JPS5910259B2 - Catalytic composition useful for the oxidation of mercaptans in sour petroleum fractions - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst composition particularly suitable for the conversion reaction of oxidizable mercabutane contained in sour petroleum fractions.

Processes for treating sour petroleum fractions in which sour petroleum fractions are contacted with oxidation catalysts under alkaline reaction conditions in the presence of an oxidizing agent are well known and widely practiced in the petroleum refining industry.

This process is typically intended to convert troublesome mercabutanes in sour petroleum fractions to harmless disulfides and is commonly referred to as sweetening.

Depending on the source of the petroleum from which the sour fraction is derived, the boiling range of the sour fraction and the processing method of the petroleum to obtain the sour fraction, sour fractions vary widely in terms of mercabutan concentration and complexity. Therefore, the sweetening process is not uniform.

One such process is one that targets petroleum fractions containing olefins.

If this fraction is to be stored for a long period of time, it is advantageous to contain an oxidation inhibitor in order to prevent cam formation.

Cono inhibitors are typically oil-soluble phenylene diamines.

If the olefin-containing fraction mentioned above contains relatively small amounts of mercaptans that are relatively easy to oxidize, phenylenediamine acts as an oxygen transfer agent and promotes the oxidation of mercaptans in the presence of alkaline reagents. Generates sulfide.

It is noteworthy that at least 1/3 of the mercabutane is consumed in interaction with olefins in the sour fraction.

This process is commonly referred to as inhibitor sweetening.

Homogeneous phenylenediamine is not recoverable and is consumed in the sweetening process.

Therefore, as the amount of phenylenediamine required to carry out the oxidation at an economical rate becomes too large, the process becomes less effective as a sweetening process.
Sweetening must resort to other means.

Inhibitor sweetening is primarily a batch process suitable for treating sour fractions during storage, but as is well known,
This process is only effective for olefin-containing cuts, as olefins are essential to the inhibitor sweetening process.

Typically, over a period of hours or days, the stored fraction will be sweetened depending on the concentration and complexity of the mercabutane it contains.

Some processes use quaternary ammonium halides in conjunction with homogeneous phenylenediamine catalysts to promote sweetening, as seen in U.S. Pat. There is no difference in the way you receive it.

In other words, inhibitor sweetening is generally not effective for sour petroleum fractions containing mercaptans other than primary and secondary mercaptans, with concentrations of about 150 ppm.
It is of little use for petroleum fractions containing mercabutan sulfur in excess of 20%.

Sour petroleum fractions that cannot be treated with inhibitor sweetening, i.e., contain higher molecular weight and/or more mercabutanes, or have a high concentration of mercabutanes, can be treated in a heterogeneous system dispersed in an aqueous caustic solution. Catalytic treatment with metal phthalocyanine catalysts is common.

The sour fraction and the catalyst-containing caustic aqueous solution constitute a one-liquid system in which mercabutane forms a disulfide in the presence of an oxidizing agent (usually air) at the interface of the two immiscible liquids. converts into

This one-liquid system is always employed in continuous operations, which require substantially less contact time than inhibitor sweetening.

Metal phthalocyanine catalysts are recovered and recycled for continuous use, but they are not only effective for oil fractions containing olefins, but also oil fractions that do not contain olefins, which can be used to produce doctor sweet. Make it into something.

High-boiling sour petroleum fractions, typically with boiling points above about 135°C, contain highly complex branched theols and aromatic theols and/or high molecular weight tertiary mercabutanes and polyfunctional However, these thiols and mercaptans are only partially soluble in the one-liquid catalyst-containing caustic solution.

Sour petroleum fractions containing these relatively difficult to oxidize mercabutanes are effectively treated by contacting them with metal phthalocyanine catalysts supported or impregnated on high surface area adsorptive support materials (usually activated Teyacol).

That is, a petroleum fraction is catalytically treated with a supported metal phthalocyanine catalyst under oxidizing conditions in the presence of an alkaline reagent; such a process is described in U.S. Pat.
It is described in No. 00.

The oxidizing agent is often air in the fraction to be treated, and the alkaline reagent is often an aqueous caustic solution, which is added continuously or intermittently to the process to keep the catalyst in a caustic wet state. Be supplied.

One of the objects of the present invention is to provide a new catalyst composition that is particularly useful for the treatment of sour petroleum fractions containing mercabutane that is difficult to oxidize.

