EP0373983B1 - Process for the simultaneous elimination of CO2 and gasoline from a gaseous hydrocarbon mixture comprising methane, C2 and higher hydrocarbons and also CO2 - Google Patents

Process for the simultaneous elimination of CO2 and gasoline from a gaseous hydrocarbon mixture comprising methane, C2 and higher hydrocarbons and also CO2 Download PDF

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Publication number
EP0373983B1
EP0373983B1 EP89403123A EP89403123A EP0373983B1 EP 0373983 B1 EP0373983 B1 EP 0373983B1 EP 89403123 A EP89403123 A EP 89403123A EP 89403123 A EP89403123 A EP 89403123A EP 0373983 B1 EP0373983 B1 EP 0373983B1
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EP
European Patent Office
Prior art keywords
solvent
rich
methane
gas
hydrocarbons
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EP89403123A
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German (de)
French (fr)
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EP0373983A1 (en
Inventor
Claude Blanc
Henri Paradowski
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Elf Exploration Production SAS
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Societe National Elf Aquitaine
Societe Nationale Elf Aquitaine Production SA
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Priority to EP93107550A priority Critical patent/EP0556875B1/en
Priority to AT89403123T priority patent/ATE100852T1/en
Publication of EP0373983A1 publication Critical patent/EP0373983A1/en
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Publication of EP0373983B1 publication Critical patent/EP0373983B1/en
Priority to GR950402736T priority patent/GR3017623T3/en
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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G5/00—Recovery of liquid hydrocarbon mixtures from gases, e.g. natural gas
    • C10G5/04—Recovery of liquid hydrocarbon mixtures from gases, e.g. natural gas with liquid absorbents
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
    • C10G2300/10—Feedstock materials
    • C10G2300/1025—Natural gas

Definitions

  • the invention relates to a process for the simultaneous decarbonation and degassing of a gaseous mixture consisting mainly of hydrocarbons consisting of methane and C2 and higher hydrocarbons and also containing CO2 and optionally one or more non-sulfurized compounds with low boiling point such as H2, CO, N2 and argon.
  • decarbonation and degassing operations are generally carried out separately and are part of a succession of operations carried out on the gas mixture to be treated and mainly comprising an elimination of the acid gas CO2, drying, adsorption of water on an appropriate solid such as a molecular sieve, separation by cryogenic distillation between -30 ° C and - 90 ° C associated or not with extraction by a solvent in order to obtain the cut of natural gas liquid, and finally reheating the treated gas to ambient temperature in order to generally supply the commercial gas network.
  • the dehydrated and refrigerated natural gas is separated, in a first column (demethanizer) at the head of which is injected an additive consisting of a liquid fraction of C4 hydrocarbons and more, into a gas phase containing methane and lighter compounds and a liquid fraction containing C2 and higher hydrocarbons and CO2.
  • This liquid fraction is separated, in a second column (de-ethanizer) into which a certain amount of the additive is also introduced, into a top fraction consisting of CO2 and a bottom fraction containing the hydrocarbons in C2 and more.
  • Said tail fraction is then separated, in a third column, into an overhead fraction consisting of a liquid cut of C2 to C4 hydrocarbons and into a tail fraction consisting of a liquid cut of C4 and higher hydrocarbons, which contains the major part of the butanes and higher hydrocarbons present in the treated natural gas and of which the appropriate quantity is taken to constitute the additive injected in the first and second columns.
  • This additive avoids the crystallization of CO2 at the top of the demethanizer and ensures the rupture of the azeotrope which forms between ethane and CO2 and facilitates the separation of this compound in the deethanizer.
  • the aforementioned process is therefore essentially based on serial distillation operations.
  • the invention provides a process for simultaneous decarbonation and degassing of gas mixtures, which are available under an absolute pressure greater than 0.5 MPa and consist mainly of hydrocarbons consisting of methane and C2 and higher hydrocarbons and also contain CO2 and optionally one or more non-sulfurized compounds with low boiling point such as H2, CO, N2 and argon, such gas mixtures being for example of the natural gas type, said process making it possible to reach more easily and at lower cost, by comparison with known processes, the objective of separating the gaseous mixture into the three components, namely treated gas consisting mainly of methane, liquid cut of hydrocarbons with predominantly C3 and more hydrocarbons and containing as required a quantity more or less important ethane and CO2 current, which have the specifications defined above.
  • the process according to the invention is of the type of process which is described in the US-A-3770622 citation and in which the gas mixture is brought into contact, in a washing zone, with a solvent consisting of a liquid which preferentially dissolves CO2 and hydrocarbons in C2 and above and which has on the one hand, at atmospheric pressure, a boiling temperature greater than 40 ° C and on the other hand, at - 30 ° C, a viscosity less than 0.1 Pa .s, operating at a sufficiently low temperature and with a ratio of the flow rates of the gaseous mixture to be treated and of the solvent such that a treated gas consisting mainly of methane and having a molar CO2 content is produced at most equal to 2% and, on the other hand, a liquid phase called rich solvent and formed of the solvent enriched in CO2 and in a fraction of C en hydrocarbons and more containing at least 80 mol% of the C en hydrocarbons and more present in the mixture g nitrogenous to be treated, the rich solvent is
  • the process according to the invention differs from the process of the US-A-3770622 citation, and is therefore characterized in that the treatment of the demethanized rich solvent is carried out by subjecting said demethanized rich solvent, previously subjected to refrigeration, to a liquid / liquid extraction, in an extraction zone, using a refrigerated hydrocarbon solvent with production, on the one hand, of a purified solvent, which contains almost all of the CO2 present in the demethanized rich solvent and has a hydrocarbon content, expressed in methane equivalent, of less than 10 mol% relative to CO2, and, on the other hand, of a hydrocarbon solvent enriched in C2 hydrocarbons and more, by fractionating said enriched hydrocarbon solvent by distillation and a fraction of C2 and higher hydrocarbons, which constitutes the hydrocarbon fraction and contains at least 80 mol% of the C3 and more hydrocarbons present in the gas mixture to be treated, and in the regenerated hydrocarbon solvent, which is recycled after refrigeration, in the extraction zone, and by subjecting the purified solvent
  • methane equivalent is meant according to the invention as many pseudo-molecules with a single carbon atom as there are carbon atoms in the considered hydrocarbon molecule.
  • the solvent which is generally defined above for bringing it into contact with the gaseous mixture to be treated for the purpose of absorbing CO2 and C2 and higher hydrocarbons, preferably has a viscosity, at -30 ° C, of less than 0.05 Pa.s.
  • the solvent according to the invention may consist in particular of one or more liquid absorbents which are selective for CO2 and used in anhydrous form or in mixture with water, the said solvent (s) being chosen from the amides of formulas aldehydes of formula formula esters Ccan to C4 alkanols, diethers of formula diether alcohols of formula R9O-C2H4-O-C2H4-OH, lactones of formula and propylene carbonate, with in these formulas R1 and R2, identical or different, designating a hydrogen atom or a C1 or C2 alkyl radical, R3 being a C3 or C4 alkyl radical, R6 being a C2 alkyl radical to C4 or a radical with R8 denoting a C1 or C2 alkyl radical and n being equal to 1 or 2, R7 being a C1 or C2 alkyl radical or a radical R9 denoting a C radical to C4 alkyl radical and p being an integer ranging from 2 to 4.
  • Nonlimiting examples of liquid organic absorbents corresponding to the above formulas are such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethoxymethane, diethoxymethane, dimethoxy-1,1 ethane, methanol, ethanol, ethylene dimethyl ether glycol, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether, butyrolactone, propiolactone and propylene carbonate.
  • the contacting temperature of the gas mixture to be treated with the solvent, in the washing zone is preferably between 0 ° C and -45 ° C.
  • the washing zone advantageously consists of one or more washing columns containing the appropriate number of theoretical washing stages, said columns being, for example, of the type of tray columns or also packed columns.
  • the temperature in each of the washing columns is kept substantially constant by indirect heat exchange, carried out at one or more points of the column considered, between the fluid medium contained in this column and a cooling fluid.
  • the demethanization treatment applied to the rich solvent is carried out, in particular, in two stages, namely a first step in which said rich solvent is subjected to a first expansion capable of releasing a large fraction of the methane dissolved in said solvent to be demethanized and in producing a first methane-rich gas and a premethanized fluid and a second step in which the premethanized fluid is subjected to a second expansion and then to distillation producing a second methane-rich gas and the demethanized rich solvent, the second methane-rich gas being compressed to the pressure of the first methane-rich gas and then mixed with the latter to form the methane-rich gas phase.
  • the methane-rich gas phase resulting from the demethanization treatment applied to the rich solvent, is advantageously compressed to the pressure of the gas mixture to be treated, then it is cooled and mixed with the gas mixture to be treated before the latter is brought into contact. with the solvent in the washing area.
  • the regeneration of the purified solvent which leads to the production of the stream of acid gas rich in CO2 and having, expressed in methane equivalent, a hydrocarbon content of less than 10 mol% relative to CO2, can be carried out by any treatment making it possible to release gaseous compounds dissolved in a liquid.
  • the regeneration of the purified solvent can be carried out by expansion of said purified solvent to a pressure greater than 100 kPa and for example between 150 kPa and 300 kPa and by stripping using an inert gas such as nitrogen. possibly associated with a heating of the purified solvent in the regeneration zone.
  • the regeneration of the purified solvent can also be carried out by heating said purified solvent to a temperature close to ambient, by dividing the heated solvent into first and second streams, by directing the first stream directly to a regeneration zone, directing the second stream to this regeneration zone after having heated it by indirect heat exchange with the regenerated purified solvent, and by subjecting the solvent to distillation in the regeneration zone to produce the regenerated solvent and the stream of acid gas rich in CO2.
  • the gaseous mixture to be treated contains water and / or C5 and higher hydrocarbons, it is advantageously subjected to a pretreatment intended to remove all or part of these compounds before being brought into contact with the solvent in the zone of washing.
  • This pretreatment can consist of a distillation possibly carried out in the presence of solvent, taken from the solvent injected into the washing zone, to produce the pretreated gas mixture having a C6 hydrocarbon content and more than 0.1% by weight, a fraction of so-called heavy hydrocarbons containing almost all of the C6 and more hydrocarbons and all or part of the C5 hydrocarbons and, optionally, a liquid consisting of a mixture of solvent and water.
  • Said distillation of the gas mixture is carried out at a temperature at least equal to the temperature prevailing in the washing zone.
  • the gaseous mixture to be treated arriving via line 1 is introduced into the lower part of a distillation column 2, in which said gaseous mixture is optionally distilled in the presence of solvent withdrawn, through an opening pipe 41 in the upper part of column 2, on the regenerated solvent 38 brought to the washing column 5, before passage of said solvent in a refrigeration zone 39 mounted on the conduit 6 for injecting the regenerated solvent into said washing column 5, so as to produce on the one hand a dried gas mixture, evacuated from column 2 via a line 3 and whose C6 and higher hydrocarbon content is less than 0.1% by weight, and on the other hand a hydrocarbon fraction containing almost all of the C6 hydrocarbons and more and possibly all or part of the C5 hydrocarbons, withdrawn from column 2 by a conduit 4 and optionally a liquid withdrawn from column 2 by a conduit 54 and consisting of a mixture of solvent and water.
  • the dried gas mixture leaving column 2 through line 3 is introduced into the lower part of a washing column 5, for example of the plate column type, in which it is brought into contact, countercurrently, with cold solvent. regenerated injected into the upper part of column 5 through line 6, after passage through the coolant 39, this contacting being carried out at a temperature of, for example, between 0 ° C and -45 ° C, said temperature being controlled by passage of the liquid medium contained in column 5 in refrigerants 7.
  • a treated gas consisting mainly of methane and depleted in CO2, said treated gas being heated in a system 9 reheating and then directed, via a conduit 10, to a zone of use, while at the bottom of said column 5 is drawn off, via a conduit 11, a liquid phase consisting of the solvent enriched in CO2 and a other compounds absorbed and called rich solvent.
  • the dried gas mixture is brought into contact with the solvent in the washing column 5 at an appropriate temperature in the range O ° C to -45 ° C and with a ratio of the flow rates of the gas mixture to be treated and of solvent such that on the one hand the treated gas collected, through line 8, at the head of column 5 has a molar CO2 content of at most equal to 2% and that on the other hand the rich solvent, flowing through line 11 , contains at least 80 mol% of C3 and higher hydrocarbons present in the dried gas mixture introduced in column 5.
  • the rich solvent circulating in the conduit 11 is introduced, after passing through the expansion valve 12, into the upper part of an expansion tank 13 in which a first gas rich in methane separates, which is removed at the head of the flask 13 by a conduit 14, and a rich predemethanized solvent, which is drawn off at the bottom of the flask 13 by a conduit 15.
  • Said predemethanized rich solvent is subjected to a second expansion through an expansion valve 16 followed by a distillation in a distillation column 17 provided with a reboiler 18, so as to produce a second gas rich in methane, which is evacuated at the top of the column 17 by a conduit 19, and a liquid phase depleted in methane, called demethanized rich solvent, which is drawn off at the bottom of the column 17 by a pipe 27.
  • the second methane-rich gas circulating in the pipe 19 is caused to pass into a compressor 20 from which it leaves, via a pipe 21, to a pressure substantially equal to that of the first methane-rich gas passing through line 14, then these two methane-rich gases are mixed in line 22 and the gas phase resulting from this mixture is recycled, by means of a compressor 23 whose the outlet is extended by a line 24, a cooler 25 and a line 26, in the line 3 for supplying the dried gas mixture to the washing column 5.
  • the demethanized rich solvent, withdrawn from the column 17 through the conduit 27, is expanded by passing through an expansion valve 29, then is refrigerated in the refrigerant system 40 with the result of the demixing of said solvent into two liquid phases, namely a phase upper hydrocarbon and a lower phase consisting of the solvent containing the majority of CO2 and a certain amount of hydrocarbons.
  • the assembly is introduced into an extraction tower 56, in which it is brought into contact, against the current, with a refrigerated hydrocarbon solvent injected, through a conduit 57, into the lower part of the extraction tower and with a stream of regenerated solvent introduced into the tower 56 through a conduit 63, so as to produce, on the one hand, a purified solvent containing the almost all of the CO2 present in the demethanized rich solvent, said purified solvent being drawn off at the bottom of the extraction tower 56 by a conduit 58 on which is mounted an expansion valve 60, and, on the other hand, a hydrocarbon solvent enriched in C2 hydrocarbons and more containing little CO2, said solvent being discharged at the head of the extraction tower 56 through a conduit 59.
  • the enriched hydrocarbon solvent 59 is introduced into a regeneration column 49 in which said solvent is fractionated by distillation into a fraction of C2 and higher hydrocarbons, which is evacuated at the top of said column 49 by a conduit 48 and constitutes the cut d hydrocarbons in C plus and more containing at least 80 mol% of hydrocarbons in C3 and more contained in the gas to be treated brought to the washing column 5 by line 3, and in a regenerated hydrocarbon solvent withdrawn from column 49 by a line 50, which regenerated hydrocarbon solvent is recycled by the pump 51, through the refrigerant system 61 and the conduit 57, to the extraction tower 56.
  • the purified solvent circulating in the conduit 58 is introduced into the upper part of a regeneration column 62 provided with a heater 69, in which said purified solvent is subjected to a regeneration comprising a stripping using a stream of inert gas, for example a stream of nitrogen, injected into the lower part of the column 62 by a conduit 43.
  • a regeneration column 62 provided with a heater 69, in which said purified solvent is subjected to a regeneration comprising a stripping using a stream of inert gas, for example a stream of nitrogen, injected into the lower part of the column 62 by a conduit 43.
  • Said regeneration produces, on the one hand, a regenerated solvent 34, which is recycled by means of a pump 37 and a pipe 38 to the washing column 5 through the heat exchanger 39 and the pipe 6, and, on the other hand, a stream 44 of acid gas rich in CO2 , which contains almost all of the CO2 present in the demethanized rich solvent and has, expressed in methane equivalent, a hydrocarbon content of less than 10 mol% relative to CO2.
  • Part of the cold regenerated solvent passing through the conduit 38 is diverted through a conduit 63 to be injected into the extraction tower 56 at a point of this tower located above the injection point of the demethanized rich solvent circulating in the conduit 27.
  • the gaseous mixture to be treated arriving via line 1 with a flow rate of 10,000 kmol / h, a temperature of 30 ° C and a pressure of 5,000 kPa was introduced into column 2 for removal of C6 and higher hydrocarbons.
  • the gas mixture to be treated being dry, no addition of solvent was carried out via line 41.
  • the pretreated gas mixture was contacted with 11,500 kmol / h of solvent having a temperature of -20 ° C and a pressure of 5000 kPa and containing, by mole, 82.34% of methanol, 14.67% of water and 2.88 hexane, said contacting being carried out in a washing column 5 comprising 14 plates and operating at -20 ° C under a pressure of 4900 kPa.
  • the refrigerants 7 fitted to the washing column 5 made it possible to maintain the temperature in said column at the desired value.
  • the treated gas, discharged through line 8, was warmed up to room temperature in the heat exchanger system 9, the heated treated gas being directed, through line 10, to a shipping pipeline.
  • the demethanization of the rich solvent firstly involved a first expansion of said solvent at a pressure of 3000 kPa, the expanded relaxed solvent supplying the expansion tank 13 in which 401 kmol / h of a first gas containing 64% molar of methane, which was discharged at the head of the flask 13 through line 14, and a predemethanized rich solvent withdrawn from said flask through line 15 and whose molar methane content has been reduced from 3.70 to 2.01%.
  • the premethanized rich solvent the temperature of which was equal to -22.5 ° C., was expanded in valve 16 and then fed to the distillation column 17 comprising 10 plates and operating at 1800 kPa.
  • the second methane-rich gas was compressed in compressor 20 to the pressure of the first methane-rich gas, namely 3000 kPa.
  • the compressed gas leaving the compressor 20, via the conduit 21, was mixed with the first methane-rich gas to constitute the methane-rich gas phase 22, which was then compressed, in the compressor 23, until the pressure of the gas mixture a treating, namely 5000 kPa, said compressed gas phase being added through line 24, the refrigerant 25 and line 26, to the pretreated gas mixture circulating in line 3.
  • the compressed methane-rich gas phase passing through line 26 had a temperature of -20 ° C, a pressure of 5000 kPa and a flow rate of 1006 kmol / h.
  • the molar composition of said methane-rich gas phase flowing in line 26 was as follows: . CO2 34.31% . Methane 53.50% . Ethane 9.84% . Propane 1.70% . Butane 0.53% . Hexane 0.09% . Methanol 0.03%
  • the extraction tower 56 included 31 trays and was supplied on the first tray with 5000 kmol / h of regenerated solvent brought in through line 63 with a temperature of -40 ° C., on tray 21 by the demethanized rich solvent coming from the system refrigeration 40 and on the plate 31 by the refrigerated hydrocarbon solvent based on hexane supplied by line 57 with a flow rate of 1600 kmol / h.
  • This extraction produced 2079 kmol / h of a rich hydrocarbon solvent having a temperature of -40 ° C and a pressure of 1200 kPa, said rich hydrocarbon solvent being evacuated at the top of tower 56 via line 59, and 18069 kmol / h purified solvent withdrawn from the bottom of said tower, via line 58, at a temperature of -40 ° C. and under a pressure of 1200 kPa.
  • the molar composition of the rich hydrocarbon solvent passing through line 59 was as follows: . CO2 0.14% . Methane 0.13% . Ethane 9.19% . Propane 7.79% . Butane 6.62% . Hexane 73.72% . Methanol 2.40%
  • the molar composition of the purified solvent passing through line 58 was as follows: . CO2 9.16% . Methane 0.01% . Ethane 0.10% . Propane 0.01% . Hexane 2.42% . Methanol 74.91% . Water 13.40%
  • the C2 and higher hydrocarbon section evacuated via line 48, had the following molar composition: . CO2 0.59% . Methane 0.54% . Ethane 38.40% . Propane 32.58% . Butane 27.67% . Hexane 0.20% . Methanol 0.02%.
  • the regenerated hydrocarbon solvent passing through line 50 contained, by mole, 95.77% hexane, 1.11% butane and 3.12% methanol. Said solvent was brought, in the pump 51, to a pressure of 1200 kPa, then refrigerated at -40 ° C in the refrigerant system 61 before being recycled, via the conduit 57, to the extraction tower 56.
  • the purified solvent from line 58 of the extraction tower 56 is expanded to a pressure of 200 kPa in the expansion valve 60, then it is introduced into the regeneration column 62 for the purpose of regeneration.
  • Said column 62 comprising 14 plates and operating under a pressure of 200 kPa, is supplied to the first plate by the purified solvent to be regenerated and to the last plate by a stream of nitrogen supplied, via line 43, with a flow rate of 650 kmol / h.
  • the heater 69 which is provided with said column 62, was located on the seventh plate.
  • the stream of CO2-rich acid gas discharged through line 44 had a pressure of 200 kPa and a temperature of -47.5 ° C and it had the following molar composition: . CO2 71.64% . Methane 0.05% . Ethane 0.77% . Propane 0.04% . Hexane 0.40% . Methanol 0.06% . Nitrogen 27.04%.
  • the regenerated solvent circulating in the conduit 34 was brought to the pressure of 5000 kPa per passage through the pump 37, then divided into two parts, namely a major part recycled to the washing column 5 after passage through the heat exchanger system 39 and the conduit 6 and a part brought into the extraction tower 56 by the conduit 63.

