KR20140026745A - Oxidative desulfurization process for hydrocarbon - Google Patents

Abstract

The present invention relates to an oxidative desulfurization process for hydrocarbon. According to one embodiment of the present invention, the oxidative desulfurization process for hydrocarbon produces desulfurized final products by converting sulfur compounds within hydrocarbon into sulfur oxide by reacting an oxidant with hydrocarbon under an oxidation catalyst and removing the sulfur oxide through extraction or adsorption. The oxidative desulfurization method for hydrocarbon removes sulfur oxide using an extractant or an adsorbent. [Reference numerals] (AA) Hydrocarbon; (BB) Oxidizer; (CC) Oxidation step 1; (DD) Oxidation step 2; (EE) Extraction; (FF) Desulfurized product

Description

Oxidative desulfurization process for hydrocarbon

The present invention relates to a method for oxidative desulfurization of hydrocarbons, and more particularly, to a method of reacting an oxidant with a hydrocarbon in the presence of an oxidation catalyst to convert sulfur compounds in hydrocarbons into sulfur oxides and then removing them by extraction or adsorption.

Hydrocarbons such as gasoline, kerosene, and diesel produced in the oil refining industry contain large amounts of sulfur impurities, and these sulfur compounds are converted into SOx during combustion, causing air pollution.

In particular, for automotive diesel, the typical requirement for sulfur content in the past was up to 0.5% by weight. The legislation enacted in 1993 limits the amount of sulfur in diesel fuel to 0.3% by weight in Europe and the United States.In 1996, Europe and the United States reduced the maximum content of sulfur in diesel to less than 0.05% by weight. Followed.

Since 2009, most countries in Europe and developed countries have regulated sulfur content below 15 ppm, and developing and developing countries are expected to tighten their sulfur content. This global trend is expected to continue to lower sulfur levels.

In order to comply with the above regulations for ultra-low sulfur content fuels, refineries will have to produce fuels with lower sulfur levels at refinery gates. Therefore, sulfur levels in fuel should be further reduced within the time frame agreed by the refinery regulators.

Commercially, hydrodesulfurization is used to remove sulfur by reacting hydrogen under CoMo and NiMo catalysts to meet sulfur content specifications. However, while conventional hydrodesulfurization catalysts can be used to remove large amounts of sulfur from petroleum distillates, they are sulphurous from the compounds when the sulfur atoms are stericly hindered from accessing the catalytically active site, as in polycyclic aromatic sulfur compounds. It is not efficient to remove it. This is particularly inefficient when sulfur heteroatoms are double interrupted. Double interruption of these sulfur heteroatoms occurs mainly at low sulfur levels, and severe process conditions are required for desulfurization. Using conventional hydrodesulfurization catalysts at high temperatures will result in yield loss, accelerated catalyst coking and product quality degradation. In addition, since the hydrodesulfurization process is a process of high temperature and high pressure and requires expensive hydrogen, research on an alternative technology that is advantageous in terms of economics is being actively conducted.

As an alternative technique, oxidative desulfurization is used. In the case of the oxidation catalyst in which titanium is supported on silica in the oxidation catalyst used, deactivation is progressed by impurities and reactants in the hydrocarbon, and thus the conversion rate of the sulfur compound is changed over time. There is a problem that is reduced.

An object of the present invention is to use an oxidative desulfurization process to remove sulfur from hydrocarbons, while continuously introducing different catalyst systems to solve the problem of rapid deactivation of the used oxidation catalyst, thereby improving the performance and lifetime of the oxidation catalyst. At the same time, the sulfur removal effect is also excellent to provide a hydrocarbon desulfurization method.

It is also an object of the present invention to provide a method of simplifying the process and reducing the running cost by using a regeneration solvent used to regenerate the oxidation catalyst using the same solvent as the regeneration solvent of the extractant or the adsorbent.

When the heavy hydrodesulfurization (RHDS) fraction treated by the hydrodesulfurization process used in the present invention was used as a reactant, it was hardly decomposable having a large molecular size such as 4,6-dimethyldibenzothiophene. Due to the high content of nitrogen compounds mainly containing sulfur compounds and reducing oxidation catalyst performance, there is a need for a solution due to the rapid decrease in catalyst performance in conventional catalysts and reaction systems. To this end, the present invention introduces a two-stage reaction system in which catalysts having different characteristics are connected in series.

