US3209047A - Recovery of aromatics - Google Patents

Recovery of aromatics Download PDF

Info

Publication number
US3209047A
US3209047A US139778A US13977861A US3209047A US 3209047 A US3209047 A US 3209047A US 139778 A US139778 A US 139778A US 13977861 A US13977861 A US 13977861A US 3209047 A US3209047 A US 3209047A
Authority
US
United States
Prior art keywords
solvent
water
aromatics
aromatic
stripper
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US139778A
Other languages
English (en)
Inventor
Eldred E Young
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shell USA Inc
Original Assignee
Shell Oil Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to NL283421D priority Critical patent/NL283421A/xx
Priority to BE622633D priority patent/BE622633A/xx
Priority to NL137161D priority patent/NL137161C/xx
Priority to US139778A priority patent/US3209047A/en
Application filed by Shell Oil Co filed Critical Shell Oil Co
Priority to GB31225/62A priority patent/GB999804A/en
Priority to FR909859A priority patent/FR1337992A/fr
Priority to DE19621468600 priority patent/DE1468600A1/de
Priority to DK408362AA priority patent/DK115043B/da
Application granted granted Critical
Publication of US3209047A publication Critical patent/US3209047A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • C10G21/00—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D11/00—Solvent extraction
    • B01D11/04—Solvent extraction of solutions which are liquid
    • B01D11/0488—Flow sheets
    • 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
    • C10G21/00—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents
    • C10G21/28—Recovery of used solvent
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S585/00—Chemistry of hydrocarbon compounds
    • Y10S585/919—Apparatus considerations
    • Y10S585/921—Apparatus considerations using recited apparatus structure
    • Y10S585/922—Reactor fluid manipulating device

