KR20150076313A - Method for Producing Valuable Aromatic From Hydrocarbons - Google Patents

Abstract

The present invention relates to a manufacturing method of a high-added value aromatic product, including a hydrotreated step of hydro-treating a hydrocarbon oil fraction under a hydrotreated catalyst having transition metal phosphide, partially saturating rings on the aromatic carbon compounds with at least two benzene rings and removing sulfur, nitrogen or oxygen compounds; and a hydrotreated decomposition step of hydro-treating the product of the hydrotreated step under the hydro-treated catalyst having the transition metal phosphide and accordingly obtaining toluene or xylene wherein sulfur, nitrogen and oxygen compounds are well known for decreasing yield of manufacturing the aromatic products and can be efficiently removed in the present invention, thereby obtaining high concentrated aromatic products while substituting for an existing material, naphtha, and leading to high-added value oil fraction derived from coal such as coal tar.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for producing a high-value aromatic product from a hydrocarbon oil,

The present invention relates to a process for preparing high-value aromatic products comprising benzene, toluene and xylene from hydrocarbon oils derived from coal or wood.

Generally, when dry distillation of raw coke in a coke oven is performed in a coke oven, a solid coke is obtained in the carbonization chamber of the coke oven. As a by-product, liquid coal tar and coke oven gas (COG ) Is obtained. Coke oven gas (COG), which has the largest amount of heat generated by steelmaking processes, is mostly recycled as a primary energy source for heating steelmaking processes. However, in the case of coal tar, carbon- Black, naphthalene, pitch and the like, and they are regenerated as low-value-added raw materials such as tire, cement admixture and aluminum refining. Therefore, there is a need for a method for efficiently using coal tar from the steel industry with high added value.

In this situation, the global demand for benzene / toluene / xylene (BTX), a high-value aromatic product, is increasing by an annual average of 4 to 6%. Conventional aromatic products (BTX) have been produced by hydrotreating and extracting Pyrolysis gasoline produced in a Naphtha pyrolysis process or by separating a reformate from a naphtha raw material. However, naphtha, which is used as a raw material for existing technologies, is a narrow boiling range oil produced in the step of distillation of crude oil at the atmospheric distillation stage, and thus there is a problem that it can not cope with the increase in world demand. Therefore, there is an increasing interest in increasing the yield of aromatic products and aromatic products that can replace naphtha.

Therefore, coal tar, which is a mixture mainly composed of aromatic carbon compounds having two or three or more benzene rings, can be a good alternative as a raw material for aroma products, and aroma commercialization using coal tar has a high added value compared to the prior art. However, coal tar contains sulfur or nitrogen compounds in comparison with naphtha, so it is necessary to review the economic efficiency and efficiency due to problems of high temperature and high pressure reaction conditions or low yield of aromatic products.

Korean Patent Publication No. 2009-0020776 discloses a method of removing aromatic compounds and sulfur compounds from a fluidized bed catalytic cracking oil having a boiling point of 170 to 360 ° C and then dehydroalkylating to obtain aromatic hydrocarbons Lt; / RTI > Korean Patent Publication No. 2010-0042914 discloses a method for obtaining an aromatic component by decomposing a light cycle oil produced from a fluidized bed catalytic cracking process in the presence of a catalytic cracking catalyst.

It is intended to provide a method for producing an aromatic product with excellent efficiency using a simple process just by using oil derived from coal.

In one embodiment of the present invention, the step of hydrotreating a hydrocarbon oil fraction by partially saturating a ring of an aromatic carbon compound having two or more benzene rings in the presence of a hydrogenation catalyst containing a transition metal phosphide to remove sulfur, nitrogen, or oxygen compounds; And a hydrolysis step of hydrolyzing the product produced in the hydrotreating step in the presence of a hydrocracking catalyst containing a transition metal phosphide to obtain benzene, toluene or xylene, And a method for producing the product.

The hydrocarbon oil fraction may be selected from the group consisting of coal tar, tar oil, diesel oil, coal oil, naphthalene oil, wash oil, anthracene oil, hard anthracene oil, heavy anthracene oil, pitch, wood tar, hardwood tar, resin tar, Or from one or more selected from coal or tree-derived hydrocarbon oils.

At this time, it is preferable that the hydrogenated catalyst is supported on a silica, alumina or silica-alumina carrier with a transition metal phosphide,

The reaction temperature in the hydrotreating step is preferably 300 to 400 ° C and the pressure is 10 to 50 atm.

The hydrocracking catalyst may be one in which the transition metal phosphide is supported on the crystalline zeolite,

The crystalline zeolite preferably has a pore size of 4 to 12 Angstroms and a Si / Al molar ratio of 5.0 to 300

The crystalline zeolite is preferably at least one selected from the group consisting of FAU, MFI, MOR and BEA.

