JP2015188790A - Hydrodesulfurization catalyst for hydrocarbon oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrodesulfurization catalyst having higher performance than conventional ones.SOLUTION: A hydrodesulfurization catalyst for hydrocarbon oil includes a support having a ratio of the diffraction peak area indicating the crystal structure of boehmite (020) plane measured in X-ray diffraction analysis to the diffraction peak area indicating the crystal structure of aluminum attributed to γ-alumina (440) plane of 1/10 or more, and at least one metal component selected from the group VIA and the group VIII in the periodic table, which is supported on the support. The molar ratio of the metal component selected from the group VIII to the metal component selected from the group VIA is 0.13 to 0.22.

Description

  The present invention relates to a hydrodesulfurization catalyst for hydrocarbon oil.

Hitherto, hydrocarbon oils have been widely used for the purpose of hydrotreating hydrocarbon carriers such as alumina, alumina-silica, titania, alumina-titania, etc. It is a catalyst carrying a metal component selected from Group VIII.
At present, the quality regulation of sulfur content in fuel oil is being strengthened from the viewpoint of environmental protection. In particular, the sulfur content in light oil is strictly regulated to 10 mass ppm or less. For this reason, development of a light oil ultra-deep desulfurization catalyst is progressing so that it can respond to this regulation.
Patent Document 1 discloses a catalyst in which a metal component selected from Group VIA and Group VIII of the periodic table is supported on a silica-titania-alumina support. This catalyst achieves high desulfurization activity by adjusting the titania content, crystal structure, specific surface area of the support, pore volume, etc., but further improvement in desulfurization activity is required.

JP 2011-072928 A

  An object of the present invention is to provide a hydrodesulfurization catalyst having higher performance than before, particularly a hydrodesulfurization catalyst for a gas oil fraction, and a method for producing the same.

  As a result of intensive studies, the present inventors have found that by using a carrier having specific properties, the desulfurization performance is greatly improved and the above-mentioned problems can be achieved.

  That is, according to the present invention, the diffraction peak area indicating the crystal structure of the boehmite (020) plane measured by X-ray diffraction analysis is compared with the diffraction peak area indicating the aluminum crystal structure attributed to the γ-alumina (440) plane. A hydrodesulfurization catalyst in which at least one metal component selected from Group VIA and Group VIII of the periodic table is supported on a carrier that is 1/10 or more, and the metal component selected from Group VIII Is a hydrodesulfurization catalyst for hydrocarbon oil, characterized in that the molar ratio is 0.13 to 0.22 with respect to a metal component selected from Group VIA.

  In the present invention, in the presence of silicate ions, a mixed aqueous solution of a titanium mineral acid salt and an acidic aluminum salt and a basic aqueous aluminum salt solution are mixed so that the pH is 6.5 to 9.5. A first step for obtaining a hydrate, a second step for obtaining a carrier by sequentially washing, molding, drying and firing the hydrate, and the carrier selected from Group VIA and Group VIII of the periodic table. In the hydrodesulfurization catalyst production method, the hydrodesulfurization catalyst is obtained in a third step of supporting at least one metal component.

  The hydrodesulfurization catalyst of the present invention has higher performance than conventional catalysts, and is particularly suitable as a hydrodesulfurization catalyst for light oil fractions.

FIG. 3 is a diagram showing X-ray diffraction spectra of a carrier a produced in Example 1 and a carrier e produced in Comparative Example 1. It is a figure which shows the transmission type Fourier-transform infrared absorption spectrum of each of the support | carrier a manufactured in Example 1, and the support | carrier e manufactured in the comparative example 1. FIG. It is a figure which shows the maximum peak position of the absorption spectrum resulting from the acidic OH group of a support | carrier, and the maximum peak position of the absorption spectrum resulting from a weakly basic OH group.

Hereinafter, the present invention will be described in detail.
The carrier in the hydrodesulfurization catalyst of the present invention includes at least both boehmite and γ-alumina, and the diffraction peak area showing the crystal structure of the boehmite (020) plane measured by X-ray diffraction analysis is γ-alumina. It is 1/10 or more with respect to the diffraction peak area which shows the aluminum crystal structure which belongs to a (440) plane.

