JP3244694B2 - Method for producing hydrotreating catalyst - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a catalyst for hydrotreating a hydrocarbon oil.

[Prior Art] Alumina, titania, and the like are used as catalysts used in hydrotreating for performing hydrogenation, desulfurization, denitrification, and cracking of hydrocarbon oils.
A catalyst in which a group 6 metal and a group 8 metal of the periodic table are supported as active metals on a porous catalyst carrier such as silica or activated carbon is used. Generally, Mo or W is used as the Group 6 metal, and Ni or Co is used as the Group 8 metal. However, these active metals are supported on the catalyst support in an oxide state and do not show activity. . Therefore, it is used as a catalyst after being subjected to an appropriate pre-sulfurization treatment in a sulfide form.

By the way, in the hydrotreating catalyst, the active site of the catalyst is formed on the surface of the active metal sulfide. Therefore, it is known that the number of active sites increases as the surface area of the metal sulfide increases, and as a result, a highly active catalyst can be obtained.
In order to increase the surface area of the sulfide, attempts have been made to make the metal sulfide finer and highly disperse, and various methods have been disclosed. For example, JP-A-59-102442 and JP-A-59-69147 disclose a method in which a mixed solution of a carboxylic acid such as citric acid or malic acid and an active metal is impregnated into a catalyst carrier such as alumina, and then dried and calcined. Is disclosed. These production methods form a complex ion between the active metal and the carboxylic acid, and are intended to prevent the aggregation of the active metal by supporting the complex ion.Both methods involve impregnation at the final stage. Is not necessarily obtained because of roasting.

[Problems to be Solved by the Invention] Recently, a nitrogen-containing organic compound such as nitrilotriacetic acid, ethylenediaminetetraacetic acid, and diethylenetriamine is used as a complexing agent in EP 0181035 (A2), and these complexing agents and active metals are used. A method was disclosed in which an alumina carrier or a silica carrier was impregnated with a mixed solution of the above, followed by drying at 200 ° C. or lower and not roasting. Certainly, the activity of the catalyst produced by this method is higher than that of the conventional product. However, according to a recently submitted report, it is required that the sulfur content in light oil be reduced to 0.05% by weight or less with the tightening of exhaust gas regulations.
In order to satisfy this requirement, the catalyst produced by the method disclosed in the above-mentioned EP 0181035 (A2) is not enough,
Further, since the complexing agent used in this method contains nitrogen, there is a problem that harmful gas such as hydrogen cyanide is likely to be generated during the pre-sulfidation treatment.

An object of the present invention is to provide a method for producing a hydrotreating catalyst which is free from the above-mentioned drawbacks and which is more active.

[Means for Solving the Problems] The method of the present invention for solving the above-mentioned problems is characterized in that a catalyst for supporting a metal belonging to Group 6 and Group 8 of the periodic table on a catalyst carrier as an active metal, Rate Table Group 6 Metals and 8
After adding a polyhydric alcohol in an amount of 0.3 to 5.0 times the molar amount of the total number of active metals in the catalyst to the catalyst supporting the group metal and phosphorus, the mixture is dried at 200 ° C. or lower, preferably Is a solution in which the catalyst support is impregnated with a solution containing a Group 6 metal and a Group 8 metal, or a solution containing the Group 6 metal and a Group 8 metal in the catalyst support and contains phosphorus. After impregnation, the impregnated material was dried at 200 ° C. or less to obtain a catalyst, and 0.3 to 5.0 with respect to the total number of moles of active metal in the catalyst.
After adding double molar amount of polyhydric alcohol, it is dried at 200 ° C. or less.

Examples of the polyhydric alcohol that can be used in the present invention include ethylene glycol, diethylene glycol, triethylene glycol, glycerin, 2,2-diethyl-1,3-propylene glycol, and butanediol.

