JP2002020766A - Hydrogenation of gas oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for hydrogenation of gas oil that can produce the gas oil meeting the severe environmental regulations as a fuel oil. SOLUTION: The gas oil is subjected to hydrogenation in the presence of a catalyst including at least one selected from heavy rare earth elements and at least one of noble metal selected from the group VIII noble metals wherein oxygen and/or organic oxygen-containing compound are allowed to exist in the reaction system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hydrotreating gas oil, and more particularly, to a method for hydrotreating gas oil in which sulfur contained in gas oil is reduced to an ultra-low depth in the presence of a specific catalyst. .

[0002]

BACKGROUND ART Diesel engines, good fuel economy, durability and reliability, are used in many commercial vehicles because of the low CO ₂ emissions. However, despite the economic advantages of this engine, the effects of diesel emissions on air pollution in urban and roadside areas are becoming more and more serious. In particular, the effects on health of particulate matter (formed from soot, organic solvent insoluble matter, sulfate, moisture, etc.) are strongly concerned, and the Central Environment Council Report (December 14, 1998) reported that A significant reduction has been reported. The effectiveness of gas oil quality improvement is being recognized around the world, and in order to reduce particulate matter, engine improvement and exhaust gas post-treatment technology are being intensively studied.

[0003] Commercial gas oil in Japan is manufactured from a straight-run gas oil base obtained by distilling crude oil, a cracked gas oil base, a kerosene base added to prevent solidification, and the like. Is an oil that has been subjected to a deep desulfurization treatment in order to make the oil content 500 ppm or less. The catalyst used for the deep desulfurization treatment is
A transition metal based on nickel, cobalt and molybdenum is supported on a porous carrier such as alumina, and mild nuclear hydrogenation, isomerization, desulfurization, etc. to promote desulfurization of sulfur-containing compounds that are difficult to desulfurize. The functions of are well controlled. Deep desulfurization of gas oil is performed under high temperature and high hydrogen pressure conditions, and the reaction temperature is raised to compensate for the decrease in catalyst performance with the lapse of processing time to produce a constant quality deep desulfurized gas oil. ing.

[0004] However, air pollution, especially in metropolitan areas, is becoming more and more serious in spite of the stricter exhaust gas regulations mentioned above. In the future, further cleanliness is required for fuel oil such as light oil. Have been. The European Union has already determined that the sulfur content should be below 350 ppm in 2000 and below 50 ppm in 2005,
Eventually, it is expected that strict regulations will follow in Japan.

Therefore, in order to comply with strict environmental regulations expected in the future, the development of a high-performance catalyst capable of reducing the sulfur content in light oil in compliance with the strict regulation values is an important issue, Development of new hydrotreating methods is required.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved gas oil hydrotreating method for producing gas oil as a fuel oil capable of meeting the aforementioned strict environmental regulations.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, in the hydrogenation treatment of gas oil, a specific heavy rare earth element and a noble metal component in the rare earth metal have been found. When a gas oil containing oxygen and / or an organic oxygen-containing compound was used in the presence of a catalyst containing, the catalyst was found to exhibit high desulfurization activity, and the present invention was completed.

That is, the present invention hydrotreats light oil in the presence of a catalyst containing at least one element selected from heavy rare earth elements and at least one noble metal selected from Group VIII noble metals of the periodic table. The present invention relates to a method for hydrotreating light oil, wherein a compound containing oxygen and / or organic oxygen is present in a reaction system.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail.

The gas oil used in the present invention is a catalytic cracking gas oil, a pyrolysis gas oil, a straight-run gas oil, a coker gas oil or a gas oil which has been hydrotreated by a conventional method, and has a sulfur content of 50 ppm or more. Oil. Preferably, deep desulfurized gas oil is used.

[0011] The amount of the oxygen and / or organic oxygen-containing compound is preferably 10,000 ppm or less and 100 ppm or more as oxygen element relative to light oil. The amount of the oxygen and / or organic oxygen-containing compound is 10
If it exceeds 000 ppm, the desulfurization activity may decrease. When the amount of the oxygen and / or organic oxygen-containing compound is less than 100 ppm as an oxygen element, the effect of the present invention may not be obtained. The optimum amount of the oxygen and / or organic oxygen-containing compound depends on the content of sulfur contained in the gas oil. As the sulfur content increases, the larger the amount of the coexisting oxygen and / or organic oxygen-containing compound, the better. It is in. A particularly preferable amount as the oxygen element is
It is desirable to select in the range of 200 to 5000 ppm.