The total content of boehmite and γ-alumina in the support is preferably 50 to 96% by mass, more preferably 58 to 83% by mass, and even more preferably 70 to 70% by mass when each is Al ₂ O _3. 83% by mass. Here, when the content of alumina is less than 50% by mass, catalyst deterioration tends to increase, such being undesirable. Moreover, when there is more content of alumina than 96 mass%, since there exists a tendency for catalyst performance to fall, it is unpreferable.

  The carrier is not particularly limited except boehmite and γ-alumina, and may include silica, titania, boria, diphosphorus pentoxide, zirconia, and the like, and particularly preferably silica and titania. is there.

Silica is preferably contained in an amount of 1 to 10% by mass as SiO _{2 on} a carrier basis, more preferably 2 to 7% by mass, and even more preferably 2 to 5% by mass. When the silica content is less than 1% by mass, the specific surface area becomes low and the titania particles tend to aggregate when the carrier is baked, and the crystal structures of anatase titania and rutile titania measured by X-ray diffraction analysis. Increases the diffraction peak area. When the titania particles are aggregated, the specific surface area is decreased, the contents of the metal component of Group VIA of the periodic table and the metal component of Group VIII of the periodic table are decreased, and the activity is decreased. On the other hand, when the content of silica exceeds 10% by mass, the sharpness of the pore distribution of the obtained carrier is deteriorated and the desired desulfurization activity may not be obtained.

The titania is preferably contained in an amount of 3 to 40% by mass as TiO _{2 on} a carrier basis, more preferably 15 to 35% by mass, and still more preferably 15 to 25% by mass. When the titania content is less than 3% by mass, the addition effect of the titania component is small, and the obtained catalyst may not obtain the desired desulfurization activity. Further, when the titania content is more than 40% by mass, the mechanical strength of the catalyst may be lowered, and the crystallization of titania particles is facilitated when the support is fired, so that the specific surface area is lowered. The desulfurization performance corresponding to the economic efficiency of the increased titania amount is not exhibited, which is not preferable.

  In the hydrodesulfurization catalyst of the present invention, at least one metal component selected from Group VIA (IUPAC Group 6) and Group VIII (IUPAC Group 8 to Group 10) of the periodic table is supported on the support. It has been done.

  Examples of the metal component of Group VIA of the periodic table include molybdenum (Mo) and tungsten (W). Examples of the metal component of Group VIII of the periodic table include cobalt (Co) and nickel (Ni). It can be illustrated. These metal components may be used alone or in combination of two or more. From the viewpoint of catalyst performance, the metal component is preferably a combination of nickel-molybdenum, cobalt-molybdenum, nickel-molybdenum-cobalt, nickel-tungsten, cobalt-tungsten, nickel-tungsten-cobalt, etc. A combination of cobalt-molybdenum and nickel-molybdenum-cobalt is more preferable.

  The supported amount of the metal component is preferably in the range of 1 to 35% by mass and more preferably in the range of 15 to 30% by mass as the oxide on the catalyst basis. In particular, the metal component of Group VIA of the periodic table is preferably in the range of 10 to 30% by mass, more preferably in the range of 13 to 24% by mass, and the metal component of Group VIII of the periodic table is as oxide. The range of 2.6 to 4.4% by mass is preferable, and the range of 2.8 to 4.2% by mass is more preferable.

  In addition, the ratio of the metal component selected from Group VIII of the periodic table must be 0.13 to 0.22 in molar ratio with respect to the metal component selected from Group VIA of the periodic table. -0.21 are preferable and 0.16-0.18 are further more preferable. A structure in which a Group VIII metal coordinates to an edge site of a Group VIA sulfide in the periodic table (in the case of Co and Mo, a CoMoS phase) is said to be a highly active species. When the ratio of the metal component selected from Group VIII of the periodic table is less than 0.13 in terms of molar ratio to the metal component selected from Group VIA of the periodic table, the CoMoS phase is not sufficiently formed, which is not preferable. On the other hand, when the proportion of the metal component selected from Group VIII of the periodic table exceeds 0.22 in terms of molar ratio with respect to the metal component selected from Group VIA of the periodic table, the CoMoS phase is covered with an inert cobalt sulfide species. This is not preferable.

