AU2006281407B2 - Method and arrangement for liquefying a stream rich in hydrocarbons - Google Patents

Method and arrangement for liquefying a stream rich in hydrocarbons Download PDF

Info

Publication number
AU2006281407B2
AU2006281407B2 AU2006281407A AU2006281407A AU2006281407B2 AU 2006281407 B2 AU2006281407 B2 AU 2006281407B2 AU 2006281407 A AU2006281407 A AU 2006281407A AU 2006281407 A AU2006281407 A AU 2006281407A AU 2006281407 B2 AU2006281407 B2 AU 2006281407B2
Authority
AU
Australia
Prior art keywords
heat exchanger
fraction
mixed refrigerant
gas fraction
liquid fraction
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.)
Active
Application number
AU2006281407A
Other versions
AU2006281407A1 (en
Inventor
Manfred Boelt
Wolfgang Foerg
Arne Fredheim
Pentti Paurola
Christian Pfeiffer
Oystein Sorensen
Manfred Steinbauer
Rudolf Stockmann
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
Publication of AU2006281407A1 publication Critical patent/AU2006281407A1/en
Assigned to SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V. reassignment SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V. Request for Assignment Assignors: FOERG, WOLFGANG
Application granted granted Critical
Publication of AU2006281407B2 publication Critical patent/AU2006281407B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • F25J1/0257—Construction and layout of liquefaction equipments, e.g. valves, machines
    • F25J1/0262—Details of the cold heat exchange 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
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B1/00—Compression machines, plants or systems with non-reversible 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
    • F25J1/0002—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
    • F25J1/0047—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
    • F25J1/02—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
    • F25J1/0254—Operation; Control and regulation; Instrumentation controlling particular process parameter, e.g. pressure, temperature
    • 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
    • F25J1/0274—Retrofitting or revamping of an existing liquefaction unit
    • 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
    • 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
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/23—Separators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
    • F25J2290/12—Particular process parameters like pressure, temperature, ratios

