AU2016227946A1 - Method for liquefying a hydrocarbon-rich fraction - Google Patents
Method for liquefying a hydrocarbon-rich fraction Download PDFInfo
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- AU2016227946A1 AU2016227946A1 AU2016227946A AU2016227946A AU2016227946A1 AU 2016227946 A1 AU2016227946 A1 AU 2016227946A1 AU 2016227946 A AU2016227946 A AU 2016227946A AU 2016227946 A AU2016227946 A AU 2016227946A AU 2016227946 A1 AU2016227946 A1 AU 2016227946A1
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- Australia
- Prior art keywords
- hydrocarbon
- fraction
- rich fraction
- liquefied
- heat exchanger
- Prior art date
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- 239000004215 Carbon black (E152) Substances 0.000 title claims abstract description 50
- 229930195733 hydrocarbon Natural products 0.000 title claims abstract description 49
- 150000002430 hydrocarbons Chemical class 0.000 title claims abstract description 49
- 238000000034 method Methods 0.000 title claims abstract description 23
- 239000003507 refrigerant Substances 0.000 claims abstract description 41
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 30
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 16
- 239000003345 natural gas Substances 0.000 claims abstract description 15
- 238000000926 separation method Methods 0.000 claims abstract description 11
- 238000001035 drying Methods 0.000 claims abstract description 8
- 239000007788 liquid Substances 0.000 claims description 30
- 238000009835 boiling Methods 0.000 claims description 13
- 239000013529 heat transfer fluid Substances 0.000 claims description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 6
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 claims description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 229910052757 nitrogen Inorganic materials 0.000 claims description 3
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 claims description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 2
- 239000005977 Ethylene Substances 0.000 claims description 2
- 239000001273 butane Substances 0.000 claims description 2
- 238000010276 construction Methods 0.000 claims description 2
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 claims description 2
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 claims description 2
- 239000001294 propane Substances 0.000 claims description 2
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 2
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims description 2
- MEUAVGJWGDPTLF-UHFFFAOYSA-N 4-(5-benzenesulfonylamino-1-methyl-1h-benzoimidazol-2-ylmethyl)-benzamidine Chemical compound N=1C2=CC(NS(=O)(=O)C=3C=CC=CC=3)=CC=C2N(C)C=1CC1=CC=C(C(N)=N)C=C1 MEUAVGJWGDPTLF-UHFFFAOYSA-N 0.000 claims 1
- 239000000203 mixture Substances 0.000 abstract description 8
- 239000012530 fluid Substances 0.000 abstract 3
- 239000007789 gas Substances 0.000 description 13
- 238000001704 evaporation Methods 0.000 description 7
- 230000008020 evaporation Effects 0.000 description 5
- 238000005057 refrigeration Methods 0.000 description 5
- 238000011144 upstream manufacturing Methods 0.000 description 5
- 238000009833 condensation Methods 0.000 description 4
- 230000005494 condensation Effects 0.000 description 4
- 239000003949 liquefied natural gas Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000000498 cooling water Substances 0.000 description 2
- 239000002808 molecular sieve Substances 0.000 description 2
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- AFYPFACVUDMOHA-UHFFFAOYSA-N chlorotrifluoromethane Chemical compound FC(F)(F)Cl AFYPFACVUDMOHA-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000004677 hydrates Chemical class 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004781 supercooling Methods 0.000 description 1
- CYRMSUTZVYGINF-UHFFFAOYSA-N trichlorofluoromethane Chemical compound FC(Cl)(Cl)Cl CYRMSUTZVYGINF-UHFFFAOYSA-N 0.000 description 1
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
- F25J1/0002—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
- F25J1/0055—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle by vaporising a liquid refrigerant stream originating from an incorporated cascade
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0211—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a multi-component refrigerant [MCR] fluid in a closed vapor compression cycle
- F25J1/0212—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a multi-component refrigerant [MCR] fluid in a closed vapor compression cycle as a single flow MCR cycle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0228—Coupling of the liquefaction unit to other units or processes, so-called integrated processes
- F25J1/0235—Heat exchange integration
