JP3263940B2 - Catalyst for hydrodesulfurization and denitrification of hydrocarbon oils - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hydrotreating catalyst for effectively removing both sulfur compounds and nitrogen compounds contained in a hydrocarbon oil. More specifically, a hydrocarbon oil containing a large amount of sulfur compounds, particularly nitrogen compounds, is treated under hydrogen pressure to convert it into hydrogen sulfide and ammonia, thereby simultaneously reducing the sulfur and nitrogen contents in the raw hydrocarbon oil. The present invention relates to a hydrotreating catalyst used in the present invention.

[0002]

2. Description of the Related Art Conventional hydrotreating catalysts mainly based on hydrodesulfurization include a catalyst support having porous alumina as a base material.
A catalyst supporting a Group 6 metal and a Group 9 or 10 metal of the periodic table is generally used. However, these hydrotreating catalysts reduce the amount of hydrogen consumed during the hydrodesulfurization reaction and show high activity in the hydrodesulfurization reaction, but have sufficient activity in the hydrodenitrogenation reaction. Not shown. On the other hand, gasoline, kerosene, and light oil (boiling point of about 340 ° C.) are generally used to produce fuel oil through a hydrodesulfurization process. In recent years, however, fuel oil with a low nitrogen content has been desired from the viewpoint of pollution control. I have.

[0003] Incidentally, in order to simultaneously remove a sulfur compound and a nitrogen compound by treating a hydrocarbon oil, in addition to a conventionally known hydrodesulfurization activity, a hydrodenitrogenation activity for cleaving a C-N bond is required. Is required.

Various studies have been made on catalysts having both hydrodesulfurization and denitrification activities. For example, US Pat. No. 3,446,730 discloses that water of crystallization of 1.2 to 2.6 is used. Nickel or a Group 6 metal or an oxide or sulfide of such a metal is supported on an alumina carrier produced by calcining the contained aluminum hydroxide, and 0.1 to 2.6
Catalysts have been proposed to which a promoter consisting of phosphorus, silicon or barium by weight is added, but the properties of the support are not described at all. Moreover, it is described that the treated oil can be applied to any distillate including residual oil, but it is apparent that the distillate is actually applied only to distillate oil.

Also, US Pat. No. 3,749,664 describes a catalyst in which molybdenum, nickel and phosphorus are supported at a specific ratio on an alumina or silica-alumina carrier. It is described that those having a pore volume of 0.6 to 1.4 cc / g are preferred,
The pore structure has not been studied at all and does not have satisfactory performance for hydrotreating hydrocarbons.

The above-mentioned improvement is disclosed in Japanese Patent Application Laid-Open No. Sho 56-40432.
Japanese Patent Application Laid-Open Publication No. H11-163873 proposes that titanium oxide is used as a carrier and a metal belonging to Group 6 and 9 or 10 of the periodic table and phosphorus or boron are similarly supported as catalyst components. Titanium is expensive, and its physical properties make it difficult to increase the specific surface area compared to alumina.Moreover, the specific surface area tends to decrease during calcination after supporting the catalyst component, and its pore distribution is reduced like alumina. It is difficult to maintain the desired range.

[0007]

As described above, any of the catalysts is used as a catalyst component in Group 6 of the periodic table and ninth of the periodic table.
Or, it is improved to increase the acid point of the catalyst by supporting phosphorus or the like having a catalyst promoting effect on an active metal belonging to Group 10 even if phosphorus is uniformly supported on the catalyst. However, when the catalyst is left in the atmosphere, there is a disadvantage that phosphorus absorbs moisture and the supported state changes.

[0008] With respect to the carrier serving as the base of the catalyst,
No consideration has been given to improving the composition of the support such as the boria-silica-alumina support in the present invention described below and improving the pore distribution of the catalyst based on this.

An object of the present invention is to solve the above-mentioned problems of the conventional catalysts and to provide an inexpensive catalyst sufficiently provided with both hydrodesulfurization and denitrification activities of hydrocarbon oil. Things.

