JPH08318158A - Catalyst for production of high calorie gas and its production - Google Patents

Abstract

PURPOSE: To produce a catalyst having superior mechanical strength, excellent in resistance to poisoning by sulfur and the deposition of carbon, hardly reducing its activity over a long time and capable of efficiently producing high calorie gas. CONSTITUTION: Carrier stock contg. aluminum hydroxide (a), at least one kind of metal oxide (b) selected from among oxides of groups II and III metals and lanthanoids and a combustible high molecular compd. (c) is molded into a carrier substrate and fired to form an activated alumina composite carrier. The amt. of the metal oxide (b) is 5-30wt.% of the amt. of the resultant catalyst. Ruthenium is then deposited on the carrier and reduced to produce the objective catalyst.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a high-calorie alternative natural gas (hereinafter referred to as S
NG) and a method for producing the catalyst.

[0002]

2. Description of the Related Art Substitute natural gas
Natural gas) is a high-calorie (approximately 40,000 kJ · m ⁻³ ) fuel gas that replaces natural gas, and is abbreviated as SNG. When natural gas, liquefied petroleum gas or the like is supplied alone as a city gas raw material, lower hydrocarbons are the main component and hydrogen is not contained. When naphtha, crude oil, etc. are used as raw materials for city gas, it is necessary to gasify them. As this gasification process, a steam reforming method using a nickel catalyst is often adopted, and a gas having a low calorific value containing hydrogen as a main component and a relatively high gas containing methane and hydrogen as a main component due to a difference in reaction conditions. Calorific gas or alternative natural gas (SNG), which consists almost entirely of methane, is produced. As a steam reforming catalyst for hydrocarbons, a nickel-based catalyst in which nickel is supported on a carrier such as alumina is widely used in practice. However, nickel-based catalysts tend to cause carbon deposition on the catalyst, and as a result, the activity of the catalyst may decrease. Therefore, in order to avoid such a problem, the ratio (hereinafter, referred to as S / C ratio) between the number of moles of water vapor during the reforming reaction and the number of carbon moles in the raw material hydrocarbon represented by the following equation is usually Set high. As an example, the steam reforming of naphtha is operated at an S / C ratio of around 3 to 5.

[0003]

[Equation 1]

On the other hand, the ruthenium-based catalyst has an effect of suppressing carbon deposition, and therefore, the S / C ratio can be reduced to about 1/2 as compared with the conventional nickel-based catalyst. Therefore, in SNG production, since the steam basic unit (the amount of steam used per unit amount of product) occupies a large proportion in the operating cost of the process, the production cost can be reduced by using the ruthenium catalyst. Regarding such a ruthenium catalyst system, a ruthenium supported on an alumina or silica carrier (JP-A-57-4)
232), a carrier using a cerium oxide added to an alkali metal oxide or an alkaline earth oxide (JP-A-4-265156), and a precursor using an alkali salt such as sodium ruthenate. (JP-A-60
No. 227834), one using zirconium oxide as a carrier (JP-A-2-302304), and the like. In conventional high-temperature steam reforming catalysts for hydrogen production, thermal carbon deposition occurs due to causes other than sulfur poisoning, so advanced catalyst design for sulfur resistance including measures for carbon deposition is not required. It was However,
In the production of SNG by low-temperature steam reforming of hydrocarbons, it is required for the catalyst that a sufficient reaction can be obtained at a reaction temperature of about 400 to 500 ° C. in terms of chemical equilibrium and that the reaction result is extremely close to the equilibrium conversion rate. To be This temperature is about half that of ordinary steam reforming, and is in a region where carbon precipitation easily occurs even in equilibrium. Furthermore, due to impurities containing sulfur in the raw material and sulfur compounds such as odorants added to the raw material,
There is a high possibility that the catalyst will be poisoned, and there is a concern that carbon deposition may occur concurrently due to this.