Examples of the oxygen source used in the present invention include oxygen gas, air, and water. Examples of the organic oxygen-containing compound include coal liquefied oil, biomass oil, and oxidized LC.
Compounds such as O, tetralone, phenols, furans, benzofurans, naphthols, cresols, alcohols, aldehydes, carboxylic acids, oxycarboxylic acids, and ketones are exemplified.

The above-mentioned compound containing oxygen and / or organic oxygen can be dissolved in gas oil as a feedstock and supplied into the reaction system, or the reaction system can be supplied by a different supply means from the gas oil as the feedstock. It may be supplied inside.

As the catalyst used in the present invention containing at least one element selected from heavy rare earth elements and at least one noble metal selected from Group VIII noble metals of the periodic table, the present inventors have previously described Proposed Japanese Patent Application 2000-063
No. 986, the aromatic hydrocarbon hydrogenation catalyst composition disclosed in Japanese Patent Application No. 11-327069 and Japanese Patent Application No.
And the catalyst described in US Pat. No. 3,580,795.

That is, the heavy rare earth element which is a component of the catalyst used in the present invention includes ytterbium (Yb), gadolinium (Gd), terbium (Tb) and dysprosium (D
y) means the four elements. As the catalyst component, at least one element selected from the heavy rare earth elements is used, and the content of the heavy rare earth element is preferably 0.5 to 40% by weight as a metal (based on the catalyst composition). Preferably, it is in the range of 2.0 to 20% by weight.

The other components of the catalyst used in the present invention are at least one noble metal selected from Group VIII noble metals of the periodic table. As the noble metal, ruthenium, rhodium, palladium, osmium, iridium,
Platinum and the like are exemplified. The content of the above-mentioned noble metal is 0.1 to 10% by weight (based on the catalyst composition) as a metal, and more preferably 0.5 to 5% by weight.

As the noble metal in the catalyst used in the present invention, it is particularly preferable to use a combination of palladium and platinum. By using palladium and platinum in combination, the resistance to sulfur compounds is increased while maintaining a high hydrogenation function. This is presumed to be because palladium has a high affinity for sulfur and thus protects against sulfur poisoning of platinum. The combination of palladium and platinum is Pd / P
It is desirable that the t atomic ratio is in the range of 0.1 / 1 to 10/1.

One of the preferred catalysts in the present invention is a carrier comprising a porous inorganic oxide comprising at least one element selected from heavy rare earth elements and at least one noble metal selected from Group VIII noble metals of the periodic table. It is a catalyst supported on.

The above-mentioned porous inorganic oxides include alumina, silica, titania, zirconia, alumina-silica, alumina-titania, alumina-boria, alumina-phosphorus, silica-titania, alumina-silica-titania, alumina-silica -Boria, alumina-phosphorus-boria, alumina-titania-boria, alumina-silica-
Usually, such as phosphorus, alumina-titania-phosphorus-boria,
Porous inorganic oxides used for hydrotreating catalysts such as gas oil can be used.

Further, another preferred catalyst of the present invention is to convert at least one element selected from heavy rare earth elements and at least one noble metal selected from Group VIII noble metals of the periodic table into a crystalline aluminosilicate zeolite. It is a supported catalyst.

Examples of the crystalline aluminosilicate zeolite include A-type zeolite, X-type zeolite, Y-type zeolite, L-type zeolite, beta-type zeolite, mordenite, chabazite, erionite, AlPO ₄ ,
Examples include MFI-type zeolites such as pentasil-type zeolites represented by SAPO and ZSM zeolites. In particular, the molar ratio of SiO ₂ / Al ₂ O ₃ is 5 or more, preferably 10 to 1000, more preferably 10 to 300.
The super-stabilized Y-type zeolite is preferred because it has a suitable solid acid.

Other preferred catalysts according to the present invention are at least one element selected from heavy rare earth elements and Periodic Table VI.
It is a catalyst in which at least one noble metal selected from Group II noble metals is supported on a carrier composed of a crystalline aluminosilicate zeolite and a porous inorganic oxide. The above-mentioned porous inorganic oxide can be used as the porous inorganic oxide, and the above-mentioned crystalline aluminosilicate zeolite can be used as the crystalline aluminosilicate zeolite.

In the hydrotreating of the present invention, ordinary conditions for hydrotreating light oil can be employed. Specifically, the reaction temperature is 200 to 400 ° C, preferably 250 to 350 ° C.
° C, the liquid hourly space velocity is 0.1 to 5.0 h ^-1 , preferably 2.0 to 4.0 h ^-1 and the hydrogen pressure is 2.9 to 14.7.
MPa, preferably 3.9 to 7.8 MPa.

