FR2843403A1 - Purification of a petroleum cut to reduce sulfur and aromatic content by a process of combined extractive and conventional distillation - Google Patents

Abstract

Purification of hydrocarbon charge of distillation range 0 - 500 degrees C, containing substantial quantities of sulfur and aromatics, by a two-zone distillation process involving extractive and conventional distillation to produce a desulfurized and dearomatized raffinate, a primary distillate(containing solvent, aromatics and part of the sulfurized compounds) and a second, conventional, distillate containing the remaining sulfur compounds. An Independent claim is also included for the installation of the process.

Description

Method and device for purifying an oil cut.

TECHNICAL AREA

  The invention relates to a process and a device for purifying petroleum fractions, for producing fuels with low contents of sulfur and / or aromatic compounds, in order to satisfy the new

  environmental rules in many countries.

  It finds its application in petroleum refineries. 10

STATE OF THE PRIOR ART.

  In many countries, environmental regulations impose maximum limits on the levels of sulfur and aromatic compounds in fuels, which are moreover

and lower.

  For example, by 2008, in European countries, the content of sulfur compounds in gasolines must be less than 10 ppm by weight and the benzene content less than 1% by volume. In order to produce gasolines which meet the specifications in force, known methods consist in successively removing the sulfur compounds, for example by hydrodesulfurization, then the aromatic compounds, by extraction or by hydrotreatment. 25 A process for the advanced desulfurization of a stream of hydrocarbons is

  described in international patent application WO 00/77124.

  This process comprises the following stages: (i) bringing the stream of hydrocarbons containing sulfur compounds into contact with a selective adsorbent mass to adsorb the sulfur compounds and produce an effluent composed of desulfurized hydrocarbons, (ii) desorption of the sulfur compounds of the adsorbent mass by passing a desorbent to obtain a desorption effluent comprising the sulfur-containing compounds and the desorbent, (iii) treatment of the desorption effluent to extract the

sulfur compounds.

  A process for extracting aromatic hydrocarbons from petrol produced by catalytic reforming is described in patent EP 0 736 588. This process consists in: bringing the vaporized petrol into contact in an extractive distillation column with a solvent capable selectively absorbing aromatic hydrocarbons, - then recovering, at the top of the column, a raffinate having a reduced content of aromatic compounds,

  - And to withdraw from the bottom of the column the liquid solvent enriched in 10 aromatic hydrocarbons.

  It goes without saying that the implementation of such processes requires, to meet the new specifications, a reconfiguration of the refineries and significant investments. To overcome these drawbacks, a process particularly suitable for the treatment of light gasoline from catalytic cracking is described in

  international patent application WO 01/59033.

  This process consists in selectively extracting from the catalytic cracking gasoline the sulfur-containing compounds and the hydrocarbons

  aromatics which it contains, by extractive distillation by means of a solvent suitable for producing, on the one hand, an essence rich in olefins partially desulfurized and de-aromatized and, on the other hand, an aromatic fraction comprising the sulfur compounds initially contained 25 in the charge.

  Similarly, there are methods of treating diesel

  allowing to obtain fuels satisfying the specifications.

  The process described in patent FR 2 704 232 relates to a process 30 for improving the qualities of a gas oil by extraction and then hydrodesulfurization. Hydrodesulfurization treatments for gasolines and gas oils are conventional and well known to those skilled in the art. However, they have the disadvantage of being very expensive, since they require large quantities of hydrogen, under high pressure, to achieve

  treat the most refractory sulfur and aromatic compounds.

  Extractive processes, for their part, have the drawbacks of being not very selective and therefore of causing significant losses in yield.

STATEMENT OF THE INVENTION

  The object of the present invention is to solve the problems

  exposed above, linked to existing processes.

  To this end, the invention provides a simple and economical method for purifying hydrocarbons making it possible to produce fuels.

  with low sulfur and aromatic content.

  The first object of the invention is therefore a process for purifying a hydrocarbon feedstock having a distillation range (determined according to standard ASTM D-86) of between 0 and 500 ° C. and 15 containing substantial amounts of aromatic compounds and / or sulfur. The process according to the invention consists in subjecting said hydrocarbon charge simultaneously to distillation in at least two zones, one being an extractive distillation zone and the other being a conventional distillation zone, in order to produce a raffinate. desulfurized and de-aromatized, - a first distillate coming from the extractive distillation zone, called extraction distillate, containing the solvent, the majority of the aromatic compounds and part of the sulfur compounds, - and a second distillate coming from the zone of conventional distillation, called conventional distillate, containing the other

part of sulfur compounds.