The catalyst composition according to the present invention consists of a metal chelate type mercaptan oxidation catalyst impregnated into a solid adsorptive carrier and a quaternary ammonium/.ride, and the quaternary ammonium/.ride has the following structural formula: Show it.

where R is a hydrocarbon group having up to 20 carbon atoms selected from alkyl, cycloalkyl, aryl, alkaryl, and aralkyl; R is a substantially linear alkyl group having 5 to 20 carbon atoms; R2 is an aryl group; selected from the group consisting of alkaryl and aralkyl groups, and X is an anion selected from halides.

As the metal chelate type mercaptan oxidation catalyst which is a component of the catalyst composition of the present invention, any metal chelate that can catalytically oxidize mercaptan in sour petroleum fraction and convert it into polysulfide can be used.

Such metal chelates are described in U.S. Patent No. 3,980,582.
Metal compounds of tetrapyridinoporphyrazine mentioned in the number, such as cobalt tetrapyridinoporphyrazine,
Porphyrin and metalloporphyrin catalysts described in U.S. Pat. No. 2,966,453, such as cobalt tetraphenylporphyrin sulfonate, and U.S. Pat.
252,892, such as cobalt choline sulfonate, and even U.S. Pat. No. 2,918.
Chelate organometallic catalysts described in No. 426, such as condensation products of Group I metals and amine phenols, are included.

Metal phthalocyanines are a preferred group of metal chelate mercaptan oxidation catalysts.

Metal phthalocyanines used as mercaptan oxidation catalysts generally include magnesium phthalocyanine, natanium phthalocyanine, hafnium phthalocyanine, vanadium phthalocyanine, tantalum phthalocyanine, molyftene phthalocyanine, manganese phthalocyanine, iron phthalocyanine, cohardphthalocyanine, ninkel phthalocyanine, Included are platinum phthalocyanine, palladium phthalocyanine, copper phthalocyanine, silver phthalocyanine, zinc phthalocyanine and tin phthalocyanine.

Among these, cobalt phthalocyanine and vanadium phthalocyanine are particularly preferred.

Derivatives of metal phthalocyanines are also frequently used, among which commercially available sulfonated derivatives such as cobalt phthalocyanine monosulfonate, cobalt phthalocyanine disulfonate or mixtures thereof are particularly preferred.

Sulfonated derivatives can be prepared, for example, by reacting cobalt, vanadium or other metal phthalocyanines with fuming sulfuric acid.

Although sulfonated derivatives are preferred, other derivatives may also be used.
In particular, carboxylated derivatives can also be used.

Incidentally, carboxylated derivatives can be easily prepared by reacting metal phthalocyanine with trichloroacetic acid.

The quaternary ammonium compound component of the catalyst composition according to the present invention is represented by the following structural formula.

Here, R is a hydrocarbon group having up to 20 carbon atoms selected from the group consisting of alkyl, cycloalkyl, aryl, alkaryl, and aralkyl, R1 is a substantially straight-chain alkyl group having 5 to 20 carbon atoms, and R2 is aryl. , alkaryl, and aralkyl, and X is an anion selected from halides.

Preferably R0 is an alkyl group having 12 to 18 carbon atoms, R2 is a benzyl group, and X is a chloride.

Accordingly, preferred quaternary ammonium compounds are quaternary ammonium chlorides, including penzyldimetheldodecyl ammonium chloride, benzyldimethyltetradecylammonium chloride, benzyldimethylhexadecyl ammonium chloride, penzyldimetheloctadecyl ammonium chloride, There are chlorides, etc.

Other suitable quaternary ammonium compounds include phenyldialkylpentelammonium chloride, phenyldialkylhexylammonium chloride, phenyldialkyl octelammmonium chloride, phenyldialkyldecylammonium chloride, phenyldialkyldodecyl ammonium chloride, phenyl dialkyltetradecylammonium chloride,
Phenyl dialkylhexadecyl ammonium chloride, phenyl dialkyl octadecyl ammonium chloride, phenyl dialkyl eicosyl ammonium chloride, naphther dialkyl pentel ammonium chloride, naphther dialkyl hexyl ammonium chloride, naphther dialkyl octela ammonium chloride, naphther dialkyl decylammonium Chloride, naphther dialkyl dodecyl ammonium chloride, naphther dialkyl tetradecyl ammonium chloride, naphthe/L/C7/l/ kylhexadecyl ammonium chloride, naphther dialkyl octadecyl ammonium chloride, penzyl dialkyl pentel ammonium chloride, penzyl dialkyl hexyl Ammonium chlorite, pendyl dialkyl octela ammonium chloride, pendyl dialkyl decylammonium chloride, pendyl dialkyl eicosyl ammonium chlorite, tolyl dialkyl pentel ammonium chlorite, tolyl dialkylhexylammonium chloride, tolyl dialkyl octela ammonium chloride, tolyl dialkyl Decyl ammonium? Chloride, tolyldialkyltetradecylammonium chloride, tolyldialkylhexadecyl ammonium chloride, tolyldialkyl octadecyl ammonium chloride, tolyldialkyl eicosyl ammonium chlorite, diphenylalkyl pentel ammonium chloride, siphenylalkylhexyl ammonium chloride, diphenyl alkyl octyl There are ammonium chloride, diphenylalkyldecyl ammonium chloride, diphenylalkyl dodecyl ammonium chloride, diphenyl alkyl tetradecyl ammonium chloride, diphenyl alkyl hexatecylammonium chloride, diphenyl alkyl octadecyl ammonium chloride, and diphenyl eicosyl ammonium chloride (however,
In the above, the alkyl group is selected from the group consisting of methyl, ethyl and probyl).

