CA2919209A1 - Process for liquefaction of natural gas - Google Patents
Process for liquefaction of natural gas Download PDFInfo
- Publication number
- CA2919209A1 CA2919209A1 CA2919209A CA2919209A CA2919209A1 CA 2919209 A1 CA2919209 A1 CA 2919209A1 CA 2919209 A CA2919209 A CA 2919209A CA 2919209 A CA2919209 A CA 2919209A CA 2919209 A1 CA2919209 A1 CA 2919209A1
- Authority
- CA
- Canada
- Prior art keywords
- stream
- natural gas
- cooled
- liquid
- liquefied
- 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.)
- Abandoned
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 179
- 239000003345 natural gas Substances 0.000 title claims abstract description 77
- 238000000034 method Methods 0.000 title claims abstract description 37
- 239000003949 liquefied natural gas Substances 0.000 claims abstract description 62
- 229910001868 water Inorganic materials 0.000 claims abstract description 21
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 20
- 238000010926 purge Methods 0.000 claims abstract description 11
- 239000007788 liquid Substances 0.000 claims description 46
- 238000010791 quenching Methods 0.000 claims description 39
- 239000012535 impurity Substances 0.000 claims description 27
- 239000007787 solid Substances 0.000 claims description 24
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 21
- 229930195733 hydrocarbon Natural products 0.000 claims description 18
- 150000002430 hydrocarbons Chemical class 0.000 claims description 18
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 16
- 238000003860 storage Methods 0.000 claims description 13
- 239000004215 Carbon black (E152) Substances 0.000 claims description 12
- 229910052757 nitrogen Inorganic materials 0.000 claims description 10
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 8
- 239000001569 carbon dioxide Substances 0.000 claims description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 5
- 239000001257 hydrogen Substances 0.000 claims description 5
- 229910052739 hydrogen Inorganic materials 0.000 claims description 5
- 239000001301 oxygen Substances 0.000 claims description 5
- 229910052760 oxygen Inorganic materials 0.000 claims description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 4
- 238000000926 separation method Methods 0.000 claims description 4
- 239000002245 particle Substances 0.000 claims description 3
- 239000000356 contaminant Substances 0.000 abstract description 15
- 238000004519 manufacturing process Methods 0.000 abstract description 7
- 239000007789 gas Substances 0.000 description 17
- 239000000110 cooling liquid Substances 0.000 description 16
- 238000001816 cooling Methods 0.000 description 11
- 239000000047 product Substances 0.000 description 7
- 238000009833 condensation Methods 0.000 description 5
- 230000005494 condensation Effects 0.000 description 5
- 239000001307 helium Substances 0.000 description 4
- 229910052734 helium Inorganic materials 0.000 description 4
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 4
- 238000000746 purification Methods 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 101100456566 Caenorhabditis elegans dpy-22 gene Proteins 0.000 description 3
- 239000002910 solid waste Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 239000012809 cooling fluid Substances 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- 230000008014 freezing Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000001335 aliphatic alkanes Chemical class 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 239000002283 diesel fuel Substances 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 239000012065 filter cake Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical compound C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000005057 refrigeration Methods 0.000 description 1
- 239000011555 saturated liquid Substances 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
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- 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
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- 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
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- 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
- F25J1/006—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the refrigerant fluid used
- F25J1/007—Primary atmospheric gases, mixtures thereof
- F25J1/0072—Nitrogen
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- 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
- F25J1/0203—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 single-component refrigerant [SCR] fluid in a closed vapor compression cycle
- F25J1/0204—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 single-component refrigerant [SCR] fluid in a closed vapor compression cycle as a single flow SCR cycle
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- 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
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/0204—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the feed stream
- F25J3/0209—Natural gas or substitute natural gas
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- 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
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/0228—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the separated product stream
- F25J3/0233—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the separated product stream separation of CnHm with 1 carbon atom or more
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- 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
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/0228—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the separated product stream
- F25J3/0238—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the separated product stream separation of CnHm with 2 carbon atoms or more
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- 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
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/0228—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the separated product stream
- F25J3/0257—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream characterised by the separated product stream separation of nitrogen
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
- C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
- C10L3/10—Working-up natural gas or synthetic natural gas
- C10L3/101—Removal of contaminants
- C10L3/106—Removal of contaminants of water
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- 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
- F25J2205/00—Processes or apparatus using other separation and/or other processing means
- F25J2205/30—Processes or apparatus using other separation and/or other processing means using a washing, e.g. "scrubbing" or bubble column for purification purposes
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- 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
- F25J2205/00—Processes or apparatus using other separation and/or other processing means
- F25J2205/84—Processes or apparatus using other separation and/or other processing means using filter
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- 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
- F25J2215/00—Processes characterised by the type or other details of the product stream
- F25J2215/04—Recovery of liquid products
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2220/00—Processes or apparatus involving steps for the removal of impurities
- F25J2220/60—Separating impurities from natural gas, e.g. mercury, cyclic hydrocarbons
- F25J2220/62—Separating low boiling components, e.g. He, H2, N2, Air
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- 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
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- 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
- F25J2220/66—Separating acid gases, e.g. CO2, SO2, H2S or RSH
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- 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
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- 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
- F25J2270/00—Refrigeration techniques used
- F25J2270/42—Quasi-closed internal or closed external nitrogen refrigeration cycle
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Separation By Low-Temperature Treatments (AREA)
Abstract
A process and system for production of liquefied natural gas (LNG) from natural gas. The natural gas is first partially purified by removal of water and other contaminants, followed by partial chilling to freeze some contaminants and to allow for production of a purge stream to remove other contaminants. These contaminants may be removed from the stream. The process has advantages of low cost and improved removal of contaminants.
Description
PROCESS FOR LIQUEFACTION OF NATURAL GAS
PRIORITY CLAIM OF EARLIER NATIONAL APPLICATIONS
[0001] This application claims priority to U.S. Application No.
