JP3298672B2 - Method for producing hydrotreating catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a catalyst for hydrotreating a hydrocarbon oil, and particularly to a method for hydrodesulfurizing a heavy oil.

[0002]

2. Description of the Related Art In general, a catalyst for hydrotreating is used in which an active ingredient selected from a group VIB metal element and a group VIII iron group metal element is supported on an alumina or silica-alumina carrier. However, in recent years, those in which phosphorus is supported as a third component have begun to be adopted because of their high hydrotreating activity. This type of catalyst is
Generally, aqueous solutions are prepared by dissolving a salt of a Group VI metal element and a salt of a Group VIII iron group metal element, and phosphorus is added to either of the aqueous solutions to prepare two types of supporting liquids. It has been prepared by impregnating the liquid with an alumina carrier, drying and firing. This is because if the above-mentioned active ingredient is prepared in one solution, the stability of the supporting solution is poor, and the activity of the obtained catalyst is not improved.

In the preparation of a catalyst, when a hydroxy acid such as citric acid is added to a carrier liquid, the stability of the carrier liquid is improved, and the active component is supported in a highly dispersed state on a carrier, and the activity of the catalyst is increased. (For example, see Japanese Patent Publication No. 3-72344), citric acid is added to a solution obtained by dissolving a salt of a Group VI metal element, a salt of a Group VIII iron group metal element and phosphorus in one solution. A method using an added carrier liquid has been proposed (Japanese Patent Application Laid-Open No. 2-14745).

[0004] However, the use of the carrier liquid to which citric acid has been added has a problem that many catalyst pellets are longitudinally cracked and cracked when the catalyst is calcined, and the yield of the final catalyst is significantly reduced. Further, in order to prevent this vertical crack, the amount of the active component carried must be reduced, and the hydrotreating activity had to be sacrificed.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and an object of the present invention is to use all the active ingredients as one.
Supported using a supporting liquid stably contained as a liquid,
While maintaining high activity, significantly reduce longitudinal cracking,
An object of the present invention is to provide a method for producing a hydrotreating catalyst having an improved catalyst yield.

[0006]

Means for Solving the Problems The present inventor has conducted intensive studies in order to solve the above-mentioned problems, and as a result, the cause of the vertical cracking during the calcination is that the group VIII iron group metal element is supported. It has been found that the vertical cracking of the catalyst can be prevented by reducing the amount of nitrate ions in the carrier liquid to a predetermined amount or less.

[0007] That is, the present invention has been made based on such knowledge, and is based on at least one kind of ammonium salt and phosphorus component selected from the group VIB metal elements of the periodic table, and from the group VIII iron group metal element of the periodic table. At least one selected salt, and at least 0.8 mol of citric acid per mol of the metal element of group VIB of the periodic table, and at least 1% by weight of nitrate ion based on 100 parts by weight of the alumina carrier. A solution containing no element is impregnated in an alumina carrier, dried and calcined. In particular, 5 to 15% by weight of the Group VIB metal element and 1 to 5 Group VIII iron group metal in the final catalyst composition are used. -5% by weight and 0.7-3% by weight of phosphorus.

In producing the catalyst of the present invention, first, an aqueous solution of citric acid is prepared, an ammonium salt of a Group VI metal element is dissolved therein, and then a phosphorus component is added and dissolved in this solution. Finally, it is particularly preferable to prepare a supporting liquid by a method of dissolving the Group VIII iron group metal element salt, since a stable supporting liquid can be obtained.

The amount of citric acid dissolved in the carrier liquid is
0.8 mole or more is required for 1 mole of the Group VIB metal element. If the amount of citric acid added is less than this, a part of the active ingredient precipitates, and a stable carrier liquid that can be uniformly carried on the carrier cannot be obtained.

The Group VIB metal element is selected from chromium, molybdenum, tungsten and the like, and may be used alone or in combination of two or more, and ammonium salts thereof are used. In particular, it is preferable to use ammonium dimolybdate or ammonium heptamolybdate. The amount of the Group VIB metal element is determined in consideration of the amount of water absorbed by the alumina carrier so that the total amount of the metal element of this group can be impregnated and supported on the alumina carrier. Is preferred.

As the phosphorus component, various phosphorus compounds can be used, but it is simple and preferable to use orthophosphoric acid. The amount of the phosphorus component added is preferably such that 0.7 to 3% by weight of phosphorus element can be supported on the alumina carrier.

The Group VIII iron group metals include nickel, cobalt, copper and the like, and particularly preferred are nickel and cobalt. These metals may be used alone or in combination of two or more. As the salt of the metal, it is preferable to use an acetate, a formate or a carbonate because nitrate ions in the carrier liquid are reduced. It is preferable that the addition amount of the Group VIII iron group metal is such that it can be supported on an alumina carrier in an amount of 1 to 5% by weight as the total amount of the metal elements of the group.

It is preferable that the carrier liquid carried by the above method contains no nitrate ion.
When the nitrate ion content is 1% by weight or less based on 00 parts by weight, the catalyst does not undergo longitudinal cracking during the firing of the catalyst and the yield of the catalyst is not extremely reduced.

The concentration of the above-mentioned carrier liquid containing the active ingredient is appropriately adjusted with water in accordance with the amount of water absorbed by the carrier, and this is impregnated with an alumina carrier. This impregnation may be performed once, or may be performed a plurality of times, for example, by dividing the carrier liquid into two or more and repeating the impregnation and drying.

As the alumina carrier, a carrier made of γ-alumina, which is generally widely used as a catalyst, can be used.