Specifically, an unsilylated oxidation catalyst is charged in a first stage reactor to induce adsorption of nitrogen compounds, which are inactivating substances included in the reactants, and unsilyylated non-silylated sulfur oxides and nitrogen oxides generated during the oxidation reaction. Some adsorption was made to the oxidation catalyst itself. Unlike the application of guard adsorption tower where adsorption of nitrogen is eliminated and oxidation does not occur, the conversion of non-degradable sulfur compounds to sulfone compounds, which are the target products of the decomposable sulfur compounds, to be removed is gradually decreased from the initial 90% or more. Up to 60% before catalyst regeneration. This can reduce the load on the conversion of sulfur compounds to sulfone compounds in the two-stage reactor and improve performance and lifespan. The two-stage reactor was filled with a silylated oxidation catalyst which has relatively improved performance and lifespan to maximize the conversion rate and lifetime of the oxidation reaction.

Oxidation desulfurization method of a hydrocarbon according to an embodiment of the present invention for achieving the above object is (a) contacting the oxidizing agent and the hydrocarbon in the presence of an oxidation catalyst to convert the sulfur compound in the hydrocarbon to sulfur oxides, (a) The steps include: i) an oxidation reaction contacting the oxidant with a hydrocarbon in the presence of an unsilylated oxidation catalyst and ii) an oxidation reaction contacting the oxidant with a hydrocarbon in the presence of a silylated oxidation catalyst, (b) It may include the step of removing the sulfur oxide with an extractant or adsorbent.

In one embodiment of the present invention, (c) may further comprise the step of regenerating the oxidation catalyst or adsorbent. Regeneration of the oxidation catalyst or adsorbent may use the same regeneration solvent. The regeneration solvent may be at least one selected from the group consisting of dimethyl carbonate, dimethyl ether, dimethylformamide, methanol, acetone, dimethyl sulfoxide, acetonitrile, polyethylene glycol, and sulfolane.

In one embodiment of the invention, the extractant may be at least one selected from the group consisting of dimethyl carbonate, dimethyl ether, dimethylformamide, methanol, acetone, dimethyl sulfoxide, acetonitrile, polyethylene glycol, and sulfolane. .

In one embodiment of the present invention, the reactor in step (a) may be composed of a one-stage reactor and a two-stage reactor. The catalyst filling ratio of the unsilylated oxidation catalyst of the first stage reactor and the silylated oxidation catalyst of the two stage reactor may be 1: 1 to 1:10, and specifically 1: 1 to 1: 5.

 In one embodiment of the present invention, the hydrocarbon may be selected from the group consisting of hydrocarbons derived from atmospheric distillation column, hydrocarbons derived from hydrodesulfurization and hydrocracking process, or hydrocarbons derived from fluidized bed catalytic cracking process.

In one embodiment of the present invention, the oxidation catalyst is a form in which a transition metal is supported on one or more carriers selected from the group consisting of silica, alumina, and silica-alumina, or on which the transition metal is supported in a chelate form. Can be. The transition metal may be any one selected from the group consisting of chromium, copper, manganese, nickel, vanadium, zinc, iridium, aluminum, iron, cobalt, or titanium. The chelating agent used in the preparation of the transition metal in the form of a chelate on the carrier is acetylacetone, 3-allyl-2,4-pentanedione, 3-acetyl-6-trimethoxysilylhexane-2-one, In the group consisting of ethyl acetoacetate, allyl acetoacetate, methacryloxyethyl acetoacetate, trifluoroacetylacetone, pentaproloacetylacetone, benzol acetone, dipivaloyl methane, dimethylmalonate, dimethylglyoxime and salicylicaldehyde It may be a single chelating agent selected or two or more chelating agents.

In one embodiment of the invention, the oxidant may be selected from the group consisting of organic peroxides, hydrogen peroxide, oxygen, and ozone.

In one embodiment of the present invention, the adsorbent may be selected from the group consisting of activated carbon, silica, alumina, and silica-alumina.

In one embodiment of the present invention, the oxidation reaction of step (a) may be carried out at a reaction temperature of 60 ~ 150 ℃. The oxidation reaction of step (a) may be carried out at a reaction pressure of 0.5 ~ 40bar. The oxidation reaction of step (a) may be performed in a molar ratio of the oxidant to the sulfur compound in the hydrocarbon in the range of 1: 2 to 1:20. The oxidation reaction of step (a) may be performed at a weight hourly space velocity (WHSV) of a hydrocarbon in the range of 0.1 to 10 hr ⁻¹ .

According to one embodiment of the present invention, using the two-stage catalyst system, the one-stage catalyst uses an unsilylated catalyst to cause the oxidation reaction of the sulfur compound to coincide with the adsorption of the inactivating agent, and the two-stage catalyst is the silylated catalyst. By proceeding the oxidation reaction to the target conversion rate, it is possible to have a high catalyst activity and a long catalyst life for a long time while preventing the deactivation of the catalyst as well as excellent desulfurization performance.

In addition, by using the same solvent as the regeneration solvent of the extractant or the adsorbent as the regeneration solvent of the oxidation catalyst, not only the configuration of the process can be simplified, but also the process investment cost and operation cost can be reduced.

