JPH0811190B2 - Hydrocarbon hydrotreating catalyst and method for activating the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a catalyst for hydrotreating a hydrocarbon oil, which can be easily activated, and a method for activating the same.

[Conventional technology]

Alumina and silica are used for so-called hydrogenation treatments such as hydrogenation, desulfurization, denitrification, and decomposition of hydrocarbon oils in the presence of hydrogen.
A catalyst in which at least one metal selected from Group 6 metals and Group 8 metals of the periodic table is supported as a hydrogenation active component on an inorganic oxide carrier such as alumina or titania is used. Mo and W, as Group 8 metals
Co and Ni are often used.

Since these metals are usually supported in the oxide state and are not active until then, pre-sulfurization, which converts the oxide state to the sulfide state and activates it, is necessary for use in the hydrotreatment reaction. is there.

Conventionally, this pre-sulfurization is generally performed by filling a reactor for hydrotreating hydrocarbon oil with a catalyst and then passing a sulfide agent through the catalyst layer together with hydrogen. The operating conditions for presulfurization differ depending on the hydrotreating process and the sulfurizing agent used, but when using hydrogen sulfide, 0.5 to 5% by volume of hydrogen should be contained, and this should be standard per catalyst. 1000-3000l converted to temperature and pressure, temperature 1
It is carried out at 80 ℃ or higher (usually 250 ℃ or higher). When using carbon disulfide, normal butyl mercaptan, dimethyl sulfide, dimethyl disulfide, etc., dilute them with light hydrocarbon oil and provide them at a temperature of 250- 350 ℃, pressure 20-100kg / c
m ² , liquid space velocity 0.5 to ² hr ^-1 , hydrogen / oil ratio 200 to 1000 Nl / l
It is done in. After performing such a preliminary sulfurization operation, the feedstock is actually switched to the feedstock to be treated, and the hydrotreating operation is started.

By the way, the pre-sulfurization operation affects the success or failure of the subsequent hydrogenation treatment, so that appropriate selection of materials to be used and careful operation are required. For example, when a diluent is used, it is necessary to use a hydrocarbon oil that does not contain olefins because the polymerization product poisons the catalyst if the diluent contains olefins. Since it has a poor moistening effect and is unsuitable for heavy oil, it is unavoidable to use a light distillate. The use of such light oil leads to high costs.
In addition, since the catalytic metal becomes passivated when it reacts with hydrogen at high temperature and is reduced, it is necessary to use a large amount of sulfiding agent in order to prevent this, and the proportion of sulfiding agent and hydrogen must be maintained appropriately. . Furthermore, such pre-sulfurization is usually performed for several days, but this operation is temporary and is often not automated. The burden on the staff is extremely large. Therefore, it has been a subject to omit the pre-sulfurization or at least to reduce the complexity of the operation.

[Problems to be solved by the invention]

Recently, a method capable of meeting such a request has been proposed. The method is carried out by using a catalyst on which an active metal is supported, the general formula RS (n) -R '(n is an integer of 3 to 20, R and R'are hydrogen atoms or 1 to 150 carbon atoms per molecule). A polysulfide represented by the formula (1), and the catalyst is heat-treated in the absence of hydrogen gas at 65 to 275 ° C. and a pressure of 0.5 to 70 bar (JP-A-61-111144). Issue). According to this method, the polysulfide impregnated in the catalyst sulfides the active metal by heat treatment, and therefore, when presulfiding in the reactor, the sulfiding agent and the diluent are not required, which facilitates the operation. Presulfurization outside the reactor is also possible, in which case the hydrotreating operation can be started immediately by charging the presulfurized catalyst into the reactor. However, the above polysulfides cannot be impregnated into the catalyst unless they are dissolved in an organic solvent, and thus this impregnation treatment requires special measures against the organic solvent.

[Means for solving problems]

As a result of various studies on the pre-sulfurizing method using a sulfurizing agent which is easier to handle than polysulfides, the present inventors have found that mercaptocarboxylic acid is suitable and arrived at the present invention.

