EA002486B1 - Alumina-supported ruthenium catalyst - Google Patents

Abstract

1. A catalyst comprising at least a ruthenium component carried by a porous alpha -alumina material, which catalyst has a specific surface area (S1) of 7-50 m<2>/g wherein the ratio S1/S2 of the specific surface area of a ruthenium-on-alumina catalyst (S1) to the surface area of the porous alpha -alumina material (S2) is 3-50. 2. The ruthenium-on-alumina catalyst according to Claim 1, wherein the catalyst has a specific surface area (S1) of 8-20 m<2>/g. 3. The ruthenium-on-alumina catalyst according to Claim 1, wherein the porous alpha -alumina material is impregnated with at least a ruthenium component and a zirconium component, and the respective amounts (contents) are such that the former accounts for 0.05-5% by weight as reduced to elemental ruthenium and the latter accounts for 0.05-20% by weight as reduced to zirconium oxide, both with respect to the weight of the porous alpha -alumina material. 4. The ruthenium-on-alumina catalyst according to Claim 1, wherein the porous alpha -alumina material is impregnated with at least a ruthenium component, a zirconium component, and an alkaline earth metal or rare earth metal component, and the respective amounts are such that the ruthenium component accounts for 0.05-5% by weight as reduced to elemental ruthenium, the zirconium component accounts for 0.05-20% by weight as reduced to zirconium oxide, and the alkaline earth metal or rare earth metal component accounts for 0.5-20% by weight as reduced to its corresponding oxide, wherein all percentages are with respect to the weight of the porous alpha -alumina material. 5. The ruthenium-on-alumina catalyst according to Claim 1, wherein the porous alpha -alumina material is impregnated with at least a ruthenium component, a zirconium component, an alkaline earth metal or rare earth metal component, and a cobalt component, and the respective amounts are such that the ruthenium component accounts for 0.05-5% by weight as reduced to elemental ruthenium, the zirconium component accounts for 0.05-20% by weight as reduced to zirconium oxide, the alkaline earth metal or rare earth metal component accounts for 0.5-20% by weight as reduced to its corresponding oxide, wherein all percentages are with respect to the weight of the porous alpha -alumina material, and the cobalt component is incorporated at a molar ratio of cobalt (Co) to (Ru), Co/Ru, of 0.01-30. 6. The ruthenium-on-alumina catalyst according to Claim 5, wherein the alkaline earth metal or rare earth metal component is magnesium. 7. A catalyst suitable for a steam reformation reaction applied to hydrocarbons, which catalyst comprises a ruthenium-on-alumina catalyst described in any of the preceding claims.

Description

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to ruthenium catalysts on alumina. More specifically, the present invention relates to ruthenium-alumina catalysts in which ruthenium or similar components are supported on a porous alpha-alumina material and which are mainly used in various hydrogen production processes, and among them, in steam reforming methods used for light hydrocarbons and oxygen-containing compounds to produce synthesis gas, a reducing gas that is suitable for use in direct reduction cast iron production methods HAND ore domestic gas and hydrogenous gas. The ruthenium alumina catalysts of the present invention are also advantageously used in a reforming apparatus to produce hydrogen in a fuel cell.

State of the art

In conventional steam reforming (or the like) reforming processes of light hydrocarbons using a catalyst, catalysts are usually prepared from a transition metal, such as nickel, supported on a catalyst support, such as gamma alumina.

In modern steam reforming processes to reduce construction and operation costs, there is a tendency to increase heat flux along with a tendency to lower water vapor / carbon ratio. Under such operating conditions, carbon is easily deposited on the catalyst, which leads to an increase in the pressure drop in the pipelines. As a result, sometimes clogging of the tubes with the catalyst occurs, which complicates the reaction. Thus, there is a great need for a catalyst for which the amount of carbon deposited is strongly suppressed compared to the amount of carbon on conventional catalysts that have high catalytic activity.

Catalysts of ruthenium on alumina containing ruthenium as a catalytically active component have gained importance as catalysts that have increased activity and which inhibit the deposition of carbon on the surface. Since ruthenium-alumina catalysts have excellent catalytic properties, which are manifested as high activity and the ability to suppress carbon deposition, even under low water vapor / carbon ratios, Japanese Patent Application Laid-Open No. 5-220397, among others, describes ruthenium-alumina catalysts in which zirconia obtained from a zirconia sol as a precursor and a ruthenium component are applied to alumina containing alkaline earth aluminate metal.

However, the ruthenium-alumina catalysts described in the above publications have the disadvantage that their activity is insufficient under conditions of reforming carried out at a low steam / carbon ratio of 2 or less and at a high temperature not lower than 680 ° C. In addition, since ruthenium is a noble metal of high cost, for the industrially efficient production of ruthenium catalysts on alumina, it is necessary, in addition to providing satisfactory catalyst characteristics, to lower the ruthenium content in order to reduce the cost of the catalyst. Moreover, due to the fact that reforming reactions with water vapor are carried out at high temperature, there is a search for improved catalysts that possess not only high activity, but are also thermally stable.

From the point of view of protecting the destruction of the environment caused by air pollution, hydrogen fuels are gaining importance as an alternative energy source instead of gasoline and others. Hydrogen fuels are converted into electrical energy, for example using a fuel cell. Hydrogen, which serves as the starting material, is usually obtained from hydrocarbons or oxygen-containing compounds by a steam reforming process. In particular, instead of hydrocarbons such as domestic gas and liquefied petroleum gas (LPG), which are traditionally used in fuel cells, it has recently been suggested that oxygen-containing compounds such as methanol and dimethyl ether will be used as fuel for transport energy sources (in electric vehicles). Ruthenium, nickel or the like metal deposited (or impregnated) on a catalyst support, such as alumina, is used as a reforming catalyst for oxygen-containing compounds.

A typical fuel cell typically contains a reforming reactor. In recent years, reforming reactors have become widespread in the form of many concentric hollow cylinders in which catalyst layers forming cylindrical shells are located in order to make the fuel cell block compact and to improve its characteristics (Japanese Patent Application Layout (Kokai) No. 3- 122001 and 60-264303).

In reforming reactors of the aforementioned type, the burner is located in the center of the shell lying deep inside, and many catalyst layers are placed so that they surround the burner, as a result of which the heat transfer surface area is maximized and the size of the reactor is reduced. Therefore, during start-up and shutdown of the reactor, the temperature inside the catalyst bed is very different from the temperature outside the catalyst bed. This temperature difference causes stress in the direction of the ring of each shell due to differences in thermal expansion, and a compression force arises in the catalyst layers that can destroy the catalyst under pressure. When the catalyst breaks down, dust is formed that clogs the catalyst beds and the next pipe, and as a result, the reactor may be interrupted due to increased flow resistance.

As a measure to prevent the destruction of the catalyst under pressure in a publication in the journal Rie1 ΛδδοοίαΙίοη 1oigia1, Volume 68, No. 3, p. 236-243 (1989) describe a ruthenium-alumina catalyst in which ruthenium acts as a catalyst and alpha alumina serves as a catalyst carrier.