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  • General Chemical & Material Sciences (AREA)
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Abstract

The gas mixture to be treated (1) is washed (5) between 0 DEG C and -45 DEG C by means of a solvent (6) for CO2 and C3 and higher hydrocarbons to produce a methane stream (8) containing not more than 2 mol% of CO2 and a CO2-rich liquid phase (11) containing at least 80 mol% of C3 and higher hydrocarbons from the gas mixture (1). The liquid phase (11) is subjected to a demethanization (12, 17) producing a demethanized rich solvent (27) and a methane-rich gas phase (22), and then the rich solvent (27) is subjected to a regeneration producing a regenerated solvent (34) which is recycled into the washing zone (5), and a gas mixture (42) containing the CO2 and the C2 and higher hydrocarbons which are present in the methanized rich solvent, the said gas mixture being separated by regenerative washing with a C5 and higher hydrocarbon solvent, into a CO2-rich acidic gas stream containing, expressed as methane equivalent, less than 10 mol% of hydrocarbons, and into a C2 and higher hydrocarbon cut (48) containing at least 80 mol% of the C3 and higher hydrocarbons present in the gas to be treated (1).

Description

L'invention concerne un procédé de décarbonatation et de dégazolinage simultanés d'un mélange gazeux constitué principalement d'hydrocarbures consistant en méthane et hydrocarbures en C₂ et plus et renfermant également CO₂ et éventuellement un ou plusieurs composés non sulfurés à bas point d'ébullition tels que H₂, CO,N₂ et argon.The invention relates to a process for the simultaneous decarbonation and degassing of a gaseous mixture consisting mainly of hydrocarbons consisting of methane and C₂ and higher hydrocarbons and also containing CO₂ and optionally one or more non-sulfurized compounds with low boiling point such as H₂, CO, N₂ and argon.

