JP2011241122A - Method for producing synthesis gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a synthesis gas containing hydrogen and carbon monoxide by reforming a hydrocarbon with carbon dioxide at a good inversion rate.SOLUTION: The synthesis gas containing hydrogen and carbon monoxide is produced by reforming a hydrocarbon with carbon dioxide in the presence of a catalyst which consists of silica and at least one kind selected from the group consisting of ruthenium and a ruthenium compound and which is supported by a carrier. The carrier is preferably titania, and the hydrocarbon is preferably at least one kind selected from the group consisting of methane and ethane.

Description

  The present invention relates to a method for producing a synthesis gas containing hydrogen and carbon monoxide by reforming a hydrocarbon with carbon dioxide in the presence of a reforming catalyst. Syngas containing hydrogen and carbon monoxide is useful as a raw material for producing methanol, dimethyl ether, synthetic petroleum and the like.

  In recent years, natural gas has attracted attention as a future oil alternative energy source. On the other hand, in recent years, effective use of carbon dioxide has become a problem due to concerns about global warming due to carbon dioxide in the atmosphere. From such a viewpoint, a method has been proposed in which a hydrocarbon, which is a component contained in natural gas, is reformed by reacting with carbon dioxide to produce a synthesis gas containing hydrogen and carbon monoxide. For example, Patent Document 1 describes a method of reforming methane with carbon dioxide in the presence of a catalyst supporting at least one metal selected from the group consisting of rhodium, ruthenium, iridium, and platinum on a carrier, In Patent Document 2, methane is reformed by a mixed gas of oxygen, steam and carbon dioxide in the presence of a catalyst supporting at least one selected from the group consisting of zirconium, ruthenium, cobalt and magnesium on a carrier, A method for producing synthesis gas containing hydrogen and carbon monoxide is described.

JP 2008-136907 A JP 2009-78267 A

  However, the conventional method described above is not necessarily sufficient in terms of reforming hydrocarbons with a good conversion rate in the production of synthesis gas containing hydrogen and carbon monoxide.

  Therefore, an object of the present invention is to provide a method for producing a synthesis gas containing hydrogen and carbon monoxide by reforming hydrocarbons with carbon dioxide at a good conversion rate.

  As a result of diligent examination, the inventors of the present invention have modified hydrocarbons with carbon dioxide in the presence of a catalyst in which at least one selected from the group consisting of ruthenium and ruthenium compounds and silica are supported on a carrier, The present inventors have found a new finding that hydrocarbons can be reformed with a good conversion rate and a synthesis gas containing hydrogen and carbon monoxide can be produced, and the present invention has been completed.

That is, the synthesis gas production method of the present invention has the following configuration.
(1) Contains hydrogen and carbon monoxide for reforming hydrocarbons with carbon dioxide in the presence of a reforming catalyst in which at least one selected from the group consisting of ruthenium and ruthenium compounds and silica are supported on a carrier. A method for producing synthesis gas.
(2) The production method according to (1), wherein the carrier is titania.
(3) The production method according to (2), wherein the titania contains rutile crystal titania.
(4) The production method according to (3), wherein the ratio of rutile crystal titania in the titania measured by X-ray diffraction method is 20% or more with respect to the total of rutile crystal titania and anatase crystal titania. .
(5) The production method according to any one of (1) to (4), wherein the hydrocarbon is at least one selected from the group consisting of methane and ethane.
(6) The production method according to any one of (1) to (5), wherein the reforming temperature is 350 to 700 ° C.

  According to the present invention, synthesis gas containing hydrogen and carbon monoxide can be produced by reforming hydrocarbons with carbon dioxide at a good conversion rate.