However, since the ruthenium-alumina catalyst described in this journal uses alpha alumina obtained by calcining gamma alumina at 1300 ° C., fused alpha alumina has insufficient crush strength for use in multi-shell reforming reactors, since they require high crush strength. Moreover, since ruthenium is supported on alpha alumina obtained by firing gamma alumina, the resulting catalyst has a very small specific surface area of about 6.6 m ² / g, and therefore, even when using highly active ruthenium as the active component of ruthenium cannot satisfactorily disperse on the surface and inside the carrier, and as a result, only slight catalytic activity can be achieved. Moreover, when alpha-alumina is prepared by calcining at a sufficiently high temperature in order to increase crush strength, the resulting alpha-alumina with a tightly packed structure is usually not suitable as a catalyst carrier, since it does not have micropores of submicron or less size and, moreover, it has only a small specific surface area, even when it is cast into the form of a catalyst carrier. In other words, when the alpha alumina catalyst support is impregnated with the active component, the specific surface area necessary to satisfactorily disperse the active components on the surface and inside the support is insufficient and thus, even with an increase in the amount of the catalyst component, satisfactory activity.

In addition, as described above, Japanese Patent Application Laid-Open No. 5-220397 discloses a ruthenium-alumina catalyst in which zirconia obtained from a precursor, zirconia sol, and a ruthenium component are applied to alumina containing aluminate alkaline earth metal.

However, given that the zirconia sol used in this publication is present in the form of particles of 100 Angstroms or more in size, it is believed that the particles of the resulting zirconium oxide product grow to large sizes. Moreover, since the alkaline earth metal aluminate is present in the form of crystals, it is believed that aluminate particles also grow to large sizes. Thus, it can be predicted that the disadvantage of this catalyst will be a reduced specific surface area and insufficient catalytic activity.

SUMMARY OF THE INVENTION

The present invention has been carried out to solve the above problems, and the aim of this invention is to develop a ruthenium-alumina catalyst in which a porous alumina material which is an effective catalyst support due to its excellent thermal and crushing strength is impregnated with an active component, ruthenium, which possesses a number of remarkable characteristics: excellent activity, in particular activity in the reforming reaction, per unit weight of ruthenium I; excellent thermal stability, which provides high activity in reactions proceeding at high temperature, and extended service life.

The above goal is achieved by a ruthenium-alumina catalyst that contains at least a ruthenium component supported on a porous alpha-alumina material, the catalyst having a specific surface area (8 ₁ ) of 8-50 m ² / g.

In a preferred embodiment of this invention, the ratio of 8 _{1/2 August} specific surface area of the above-mentioned catalyst ruthenium on alumina (8 ₁₎ to the specific surface area of the porous material alfaalyuminiyoksidnogo (8 ₂₎ is 3-50.

In another preferred embodiment of this invention, the ruthenium-alumina catalyst has a micropore profile with at least one peak that is in the range of 5 to 1000 Angstroms.

In another preferred embodiment of this invention, the porous alpha-aluminum oxide material is impregnated with at least the ruthenium component and the zirconium component, the corresponding amounts (content) being such that the first component is 0.05-5 wt.% In the form of ruthenium reduced to the element, and the second component is 0.05-20 wt.% in the form of reduced to zirconium oxide, both contents are based on the weight of the porous alpha-alumina material.

In a further preferred embodiment of this invention, the porous alpha-aluminum oxide material is impregnated with at least the ruthenium component, the zirconium component and the alkaline earth metal or rare earth metal component, the corresponding amounts being such that the ruthenium component is 0.05-5 wt.% In the form reduced to a ruthenium element, the zirconium component is 0.05-20 wt.% in the form of reduced to zirconium oxide and a component of an alkaline earth metal or rare earth metal wish to set up 0.5-20 wt.% as reduced to the corresponding oxide, wherein all percentages are based on the weight of porous alpha-alumina material.

In yet another preferred embodiment of this invention, the porous alpha-aluminum oxide material is impregnated with at least a ruthenium component, a zirconium component, an alkaline earth metal or rare earth metal component, and a cobalt component, the corresponding amounts being such that the ruthenium component is 0.05-5 wt.% In in the form of ruthenium reduced to an element, the zirconium component is 0.05-20 wt.% in the form of zirconium reduced to zirconium oxide and an alkaline earth metal component or rarely the ground metal is 0.5-20 wt.% in the form of reduced to the corresponding oxide, and all percentages are based on the weight of the porous alpha-alumina material and the cobalt component is introduced in a molar ratio of cobalt (Co) to ruthenium Co / Ki equal to 0 01-30.

In addition, a catalyst is provided for a steam reforming process for converting hydrocarbons using the ruthenium-alumina catalyst described above.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, various embodiments of the ruthenium-alumina catalyst of the present invention will be described.

I. Porous alpha alumina material.

In the present invention, a porous alpha-alumina material is used as an alumina carrier. This porous alpha-alumina material that can be used in the present invention is selected from conventional materials whose composition and properties are controlled or controlled by the addition of additives, pre-treatment or the selection of a suitable preparation method. For example, the porous alpha-alumina material may be chemically treated, such as acid treatment, alkaline treatment or ion exchange treatment, in order to regulate its acidity; heating or calcining in order to adjust the water or hydroxyl groups on the surface of the alumina material; or various treatments in order to control the size and distribution of micropores and the associated surface area.

The shape and dimensions of the porous alpha-aluminum oxide material of the present invention are not particularly limited. The alpha alumina powder that serves as the starting material may be granular, extruded, molded, or it may undergo other suitable processes for producing powders, granules, beads, small columns, tablets, or Raschig rings that can all be conveniently used in the present invention. Alternatively, a support substrate that has a specific structure, such as a monolithic block, and is obtained from materials that are inert to the chemical reaction, may be spray coated with the starting alpha-alumina powder in order to obtain the catalyst carrier of the present invention.

Of these, preferred catalyst supports are porous alpha-aluminum oxide materials granular or cast in the form of spheres, beads, tablets or Raschig rings, and coated materials obtained by coating special structures, such as a monolithic structure, alpha-alumina, from the point of view of ensuring a sufficient specific area the surface of the catalyst, reducing pressure loss in the catalyst bed during the reaction and improving thermal conductivity with respect to the reaction fluid. Of the materials of this type, spheres, beads, Raschig rings and coated monolithic substrate substrates are particularly preferred, for reasons of high compressive strength.

Next, physical properties and methods for producing the porous alpha-aluminum oxide material used in the present invention will be described.

1. Physical properties of the porous alpha-aluminum oxide material.

The porous alpha-alumina material used in the present invention preferably has the following physical properties.

