CA2405201A1 - Caustic extraction of mercaptans - Google Patents
Caustic extraction of mercaptans Download PDFInfo
- Publication number
- CA2405201A1 CA2405201A1 CA002405201A CA2405201A CA2405201A1 CA 2405201 A1 CA2405201 A1 CA 2405201A1 CA 002405201 A CA002405201 A CA 002405201A CA 2405201 A CA2405201 A CA 2405201A CA 2405201 A1 CA2405201 A1 CA 2405201A1
- Authority
- CA
- Canada
- Prior art keywords
- ethanol
- mercaptans
- extraction
- base
- extractant
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
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
- C10G21/06—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents characterised by the solvent used
-
- 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
- C10G67/00—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only
- C10G67/02—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only plural serial stages only
- C10G67/04—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only plural serial stages only including solvent extraction as the refining step in the absence of hydrogen
Abstract
The invention describes a method for preparing a low sulfur motor gasoline utilizing ethanol and caustic extraction.
Description
CAUSTIC EXTRACTION OF MERCAPTANS
FIELD OF THE INVENTION
The invention describes a process for decreasing the amount of mercaptans in petroleum streams, particularly naphtha streams.
BACKGROUND OF THE INVENTION
Future environmental regulations will require significantly lower sulfur levels in motor gasoline. The proposed regulations will require the complete desulfurization of cat naphtha, which contains the vast majority of the sulfur in gasoline. There is a large economic incentive to remove or reduce the sulfur in cat naphtha while retaining olefins which are important for octane.
Selective cat naphtha hydroprocessing requires the selective conversion of organosulfur to hydrogen sulfide (HDS) while minimizing olefin saturation (SAT).
In the late '30's, '40's and early '50's, before the advent of large scale fluid cat cracking (FCC), a range of improved technologies for extracting C6 to C9 mercaptan sulfur from thermal cracked naphtha were developed.
These technologies were required because mercaptan and disulfide sulfur had a strong negative interaction with tetraethyl lead, which was then used in considerable quantities to improve gasoline octane. These technologies relied on solutizing additives, such as methanol, ethanol, or isopropanol to significantly improve the extractability of gasoline range mercaptans. With the advent of FCC
technology, the solutizing technologies were no longer required since FCC does not produce mercaptans in this product range.
Several references teach the removal of mercaptans and phenolic compounds from petroleum distillates. For example, U.S. 2,309,651 teaches the use of a countercurrent extraction utilizing an alkaline reagent and solvent such as methanol. Although the reference teaches other alcohols, such as ethanol, propanol, isopropanol etc., methanol is preferred.
US 2,347,348 teaches the removal of mercaptans from gasoline utilizing a caustic methanol solution. Though the reference speaks of other suitable organic solvents such as ethanol, propanol, acetone, ethylene glycol etc.
methanol is the preferred solvent.
What is needed in the art is a method for economically and effectively removing mercaptans from petroleum streams.
SUMMARY OF THE INVENTION
The invention includes a method for decreasing the amount of mercaptans in a petroleum stream comprising the steps of:
(a) extracting said petroleum stream containing mercaptans with an extractant comprising ethanol and an aqueous base to produce a product having a decreased concentration of mercaptans and a used extractant comprising said extracted mercaptans, ethanol and base;
(b) recovering said product having a decreased amount of mercaptans.
Surprisingly, applicants have discovered that when ethanol is utilized in conjunction with a base to extract mercaptans from a hydrodesulfurized petroleum stream, or a petroleum stream containing mercaptans, it is much more effective than other alcohols, including methanol, which is taught as the preferred alcohol in the solutizing art. Furthermore, since ethanol is a beneficial component of mogas, the instant extraction method is economical and practical.
BRIEF DESCRIPTION OF THE FIGURE
Figure 1 depicts the effect of alcohol content on 1-heptanethiol extraction.
DETAILED DESCRIPTION OF THE INVENTION
The invention includes the use of ethanol as a solutizing agent in conjunction with base to extract mercaptans from petroleum streams including streams which have been hydrodesulfi~rized by any known technique.
Surprisingly, ethanol is a much more effective solutizing agent than the preferred alcohol, methanol, taught by the art.
Hydrodesulfurization processes are well known in the art. During such processes, an addition reaction occurs whereby the hydrogen sulfide produced during the process reacts with feed olefins to form alkylmercaptans.
This reaction is commonly referred to as mercaptan reversion. The extraction step taught herein allows for the removal of the mercaptans produced, hence, allowing for a lower sulfur product. The ethanol amount utilized is greater than vol%, more preferably greater than 25 vol%, and most preferably greater than 45 vol% of the combination of ethanol and aqueous base.
The extraction process may utilize any basic reagent which is capable of extracting mercaptans from the feed stream. A preferred basic reagent comprises an aqueous solution of ammonia or an alkaline metal hydroxide, such as sodium or potassium hydroxide. Aqueous base may be used in concentrations of from 1 to 50 wt% with a preferred concentration range being from about 5 to 50 wt% of the combination of aqueous base and ethanol.