The preferred penzyl dimethel alkyl ammonium chloride is commercially available from Mason Chemical Company under the trade name Maquats.

However, this penzyldimethylalkylammonium chloride can also be prepared by the following method.

First, add ammonia and a carboxylic acid of C1 to CCl8 to about 50%
React by contacting with silica gel at 0 °C, C2~CtS
of nitrile.

The nitrile is then reduced with hydrogen by contacting it with Ninkel's catalyst at about 140°C.

C1 thus obtained.

The ~C18 amine is separated from the reaction mixture and reacted with a 2 molar excess of mether chloride.

After neutralizing the reaction mixture, the amine is further reacted with one molar equivalent of penzyl chloride to yield the desired penzyl dimethel alkyl ammonium chloride.

Mether chloride, including penzyl chloride, is preferably reacted with the amine in methanol solution at a temperature of about 150°C.

The product thus obtained can be used as is or after treatment with activated Teyacol to remove impurities.

As the solid adsorbent carrier used in the present invention, any known solid adsorbent material that is generally used as a catalyst carrier can be used.

Preferred adsorptive materials include Teyacols obtained by cracking distillation of wood, beets, lignite, nut shells, bones and other carbonaceous materials, which Teyacols are preferably heat treated and/or chemically treated. This creates a porous structure with a large adsorption capacity, and these are usually called activated carbon or activated Teyacol.

The adsorbent carrier of the present invention also includes naturally occurring clays and silicates, such as diatomaceous earth, Fuller's earth, Kieselguhr, Attapulga clay, Felsbar, montmorillonite,
Halloysite and kaolin are included, as well as alumina,
Included are naturally occurring or synthetic high temperature inorganic oxides such as silica, zirconia, doria and boria, as well as combinations of oxides such as silica alumina, silica zirconia and alumina zirconia.

Which solid adsorptive carrier to use is determined in consideration of stability under the conditions of use.

By the way, in the processing of the sour petroleum fraction mentioned above,
The solid adsorptive support must be insoluble in the petroleum fraction or otherwise inert under the alkaline reaction conditions of the processing zone.

In the latter case Teyacol is preferred, especially activated Teyacol.

This is because it has a high capacity for metallurgical cyanine and is stable under processing conditions.

The quaternary ammonium compound of the present invention, like a metal chelate type mercaptan oxidation catalyst, particularly a metal phthalocyanine, is easily adsorbed onto a solid adsorbent carrier.

The quaternary ammonium salt can constitute up to 50 wt% of the catalyst composition.

The sweetening process contemplated by the present invention allows the quaternary ammonium salt to account for 1 to 50 wt% of the catalyst composition, preferably 5 to 35 wt%.

Typically up to about 25 wtφ of metal phthalocyanine can be adsorbed onto the solid adsorption support and still form a stable catalyst composition.

Amounts as low as 0.1 to 10 wtφ generally provide suitably active catalyst compositions, usually 0.1 to 2. Owt
% is preferred.

Conventionally, it has been believed that the use of metal cap cyanine at a high concentration exceeding 2 wt% does not have any particular effect on catalyst activity.

However, in view of the considerable increase in activity obtained by using the quaternary ammonium salts of the present invention in combination with minimal concentrations of metal phthalocyanines, even higher concentrations are possible, especially in the case of difficult-to-process sour petroleum fractions. It is expected that the oxidation rate of mercabutane can be further accelerated.

The quaternary ammonium compound and the metal chelate component are impregnated into the solid adsorptive carrier in a conventional manner or by any other suitable method.

Furthermore, both of the above-mentioned components can be impregnated onto the carrier simultaneously from a common aqueous or alcoholic solution and/or dispersion, or they can be impregnated separately.