61/860,319 filed July 31, 2013 and U.S. Application No. 14/338,982 filed July 23, 2014.
BACKGROUND OF THE INVENTION
PRIORITY CLAIM OF EARLIER NATIONAL APPLICATIONS
[0001] This application claims priority to U.S. Application No.
61/860,319 filed July 31, 2013 and U.S. Application No. 14/338,982 filed July 23, 2014.
BACKGROUND OF THE INVENTION
[0002] Liquefied natural gas or LNG is natural gas (predominantly methane, CH4) that has been converted to liquid form for ease of storage or transport. The liquefaction process involves removal of certain components, such as dust, acid gases, helium, water, and heavy hydrocarbons, which could cause difficulty downstream in the liquefaction process.
The natural gas is condensed into a liquid at ambient pressure. It is typically liquefied at ambient pressure at ¨101 C (maximum transport pressure set at around 25 kPa (3.6 psi) and then cooled to ¨162 C by using a Joule-Thompson expansion or through the use of a subcooler. By raising the pressure of liquefaction, the latent duty is reduced, improving the efficiency of the liquefaction cycle. LNG achieves a higher reduction in volume than compressed natural gas (CNG) so that the energy density of LNG is 2.4 times greater than that of CNG and 60% of that of diesel fuel. This makes LNG cost efficient to transport over long distances where pipelines do not exist.
The natural gas is condensed into a liquid at ambient pressure. It is typically liquefied at ambient pressure at ¨101 C (maximum transport pressure set at around 25 kPa (3.6 psi) and then cooled to ¨162 C by using a Joule-Thompson expansion or through the use of a subcooler. By raising the pressure of liquefaction, the latent duty is reduced, improving the efficiency of the liquefaction cycle. LNG achieves a higher reduction in volume than compressed natural gas (CNG) so that the energy density of LNG is 2.4 times greater than that of CNG and 60% of that of diesel fuel. This makes LNG cost efficient to transport over long distances where pipelines do not exist.
[0003] Specially designed cryogenic sea vessels (LNG carriers) or cryogenic road tankers are used for its transport. The natural gas fed into the LNG plant is treated to remove water, hydrogen sulfide, carbon dioxide and other components that will freeze (such as benzene) under the low temperatures needed for storage or be destructive to the liquefaction facility. Also, hydrocarbons heavier than methane are removed for higher value uses. LNG
typically contains more than 90% methane. It also contains small amounts of ethane, propane, butane, some heavier alkanes, and Nitrogen. The purification process can be designed to give almost 100% methane.
typically contains more than 90% methane. It also contains small amounts of ethane, propane, butane, some heavier alkanes, and Nitrogen. The purification process can be designed to give almost 100% methane.
[0004] The cost of building an LNG liquefaction plant has steadily increased by five times more as compared to ten years ago, largely due to high raw material prices as well as other factors. Due to these high costs it is desirable to develop more efficient processes and equipment for producing LNG.
[0005] Pipeline natural gas typically contains levels of H20, CO2, and other materials which are perceived to require removal prior to liquefaction. Due to their freeze points, during the cooling process, these materials will tend to foul the heat exchangers and lead to blockages. Therefore, in order to solve this problem, the industry will typically use PSA, solvent scrubbers and membranes in order to remove these contaminants prior to liquefaction.
While cost effective in large scale units, the additional costs in small scale units tends to drive up the total cost of ownership for the production of LNG. The issue therefore is to extract these contaminants without adding large amounts of capital cost.
SUMMARY OF THE INVENTION
While cost effective in large scale units, the additional costs in small scale units tends to drive up the total cost of ownership for the production of LNG. The issue therefore is to extract these contaminants without adding large amounts of capital cost.
SUMMARY OF THE INVENTION
[0006] The invention provides a process and a system for producing a LNG
product.
There are several variations of the process and the system. The process, which uses several purification devices, chillers and a column, includes multiple steps.
product.
There are several variations of the process and the system. The process, which uses several purification devices, chillers and a column, includes multiple steps.
[0007] In an embodiment of the process, at least a portion of the supply of natural gas is at least partially purified with removal of water and other contaminants. The next step is to feed a stream of LNG as well as the supply of natural gas to a column such as a quench tower. The first section of the process uses latent heat in the LNG to cool the feed incoming natural gas. The first section is run with excess liquid such that the volatile components in the natural gas as condensed and frozen into the cooling liquid.
[0008] The chilled gas may be a quantity of the product from the process, liquefied natural gas. A portion of at least one contaminant condenses, solidifies or dissolves. The next step may be to filter out these contaminants followed by further cooling to the necessary temperature to produce LNG. In another embodiment of the invention, solids may end up in the end product.
[0009] The process involves liquefaction of natural gas, comprising cooling a natural gas stream to a temperature from 00 to ¨100 C to produce a cooled natural gas stream, sending the cooled natural gas stream to a quench unit, sending a quantity of liquefied natural gas to the quench unit to be combined with the cooled natural gas steam to produce a bottoms stream comprising an intermediate cooled natural gas stream comprising solid impurities and a top stream comprising methane and incondensable impurities, The bottoms stream is then sent to a unit to remove solid impurities to a produce a purified bottoms stream; and the purified bottoms stream is then cooled to produce liquefied natural gas. Prior to the cooling of the natural gas stream, at least a portion of water is removed as well as other contaminants.
The natural gas stream may be cooled to a temperature of ¨25 to ¨75 C or ¨55 to ¨60 C.
