JPS5946133A - Catalyst for preparing high calorie gas, preparation thereof and preparation of high calorie gas - Google Patents

Abstract

PURPOSE:To prepare a catalyst for preparing high calorie gas, by supporting ferrous metal as a catalyst substrate in combination with mangnanese oxide and platinum group metal by a carrier comprising silica and/or alumina. CONSTITUTION:Ferrous metal as a catalyst substrate is supported in combination with manganese oxide and platinum group metal on a carrier comprising silica and/or alumina. In this case, the ferrous metal is used in an amount of 3-15wt%; manganese oxide is used in such an amount that the atomic ratio of the ferrous metal element and the manganese element satisfies (5:1)-(5:4) and the platinum group metal is in such an amount that the atomic ratio of the ferrous metal element and the platinum group metal element satisfies (30:1)- (5:2). An especially pref. method in preparing this catalyst is one wherein the platinum group metal is at first supported by the carrier of silica or alumina and the ferrous metal and manganese oxide are subsequently supported simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a catalyst for obtaining high calorie gas from low calorie gas, a method for producing the same, and a method for producing high calorie gas from low calorie gas. The present invention relates to a method for producing a high-calorie fuel gas containing hydrocarbons of numbers 1 to 4.

Traditionally, coke oven gas has been the mainstream source of city gas, but in recent years it has been reviewed from the viewpoints of protecting the living environment, rationalizing supply methods, non-toxic safety, etc., and there is a sudden shift to high-calorie natural gas. Things are progressing on the pitch. For this reason, the use of coke oven gas as city gas is being limited, but since a huge amount is produced as a by-product in the production of coke for the core industry of steelmaking, it is an important issue to develop effective uses for this. It has become. However, in order to continue to utilize this coke oven gas as a fuel, it is necessary to improve its current low calorie property and convert it into a high calorie gas comparable to natural gas.

Traditionally, alternative natural gas (SNG) production methods have been to synthesize methane from gas from coal-based resources, such as coal gasified gas, or to add expensive naphtha or L to coke oven gas.
A method has been proposed in which PG is added and catalytically reformed to produce methane. The methane-based SNG obtained here only has a calorie of 9,000 Kcal/Nm^3 or less at most, and in order to supply it as city gas comparable to natural gas, it must be heated by adding LPG, etc. There is a need.

In view of the above-mentioned circumstances, the present inventors conducted various studies in order to obtain a fuel gas having a higher calorie content, and as a result, completed the present invention.

That is, to describe the purpose of the present invention more specifically, a gas containing hydrogen and carbon monoxide, or a gas containing hydrogen, carbon monoxide, and carbon dioxide (hereinafter simply referred to as a low-calorie gas) can be The purpose of the present invention is to provide a ternary composition catalyst capable of converting gas into a gas with a much higher calorie than the existing method, a method for producing the same, and a method for producing a high calorie gas using the catalyst. That is, the present invention aims at converting a low-calorie gas into a high-calorie gas containing not only methane but also hydrocarbons having 2 to 4 carbon atoms by contacting the above-mentioned catalyst with the low-calorie gas. When converting low calorie gas to high calorie gas containing hydrocarbons,
Generally, carbon dioxide is produced as a by-product, and traditionally this was separated and removed. Therefore, by combining two systems of ternary composition catalysts, the present inventors achieved the following:
Another objective is to provide a method for simultaneously converting this by-product carbon dioxide into hydrocarbons, and if this objective is achieved, there will be an advantage that no carbon dioxide separation operation is required.

The present invention will be explained in further detail. First, the carrier in the catalyst of the present invention is silica or alumina, and any commercially available carrier may be used, for example, one having a specific surface area of 200 m^2/g or less. Iron group metals are used as substrates for the catalysts supported on the carriers as described above, and cobalt and iron are particularly preferred as the iron group metals. The catalyst of the present invention includes manganese oxide and platinum group metals such as ruthenium, rhodium,
A combination of palladium, platinum, iridium, etc. is supported on the carrier.