The impregnated alumina carrier may be at room temperature to 150
C., preferably after drying at 100-130 ° C. for 0.5 hours or more, 350-800 ° C., preferably 450-800 ° C.
The catalyst can be prepared by calcining at 600 ° C. for 0.5 hours or more.

In this catalyst, the Group VI metal element in the final catalyst composition is preferably 5 to 15% by weight. When the content is less than 5% by weight, the desulfurization activity is not sufficiently exhibited. Further, if the content exceeds 15% by weight, the activity is not significantly improved, and the economical merit is rather small, so that it is not preferable. Further, it is preferable that the Group VIII iron group metal element is 1 to 5% by weight in the final catalyst composition. 1% by weight
If it is less than 5, the effect as a cocatalyst is not sufficiently exhibited, and 5
If the amount is increased beyond the weight%, the activity is not significantly improved and is not economically preferable. Further, the phosphorus is preferably in the range of 0.7 to 3% by weight in the final catalyst composition. If the amount is less than 0.7% by weight, a stable carrier liquid cannot be obtained. If the amount exceeds 3% by weight, the activity is not significantly improved, and it is not economically preferable.

The catalyst prepared by such a method is a catalyst for hydrotreating heavy oils such as hydrocarbon oils, in particular, crude oil distillation residue or vacuum distillation fraction or this residue oil, especially Is suitably used as a catalyst for hydrodesulfurization.

[0019]

EXAMPLES Preparation of Catalyst (Catalyst A) 20 g of citric acid monohydrate was dissolved in 100 cc of water, and 34.5 ammonium molybdate was added to the solution.
9 g (equivalent to 10% by weight of Mo of the obtained catalyst) was added and dissolved by heating. After cooling to room temperature, 5.24 g of phosphoric acid (0.75% by weight of P of the obtained catalyst was obtained).
And dissolved at room temperature. Finally, 10.44 g of cobalt carbonate (equivalent to 2.75% by weight in terms of the Co amount of the obtained catalyst) was added, and the mixture was heated and dissolved. Finally, water was added to adjust to 180 ml. The carrier liquid thus obtained was divided into halves, diluted to 110 cc, impregnated with 150 g of an alumina carrier, dried at 130 ° C. overnight, diluted with the remaining carrier liquid to 95 cc, and again This was impregnated, dried at the same temperature overnight, and calcined at 500 ° C. for 30 minutes to prepare a catalyst.

(Catalyst B) A catalyst was prepared in exactly the same manner as in the preparation of the above-mentioned catalyst A, except that cobalt acetate was used in place of cobalt carbonate so as to have an equimolar amount of Co.

(Catalyst C) A catalyst was prepared in exactly the same manner as in the preparation of the catalyst A, except that cobalt formate was used in place of cobalt carbonate in an equimolar amount as Co.

(Catalyst D) A catalyst was prepared in exactly the same manner as in the preparation of the catalyst A, except that cobalt nitrate was used in place of cobalt carbonate so as to have an equimolar amount of Co.

(Catalyst E) Ammonium molybdate 3
After dissolving 4.59 g in water, cool to room temperature,
After adding 15.2 ml of aqueous ammonia and impregnating 150 g of the alumina carrier with this liquid and then drying it at 130 ° C. overnight, 5.24 g of phosphoric acid and 25.53 g of cobalt nitrate (the Co amount of the resulting catalyst was 2%). (Corresponding to 0.75% by weight) and re-impregnated with a carrier liquid adjusted to 95 cc.
C. overnight, and calcined at 500.degree. C. for 30 minutes to prepare a catalyst. This is a method of carrying the solution twice using two liquids, the operation is complicated, and it takes time to prepare the catalyst.

Activity Test and Evaluation of Cracking The catalyst obtained by the above-mentioned preparation method was subjected to distillation of Arabian light atmospheric distillation residue [specific gravity (15 ° C./4° C.): 0.9611, sulfur content: 3.33% by weight, nitrogen Min: 0.19% by weight] as a feed oil, hydrogen pressure: 120 kg / cm ² , reaction temperature: 36
0 and 380 ° C., LHSV: 1.0 hr ⁻¹ , H ₂ / Oil ratio:
The reaction was carried out under an oil passing condition of 1000 cc / cc, and the sulfur content and the nitrogen content of the produced oil were measured. From the results and the catalyst pellets obtained after the calcination, the amount of cracks caused by vertical cracking was obtained and the weight% of the catalyst obtained as a vertical cracking amount is shown in Table 1.

[0025]

[Table 1]

From the above results, it can be seen that the use of the carrier liquid containing nitrate ions significantly increases the amount of vertical cracks and decreases the catalyst yield. Also, it can be seen that the desulfurization activity and the denitrification activity are maintained even if the Group VIII iron group metal salt is other than nitrate.

[0027]

According to the method of the present invention, while maintaining the same desulfurization and denitrification activity as the catalyst prepared by the conventional method, longitudinal cracking of the catalyst can be prevented, and the catalyst yield can be significantly improved.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01J 21/00-37/36 C10G 45/08

Claims (2)

(57) [Claims] 1. An at least one ammonium salt and a phosphorus component selected from Group VIB metal elements of the periodic table, at least one salt selected from Group VIII iron group metal elements of the Periodic Table, and the period A solution containing at least 0.8 mole of citric acid per mole of Group VIB metal element and containing no more than 1 part by weight of nitrate ion per 100 parts by weight of alumina support is impregnated into the alumina support and dried. And producing the catalyst for hydrotreating. 2. The method for producing a hydrotreating catalyst according to claim 1, wherein the metal element of Group VIB of the Periodic Table in the final catalyst composition of the hydrotreating catalyst is 5 to 15% by weight,
1 to 5% by weight of Group VIII iron group metal and 0.7 to 3 phosphorus
% By weight.