JPH10192711A - Method for regenerating hydrogenation catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To almost completely reactivate a palladium-base hydrogenation catalyst by removing the catalyst poison from the catalyst deteriorated in activity and improving the dispersion of metal. SOLUTION: A palladium-base hydrogenation catalyst contg. chlorine and deteriorated in activity is steamed and then catalytically treated with an oxygen- contg. gas at 100-500 deg.C. Consequently, the catalyst poison is removed, the dispersion of metal is improved, and an almost completely reactivated palladium-base hydrogenation catalyst is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for regenerating a hydrogenation catalyst, and more particularly, to a method for removing poisonous substances such as chlorine and coke from a palladium-based hydrogenation catalyst whose activity has deteriorated, The present invention relates to a method for almost completely reactivating the palladium-based hydrogenation catalyst by reducing the particle size and improving the degree of metal dispersion.

[0002]

2. Description of the Related Art In recent years, palladium-based hydrogenation catalysts have
In the fields of petroleum refining industry, petrochemical industry, general chemical industry and the like, it is widely used as a catalyst for various hydrogenation reactions. For example, crude oil, crude oil excluding the naphtha fraction, straight run naphtha, kerosene, light oil, vacuum distillate, atmospheric residue, vacuum residue, pyrolysis gasoline, coker and bis Hydrogenation reaction and reforming of hydrocarbon oils heat-treated by breakers, naphtha fractions produced by catalytic crackers and recycled oils, and hydrocarbon oils such as shale oil, tar sands oil, and synthetic oils from coal It is used as a catalyst in reactions, hydrogenation reactions of various unsaturated hydrocarbons, and hydrocracking reactions of paraffinic hydrocarbons.

[0003] However, it is known that the catalytic activity of a palladium-based hydrogenation catalyst used in such a hydrogenation reaction gradually decreases over a long period of time. It is said that the decrease in the catalytic activity is caused by accumulation of impurities and formation of coke on the palladium metal, and further, an increase in the particle diameter of the palladium metal, that is, a reduction in the degree of metal dispersion. And, since the particle diameter of palladium metal once increased by using it can not be restored by normal regeneration processing,
It is also referred to as permanent deterioration, and in this case, the actual situation is that palladium is unavoidably recovered and reactivated. For the regeneration of the deactivated palladium hydrogenation catalyst,
Various methods have been proposed so far. For example, a method has been proposed in which a platinum or palladium catalyst poisoned by arsenic contained in a petroleum fraction is reactivated by oxidizing it with a gas containing oxygen at a temperature of room temperature to 250 ° C. 60-57897). However, this method has a problem that even if it is possible to remove an arsenic compound, it is impossible to improve the metal dispersion of platinum or palladium. Also, a method has been proposed in which platinum and palladium catalysts are reactivated at a temperature of 300 to 350 ° C. by using a gas obtained by further mixing dry hydrogen chloride with a mixed gas of chlorine and air (East German Patent No. 120589). Specification). However, this method
Since chlorine, which easily becomes a catalyst poison of platinum or palladium, is used, and it is not a method for improving the metal dispersion of platinum or palladium, it cannot be said that this is an essential method for reactivating the catalyst.

[0004]

SUMMARY OF THE INVENTION Under such circumstances, the present invention is to remove the poisoning substance of the palladium-based hydrogenation catalyst whose activity has deteriorated and to reduce the particle diameter of palladium metal, It is an object of the present invention to provide a method for improving the degree of dispersion to almost completely reactivate the palladium-based hydrogenation catalyst.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on a method for reactivating a palladium-based hydrogenation catalyst whose activity has deteriorated, and as a result, as a palladium-based hydrogenation catalyst whose activity has deteriorated, By using a palladium-based hydrogenation catalyst degraded in activity by adhering or adsorbing at least chlorine, by steaming this, and then contacting it with an oxygen-containing gas at a specific temperature,
It has been found that while poisonous substances such as chlorine and coke are effectively removed, the degree of dispersion of the palladium metal is unexpectedly improved, and it can be almost completely reactivated. The present invention has been completed based on such findings.