  When the metal component of Group VIA of the periodic table is supported and contained in the carrier of the hydrodesulfurization catalyst of the present invention, it is preferable to dissolve the metal component using an acid. Here, it is preferable to use phosphoric acid and / or an organic acid as the acid.

  When using phosphoric acid, phosphorus preferably supports 3 to 25% by mass of phosphoric acid, more preferably 10 to 15% by mass based on 100% by mass of the metal component of Group VIA of the periodic table. It is preferable to be carried in a range. If the loading amount exceeds 25% by mass, the catalyst performance tends to decrease, which is not preferable. If the loading amount is less than 3% by mass, the stability of the supported metal solution deteriorates, which is not preferable.

  The method for supporting and containing the metal component or further phosphorus in the carrier is not particularly limited, and a known method such as an impregnation method (equilibrium adsorption method, pore filling method, initial wetting method), ion exchange method or the like can be used. Can be used. Here, the impregnation method is a method of impregnating a support containing a solution containing an active metal, followed by drying and firing.

  In the impregnation method, it is preferable to simultaneously support a metal component of Group VIA of the periodic table and a metal component of Group VIII of the periodic table. If the metals are supported separately, the desulfurization activity or denitrification activity may be insufficient. When the loading is carried out by the impregnation method, the dispersibility of the metal component of Group VIA of the periodic table on the support becomes high, and the desulfurization activity and denitrogenation activity of the resulting catalyst become higher. The reaction is preferably carried out in the presence of phosphoric acid or organic acid. In that case, it is preferable to add 3-25 mass% phosphoric acid with respect to 100 mass% of metal components of a VIA group periodic table.

The hydrodesulfurization catalyst of the present invention preferably has a specific surface area (SA) measured by the BET method of 150 m ² / g or more, more preferably 170 m ² / g or more. If the specific surface area (SA) is less than 150 m ² / g, the active point of the desulfurization reaction is decreased, and there is a possibility that the desulfurization performance may be deteriorated. On the other hand, the upper limit is not particularly limited, but if the specific surface area (SA) exceeds 300 m ² / g, the catalyst strength tends to decrease. Therefore, it is preferably 300 m ² / g or less, and preferably 280 m ² / g or less. Is more preferable.

The carrier of the hydrodesulfurization catalyst of the present invention has an aluminum crystal structure in which the diffraction peak area indicating the crystal structure of the boehmite (020) plane measured by X-ray diffraction analysis is attributed to the γ-alumina (440) plane. The diffraction peak area needs to be 1/10 or more, preferably 1/5 or more, and more preferably 1/4 or more. The upper limit is not particularly limited, but is preferably 1 or less, and more preferably 4/5 or less. The diffraction peak area showing the crystal structure of the boehmite (020) plane measured by X-ray diffraction analysis is less than 1/10 of the diffraction peak area showing the aluminum crystal structure attributed to the γ-alumina (440) plane. In this case, the dispersity of the metal component of Group VIA of the periodic table and the metal component of Group VIII of the periodic table is lowered, and as a result, sufficient activity cannot be obtained. On the other hand, if it exceeds 1, the proportion of boehmite is excessively increased and the strength is lowered, which is not preferable.
Here, the diffraction peak showing the crystal structure of the boehmite (020) plane was measured at 2θ = 14 °, and the diffraction peak showing the aluminum crystal structure attributed to the γ-alumina (440) plane was 2θ = 67 °. It was measured by.

  Each diffraction peak area is calculated by fitting a graph obtained by X-ray diffraction analysis with an X-ray diffractometer using the least square method and correcting the baseline to obtain the height from the maximum peak value to the baseline ( Peak intensity W) A peak width (half-value width) at a half value (1/2 W) of the obtained peak intensity was determined, and the product of this half-value width and peak intensity was defined as a diffraction peak area. From each calculated diffraction peak area, “boehmite diffraction peak area / γ-alumina diffraction peak area” was calculated.