The amount of the combination of aqueous base and ethanol to be used to treat the product of the HDS unit for mercaptans removal or a mercaptan containing petroleum stream can range from at least about 25 volume % upward. Prefer-ably about 10 to 75 volume %, more preferably to about 25 to about 65 volume %, and most preferably about 40 to 60 volume % will be used. Typically, the aqueous base and ethanol extractant will be at least 1N, preferably, at least 6N.
The maximum normality permissible is readily determined by the skilled artisan based on the extraction being conducted.
Thus, in one aspect of the instant invention a hydroprocessing step may be combined with a mercaptans extraction step conducted using a base (caustic) in combination with ethanol.
Any HDS process known in the art can be utilized. For example, both thermal and catalytic HDS can precede the extraction. Such processes are well known to the skilled artisan.
The conditions for the extraction step utilized herein can be easily selected by the skilled artisan. Preferably, the conditions utilized will be those described in US Patent 4,626,341 herein incorporated by reference.
For example, the conditions employed in the extraction zone may vary greatly depending on such factors as the nature of the hydrocarbon stream being treated and its mercaptan content, etc. The skilled artisan can readily select such conditions with reference to the solutizing art. However, in general, the mercaptan extraction may be performed at an ambient temperature above about 60 degrees Fahrenheit 15 degrees Celsius) and at a pressure sufficient to ensure liquid state operation. With very light material in the feed stream, this may be impractical and the extraction is performed with a vapor phase feed stream. The pressure may range from atmospheric up to 6895 kPag ( 1000 psig) or more, but a pressure in the range of from about 1000 to 2400 kPag ( 145 to about 348 psig) is preferred.
The temperature in the mercaptan extraction zone is confined within the range of 10 to 121 degrees Celsius (50 to 250 degrees Fahrenheit), preferably from 27 to 49 degrees Celsius (80 to 120 degrees Fahrenheit). The rate of flow of the ethanol and aqueous base extractant will typically be about 1 to 3% of the rate of flow of an the petroleum stream being treated and may be up to about 20% of the stream. The extraction zone is preferably a vertically frayed column having a large number of circular perforations. Optimum extraction in this liquid system is obtained with a velocity through the perforations of from about 5 to about 10 feet per second. A packed column and other types of extraction equipment could be employed if desired.
Once the petroleum stream having organo sulfur and mercaptans removed therefrom is separated from the used extractant mixture, the used extractant mixture can then be recycled to extract a fresh petroleum containing mercaptan or hydroprocessed petroleum stream or regenerated to remove mercaptans and the base and ethanol then recycled. The preferred streams treated in accordance herewith are naphtha streams, more preferably, intermediate naphtha streams. Regeneration of the spent base can occur using either steam stripping as described in The Oil and Gas Journal, September 9, 1948, pp. 95-103 or oxidation followed by extraction into a hydrocarbon stream.
Typically regeneration of the mercaptan containing used extractant is accomplished by mixing the stream with an air stream supplied at a rate which supplies at least the stoichiometric amount of oxygen necessary to oxidize the mercaptans in the caustic stream. The air or other oxidizing agent is well admixed with the base and the mixed-phase admixture is then passed into the oxidation zone. The oxidation of the mercaptans is promoted through the presence of a catalytically effective amount of an oxidation catalyst capable of functioning at the conditions found in the oxidizing zone. Several suitable materials are known in the art.
Preferred as a catalyst is a metal phthalocyanine such as cobalt phthalocyanine or vanadium phthalocyanine, etc. Higher catalytic activity may be obtained through the use of a polar derivative of the metal phthalocyanine, especially the monosulfo, disulfo, trisulfo, and tetrasulfo derivatives.
The preferred oxidation catalysts may be utilized in a form which is soluble or suspended in the alkaline solution or it may be placed on a solid carrier material. If the catalyst is present in the solution, it is preferably cobalt or vanadium phthalocyanine disulfonate at a concentration of from about 5 to 1000 wt. ppm. Carrier materials should be highly absorptive and capable of withstanding the alkaline environment. Activated charcoals have been found very suitable for this purpose, and either animal or vegetable charcoals may be used. The carrier material is to be suspended in a fixed bed which provides efficient circulation of the caustic solution. Preferably the metal phthalocyanine compound comprises about 0.1 to 2.0 wt% of the final composite.
The oxidation conditions utilized include a pressure of from atmospheric to about 6895 kPag (1000 psig). This pressure is normally less than 500 kPag (72.5 psig). The temperature may range from ambient to about 95 degrees Celsius (203 degrees Fahrenheit) when operating near atmospheric pressure and to about 205 degrees Celsius (401 degrees Fahrenheit) when operating at superatmospheric pressures. In general, it is preferred that a temperature within the range of about 38 to about 80 degrees Celsius is utilized.
To separate the mercaptans from the base, the pressure in the phase separation zone may range from atmospheric to about 2068 kPag (300 psig) or more, but a pressure in the range of from about 65 to 300 kPag is preferred.