The solid impurities that are removed include carbon dioxide, C5 and C6 hydrocarbons and water. The incondensable impurities are selected from the group consisting of nitrogen, helium, oxygen and hydrogen. Typically, the bottoms stream is at a temperature from ¨75 to ¨120 C and preferably it is at a temperature from ¨90 to ¨100 C. The invention also comprises a system for producing liquefied natural gas from a supply of natural gas, comprising a device for supplying a stream of natural gas, a separation device to remove water and other impurities from the stream of natural gas to produce a partially dried stream of natural gas, a means for feeding the partially dried stream of natural gas to a chilling device and then to a quench tower, a means for feeding a quantity of a chilled liquid to the quench tower where the chilled liquid and said partially dried stream of natural gas are present in said quench tower and a means to vent a purge stream from said quench tower; a means to transport a combination of the chilled liquid and the partially dried stream of natural gas to a filter unit; a means to transport a purified stream from the filter unit to a chiller to produce liquefied natural gas and a means to the said liquefied natural gas to a storage device.
The LNG may then be transported by ship or truck to a customer.
The natural gas stream may be cooled to a temperature of ¨25 to ¨75 C or ¨55 to ¨60 C.
The solid impurities that are removed include carbon dioxide, C5 and C6 hydrocarbons and water. The incondensable impurities are selected from the group consisting of nitrogen, helium, oxygen and hydrogen. Typically, the bottoms stream is at a temperature from ¨75 to ¨120 C and preferably it is at a temperature from ¨90 to ¨100 C. The invention also comprises a system for producing liquefied natural gas from a supply of natural gas, comprising a device for supplying a stream of natural gas, a separation device to remove water and other impurities from the stream of natural gas to produce a partially dried stream of natural gas, a means for feeding the partially dried stream of natural gas to a chilling device and then to a quench tower, a means for feeding a quantity of a chilled liquid to the quench tower where the chilled liquid and said partially dried stream of natural gas are present in said quench tower and a means to vent a purge stream from said quench tower; a means to transport a combination of the chilled liquid and the partially dried stream of natural gas to a filter unit; a means to transport a purified stream from the filter unit to a chiller to produce liquefied natural gas and a means to the said liquefied natural gas to a storage device.
The LNG may then be transported by ship or truck to a customer.
[0010]
The invention overcomes the issue of fouling or blocking of the heat exchange device used to liquefy the natural gas by undertaking the majority of the cooling duty of the natural gas stream through direct contact with sub cooled LNG or saturated LNG. The natural gas stream is introduced to a quench unit and sending a quantity of liquefied natural gas to the quench unit to be combined with the natural gas stream, a bottoms stream comprising solid impurities in a liquefied hydrocarbon is produced and a top stream comprising methane and incondensable impurities. The bottoms stream is then sent to a unit to remove solid impurities to a produce a purified bottoms stream. The bottoms stream may be cooled to the liquefied natural gas temperature prior to or after purification. Without a reduction in pressure, this cooling of the natural gas will produce a sub cooled liquefied natural gas. A
portion of the impurities, such as water, may be removed by first passing the gas through other impurity removal devices in order to enable some of the cooling to be undertaken in an indirect heat exchange device. In such a case, the natural gas stream may be cooled to a temperature of ¨25 to ¨75 C prior to introduction into the quench device. The solid impurities that are removed include carbon dioxide, C5 and C6 hydrocarbons and water. The incondensable impurities are selected from the group consisting of nitrogen, oxygen, helium and hydrogen. Typically, the bottoms stream is at a temperature from ¨75 to ¨120 C and preferably it is at a temperature from ¨90 to ¨100 C. The top stream may be condensed using either an indirect liquefaction process, such as a heat exchanger, or through direct contact with a portion of the sub cooled liquefied natural gas. Further, by running this top stream liquefied with excess sub cooled natural gas, a feed stream of sub cooled or saturated LNG may be provided to the quench unit. A means to transport a purified stream from the filter unit to a chiller to produce liquefied natural gas and a means to the said liquefied natural gas to a storage device. The LNG may then be transported by ship or truck to a customer.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention overcomes the issue of fouling or blocking of the heat exchange device used to liquefy the natural gas by undertaking the majority of the cooling duty of the natural gas stream through direct contact with sub cooled LNG or saturated LNG. The natural gas stream is introduced to a quench unit and sending a quantity of liquefied natural gas to the quench unit to be combined with the natural gas stream, a bottoms stream comprising solid impurities in a liquefied hydrocarbon is produced and a top stream comprising methane and incondensable impurities. The bottoms stream is then sent to a unit to remove solid impurities to a produce a purified bottoms stream. The bottoms stream may be cooled to the liquefied natural gas temperature prior to or after purification. Without a reduction in pressure, this cooling of the natural gas will produce a sub cooled liquefied natural gas. A
portion of the impurities, such as water, may be removed by first passing the gas through other impurity removal devices in order to enable some of the cooling to be undertaken in an indirect heat exchange device. In such a case, the natural gas stream may be cooled to a temperature of ¨25 to ¨75 C prior to introduction into the quench device. The solid impurities that are removed include carbon dioxide, C5 and C6 hydrocarbons and water. The incondensable impurities are selected from the group consisting of nitrogen, oxygen, helium and hydrogen. Typically, the bottoms stream is at a temperature from ¨75 to ¨120 C and preferably it is at a temperature from ¨90 to ¨100 C. The top stream may be condensed using either an indirect liquefaction process, such as a heat exchanger, or through direct contact with a portion of the sub cooled liquefied natural gas. Further, by running this top stream liquefied with excess sub cooled natural gas, a feed stream of sub cooled or saturated LNG may be provided to the quench unit. A means to transport a purified stream from the filter unit to a chiller to produce liquefied natural gas and a means to the said liquefied natural gas to a storage device. The LNG may then be transported by ship or truck to a customer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates a flow scheme for the production of liquefied natural gas from natural gas through indirect condensation
[0012] FIG. 2 illustrates an alternative flow scheme of the production of liquefied natural gas from natural gas through direct condensation
[0013] FIG. 3 illustrates a flow scheme in which LNG is generated from the quench condensate DETAILED DESCRIPTION
[0014] The invention solves the problem by undertaking the liquefaction in a way which does not lead to blockage of the condenser. Therefore, contaminants can be introduced into this unit, and then removed as a solid from the resulting LNG. While it is feasible to purify the natural gas to a level that allows for production of LNG, the present invention provides a process to reduce overall costs of production.