[0010]

Means for Solving the Problems In order to achieve the above-mentioned object, the present inventors have made improvements by focusing on increasing the acid point of a carrier serving as a substrate of a catalyst. It has been found that a carrier comprising an alumina composition can exert an excellent effect, and the carrier supports a Group 6 metal of the Periodic Table and a Group 9 or 10 metal of the Periodic Table conventionally supported as a catalytically active component. After drying and drying, the performance of the calcined catalyst was examined.In order to simultaneously satisfy both the hydrodesulfurization and denitrification reactions, the composition ratio and catalyst in the boria-silica-alumina composition as a carrier were determined. The present inventors have found that a preferable specific range exists in the pore diameter of the present invention, and have completed the present invention.

That is, in order to achieve the above object, the present invention provides an oxide carrier based on boria-silica-alumina, wherein at least one kind of metal selected from Group 6 metals of the periodic table is used as an active metal component. 17 to 28% by weight of metal in terms of oxide and 3 to 8% by weight of at least one metal selected from metals of Group 9 or 10 of the periodic table in terms of oxide, drying, and firing The oxide catalyst has an average pore diameter of 60 to 90 angstroms as measured by a mercury intrusion method, and further has an average pore diameter of ± 10 angstroms. A catalyst for hydrodesulfurization and denitrification of hydrocarbon oils, wherein the volume occupied by pores having a diameter is 60% or more of the volume occupied by all pores.

In the catalyst of the present invention, the composition of the oxide support based on boria-silica-alumina is B ₂ O ₃
In the range of 3 to 10% by weight as SiO ₂ ,
It is preferable to use a composition consisting essentially of alumina, and the Group 6 metal of the periodic table supported as an active metal component is molybdenum. Group 9 metal is nickel, Periodic Table No. 10
Preferably, the group metal is cobalt.

[0013]

The details of the present invention and its operation will be described below. The carrier of the present invention comprises a boria-silica-alumina composition as described above, the composition of which is in the range of ₃ to 10% by weight as B ₂ O ₃ and 3 to 8% in terms of SiO _2.
If the balance is not Al ₂ O _3, no significant improvement in denitrification activity is observed. This improvement in activity is considered to be due to the synergistic effect of the above three components of the carrier.

The Group 6 metal of the periodic table used as a catalytically active component is selected from chromium, molybdenum and tungsten, and among these, molybdenum is particularly preferred. The metals of Group 9 or 10 of the periodic table are selected from iron, cobalt and nickel, and particularly preferred among these are nickel and cobalt. Both of the metals in Table 9 or 10 are used in an appropriate combination.

The content of the active metal component is from 17 to 17 with respect to the total amount of the catalyst in terms of oxides for Group 6 metals of the periodic table.
It is 28% by weight, and 3 to 8% by weight in terms of oxide for a metal of Group 9 or 10 of the periodic table. And the lower limit of these metal components indicates the minimum necessary for the desired generation of hydrodesulfurization and denitrification activity. No increase is observed.

Regarding the pore diameter and pore distribution of the catalyst based on boria-silica-alumina, the number of pores having a pore diameter effective for desulfurization and denitrification is increased as much as possible to suppress other harmful reactions. For this purpose, the pore distribution is dense, the average pore diameter has an average pore diameter in the range of 60 to 90 angstroms, and the volume occupied by the pores having an average pore diameter of ± 10 angstroms is the total pores. It was found that the effect of desulfurization and denitrification of the catalyst obtained when the volume was at least 60% was the most excellent.

When the average pore diameter of the boria-silica-alumina oxide catalyst is smaller than this, the diffusion resistance of the reactants in the catalyst particles is large, and both hydrodesulfurization and denitrification activities are reduced. . Also, even if the average pore diameter of the boria-silica-alumina oxide catalyst falls within the range of 60% of the pores having an average pore diameter of ± 10 angstroms, pores effective for hydrodesulfurization and denitrification of hydrocarbon oils are reduced. And both activities decrease.