1.1. The volume of micropores.

The preferred micropore volume of the porous alpha-alumina material is typically 0.05-0.5 cm ³ / g, more preferably 0.1-0.4 cm ³ / g, and most preferably 0.1-0.3 cm ³ / g. If the pore volume is less than 0.05 cm ³ / g, alpha alumina absorbs too little liquid; that is, it cannot absorb a sufficient amount of the impregnation solution mentioned below containing the active component of the catalyst. As a result, the catalyst components can only be introduced into the carrier in an insufficient amount. On the other hand, when the micropore volume is greater than 0.5 cm ³ / g, which indicates incomplete sintering of alpha alumina, insufficient crushing strength may be observed.

1.2. The average size of micropores.

Typically, the preferred micropore size of the porous alpha-alumina material is 0.01-100 microns, preferably 0.05-50 microns, more preferably 0.1-10 microns. When the pore size exceeds 100 μm, the support cannot hold the impregnating solution during the step of impregnating the support with the active component of the catalyst described below, and therefore not only repeated impregnation steps will be required, but also a low work efficiency. On the other hand, when the pore size is less than 0.01 μm, the starting hydrocarbon material cannot easily diffuse into the micropores of the catalyst during the reaction. In this case, it is impossible to realize catalytic activity commensurate with the amount of active component of the catalyst supported on a porous alpha-alumina material.

1.3. Specific surface area.

In order to increase the specific surface area of the catalyst obtained by incorporating the active component into the porous alpha-alumina material, preferably the porous alpha-alumina material itself has an increased surface area. However, generally speaking, with an increase in the specific surface area of alpha alumina, there is a tendency to decrease its mechanical strength. In the present invention, the actual surface area of the carrier, alpha alumina, is usually 0.05-0.5 m ² / g or more, preferably 0.1-3 m ² / g and more preferably 0.2-1 m ² / g

1.4. Crush strength.

The crush strength of the porous alpha-alumina material is usually 20 kgf (kg force) or more, preferably 20-100 kgf and more preferably 40-100 kgf, which is determined using a Kia crush strength measuring device. When using a carrier having a strength of 20 kgf or less, the catalyst can be crushed during use in the reaction, especially during heating or cooling of the reactor, while even with a strength exceeding 100 kgf, technical advantages corresponding to this strength cannot be obtained.

1.5. The degree of crystallinity.

The crystallinity of the porous alpha-alumina material is usually 70% or more, preferably 90% or more, more preferably 95% or more. When the crystallinity of the porous alpha-alumina material is less than 70%, the porous material itself or the product obtained from it, the catalyst, has low crushing strength, resulting in the formation of fine dust in the reactor when using the catalyst in the reaction. When the porous alpha alumina material is subjected to X-ray structural analysis, the ratio of 1/1 _and the intensity of the strongest peak attributed to compounds other than alpha-alumina (1 _s), to the intensity of the strongest peak attributed to the alpha-alumina (1 _and ), is preferably 0.1 or less, more preferably 0.01 or less, and compounds other than alpha alumina include gamma, eta, and beta alumina. When the intensity ratio of peaks 1/1 _and greater than 0.1, the catalytic activity of the catalyst prepared from this porous alpha alumina material is usually small.

2. A method of obtaining a porous alpha-aluminum oxide material.

2.1. Source powder material.

The porous alpha-alumina material that is used in the present invention is obtained by granulation or molding, followed by sintering of the starting material — alpha alumina powder.

The grain size of the starting powder material is preferably 0.01-100 microns, more preferably 0.05-50 microns and most preferably 0.1-10 microns.

When the grain size is less than 0.01 μm, it is not always possible to obtain the micropore size or micropore volume that is required for the catalyst, whereas if the grain size is larger than

100 microns, grains cannot easily sinter, and therefore it is impossible to obtain a porous material with sufficient mechanical strength.

2.2. Additives.

Typically, many additives are mixed with alpha alumina powder in order to accelerate the sintering process or the formation of pores. Examples of such additives include inorganic additives such as alumina materials and water glass (sodium silicate); and organic additives, such as various types of cereal starch (corn, wheat, common ower, lily and potato), polyethylene glycol, polyvinyl alcohol (PVA), methyl cellulose (MC), carboxymethyl cellulose (CMC), glycerin, sorbitol, urea, acrylic emulsions waxes. Examples of alumina materials include kaolin, bentonite and gyromic clay.

When the additive is an inorganic material, the granule size of the additive is preferably 0.01-100 μm, more preferably 0.05-50 μm, and most preferably 0.1-10 μm.

Additives are preferably administered in an amount of less than 50 parts by weight, more preferably in an amount of less than 20 parts by weight. per 100 parts by weight alpha alumina.

2.3. The method of molding.

The porous alpha-alumina material of the present invention can usually be obtained by various molding methods using starting powder materials containing various additives. There are no restrictions on the molding method, and examples of such methods include pressing, rolling granulation, wet injection molding, C1 molding, granulation and injection molding of the powder. Alternatively, the porous alpha-alumina material of the present invention can be prepared by spray coating a monolithic structure prepared separately.

The molded product, if necessary, is sorted and fired, for example in a gas furnace at a temperature of 11001600 ° C, in order to obtain the final product, the porous alpha-alumina material of the present invention.

II. Metallic components (components supported on alpha alumina).

In the present invention, the ruthenium component, which has been found to exhibit high activity, at least in reforming reactions, is introduced into the alpha-alumina carrier described above. Multicomponent catalyst systems, which also contain the other components described below, are preferred by the industry due to their increased catalytic activity and guaranteed long service life. The introduction of such other components also reduces the amount of ruthenium, which is expensive since it is a noble metal, and thus the unit costs of producing the catalyst are reduced.

1. Two-component system (ruthenium and zirconium).

In a preferred embodiment of the present invention, there is provided a catalyst comprising a ruthenium component and a zirconium component as two main metal components.

When these two metal components are introduced into an aluminum oxide support, zirconia is present in the form of very fine particles, and therefore the resulting catalyst acquires a significantly developed surface area. As a result, the catalyst has high activity and excellent thermal stability.

The amount of appropriate metal components can be well chosen in accordance with significant factors and conditions, which include the properties of the carrier (such as type, surface area, etc.) or the use of a catalyst (i.e. the type and properties of the reaction of interest). For example, the amount of the ruthenium component used in the present invention is usually 0.05-5 wt.%, Preferably 0.05-2 wt.%, More preferably 0.1-2 wt.% (Based on metallic ruthenium) relative to carrier weight. The amount of the zirconium component is usually 0.05-20 wt.%, Preferably 0.1-15 wt.% And more preferably 1.0-15 wt.% (Calculated on zirconium oxide) relative to the weight of the carrier.