  In addition, the invention has for second object a device specially designed for the implementation of the above method. This invention has an application for the purification of gasolines for which the specifications impose a sulfur content of less than 10 ppm by weight. It also applies to the purification of gas oils, where the specification of maximum sulfur content is today 50 35 ppm by weight, but will be lowered to 10 ppm by weight in the

coming years.

  The solvents used to carry out the extractive distillation are organic solvents which can be chosen from sulfur solvents,

nitrogen or oxygenated.

  Thus, according to a first preferred embodiment of the invention, the charge of hydrocarbons to be purified is a gasoline cut possibly containing substantial quantities of olefins, having a distillation interval (determined according to standard ASTM D-86 ) between 0 C and 200 C and having a sulfur compound content of less than or equal to 1000 ppm by weight. Such a gasoline cut can therefore advantageously be a gasoline cut from catalytic cracking. The solvent used for the extractive distillation of such a gasoline cut, which remains liquid throughout the extractive distillation zone, has a boiling point at least 50 ° C. above the maximum operating temperature of said zone. It can be chosen from the group consisting of sulfolane, 3-methyl-sulfolane, 2,4-dimethylsulfolane, 3-ethyl-sulfolane, N-methyl-pyrrolidone, 220 pyrrolidone, N-ethyl-pyrrolidone, N-propyl-pyrrolidone, Nformylmorpholine, dimethyl-sulfone, diethylsulfone, methylethylsulfone, dipropyl-sulfone, dibutyl-sulfone, tetraethylene glycol, triethylene glycol, dimethylene glycol, ethylene glycol,

  ethylene carbonate, propylene carbonate and mixtures thereof. The preferred solvent is sulfolane.

  Within the framework of the implementation of the process applied to gasolines, the corresponding device can be constituted by a single column. It comprises at least one extractive distillation zone located in the lower part of the column and at least one conventional distillation zone situated in the upper part of

the column.

  If the treated gasoline contains olefins, then the conventional distillate which leaves the top of the column is rich in olefins. It is

  a first advantage of the invention: the olefins initially present in the feed are preserved and there is no loss of octane number.

  Furthermore, the conventional distillate contains only sulfur compounds of the mercaptan type. It can be easily recovered: for example, after a conventional mercaptan extraction or hydrofinishing treatment, it can be remixed with the raffinate before sending it to the petrol pool. The raffinate is drawn off at the bottom of the distillation zone

  conventional, at the intermediate level of the column, at the interface between the conventional distillation zone and the extractive distillation zone. It no longer contains sulfur compounds or aromatic compounds.

  The extraction distillate is drawn off at the bottom of the extractive distillation zone, at the bottom of the column. This extraction distillate is rich in sulfur compounds and it contains the solvent, as well as the major part

  aromatic compounds initially present in the feed.

  This is a second advantage of the process of the invention: it makes it possible to obtain three different cuts, having different characteristics

  and who can find valuations.

  The raffinate is a desulfurized and de-flavored essence: it can be

  sent directly to the petrol pool.

  Another advantage of the process according to the invention is its selectivity: the yield of purified light gasoline is good, since there is little loss of

  produced in the extraction distillate.

  According to a second also preferred embodiment of the invention, the charge of hydrocarbons to be purified is a diesel cut having a distillation interval (determined according to standard ASTM D86) of between 150 and 500 ° C. and having a content in compounds

  sulfur less than or equal to 5% by weight.

  In the same way as for gasolines, the choice of solvent 30 depends on the operating temperature of the extractive distillation zone. The solvent used to carry out the extractive distillation of gas oils is preferably chosen from the group consisting of methanol, acetonitrile, monomethylformamide, dimethylformamide, dimethylacetamide, furfural, N-methylpyrrolidone,

  dimethyl sulfoxide and mixtures thereof.

  Particularly preferred solvents are dimethylformamide,

  furfural and N-methylpyrrolidone.

  For the implementation of the invention applied to the purification of gas oils, the device used can be constituted by a single column.

  It includes at least one extractive distillation zone located in the upper part of the column and at least one distillation zone

  located at the bottom of the column.

  The extraction distillate leaves at the top of the column. It is rich in

  aromatics and contains the solvent.