Le procédé selon l'invention permet de séparer directement un mélange gazeux du type précité en trois composantes, à savoir :

  • un gaz traité consistant principalement en méthane et hydrocarbures en C₂ et dont la teneur molaire en CO₂ est au plus égale à 2 %,
  • une coupe d'hydrocarbures contenant au moins 80 % molaire des hydrocarbures en C₃ et plus présents dans le mélange gazeux à traiter, et
  • un courant de gaz acide consistant en CO₂ renfermant moins de 10 % molaire d'hydrocarbures, exprimés en équivalent méthane, par rapport au CO₂.
The method according to the invention makes it possible to directly separate a gas mixture of the aforementioned type into three components, namely:
  • a treated gas consisting mainly of methane and C₂ hydrocarbons and whose CO₂ molar content is at most equal to 2%,
  • a hydrocarbon section containing at least 80 mol% of C₃ and more hydrocarbons present in the gas mixture to be treated, and
  • an acid gas stream consisting of CO₂ containing less than 10 mol% of hydrocarbons, expressed in methane equivalent, relative to CO₂.

On connaît plusieurs procédés, utilisés industriellement, pour le traitement de mélanges gazeux tels que définis plus haut et dont les principaux exemples sont représentés par les divers gaz naturels, qui comportent une opération de décarbonatation, c'est-à-dire une élimination du CO₂, et une opération de dégazolinage, c'est-à-dire une séparation des hydrocarbures lourds par exemple en C₃ et plus, du mélange gazeux et permettent de réaliser le fractionnement dudit mélange gazeux en les trois composantes mentionnées ci-dessus.Several processes are known, used industrially, for the treatment of gas mixtures as defined above and the main examples of which are represented by the various natural gases, which include a decarbonation operation, that is to say removal of CO₂ , and a degassing operation, that is to say a separation of heavy hydrocarbons for example in C₃ and above, from the gas mixture and make it possible to carry out the fractionation of said gas mixture into the three components mentioned above.

Ces opérations de décarbonatation et de dégazolinage sont généralement mises en oeuvre de manière séparée et font partie d'une succession d'opérations réalisées sur le mélange gazeux à traiter et comportant principalement une élimination du gaz acide CO₂ un séchage, une adsorption de l'eau sur un solide approprié tel qu'un tamis moléculaire, une séparation par distillation cryogénique entre -30°C et - 90°C associée ou non à une extraction par un solvant afin d'obtenir la coupe de liquide de gaz naturel, et enfin un réchauffage du gaz traité jusqu'à la température ambiante pour, généralement, alimenter le réseau de gaz commercial.These decarbonation and degassing operations are generally carried out separately and are part of a succession of operations carried out on the gas mixture to be treated and mainly comprising an elimination of the acid gas CO₂, drying, adsorption of water on an appropriate solid such as a molecular sieve, separation by cryogenic distillation between -30 ° C and - 90 ° C associated or not with extraction by a solvent in order to obtain the cut of natural gas liquid, and finally reheating the treated gas to ambient temperature in order to generally supply the commercial gas network.

Dans un tel schéma de traitement d'un mélange gazeux du type gaz naturel renfermant les constituants précités, l'abaissement de la température du mélange gazeux est imposé par la seule production de la coupe de liquide de gaz naturel, aucune autre opération n'étant effectuée à ce niveau de température.In such a treatment scheme for a gaseous mixture of the natural gas type containing the above-mentioned constituents, the lowering of the temperature of the gaseous mixture is imposed by the sole production of the cut of natural gas liquid, no other operation being performed at this temperature level.

Dans ce type de schéma de traitement, la réalisation en série d'opérations, qui s'appuient sur des principes très différents et sont conduites à des niveaux de température divers, présente de sérieux inconvénients. Il n'y a que peu de possibilité d'intégration thermique, ce qui rend ledit schéma de traitement extrêmement onéreux au plan énergétique et au plan des investissements.In this type of treatment scheme, the carrying out in series of operations, which are based on very different principles and are carried out at different temperature levels, has serious drawbacks. There is little possibility of thermal integration, which makes said treatment scheme extremely expensive from an energy and investment point of view.

On connait également des procédés de traitement de mélanges gazeux du type des gaz naturels, qui permettent de réaliser simultanément l'élimination du CO₂ contenu dans le mélange gazeux et la production d'hydrocarbures gazeux et d'hydrocarbures liquides et dont le type est le procédé connu sous le nom de procédé RYAN-HOLMES et décrit, notamment, par J. RYAN et F. SCHAFFERT dans la revue CHEMICAL ENGINEERING PROGRESS, Octobre 1984, pages 53 à 56. Dans un tel procédé, le gaz naturel à traiter, après avoir été déshydraté de manière conventionnelle puis réfrigéré, est soumis à une distillation à basse température mise en oeuvre en trois ou quatre étapes successives.There are also known processes for treating gaseous mixtures of the natural gas type, which make it possible to simultaneously carry out the elimination of CO₂ contained in the gaseous mixture and the production of gaseous hydrocarbons and liquid hydrocarbons, the type of which is the process. known as the RYAN-HOLMES process and described, in particular, by J. RYAN and F. SCHAFFERT in the journal CHEMICAL ENGINEERING PROGRESS, October 1984, pages 53 to 56. In such a process, the natural gas to be treated, after having been dehydrated in a conventional manner and then refrigerated, is subjected to a low temperature distillation carried out in three or four successive stages.

Dans le mode de réalisation en trois étapes, le gaz naturel déshydraté et réfrigéré est séparé, dans une première colonne (déméthaniseur) en tête de laquelle est injecté un additif consistant en une fraction liquide d'hydrocarbures en C₄ et plus, en une phase gazeuse renfermant le méthane et les composés plus légers et une fraction liquide contenant les hydrocarbures en C₂ et plus et le CO₂. Cette fraction liquide est séparée, dans une deuxième colonne (dé-éthaniseur) dans laquelle on introduit également une certaine quantité de l'additif, en une fraction de tête consistant en CO₂ et en une fraction de queue renfermant les hydrocarbures en C₂ et plus.In the three-stage embodiment, the dehydrated and refrigerated natural gas is separated, in a first column (demethanizer) at the head of which is injected an additive consisting of a liquid fraction of C₄ hydrocarbons and more, into a gas phase containing methane and lighter compounds and a liquid fraction containing C₂ and higher hydrocarbons and CO₂. This liquid fraction is separated, in a second column (de-ethanizer) into which a certain amount of the additive is also introduced, into a top fraction consisting of CO₂ and a bottom fraction containing the hydrocarbons in C₂ and more.

Ladite fraction de queue est ensuite séparée, dans une troisième colonne, en une fraction de tête consistant en une coupe liquide d'hydrocarbures en C₂ à C₄ et en une fraction de queue consistant en une coupe liquide d'hydrocarbures en C₄ et plus, qui contient la majeure partie des butanes et des hydrocarbures supérieurs présents dans le gaz naturel traité et dont on prélève la quantité appropriée pour constituer l'additif injecté dans les première et seconde colonnes. L'utilisation de cet additif évite la cristallisation de CO₂ en tête du déméthaniseur et assure la rupture de l'azéotrope qui se forme entre l'éthane et CO₂ et facilite la séparation de ce composés dans le dééthaniseur. Le procédé précité repose donc pour l'essentiel sur des opérations de distillation en série.Said tail fraction is then separated, in a third column, into an overhead fraction consisting of a liquid cut of C₂ to C₄ hydrocarbons and into a tail fraction consisting of a liquid cut of C₄ and higher hydrocarbons, which contains the major part of the butanes and higher hydrocarbons present in the treated natural gas and of which the appropriate quantity is taken to constitute the additive injected in the first and second columns. The use of this additive avoids the crystallization of CO₂ at the top of the demethanizer and ensures the rupture of the azeotrope which forms between ethane and CO₂ and facilitates the separation of this compound in the deethanizer. The aforementioned process is therefore essentially based on serial distillation operations.

L'invention propose un procédé de décarbonatation et de dégazolinage simultanés de mélanges gazeux, qui sont disponibles sous une pression absolue supérieure à 0,5 MPa et sont constitués principalement d'hydrocarbures consistant en méthane et hydrocarbures en C₂ et plus et renferment également CO₂ et éventuellement un ou plusieurs composés non sulfurés à bas point d'ébullition tels que H₂, CO, N₂ et argon, de tels mélanges gazeux étant par exemple du type des gaz naturels, ledit procédé permettant d'atteindre plus facilement et à moindre coût, en comparaison aux procédés connus, l'objectif d'une séparation du mélange gazeux en les trois composantes, à savoir gaz traité consistant principalement en méthane, coupe liquide d'hydrocarbures à majorité d'hydrocarbures en C₃ et plus et renfermant selon les besoins une quantité plus au moins importante d'éthane et courant de CO₂, qui ont les spécifications définies plus haut.The invention provides a process for simultaneous decarbonation and degassing of gas mixtures, which are available under an absolute pressure greater than 0.5 MPa and consist mainly of hydrocarbons consisting of methane and C₂ and higher hydrocarbons and also contain CO₂ and optionally one or more non-sulfurized compounds with low boiling point such as H₂, CO, N₂ and argon, such gas mixtures being for example of the natural gas type, said process making it possible to reach more easily and at lower cost, by comparison with known processes, the objective of separating the gaseous mixture into the three components, namely treated gas consisting mainly of methane, liquid cut of hydrocarbons with predominantly C₃ and more hydrocarbons and containing as required a quantity more or less important ethane and CO₂ current, which have the specifications defined above.

Le procédé selon l'invention est du type du procédé qui est décrit dans la citation US-A-3770622 et dans lequel on met le mélange gazeux en contact, dans une zone de lavage, avec un solvant consistant en un liquide qui dissout préférentiellement CO₂ et les hydrocarbures en C₂ et plus et qui possède d'une part, à la pression atmosphérique, une température d'ébullition supérieure à 40°C et d'autre part, à - 30°C, une viscosité inférieure à 0,1 Pa.s, en opérant à une température suffisamment basse et avec un rapport des débits de mélange gazeux à traiter et de solvant tel que l'on produise, d'une part, un gaz traité consistant principalement en méthane et présentant une teneur molaire en CO₂ au plus égale à 2 % et, d'autre part, une phase liquide appelée solvant riche et formée du solvant enrichi en CO₂ et en une fraction d'hydrocarbures en C₂ et plus renfermant au moins 80 % molaire des hydrocarbures en C₃ et plus présents dans le mélange gazeux à traiter, on soumet le solvant riche à un traitement de déméthanisation au moins partielle par détente séparant ledit solvant riche en une phase liquide appauvrie en méthane et appelée solvant riche déméthanisé et en une phase gazeuse riche en méthane, qui peut être éventuellement réunie au mélange gazeux à traiter avant la mise en contact de ce dernier avec le solvant, et on soumet le solvant riche déméthanisé à un traitement produisant un courant de gaz acide, qui renferme le CO₂ présent dans le solvant riche déméthanisé, produisant également un mélange d'hydrocarbures appelé coupe d'hydrocarbures et produisant enfin un solvant régénéré, qui est recyclé vers la zone de lavage.The process according to the invention is of the type of process which is described in the US-A-3770622 citation and in which the gas mixture is brought into contact, in a washing zone, with a solvent consisting of a liquid which preferentially dissolves CO₂ and hydrocarbons in C₂ and above and which has on the one hand, at atmospheric pressure, a boiling temperature greater than 40 ° C and on the other hand, at - 30 ° C, a viscosity less than 0.1 Pa .s, operating at a sufficiently low temperature and with a ratio of the flow rates of the gaseous mixture to be treated and of the solvent such that a treated gas consisting mainly of methane and having a molar CO₂ content is produced at most equal to 2% and, on the other hand, a liquid phase called rich solvent and formed of the solvent enriched in CO₂ and in a fraction of C en hydrocarbons and more containing at least 80 mol% of the C en hydrocarbons and more present in the mixture g nitrogenous to be treated, the rich solvent is subjected to an at least partial demethanization treatment by expansion separating said rich solvent into a liquid phase depleted in methane and called demethanized rich solvent and into a gaseous phase rich in methane, which can optionally be combined with gas mixture to be treated before the latter is brought into contact with the solvent, and the demethanized rich solvent is subjected to a treatment producing a stream of acid gas, which contains the CO₂ present in the demethanized rich solvent, also producing a mixture of hydrocarbons called hydrocarbon cut and finally producing a regenerated solvent, which is recycled to the washing zone.