This impregnation is carried out in a conventional manner, in which spherical, pill-like, pellet-like or granular carrier particles of uniform or non-uniform size and shape are mixed with an aqueous or alcoholic impregnating solution and/or impregnating dispersion. Soak it in water, suspend it, dimp it once or more, or pickle it in a pot.
A predetermined amount of ammonium salt component and metal chelate component are adsorbed onto the carrier.

One preferred method uses a rotary dryer with a steam jacket.

In this method, the carrier is immersed in an impregnating solution and/or dispersion contained in a dryer, and the dryer is rotated to roll the carrier.

Evaporation of the liquid in contact with the carrier is promoted by supplying steam to the jacket of the dryer.

In any case, the resulting composition is dried at ambient temperature or at elevated temperature by any suitable means, such as in an oven or in a stream of hot gas.

A convenient alternative method for adsorbing aluminum compounds and metal chelate components onto a solid adsorptive support is to preload the sour petroleum distillate treatment zone with a fixed bed of support, and then load the ammonium compounds and metal chelate into this fixed bed. This is a method of obtaining a catalyst composition by flowing the impregnating solution and/or dispersion liquid contained therein.

In this method, the solution and/or dispersion described above can be circulated once or twice or more to adjust the ammonium salt and metal chelate component on the carrier to a desired concentration.

As a further alternative, the support can be pre-filled into the treatment zone, which is then filled with the impregnating solution and/or dispersion, and the support can be immersed for a predetermined period of time.

Sweetening processes for sour petroleum fractions have traditionally involved oxidizing mercaptans in the fraction in the presence of alkaline reagents.

The supported mercabutane oxidation catalyst is typically first saturated with an alkaline reagent, which is then mixed with the sour petroleum fraction and passed through the catalyst bed either continuously or intermittently.

In this case, any suitable alkaline reagent can be used.

Aqueous solutions of alkali metal hydroxides, for example sodium hydroxide hydroxide, are most commonly used.

This solution contains a solubilizing agent that enhances the solubility of mercabutane, such as an alcohol, especially methanol, ethanol, n
- Can contain propanol or isopropanol, as well as phenol and cresol.

A particularly preferred alkaline reagent is an aqueous caustic solution containing 2 to 30 wt% sodium hydroxide.

The solubilizing agent is preferably methanol, and the alkaline solution suitably contains 2 to 100 vol% of the solubilizing agent.

Sodium hydroxide} IJium hydroxide and potassium hydroxide are preferred alkaline reagents, but lithium hydroxide, rubidium hydroxide, cesium hydroxide, etc. may also be used as appropriate.

When the catalyst composition of the present invention contains a quaternary ammonium hydroxide component, petroleum fractions containing relatively easily oxidized mercabutane can be treated without the addition of alkaline reagents.

The sweetening process of the present invention can be carried out under conditions similar to conventional processing conditions.

That is, the process is typically performed at ambient temperature, although temperatures up to about 105° C. can be employed.

Although atmospheric pressure or substantially atmospheric pressure is originally suitable for the pressure,
It can be carried out at pressures up to 69 atmospheres.

Although a contact time corresponding to a liquid hourly space velocity of 0.5 to 10 is effective in reducing the mercaptan content in sour petroleum fractions as desired, the optimum contact time depends on the size of the treatment zone;
It depends on the amount of catalyst in the zone and the nature of the fraction being treated.

As mentioned above, in the sweetening process of sour petroleum fractions, mercabutane is oxidized to disulfide.

The process is therefore carried out in the presence of an oxidizing agent, which is preferably air, although oxygen or oxygen-containing gases other than air can also be used as oxidizing agent.

The sour petroleum fraction can pass upwardly or downwardly through the catalyst bed.

Although sour petroleum fractions contain significant amounts of entrained air, air is generally admixed with the sour petroleum fraction and fed co-currently to the processing zone.

It may be advantageous if the air and the petroleum fraction are fed separately to the treatment zone, with countercurrent flow between the two.

The catalyst compositions of the present invention are active and stable.

Accordingly, the composition can be used as a fixed bed in the treatment of large volumes of sour petroleum fractions, especially petroleum fractions containing mercabutane, which is difficult to oxidize.

As mentioned above, the quaternary ammonium compound and metal phthalocyanine component of the catalyst composition according to the present invention are easily adsorbed on the solid adsorbent carrier.

Therefore, the quaternary ammonium salt or metal phthalocyanine component that sooner or later leaches from the carrier and is carried away into the reaction stream,
For example, one or both of the components can be mixed with an alkaline reagent and flowed into the processing zone for easy replenishment.

The following examples are preferred specific examples of the present invention, and are not intended to unduly limit the technical scope of the present invention.