As a method for solving these problems, the present inventors have found that components (hereinafter
It may also be the third component. ) As a rare earth metal or alkaline earth metal in an alumina carrier, and
It has been proposed to use a catalyst in which ruthenium which is an active metal component is highly dispersed (Japanese Patent Application No. 6-189404).
However, since the steam reforming catalyst in industrial SNG production is exposed to steam for a long period of time at a reaction temperature of 400 to 500 ° C., it must be a catalyst having sufficient mechanical strength. For the purpose of merely improving the mechanical strength, compression molding and high temperature firing may be carried out.However, while such a conventional method can improve the mechanical strength, it significantly reduces the specific surface area and blocks pores. It is likely to cause it. From the viewpoint of industrial SNG production, items such as improvement of mechanical strength, addition of a third component for imparting sulfur poisoning resistance and carbon deposition resistance, and control of dispersibility of supported metal are important. In order to achieve these items, improve the mechanical strength of the catalyst without impairing the specific surface area and pore volume of the catalyst carrier to which the third component is added, and maintain high dispersibility of the supported metal, A precise catalyst design is required, but so far no ruthenium-based catalysts have been found that serve the purpose.

[0006]

Therefore, the object of the present invention is to have excellent mechanical strength, excellent resistance to sulfur poisoning and carbon precipitation, less decrease in activity over a long period of time, and high efficiency. It is intended to provide a catalyst for producing high-calorie gas capable of producing calorie gas and a method for producing the same.

[0007]

Therefore, as a result of repeated studies to solve the above problems, the present inventors have found that aluminum hydroxide is a precursor of alumina and a Group 2 metal referred to in the periodic table of elements. (Hereinafter simply referred to as Group 2 metal oxide), Group 3 metal oxide (hereinafter simply referred to as Group 3 metal oxide) or lanthanoid metal oxide (hereinafter simply referred to as Lanthanoid metal oxide), Furthermore, by using a carrier raw material to which a flammable polymer compound is added, the carrier is molded into a carrier substrate, and ruthenium is supported on an alumina composite carrier obtained by firing at a relatively low temperature. When used in the steam reforming reaction of hydrocarbons in, it was found that not only SNG can be produced with good reaction results close to equilibrium conversion, but also that the catalyst has practically sufficient strength, and the present invention was completed. You It led to.

That is, in the present invention, at least one metal oxide selected from the group consisting of (a) aluminum hydroxide, (b) Group 2 metal, Group 3 metal, and lanthanoid metal oxide is used as a catalyst based on 5 ˜30% by weight, and (c) a carrier raw material containing a flammable polymer compound, is molded into a carrier substrate, and ruthenium is supported on an activated alumina composite carrier obtained by firing, followed by reduction treatment. The present invention provides a catalyst for producing high-calorie gas, which is obtained. Furthermore, the present invention provides (a) aluminum hydroxide,
(B) 5 to 30% by weight of at least one metal oxide selected from the group consisting of oxides of Group 2 metals, Group 3 metals and lanthanoid metals on a catalyst basis, and (c) a flammable polymer compound. Ruthenium is supported on the activated alumina composite carrier obtained by molding the carrier raw material contained in the carrier base material and firing it, and ruthenium is insoluble in an alkaline aqueous solution.
The present invention provides a method for producing a catalyst for producing high-calorie gas, which comprises immobilizing and then reducing. Hereinafter, the present invention will be described in detail.

In the catalyst for producing high calorie gas of the present invention, (a) aluminum hydroxide, (b) group 2 metal, 3
A carrier raw material containing at least one metal oxide selected from the group consisting of oxides of group metals and lanthanoid metals, and (c) a flammable polymer compound is used. Examples of the Group 2 metal oxide include beryllium, magnesium,
Although oxides of calcium, strontium, barium and radium can be used, it is particularly preferable to use oxides of magnesium and barium. As the Group 3 metal oxide, oxides such as scandium and yttrium can be used, but it is preferable to use yttrium oxide. As the lanthanoid metal oxide, oxides of lanthanum, cerium, praseodymium, neodymium, promethium, samarium and the like can be used, but lanthanum and cerium oxides are particularly preferable. As the Group 2 metal oxide, the Group 3 metal oxide, and the lanthanoid metal oxide, in addition to the oxide form, chloride, nitrate, and other forms can be used.