In the presence of a catalyst containing at least one element selected from heavy rare earth elements and at least one noble metal selected from Group VIII noble metals of the periodic table, a trace amount of oxygen is present in the reaction system. The reason why the desulfurization activity is increased by hydrotreating gas oil is not clear at present, but it is observed that the desulfurization activity increases as an experimental fact.

In the hydrotreating method of the present invention, the amount of the oxygen and / or organic oxygen-containing compound present in the reaction system is controlled with respect to the light oil or the sulfur content in the light oil, so that the desulfurization activity can be selectively increased. It is capable of improving and suppressing the hydrogenation activity, and has a feature that a high desulfurization rate can be obtained with a small amount of hydrogen consumption. Further, the hydrotreating method according to the present invention comprises:
Unlike the conventional oxidative desulfurization method using hydrogen peroxide, etc., there is no sludge generation, and the distillation and extraction of oxidized oil to remove sulfur compounds in which oxygen compounds coexist.
It is characterized in that a separation operation by adsorption or the like is unnecessary.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples and reference examples, but the present invention is not limited to these examples.

Reference Example 1 (Preparation of Catalyst) As a zeolite for supporting a heavy rare earth element, an ultra-stabilized Y-type zeolite [HSZ-360HUA, manufactured by Tosoh Corporation]
iO ₂ / Al ₂ O ₃ , molar ratio = 13.9, H-type zeolite] (hereinafter simply referred to as zeolite A), and Yb heavy rare earth element was carried on the zeolite A by an ion exchange method. That is, about 15 g of zeolite A is immersed in 3 L of an aqueous solution having a Yb metal ion concentration of 0.16 mol / L, stirred at room temperature for 24 hours, filtered, washed with pure water, and then dried at 110 ° C. overnight. did. In this way,
Zeolite A supporting Yb as a metal ion (Yb
-Zeolite A, Yb content; 2.2 wt%).

Next, this heavy rare earth element-supported zeolite A
On the other hand, Pd and Pt were supported by an impregnation method. That is,
[Pd (NH₃)₄] Cl₂0.109 g of [Pt
(NH ₃)₄] Cl₂0.039g of 5.5ml pure
Dissolve in water to form an impregnating solution, and pump this solution down.
Was sucked into 5.0 g of the rare earth element-supported zeolite thus obtained.
After drying at 60 ° C. for 6 hours in a vacuum,
After shaping into a disc shape, crushed and 22-48me
sh. The obtained catalyst A (Pd content: 0.69
wt%, Pt content: 0.31 wt%)
The aqueous solution of sodium was stored in a desiccator saturated with water.
The catalyst A was placed in an oxygen stream (2 L / m2) immediately before the activity evaluation.
ing), 300 ° C. for 3 hours (heating rate: 0.5 ° C./m)
in) Fired. In addition, the reduction of the catalyst A was performed before the activity evaluation.
The treatment was performed in the reaction system.

Example 1 (Evaluation by Model Substance: Addition of α-Tetralone as Organic Oxygen Compound) Using Catalyst A of Reference Example 1 (Pd-Pt / Yb / USY), Desulfurization Activity and Hydrogenation of Aromatic Hydrocarbons Activity was evaluated.
The catalyst was reduced before the reaction. The catalyst is filled in a reaction tube, and is heated to 300 ° C. in a hydrogen stream (normal pressure, 0.2 L / min).
For 3 hours (heating rate; 0.5 ° C./min). In the reaction test, the desulfurization activity and the hydrogenation activity of four kinds of model substances as feedstocks were examined using a high-pressure fixed-bed flow reactor (upflow mode). The content of the prepared model substance is
(1) tetralin / n-hexadecane = about 30 wt% /
In a mixed solution of about 70 wt%, 4,6-dimethyldibenzothiophene (4,6-DMDBT, sulfur concentration 300 pp
m) and n-hexadecane (NBA, nitrogen concentration 20 pp)
m), and (2) 4,6-DMD was added to a mixed solution of tetralin / n-hexadecane = about 30 wt% / about 70 wt%.
BT (sulfur concentration 300 ppm) and NBA (nitrogen concentration 20
ppm) and α-tetralone (oxygen concentration 1000ppm)
(3) tetralin / n-hexadecane = about 30
4,6-DMDBT in a mixed solution of wt% / about 70 wt%
(Sulfur concentration 300 ppm) and NBA (nitrogen concentration 20 pp)
m) and α-tetralone (oxygen concentration 2000 ppm), and (4) tetralin / n-hexadecane = about 30 wt.
% / About 70 wt% mixed solution in 4,6-DMDBT (sulfur concentration 300 ppm) and NBA (nitrogen concentration 20 ppm)
And α-tetralone (oxygen concentration: 3000 ppm). In the reaction, the catalyst amount was 0.25 g, the hydrogen partial pressure was 3.9 MPa, the reaction temperature was 280 ° C., and the space velocity (WHS
V) The test was performed under the conditions of 16 h ^-1 and a H ₂ / Oil ratio of 500 NL / L. Liquid products were collected periodically and analyzed on a gas chromatograph equipped with a FID detector and a capillary column. A sulfur analyzer by coulometric titration was used for sulfur analysis.

