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
  • 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
• • 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
• • 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
• • 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
• • 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
  • F25J3/028—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 noble gases
  • F25J3/029—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 noble gases of helium
• • 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
  • F25J2200/00—Processes or apparatus using separation by rectification
  • F25J2200/04—Processes or apparatus using separation by rectification in a dual pressure main column system
  • F25J2200/06—Processes or apparatus using separation by rectification in a dual pressure main column system in a classical double column flow-sheet, i.e. with thermal coupling by a main reboiler-condenser in the bottom of low pressure respectively top of high pressure column
• • 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
  • F25J2205/02—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum
• • 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
  • F25J2205/02—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum
  • F25J2205/04—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum in the feed line, i.e. upstream of the fractionation step
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2235/00—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams
  • F25J2235/60—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams the fluid being (a mixture of) hydrocarbons
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
  • F25J2290/34—Details about subcooling of liquids

Definitions

• the present invention relates to a method for producing helium from a source gas stream comprising at least helium, methane and nitrogen.
• Helium is obtained commercially almost exclusively from a mixture of volatile components of natural gas, this mixture comprising, as well as helium, typically methane and nitrogen and traces of hydrogen, argon and other noble gases.
• helium is made available as a component of the gas that accompanies mineral oil, or as part of the production of natural gas. It is theoretically possible to obtain helium in the atmosphere, but it is not economical because of the low concentrations (typical concentration of helium in the air of the order of 5.2 ppmv).
• Raw natural gas can contain a large number of troublesome impurities to be removed.
• Nitrogen is one example. From a certain concentration of nitrogen in natural gas, it is typically not salable because of its low calorific value. To remove the nitrogen is most often used a cryogenic process implemented in a unit called Nitrogen Rejection Unit (NRU).
• NRU Nitrogen Rejection Unit
• helium in natural gas, there is economic interest in extracting a helium-rich stream separately to produce helium and market it.
• the helium is concentrated in the cryogenic process and finally purified in a PSA (Pressure Swing Adsorption) type adsorption process.
• PSA Pressure Swing Adsorption
• the present invention relates to a method for producing a helium gas stream from a source gas stream comprising at least helium, methane, and nitrogen, comprising at least the following steps:
• the present invention also relates to:
• a process as defined above characterized in that it comprises a step g): use, as a refrigerant, of the liquid phase after expansion from step f) in said heat exchanger implemented at step e).
• step g said liquid phase is vaporized at a pressure between
• step a) the gaseous stream is introduced into the high-pressure column at at least two feed levels, the steam fraction of the first feed being more weak that the vapor fraction of the second and the first feed being introduced at a higher level of said high pressure column than the second.
• a process as defined above comprising a step h): extraction of the gaseous phase from step f) as a product rich in helium, containing at least 75% by volume of helium.
• a process as defined above characterized in that the temperature at the condenser outlet in step b) is between -150 ° C. and
• step c) is between - 160 ° C and - 180 ° C.
• step e) is between - 180 ° C and - 210 ° C.
• a process as defined above characterized in that the liquid phase from step d) is introduced into the low pressure column of said reject unit.
• a process as defined above comprising a further step of producing a nitrogen enriched stream comprising less than 2% by volume of methane from a gaseous stream from the low pressure column head.
• At least one nitrogen rejection unit provided with a double column, said double column comprising a high pressure distillation column, a low pressure distillation column and a condenser connecting the high pressure column with the column at low pressure, and
• a helium extraction unit comprising a first phase separator pot located upstream of a heat exchanger itself located upstream of a second phase separator pot;
• the nitrogen rejection unit is located upstream of the helium extraction unit
• helium extraction unit does not contain a distillation column, a rectification column or a multi-feed phase separator pot.
