (1).

Description

  • The present invention relates to a method for starting up a plant for the liquefaction of a hydrocarbon stream such as natural gas. The present invention is especially directed to starting up a new plant.
  • It is desirable to liquefy a hydrocarbon stream such as natural gas for a number of reasons. As an example, natural gas can be stored and transported over long distances more readily as a liquid than in gaseous form, because it occupies a smaller volume and does not need to be stored at high pressures.
  • The starting-up of a plant for the liquefaction of a hydrocarbon stream, such as an LNG (Liquefied Natural Gas) plant may take a considerable amount of time as the various elements need to be purged and cooled down to the desired operating temperatures.
  • A known method for starting up a plant for the liquefaction of natural gas is disclosed in the presentation "Passing the Baton Cleanly" by F.W. Richardson, P. Hunter, T. Diocee and J. Fisher, at GasTech 2000, 12-17 November 2000. This presentation discusses the commissioning, start-up and operation of the Atlantic LNG facilities located at Point Fortin in Trinidad.
  • A problem of the above known method for starting up the plant is that it takes a considerable amount of time; as can be learned form the above presentation, the starting up of an LNG plant may easily take more than 6 months. The above problem is even more pertinent if no on-spec fuel gas is available.
  • A further problem of the above method is that in the process of starting up of the plant fuel gas that is available during the starting up is used for firing a gas turbine for driving one or more compressors in the refrigerant cycles. A disadvantage is that this fuel gas being available during the starting up may not be on-spec for the gas turbine. Furthermore, the gas turbine is only started up after some fuel gas becomes available to the plant, resulting in a significant loss of time.
  • It is an object of the invention to minimize one or more of the above problems.
  • It is a further object of the present invention to provide an alternative method for starting up a plant for the liquefaction of a hydrocarbon stream, in particular natural gas.
  • One or more of the above or other objects are achieved according to the present invention by providing a method for starting up a plant, preferably a new plant, for the liquefaction of a hydrocarbon feed stream such as natural gas, wherein a liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is used.
  • It has surprisingly been found that, by using liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant, a significant gain of time may be achieved.
  • A further advantage of the present invention is that the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may have a more desired composition than the fuel gas that is available during the starting up of the plant.
  • An even further advantage of the present invention is that equipment and piping systems being situated at the more downstream side of the plant may be started up at an earlier moment, i.e. well before the finalization of the start-up of the upstream elements of the liquefaction plant and even before any hydrocarbon feed stream to be liquefied is present.
  • According to the present invention, the term "starting up" includes the restarting up of an already existing plant as well as the starting up of a new plant. Furthermore, the term "starting up" is not limited to activities performed for cooling down the plant, but also includes the commissioning of a plant, i.e. the activities performed after equipment of the plant has been installed but before the plant is cooled down or before a hydrocarbon feed stream is introduced for actual production of a liquefied hydrocarbon product and fuel gases. This commissioning may e.g. include testing, purging and drying out the various equipment and piping systems. In this respect also reference is made to the activities as mentioned under "Milestones" in the above-mentioned GasTech 2000 article.
  • The hydrocarbon feed stream to be liquefied may be any suitable hydrocarbon-containing stream to be liquefied, but is usually a natural gas stream obtained from natural gas or petroleum reservoirs. As an alternative the natural gas stream may also be obtained from another source, also including a synthetic source such as a Fischer-Tropsch process.
  • Usually the natural gas stream is comprised substantially of methane. Depending on the source, 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.
  • If desired, the feed stream containing the natural gas may be pre-treated before liquefaction. This pretreatment may comprise removal of undesired components such as CO2 and H2S, or other steps such as pre-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.
  • The person skilled in the art will understand that the liquefaction plant to be started up may be one of various line-ups, without being limited to a specific line-up. As the person skilled readily understands how to liquefy a hydrocarbon stream, this is not further discussed here in full detail. The plant may e.g. comprise one or more heat exchangers with respective refrigerant cycles to cool the feed stream in one or more steps; one or more pre-treating units for removing undesired components from the feed stream such as H2O, N2, CO2, H2S and other sulphur compounds; a so-called NGL (natural gas liquids) extraction unit to remove one or more hydrocarbons heavier than methane such as ethane, propane, butanes and pentanes; storage tanks for the storage of liquefied product; etc.