The carrier of the hydrodesulfurization catalyst of the present invention has an absorbance per unit surface area of the carrier and a weakly basic OH group due to the acidic OH group measured by a transmission Fourier transform infrared absorption spectrum measuring apparatus (FT-IR). The resulting absorbance ratio per unit surface area of the carrier is preferably 0.9 or more, more preferably 1.0 or more, and even more preferably 1.1 or more. When the ratio of acidic OH groups is increased, the metal component of Group VIA of the periodic table and the metal component of Group VIII of the periodic table are supported on the support in a highly dispersed state, and as a result, the number of active sites increases and the activity increases, which is preferable.
Here, the wave number of the maximum peak position of the absorption spectrum due to the acidic OH group is in the range of 3670 to 3695 cm ⁻¹ , and the wave number of the maximum peak position of the absorption spectrum due to the weakly basic OH group is 3720 to 3740 cm. ⁻¹ (see FIG. 3).
The above-described measurement method using FT-IR will be described later.

The hydrodesulfurization catalyst of this invention is used suitably for the hydroprocessing of hydrocarbon oil, especially a light oil fraction. The hydrodesulfurization treatment using the catalyst is carried out under a high-temperature and high-pressure condition in a hydrogen atmosphere by filling the catalyst in a fixed bed reactor.
Gas oil fractions include straight-run light oil obtained from a crude oil atmospheric distillation apparatus, straight-run heavy oil obtained from an atmospheric distillation apparatus and residual oil obtained by treating the crude oil with a vacuum distillation apparatus, Examples include catalytic cracking gas oil obtained by catalytic cracking of light diesel oil or desulfurized heavy oil, hydrocracked gas oil obtained by hydrocracking depressurized heavy gas oil or desulfurized heavy oil and the like.

  The reaction pressure (hydrogen partial pressure) is preferably 3 to 15 MPa, more preferably 4 to 10 MPa. If the reaction pressure is less than 3 MPa, desulfurization and denitrogenation tend to be remarkably reduced, and if it exceeds 15 MPa, hydrogen consumption increases and the operating cost increases, which is not preferable.

  The reaction temperature is preferably 300 to 420 ° C, more preferably 320 to 380 ° C. If the reaction temperature is less than 300 ° C., the desulfurization and denitrification activities tend to be remarkably lowered, which is not practical. Moreover, when it exceeds 420 degreeC, while catalyst deterioration will become remarkable and it will approach the heat resistant temperature (usually about 425 degreeC) of a reaction apparatus, it is unpreferable.

But not liquid hourly space velocity particularly limited, is preferably a 0.5～4.0H ^-1, more preferably 0.5~2.0h ^-1. If the liquid space velocity is less than 0.5 h ⁻¹ , the throughput is low and the productivity is low, which is not practical. Further, if the liquid space velocity exceeds 4.0 h ⁻¹ , the reaction temperature is increased, and the catalyst deterioration is accelerated.

  The hydrogen / oil ratio is preferably 120 to 420 NL / L, more preferably 170 to 340 NL / L. A hydrogen / oil ratio of less than 120 NL / L is not preferable because the desulfurization rate decreases. Moreover, even if it exceeds 420 NL / L, since there is no big change in desulfurization activity and only an operating cost increases, it is not preferable.

Next, the manufacturing method of the hydrodesulfurization catalyst of this invention is demonstrated.
The method for producing a hydrodesulfurization catalyst of the present invention comprises a mixed aqueous solution of a titanium mineral acid salt and an acidic aluminum salt (hereinafter also simply referred to as “mixed aqueous solution”), a basic aluminum salt aqueous solution, in the presence of silicate ions. The first step of obtaining a hydrate by mixing the hydrate so that the pH is 6.5 to 9.5, and the second step of obtaining a carrier by sequentially washing, molding, drying and baking the hydrate And a third step of supporting at least one metal component selected from Group VIA (IUPAC Group 6) and Group VIII (IUPAC Group 8 to Group 10) on the carrier. Hereinafter, each process will be described.

(First step)
First, in the presence of silicate ions, a mixed aqueous solution of a titanium mineral acid salt and an acidic aluminum salt (this is an acidic aqueous solution) and a basic aqueous aluminum salt solution (this is an alkaline aqueous solution), Mixing so that the pH is 6.5 to 9.5, preferably 6.5 to 8.5, more preferably 6.5 to 7.5, to obtain a hydrate containing silica, titania and alumina. .