The reaction temperature of the hydrocracking step may be 350 to 500 ° C and the pressure may be 10 to 60 atm.

Further, the transition metal phosphide included in the hydrotreating catalyst and the hydrocracking catalyst may include at least one metal selected from the group consisting of Group 6, Group 8, Group 9 and Group 10 metals,

The transition metal phosphide is preferably at least one selected from the group consisting of Ni ₂ P, Co ₂ P, Fe ₂ P, MoP and WP.

In the production of aromatic products, high concentrations of aromatic products can be obtained by effectively removing sulfur, nitrogen and oxygen compounds, which are the main factors inhibiting yield.

In addition, it is possible to substitute naphtha, which is an existing raw material, to enhance the high value of the oil derived from coal such as coal tar, and to provide a manufacturing method that can meet the demand of the world-wide aromatic products.

1 is a schematic view showing a process for producing an aromatic product according to an embodiment of the present invention.
FIG. 2 is a view showing a molecular structure of a process of decomposing naphthalene into a high-value aromatic product (BTX) according to an embodiment of the present invention.

According to one aspect of the present invention, there is provided a process for producing a hydrocarbons, comprising: a hydrotreating step of partially saturating a ring of an aromatic carbon compound having two or more benzene rings in the presence of a hydrotreating catalyst containing a transition metal phosphide to remove sulfur, nitrogen, or oxygen compounds; And a hydrocracking step of hydrolyzing the product produced in the hydrotreating step in the presence of a hydrocracking catalyst containing a transition metal phosphide to obtain benzene, toluene or xylene, A method for producing an aromatic product can be provided.

The high-value aromatic production process according to an embodiment of the present invention can be confirmed by referring to FIG. That is, a raw material and hydrogen are introduced into a fixed-bed catalytic reactor and hydrotreated in the presence of a catalyst (hydrogenation catalyst). The hydrocracking reaction is carried out in the presence of a catalyst (hydrocracking catalyst) by introducing a reaction product in which sulfur, nitrogen, and oxygen compounds have been removed by hydrogenation reaction into a separate fixed bed catalytic reactor together with hydrogen. When the hydrocracking reaction is complete, the final BTX can be obtained.

In the case of the present invention, there is a simpler process than the conventional process for producing an aromatic product. In the conventional case, the intermediate product, toluene and trimethylbenzene are transalkylated to increase the yield of BTX. On the other hand, according to the present invention, not only the content of trimethylbenzene in the intermediate product is low but also the content of trimethylbenzene The process can be simplified because the yield of xylene with high added value is high without transalkylation.

According to a preferred embodiment of the present invention, the hydrocarbon oil is selected from the group consisting of coal tar, tar oil, diesel oil, coal oil oil, naphthalene oil, wash oil, anthracene oil, light anthracene oil, heavy anthracene oil, pitch, Or a mixture thereof. ≪ / RTI > More preferably Coal tar produced from the metallurgical coke production process and most preferably a liquid coal tar which is a mixture of an aromatic carbon compound and a sulfur or nitrogen compound having two or more benzene rings

At this time, the coal tar is typically a hydrocarbon mixture containing about 80-90% of an aromatic component having two or more benzene rings, 2 to 3 wt% of a sulfur compound, 2 to 3 wt% of a nitrogen compound, and 4 to 5 wt% .

According to the present invention, in the hydrotreating step, a hydrogenation reaction is performed in which sulfur, nitrogen and oxygen compounds are removed in the presence of a hydrotreating catalyst containing a transition metal phosphide, and a benzene ring partially saturates rings of two or more aromatic carbon compounds . More preferably, the aromatic component having two or more benzene rings may be completely saturated while leaving one benzene ring. However, there may be an aromatic component having two or more benzene rings even after partial saturation depending on the case. Do not. In this case, partial saturation means that the unsaturated bonds of the remaining benzene rings except one or two benzene rings out of two or more benzene rings are broken to form a saturated bond. For example, as shown in FIG. 2, when naphthalene is partially saturated, it may become tetralin.

According to a preferred embodiment of the present invention, as the hydrogenation catalyst, silica, alumina or a silica-alumina carrier carrying a transition metal phosphide can be used. In this case, the transition metal phosphide may include at least one transition metal selected from the group consisting of Group 6, Group 8, Group 9 and Group 10 metals of the periodic table, more preferably nickel, cobalt, iron, (Ni ₂ P, Co ₂ P, Fe ₂ P, MoP, and WP) including at least one transition metal selected from the group consisting of molybdenum and tungsten.