• the solution that is the subject of the present invention makes it possible to separate a stream composed of methane, nitrogen and helium into three streams of pure methane, pure nitrogen and rich in helium.
• the present invention solves the problem of solutions by partial condensation by obtaining both a high yield (> 85%) and a high helium content (> 50%) and this without using a column dedicated to the separation of the helium.
• the method which is the subject of the invention consists of a double-column NRU unit in which the condenser of the HP high-pressure column is completely (or almost completely because of the presence of incondensables) condensed.
• the liquid produced at the top of this HP column is partly used as reflux of the HP column and partly for use as reflux of the LP low pressure column.
• the particularity of the invention is to relax the fluid produced and not used as reflux of the HP column at an intermediate pressure so as to "flash” or vaporize instantly (by “flash” gas is meant: instantaneous steam) all the helium desired in a first helium separator pot (performance control) and then to a partial condensation of the gas of said "flash" (or instantaneous vapor) to obtain a gas having a high helium content in a second separator pot of helium.
• FIG. 1 The method that is the subject of the present invention is illustrated in FIG.
• a source gas stream 1 comprising at least helium, methane, and nitrogen is introduced at a pressure of approximately 50 bar absolute in a heat exchanger 2.
• the output stream 3 of said The exchanger 2 is expanded using, for example, a valve 4 before being introduced into a high-pressure column 5 of a double-column unit 6 comprising a high-pressure distillation column 5, a column of distillation 7 at low pressure and a condenser 8 connecting the column 5 at high pressure with the column 7 at low pressure.
• the source gas stream 1 comprises 100% by volume, for example, from 20% by volume to 80% by volume of methane, from 20% by volume to 80% by volume of nitrogen and from 1% by volume to 1% by volume. helium volume.
• the pressure of the high pressure column is for example 30 bara and the pressure in the low pressure column is for example 2 bara.
• nitrogen rejection unit refers to a device in which nitrogen and methane are separated by cryogenic rectification.
• a part (3d) of the stream 3 being introduced mainly in liquid form and a part (3c) is introduced mainly in gaseous form in the tank column 5 to vaporize the helium that would otherwise be entrained in the liquid methane.
• a portion 9 of the liquid stream 1 1 leaving the condenser 8 located in the lower part of the column 7 at low pressure is used as reflux in the upper part of the column 5 at high pressure.
• the rest of the liquid 1 1 is cooled and then expanded to be used directly as reflux of the low pressure column.
• the object of the present invention is to use a portion 12 of said liquid stream 1 1 to extract the helium before using it as reflux of the low pressure column.
• This liquid stream 1 1 typically contains less than 2% by volume of methane, more than 95% by volume of nitrogen and 0.5% by volume to 3% by volume of helium.
• the temperature of the liquid stream 12 is for example between - 150 ° C and - 165 ° C.
• This liquid stream 12 is expanded to an intermediate pressure using, for example, a valve 13.
• This intermediate pressure is typically of the order of 8 bara to 15 bara. For example 12 bara.
• the stream 14 thus produced contains a majority of liquid and a minority of gases.
• This gas is enriched in helium.
• This helium-enriched gas comprises at least 80% by volume of the helium contained in the liquid stream 12.
• the two-phase current 14 is introduced into a first phase separator pot.
• the pot 15 produces a liquid stream 16 and a gas stream 17.
• the gas stream 17 contains more than 80% by volume of the helium contained in the source stream 1.
• this gaseous stream 17 contains nitrogen.
• the gas stream 17 enriched with helium typically contains more than
• This gaseous stream 27 comprises more than 50% by volume of helium, preferably more than 60% by volume of helium and more particularly more than 70% by volume of helium.
• the gas stream 27 may, optionally, be ironed in a heat exchanger 24.
• the liquid phase 28 issuing from the separator 26 is used to cool the exchanger 24 after being expanded to a pressure of less than 3 bara, for example using an expander such as a valve 29.
• This liquid stream 28 is pure nitrogen, for example it contains more than 99% by volume of nitrogen.

Landscapes

• 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)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=54356501

Family Applications (1)

Country Status (6)

Families Citing this family (2)

Citations (1)

Family Cites Families (8)

• 2015
  • 2015-07-16 FR FR1556739A patent/FR3038973B1/fr not_active Expired - Fee Related
• 2016
  • 2016-07-12 PL PL16750950.4T patent/PL3322949T3/pl unknown
  • 2016-07-12 RU RU2018103764A patent/RU2717666C2/ru active
  • 2016-07-12 EP EP16750950.4A patent/EP3322949B1/fr active Active
  • 2016-07-12 US US15/744,987 patent/US20180209725A1/en not_active Abandoned
  • 2016-07-12 WO PCT/FR2016/051786 patent/WO2017009573A1/fr active Application Filing

Patent Citations (1)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events