JP2006104270A - Method for producing organosulfur oxide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an organosulfur oxide in a manner excellent in workability and operability, low in cost, and excellent in mass productivity and production output, in which an organosulfur compound such as a dibenzothiophene is selectively oxidized into a polar organosulfur oxide such as a sulfoxide or sulfone derivative within a short time, and the organosulfur compound is effectively separated from a hydrocarbon oil to produce the desired useful organosulfur oxide in a high purity and a high recovery rate. <P>SOLUTION: The method comprises the step of treating a mixture containing a hydrocarbon oil, a solvent, and an oxidizing agent under supercritical or subcritical high-temperature and high-pressure conditions of the organic solvent to dissolve an organosulfur oxide obtained by oxidizing an organosulfur compound contained in the hydrocarbon oil in the solvent, the step of separating the sulfur-containing solvent in which the organosulfur oxide is dissolved from the hydrocarbon oil, and the sulfur oxide recovery step of purifying and recovering the organosulfur oxide dissolved in the sulfur-containing solvent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic sulfur oxide production method for producing organic sulfur oxides such as dibenzothiophene sulfone useful as raw materials for pharmaceuticals, agricultural chemicals, synthetic resin products, electronic products, etc. from hydrocarbon oils containing organic sulfur compounds. Is.

  Hydrocarbon oils obtained from petroleum, oil sands, oil shale, coal, etc. contain various organic sulfur compounds. For example, organic sulfur compounds contained in diesel oil used as diesel fuel oil are released into the environment as SOx by combustion exhaust gas, causing environmental pollution and becoming a catalyst poison of exhaust gas treatment equipment using a platinum catalyst, Various techniques for reducing organic sulfur compounds contained in hydrocarbon oils have been studied.

On the other hand, organic sulfur compounds contained in hydrocarbon oils are attracting attention as valuable industrial raw materials for producing pharmaceuticals, agricultural chemicals, synthetic resin products, electronic products and the like. For example, benzothiophene, dibenzothiophene derivatives and the like have the potential as useful industrial raw materials. If these are produced from inorganic sulfur, a complicated production process and a great production cost are required. Therefore, a technique for separating and recovering an organic sulfur compound contained in hydrocarbon oil has been studied.
However, dibenzothiophenes contain alkyl-substituted dibenzothiophenes having a substituent such as an alkyl group around the sulfur atom, and the substituent becomes a steric hindrance and the catalytic reaction active site is located on the sulfur atom located in the back of the planar structure. Is a compound that is chemically stable and difficult to hydrodesulfurize, and is extremely difficult to separate and recover from hydrocarbon oil.
Therefore, various techniques for producing dibenzothiophenes from hydrocarbon oil have been studied.

For example, (Patent Document 1) states that “a liquid oil containing an organic sulfur compound is reacted with an oxidizing agent while stirring in a temperature range of 0 to 100 ° C., and after the reaction, distillation, adsorption, etc. are performed from the oil containing the oxidation reaction product. In which the oxidized organic sulfur compound is recovered from the liquid oil.
(Patent Document 2) “After adding a solvent having a high solubility in an organic sulfur compound to light oil or the like and mixing the organic sulfur compound into the solvent, the solvent containing the organic sulfur compound is separated, and then the solvent In which an organic sulfur compound is recovered as an evaporation residue is disclosed.
(Patent Document 3) describes a method for oxidative desulfurization of fuel oil in which a fuel oil containing a sulfur compound is treated with an oxidizing agent in the presence of a polar organic solvent and a transition metal catalyst at a reaction temperature of −100 to 120 ° C. Is disclosed.
Japanese Patent Laid-Open No. 5-286869 Japanese Patent Laid-Open No. 7-197036 JP 2001-354978 A

However, the above conventional techniques have the following problems.
(1) In the technique disclosed in (Patent Document 1), the organic sulfur compounds to be recovered are benzothiophene and dibenzothiophene derivatives. However, there is a problem that the recovery rate of dibenzothiophene derivatives that are particularly useful and have high added value is low. Was.
(2) The technique disclosed in (Patent Document 2) can recover the dissolved organic sulfur compound by evaporating the solvent after dissolving the organic sulfur compound in the solvent in a relatively short time. Since the oxidation is insufficient, there is a problem that organic sulfur oxides such as dibenzothiophene sulfone which is industrially particularly useful and has high added value cannot be efficiently recovered.
(3) Since the techniques disclosed in (Patent Document 1) to (Patent Document 3) are all reacted under normal pressure, the reaction temperature is the boiling point of the solvent (about 66 ° C. in the case of methanol, about 82 in the case of acetonitrile). C.), the reactivity is poor, a long reaction time is required, and the productivity is extremely low.

  The present invention solves the above-mentioned conventional problems, and selectively converts organic sulfur compounds such as dibenzothiophenes that have been difficult to recover in a short time to organic sulfur oxides of polar compounds such as sulfoxides and sulfone derivatives. Oxidation over time and efficient separation of organic sulfur compounds from hydrocarbon oils enables production of desired useful organic sulfur oxides with high purity and high recovery rate, excellent workability and operability, low cost and mass productivity Another object of the present invention is to provide a method for producing an organic sulfur oxide which is excellent in productivity and further reduces the load of a hydrocarbon oil desulfurization process.