Description

Method and Arrangement for Liquefying a Stream Enriched with Hydrocarbons 5 Field of Technology This invention relates to a method and an arrangement for liquefying a hydrocarbon rich stream by an indirect heat exchange with the mixed refrigerant of at least one mixed refrigerant cycle, which takes place by means of at least one heat exchanger. After expansion, the mixed refrigerant is vaporized against the hydrocarbon rich stream 10 which is to be liquefied, and against itself. Background Art Today, natural gas liquefaction plants are usually operated with so-called mixed cycles as the refrigerant cycles. Therefore, the refrigerant is a mixture comprising two or more components of the following substances: nitrogen, methane, ethane or ethylene, is propane or propylene, butane and optionally even higher boiling hydrocarbons. The publication WO 2003/106,906 Al discloses a method for liquefying a stream, enriched with hydrocarbons, in particular a natural gas stream, with the simultaneous recovery of a high yield fraction, enriched with C3+. In this case, the liquefaction of the stream enriched with hydrocarbons takes place by a heat exchanger 20 using a mixed refrigerant recirculating cascade. The publication DE 199 37 623 Al discloses a method, conforming to its genre, for liquefying a stream, which is enriched with hydrocarbons, in particular a natural gas stream, by an indirect heat exchanger with at least one mixed refrigerant cycle. By citing the publication DE 199 37 623 Al, the entire text of this disclosure is incorporated by 25 reference in the text disclosed in this patent application. In this method, known from the publication DE 199 37 623 Al, the mixed refrigerant is a two phase stream prior to compression. The separation of the two phase stream into gaseous stream and a liquid stream may take place by means of a separator and/or by means of a separating column. At the same time, the liquid fraction of the two 30 phase stream may amount to as much as fifteen percent. Another method, conforming to its genre, the liquefying a stream, which is enriched with hydrocarbons, in particular a natural gas stream, by an indirect heat exchanger is disclosed in the publication DE 197 16 415 Cl. By citing the publication DE 197 16 415 Cl, the entire text of this disclosure is incorporated by reference into the 35 text disclosed in this patent application.
2 In this method, known from publication DE 197 16 415 Cl, the mixed refrigerant is compressed in a single-staged or multi-staged compressor, cooled, liquefied and super-cooled in one heat exchanger or a plurality of (optionally different) heat exchangers. After its expansion in a valve or in an expansion turbine, the mixed 5 refrigerant is totally vaporized in the downcoming stream, for example, in the external space of a coiled heat exchanger and heated five Kelvin up to 15 Kelvin above its dew point so that is ensured that said mixed refrigerant will be compressed again in the recirculating compressor. It has turned out now that heat exchangers, in which total evaporation and super io heating of the circulating medium or rather the mixed refrigerant take place, develop leaks in the case of coiled heat exchanger in the coiled tubes. The stress on the tubes of the coiled heat exchanger is caused by thermal and acoustical vibrations, which are generated in the dry section of the heat exchanger. However, it has also turned out that heat exchangers, which are totally wetted, do is not develop any leaks. This effect can be observed, in particular, in two-tiered and three tiered heat exchangers, in which the upper, totally wetted heat exchangers do not develop any leaks. Object of the Invention It is the object of the present invention to substantially overcome or at least 20 ameliorate one or more of the disadvantages of the prior art, or to provide a useful alternative. Presentation of the Invention In a first aspect, the present invention provides a method for liquefying a hydrocarbon rich stream by an indirect heat exchange with the mixed refrigerant of at 25 least one mixed refrigerant cycle, which takes place by means of at least one heat exchanger, whereby, after expansion, the mixed refrigerant is vaporized against the hydrocarbon rich stream which is to be liquefied, and against itself, wherein the process is designed in such a manner that between approximately 90 percent and approximately 99 percent of the 30 mixed refrigerant stream, which is to be vaporized, vaporizes; that subsequently the partially vaporized stream of mixed refrigerant is separated into a gas fraction and into a liquid fraction; that the gas fraction is compressed to a desired final pressure; that the liquid fraction is pumped; and 3 that finally the gas fraction and the liquid fraction are combined after respective expansion; and wherein the liquid fraction is fed after pumping and separately from the gas fraction to the heat exchanger; 5 is super-cooled, separately from the gas fraction, in the heat exchanger; is expanded after removal from the heat exchanger and separately from the gas fraction to approximately the pressure of the gas fraction, which is expanded; and is combined with the expanded gas fraction, prior to feeding to the heat exchanger. 1o In a second aspect, the present invention provides a method for liquefying a hydrocarbon rich stream by an indirect heat exchange with the mixed refrigerant of at least one mixed refrigerant cycle, which takes place by means of at least one heat exchanger, whereby, after expansion, the mixed refrigerant is vaporized against the hydrocarbon rich stream which is to be liquefied, and against itself, wherein is between approximately 90 percent and approximately 99 percent of the mixed refrigerant stream, which is to be vaporized, vaporizes; subsequently the partially vaporized stream of mixed refrigerant is separated into a gas fraction and into a liquid fraction; the gas fraction is compressed to a desired final pressure; 20 the liquid fraction is pumped; and finally the gas fraction and the liquid fraction are combined after respective expansion; and wherein the liquid fraction is fed after pumping and separately from the gas fraction to the heat exchanger; 25 is super-cooled, separately from the gas fraction, in the heat exchanger; is expanded after removal from the heat exchanger and separately from the gas fraction to approximately the pressure of the gas fraction, which is expanded; and is combined with the expanded gas fraction, prior to feeding to the heat exchanger. 