  • Further the person skilled in the art will readily understand that after liquefaction, the liquefied natural gas may be further processed, if desired.
  • According to the present invention with "a liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant" is meant that an already existing liquefied hydrocarbon stream is used that has not been liquefied in the plant being started up but that has previously been liquefied in a different liquefaction plant. The liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may have been produced in a nearby liquefaction train that has already been started up. However, usually the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant will have been produced in a remote location and shipped or otherwise transported to the location where the plant to be started up is located. Thus, the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is preferably obtained from an offloading LNG carrier vessel.
  • The person skilled in the art will understand that the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be stored temporarily in a storage tank before it is used in the plant to be started up, e.g. in a storage tank at an LNG import terminal. If desired, the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be even be stored temporarily in the storage tank forming part of the plant to be started up (i.e. the storage tank wherein the liquefied hydrocarbon stream produced in the plant to be started up will be stored).
  • The liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be used in various ways during the starting up of the liquefaction plant.
  • According to a first embodiment at least a part of the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is vaporized and subsequently used as a fuel gas in the plant. The fuel gas may be used e.g. to commission fuel gas systems, for power generation of any gas turbines in the plant, to commission electrical distribution systems, to fire heaters, etc.
  • Preferably the fuel gas is used for firing a gas turbine of the plant, in particular for driving a compressor, preferably a compressor forming part of a refrigerant cycle used for cooling at least a part of the hydrocarbon feed stream to be liquefied in the plant being started up.
  • According to a second embodiment (which may also be used in combination with the above-mentioned first embodiment), at least a part of the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is used for providing electric power to the plant.
  • Furthermore at least a part of the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be vaporized and subsequently used as a commissioning gas in the plant, e.g. in a hydrocarbon purge process train, to dry out a mercury removal bed, to regenerate molecular sieves, to test refrigerant compressors, etc.
  • According to a further embodiment, at least a part of the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant is introduced into the plant, in particular for cooling down the plant. To this end the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be introduced in e.g. the piping system and equipment of the plant. As an example, the liquefied hydrocarbon that has been liquefied in a different liquefaction plant may be used to cool down the loading system, tanks and associated equipment and an end-flash system. Furthermore, at least a part of the liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant may be heat exchanged against a stream used in the plant to be started up.
  • In a further aspect the present invention provides a system for starting up a plant for the liquefaction of a hydrocarbon feed stream such as natural gas, the system at least comprising:
    • a plant for the liquefaction of a hydrocarbon feed stream, the plant at least comprising a heat exchanger having an inlet for the feed stream to be cooled and an outlet for a cooled stream, wherein the feed stream can be heat exchanged against a refrigerant being cycled in a refrigerant cycle containing at least a compressor for compressing evaporated refrigerant;
    • a storage tank for storing a liquefied hydrocarbon stream produced in the plant; and
    • a source of a liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant.
  • Preferably the system further comprises one or more of: a vaporizer connected to an outlet of the source for vaporizing at least a part of the liquefied hydrocarbon stream from said source; a gas turbine connected to an outlet of the vaporizer; etc.
  • Hereinafter the invention will be further illustrated by the following non-limiting drawing. Herein shows:
    • Fig. 1 schematically a process scheme in accordance with the present invention.
  • For the purpose of this description, a single reference number will be assigned to a line as well as a stream carried in that line. Same reference numbers refer to similar components.
  • Figure 1 schematically shows a process scheme and system (generally indicated with reference no. 100) used during the starting up of a liquefaction plant 1 for the liquefaction of a hydrocarbon feed stream 10 such as natural gas. The feed stream 10 may have been previously treated e.g. to remove propane and heavier hydrocarbons and/or other undesired components (such as H2O, N2, CO2 and H2S) to a certain extent before the actual liquefaction takes place.