The oxides of Group 2 metals, Group 3 metals and lanthanoid metals of component (b) may be used alone or in combination of two or more. In the catalyst of the present invention, aluminum hydroxide as the component (a) is used as the alumina precursor, but aluminum hydroxide anhydride, aluminum hydroxide hydrate or the like can be used as the aluminum hydroxide. In the case of a hydrate, it may be used as it is or may be used after being pre-dehydrated. In the present invention, it is preferable to use an anhydride because it is easy to handle.

Examples of the flammable polymer compound as the component (c) include various flammable polymers such as polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyvinyl acetate (PVAc), and cyclodextrin (CD). Compounds can be used. Here, when water is used as the solvent or dispersion medium, PVA, PVP, CD or the like is preferably used, and when alcohols such as methanol are used as the solvent or dispersion medium, PVAc or the like is preferably used. When PVAc is used, if it is appropriately saponified with an alkali such as caustic soda or caustic, it can be used as either an aqueous type or a non-aqueous type depending on the degree of saponification. The type of flammable polymer compound is not limited to these, but a flammable polymer compound that does not generate a corrosive gas or the like during catalyst firing is easy to handle.
The flammable polymer compound as the component (c) may be used alone or in combination of two or more.

The content of the Group 2 metal oxide, the Group 3 metal oxide and the lanthanoid metal oxide in the carrier raw material is 5 to 30% by weight, preferably 10 to 30% by weight, based on the catalyst.
More preferably, it should be 15 to 25% by weight. If this value is less than 5% by weight, it is difficult to obtain a sufficient effect on sulfur resistance. Therefore, sulfur poisoning and carbon deposition are accompanied, and it may not be possible to expect a sufficient extension of the life of the catalyst. That is, if the value is appropriate, the sulfur compound contained in the raw material is adsorbed and absorbed by the group 2 metal oxide, the group 3 metal oxide, and the lanthanoid metal oxide, so that the ruthenium which is the active ingredient is poisoned. Less likely to occur and prolong life. On the other hand, if this value exceeds 30% by weight, the amount of alumina is relatively decreased, which is not preferable. That is, alumina is effective in improving the specific surface area and mechanical strength, and therefore, if the amount of alumina is extremely small, it is difficult to expect these improving effects.

The content of the flammable polymer compound in the carrier raw material is usually 2 with respect to the weight of the activated alumina composite carrier.
10 to 10% by weight, preferably 3 to 7% by weight, particularly preferably 4 to 6% by weight. When the content of the flammable polymer compound is less than 2% by weight, the specific surface area and pore volume of the carrier are too small to retain a desired amount of ruthenium, and the dispersibility of ruthenium tends to be lowered. Furthermore, since the surface exposure of the third component is reduced, sulfur poisoning resistance and carbon deposition resistance tend to be impaired. On the other hand, if the amount of the polymer compound added is more than 10% by weight, the carrier component and the polymer compound are not mixed uniformly, and the mechanical strength of the catalyst decreases due to macropores formed in the carrier after calcination. Or the polymer compound may not be sufficiently combusted during firing to generate carbon lumps, which is not preferable.

In preparing the carrier raw material, at least one metal oxide selected from the group consisting of oxides of Group 2 metals, Group 3 metals and lanthanoid metals is mixed with aluminum hydroxide and a flammable polymer compound. However, if necessary, a predetermined amount may be dissolved or dispersed in a solvent or dispersion medium of water or alcohols such as methanol and ethanol. The type of solvent or dispersion medium is not limited to water and alcohols, and ketones such as acetone, aromatic compounds, saturated / unsaturated hydrocarbons, alicyclic organic compounds and the like can be used. In any case, a compound that leaves no residue upon firing should be selected. The order of mixing the aluminum hydroxide with the metal oxide and the flammable polymer compound is not particularly limited. For example, a flammable polymer compound may be added to a slurry in which aluminum hydroxide and a metal oxide are mixed and mixed sufficiently, or a polymer compound solution and aluminum hydroxide may be mixed and the metal oxide may be added thereto. May be added and mixed well, or aluminum hydroxide may be mixed with a mixture of a metal oxide and a flammable polymer compound. In addition, other components such as other metal oxides can be added to the above carrier raw material within a range that does not impair the effects of the present invention.