[0015] Low cost precleaning of the natural gas stream may also take place as needed, reducing the load on the filters. In an embodiment, the design would spray supercooled LNG
into the top of a column, and introduce the warmer natural gas feed into the bottom where the supercooled LNG and warmer natural gas feed would mix. While the two fluids would be thermally in equilibrium at the top of the column, at the bottom there may be more than a 38 C (100 F) temperature difference in temperature between the liquid and the gas. The thermal equilibrium will occur partway down the column. Given that at the top of the column, liquefaction of the methane rich gas is taking place through contact with a methane rich liquid, the liquid must be at a colder temperature than the gas phase.
into the top of a column, and introduce the warmer natural gas feed into the bottom where the supercooled LNG and warmer natural gas feed would mix. While the two fluids would be thermally in equilibrium at the top of the column, at the bottom there may be more than a 38 C (100 F) temperature difference in temperature between the liquid and the gas. The thermal equilibrium will occur partway down the column. Given that at the top of the column, liquefaction of the methane rich gas is taking place through contact with a methane rich liquid, the liquid must be at a colder temperature than the gas phase.
[0016] This quenching operation at the bottom of the column preferentially extracts the contaminants into the liquid phase where they can be extracted. The lighter components rise up the column, where they in turn condense. Some of the nitrogen, helium, hydrogen, argon and oxygen may exit the top of the column as a small purge stream while some of these gases may form part of the product. A small portion of the methane stream will also escape into the purge stream. All other components, including carbon dioxide and water, are condensed into a 'dirty' LNG then passes through a series of filters to be cleaned and then cooled to the necessary storage tank temperature of ¨161 C (-257 F) by using Joule-Thompson expansion or a subcooler. From this tank, liquid is pumped to the top of the column in order to condense the feed. Periodically, the hydrocarbon/carbon dioxide filter cake would be removed and either combusted or used in other applications. The unit therefore would consist of a low cost front end bed (dryer or similar unit), precooler, wash column, filter, subcooler, storage tank and pump.
[0017] US 6,637,240 described a method for making nitrogen gas using a tank of liquid nitrogen. Cool air is introduced into the bottom, and liquid nitrogen is introduced at the top.
Akin to this unit, the temperature difference at the bottom of the column produces the same sort of cryogenic quench. Further the bottoms (a crude dirty liquid oxygen) is viewed as waste and not subsequently subcooled in order to generate both a product as well as the quenching liquid. In other cryogenic nitrogen patents, the crude liquid oxygen is sub cooled through a Joule Thompson effect and used to provide liquid to the top of the column.
However, it achieves this though indirect heat exchange with the top gases and not by direct contact. Due to the higher temperature difference between the freeze point of the solids and the internal surfaces of the column, the solids do not foul the column. It is only with low temperature differential during freezing that the two solids can form a cohesive bond. One key factor is that fouling does not take place in the quench because of the high temperature difference between the solid surfaces and the incoming natural gas. Adhesion during the freezing stage only takes place if there is a low temperature difference. The high temperature difference therefore precludes this adhesion taking place and the formed solids will be washed away with the liquid.
Akin to this unit, the temperature difference at the bottom of the column produces the same sort of cryogenic quench. Further the bottoms (a crude dirty liquid oxygen) is viewed as waste and not subsequently subcooled in order to generate both a product as well as the quenching liquid. In other cryogenic nitrogen patents, the crude liquid oxygen is sub cooled through a Joule Thompson effect and used to provide liquid to the top of the column.
However, it achieves this though indirect heat exchange with the top gases and not by direct contact. Due to the higher temperature difference between the freeze point of the solids and the internal surfaces of the column, the solids do not foul the column. It is only with low temperature differential during freezing that the two solids can form a cohesive bond. One key factor is that fouling does not take place in the quench because of the high temperature difference between the solid surfaces and the incoming natural gas. Adhesion during the freezing stage only takes place if there is a low temperature difference. The high temperature difference therefore precludes this adhesion taking place and the formed solids will be washed away with the liquid.
[0018] FIG. 3 shows a simplified flow sheet of the process of the present invention. In an example of the process, 11.34 kg (25 lb) mol/hr of natural gas is scrubbed of a portion of the water (but not to LNG specifications) and introduced into a prechiller cooling it to ¨58 C.
This cooled natural gas is then introduced into a quencher and cooled using 17 kg (37.5 lb) mol/hr of sub cooled LNG that is at ¨162 C, the standard temperature for LNG.
The majority of the feed stream is condensed. The quencher is fed from 62 which is a partial condenser.
The quencher itself is fed with a saturated liquid from the partial condenser 62. While there may be one column, in the embodiment shown in FIG. 3, there are two columns.
This cooled natural gas is then introduced into a quencher and cooled using 17 kg (37.5 lb) mol/hr of sub cooled LNG that is at ¨162 C, the standard temperature for LNG.
The majority of the feed stream is condensed. The quencher is fed from 62 which is a partial condenser.
The quencher itself is fed with a saturated liquid from the partial condenser 62. While there may be one column, in the embodiment shown in FIG. 3, there are two columns.
[0019] A purge stream containing the incondensable contaminants exits from the top of the column as well as a portion of the methane. A bottom stream at ¨100 C
contains all of the impurities left by the feed scrubber. Due to the cold temperature, these are in the solid form. A simple mesh filter would then be used to remove these particles, and the liquid would then be further chilled to ¨161 C (-257 F) for storage. During operation, subcooled LNG
would be extracted from the storage tank and used in the quench chiller.