In the above combination, the supported amount of iron group metal serving as a catalyst substrate is 5 to 15% (wt%, same below) based on the total catalyst.
, particularly preferably 4 to 12%. In addition, the amount of manganese oxide supported is set so that the atomic ratio of iron group metal element to manganese element satisfies the range of (5:1) to (5:4), and the amount of supported platinum group metal is set so that the atomic ratio of iron group metal element to manganese element satisfies the range of (5:1) to (5:4). The atomic ratio of group metal element to platinum group metal element is set to satisfy the range of (30:1) to (5:2).

A particularly preferred method for preparing the catalyst of the present invention comprises a first step of first supporting a platinum group metal on a silica or alumina carrier, and a second step of simultaneously supporting an iron group metal and manganese oxide. . That is, the catalyst obtained by supporting each catalyst component according to the above procedure effectively exhibits the ability to convert low calorie gas into high calorie gas containing C_1 to C_4 hydrocarbons, but methods other than the above, For example, by first supporting iron group metals and manganese oxide,
After that, a platinum group metal is supported, or a platinum group metal, manganese oxide, and an iron group metal are supported at the same time.
The present inventors have confirmed that it is extremely difficult to obtain a high-calorie gas containing hydrocarbons having 1 to 4 carbon atoms because the composite effect as a catalyst based on the original composition is not sufficiently exhibited.

The catalyst of the present invention is produced according to the above-mentioned basic structure, but will be described more specifically. An iron group metal, manganese, or platinum group metal is added to a silica or alumina support in the form of an aqueous nitrate solution or an aqueous chloride solution. It can be prepared by impregnating it by means such as spraying, scattering, or dipping, and then sequentially performing steps such as drying, ammonia treatment, thermal decomposition, and hydrogen reduction. Note that the ammonia treatment step may be omitted in some cases.

Specific preparation examples of the catalyst of the present invention are as follows.

First, a molded carrier made of silica or alumina is impregnated with an aqueous solution of a platinum group metal nitrate or chloride in an amount equal to the pore volume of the carrier, and the carrier is air-dried at room temperature while being gently rolled. Next, the treated product is exposed for 2 to 3 minutes to an atmosphere containing 10 to 11% ammonia and 2 to 6% water vapor. Thereafter, it is heated to about 350° C. in air to decompose the impregnated platinum group metal nitrate or chloride into an oxide. Hydrogen concentration 1 diluted with inert gas
The temperature is raised from room temperature to 400° C. in a 0 to 20% air flow, maintained at the same temperature for 30 minutes for reduction, and then cooled to room temperature again in the same air flow. The platinum group metal support thus obtained is impregnated with a mixed solution of an aqueous nitrate solution of an iron group metal, for example, and an aqueous nitrate solution of manganese, by the same impregnation method as described above. Then, a desired ternary composition catalyst can be obtained by performing steps such as air drying, ammonia treatment, thermal decomposition, and hydrogen reduction in the same manner as in the case of supporting the platinum group metal. When the ternary composition catalyst of the present invention is brought into contact with a low-calorie gas such as coke oven gas, steam reformed gas of naphtha heavy oil, water gas, or coal gasification gas, these gases, in addition to methane, It is converted into a high-calorie gas containing a considerably high concentration of C_2 to C_4 hydrocarbons.

By using the catalyst of the present invention, low calorie gas can be converted into carbon atoms having 1 to 4 carbon atoms.
The conversion into a high-calorie gas containing hydrocarbons can be carried out, for example, as follows. That is, the catalyst obtained as described above is packed into a reaction tower, and the temperature of the catalyst layer is set to 150 to 300°C, preferably 180 to 240°C.
℃ under a pressure of 5 to 30 kg/cm^2G, preferably 10 to 20 kg/cm^2G with a catalyst capacity of 1 liter.
per hour, 1~10m^3/hr, preferably 2~5cm^
3/hr low calorie gas is introduced. Then, in the catalyst layer, a high-calorie gas containing hydrocarbons with a carbon heat value of 1 to 4 is generated, but at that time, the by-product water is
As shown in the formula, a shift reaction occurs with carbon monoxide in the raw material low-calorie gas to produce carbon dioxide as a by-product. Further, in some cases, carbon monoxide itself in the raw material low-calorie gas may undergo a disproportionation reaction according to equation (2), and carbon dioxide may be produced as a by-product.