Definitions

  • This invention relates to an improved extraction process for recovering aromatic components from aromatic-containing feedstocks. More specifically, this invention is directed to an improved extraction process for the recovery of high-purity aromatics wherein the solvent passing from the extractor is recovered and recycled to the extractor without contaminating the extract removed from the extractor with non-aromatics, thereby producing a highpurity aromatic extract.
  • FIGURE 1 is a schematic diagram of such a conventional process.
  • solvent such as sulfolane or diethylene glycol.
  • FIGURE 1 is a schematic diagram of such a conventional process.
  • This solvent can be conveniently recovered by washing the raflinate with water in a raflinate washer 44.
  • the resultant water-solvent mixture can then be introduced directly (not shown) into solvent stripper 46, where the solvent is recovered and the water serves as stripping steam.
  • FIGURE 1 is a schematic diagram of a conventional extraction process wherein a water still is used to recover a solvent phase and a rafiinate/ water phase from the rafiinate wash water, thus avoiding contaminating the aromatic-rich extract with raffinate.
  • FIGURE 2 is a schematic diagram of a preferred embodiment of the invention wherein raffinate wash water is used as stripping water in an extractive stripper, thereby avoiding the use of a water still for solvent recovery while producing a high-purity aromatic product.
  • the invention is directed to an improved extraction process for recovering aromatic components from a mixed hydrocarbon feedstock wherein the hydrocarbon feedstock is introduced into a solvent extraction zone and the aromatic contained therein are selectively dissolved by .a selective solvent such as sulfolane. A small portion of the solvent is dissolved in the raffinate phase and passes overhead with the rafiinate from the extractor. This portion of the solvent is subsequently recovered by washing the rafiinate with water.
  • a selective solvent such as sulfolane
  • the rafiinate wash water can be used as stripping water in an extractive stripper (a column in which the more volatile components contained in the fat solvent are partially distilled overhead) without danger of contaminating the aromatic extract introduced into the stripper with the raffinate components contained in the rafiinate wash water.
  • an extractive stripper a column in which the more volatile components contained in the fat solvent are partially distilled overhead
  • any saturated hydrocarbons entrained in the solvent are vaporized and returned to the extractor along with the tops from the extractive stripper stream with the high-purity aromatics being Withdrawn as extractive stripper bottoms.
  • the water, being relatively non-volatile as compared to the saturated hydrocarbon raffinate, will be largely transferred with the extractive stripper bottoms to a solvent stripper where it can be vaporized as stripping steam.
  • the relative volatility of normal nonane with respect to benzene would be about 5 in a conventional operation such as shown in FIGURE 1, with 5% mole water in sulfolane in the extractive stripper bottoms, whereas in the process as disclosed in FIGURE 2 with 20% mole water in sulfolane, the relative volatility of normal nonane with respect to benzene is estimated to be about 10. Further, the addition of water serves to reduce the required solvent circulation rate, resulting in savings both in capital investment and operating cost.
  • the conditions of temperature, pressure and concentration of solvent in the extraction zone are selected to insure optimum recovery of high-purity aromatics from the feed charge.
  • a lean, relatively aromatic-free solvent selective for aromatic hydrocarbon-s and which is relatively immiscible with non-aromatic hydrocarbons is admitted to one end of an extraction zone and in extractive contact with the aromatics contained in the feed charge.
  • Such a solvent should have a relatively high selective solubility for aro-.
  • the liquid feed is introduced at a point midway up the extraction column.
  • the solvent flows through the zone countercurrent to the feed charge.
  • the fat solvent containing the selectively dissolved aromatics is continuously withdrawn from the ex- 7 traction Zone at the end opposite the end where the feed is introduced, and is then introduced into an extractive stripper.
  • the raffinate containingsome of the solvent passes out of the extraction zone and is introduced into a raffinate washer to remove the solvent.
  • the solventcontaining wash water from the raftinate Washer is then introduced into the lower section of an extractive stripper.
  • the distillate from the extractive stripper containing the non-aromatic hydrocarbons is recycled to the extractor as part of the feedstock, with the water-sulfolane-aromatic hydrocarbon extractive stripper bottoms being introduced into a solvent stripper.
  • the stripped lean solvent is then recycled to the extractor with the aromatics product passing overhead along with the water. Subsequently the aromatics are separated from the water as a high-purity aromatic product.
  • the selective solvents which can be used according to the invention should be selective to aromatics, and must have some miscibility with water to insure that the solvent will pass out of the bottom of the extractive stripper along with the water. Further, the solvent must be stable at the extractive stripper and solvent stripper temperatures. That is, the solvent must be sufficiently heat-stable so that it may at least partially vaporize without decomposition in the presence of the components of the mixture to be selectively extracted.
  • the preferred solvents are the glycols, including particularly diethylene glycol, and the various sulfolane solvents.
  • Various other common selective solvents for aromatics such as phenol, nitrobenzene, acetonitrile and furfural may also be used.
  • sulfolane solvents having the following general formula are used in the improved extraction process:
  • R can be a hydrogen atom, an alkyl group having up to 10 carbon atoms, an alkoxy radical having up to 8 carbon atoms, an aryl alkyl radical having up to 12 carbon atoms or mixtures thereof. In a particularly preferred embodiment, all Rs are hydrogen.
  • aromatic/non-aromatic mixtures may be separated by the extraction process of the present invention.
  • a preferred embodiment of the invention is the recovery of aromatics from hydrocarbon feed mixtures containing substantial concentrations of aromatics.
  • the apparatus employed in this process may be any conventional or convenient type known to those skilled in the art.