FIG. 1 shows the results of the hydrodesulfurization reaction, and FIG. 2 shows the hydrogenation activity. FIG. 3 shows the desulfurization activity when the oil passing time is 50 hours. It can be seen that when the reaction is stabilized when the oil passing time is about 50 hours, high desulfurization activity is exhibited when oxygen is present at about 1000 ppm.

Example 2 (Evaluation by Model Substance: Bubbling with Pure Oxygen Gas) The desulfurization activity and hydrogenation activity of aromatic hydrocarbons were evaluated using catalyst A (Pd-Pt / Yb / USY) of Reference Example 1. .
The catalyst was reduced before the reaction. The catalyst is filled in a reaction tube, and is heated to 300 ° C. in a hydrogen stream (normal pressure, 0.2 L / min).
For 3 hours (heating rate; 0.5 ° C./min). In the reaction test, the desulfurization activity and the hydrogenation activity of two types of model materials as feedstocks were examined using a high-pressure fixed-bed flow reactor (upflow mode). The content of the prepared model substance is
(1) Tetraline / n-hexadecane containing pure oxygen gas having an oxygen concentration of 1000 ppm = about 30 wt% / about 70
In a wt% mixed solution, 4,6-dimethyldibenzothiophene (4,6-DMDBT, sulfur concentration 300 ppm) and n
Hexadecane (NBA, nitrogen concentration 20 ppm) was added. (2) 4,6-DMDBT (sulfur) was added to a mixed solution of tetralin / n-hexadecane = about 30 wt% / about 70 wt% containing pure oxygen gas having an oxygen concentration of 3000 ppm. (Concentration: 300 ppm) and NBA (nitrogen concentration: 20 ppm). In the reaction, the catalyst amount was 0.25 g, the hydrogen partial pressure was 3.9 MPa, the reaction temperature was 280 ° C., and the space velocity (WHS
V) The test was performed under the conditions of 16 h ^-1 and an H ₂ / Oil ratio of 500 NL / L. Liquid products were collected periodically and analyzed on a gas chromatograph equipped with a FID detector and a capillary column. A sulfur analyzer by coulometric titration was used for sulfur analysis. The result is shown in FIG. 3 together with the result of Example 1. It can be seen that the coexistence of oxygen in the reaction system reduces the hydrogenation activity but increases the desulfurization activity with the amount of oxygen.

Example 3 (Evaluation by Model Substance) Catalyst A obtained in Reference Example 1 and Catalyst B containing no heavy rare earth element (Pd-Pt / USY: the same components as in Catalyst A but containing Yb) The catalyst was evaluated for its desulfurization activity and hydrogenation activity. Each catalyst was reduced before the reaction. The catalyst was filled in a reaction tube, and reduced in a hydrogen stream (normal pressure, 0.2 L / min) at 300 ° C. for 3 hours (heating rate: 0.5 ° C./min). The reaction test was performed using a high-pressure fixed-bed flow-type reactor (up-flow mode) using a feedstock of tetralin / n-hexadecane = about 30 wt%.
The desulfurization activity and the hydrogenation activity of a mixture obtained by adding 4,6-DMDBT (sulfur concentration: 300 ppm), NBA (nitrogen concentration: 20 ppm) and α-tetralone (oxygen concentration: 1000 ppm) to a mixed solution of about / 70 wt% were examined. In the reaction, the catalyst amount was 0.25 g, the hydrogen partial pressure was 3.9 MPa, and the reaction temperature was 280.
C., a space velocity (WHSV) of 16 h ^-1 and an H ₂ / Oil ratio of 500 NL / L. Liquid products were collected periodically and analyzed on a gas chromatograph equipped with a FID detector and a capillary column. A sulfur analyzer by coulometric titration was used for sulfur analysis. The results are shown in FIGS. It can be seen from FIG. 4 that the catalyst A has a higher desulfurization activity than the catalyst B in the reaction system in which oxygen coexists after the reaction is stabilized.