1 is a schematic view showing an oxidative desulfurization process according to an embodiment of the present invention.
2 is a schematic view showing an oxidative desulfurization process and a regeneration process according to an embodiment of the present invention.
Figure 3 is a graph showing the sulfur conversion rate with time of the oxidative desulfurization process using the oxidation catalyst according to Experimental Examples 1 to 8.
4 is a graph showing experimental results when methanol was used as a regenerating solvent of the adsorbent according to Experimental Example 15.
5 is a graph showing experimental results when acetone was used as a regenerating solvent of the adsorbent according to Experimental Example 16.
6 is a graph showing experimental results when dimethyl ether was used as a regenerating solvent of the adsorbent according to Experimental Example 17. FIG.
7 is a graph showing experimental results when dimethyl carbonate was used as a regenerating solvent of the adsorbent according to Experimental Example 18.
8 is a graph showing experimental results when methyl tert-butyl ether was used as a regenerating solvent of the adsorbent according to Experimental Example 19. FIG.

Hereinafter, the preferable specific example of this invention is demonstrated concretely.

In one embodiment of the present invention, in order to prevent deactivation of the catalyst, two steps of oxidation reactions may be performed using different oxidation catalysts. Specifically, an oxidation reaction is carried out by contacting an oxidant with a hydrocarbon in the presence of an unsilylated oxidation catalyst, followed by an additional oxidation reaction in the presence of a silylated oxidation catalyst to convert the sulfur compound in the hydrocarbon into a sulfur oxide, for example, sulfone. Or sulfoxide. The converted sulfur oxides can be removed using an extractant or adsorbent and then the final desulfurized product can be produced.

In one embodiment of the present invention, an oxidation reaction occurs simultaneously with adsorption using an unsilylated oxidation catalyst, and the oxidation reaction may be advanced to a target conversion rate using a successively silylated oxidation catalyst. Here, the oxidation reaction may be made of a one-stage reactor and a two-stage reactor. Referring to FIG. 1, a first stage reactor (one stage oxidation reaction) and a two stage reactor (two stage oxidation reaction) may be connected in series. The first stage reactor may be filled with an unsilylated oxidation catalyst, and the two stage reactor may be filled with a silylated oxidation catalyst, wherein the ratio of catalyst filling between the unsilylated oxidation catalyst and the silylated oxidation catalyst is It may be 1: 1 to 1:10, and specifically 1: 1 to 1: 5. Alternatively, one reactor may be used, but an unsilylated catalyst may be charged in the upper portion and a silylated catalyst in the lower portion at the same catalyst fill rate as the two-stage reactor.

Here, when the filling ratio of the unsilylated oxidation catalyst and the silylated oxidation catalyst is less than 1: 1, the ratio of the silylated oxidation catalyst having a relatively high oxidative desulfurization activity may be too low, indicating a low initial activity and a rapid decrease in activity. In addition, when the filling ratio is greater than 1:10, as the ratio of the unsilylated oxidation catalyst is excessively low, the role of eliminating inactivation agents and at the same time lacking some conversion roles of sulfur compounds may decrease activity and stability. Therefore, the ratio of the unsilylated oxidation catalyst and the silylated oxidation catalyst is preferably controlled within 1:10, and more specifically, when controlled within 1: 5, maximum activity and stability can be ensured.

In one embodiment of the invention, the hydrocarbon is not particularly limited as long as it is a hydrocarbon containing sulfur, for example, hydrocarbons derived from natural petroleum, specifically hydrocarbons derived from atmospheric distillation column, hydrodesulfurization and hydrocracking process Hydrocarbons derived from or hydrocarbons derived from a fluidized bed catalytic cracking process.

In one embodiment of the present invention, the oxidation catalyst may be an oxidation catalyst in which a transition metal is supported on at least one carrier selected from the group consisting of silica, alumina and silica-alumina. The silica carrier may be silica molecular sieve, silica nanoparticles, silica crystals, silica gel, silica beads, or mesoporous silica, and preferably have a pore size of 2 to 50 nm and a specific surface area of 150 to 1000 m ^2. You can select / g. The transition metal may be chromium, copper, manganese, nickel, vanadium, zinc, iridium, aluminum, iron, cobalt, or titanium, and generally may be used as a precursor of the metal. In addition, the oxidation catalyst may be in the form of supporting the transition metal in the form of chelate on the support.

The oxidation catalyst may be an unsilylated or silylated catalyst. Unsilylated or silylated oxidation catalysts can be prepared by a variety of methods known in the art, for example, by impregnation, initial wetting, and the like, and then in dried and calcined form. .

In the method of supporting the transition metal in the chelate form, for example, the transition metal precursor and the chelating agent may be added to an organic solvent to prepare a stable chelated transition metal through chemical modification. In this regard, all of the contents of the applicant's Korean Publication No. 2012-0040614 are incorporated herein.