The temperature in this zone is confined within the range of from about 10 to about I20 degrees Celsius (50 to 248 degrees Fahrenheit), and preferably from about 26 to 54 degrees Celsius. The phase separation zone is sized to allow the denser caustic mixture to separate by gravity from the disulfide compounds. This may be aided by a coalescing means located in the zone.
The above describes one possible method for regenerating used extractant. Other methods known to the skilled artisan may also be employed.
The following examples are meant to be illustrative and not limiting.
EXAMPLES
Example 1:
A model feed composed of 2000 wppm sulfur as 1-heptanethiol in 67 wt% m-xylene and 33 wt% 1-octene was subjected to extraction by various basic agents. Treatments were done by merely shaking either 1 part or 3 parts of -g_ the base with 1 part of the heptanethiol solution. The organic layer was then sampled and tested using capillary and simultaneous GC and SCD detection. The remaining heptanethiol in the organic fraction is shown in Table 1. 1 N NaOH, representative of standard Merox extraction, results in less than 5%
extraction regardless of treat rate. The addition of methanol or ethanol at 50 volume %
to the caustic solution results in significantly higher extraction of the mercaptan.
Ethanol is cleaxly superior to methanol at an equal treat rate. Increasing the base to 20 wt% or 6.2 N results in greater than 95 % extraction of the mercaptan.
Extractant 1:1 Caustic: feed 3:1 Caustic:feed volume volume wppm S as wppm S as 1-he tanethiol remainin1-he tanethiol remainin 1N NaOH 1972 1921 50% MeOH 1365 755 1N NaOH
50% EtOH 43 8 215 I N NaOH
50% EtOH ~ 84 -----(6.2 N NaOH) Example 2:
The effect of alcohol content on the level of heptanethiol left in the organic layer after a I:1 extraction was tested. The effect of alcohol concentra-tion is not linear.
The results of varying methanol and ethanol volume % in 1N
NaOH are shown in Table 2. The starting petroleum product contained approximately 2000 wppm heptanethiol.
Table 2 Alcohol Vol % in caustic Remainin he tanethiol MeOH 0 2000 MeOH 30 1800 MeOH 50 750 EtOH 0 2000 EtOH 3 0 1600 EtOH 50 S00 Example 3:
A hydroprocessed intermediate catalytic cracked naphtha with 52 wppm sulfur content and 47 wppm sulfur as mercaptan sulfur was subjected to extraction using either aqueous 20 wt% NaOH, representative of standard Merox extraction, or to ethanol/causiic extraction representative of this invention.
The treat rate employed was 2:1 caustic:feed. Sulfur levels in the extracted organic layer are shown in Table 3. Caustic extraction results in only about 20 wt%
extraction, whereas ethanol enhanced extraction results in greater than 80%
extraction.
Extractant m total sulfur m mercy tan sulfur 20% NaOH 43 3 8 20% NaOH in 50% ethanol13 8 Example 4:
The hydroprocessed intermediate catalytic cracked naphtha of Example 3 was subjected to staged extraction with 20% NaOH and with 20%
NaOH in ethanol/water. Equal volumes of hydrocarbon and caustic solutions were shaken for two minutes. The caustic and hydrocarbon layers were allowed to separate, the caustic layer was replaced with fresh caustic solutions, and the mixture shaken for a 2nd two minute period. The layers were allowed to separate, the caustic solutions were replaced with fresh caustic solutions, and a final two minute shaking followed. The NaOH control removed 7% of the feed sulfur while the caustic solution/alcohol extracted > 80% of the sulfur.
Example 5:
The procedure of Example 4 was followed using an intermediate catalytic cracked naphtha containing 455 ppm sulfur, of which ~ 100 ppm was mercaptan sulfur. Staged extraction with 20% NaOH removed only 5% of the sulfur. Staged extraction with 20% NaOH in ethanol/water removed 32% of the total sulfur and essentially all of the mercaptan sulfur.
FIELD OF THE INVENTION
The invention describes a process for decreasing the amount of mercaptans in petroleum streams, particularly naphtha streams.
BACKGROUND OF THE INVENTION
Future environmental regulations will require significantly lower sulfur levels in motor gasoline. The proposed regulations will require the complete desulfurization of cat naphtha, which contains the vast majority of the sulfur in gasoline. There is a large economic incentive to remove or reduce the sulfur in cat naphtha while retaining olefins which are important for octane.
Selective cat naphtha hydroprocessing requires the selective conversion of organosulfur to hydrogen sulfide (HDS) while minimizing olefin saturation (SAT).
In the late '30's, '40's and early '50's, before the advent of large scale fluid cat cracking (FCC), a range of improved technologies for extracting C6 to C9 mercaptan sulfur from thermal cracked naphtha were developed.
These technologies were required because mercaptan and disulfide sulfur had a strong negative interaction with tetraethyl lead, which was then used in considerable quantities to improve gasoline octane. These technologies relied on solutizing additives, such as methanol, ethanol, or isopropanol to significantly improve the extractability of gasoline range mercaptans. With the advent of FCC
technology, the solutizing technologies were no longer required since FCC does not produce mercaptans in this product range.