Example Deionized water in rotary steam evaporator 2
An impregnating solution was prepared by adding 0.75 g of cobalt phthalocyanine monosulfone and 23.5 g of a 50% alcohol solution of dimetherbenzylalkylammonium chloride into 50 ml of the solution.

The nopenzyldimethylalkyl ammonium chloride includes penzyldimetheldodecyl ammonium chloride (61%), benzyldimethyltetradecylammonium chloride (23%), benzyldimethylhexadecyl ammonium chloride (11%) and penzyldimethel Consists of octadecyl ammonium chloride.

250 cc of activated charcoal grains of 10×30 mensch were immersed in the impregnating solution, and the evaporator was rotated to tumble the Teyacol grains for 1 hour.

Thereafter, the stem was fed to the Jaquent evaporator, and the impregnated liquid was evaporated to dryness while being in contact with the rolling charcoal grains for over 1 hour.

The catalyst composition thus prepared (hereinafter referred to as catalyst A) was subjected to a comparative test with a standard catalyst.

This standard catalyst (hereinafter referred to as Catalyst B) was prepared in the same manner as described above, except that the penzyldimethelalkylammonium chloride component was not used.

A comparative test was carried out by flowing sour kerosene over 100 cc of catalyst contained as a fixed bed in a vertical tubular reactor.

Kerosene was supplied at LHSV = 0.5 under an air pressure of 364 atm, and the amount of air under these conditions was approximately 1.5 times the stoichiometric amount of oxygen required to oxidize mercaptans in kerosene. do.

Each comparative test first wetted the catalyst bed with 10 cc of 8% aqueous sodium hydroxide solution, then added 10 cc of the aqueous solution to
It was mixed with the feed kerosene and fed to the catalyst bed at 2 hour intervals.

The mercaptan sulfur of the treated kerosene was analyzed periodically.

Note that the kerosene before treatment contained 533 ppm of mercaptan sulfur.

A curve was obtained by plotting the mercaptan sulfur content of the treated kerosene against the through time, which yielded the data shown in the following table.

Claims (1)

[Scope of Claims] 1 Consisting of a metal chelate type mercaptan oxidation catalyst impregnated in a solid adsorptive carrier and a quaternary ammonium ride, the quaternary ammonium ride has the structural formula (wherein R is an alkyl a hydrocarbon group selected from a group, a cycloalkyl group, an aryl group, an alkaryl group, and an aralkyl group and having up to 20 carbon atoms, R is a substantially straight-chain alkyl group having 5 to 20 carbon atoms, and R2 is an aryl group. aralkyl group, alkaryl group, and aralkyl group, and X is an anion selected from halogenide. 2 Quaternary ammonium...ride is 1~ of the catalyst composition
A catalyst composition according to claim 1 comprising 50 wt%. 3 Quaternary ammonium...ride is 5~ of the catalyst composition
Catalyst composition according to claim 1 or 2, comprising 35 wt%. 4. A catalyst composition according to any one of claims 1 to 3, wherein 4R, is a substantially straight-chain alkyl group containing 12 to 18 carbon atoms. 5. The catalyst composition according to any one of claims 1 to 4, wherein R2 is a benzyl group. 6. The catalyst composition according to claim 1, wherein the quaternary ammonium chloride is quaternary ammonium chloride. 7 Claims in which the quaternary ammonium chloride is selected from the group consisting of penzyldimeterdodecylammonium chloride, penzyldimetertetradecylammonium chloride, penzylcymeterhexadecyl ammonium chloride, and penzyldimeteloctadecyl ammonium chloride. 7. Catalyst composition according to item 6. 8. The catalyst composition according to any one of claims 1 to 7, wherein the solid adsorptive carrier is activated Teyacol. 9. Claims 1 to 8, wherein the metal chelate type mercaptan oxidation catalyst is a metal phthalocyanine.
Catalyst composition as described in . 10. The catalyst composition according to any one of claims 1 to 9, wherein the 10 metal chelate type mercabutane oxidation catalyst accounts for 0.1 to 10 wt% of the catalyst composition. 11. The catalyst composition according to any one of claims 1 to 10, wherein the metal chelate type mercaptan oxidation catalyst accounts for 0.1 to 2 wt% of the catalyst composition. 12. The catalyst composition according to claim 1, wherein the 12 metal chelate type mercaptan oxidation catalyst is vanadium phthalocyanine. The catalyst composition according to any one of claims 1 to 11, wherein the 13 metal chelate type mercabutane oxidation catalyst is cobalt phthalocyanine. 14. The catalyst composition according to claim 13, wherein the 14 metal chelate type mercabutane oxidation catalyst is cobalt phthalocyanine monosulfonate.