In the catalyst of the present invention, the carrier raw material is molded into a carrier substrate and fired to obtain an activated alumina composite carrier. When the carrier raw material contains a solvent or a dispersion medium, it is preferable to completely remove the solvent or the dispersion medium during the molding into the carrier substrate. The removal is usually performed by drying under normal pressure or reduced pressure at room temperature or under heating. When heating and drying, 90 to 100 ° C. is usually preferable. In addition, it is preferable that the raw materials of the carrier are uniformly mixed into a fine powder before the molding into the carrier substrate. The particle size of this powder is preferably such that it usually passes through a 50-mesh net, more preferably through a 100-mesh net, and particularly preferably through a 200-mesh net.

As the molding for the carrier substrate, various molding methods such as pressure molding and extrusion molding can be applied, but pressure molding is preferable. Examples of the pressure molding include tablet molding, injection molding, press molding and the like, but tablet molding is preferable.
The pressure degree of the pressure molding is usually 5 to 30 ton / cm ² , preferably 10 to 20 ton / cm ² , and particularly preferably 1
It is preferably ³ to 17 ton / cm ² . The shape of the carrier substrate is not particularly limited, and various granular bodies such as spherical, elliptic spherical, spindle-shaped, prismatic, cylindrical, tablet-shaped, needle-shaped, and the like,
Although various shapes such as a film can be mentioned, columnar particles are preferable. The particle size of the particles of the carrier substrate is not particularly limited, but in the case of columnar particles, the diameter of the cross section circle is 2 to 5 mm.
It is preferably φ and has a length of 2 to 5 mm.

The shaped carrier substrate is fired. The calcination can be performed under reduced pressure, normal pressure or increased pressure in an air atmosphere or an inert gas atmosphere. The firing temperature is usually 600 ° C or lower, preferably 450 to 550 ° C. The firing time is usually 1 to 20 hours.
The specific surface area of the obtained alumina composite carrier is 50 m ² / g
Or more, preferably 50 to 150 m ² / g, more preferably 50 to 90 m ² / g, and the pore volume is 0.
2 to 0.5 ml / g, preferably 0.3 to 0.4 ml /
g is good. When the specific surface area or pore volume of the carrier is smaller than this, the dispersibility of the ruthenium to be supported becomes poor,
The catalytic activity during SNG production tends to be impaired. In such a case, since the carrier component is not sufficiently exposed on the surface, the third component added in the corner does not function, the sulfur poisoning resistance and the like are significantly impaired, and a predetermined amount of ruthenium cannot be supported. Can also happen. In any case, as a result, the catalytic activity tends to decrease. On the contrary, when the specific surface area is extremely increased, dispersibility, sulfur poisoning resistance,
Although the effect of improving the carbon deposition resistance can be seen, on the other hand, it becomes impossible to obtain sufficient mechanical strength of the catalyst. Breaking strength (DWL: Dead Wei) of the carrier obtained in the above process
ght Load) is usually 20 kg or more.

Next, ruthenium is supported on the activated alumina composite carrier. As a method for supporting ruthenium on the alumina composite carrier, known methods such as an impregnation method, an adsorption method, and a kneading method can be used, but the impregnation method is preferable. In the impregnation method, the impregnation temperature is usually 10 to 60 ° C.
The impregnation time is usually 1 to 3 hours. As ruthenium as an active ingredient, precursors such as ruthenium trichloride anhydrous, ruthenium trichloride hydrate and ruthenium nitrate can be used. It is particularly preferable to use ruthenium trichloride monohydrate because of its high solubility. The amount of ruthenium supported is 0.5 to 4% by weight, preferably 0.5 to 2% by weight, based on the catalyst, as metal ruthenium. If the supported amount is less than 0.5% by weight, the number of active sites is too small,
The activity of the catalyst may not be sufficiently expressed. When the supported amount is more than 4% by weight, not only the catalytic activity cannot be improved in proportion to the increased supported amount, but also the dispersibility of ruthenium tends to decrease.