In order to solve the above conventional problems, the method for producing an organic sulfur oxide of the present invention has the following configuration.
In the method for producing an organic sulfur oxide according to claim 1 of the present invention, a mixed liquid containing a hydrocarbon oil, a solvent and an oxidizing agent is treated under high temperature and high pressure in a supercritical state or a subcritical state of the solvent. A critical treatment step for eluting the organic sulfur oxide obtained by oxidizing the organic sulfur compound contained in the hydrocarbon oil into the solvent, and a solvent for separating the sulfur-containing solvent from which the organic sulfur oxide is eluted from the hydrocarbon oil A separation step and a sulfur oxide recovery step for purifying and recovering the organic sulfur oxide eluted in the sulfur-containing solvent.
With this configuration, the following effects can be obtained.
(1) Since the liquid mixture containing hydrocarbon oil, solvent and oxidant is treated with a solvent having a boiling point or higher in the supercritical state or subcritical state of the solvent, this is contrary to the hydrogenation reaction. The relative reactivity of dibenzothiophenes increases, and dibenzothiophenes can be oxidized to organic sulfur oxides of polar compounds such as sulfoxides and sulfone derivatives in a short time and transferred from hydrocarbon oil to solvent. As a result, the organic sulfur compound can be efficiently separated from the hydrocarbon oil, and the recovery rate of organic sulfur oxides such as dibenzothiophene sulfone can be increased.
(2) Since the oxidized organic sulfur compound can be easily eluted in the solvent, after separating the sulfur-containing solvent in the solvent separation step, the organic sulfur oxide is efficiently obtained by purifying the sulfur-containing solvent. It can be recovered and manufactured.
(3) The hydrocarbon oil separated from the sulfur-containing solvent in the solvent separation step has a low sulfur concentration by removing organic sulfur compounds, and dibenzothiophenes that are particularly difficult to hydrodesulfurize are removed. If hydrogen oil is hydrodesulfurized, low sulfur concentration oil or sulfur-free oil can be easily obtained.
(4) Since the mixed solution is processed under high temperature and high pressure in the subcritical or supercritical state of the solvent in the critical treatment step, the aromatic ring such as dibenzothiophene sulfone whose alkyl group is substituted on the aromatic ring is promoted significantly. It can be oxidized and the organic sulfur oxide recovered in the sulfur oxide recovery step can be easily purified.

Here, as the hydrocarbon oil, oils derived from organic fossil resources such as petroleum, coal, oil sand, oil shale, and orimulsion are used. Specifically, distillation products consisting of specific fractions such as gasoline, kerosene, light oil, and heavy oil, and crude oil resources, coal tar, liquefied oil, and other coal resources, oil sands, oil shale, and oil Coal-like resource oils such as extracts from oil, heavy oils, super heavy oils, refined oils and the like are used.
In particular, light gas oil, heavy gas oil obtained by fractionating petroleum resource oils, etc. using an atmospheric distillation unit, gas oil fraction obtained by fractionating an atmospheric residue of an atmospheric distillation unit using a vacuum distillation unit, and heavy oil A Etc. are suitable. This is because the organic sulfur compound contains a large amount of benzothiophene and polybenzothiophene.
Among these, a fraction of 230 to 360 ° C. distilled at normal pressure is preferably used. This is because organic sulfur compounds such as thiol and cyclic sulfide are removed as a light fraction and the content of benzothiophene and polybenzothiophenes is high. As the distillation temperature drops below 230 ° C, the content of thiols, cyclic sulfides, etc. increases, and the purity of dibenzothiophene sulfone, which is produced by critical processing, tends to decrease, and as it rises above 360 ° C. Since the content of metal compounds such as vanadium and nickel increases and the purity of dibenzothiophene sulfone produced by the critical treatment tends to decrease, neither is preferable.
It is preferable to use a hydrocarbon oil after atmospheric distillation and before hydrodesulfurization. This is because the hydrodesulfurization reduces the concentration of the organic sulfur compound that is the raw material for the organic sulfur oxide, and thus the productivity is reduced. In addition, it is possible to reduce the hard-to-decompose substances in hydrodesulfurization in the critical treatment step, and to improve the desulfurization efficiency of hydrodesulfurization by hydrodesulfurizing the critically treated hydrocarbon oil. .

Examples of the organic sulfur compound include compounds such as thiols and thioethers containing a sulfur atom in the carbon chain constituting the aliphatic hydrocarbon, and groups containing a sulfur atom in the carbon chain as a substituent of the aromatic hydrocarbon. Examples thereof include compounds such as thiophenols and thioanisoles, and heterocyclic compounds such as thiophenes, benzothiophenes, and dibenzothiophenes containing a sulfur atom in the skeleton.
Examples of the compound contained in the dibenzothiophenes include dibenzothiophene, alkylated derivatives such as dibenzothiophene monoalkylated or dialkylated compounds, and compounds having a dibenzothiophene skeleton in the molecule.

  As the solvent, a polar solvent that has low solubility in hydrocarbon oil and that extracts the organic sulfur compound and its oxidation product contained in the hydrogenated refined oil is used. Specifically, acetonitrile, propionitrile, butyronitrile, valeronitrile, acetic acid, propionic acid, butyric acid, formic acid, peracid, methanol, ethanol, butanol, 2-butanone, acetylacetone, nitromethane, nitroethane, nitropropane, N, N Pyrrolidone such as' -dimethylformamide, N, N'-dimethylacetamide, trimethyl phosphate ester, triethyl phosphate ester, hexamethyl phosphate amide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolide Imidazolidinones such as non, pyrimidinones such as 1,3-dimethyl-3,4,5,6-tetrahydro-2-pyrimidinone, trimethylpyridium hydrobromide, 1,2,4,6-tetramethylpyridinium iodide, etc. One kind of pyridium salt Alternatively, multiple types can be used.

As the solvent, it is preferable to use a solvent having a mutual solubility in the range of 0.1 to 5% with respect to the hydrocarbon oil. This is because the extraction of the organic sulfur compound from the hydrocarbon oil in the critical treatment step and the separation of the sulfur-containing solvent and the hydrocarbon oil in the solvent separation step can be made compatible, and both workability can be improved. .
Here, as the mutual solubility of the solvent in the hydrocarbon oil becomes smaller than 0.1%, the extraction efficiency of the organic sulfur compound from the hydrocarbon oil tends to decrease in the critical treatment step, and the mutual solubility is more than 5%. Accordingly, since the separation efficiency of the sulfur-containing solvent and the hydrocarbon oil tends to decrease in the solvent separation step, neither is preferable.
As such a solvent, for example, alcohols such as methanol are preferably used. This is because it is excellent in separability from hydrocarbon oil, and does not exhibit strong corrosivity, so that it is easy to handle, and the solubility of organic sulfur compounds and organic sulfur oxides is high.