Simulations suggested that a simple closed nitrogen refrigeration cycle would provide sufficient cooling for this process using 309 hp of power in order to condense 9071 kg (10 tons)/day of LNG.
Rather than requiring steam, solvents and other front end purification processes, this unit would run using higher power, a quench tower and a simple filtration device.
contains all of the impurities left by the feed scrubber. Due to the cold temperature, these are in the solid form. A simple mesh filter would then be used to remove these particles, and the liquid would then be further chilled to ¨161 C (-257 F) for storage. During operation, subcooled LNG
would be extracted from the storage tank and used in the quench chiller.
Simulations suggested that a simple closed nitrogen refrigeration cycle would provide sufficient cooling for this process using 309 hp of power in order to condense 9071 kg (10 tons)/day of LNG.
Rather than requiring steam, solvents and other front end purification processes, this unit would run using higher power, a quench tower and a simple filtration device.
[0020] FIG. 1 presents one embodiment of the invention which does not generate LNG
though direct condensation, nor does it use the bottoms liquid as a source of the product. A
natural gas stream 2 is introduced into a simple PSA 6 wherein a portion of the water is removed producing a dry natural gas stream 8 with a dew point below ¨50 C and a purge stream 10 containing the removed moisture. Stream 8 is then cooled to ¨50 C in an indirect heat exchanger 12 to produce a chilled dry natural gas stream 14. Stream 14 is then introduced into the quench column 16 wherein it is cooled to ¨100 C through direct contact with a primary cooling liquid and a substantial portion of the heavy components within stream 14 condense and solidify into the dirty heavy bottom liquid 18. A
portion of the primary cooling liquid is evaporated during this process and mixes with the light components of stream 14 and exits the quench column 16 as the chilled medium gas 20.
Stream 20 is then further cooled through direct contact in a secondary cooler 22 with a secondary cooling liquid, removing further impurities such as C2 and C3 to producing a medium bottom liquid 24 which is fed to the quench column 16 to provide a portion of the primary cooling liquid.
The solids in stream 18 are removed through the use of a filter 28 producing a heavy liquid 30 and a solid waste stream 32. Stream 30 is then raised in pressure in recycle pump 34 and fed as heavy cooling liquid 36 to quench column 16 where it forms part of the primary cooling fluid. The remaining uncondensed portion of stream 20 exits the secondary cooler 22 as a light chilled gas 26 and is fully condensed in a liquefier 38 and fed as a light liquid stream 40 to a storage tank 42. When required, a draw stream 44 is removed from tank 42, reduced in pressure by regulator 46 and delivered as liquefied natural gas 48.
Meanwhile, a light liquid draw stream 50 is withdrawn from tank 42, raised in pressure in pump 52 in order to be fed to secondary cooler 22 as a light cooling liquid 54. The LNG may be transported by ship, truck or other transport means.
though direct condensation, nor does it use the bottoms liquid as a source of the product. A
natural gas stream 2 is introduced into a simple PSA 6 wherein a portion of the water is removed producing a dry natural gas stream 8 with a dew point below ¨50 C and a purge stream 10 containing the removed moisture. Stream 8 is then cooled to ¨50 C in an indirect heat exchanger 12 to produce a chilled dry natural gas stream 14. Stream 14 is then introduced into the quench column 16 wherein it is cooled to ¨100 C through direct contact with a primary cooling liquid and a substantial portion of the heavy components within stream 14 condense and solidify into the dirty heavy bottom liquid 18. A
portion of the primary cooling liquid is evaporated during this process and mixes with the light components of stream 14 and exits the quench column 16 as the chilled medium gas 20.
Stream 20 is then further cooled through direct contact in a secondary cooler 22 with a secondary cooling liquid, removing further impurities such as C2 and C3 to producing a medium bottom liquid 24 which is fed to the quench column 16 to provide a portion of the primary cooling liquid.
The solids in stream 18 are removed through the use of a filter 28 producing a heavy liquid 30 and a solid waste stream 32. Stream 30 is then raised in pressure in recycle pump 34 and fed as heavy cooling liquid 36 to quench column 16 where it forms part of the primary cooling fluid. The remaining uncondensed portion of stream 20 exits the secondary cooler 22 as a light chilled gas 26 and is fully condensed in a liquefier 38 and fed as a light liquid stream 40 to a storage tank 42. When required, a draw stream 44 is removed from tank 42, reduced in pressure by regulator 46 and delivered as liquefied natural gas 48.
Meanwhile, a light liquid draw stream 50 is withdrawn from tank 42, raised in pressure in pump 52 in order to be fed to secondary cooler 22 as a light cooling liquid 54. The LNG may be transported by ship, truck or other transport means.
[0021] FIG. 2 is an example of the process which generates LNG though direct condensation, but does not uses the bottoms liquid as a source of the product.
In this example, A natural gas stream 2 is introduced into a simple PSA 6 wherein a portion of the water is removed producing a dry natural gas stream 8 with a dew point below ¨50 C and a purge stream 10 containing the removed moisture. Stream 8 is then cooled to ¨50 C in an indirect heat exchanger 12 to produce a chilled dry natural gas stream 14. Stream 14 is then introduced into the quench column 16 wherein it is cooled to ¨100 C through direct contact with a primary cooling liquid and a substantial portion of the heavy components within stream 14 condense and solidify into the dirty heavy bottom liquid 18. A
portion of the primary cooling liquid is evaporated during this process and mixes with the light components of stream 14 and exits the quench column 16 as the chilled medium gas 20.
Stream 20 is then further cooled through direct contact in a secondary cooler 22 with a secondary cooling liquid, removing further impurities such as C2 and C3 to producing a medium bottom liquid 24 which is fed to the quench column 16 to provide a portion of the primary cooling liquid.