In this step, (1) a mixed aqueous solution may be added to the basic aluminum salt aqueous solution containing silicate ions, and (2) a basic aluminum salt aqueous solution may be added to the mixed aqueous solution containing silicate ions.
Here, in the case of (1), the silicate ion contained in the basic aluminum salt aqueous solution can be basic or neutral. As the basic silicate ion source, a silicate compound that generates silicate ions in water such as sodium silicate can be used. In the case of (2), the silicate ions contained in the mixed solution of the titanium mineral acid salt and the acidic aluminum salt aqueous solution can be acidic or neutral. As the acidic silicate ion source, a silicate compound that generates silicate ions in water such as silicic acid can be used.

  As the basic aluminum salt, sodium aluminate, potassium aluminate or the like is preferably used. Further, as the acidic aluminum salt, aluminum sulfate, aluminum chloride, aluminum nitrate and the like are preferably used, and as the titanium mineral acid salt, titanium tetrachloride, titanium trichloride, titanium sulfate, titanium nitrate and the like are exemplified. Titanium is preferably used because it is inexpensive.

  For example, a basic aluminum salt aqueous solution containing a predetermined amount of basic silicate ions is placed in a tank equipped with a stirrer, and is usually kept at 40 to 90 ° C., preferably 50 to 70 ° C., and the temperature of this solution ± A mixed aqueous solution of a predetermined amount of a titanium mineral acid salt and an acidic aluminum salt aqueous solution heated to 5 ° C., preferably ± 2 ° C., more preferably ± 1 ° C. has a pH of 6.5 to 9.5, preferably 6.5. It is added continuously in 5 to 20 minutes, preferably 7 to 15 minutes so as to be ˜8.5, more preferably 6.5 to 7.5, to form a precipitate, thereby obtaining a hydrate slurry. Here, the addition of the mixed aqueous solution to the basic aluminum salt aqueous solution is desirably 15 minutes or less because undesirable crystals such as bayerite and gibbsite may be generated in addition to pseudoboehmite as time goes on. More preferably less than a minute. Bayerite and gibbsite are not preferred because their specific surface area decreases when fired.

(Second step)
The hydrate slurry obtained in the first step is aged as desired, and then washed to remove by-product salts to obtain a hydrate slurry containing silica, titania and alumina. The obtained hydrate slurry is further heat-aged if desired, and then, by conventional means, for example, heat-kneaded to form a kneaded product, which is then molded into a desired shape by extrusion molding or the like. In general, after drying at 70 to 150 ° C, preferably 90 to 130 ° C, preferably 400 to 500 ° C, more preferably 400 to 480 ° C, still more preferably 430 to 470 ° C, most preferably 440 to 460 ° C, The silica-titania-alumina carrier containing silica, titania and alumina is usually obtained by firing for 0.5 to 10 hours, preferably 2 to 5 hours.
Aluminum whose diffraction peak area indicating the crystal structure of the boehmite (020) plane measured by X-ray diffraction analysis is attributed to the γ-alumina (440) plane by controlling the firing conditions at this time, particularly the firing temperature. A carrier that is 1/10 or more of the diffraction peak area showing the crystal structure can be prepared.

(Third step)
After loading the obtained silica-titania-alumina support with at least one metal component selected from Group VIA and Group VIII of the periodic table by conventional means (impregnation method, dipping method, etc.) as described above. The hydrodesulfurization catalyst of the present invention is preferably calcined at 400 to 500 ° C., more preferably 400 to 480 ° C., further preferably 430 to 470 ° C., usually for 0.5 to 10 hours, preferably 2 to 5 hours. To manufacture.
As a raw material for the metal component, for example, nickel nitrate, nickel carbonate, cobalt nitrate, cobalt carbonate, molybdenum trioxide, ammonium molybdate, and ammonium paratungstate are preferably used.