[Action] The catalyst used in the present invention is a porous carrier such as alumina, silica, titania, zirconia, or activated carbon as a carrier for the catalyst, and activated with a Group 6 metal and a Group 8 metal in the periodic table. It is carried as a metal, or carries a Group 6 metal, a Group 8 metal and phosphorus in the periodic table. Then, Mo or / and W is used as the group 6 metal, and Co or / and Ni is used as the group 8 metal. The loading amount of each active metal is a value generally adopted as a catalyst for hydrotreating, that is, the Group 6 metal is 5 to 30% by weight as an oxide, and the Group 8 metal is 1 to 8% by weight as an oxide. It is preferable to set the weight%. When carrying these metals, for example, molybdenum oxide and cobalt carbonate are suspended in water,
Then, the mixture is dissolved and impregnated by boiling. The impregnated material is preferably dried at a temperature of 200 ° C. or lower to prevent aggregation of the active metal.

Phosphorus also appears to act as a stabilizer when impregnating the active metal, further enhancing activity. Therefore, phosphorus is preferably contained in an amount of 0.1 to 8% by weight as P ₂ O ₅ , and various phosphoric acids such as orthophosphoric acid can be used as a phosphorus source.

In the hydrotreating catalyst of the present invention, a complex compound is formed with the active metal or the polyhydric alcohol and is stably supported on the catalyst carrier. It is not clear why the selection of a polyhydric alcohol as a complexing agent results in higher activity than that using the nitrogen-containing organic compound as a complexing agent. The present inventor presumes that basic compounds such as ammonia and amines generated by decomposition of the nitrogen-containing organic compound at the time of preliminary sulfurization are not completely removed from the catalyst, and the active sites are poisoned by these basic compounds. Further, since the value of the active metal surface area of the catalyst produced by the method of the present invention is extremely large, it is presumed that the stability and decomposition behavior of the complex compound formed prevent aggregation of the active metal during presulfurization. are doing.

The drying temperature of the catalyst of the present invention is set to 200 ° C. or lower in order to prevent decomposition and volatilization of the polyhydric alcohol as the complexing agent. The amount of addition is 0.3 to 0.3 of the total molar amount of the active metal in the number of moles.
If it is less than 0.3 times, the complexing agent is not completely decomposed and removed at the time of preliminary sulfurization, and carbon is deposited on the active metal and the sulfur content is reduced. Is to interfere with the activity and reduce the activity.

Example 1 193 g of molybdenum trioxide, 82 g of cobalt carbonate, 85 g of 85 g of 85 g / alumina carrier having a specific surface area of 280 m ² / g and a pore volume of 0.75 ml / g
800ml of active metal aqueous solution prepared from 61.5g of 6% phosphoric acid and water
And dried at 110 ° C. for 10 hours. This was repeated to obtain a required amount of dried product. Next, to 250 g of the dried product,
Each of the complexing agents shown in Table 1 was impregnated in accordance with the impregnation amount shown in the table, dried at 110 ° C. for 10 hours, and used for the catalysts A, B, C, D, E, F, G, H and EP 018103
Catalyst I prepared by the method disclosed in JP-A-5 (A2),
J, K, and L were created. The impregnation amount in Table 1 is a multiple of the total number of moles of Mo and Co contained in the catalyst, and when this value is 1, it means that the impregnation was performed in an equimolar amount.

Catalysts A, B, C, D, E, F, G, H, I, J, K,
L has a Mo content of 15% by weight as MoO ₃ ,
Was 4 wt% as CoO, and the P content was 3 wt% as P ₂ O ₅ .

The catalysts A, B, C, D, E, F, G, H, I, J,
Using K and L, a hydrodesulfurization test of Kuwait atmospheric gas oil having the following properties was performed under the following conditions.

(Properties of Kuwait atmospheric gas oil) Specific gravity (15/4 ℃) 0.844 Sulfur (wt%) 1.55 Distillation properties (initial boiling point ℃) 231 (50Vol% ℃) 313 (End point ℃) 390 (Test conditions) Catalyst amount (ml) ) 15 Raw material oil liquid space velocity (Hr ^-1 ) 2 Reaction hydrogen pressure (kg / cm ² G) 30 Reaction temperature (° C) 330 Hydrogen / oil flow rate ratio (Nl / l) 300 Oil flow time (Hr) 88 obtained The hydrodesulfurization activity was indicated by the relative value of the reaction rate constant, and the rate constant was calculated assuming that the desulfation reaction rate was proportional to the 1.75 power of the sulfur concentration of the atmospheric gas oil as the raw material. The reference used was the catalyst L of the conventional example, and its rate constant was 100.

 The results obtained are shown in Table 1.