  The raffinate is drawn off at the bottom of the extractive distillation zone, at the intermediate level of the column. He is rid of the majority of

sulfur compounds.

  The conventional distillate comes out at the bottom of the column. It contains the sulfur compounds initially present in the feed and can

  easily be treated in a conventional desulfurization unit.

  The advantage of this process is to provide, in addition to the raffinate, two distillates having different characteristics. This selectivity allows them to be applied downstream of specific treatments and valuations. According to another embodiment of the invention, the extraction distillate is subjected in a manner known per se to distillation, in a solvent regeneration column, to produce a solvent

  regenerated and an extract rich in sulfur and / or aromatic compounds.

  Preferably, the regenerated solvent is recycled to achieve the

extractive distillation.

  Generally, a person skilled in the art can easily adapt

  the method and the device of the invention as a function of the nature of the fillers to be purified and of the desired composition of the different cuts obtained. Pre-treatment and / or post-treatment units, moreover well known, may take place upstream and / or downstream of the device of the invention.

  For example, a light gasoline of catalytic cracker containing mercaptans, may undergo a selective hydrogenation pretreatment to eliminate all or part of said mercaptans. In this case, the conventional distillation zone makes it possible to separate the light gases.

  raffinate; it is then called pasteurization zone.

BRIEF DESCRIPTION OF THE DRAWINGS

  The invention will be better understood with the aid of the appended drawings, in which:

  - Figure 1 schematically shows a purification unit 10 of a gasoline cut.

  - Figure 2 shows schematically a purification unit

a diesel cut.

DETAILED DESCRIPTION OF THE INVENTION 15

  FIG. 1 schematically represents a unit for purifying a gasoline cut containing substantial quantities of olefins, having a distillation range between 0 C and 200 C and

  a sulfur compound content of less than 1000 ppm by weight.

  The single equipment 1 is divided into two distinct zones. It has at its lower part an extractive distillation zone 2 and at

  its upper part a conventional distillation zone 3.

  The gasoline cut to be purified is injected into the middle part of the single equipment 1 through line 4. The gasoline cut injected through line 4 is separated into two fractions: a light fraction and a heavy fraction. The extraction solvent is injected in the liquid state into the part

  upper of zone 2 of extractive distillation by line 5.

  The preferred solvent for carrying out the extractive distillation is sulfolane.

  The light fraction rises to zone 3, where it is subjected to distillation to produce, at the top of the equipment 1, a conventional distillate free of aromatic compounds and containing only 35 sulfur-containing compounds of mercaptan type. Indeed, the cutting point is low enough to concentrate the mercaptans at the head of

equipment 1.

  This conventional distillate is withdrawn through line 8. It can then be sent to the mercaptan elimination unit 10 to undergo an extraction or hydrofinishing treatment. This is an additional advantage of the process of the invention: it allows a gain in level 5 in the dimensioning of the mercaptan elimination unit, because only the light cut, in which the mercaptans are concentrated, undergoes this

specific treatment.

  The conventional mercaptan-free distillate thus obtained is

drawn off by line 1 1.

  The raffinate is drawn off at the intermediate level of equipment 1

  by line 7. It is a gasoline cut free of sulfur and aromatic compounds. It can be sent directly to the petrol pool, or mixed with the conventional distillate free of mercaptans from line 11, then this mixture is then sent to the petrol pool.

  In equipment 1, the heavy fraction descends towards zone 2 where it undergoes an extractive distillation by means of the solvent injected through line 5. The extraction distillate is drawn off at the bottom of equipment 1 through line 6. It contains the solvent, the majority of aromatic compounds

and is rich in sulfur.

  This extraction distillate feeds a solvent regeneration column 9, in which it is subjected to distillation in order to produce, on the one hand, an extract rich in aromatic and sulfur compounds drawn off by line 14 and, on the other hand , a regenerated solvent withdrawn from the bottom of column 9 and recycled to zone 2 for extractive distillation via line 5. FIG. 2 schematically represents a purification unit 30 of a diesel cut having a distillation interval of between 150

  and 500 C and may contain up to 5% by weight of sulfur compounds.

  The single equipment 21 is divided into two distinct zones. It has at its upper part an extractive distillation zone 22 and

  at its lower part a conventional distillation zone 23.

  The diesel cut to be purified is injected, via line 24, at the top of the single equipment 21, above the zone 22 of extractive distillation and the zone 23 of conventional distillation. The extraction solvent is injected into the lower part of zone 22 of

  extractive distillation via line 25.