<Absorptivity of acidic OH group, absorbance of weakly basic OH group>
Using a transmission type Fourier transform infrared spectrometer (manufactured by JASCO Corporation: FT-IR / 6100), the maximum peak wave number of the acidic OH group, the absorbance at that wave number, the maximum of the weak basic OH tomb The peak wave number and the absorbance at that wave number were measured.

(Measurement method)
20 mg of a sample was filled in a molding container (inner diameter 20 mm), and compressed and compressed with 4 ton / cm ² (39227 N / cm ² ), and molded into a thin disk shape. The molded body was held at 400 to 500 ° C. for 2 hours under a condition where the degree of vacuum was 1.0 × 10 ⁻³ Pa or less, and then cooled to room temperature, and the absorbance was measured.
Specifically, in TGS detector, resolution ^{4 cm -1,} the number of integrations is 200 times baseline corrected wavenumber range 3000～4000Cm ^-1, then corrected with a specific surface area. Absorbance was converted per unit surface area.
Absorbance per unit surface area (m ⁻² ) = (Absorbance) / (Molded body mass × Specific surface area)

In any of the following Examples and Comparative Examples, the wave number at the maximum peak position of the absorption spectrum due to the acidic OH group is in the range of 3670 to 3695 cm ⁻¹ , and the maximum peak of the absorption spectrum due to the weak basic OH group. The wave number of the position was in the range of 3720-3740 cm ⁻¹ .

Hereinafter, the content of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these.

[Example 1: Preparation of hydrodesulfurization catalyst a]
A tank with a capacity of 100 L and a steam jacket is charged with 8.16 kg of a 22 mass% sodium aluminate aqueous solution (manufactured by JGC Catalysts & Chemicals Co., Ltd.) in terms of Al ₂ O ₃ concentration, diluted with 41 kg of ion-exchanged water, and then SiO 2 ₂ converted concentration of 5 wt% of sodium silicate solution (manufactured by AGC Si-Tech (Ltd.); SiO ₂ concentration of 24% by mass) 1.80 kg was added with stirring, warmed to 60 ° C., basic aluminum salt solution It was created. In addition, an acidic aluminum salt aqueous solution obtained by diluting 7.38 kg of an aluminum sulfate aqueous solution (manufactured by JGC Catalysts and Chemicals Co., Ltd.) of 7% by mass in terms of Al ₂ O ₃ concentration with 13 kg of ion-exchanged water, and 33% by mass in terms of TiO ₂ concentration % Of titanyl sulfate (manufactured by Teika Co., Ltd.) (1.82 kg) was mixed with an aqueous solution of titanium mineral salt dissolved in 10 kg of ion exchange water, and heated to 60 ° C. to prepare a mixed aqueous solution. Add a mixed aqueous solution to a tank containing a basic aqueous aluminum salt solution at a constant rate using a roller pump until the pH is 7.2 (addition time: 10 minutes), and hydrate containing silica, titania, and alumina. A slurry a of the product was prepared.

The obtained hydrate slurry a was aged at 60 ° C. for 1 hour with stirring, dehydrated using a flat plate filter, and further washed with 150 L of a 0.3 mass% aqueous ammonia solution. The cake-like slurry after washing was diluted with ion-exchanged water so as to be 10% by mass in terms of Al ₂ O ₃ concentration, and then the pH was adjusted to 10.5 with 15% by mass ammonia water. This was transferred to an aging tank equipped with a reflux machine and aged at 95 ° C. for 10 hours with stirring. The slurry after completion of aging was dehydrated and concentrated and kneaded to a predetermined moisture content while kneading with a double-arm kneader equipped with a steam jacket. The obtained kneaded product was molded into a cylindrical shape having a diameter of 1.8 mm by an extrusion molding machine and dried at 110 ° C. The dried molded product was baked in an electric furnace at a temperature of 450 ° C. for 3 hours to obtain a carrier a. As for the carrier a, silica is 3% by mass in terms of SiO ₂ (support standard), titania is 20% by mass in terms of TiO ₂ (support standard), and aluminum is 77% by mass in terms of Al ₂ O ₃ concentration (support standard). Contained.