Le procédé selon l'invention se distingue du procédé de la citation US-A-3770622, et se caractérise donc, en ce que le traitement du solvant riche déméthanisé est réalisé en soumettant ledit solvant riche déméthanisé, préalablement soumis à une réfrigération, a une extraction liquide/liquide, dans une zone d'extraction, au moyen d'un solvant hydrocarboné réfrigéré avec production, d'une part, d'un solvant purifié , qui renferme la quasi-totalité du CO₂ présent dans le solvant riche déméthanisé et possède une teneur en hydrocarbures, exprimée en équivalent méthane, inférieure à 10% molaire par rapport au CO₂, et, d'autre part, d'un solvant hydrocarboné enrichi en hydrocarbures en C₂ et plus , en fractionnant ledit solvant hydrocarboné enrichi par distillation et une fraction d'hydrocarbures en C₂ et plus, qui constitue la coupe d'hydrocarbures et renferme au moins 80% molaire des hydrocarbures en C₃ et plus présents dans le mélange gazeux a traiter, et en le solvant hydrocarboné régénéré , que l'on recycle, après réfrigération, à la zone d'extraction, et en soumettant le solvant purifié à une régénération par détente et stripage produisant le solvant régénéré et le courant de gaz acide , qui consiste en la quasi-totalité du CO₂ présent dans le solvant riche déméthanisé renfermant une teneur en hydrocarbures, exprimée en équivalent méthane, inférieure à 10% molaire par rapport au CO₂.The process according to the invention differs from the process of the US-A-3770622 citation, and is therefore characterized in that the treatment of the demethanized rich solvent is carried out by subjecting said demethanized rich solvent, previously subjected to refrigeration, to a liquid / liquid extraction, in an extraction zone, using a refrigerated hydrocarbon solvent with production, on the one hand, of a purified solvent, which contains almost all of the CO₂ present in the demethanized rich solvent and has a hydrocarbon content, expressed in methane equivalent, of less than 10 mol% relative to CO₂, and, on the other hand, of a hydrocarbon solvent enriched in C₂ hydrocarbons and more, by fractionating said enriched hydrocarbon solvent by distillation and a fraction of C₂ and higher hydrocarbons, which constitutes the hydrocarbon fraction and contains at least 80 mol% of the C₃ and more hydrocarbons present in the gas mixture to be treated, and in the regenerated hydrocarbon solvent, which is recycled after refrigeration, in the extraction zone, and by subjecting the purified solvent to a regeneration by expansion and stripping producing the regenerated solvent and the acid gas stream, which consists of almost all of the CO₂ present in the rich demethanized solvent containing a hydrocarbon content, expressed in methane equivalent, less than 10 mol% relative to CO₂.

Par "équivalent méthane", on désigne suivant l'invention autant de pseudo-molécules à un seul atome de carbone qu'il y a d'atomes de carbone dans la molécule considérée d'hydrocarbure.By "methane equivalent" is meant according to the invention as many pseudo-molecules with a single carbon atom as there are carbon atoms in the considered hydrocarbon molecule.

Le solvant, qui est défini généralement ci-dessus pour la mise en contact avec le mélange gazeux à traiter aux fins d'absorption du CO₂ et des hydrocarbures en C₂ et plus, possède de préférence une viscosité, à -30°C, inférieure à 0,05 Pa.s.The solvent, which is generally defined above for bringing it into contact with the gaseous mixture to be treated for the purpose of absorbing CO₂ and C₂ and higher hydrocarbons, preferably has a viscosity, at -30 ° C, of less than 0.05 Pa.s.

Le solvant suivant l'invention peut consister en particulier en un ou plusieurs absorbants liquides sélectifs du CO₂ et utilisés sous forme anhydre ou en mélange avec de l'eau, le ou lesdits solvants étant choisis parmi les amides de formules

Figure imgb0001

les aldéhydes de formule
Figure imgb0002
les esters de formules
Figure imgb0003
Figure imgb0004
les alcanols en C₁ à C₄ , les diéthers de formule
Figure imgb0005
les diéthers alcools de formule R₉O-C₂H₄-O-C₂H₄-OH, les lactones de formule
Figure imgb0006
et le carbonate de propylène, avec dans ces formules R₁ et R₂, identiques ou différents, désignant un atome d'hydrogène ou un radical alcoyle en C₁ ou C₂, R₃ étant un radical alcoyle en C₃ ou C₄, R₆ étant un radical alcoyle en C₂ à C₄ ou un radical
Figure imgb0007
avec R₈ désignant un radical alcoyle en C₁ ou C₂ et n étant égal à 1 ou 2, R₇ étant un radical alcoyle en C₁ ou C₂ ou un radical
Figure imgb0008
R₉ désignant un radical alcoyle en C₁ à C₄ et p étant un nombre entier allant de 2 à 4.The solvent according to the invention may consist in particular of one or more liquid absorbents which are selective for CO₂ and used in anhydrous form or in mixture with water, the said solvent (s) being chosen from the amides of formulas
Figure imgb0001
aldehydes of formula
Figure imgb0002
formula esters
Figure imgb0003
Figure imgb0004
Ccan to C₄ alkanols, diethers of formula
Figure imgb0005
diether alcohols of formula R₉O-C₂H₄-O-C₂H₄-OH, lactones of formula
Figure imgb0006
and propylene carbonate, with in these formulas R₁ and R₂, identical or different, designating a hydrogen atom or a C₁ or C₂ alkyl radical, R₃ being a C₃ or C₄ alkyl radical, R₆ being a C₂ alkyl radical to C₄ or a radical
Figure imgb0007
with R₈ denoting a C₁ or C₂ alkyl radical and n being equal to 1 or 2, R₇ being a C₁ or C₂ alkyl radical or a radical
Figure imgb0008
R₉ denoting a C radical to C₄ alkyl radical and p being an integer ranging from 2 to 4.

Des exemples non limitatifs d'absorbants organiques liquides répondant aux formules ci-dessus sont tels que N,N-diméthylformamide, N,N-diméthylacétamide, diméthoxyméthane, diéthoxyméthane, diméthoxy-1,1 éthane, méthanol, éthanol, diméthyléther de l'éthylène glycol, diméthyléther du diéthylèneglycol, monométhyléther de l'éthylèneglycol, butyrolactone, propiolactone et carbonate de propylène.Nonlimiting examples of liquid organic absorbents corresponding to the above formulas are such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethoxymethane, diethoxymethane, dimethoxy-1,1 ethane, methanol, ethanol, ethylene dimethyl ether glycol, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether, butyrolactone, propiolactone and propylene carbonate.

La température de mise en contact du mélange gazeux à traiter avec le solvant, dans la zone de lavage, est de préférence comprise entre 0°C et -45°C.The contacting temperature of the gas mixture to be treated with the solvent, in the washing zone, is preferably between 0 ° C and -45 ° C.

La zone de lavage consiste avantageusement en une ou plusieurs colonnes de lavage renfermant le nombre approprié d'étages théoriques de lavage, lesdites colonnes étant, par exemple, du type des colonnes à plateaux ou encore des colonnes à garnissage. Avantageusement on maintient substantiellement constante la température dans chacune des colonnes de lavage par échange indirect de chaleur, effectué en un ou plusieurs points de la colonne considérée, entre le milieu fluide contenu dans cette colonne et un fluide réfrigérant.The washing zone advantageously consists of one or more washing columns containing the appropriate number of theoretical washing stages, said columns being, for example, of the type of tray columns or also packed columns. Advantageously, the temperature in each of the washing columns is kept substantially constant by indirect heat exchange, carried out at one or more points of the column considered, between the fluid medium contained in this column and a cooling fluid.

Le traitement de déméthanisation appliqué au solvant riche est réalisé, en particulier, en deux étapes, à savoir une première étape dans laquelle ledit solvant riche est soumis à une première détente propre à libérer une fraction importante du méthane dissous dans ledit solvant à déméthaniser et à produire un premier gaz riche en méthane et un fluide prédéméthanisé et une seconde étape dans laquelle le fluide prédéméthanisé est soumis à une seconde détente puis à une distillation produisant un second gaz riche en méthane et le solvant riche déméthanisé, le second gaz riche en méthane étant comprimé jusqu'à la pression du premier gaz riche en méthane puis mélangé à ce dernier pour constituer la phase gazeuse riche en méthane.The demethanization treatment applied to the rich solvent is carried out, in particular, in two stages, namely a first step in which said rich solvent is subjected to a first expansion capable of releasing a large fraction of the methane dissolved in said solvent to be demethanized and in producing a first methane-rich gas and a premethanized fluid and a second step in which the premethanized fluid is subjected to a second expansion and then to distillation producing a second methane-rich gas and the demethanized rich solvent, the second methane-rich gas being compressed to the pressure of the first methane-rich gas and then mixed with the latter to form the methane-rich gas phase.

La phase gazeuse riche en méthane, résultant du traitement de déméthanisation appliqué au solvant riche, est avantageusement comprimée jusqu'à la pression du mélange gazeux à traiter, puis elle est refroidie et mélangée au mélange gazeux à traiter avant la mise en contact de ce dernier avec le solvant dans la zone de lavage.The methane-rich gas phase, resulting from the demethanization treatment applied to the rich solvent, is advantageously compressed to the pressure of the gas mixture to be treated, then it is cooled and mixed with the gas mixture to be treated before the latter is brought into contact. with the solvent in the washing area.

La régénération du solvant purifié, qui conduit à la production du courant de gaz acide riche en CO₂ et présentant, exprimée en équivalent méthane, une teneur en hydrocarbures inférieure à 10 % molaire par rapport au CO₂, peut être réalisée par tout traitement permettant de libérer les composés gazeux dissous dans un liquide. En particulier, la régénération du solvant purifié peut être effectuée par détente dudit solvant purifié jusqu'à une pression supérieure à 100 kPa et par exemple comprise entre 150 kPa et 300 kPa et par stripage au moyen d'un gaz inerte tel que l'azote associé éventuellement à un réchauffage du solvant purifié dans la zone de régénération.The regeneration of the purified solvent, which leads to the production of the stream of acid gas rich in CO₂ and having, expressed in methane equivalent, a hydrocarbon content of less than 10 mol% relative to CO₂, can be carried out by any treatment making it possible to release gaseous compounds dissolved in a liquid. In particular, the regeneration of the purified solvent can be carried out by expansion of said purified solvent to a pressure greater than 100 kPa and for example between 150 kPa and 300 kPa and by stripping using an inert gas such as nitrogen. possibly associated with a heating of the purified solvent in the regeneration zone.

La régénération du solvant purifié peut encore être réalisée en réchauffant ledit solvant purifié jusqu'à une température proche de l'ambiante, en partageant le solvant réchauffé en un premier et un second courants, en dirigeant le premier courant directement vers une zone de régénération, en dirigeant le second courant vers cette zone de régénération après l'avoir réchauffé par échange indirect de chaleur avec le solvant purifié régénéré, et en soumettant le solvant à une distillation dans la zone de régénération aux fins de produire le solvant régénéré et le courant de gaz acide riche en CO₂.The regeneration of the purified solvent can also be carried out by heating said purified solvent to a temperature close to ambient, by dividing the heated solvent into first and second streams, by directing the first stream directly to a regeneration zone, directing the second stream to this regeneration zone after having heated it by indirect heat exchange with the regenerated purified solvent, and by subjecting the solvent to distillation in the regeneration zone to produce the regenerated solvent and the stream of acid gas rich in CO₂.