The preferred method for supporting ruthenium on the alumina composite carrier is as follows. As a preliminary preparation for supporting ruthenium on the carrier, first weigh the carrier,
Water is added dropwise to this with a buret so that the carrier absorbs water sufficiently. This water supply is preferably performed until the inside of the carrier is saturated. In this way, the saturated water absorption amount is obtained in advance. Here, a solution prepared by dissolving a predetermined amount of ruthenium trichloride monohydrate in ion-exchanged water or distilled water in an amount equal to the saturated water amount is absorbed in the alumina composite carrier. Then, 10 to 15% by volume of ammonia water is dripped in excess with respect to the ruthenium concentration, and ruthenium chloride is converted into hydroxide as shown in Chemical formula 1, whereby ruthenium is insoluble and immobilized on the carrier.

[0020]

Embedded image

As shown in the above formula, this method is characterized in that the chlorine anion becomes water-soluble ammonium chloride, so that dechlorination can be efficiently performed in the washing process. For immobilization, an aqueous alkaline solution such as sodium carbonate, sodium hydrogen carbonate, sodium hydroxide, potassium hydroxide or the like can be used in addition to aqueous ammonia. However, in the case of sodium salts and potassium salts, alkali metal cations may remain during cleaning, so
Ammonia water is the easiest to handle. The ruthenium-immobilized carrier is preferably dried at less than 200 ° C., preferably 150 ° C. or less, more preferably 100 ° C. or less under reduced pressure or normal pressure. If the drying temperature is too high, some of the hydroxide will change to oxide. In order to reduce the carrier mixed with oxides, a temperature of 200 ° C. or higher is required, so that the dispersibility of ruthenium after the reduction treatment becomes worse due to the higher reduction temperature. From this point as well, it is preferable to avoid the presence of oxides during drying. Further, if the drying temperature is too low, the drying time becomes extremely long, which is not preferable. The drying time may be appropriately selected according to the drying temperature and other conditions, and is usually 1 to 20 hours.

When the ruthenium-supported catalyst thus obtained is reduced at a relatively low temperature, the dispersibility of the supported ruthenium can be kept high. The reduction temperature is 80 to 450 ° C, preferably 100 to 250 ° C, more preferably 100 to 2
It is better to carry out at 00 ° C. When reduced in this temperature range, the dispersibility of ruthenium becomes highest. Hydrogen gas, hydrogen / steam mixed gas, and carbon monoxide can be used for the reduction of supported ruthenium. Among these, it is preferable to use hydrogen gas or hydrogen / steam mixed gas, and it is particularly preferable to use hydrogen gas. The reduction time may be appropriately selected according to the reduction temperature and other conditions, but is usually 1 to 20 hours. It is preferable that the obtained catalyst has a carbon monoxide (hereinafter sometimes abbreviated as CO) adsorption amount of 2 ml / g or more and a ruthenium metal dispersibility of 60% or more. The catalyst thus obtained is
It has sufficient mechanical strength, is highly resistant to sulfur poisoning, and exhibits good reaction results close to equilibrium conversion. Therefore,
Since this catalyst can be used even in a raw material containing a sulfur compound, it is a very practical catalyst for SNG production.

High-calorie gas can be produced using the catalyst of the present invention. Here, high-calorie gas means
It is a high calorific value alternative natural gas (SNG) mainly used as city gas. When producing a high-calorie gas using the catalyst of the present invention, the hydrocarbon as the main component of the raw material has 2 to 16 carbon atoms, preferably 2 to 10 carbon atoms, and particularly preferably 3 to 8 carbon atoms. Is good. The reaction temperature is 350 to 500 ° C., preferably 400 to 450 ° C., the reaction pressure is 20 kg / cm ² G or less, preferably atmospheric pressure to 15
kg / cm ² G, more preferably 8 to 10 kg / cm ² G
And GHSV is preferably 600 to 1200 h-1. Further, it is preferable to add water vapor to the reaction system, and the S / C value is preferably in the range of 0.7 to 10. The above-mentioned method for producing high-calorie gas can be carried out by a batch type, semi-continuous type or continuous type operation using a fixed bed or moving bed catalyst device.