That is, the present invention provides (1) a steaming treatment of a palladium-based hydrogenation catalyst having deteriorated activity by adhering or adsorbing at least chlorine, and then using an oxygen-containing gas in a temperature range of 100 to 500 ° C. A method for regenerating a catalyst for hydrogenation, which comprises carrying out a contact treatment at a temperature; (2) a catalyst used for a hydrogenation reaction of an isobutylene polymer, wherein the palladium has a reduced activity by adhering or adsorbing chlorine System hydrogenation catalyst, 1
(3) a method for regenerating a catalyst for hydrogenation, comprising performing a steaming treatment at a temperature in the range of 50 to 250 ° C, and then performing a contact treatment with an oxygen-containing gas at a temperature in the range of 100 to 500 ° C. A catalyst for use in the selective hydrogenation reaction of methylacetylene and / or propadiene in a palladium-based hydrogenation catalyst having a reduced activity by adhering or adsorbing at least chlorine to a catalyst in the range of 200 to 350 ° C. Steaming at temperature and then 100-
An object of the present invention is to provide a method for regenerating a hydrogenation catalyst, which comprises performing a contact treatment at a temperature in the range of 500 ° C.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As a palladium-based hydrogenation catalyst with reduced activity to which the method of the present invention is applied, any catalyst may be used as long as it has at least chlorine attached or adsorbed. In the fields of petroleum refining industry, petrochemical industry, general chemical industry and the like, it can be arbitrarily selected from those used as catalysts in hydrogenation reactions. Examples of such products include crude oil excluding crude oil and naphtha fraction, straight run naphtha, kerosene, light oil, vacuum distillate, atmospheric residual oil, vacuum residual oil, and by-products in the thermal cracking unit of ethylene plant. Pyrolysis gasoline, hydrocarbon oils heat-treated by cokers, visbreakers, etc., naphtha fractions produced by catalytic crackers and recycled oils, and hydrocarbon oils such as shale oil, tar sands oil, and synthetic oils from coal Hydrogenation of oligomers obtained by polymerizing lower olefins such as propylene, butylene, etc. to about 2- to 4-mers using an acid catalyst, etc. Used for the hydrogenation reaction in the production of isoparaffinic gasoline, for the selective hydrogenation of methylacetylene and propadiene in propylene Or the like can be mentioned those that have been use.

The type of the palladium-based hydrogenation catalyst is not particularly limited, and examples thereof include those conventionally used as catalysts in the above-mentioned reactions and the like. As the palladium-based hydrogenation catalyst, palladium alone may be used, but usually a palladium supported on a suitable carrier is used. In addition to palladium, Ag, as a second metal,
What carried Pb, Cu, Au, Sn, Zn, Cd, etc. may be used. Here, the palladium carrier is not particularly limited, and is appropriately selected according to the use of the catalyst. As this carrier, for example, silica, alumina,
Silica alumina, titania, magnesia, zirconia,
Crystalline aluminosilicate (zeolite) and the like can be mentioned. The zeolite may be any of synthetic zeolite and natural zeolite, and may be X-type, Y-type,
Any type such as L type, mordenite type, ZSM-5 type and the like may be used. The amount of palladium carried is not particularly limited, but is usually about 0.01 to 10% by weight as palladium metal with respect to the total amount of the catalyst.

In the present invention, it is necessary to use, as the palladium-based hydrogenation catalyst whose activity has been deteriorated, a catalyst to which at least chlorine is attached or adsorbed. When chlorine is contained in the palladium-based hydrogenation catalyst, an effect of reducing the particle diameter of palladium metal (improving the degree of metal dispersion) in the following catalyst reactivation process is exerted. The amount of chlorine adhering or adsorbing is not particularly limited, but is usually in the range of 0.005 to 5% by weight. If the amount is less than 0.005% by weight, the effect of improving the degree of dispersion of palladium metal may not be sufficiently exhibited.
If it exceeds, the catalytic activity is remarkably reduced, and it is not usually used as a catalyst in the hydrogenation reaction, so that it is difficult to exist.