  • The system 100 comprises a liquefaction plant 1 for the liquefaction of a natural gas feed stream 10, a storage tank 5 for storing the liquefied natural gas (LNG) as produced during normal operation (i.e. after the plant 1 has been started up) and a separate source 4 (in casu a storage tank, e.g. at an LNG import terminal) of already existing LNG that has been previously produced in a separate plant (not shown). If desired, the previously produced LNG may even be temporarily stored in the storage tank 5 forming part of the plant 1 to be started up as a result of which the tanks 4 and 5 may be one and the same.
  • The liquefaction plant 1 comprises a first heat exchanger 2 in which the feed stream 10 is heat exchanged against an evaporating refrigerant being cycled in a first refrigerant cycle 6. The first refrigerant cycle comprises a compressor 8 for recompressing refrigerant stream 40 being evaporated in the first heat exchanger 2 and a cooler 9 such as an air or water cooler for cooling the compressed stream 50. After cooling in the cooler 9 the refrigerant is recycled as stream 60 to the first heat exchanger 2 in which it is again evaporated to remove heat from the feed stream 10.
  • As shown in Fig. 1 the first heat exchanger 2 has an inlet 21 for the feed stream 10 and an outlet 22 for cooled stream 20.
  • The cooled stream 20 is passed to the inlet 31 of a second heat exchanger 3 in which during normal operation the actual liquefaction will take place. To this end the cooled stream 20 is heat exchanged in second heat exchanger 3 against an evaporating refrigerant being cycled in a second refrigerant cycle 7. Similar to the first refrigerant cycle 6, the second refrigerant cycle 7 comprises a compressor 11 for recompressing refrigerant stream 70 being evaporated in the second heat exchanger 3 and a cooler 12 such as an air or water cooler for cooling the compressed stream 80. After cooling in the cooler 12 the refrigerant is recycled as stream 90 to the second heat exchanger 3 in which it is again evaporated to remove heat from the cooled stream 20.
  • During normal operation of the plant 1 a liquefied stream 30 is removed at the outlet 32 of the second heat exchanger 3 and passed to a storage tank 5. If desired, more than the two refrigerant cycles 6, 7 may be present.
  • In the embodiment of Figure 1, the compressor 8 of the first refrigerant cycle 6 is driven by a gas turbine 13 that is fired using LNG taken (as stream 110) from the separate source 4 (at outlet 41) after it has been vaporized in vaporizer 15. The vaporized stream is passed on as stream 120 to the gas turbine 13. Reference number 130 indicates that the gas turbine can be mechanically connected to the compressor 8.
  • The person skilled in the art will understand that stream 110 may - alternatively or in addition - be used for firing a gas turbine (not shown), e.g. for driving the compressor 11 in the second refrigerant cycle 7.
  • During starting up of the plant 1 according to the present invention, liquefied stream 110 will be taken from the separate source 4 to assist in the starting up of the plant 1.
  • As an example, at least a part of the liquefied hydrocarbon stream 110 may be vaporized in vaporizer 15 and subsequently used as a fuel gas in the plant 1. The fuel gas may be used e.g. to commission fuel gas systems, for power generation of any gas turbines in the plant, to commission electrical distribution systems, to fire heaters, etc.
  • As shown in the embodiment of Figure 1, the fuel gas is passed on as stream 120 and used for firing the gas turbine 13 for driving the compressor 8 forming part of the refrigerant cycle 6 used for cooling at least a part of the hydrocarbon feed stream 10.
  • If desired, at least a part of the liquefied hydrocarbon stream 110 may also be used for providing electric power to the plant 1.
  • Furthermore at least a part of the liquefied hydrocarbon stream 110 may be vaporized in the vaporizer 15 and subsequently used as a commissioning gas in the plant 1, e.g. in a hydrocarbon purge process train, to dry out a mercury removal bed, to regenerate molecular sieves, to test refrigerant compressors, etc.
  • Further, at least a part of the liquefied hydrocarbon stream 110 may be introduced into the plant 1, in particular for cooling down the plant 1. To this end the liquefied hydrocarbon stream 110 may be introduced in e.g. the piping system and equipment of the plant. As an example, the liquefied hydrocarbon stream 110 may be used to cool down the loading system, piping systems (such as lines 10, 20 and 30), tanks (such as tank 5) and associated equipment and an end-flash system.
  • After the plant 1 has been started up, normal operation will take place and the separate source 4 may be disconnected from the plant 1, as the plant will then be in a position to generate its own fuel gas, if necessary.
  • The person skilled in the art will readily understand that many modifications may be made without departing from the scope of the invention. As an example, the compressors may comprise two or more compression stages. Further, each heat exchanger may comprise a train of heat exchangers.