Further, the carrier a was subjected to X-ray diffraction analysis with an RINT2100 X-ray diffractometer manufactured by Rigaku (the same applies to the following examples). The result is shown in FIG. Here, the obtained graph was fitted by the least square method, the baseline was corrected, and the half width of the diffraction peak indicating the crystal structure of the boehmite (020) plane shown at 2θ = 14 ° was obtained. The product of the peak intensity from the line was defined as the boehmite diffraction peak area. Similarly, the half value of the diffraction peak indicating the aluminum crystal structure attributed to the γ-alumina (440) plane shown at 2θ = 67 ° is determined, and the product of the half value and the peak intensity from the baseline is determined as γ-alumina. The diffraction peak area was used. The diffraction peak area showing the crystal structure of boehmite was 1/3 of the diffraction peak area showing the crystal structure attributed to γ-alumina (boehmite diffraction peak area / γ-alumina diffraction peak area = 1 / 3. The same shall apply hereinafter.
FIG. 2 shows a transmission Fourier transform infrared absorption spectrum of the carrier a.

Furthermore, 268 g of molybdenum trioxide (manufactured by Climax Co., Ltd .; MoO ₃ concentration 99% by mass) and 66 g of cobalt carbonate (manufactured by Tanaka Chemical Laboratory Co., Ltd .; CoO concentration 61% by mass) are suspended in 500 ml of ion-exchanged water. The suspension was heated at 95 ° C. for 5 hours with an appropriate refluxing apparatus so that the liquid volume did not decrease, and then phosphoric acid (manufactured by Kanto Chemical Co., Inc .; P ₂ O ₅ concentration 62 mass%) 54 g Was added and dissolved to prepare an impregnating solution. The impregnating solution is spray impregnated on 1000 g of support a, dried at 250 ° C., and further calcined at 450 ° C. for 1 hour in an electric furnace to be hydrodesulfurized catalyst a (hereinafter also simply referred to as “catalyst a”. The same applies to the examples of the above. Table 1 shows the properties of catalyst a.

[Example 2: Preparation of hydrodesulfurization catalyst b]
A catalyst b was obtained in the same manner as the catalyst a except that 270 g of molybdenum trioxide, 78 g of cobalt carbonate, and 55 g of phosphoric acid were used in the preparation of the impregnation solution using the carrier a. Table 1 shows the properties of the catalyst b.

[Example 3: Preparation of hydrodesulfurization catalyst c]
A catalyst c was obtained in the same manner as the catalyst a except that 272 g of molybdenum trioxide, 90 g of cobalt carbonate, and 55 g of phosphoric acid were used in the preparation of the impregnation solution using the carrier a. Table 1 shows the properties of the catalyst c.

[Example 4: Preparation of hydrodesulfurization catalyst d]
In the carrier preparation, a carrier d was obtained in the same manner as the carrier a except that the dried molded product was baked at 480 ° C. in an electric furnace. As a result of X-ray diffraction analysis (not shown) as in Example 1, the boehmite diffraction peak area / γ-alumina diffraction peak area was 1/9. The impregnation solution was prepared in the same manner as catalyst a to obtain catalyst d. Table 1 shows the properties of the catalyst d.

[Comparative Example 1: Preparation of hydrodesulfurization catalyst e]
In the carrier preparation, a carrier e was obtained in the same manner as the carrier a except that the dried molded product was fired at 550 ° C. in an electric furnace. As a result of performing X-ray diffraction analysis in the same manner as in Example 1, no boehmite diffraction peak was present as shown in FIG. 1, and the boehmite diffraction peak area / γ-alumina diffraction peak area was zero. The impregnating solution was prepared in the same manner as catalyst a to obtain catalyst e. Table 1 shows the properties of the catalyst e.

[Comparative Example 2: Preparation of hydrodesulfurization catalyst f]
Using the carrier e, the impregnating liquid was the same liquid as the catalyst b to obtain a catalyst f. Table 1 shows the properties of the catalyst f.

[Comparative Example 3: Preparation of hydrodesulfurization catalyst g]
The carrier e was used, and the impregnation liquid was the same liquid as the catalyst c to obtain a catalyst g. Table 1 shows the properties of catalyst g.