[0010] In the method of the present invention, a steaming treatment is first performed on a palladium-based hydrogenation catalyst whose activity has been deteriorated due to the attachment or adsorption of at least chlorine. The conditions for the steaming treatment are not particularly limited, and are appropriately selected depending on the origin, type, degree of deterioration, and the like of the catalyst whose activity has deteriorated.
It is steamed at a temperature in the range of ° C. When this temperature is lower than 150 ° C., the catalyst is hardly reactivated, requires a long time, and is not practical. On the other hand, if the temperature exceeds 350 ° C., the reactivation rate does not improve much for the temperature, but it is economically disadvantageous, and in some cases, the shape of the catalyst may be destroyed. Furthermore, the amount of steam during the steaming treatment, that is, LHSV (liquid hourly space velocity; amount of steam circulated per unit time / amount of catalyst to be treated) may be appropriately selected depending on the situation. 5-5hr
It is in the range of ^-1 . The pressure of the steaming process is not particularly limited, but the process is usually performed under atmospheric pressure.
The processing time depends on the origin and type of the catalyst whose activity has deteriorated,
Dependent on various conditions such as the degree of deterioration, processing temperature, LHSV and the like, it cannot be determined unconditionally.
About an hour is enough.

In the present invention, the palladium-based hydrogenation catalyst having deteriorated activity is preferably a polymer of isobutylene,
For example, when the catalyst obtained by polymerizing isobutylene in the presence of an acid catalyst such as aluminum chloride is used to produce a hydrocarbon mixture by hydrogenation,
At a temperature in the range of ２５０250 ° C. and 200-350 ° C. for the catalyst used for the selective hydrogenation of methylacetylene and / or propadiene in propylene.
It is advantageous to perform the steaming treatment at a temperature in the range of from the viewpoints of catalyst reactivation efficiency and economy. The other steaming processing conditions are the same as described above.

Next, the catalyst subjected to the steaming treatment in this manner is further subjected to a contact treatment with an oxygen-containing gas. Here, the oxygen-containing gas may be oxygen gas alone, or an oxygen gas and an inert gas such as nitrogen,
A mixture with a gas such as argon or helium may be used, but air is particularly preferred from the viewpoint of decoking properties and economy. The contact treatment temperature with the oxygen-containing gas is selected in the range of 100 to 500 ° C. This temperature is 1
If the temperature is lower than 00 ° C., the catalyst is hardly reactivated and is not practical. On the other hand, if the temperature exceeds 500 ° C., the reactivation rate cannot be improved much for the temperature, but it is economically disadvantageous, and in some cases, the shape of the catalyst may be destroyed.

Further, the amount of oxygen-containing gas at the time of the contact treatment, that is, GHSV (gas hourly space velocity; flow rate of oxygen-containing gas per unit time / amount of catalyst to be treated) may be appropriately selected depending on the situation. Suffice, but usually 100-200
0 hr ^-1 . The pressure for this contact treatment is not particularly limited, but the treatment is usually performed under atmospheric pressure. In addition, the treatment time is influenced by various conditions such as the origin and type of the catalyst whose activity has deteriorated, the degree of deterioration, the treatment temperature, and the LHSV, and cannot be determined unconditionally.
About 100 hours is enough. In the present invention, the palladium-based hydrogenation catalyst with reduced activity is a polymer obtained by polymerizing isobutylene in the presence of an acid catalyst such as a polymer of isobutylene, for example, aluminum chloride. When the catalyst used to produce the mixture, at a temperature in the range of 100-500 ° C., and when used in the selective hydrogenation reaction of methylacetylene and / or propadiene in propylene,
It is advantageous to carry out the contact treatment with an oxygen-containing gas at a temperature in the range of 100 to 500 ° C. from the viewpoints of the catalyst reactivation efficiency and economy. Other contact processing conditions are the same as described above.

In this way, by regenerating at least the palladium-based hydrogenation catalyst whose activity is deteriorated due to the adhesion or adsorption of chlorine, poisonous substances such as chlorine and coke are removed, and the palladium metal is removed. An almost completely reactivated palladium-based hydrogenation catalyst having an improved degree of dispersion is obtained.

[0015]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The regeneration of the catalyst was performed according to the following method. <Catalyst regeneration method> A 1-inch outer diameter stainless steel reaction tube is filled with 10 cc of used catalyst, heated to a predetermined temperature under nitrogen, and when the desired temperature is reached, water is supplied to the heater by a pump. I do. The supplied water is heated to a predetermined temperature,
The water vapor is introduced into the stainless steel reaction tube. After a predetermined time, the supply of water is stopped, the air is switched to air, the temperature of the air is raised to a predetermined temperature, and a contact treatment (air oxidation treatment) is performed at a predetermined temperature for a predetermined time to regenerate the used catalyst.