The chelating agent is not particularly limited, but any organic compound having at least two atomic groups having a free electron pair or an electron gap capable of forming a complex compound can be used. Specifically, a single chelating agent or two or more chelating agents selected from the group consisting of dioximes, alpha, beta-hydroxycarbonyl compounds, hydrocarboxylic acids, ketones, aldehydes, and beta-diketones Can be used. More specifically, acetylacetone, 3-allyl-2,4-pentanedione, 3-acetyl-6-trimethoxysilylhexane-2-one, 3-acetyl -6-trimethoxysilylhexane-2-one, ethyl acetoacetate, allyl acetoacetate, methacryloxyethyl acetoacetate, trifluoro acetylacetone, pentaproroacetyl acetone, benzol acetone, dipivaloyl methane ( dipivaloyl methane), dimethylmalonate, dimethylglyoxime, and salicyaldehyde, or a single chelating agent selected from the group consisting of two or more chelating agents can be used.

As the organic solvent, a general organic solvent may be used, and specifically, an alcohol having 1 to 6 carbon atoms (C1 to C6) may be used. For example, methanol, ethanol, propanol and the like can be used.

It is preferable that the molar ratio of the transition metal and a chelating agent in the said transition metal precursor is 1: 0.5-5. If the molar ratio is less than 1: 0.5, the chelating becomes smaller, resulting in a lower coordination catalyst active point, resulting in lower catalytic activity. If the molar ratio is greater than 1: 5, the chelating reaction point of the transition metal precursor is greater than that of the chelating reaction point. Many chelating agents do not enter and react, which is uneconomical.

In one embodiment of the present invention, the oxidant may use, for example, organic peroxides, hydrogen peroxide, oxygen, ozone, and the like. Specifically, the organic peroxide may be a hydrocarbon hydroperoxide having 3 to 20 carbon atoms. In addition, the organic peroxide may be a secondary or tertiary hydroperoxide having 3 to 14 carbon atoms. For example, it may be t-butyl hydroperoxide, cyclohexyl hydroperoxide, ethylbenzene hydroperoxide, cumene hydroperoxide.

In one embodiment of the invention, the molar ratio of oxidant to sulfur compound in the hydrocarbon in the oxidation reaction is not particularly limited, but may be about 1: 2 to about 1:20, specifically, about 1: 2 to about 1: May be five. If the ratio of oxidant to hydrocarbon is less than 1: 2, the amount of oxidant lower than the stoichiometric ratio of the oxidation reaction is fundamentally limited so that the oxidation activity is at least 1: 2 or higher. However, in the case of organic oxidants, the oxidant price is high, and the economic efficiency is drastically lowered when used excessively, and the oxidation stability of the final product may be reduced by the unreacted oxidant. Therefore, an appropriate ratio in consideration of oxidative performance, process economics, and product quality is required, and specifically, may be about 1: 2 to 1: 5.

The oxidation reaction can be carried out under suitable temperature and pressure known in the art. For example, the reaction temperature may be carried out at about 0-200 ° C. or about 25-150 ° C. or about 60-150 ° C., and the reaction pressure may be carried out at atmospheric pressure, for example, about 1 atmosphere to 100 atmospheres. It can be carried out in the range of 0.5 bar to 40 bar.

The oxidation reaction may use a reactor known in the art used in the oxidation process, it may be a batch or continuous reactor. The oxidation catalyst can be used, for example, in the form of a fixed bed or slurry.

In one embodiment of the present invention, an extractant may be used to remove sulfur oxides in which the sulfur compound in the hydrocarbon is oxidized. The extractant may be, for example, dimethyl carbonate, dimethyl ether, dimethylformamide, methanol, acetone, dimethyl sulfoxide, acetonitrile, polyethylene glycol, sulfolane and mixtures thereof.

In one embodiment of the present invention, an adsorbent may be used to remove sulfur oxides in which the sulfur compound in the hydrocarbon is oxidized. The adsorbent can be used without particular limitation as long as it can remove sulfur oxides. For example, activated carbon, silica, alumina, silica-alumina, and the like can be used. At least one adsorbent may be used to remove sulfur oxides in the hydrocarbons that have undergone two stages of oxidation with a solid-liquid extraction device. Specifically, the adsorbent may use activated carbon whose surface is modified through CO ₂ activation at 700 to 1100 ° C. In addition, silica, alumina, and silica-alumina have pores having a diameter of 4 to 9 nm and have a surface area of 300 to 600 m 2 / g and a pore volume of silica of 0.01 to 0.3 ml / g. In the case of silica, alumina, and silica-alumina, for one minute to two hours using an acid containing any one of sulfuric acid, nitric acid, hydrochloric acid, acetic acid, hydrofluoric acid, or a mixture thereof, at a concentration of 0.1 to 10 M in order to increase the adsorption amount. After the contact, the heat treatment before the sulfur oxide adsorption may be carried out between 100 ~ 200 ℃.

