JPS60227834A - Manufacture of ruthenium catalyst - Google Patents

Abstract

PURPOSE:To manufacture inexpensively the titled Ru catalyst showing high catalytic activity in the steam-reforming reaction of hydrocarbon or the like by adsorbing organic substances on a carrier previously and depositing ruthenate thereon. CONSTITUTION:Organic substances such as lower alcohol are previously saturated and adsorbed on a carrier of alumina or the like and ruthenate such as sodium ruthenate or potassium ruthenate is deposited thereon. It is reduced to RuO2 by performing the decomposition and reduction of the ruthenate by means of organic substances simultaneously with the deposition of the ruthenate. Then, the harmful metallic atoms such as Na and K are removed by washing it with water till the pH is reached to almost 8 and it is dried to manufacture the catalyst. By this method, the removal of chlorine being catalytic poison and metallic atoms such as Na or K which give adverse effect to the catalyst performance is made easy and the catalyst performance is improved and the Ru catalyst is inexpensively manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a ruthenium catalyst, and more particularly to a method for producing at a low cost a ruthenium catalyst that exhibits high catalytic activity in steam reforming reactions of hydrocarbons and the like.

Conventional methods for producing ruthenium catalysts include, for example, impregnating a suitable carrier with an aqueous solution of ruthenium chloride by a liquid phase impregnation method or a bore filling method, drying it, performing hydrogen reduction, and then washing with water to remove chloride ions. A method is known in which dechlorination is carried out by continuing to flow hydrogen until hydrogen chloride is removed or hydrogen chloride is exhausted. However, this method requires washing with many mouths of water or a long reduction operation in order to remove chloride ions, which increases the production cost of the catalyst. Additionally, this method generally has the disadvantage that chlorine ions cannot be completely removed.

Also known is a method in which sodium ruthenate or potassium ruthenate is used instead of ruthenium chloride to pre-impregnate with ruthenium salt, dry, and then reduce, followed by washing with water. However, in this method, the solution of sodium ruthenate or potassium ruthenate is usually pl-
Since it is strongly alkaline with a value of 113.5 to 14.0,
During heating operations such as drying and reduction after impregnation, the carrier reacts with alkali, causing a decrease in specific surface area and chemical alteration, resulting in deterioration of catalyst performance.

By the way, it has been known for a long time that sodium ruthenate and potassium ruthenate are easily reduced to ruthenium dioxide by organic substances, and a method of impregnating a carrier with this compound and then treating it with an organic substance is also considered. However, even with this method, it is necessary to impregnate the carrier with an aqueous solution such as sodium ruthenate, dry it, and then treat it with an organic substance. During the drying operation, the carrier reacts with the strong alkali of the ruthenate salt, and deterioration of the carrier is unavoidable. Furthermore, if the carrier is reduced without drying, the carrier is filled with an aqueous solution, so it takes a long time to be sufficiently reduced to the inside of the carrier, and furthermore, there are problems such as the organic matter not penetrating into the interior of the carrier.

In view of the problems of the prior art described above, the present invention facilitates the removal of chlorine, which is a catalyst poison, and metal atoms such as sodium or potassium that adversely affect catalyst performance, improves catalyst performance, and inexpensively produces ruthenium catalysts. The purpose is to provide a method for manufacturing.

As a result of intensive research in line with the above objectives, the present inventors noticed that ruthenate salts such as sodium ruthenate or potassium ruthenate are easily reduced to ruthenium dioxide by organic substances, and that ruthenium dioxide is not water-soluble. However, when using inexpensive ruthenium MFA such as sodium ruthenate or potassium ruthenate as a ruthenium raw material, organic substances such as methanol are adsorbed onto the carrier in advance, and then ruthenate is added to reduce and fix ruthenium onto the carrier. Furthermore, since sodium, potassium, etc. are Mwi, they can be easily washed.
We have discovered that it can be removed and have arrived at the present invention.

That is, the present invention is a method for producing a ruthenium catalyst characterized by adsorbing an organic substance onto a carrier in advance, and then impregnating and supporting a ruthenate salt.

In the present invention, organic substances are first adsorbed onto a carrier. The adsorption method is not particularly limited; however, the carrier is placed in a container saturated with organic matter vapor, and the organic matter is absorbed in a saturated manner;
A method of curving is preferably used.

Supports that can be used in the present invention include alumina, silica,
Examples include alumina, zirconia, titania, activated carbon, etc., and γ-alumina is particularly preferably used.

As the organic substance, alcohols such as methanol and tanol, carboxylic acids such as acetic acid, or ketones such as acetone can be used.

However, methanol is preferred in view of cost, high vapor pressure even at room temperature, and danger.

Furthermore, in the case of methanol, the adsorption rate increases at high temperatures, but since it adsorbs at a sufficiently high rate even at room temperature, there is no particular need for heating, which is advantageous in that it does not alter the quality of the carrier.

Next, the carrier adsorbed with organic matter is immersed in an aqueous solution of ruthenate, or ruthenate is poured into the carrier by bore filling, etc., and at the same time the ruthenate is impregnated, the ruthenate is decomposed and reduced. Do the following. Examples of ruthenate salts that can be used in the present invention include sodium ruthenate, potassium ruthenate, rubidium ruthenate, and cesium ruthenate. From the viewpoint of cost, sodium ruthenate or potassium ruthenate is preferred.

Next, harmful metal atoms such as sodium are removed by washing with water until I)H'=8, and the catalyst is prepared by drying.

In the present invention, in order to increase the amount of ruthenium supported, the above-mentioned operations up to washing and removal may be repeated.