[Comparative Example 4: Preparation of hydrodesulfurization catalyst h]
A catalyst h was obtained by using the carrier a and preparing an impregnation solution in the same manner as the catalyst a except that 267 g of molybdenum trioxide and 55 g of cobalt carbonate were used. Table 1 shows the properties of catalyst h.

[Comparative Example 5: Preparation of hydrodesulfurization catalyst i]
A catalyst i was obtained in the same manner as in the catalyst a except that 274 g of molybdenum trioxide, 101 g of cobalt carbonate, and 56 g of phosphoric acid were used in the preparation of the impregnation solution using the carrier a. Table 1 shows the properties of catalyst i.

[Hydrodesulphurization test]
Using the catalysts a to i, a raw material oil having the following properties was hydrotreated by a hydrodesulfurization device manufactured by Zeitel. The hydrotreatment reaction was performed under the following conditions. Table 1 shows the average of the relative desulfurization activities obtained by determining the reaction rate constants at reaction temperatures of 330 ° C. and 340 ° C. for each catalyst and determining the reaction rate constant of catalyst c as 100 for each of 330 ° C. and 340 ° C.
<Properties of raw oil>
Raw material oil: straight run diesel oil (boiling range 208-390 ° C)
Density @ 15 ° C: 0.8493 g / cm ³
Sulfur content: 1.32% by mass
Nitrogen content: 105 ppm by mass
<Reaction conditions>
Reaction temperature: 330 ° C, 340 ° C
Liquid space velocity: 1.36 hr ⁻¹
Hydrogen pressure: 6.0 MPa
Hydrogen / oil ratio: 250 NL / L

When the cobalt / molybdenum ratio is in the range of 0.13 to 0.22, it can be seen that the desulfurization activity is improved by including boehmite in the support. By containing boehmite on the support, a relatively large amount of acidic OH groups remain, and as a result, molybdenum is highly dispersed and supported. Since the active point of the desulfurization catalyst is cobalt coordinated at the edge site of molybdenum sulfide, so-called CoMoS structure, when molybdenum is highly dispersed, Co is also highly dispersed, and the number of CoMoS is increased and the activity is improved. However, even if boehmite is contained, the activity is low because the number of CoMoS is not sufficient when the amount of cobalt is low, and the active site is covered with an inactive cobalt species that does not coordinate to molybdenum sulfide when the amount of cobalt is large. Becomes lower.

Claims (6)

  The diffraction peak area showing the crystal structure of the boehmite (020) plane measured by X-ray diffraction analysis is 1/10 or more than the diffraction peak area showing the aluminum crystal structure attributed to the γ-alumina (440) plane. A hydrodesulfurization catalyst comprising at least one metal component selected from Group VIA and Group VIII of the periodic table supported on the carrier, wherein the metal component selected from Group VIII is selected from Group VIA A hydrodesulfurization catalyst for hydrocarbon oil, characterized in that the molar ratio is 0.13 to 0.22 with respect to the metal component.   The hydrodesulfurization catalyst for hydrocarbon oil according to claim 1, wherein the support contains at least one selected from silica and titania.   The hydrodesulfurization catalyst for hydrocarbon oil according to claim 1 or 2, wherein the metal component selected from Group VIA and Group VIII of the periodic table is selected from molybdenum, tungsten, cobalt, and nickel. .   The hydrodesulfurization catalyst for hydrocarbon oil according to any one of claims 1 to 3, wherein the metal component selected from Group VIII contains 2.6 to 4.4 mass% as an oxide.   In the presence of silicate ions, a mixed aqueous solution of titanium mineral acid and acidic aluminum salt and an aqueous basic aluminum salt solution are mixed so that the pH is 6.5 to 9.5 to obtain a hydrate. One step, a second step of sequentially obtaining, washing, molding, drying and firing the hydrate to obtain a carrier, and the carrier comprising at least one metal component selected from Group VIA and Group VIII of the Periodic Table A method for producing a hydrodesulfurization catalyst according to claim 1, wherein the hydrodesulfurization catalyst according to claim 1 is obtained by a third step of supporting the catalyst.   The method for producing a hydrodesulfurization catalyst according to claim 5, wherein the firing temperature in the second step is 400 to 500C.

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