When a transition metal phosphide is included in the catalyst, the catalyst is excellent in stability and can function as a multifunctional catalyst having an acid site and hydrogenation activity. In addition, sulfur, nitrogen, and oxygen compounds are subjected to hydrogenation reaction to produce H ₂ S, NH ₃ Or it can be smoothly help the reaction that is converted in the form of H ₂ O.

If only the transition metal is used in the reaction, it easily exhibits sulphide (poisoning) behavior and the hydrogenation reaction of sulfur, nitrogen, and oxygen compounds may be inactivated. On the other hand, when the transition metal phosphide is used, not only the hydrotreating activity inherent to the transition metal is maintained but also the linearity is improved, so that the catalytic activity can be improved. As a result, most of the sulfur, nitrogen and oxygen compounds can be removed from the product produced in the hydrotreating step, so that the hydrocracking reaction can easily occur and consequently the final BTX yield can be increased.

According to a preferred embodiment of the present invention, the hydrogenation step may be carried out at a temperature of 300 to 400 ° C. and a pressure of 10 to 50 atm, preferably at a temperature of 350 to 375 ° C., at a pressure of 25 to 35 atm The reaction can be carried out. Further, the space velocity (LHSV) during the reaction may be 0.1 to 5.0 ^hr < -1 >, preferably 1.0 to 3.0 ^hr < ^-1 >. Since the partial saturation reaction activity of the aromatic ring by the transition metal phosphide catalyst is excellent, the reaction can be carried out at the space velocity within the above range.

On the other hand, in the hydrogenolysis step, the product produced in the hydrotreating step is preferably one or two or more aromatic carbon compounds in which the benzene ring is substituted with an alkyl group, and a mixed aromatic carbon compound thereof in the presence of a transition metal phosphide And then hydrogenolysis is carried out in the presence of a hydrocracking catalyst to produce benzene, toluene, or xylene. In the hydrogenolysis step, an alkane chain having a carbon-carbon bond or a naphthene ring is broken to form an unsaturated hydrocarbon, and then an unsaturated hydrocarbon is added with hydrogen to convert to a saturated hydrocarbon.

At this time, according to a preferred embodiment of the present invention, a hydrocracking catalyst containing a transition metal phosphide may also be used in the hydrocracking step. In this case, the transition metal phosphide may include at least one transition metal selected from the group consisting of Group 6, Group 8, Group 9 and Group 10 metals of the periodic table as well as those included in the hydroxide catalyst, it may be a nickel, cobalt, iron, molybdenum and a transition metal phosphide to at least one selected from the group comprising tungsten, the transition comprises a metal _{(Ni 2 P, Co 2 P} , Fe 2 P, MoP, WP). However, it is preferable that the transition metal phosphide of the catalyst to be added at the hydrolysis is supported on the crystalline molecular sieve having acid sites, i.e., crystalline zeolite.

According to a preferred embodiment of the present invention, the crystalline zeolite may have a pore size of 4-12 angstroms and a Si / Al molar ratio of 5.0-300. The size of the pores may be more preferably 6 to 12 Å so that the aromatic component can react in the pores. Accordingly, the crystalline zeolite may be at least one selected from the group consisting of FAU, MFI, MOR, and BEA, and more preferably FAU or BEA represented by Y (or ReY, USY).

According to a preferred embodiment of the present invention, the hydrocracking step may be carried out at a temperature of from 350 to 500 ° C. and a pressure of from 10 to 60 atm, preferably from 375 to 450 ° C. and a pressure of from 25 to 35 atm The reaction can be carried out. In addition, the space velocity in the reaction may be 0.1 to 5.0 ^hr < ^{-1 &} gt ;, preferably 1.0 to 3.0 ^hr < ^-1 >.

In the hydrocracking step, a reaction can easily occur due to a sufficient desulfurization, denitrification, and deoxygenation of the product as a reactant in the hydrotreating step. In addition, the use of the transition metal phosphide which is excellent in the catalyst stability and the reaction activity enhancing action is included in the catalyst, so that the hydrogenation reaction occurs at a high rate. This leads to a significant increase in the yield of high-value aromatic products such as benzene, toluene and xylene through the hydrocracking step. At this time, it is preferable that the gas generated together with BTX is separated and removed separately.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for the purpose of illustrating the present invention more specifically, and the present invention is not limited thereto.