Several references teach the removal of mercaptans and phenolic compounds from petroleum distillates. For example, U.S. 2,309,651 teaches the use of a countercurrent extraction utilizing an alkaline reagent and solvent such as methanol. Although the reference teaches other alcohols, such as ethanol, propanol, isopropanol etc., methanol is preferred.
US 2,347,348 teaches the removal of mercaptans from gasoline utilizing a caustic methanol solution. Though the reference speaks of other suitable organic solvents such as ethanol, propanol, acetone, ethylene glycol etc.
methanol is the preferred solvent.
What is needed in the art is a method for economically and effectively removing mercaptans from petroleum streams.
SUMMARY OF THE INVENTION
The invention includes a method for decreasing the amount of mercaptans in a petroleum stream comprising the steps of:
(a) extracting said petroleum stream containing mercaptans with an extractant comprising ethanol and an aqueous base to produce a product having a decreased concentration of mercaptans and a used extractant comprising said extracted mercaptans, ethanol and base;
(b) recovering said product having a decreased amount of mercaptans.
Surprisingly, applicants have discovered that when ethanol is utilized in conjunction with a base to extract mercaptans from a hydrodesulfurized petroleum stream, or a petroleum stream containing mercaptans, it is much more effective than other alcohols, including methanol, which is taught as the preferred alcohol in the solutizing art. Furthermore, since ethanol is a beneficial component of mogas, the instant extraction method is economical and practical.
BRIEF DESCRIPTION OF THE FIGURE
Figure 1 depicts the effect of alcohol content on 1-heptanethiol extraction.
DETAILED DESCRIPTION OF THE INVENTION
The invention includes the use of ethanol as a solutizing agent in conjunction with base to extract mercaptans from petroleum streams including streams which have been hydrodesulfi~rized by any known technique.
Surprisingly, ethanol is a much more effective solutizing agent than the preferred alcohol, methanol, taught by the art.
Hydrodesulfurization processes are well known in the art. During such processes, an addition reaction occurs whereby the hydrogen sulfide produced during the process reacts with feed olefins to form alkylmercaptans.
This reaction is commonly referred to as mercaptan reversion. The extraction step taught herein allows for the removal of the mercaptans produced, hence, allowing for a lower sulfur product. The ethanol amount utilized is greater than vol%, more preferably greater than 25 vol%, and most preferably greater than 45 vol% of the combination of ethanol and aqueous base.
The extraction process may utilize any basic reagent which is capable of extracting mercaptans from the feed stream. A preferred basic reagent comprises an aqueous solution of ammonia or an alkaline metal hydroxide, such as sodium or potassium hydroxide. Aqueous base may be used in concentrations of from 1 to 50 wt% with a preferred concentration range being from about 5 to 50 wt% of the combination of aqueous base and ethanol.
The amount of the combination of aqueous base and ethanol to be used to treat the product of the HDS unit for mercaptans removal or a mercaptan containing petroleum stream can range from at least about 25 volume % upward. Prefer-ably about 10 to 75 volume %, more preferably to about 25 to about 65 volume %, and most preferably about 40 to 60 volume % will be used. Typically, the aqueous base and ethanol extractant will be at least 1N, preferably, at least 6N.
The maximum normality permissible is readily determined by the skilled artisan based on the extraction being conducted.
Thus, in one aspect of the instant invention a hydroprocessing step may be combined with a mercaptans extraction step conducted using a base (caustic) in combination with ethanol.
Any HDS process known in the art can be utilized. For example, both thermal and catalytic HDS can precede the extraction. Such processes are well known to the skilled artisan.
The conditions for the extraction step utilized herein can be easily selected by the skilled artisan. Preferably, the conditions utilized will be those described in US Patent 4,626,341 herein incorporated by reference.
For example, the conditions employed in the extraction zone may vary greatly depending on such factors as the nature of the hydrocarbon stream being treated and its mercaptan content, etc. The skilled artisan can readily select such conditions with reference to the solutizing art. However, in general, the mercaptan extraction may be performed at an ambient temperature above about 60 degrees Fahrenheit 15 degrees Celsius) and at a pressure sufficient to ensure liquid state operation. With very light material in the feed stream, this may be impractical and the extraction is performed with a vapor phase feed stream. The pressure may range from atmospheric up to 6895 kPag ( 1000 psig) or more, but a pressure in the range of from about 1000 to 2400 kPag ( 145 to about 348 psig) is preferred.
The temperature in the mercaptan extraction zone is confined within the range of 10 to 121 degrees Celsius (50 to 250 degrees Fahrenheit), preferably from 27 to 49 degrees Celsius (80 to 120 degrees Fahrenheit). The rate of flow of the ethanol and aqueous base extractant will typically be about 1 to 3% of the rate of flow of an the petroleum stream being treated and may be up to about 20% of the stream. The extraction zone is preferably a vertically frayed column having a large number of circular perforations. Optimum extraction in this liquid system is obtained with a velocity through the perforations of from about 5 to about 10 feet per second. A packed column and other types of extraction equipment could be employed if desired.