2. The three-component system (ruthenium, zirconium and alkaline earth metal or rare earth metal).

In the present invention, in addition to the ruthenium component and the zirconium component, one or more components selected from the components — alkaline earth metal or rare earth metal — can be introduced into the carrier. Examples of components, alkaline earth metals and rare earth metals include beryllium (Be), magnesium (MD), calcium (Ca), strontium (8t), barium (Ba), yttrium (Υ), lanthanum (ba), cerium (Ce ), praseodymium (Pr), neodymium (N6), promethium (Pt), samarium (8t), europium (She), gadolinium (Ob), terbium (Tb), dysprosium (Oy), holmium (But), erbium (Er ), thulium (Tm), ytterbium (ΥΕ), and lutetium (Li). Of these, magnesium is preferable in connection with its significant effect, enhancing the thermal stability of the zirconium component. The total amount of these components is usually 0.5-20% by weight, preferably 0.5-15% by weight, more preferably 1.011% by weight, based on the corresponding oxides of the components of an alkaline earth metal or rare earth metal.

Below, a description will be given of catalysts comprising a magnesium component, which is taken as a representative example among the components of an alkaline earth metal and a rare earth metal.

In this case, ruthenium, zirconium and magnesium are introduced into the catalyst as three primary components.

In a catalyst in which these three metal components are incorporated into an aluminum oxide support, zirconium and magnesium are present as very fine particles of zirconium oxide and magnesium oxide, respectively. These two substances interact, inhibiting the formation of crystals and the growth of granules. As a result, the catalyst acquires a highly developed surface area, and thereby provides its high catalytic activity and excellent thermal stability.

The amount of metal components used in the present invention can be selected appropriately, taking into account the above conditions. For example, the amount of the ruthenium component relative to the weight of the carrier is usually 0.05-5 wt.%, Preferably 0.05-2 wt.%, More preferably 0.1-2 wt.% Based on metallic ruthenium. The amount of the zirconium component is usually 0.05-20 wt.%, Preferably 0.1-15 wt.% And more preferably 1.0-15 wt.% Based on zirconium oxide. The amount of the magnesium component is usually 0.5-20% by weight, preferably 0.5-15% by weight, based on magnesium oxide. When the amount of the magnesium component is less than 0.5 wt.%, The catalytic activity may be low.

The molar ratio of the magnesium component to the zirconium component contained in the catalyst, MD / Ζτ, is usually 0.1-10, preferably 0.5-5 and more preferably 1-2, and the ratio MD / Ζτ is the molar ratio of magnesium atoms (MD ) to zirconium atoms (Ζγ). When the molar ratio MD / Ζτ is less than 0.1, the suppressing effect of the introduced components on the process of reducing the surface area is not fully manifested, and the effect of increasing the thermal resistance may become insignificant. On the other hand, even with a molar ratio exceeding 10, the improvement in thermal stability may not be appropriate.

In the present invention, a cobalt component, which is described below, is preferably introduced to further increase the activity of the catalyst.

3. The four-component system (ruthenium, zirconium, alkaline earth metal or rare earth metal and cobalt).

The amount of cobalt component, which is an optional component of the present invention, is usually such that the molar ratio of cobalt to ruthenium (Co / Ki) is 0.01-30, preferably 0.1-30, more preferably 0.1-10. When this molar ratio is less than 0.01, the cobalt content decreases, and as a result, the expected effect of increased activity cannot be achieved. On the other hand, when this molar ratio is greater than 30, the relative content of ruthenium decreases. In this case, it is difficult to maintain a high activity of a ruthenium-containing steam reforming catalyst as applied to hydrocarbons. Moreover, the effect of inhibiting carbon deposition can be difficult, even under operating conditions of a low water vapor / carbon ratio.

III. The specific surface area of the catalyst.

In the present invention, a catalyst having a significantly developed surface area can be obtained by impregnating the porous alpha-alumina material with specific metal components. This is due to the fact that the corresponding metal components are present in the form of very small particles, and they still do not clog the micropores of the porous alpha-aluminum oxide material.

Moreover, the catalyst of the present invention exhibits not only high catalytic activity, but also the mechanical strength and thermal resistance that are characteristic of alpha alumina.

The specific surface area of the catalyst of the present invention is usually 7-50 m ² / g, preferably 8-20 m ² / g, more preferably 8-15 m ² / g. The specific surface area of less than 7 m ² / g cannot provide satisfactory catalytic activity, since the metal components cannot be substantially dispersed on the surface and inside the carrier. On the other hand, with a specific surface area of more than 50 m ² / g, the micropores are too small, and thus diffusion of the starting materials into micropores is difficult. In this case, the increased specific surface area may not provide any effect.

Ratio of 8 _{1/8 2,} i.e. the specific surface area of the catalyst of the present invention (8ι) to the specific surface area of the porous alpha-alumina material acting as a carrier (8 ₂ ) is preferably 3 or more, more preferably 5-50, particularly preferably 10-30. When this ratio is less than three, it is possible to obtain a catalyst having a specific surface area that is insufficient 13 to provide satisfactory catalytic activity.

IV. Peak in the distribution profile of the micropores of the catalyst.

The catalyst of the present invention has micropores. The pore distribution profile of the catalyst is such that at least one peak falls within the range of 5 to 1000 Angstroms, preferably 10-100 Angstroms. Micropores are formed by components deposited on a porous alumina material. The distribution of micropores is calculated using the amount of adsorbed nitrogen, which is determined from the adsorption-desorption characteristics of nitrogen at various pressures. The absence of a peak in the distribution of micropore diameter in the range of less than 1000 Angstroms indicates that satisfactory micropores have not formed: the specific surface area is insufficient, so that the active components are not sufficiently distributed on the carrier, which leads to reduced reactivity. However, when there is a peak in the range of less than 5 Angstroms, micropores are too small and the entry of reactive substances into micropores is difficult, which leads to the absence of an effect of improved activity.

V. Introduction of metallic components into porous alpha-alumina material.

1. The method of introduction.

In the present invention, methods for introducing metal components into a porous alpha-alumina material are practically unlimited. For example, the aforementioned porous alpha-alumina material may be impregnated with a solution containing at least one or more ruthenium compounds and optionally containing at least one or more zirconium compounds, one or more compounds selected from alkaline earth compounds metals and compounds of rare earth metals (for example, one or more compounds of magnesium), and, in addition, optionally one or more compounds of cobalt. In this method, the ruthenium component and optional components such as the zirconium component, the alkaline earth metal component, the rare earth component and the cobalt component can be uniformly deposited on the surface of the porous alpha-alumina material or incorporated into micropores of the porous alpha-alumina material with excellent distribution. Moreover, even with typical pretreatments such as high temperature calcination and reduction, the ruthenium component and zirconium oxide remain in a well dispersed state, and high performance characteristics of the ruthenium containing catalyst are easily ensured.

1.1. Solution.

The pH of a solution containing metal compounds used in the above method of administration is preferably set to 3 or less, more preferably 1.5 or less by adding acid, etc. If the pH of the solution exceeds 3, one or more compounds contained in solution will tend to precipitate or coagulate with the formation of a gel, and as a result, the component (s) of the metal cannot be on the carrier in a well dispersed state. On the contrary, when the pH of the solution is three or less, it is assumed that the ruthenium compound interacts with a zirconium compound and others to form a complex type compound, which is also introduced into the carrier as it forms, thereby providing a catalyst having further improved catalytic activity.