Lorsque le mélange gazeux à traiter renferme de l'eau et/ou des hydrocarbures en C₅ et plus, il est avantageusement soumis à un prétraitement destiné à éliminer tout ou partie de ces composés avant d'être mis en contact avec le solvant dans la zone de lavage.When the gaseous mixture to be treated contains water and / or C₅ and higher hydrocarbons, it is advantageously subjected to a pretreatment intended to remove all or part of these compounds before being brought into contact with the solvent in the zone of washing.

Ce prétraitement peut consister en une distillation réalisée éventuellement en présence de solvant, prélevé sur le solvant injecté dans la zone de lavage, pour produire le mélange gazeux prétraité présentant une teneur en hydrocarbures en C₆ et plus inférieure à 0,1 % en poids, une fraction d'hydrocarbures dits lourds renfermant la quasitotalité des hydrocarbures en C₆ et plus et tout ou partie des hydrocarbures en C₅ et, éventuellement, un liquide consistant en un mélange de solvant et d'eau. Ladite distillation du mélange gazeux est effectuée à une température au moins égale à la température régnant dans la zone de lavage.This pretreatment can consist of a distillation possibly carried out in the presence of solvent, taken from the solvent injected into the washing zone, to produce the pretreated gas mixture having a C₆ hydrocarbon content and more than 0.1% by weight, a fraction of so-called heavy hydrocarbons containing almost all of the C₆ and more hydrocarbons and all or part of the C₅ hydrocarbons and, optionally, a liquid consisting of a mixture of solvent and water. Said distillation of the gas mixture is carried out at a temperature at least equal to the temperature prevailing in the washing zone.

L'invention sera mieux comprise à la lecture de la description donnée ci-après de l'une de ses formes de mise en oeuvre faisant appel à l'installation schématisée sur la figure du dessin annexé.The invention will be better understood on reading the description given below of one of its forms of implementation using the installation shown schematically in the figure of the accompanying drawing.

En se référant à la figure, le mélange gazeux a traiter arrivant par le conduit 1 est introduit dans la partie inférieure d'une colonne 2 de distillation, dans laquelle ledit mélange gazeux est distillé éventuellement en présence de solvant prélevé, par un conduit 41 débouchant dans la partie supérieure de la colonne 2, sur le solvant régénéré 38 amené à la colonne 5 de lavage, avant passage dudit solvant dans une zone 39 de réfrigération montée sur le conduit 6 d'injection du solvant régénéré dans ladite colonne 5 de lavage, de manière à produire d'une part un mélange gazeux séché, évacué de la colonne 2 par un conduit 3 et dont la teneur en hydrocarbures en C₆ et plus est inférieure à 0,1 % en poids, et d'autre part une coupe hydrocarbonée renfermant la quasi-totalité des hydrocarbures en C₆ et plus et éventuellement tout ou partie des hydrocarbures en C₅, soutirée de la colonne 2 par un conduit 4 et éventuellement un liquide soutiré de la colonne 2 par un conduit 54 et consistant en un mélange de solvant et d'eau.Referring to the figure, the gaseous mixture to be treated arriving via line 1 is introduced into the lower part of a distillation column 2, in which said gaseous mixture is optionally distilled in the presence of solvent withdrawn, through an opening pipe 41 in the upper part of column 2, on the regenerated solvent 38 brought to the washing column 5, before passage of said solvent in a refrigeration zone 39 mounted on the conduit 6 for injecting the regenerated solvent into said washing column 5, so as to produce on the one hand a dried gas mixture, evacuated from column 2 via a line 3 and whose C₆ and higher hydrocarbon content is less than 0.1% by weight, and on the other hand a hydrocarbon fraction containing almost all of the C₆ hydrocarbons and more and possibly all or part of the C₅ hydrocarbons, withdrawn from column 2 by a conduit 4 and optionally a liquid withdrawn from column 2 by a conduit 54 and consisting of a mixture of solvent and water.

Le mélange gazeux séché sortant de la colonne 2 par le conduit 3 est introduit dans la partie inférieure d'une colonne 5 de lavage, par exemple du type colonne à plateaux, dans laquelle il est mis en contact, à contrecourant, avec du solvant froid régénéré injecté dans la partie supérieure de la colonne 5 par le conduit 6, après passage dans le réfrigérant 39, cette mise en contact étant effectuée à une température comprise, par exemple, entre O°C et -45°C, ladite température étant contrôlée par passage du milieu liquide contenu dans la colonne 5 dans des réfrigérants 7. En tête de la colonne 5 on évacue, par un conduit 8, un gaz traité consistant Principalement en méthane et appauvri en CO₂, ledit gaz traité étant réchauffé dans un système 9 de réchauffage puis dirigé, par un conduit 10, vers une zone d'utilisation, tandis qu'en fond de ladite colonne 5 on soutire, par un conduit 11, une phase liquide constituée du solvant enrichi en CO₂ et autres composés absorbés et appelée solvant riche.The dried gas mixture leaving column 2 through line 3 is introduced into the lower part of a washing column 5, for example of the plate column type, in which it is brought into contact, countercurrently, with cold solvent. regenerated injected into the upper part of column 5 through line 6, after passage through the coolant 39, this contacting being carried out at a temperature of, for example, between 0 ° C and -45 ° C, said temperature being controlled by passage of the liquid medium contained in column 5 in refrigerants 7. At the head of column 5 there is discharged, via a conduit 8, a treated gas consisting mainly of methane and depleted in CO₂, said treated gas being heated in a system 9 reheating and then directed, via a conduit 10, to a zone of use, while at the bottom of said column 5 is drawn off, via a conduit 11, a liquid phase consisting of the solvent enriched in CO₂ and a other compounds absorbed and called rich solvent.

On réalise la mise en contact du mélange gazeux séché avec le solvant dans la colonne 5 de lavage à une température appropriée dans l'intervalle O°C à -45°C et avec un rapport des débits de mélange gazeux à traiter et de solvant tel que d'une part le gaz traité recueilli, par le conduit 8, en tête de la colonne 5 ait une teneur molaire en CO₂ au plus égale à 2 % et que d'autre part le solvant riche, s'écoulant par le conduit 11, renferme au moins 80 % molaire des hydrocarbures en C₃ et plus présents dans le mélange gazeux séché introduit dans la colonne 5.The dried gas mixture is brought into contact with the solvent in the washing column 5 at an appropriate temperature in the range O ° C to -45 ° C and with a ratio of the flow rates of the gas mixture to be treated and of solvent such that on the one hand the treated gas collected, through line 8, at the head of column 5 has a molar CO₂ content of at most equal to 2% and that on the other hand the rich solvent, flowing through line 11 , contains at least 80 mol% of C₃ and higher hydrocarbons present in the dried gas mixture introduced in column 5.

Le solvant riche circulant dans le conduit 11 est introduit, après passage à travers la vanne 12 de détente, dans la partie supérieure d'un ballon de détente 13 dans lequel se sépare un premier gaz riche en méthane, que l'on évacue en tête du ballon 13 par un conduit 14, et un solvant riche prédéméthanisé, que l'on soutire en fond du ballon 13 par un conduit 15. Ledit solvant riche prédéméthanisé est soumis à une seconde détente à travers une vanne de détente 16 suivie d'une distillation dans une colonne 17 de distillation pourvue d'un rebouilleur 18, de manière à produire un second gaz riche en méthane, que l'on évacue en tête de la colonne 17 par un conduit 19, et une phase liquide appauvrie en méthane, appelée solvant riche déméthanisé, qui est soutirée en fond de la colonne 17 par un conduit 27. Le second gaz riche en méthane circulant dans le conduit 19 est amené à passer dans un compresseur 20 d'où il sort, par un conduit 21, à une pression sensiblement égale à celle du premier gaz riche en méthane passant dans le conduit 14, puis ces deux gaz riches en méthane sont mélangés dans le conduit 22 et la phase gazeuse résultant de ce mélange est recyclée, par l'intermédiaire d'un compresseur 23 dont la sortie est prolongée par un conduit 24, un réfrigérant 25 et un conduit 26, dans le conduit 3 d'amenée du mélange gazeux séché à la colonne 5 de lavage.The rich solvent circulating in the conduit 11 is introduced, after passing through the expansion valve 12, into the upper part of an expansion tank 13 in which a first gas rich in methane separates, which is removed at the head of the flask 13 by a conduit 14, and a rich predemethanized solvent, which is drawn off at the bottom of the flask 13 by a conduit 15. Said predemethanized rich solvent is subjected to a second expansion through an expansion valve 16 followed by a distillation in a distillation column 17 provided with a reboiler 18, so as to produce a second gas rich in methane, which is evacuated at the top of the column 17 by a conduit 19, and a liquid phase depleted in methane, called demethanized rich solvent, which is drawn off at the bottom of the column 17 by a pipe 27. The second methane-rich gas circulating in the pipe 19 is caused to pass into a compressor 20 from which it leaves, via a pipe 21, to a pressure substantially equal to that of the first methane-rich gas passing through line 14, then these two methane-rich gases are mixed in line 22 and the gas phase resulting from this mixture is recycled, by means of a compressor 23 whose the outlet is extended by a line 24, a cooler 25 and a line 26, in the line 3 for supplying the dried gas mixture to the washing column 5.

Le solvant riche déméthanisé, soutiré de la colonne 17 par le conduit 27, est détendu par passage dans une vanne 29 de détente, puis est réfrigéré dans le système réfrigérant 40 avec comme résultat la démixtion dudit solvant en deux phases liquides, à savoir une phase supérieure hydrocarbonée et une phase inférieure constituée du solvant renfermant la majorité du CO₂ et une certaine quantité d'hydrocarbures. L'ensemble est introduit dans une tour d'extraction 56, dans laquelle il est mis en contact, à contre-courant, avec un solvant hydrocarboné réfrigéré injecté, par un conduit 57, dans la partie inférieure de la tour d'extraction et avec un courant de solvant régénéré introduit dans la tour 56 par un conduit 63, de manière à produire, d'une part, un solvant purifié renfermant la quasi-totalité du CO₂ présent dans le solvant riche déméthanisé, ledit solvant purifié étant soutiré en fond de la tour d'extraction 56 par un conduit 58 sur lequel est monté une vanne de détente 60, et, d'autre part, un solvant hydrocarboné enrichi en hydrocarbures en C₂ et plus renfermant peu de CO₂, ledit solvant étant évacué en tête de la tour d'extraction 56 par un conduit 59.The demethanized rich solvent, withdrawn from the column 17 through the conduit 27, is expanded by passing through an expansion valve 29, then is refrigerated in the refrigerant system 40 with the result of the demixing of said solvent into two liquid phases, namely a phase upper hydrocarbon and a lower phase consisting of the solvent containing the majority of CO₂ and a certain amount of hydrocarbons. The assembly is introduced into an extraction tower 56, in which it is brought into contact, against the current, with a refrigerated hydrocarbon solvent injected, through a conduit 57, into the lower part of the extraction tower and with a stream of regenerated solvent introduced into the tower 56 through a conduit 63, so as to produce, on the one hand, a purified solvent containing the almost all of the CO₂ present in the demethanized rich solvent, said purified solvent being drawn off at the bottom of the extraction tower 56 by a conduit 58 on which is mounted an expansion valve 60, and, on the other hand, a hydrocarbon solvent enriched in C₂ hydrocarbons and more containing little CO₂, said solvent being discharged at the head of the extraction tower 56 through a conduit 59.

