JP2002102716A - Method for regenerating catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new method for regenerating various active component- carrying catalyst used in various fields of industry. SOLUTION: In this regenerating method, a catalytically active component- carrying TiO2 catalyst poisoned by sulfur compounds is washed with an aqueous solution containing at least one compound selected from the group consisting of the hydroxides, carbonates, nitrates and sulfates of alkali metals and alkaline earth metals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a catalyst active component comprising Ti
The present invention relates to a method for regenerating a catalyst supported on O ₂ .

[0002]

2. Description of the Related Art Catalysts having a catalytically active component supported on a carrier are used for steam reforming, hydrocracking, and partial combustion of hydrocarbons; wet oxidation treatment of organic-containing wastewater; and wet gas treatment of organic-containing wastewater. Alternatively, it is used in a very wide field such as methanol production. As a carrier in such a catalyst, usually, alumina, zirconia, titania,
Magnesia, silica, silica-alumina, titania-zirconia, etc. are used, and as the catalytically active metal,
Depending on the field of use, Ru, Pd, Rh, Pt, Ni, Co, Mn, Ce,
Au, Ir, Os, Fe, etc. are used.

[0003] Such catalysts are very expensive, but exhibit excellent catalytic activity in any field, and are therefore widely used on an industrial scale. However, even in such a catalyst, with the passage of time, a poisoning substance mainly composed of a sulfur compound precipitates on the surface,
Since the catalyst activity is reduced, it is necessary to regenerate the deteriorated catalyst at an appropriate timing and use it repeatedly. Conventionally,
In order to regenerate this type of catalyst, treatment with hydrogen, steam, oxygen, etc. has been performed. In such a regeneration treatment method, although poisoning substances deposited on the catalyst surface are removed relatively satisfactorily. And as expected from removal of poisons,
There is a problem that the catalyst activity is not sufficiently recovered.

[0004] Japanese Patent Publication Nos. 3-61497 and 3-61498 by the present applicant disclose that a platinum group metal catalyst with a carrier for steam reforming, hydrocracking or partial combustion of hydrocarbons is used as an alkali. A method for regenerating a catalyst which is treated with an aqueous solution of a metal and / or an alkaline earth compound and then treated again with an aqueous solution of a reducing agent such as hydrazine "has been proposed. Since the treatment method requiring the two-step washing remarkably recovers the activity of the specific catalyst used in the above-mentioned various reactions using hydrocarbon as a raw material, an extremely excellent effect as a method for regenerating the specific catalyst is obtained. Has been demonstrated.

The inventor of the present invention has proposed a catalyst used in other reactions in the above two-stage washing treatment method, for example, a catalyst used in wet oxidation treatment of wastewater containing organic matter, methane production by wet treatment of wastewater containing organic matter, or methanol. With the idea of using it for the regeneration of catalysts used in production, we have been conducting intensive research. However, in the course of this research, it was found that the findings obtained by the above-described treatment method requiring two-step washing were not necessarily universally applicable to all active component-supported catalysts.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a new method for regenerating various active component-supported catalysts used in a wide range of industrial fields.

[0007]

Means for Solving the Problems The present inventor conducted further research based on the knowledge obtained in the course of the above research, and as a result, a specific metal was used as a catalytically active component, and TiO ₂ was used as a carrier. Unexpectedly, poisoning can be easily removed by washing with an aqueous solution of an alkali metal compound and / or an alkaline earth metal compound, regardless of the reaction involving the catalyst. It was found that the activity was significantly restored.

The present invention has been completed based on such new findings, and provides the following catalyst regeneration method. 1. Catalytically active component-supported Ti poisoned by sulfur compounds
A method for regenerating a catalyst, comprising washing an O ₂ catalyst with an aqueous solution containing at least one compound selected from the group consisting of hydroxides, carbonates, nitrates and sulfates of alkali metals and alkaline earth metals. . 2. The catalytically active component is Ru, Pd, Rh, Pt, Ni, Co, Mn, C
3. The method for regenerating a catalyst according to the above item 1, wherein the catalyst is at least one selected from the group consisting of e, Au, Ir, Os and Fe. 3. Item 2. The method for regenerating a catalyst according to Item 1, wherein the aqueous solution is an aqueous solution of Na ₂ CO ₃ . 4. The above item 1 in which the catalyst is washed with an aqueous solution at 20 to 100 ° C.
The method for regenerating a catalyst according to the above.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The poisoning catalysts to be subjected to the regeneration treatment of the present invention include Ru, Pd, Rh, Pt, Ni, Co, Mn, Ce, Au, Ir,
The catalyst uses at least one selected from the group consisting of Os and Fe as a catalytically active component and TiO ₂ as a carrier.