- F25J1/0237—Heat exchange integration integrating refrigeration provided for liquefaction and purification/treatment of the gas to be liquefied, e.g. heavy hydrocarbon removal from natural gas
- F25J1/0238—Purification or treatment step is integrated within one refrigeration cycle only, i.e. the same or single refrigeration cycle provides feed gas cooling (if present) and overhead gas cooling
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
- F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
- F25J1/0291—Refrigerant compression by combined gas compression and liquid pumping
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2220/00—Processes or apparatus involving steps for the removal of impurities
- F25J2220/60—Separating impurities from natural gas, e.g. mercury, cyclic hydrocarbons
- F25J2220/68—Separating water or hydrates
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Separation By Low-Temperature Treatments (AREA)
Abstract
The invention relates to a method for liquefying a hydrocarbon-rich fraction, in particular natural gas, wherein - the hydrocarbon-rich fraction is pre-cooled before liquefying, is subjected to water separation and a subsequent drying process, and the hydrocarbon-rich fraction is liquefied against at least one mixture refrigerant circuit, wherein - the refrigerant circulating in the mixture refrigerant circuit is compressed in at least two stages, then at least partially condensed and the fluid fraction generated in the process is mixed at least partially with the refrigerant compressed to an intermediate pressure. According to the invention, a partial flow of the fluid fraction (17) is used to pre-cool the hydrocarbon-rich fraction (1, 2) to be liquefied, before the introduction of same to the water separation (D4), wherein the heat exchange between the fluid fraction (17) and the hydrocarbon-rich fraction (1, 2) to be liquefied occurs via at least one heat exchange system (E4).
Description
P15C028WO 1
Description
Method for liquefying a hydrocarbon-rich fraction
The invention relates to a process for liquefying a hydrocarbon-rich fraction, in particular natural gas, where the hydrocarbon-rich fraction is precooled and subjected to water separation and a subsequent drying process before liquefaction and the hydrocarbon-rich fraction is liquefied against at least one mixed refrigerant circuit, where the refrigerant circulating in the mixed refrigerant circuit is compressed in at least two stages, subsequently at least partially condensed and the liquid fraction formed here is at least partly mixed into the refrigerant which has been compressed to an intermediate pressure.
To liquefy hydrocarbon-rich gas fractions, in particular natural gas, use is made of, inter alia, processes employing a refrigerant mixture consisting of light hydrocarbons and nitrogen, with the refrigerant mixture being at least partially condensed at elevated pressure compared to the surroundings. In order to liquefy natural gas, the liquid refrigerant is subsequently vaporized under reduced pressure by indirect heat exchange with the natural gas. Since, in the case of a (non-azeotropic) mixture, the dew point at a given pressure is always above the boiling point, the refrigerant evaporation takes place, depending on the composition, gradually over a temperature range which extends, depending on the process, over at least 20°C, sometimes even over 200°C.
If the capital costs for a natural gas liquefaction plant are to be kept low, a mixture circuit of the above-described type is used exclusively for the entire temperature range from ambient temperature to LNG (Liquefied Natural Gas) product temperature (about -160°C). The use of a separate precooling circuit for the temperature range from ambient temperature to about -50°C is dispensed with here.
In a procedure of this type, which is usually referred to as SMR (Single Mixed Refrigerant) process, only one refrigerant, or substreams thereof, which displays
P15C028WO 2 gradual evaporation is thus available. Such a natural gas liquefaction process is known, for example, from DE 19722490.
Before liquefaction, the natural gas is generally freed of acidic gas components, such as C02 and H2S, by means of a chemical scrub, for example an amine scrub. As a result, the natural gas is saturated with water (vapor). In order to achieve an economical design of the subsequent drying, which is generally based on adsorption on a zeolitic molecular sieve, the natural gas is cooled as far as possible and the water concentration is reduced by partial water condensation and subsequent water separation to such an extent that a limit is imposed on the threshold formation of hydrates or water ice. This limit is, depending on the gas composition, attained at a temperature of up to 20°C.