In one embodiment of the present invention, when the oxidation catalyst in the oxidation reaction process is used repeatedly or in a continuous process, the deactivation of the oxidation catalyst proceeds, the regeneration solvent for a certain time to regenerate the activity of the deactivated oxidation catalyst Can be used to regenerate the catalyst. In addition, the activity of the adsorbent is also lowered due to repeated continuous use of the adsorbent in the adsorption process. In order to regenerate the activity of the desorbed adsorbent, the catalyst may be regenerated by using a regeneration solvent for a predetermined time. The regeneration solvent of the oxidation catalyst and the regeneration solvent of the adsorbent are, for example, dimethyl carbonate, dimethyl ether, dimethylformamide, methanol, acetone, dimethyl sulfoxide, acetonitrile, polyethylene glycol, sulfolane and their Mixtures and the like can be used.

To further illustrate the principles of the present invention, an embodiment will be described below. However, the present embodiments are not intended to limit the scope of the invention which the present inventors consider.

Example

Manufacturing example  One: Unsilylated  Preparation of Oxidation Catalyst

Mesoporous silica SBA-15 is described in M. Choi, W. Heo, F. Kleitz, and R. Ryoo, Chem. Commun. (2003) It was prepared by the method of 1340-1341 as follows. 6.0 g of triple copolymer polymer Pluronic and P123 were added to a solution containing 114 g of distilled water and 3.5 g of 37% hydrochloric acid, followed by vigorous stirring until a uniform mixture was obtained under a temperature condition of 35 ° C. 13.0 g of tetraethyl orthosilicate (TEOS) was added to the homogeneously mixed solution, followed by vigorous stirring for 24 hours under a temperature condition of 35 ° C. The mixtures were aged for 24 hours under temperature conditions of 100 ° C., respectively. After filtration and drying for 12 hours under the temperature condition of 100 ℃, the temperature increase rate was set to 1 ℃ / min per minute and calcined at 550 ℃ for 6 hours to prepare SBA-15.

145 g of distilled water was added to 5 g of SBA-15 prepared above, and 15 g of ethanol and ammonia water were added to adjust the pH of the mixed solution to 7. 20 g of ethanol was added to a separate beaker and mixed with a molar ratio of titanium isopropoxide and acetyl acetone to 3.15. At this time, titanium isopropoxide was carried by 5 parts by weight, based on 100 parts by weight of the silica carrier. The previous two mixtures were mixed uniformly and stirred vigorously for 2 hours under the temperature condition of 5 ℃. The mixture was collected by filtration and washed with 380 ml of ethanol. After drying for 24 hours in an oven at 100 ℃, the temperature increase rate at 550 ℃ was calcined at 2 ℃ per minute for 3 hours to prepare an unsilylated Ti oxidation catalyst.

Manufacturing example  2: Silylated  Preparation of Oxidation Catalyst

In order to hydrophobically modify the silica catalyst surface, the following experiment was carried out using tetramethyldisilazane (TMDS). Toluene was used as the solvent and a weight ratio of toluene to silica catalyst was added at 20 under a nitrogen atmosphere. The molar ratio of HMDS to silica catalyst was added at 0.256 and then refluxed at 120 ° C. for 2 hours. The refluxed sample was filtered, washed with toluene and dried for 8 hours in a vacuum oven at 80 ℃ to prepare a silylated Ti oxidation catalyst.

Experimental Example  1: of oxidation catalyst Performance test

A nitrogen adsorbent or the prepared silylated or unsilylated titanium supported mesoporous catalyst was sieved to a size of 850 μm˜2 mm using a mesh (10/20 mesh). First, the weight of the unsilylated oxidation catalyst was measured and introduced into a tubular fixed bed single stage reactor made of 1/2 inch stainless steel (SUS316). In addition, a titanium-supported hydrophobic mesoporous catalyst having modified surface was introduced into a fixed bed two stage reactor in the same manner. The weight ratio of the unsilylated / silylated catalysts charged in the first and second stage reactors was adjusted to 1/1, and a glass bead was placed at the top and bottom of the catalyst layer in each reactor so that a thermocouple for temperature detection was added to the catalyst layer. To stay. The catalyst packed one-stage and two-stage fixed bed reactors were sequentially connected, and the fixed bed reactor was equipped with a thermostat and a liquid metering pump. The reactant RHDS gas oil fraction was used an oxidant solution in which decane and tetrabutyl hydroperoixde (TBHP) were mixed at a concentration of 6 M, and the molar ratio of oxidant / sulfur in the RHDS gas oil fraction was 15. Used to add. The reactor was fed at a flow rate of 0.1 cc / min per minute (WHSV = 5 h ⁻¹ ) and the reaction temperature was performed at 100 ° C. 1 atm. Sulfur compounds and sulfone compounds before and after the reaction were analyzed using a gas chromatography (SGE BPI column) equipped with a pulsed flame photometric detector (PFPD).

