AU785125B2 - A method and a device for the liquefaction of natural gas - Google Patents

A method and a device for the liquefaction of natural gas Download PDF

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Publication number
AU785125B2
AU785125B2 AU35610/02A AU3561002A AU785125B2 AU 785125 B2 AU785125 B2 AU 785125B2 AU 35610/02 A AU35610/02 A AU 35610/02A AU 3561002 A AU3561002 A AU 3561002A AU 785125 B2 AU785125 B2 AU 785125B2
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Australia
Prior art keywords
natural gas
gas
liquefied natural
process according
heating
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AU35610/02A
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AU3561002A (en
Inventor
Manfred Bolt
Pentti Paurola
Rainer Sapper
Rudolf Stockmann
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Linde GmbH
Equinor ASA
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Statoil ASA
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Assigned to LINDE AKTIENGESELLSCHAFT, STATOIL ASA reassignment LINDE AKTIENGESELLSCHAFT Amend patent request/document other than specification (104) Assignors: DEN NORSKE STATS OLJESELSKAP A.S., LINDE AKTIENGESELLSCHAFT
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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
    • F25J1/003—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"
    • F25J1/0045—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 vaporising a liquid return stream
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C3/00—Gas-turbine plants characterised by the use of combustion products as the working fluid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C3/00—Gas-turbine plants characterised by the use of combustion products as the working fluid
    • F02C3/20—Gas-turbine plants characterised by the use of combustion products as the working fluid using a special fuel, oxidant, or dilution fluid to generate the combustion products
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C3/00—Gas-turbine plants characterised by the use of combustion products as the working fluid
    • F02C3/20—Gas-turbine plants characterised by the use of combustion products as the working fluid using a special fuel, oxidant, or dilution fluid to generate the combustion products
    • F02C3/24—Gas-turbine plants characterised by the use of combustion products as the working fluid using a special fuel, oxidant, or dilution fluid to generate the combustion products the fuel or oxidant being liquid at standard temperature and pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/0002—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the fluid to be liquefied
    • F25J1/0022—Hydrocarbons, e.g. natural gas
    • 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
    • F25J1/02—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
    • F25J1/0228—Coupling of the liquefaction unit to other units or processes, so-called integrated processes
    • F25J1/0229—Integration with a unit for using hydrocarbons, e.g. consuming hydrocarbons as feed stock
    • F25J1/023—Integration 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0244—Operation; Control and regulation; Instrumentation
    • F25J1/0245—Different modes, i.e. 'runs', of operation; Process control
    • F25J1/0247—Different modes, i.e. 'runs', of operation; Process control start-up of the process
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
    • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0257—Construction and layout of liquefaction equipments, e.g. valves, machines
    • F25J1/0262—Details of the cold heat exchange system
    • F25J1/0264—Arrangement of heat exchanger cores in parallel with different functions, e.g. different cooling streams
    • F25J1/0265—Arrangement of heat exchanger cores in parallel with different functions, e.g. different cooling streams comprising cores associated exclusively with the cooling of a refrigerant stream, e.g. for auto-refrigeration or economizer
    • 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
    • F25J1/0284—Electrical motor 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
    • F25J2210/00—Processes characterised by the type or other details of the feed stream
    • F25J2210/06—Splitting of the feed stream, e.g. for treating or cooling in different ways
    • 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
    • F25J2220/64—Separating heavy hydrocarbons, e.g. NGL, LPG, C4+ hydrocarbons or heavy condensates in general
    • 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
    • F25J2235/00—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams
    • F25J2235/60—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams the fluid being (a mixture of) hydrocarbons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2245/00—Processes or apparatus involving steps for recycling of process streams
    • F25J2245/02—Recycle of a stream in general, e.g. a by-pass 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
    • F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
    • F25J2290/62—Details of storing a fluid in a tank

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (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)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)