CO+H_2O=CO_2+H_2(1)2CO=CO
_2+C(2) In the present invention, C_1 to C_4 gases mixed with by-product carbon dioxide gas from the above hydrocarbonization reaction are supported on a carrier made of silica or alumina with nickel, rare earth element oxides, and platinum group metals. By subsequent contact with a ternary composition catalyst, the by-product carbon dioxide was also successfully converted into methane.

To explain the ternary composition catalyst for converting the above-mentioned by-product carbon dioxide into methane, its preparation involves drying granular silica or alumina (commercially available products as necessary) with a particle size of 2 to 4 mm, for example. The carrier is used as a carrier.

The substrate of the catalyst supported on the carrier is nickel, and the substrate metal is a rare earth element oxide (for example, a type of oxide of lanthanum, cerium, praseodymium, thorium, or samarium) and a platinum group metal (for example, ruthenium, platinum, palladium). , rhodium, or iridium), but when considering the catalytic effect and economic efficiency, lanthanum oxide and cerium oxide are recommended as oxides of rare earth elements, and ruthenium and cerium oxide are used as platinum group metals. Palladium can be mentioned as the most preferred. In the above combination, the supported amount of nickel serving as a catalyst substrate is in the range of 3 to 12%, particularly preferably 4 to 6%, based on the total catalyst. In addition, in rare earth element oxides, the atomic ratio of nickel element to rare earth element is (2:1) ~
(10:1), and furthermore, platinum group metal has an atomic ratio of nickel element to platinum group metal element of (10:1).
It is preferable to support each of them so as to satisfy the ratio of 30:1 to 30:1. It should be noted that even if each catalyst component is supported in an amount exceeding the above range, the catalytic effect will not be improved any further, but rather the pores of the carrier will be clogged and the catalytic performance will tend to deteriorate, which is not preferable. In producing this ternary composition catalyst, a granular support of silica or alumina is impregnated with nickel, rare earth elements, and platinum group metals, for example in the form of an aqueous nitrate solution, by spraying, scattering, dipping, etc. After natural drying or heating drying at 60 to 100°C, ammonia treatment, thermal decomposition, and hydrogen reduction are performed. In preparing this catalyst, nickel, rare earth element oxides, and platinum group metals may be supported on a silica or alumina granular support individually in any order or in combination of two or more thereof. Catalysts obtained by first supporting a platinum group metal on a carrier and then simultaneously supporting nickel and a rare earth element oxide have particularly excellent conversion properties from carbon dioxide to hydrocarbons.

A specific example of adjusting the catalyst is as follows. That is, a granular carrier of silica or alumina is impregnated with an aqueous solution of a platinum group metal salt, such as a nitrate or a chloride, in an amount sufficient to fill the voids in the carrier, and then dried in the air or heated at 60 to 100°C. At this time, the concentration of platinum group metal nitrates and platinum chlorides is determined so that a predetermined amount is contained in the impregnating solution, and after drying and ammonia treatment, the impregnated material is heated to 350 ml in the atmosphere.
The nitrates and chlorides are decomposed by heating to .degree. When the platinum group metal support thus obtained is impregnated with a mixed solution of an aqueous solution of a nickel inorganic acid salt, such as a nitrate, and an aqueous solution of an inorganic acid salt of a rare earth element, such as a nitrate, to support the platinum group metal. The trunk was dried, ammonia treated, and thermally decomposed in the same manner as above, and further diluted with inert gas and heated from room temperature to 400°C in an air stream with a hydrogen concentration of 10 to 20%.
The production of the catalyst is completed by raising the temperature to 100%, maintaining the same temperature for 30 minutes for reduction, and then cooling to room temperature in the same air flow.