That is, the present invention relates to a catalyst in which an oxide of at least one metal selected from Group 6 metals and Group 8 metals of the Periodic Table is supported on an inorganic oxide carrier, and a mercaptocarboxylic acid, an alkali metal salt of mercaptocarboxylic acid. , A catalyst for hydrotreating a hydrocarbon oil characterized by being impregnated with at least one of an alkaline earth metal salt and an ammonium salt, and treating the catalyst at room temperature to 400 ° C. in the presence of hydrogen. It is an activation method that is characterized in that

As well known in the art, examples of the inorganic oxide carrier include alumina, silica-alumina, titania and the like, and particularly alumina or silica-alumina is typical.

Further, as conventionally known, an oxide of Mo and / or W is preferable as the oxide of the Group 6 metal of the periodic table, which is supported as an active metal, and an oxide of the Group 8 metal is preferable.
Co and / or Ni oxides are preferred. The Group 6 metal oxide and the Group 8 metal oxide may be used alone or in combination.

Mercaptocarboxylic acids include mercaptoacetic acid (HS
CH ₂ COOH), β-mercaptopropionic acid (HSCH ₂ CH ₂ COO
H) etc. can be mentioned as a preferable example.

In addition, corresponding alkali metal salts, alkaline earth metal salts,
Although an ammonium salt can be used, a metal ion-free acid type and an ammonium salt type that do not leave a substance that becomes a catalyst poison in the hydrogenation reaction are preferable.

The mercaptocarboxylic acid and the salt are supported as a solution by an impregnation method on a catalyst containing an oxide of at least one of Group 6 metal and Group 8 metal of the periodic table on an inorganic oxide carrier. In this case, it is most economical to use an aqueous solution.

The supported amount of mercaptocarboxylic acid and its salt is sufficient to form a sulfided form (for example, MoS ₂ , WS ₂ , CoS, NiS) in which Group 6 metal and Group 8 metal of the Periodic Table show high activity in the hydrogenation reaction. It is preferably 1 to 3 times the required amount of sulfur. If the loading amount is less than this, the activity is lowered, and even if it is used more than that, the activity cannot be expected to be improved so much, which is uneconomical.

The catalyst carrying mercaptocarboxylic acid and its salt,
Some of them have an activity up to that point, but those which do not show an activity up to that point are dried at room temperature to 400 ° C in the presence of hydrogen after the solvent used to dissolve the mercaptocarboxylic acid and its salt is removed by drying. It is treated and activated at a temperature of ° C.
Removal of the solvent may be carried out at the time of activation in the presence of hydrogen, and it does not mean that a drying operation is particularly required before activation.

In the activation treatment in the presence of hydrogen, the mercaptocarboxylic acid and its salt coordinated to the metal of Group 6 and / or the metal of Group 8 of the Periodic Table are hydrogenated and separated, and the metal component is hydrogenated in the hydrogenation reaction. It changes to sulfide which is an active species.

In the activation treatment in the presence of hydrogen, the reaction pressure is not limited and hydrocarbons may be mixed. Therefore, the activation treatment can be carried out in a treatment apparatus separate from the hydrocarbon hydrotreating reactor in which the catalyst is used, or after the hydrotreating reactor is loaded. Is.

Activation is at room temperature to 400 ° C, preferably 100 to 300
It is carried out at a temperature of ° C. Temperatures higher than 400 ° C are not preferable because the hydrogenation activity of the treated catalyst decreases.

[Action]

The catalysts prepared according to the present invention exhibit better activity in hydrodesulfurization of hydrocarbon oils than catalysts sulfided by the prior art. The reason is not clear, but in the presence of hydrogen, the mercaptocarboxylic acid and its salt are supported by forming a coordination compound with a Group 6 metal and / or a Group 8 metal of the periodic table in the presence of hydrogen. It is believed that this is because it effectively acts to form a preferable metal sulfide body during the activation treatment of.