30 In a third aspect, the present invention provides an arrangement for liquefying a hydrocarbon rich stream, exhibiting at least one heat exchanger for liquefying the hydrocarbon rich stream against a mixed refrigerant of at least one mixed refrigerant cycle, and at least one expansion unit for expansion of the mixed refrigerant so as to 35 perform refrigeration, wherein -4 4 an evaporation, which takes place after expansion and which ranges from approximately 90 percent to approximately 99 percent of the mixed refrigerant stream against the hydrocarbon rich stream which is to be liquefied, and against itself, at least one separator for separating the partially vaporized mixed refrigerant 5 stream into a gas fraction and into a liquid fraction, at least one compressor for compressing the gas fraction to a desired final pressure, at least one pump for drawing off the liquid fraction from the separator, and a subsequent unification of the gas fraction and the liquid fraction after the 10 separate expansion, and wherein an infeed of the liquid fraction, which takes place behind the pump separately from the gas fraction, to the heat exchanger, a super-cooling of the liquid fraction, which takes place separately from the gas fraction, in the heat exchanger, is an expansion of the liquid fraction, which takes place separately from the gas fraction, after removal from the heat exchanger, by means of an expansion unit that is assigned to the liquid fraction, to approximately the pressure of the gas fraction, which is expanded by means of an expansion unit assigned to the gas fraction, and a unification of the expanded liquid fraction with the expanded gas fraction prior 20 to the infeed to the heat exchanger. Against this background of the aforementioned drawbacks and inadequacies as well as in consideration of the briefly described state of art, the present invention at least in a preferred embodiment provides a method of the type described in the introductory part as well as an arrangement of the aforementioned type in such way that the aforesaid 25 problems are avoided. Brief Description of the Drawings As stated above, there are a number of different possibilities of constructing and improving the teaching of this invention. On the other hand, additional embodiments, features and advantages of this invention are explained in detail below with reference to 30 the two embodiments, depicted in Figure 1 and Figure 2. Hence, Figure 1 is schematic drawing of a first embodiment of an inventive arrangement, wherein the process entails pumping the liquid fraction to the same pressure at which the gas fraction is compressed and then combining the two fractions; and WO 2007/020252 5 PCT/EP2006/065278 [0024] Figure 2 is schematic drawing of a second embodiment of an inventive arrangement, wherein the process entails pumping the liquid fraction only to the extent that - after super cooling in its own heat exchanger passage - this liquid fraction is admixed to the expanded gas fraction. Way(s) of Carrying Out the Invention [0025] In order to avoid superfluous repetition, the following explanations regarding the embodiments, features and advantages of this invention (unless stated otherwise) relate to the first embodiment of an inventive arrangement, which works according to the method of the invention and is depicted in Figure 1, as well as to the second embodiment of an inventive arrangement, which works according to the method of the invention and is depicted in Figure 2. [0026] A stream, which is enriched with hydrocarbons and is to be liquefied, for example a natural gas stream, is fed, as illustrated in Figure 1, through line A to a heat exchanger E. [0027] In this heat exchanger E, a pre-cooling or a liquefaction or a super-cooling of the stream, enriched with hydrocarbons, takes place only in exchange heat with a mixed refrigerant, which will be discussed in detail below. Following pre-cooling or liquefaction or super-cooling, the stream enriched with hydrocarbons is drawn off from the heat exchanger E by way of line B and conveyed away for further use. [0028] The pressurized mixed refrigerant is fed through line 1 to the heat exchanger E and liquefied and super-cooled in the heat exchanger E. The super-cooled mixed refrigerant is drawn off from the heat exchanger E by way of line 2 and expanded or rather expanded so as to perform refrigeration in the expansion unit 3, which is a valve or an expansion turbine. [0029] Finally, at this point, the mixed refrigerant in the heat exchanger E is evaporated - as compared to the liquefaction process known from the prior art - only to the extent that it exhibits a residual liquid ranging from approximately one percent to approximately ten percent, preferably a residual liquid of approximately five percent, at the outlet of the heat exchanger E. [0030] This two phase mixture is fed through line 4 to a separator D. The gas fraction of the mixed refrigerant is drawn off at the head of the separator D by way of line 5 and 6 compressed to the desired cycle pressure using the cold-intake, single-staged or multi-staged compressor V. The liquid fraction of the mixed refrigerant is drawn off from the bottom of the separator D by way of line 6 and is also pumped to the desired cycle pressure using a s pump P and then fed to the gas fraction of the mixed refrigerant that is drawn off from the separator D by