Description

AUSTRALIA
PATENTS ACT 1990 COMPLETE SPECIFICATION NAME OF APPLICANT(S): 4 +cjS,;l AI;A Linde Aktiengesellschaft AND D.e noke st at s lj.l.kp a. 104 ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Little Collins Street, Melbourne, 3000.
INVENTION TITLE: A method and a device for the liquefaction of natural gas The following statement is a full description of this invention, including the best method of performing it known to me/us:- -lA- Description The invention relates to a method for the liquefaction of natural gas by using at least one refrigerant cycle stream, which is compressed by means of at least one compressor, as well as a device for executing the method.
Natural gas is liquefied in so-called LNG base load plants, i.e. plants for the base load supply with liquefied natural gas (LNG), in order to supply, at other locations, the energy market with natural gas as the primary energy. As a rule, such plants have several refrigerant cycles with compressors to compress the refrigerant cycle streams.
Large amounts of energy are required for the compression of refrigerant cycle streams.
Usually, the compressors are driven by means of gas turbines which are supplied with fuel. The energy generated in the gas turbines during the combustion of the fuel is transferred either direct to the compressor drive shafts or is used for the power generation by means of generators in order to drive, with the power thus generated, electric drive motors which drive the compressors. To supply the gas turbines with fuel.
residual gases or gases from the liquefaction process, for instance from the nitrogen removal, or also raw gas are used. These fuel gases are compressed in fuel gas compressors to the necessary fuel gas pressures of between approx. 20 to approx. 30 bar.
In order to keep the energy consumption for the compression of the refrigerant cycle streams as low as possible, attempts are made to use the latest available gas turbines offering the greatest efficiencies. These so-called air-derivative gas turbines require for their operation fuel gases with slightly higher pressures than conventional gas turbines.
Furthermore, they are sensitive to small short-term and medium-term changes in the composition of the fuel gases or fluctuations in the heating value of the fuel gases. For instance even fluctuations in the heating value or the specific gravity or the Wobbe index of the fuel gas of 1 within 30 seconds are critical for the operation of highly efficient gas turbines. This means that a continuous operation of these gas turbines with the fuel gases used up to date cannot be ensured, because in view of a possible gas turbine failure the availability of the natural gas liquefaction process as a whole cannot be guaranteed. The reduced availability of the natural gas liquefaction process resulting P %OPERWSAS~uIDc 06\2526497 sops1 doc-25A1tO6 -2therefrom would lead to a reduction of the annually produced quantity of liquefied natural gas.
It would be desirable to provide a method of the type mentioned at the outset, as well as a device for the execution of the method, by means of which a reliable and economical operation of the compressors is rendered possible.
According to one aspect of the present invention, there is provided a process for liquefying natural gas using at least one refrigeration circuit stream which is compressed by means of at least one compressor, wherein the compressor is driven by energy from the combustion of a part of the liquefied natural gas, which is drawn off in liquid form and is evaporated prior to combustion.
The drive energy for the operation of the compressor(s) is thus provided by the combustion of liquefied natural gas (LNG). Advantageously, liquefied natural gas is available at all times, since already for starting up a natural gas liquefaction plant, liquefied natural gas is S-filled into storage tanks and, during the operation of the liquefaction plant, liquefied natural gas is continuously produced and introduced into tanks. Based on the example described in the specification of the operation of the natural gas liquefaction plant, the *o liquefied natural gas may have a very constant composition and a constant heating value.
Thus also highly efficient gas turbines of the latest generation, which react critically to fluctuations in the composition or the heating value of the fuel gas, can be operated with the liquefied natural gas.
On principle, any conceivable fuel-operated drive units can be used for driving the compressors. Appropriately, gas turbines with high levels of efficiency, in particular those of the latest generation, may be used. In practical applications, the fuel gas produced from the liquefied natural gas by vaporisation of a portion of the liquefied natural gas may be supplied to at least one gas turbine for combustion, which mechanically drives at least one compressor. The gas turbine can however also be employed to drive a generator for power generation, where with the power thus generated at least one electric motor is operated which drives the at least one compressor. Appropriately one portion of the liquefied natural gas may be withdrawn from the storage tank for liquefied natural gas by means of a PAOPERZSASUh.DeCc 06U526497 scp- -3pump and supplied to the gas turbine. For reaching the necessary fuel gas pressure one pump inside or outside the storage tank may be sufficient, but, if appropriate, a further pump can be employed outside the storage tank. This means that by using liquefied natural gas, the required fuel gas pressure for the gas turbines can be achieved with relatively little energy expenditure and low investment costs. An expensive and energyintensive compression of fuel gas in special fuel gas compressors, as is required in prior art systems, can be dispensed with.
Appropriately, the portion of the liquefied natural gas intended to be used as fuel gas, may be converted into the gaseous state by heating. The heating up of the liquefied natural gas is preferably performed by heat exchange with streams which are in any case available in the natural gas liquefaction process. Advantageously, the liquefied natural gas is subjected to heat exchange with a split stream of a top product of a column separating heavy hydrocarbons from the natural gas. In addition or alternatively, the liquefied natural gas can be heated up by heat exchange with a subcooling cycle available in the natural gas liquefaction process. In accordance with a particularly preferred embodiment, the liquid compressed natural gas is vaporised in one or in two successive heat exchangers by heat exchange with a split stream of the top product of the column separating heavy *o hydrocarbons from a reclaiming tank, which split stream amounts to approx. 5% to 10% of 20 the raw gas, and against a split stream of the subcooling cycle (SC) which amounts to approx. 5% to 10% of the subcooling cycle stream.
A further variant of the invention proposes to subject to heat exchange a portion of the ***liquefied natural gas intended for the production of fuel gas with a split stream of the raw 25 gas to be liquefied. Furthermore, the liquefied natural gas can also be heated up by an external heating medium, in particular hot steam or hot oil, or by means of an electric S• heating system.
In an embodiment of the invention which is particularly well suited to practical applications, a portion of the liquefied natural gas is pumped out of a storage tank for liquefied natural gas, subsequently heated up and vaporised at approx. 30 to 50 bar into fuel gas and finally the fuel gas is supplied to the gas turbine for combustion.
P lOPERISASVUI-D. 06\2526497 sopal doc.253 -4- According to a further aspect of the present invention, there is provided apparatus for liquefying natural gas, having at least one refrigeration circuit and at least one compressor for compressing the refrigeration circuit stream, the compressor being operatively connected to at least one fuel-operated drive unit, wherein the drive unit is in communication, via a liquid natural gas line which serves as a fuel feed line, with a storage vessel for liquefied natural gas.