[0024]

EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to these. In addition, in the following examples, a stainless steel (SUS) tube (inner diameter 3 mmφ × 2 m) was used for the analysis of the product.
It was carried out by a gas chromatograph (GC8A, manufactured by Shimadzu Corporation) equipped with a thermal conductivity type detector (TCD) equipped with a separation column filled with -80 mesh Unibeads-C (manufactured by GL Science). The specific surface area and pore volume of the carrier are measured by a surface area measuring device (Bellsoap 25, manufactured by Bell), and the carbon monoxide (CO) adsorption amount is measured by an automatic adsorption device (R6015, manufactured by Okura Riken) with a built-in TCD gas chromatograph. did. The amount of supported ruthenium was measured by inductively coupled plasma emission spectrometry (ICP). The breaking strength (DWL) of the catalyst was measured with a Kiya hardness meter (Kiya Seisakusho).

(Example 1) Cerium oxide (CeO ₂ , manufactured by Wako Pure Chemical Industries, Ltd.) powder 19.6 g and aluminum hydroxide (Al (OH) ₃ , manufactured by Kanto Chemical Co., Ltd.) powder 125.7 g were sufficiently used in an agate mortar. Mix and add to this about 50 g of warm water.
An aqueous solution in which 3 g of completely saponified polyvinyl alcohol (PVA, manufactured by Nippon Gosei Co., Ltd.) was dissolved was added and further kneaded. 90 ~ 10 by using a thermostatic dryer paste mixture
It was dried at 0 ° C. for several hours to completely remove water. The solidified mixture was made into a powder of about 200 mesh in an agate mortar, and pressed at room temperature using a tablet molding machine at 15 ton / cm ² to form a tablet having an outer diameter of 3.2 mmφ and a length of 3 mm.
This was baked in a muffle electric furnace at 500 ° C. for 3 hours to prepare a strength-reinforced composite carrier. The specific surface area of the composite carrier at this time was 80.5 m2 / g, and the pore volume was 0.4 ml.
/ G, the breaking strength (DWL) was 22 kg. In an aqueous solution prepared by dissolving 1 g of ruthenium trichloride monohydrate (RuCl ₃ · nH 2 O, manufactured by Kanto Chemical Co., Inc.) in 37 ml of pure water,
25.4 g of the above-mentioned tableting carrier is immersed for 1 hour, and the remaining liquid is rotatory-evaporated to about 2.7 kPa (20 m
(mHg) was removed by evaporation under vacuum, and then heated to 40 to 45 ° C. with an infrared hot plate to remove water. Approximately 4 with this carrier immersed in 7 to 10N ammonia water
The mixture was kept at 0 ° C., stirred for 2 hours, insoluble and fixed, and then the catalyst was separated with a Buchner funnel and washed thoroughly with pure water (washing with dilute aqueous solution of silver nitrate was added to the leak until no cloudiness due to silver chloride was generated. Was done). Further, this was dried in a vacuum drier at 40 to 45 ° C. for 8 hours to prepare a catalyst composed of 1.6% by weight of ruthenium as a metal, 21.6% by weight of cerium oxide, and the balance alumina.

10 ml of the catalyst obtained above was used for an inner diameter of 16 mmφ.
Filled in a cylindrical reaction tube made of SUS of 8 kg / cm ² ,
Hydrogen reduction was performed for 8 hours at GHSV 3000h-1 at a reduction temperature of 150 ° C. The amount of CO adsorbed on the catalyst after the reduction treatment was 2.85 ml / g (standard state, hereinafter referred to as STP). Table 1 shows the physical properties of the obtained catalyst. Next, commercially available LPG gas (manufactured by Cosmogas, n-butane (63.8Vo
l. %) / Iso-butane (36.2 Vol.%) Molar ratio = about 1.8) to which 10 ppm of hydrogen sulfide was added was introduced into a reactor filled with catalyst together with steam. Operating conditions are reaction pressure 8 kg / cm ² G, reaction temperature 4
It carried out at 50 degreeC, GHSV600h-1, and S / C ratio. The reaction results at this time are shown in Table 2.