The poisoned catalyst regenerated by the method of the present invention comprises:
The reaction involving the catalyst or the use in which the catalyst is used, the production method, and the like are not limited, as long as the catalyst active component / TiO ₂ carrier is combined. Examples of such a reaction or use include, more specifically, steam reforming, hydrocracking, and partial combustion of hydrocarbons; wet oxidation treatment of organic matter-containing wastewater; fuel gas production or methanol production by wet treatment of organic matter-containing wastewater. And the like. Such a catalyst is produced by a known method, and more specifically, for example, Ti
By immersing the O ₂ carrier in an aqueous solution of the catalytically active component,
It is manufactured by a method of precipitating a catalytically active component on the surface of a carrier.

Examples of the cleaning solution for the poisoning catalyst include hydroxides, carbonates, nitrates of alkali metals and alkaline earth metals,
An aqueous solution containing at least one compound such as a sulfate is used.

Examples of the compound of an alkali metal and an alkaline earth metal include sodium carbonate and sodium hydroxide. Among these compounds, sodium carbonate is more preferred. The concentration as an aqueous solution may vary depending on the amount of the supported catalytically active component, the degree of reduction in the catalytic activity (particularly the amount of the poisoning substance precipitated, the degree of the decrease in dispersibility), the temperature during washing, and the like, but is usually 0.001 to 10 N. And more preferably about 0.001 to 5N. Such catalyst washing with an aqueous solution can be performed at a temperature of about 20 to 100 ° C. To shorten the catalyst cleaning time,
It is preferable to perform the cleaning on the high temperature side of about 0 ° C. The catalyst that has been washed with the above aqueous solution may be further used if necessary.
Washed and dried.

The cleaning of the poisoned catalyst may be carried out by introducing a cleaning liquid into the reaction vessel while the catalyst is held in the reactor in which the predetermined reaction has been carried out, or by removing the catalyst outside the reaction vessel. You may take it out.

[0014]

According to the method of the present invention, the poisoned catalyst can be regenerated by a simple method of washing with an aqueous solution of a specific compound.

Further, the catalyst re-poisoned by use after regeneration can be regenerated by a similar method.

The catalyst to be regenerated is a catalytically active component /
There is no restriction on the reaction involving the catalyst or the field of use of the catalyst as long as it is composed of a combination with a support (TiO ₂ ).

[0017]

EXAMPLES Examples are shown below to further clarify the features of the present invention. Gasification activity was regenerated by washing Ru2% -TiO ₂ catalyst was reduced undergoing Example 1 sulfur poisoning. In other words, the poisoned catalyst is
Washed by boiling for 1 hour in 5 times volume of Na ₂ CO ₃ aqueous solution (concentration = 0.375 N, temperature = 98 ° C), and washed with 5 times volume of distilled water in the same vessel for 5 minutes (repeated 3 times) Then, it was dried in air at 100 ° C. for 2 hours.

[0018] using Ru2% -TiO ₂ catalyst was thereby subjected to reproduction as described above, in the supercritical conditions (400 ℃ × 25MPa), the production of fuel gas mainly composed of methane again hexane as a raw material went.

The results are shown in Table 1. After playing the same various operations as in Example 2 catalyst poisoning receiving and Ni @ 2% gasification activity decreased -TiO ₂ catalyst of Example 1, the production of fuel gas mainly composed of methane again hexane as a raw material Was done. The results are shown in Table 1.

[0020]

[Table 1]

As is evident from the results shown in Table 1, the catalyst regenerated by the method of the present invention from a state in which the hexane decomposability has been significantly reduced exhibits the ability to completely decompose hexane similarly to the original catalyst. .

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) B01J 23/96 B01J 23/74 321M (72) Inventor Tatsuo Kume 4-1-2 Hiranocho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Yoshiaki Harada 4-1-2, Hirano-cho, Chuo-ku, Osaka City, Osaka Prefecture BC62A BC66A BC67A BC68A BC68B BC70A BC70B BC71A BC72A BC73A BC74A BC75A CC17 GA12 GA16

Claims (4)

[Claims] 1. The method of claim 1, wherein the catalytically active component-supported TiO ₂ catalyst poisoned by the sulfur compound comprises at least a compound selected from the group consisting of hydroxides, carbonates, nitrates and sulfates of alkali metals and alkaline earth metals. A method for regenerating a catalyst, comprising washing with an aqueous solution containing one kind. 2. The catalyst active component is Ru, Pd, Rh, Pt, Ni, C
The method for regenerating a catalyst according to claim 1, wherein the catalyst is at least one selected from the group consisting of o, Mn, Au, Ir, Os, Fe and Ce. 3. The method for regenerating a catalyst according to claim 1, wherein the aqueous solution is an aqueous solution of Na ₂ CO ₃ . 4. The method for regenerating a catalyst according to claim 1, wherein the catalyst is washed with an aqueous solution at 20 to 100 ° C.