Le solvant hydrocarboné enrichi 59 est introduit dans un colonne 49 de régénération dans laquelle ledit solvant est fractionné par distillation en une fraction d'hydrocarbures en C₂ et plus, qui est évacuée en tête de ladite colonne 49 par un conduit 48 et constitue la coupe d'hydrocarbures en C₂ et plus renfermant au moins 80 % molaire des hydrocarbures en C₃ et plus contenus dans le gaz à traiter amené à la colonne 5 de lavage par le conduit 3, et en un solvant hydrocarboné régénéré soutiré de la colonne 49 par un conduit 50, lequel solvant hydrocarboné régénéré est recyclé par la pompe 51, à travers le système réfrigérant 61 et le conduit 57, à la tour d'extraction 56.The enriched hydrocarbon solvent 59 is introduced into a regeneration column 49 in which said solvent is fractionated by distillation into a fraction of C₂ and higher hydrocarbons, which is evacuated at the top of said column 49 by a conduit 48 and constitutes the cut d hydrocarbons in C plus and more containing at least 80 mol% of hydrocarbons in C₃ and more contained in the gas to be treated brought to the washing column 5 by line 3, and in a regenerated hydrocarbon solvent withdrawn from column 49 by a line 50, which regenerated hydrocarbon solvent is recycled by the pump 51, through the refrigerant system 61 and the conduit 57, to the extraction tower 56.

A la sortie de la vanne de détente 60, le solvant purifié circulant dans le conduit 58 est introduit à la partie supérieure d'une colonne 62 de régénération pourvue d'un réchauffeur 69, dans laquelle ledit solvant purifié est soumis à une régénération comportant un stripage à l'aide d'un courant de gaz inerte, par exemple un courant d'azote, injecté à la partie inférieure de la colonne 62 par un conduit 43. Ladite régénération produit, d'une part, un solvant régénéré 34, qui est recyclé au moyen d'une pompe 37 et d'un conduit 38 à la colonne de lavage 5 à travers l'échangeur de chaleur 39 et le conduit 6, et, d'autre part, un courant 44 de gaz acide riche en CO₂, qui renferme la quasi-totalité du CO₂ présent dans le solvant riche déméthanisé et possède, exprimée en équivalent méthane, une teneur en hydrocarbures inférieure à 10 % molaire par rapport au CO₂.At the outlet of the expansion valve 60, the purified solvent circulating in the conduit 58 is introduced into the upper part of a regeneration column 62 provided with a heater 69, in which said purified solvent is subjected to a regeneration comprising a stripping using a stream of inert gas, for example a stream of nitrogen, injected into the lower part of the column 62 by a conduit 43. Said regeneration produces, on the one hand, a regenerated solvent 34, which is recycled by means of a pump 37 and a pipe 38 to the washing column 5 through the heat exchanger 39 and the pipe 6, and, on the other hand, a stream 44 of acid gas rich in CO₂ , which contains almost all of the CO₂ present in the demethanized rich solvent and has, expressed in methane equivalent, a hydrocarbon content of less than 10 mol% relative to CO₂.

Une partie du solvant régénéré froid passant dans le conduit 38 est dérivée par un conduit 63 pour être injectée dans la tour d'extraction 56 en un point de cette tour situé au-dessus du point d'injection du solvant riche déméthanisé circulant dans le conduit 27.Part of the cold regenerated solvent passing through the conduit 38 is diverted through a conduit 63 to be injected into the extraction tower 56 at a point of this tower located above the injection point of the demethanized rich solvent circulating in the conduit 27.

Pour compléter la description qui précède, on donne ci-après, à titre non limitatif, un exemple de mise en oeuvre du procédé selon l'invention.To complete the above description, an example of implementation of the method according to the invention is given below, without implied limitation.

EXEMPLE : EXAMPLE :

En faisant appel à une installation analogue à celle schématisée sur la figure du dessin annexé et fonctionnant comme décrit précédemment, on traitait un mélange gazeux ayant la composition molaire suivante : . CO₂ 18 % . Méthane 71,5 % . Ethane 5,1 % . Propane 1,8 % . Butane 1,8 % . Hexane 1,8 % Using an installation similar to that shown diagrammatically in the figure of the appended drawing and operating as described above, a gas mixture having the following molar composition was treated: . CO₂ 18% . Methane 71.5% . Ethane 5.1% . Propane 1.8% . Butane 1.8% . Hexane 1.8%

Le mélange gazeux à traiter, arrivant par le conduit 1 avec un débit de 10 000 kmoles/h, une température de 30°C et une pression de 5 000 kPa était introduit dans la colonne 2 d'élimination des hydrocarbures en C₆ et plus. Dans cet exemple, le mélange gazeux à traiter étant sec, aucune addition de solvant n'était réalisée par le conduit 41.The gaseous mixture to be treated, arriving via line 1 with a flow rate of 10,000 kmol / h, a temperature of 30 ° C and a pressure of 5,000 kPa was introduced into column 2 for removal of C₆ and higher hydrocarbons. In this example, the gas mixture to be treated being dry, no addition of solvent was carried out via line 41.

Par le conduit 4 de la colonne 2, on évacuait 352 kmoles/h d'une coupe hydrocarbonée lourde ayant une pression de 5 000 kPa et une température égale à 30°C, ladite coupe ayant la composition suivante : . CO₂ 9,26 % . Méthane 18 % . Ethane 5,01 % . Propane 4,71 % . Butane 12,05 % . Hexane 50,97 % Via line 4 of column 2, 352 kmol / h of a heavy hydrocarbon fraction having a pressure of 5,000 kPa and a temperature equal to 30 ° C. was removed, said fraction having the following composition: . CO₂ 9.26% . Methane 18% . Ethane 5.01% . Propane 4.71% . Butane 12.05% . Hexane 50.97%

Par le conduit 3 en tête de la colonne 2 on évacuait 9648 kmoles/h d'un mélange gazeux prétraité ayant une température de -20°C et une pression de 4950 kPa, ledit mélange gazeux prétraité ayant la composition molaire suivante : . CO₂ 18,32 % . Méthane 73,45 % . Ethane 5,10 % . Propane 1,69 % . Butane 1,43 % . Hexane 0,01 % Via line 3 at the head of column 2, 9648 kmol / h of a pretreated gas mixture having a temperature of -20 ° C. and a pressure of 4950 kPa were discharged, said pretreated gas mixture having the following molar composition: . CO₂ 18.32% . Methane 73.45% . Ethane 5.10% . Propane 1.69% . Butane 1.43% . Hexane 0.01%

Le mélange gazeux prétraité était mis en contact avec 11500 kmoles/h de solvant ayant une température de -20°C et une pression de 5000 kPa et renfermant, en mole, 82,34 % de méthanol, 14,67 % d'eau et 2,88 d'hexane, ladite mise en contact étant réalisée dans une colonne 5 de lavage comportant 14 plateaux et opérant à -20°C sous une pression de 4900 kPa. Les réfrigérants 7 équipant la colonne 5 de lavage permettaient de maintenir la température dans la dite colonne à la valeur désirée.The pretreated gas mixture was contacted with 11,500 kmol / h of solvent having a temperature of -20 ° C and a pressure of 5000 kPa and containing, by mole, 82.34% of methanol, 14.67% of water and 2.88 hexane, said contacting being carried out in a washing column 5 comprising 14 plates and operating at -20 ° C under a pressure of 4900 kPa. The refrigerants 7 fitted to the washing column 5 made it possible to maintain the temperature in said column at the desired value.

En tête de la colonne 5, on évacuait, par le conduit 8, 7499 kmoles/h d'un gaz traité ayant une pression de 4900 kPa et une température de -20°C, ledit gaz traité ayant la composition molaire suivante : . CO₂ 1,68 % . Méthane 94,44 % . Ethane 3,78 % . Méthanol 0,02 % At the head of column 5, 7,499 kmol / h of a treated gas having a pressure of 4,900 kPa and a temperature of -20 ° C. were removed via line 8, said treated gas having the following molar composition: . CO₂ 1.68% . Methane 94.44% . Ethane 3.78% . Methanol 0.02%

Le gaz traité, évacué par le conduit 8, était réchauffé jusqu'à température ambiante dans le système échangeur de chaleur 9, le gaz traité réchauffé étant dirigé, par le conduit 10, vers un gazoduc d'expédition.The treated gas, discharged through line 8, was warmed up to room temperature in the heat exchanger system 9, the heated treated gas being directed, through line 10, to a shipping pipeline.

En fond de la colonne de lavage, on soutirait, par le conduit 11, 14655 kmoles/h de solvant riche ayant une température de -20°C et une pression de 4900 kPa, ledit solvant riche ayant la composition molaire ci-après: . CO₂ 13,64 % . Méthane 3,70 % . Ethane 2,10 % . Propane 1,23 % . Butane 0,98 % . Hexane 2,24 % . Méthanol 64,61 % . Eau 11,51 % At the bottom of the washing column, 14655 kmol / h of rich solvent having a temperature of -20 ° C. and a pressure of 4900 kPa were withdrawn via line 11, said rich solvent having the following molar composition: . CO₂ 13.64% . Methane 3.70% . Ethane 2.10% . Propane 1.23% . Butane 0.98% . Hexane 2.24% . Methanol 64.61% . Water 11.51%

La déméthanisation du solvant riche comportait tout d'abord une première détente dudit solvant à une pression de 3000 kPa, le solvant riche détendu alimentant le ballon 13 de détente dans lequel on produisait 401 kmoles/h d'un premier gaz renfermant 64 % molaire de méthane, que l'on évacuait en tête du ballon 13 par le conduit 14, et un solvant riche prédéméthanisé soutiré dudit ballon par le conduit 15 et dont la teneur molaire en méthane a été réduite de 3,70 à 2,01 %. Le solvant riche prédéméthanisé, dont la température était égale à -22,5°C, était détendu dans la vanne 16 et alimentait ensuite la colonne 17 de distillation comportant 10 plateaux et opérant à 1800 kPa.The demethanization of the rich solvent firstly involved a first expansion of said solvent at a pressure of 3000 kPa, the expanded relaxed solvent supplying the expansion tank 13 in which 401 kmol / h of a first gas containing 64% molar of methane, which was discharged at the head of the flask 13 through line 14, and a predemethanized rich solvent withdrawn from said flask through line 15 and whose molar methane content has been reduced from 3.70 to 2.01%. The premethanized rich solvent, the temperature of which was equal to -22.5 ° C., was expanded in valve 16 and then fed to the distillation column 17 comprising 10 plates and operating at 1800 kPa.

La colonne 17 produisait 604 kmoles/h d'un second gaz riche en méthane, évacué par le conduit 19 sous une pression de 1800 kPa et à une température de -25°C, et un solvant déméthanisé soutiré de la colonne 17, par le conduit 27, avec un débit de 13649 kmoles/h, une température de 1°C et une pression de 1800 kPa
   Le solvant riche déméthanisé passant dans le conduit 27 avait la composition molaire suivante : . CO₂ 12,11 % . Méthane 0,03 % . Ethane 1,53 % . Propane 1,20 % . Butane 1,01 % . Hexane 2,39 % . Méthanol 69,37 % . Eau 12,36 % Column 17 produced 604 kmol / h of a second gas rich in methane, evacuated through line 19 under a pressure of 1800 kPa and at a temperature of -25 ° C, and a demethanized solvent withdrawn from column 17, through conduit 27, with a flow rate of 13,649 kmol / h, a temperature of 1 ° C and a pressure of 1,800 kPa
The demethanized rich solvent passing through line 27 had the following molar composition: . CO₂ 12.11% . Methane 0.03% . Ethane 1.53% . Propane 1.20% . Butane 1.01% . Hexane 2.39% . Methanol 69.37% . Water 12.36%

Le second gaz riche en méthane était comprimé, dans le compresseur 20, jusqu'à la pression du premier gaz riche en méthane, à savoir 3000 kPa. Le gaz comprimé sortant du compresseur 20, par le conduit 21, était mélangé au premier gaz riche en méthane pour constituer la phase gazeuse riche en méthane 22, qui était ensuite comprimée, dans le compresseur 23, jusqu'à la pression du mélange gazeux a traiter, à savoir 5000 kPa, ladite phase gazeuse comprimée étant ajoutée à travers le conduit 24, le réfrigérant 25 et le conduit 26, au mélange gazeux prétraité circulant dans le conduit 3.The second methane-rich gas was compressed in compressor 20 to the pressure of the first methane-rich gas, namely 3000 kPa. The compressed gas leaving the compressor 20, via the conduit 21, was mixed with the first methane-rich gas to constitute the methane-rich gas phase 22, which was then compressed, in the compressor 23, until the pressure of the gas mixture a treating, namely 5000 kPa, said compressed gas phase being added through line 24, the refrigerant 25 and line 26, to the pretreated gas mixture circulating in line 3.