  • the drawings do not show all the pumps, tanks, heat exchangers, valves, bypasses, vents, reboilers, condensers, coolers and other auxiliaries that may be necessary for the proper operation of the process, but the inclusion of which will be evident to those skilled in the art.
  • the temperature for the extraction column may range within wide limits provided it is below the bubble temperature of the mixture and above the solidification temperature of the selective solvent under the pressure and temperature conditions maintained in the column.
  • the most suitable operating temperatures vary with the pressure maintained during the operation and are generally a compromise since in general the selectivity of these solvents seems to decrease with an increase in temperature.
  • substantially atmospheric pressures are maintained in the extraction column.
  • the amount of solvent should be at least suificient to dissolve the constituent to be extracted. In some cases a considerable excess over this amount may be used, especially when it is desired to recover the last traces of the more soluble constituents from the raffinate.
  • the most economic amount varies with the nature of the particular selective solvent being used and the temperatures and pressures employed in the particular feed mixture. This amount can be determined experimentally.
  • Useful solvent to feed ratios in the extraction zone may range from about /2:1 to about 20:1 by volume and preferably not more than about 5:1 by volume.
  • the optimum temperature to be employed in the extraction step varies with the particular feedstock to be treated and the solvent to be used, and may range up to about 350 F. or more, but in most instances temperatures below about 250 F. and particularly those in the range of from about to about 200 F. are preferred.
  • Extractor 2 can be a conventional liquid-liquid extraction column, such as a column containing a plurality of perforated plates horizontally positioned therein, or in a preferred embodiment of the invention, column 2 is a rotating disc contactor, as described in US. Patent to Reman, 2,601,674 issued June 24, 1952.
  • a lean solvent stream containing water is introduced via line 3 into the upper portion of extractor 2.
  • the selective solvent flows down column 2 countercurrent to the feed charge and selectively dissolves the aromatics therefrom with the fat solvent containing the selectively dissolved aromatics and water passing out of extractor 2 via line 4.
  • the fat solvent is then introduced into the top of extractive stripper 5.
  • the raflinate from extractor 2 is passed overhead via line 6 to raffinate washer 7.
  • the raffinate normally contains in addition to the non-aromatic hydrocarbons a portion of the selective solvent.
  • the ratfinate washer can be any conventional contacting device and in a preferred embodiment of the invention, it is a rotating disc contactor. Wash water is introduced into raffinate wash column 7 via line 9. Washed raffinate (solvent-free) is passed out of the raflinate washer 7 via line 8. The ratfinate wash water containing the solvent and some entrained hydrocarbons is passed out of column 7 via line 10 and is introduced into extractive stripper 5 at a point near the bottom thereof.
  • the ralfinate wash water is introduced into extractive stripper 5 at a point above the bottom tray such that any saturated hydrocarbons contained therein will be vaporized and returned to feed line 1 by means of recycle stream 11. Therefore, any saturated hydrocarbons introduced into extractive stripper 5 with the rafiinate wash water via line 10 or with the fat solvent via line 4 is passed out of the extractive stripper as overhead via line 11 and recycled and reintroduced into feed charge line 1, thereby improving the purity of the aromatic product withdrawn from the extractive stripper via line 13. Extractive stripper column 5 is equipped with reboiler 12.
  • the extract phase taken from the bottom of extractive stripper 5 via line 13 contains the extracted aromatics in addition to the selective solvent and water.
  • This mixture is introduced into solvent stripper 14 at a point midway up to stripper column.
  • the stripped aromatics are passed overhead along with the water.
  • the water is separated from the aromatic product (not shown) and returned to rafiinate washer 7 via line 9 with the water-free high-purity aromatics passing out of the system as an end product.
  • the lean selective solvent which may contain some water, is introduced into extractor 2 via line 3 and can be passed through reboiler 12 prior to introduction into extractor 2 (see dotted lines), thus serving as a heat-exchange medium.
  • Solvent stripper 14 is equipped with reboiler 15.
  • the lean solvent can contain up to about 20% by volume water, with the exact concentration desired being maintained by controlling solvent stripper column conditions. Controlling the stripper column conditions will not endanger the recovery of a high-purity aromatic overhead since the control of the stripper column is merely a function of steam rate and afiects only the material coming into the stripper. Valved line 16 is provided for the addition of fresh solvent to the system as required. A slip stream of lean solvent of approximately to by volume of the total solvent inventory can be taken by line 17 to a solvent clean-up flasher or vacuum column (not shown) during each 24-hour period to remove contaminants. After cleanup, the solvent can be returned to the system through line 3.
  • a liquid-liquid solvent extraction process for separating an aromatic product from a mixture of aromatic and non-aromatic which comprises:
  • a process according to claim 1 wherein the selective solvents contain from about 1 to about 20% by volume water.
  • a process according to claim 1 wherein the selective solvent is selected from the group consisting of sulfolane solvents, glycol solvents, phenol solvents and furfural.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
US139778A 1961-09-21 1961-09-21 Recovery of aromatics Expired - Lifetime US3209047A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
NL283421D NL283421A (de) 1961-09-21
BE622633D BE622633A (de) 1961-09-21
NL137161D NL137161C (de) 1961-09-21
US139778A US3209047A (en) 1961-09-21 1961-09-21 Recovery of aromatics
GB31225/62A GB999804A (en) 1961-09-21 1962-08-14 Process for the separation of a mixture by means of liquid-liquid extraction
FR909859A FR1337992A (fr) 1961-09-21 1962-09-19 Procédé de séparation d'un mélange par extraction d'un liquide par un liquide
DE19621468600 DE1468600A1 (de) 1961-09-21 1962-09-19 Verfahren zur Auftrennung einer Mischung mittels einer Fluessig-Fluessig-Extraktion
DK408362AA DK115043B (da) 1961-09-21 1962-09-19 Fremgangsmåde ved fraktionering af blandinger af vanduopløselige organiske væsker.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US139778A US3209047A (en) 1961-09-21 1961-09-21 Recovery of aromatics