The solids in stream 18 are removed through the use of a filter 28 producing a heavy liquid and a solid waste stream 32. Stream 30 is then raised in pressure in recycle pump 34 and fed as heavy cooling liquid 36 to quench column 16 where it forms part of the primary cooling fluid. The remaining uncondensed portion of stream 20 exits the secondary cooler 22 as a light chilled gas 26 and is fully condensed in a liquefier 38 and fed as a light liquid 30 stream 40 to a storage tank 42. When required, a draw stream 44 is removed from tank 42, reduced in pressure by regulator 46 and delivered as liquefied natural gas 48.
Meanwhile, a light liquid draw stream 50 is withdrawn from tank 42, raised in pressure in pump 52 in order to be fed to secondary cooler 22 as a light cooling liquid 54. a secondary light liquid draw stream 56 is removed from tank 42, raised in pressure in pump 58 to form light condensing fluid 60 and introduced into direct condenser 62. The light chilled gas 26 is also introduced into the direct condenser 62 where the majority of the stream is condensed forming light condensate 64. Stream 64 is cooled even further in exchanger 66 to form stream 40. Any incondensable gases leave direct condenser 62 as purge 68.
In this example, A natural gas stream 2 is introduced into a simple PSA 6 wherein a portion of the water is removed producing a dry natural gas stream 8 with a dew point below ¨50 C and a purge stream 10 containing the removed moisture. Stream 8 is then cooled to ¨50 C in an indirect heat exchanger 12 to produce a chilled dry natural gas stream 14. Stream 14 is then introduced into the quench column 16 wherein it is cooled to ¨100 C through direct contact with a primary cooling liquid and a substantial portion of the heavy components within stream 14 condense and solidify into the dirty heavy bottom liquid 18. A
portion of the primary cooling liquid is evaporated during this process and mixes with the light components of stream 14 and exits the quench column 16 as the chilled medium gas 20.
Stream 20 is then further cooled through direct contact in a secondary cooler 22 with a secondary cooling liquid, removing further impurities such as C2 and C3 to producing a medium bottom liquid 24 which is fed to the quench column 16 to provide a portion of the primary cooling liquid.
The solids in stream 18 are removed through the use of a filter 28 producing a heavy liquid and a solid waste stream 32. Stream 30 is then raised in pressure in recycle pump 34 and fed as heavy cooling liquid 36 to quench column 16 where it forms part of the primary cooling fluid. The remaining uncondensed portion of stream 20 exits the secondary cooler 22 as a light chilled gas 26 and is fully condensed in a liquefier 38 and fed as a light liquid 30 stream 40 to a storage tank 42. When required, a draw stream 44 is removed from tank 42, reduced in pressure by regulator 46 and delivered as liquefied natural gas 48.
Meanwhile, a light liquid draw stream 50 is withdrawn from tank 42, raised in pressure in pump 52 in order to be fed to secondary cooler 22 as a light cooling liquid 54. a secondary light liquid draw stream 56 is removed from tank 42, raised in pressure in pump 58 to form light condensing fluid 60 and introduced into direct condenser 62. The light chilled gas 26 is also introduced into the direct condenser 62 where the majority of the stream is condensed forming light condensate 64. Stream 64 is cooled even further in exchanger 66 to form stream 40. Any incondensable gases leave direct condenser 62 as purge 68.
[0022] FIG. 3 does generate LNG though direct condensation and uses the bottoms liquid as a source of the product. In this example, natural gas stream 2 is introduced into a simple PSA 6 wherein a portion of the water is removed producing a dry natural gas stream 8 with a dew point below ¨50 C and a purge stream 10 containing the removed moisture.
Stream 8 is then cooled to ¨50 C in an indirect heat exchanger 12 to produce a chilled dry natural gas stream 14. Stream 14 is then introduced into the quench column 16 wherein it is cooled to ¨100 C through direct contact with a primary cooling liquid and a substantial portion of the heavy components within stream 14 condense and solidify into the dirty heavy bottom liquid 18. A portion of the cooling is evaporated during this process and mixes with the light components of stream 14 and exits the quench column 16 as the chilled medium gas 20.
Stream 20 chilled medium gas 20 is instead sent to direct condenser 62 to produce the medium bottom liquid 24. Medium bottom liquid 24 which is fed to the quench column 16 to provide a portion of the primary cooling liquid. The solids in stream 18 are removed through the use of a filter 28 producing a heavy liquid 30 and a solid waste stream 32. Heavy liquid stream 30 is cooled in exchanger 66 to form stream 40 and be fed to tank 42.
The remaining uncondensed portion of stream 20 exits the secondary cooler 22 as a light chilled gas 26 and is fully condensed in a liquefier 38 and fed as a light liquid stream 40 to a storage tank 42.
When required, a draw stream 44 is removed from tank 42, reduced in pressure by regulator 46 and delivered as liquefied natural gas 48. Meanwhile, a light liquid draw stream 50 is withdrawn from tank 42, raised in pressure in pump 52 in order to be fed to secondary cooler 22 as a light cooling liquid 54.
Stream 8 is then cooled to ¨50 C in an indirect heat exchanger 12 to produce a chilled dry natural gas stream 14. Stream 14 is then introduced into the quench column 16 wherein it is cooled to ¨100 C through direct contact with a primary cooling liquid and a substantial portion of the heavy components within stream 14 condense and solidify into the dirty heavy bottom liquid 18. A portion of the cooling is evaporated during this process and mixes with the light components of stream 14 and exits the quench column 16 as the chilled medium gas 20.
Stream 20 chilled medium gas 20 is instead sent to direct condenser 62 to produce the medium bottom liquid 24. Medium bottom liquid 24 which is fed to the quench column 16 to provide a portion of the primary cooling liquid. The solids in stream 18 are removed through the use of a filter 28 producing a heavy liquid 30 and a solid waste stream 32. Heavy liquid stream 30 is cooled in exchanger 66 to form stream 40 and be fed to tank 42.