La phase gazeuse comprimée riche en méthane passant dans le conduit 26 avait une température de -20°C, une pression de 5000 kPa et un débit de 1006 kmoles/h. La composition molaire de ladite phase gazeuse riche en méthane circulant dans le conduit 26 était la suivante : . CO₂ 34,31 % . Méthane 53,50 % . Ethane 9,84 % . Propane 1,70 % . Butane 0,53 % . Hexane 0,09 % . Méthanol 0,03 % The compressed methane-rich gas phase passing through line 26 had a temperature of -20 ° C, a pressure of 5000 kPa and a flow rate of 1006 kmol / h. The molar composition of said methane-rich gas phase flowing in line 26 was as follows: . CO₂ 34.31% . Methane 53.50% . Ethane 9.84% . Propane 1.70% . Butane 0.53% . Hexane 0.09% . Methanol 0.03%

Le solvant riche déméthanisé, détendu dans la vanne 29 et réfrigéré à -40°C dans le système réfrigérant 40, était mis en contact, à contre-courant, dans la tour 56 d'extraction liquide/liquide avec un solvant hydrocarboné réfrigéré à teneur majoritaire en hexane, ledit solvant hydrocarboné étant constitué, en mole, de 95,77 % d'hexane, 1,11 % de butane et 3,12 % de méthanol. La tour 56 d'extraction comportait 31 plateaux et était alimentée sur le premier plateau par 5000 kmoles/h de solvant régénéré amené par le conduit 63 avec une température de -40°C, sur le plateau 21 par le solvant riche déméthanisé issu du système de réfrigération 40 et sur le plateau 31 par le solvant hydrocarboné réfrigéré à base d'hexane amené par le conduit 57 avec un débit de 1600 kmoles/h. Cette extraction produisait 2079 kmoles/h d'un solvant hydrocarboné riche ayant une température de -40°C et une pression de 1200 kPa, ledit solvant hydrocarboné riche étant évacué en tête de la tour 56 par le conduit 59, et 18069 kmoles/h de solvant épuré soutiré en fond de ladite tour, par le conduit 58, à une température de -40°C et sous une pression de 1200 kPa.The demethanized rich solvent, expanded in the valve 29 and refrigerated at -40 ° C in the refrigerant system 40, was brought into contact, against the current, in the liquid / liquid extraction tower 56 with a refrigerated hydrocarbon solvent with content predominantly in hexane, said solvent hydrocarbon consisting, in mole, of 95.77% hexane, 1.11% butane and 3.12% methanol. The extraction tower 56 included 31 trays and was supplied on the first tray with 5000 kmol / h of regenerated solvent brought in through line 63 with a temperature of -40 ° C., on tray 21 by the demethanized rich solvent coming from the system refrigeration 40 and on the plate 31 by the refrigerated hydrocarbon solvent based on hexane supplied by line 57 with a flow rate of 1600 kmol / h. This extraction produced 2079 kmol / h of a rich hydrocarbon solvent having a temperature of -40 ° C and a pressure of 1200 kPa, said rich hydrocarbon solvent being evacuated at the top of tower 56 via line 59, and 18069 kmol / h purified solvent withdrawn from the bottom of said tower, via line 58, at a temperature of -40 ° C. and under a pressure of 1200 kPa.

La composition molaire du solvant hydrocarboné riche passant dans le conduit 59 était la suivante : . CO₂ 0,14 % . Méthane 0,13 % . Ethane 9,19 % . Propane 7,79 % . Butane 6,62 % . Hexane 73,72 % . Méthanol 2,40 % The molar composition of the rich hydrocarbon solvent passing through line 59 was as follows: . CO₂ 0.14% . Methane 0.13% . Ethane 9.19% . Propane 7.79% . Butane 6.62% . Hexane 73.72% . Methanol 2.40%

La composition molaire du solvant purifié passant dans le conduit 58 était la suivante : . CO₂ 9,16 % . Méthane 0,01 % . Ethane 0,10 % . Propane 0,01 % . Hexane 2,42 % . Méthanol 74,91 % . Eau 13,40 % The molar composition of the purified solvent passing through line 58 was as follows: . CO₂ 9.16% . Methane 0.01% . Ethane 0.10% . Propane 0.01% . Hexane 2.42% . Methanol 74.91% . Water 13.40%

Par fractionnement du solvant hydrocarboné enrichi 59 dans la colonne 49 de régénération comportant 28 plateaux et opérant à 700 kPa, on produisait d'une part, en tête de la colonne 49, 497 kmoles/h d'une coupe d'hydrocarbures en C₂ et plus ayant une température de 28°C et une pression de 700 kPa, que l'on évacuait par le conduit 48, et d'autre part, en fond de ladite colonne, 1600 kmoles/h de solvant hydrocarboné régénéré ayant une température de 142,7°C et une pression de 670 kPa, que l'on soutirait par le conduit 50.By fractionation of the enriched hydrocarbon solvent 59 in the regeneration column 49 comprising 28 plates and operating at 700 kPa, there was produced on the one hand, at the top of column 49, 497 kmol / h of a C coupe hydrocarbon fraction and plus with a temperature of 28 ° C and a pressure of 700 kPa, which was evacuated via line 48, and on the other hand, at the bottom of said column, 1600 kmol / h of regenerated hydrocarbon solvent having a temperature of 142.7 ° C and a pressure of 670 kPa, that it would be drawn off through the conduit 50.

La coupe d'hydrocarbures en C₂ et plus, évacuée par le conduit 48, avait la composition molaire suivante : . CO₂ 0,59 % . Méthane 0,54 % . Ethane 38,40 % . Propane 32,58 % . Butane 27,67 % . Hexane 0,20 % . Méthanol 0,02 %. The C₂ and higher hydrocarbon section, evacuated via line 48, had the following molar composition: . CO₂ 0.59% . Methane 0.54% . Ethane 38.40% . Propane 32.58% . Butane 27.67% . Hexane 0.20% . Methanol 0.02%.

Le solvant hydrocarboné régénéré passant dans le conduit 50 renfermait, en mole, 95,77 % d'hexane, 1,11 % de butane et 3,12 % de méthanol. Ledit solvant était amené, dans la pompe 51, jusqu'à une pression de 1200 kPa, puis réfrigéré à -40°C dans le système réfrigérant 61 avant d'être recyclé, par le conduit 57, à la tour 56 d'extraction.The regenerated hydrocarbon solvent passing through line 50 contained, by mole, 95.77% hexane, 1.11% butane and 3.12% methanol. Said solvent was brought, in the pump 51, to a pressure of 1200 kPa, then refrigerated at -40 ° C in the refrigerant system 61 before being recycled, via the conduit 57, to the extraction tower 56.

Le solvant purifié issu, par le conduit 58, de la tour 56 d'extraction est détendu à une pression de 200kPa dans la vanne de détente 60, puis il est introduit dans la colonne de régénération 62 aux fins de régénération. Ladite colonne 62, comportant 14 plateaux et opérant sous une pression de 200 kPa, est alimentée sur le premier plateau par le solvant purifié à régénérer et sur le dernier plateau par un courant d'azote amené, par le conduit 43, avec un débit de 650 kmoles/h. Le réchauffeur 69, dont est munie ladite colonne 62, était situé sur le septième plateau.The purified solvent from line 58 of the extraction tower 56 is expanded to a pressure of 200 kPa in the expansion valve 60, then it is introduced into the regeneration column 62 for the purpose of regeneration. Said column 62, comprising 14 plates and operating under a pressure of 200 kPa, is supplied to the first plate by the purified solvent to be regenerated and to the last plate by a stream of nitrogen supplied, via line 43, with a flow rate of 650 kmol / h. The heater 69, which is provided with said column 62, was located on the seventh plate.

La régénération du solvant purifié produisait, d'une part, 2289 kmoles/h d'un courant de gaz acide riche en CO₂, ledit courant étant évacué par le conduit 44 en tête de la colonne 62 et, d'autre part, un solvant régénéré soutiré en fond de la colonne 62 par le conduit 34.The regeneration of the purified solvent produced, on the one hand, 2289 kmol / h of a stream of acid gas rich in CO₂, said stream being discharged through line 44 at the head of column 62 and, on the other hand, a solvent regenerated withdrawn from the bottom of the column 62 through the conduit 34.

Le courant de gaz acide riche en CO₂ évacué par le conduit 44 avait une pression de 200 kPa et une température de -47,5°C et il présentait la composition molaire suivante: . CO₂ 71,64 % . Méthane 0,05 % . Ethane 0,77 % . Propane 0,04 % . Hexane 0,40 % . Méthanol 0,06 % . Azote 27,04 %. The stream of CO₂-rich acid gas discharged through line 44 had a pressure of 200 kPa and a temperature of -47.5 ° C and it had the following molar composition: . CO₂ 71.64% . Methane 0.05% . Ethane 0.77% . Propane 0.04% . Hexane 0.40% . Methanol 0.06% . Nitrogen 27.04%.

Le solvant régénéré circulant dans le conduit 34 était porté à la pression de 5000 kPa par passage dans la pompe 37, puis partagé en deux parties, à savoir une majeure partie recyclée vers la colonne de lavage 5 après passage dans le système échangeur de chaleur 39 et le conduit 6 et une partie amenée dans la tour 56 d'extraction par le conduit 63.The regenerated solvent circulating in the conduit 34 was brought to the pressure of 5000 kPa per passage through the pump 37, then divided into two parts, namely a major part recycled to the washing column 5 after passage through the heat exchanger system 39 and the conduit 6 and a part brought into the extraction tower 56 by the conduit 63.

Claims (9)