(Example 2) Yttrium oxide (Y ₂ O ₃ ,
(Kanto Chemical Co., Ltd.) powder 21.1 g and aluminum hydroxide 1
Using 20.0 g, a tableting carrier having a specific surface area of 80.3 m ² / g, a pore volume of 0.4 ml / g and a breaking strength (DWL) of 21.5 kg was prepared in the same manner as in Example 1, As ruthenium 1.6% by weight, yttrium oxide 22.2
A catalyst consisting of wt% balance alumina was prepared. This catalyst was subjected to a reduction treatment in the same manner as in Example 1 and then subjected to a steam reforming reaction. In addition, C after reducing the above catalyst
The amount of O adsorbed was 2.51 ml / g (STP). The physical properties of the catalyst and the reaction results are shown in Tables 1 and 2.

Example 3 Using 20.5 g of lanthanum oxide (La ₂ O ₃ , manufactured by Wako Pure Chemical Industries, Ltd.) powder and 121.8 g of aluminum hydroxide, a specific surface area of 80. A tableting carrier having 9 m ² / g, a pore volume of 0.3 ml / g, and a breaking strength (DWL) of 22.7 kg was prepared, and 1.6 wt% of ruthenium as a metal, 21.1 wt% of lanthanum oxide, and the remaining alumina were used. Was prepared. This catalyst was subjected to a reduction treatment in the same manner as in Example 1 and then subjected to a steam reforming reaction. The CO adsorption amount after the reduction of the catalyst was 2.68 ml / g (STP). The physical properties of the catalyst and the reaction results are shown in Tables 1 and 2.

Example 4 Magnesium oxide (MgO,
Wako Pure Chemical Industries, Ltd.) 20.3 g of powder and 121.6 g of aluminum hydroxide were used in the same manner as in Example 1 to give a specific surface area of 61.8 m ² / g, pore volume of 0.3 ml, and breaking strength (DWL). A tableting carrier of 21.3 kg was prepared, and ruthenium as a metal was 1.5 wt% and magnesium oxide was 20.5.
A catalyst consisting of wt% balance alumina was prepared. This catalyst was subjected to a reduction treatment in the same manner as in Example 1 and then subjected to a steam reforming reaction. The CO adsorption amount after reducing the catalyst was 2.41 ml / g (STP). The physical properties of the catalyst and the reaction results are shown in Tables 1 and 2.

(Embodiment 5) A specific surface area of 60.1 m ² / using 20.7 g of barium oxide (BaO, manufactured by Wako Pure Chemical Industries, Ltd.) powder and 120.8 g of aluminum hydroxide powder in the same manner as in Embodiment 1. g, a pore volume of 0.3 ml / g, and a breaking strength of 22.5 kg were prepared, and a catalyst composed of ruthenium (1.5 wt%), barium oxide (21.5 wt%), and the balance alumina was prepared. This catalyst was subjected to a reduction treatment in the same manner as in Example 1 and then subjected to a steam reforming reaction. The CO adsorption amount after reducing the above catalyst is 2.11 ml.
/ G (STP). The physical properties of the catalyst and the reaction results are shown in Tables 1 and 2.

(Comparative Example 1) 19.8 g of cerium oxide powder
And activated alumina (Al ₂ O ₃ , aluminum oxide 9
0, Type I, manufactured by Merck & Co., Inc.) 82.2 g was thoroughly mixed in a mortar, and then about 40 ml of pure water was added and kneaded. Approximately 2.7k pasty mixture on rotary evaporator
It was dried under a vacuum of Pa and further heated to 60 to 70 ° C. with an infrared hot plate to remove water. 110 this
After preliminarily drying in a constant temperature dryer kept at 0 ° C., tableting was carried out in the same manner as in Example 1. This in a muffle furnace at 500 ℃ 3
A carrier was prepared by firing for a period of time. The specific surface area of the catalyst at this time is 33.6 m ² / g, and the pore volume is 0.1 to 0.2 ml /
g, breaking strength (DWL) was 24.5 kg. This carrier was impregnated with ruthenium as in Example 1 and then immobilized.
Ruthenium as metal 1.1 wt%, cerium oxide 2
A catalyst was prepared consisting of 1.5 wt% balance alumina.
This catalyst was subjected to a reduction treatment in the same manner as in Example 1 and then subjected to a steam reforming reaction. C after reducing the above catalyst
The amount of O adsorbed was 0.75 ml / g (STP). The physical properties of the catalyst and the reaction results are shown in Tables 1 and 2.