Experimental Example  2 to 8: of oxidation catalyst Performance test

Experimental Examples 2 to 8 were performed in the same manner as in Experiment 1 except that the one-stage catalyst and the two-stage catalyst and their catalyst contents were changed as described in Table 1 below, and the results are shown in FIG. 3. .

1 stage catalyst Two stage catalyst Weight (g) / weight (g) Experimental Example 1 Nitrogen Adsorbent Silylation Ti Oxidation Catalyst 3g / 3g Experimental Example 2 Silylation Ti Oxidation Catalyst Silylation Ti Oxidation Catalyst 3g / 3g Experimental Example 3 Unsilylated Ti Oxidation Catalyst Silylation Ti Oxidation Catalyst 5g / 1g Experimental Example 4 Unsilylated Ti Oxidation Catalyst Silylation Ti Oxidation Catalyst 4g / 2g Experimental Example 5 Unsilylated Ti Oxidation Catalyst Silylation Ti Oxidation Catalyst 3g / 3g Experimental Example 6 Unsilylated Ti Oxidation Catalyst Silylation Ti Oxidation Catalyst 2g / 4g Experimental Example 7 Unsilylated Ti Oxidation Catalyst Silylation Ti Oxidation Catalyst 1.5g / 4.5g Experimental Example 8 Unsilylated Ti Oxidation Catalyst Silylation Ti Oxidation Catalyst 1.2g / 4.8g

In Table 1, the nitrogen adsorbent used silica, the silylated Ti oxidation catalyst was prepared according to the preparation method of Preparation Example 2, the unsilylated Ti oxidation catalyst was prepared according to the preparation method of Preparation Example 1 Was used.

Referring to FIG. 3, the case of filling the nitrogen adsorbent in the first stage and the silylated oxidation catalyst in the second stage (Experimental Example 1) and the case of filling the silylated catalyst in both the first and second stages (experimental) When the unsilylated oxidation catalyst was charged in the first stage and the silylated oxidation catalyst in the second stage (Experimental Example 5 to Experimental Example 8) compared to Example 2), the best catalyst performance and lifetime were shown. In addition, the change in catalyst performance was examined by adjusting the filling ratio (weight ratio) of the first and second stage catalysts under the same catalyst amount conditions. The maximum activity was shown when the catalyst filling ratio was 1/4 (Experimental Example 8). However, as described above, when all of the 1/2 stages were filled with the silylated oxidation catalyst, a rapid decrease in catalytic activity (Experimental Example 2) was observed.

When the oxidation reaction is carried out through the catalyst system, the catalyst performance decreases and the catalyst regeneration procedure should be performed at an appropriate time. Regeneration of the catalyst is carried out using a regeneration solvent that can effectively remove sulfur oxides and nitrogen oxides and hydrocarbon fractions deposited on the catalyst. At this time, acetone, methanol, acetonitrile, dimethylformamide, dimethyl ether, dimethyl carbonate, dimethyl sulfoxide and sulfolane may be used as the regeneration solvent.

Experimental Example  9: Regeneration Performance of Catalyst According to Regeneration Solvent

After the oxidation reaction, when the sulfur content in the reaction effluent reached 10 ppmw or more, a regeneration solvent was continuously flowed into the first and second stage fixed bed reactors to regenerate the catalyst. Acetone was used as the regeneration solvent, and the flow rate was 0.3 cc / min per minute so that the weight ratio of the regeneration solvent per catalyst was 10 (regeneration solvent / catalyst = 10 (weight / weight)), and the regeneration temperature and pressure were at room temperature and 1 atm. It was performed at.

Experimental Example  10 to 14: regeneration performance of the catalyst according to the type of regeneration solvent

Experimental Examples 10 to 14 were the same experiment as Experimental Example 9 except for changing the acetone in Experimental Example 9 to the regeneration solvent shown in Table 2.