Example 1 Palladium-supported γ-alumina catalyst (palladium-supported amount:
0.5% by weight of used catalyst (used for isobutylene reaction, coke amount: 0.63% by weight, adhered chlorine amount: 1.20% by weight, metal dispersity: 0.27) 10cc of stainless steel reaction tube , Temperature: 200 ° C, water supply: 35 cc
After steaming for 16 hours under the condition of / hr, temperature: 300 ° C, air flow rate: 2 l under the condition of 6 liter / hr
The contact treatment with air was performed for 4 hours, and the used catalyst was regenerated. Table 1 shows the physical properties of the regenerated catalyst. In addition,
The metal dispersity is a value determined according to the following method (the same applies hereinafter). Determining the degree of metal dispersion: 3 to 5 g of a catalyst is filled in a glass tube and dried at a flow rate of 200 cc / min.
For 8 hours to remove water on the catalyst. Thereafter, pre-reduction was performed at a flow rate of 200 cc / min under H ₂ for 8 hours. 0.65 cc of CO was once injected into the pre-reduced catalyst in a pulsed manner until CO adsorption disappeared. The degree of metal dispersion was determined by (mol number of adsorbed CO / mol atom of Pd of catalyst).

Comparative Example 1 In Example 1, the temperature of the contact treatment with air was set to 300 ° C.
The regeneration process of the used catalyst was performed in the same manner as in Example 1 except that the temperature was changed to 80 ° C. First property of regenerated catalyst
It is shown in the table.

COMPARATIVE EXAMPLE 2 In Example 1, the conditions of the contact treatment with air without performing the steaming treatment were as follows: temperature: 200 ° C., time: 4
Except for changing to 8 hours, the used catalyst was regenerated in the same manner as in Example 1. Table 1 shows the physical properties of the regenerated catalyst.

Comparative Example 3 In Example 1, the used catalyst was a palladium-supported γ-alumina catalyst (amount of palladium supported: 0.5% by weight).
The used catalyst was subjected to a regeneration treatment in the same manner as in Example 1 except that the used catalyst (coke amount: 0.50% by weight, attached chlorine amount: none, metal dispersity: 0.25) was used. . Table 1 shows the physical properties of the regenerated catalyst.

[0020]

[Table 1]

[Note] Spent catalyst A: 1.20% by weight of adhering chlorine, 0.
63% by weight, metal dispersity 0.27 Spent catalyst B: adhering chlorine: none, coke weight 0.5
0%, metal dispersion 0.25

Example 2 A spent catalyst in the selective hydrogenation of methylacetylene and propadiene in propylene was used. Spent catalyst of palladium-supported γ-alumina catalyst (palladium-supported amount: 0.1% by weight) (coke amount: 1.05% by weight, attached chlorine amount: 2700% by weight, metal dispersity: 0.015) 1
0 cc into a stainless steel reaction tube, temperature: 300
After steaming for 10 hours at a temperature of 35 ° C. and a supply amount of water of 35 cc / hr, a temperature of 400 ° C. and an air amount of:
The contact treatment with air was performed for 8 hours under the condition of 2 liters / hr, and the used catalyst was regenerated. Table 2 shows the physical properties of the regenerated catalyst. Next, 10 cc of the regenerated catalyst was filled in a stainless steel reaction tube having an inner diameter of 10 mm and an outer diameter of 12 mm, and propylene and hydrogen containing 1.73% by weight of methylacetylene and 1.54% by weight of propadiene were added thereto.
Hydrogen / (methylacetylene + propadiene) molar ratio is 1.
5, and a selective hydrogenation reaction of methylacetylene and propadiene was performed under the conditions of pressure: 20 kg / cm ² G, temperature: 40 ° C., and LHSV: 25 hr ⁻¹ . Table 2 shows the reaction results.

Comparative Example 4 In Example 2, a selective hydrogenation reaction of methylacetylene and propadiene was carried out in the same manner as in Example 2 except that the used catalyst was not used for regeneration treatment but was used as a catalyst. Table 2 shows the physical properties and reaction results of the used catalyst.

Comparative Example 5 The procedure of Example 2 was repeated, except that the steam regeneration of the used catalyst was not performed in the regeneration of the catalyst in Example 2. Table 2 shows the physical properties and reaction results of the regenerated catalyst.

COMPARATIVE EXAMPLE 6 The procedure of Example 2 was repeated, except that the contact treatment with air was not performed in the regeneration treatment of the catalyst in Example 2. Table 2 shows the physical properties and reaction results of the regenerated catalyst.