  The preferred solvent for carrying out the extractive distillation is furfural. The diesel cut injected by line 24 descends to the bottom of the equipment 21, to undergo successively an extractive distillation

  and conventional distillation.

  When it arrives in zone 22, the diesel cut is subjected to an extractive distillation to produce, at the top of the equipment 21, an extraction distillate containing the solvent and rich in aromatic compounds. It is drawn off through line 26 then it feeds a solvent regeneration column 29, in which it is subjected to distillation 15 to produce, on the one hand, an extract rich in aromatic compounds drawn off through line 34, and on the other hand a regenerated solvent drawn off at the bottom of the column 29 and recycled to the zone 22 for extractive distillation

by line 25.

  The raffinate is drawn off by line 27 at the intermediate level of equipment 21. It is a diesel fuel free from sulfur compounds and aromatic compounds. It can be sent directly to the diesel pool. The heaviest part of the diesel cutter arrives in zone 23 in the lower part of the equipment 21, where it undergoes conventional distillation. The conventional distillate is drawn off at the bottom of the equipment 21 by the line 28. It is a heavier diesel oil than the

  raffinate and rich in sulfur compounds.

  It can easily be sent to a conventional hydrotreating unit 32 to produce a conventional distillate

  desulfurized, drawn off via line 33.

  This is an additional advantage of the process of the invention: the sulfur compounds are concentrated in the conventional distillate, which allows savings to be made on the dimensioning of the hydrotreating unit 32.

  The following examples illustrate implementations of the invention.

EXAMPLE 1

  The petroleum cut treated by the process of the invention is a light essence of catalytic cracker, the characteristics of which are

in Tables 1, 2 and 3.

  This cut is not previously treated in a unit

mercaptans extraction.

  The conditions for extractive distillation and conventional separation are as follows: - temperature at the bottom of the column: 160 C, - temperature of the solvent: 105 C, - pressure at the top of the column: 1, 3. 105Pa, 15 pressure at the bottom of the column : 2.105 Pa, - solvent / charge volume ratio: 2.5,

- solvent: sulfolane.

  The conventional distillate undergoes a treatment for removing mercaptans of the MEROX type or hydrofinishing, before being mixed with

  raffinate for incorporation into the species pool.

  TABLE 1: ASTM load distillation.

  Load% distilled Temperature in degrees C Initial point 32

47

51

65

85

111

142

152

End point 162

  These values were obtained by the method described in standard ASTM D 86.

  TABLE 2: Characteristics of the load.

  Load Characteristics Values Density at 15 C 0.720 Olefin content (% by weight) 54 Aromatic content (% by weight) 11 Saturated hydrocarbon content (% 35 by weight) Research octane number 93 Motor octane number 80 TABLE 3 : Content of compounds

burden sulfur.

  Load Nature of sulfur-containing compounds Composition in ppm by weight Methylmercaptan 1.6 Ethylmercaptan 59.0 Isopropylmercaptan 24.0 npropylmercaptan 18.0 Terbutylmercaptan 1.6 Methylethylsulfide 3.2 Thiophenes 70 C l-thiophenes 169 Tetrahydrothiophenes 35.5 C2-thiophenes 240 C3 -thiophenes 109.5 Benzothiophenes 5.8 Benzothiophenes + 3.2 Others 9.6 Total 750

  TABLE 4: Composition of the purified section in comparison with the charge.

  Load Conventional distillate Raffinate Mixture of conventional distillate and raffinate Yields in% in 31 52 83 weight Sulfur compounds in 750 223 5 30 ppm by weight Olefins in% in 54 62 59 60.5 Aromatics in% in 12.4 0 0 0 weight Octane number 93 96 95.2 95.5 research Octane number 80 82.5 81 81.6 engine Density 0.720 0.650 0.682 0.670 The results recorded in Table 4 show that the total yield of treated gasoline, that is to say the mixture constituted by

  the raffinate and the conventional distillate, reached 83%.

  The content of sulfur compounds increased from 750 ppm by weight in the feed to 30 ppm by weight in the mixture constituted by the raffinate and the conventional distillate which, moreover, is completely flavored. The raffinate is almost completely desulphurized, since it does not

  contains more than 5 ppm of sulfur compounds.