Appropriately the drive unit may be a gas turbine. Furthermore, at least one heat exchanger for heating up the liquefied natural gas may be incorporated into the fuel supply line. The heat exchanger is preferably connected with a top product discharge duct of a column for separating heavy hydrocarbons from the natural gas. In addition or alternatively, the heat exchanger can also be connected with a subcooling cycle of the natural gas liquefaction plant. The heat exchanger can also be connected with a raw gas split stream line which branches off from the supply line to the natural gas liquefaction plant.
•oo Preferred embodiments of the present invention offer a number of advantages.
For the operation of highly efficient gas turbines according to the latest state of the art, the so-called air-derivative gas turbines, a fuel gas is made available which is stable with regard to its composition and heating value. Thus, the probability of a failure of the gas turbines due to variations in the quality of the fuel gas is reduced to a minimum. Through the vaporisation of the liquefied natural gas by heat exchange with a raw gas split stream or a cycle split stream, the available coldness of the liquefied natural gas is practically fully 25 recovered. The high energy expenditure involved in the compression of the fuel gas in the gaseous state in prior art plants is therefore dispensed with. The investment costs of the hydraulic pumps for the compression to fuel gas pressure are lower than the investment costs incurred for the fuel gas compressors in the prior art plants. With the heat exchangers proposed, the temperature of the fuel gas can be set whilst observing the required distance from the dew point. Advantageously, preferred embodiments of the present invention provide a fuel gas for the gas turbine operation which is conditioned with regard to its composition and heating value and is temporally stable in a technically elegant and economical manner. Therefore, the disadvantage of a lower liquefaction capacity of p.\OPER\SASUI-Dm 06\2526497 opaI doc.25=806 the natural gas liquefaction plant using conventional gas turbines with lower efficiency levels may be avoided.
Various embodiments of a process and apparatus according to the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic diagram of a method for conditioning fuel gas for gas turbines in a natural gas liquefaction plant Figure 2 and 3 are schematic diagrams of alternative methods to the method shown in Figure 1, with different heat exchanger embodiments.
From the storage tank D1 for liquefied natural gas shown in Figure 1, the fuel gas volume required for the operation of the gas turbines is pumped out in the form of liquefied natural gas by means of pump P1. The compression to the required fuel gas pressure can be :executed fully by means of pump P1 positioned in side the storage tank D1 or by pump P2 i: arranged outside, or also in two steps. This means that the compression can also be executed by means of a pump P1 positioned in the storage tank D1 and with a second 20 pump P2 outside of the storage tank D1, in order to minimise for instance the heat input and therefore the so-called boil-off-gas volume of the storage tank D1. In a heat exchanger El, the liquefied natural gas is gasified to between 30 and 50 bar in heat exchange with a split stream of the gas stream from the reclaiming tank D2 of the HHC column TI (column for the separation of heavy hydrocarbons). In a further heat exchanger E2 the cold fuel gas stream is heated up by heat exchange with a split stream of the subcooling cycle (SC) to ambient temperature and the required superheating to reach the dew point temperature is S. adjusted. The split stream of the top product of the HHC column T1 cooled by the pumped, liquefied gas, which is being heated up, is liquefied at the outlet of the heat exchanger El and sufficiently subcooled, so that it can again be mixed with the main stream of the liquefied, subcooled natural gas of the process. The mixed, subcooled natural gas stream can then be fed into the storage tank D1 via a liquid expansion turbine X1 or a Joule-Thomson Valve V I. This means that also the split top product stream is used for the refrigerating process.
The split stream of the subcooling cycle also used for heating, is discharged from the heat exchanger E2 in two phases and is again mixed with the two-phase main stream of the subcooling cycle. Due to the stable temperature conditions and prevailing process pressures, the heat exchangers El and E2 can be designed as aluminium plate heat exchangers. Also the use of wound heat exchangers or welded stainless steel plate heat exchangers is advantageous. In a further variant type, the heat exchangers El and E2 can also be combined to one heat exchanger, in which case this heat exchanger can be designed as an aluminium plate heat exchanger or a wound heat exchanger.
The heating up of the fuel gas stream in the heat exchanger E2, in an alternative to heating by heat exchange with a split stream of the subcooling cycle, can also be executed by heat exchange with the following split streams: a split stream of the dry natural gas stream entering into the liquefaction part of the plant or a split stream of a further refrigerant cycle entering the plant, for instance by heat exchange with a split stream of the liquefaction cycle (LC) or the precooling cycle (PC).
In the variant shown in Figure 2, the liquefied natural gas pumped and pressurised to fuel gas pressure is heated up in the heat exchangers El and E3 or exclusively in heat exchanger E3. In this case, the heat exchanger E3 is designed as follows. The heat exchanger contains two tube nests, with one tube nest being heated by high pressure steam or hot oil. The liquid natural gas or the now gaseous natural gas vaporised in heat exchanger El are contained in the second tube nest. Both tube nests are positioned in a closed container, which is filled with a transfer medium for the purpose of heat transfer between the two tube nests. As the heat transfer medium, a medium is selected which vaporises or condenses in the temperature range between the heating medium, namely steam or hot oil of approx. 100°C to approx. 250'C, and the vaporising or heating up liquid natural gas of approx. -160 'C to -50 0 C, under medium pressures of about 10-25 bar. Furthermore the medium should have good heat transfer properties and the melting point should be below approx. -160'C. The following media may be taken into consideration: ethane, propane, propylene. In the present example, propane was selected. For propane a boiling pressure of 12 bar was selected, which corresponds to a boiling temperature of 34C. The arrangement presented in Figure 2 for the vaporisation or heating up of the liquid natural gas in the heat exchanger E3 is an option which can be used in one phase of the starting period until the corresponding refrigerant cycles have been set into operation. In this option the liquefied natural gas pumped from the storage tank D1 is conveyed, via a bypass around the heat exchanger El, direct to the heat exchanger E3 and is there vaporised and heated up.
Figure 3 shows a variation of the method where, instead of the liquid natural gas pumped and pressurised to fuel gas pressure being heated up in the heat exchangers El and E2, the heating up is perfbrmed in the heat exchanger E4. The heat exchanger E4 is designed as an electric heater. The electric heater is either dimensioned for continuous operation or only for the starting operation. This arrangement is a further option which can be used during the starting period, i.e. until the corresponding refrigerant cycles have been set into operation.
Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.
The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Claims (21)