  In the mixed liquid containing the hydrocarbon oil, the solvent and the oxidizing agent, the amount of the hydrocarbon oil relative to the solvent is 0.1 to 2.5 times, preferably 0.3 to 2 times the amount of the hydrocarbon oil. 0.5 to 1.5 times is preferably used. As the amount of hydrocarbon oil with respect to the solvent becomes less than 0.5 times, the migration rate of the sulfur component into the solvent increases. However, the amount of solvent increases, so the man-hours are required for the concentration operation in the sulfur oxide recovery process. There is a tendency for productivity to decrease, and as the amount increases more than 1.5 times, the amount of solvent decreases, so the sulfur concentration of the sulfur-containing solvent can be increased, and the number of steps in the sulfur oxide recovery process can be reduced. There is a tendency that the transfer rate of the sulfur component into the solvent decreases and the recovery efficiency decreases. In addition, this tendency becomes remarkable as the amount of hydrocarbon oil with respect to the solvent is less than 0.3 times, and as it becomes more than twice, 4-methyldibenzothiophene sulfone (hereinafter referred to as 4-methyl DBTS) useful as an organic EL material. ) And 4,6-dimethyldibenzothiophene sulfone (hereinafter referred to as 4,6-dimethyl DBTS) and the like, the migration rate of other organic sulfur-substituted organic sulfur oxides increases or is not oxidized. There is a tendency for the organic sulfur compounds to increase. In particular, if it is less than 0.1 times or more than 2.5 times, these tendencies become remarkable, which is not preferable.

  Oxidizing agents include oxygen gas, air, nitrogen dioxide, ozone gas, nitric acid, organic hydroperoxides such as t-butyl hydroperoxide, sodium metaperiodate, potassium dichromate, potassium permanganate, anhydrous chromic acid, hypochlorous acid. Chloric acid, hydrogen peroxide, peracetic acid, a mixture of hydrogen peroxide and acetic acid, formic acid, a mixture of hydrogen peroxide and formic acid, metachloroperbenzoic acid, a mixture of hydrogen peroxide and metachlorobenzoic acid, perchloroacetic acid , Hydrogen peroxide water and chloroacetic acid mixture, perdichloroacetic acid, hydrogen peroxide water and dichloroacetic acid mixture, pertrichloroacetic acid, hydrogen peroxide water and trichloroacetic acid mixture, pertrifluoroacetic acid, hydrogen peroxide water and trifluoroacetic acid Mixtures of permethanesulfonic acid, hydrogen peroxide water and methanesulfonic acid, persulfuric acid, hydrogen peroxide water and sulfuric acid mixture One or more of is used. Of these, hydrogen peroxide is preferably used. This is because it is easy to obtain and has little corrosiveness, irritation and the like, and even if it is further decomposed, only water and oxygen remain, and it is easy to handle.

  The addition amount of the oxidizing agent is 3 to 100 times mol, preferably 10 to 100 times mol, with respect to the sulfur content contained in the hydrocarbon oil. As the amount of oxidant added is less than 10 times the mole of sulfur, the amount of oxidant is small and the collision probability is reduced, and there is a tendency that unoxidized organic sulfur compounds tend to remain in the hydrocarbon oil. If the amount is less than double moles, this tendency becomes remarkable, which is not preferable. As the amount exceeds 100 times the molar amount, the amount of oxidizing agent increases and the running cost increases, and the internal pressure in the reactor used in the critical treatment step tends to increase and an excessive load tends to be applied to the reactor.

  The oxidizing agent is preferably added to the mixed atmosphere in which the temperature and pressure in the reactor are stable and the stable supercritical state or subcritical state is obtained. This is to prevent the oxidizing agent from being decomposed before contributing to the oxidation reaction of the organic sulfur compound.

The supercritical state in the critical treatment step refers to a state where the temperature in the reaction system is higher than the critical temperature of the solvent and the pressure is higher than the critical pressure of the solvent. The subcritical state refers to a state where the temperature in the reaction system is equal to or higher than the boiling point of the solvent and the pressure is equal to or higher than the vapor pressure of the solvent (excluding a critical state higher than the critical temperature of the solvent and higher than the critical pressure). . Therefore, the temperature in the reaction system is 150 to 500 ° C. and the pressure is in the range of 1 to 30 MPa, preferably the temperature is 180 to 300 ° C. and the pressure is in the range of 1 to 30 MPa, more preferably the temperature is 180 to 230 ° C. and the pressure is In the range of 2-10 Pa, it can select suitably according to a solvent. This facilitates dissociation of substituents such as alkyl groups substituted with dibenzothiophenes to promote decomposition, and also increases the elution rate from hydrocarbon oil to the solvent and shortens the reaction time for critical processing. Can increase the sex.
Here, as the pressure becomes lower than 2 MPa or the temperature becomes lower than 180 ° C., the rate of migration of the organic sulfur compound to the solvent tends to decrease, and the pressure becomes higher than 30 MPa or the temperature becomes lower than 230 ° C. As it becomes higher, the migration rate of the organic sulfur compound to the solvent tends to decrease, the running cost increases, and the pressure increases, so that a lot of safety measures are required. As the pressure rises above 30 MPa or the temperature rises above 300 ° C., the solvent or hydrocarbon oil after the critical treatment tends to become brown and the hydrocarbon oil or solvent tends to be altered, and the oxidant is easily decomposed before the reaction. There is a tendency to become. In particular, when the pressure is lower than 1 MPa or the temperature is higher than 500 ° C., these tendencies tend to become remarkable, so that neither is preferable.
In the critical treatment step, those that treat the mixed solution in a subcritical state are preferably used. Since the temperature and pressure are lower than in the supercritical state, the energy saving property is excellent, and the heating temperature is low, so that the oxidation of organic sulfur compounds such as 4,6-dimethyldibenzothiophene is selectively promoted. This is because the production of dimethyl DBTS and the like is accelerated.

  The reaction time for the critical treatment can be appropriately selected within the range of 1 second to 2 hours, preferably 1 minute to 30 minutes, depending on the reaction conditions. As the reaction time becomes shorter than 1 minute, the unreacted organic sulfur compound tends to decrease and the recovery rate tends to decrease, and as the reaction time becomes longer than 30 minutes, the running cost of making the mixed solution at a high temperature and high pressure in the reaction system increases. The reaction time tends to be long, so that the productivity tends to decrease. In particular, as the time becomes shorter than 1 second or longer than 2 hours, these tendencies become remarkable, so that neither is preferable.

  The type of the reactor for critically processing the mixed liquid is not particularly defined, but various types of reactors such as a batch reactor, a continuous tank reactor, a piston flow reactor, a tower reactor, etc. A reactor can be used.

In the liquid mixture for critical treatment, tungsten compounds such as phosphotungstic acid, tungsten oxide, tungsten chloride, vanadium oxide, vanadium oxide acetylacetone complex, vanadium compounds such as vanadium chloride, molybdenum oxide, molybdenum oxide acetylacetone complex, phosphomolybdic acid, etc. It is also possible to add a transition metal catalyst such as a molybdenum compound. This is because the transition metal catalyst acts on the solvent to promote the oxidation of the organic sulfur compound. Of these, phosphotungstic acid is preferably used. This is because, as a result of experiments, it was found that the recovery rate of 4-methyl DBTS and 4,6-dimethyl DBTS was extremely high.
The transition metal catalyst added to the mixed solution is left in the residue using a means such as distillation under reduced pressure or normal pressure in the case of phosphotungstic acid or the like, and in the case of vanadium oxide or the like, sedimentation separation or filtration separation, etc. It is possible to separate them using the following means.

In the solvent separation step, as a means for separating the sulfur-containing solvent and the hydrocarbon oil, liquid separation operations such as centrifugation and sedimentation, filtration operations, and the like are used. This is because, since a polar solvent such as acetonitrile is used as the solvent, the solubility in the hydrocarbon oil is small and the solvent can be easily separated by liquid separation or filtration.
Moreover, by cooling the liquid mixture of a sulfur containing solvent and hydrocarbon oil, hydrocarbon oil can be aggregated and a sulfur containing solvent can also be isolate | separated.

In the sulfur oxide recovery step, the organic sulfur oxide eluted in the sulfur-containing solvent can be purified using an adsorption operation. As the adsorbent, one or more kinds of inorganic adsorbents such as zeolite, clay mineral, activated clay, silica gel, alumina, magnesia, titania, carbon and activated carbon, and organic adsorbents such as polymers can be used.
Organic sulfur oxides adsorbed on these adsorbents are extracted using extractants such as acetonitrile, methanol, ethanol, propanol, butanol, acetone, hexane, heptane, octane, nonane, decane, dimethyl sulfoxide, dimethylformamide, sulfolane, etc. Can be recovered. A mixture of these extractants with water can also be used.

Invention of Claim 2 of this invention is a manufacturing method of the organic sulfur oxide of Claim 1, Comprising: The said hydrocarbon oil from which the said sulfur containing solvent was isolate | separated in the said solvent separation process is mixed with a solvent. Then, an elution treatment step for eluting the residual organic sulfur oxide remaining in the hydrocarbon oil into the solvent, and a second solvent for separating the residual sulfur-containing solvent from which the residual organic sulfur oxide eluted from the hydrocarbon oil A separation step and a second sulfur oxide recovery step for purifying and recovering the residual organic sulfur oxide eluted in the residual sulfur-containing solvent.
With this configuration, in addition to the operation obtained in the first aspect, the following operation can be obtained.
(1) An elution treatment step for eluting residual organic sulfur oxide remaining in hydrocarbon oil into a solvent, a second solvent separation step for separating residual sulfur-containing solvent from hydrocarbon oil, and a residue eluted in residual sulfur-containing solvent A second sulfur oxide recovery step for refining and recovering the organic sulfur oxide, so that residual organic sulfur oxide oxidized in the critical treatment step and remaining in the hydrocarbon oil can also be recovered. % Or higher recovery rate can be obtained.

  Here, in the elution treatment process, the solvent and hydrocarbon oil increase the area of the interface between the solvent and hydrocarbon oil by operations such as heating, stirring, vibration, diffusion, flow channel mixing, and centrifugal force application. Elution efficiency can be increased. Specific examples include spray towers, packed towers, baffle towers, perforated plate extraction towers, orifice towers, injectors, non-powered extraction devices such as flow mixers such as static mixers, mixer-settler extraction devices, Seibel towers, rotating disk extractions Stirring extraction devices such as towers, Mixco towers, Graesser towers, louver extractors, Kuni towers, pulsating / vibrating extraction devices such as pulsation packed towers, pulsating perforated plate towers, diaphragm towers, Podovirniak extractors, luwesta extractors A power extraction device such as a centrifugal extraction device can be used.

  As the temperature and pressure of the solvent and hydrocarbon oil in the elution treatment step, it is preferable that the temperature is lower than the boiling point of the solvent and the pressure is lower than the vapor pressure of the solvent. Specifically, it is preferable that the temperature is 0 to 50 ° C. and the pressure is 0.1 to 1 MPa. The elution treatment step is not a treatment aimed at oxidation (sulfonation) as in the critical treatment step, but is intended to elute and recover the organic sulfur oxides already oxidized in the critical treatment step. This is because the organic sulfur oxide can be eluted into the solvent by contacting and mixing the hydrocarbon oil and the solvent under normal temperature and normal pressure conditions.

  The amount of the hydrocarbon oil relative to the solvent in the elution treatment step is preferably 0.1 to 2.5 times the amount of the hydrocarbon oil. As the amount of the hydrocarbon oil with respect to the solvent becomes less than 0.1 times, the amount of the solvent increases, so that a man-hour is required for the concentration operation in the second sulfur oxide recovery step, and the productivity tends to decrease. Since the migration rate of sulfur oxides into the solvent decreases and the recovery efficiency tends to decrease as the number increases more than 5 times, neither is preferable.

Invention of Claim 3 of this invention is a manufacturing method of the organic sulfur oxide of Claim 1 or 2, Comprising: The said solvent is 1 type or 2 selected from alcohol, such as methanol and ethanol It has a configuration that is more than seeds.
With this configuration, in addition to the operation obtained in the first or second aspect, the following operation can be obtained.
(1) Alcohols such as methanol and ethanol are excellent in separability from hydrocarbon oils, have excellent handling properties because they do not exhibit strong corrosiveness, and have high solubility of organic sulfur compounds and organic sulfur oxides. Recovery efficiency can be obtained.

  Here, as alcohols, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, isobutyl alcohol, 2-butanol, t-butanol, allyl alcohol and the like are used. Among these, monohydric alcohols having 1 to 24 carbon atoms in the aliphatic group are preferably used because they are not easily decomposed even in a high-temperature and high-pressure critical processing state. As the carbon number increases, the critical temperature rises, and the rate of migration of organic sulfur compounds to the solvent tends to decrease, and the solvent and hydrocarbon oil after the critical treatment turn brown and the hydrocarbon oil and solvent change. This is because it tends to be easier. These alcohols can be used alone or as a mixture of two or more.

As described above, according to the method for producing an organic sulfur oxide of the present invention, the following advantageous effects can be obtained.
According to the invention of claim 1,
(1) Organic sulfur compounds such as dibenzothiophenes can be oxidized to polar organic sulfur oxides such as sulfoxides and sulfone derivatives in a short time and transferred from hydrocarbon oil to solvent. As a result, organic sulfur The compound can be efficiently separated from the hydrocarbon oil, and the recovery rate of organic sulfur oxides such as dibenzothiophene sulfone can be increased, and a method for producing organic sulfur oxides excellent in productivity can be provided.
(2) Since the oxidized organic sulfur compound can be easily eluted in the solvent, after separating the sulfur-containing solvent in the solvent separation step, the organic sulfur oxide is efficiently obtained by purifying the sulfur-containing solvent. The manufacturing method of the organic sulfur oxide excellent in the operativity which can be collect | recovered and manufactured can be provided.
(3) The hydrocarbon oil separated from the sulfur-containing solvent in the solvent separation step has a low sulfur concentration by removing organic sulfur compounds, and dibenzothiophenes that are particularly difficult to hydrodesulfurize are removed. By hydrodesulfurizing hydrogen oil, it is possible to provide a method for producing an organic sulfur oxide that can easily obtain a low sulfur concentration oil or sulfur-free oil having a sulfur content of about 10 ppm or less as a by-product.
(4) Since the mixed solution is processed under high temperature and high pressure in the subcritical or supercritical state of the solvent in the critical treatment step, the aromatic ring such as dibenzothiophene sulfone whose alkyl group is substituted on the aromatic ring is promoted significantly. The manufacturing method of the organic sulfur oxide which can oxidize and can make it easy to refine | purify the organic sulfur oxide collect | recovered in the sulfur oxide collection | recovery process can be provided.

According to invention of Claim 2, in addition to the effect of Claim 1,
(1) Provided is a method for producing an organic sulfur oxide capable of recovering a residual organic sulfur oxide which is oxidized in a critical treatment step and remains in a hydrocarbon oil, and can obtain a high recovery rate of 90% or more. be able to.

According to invention of Claim 3, in addition to the effect of Claim 1 or 2,
(1) Alcohols such as methanol and ethanol are excellent in separability from hydrocarbon oils, have excellent handling properties because they do not exhibit strong corrosiveness, and have high solubility of organic sulfur compounds and organic sulfur oxides. The manufacturing method of the organic sulfur oxide which can acquire collection | recovery efficiency can be provided.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a flowchart showing a method for producing an organic sulfur oxide in the first embodiment.
Hereinafter, a method for producing an organic sulfur oxide will be described with reference to the drawings.
In a critical treatment process, a predetermined amount of phosphotungsten is added to a mixture of a light gas oil containing an organic sulfur compound such as dibenzothiophene or a hydrocarbon oil such as heavy gas oil and a predetermined amount of a solvent such as methanol or ethanol. A transition metal catalyst such as an acid is added and introduced into a reactor such as a batch reactor, and the reactor is heated to a high temperature and a high pressure to bring the solvent into a supercritical or subcritical state. When the temperature and pressure in the reactor are stabilized, a predetermined amount of an oxidizing agent such as aqueous hydrogen peroxide is injected into the reactor and a critical treatment is performed for a reaction time of 1 second to 2 hours, preferably 1 to 30 minutes. The organic sulfur oxide obtained by oxidizing the organic sulfur compound contained in the hydrocarbon oil is eluted in the solvent (S1).
Next, in the solvent separation step, the sulfur-containing solvent from which the organic sulfur oxide is eluted is separated from the hydrocarbon oil by using a liquid separation operation such as centrifugation or sedimentation (S2).
In the sulfur oxide recovery process, the sulfur-containing solvent from which hydrocarbon oil has been separated is used as an inorganic adsorbent such as zeolite, clay mineral, activated clay, silica gel, alumina, magnesia, titania, carbon, activated carbon, and organic adsorbent such as polymer. Organic sulfur oxides such as sulfoxides and sulfone derivatives adsorbed on these adsorbents are adsorbed and purified using one or more of these, etc., using an extractant such as methanol or ethanol. Extract and collect (S3) to obtain an organic sulfur oxide.
On the other hand, the hydrocarbon oil separated from the sulfur-containing solvent is mixed with a solvent such as methanol or ethanol in the elution process, and is subjected to operations such as heating, stirring, vibration, diffusion, flow channel mixing, and addition of centrifugal force. The residual organic sulfur oxide remaining in the hydrocarbon oil is eluted in the solvent (S4).
Next, in the second solvent separation step, the residual sulfur-containing solvent from which the residual organic sulfur oxide is eluted is separated from the hydrocarbon oil by using a liquid separation operation such as centrifugation or sedimentation (S5).
Next, in the second sulfur oxide recovery step, the residual organic sulfur oxide eluted in the residual sulfur-containing solvent is adsorbed and purified using one or more of inorganic adsorbents, organic adsorbents, etc. Organic sulfur oxides such as sulfoxide and sulfone derivatives adsorbed on the adsorbent are extracted and recovered using an extractant such as methanol and ethanol (S6) to obtain organic sulfur oxides.
The hydrocarbon oil separated from the residual sulfur-containing solvent can be used as a raw material for fuel oil, lubricating oil, and the like.

According to the method for producing an organic sulfur oxide in the first embodiment as described above, the following operation is obtained.
(1) Since the liquid mixture containing hydrocarbon oil, solvent and oxidant is treated with a solvent having a boiling point or higher in the supercritical state or subcritical state of the solvent, this is contrary to the hydrogenation reaction. The relative reactivity of dibenzothiophenes increases, and dibenzothiophenes can be oxidized to organic sulfur oxides of polar compounds such as sulfoxides and sulfone derivatives in a short time and transferred from hydrocarbon oil to solvent. As a result, the organic sulfur compound can be efficiently separated from the hydrocarbon oil, and the recovery rate of the organic sulfur oxide can be increased.
(2) Since the oxidized organic sulfur compound can be easily eluted in the solvent, after separating the sulfur-containing solvent in the solvent separation step, the organic sulfur oxide is efficiently obtained by purifying the sulfur-containing solvent. It can be recovered and manufactured.
(3) Since the mixed solution is treated under high temperature and high pressure in a subcritical or supercritical state of the solvent in the critical treatment step, an aromatic ring such as dibenzothiophene sulfone whose alkyl ring is substituted on the aromatic ring is significantly accelerated. It can be oxidized and the organic sulfur oxide recovered in the sulfur oxide recovery step can be easily purified.
(4) Since an oxidizing agent is added to the liquid mixture, an organic sulfur compound such as dibenzothiophenes contained in the hydrocarbon oil is selectively oxidized to be oxidized into a polar compound such as a sulfoxide or a sulfone derivative, The recovery efficiency of organic sulfur oxides such as dibenzothiophene sulfone from hydrocarbon oil can be increased.
(5) An elution treatment step for eluting residual organic sulfur oxide remaining in hydrocarbon oil into the solvent, a second solvent separation step for separating the residual sulfur-containing solvent from the hydrocarbon oil, and a residue eluted in the residual sulfur-containing solvent A second sulfur oxide recovery step for refining and recovering the organic sulfur oxide, so that residual organic sulfur oxide oxidized in the critical treatment step and remaining in the hydrocarbon oil can also be recovered. % Or higher recovery rate can be obtained.
(6) Since the hydrocarbon oil separated from the sulfur-containing solvent in the second solvent separation step has organic sulfur compounds removed, the sulfur concentration is low, and dibenzothiophenes that are particularly difficult to hydrodesulfurize are removed. If this hydrocarbon oil is hydrodesulfurized, low sulfur concentration oil or sulfur-free oil can be obtained.

Hereinafter, the present invention will be specifically described by experimental examples. The present invention is not limited to these experimental examples.
(Experimental example 1)
The batch reactor was opened, 150 mL of light oil (made by Idemitsu) as hydrocarbon oil and 150 mL of methanol (made by Wako Pure Chemicals, first grade) as solvent were introduced into the reactor, and phosphotungstic acid ( 30 mg of Wako Pure Chemicals, special grade) was added. Thereafter, the reactor is closed and sealed, and the temperature in the reactor is increased to 200 ° C. When the temperature and pressure are stabilized, 30% hydrogen peroxide water (made by Wako Pure Chemicals, reagent special grade) is used as the oxidizing agent. Then, 50 times the molar ratio of the sulfur content of the hydrocarbon oil was injected for critical processing (critical processing step). The pressure in the reactor during the critical treatment was 3.4 MPa, which is the saturated vapor pressure of methanol at 200 ° C.
The critically treated mixture was sampled every 10 minutes, 20 minutes, 30 minutes, 60 minutes, 120 minutes, 180 minutes, and 240 minutes after the oxidant injection. The sampled mixed liquid was naturally cooled in a solvent separation step and separated into a sulfur-containing solvent and a hydrocarbon oil by a separatory funnel.
The concentration of sulfur in the hydrocarbon oil before the critical treatment used in the experiment was 336 ppm as a result of analysis with a fluorescent X-ray analyzer (RIX2000, manufactured by Rigaku).
Next, the hydrocarbon oil before critical treatment used in the experiment was sampled after 10 minutes and 20 minutes, and the sulfur-containing solvent separated from the hydrocarbon oil was gas chromatographed with a flame photometric detector (FPD) (Shimadzu). (Manufactured by Seisakusho, GC-2010, hereinafter referred to as GC-FPD).
FIG. 2 is a chart obtained by analyzing a hydrocarbon oil (light oil) before critical treatment, a sulfur-containing solvent for 10 minutes of critical treatment, and a sulfur-containing solvent for 20 minutes of critical treatment using GC-FPD.
As shown in FIG. 2, the peaks of 4-methyl DBT and 4,6-dimethyl DBT observed in the hydrocarbon oil (light oil) before the critical treatment are not observed in the sulfur-containing solvent after the critical treatment. Oxidized 4-methyl DBTS and 4,6-dimethyl DBTS peaks were observed.
4-Methyl DBT and 4,6-dimethyl DBT are produced from commercially available dibenzothiophene (DBT) by the method described in JP-A-7-252249, and a standard chart is prepared using GC-FPD. Based on this, identification was made. Further, 4-methyl DBTS and 4,6-dimethyl DBTS are oxidized by subjecting 4-methyl DBT and 4,6-dimethyl DBT produced from the above-mentioned DBT to the critical treatment for 20 minutes as in Experimental Example 1. A reference chart was prepared using GC-FPD and identified based on this.
FIG. 3 is a GC-FPD chart of DBT, 4-methyl DBT, 4,6-dimethyl DBT, 4-methyl DBTS, and 4,6-dimethyl DBTS prepared by the method described above. In the following experimental examples, identification was made based on this chart.

Next, the relationship between the reaction time of the critical treatment and the area of each peak detected by GC-FPD of 4-methyl DBTS and 4,6-dimethyl DBTS in the sulfur-containing solvent was calculated. Since the concentration of each component depends on the area of each peak, the change in the reaction state with time can be examined.
FIG. 4 is a diagram showing the relationship between the reaction time of critical processing and the area of each peak detected by GC-FPD of 4-methyl DBTS and 4,6-dimethyl DBTS.
As shown in FIG. 4, it is clear that 4-methyl DBT and 4,6-dimethyl DBT are oxidized in a short reaction time of about 20 minutes under the conditions of this experimental example.
After the critical treatment for 240 minutes, the sulfur concentration of the hydrocarbon oil was reduced to 135 ppm as a result of X-ray fluorescence analysis. As a result, if the hydrocarbon oil after critical treatment is hydrodesulfurized, it is presumed that low sulfur concentration oil or sulfur-free oil can be easily obtained because DBTs that are difficult to hydrodesulfurize are removed. Is done.

(Experimental example 2)
In Experimental Example 2, the ratio between the hydrocarbon oil and the solvent in the critical treatment process was examined.
Various liquid mixtures using light oil and methanol similar to Experimental Example 1 and changing the ratio of light oil and methanol were subjected to critical treatment under the same conditions as in Experimental Example 1 with a reaction time of 20 minutes. The hydrocarbon oil (light oil) and sulfur-containing solvent (methanol) after the critical treatment were analyzed using GC-FPD, the proportion of sulfur transferred into methanol, the oxidation rate of 4-methyl DBTS, 4,6- The oxidation rate of dimethyl DBTS was determined. The oxidation rate of 4-methyl DBTS and the oxidation rate of 4,6-dimethyl DBTS are based on the amounts of 4-methyl DBT and 4,6-dimethyl DBT present in the hydrocarbon oil before the critical treatment. Conversion was made from the amount of 4-methyl DBTS and 4,6-dimethyl DBTS present in the sulfur-containing solvent (methanol) after the critical treatment.
FIG. 5 shows the relationship between the ratio of light oil (hydrocarbon oil) to methanol (solvent), the ratio of sulfur transferred into methanol, the oxidation rate of 4-methyl DBTS, and the oxidation rate of 4,6-dimethyl DBTS. FIG.
From FIG. 5, it was confirmed that as the amount of hydrocarbon oil relative to the solvent decreases, the proportion of the sulfur content that migrates into the solvent tends to increase. However, it has been found that the oxidation rate of 4-methyl DBTS and 4,6-dimethyl DBTS decreases as the ratio of hydrocarbon oil to solvent is less or greater than 1.0. The reason why the oxidation rate of 4-methyl DBTS exceeds 100% is presumed that a part of 4,6-dimethyl DBTS was decomposed into 4-methyl DBTS.
From the above results, it was confirmed that the amount of the hydrocarbon oil relative to the solvent was 0.1 to 2.5 times, preferably 0.3 to 2 times, more preferably 0.5 to 1.5 times.

(Experimental example 3)
In Experimental Example 3, the reaction temperature in the critical treatment process was examined.
The batch reactor was opened, and 100 mL of light oil as hydrocarbon oil and 100 mL of methanol (manufactured by Wako Pure Chemical, first grade) as a solvent were introduced into the reactor. , Special grade) 20 mg was added. Thereafter, the reactor was closed and sealed, and the inside of the reactor was raised to a predetermined temperature. When the temperature and pressure were stabilized, 30 mg of hydrogen peroxide (manufactured by Wako Pure Chemicals, reagent special grade) 6 mg was added as an oxidizing agent. Injection and critical processing (critical processing step). The pressure in the reactor during the critical treatment is the saturated vapor pressure of methanol at each reaction temperature.
Twenty minutes after injecting the oxidizing agent, the critically treated mixture was sampled. The sampled mixed liquid was naturally cooled in a solvent separation step and separated into a sulfur-containing solvent and a hydrocarbon oil using a separatory funnel.
The separated sulfur-containing solvent and hydrocarbon oil are analyzed by GC-FPD, the sulfur content of the sulfur-containing solvent and hydrocarbon oil, the migration rate of 4-methyl DBTS and 4,6-dimethyl DBTS in the sulfur-containing solvent. Asked. In addition, the density | concentration of the sulfur content in the hydrocarbon oil before the critical process used for experiment was 1639 ppm as a result of the fluorescent X ray analysis.
FIG. 6 is a graph showing the relationship between the reaction temperature and the sulfur concentration of the sulfur-containing solvent and hydrocarbon oil. FIG. 7 shows the reaction temperature and 4-methyl DBTS and 4,6-dimethyl DBTS in the sulfur-containing solvent (methanol). It is a figure which shows the relationship with the transfer rate.
From the figure, when the reaction temperature is 180 to 220 ° C., the sulfur concentration of the sulfur-containing solvent is high, the migration rate of 4-methyl DBTS and 4,6-dimethyl DBTS in the sulfur-containing solvent is also high, and the organic sulfur oxide is recovered. It became clear that efficiency could be increased.

The sulfur-containing solvent having a reaction temperature of 200 ° C. obtained in Experimental Example 2 was separated and purified using liquid chromatography (manufactured by GL Sciences, model name PLC-561, column model name ODS-3), and methanol and water. 4-Methyl DBTS and 4,6-dimethyl DBTS were extracted using an extractant mixed with. The extractant was dried to obtain crystals of 4-methyl DBTS and 4,6-dimethyl DBTS. The purity analyzed using GC-FPD was as high as 97.6% for 4-methyl DBTS and 99% for 4,6-dimethyl DBTS.
The fluorescence values of the obtained powdery 4-methyl DBTS and 4,6-dimethyl DBTS were measured using a fluorescence spectrometer (model name FL3-22) at an excitation wavelength of 270 nm using a xenon lamp as a light source. As a result, strong fluorescence was observed with 4-methyl DBTS having a peak wavelength of 392.5 nm and 4,6-dimethyl DBTS with a peak wavelength of 387.6 nm.
From the above, it was suggested that 4-methyl DBTS and 4,6-dimethyl DBTS produced from hydrocarbon oil in this experimental example are extremely useful as raw materials for electronic products such as organic EL elements.

(Comparative Example 1)
In the reactor, 150 mL of light oil as hydrocarbon oil (manufactured by Idemitsu, the concentration of sulfur content analyzed by fluorescent X-ray analysis was 336 ppm) and 150 mL of methanol (manufactured by Wako Pure Chemicals, first grade) as solvent were added. 30 mg of acid (made by Wako Pure Chemicals, special grade) was added. After connecting the reflux condenser to the reactor, the reactor was heated to 120 ° C. from the outside under normal pressure, and when the temperature was stabilized, 30% hydrogen peroxide solution (made by Wako Pure Chemicals, reagent grade) was used as the oxidizing agent. An amount 50 times the molar ratio of the sulfur content of the hydrocarbon oil was injected.
The mixed solution was sampled every 4 hours, 8 hours, and 24 hours after the oxidant injection. The sampled liquid mixture was naturally cooled, separated into a solvent and a hydrocarbon oil using an organic solvent membrane filter (0.2 μm), and the solvent was analyzed by GC-FPD.
FIG. 8 is a chart in which a GC-FPD is used to analyze a hydrocarbon oil (light oil) before treatment and a solvent reacted for 4 hours, 8 hours, and 24 hours under normal pressure.
As shown in FIG. 8, according to this comparative example, it is clear that a long-time reaction of 8 hours or more is required under normal pressure, and the productivity is remarkably lacking.

  As described above, according to this example, organic sulfur compounds such as dibenzothiophenes that were difficult to recover in a short time were selectively converted into organic sulfur oxides of polar compounds such as sulfoxides and sulfone derivatives in a short time. Oxidation and organic sulfur compounds can be efficiently separated from hydrocarbon oils, and organic sulfur oxides that are useful as raw materials for organic EL devices can be produced with high purity and high recovery rate. It has become clear that organic sulfur oxides with excellent mass productivity and productivity can be produced at low cost.

  The present invention relates to a method for producing an organic sulfur oxide, which produces an organic sulfur oxide such as dibenzothiophene sulfone, which is useful as a raw material for pharmaceuticals, agricultural chemicals, synthetic resin products, electronic products, etc., from a hydrocarbon oil containing an organic sulfur compound. In addition, organic sulfur compounds such as dibenzothiophenes, which were difficult to recover in a short time, are selectively oxidized to polar organic sulfur oxides such as sulfoxides and sulfone derivatives in a short time and the organic sulfur compounds are converted into hydrocarbon oils. The desired useful organic sulfur oxides can be produced efficiently with high purity and high recovery rate, excellent workability and operability, low cost, excellent mass production and productivity, and hydrocarbon oil desulfurization The manufacturing method of the organic sulfur oxide which also reduces the load of a process can be provided.

The flowchart which shows the manufacturing method of the organic sulfur oxide in Embodiment 1 Chart of analysis of hydrocarbon oil (light oil) before critical treatment, sulfur-containing solvent for 10 minutes of critical treatment, and sulfur-containing solvent for 20 minutes of critical treatment using GC-FPD GC-FPD chart of DBT, 4-methyl DBT, 4,6-dimethyl DBT, 4-methyl DBTS, 4,6-dimethyl DBTS The figure which shows the relationship between the reaction time of a critical process, and the area of each peak detected by GC-FPD of 4-methyl DBTS and 4, 6- dimethyl DBTS. The figure which shows the relationship between the ratio of the light oil (hydrocarbon oil) with respect to methanol (solvent), the ratio of the sulfur content which moved into methanol, the oxidation rate of 4-methyl DBTS, and the oxidation rate of 4, 6- dimethyl DBTS. Diagram showing the relationship between reaction temperature and sulfur concentration of sulfur-containing solvents and hydrocarbon oils The figure which shows the relationship between reaction temperature and the transfer rate of 4-methyl DBTS and 4, 6- dimethyl DBTS in a sulfur containing solvent (methanol). Chart of analysis of hydrocarbon oil (light oil) before treatment and solvent reacted at normal pressure for 4 hours, 8 hours and 24 hours using GC-FPD

Claims (3)

Organic sulfur oxidation obtained by treating a mixed liquid containing hydrocarbon oil, a solvent and an oxidizing agent under high temperature and high pressure in a supercritical state or subcritical state of the solvent to oxidize an organic sulfur compound contained in the hydrocarbon oil A critical treatment step for eluting a substance into the solvent;
A solvent separation step of separating the sulfur-containing solvent from which the organic sulfur oxide is eluted from the hydrocarbon oil;
A sulfur oxide recovery step for purifying and recovering the organic sulfur oxide eluted in the sulfur-containing solvent;
A method for producing an organic sulfur oxide, comprising: An elution treatment step of eluting residual organic sulfur oxide remaining in the hydrocarbon oil into the solvent after mixing the hydrocarbon oil from which the sulfur-containing solvent has been separated in the solvent separation step with a solvent;
A second solvent separation step of separating the residual sulfur-containing solvent from which the residual organic sulfur oxide is eluted from the hydrocarbon oil;
A second sulfur oxide recovery step for purifying and recovering the residual organic sulfur oxide eluted in the residual sulfur-containing solvent;
The method for producing an organic sulfur oxide according to claim 1, comprising:   The method for producing an organic sulfur oxide according to claim 1 or 2, wherein the solvent is one or more selected from alcohols such as methanol and ethanol.

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