  In addition, the olefin content of the mixture in question is high not only has the process of the invention made it possible to avoid the loss of octane number, but it makes it possible to obtain a gasoline having a better index of octane as the charge, thanks to the concentration effect

olefins.

  EXAMPLE 2 (Comparative Example A light gasoline of catalytic cracker of identical nature to that of Example 1 is treated beforehand in a unit of extraction of mercaptans (type MEROX or hydrofinishing) before

  undergo conventional distillation.

  The operating conditions of conventional distillation are chosen so as to obtain, at the head of the column, a raffinate containing ppm by weight of sulfur-containing compounds. 10

  TABLE 5: Composition of the raffinate in comparison with the charge.

  Charge | Raffinate Yields in% by weight 31 Sulfur compounds in ppm 750 30 by weight Olefins in% by weight 54 60.1 Aromatics in% in 12.4 1.5 weight Research octane number 93 94.8 Motor octane number 80 81.3 Density 0.720 0.663 The comparison of the results of Table 4 of Example 1 and Table 5 of Example 2 makes it possible to highlight the advantages of the

method of the invention.

  It can be seen that at an identical desulfurization rate, i.e. 30 ppm, the

  The process of the invention is much more efficient than a conventional separation, since it makes it possible to obtain a much greater final yield of gasoline.

  The process of the invention has the main advantage of achieving the sulfur content specifications while maintaining a good yield.

final in essence.

EXAMPLE 3

  The petroleum cut here treated by the process of the invention is a light essence of catalytic cracker whose characteristics appear in Tables 6, 7 and 8. This cut is not previously treated in a unit

mercaptans extraction.

  The conditions for extractive distillation and conventional separation are as follows: - temperature at the bottom of the column: 160 C, - solvent temperature: 105 C, - column head pressure: 1, 3.105Pa,

  - column bottom pressure: 2.105 Pa, - solvent / charge volume ratio: 2.5, 1 S - solvent: sulfolane.

  The conventional distillate undergoes a treatment for removing mercaptans of the MEROX type or hydrofinishing, before being mixed with

  raffinate for incorporation into the species pool.

  TABLE 6: ASTM load distillation.

  Charge% distilled Temperature in degrees C Initial point 30

35

40

49

61

69

96

103

End point 120

  These values were obtained by the method described in standard ASTM D 86.

  TABLE 7: Characteristics of the load.

  Load Characteristics Values Density at 15 C 0.680 Olefin content (% by weight) 36 Aromatic content (% by weight) 7.9 Saturated hydrocarbon content (% 56.1 by weight) Research octane number 92.7 Index d motor octane 79.7 TABLE 8: Content of sulfur-containing compounds in the feedstock Type of sulfur-containing compounds Composition in ppm by weight Methylmercaptan 0.6 Ethylmercaptan 23.6 Isopropylmercaptan 7.4 npropylmercaptan 14.2 Terbutylmercaptan 0.5 Methylethylsulfide 2.8 Thiophenes 56 C 1-thiophenes 64 Tetrahydrothiophenes 11.6 C2-thiophenes 18.3 Total 199

  TABLE 9: Composition of the purified section in comparison with the charge.

  Charge Distillate Raffinate Conventional light cut + Raffinate Yields in% in 52 38 90 weight Sulfur compounds in 199 89 5 10 ppm by weight Olefins in% by weight 36 43.8 33.6 39.5 Aromatics in% in 7.9 0 0 0 weight Octane number 92.7 - 93.6 research Motor octane number 79, 7 80.1 Density 0.680 - 0.655 The treatment of the gasoline cut of this example, by the process of the invention, makes it possible to obtain a 10 ppm desulphurized petrol

  sulfur, with a yield of 90% compared to the charge.

  Of course, the implementation of the process of the invention is not limited to the treatment of essences and it can also be applied from

  advantageous treatment of diesel cuts. Those skilled in the art will easily adapt the operating parameters and the choice of extraction solvent according to the characteristics of the load to be treated. The process thus implemented makes it possible to obtain a desulfurized and de-aromatized diesel cut.