Moreover, the catalyst containing additives in the form of components of an alkaline earth metal or rare earth metal, in addition to the ruthenium component and zirconium component, has a specific surface area that has significant thermal stability. This thermal stability is maintained during reactions after firing or reactions at high temperature. Thus, this catalyst exhibits long-term thermal stability.

1.2. Solvent.

The solvent used in the above solution is not particularly limited, and any solvent that can dissolve at least the ruthenium compound and optional compounds, i.e. a zirconium compound, an alkaline earth metal component or a rare earth metal component, and a cobalt compound. Examples of the solvent include water, a water-based solvent, and an organic solvent such as alcohol and ether. Of these, water or a water-based solvent is preferable, given that the above compounds are well soluble.

1.3. Raw materials of metal components.

The type and shape of the compounds that are used as starting materials of the metal components are practically not limited, as long as these compounds can dissolve in the above solvents. Examples of starting materials are provided below.

1.3.1. Ruthenium compounds.

Examples of ruthenium compounds that may be used in the present invention include ruthenium halides such as ruthenium trichloride; halotrutinate salts such as potassium hexachlororuthenate; salts of ruthenate, such as potassium tetraoxoruthenate; ruthenium tetroxide; salts of amine complexes, such as hexa-amminruthenium trichloride; and salts of cyanocomplexes, such as potassium hexacyanoruthenate. Moreover, in the present invention, compounds which essentially have low solubility in a solvent can also be used as starting materials, since they become soluble when added or in the presence of an acid or acidic compound. For example, although ruthenium oxide (such as diruthenium trioxide), ruthenium hydroxides and ruthenium oxyhalides, etc. are insoluble or slightly soluble in water at a pH of about 7, they can be used in the present invention because they become soluble by adding an acid such as hydrochloric acid. These ruthenium compounds can be used individually or in combination of two or more kinds.

Of these ruthenium compounds, ruthenium trichloride is particularly preferred due to the fact that it is widely used in industry and is readily available.

1.3.2. Zirconium compounds.

Examples of zirconium compounds that can be used in the present invention include halides such as zirconium tetrachloride or partially hydrolyzed halide products; oxyhalides such as zirconyl chloride (zirconium oxychloride); acidic oxysalts such as zirconyl sulfate, zirconium nitrate and zirconyl nitrate; zirconate salts such as potassium tetraoxociriconate and sodium hexafluorozirconate; salts of organic acids or organic coordination compounds such as zirconium acetate, zirconyl acetate, zirconyl oxalate and potassium tetraoxalate zirconate; zirconium alkoxides; zirconium hydroxides; and complex zirconium salts. These compounds, in addition to compounds that are soluble in solvents under normal conditions (i.e., in the absence of an acid), include compounds that are soluble in acidic solvents containing an acid, such as hydrochloric acid or an acidic compound.

Of these zirconium compounds, zirconium oxychlorides are particularly preferred. Examples of oxychlorides include hydrates represented by formulas

ΖτΘΟΙ ^ ηΗΟ or 2gO (OH) C1'nH2O and their industrially available solutions based on water. It is believed that zirconium oxychloride forms some compound with ruthenium complex type. These zirconium compounds can be used individually or in combination of two or more types of compounds.

1.3.3. Alkaline earth metal compounds and rare earth metal compounds.

Alkaline earth metal compounds and rare earth metal compounds that can be used in the present invention include alkali earth metal and rare earth metal nitrates, chlorides, acetates and oxalates, as well as alkoxide compounds of these metals. Examples of such compounds include nitrates such as magnesium nitrate, calcium nitrate, strontium nitrate, lanthanum nitrate and cerium nitrate; chlorides such as magnesium chloride, calcium chloride, strontium chloride, lanthanum chloride and cerium chloride; acetates such as magnesium acetate and calcium acetate; oxalates such as magnesium oxalate, calcium oxalate and strontium oxalate; and alkoxide compounds such as magnesium methoxide, magnesium ethoxide, calcium methoxide and calcium ethoxide. These compounds include those that become soluble in the solvent as a result of the addition of an acid, such as hydrochloric acid, an acid compound, or an alcohol, such as methanol. Of these compounds, nitrates and chlorides are preferred given their high solubility. These compounds can be used individually or in combination of two or more varieties.

1.3.4. Compounds of cobalt.

Cobalt compounds that can be used in the present invention include compounds that are soluble in particular solvents, as well as compounds that become soluble after adjusting the pH of the solvent by the addition of an acid, such as hydrochloric acid, or an acidic compound. Examples of such compounds include cobalt nitrate, basic cobalt nitrate, cobalt dichloride and hydrates thereof. Of these compounds, cobalt nitrates and chlorides are preferred in view of their high solubility, with cobalt nitrate being particularly preferred. These cobalt compounds can be used individually or in combination of two or more varieties.

1.4. Preparation of solutions.

1.4.1. Stage preparation solutions.

In the preparation of the above solutions, there are no specific restrictions regarding the order and method of adding, mixing or dissolving the corresponding components, including solvents, ruthenium compounds, zirconium compounds, alkaline earth metal compounds or rare earth compounds, cobalt compounds and acids. For example, special components can be added simultaneously or sequentially to a solvent or to an acidic solution with added acid. Alternatively, solutions of the respective components that were prepared independently can be mixed. A solution containing a portion of the components may be prepared, and then the remaining components may be added to it. Although preferably a solution is prepared at about room temperature, the solution can be heated to about 80 ° C when accelerated dissolution is desired.

Inorganic acids (such as hydrochloric acid, sulfuric acid and nitric acid) and organic acids (such as acetic acid and oxalic acid) can be used to enhance the solubility of the starting compounds in a solvent and to adjust the pH of the solution.

1.4.2. The number of input metal components.

When zirconia, which is also a catalyst component, is used in combination with ruthenium, the ratio of zirconium to ruthenium compound, which is represented by a molar ratio of zirconium to ruthenium (Ζτ / Ki), is 100 or less, preferably 1-50, more preferably 2- twenty. When the molar ratio Ζτ / Ki is less than 1, the dispersed state of the ruthenium component on the carrier may deteriorate or the ruthenium component cannot be kept near the zirconium component. It is believed that the reason for this is that part of the ruthenium compound cannot form a complex type compound. On the other hand, when the molar ratio Ζτ / Ki is greater than 100, the dispersed state of the ruthenium component on the carrier and inside it does not improve anymore and, even worse, the ruthenium component is covered by the zirconium component and, as a result, the catalytic activity decreases due to the fact that on the surface the carrier decreases the amount of ruthenium component available. In addition, the excellent performance of the porous alpha-alumina material may be degraded.