Under many climatic conditions, it is not possible to cool the natural gas to sufficiently close (not more than 10°C, preferably 5°C, above the hydrate temperature) to the abovementioned limit temperature against air and/or cooling water.
Mixed refrigerants are, owing to the gradual evaporation, not very suitable for very precisely attaining the optimum temperature of the moist natural gas before drying in an economical way without at the same time going below the hydrate temperature at least in parts of the heat exchanger used.
It is an object of the present invention to provide a process of the type in question for liquefying a hydrocarbon-rich fraction, which makes it possible for the hydrocarbon-rich fraction to be liquefied to be precooled before drying without use of a complete precooling circuit, i.e. without an additional compressor. In particular, the hydrocarbon-rich fraction should be precooled to a temperature of not more than 10°C above, preferably not more than 5°C above, the hydrate temperature without the moist hydrocarbon-rich fraction coming into thermal contact with temperatures below the hydrate point.
To achieve this object, a process of the type in question for liquefying a hydrocarbon-rich fraction, which is characterized in that a substream of the liquid fraction serves for precooling the hydrocarbon-rich fraction to be liquefied before the latter fraction is fed to the water separation, where heat exchange between the liquid fraction and the
P15C028WO 3 hydrocarbon-rich fraction to be liquefied is effected by means of at least one heat exchanger system, is proposed.
In a further embodiment of the process of the invention for liquefying a hydrocarbon-rich fraction, it is proposed that a substream of the liquid fraction of the refrigerant be depressurized to a pressure of at least 0.3 bar above, preferably at least 0.7 bar above, the suction pressure of the second or last compressor stage and only the liquid fraction formed here be used for precooling the hydrocarbon-rich fraction to be liquefied before the latter is fed to the water separation.
According to the invention, the precooling of the hydrocarbon-rich fraction to be liquefied before this fraction is fed to the water separation is effected against a substream of the liquid fraction formed in the partial condensation of the compressed refrigerant. Here, the heat exchange between this liquid fraction and the hydrocarbon-rich fraction to be liquefied is achieved by means of a heat exchanger system. The heat exchanger system serves to effect indirect heat transfer between the hydrocarbon-rich fraction to be liquefied and the gradually evaporating refrigerant.
For the purposes of the present invention, the term “heat exchanger system” refers to any system in which indirect heat transfer occurs between at least two media by means of a heat transfer fluid. Such a heat exchanger system is known, for example, from the US patent 2,119,091.
Such heat exchanger systems preferably use a boiling pure material which is present in liquid form in the temperature range from 0 to 30°C, which can be, for example, ethane, ethylene, propane, propylene, butane, carbon dioxide or ammonia, as heat transfer fluid.
The heat exchanger system is preferably made up of two bundles of straight tubes, two helically coiled heat exchangers, two plate exchangers or any combination of these construction types, where the aforementioned heat exchanger components have preferably been installed in a pressure vessel which contains the boiling heat transfer fluid.
P15C028WO 4
Suitable selection of the pure material heat transfer fluid and regulation of the operating pressure thereof and thus the boiling point thereof enable the hydrocarbon-rich fraction to be cooled to very close to the hydrate temperature without coming directly into thermal contact with an unacceptably cold refrigerant stream. The heat transfer fluid brings about the desired heat transfer comparatively efficiently by continual condensation on the refrigerant side and evaporation on the side of the hydrocarbon-rich fraction. In contrast to the gradually evaporating mixed refrigerant, the heat transfer fluid operates at constant boiling point and thus dew point. Even if the condensation of the heat transfer fluid occurs at least partially against a mixed refrigerant which vaporizes below the hydrate temperature of the hydrocarbon-rich fraction, the hydrocarbon-rich fraction and the mixed refrigerant are effectively separated thermally by the heat transfer fluid.