〔Example〕

 Hereinafter, examples and comparative examples of the present invention will be described.

Example 1 Using γ-alumina as a carrier, 15% by weight of MoO ₃ and 4 of CoO were used.
Commercially available catalyst containing wt% (KF manufactured by Nippon Ketzien Co., Ltd.)
-742) was impregnated with ²⁰ g of an aqueous solution containing 6.0 g of mercaptoacetic acid (d ²⁰ = 1.33), followed by drying at 80 ° C for 16 hours to obtain catalyst A. Further, catalysts B and C were obtained in the same manner as described above except that 9.0 g and 12.0 g of mercaptoacetic acid were used, respectively. Furthermore,
20 g of the commercially available catalyst, an aqueous solution containing 7.5 g of mercaptoacetic acid 1
An operation of impregnating the whole amount of 2 ml was repeated twice with a drying operation at 80 ° C. for 16 hours, and then a drying operation was performed at 80 ° C. for 16 hours to obtain a catalyst D.

The supported amount of mercaptoacetic acid on catalysts A, B, C and D is
The theoretical amounts of sulfur required for Mo and Co to become MoS ₂ and CoS were 1.2, 1.8, 2.4 and 3.0 times, respectively.

Example 2 500 g of an alumina carrier having a specific surface area of 310 m ² / g and a pore volume of 0.70 ml / g for KF-742 used in Example 1, 111 g of ammonium paramolybdate, 101 g of nickel nitrate hexahydrate, and concentrated ammonia. Impregnate the impregnating solution prepared from 150 g of water, 110 ℃, 1
After drying for 6 hours, it was calcined at 500 ° C. for 2 hours to obtain a catalyst containing 15% by weight of MoO ₃ and 4% by weight of NiO. The catalyst was loaded with mercaptoacetic acid in the same manner as in Example 1 to obtain catalyst E,
F, G and H were obtained.

The supported amount of mercaptoacetic acid on catalysts E, F, G and H is M
It was 1.2, 1.8, 2.4, and 3.0 times that of the theoretical amount of sulfur required for o and Ni to become MoS ₂ and NiS, respectively.

Example 3 20 g of the commercially available catalyst used in Example 1 was impregnated with 12 ml of an aqueous solution containing 10.0 g of mercaptopropionic acid (d ²⁰ = 1.22), followed by drying at 80 ° C. for 16 hours to obtain catalyst I.

The supported amount of mercaptopropionic acid on catalyst I was Mo,
It was 1.8 times the theoretical amount of sulfur required for Co to become MoS ₂ and CoS.

Example 4 (Activation treatment) 3 ml of each of catalysts A, B, C, D, E, F, G, H and I was loaded into a stainless steel fixed bed flow reaction tube and activated under the following conditions.

Catalyst amount 3ml Pressure Atmospheric pressure Hydrogen flow rate 48Nl / hr Time 3hr Temperature 200 ° C (Activity evaluation) Using the catalyst activated under the above conditions, hydrodesulfurization reaction of Kuwait atmospheric gas oil was performed. Also, catalyst B
The same desulfurization reaction was carried out for those which were not subjected to the above activation treatment (this catalyst is designated as B '). The properties of atmospheric gas oil used in the reaction are as follows.

Specific gravity (15/4 ℃) 0.848 Sulfur (wt%) 1.61 Nitrogen (wtppm) 157 Distillation property (initial boiling point, ° C) 211〃 (50vol% point, ° C) 340〃 (endpoint, ° C) 406 Reaction is flow type The reaction was carried out under the following reaction conditions using a reactor.

Catalyst amount 3ml Space velocity of raw oil liquid 2.0hr ^-1 Reaction pressure (hydrogen pressure) 30kg / cm ² Reaction temperature 330 ℃ Hydrogen / oil ratio 300Nl / l Oil passage time 8hr Treated oil is sampled every 2 hours to determine sulfur content It measured and determined the desulfurization rate. The average value of the desulfurization rate obtained from the sulfur content of the treated oil sampled at the 4th, 6th and 8th hours is shown in the table below.