In producing high calorie gas according to the present invention,
3 consisting of the iron group metal-manganese oxide-platinum group metal
A low-calorie gas as a raw material is introduced under the above conditions into a reaction column filled with a catalyst based on the original composition.

If by-product carbon dioxide is contained in the gas generated here, the gas is subsequently transferred to a separate chamber filled with a second ternary composition catalyst consisting of nickel, rare earth element oxide, and platinum group metal. Alternatively, the above two types of catalysts may be packed in series in one reaction column, and the low calorie gas is first introduced into the first reactor of the present invention consisting of iron group metal-manganese oxide-platinum group metal. It may be brought into contact with the first ternary composition catalyst layer, and then brought into contact with the second ternary composition catalyst layer. In this case, the first catalyst volume is the minimum amount necessary to reach a conversion rate of 100% of carbon monoxide, and the second catalyst volume is the minimum amount necessary to reach a conversion rate of 100% of the contained carbon dioxide. Any amount is fine. In addition, in actual operation,
The temperature of the second catalyst layer is about 5% lower than the temperature of the first catalyst layer.
If the temperature is maintained at about 0° C., complete conversion of carbon dioxide into hydrocarbons becomes easier.

When the catalyst of the present invention is brought into contact with a low-calorie gas, "complete utilization of all carbon oxides in the raw material gas", which was not achieved with conventional catalysts, is achieved, and moreover, the number of carbon atoms is higher than that of conventional catalysts. A high-calorie gas containing more 2-4 hydrocarbons can be obtained. Furthermore, in obtaining a high-calorie gas containing hydrocarbons having 2 to 4 carbon atoms in addition to methane using the catalyst of the present invention, a second ternary composition system consisting of nickel, a rare earth element oxide, and a platinum group metal is used. By bringing a combination of catalysts into contact, the by-product carbon dioxide can be completely methanated, so a carbon dioxide separation and recovery device is not required, which is extremely effective in terms of the process.

Next, the present invention will be explained with reference to examples, but the present invention can be modified and implemented in various ways without departing from the gist of the invention.

In the description, "parts" represent parts by weight.

Example 1 A commercially available alumina carrier with a specific surface area of 170 m^2/g (5.0
9 parts) was impregnated with an aqueous solution of RuCl_3 H_2O (0.107 parts) dissolved in water (4 parts) by a spray method,
Then, the impregnated product was obtained by air-drying it overnight while rolling gently. This impregnated material was prepared in an atmosphere 120 in which the atmosphere was adjusted to 10 to 11% by volume of ammonia and 6% by volume of water vapor.
The metal salt was exposed for seconds and then heated to about 850° C. in air to decompose and oxidize the metal salt. Next, the temperature was raised from room temperature to 400° C. in an electric furnace while passing a nitrogen stream containing a hydrogen concentration of 20% by volume, and the temperature was maintained at that temperature for 30 minutes to reduce the metal oxide. The mixture was then cooled to room temperature in the same air flow to obtain a ruthenium catalyst (5.13 parts).

Co(NO_3)_2・6H_2 on this ruthenium catalyst
O (1.4 parts) and Mn (NO_3)_3・6H_2
A solution of O (0.26 parts) dissolved in water (4 parts) was impregnated, dried, and reduced in the same manner as above to obtain 5% Co.
A ternary composition catalyst (5.37 parts) supporting -0.9% Mn_2O_3 -0.35% Ru was obtained.