When the alkaline earth metal compound and the rare earth metal compound are used in combination, the molar ratio of alkaline earth metal or rare earth metal (M) to zirconium, represented as Μ / Ζτ, is usually 0.01-10, preferably 0.05-5, more preferably 0.1-5. When this molar ratio Μ / Ζτ is less than 0.01, the addition of an alkaline earth metal compound and a rare earth metal compound does not give the expected effect. Namely, the specific surface area of the catalyst may decrease, and the thermal stability of the carrier may not increase when the catalyst is exposed to high temperatures during the reaction or firing. On the other hand, even if the molar ratio Μ / Ζτ exceeds 10, an increase in thermal stability may not be appropriate.

In cases where the cobalt compound is used in combination, this compound is usually used in a molar ratio of cobalt to ruthenium (Co / Ki) of 0.01-30, preferably 0.1-30, and more preferably 0.1-10. When this molar ratio is less than 0.01, with a low cobalt content, the expected effect of increased activity cannot be achieved, whereas if this molar ratio exceeds 30, the relative amount of ruthenium in the catalyst decreases. In this case, it is difficult to maintain a high activity of the ruthenium-containing catalyst during the reforming of hydrocarbons with water vapor and, in addition, the effect of suppressing carbon deposition under operating conditions at a low water vapor / carbon ratio may be lost.

1.4.3. The concentration of each component.

There are no specific restrictions on the amount (concentration) of each component that will be dissolved in the above solvent. Typically, the concentration of the ruthenium component is chosen to be 0.001 mol / L or more, preferably 0.01-1 mol / L and more preferably 0.1-0.5 mol / L in units of the molar concentration of ruthenium.

The above solution may contain, in addition to the essential ruthenium compound, zirconium compound, alkaline earth metal compound or rare earth compound, cobalt compound, dissolution promoting components and other components, if necessary, as this does not interfere with the effect of the present invention.

1.4.4. Homogeneous dissolution.

For the homogeneous dissolution of each component in a solvent, the pH of the solution is set to 3 or less, preferably 1.5 or less. If the pH value exceeds 3, then zirconium compounds are easily hydrolyzed to form a hydroxide-like sol or gel. It is believed that the aforementioned compound of the complex type with the ruthenium component is difficult to form from the sol or gel formed, and therefore the addition of the zirconium component cannot lead to an increase in the degree of dispersion of the ruthenium component.

2. Impregnation.

2.1. Types of impregnation methods.

Each metal component can be applied to a porous alpha-alumina material using a conventional impregnation method using a solution prepared in the above manner. Examples of the method include a variety of impregnation methods (thermal impregnation, impregnation at normal temperature, impregnation at atmospheric pressure, impregnation-drying process, pore filling process, arbitrary combinations of these processes), immersion method, easy wetting method, solution adsorption method, spray method, coating method and combinations of these methods. Any method can be used because it provides contact between the solution and the porous alpha-alumina material in order to deposit metal components on the alpha alumina material. Although in the present invention it is necessary to carry out at least one sequence of stages of impregnation, drying and firing, if desired, each stage can be repeated several times.

2.2. The ratio of the amounts of porous alpha-alumina material and the impregnating solution.

The ratio of the amount of alumina carrier to the impregnating solution can be determined in accordance with the specified number of active metal components to be applied, the concentration of metal compounds in the aqueous solution to be used, the type of impregnation method, the micropore volume and the specific surface area of the porous alpha-alumina material, which will be used.

2.3. Working conditions.

There are no specific restrictions on the conditions of the impregnation process. Typically, the impregnation process is carried out at a temperature ranging from ambient temperature to about 80 ° C, preferably at room temperature or at a temperature close to room temperature and at atmospheric or reduced pressure (during evacuation).

2.4. Drying after impregnation.

The porous alpha-alumina material impregnated with the above metal components is subsequently dried. There are no specific restrictions on the drying conditions. Typically, drying is carried out at a temperature of 50-150 ° C for 1 h or more, preferably at a temperature of 100-120 ° C for 12 h or more. In the case of air drying, it is carried out approximately throughout the day and night (24 hours). Significant amounts of moisture can evaporate, depending on the type of impregnation method used, and porous alpha-aluminum oxide material can be obtained which is already substantially dried. In this case, it is not necessary to carry out a separate drying step.

2.5. Firing after drying.

The porous alpha-alumina material dried as described above is subsequently fired to obtain a catalyst. Typically, calcination is carried out in air or in a stream of air for approximately 124 hours at a temperature of 400-800 ° C, preferably at 450-800 ° C, more preferably at 450-600 ° C. In a firing atmosphere, a fully or partially oxygen-containing gas, such as pure oxygen and oxygen enriched air, can be used.

A catalyst is a product obtained by calcination that contains a ruthenium component and optionally a zirconium component, an alkaline earth metal compound and a rare earth metal compound, and a cobalt component, and these components are usually applied in the form of oxides or oxide complexes. These components are adjacent to each other and are deposited on a porous alpha-alumina material in a highly dispersed state.

2.6. Preliminary processing.

The catalyst thus obtained can be used directly as a catalyst or component in a particular catalytic reaction, or it can be activated by suitable pretreatment methods for subsequent use in the catalytic reaction. This pre-treatment can be carried out using a conventional method. For example, the ruthenium component can be reduced with a reducing agent, such as hydrogen, to turn it into a highly dispersed metallic ruthenium for use in the reaction.

The hydrogen reduction process is usually carried out at 500-850 ° C. until the consumption of hydrogen ceases.

VI. The reforming reaction of hydrocarbons and oxygen-containing compounds with water vapor.

The reforming reaction of hydrocarbons and oxygen-containing compounds with water vapor, in the presence of the catalyst of the present invention, ruthenium on alumina, will be described below.

1. Raw materials (hydrocarbons, oxygen-containing compounds and water).

1.1. Hydrocarbons and oxygen compounds.

The hydrocarbons and oxygenates that are used in this reaction are not particularly limited. Examples of hydrocarbons containing from about 1 to 16 carbon atoms include linear or branched saturated aliphatic hydrocarbons such as methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane and decane; alicyclic saturated hydrocarbons such as cyclohexane, methylcyclohexane and cyclooctane; and monocyclic or polycyclic aromatic hydrocarbons. Examples of oxygen-containing compounds (hereinafter, sometimes referred to as hydrocarbons) include alcohols, such as methanol and ethanol, and ethers, such as dimethyl ether and diethyl ether. In addition, natural gas having a boiling range of about 300 ° C. or lower, liquefied petroleum gas (LPG), naphtha, methanol for the production of kerosene and dimethyl ether dissolved in carbon dioxide to reduce the formation of nitrogen oxides can be used as preferred starting materials. during combustion, etc. Mixtures of two or more of these hydrocarbons may be used as starting materials. If these hydrocarbons contain sulfur, they are preferably desulfurized prior to use in order to reduce the sulfur content to about 1 ppm (ppm) or less. With a sulfur content of more than about 1 ppm, catalyst deactivation may occur. Desulfurization methods are not particularly limited, and examples of desulfurization include hydrogenation and adsorption.