way of line 5 and compressed. The process, depicted in Figure 1, is suitable in particular for retrofitting pre existing plants. With respect to the process, depicted in Figure 2, for the arrangement according 10 to the second embodiment, reference is made to Figure 1 with respect to the content. This distinction between the process, according to Figure 2, and the process, according to Figure 1 lies in the fact that the liquid fraction of the mixed refrigerant that is drawn off from the bottom of the separator D by way of line 6 does not have to be pumped to the desired cycle pressure with the pump P. Rather an increase in pressure is is adequate to compensate for the pressure losses caused by line 7, caused by its own passage (middle in Figure 2) of the heat exchanger E, or by line 8 or by the expansion unit 9, which may be a valve. Compared to the process depicted in Figure 1, this process has the major advantage that lines, located between the compressor V and the heat exchanger E, and the 20 heat exchanger do not have to be designed for a range between approximately 101 percent and approximately 110 percent and that the pump P needs to be designed only for a correspondingly smaller pressure increase. Finally the liquid fraction is fed to the heat exchanger E by way of line 7, (which is an additional line, as compared to the process according to Figure 1), and is super 25 cooled in the heat exchanger E (in an additional passage, as compared to the process, according to Figure 1). The liquid fraction is fed 7 to its own and/or a separate passage of the heat exchanger E. Following removal from the heat exchanger E by way of line 8 (which is an additional line, as compared to the process, according to Figure 1), there is a slight 30 expansion in the valve 9 (which is an additional valve, as compared to the process, according to Figure 1) to the pressure of the expanded "gas fraction" in line 2', where the two fractions are combined prior to feeding into the heat exchanger E. The process, depicted in Figure 2, is suitable especially for new plants. The process, according to at least a preferred embodiment of the invention, 35 makes it possible to avoid entirely, or at least largely, the formation of leaks owing to the total wetting of the heat exchanger tubes, because thermal and acoustical vibrations in the heat exchanger passages are avoided or rather significantly reduced.
'I 7 According to at least a preferred embodiment of the present invention, between approximately 90 percent and approximately 99 percent, preferably approximately 95 percent, of the mixed refrigerant stream, which is to be vaporized, vaporizes. Then the partially vaporized stream of mixed refrigerant is separated into a gas fraction and into a 5 liquid fraction. The gas fraction is compressed to the desired final pressure preferably by means of at least one cold-intake compressor. The liquid fraction is pumped, and then the two fractions are combined. According to a preferred embodiment of the present invention the method and the inventive arrangement, the gas fraction and the liquid fraction may be combined either 1o before or after their expansion. If both fractions are combined as early as before their expansion, the liquid fraction is pumped preferably to the same pressure as the gas fraction. The circulating medium or rather the mixed refrigerant is enriched in a practical way with heavier components to the extent that there is no total evaporation, bur rather a is residual liquid, ranging from approximately one percent to approximately ten percent, remains; preferably a residual liquid of approximately five percent remains. However, this wet vapour may not be fed into the compressor; rather this wet vapour must be separated into a gas fraction and into a liquid fraction by means of at least one separator. The gas fraction is compressed in a preferable manner by means of at least one 20 cold-intake compressor. The liquid fraction is pumped by means of at least one suitable pump, during which process the liquid fraction is slightly super-cooled in an advantageous way prior to pumping. The design and/or the operation of the pump takes the Net Positive Suction Head (NPSH) value into consideration. The NPSH value of the pump is the product of the type 25 of construction and the pump speed. The higher the pump seed, the larger the NPSH value of the pump is. Finally, the present invention at least in a preferred embodiment relates to the use of a method, according to the above described type, and/or at least an arrangement, according to the above described type, for liquefying, in particular by pre-cooling or by 30 super-cooling, a stream, enriched with hydrocarbons, in particular a natural gas stream. Furthermore, the Liquefied Natural Gas (LNG) technology is a preferred field of application for this invention. Therefore, at least in a preferred embodiment the procedure of the present invention may be applied to all liquefaction methods, wherein the heat exchange between 35 the stream, which is enriched with hydrocarbons and is to be liquefied, and the mixed refrigerant takes place in one or more coiled heat exchanger(s) and/or in one or more plate-type heat exchanger(s).
7a Furthermore, in principle, procedure may be implemented with all mixed cycles, in particular with the so-called Mixed Fluid Cascade processes, with the socalled C3 Mixed Refrigerant Cycle (MRC) process (propane pre-cooled mixed refrigerant process) of the company Air Products, with the so-called Dual Flow Mixed Refrigerant Cycle 5 (MRC) process of the company Shell and/or with the so-called Single Flow Mixed Refrigerant Cycle (MRC) process of the company Linde and/or company Statoil. In principle, it holds true that to the extent two or more mixed refrigerant cycles are used in the method and/or in the arrangement, said at least two mixed refrigerant cycles may be arranged in succession one after the other and/or configured in the manner 10 of cascade.