1. A process for liquefying natural gas using at least one refrigeration circuit stream which is compressed by means of at least one compressor, wherein the compressor is driven by energy from the combustion of part of the liquefied natural gas, which is drawn off in liquid form and is evaporated prior to combustion.
2. A process according to claim 1, wherein fuel gas which is obtained by evaporation of part of the liquefied natural gas is fed for combustion to at least one gas turbine which mechanically drives the at least one compressor.
3. A process according to claim 1, wherein fuel gas which is obtained by evaporation of part of the liquefied natural gas is fed for combustion to at least one gas turbine which drives at least one generator for generating electric current, the current which is generated 15 being used to operate at least one electric motor which drives the at least one compressor.
4. A process according to any one of claims 1 to 3, wherein the part of the liquefied natural gas is heated.
5. A process according to claim 4, wherein the heating of the liquefied natural gas is carried out by heat exchange with a circuit stream which is present in the natural gas oo*o liquefaction.
6. A process according to claim 4 or claim 5, wherein the heating of the liquefied 25 natural gas is carried out by heat exchange with a partial stream of a top product of a column for separating heavy hydrocarbons out of the natural gas.
7. A process according to any one of claims 4 to 6, wherein the heating of the liquefied natural gas is carried out by heat exchange with a partial stream of a supercooling circuit which is present in the natural gas liquefaction. PAOPERSASUuI-D 0o6\2526497 op. I doc.25 A6 -9-
8. A process according to any one of claims 4 to 7, wherein the heating of the liquefied natural gas is carried out by heat exchange with a partial stream of the natural gas which is to be liquefied.
9. A process according to any one of claims 4 to 8, wherein the heating of the liquefied natural gas is carried out by the application of heat using an external heating medium.
A process according to claim 9, wherein the external heating medium includes hot steam or hot oil.
11. A process according to any one of claims 4 to 10, wherein the heating of the liquefied natural gas is carried out by means of electrical heating. 15
12. A process according to claim 2 or claim 3, or any one of claims 4 to 11 when ooooo dependent on claim 2 or claim 3, wherein part of the liquefied natural gas is pumped out of a storage tank for liquefied natural gas and is then heated and evaporated to form fuel gas •at approximately 30 to approximately 50 bar, and the fuel gas is fed for combustion to the S• gas turbine.
13. Apparatus for liquefying natural gas, having at least one refrigeration circuit and at least one compressor for compressing the refrigeration circuit stream, the compressor *being operatively connected to at least one fuel-operated drive unit, wherein the drive unit •is in communication, via a liquid natural gas line which serves as a fuel feed line, with a storage vessel for liquefied natural gas.
14. Apparatus according to claim 13, wherein the drive unit is designed as a gas turbine.
15. Apparatus according to claim 13, or claim 14, wherein at least one heat exchanger for heating the liquefied natural gas is connected into the liquid natural gas line. P kOPERMSASWID 06\2526497 sopaI
16. Apparatus according to claim 15, wherein the heat exchanger is connected to a top- product extraction line of a column for separating heavy hydrocarbons out of the natural gas.
17. Apparatus according to claim 15 or claim 16, wherein the heat exchanger is connected to a supercooling circuit, liquefaction circuit or pre-cooling circuit of the natural gas liquefaction installation.
18. Apparatus according to any one of claims 15 to 17, wherein the heat exchanger is connected to a crude-gas partial-stream line.
19. Apparatus according to any one of claims 15 to 18, wherein the heat exchanger is equipped with an external heater which can be operated electrically or with hot oil or with 15 hot stream. S
20. A process for liquefying natural gas, substantially as hereinbefore described with reference to the accompanying drawings. o
21. Apparatus for liquefying natural gas, substantially as hereinbefore described with reference to the accompanying drawings. Dated this 25th day of August, 2006 Linde Aktiengesellschaft AND Statoil ASA By DAVIES COLLISON CAVE Patent Attorneys for the applicant
AU35610/02A 2001-04-23 2002-04-23 A method and a device for the liquefaction of natural gas Ceased AU785125B2 (en)