Example 4 (Evaluation with light oil) The desulfurization activity and hydrogenation activity of light oil were evaluated using catalyst A and catalyst B described above. Each catalyst was reduced before the reaction.
The catalyst was filled in a reaction tube, and was placed in a hydrogen stream (normal pressure, 0.2 L /
min) at 300 ° C for 3 hours (heating rate; 0.5 ° C / m
in) reduced. The reaction test was conducted using a high-pressure fixed-bed flow reactor (up-flow mode), in which the desulfurization activity and hydrogen of the deep desulfurized gas oil (sulfur content: 263 ppm, nitrogen content: 8 ppm, total aromatic content: 26.3 wt%) of the feedstock oil were measured. Activating activity was examined. In addition, dissolved oxygen in deep desulfurized gas oil is 1100 pp.
m. In this reaction, the catalyst amount was 1.0 g, the hydrogen partial pressure was 3.9 MPa, the reaction temperature was 280 ° C., and the space velocity (WHS
V) The test was performed under the conditions of 4h ^-1 and an H ₂ / Oil ratio of 500 NL / L. Liquid products were collected periodically and analyzed on a supercritical chromatograph equipped with a FID detector. A sulfur analyzer by coulometric titration was used for sulfur analysis. The results are shown in FIGS. 6 and 7, it can be seen that, in the reaction system in which oxygen coexists, as the oil passing time of the catalyst A becomes longer than that of the catalyst B, both the desulfurization activity and the hydrogenation activity become higher.

[0034]

(1) According to the hydrotreating method of the present invention, a high degree of desulfurization is possible by bringing light oil containing oxygen and / or organic oxygen-containing compounds into contact with a noble metal catalyst containing heavy rare earth elements. . (2) The hydrotreating method of the present invention can selectively improve the desulfurization activity and stabilize the hydrogenation activity by controlling the amount of the oxygen and / or organic oxygen-containing compound, and can reduce the hydrogen consumption. High desulfurization is possible.

[Brief description of the drawings]

FIG. 1 shows the effect of a difference in oxygen concentration in a feed oil on desulfurization activity (Example 1).

FIG. 2 shows the effect of a difference in oxygen concentration in a feed oil on hydrogenation activity (Example 1).

FIG. 3 shows the relationship between the oxygen content in the feedstock oil, the desulfurization activity and the hydrogenation activity (Examples 1 and 2).

FIG. 4 shows the effect of heavy rare earth elements on the desulfurization reaction of oxygen-containing compound feedstock (Example 3).

FIG. 5 shows the effect of heavy rare earth elements on the hydrogenation reaction of oxygen-containing compound feedstock (Example 3).

FIG. 6 shows the effect of heavy rare earth elements on the desulfurization reaction of oxygen-containing compound feedstock (Example 4).

FIG. 7 shows the effect of heavy rare earth elements on the hydrogenation reaction of oxygen-containing compound feedstock (Example 4).

Continuation of the front page (71) Applicant 597126929 Hiroyuki Yasuda 1-408-101, Azuma, Tsukuba, Ibaraki (71) Applicant 597126930 Toshio Sato 702-69, Shimohirooka, Tsukuba, Ibaraki (71) Applicant 599069079 Norihito Kijima Ibaraki 1-401-409, Azuma, Tsukuba (74) The above five agents 100094466 Patent Attorney Eiji Tomomatsu (72) Inventor Yuji Yoshimura 5-526-201, Matsushiro, Tsukuba, Ibaraki Prefecture (72) Inventor Hiroyuki Yasuda Ibaraki Prefecture 1-408-101, Azuma, Tsukuba (72) Inventor Toshio Sato 702-69, Shimohirooka, Tsukuba, Ibaraki Prefecture (72) Inventor Tomohito Kijima 1-401-409, Azuma, Tsukuba, Ibaraki Prefecture (72) Inventor Takashi Kameoka Fukuoka 13-2 Kitaminato-cho, Wakamatsu-ku, Kitakyushu-shi, Japan Catalyst inside the Wakamatsu Plant of Kasei Kogyo Co., Ltd. (72) Koji Nakano 13-2 Kitaminato-cho, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Sumio 580, Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Catalyst F-term (reference) 4G069 AA 03 BA07B BC38A BC44B BC69A BC72B BC75B CC02 ZA05B 4H029 CA00 DA00

Claims (2)

[Claims] 1. A method for hydrotreating gas oil in the presence of a catalyst containing at least one element selected from heavy rare earth elements and at least one noble metal selected from Group VIII noble metals of the periodic table. A method for hydrotreating light oil, wherein a compound containing oxygen and / or organic oxygen is present in the reaction system. 2. The method for hydrotreating light oil according to claim 1, wherein the amount of the compound containing oxygen and / or organic oxygen is 10000 ppm or less as oxygen element relative to light oil.