Comparative Example The MoO ₃ / CoO-based and MoO ₃ / NiO-based catalysts used in Examples 1 and 2 were subjected to sulfurization (or pre-sulfurization) treatment with quat atmospheric gas oil mixed with n-butyl mercaptan and used for the reaction.

(Sulfurization treatment) Sulfurized oil 3% by weight n-butyl mercaptan / quat normal pressure light oil Catalyst amount 3ml Space velocity of feedstock liquid 2.0hr ^-1 Reaction pressure 30kg / cm ² Reaction temperature 316 ℃ Hydrogen / oil ratio 300Nl / l Oil passage time 8 hr (Activity evaluation) The conditions for activity evaluation are exactly the same as in Example 4. The average value of the desulfurization rate obtained from the sulfur content of the treated oil sampled at the 4th, 6th and 8th hours is shown in the table below.

Both Mo / Co-based catalysts and Mo / Ni-based catalysts that carry mercaptoacetic acid and mercaptopropionic acid are higher than catalysts that are sulfided using quat atmospheric gas oil mixed with 3% by weight of n-butyl mercaptan. Shows activity. The supported amount of mercaptoacetic acid was changed, but for the Mo / Co system, 1.2 times the theoretical amount of sulfur required to form MoS ₂ and CoS is sufficient, and the supported amount is further increased. No increase in activity is observed even if increased. It is not preferable to extremely increase the loading amount because not only the sulfiding agent is wasted but also the loading cannot be carried out further. The activity of catalyst B'is slightly inferior to that of catalyst B, but higher than the conventional legal presulfurization catalyst with n-butyl mercaptan. For Mo / Ni system, the optimum supported amount seems to be larger than that for Mo / Co system, but it is within 1.8 times the theoretical amount.

[Effects of the Invention] According to the present invention, a hydrocarbon hydrotreating catalyst having excellent performance can be obtained by an operation that is more simplified than in the conventional sulfurization method.

Claims (7)

[Claims] 1. An inorganic oxide as a carrier, and at least one oxide of a Group 6 metal and a Group 8 metal of the periodic table, a mercaptocarboxylic acid, an alkali metal salt of a mercaptocarboxylic acid, an alkaline earth metal salt, A catalyst for hydrotreating hydrocarbons, which comprises at least one of ammonium salts. 2. The hydrocarbon according to claim 1, wherein the Group 6 metal of the periodic table is at least one of Mo and W, and the Group 8 metal is at least one of Co and Ni. Hydrotreating catalyst. 3. The catalyst for hydrotreating hydrocarbons according to claim 1, wherein the mercaptocarboxylic acid is mercaptoacetic acid and / or mercaptopropionic acid. 4. A catalyst containing an inorganic oxide as a carrier and containing at least one of a Group 6 metal and a Group 8 metal of the periodic table as an oxide, a mercaptocarboxylic acid, an alkali metal salt of a mercaptocarboxylic acid, and an alkaline earth. Hydrocarbon hydrogenation characterized by treating a hydrocarbon hydrotreating catalyst impregnated with at least one of a group metal salt and an ammonium salt at room temperature to 400 ° C in the presence of hydrogen. A method for activating a treatment catalyst. 5. A hydrocarbon according to claim 4, wherein the Group 6 metal of the periodic table is at least one of Mo and W and the Group 8 metal is at least one of Co and Ni. A method for activating a hydrotreating catalyst. 6. Activation of a hydrocarbon hydrotreating catalyst according to claim 4, wherein the mercaptocarboxylic acid is mercaptoacetic acid and / or mercaptopropionic acid. Method. 7. A method for activating a hydrocarbon hydrotreating catalyst according to any one of claims (4), (5) and (6), wherein the treatment temperature is 100 to 300 ° C. .