Once the petroleum stream having organo sulfur and mercaptans removed therefrom is separated from the used extractant mixture, the used extractant mixture can then be recycled to extract a fresh petroleum containing mercaptan or hydroprocessed petroleum stream or regenerated to remove mercaptans and the base and ethanol then recycled. The preferred streams treated in accordance herewith are naphtha streams, more preferably, intermediate naphtha streams. Regeneration of the spent base can occur using either steam stripping as described in The Oil and Gas Journal, September 9, 1948, pp. 95-103 or oxidation followed by extraction into a hydrocarbon stream.
Typically regeneration of the mercaptan containing used extractant is accomplished by mixing the stream with an air stream supplied at a rate which supplies at least the stoichiometric amount of oxygen necessary to oxidize the mercaptans in the caustic stream. The air or other oxidizing agent is well admixed with the base and the mixed-phase admixture is then passed into the oxidation zone. The oxidation of the mercaptans is promoted through the presence of a catalytically effective amount of an oxidation catalyst capable of functioning at the conditions found in the oxidizing zone. Several suitable materials are known in the art.
Preferred as a catalyst is a metal phthalocyanine such as cobalt phthalocyanine or vanadium phthalocyanine, etc. Higher catalytic activity may be obtained through the use of a polar derivative of the metal phthalocyanine, especially the monosulfo, disulfo, trisulfo, and tetrasulfo derivatives.
The preferred oxidation catalysts may be utilized in a form which is soluble or suspended in the alkaline solution or it may be placed on a solid carrier material. If the catalyst is present in the solution, it is preferably cobalt or vanadium phthalocyanine disulfonate at a concentration of from about 5 to 1000 wt. ppm. Carrier materials should be highly absorptive and capable of withstanding the alkaline environment. Activated charcoals have been found very suitable for this purpose, and either animal or vegetable charcoals may be used. The carrier material is to be suspended in a fixed bed which provides efficient circulation of the caustic solution. Preferably the metal phthalocyanine compound comprises about 0.1 to 2.0 wt% of the final composite.
The oxidation conditions utilized include a pressure of from atmospheric to about 6895 kPag (1000 psig). This pressure is normally less than 500 kPag (72.5 psig). The temperature may range from ambient to about 95 degrees Celsius (203 degrees Fahrenheit) when operating near atmospheric pressure and to about 205 degrees Celsius (401 degrees Fahrenheit) when operating at superatmospheric pressures. In general, it is preferred that a temperature within the range of about 38 to about 80 degrees Celsius is utilized.
To separate the mercaptans from the base, the pressure in the phase separation zone may range from atmospheric to about 2068 kPag (300 psig) or more, but a pressure in the range of from about 65 to 300 kPag is preferred.
The temperature in this zone is confined within the range of from about 10 to about I20 degrees Celsius (50 to 248 degrees Fahrenheit), and preferably from about 26 to 54 degrees Celsius. The phase separation zone is sized to allow the denser caustic mixture to separate by gravity from the disulfide compounds. This may be aided by a coalescing means located in the zone.
The above describes one possible method for regenerating used extractant. Other methods known to the skilled artisan may also be employed.
The following examples are meant to be illustrative and not limiting.
EXAMPLES
Example 1:
A model feed composed of 2000 wppm sulfur as 1-heptanethiol in 67 wt% m-xylene and 33 wt% 1-octene was subjected to extraction by various basic agents. Treatments were done by merely shaking either 1 part or 3 parts of -g_ the base with 1 part of the heptanethiol solution. The organic layer was then sampled and tested using capillary and simultaneous GC and SCD detection. The remaining heptanethiol in the organic fraction is shown in Table 1. 1 N NaOH, representative of standard Merox extraction, results in less than 5%
extraction regardless of treat rate. The addition of methanol or ethanol at 50 volume %
to the caustic solution results in significantly higher extraction of the mercaptan.
Ethanol is cleaxly superior to methanol at an equal treat rate. Increasing the base to 20 wt% or 6.2 N results in greater than 95 % extraction of the mercaptan.
Extractant 1:1 Caustic: feed 3:1 Caustic:feed volume volume wppm S as wppm S as 1-he tanethiol remainin1-he tanethiol remainin 1N NaOH 1972 1921 50% MeOH 1365 755 1N NaOH
50% EtOH 43 8 215 I N NaOH
50% EtOH ~ 84 -----(6.2 N NaOH) Example 2:
The effect of alcohol content on the level of heptanethiol left in the organic layer after a I:1 extraction was tested. The effect of alcohol concentra-tion is not linear.
The results of varying methanol and ethanol volume % in 1N
NaOH are shown in Table 2. The starting petroleum product contained approximately 2000 wppm heptanethiol.
Table 2 Alcohol Vol % in caustic Remainin he tanethiol MeOH 0 2000 MeOH 30 1800 MeOH 50 750 EtOH 0 2000 EtOH 3 0 1600 EtOH 50 S00 Example 3:
A hydroprocessed intermediate catalytic cracked naphtha with 52 wppm sulfur content and 47 wppm sulfur as mercaptan sulfur was subjected to extraction using either aqueous 20 wt% NaOH, representative of standard Merox extraction, or to ethanol/causiic extraction representative of this invention.