Claims (20)

1. Method for liquefying a hydrocarbon rich stream by an indirect heat exchange with the mixed refrigerant of at least one mixed refrigerant cycle, which takes 5 place by means of at least one heat exchanger, whereby, after expansion, the mixed refrigerant is vaporized against the hydrocarbon rich stream which is to be liquefied, and against itself, wherein the process is designed in such a manner that between approximately 90 percent and approximately 99 percent of the io mixed refrigerant stream, which is to be vaporized, vaporizes; that subsequently the partially vaporized stream of mixed refrigerant is separated into a gas fraction and into a liquid fraction; that the gas fraction is compressed to a desired final pressure; that the liquid fraction is pumped; and is that finally the gas fraction and the liquid fraction are combined after respective expansion; and wherein the liquid fraction is fed after pumping and separately from the gas fraction to the heat exchanger; is super-cooled, separately from the gas fraction, in the heat exchanger; 20 is expanded after removal from the heat exchanger and separately from the gas fraction to approximately the pressure of the gas fraction, which is expanded; and is combined with the expanded gas fraction, prior to feeding to the heat exchanger. 25
2. Method for liquefying a hydrocarbon rich stream by an indirect heat exchange with the mixed refrigerant of at least one mixed refrigerant cycle, which takes place by means of at least one heat exchanger, whereby, after expansion, the mixed refrigerant is vaporized against the hydrocarbon rich stream which is to be liquefied, and against itself, wherein 30 between approximately 90 percent and approximately 99 percent of the mixed refrigerant stream, which is to be vaporized, vaporizes; subsequently the partially vaporized stream of mixed refrigerant is separated into a gas fraction and into a liquid fraction; the gas fraction is compressed to a desired final pressure; 35 the liquid fraction is pumped; and 9 finally the gas fraction and the liquid fraction are combined after respective expansion; and wherein the liquid fraction is fed after pumping and separately from the gas fraction to the heat exchanger; 5 is super-cooled, separately from the gas fraction, in the heat exchanger; is expanded after removal from the heat exchanger and separately from the gas fraction to approximately the pressure of the gas fraction, which is expanded; and is combined with the expanded gas fraction, prior to feeding to the heat exchanger. I0
3. Method as claimed in claim I or claim 2, wherein the pumping of said liquid fraction is by means of at least one pump.
4. Method as claimed in claim 3, wherein the liquid fraction, which is is slightly super-cooled prior to feeding to the pump, is pumped by means of the pump to the same pressure at which the gas fraction is compressed.
5. Method as claimed in claim 3, wherein the liquid fraction, which is slightly super-cooled prior to feeding to the pump, is pumped by means of the pump to a 20 pressure, by means of which the pressure losses that are induced by the lines assigned to the liquid fraction, and by the heat exchanger and/or by at least one expansion unit that is assigned to the liquid fraction are at least somewhat compensated.
6. Method as claimed in any one of claims I to 5, wherein at least two 25 mixed refrigerant cycles are used, wherein the mixed refrigerant cycles are arranged in succession one after the other.
7. Method as claimed in any one of the claims 1 to 6, wherein at least two mixed refrigerant cycles are used, wherein the mixed refrigerant cycles are arranged in 30 the manner of a cascade.
8. Method as claimed in any one of the claims I to 7, wherein the method for liquefying is by pre-cooling or by super-cooling. 10
9. Method as claimed in any one of the claims I to 8, wherein the hydrocarbon rich stream is a stream of natural gas.
10. Method as claimed in any one of the claims I to 9, wherein the s compressing of said gas fraction to the desired pressure is by means of at least one cold intake compressor.
11. Method as claimed in any one the claims I to 10, wherein the liquid fraction is in its own and/or a separate passage of the heat exchanger. 10
12. Method as claimed in any one of the claims I to 11, wherein the expanding of the liquid fraction after removal from the heat exchanger is by means of an expansion unit assigned to the liquid fraction, and wherein the expansion of the gas fraction is by means of at least one expansion unit assigned to the gas fraction. 15
13. Method as claimed in claim 12, wherein the expansion unit assigned to the liquid fraction comprises at least one valve, and wherein the expansion unit assigned to the gas fraction comprises at least one valve or at least one expansion turbine. 20
14. Method as claimed in any one of the claims I to 13, wherein the heat exchanger comprises at least one of the group consisting of coiled heat exchanger and plate-type exchanger.
15. Arrangement for liquefying a hydrocarbon rich stream, exhibiting 25 at least one heat exchanger for liquefying the hydrocarbon rich stream against a mixed refrigerant of at least one mixed refrigerant cycle, and at least one expansion unit for expansion of the mixed refrigerant so as to perform refrigeration, wherein an evaporation, which takes place after expansion and which ranges from 30 approximately 90 percent to approximately 99 percent of the mixed refrigerant stream against the hydrocarbon rich stream which is to be liquefied, and against itself, at least one separator for separating the partially vaporized mixed refrigerant stream into a gas fraction and into a liquid fraction, at least one compressor for compressing the gas fraction to a desired final 35 pressure, 11 at least one pump for drawing off the liquid fraction from the separator, and a subsequent unification of the gas fraction and the liquid fraction after the separate expansion, and wherein an infeed of the liquid fraction, which takes place behind the pump separately 5 from the gas fraction, to the heat exchanger, a super-cooling of the liquid fraction, which takes place separately from the gas fraction, in the heat exchanger, an expansion of the liquid fraction, which takes place separately from the gas fraction, after removal from the heat exchanger, by means of an expansion unit that is 10 assigned to the liquid fraction, to approximately the pressure of the gas fraction, which is expanded by means of an expansion unit assigned to the gas fraction, and a unification of the expanded liquid fraction with the expanded gas fraction prior to the infeed to the heat exchanger. 15
16. Arrangement as claimed in claim 15, wherein the heat exchanger comprises at least one of the group consisting of coiled heat exchanger and plate-type exchanger.
17. Arrangement as claimed in claim 15 or claim 16, wherein there are at 20 least two mixed refrigerant cycles, which are arranged in succession one after the other and/or in the manner of a cascade.
18. Application of a method as claimed in any one of the claims 1 to 14, and/or at least one arrangement as claimed in any one of the claims 15 to 17, in the 25 Liquefied Natural Gas technology for liquefying a hydrocarbon rich stream with a process of the group consisting of the Mixed Fluid Cascade process, the C3 Mixed Refrigerant Cycle process (propane pre-cooled mixed refrigerant process), the Dual Flow Mixed Refrigerant Cycle process and the Single Flow Mixed Refrigerant Cycle process. 30
19. Method for liquefying hydrocarbon rich stream by an indirect refrigerant cycle substantially as hereinbefore described with reference to the accompanying drawings. 12
20. Arrangement for liquefying a hydrocarbon rich stream substantially as hereinbefore described with reference to the accompanying drawings. Dated 11 February, 2010 5 Shell Internationale Research Maatschappij B.V. Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON
AU2006281407A 2005-08-12 2006-08-11 Method and arrangement for liquefying a stream rich in hydrocarbons Active AU2006281407B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102005038266A DE102005038266A1 (en) 2005-08-12 2005-08-12 Process for liquefying a hydrocarbon-rich stream
DE102005038266.5 2005-08-12
PCT/EP2006/065278 WO2007020252A2 (en) 2005-08-12 2006-08-11 Method and arrangement for liquefying a stream rich in hydrocarbons