Claims (12)

  1. Method for starting up a plant (1), preferably a new plant, for the liquefaction of a hydrocarbon feed stream (10) such as natural gas, wherein a liquefied hydrocarbon stream (110) that has been liquefied in a different liquefaction plant is used.
  2. Method according to claim 1, wherein at least a part of the liquefied hydrocarbon stream (110) that has been liquefied in a different liquefaction plant is vaporized and subsequently used as a fuel gas in the plant (1).
  3. Method according to claim 2, wherein the fuel gas is used for firing a gas turbine (13) of the plant (1), in particular for driving a compressor, preferably a compressor (8) forming part of a refrigerant cycle (6) used for cooling at least a part of the hydrocarbon feed stream (10).
  4. Method according to claim 2 or 3, wherein the fuel gas is used for providing electric power to the plant (1).
  5. Method according to one or more of the preceding claims, wherein at least a part of the liquefied hydrocarbon stream (110) that has been liquefied in a different liquefaction plant is vaporized and subsequently used as a commissioning gas in the plant (1).
  6. Method according to one or more of the preceding claims, wherein at least a part of the liquefied hydrocarbon stream (110) that has been liquefied in a different liquefaction plant is introduced into the plant (1), in particular for cooling down the plant (1).
  7. Method according to one or more of the preceding claims, wherein at least a part of the liquefied hydrocarbon stream (110) that has been liquefied in a different liquefaction plant is heat exchanged against a stream used in the plant (1).
  8. Method according to one or more of the preceding claims, wherein the liquefied hydrocarbon stream (110) that has been liquefied in a different liquefaction plant is obtained from an offloading LNG carrier vessel.
  9. System (100) for starting up a plant (1) for the liquefaction of a hydrocarbon feed stream (10) such as natural gas, the system (100) at least comprising:
    - a plant (1) for the liquefaction of a hydrocarbon feed stream (10), the plant (1) at least comprising a heat exchanger (2) having an inlet (21) for the feed stream (10) to be cooled and an outlet (22) for a cooled stream (20), wherein the feed stream (10) can be heat exchanged against a refrigerant being cycled in a refrigerant cycle (6) containing at least a compressor (8) for compressing evaporated refrigerant (40);
    - a storage tank (5) for storing a liquefied hydrocarbon stream (30) produced in the plant (1); and
    - a source (4) of a liquefied hydrocarbon stream that has been liquefied in a different liquefaction plant.
  10. System (100) according to claim 9, further comprising:
    - a vaporizer (15) connected to an outlet (41) of the source (4) for vaporizing at least a part of the liquefied hydrocarbon stream from the source (4).
  11. System (100) according to claim 10, further comprising:
    - a gas turbine (13) connected to an outlet of the vaporizer (15).
  12. System (100) according to claim 11, wherein the gas turbine (13) can drive a compressor (8) for compressing the evaporated refrigerant (40).
EP06119677A 2006-08-29 2006-08-29 Method for starting up a plant for the liquefaction of a hydrocarbon stream Withdrawn EP1895254A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP06119677A EP1895254A1 (en) 2006-08-29 2006-08-29 Method for starting up a plant for the liquefaction of a hydrocarbon stream

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP06119677A EP1895254A1 (en) 2006-08-29 2006-08-29 Method for starting up a plant for the liquefaction of a hydrocarbon stream

Publications (1)

Publication Number Publication Date
EP1895254A1 true EP1895254A1 (en) 2008-03-05

Family

ID=37836932

Family Applications (1)

Application Number Title Priority Date Filing Date
EP06119677A Withdrawn EP1895254A1 (en) 2006-08-29 2006-08-29 Method for starting up a plant for the liquefaction of a hydrocarbon stream

Country Status (1)

Country Link
EP (1) EP1895254A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012050068A1 (en) * 2010-10-13 2012-04-19 三菱重工業株式会社 Liquefaction method, liquefaction device, and floating liquefied gas production equipment comprising same
AU2011219782B2 (en) * 2010-02-26 2015-06-04 Statoil Petroleum As Method for start-up of a liquefied natural gas (LNG) plant
WO2021171595A1 (en) * 2020-02-28 2021-09-02 日揮グローバル株式会社 Start up method for lng production equipment, and lng production equipment
US11874055B2 (en) * 2014-03-04 2024-01-16 Conocophillips Company Refrigerant supply to a cooling facility

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1253388A1 (en) * 2001-04-23 2002-10-30 Linde Aktiengesellschaft Process and apparatus for liquefaction of natural gas
US20050005615A1 (en) * 2001-09-13 2005-01-13 Runbalk David Bertil Floating system for liquefying natural gas
DE102004028052A1 (en) * 2004-06-09 2005-12-29 Linde Ag Process to liquefy natural gas by first-stage introduction of hydrocarbon-enriched fraction

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1253388A1 (en) * 2001-04-23 2002-10-30 Linde Aktiengesellschaft Process and apparatus for liquefaction of natural gas
US20050005615A1 (en) * 2001-09-13 2005-01-13 Runbalk David Bertil Floating system for liquefying natural gas
DE102004028052A1 (en) * 2004-06-09 2005-12-29 Linde Ag Process to liquefy natural gas by first-stage introduction of hydrocarbon-enriched fraction