The treat rate employed was 2:1 caustic:feed. Sulfur levels in the extracted organic layer are shown in Table 3. Caustic extraction results in only about 20 wt%
extraction, whereas ethanol enhanced extraction results in greater than 80%
extraction.
Extractant m total sulfur m mercy tan sulfur 20% NaOH 43 3 8 20% NaOH in 50% ethanol13 8 Example 4:
The hydroprocessed intermediate catalytic cracked naphtha of Example 3 was subjected to staged extraction with 20% NaOH and with 20%
NaOH in ethanol/water. Equal volumes of hydrocarbon and caustic solutions were shaken for two minutes. The caustic and hydrocarbon layers were allowed to separate, the caustic layer was replaced with fresh caustic solutions, and the mixture shaken for a 2nd two minute period. The layers were allowed to separate, the caustic solutions were replaced with fresh caustic solutions, and a final two minute shaking followed. The NaOH control removed 7% of the feed sulfur while the caustic solution/alcohol extracted > 80% of the sulfur.
Example 5:
The procedure of Example 4 was followed using an intermediate catalytic cracked naphtha containing 455 ppm sulfur, of which ~ 100 ppm was mercaptan sulfur. Staged extraction with 20% NaOH removed only 5% of the sulfur. Staged extraction with 20% NaOH in ethanol/water removed 32% of the total sulfur and essentially all of the mercaptan sulfur.
Claims (8)
1. A method for decreasing the amount of reversion mercaptans in a petroleum stream comprising:
(a) extracting said petroleum stream containing reversion mercaptans with an extractant comprising ethanol and an aqueous base to produce a product having a decreased concentration of reversion mercaptans and a used extractant comprising said extracted reversion mercaptans, ethanol and base;
and (b) recovering said product having a decreased amount of reversion mercaptans.
(a) extracting said petroleum stream containing reversion mercaptans with an extractant comprising ethanol and an aqueous base to produce a product having a decreased concentration of reversion mercaptans and a used extractant comprising said extracted reversion mercaptans, ethanol and base;
and (b) recovering said product having a decreased amount of reversion mercaptans.
2. The method of claim 1 wherein said petroleum stream is a hydroprocessed stream.
3. The method of claim 1 wherein said base is present in said extractant in an amount of about 1 to about 50 wt% based on the weight of the base and ethanol.
4. The method of claim 1 wherein said ethanol is present in amount at least about 10 volume % based on the volume of the ethanol and aqueous base.
5. The method of claim 2 wherein said hydroprocessed petroleum stream is thermally hydroprocessed or catalytically hydroprocessed.
6. The method of claim 1 wherein said petroleum feedstream is a naphtha feedstream.
7. The method of claim 1 wherein said used extractant is recycled to said step (a).
8. The method of claim 7 wherein said used extractant is first regenerated to remove reversion mercaptans.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US09/551,006 | 2000-04-18 | ||
| US09/551,006 US6352640B1 (en) | 2000-04-18 | 2000-04-18 | Caustic extraction of mercaptans (LAW966) |
| PCT/US2001/008896 WO2001079384A1 (en) | 2000-04-18 | 2001-03-20 | Caustic extraction of mercaptans |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2405201A1 true CA2405201A1 (en) | 2001-10-25 |
Family
ID=24199434
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002405201A Abandoned CA2405201A1 (en) | 2000-04-18 | 2001-03-20 | Caustic extraction of mercaptans |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US6352640B1 (en) |
| EP (1) | EP1285043A4 (en) |
| JP (1) | JP2004501217A (en) |
| AU (1) | AU2001249291A1 (en) |
| CA (1) | CA2405201A1 (en) |
| NO (1) | NO20024975L (en) |
| WO (1) | WO2001079384A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3942841B2 (en) | 2001-04-20 | 2007-07-11 | バンドー化学株式会社 | Conductive member for OA equipment |
| US7029573B2 (en) * | 2001-06-19 | 2006-04-18 | Exxonmobil Research And Engineering Company | Composition and control method for treating hydrocarbon |
| US7799210B2 (en) * | 2004-05-14 | 2010-09-21 | Exxonmobil Research And Engineering Company | Process for removing sulfur from naphtha |
| US20060151359A1 (en) * | 2005-01-13 | 2006-07-13 | Ellis Edward S | Naphtha desulfurization process |
| FR2884521B1 (en) * | 2005-04-19 | 2009-08-21 | Inst Francais Du Petrole | NOVEL METHOD OF DESULFURIZING ESSENCES BY ALIGNING SULFUR COMPOUNDS |