Claims (15)

  1. Method for purifying a hydrocarbon feedstock having a distillation range of between 0 and 500 ° C. and containing substantial quantities of aromatic and / or sulfur compounds, characterized in that said hydrocarbon feedstock is subjected simultaneously with a distillation in at least two zones, one being an extractive distillation zone and the other a conventional distillation zone, to produce: - a desulphurized and de-aromatized raffinate, a first distillate coming from the distillation zone extractive, called extraction distillate, containing the solvent, the majority of the aromatic compounds and part of the sulfur-containing compounds, - and a second distillate coming from the distillation zone   conventional, called conventional distillate, containing the other part of the sulfur compounds.   2. Method according to claim 1, characterized in that the extraction distillate is subjected to conventional distillation to produce   a regenerated solvent and an extract.   3. Method according to one of claims 1 or 2, characterized in that the solvent used to carry out the extractive distillation is chosen   in the group consisting of sulfur solvents, nitrogen solvents and oxygenated solvents.   4. The method of claim 1 or 2, wherein the feedstock of hydrocarbons to be purified is a gasoline fraction, having a distillation range between 0 C and 200 C and having a content of   sulfur compounds less than or equal to 1000 ppm by weight.   5. Method according to claim 4, characterized in that the   solvent used to carry out the extractive distillation is chosen from the group consisting of sulfolane, 3-methyl-sulfolane, 2,430 dimethyl-sulfolane, 3-ethyl-sulfolane, N-methyl-pyrrolidone, 2pyrrolidone, N- ethyl-pyrrolidone, N-propyl-pyrrolidone, Nformylmorpholine, dimethyl-sulfone, diethylsulfone, methylethylsulfone, dipropyl-sulfone, dibutyl-sulfone, tetraethylene glycol, triethylene glycol, dimethylene glycol, ethylene glycol, ethylene carbonate, propylene carbonate and mixtures thereof.   6. Method according to claim 4, characterized in that the solvent   used to carry out the extractive distillation is sulfolane.   7. Method according to one of claims 1 or 2, wherein the   charge of hydrocarbons to be purified is a diesel cut having a distillation range between 150 C and 500 C and having a   sulfur compounds content less than or equal to 5% by weight.   8. Method according to claim 7, characterized in that the solvent   used to carry out the extractive distillation is chosen from the group consisting of methanol, acetonitrile, monomethylformamide, dimethylformamide, dimethylacetamide, furfural, Nmethylpyrrolidone, dimethylsulfoxide and their mixtures.   9. Method according to claim 7, characterized in that the solvent   used to carry out the extractive distillation is chosen from the group consisting of dimethylformamide, furfural and Nmethylpyrrolidone.   10. Method according to any one of claims 1 to 9, characterized in that the regenerated solvent is recycled to carry out the extractive distillation.   11. Device which can be used in particular for purifying a hydrocarbon feedstock having a distillation range of between 0 and 500 ° C. and containing substantial quantities of aromatic and / or sulfur-containing compounds, characterized in that it comprises equipment ( 1, 21) comprising at least one distillation zone (2, 22)   extractive and at least one zone (3, 23) of conventional distillation.   12. Device according to claim 11, usable in particular for the purification of a hydrocarbon feed having a distillation interval of between 0 C and 200 C, characterized in that the equipment (1) comprises at least: - a extractive distillation zone (2) comprising means (6) for withdrawing the extraction distillate, - a conventional distillation zone (3) comprising means (8) for withdrawing the conventional distillate, - means (4) d introduction of the charge of hydrocarbons to be purified, between the zone (2) of extractive distillation and the zone (3) of conventional distillation, - means (5) for injecting the solvent into the upper part 35 of the zone ( 2) extractive distillation, - and means (5) for injecting the solvent into the upper part of the zone (2) for extractive distillation. 13. Device according to claim 11 usable in particular for the purification of a hydrocarbon feed having a distillation interval of between 150 C and 500 C, characterized in that the equipment (21) comprises at least: - a zone (22) of extractive distillation comprising means (26) for withdrawing the extraction distillate, - a zone (23) of conventional distillation comprising 10 means (28) for withdrawing the conventional distillate, means (24) for introduction the load of hydrocarbons to be purified, at the head of the equipment (21), above the zone (22) of extractive distillation,   - And means (25) for injecting the solvent into the upper part of the extractive distillation zone (22).   14. Device according to any one of claims 12 and 13,   characterized in that it comprises a solvent regeneration column (9, 29) comprising means for supplying extraction distillate connected to the means (6, 26) for withdrawing from the extractive distillation zone (22), to produce, on the one hand, a regenerated solvent and, on the other   part, an extract rich in aromatic and / or sulfur compounds.   15. Device according to claim 14, characterized in that it comprises means (5, 25) for recycling the regenerated solvent to the   extractive distillation zone (2, 22).