Example 2 A commercially available silica carrier with a specific surface area of 100 m^2/g (6.87
part) was impregnated with an aqueous solution of RuCl_3.3H_2O (0.057 parts) dissolved in water (5 parts) by a spraying method,
Then, the impregnated product was obtained by air-drying it overnight while rolling gently. This impregnated material was placed in an atmosphere adjusted in advance to have 10 to 11% by volume of ammonia and 6% by volume of water vapor.
It was exposed for 20 seconds and then heated in air to about 350°C to decompose and oxidize the metal salt. Next, while passing a nitrogen stream containing a hydrogen concentration of 20% by volume, the temperature was raised from room temperature to 400° C. over about 1 hour and held at that temperature for 30 minutes to reduce the metal oxide. The mixture was then cooled to room temperature in the same air stream to obtain a ruthenium catalyst (6.9 parts). Co(NO_3)_2.6H_2O (1.847 parts) was added to this ruthenium catalyst.
and Mn(NO_3)_3・6H_2O(0.383
Part) dissolved in water (5 parts) was impregnated, dried, and reduced in the same manner as above to obtain 4.6%Co-2.8%
A ternary composition catalyst (7.33 parts) supporting Mn_2O_3-0.67% Ru was obtained.

Example 3 An alumina molded carrier (diameter 1 mm) was prepared by the method of Example 1.
x length 5-10 mm), 5%Co-0.9%Mn_2
O_3-The test gas shown in Table 1 was applied onto the catalyst supporting 0.35% Ru at a pressure of 10 kg/cm^2G and SV25.
When the gas was passed once at a temperature of 230° C. for 00 hr^-^1, a gas having the composition shown in Table 2 was obtained with a CO conversion rate of 100%. For comparison, the test gas shown in Table 1 was applied under the same conditions as in this example on a monocomponent catalyst in which 5% cobalt was supported on an alumina molded carrier of the same size as in Example 1. The results of one pass are also listed in Table 2.

As is clear from the above results, when the catalyst of Example 1 is used, the content of C_2 to C_4 hydrocarbons in the produced gas is higher than when the catalyst of Comparative Example is used.

Example 4 A silica molded carrier (diameter 0.5~
2mm), 4.6%Co-2.8%Mn_2O_3-
The same test gas consisting of hydrogen and carbon monoxide as in Example 3 was applied onto the catalyst supporting 0.67% Ru under the same pressure, SV and temperature conditions as described in Example 3. 1
When the gas was passed through the gas twice, a gas having the composition shown in Table 3 was obtained with a CO conversion rate of 100%.

Example 5 A silica molded carrier (diameter 0.5~
2mm), 4.6%Co-2.8%Mn_2O_3-
The catalyst of the present invention (first catalyst) supporting 0.67% Ru and 4.3%Ni-2.4%L on the same silica molded support.
a_2O_3-A second catalyst supporting 0.67% Ru, and a test gas containing hydrogen and carbon monoxide having the same composition as in Example 3 was applied to the first catalyst and then to the second catalyst.
was passed over the catalyst once.

The conditions at this time are: SV 2500hr^-^1, temperature 240℃, pressure 20℃ when passing over the first catalyst.
kg/cm^3G, and when passing over the second catalyst, the SV was 1600hr^-^1, and the other conditions were the same as when passing over the first catalyst.

As a result, a gas having a composition shown in Table 4 was obtained with a CO conversion rate of 100%.

As is clear from the above results, by combining the first catalyst and the second catalyst according to the present invention and bringing them into contact with a low-calorie gas containing hydrogen and carbon monoxide, the number of carbon atoms in addition to methane can be reduced. It can be seen that a high calorie gas containing 2 to 4 hydrocarbons and no carbon dioxide is obtained.

Example 6 The same two catalysts used in Example 5 were combined, and a test gas having the composition shown in Table 5 was applied to the first catalyst.
It was then passed once over a second catalyst. The conditions at this time were SV 2,000 hr on the first catalyst and temperature 240 hr.
℃, pressure 20kg/cm^3G, and then the second
When passing over the catalyst, SV1,000hr^-^
1. The temperature was 280° C., and the other conditions were the same as in the case of passing over the first catalyst. As a result, a gas having a CO conversion rate of 100% and a composition shown in Table 6 was obtained.

As is clear from the above results, by combining the first catalyst of the present invention and the second catalyst and bringing them into contact with the test gas having the composition shown in Table 5, a
It can be seen that a high calorie gas of 00 Kcal/Nm^3 can be obtained, and that oxygen contained in the sample gas can also be completely removed without any effect on the selectivity of the reaction.