Publications (2)

Publication Number Publication Date
AU2006281407A1 AU2006281407A1 (en) 2007-02-22
AU2006281407B2 true AU2006281407B2 (en) 2010-04-01

Family

ID=37681111

Family Applications (1)

Application Number Title Priority Date Filing Date
AU2006281407A Active AU2006281407B2 (en) 2005-08-12 2006-08-11 Method and arrangement for liquefying a stream rich in hydrocarbons

Country Status (4)

Country Link
EP (1) EP1913319A2 (en)
AU (1) AU2006281407B2 (en)
DE (1) DE102005038266A1 (en)
WO (1) WO2007020252A2 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2432534C2 (en) 2006-07-14 2011-10-27 Шелл Интернэшнл Рисерч Маатсхаппий Б.В. Procedure for liquefaction of hydrocarbon flow and device for its realisation
DE102006039661A1 (en) * 2006-08-24 2008-03-20 Linde Ag Process for liquefying a hydrocarbon-rich stream
DE102007053608A1 (en) 2007-11-08 2009-05-20 GFL Gesellschaft für Labortechnik mbH Refrigerant mixture and cooling system containing refrigerant mixture
ITMI20091768A1 (en) * 2009-10-15 2011-04-16 Ecoproject Sas Di Luigi Gazzi E C PROCESS FOR LNG PLANTS ALSO WITH LARGE CAPACITY ASKING FOR LOW VOLUMETRIC REACHES TO REFRIGERATING COMPRESSORS
EP4019869A1 (en) * 2020-12-23 2022-06-29 Linde GmbH Method for liquefying natural gas