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
RICHARDSON F W ET AL: "PASSING THE BATON CLEANLY", GASTECH, XX, XX, 2000, pages 1 - 12, XP009073105 *

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2011219782B2 (en) * 2010-02-26 2015-06-04 Statoil Petroleum As Method for start-up of a liquefied natural gas (LNG) plant
AU2011219783B2 (en) * 2010-02-26 2015-06-04 Statoil Petroleum As Method for turndown of a liquefied natural gas (LNG) plant
US10527346B2 (en) 2010-02-26 2020-01-07 Statoil Petroleum As Method for start-up of a liquefied natural gas (LNG) plant
US10907896B2 (en) 2010-02-26 2021-02-02 Equinor Energy As Method for turndown of a liquefied natural gas (LNG) plant
WO2012050068A1 (en) * 2010-10-13 2012-04-19 三菱重工業株式会社 Liquefaction method, liquefaction device, and floating liquefied gas production equipment comprising same
JP2012083051A (en) * 2010-10-13 2012-04-26 Mitsubishi Heavy Ind Ltd Liquefaction method, liquefaction apparatus and floating liquefied gas production equipment including the same
CN102959351A (en) * 2010-10-13 2013-03-06 三菱重工业株式会社 Liquefaction method, liquefaction device, and floating liquefied gas production equipment comprising same
CN102959351B (en) * 2010-10-13 2015-04-22 三菱重工业株式会社 Liquefaction method, liquefaction device, and floating liquefied gas production equipment comprising same
KR101536394B1 (en) * 2010-10-13 2015-07-13 미츠비시 쥬고교 가부시키가이샤 Liquefaction method, liquefaction device, and floating liquefied gas production equipment comprising same
US11874055B2 (en) * 2014-03-04 2024-01-16 Conocophillips Company Refrigerant supply to a cooling facility
WO2021171595A1 (en) * 2020-02-28 2021-09-02 日揮グローバル株式会社 Start up method for lng production equipment, and lng production equipment

Similar Documents

Publication Publication Date Title
RU2205337C2 (en) Updated method of liquefaction of natural gas
JP5107896B2 (en) Natural gas stream liquefaction method and apparatus
CN1969161B (en) Semi-closed loop process
JP5147845B2 (en) Methods for liquefying hydrocarbon streams
KR101710341B1 (en) Method of cooling boil off gas and an apparatus therefor
HU222696B1 (en) Improved cascade refrigeration process for liquefaction of natural gas
US20120167617A1 (en) Method for treating a multi-phase hydrocarbon stream and an apparatus therefor
US20140345319A1 (en) Method and apparatus for removing nitrogen from a cryogenic hydrocarbon composition
KR20010014039A (en) Improved multi-component refrigeration process for liquefaction of natural gas
WO2013087570A2 (en) Method and apparatus for removing nitrogen from a cryogenic hydrocarbon composition
MXPA05003331A (en) A reduced carbon dioxide emission system and method for providing power for refrigerant compression and electrical power for a light hydrocarbon gas liquefaction process using cooled air injection to the turbines.
EP1895254A1 (en) Method for starting up a plant for the liquefaction of a hydrocarbon stream
US20100126186A1 (en) Method and apparatus for generating a gaseous hydrocarbon stream from a liquefied hydrocarbon stream
JP2010507771A (en) Method and apparatus for liquefying a hydrocarbon stream
AU2011273538B2 (en) Method of treating a hydrocarbon stream comprising methane, and an apparatus therefor
RU2612974C2 (en) Method and apparatus for removing nitrogen from cryogenic hydrocarbon composition
KR101302097B1 (en) Apparatus and method for separation heavy hydrocarbon from feed gas using boil-off gas
US20150300731A1 (en) Method of treating a hydrocarbon stream comprising methane, and an apparatus therefor
KR101977969B1 (en) A Gas Treatment System Of Boil-off Gas And Flash Gas Of LNG For LNG FPSO
WO2009103715A2 (en) Method and apparatus for cooling and separating a hydrocarbon stream
KR20220103249A (en) Apparatus for controlling pressure of LPG Fuel Tank
WO2018070039A1 (en) Natural gas liquefaction apparatus
WO2019064347A1 (en) Floating structure for producing lng and maintenance method of lng tank in the floating structure

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

AK Designated contracting states

Kind code of ref document: A1

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 NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA HR MK YU

AKX Designation fees paid
REG Reference to a national code

Ref country code: DE

Ref legal event code: 8566

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: 20080806