Hereinafter, the present invention will be explained in detail based on Examples, Comparative Examples, and Experimental Examples.

Example 1 Pour methanol into the bottom of the desiccator, and add specific surface v to the top of the desiccator.
4170m10, llr hole u product 0.6CC/(] (
7) A beaker containing 100 liters of T-alumina was placed, and methanol was saturatedly adsorbed onto the γ-alumina at room temperature.

At this time, it took 1 to 2 hours to reach adsorption equilibrium, and the amount of methanol adsorbed was about 1 mmoJ10.

A sodium ruthenate aqueous solution was poured into this γ-alumina, and ruthenium was supported by a bore filling method.

Next, this catalyst was washed with water until the pH became 8 or less, and
Catalyst A was prepared by drying at ℃ for 15 hours.

The Na content of the obtained catalyst A was 0% by weight or less, and the amount of ruthenium supported was 2% by weight. Also,
When catalyst A after drying was observed by X-ray diffraction, no alteration of γ-alumina was observed.

Example 2 Catalyst B was prepared in the same manner as in Example 1 except that ethanol was used instead of methanol.

The Na content of the obtained catalyst B was 0.1 wt.% or less, and no alteration of γ-alumina was observed.

Example 3 Catalyst C was prepared in the same manner as in Example 1 except that potassium ruthenate was used instead of butrium ruthenate.

The content of 1q of catalyst C was less than 0.1 wt.%, and no alteration of γ-noflumina was observed.

Example 4 In order to produce a catalyst with increased ruthenium supported amount ω, first, the same method as in Example 1 was used until the amount of ruthenium supported was 2 w.
After preparing and sufficiently drying a catalyst of 4 wt.% of ruthenium, adsorption of methanol and bore filling of sulfur to lithium ruthenium acid were repeated to prepare a catalyst having a supported amount of 4 wt.% of ruthenium.

Comparative Example 1 γ-Alumina was impregnated with a sodium ruthenate solution by a pore filling method, and then dried at 110° C. for 15 hours.

The sodium ruthenate was then poured into methanol to reduce it. After standing still at room temperature for one minute, methanol was removed, and 1) H8Jy was washed with water until it reached the bottom, and further dried at 110° C. for 15 hours to prepare catalyst E.

Although the Na content of the obtained catalyst F could be reduced to 0.1 wt.% or less, most of the γ-alumina was transformed into bayerite and the specific surface area was reduced to 130 TIt/(].

Comparative Example 2 A sodium ruthenate solution was impregnated and supported on γ-alumina by a pore filling method, and then dried at 110° C. for 15 hours. Next, catalyst F was prepared by reducing with hydrogen at 300°C.

The Na content of the obtained catalyst F was 3.5 wt%, and γ
-Most of the alumina is transformed into bayerite, and the specific surface area is 110-rI! , decreased to 7g.

Experiment 30 catalysts were placed in an exceptional type 20 III stainless steel reaction tube.
Filled with rnJ, reaction temperature 450°C, pressure 20/9/
A steam reforming reaction of hydrocarbons was carried out in ci-(J.

Light naphtha is used as the raw material hydrocarbon, and the supply amount (Feed amount) of light naphtha is 150 cm'/h.
, H20/C-1,71110J/at0111
I did it.

The catalytic activity is determined by the amount of catalyst required to add 100% of the above naphtha (W(catalyst weight/F(raw material feed rate>((1-
cat /Q-Feedh-')) was determined from the temperature distribution. The smaller this value is, the higher the activity of the catalyst is. Table 1 below shows the catalytic activity of each catalyst in steam reforming after 10 hours and 100 hours.

Table 1 As shown in Table 1, catalyst A-
It can be seen that D has high catalytic activity and little deterioration in activity after 100 hours. On the other hand, in catalysts E and F, which are comparative examples, the activity after 10 hours was low, and the activity deterioration after 100 hours was also large.

As explained above, the present invention provides the following effects.

■ Ruthenate, which is cheaper than the conventional raw material ruthenium chloride, is used as a raw material, and there is less loss of raw materials during catalyst production, making it possible to reduce costs.

■ With conventional methods, it was very difficult to remove chlorine ions, but with the method of the present invention, chlorine ions, which are catalyst poisons, can be easily removed, and metals such as sodium and potassium, which have a negative effect on catalyst performance, can be removed easily. Atom removal is also easy.

(2) Since the time during which the catalyst is exposed to strongly basic conditions is short, there is very little deterioration of the carrier and good catalytic activity is achieved.

(2) When using the ruthenium chloride raw material in the conventional method, it was necessary to use corrosion-resistant materials in the equipment because hydrochloric acid was produced during the reduction reaction, but in the present invention, there is no need to use special materials. Therefore, manufacturing costs can be reduced.

Patent applicant: JGC Corporation Agent: Patent Attorney Tatsuo Ito Agent: Patent Attorney Tetsuya Ito

Claims (1)

[Claims] 1. A method for producing a ruthenium catalyst, which comprises adsorbing an organic substance onto a carrier in advance, and then supporting a ruthenate. 2. Claim 1, wherein the adsorption is saturated adsorption
The method for producing the ruthenium catalyst described in 2. 3. The method for producing a ruthenium catalyst according to claim 1 or 2, wherein the organic substance is a lower alcohol. 4. The method for producing a ruthenium catalyst according to claim 3, wherein the lower alcohol is methanol. 5. Claim 1, wherein the ruthenium M salt is sodium ruthenate or potassium ruthenate.
4. The method for producing a ruthenium catalyst according to any one of items 4 to 4.