Table 1 shows that the activity of the catalyst prepared by the method of the present invention is the highest among the conventional catalysts.
It can be seen that it is extremely high as compared with catalysts I, J, K, and L prepared by the method disclosed in JP-A-0181035 (A2).

Example -2 pseudoboehmite alumina support (Al ₂ O ₃ 92.8 wt%) 200 g
35.7 g of molybdenum trioxide, 15.23 g of cobalt carbonate, 85%
It was impregnated with 150 ml of an active metal aqueous solution prepared from 11.4 g of phosphoric acid and water and dried at 110 ° C. for 5 hours. Next, 100 g of the dried product was impregnated with diethylene glycol (catalyst M) and glycerin (catalyst N) according to the impregnation amounts shown in Table 1, respectively, dried at 110 ° C. for 10 hours, and dried at 110 ° C. for the catalyst M according to the method of the present invention.
N was obtained.

Mo content of both catalysts M and N is 15% by weight as MoO ₃
The content of Co was 4% by weight as CoO, and the content of P was 3% by weight as P ₂ O ₅ .

Using these catalysts M and N, a hydrodesulfurization test was performed in the same manner as in Example-1. The results obtained are shown in Table 1.

Table 1 shows that the catalysts M and N are much more active than the catalysts I, J, K and L.

[Example 3] 200 g of a silica / alumina carrier (10% by weight as SiO ₂ , specific surface area of 325 m ² / g, pore volume of 0.69 ml / g), 38.5 g of molybdenum trioxide, 16.2 g of nickel carbonate, 85% phosphoric acid It was impregnated with 160 ml of an aqueous active metal solution prepared from 12.3 g and water, and dried at 110 ° C. for 5 hours. Next, 100 g of the dried product was impregnated with diethylene glycol (catalyst O) according to the impregnation amount shown in Table 1, and dried at 110 ° C. for 10 hours to obtain catalyst O according to the method of the present invention.

The Mo content of the catalyst O was 15% by weight as MoO ₃ , the content of Co was 4% by weight as CoO, and the content of P was 3% by weight as P ₂ O ₅ .

Using this catalyst O, a hydrodesulfurization test was performed in the same manner as in Example-1. The results obtained are shown in Table 1.

From Table 1, it can be seen that the activity of the catalyst O is much higher than that of the catalysts I, J, K and L.

From the above, it can be seen that the activity of the catalyst prepared by the method of the present invention is extremely high, and the catalyst impregnated with diethylene glycol is more preferable.

[Effect of the Invention] The activity of the catalyst produced by the method of the present invention is extremely high, and as a result, advanced hydrotreating such as deep desulfurization and denitrification of hydrocarbon oils becomes possible.

Claims (4)

(57) [Claims] 1. A catalyst in which a group 6 metal and a group VIII metal of the periodic table are supported as active metals on a catalyst carrier, in an amount of 0.3 to 5.0 times the total number of moles of the active metals in the catalyst. A method for producing a hydrotreating catalyst, comprising adding the polyhydric alcohol and drying the mixture at 200 ° C. or lower. 2. A catalyst in which a metal of Group 6 of the Periodic Table, a Group VIII metal and phosphorus are supported on a catalyst carrier is added in an amount of 0.3 to 5.0 times the molar amount of the total amount of active metals in the catalyst. A method for producing a hydrotreating catalyst, comprising adding a polyhydric alcohol and then drying at 200 ° C. or lower. 3. A catalyst carrier is impregnated with a solution containing a Group 6 metal and a Group 8 metal in the periodic table, and the impregnated material is dried at 200 ° C. or lower to obtain a catalyst. A method for producing a hydrotreating catalyst, comprising adding a polyhydric alcohol in a molar amount of 0.3 to 5.0 times the total number of moles of a metal, and then drying the resultant at 200 ° C or lower. 4. After impregnating a catalyst support with a solution containing a Group 6 metal and a Group 8 metal in the periodic table and containing phosphorus, the impregnated product is dried at 200 ° C. or lower to obtain a catalyst. A method for producing a hydrotreating catalyst, comprising adding a polyhydric alcohol in an amount of 0.3 to 5.0 times the molar number of the total number of active metals in the catalyst, followed by drying at 200C or lower.