1.2. Water content.

There are no specific restrictions on the nature of the water that is involved in the reaction with hydrocarbons. Water can be mixed with hydrocarbons in advance.

2. The reforming reaction.

2.1. The ratio of water vapor / carbon.

The steam / carbon ratio in the hydrocarbon reforming reaction is usually 1.5-10, preferably 1.5-5, more preferably 2-4. When using oxygen-containing compounds, the amount of steam can be reduced due to the oxygen contained in the feed. Hydrogen-enriched gas is obtained by adjusting the water vapor / carbon ratio so that it is within the above ranges. In steam reforming using the catalyst of the present invention, carbon deposition is prevented even when the steam / carbon ratio is set to 3 or less. Therefore, the waste heat is utilized efficiently.

2.2. Reaction conditions

2.2.1. Reaction temperature.

The reaction temperature is usually 100-900 ° C, preferably 150-850 ° C, more preferably 200-800 ° C. There is no need to determine the reaction temperature in advance, since it depends on many factors, such as the starting materials used in this reaction.

2.2.2. Reactionary pressure.

The reaction overpressure is usually 0-3.0 MPa (0-30 at), preferably 0-1.0 MPa.

2.3. The method of carrying out the reaction.

2.3.1. Reaction process.

Any continuous flow process or a single process can be used, with a flow process being preferred.

In the case of a continuous flow process, the volumetric flow rate of a gas (OSG) or a mixture of gaseous hydrocarbons and steam is usually 1000-100000 h ^-1 , preferably 2000-50000 h ^-1 , more preferably 2000-40000 h ^-1 .

2.3.2. Type of reaction.

There are no specific restrictions on the type of reaction or reactor. Examples of reactor types include a fixed-bed reactor, a moving-bed reactor, and a fluidized-bed reactor. A tubular type reactor may be used as a reactor.

3. Reaction products.

The interaction of hydrocarbons and water in the presence of a catalyst of the present invention under the above conditions gives mixtures containing hydrogen, methane, carbon monoxide and other products. Since these mixtures typically contain 50 vol% hydrogen or more, the reforming process of the present invention can conveniently be used to produce hydrogen for fuel cells.

The present invention will be further described in detail using examples.

Example 1

Alpha-alumina powder having a particle size of 3-5 μm and water (in an amount of 20% by weight of the powder) are mixed in a kneading machine to obtain a mixture which is pressed under a pressure of 15 MPa (150 kgf / cm ² ) to get a pressed product in the form of rods (diameter 5 mm, height 5 mm). This compressed product is dried by the residual heat of a gas kiln and then calcined in a gas oven at 1280 ° C. for 26 hours to obtain a porous material. This material is used as a catalyst carrier. The crushing strength, which is measured in the device Kia to determine the crushing strength, is at least 50 kgf. In an X-ray structural analysis, the ratio 1 _b / 1 _{a of the} intensity of the strongest peak attributed to compounds other than alpha alumina (1 _b ) to the intensity of the strongest peak attributed to alpha alumina (1 _a ) is 0.001. The micropore volume and average micropore size, which are measured by the method described below, are 0.26 cm ³ / g and 1.6 μm, respectively.

The impregnating solution is prepared as follows. Ruthenium trichloride (CuCl ₃ 'pN ₂ O; ruthenium content 38%, 0.66 g), magnesium nitrate (MD (LO ₃ ) ₂ ' 6H ₂ O, 6.36 g) and cobalt nitrate (Co (LO ₃ ) ₂ '6H ₂ O, 2.47 g) was dissolved in an aqueous solution of zirconium oxychloride (2gO (OH) C1, S-2, a product of EaysY Kate E1etei1 1pb81u Co.) To obtain a solution having a total volume of 10 ml. After stirring for at least 1 hour, the solution is used for impregnation. This impregnating solution has a red-orange color and a pH value of 0.5 or lower. This solution is impregnated with 50 g of the aforementioned porous alpha-aluminum oxide material by the pore filling method.

Freshly impregnated carrier has an orange color, whereas after 5 hours drying at 120 ° C it turns green. The finally impregnated support is calcined in air at 500 ° C. for 2 hours to obtain a catalyst. In the analysis of the composition, it was found that in the obtained catalyst the metal components are contained in the following proportions: 5.0 wt.% ΖγΖ ₂ , 2.0 wt.% MDO, 0.5 wt.% Ci and 1.0 wt.% Co.

The physical properties of the porous alpha-aluminum oxide material and catalyst are measured by the following method.

The micropore volume and average micropore size are determined using the following instrument, which measures the distribution of micropores (mercury porosimeter), which uses the method of permeability of mercury in the following conditions.

Device: Autopor 9220, Micrometrix company.

Conditions. The catalyst is dried for at least 1 hour, then mercury is pressed into the catalyst at an elevated pressure of 345 MPa in accordance with the operating instructions of the device. The micropore size (average diameter) at the maximum pore volume obtained from the total pore volume and the distribution of micropores is defined as the average pore size. The measurement results are summarized in table. one.

The distribution of micropores and the specific surface area of the catalyst by the BET method (Brunauer-Emmett-Teller) is determined under the following conditions using the device indicated below.

Instrument: Omnisorb 360, manufactured by OtIpigop Tesnobo§u Co.

Conditions. The catalyst is ground and a 16-32 mesh fraction is taken. This catalyst fraction (5 g) is placed in the sample cell and this cell is installed in the device. The sample is pumped to a pressure of 0.1 Torr or lower and heated for 3 hours at 300 ° C and then nitrogen is adsorbed at a pressure of up to 150 Torr. The micropore distribution and specific surface area by BET are calculated from the amount of nitrogen adsorbed on the catalyst, which is determined by desorption. Using this method, it is possible to calculate the distribution profile of micropores in the range of 2.5-2000 Angstroms, as well as the specific surface area associated with pores. The measurement results are summarized in table. one.

The activity of the catalyst in the reaction of the reforming of propane with water vapor is determined as follows.

1 ml of catalyst is loaded into a quartz tube reactor (inner diameter of 20 mm), then it is reduced in a stream of hydrogen, the volumetric flow rate of gaseous (OSPG) hydrogen is 6000 h ^-1 , at 500 ° C for 2 hours. Propane and water vapor are introduced into steam reforming reactor under the following conditions: reaction temperature 450 ° C and 500 ° C, OSPG propane 6000 h ^-1 , the water vapor / carbon ratio is 3.0. The resulting gas is taken for analysis by gas chromatography. The results of the analysis are used to calculate the degree of conversion of propane in accordance with the following equation:

100-- ^3x ( ^C s # E -------------------- _x100 60 / X

СО + СО ₂ + СН ₄ + 2х (С ₂ Н ₄ + С ₂ Н ₆ ) + Зх (С ₃ Н ₆ + С ₃ Я ₃ ) ^ν

The calculation results are given in table. 2.