The remaining uncondensed portion of stream 20 exits the secondary cooler 22 as a light chilled gas 26 and is fully condensed in a liquefier 38 and fed as a light liquid stream 40 to a storage tank 42.
When required, a draw stream 44 is removed from tank 42, reduced in pressure by regulator 46 and delivered as liquefied natural gas 48. Meanwhile, a light liquid draw stream 50 is withdrawn from tank 42, raised in pressure in pump 52 in order to be fed to secondary cooler 22 as a light cooling liquid 54.
[0023] Those experienced in the art will recognize that columns 62, 22 and 16, while shown as separate units could be combined into one single column or their roles could be split across multiple different columns.
SPECIFIC EMBODIMENTS
SPECIFIC EMBODIMENTS
[0024] While the following is described in conjunction with specific embodiments, it will be understood that this description is intended to illustrate and not limit the scope of the preceding description and the appended claims.
[0025] A first embodiment of the invention is a process for liquefaction of natural gas, the process comprising a) sending the cooled natural gas stream to a quench unit; b) sending a quantity of liquefied natural gas to the quench unit to be combined with the cooled natural gas steam to produce a bottoms stream comprising a liquid stream comprising solid impurities and a top stream comprising methane and incondensable impurities;
and c) cooling the bottoms stream to produce liquefied natural gas. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the natural gas stream is cooled to a temperature from 00 to ¨100 C to produce a cooled natural gas stream. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph further comprising sending the bottoms stream to a unit to remove the solid impurities to a produce a purified bottoms stream. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein a portion of the bottom stream is returned to the quench unit. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein before the natural gas stream is cooled, at least a portion of water within the natural gas stream is removed. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the natural gas stream is cooled to a temperature of ¨25 to ¨75 C. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the natural gas stream is cooled to a temperature of ¨55 to ¨60 C. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the solid impurities are selected from the group consisting of carbon dioxide, C5 and C6 hydrocarbons and water.
An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the incondensable impurities are selected from the group consisting of nitrogen, oxygen and hydrogen. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the bottoms stream is at a temperature from ¨750 to ¨120 C. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the bottoms stream is at a temperature from ¨90 to ¨100 C.
and c) cooling the bottoms stream to produce liquefied natural gas. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the natural gas stream is cooled to a temperature from 00 to ¨100 C to produce a cooled natural gas stream. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph further comprising sending the bottoms stream to a unit to remove the solid impurities to a produce a purified bottoms stream. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein a portion of the bottom stream is returned to the quench unit. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein before the natural gas stream is cooled, at least a portion of water within the natural gas stream is removed. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the natural gas stream is cooled to a temperature of ¨25 to ¨75 C. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the natural gas stream is cooled to a temperature of ¨55 to ¨60 C. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the solid impurities are selected from the group consisting of carbon dioxide, C5 and C6 hydrocarbons and water.
An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the incondensable impurities are selected from the group consisting of nitrogen, oxygen and hydrogen. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the bottoms stream is at a temperature from ¨750 to ¨120 C. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the bottoms stream is at a temperature from ¨90 to ¨100 C.
[0026] A second embodiment of the invention is a system for producing liquefied natural gas from a supply of natural gas, comprising a) a device for supplying a stream of natural gas;
b) a separation device to remove water from the stream of natural gas to produce a partially dried stream of natural gas; c) a means for feeding the partially dried stream of natural gas to a chilling device and then to a column; d) a means for feeding a quantity of a chilled liquid to the column where the chilled liquid and the partially dried stream of natural gas are present in the column and a means to vent a purge stream from the quench tower; e) a means to transport a combination of the chilled liquid and the partially dried stream of natural gas to a particle removal unit; f) a means to transport a purified stream from the filter unit to a chiller to produce liquefied natural gas; and g) a means to send the liquefied natural gas to a storage device. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the separation device removes additional contaminants from the stream of natural gas. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the column is a quench tower. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the chilled liquid is a quantity of liquefied natural gas.
b) a separation device to remove water from the stream of natural gas to produce a partially dried stream of natural gas; c) a means for feeding the partially dried stream of natural gas to a chilling device and then to a column; d) a means for feeding a quantity of a chilled liquid to the column where the chilled liquid and the partially dried stream of natural gas are present in the column and a means to vent a purge stream from the quench tower; e) a means to transport a combination of the chilled liquid and the partially dried stream of natural gas to a particle removal unit; f) a means to transport a purified stream from the filter unit to a chiller to produce liquefied natural gas; and g) a means to send the liquefied natural gas to a storage device. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the separation device removes additional contaminants from the stream of natural gas. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the column is a quench tower. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the chilled liquid is a quantity of liquefied natural gas.
[0027] Without further elaboration, it is believed that using the preceding description that one skilled in the art can utilize the present invention to its fullest extent and easily ascertain the essential characteristics of this invention, without departing from the spirit and scope thereof, to make various changes and modifications of the invention and to adapt it to various usages and conditions. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limiting the remainder of the disclosure in any way whatsoever, and that it is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.
[0028] In the foregoing, all temperatures are set forth in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.
Claims (10)
1. A process for liquefaction of a hydrocarbon stream, said process comprising:
a) sending a cooled hydrocarbon stream to a quench unit; and b) sending a quantity of a liquefied hydrocarbon stream to said quench unit to be combined with said cooled hydrocarbon steam to produce a bottoms stream comprising a liquid stream comprising solid impurities and a top stream comprising methane and incondensable impurities.
a) sending a cooled hydrocarbon stream to a quench unit; and b) sending a quantity of a liquefied hydrocarbon stream to said quench unit to be combined with said cooled hydrocarbon steam to produce a bottoms stream comprising a liquid stream comprising solid impurities and a top stream comprising methane and incondensable impurities.