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US9605556B2 (en) 2007-02-14 2017-03-28 General Electric Company Power station and method for its operation

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EG24658A (en) * 2002-09-30 2010-04-07 Bpcorporation North America In All electric lng system and process
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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999030094A1 (en) * 1997-12-11 1999-06-17 Bhp Petroleum Pty. Ltd. Liquefaction process and apparatus

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3735600A (en) * 1970-05-11 1973-05-29 Gulf Research Development Co Apparatus and process for liquefaction of natural gases
GB1471404A (en) * 1973-04-17 1977-04-27 Petrocarbon Dev Ltd Reliquefaction of boil-off gas
DE2434238A1 (en) * 1974-07-16 1976-01-29 Linde Ag System to store and retrieve stored energy - has gas type auxiliary energy storage medium which is liquefied when energy requirements are low
JP3563143B2 (en) * 1995-02-14 2004-09-08 千代田化工建設株式会社 Compressor drive of natural gas liquefaction plant
TW366411B (en) * 1997-06-20 1999-08-11 Exxon Production Research Co Improved process for liquefaction of natural gas

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999030094A1 (en) * 1997-12-11 1999-06-17 Bhp Petroleum Pty. Ltd. Liquefaction process and apparatus

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7944094B2 (en) 2007-02-14 2011-05-17 Alstom Technology Ltd. Power station having a consumer and method for its operation
US8373295B2 (en) 2007-02-14 2013-02-12 Alstom Technology Ltd Method for operating a power plant
US8796874B2 (en) 2007-02-14 2014-08-05 Alstom Technology Ltd Method for operating a power plant
US9605556B2 (en) 2007-02-14 2017-03-28 General Electric Company Power station and method for its operation
AU2009249761B2 (en) * 2008-05-20 2012-10-04 Shell Internationale Research Maatschappij B.V. Method of cooling and liquefying a hydrocarbon stream, an apparatus therefor, and a floating structure, caisson or off-shore platform comprising such an apparatus

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AU3561002A (en) 2002-10-24
NO323134B1 (en) 2007-01-08
NO20021896D0 (en) 2002-04-22
NO20021896L (en) 2002-10-24
EP1253388A1 (en) 2002-10-30

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