Examples 2-14.

Porous alpha-alumina material is obtained in a similar manner, except that alpha-alumina powder having a particle size of 3-5 μm (90 wt.%) And bentonite (particle size of 0.5-30 μm, 10 weight are mixed). %) with water (in an amount of 20% by weight of the powder) in a kneading machine. The crushing strength of this porous material is at least 50 kgf. In X-ray diffraction analysis, the ratio 1 _b / 1 _{a of the} intensity of the strongest peak attributed to compounds other than alpha alumina (1 _b ) to the intensity of the strongest peak attributed to alpha alumina (1 _a ) is 0.005. The micropore volume and average micropore size are 0.20 cm ³ / g and 2.2 μm, respectively.

The catalysts of Examples 2-14 are prepared from the same starting materials, so that predetermined amounts of the corresponding elements are applied to the alpha alumina material.

When analyzing the composition of the obtained catalysts, the content of metal elements was found, the results are shown in table. one.

The physical properties and activity of porous alpha-alumina materials and catalysts are measured by the method used in example 1. The reaction of propane reforming with steam is investigated as described in example 1. The catalytic activity at reaction temperatures of 450 and 500 ° C is also evaluated in examples 3 -14. The results of the evaluation of the catalysts are given in table. 2.

Table 1

Example No. The content of catalyst components, wt.% The specific surface area, m ² / g The area ratio of the specific surface 8 _{2/8 1} Peak micropore size, A Neither With ΖγΘ MDO carrier, 8! catalyst, 8 ₂ one 0.5 1,0 5,0 2.0 0.8 13.5 16.9 35 2 0.5 1,0 5,0 2.0 0.4 10,4 26.0 35 3 0.5 0,0 5,0 2.0 0.4 8.2 20.5 38 4 0.5 0.06 5,0 2.0 0.4 8.5 21.3 38 5 0.5 0.15 5,0 2.0 0.4 9.1 22.8 36 6 0.5 0.29 5,0 2.0 0.4 9.8 24.5 34 7 0.5 0.58 5,0 2.0 0.4 9.2 23.0 36 8 0.5 1,0 5,0 2.0 0.4 8.6 21.5 38 nine 0.5 0.15 6.1 0.2 0.4 8.1 20.3 38 10 0.5 0.15 6.1 3.0 0.4 8.8 22.0 36 eleven 0.5 0.15 6.1 1,0 0.4 8.2 20.5 38 12 0.5 0.15 6.1 0.5 0.4 8.2 20.5 38 thirteen 0.5 0.15 6.1 2.0 0.4 8.6 21.5 36 14 0.5 0.15 6.1 0,0 0.4 8.1 20.3 38

Note: Ni - Ruthenium; Co - cobalt; ΖτΟ zirconium oxide; MdO - magnesium oxide

table 2

Example No. The degree of conversion of propane,% 400 ° C 450 ° C 500 ° C 550 ° C one - 25 - 94 2 - 21 - 92 3 2.0 12 58 84 4 2,4 eleven 41 85 5 4.4 22 88 93 6 5.7 28 94 94 7 4.6 23 93 91 8 2.7 12 43 82 nine 0.8 one 8 7 10 4,5 23 92 91 eleven 0.9 4 14 52 12 0.3 one 3 10 thirteen 3.2 14 fifty 68 14 1.4 4 10 nineteen

As can be seen from the table. 1 and 2, the catalysts of examples 1 and 2, which both have a large specific surface area and micropore size less than 1000 A, provide a high degree of propane conversion and have high catalytic activity.

As described above, the ruthenium-alumina catalyst of the present invention, having a special porous alpha-aluminum oxide material as a catalyst support, has excellent crush strength. Accordingly, the catalyst of the present invention is not destroyed in the reforming reactor and blocking of the catalyst bed and pipelines by catalyst dust is prevented. The catalyst of the present invention has an increased specific surface area, 7-50 m ² / g, which ensures the efficient deposition of metal components. In the catalyst of the present invention, the ruthenium component and optional cobalt component and magnesium component are deposited near the zirconium component in a highly dispersed state and they have good thermal stability. When used in the process of reforming hydrocarbons with water vapor, the catalyst has a high activity based on the content of the ruthenium component and excellent thermal stability. This high catalytic activity is satisfactorily maintained under high temperature conditions. The catalyst of the present invention is particularly suitable in view of its cost as well as its catalytic activity for the steam reforming process in the production of hydrogen for fuel cells. Thus, this catalyst is of great importance to industry.

Claims (7)

CLAIM 1. A catalyst containing at least ruthenium component supported on porous alpha-alumina material, wherein the catalyst has a specific surface (8 _1), equal to 7-50 m ² / g and a ratio of 8 _{1/2 August} specific surface ruthenium on alumina (81) to the surface of porous alpha-alumina (8 ₂ ) is 3-50. 2. The catalyst according to claim 1, which has a specific surface area (8 ₁ ) equal to 8-20 m ² / year 3. The catalyst according to claim 1, in which the porous alpha-alumina material is impregnated with at least the ruthenium component and the zirconium component, and their respective amounts are such that the amount of ruthenium is 0.05-5 wt.% In the form, restored to elemental ruthenium, and the amount of zirconium component is 0.0520 weight. % in the form reduced to zirconium oxide, all percentages relate to the weight of the porous alpha-alumina material. 4. The catalyst according to claim 1, in which the porous alpha-alumina material is impregnated with at least a ruthenium component, a zirconium component and an alkaline earth metal component or a rare earth component, and their respective amounts are such that the amount of ruthenium is 0.05 -5 wt.% In the form reduced to elemental ruthenium, the amount of the zirconium component is 0.0520 wt.% In the form reduced to zirconium, and the alkaline earth metal or rare earth metal component It accounts for 0.5–20 wt.% in the form reduced to the corresponding oxides, while all percentages relate to the weight of the porous alpha-aluminum oxide material. 5. The catalyst according to claim 1, in which the porous alpha-alumina material is impregnated with at least a ruthenium component, a zirconium component, an alkaline earth metal or rare earth metal component, and a cobalt component, and their corresponding amounts are such that the amount of ruthenium is 0 , 05-5 wt.% In the form, reduced to elemental ruthenium, the amount of zirconium component is 0.05-20 wt.% In the form, reduced to zirconium oxide, a component of an alkaline earth metal or rare earth the metal is 0.5-20 wt.% in the form, reduced to the corresponding oxides, while all percentages relate to the weight of the porous alpha-aluminum oxide material, and the cobalt component is introduced in a molar ratio of cobalt / ruthenium, Co / Ki equal to 0.01-30 . 6. The catalyst of claim 5, wherein the alkaline earth metal or rare earth metal compound is magnesium. 7. The use of the catalyst described in any of the preceding paragraphs in the process of reforming hydrocarbons or oxygen-containing compounds with water vapor.