  1. Method for simultaneously decarbonating and gasoline stripping a gaseous mixture, which has an absolute pressure greater than 0.5 MPa and contains mainly hydrocarbons consisting of methane and hydrocarbons of C2 and more, and also comprises CO2, and optionally, one or a plurality of low boiling point non-sulphurated compounds such as H₂, CO, N₂ and Ar, in which the gaseous mixture is put into contact in a washing area (5), with a solvent (6) consisting of a fluid, which preferentially dissolves CO₂ and the hydrocarbons of C₂ and more, and which has on the one hand a boiling temperature at atmospheric pressure which is greater than 40°C, and on the other hand, a viscosity at -30°C which is lower than 0.1 Pa.s, by operating at a sufficiently low temperature and with a flow ratio of gaseous mixture to be processed and solvent, such that on the one hand there is produced a processed gas (8) which consists mainly of methane and has a molar content of CO₂ of 2% at the most, and, on the other hand, a so-called rich solvent (11) liquid phase consisting of the solvent enriched by CO₂ and of a fraction of C₂ and higher hydrocarbons containing at least 80 molar % of the C₃ and higher hydrocarbons present in the gaseous mixture to be processed, the rich solvent is subjected to at least partial demethanisation processing (12, 17), by means of expansion which separates the said rich solvent into a methane-depleted liquid phase called rich demethanised solvent (27), and into a gaseous phase rich in methane (22), and the rich demethanised solvent is subjected to processing which produces an acid gas current (44), which contains the CO₂ present in the rich demethanised solvent, also producing a mixture of hydrocarbons called hydrocarbon fraction (48), and finally producing a regenerated solvent (34) which is recycled towards the washing area (5), the said method being characterised in that processing of the rich demethanised solvent is performed by subjecting the said rich demethanised solvent, which has previously been subjected to cooling (40), to fluid/fluid extraction in an extraction area (56), by means of a cooled hydrocarbon solvent, with production on the one hand of a purified solvent (58), which contains almost all the CO₂ present in the rich demethanised solvent, and has a hydrocarbon content, expressed in methane equivalent, of less than 10 molar % relative to the CO₂, and, on the other hand, a hydrocarbon solvent enriched by C₂ and higher hydrocarbons (59), by fractionating the said enriched hydrocarbon solvent (59) by distillation (49) into a C₂ and higher hydrocarbon fraction, which constitutes the hydrocarbon fraction (48), and contains at least 80 molar % of the C₃ and higher hydrocarbons present in the gaseous mixture to be processed, and in the regenerated hydrocarbon solvent (50), which after cooling is recycled to the extraction area, and by submitting the purified solvent (58) to regeneration by expansion and stripping (60, 62), thus producing the regenerated solvent (34) and the acid gas current (44), which consists of almost all the CO₂ present in the rich demethanised solvent containing a hydrocarbon content, expressed in methane equivalent, of less than 10 molar % relative to the CO₂.
  2. Method according to claim 1, characterised in that the solvent put into contact with the gaseous mixture to be processed has a viscosity at -30°C of less than 0.05 Pa.s.
  3. Method according to claim 1 or claim 2, characterised in that the solvent put into contact with the gaseous mixture to be processed in the washing area (5) consists in one or a plurality of absorbent organic liquids, used in anhydrous form, or in a mixture with water, the said absorbent or absorbents being selected from amongst the amides with formulae
    Figure imgb0016
     aldehydes of formula
    Figure imgb0017
     esters of formulae
    Figure imgb0018
     C₁ to C₄ alkanols, diethers of formula
    Figure imgb0019
     , alcohol diethers of formula R₉O - C₂H₄ - O C₂H₄-OH , lactones of formula
    Figure imgb0020
     and propylene carbonate, wherein R₁ and R₂, which may be identical or different, designate in these formulae a hydrogen atom or a C₁ or C₂ alkyl radical, R₃ being a C₃ or C₄ radical, R₆ being a C₂ to C₄ alkyl radical or a
    Figure imgb0021
     radical with R₈ designating a C₁ or a C₂ radical, and n representing 1 or 2, R₇ being a C₁ or C₂ alkyl radical or a
    Figure imgb0022
     radical, R₉ designating a C₁ to C₄ alkyl radical, and p being a whole number from 2 to 4.
  4. Method according to any one of claims 1 to 3, characterised in that the temperature at which the gaseous mixture to be processed is put into contact with the solvent in the washing area (5), is between 0°C and -45°C.
  5. Method according to any one of claims 1 to 4, characterised in that the demethanisation processing applied to the rich solvent (11) is performed in two stages, i.e. a first stage in which the said rich solvent is subjected to a first expansion (12, 13) designed to release a considerable fraction of the methane dissolved in the said solvent, and to produce a first gas rich in methane (14) and a predemethanised fluid (15), and a second stage in which the predemethanised fluid is subjected to a second expansion (16) then to distillation (17), thus producing a second gas rich in methane (19) and the rich demethanised solvent (27), the second gas rich in methane being compressed to the pressure of the first gas rich in methane, then mixed with the latter in order to constitute the gaseous phase (22) rich in methane.
  6. Method according to any one of claims 1 to 5, characterised in that the gaseous phase (22) which is rich in methane is compressed to the pressure of the gaseous mixture to be processed, and is then cooled (25) and mixed with the gaseous mixture to be processed before the latter is put into contact with the solvent in the washing area (5).
  7. Method according to any one of claims 1 to 6, characterised in that the purified solvent is regenerated by expansion of the said solvent to a pressure greater than 100 kPa, and in particular between 150 kPa and 300 kPa, and by stripping (43) by means of an inert gas such as nitrogen, optionally associated with reheating (69) of the purified solvent in the regeneration column.
  8. Method according to any one of claims 1 to 6, characterised in that the regeneration of the purified solvent (58) consists of reheating (28) the said solvent to a temperature close to ambient temperature, of dividing the solvent reheated into a first current (30) and a second current (31), of directing the first current (30) directly towards a regeneration area (33), of directing the second current (31) towards this regeneration area, after having reheated it by indirect exchange of heat (35) with the regenerated purified solvent (34), and of subjecting the purified solvent to distillation in the regeneration area (33), for the purpose of producing the acid gas current (44) which is rich in CO₂ and the regenerated solvent (34).
  9. Method according to any one of claims 1 to 8, characterised in that the gaseous mixture to be processed contains water and/or C₃ and higher hydrocarbons and in that the said gaseous mixture is subjected to pre-processing consisting of distillation (2) performed at a temperature at least equal to that existing in the washing area (5), and, optionally, in the presence of solvent, taken from the solvent introduced into the washing area (5), thus producing a so-called heavy hydrocarbon fraction (4), which contains almost all the C₆ and higher hydrocarbons, and optionally all or part of the C₅ hydrocarbons, a pre-treated gaseous mixture (3), having a content of C₆ and higher hydrocarbons of less than 1 weight %, and, optionally, a fluid (54) consisting of a mixture of solvent and water.
EP89403123A 1988-11-15 1989-11-14 Process for the simultaneous elimination of CO2 and gasoline from a gaseous hydrocarbon mixture comprising methane, C2 and higher hydrocarbons and also CO2 Expired - Lifetime EP0373983B1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP93107550A EP0556875B1 (en) 1988-11-15 1989-11-14 Process for the simultaneous elimination of CO2 and gasoline from a gaseous hydrocarbon mixture comprising methane, C2 and higher hydrocarbons and also CO2
AT89403123T ATE100852T1 (en) 1988-11-15 1989-11-14 PROCESS FOR THE SIMULTANEOUS REMOVAL OF CO2 AND BEARIN FROM METHANE, C2 AND HIGHER HYDROCARBONS AND CO2-CONTAINING GASEOUS HYDROCARBONS.
GR950402736T GR3017623T3 (en) 1988-11-15 1995-10-04 Process for the simultaneous elimination of CO2 and gasoline from a gaseous hydrocarbon mixture comprising methane, C2 and higher hydrocarbons and also CO2.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8814784 1988-11-15
FR888814784A FR2641542B1 (en) 1988-11-15 1988-11-15 PROCESS FOR SIMULTANEOUS DECARBONATION AND DEGAZOLINATION OF A GASEOUS MIXTURE MAINLY CONSISTING OF METHANE AND HYDROCARBONS OF C2 AND MORE AND INCLUDING CO2

Related Child Applications (1)

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EP0373983B1 true EP0373983B1 (en) 1994-01-26

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NO302567B1 (en) * 1994-02-14 1998-03-23 Norsk Hydro As Feeding device
FR2743083B1 (en) * 1995-12-28 1998-01-30 Inst Francais Du Petrole METHOD FOR DEHYDRATION, DEACIDIFICATION AND DEGAZOLINATION OF A NATURAL GAS, USING A MIXTURE OF SOLVENTS
JP5383338B2 (en) 2009-06-17 2014-01-08 三菱重工業株式会社 CO2 recovery device and CO2 recovery method
GB201520405D0 (en) * 2015-11-19 2016-01-06 Isis Innovation Ltd And King Abdulaziz City For Science And Technology Hydrocarbon separation process

Family Cites Families (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1838444A (en) * 1930-04-03 1931-12-29 Wehrle Co Towel bar
US1898579A (en) * 1930-05-30 1933-02-21 Union Oil Co Method and apparatus for absorption of constituents from gases and vaporous mixtures
US1972060A (en) * 1930-10-24 1934-08-28 Texas Co Recovery of gasoline from natural gas
US1953043A (en) * 1930-10-24 1934-03-27 Texas Co Recovery of gasoline from natural gas
US2487576A (en) * 1945-11-13 1949-11-08 Phillips Petroleum Co Process for the removal of acidic material from a gaseous mixture
US2930752A (en) * 1952-06-12 1960-03-29 Socony Mobil Oil Co Inc Process for stripping of absorption liquids
US3210270A (en) * 1961-12-01 1965-10-05 Phillips Petroleum Co Fluid separation and gas dehydration process
US3247649A (en) * 1963-04-29 1966-04-26 Union Oil Co Absorption process for separating components of gaseous mixtures
US3347621A (en) * 1964-11-02 1967-10-17 Shell Oil Co Method of separating acidic gases from gaseous mixtures
US3702296A (en) * 1970-12-23 1972-11-07 Atlantic Richfield Co Oil and gas treatment
US3770622A (en) * 1970-12-28 1973-11-06 Fluor Corp Treatment of wet natural gas mixtures to recover liquid hydrocarbons
US3829521A (en) * 1972-07-03 1974-08-13 Stone & Webster Eng Corp Process for removing acid gases from a gas stream
JPS562985B2 (en) * 1975-03-20 1981-01-22
DE2909335A1 (en) * 1979-03-09 1980-09-18 Linde Ag METHOD AND DEVICE FOR DISASSEMBLING NATURAL GAS
US4293322A (en) * 1980-04-23 1981-10-06 Helix Technology Corporation Distillative separation of carbon dioxide from hydrogen sulfide
JPS5710378A (en) * 1980-06-19 1982-01-19 Satake Eng Co Ltd Wind supplying and discharging device for cereal grain selector
DE3148475A1 (en) * 1981-02-23 1982-09-23 Gebrüder Bühler AG, 9240 Uzwil "SEPARATING DEVICE FOR CEREALS AND SIMILAR GRAIN GOODS"
DE3112661A1 (en) * 1981-03-31 1982-10-14 Basf Ag, 6700 Ludwigshafen METHOD FOR SEPARATING CONDENSIBLE ALIPHATIC HYDROCARBONS AND ACID GASES FROM NATURAL GASES
CA1215217A (en) * 1983-06-24 1986-12-16 Yuv R. Mehra Process for extracting natural gas streams with physical solvents
US4568452A (en) * 1984-06-15 1986-02-04 Exxon Research And Engineering Co. Process for upgrading a contaminated absorbent oil
US4654062A (en) * 1986-07-11 1987-03-31 Air Products And Chemicals, Inc. Hydrocarbon recovery from carbon dioxide-rich gases
US4747858A (en) * 1987-09-18 1988-05-31 Air Products And Chemicals, Inc. Process for removal of carbon dioxide from mixtures containing carbon dioxide and methane
US4775396A (en) * 1987-11-05 1988-10-04 Union Carbide Corporation Selective adsorption of CO2 on zeolites
DE3829878A1 (en) * 1988-09-02 1990-03-08 Metallgesellschaft Ag METHOD FOR THE TREATMENT OF HYDROCARBONS AND H (ARROW ABBEERTS) 2 (ARROW DOWN) S INGREDIENT NATURAL GAS

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DE68923459T2 (en) 1996-04-04
NO903128D0 (en) 1990-07-13
DE68912746T2 (en) 1994-08-11
NO180687C (en) 1997-05-28
ES2077452T3 (en) 1995-11-16
JPH03503779A (en) 1991-08-22
ES2050833T3 (en) 1994-06-01
AU627250B2 (en) 1992-08-20
FR2641542B1 (en) 1994-06-24
DE68912746D1 (en) 1994-03-10
AU4637589A (en) 1990-06-12
NO903128L (en) 1990-09-11
CA2002826A1 (en) 1990-05-15
US5298156A (en) 1994-03-29
CA2002826C (en) 1999-06-29
EP0556875A2 (en) 1993-08-25
EP0556875A3 (en) 1993-11-10
JP2742328B2 (en) 1998-04-22
BR8907193A (en) 1991-03-05
NO180687B (en) 1997-02-17
EP0373983A1 (en) 1990-06-20
RU1836407C (en) 1993-08-23
EP0556875B1 (en) 1995-07-12
FR2641542A1 (en) 1990-07-13

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