[0026]

[Table 2]

[Note] In Comparative Example 4, since the used catalyst was used for the reaction without performing the catalyst regeneration treatment, the catalyst physical property data is the data of the used catalyst.

Example 3 A used catalyst in a hydrogenation reaction of an isobutylene polymer obtained by polymerizing isobutylene in the presence of an aluminum chloride catalyst was used. Spent catalyst of palladium-supported γ-alumina catalyst (palladium-supported amount: 0.5% by weight) (coke amount: 0.63% by weight, attached chlorine amount: 1.2% by weight,
Metal dispersity: 0.27) Fill 10 cc into a stainless steel reaction tube, temperature: 200 ° C., water supply: 35 cc / h
After performing a steaming treatment for 16 hours under the conditions of r, the temperature is 400 ° C., the amount of air is 20 l under the conditions of 6 liters / hr.
The contact treatment with air was performed for a time, and the used catalyst was regenerated. Table 3 shows the physical properties of the regenerated catalyst. Next, 10 cc of the regenerated catalyst was filled into a stainless steel reaction tube having an inner diameter of 10 mm and an outer diameter of 12 mm, and isobutylene was polymerized in the presence of an aluminum chloride catalyst to obtain an isobutylene polymer having an average degree of polymerization of 3. And hydrogen were charged so that the hydrogen / isobutylene polymer molar ratio was 2.0, and a hydrogenation reaction of the isobutylene polymer was performed under the conditions of pressure: 25 kg / cm ² G and temperature: 220 ° C. Table 3 shows the reaction results.

Comparative Example 7 A hydrogenation reaction of an isobutylene polymer was carried out in the same manner as in Example 3 except that the used catalyst was used as a catalyst in Example 3 without regenerating the used catalyst. Table 3 shows the physical properties of the used catalyst and the reaction results.

Comparative Example 8 The procedure of Example 3 was repeated, except that the steaming treatment of the used catalyst was not performed in the regeneration treatment of the catalyst in Example 3. Table 3 shows the physical properties and reaction results of the regenerated catalyst.

Comparative Example 9 The same procedure as in Example 3 was carried out, except that the contact treatment with air was not performed in the regeneration treatment of the catalyst in Example 3. Table 3 shows the physical properties and reaction results of the regenerated catalyst.

[0032]

[Table 3]

[Note] In Comparative Example 7, since the used catalyst was used for the reaction without performing the catalyst regeneration treatment, the catalyst physical property data is the data of the used catalyst.

[0034]

According to the method of the present invention, a catalyst whose activity has been reduced is subjected to a regeneration treatment using a palladium-based hydrogenation catalyst to which chlorine is attached or adsorbed, so that the catalyst such as chlorine or coke can be treated. The poisonous substance is removed, the degree of metal dispersion is improved, and a palladium-based hydrogenation catalyst almost completely reactivated can be obtained. Therefore, the method of the present invention can significantly reduce the frequency of catalyst replacement and replacement, and is industrially useful.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07B 61/00 300 C07B 61/00 300 C07C 5/03 C07C 5/03

Claims (3)

[Claims] 1. A palladium-based hydrogenation catalyst having a deteriorated activity by adhering or adsorbing at least chlorine is subjected to a steaming treatment, and then is subjected to a steam-treating process using an oxygen-containing gas.
A method for regenerating a catalyst for hydrogenation, comprising performing a contact treatment at a temperature in the range of 0 ° C. 2. A catalyst for use in a hydrogenation reaction of an isobutylene polymer, which is a catalyst for hydrogenation of a palladium-based catalyst whose activity has been deteriorated by adhering or adsorbing at least chlorine, at a temperature in the range of 150 to 250 ° C. Steaming, then 100-500 by oxygen containing gas
A method for regenerating a catalyst for hydrogenation, comprising performing a contact treatment at a temperature in the range of ° C. 3. Methylacetylene and / or propylene in propylene
Or a catalyst used for the selective hydrogenation reaction of propadiene, which is a palladium-based hydrogenation catalyst having a reduced activity by adhering or adsorbing chlorine at least,
A method for regenerating a hydrogenation catalyst, comprising performing a steaming treatment at a temperature in the range of 350 ° C, and then performing a contact treatment with an oxygen-containing gas at a temperature in the range of 100 to 500 ° C.