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1572900A (en) * 1976-04-21 1980-08-06 Shell Int Research Process of the liquefaction of natural gas
DE19937623A1 (en) * 1999-08-10 2001-02-15 Linde Ag Process for liquefying a hydrocarbon-rich stream e.g. natural gas, comprises carrying out indirect heat exchange with at least one cycle using a two-phase coolant mixture stream before compression
US6250105B1 (en) * 1998-12-18 2001-06-26 Exxonmobil Upstream Research Company Dual multi-component refrigeration cycles for liquefaction of natural gas
AU2005262611A1 (en) * 2004-06-23 2006-01-19 Exxonmobil Upstream Research Company Mixed refrigerant liquefaction process

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4180123A (en) * 1977-02-14 1979-12-25 Phillips Petroleum Company Mixed-component refrigeration in shell-tube exchanger
FR2471566B1 (en) * 1979-12-12 1986-09-05 Technip Cie METHOD AND SYSTEM FOR LIQUEFACTION OF A LOW-BOILING GAS
DE19716415C1 (en) 1997-04-18 1998-10-22 Linde Ag Process for liquefying a hydrocarbon-rich stream

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1572900A (en) * 1976-04-21 1980-08-06 Shell Int Research Process of the liquefaction of natural gas
US6250105B1 (en) * 1998-12-18 2001-06-26 Exxonmobil Upstream Research Company Dual multi-component refrigeration cycles for liquefaction of natural gas
DE19937623A1 (en) * 1999-08-10 2001-02-15 Linde Ag Process for liquefying a hydrocarbon-rich stream e.g. natural gas, comprises carrying out indirect heat exchange with at least one cycle using a two-phase coolant mixture stream before compression
AU2005262611A1 (en) * 2004-06-23 2006-01-19 Exxonmobil Upstream Research Company Mixed refrigerant liquefaction process

Also Published As

Publication number Publication date
EP1913319A2 (en) 2008-04-23
AU2006281407A1 (en) 2007-02-22
DE102005038266A1 (en) 2007-02-15
WO2007020252A3 (en) 2007-05-18
WO2007020252A2 (en) 2007-02-22

Similar Documents

Publication Publication Date Title
AU2008246345B2 (en) Natural gas liquefaction process
JP5725856B2 (en) Natural gas liquefaction process
US6253574B1 (en) Method for liquefying a stream rich in hydrocarbons
JP7022140B2 (en) Precooling of natural gas by high pressure compression and expansion
US6751985B2 (en) Process for producing a pressurized liquefied gas product by cooling and expansion of a gas stream in the supercritical state
JP5410443B2 (en) Method and system for adjusting the cooling capacity of a cooling system based on a gas expansion process
JP4741468B2 (en) Integrated multi-loop cooling method for gas liquefaction
TWI388788B (en) Liquefaction method and system
JP4938452B2 (en) Hybrid gas liquefaction cycle with multiple expanders
AU2006215629C1 (en) Plant and method for liquefying natural gas
US6378330B1 (en) Process for making pressurized liquefied natural gas from pressured natural gas using expansion cooling
AU2008208879B2 (en) Method and apparatus for cooling a hydrocarbon stream
US20140352353A1 (en) Natural Gas Liquefaction System for Producing LNG and Merchant Gas Products
AU2007253406B2 (en) Method and apparatus for treating a hydrocarbon stream
CN107560319A (en) A kind of natural gas ethane recovery device and method using cascade refrigeration
AU2006280426A1 (en) Natural gas liquefaction process for LNG
JP2015501410A (en) Multiple nitrogen expansion process for LNG production
CN205957595U (en) A equipment for single mixed refrigerant process
NO329177B1 (en) Process and system for forming liquid LNG
CN102155841A (en) Cryogenic separation method and apparatus
JP2021526625A (en) Pretreatment and precooling of natural gas by high pressure compression and expansion
AU2006281407B2 (en) Method and arrangement for liquefying a stream rich in hydrocarbons
WO2013148799A2 (en) Process for the separation of air by cryogenic distillation
AU2010213188B2 (en) Method for liquefying a hydrocarbon-rich stream
AU2010238844A1 (en) Method for liquefying a hydrocarbon-rich fraction

Legal Events

Date Code Title Description
PC1 Assignment before grant (sect. 113)

Owner name: SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V.

Free format text: FORMER APPLICANT(S): FOERG, WOLFGANG

FGA Letters patent sealed or granted (standard patent)