Comparative Example 2 Magnesium oxide powder 20.
3 g and 80.2 g of activated alumina powder were used in the same manner as in Comparative Example 1 to give a specific surface area of 30.5 m ² / g and a pore volume of 0.
1 to 0.2 ml / g, breaking strength (DWL) 24.7 kg
Of the carrier, and then ruthenium 1.0 as the metal
A catalyst was prepared which was composed of wt%, magnesium oxide 21.5 wt%, and the balance alumina. This catalyst was subjected to a reduction treatment in the same manner as in Example 1 and then subjected to a steam reforming reaction. CO adsorption amount after reducing the above catalyst is 0.62 ml
/ G (STP). The physical properties of the catalyst and the reaction results are shown in Tables 1 and 2.

[0033]

[Table 1] The Ru dispersibility in the table is the percentage of (moles of adsorbed CO) to (moles of Ru).

[0034]

[Table 2] In Examples 1 to 5 and Comparative Examples 1 and 2, the conversion rates and selectivities shown in Table 2 were calculated by Equations 2 and 3.

[0035]

[Equation 2]

[0036]

(Equation 3)

As is clear from Tables 1 and 2, Comparative Examples 1 and 2 using the carrier prepared by the conventional method only show an improvement in the mechanical strength of the catalyst, and the conversion and selectivity are Low. This is because the catalyst specific surface area is reduced and the pores are clogged in the process of tableting and firing, so that a predetermined amount of ruthenium cannot be supported, in other words, the amount of ruthenium that can be an active site is small in the first place, and ruthenium dispersibility is also low. Low,
Since the surface exposure of the third component is small, sulfur poisoning occurs,
As a result, it can be interpreted that carbon precipitation also occurs. On the other hand, the catalysts of Examples 1 to 5 according to the present invention retain a practical level of strength, but do not impair the surface area and pore volume in the preparation process, and therefore can carry a predetermined amount of ruthenium in a highly dispersed manner, and , Has excellent catalytic activity. Further, as a result of the third component in the carrier being sufficiently exposed on the catalyst surface, even if there is sulfur content in the raw material, the sulfur content is absorbed by the carrier side, so that sulfur poisoning of the catalyst and carbon deposition can occur. You can avoid the problem.

[0038]

As described above, since the catalyst of the present invention has a practical level of mechanical strength, it has both sulfur poisoning resistance and carbon deposition resistance.
If the catalyst is used in an industrial process for producing high-calorie alternative natural gas (SNG) from hydrocarbons, high conversion rate,
It is possible to maintain excellent reaction results with high selectivity for a long period of time.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication C01B 3/40 B01J 23/56 301M (72) Inventor Takashi Yoshizawa 1134-2 Gongendo, Satte City, Saitama Prefecture Cosmo Research Institute Co., Ltd.

Claims (2)

[Claims] 1. At least one metal oxide selected from the group consisting of (a) aluminum hydroxide, (b) Group 2 metal, Group 3 metal and lanthanoid metal oxides in an amount of from 5 to 30% by weight based on the catalyst. , And (c) a carrier raw material containing a flammable polymer compound is molded into a carrier substrate, and ruthenium is supported on an activated alumina composite carrier obtained by firing.
A catalyst for producing a high-calorie gas, which is obtained by subsequent reduction. 2. At least one metal oxide selected from the group consisting of (a) aluminum hydroxide, (b) Group 2 metal, Group 3 metal and lanthanoid metal oxides in an amount of 5 to 30% by weight based on the catalyst. , And (c) a carrier raw material containing a flammable polymer compound is molded into a carrier substrate, and ruthenium is supported on an activated alumina composite carrier obtained by firing.
Ruthenium is insoluble and immobilized using an alkaline aqueous solution,
Then, a method for producing a catalyst for producing a high-calorie gas, which comprises reducing.