Regeneration Solvent Regeneration cycle (h), sulfur content 10ppmw or less Reaction / Regeneration Conditions Experimental Example 9 Acetone 60 1.Sulfur / nitrogen content of the reactants: 310ppmw-S, 169 ppmw-N
2. Reaction conditions: space velocity (WHSV) 1.1 ^h-1 , 120 ° C., organic oxidizing agent (TBHP) / sulfur = 15 (mol / mol), unsilylated catalyst / silylated catalyst = 1.2g / 4.8g
3. Regeneration condition: Regeneration solvent / catalyst = 10 (weight / weight) Experimental Example 10 Methanol 74 Experimental Example 11 Acetone / Methanol ^{1 )} 171 Experimental Example 12 Dimethyl ether 52 Experimental Example 13 Dimethyl ether / Methanol ^{2 )} 156 Experimental Example 14 Dimethyl carbonate 189

1) The weight ratio of acetone / methanol is 2

2) The weight ratio of dimethyl ether / methanol is 2

In Experimental Examples 9 and 10, regeneration with acetone alone or methanol alone showed a gradual decrease in regeneration cycle as the regeneration was repeated. When the mixture was regenerated by mixing acetone and methanol in Experimental Example 11, hydrocarbon deposition and removal of polar sulfone / nitrogen compounds were better. The mixing ratio of the two solvents was relatively good when the acetone / methanol ratio of 2. If acetone is regenerated first and then methanol is regenerated sequentially, regeneration performance is superior to that of a mixed solvent, but may cause complexity of the regeneration solvent recovery process.

In the regeneration solvent determination of the oxidative desulfurization and sulfur oxide adsorption and desorption processes, the separation efficiency of the regeneration solvent should be considered. In particular, when excessive energy is consumed during the separation of the regeneration solvent, it is a decisive factor deteriorating the overall integrated process economics. Therefore, the latent heat of evaporation was considered in addition to the polarity of the regeneration solvent. The latent evaporation potential of methanol is 1,104 kJ / kg and the acetone evaporation potential is 518 kJ / kg, whereas dimethyl ether has a latent evaporation potential of 467 kJ / kg. In addition, dimethyl ether has a low boiling point, there is an advantage that a simple flash drum (flash drum) can be used for separation / recovery. However, in order to perform the regeneration in the liquid form, there is also a disadvantage in that reliquefaction of the separated gaseous dimethyl ether is required and a compression system for this is required. Compared with acetone / methanol sequential regeneration, when only dimethyl ether was used (Experimental Example 12), it was confirmed that regeneration efficiency was very low due to the steep decline in performance and a steep decline in performance. When dimethyl ether is used as acetone replacement regeneration solvent (Experimental Example 12), the integrated process economics are higher than when using acetone / methanol.

The boiling point of dimethyl carbonate is slightly higher than acetone, methanol and dimethyl ether, but relatively low at 90 ° C., and latent heat of evaporation is also significantly lower than that of other regeneration solvents. Three repeated regeneration experiments were carried out, and as a result, it was confirmed that the regeneration performance was almost the same as that of dimethyl ether / methanol sequential regeneration (Experimental Example 13) (Experimental Example 14). In addition, the amount of dimethyl carbonate used showed a stable regeneration efficiency within 10 times the catalyst weight.

Experimental Example  15: Regeneration Performance of Adsorbent According to Regeneration Solvent Type

The breakthrough of the sulfur oxides, ie, the saturated adsorbing point, removes the sulfur oxides adsorbed using a regeneration solvent and then uses the sulfur oxides for adsorption. Methanol was used as a regeneration solvent. The adsorption tower packed with the adsorbent was maintained at 40 ° C. for regeneration. Methanol, a regeneration solvent, was flowed at a rate of 1.0 h-1 at a space velocity of 10 times the weight of the adsorbent. After the regeneration step, the adsorbent was repeatedly used in the sulfur oxide adsorption process.

Experimental Example  16 to 19: regeneration performance of the adsorbent according to the type of regeneration solvent

Experimental Examples 16 to 19 were the same as in Experimental Example 15 except for changing the methanol in Experimental Example 15 to the regeneration solvent shown in Table 3.

Regeneration Solvent Regeneration cycle (h), sulfur content 10ppmw or less Reaction / Regeneration Conditions Experimental Example 15 Methanol 6 or less 1.Sulfur / nitrogen content of the reactants: 150 ppmw-S, 169 ppmw-N
2. Adsorption condition: Space velocity (WHSV) 1.0 h ^-1 , 40 ℃
3. Desorption condition: Desorption space velocity (0.2 ~ 1.0 h ^-1 ) 40 ℃ Experimental Example 16 Acetone 6 or less Experimental Example 17 Dimethyl ether More than 14 Experimental Example 18 Dimethyl carbonate More than 14 Experimental Example 19 Methyl tert-butyl ether 14 or more

4 and 5, when methanol and acetone were used as regeneration solvents of the adsorbent, the adsorption amount (adsorption drainage) gradually decreased as the adsorption process was repeated. Although the initial amount of sulfur oxides was 12-14 times higher than the weight of the adsorbent, the adsorption capacity decreased as the regeneration of the adsorbent with methanol and acetone was repeated.