Example

Oil fractions having a boiling point in the range of 290 ° C or lower were prepared as raw materials from coal tar oil, and the components thereof are shown in Table 1 below.

compound Content (wt%) BTX 0.7 phenol 1.5 Inden 2.6 naphthalene 59.2 Benzothiopine 1.7 Quinoline 1.4 2-methylnaphthalene 5.4 1-methylnaphthalene 2.3 Bai Pan 1.7 Dimethylnaphthalene 2.8 Acenaphthene 4.7 Dibenzofuran 5.7 Fluorine 4.2 Phenanthrene 0.1 Etc 6

The coal tar was fed into a fixed-bed catalytic reactor and hydrotreated. Nickel phosphide (Ni ₂ P) was used as the catalyst, and silica was used as the support. The temperature of the reactor was controlled at 375 ° C, the pressure was 30 atm and the space velocity was controlled to 3 hr ^-1 . The product was sampled every 1 hour to collect 1 ml of product. The compounds obtained according to the hydrotreating reaction results and their contents are shown in Table 2 below.

compound Content (wt%) naphthalene 25.1 Tetralin 54.1 C1-naphthalene 3.5 C2-naphthalene 5 C3-naphthalene 4 C4-naphthalene 0.1 Phenanthrene 0.1 Etc 8.1

Comparing Tables 1 and 2, the content of naphthalene decreased from 59.2 wt% to 25 wt%, and most of the carbon compounds having two or more benzene rings were partially saturated to reduce the content thereof, but they were no longer present . In addition, the contents of sulfur compounds and nitrogen compounds in the products obtained after the hydrotreating reaction were analyzed by an elemental analyzer. It was found that most of the sulfur compounds and nitrogen compounds were removed by hydrogenation reaction under 10 ppm.

Then, the product obtained after the hydrotreating reaction was introduced into another fixed bed catalytic reactor and hydrocracked in the presence of a hydrocracking catalyst. At this time, as the hydrocracking catalyst, nickel phosphide supported on the crystalline zeolite molecular sieve of BEA structure was used. The reaction temperature was controlled at 375 ° C., the reaction pressure was 30 atm, and the space velocity was controlled to ³ hr -1. The results of hydrocracking reaction are shown in Table 3 below.

compound Content (wt%) benzene 2.3 toluene 5.3 Xylene 41.5 Ethylbenzene 5.1 Trimethylbenzene 0.5 Decalin 4.9 Tetralin 4.2 naphthalene 2.2 Alkane 21.0 Etc 13.0

As can be seen from the above results, benzene, toluene and xylene were produced with a total yield of 50 wt% after the hydrocracking reaction. Particularly, in the case of xylene, a high proportion of 40 wt% was obtained. The high yield BTX product was obtained because it was possible to remove the sulfur compounds and nitrogen compounds in the raw material during the hydrotreating reaction and the hydrocracking reaction could easily occur.

Claims (10)

A hydrogenation step of hydrotreating hydrocarbon oil in the presence of a hydrotreating catalyst containing a transition metal phosphide to partially saturate a ring of aromatic carbon compounds having two or more benzene rings and removing sulfur, nitrogen, or oxygen compounds; And
And a hydrolysis step of hydrolyzing the product produced in the hydrotreating step in the presence of a hydrocracking catalyst containing a transition metal phosphide to obtain benzene, toluene or xylene, ≪ / RTI >
The method according to claim 1, wherein the hydrocarbon oil is selected from the group consisting of coal tar, tar oil, diesel oil, phenol oil, naphthalene oil, wash oil, anthracene oil, hard anthracene oil, heavy anthracene oil, pitch, wood tar, Wherein the hydrocarbon fraction is one or more selected from the group consisting of coal or wood-derived hydrocarbon oils.
The process according to claim 1, wherein the hydrotreating catalyst is supported on a silica, alumina or silica-alumina carrier with a transition metal phosphide.
The process according to claim 1, wherein the hydrogenation step has a reaction temperature of 300 to 400 ° C and a pressure of 10 to 50 atm.
The method of claim 1, wherein the hydrocracking catalyst is a crystalline zeolite having a transition metal phosphide supported thereon.
6. The method of claim 5, wherein the crystalline zeolite has a pore size of 4-12 Angstroms and a Si / Al molar ratio of 5.0-300.
6. The method of claim 5, wherein the crystalline zeolite is at least one selected from the group consisting of FAU, MFI, MOR, and BEA.
The process according to claim 1, wherein the hydrocracking step has a reaction temperature of 350 to 500 ° C and a pressure of 10 to 60 atm.
6. The method of claim 3 or 5, wherein the transition metal phosphide comprises at least one metal selected from the group consisting of Group 6, Group 8, Group 9 and Group 10 metals.
The method of claim 3 or 5, wherein the transition metal phosphide is at least one selected from the group consisting of Ni ₂ P, Co ₂ P, Fe ₂ P, MoP and WP.

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