The procedure according to the invention makes it possible for the load on the drying process to be optimally reduced by cooling of the hydrocarbon-rich fraction to be liquefied or of the natural gas to be liquefied down to close to the hydrate point, and also enables water separation.
The process of the invention for liquefying a hydrocarbon-rich fraction and also further advantageous embodiments thereof are illustrated in more detail by the working examples depicted in figures 1 and 2.
In the working examples depicted in figures 1 and 2, which differ merely in terms of the actual liquefaction process, the hydrocarbon-rich fraction 1 to be liquefied, which normally has a temperature in the range from 40 to 80°C, is cooled to a temperature in the range from 30 to 60°C against cooling air and/or cooling water in the heat exchanger E3. The hydrocarbon-rich fraction 2 to be liquefied is subsequently fed to a heat exchanger system E4 and precooled in this to a temperature of not more than 10°C above, preferably not more than 5°C above, its hydrate temperature. The hydrocarbon-rich fraction 3 which has been pre-cooled in this way is fed to a separator D4 at the bottom of which the condensed-out water 4 is obtained. The hydrocarbon-rich fraction 5 taken off at the top of the separator D4 is then fed to a drying process T which is depicted merely as a black box. This is normally an adsorption process in which a zeolitic molecular sieve is normally used as adsorbent. The hydrocarbon-rich fraction 6 which is to be liquefied and has been pretreated in this way is subsequently
P15C028WO 5 cooled, liquefied and optionally supercooled in the heat exchanger E against the refrigeration circuit yet to be explained, so that, in the case of natural gas liquefaction, an LNG product stream can be taken off via conduit 7.
The liquefaction of the hydrocarbon-rich fraction occurs against a mixed refrigerant circuit in the working examples depicted in figures 1 and 2. Such mixed refrigerant circuits usually have nitrogen and at least one Ci+-hydrocarbon as refrigerant. The refrigerant 10 to be compressed is compressed to an intermediate pressure in the first compressor stage C1. The compressed refrigerant 11 is subsequently partially condensed in the after-cooler E1 and separated in the separator D2 into a relatively low-boiling gas fraction 12 and a relatively high-boiling liquid fraction 15. Only the lower-boiling gas fraction 12 is compressed to the maximum circuit pressure in the second compressor stage C2. The compressed refrigerant 13 is again partially condensed in the after-cooler E2 and separated in the separator D3 into a gas fraction 14 and a liquid fraction 17/17’. In the working example depicted in figure 1, the gas fraction 14 and the abovementioned, relatively high-boiling refrigerant liquid fraction 15, which is pumped by means of the pump P to the pressure of the refrigerant gas fraction 14, are together cooled against themselves in the heat exchanger E and subsequently depressurized in the depressurization valve V4 in order to provide refrigeration. The refrigeration-providing depressurized refrigerant 16 is then completely vaporized in the heat exchanger E against the hydrocarbon-rich fraction 6 to be liquefied and is again fed to the separator D1 located upstream of the first compressor stage C1; this serves to secure the compressor stage C1 since liquid fractions which may be entrained therein are separated off.
Whereas the refrigerant liquid fraction 17’ taken off from the separator D3 is entirely recirculated via the depressurization valve V1 to a point upstream of the separator D2 in the methods of the prior art, a substream 17 of this liquid fraction is now employed for precooling the hydrocarbon-rich fraction 1/2 to be liquefied. For this purpose, the above-described substream 17 of the liquid fraction is depressurized in the valve V2, preferably to a pressure of at least 0.3 bar above, in particular at least 0.7 bar above, the suction pressure of the second compressor stage C2, and the resulting two-phase stream is fed to the separator D5. The gas fraction 19 present therein is recirculated via the regulating valve V3 to a point upstream of the separator D2, while the liquid fraction 18 obtained in the separator D5 is employed for precooling the hydrocarbon-rich
P15C028WO 6 fraction 1/2 to be liquefied and the liquid fraction 18 is subsequently likewise recirculated to a point upstream of the separator D2.