The catalyst based on boria-silica-alumina having a fine pore distribution and an average pore diameter within a predetermined range as described above is produced by a general catalyst carrier production method such as a mixing method. An alumina hydrate slurry produced by mixing and hydrolyzing an aqueous solution of aluminum sulfate and sodium aluminate has a silica content of 3 to 8% by weight as SiO ₂ when used as a catalyst carrier. An aqueous solution of sodium silicate was added as described above, followed by filtration and washing to obtain a silica-alumina catalyst containing 0.1% by weight as Na ₂ O and 0.5% by weight as SO _4. An aqueous boric acid solution is added so that the boria content when used as a carrier in the product is ₃ to 10% by weight as B ₂ O ₃ , and the mixture is kneaded until the water becomes moldable.
It can be manufactured by molding into a general catalyst carrier shape such as a circular shape, a spherical shape, a three-leaf shape, a four-leaf shape, drying, and then firing.

When an organic acid such as gluconic acid or tartaric acid is added during the hydrolysis reaction to obtain the alumina hydrate, it is effective to obtain a catalyst whose pore distribution is concentrated within a specific range. is there.

Further, as a boria raw material used for producing the boria-silica-alumina composition,
For example, boric acid, water-soluble salts such as tetraboric acid, and the like,
Examples of the silica raw material include water-soluble salts such as sodium silicate and silicon tetrachloride. Examples of the alumina raw material include aluminum nitrate, aluminum sulfate, aluminum chloride, sodium aluminate and the like, and water-soluble salts thereof. Is mentioned.

In order to support the active metal component on the thus-obtained carrier based on boria-silica-alumina having a desired pore structure, for example, molybdenum trioxide, nickel carbonate, or cobalt carbonate is used. Organic acids such as citric acid and tartaric acid are added to the slurry suspended in water,
Prepare an aqueous solution by heating and dissolving the aqueous solution by impregnating a boria-silica-alumina carrier into the aqueous solution,
The catalyst of the present invention is adjusted by adjusting the concentration of the aqueous solution so that a desired amount of the active metal component can be supported, or by dissolving the desired active metal and adsorbing the entire aqueous solution, followed by drying and calcining. Obtainable.

The catalyst of the present invention obtained by the above-mentioned production method is used for hydrodesulfurization and denitrification of hydrocarbon oils.
The catalyst obtained by impregnating the oxide carrier with an active metal, drying and calcining has a remarkably superior activity as compared with a catalyst obtained by subjecting the catalyst to a sulfidation treatment. Although the reason is not clear, the active metal component contained in the catalyst obtained by final calcination in the prior art is in an oxide state, so that molybdenum sulfide or the like generated in the sulfurization treatment step is used. It is considered that the activity is inferior to that according to the present invention because the particle size is smaller than that according to the present invention and is in a highly dispersed state.

[0023]