| US7772449B2 (en) * | 2007-08-01 | 2010-08-10 | Stone & Webster Process Technology, Inc. | Removal of acid gases and sulfur compounds from hydrocarbon gas streams in a caustic tower |
Family Cites Families (44)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1796621A (en) | 1926-08-27 | 1931-03-17 | Gyro Process Co | Process of refining hydrocarbon oils |
| US1968842A (en) | 1930-11-03 | 1934-08-07 | Atiantic Refining Company | Treatment of hydrocarbons |
| US1973499A (en) | 1930-11-22 | 1934-09-11 | Universal Oil Prod Co | Treatment of hydrocarbon oils |
| US2059075A (en) | 1936-05-18 | 1936-10-27 | Shell Dev | Process of sweetening a sour hydrocarbon distillate |
| US2152166A (en) | 1936-09-28 | 1939-03-28 | Shell Dev | Process of separating mercaptans contained in a hydrocarbon distillate |
| US2160632A (en) | 1937-05-07 | 1939-05-30 | Shell Dev | Process for removing acid components from hydrocarbon solutions |
| US2152721A (en) | 1937-05-26 | 1939-04-04 | Shell Dev | Process for the removal of mercaptans from hydrocarbon distillates |
| US2152723A (en) | 1937-11-01 | 1939-04-04 | Shell Dev | Process for removing acid components from hydrocarbon distillates |
| US2152730A (en) | 1938-07-14 | 1939-04-04 | Cory Harry Thomas | Stripping harvester |
| US2168078A (en) | 1939-02-07 | 1939-08-01 | Shell Dev | Process for removing acid components from hydrocarbon distillates |
| US2212106A (en) | 1939-02-07 | 1940-08-20 | Shell Dev | Process for removing acid components from hydrocarbon distillates |
| US2212107A (en) | 1939-02-07 | 1940-08-20 | Shell Dev | Process for removing acid components from hydrocarbon distillates |
| US2183801A (en) | 1939-02-07 | 1939-12-19 | Shell Dev | Process for removing acid components from hydrocarbon distillates |
| US2212105A (en) | 1939-02-07 | 1940-08-20 | Shell Dev | Process for removing acid components from hydrocarbon distillates |
| US2186398A (en) | 1939-02-07 | 1940-01-09 | Shell Dev | Process for removing acid components from hydrocarbon distillates |
| US2297866A (en) | 1939-09-25 | 1942-10-06 | Universal Oil Prod Co | Treatment of hydrocarbon oil |
| US2309651A (en) | 1941-02-13 | 1943-02-02 | Atlantic Refining Co | Treatment of hydrocarbon oil |
| GB556606A (en) * | 1941-02-13 | 1943-10-13 | Atlantic Refining Co | Method of removing acidic organic compounds from hydrocarbon oil |
| US2437348A (en) | 1944-11-04 | 1948-03-09 | Universal Oil Prod Co | Process for the refining of hydrocarbon oil containing mercaptans |
| US2425777A (en) | 1945-08-22 | 1947-08-19 | Standard Oil Co | Process for the extraction of mercaptans from hydrocarbon oil |
| US2593851A (en) | 1948-03-20 | 1952-04-22 | Cities Service Refining Corp | Method of removing mercaptans from hydrocarbons |
| US2570277A (en) | 1949-02-24 | 1951-10-09 | Standard Oil Dev Co | Sweetening process |
| US2634230A (en) | 1949-11-29 | 1953-04-07 | Standard Oil Co | Desulfurization of olefinic naphtha |
| US2608519A (en) | 1949-11-29 | 1952-08-26 | Standard Oil Co | Desulfurization of olefinic naphtha |
| US2776929A (en) | 1950-08-22 | 1957-01-08 | Exxon Research Engineering Co | Gasoline sweetening process |
| US2792332A (en) | 1953-12-04 | 1957-05-14 | Pure Oil Co | Desulfurization and dearomatization of hydrocarbon mixtures by solvent extraction |
| US3956112A (en) * | 1973-01-02 | 1976-05-11 | Allied Chemical Corporation | Membrane solvent extraction |
| US4124493A (en) | 1978-02-24 | 1978-11-07 | Uop Inc. | Catalytic oxidation of mercaptan in petroleum distillate including alkaline reagent and substituted ammonium halide |
| US4206079A (en) | 1978-02-24 | 1980-06-03 | Uop Inc. | Catalytic composite particularly useful for the oxidation of mercaptans contained in a sour petroleum distillate |
| US4290913A (en) | 1978-07-24 | 1981-09-22 | Uop Inc. | Catalytic composite useful for the treatment of mercaptan-containing sour petroleum distillate |
| US4337147A (en) | 1979-11-07 | 1982-06-29 | Uop Inc. | Catalytic composite and process for use |
| US4362614A (en) * | 1981-04-30 | 1982-12-07 | Uop Inc. | Mercaptan extraction process with recycled alkaline solution |
| US4562300A (en) * | 1985-04-19 | 1985-12-31 | Phillips Petroleum Company | Mercaptan extraction process |
| US4626341A (en) | 1985-12-23 | 1986-12-02 | Uop Inc. | Process for mercaptan extraction from olefinic hydrocarbons |
| US4753722A (en) | 1986-06-17 | 1988-06-28 | Merichem Company | Treatment of mercaptan-containing streams utilizing nitrogen based promoters |