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Claims (15)

[Claims] (1) A catalyst for producing a high-calorie gas, characterized in that a carrier made of silica or alumina supports a combination of manganese oxide and a platinum group metal on an iron group metal as a catalyst substrate. (2) The catalyst for producing high-calorie gas according to claim 1, wherein the iron group metal is either cobalt or iron. (3) The catalyst for producing high-calorie gas according to claim 1 or 2, wherein the platinum group metal is ruthenium, rhodium, palladium, platinum or iridium. (4) Iron group metal: 5 to 15% (weight%, same hereinafter) Manganese oxide: The atomic ratio of iron group metal element to manganese element is (5%)
:1) to (5:4), and the atomic ratio of platinum group metal: iron group metal element to platinum group metal element is (30:1) to (5).
The catalyst for producing high-calorie gas according to any one of claims 1 to 3, which is in an amount satisfying: 2). (5) A catalyst for producing high-calorie gas, comprising a first step of supporting a platinum group metal on a carrier made of silica or alumina, and a second step of simultaneously supporting an iron group metal and manganese oxide. Manufacturing method. (6) The method for producing a catalyst for producing high-calorie gas according to claim 5, wherein the iron group metal is either cobalt or iron. (7) The method for producing a catalyst for producing a high-calorie gas according to claim 5 or 6, which produces a catalyst in which the platinum group metal is ruthenium, rhodium, palladium, platinum, or iridium. (8) Iron group metal: 5 to 12%, manganese oxide: atomic ratio of iron group metal element to manganese element is (5:1) to (5:4)
Claims 5 to 7 for producing a catalyst in which the atomic ratio of platinum group metal: iron group metal element to platinum group metal is in an amount that satisfies (30:1) to (5:2). A method for producing a catalyst for producing high-calorie gas according to any one of paragraphs. (9) A gas containing hydrogen and carbon monoxide, or a gas containing hydrogen and carbon monoxide, is applied onto a catalyst made of a combination of manganese oxide and platinum group metal supported on an iron group metal as a catalyst substrate on a carrier made of silica or alumina. A method for producing high-calorie gas, characterized by conducting a gas containing carbon oxide and carbon dioxide. (10) The method for producing high-calorie gas according to claim 9, which uses a catalyst in which the ferrous metal is either cobalt or iron. (11) The method for producing a high-calorie gas according to claim 9 or 10, using a catalyst in which the platinum group metal is ruthenium, rhodium, palladium, platinum or iridium. (12) Iron group metal: 5 to 15%, manganese oxide: atomic ratio of iron group metal element to manganese element is (5:1) to (5:4)
), and the atomic ratio of platinum group metal: iron group metal element to platinum group metal element is (30:1) to (5:2). 12. The method for producing high-calorie gas according to any one of Item 11. (13) Hydrogen and carbon monoxide are placed on a first catalyst in which a combination of manganese oxide and platinum metal is supported on a carrier made of silica or alumina, and an iron group metal made of either cobalt or iron as a catalyst substrate. or a gas containing hydrogen, carbon monoxide, and carbon dioxide, and then a combination of a rare earth element oxide and a platinum group metal is supported on nickel as a catalyst substrate on a carrier made of silica or alumina. A method for producing a high-calorie gas, which comprises passing the gas obtained in the step over a second catalyst. (14) The method for producing a high-calorie gas according to claim 13, using the first catalyst in which the platinum group metal is ruthenium, rhodium, palladium, platinum, or iridium. (15) Iron group metal: 5 to 15%, manganese oxide: an amount that satisfies the atomic ratio of iron group metal element to manganese element (5:1) to (5:4), platinum group metal: iron group metal element Atomic ratio of platinum group metal element to (30:1) ~
15. The method for producing high-calorie gas according to claim 13 or 14, using the first catalyst in an amount that satisfies the ratio (5:2).