Publications (1)

Publication Number Publication Date
US3209047A true US3209047A (en) 1965-09-28

Family

ID=22488256

Family Applications (1)

Application Number Title Priority Date Filing Date
US139778A Expired - Lifetime US3209047A (en) 1961-09-21 1961-09-21 Recovery of aromatics

Country Status (7)

Country Link
US (1) US3209047A (de)
BE (1) BE622633A (de)
DE (1) DE1468600A1 (de)
DK (1) DK115043B (de)
FR (1) FR1337992A (de)
GB (1) GB999804A (de)
NL (2) NL283421A (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3308059A (en) * 1965-03-31 1967-03-07 Shell Oil Co Sulfolane solvent recovery from water wash
US3329606A (en) * 1965-08-30 1967-07-04 Phillips Petroleum Co Method for refining a phenolic water solvent
US3361664A (en) * 1966-04-05 1968-01-02 Universal Oil Prod Co Flashing and extractively distilling an extract
US3396101A (en) * 1966-08-31 1968-08-06 Universal Oil Prod Co Solvent extraction of highly aromatic charge stocks
US3433735A (en) * 1966-09-29 1969-03-18 Universal Oil Prod Co Solvent disperse phase extraction of aromatic hydrocarbons
US3537984A (en) * 1968-12-05 1970-11-03 Universal Oil Prod Co Process for the extraction and recovery of aromatic hydrocarbons
US3544453A (en) * 1968-12-05 1970-12-01 Universal Oil Prod Co Process for the extraction and recovery of aromatic hydrocarbons
US3619419A (en) * 1969-06-23 1971-11-09 Universal Oil Prod Co Solvent recovery process
US4230638A (en) * 1979-05-04 1980-10-28 Phillips Petroleum Company Separation of cyclohexylbenzene from a cyclohexylbenzene-cyclohexanone-phenol admixture
US4306945A (en) * 1977-08-09 1981-12-22 Snamprogetti, S.P.A. Extracting aromatic hydrocarbons from mixtures containing same
US20140251872A1 (en) * 2010-12-15 2014-09-11 Saudi Arabian Oil Company Integrated desulfurization and denitrification process including mild hydrotreating of aromatic-lean fraction and oxidation of aromatic-rich fraction

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE788871A (fr) * 1971-09-16 1973-03-15 Union Carbide Corp Procede de separation par extraction et
CA1169012A (en) * 1980-10-16 1984-06-12 Walter C.G. Kosters Process for the simultaneous separation in aromatics and non-aromatics of a heavy hydrocarbon stream and a light hydrocarbon stream
DE102014110489A1 (de) * 2014-07-24 2016-01-28 L'Air Liquide, Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude Verfahren zur Abtrennung von Phenolen und BTX-Aromaten aus Gaskondensat

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2773918A (en) * 1952-01-07 1956-12-11 Universal Oil Prod Co Solvent extraction process
US2792332A (en) * 1953-12-04 1957-05-14 Pure Oil Co Desulfurization and dearomatization of hydrocarbon mixtures by solvent extraction
US2886610A (en) * 1954-04-28 1959-05-12 American Oil Co Solvent recovery system
US2921015A (en) * 1957-07-29 1960-01-12 Shell Dev Preparation of aromatics from a naphtha feed
US2936283A (en) * 1957-11-08 1960-05-10 Pure Oil Co Extraction process wherein the desired material is recovered by azeotropic distillation of the extract