Heat exchange between the liquid fraction 17 or the liquid fraction 18 obtained after depressurization in the valve V2 and the hydrocarbon-rich fraction 1/2 to be liquefied is effected by means of the heat exchanger system E4.
In the working example depicted in figure 2, the relatively high-boiling liquid fraction 50 of the refrigerant which has been taken off from the separator D2 and the refrigerant gas fraction 40 which has been taken off from the separator D3 are cooled separately in the precooling zone a of the heat exchanger E’. While the relatively high-boiling liquid fraction 50 is depressurized in the valve V5 to provide refrigeration and subsequently vaporized in countercurrent to the hydrocarbon-rich fraction 6 to be liquefied, the abovementioned gas fraction 40 is partially condensed and separated in the separator D6 into a further gas fraction 41 and a further liquid fraction 42. The gas fraction 41 is cooled and partially condensed in the liquefaction and supercooling zones b and c of the heat exchanger E’. It is subsequently depressurized in the depressurization valve V7 to provide refrigeration and completely vaporized in countercurrent to the hydrocarbon-rich fraction 6 which is to be liquefied and optionally to be supercooled. The liquid fraction 42 obtained in the separator D6 is cooled further in the liquefaction zone b of the heat exchanger E’, depressurized in the depressurization valve V6 to provide refrigeration and completely vaporized in countercurrent to the hydrocarbon-rich fraction 6 to be liquefied. If the heat exchanger E’ depicted in figure 2 is configured as a so-called helically coiled heat exchanger, evaporation of the abovementioned refrigerant streams 41,42 and 50 occurs in the outer jacket of the helically coiled heat exchanger. The refrigerant streams 41,42 and 50 which have been combined in the heat exchanger E’ and completely vaporized therein are fed via conduit 43 to the separator D1 located upstream of the first compressor stage C1.
Claims (5)
- Patent Claims1. A process for liquefying a hydrocarbon-rich fraction, in particular natural gas, where - the hydrocarbon-rich fraction is precooled and subjected to water separation and a subsequent drying process before liquefaction and - the hydrocarbon-rich fraction is liquefied against at least one mixed refrigerant circuit, - where the refrigerant circulating in the mixed refrigerant circuit is compressed in at least two stages, subsequently at least partially condensed and the liquid fraction formed here is at least partly mixed into the refrigerant which has been compressed to an intermediate pressure, characterized in that a substream of the liquid fraction (17) serves for precooling the hydrocarbon-rich fraction to be liquefied (1,2) before it is fed to the water separation (D4), where heat exchange between the liquid fraction (17) and the hydrocarbon-rich fraction to be liquefied (1,2) is effected by means of at least one heat exchanger system (E4).
- 2. The process as claimed in claim 1, characterized in that the substream of the liquid fraction (17) is depressurized to a pressure of at least 0.3 bar above, preferably at least 0.7 bar above, the suction pressure of the second or last compressor stage (V2) and only the liquid fraction (18) formed here serves for precooling the hydrocarbon-rich fraction to be liquefied (1,2) before it is fed to the water separation (D4).
- 3. The process as claimed in claim 1 or 2, characterized in that a boiling pure material which is present in liquid form in the temperature range from 0 to 30°C, preferably ethane, ethylene, propane, propylene, butane, C02 or NH3, is used as heat transfer fluid of the heat exchanger system (E4).
- 4. The process as claimed in any of claims 1 to 3, characterized in that the heat exchanger system (E4) is made up of two bundles of straight tubes, two helically coiled heat exchangers, two plate exchangers or any combination of these construction types, where the heat exchanger components have preferably been installed in a pressure vessel which contains the boiling heat transfer fluid.