2. The process of claim 1 wherein said liquefied hydrocarbon stream is at least 15 degrees C cooler than a freeze point of solid impurities in the cooled hydrocarbon stream.
3. The process of claim 1 wherein the liquefied hydrocarbon is relatively evenly distributed across the quench unit.
4. The process of claim 1 wherein a portion of said bottom stream is used to produce liquefied natural gas.
5. The process of claim 1 further comprising sending said bottoms stream to a unit to remove said solid impurities to a produce a purified bottoms stream.
6. The process of claim 1 wherein a portion of said bottom stream is returned to said quench unit.
7. The process of claim 1 wherein before said hydrocarbon stream is cooled, at least a portion of water within said hydrocarbon stream is removed.
8. The process of claim 1 wherein said hydrocarbon stream is cooled to a temperature of ¨25 to ¨75 C and said bottoms stream is at a temperature from ¨75 to ¨120 C.
9. The process of claim 1 wherein said solid impurities are selected from the group consisting of carbon dioxide, C5 and C6 hydrocarbons and water and said incondensable impurities are selected from the group consisting of nitrogen, oxygen and hydrogen.
10. A system for producing liquefied natural gas from a supply of natural gas, comprising:
a) a device for supplying a stream of natural gas;
b) a separation device to remove water from said stream of natural gas to produce a partially dried stream of natural gas;
c) a means for feeding said partially dried stream of natural gas to a chilling device and then to a column;
d) a means for feeding a quantity of a chilled liquid to said column where said chilled liquid and said partially dried stream of natural gas are present in said column and a means to vent a purge stream from said quench tower;
e) a means to transport a combination of said chilled liquid and said partially dried stream of natural gas to a particle removal unit;
f) a means to transport a purified stream from said filter unit to a chiller to produce liquefied natural gas; and g) a means to send said liquefied natural gas to a storage device.
a) a device for supplying a stream of natural gas;
b) a separation device to remove water from said stream of natural gas to produce a partially dried stream of natural gas;
c) a means for feeding said partially dried stream of natural gas to a chilling device and then to a column;
d) a means for feeding a quantity of a chilled liquid to said column where said chilled liquid and said partially dried stream of natural gas are present in said column and a means to vent a purge stream from said quench tower;
e) a means to transport a combination of said chilled liquid and said partially dried stream of natural gas to a particle removal unit;
f) a means to transport a purified stream from said filter unit to a chiller to produce liquefied natural gas; and g) a means to send said liquefied natural gas to a storage device.
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US201361860319P | 2013-07-31 | 2013-07-31 | |
US61/860,319 | 2013-07-31 | ||
US14/338,982 US20150033793A1 (en) | 2013-07-31 | 2014-07-23 | Process for liquefaction of natural gas |
US14/338,982 | 2014-07-23 | ||
PCT/US2014/048522 WO2015017357A1 (en) | 2013-07-31 | 2014-07-29 | Process for liquefaction of natural gas |
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EP2789957A1 (en) | 2013-04-11 | 2014-10-15 | Shell Internationale Research Maatschappij B.V. | Method of liquefying a contaminated hydrocarbon-containing gas stream |
US10619918B2 (en) | 2015-04-10 | 2020-04-14 | Chart Energy & Chemicals, Inc. | System and method for removing freezing components from a feed gas |
TWI707115B (en) | 2015-04-10 | 2020-10-11 | 美商圖表能源與化學有限公司 | Mixed refrigerant liquefaction system and method |
CA3006860A1 (en) | 2015-12-03 | 2017-06-08 | Shell Internationale Research Maatschappij B.V. | Method of liquefying a co2 contaminated hydrocarbon-containing gas stream |
US10788259B1 (en) * | 2015-12-04 | 2020-09-29 | Chester Lng, Llc | Modular, mobile and scalable LNG plant |
WO2017162566A1 (en) | 2016-03-21 | 2017-09-28 | Shell Internationale Research Maatschappij B.V. | Method and system for liquefying a natural gas feed stream |
EP4035759A1 (en) * | 2021-01-29 | 2022-08-03 | Hitachi Zosen Inova AG | Method for removing co2 from a methane-containing gas |
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US5325673A (en) * | 1993-02-23 | 1994-07-05 | The M. W. Kellogg Company | Natural gas liquefaction pretreatment process |
AU2003900534A0 (en) * | 2003-02-07 | 2003-02-20 | Shell Internationale Research Maatschappij B.V. | Process and apparatus for removal of a contaminant from a natural gas feed stream |
US20080016910A1 (en) * | 2006-07-21 | 2008-01-24 | Adam Adrian Brostow | Integrated NGL recovery in the production of liquefied natural gas |
JP2009019192A (en) * | 2007-06-11 | 2009-01-29 | Hitachi Ltd | Method of refining natural gas and natural gas refining system |
AU2011213249B2 (en) * | 2010-02-03 | 2016-05-19 | Exxonmobil Upstream Research Company | Systems and methods for using cold liquid to remove solidifiable gas components from process gas streams |
CA2805513C (en) * | 2010-07-30 | 2016-10-04 | Exxonmobil Upstream Research Company | Cryogenic systems for removing acid gases from a hydrocarbon gas stream using co-current separation devices |
KR101076271B1 (en) * | 2010-10-15 | 2011-10-26 | 대우조선해양 주식회사 | Method for producing pressurized liquefied natural gas and productive system thereof |
WO2013095828A1 (en) * | 2011-12-20 | 2013-06-27 | Exxonmobil Upstream Research Company | Method of separating carbon dioxide from liquid acid gas streams |
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- 2014-07-23 US US14/338,982 patent/US20150033793A1/en not_active Abandoned
- 2014-07-29 CA CA2919209A patent/CA2919209A1/en not_active Abandoned
- 2014-07-29 WO PCT/US2014/048522 patent/WO2015017357A1/en active Application Filing
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