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2773918A (en) * 1952-01-07 1956-12-11 Universal Oil Prod Co Solvent extraction process
US2792332A (en) * 1953-12-04 1957-05-14 Pure Oil Co Desulfurization and dearomatization of hydrocarbon mixtures by solvent extraction
US2886610A (en) * 1954-04-28 1959-05-12 American Oil Co Solvent recovery system
US2921015A (en) * 1957-07-29 1960-01-12 Shell Dev Preparation of aromatics from a naphtha feed
US2936283A (en) * 1957-11-08 1960-05-10 Pure Oil Co Extraction process wherein the desired material is recovered by azeotropic distillation of the extract

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3308059A (en) * 1965-03-31 1967-03-07 Shell Oil Co Sulfolane solvent recovery from water wash
US3329606A (en) * 1965-08-30 1967-07-04 Phillips Petroleum Co Method for refining a phenolic water solvent
US3361664A (en) * 1966-04-05 1968-01-02 Universal Oil Prod Co Flashing and extractively distilling an extract
US3396101A (en) * 1966-08-31 1968-08-06 Universal Oil Prod Co Solvent extraction of highly aromatic charge stocks
US3433735A (en) * 1966-09-29 1969-03-18 Universal Oil Prod Co Solvent disperse phase extraction of aromatic hydrocarbons
US3537984A (en) * 1968-12-05 1970-11-03 Universal Oil Prod Co Process for the extraction and recovery of aromatic hydrocarbons
US3544453A (en) * 1968-12-05 1970-12-01 Universal Oil Prod Co Process for the extraction and recovery of aromatic hydrocarbons
US3619419A (en) * 1969-06-23 1971-11-09 Universal Oil Prod Co Solvent recovery process
US4306945A (en) * 1977-08-09 1981-12-22 Snamprogetti, S.P.A. Extracting aromatic hydrocarbons from mixtures containing same
US4230638A (en) * 1979-05-04 1980-10-28 Phillips Petroleum Company Separation of cyclohexylbenzene from a cyclohexylbenzene-cyclohexanone-phenol admixture
US20140251872A1 (en) * 2010-12-15 2014-09-11 Saudi Arabian Oil Company Integrated desulfurization and denitrification process including mild hydrotreating of aromatic-lean fraction and oxidation of aromatic-rich fraction

Also Published As

Publication number Publication date
FR1337992A (fr) 1963-09-20
NL283421A (de)
BE622633A (de)
DE1468600A1 (de) 1968-12-05
DK115043B (da) 1969-09-01
GB999804A (en) 1965-07-28
NL137161C (de)

Similar Documents

Publication Publication Date Title
US3209047A (en) Recovery of aromatics
US3361664A (en) Flashing and extractively distilling an extract
KR840000579B1 (ko) 탄화수소유의 용매 추출법
US2727848A (en) Solvent recovery in solvent extraction
US2886610A (en) Solvent recovery system
USRE26255E (en) Recovery of aromatics
US3492222A (en) Solvent recovery process
US4048062A (en) Aromatic extraction with solvent recovery and regeneration
US3338824A (en) Water-washing raffinate to recover the sulfolane solvent
JPH0680019B2 (ja) 炭化水素混合物から芳香族を分離する方法
US3551327A (en) Extractive distillation of aromatics with a sulfolane solvent
US3642614A (en) Reduction of soluble contaminants in lean solvent
US3207692A (en) Process for separation of a solvent by distillation
US3590092A (en) Method for aromatic hydrocarbon recovery
US3864245A (en) Solvent extraction with increased polar hydrocarbon purity
US3306849A (en) Hydrocarbon solvent refining process
US3544453A (en) Process for the extraction and recovery of aromatic hydrocarbons
US3222416A (en) Extraction process
US3788980A (en) Process for the separation of aromatic hydrocarbons from a mixed hydrocarbon feedstock
US3396101A (en) Solvent extraction of highly aromatic charge stocks
US2921015A (en) Preparation of aromatics from a naphtha feed
US3470088A (en) Method for aromatic hydrocarbon recovery
US3537984A (en) Process for the extraction and recovery of aromatic hydrocarbons
US3864244A (en) Solvent extraction with internal preparation of stripping steam
US2457975A (en) Removing mercaptans