Next, an embodiment of the present invention will be described. (1)
Manufacture of carrier Example 1 204 g of gluconic acid solution (manufactured by Wako Pure Chemical Industries, Ltd.) having a concentration of 49.5 liters of water and a concentration of 50% were placed in a stainless steel reaction tank with a stirrer having an inner volume of 100 liters (produced by hydrolysis) Al ₂ O ₃ 0.05 wt%) were placed in a reaction vessel with respect, to 70 ° C. and held warmed while stirring _Al 2 _{O 3}
Aluminum sulfate aqueous solution containing 774 g
9540 g of Shimada Shoten, 8% sulfuric acid band) and Al ₂
A total of 6930 g of an aqueous solution of sodium aluminate (NA-170, manufactured by Sumitomo Chemical Co., Ltd.) containing 1275 g of O ₃ was added dropwise to obtain an alumina hydrate slurry having a pH of 9.0. Next, after aging this slurry for 30 minutes,
25 g of 1% nitric acid was added to pH 8.3, and then S
iO aqueous sodium silicate (manufactured by Wako Pure Chemical Industries, Ltd.) containing 130g as ₂ 929 g with the total amount added dropwise, p
A silica-alumina hydrate having an H of 8.8 was obtained. This hydrate was aged for 30 minutes, then filtered and washed to obtain 2500 g of a silica-alumina hydrate cake (SiO ₂ -A
47 g of boric acid (manufactured by Wako Pure Chemical Industries, Ltd.) (26.6 g as B ₂ O ₃ ) was added to l ₂ O ₃ (containing 20% by weight), and the mixture was heated and kneaded in a kneader equipped with a heating jacket.
63% by weight as B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ concentration
The kneaded product is then molded with an extruder having a die having a diameter of 1.5 mmφ, dried, and fired at 700 ° C. for 2 hours in an electric furnace to obtain B ₂ O _3. A boria-silica-alumina carrier A containing 5% by weight and 5.7% by weight as SiO ₂ was obtained.

[0024] Silica obtained in Example 1 - except for changing the addition amount of boric acid added to the alumina hydrate in much the same way as the method shown in Example 1, as a B ₂ O ₃ 3% by weight, SiO ₂
-Bore-silica-alumina carrier B containing 5.8% by weight as B and 10% by weight as B ₂ O ₃ , and 5% as SiO ₂ .
A boria-silica-alumina support C containing 4% by weight was obtained.

Example 3 The amount of the aqueous sodium silicate solution to be added to the alumina hydrate slurry obtained in substantially the same manner as in Example 1 was changed to Si.
5% by weight of B ₂ O ₃ was added in substantially the same manner as in Example 1 except that O ₂ was 3% by weight and 8.5% by weight, respectively, 2.9% by weight of SiO ₂ and B ₂ O. ₃
-Silica-alumina carrier D containing 5% by weight as
And a boria-silica-alumina carrier E containing 8.1% as SiO ₂ and 5% by weight as B ₂ O ₃ was obtained.

(2) Preparation of catalyst Example 4 39.7 g of molybdenum trioxide and 13.4 g of nickel carbonate
Was suspended in 50 g of water, 2.0 g of tartaric acid was added and dissolved under heating, and the impregnating solution obtained by adjusting the amount of water with water to the amount corresponding to the amount of water absorbed by the carrier was used as the boria-silica obtained in Example 1. -Impregnated in 100 g of alumina carrier A, allowed to stand for 2 hours, dried at 110 ° C for 16 hours, and calcined the dried product at 500 ° C for 2 hours to obtain Catalyst A.

Example 5 23.4 g of molybdenum trioxide and 16.5 g of nickel carbonate
Was suspended in 50 g of water, 2.0 g of tartaric acid was added and dissolved under heating, and the impregnation liquid obtained by adjusting the liquid amount with water to a liquid amount corresponding to the water absorption amount of the carrier was obtained in Example 1. Impregnated in 100 g of silica-alumina carrier A, left for 2 hours, and
For 16 hours, and the dried product was calcined at 500 ° C. for 2 hours to obtain a catalyst.

Example 6 23.4 g of molybdenum trioxide, 15.1 g of cobalt carbonate
Was suspended in 50 g of water, 2.0 g of tartaric acid was added and dissolved under heating, and the impregnation liquid obtained by adjusting the liquid amount with water to a liquid amount corresponding to the water absorption amount of the carrier was obtained in Example 1. Impregnated in 100 g of silica-alumina carrier A, left for 2 hours, and
For 16 hours, and the dried product was calcined at 500 ° C. for 2 hours to obtain Catalyst C.