- 5. The process as claimed in any of claims 1 to 4, characterized in that the refrigerant circulating in the mixed refrigerant circuit comprises nitrogen and at least one C1+-hydrocarbon.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102015002822.7 | 2015-03-05 | ||
DE102015002822.7A DE102015002822A1 (en) | 2015-03-05 | 2015-03-05 | Process for liquefying a hydrocarbon-rich fraction |
PCT/EP2016/000231 WO2016138978A1 (en) | 2015-03-05 | 2016-02-11 | Method for liquefying a hydrocarbon-rich fraction |
Publications (1)
Publication Number | Publication Date |
---|---|
AU2016227946A1 true AU2016227946A1 (en) | 2017-09-28 |
Family
ID=55349784
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AU2016227946A Abandoned AU2016227946A1 (en) | 2015-03-05 | 2016-02-11 | Method for liquefying a hydrocarbon-rich fraction |
Country Status (6)
Country | Link |
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US (1) | US20180045459A1 (en) |
CN (1) | CN107407519A (en) |
AU (1) | AU2016227946A1 (en) |
DE (1) | DE102015002822A1 (en) |
RU (1) | RU2705130C2 (en) |
WO (1) | WO2016138978A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2020204218A1 (en) * | 2019-04-01 | 2020-10-08 | 삼성중공업 주식회사 | Cooling system |
WO2024096757A1 (en) * | 2022-11-02 | 2024-05-10 | Gasanova Olesya Igorevna | Natural gas liquefaction method |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
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US2119091A (en) | 1935-11-29 | 1938-05-31 | Standard Oil Dev Co | Process and apparatus for indirect heat transfer between two liquid materials |
FR2471566B1 (en) * | 1979-12-12 | 1986-09-05 | Technip Cie | METHOD AND SYSTEM FOR LIQUEFACTION OF A LOW-BOILING GAS |
US4970867A (en) * | 1989-08-21 | 1990-11-20 | Air Products And Chemicals, Inc. | Liquefaction of natural gas using process-loaded expanders |
DE19722490C1 (en) | 1997-05-28 | 1998-07-02 | Linde Ag | Single flow liquefaction of hydrocarbon-rich stream especially natural gas with reduced energy consumption |
DE102006021620B4 (en) * | 2006-05-09 | 2019-04-11 | Linde Ag | Pretreatment of a liquefied natural gas stream |
DE102009018248A1 (en) * | 2009-04-21 | 2010-10-28 | Linde Aktiengesellschaft | Process for liquefying a hydrocarbon-rich fraction |
US20100281915A1 (en) * | 2009-05-05 | 2010-11-11 | Air Products And Chemicals, Inc. | Pre-Cooled Liquefaction Process |
US20150300731A1 (en) * | 2012-11-21 | 2015-10-22 | Shell Oil Company | Method of treating a hydrocarbon stream comprising methane, and an apparatus therefor |
RU2538192C1 (en) * | 2013-11-07 | 2015-01-10 | Открытое акционерное общество "Газпром" | Method of natural gas liquefaction and device for its implementation |
-
2015
- 2015-03-05 DE DE102015002822.7A patent/DE102015002822A1/en not_active Withdrawn
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2016
- 2016-02-11 CN CN201680013941.6A patent/CN107407519A/en active Pending
- 2016-02-11 RU RU2017132312A patent/RU2705130C2/en active
- 2016-02-11 AU AU2016227946A patent/AU2016227946A1/en not_active Abandoned
- 2016-02-11 WO PCT/EP2016/000231 patent/WO2016138978A1/en active Application Filing
- 2016-02-11 US US15/555,745 patent/US20180045459A1/en not_active Abandoned
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DE102015002822A1 (en) | 2016-09-08 |
CN107407519A (en) | 2017-11-28 |
US20180045459A1 (en) | 2018-02-15 |
RU2017132312A3 (en) | 2019-04-08 |
WO2016138978A1 (en) | 2016-09-09 |
RU2705130C2 (en) | 2019-11-05 |
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