| FR2619822B1 (en) * | 1987-08-24 | 1990-01-12 | Inst Francais Du Petrole | PROCESS OF CONTINUOUS SOFTENING OF OIL CUTS IN LIQUID PHASE |
| US4824818A (en) | 1988-02-05 | 1989-04-25 | Uop Inc. | Catalytic composite and process for mercaptan sweetening |
| US5273646A (en) | 1990-08-27 | 1993-12-28 | Uop | Process for improving the activity of a mercaptan oxidation catalyst |
| US5167797A (en) | 1990-12-07 | 1992-12-01 | Exxon Chemical Company Inc. | Removal of sulfur contaminants from hydrocarbons using n-halogeno compounds |
| US5346609A (en) | 1991-08-15 | 1994-09-13 | Mobil Oil Corporation | Hydrocarbon upgrading process |
| CA2133270C (en) | 1994-03-03 | 1999-07-20 | Jerry J. Weers | Quaternary ammonium hydroxides as mercaptan scavengers |
| US5582714A (en) | 1995-03-20 | 1996-12-10 | Uop | Process for the removal of sulfur from petroleum fractions |
| US6013598A (en) | 1996-02-02 | 2000-01-11 | Exxon Research And Engineering Co. | Selective hydrodesulfurization catalyst |
| US5985136A (en) | 1998-06-18 | 1999-11-16 | Exxon Research And Engineering Co. | Two stage hydrodesulfurization process |
-
2000
- 2000-04-18 US US09/551,006 patent/US6352640B1/en not_active Expired - Fee Related
-
2001
- 2001-03-20 AU AU2001249291A patent/AU2001249291A1/en not_active Abandoned
- 2001-03-20 CA CA002405201A patent/CA2405201A1/en not_active Abandoned
- 2001-03-20 JP JP2001577368A patent/JP2004501217A/en active Pending
- 2001-03-20 WO PCT/US2001/008896 patent/WO2001079384A1/en not_active Application Discontinuation
- 2001-03-20 EP EP01922495A patent/EP1285043A4/en not_active Withdrawn
-
2002
- 2002-10-16 NO NO20024975A patent/NO20024975L/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| JP2004501217A (en) | 2004-01-15 |
| EP1285043A4 (en) | 2003-07-23 |
| US6352640B1 (en) | 2002-03-05 |
| EP1285043A1 (en) | 2003-02-26 |
| AU2001249291A1 (en) | 2001-10-30 |
| NO20024975L (en) | 2002-12-06 |
| NO20024975D0 (en) | 2002-10-16 |
| WO2001079384A1 (en) | 2001-10-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7244352B2 (en) | Selective hydroprocessing and mercaptan removal | |
| US4362614A (en) | Mercaptan extraction process with recycled alkaline solution | |
| EP1620528B1 (en) | Process for the extractive oxidation of contaminants from raw hydrocarbon streams | |
| US7790021B2 (en) | Removal of sulfur-containing compounds from liquid hydrocarbon streams | |
| KR100807159B1 (en) | Process comprising two gasoline hydrodesulfurization stages and intermediate elimination of h2s formed during the first stage | |
| US20060108263A1 (en) | Oxidative desulfurization and denitrogenation of petroleum oils | |
| US20060151359A1 (en) | Naphtha desulfurization process | |
| US2794767A (en) | Refining process including regeneration of used alkaline reagents | |
| KR20010086218A (en) | A combined process for improved hydrotreating of diesel fuels | |
| JPS62164790A (en) | Continuous extraction of mercaptan from highly olefinic feedstream | |
| CA1094005A (en) | Mercaptan extraction process | |
| US6352640B1 (en) | Caustic extraction of mercaptans (LAW966) | |
| CN101255352A (en) | Method for removing sulfides in gasoline by oxidation-absorption under mild conditions | |
| CN108003934B (en) | Method for deep desulfurization of gasoline and equipment for deep desulfurization of gasoline | |
| JP2013538900A (en) | Removal of sulfone from oxidized hydrocarbon fuels. | |
| US2937986A (en) | Spent caustic treating process | |
| CS207616B2 (en) | Method of catalyctic treating the acidic petroleum distillates containing the mercaptanes | |
| US6485633B2 (en) | Process for the demercaptanization of petroleum distillates | |
| RU2341549C2 (en) | Method of reducing content of sulfur and/or nitrogen in distillate raw material | |
| EP0307146A1 (en) | Process for improving the thermal stability of jet fuels sweetened by catalytic oxidation | |
| CN108018083B (en) | Method for deep desulfurization of gasoline and equipment for deep desulfurization of gasoline | |
| CN108003931B (en) | Method for deep desulfurization of gasoline and equipment for deep desulfurization of gasoline | |
| CN101928596B (en) | Method for producing clean solvent oil without hydrogen | |
| CN108018081B (en) | Method for deep desulfurization of gasoline and equipment for deep desulfurization of gasoline | |
| CN108003926B (en) | Method for deep desulfurization of gasoline and equipment for deep desulfurization of gasoline |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |