TWI399430B - Method for removing sulfur compounds in oil - Google Patents

Description

Method for removing sulfur compounds in oil

The present invention relates to a method for removing sulfur compounds in oils, and more particularly to a method for removing sulfur compounds in oils using special catalysts and specific organic compounds.

Fuel cells are currently the hot alternative to hydrogen, and the main source of power is hydrogen, while the most safe source of hydrogen is produced through fuel oil. However, in the existing fuel oil, since the sulfur content of the fuel oil far exceeds the acceptable range of the fuel cell, it needs to be desulfurized before use, and can be applied to the fuel cell. In addition, for low-cost diesel, such as the removal of sulfur compounds, it will be more effective to enhance the market competitiveness of hydrogen production using fuel oil.

The traditional sulfur removal method for fuel oil is hydrodesulfurization (HDS), which is extremely difficult to reduce the sulfur content in the oil to less than 15 ppm, is extremely energy intensive and does not conform to the low carbon process, and contains olefin-containing cyclic sulfides. [4,6-dimethyldibenzothiophene (4,6-DMDBT) is the most difficult to remove] has a low removal rate. At present, the new sulfur removal technology uses organic acid and oxygen to make peroxide, or directly uses hydrogen peroxide to oxidize sulfur compounds in the oil. This new sulfur removal technology can enhance sulfur. The amount of removal, but the peroxide needs to be produced on site and used immediately after the production, in addition to the inconvenience in use, there are more explosions of doubt.

With regard to the disadvantages of the above various methods, for example, a method for effectively removing a sulfur-containing compound in an oil product, particularly a method for removing a sulfide containing an olefin ring group, can effectively expand fuel oil (or even recovered fuel). The use of oil).

Accordingly, it is an object of the present invention to provide a method for removing sulfur-containing compounds from oils which is effective for removing sulfur-containing compounds at low temperatures, for a short period of time, and without the addition of a phase transfer agent.

Thus, the method of the present invention for removing a sulfur-containing compound in an oil comprises the steps of: (a) allowing an organic compound and an oil in the presence of a catalyst represented by the following formula (I) and oxygen; Mixing and reacting, wherein the organic compound is oxidized with oxygen to form a peroxyacid under the catalysis of the catalyst, and the peroxyacid is then oxidized with the sulfur-containing compound in the oil to be converted into碸 compound:

In the formula (I), M represents Co, Mn, Fe, Cr or Cd, and the content ratio of a to b ranges from 5:95 to 60:40;

(b) removing the hydrazine compound from the oil to obtain a sulfur-removed oil.

The method for removing the sulfur-containing compound in the oil of the present invention uses the special catalyst of the formula (I) and a specific organic compound, and then the organic compound is oxidized to react with oxygen under the catalyst of the catalyst. An oxo acid, which in turn is oxidized with a sulfur-containing compound, such that the sulfur-containing compound in the oil is oxidized to a ruthenium compound which is highly polar and soluble in a part of the solvent, and finally removed from the oil. The hydrazine compound can obtain a sulfur-removed oil. In addition, the specific organic compound used in the method of the present invention has lipophilic properties, can be compatible with the oil and can be oxidized with the sulfur-containing compound without adding a phase transfer agent, and the special catalyst is more convenient. The advantages of recovery, low cost, safety and high efficiency, so the sulfur removal efficiency of the method of the invention can be up to 100%.

The above "organic compound" is an organic compound which is oxidized to a peroxy acid under the catalysis of the catalyst represented by the formula (I) and oxygen. Preferably, the organic compound is a compound containing an aldehyde group; more preferably, the organic compound is selected from benzaldehyde, isobutyraldehyde, octanal or a combination thereof. In one embodiment of the invention, the organic compound is benzaldehyde.

The catalyst represented by the formula (I) is a novel catalyst developed by the inventors, mainly using divinyl benzene and glycidyl methacrylate to form a bridge-type polymer. Then, it is modified with a strong chelating agent, iminodiacetic acid, to obtain a polymer carrier represented by the following formula (i):

The content ratio of a and b of the formula (i) ranges from 5:95 to 60:40. Next, the polymer supported by the above formula (i) and a solution containing a metal ion are subjected to a chelate reaction to obtain a catalyst represented by the formula (I). Preferably, in the metal ion-containing solution, the metal ion is a cobalt ion, and the solution containing the cobalt ion may include, but is not limited to, an aqueous cobalt acetate solution.

Preferably, the catalyst has a bridging degree of 5% to 50%.

The amount of the catalyst and the organic compound in the step (a) of the method of the present invention can be adjusted according to actual needs. Preferably, the total weight of the oil in the step (a) is 100 wt%, and the amount of the catalyst is used. It is 0.04 wt% to 0.12 wt%, and the amount of the organic compound is in the range of 0.4 wt% to 4 wt%.

Preferably, the temperature of the oxidation reaction in the step (a) ranges from 25 ° C to 60 ° C.

The oxidation reaction of the step (a) can be adjusted according to a conventional manner, for example, the catalyst, the organic compound and the oil can be placed in the reactor together, and oxygen can be introduced into the reactor, or alternatively, the step (a) is composed of a step (a1) and a step (a2), wherein the organic compound is subjected to an oxidation reaction in the presence of a catalyst represented by the formula (I) and oxygen. Obtaining the peroxyacid, the step (a2) is: in the same environment as the step (a1), oxidizing the peroxyacid with the sulfur-containing compound in the oil to oxidize the sulfur-containing compound into碸 compound. Alternatively, the step (a) is composed of a step (a3) and a step (a4), wherein the step (a3) is performed in the presence of the catalyst and oxygen represented by the formula (I). The oil is thoroughly mixed with oxygen. In the same environment as in the step (a3), benzaldehyde is added to the oil to oxidize the benzaldehyde to a peroxyacid, and then to the oil. The sulfur-containing compound is subjected to an oxidation reaction to oxidize the sulfur-containing compound to a ruthenium compound.

The method for removing the ruthenium compound in the step (b) can be carried out according to a conventionally used method, for example, by solvent extraction to remove the ruthenium compound, and the solvent used can be any polar solvent such as dimethylformamide ( Solvents such as dimethylformamide, DMF) or acetonitrile.

The method of the invention can effectively remove the sulfur-containing compound in the oil, and the sulfur removal rate is up to 99% or more, and the required time is as short as 15 min (at 60 ° C).

The present invention will be further illustrated by the following examples, but it should be understood that this embodiment is intended to be illustrative only and not to be construed as limiting.

< Example > [Preparation Example 1] Preparation of Catalyst

Divinylbenzene and glycidyl methacrylate (the weight ratio of the two are 1:9) were previously dissolved in cyclohexanol to prepare a reaction liquid. Further, an appropriate amount of polyvinyl alcohol was mixed with distilled water in a four-neck reactor, and then nitrogen gas was introduced into the reactor to ensure that the oxygen in the reactor and the solvent was sufficiently removed. Then, the reactor is heated, and after the temperature reaches 80 ° C, the above reaction solution and the initiator azoisobutylonitrile (AIBN) are added to the reactor, and polymerization is carried out, after reacting for 4 hours. Then, it is washed with ethanol and distilled water, and finally filtered and dried to obtain a polymer.

An appropriate amount of the polymer is dissolved in distilled water, followed by the addition of divinylbenzene, sodium hydroxide (the molar ratio of the two is 1:2) and dimethylacetamide, and the reaction is carried out under stirring at a temperature of 95 ° C. After 12 hours of reaction, filtration, washing and drying were carried out to obtain a polymer carrier.

A saturated aqueous solution of cobalt acetate (cobalt (II) acetate tertrahydrate, purchased from Japan Showa Chemical Industry Co., Ltd.) was added to water, and then the polymer carrier obtained above was added, and the mixture was stirred well. After 24 hours, the unchelated metal ions attached to the catalyst were repeatedly washed with distilled water and ethanol, and immediately detected by ultraviolet visible light spectrometer until the metal ion absorption intensity was less than 0.01, and the reaction was terminated, and finally filtered and dried. That is, the catalyst represented by the formula (I) is obtained.

The catalyst thus obtained was observed by an electron scanning microscope (SEM), and the amount of chelation was measured by an atomic absorption spectrophotometer (manufactured by Perkin Elmer Co., Ltd.). As a result of the analysis, the chelating amount was 89.89 mg of cobalt ion per 1000 mg of the catalyst, the surface area was 3.65 m ² /g, the pore volume was 0.012 cm ² /g, and the pore size was 13.26 nm.

[Preparation Example 2] Preparation of oil

1 g of 4,6-dimethyldibenzothiophene was dissolved in n-octane to obtain a solution having a concentration of 5000 ppm. The above solution was then formulated into a simulated diesel solution having a concentration of 100 ppm.

[Example 1]

250 mL of simulated diesel solution was placed in a four-necked reactor, and then 0.3 g of the catalyst prepared in Preparation Example 1 was added to the reactor, and the reactor was heated to 30 ° C, and then oxygen gas was introduced (oxygen flow rate was 400 mL). /min), the simulated diesel solution is thoroughly mixed with oxygen.

After 30 minutes, 2.5 g of benzaldehyde was added to the reactor to carry out an oxidation reaction. During the reaction, samples were taken every 30 minutes, and the reaction was stopped after 300 minutes. The sample taken must be filtered first, then extracted with acetonitrile, and then analyzed by high performance liquid chromatography (HPLC). The results are shown in Figure 1.

[Embodiment 2]

Except that the amount of benzaldehyde was changed to 5 g, the other production processes and test procedures were the same as in Example 1, and the results obtained are shown in FIG.

[Example 3]

Except that the amount of benzaldehyde was changed to 10 g, the other production processes and test procedures were the same as in Example 1, and the results obtained are shown in FIG.

[Example 4]

Except that the amount of benzaldehyde was changed to 5 g and the amount of catalyst was changed to 0.1 g, the other production processes and test procedures were the same as in Example 1, and the results obtained are shown in FIG. 2 .

[Example 5]

Except that the amount of benzaldehyde was changed to 5 g and the amount of catalyst was changed to 0.2 g, the other production processes and test procedures were the same as in Example 1, and the results obtained are shown in FIG. 2 .

[Comparative example]

Except that the amount of benzaldehyde was changed to 5 g and the amount of catalyst was not added, the other production processes and test procedures were the same as in Example 1, and the results obtained are shown in FIG. 2 .

[result]

From the results of Fig. 1, it can be found that the sulfur removal amount of Examples 1 to 3 is more than 45% in 15 minutes and more than 90% after 300 minutes. In the third embodiment, the sulfur removal rate of 100% can be achieved after 120 minutes, which proves that the method for removing sulfur compounds in the oil of the present invention can effectively remove the sulfur-containing compound. Further, from the results of Examples 1 to 3, it was found that the more the amount of benzaldehyde added, the higher the sulfur removal rate, and the reaction time can be greatly shortened.

From the results of Fig. 2, it was found that the sulfur removal rate after 300 minutes was maintained at about 40% in the comparative example because no catalyst was added, and the sulfur removal rates of Examples 1, 4 and 5 increased with time. The results prove that if only benzaldehyde is used alone, the sulfur removal rate cannot be effectively increased. Therefore, it is necessary to use benzaldehyde in combination with a catalyst to effectively increase the sulfur removal rate.

In addition, the inventors further attempted to increase the reaction temperature to 60 ° C. The production process and the test procedure were the same as in Example 1. It was found that when the temperature was raised to 60 ° C, the sulfur removal rate was increased to 100% at 15 minutes.

In summary, the method for removing a sulfur-containing compound in an oil of the present invention can effectively remove a sulfur-containing compound in an oil by using a special catalyst and a specific organic compound, and when the reaction temperature is 60 ° C. The reaction time can be as short as 15 min, and the sulfur removal rate of 100% can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

1 is a graph illustrating test results of Examples 1 to 3;

Fig. 2 is a graph showing the test results of Examples 1, 4 and 5 and Comparative Examples.

Claims (14)

A method for removing a sulfur-containing compound in an oil, comprising the steps of: (a) mixing an organic compound with an oil in the presence of a catalyst represented by the following formula (I) and oxygen; a reaction in which the organic compound is oxidized to a peroxyacid by catalysis of the catalyst, and the peroxyacid is then oxidized with a sulfur-containing compound in the oil to be converted into a hydrazine compound: In the formula (I), M represents Co, Mn, Fe, Cr or Cd, and the content ratio of a to b ranges from 5:95 to 60:40; and (b) the hydrazine is removed from the oil. Compound to obtain a sulfur-removed oil. The method for removing a sulfur-containing compound in an oil according to claim 1, wherein the organic compound of the step (a) is selected from benzaldehyde, isobutyraldehyde, octanal or a combination thereof. . The method for removing a sulfur-containing compound in an oil according to the second aspect of the patent application, wherein the organic compound of the step (a) is benzaldehyde. The method for removing a sulfur-containing compound in an oil according to the first aspect of the patent application, wherein the catalyst of the step (a) is a polymer carrier represented by the following formula (i) and a metal ion-containing compound. The solution is prepared by a chelation reaction: The ratio of a and b ranges from 5:95 to 60:40. A method of removing a sulfur-containing compound in an oil according to claim 4, wherein the metal ion is a cobalt ion. The method for removing a sulfur-containing compound in an oil according to the fourth aspect of the patent application, wherein the bridging degree of the formula (i) ranges from 5% to 50%. The method for removing a sulfur-containing compound in an oil according to claim 1, wherein the amount of the catalyst is 0.04 wt% based on the total weight of the oil of the step (a): 100 wt% ~0.12wt%. The method for removing a sulfur-containing compound in an oil according to claim 1, wherein the organic compound is used in an amount of 0.4% by weight based on 100% by weight of the total oil of the step (a). ~4wt%. . The method for removing a sulfur-containing compound in an oil according to the first aspect of the invention, wherein the temperature of the oxidation reaction in the step (a) ranges from 25 to 60 °C. The method for removing a sulfur-containing compound in an oil according to the first aspect of the invention, wherein the sulfur-containing compound of the step (a) is a sulfide containing an olefin ring group. A method for removing a sulfur-containing compound in an oil according to claim 10, wherein the sulfur-containing compound of the step (a) is 4,6-dimethyldibenzothiophene. A method for removing a sulfur-containing compound in an oil according to the invention of claim 11, wherein the second oxidation product of the step (b) is 4,6-dimethyldibenzofluorene. The method for removing a sulfur-containing compound in an oil according to the first aspect of the patent application, wherein the step (a) is composed of a step (a1) and a step (a2), wherein the step (a1) is The organic compound is subjected to an oxidation reaction in the presence of a catalyst represented by the formula (I) and oxygen to obtain the peroxyacid, and the step (a2) is carried out in the same environment as in the step (a1). The peroxyacid is oxidized with a sulfur-containing compound in the oil to oxidize the sulfur-containing compound to a ruthenium compound. The method for removing a sulfur-containing compound in an oil according to the first aspect of the invention, wherein the step (b) is to remove the ruthenium compound by solvent extraction.