6 to 8, in the case of using dimethyl ether (DME), dimethyl carbonate (DMC), and methyl tert-butyl ether (MTBE), even if the adsorption process is repeated, There was no big change. This is because DME, DMC, and MTBE, which are used as regeneration solvents, effectively remove sulfur oxides adsorbed on the adsorbent and impurities including various polar substances and hydrocarbons. Through this, it can be seen that DME, DMC, MTBE is a regeneration solvent suitable for regeneration of the adsorbent used in the sulfur oxide separation process.

On the other hand, the present invention is not limited to the embodiments described, it is apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations will have to be belong to the claims of the present invention.

Claims (17)

(a) contacting an oxidant with a hydrocarbon in the presence of an oxidation catalyst to convert sulfur compounds in the hydrocarbon to sulfur oxides,
Step (a) comprises i) an oxidation reaction step of contacting the oxidant with a hydrocarbon in the presence of an unsilylated oxidation catalyst and ii) an oxidation reaction step of contacting the oxidant with a hydrocarbon in the presence of a silylated oxidation catalyst; ,
(b) removing sulfur oxides with an extractant or adsorbent. The method according to claim 1,
(c) further comprising the step of regenerating the oxidation catalyst or the adsorbent. The method according to claim 2,
The oxidation desulfurization method of a hydrocarbon, wherein the regeneration of the oxidation catalyst or the adsorbent uses the same regeneration solvent. The method of claim 3,
The regeneration solvent is at least one selected from the group consisting of dimethyl carbonate, dimethyl ether, dimethylformamide, methanol, acetone, dimethyl sulfoxide, acetonitrile, polyethylene glycol, and sulfolane. The method according to claim 1,
The extracting agent is a oxidative desulfurization method of a hydrocarbon, characterized in that at least one selected from the group consisting of dimethyl carbonate, dimethyl ether, dimethylformamide, methanol, acetone, dimethyl sulfoxide, acetonitrile, polyethylene glycol, and sulfolane. The method according to claim 1,
The reactor in step (a) is a oxidative desulfurization method of a hydrocarbon, characterized in that consisting of a one-stage reactor and a two-stage reactor. The method of claim 6,
A method of oxidative desulfurization of hydrocarbons, characterized in that the catalyst filling ratio of the unsilylated oxidation catalyst of the first stage reactor and the silylated oxidation catalyst of the two stage reactor is 1: 1 to 1:10. The method according to claim 1,
The hydrocarbon oxidative desulfurization method of the hydrocarbon, characterized in that selected from the group consisting of hydrocarbons derived from atmospheric distillation column, hydrocarbons derived from hydrodesulfurization and hydrocracking process, or hydrocarbons derived from fluidized bed catalytic cracking process. The method according to claim 1,
The oxidation catalyst is oxidative desulfurization of a hydrocarbon, characterized in that the transition metal is supported on one or more carriers selected from the group consisting of silica, alumina, and silica-alumina, or the transition metal is supported on a carrier in a chelate form. Way. The method of claim 9,
The transition metal is a oxidative desulfurization method of a hydrocarbon, characterized in that any one selected from the group consisting of chromium, copper, manganese, nickel, vanadium, zinc, iridium, aluminum, iron, cobalt or titanium. The method of claim 9,
Chelating agents used in the preparation of the transition metal in the form of a chelate on the carrier are acetylacetone, 3-allyl-2,4-pentanedione, 3-acetyl-6-trimethoxysilylhexane-2-one, ethyl Selected from the group consisting of acetoacetate, allyl acetoacetate, methacryloxyethyl acetoacetate, trifluoro acetylacetone, pentaproloacetylacetone, benzol acetone, dipivaloyl methane, dimethylmalonate, dimethylglyoxime and salicylicaldehyde A method for oxidative desulfurization of a hydrocarbon, characterized in that it is a single chelating agent or two or more chelating agents. The method according to claim 1,
Wherein the oxidant is selected from the group consisting of organic peroxides, hydrogen peroxide, oxygen and ozone. The method according to claim 1,
The adsorbent is oxidative desulfurization of hydrocarbons, characterized in that selected from the group consisting of activated carbon, silica, alumina, and silica-alumina. The method according to claim 1,
The oxidation reaction of step (a) is oxidative desulfurization of a hydrocarbon, characterized in that the reaction temperature is carried out at 0 ~ 200 ℃. The method according to claim 1,
The oxidation reaction of step (a) is oxidative desulfurization of a hydrocarbon, characterized in that the reaction pressure is carried out at 0.5 ~ 40bar. The method according to claim 1,
The oxidation reaction of step (a) is a oxidative desulfurization method of a hydrocarbon, characterized in that the molar ratio of the oxidant to the sulfur compound in the hydrocarbon ranges from 1: 2 to 1:20. The method according to claim 1,
The oxidation reaction of step (a) is oxidative desulfurization of a hydrocarbon, characterized in that carried out at a space velocity of the hydrocarbon in the range of 0.1 ~ 10 hr ^-1 .

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