Reference Example 1 23.4 g of molybdenum trioxide and 11.8 g of nickel carbonate
Was suspended in 50 g of water, 2.0 g of tartaric acid was added and dissolved under heating, and the impregnating liquid was adjusted with water to a liquid amount corresponding to the water absorption of the carrier. The average pore diameter in the range of the present invention obtained in Example 3 and the volume occupied by the pores in the average pore diameter ± 10 angstroms are 6% of the total pore volume.
100 g of each of the boria-silica-alumina supports A, B, C, D and E having a pore structure of not less than 0% is impregnated, dried for 2 hours at 110 ° C. after standing for 2 hours, and the catalyst (unfired) (Catalyst) d, e, f, g, and h were obtained.

[0030]

[0031] Example 4, Example 5 and Example 6, molybdenum active metal supported on the catalyst was Oite prepared in Reference Example 1, the supported amount in terms of oxides for nickel and phosphorus as shown in Table 1 .

(3) Catalyst Performance Evaluation Test The hydrodesulfurization of hydrocarbon oil was carried out for each of the catalysts shown in Table 1 using a fixed bed flow reactor with a catalyst loading of 15 ml.
The activity of the denitrification reaction was examined. The catalyst was sulfurized under a light gas oil containing 2.5% by weight of dimethyl disulfide and a hydrogen / oil supply ratio of 300 Nl / L, LH
The temperature was increased from 100 ° C. to 315 ° C. over 7 hours under the conditions of SV = 2.0 hr ⁻¹ and a pressure of 30 kg / cm ² G, and the same temperature was maintained for 16 hours to perform preliminary sulfurization.

Next, a sulfur content of 1.15% by weight and a nitrogen content of 6%
Using quat ordinary pressure light oil containing 8 ppm, pressure 30 kg
/ Cm ² G, LHSV = 2.0 hr ⁻¹ , hydrogen / oil supply ratio 300 Nl / l, temperature 360 ° C., and analyze the sulfur content and nitrogen content in the treated oil 100 hours after the start of the reaction Table 1 shows the desulfurization rate and denitrification rate.
Are also shown. Analysis of sulfur content is made by Horiba Seisakusho S
The LFA-920 type and the TN-05 type manufactured by Mitsubishi Kasei Co., Ltd. were used for the analysis of nitrogen content. In addition,
The desulfurization rate and denitrification rate shown in Table 1 are generally the values of hydrodesulfurization and desulfurization.
Alumina-based support as catalyst showing nitrogen activity
Having MoO ₃ , NiO and P ₂ O ₆ supported thereon
With almost the same properties as those marketed as
It is a relative activity value when the medium is 100. Furthermore, the catalyst prepared in Reference Example 1 D, E, F, DOO, with Ji, in,
Table 1 also shows the values relating to the pore structure measured by the mercury intrusion method.

[0034]

[Table 1]

As is clear from the results shown in Table 1, the catalysts A, B, and C obtained by calcination of the present invention correspond to the unfired catalysts D, E, F, C, and C of the reference examples. It shows a sufficiently high desulfurization rate and denitrification rate as compared with those of Example 1.

[0036]

As described above, the catalyst for hydrodesulfurization and denitrification of hydrocarbon oil according to the present invention performs desulfurization and denitrification much more efficiently than conventionally proposed catalysts of this type. be able to. Therefore, if the catalyst of the present invention is used instead of the conventional catalyst, it becomes possible to obtain a fuel oil having a low sulfur content and a low nitrogen content.

Claims (1)

(57) [Claims] 1. An oxide carrier based on boria-silica-alumina, wherein at least one metal selected from Group 6 metals of the periodic table as an active metal component is converted into an oxide.
A catalyst comprising 7 to 28% by weight and 3 to 8% by weight of at least one metal selected from metals of Group 9 or 10 in the periodic table in terms of oxide, dried and calcined, The oxide catalyst has an average pore diameter of 60 to 90 angstroms as measured by a mercury intrusion method, and further has an average pore diameter of ± 10 angstroms. A catalyst for hydrodesulfurization and denitrification of hydrocarbon oils, wherein the occupied volume is 60% or more of the volume occupied by all the pores.