The present invention will be described in detail below. The reforming catalyst used in the present invention is a catalyst in which at least one selected from the group consisting of ruthenium and a ruthenium compound (hereinafter sometimes referred to as “ruthenium component”) and silica are supported on a carrier. . Examples of ruthenium include metal ruthenium which is ruthenium of a simple metal, and examples of ruthenium compounds include RuO ₂ , RuO (OH), RuO (OH) ₂ , Ru (OH) ₃ , and Ru (OH) ₄ . Oxides such as oxides, oxyhydroxides or hydroxides; halides such as RuCl ₃ , RuBr ₃ ; oxoacid salts such as K ₂ RuO ₄ ; oxys such as Ru ₂ OCl ₄ , Ru ₂ OCl ₅ , Ru ₂ OCl ₆ Halide: K ₂ [RuCl ₅ (NO)], [Ru (NH ₃ ) ₅ (NO)] Cl ₃ , [Ru (OH) (NH ₃ ) ₄ (NO)] (NO ₃ ) ₂ , [Ru ( Nitrosyl complexes such as NO)] (NO ₃ ) ₃ ; K ₂ [RuCl ₅ (H ₂ O) ₄ ], [RuCl ₂ (H ₂ O) ₄ ] Cl, K ₂ [Ru ₂ OCl ₁₀ ], Cs ₂ [ Ru ₂ O Halogeno complexes such as Cl ₄ ]; [Ru (NH ₃ ) ₅ H ₂ O] Cl ₂ , [Ru (NH ₃ ) ₅ Cl] Cl ₂ , [Ru (NH ₃ ) ₆ ] Cl ₂ , [Ru (NH ₃ ) ₆ ] Cl ₃ , [Ru (NH ₃ ) ₆ ] Br ₃ ; Ammine complexes; Ru (CO) ₅ , Ru ₃ (CO) ₁₂ carbonyl complexes; [Ru ₃ O (OCOCH ₃ ) ₆ (H ₂ Carboxylato complexes such as O) ₃ ] OCOCH ₃ and [Ru ₂ (OCOR) ₄ ] Cl (R = an alkyl group having 1 to 3 carbon atoms); phosphine complexes; amine complexes; acetylacetonato complexes and the like. In addition, as a ruthenium compound, the hydrate may be sufficient and the 2 or more types of mixture which consists of arbitrary combinations of these may be sufficient. Among these, an oxide is preferable, that is, a catalyst in which ruthenium oxide and silica are supported on a carrier is preferable as a catalyst. The ruthenium oxidation number in the supported ruthenium oxide is usually +4, and the ruthenium oxide is ruthenium dioxide (RuO ₂ ), but other ruthenium oxides or other forms of ruthenium oxide are included. Also good. Depending on the reaction conditions, in the catalyst, the supported ruthenium may become ruthenium oxide after the reaction, or the supported ruthenium compound may become metal ruthenium.

  Examples of the support in the reforming catalyst include metal oxides such as titania, zirconia, niobium oxide, magnesia, alumina, calcium oxide, and lanthanum oxide, and if necessary, use two or more of them. You can also. Of these, titania is preferable. As such a carrier, a powdery or sol-like carrier kneaded and molded, and then fired can be used. The calcined carrier can be prepared based on a known method. For example, a powdery carrier or a sol-like carrier is kneaded with a molding aid such as an organic binder and water, and extruded into a noodle shape. It can be prepared by drying, crushing to obtain a molded body, and then firing the obtained molded body in an oxidizing gas atmosphere such as air.

  Further, as titania, it is composed of rutile type titania (titania having a rutile type crystal structure), anatase type titania (titania having anatase type crystal structure), amorphous titania, etc., or a mixture thereof. It may be a thing. In the present invention, a titania carrier composed of rutile titania and / or anatase titania is preferable. Among them, the ratio of rutile titania to the total of rutile titania and anatase titania in the titania carrier (hereinafter referred to as a rutile titania ratio). Is preferably 20% or more of titania carrier, more preferably 30% or more titania carrier, and still more preferably 90% or more titania carrier. The higher the rutile titania ratio, the better the catalytic activity of the resulting catalyst. The rutile-type titania ratio can be measured by an X-ray diffraction method (hereinafter referred to as XRD method) and is represented by the following formula (1).

Rutile titania ratio [%] = _{[I R / (I A + I} R) ] × 100 (1)

I _R : Intensity of diffraction line showing rutile type titania (110) plane I _A : Intensity of diffraction line showing anatase type titania (101) plane

Examples of the reforming catalyst in the present invention include those shown in the following (i) to (iv).
(I) A material obtained by supporting a silicon compound on a carrier, then supporting a raw material ruthenium compound, and then firing in an oxidizing gas atmosphere.
(Ii) A titanium compound and a silicon compound are heat-treated in an oxidizing gas atmosphere to obtain a titania carrier on which silica is supported, and after the raw material ruthenium compound is supported on the carrier, an oxidizing gas and a reducing gas are obtained. Or obtained by firing in an inert gas atmosphere.
(Iii) A material obtained by supporting a raw material ruthenium compound on a carrier, then supporting a silicon compound, and then firing in an oxidizing gas atmosphere.
(Iv) What is obtained by supporting a silicon compound and a raw material ruthenium compound on a carrier and then firing in an oxidizing gas atmosphere.

In (i), the silicon compound is supported and then fired in an oxidizing gas atmosphere. In (iii), the raw material ruthenium compound is supported and then fired in an oxidizing gas atmosphere. You can also. In (ii), examples of the titanium compound include titanium chloride (TiCl ₄ ) and titanium bromide (TiBr ₄ ). After the treatments (i) to (iv), the ruthenium compound supported on the carrier can be appropriately reduced to ruthenium using a reducing gas. In the present invention, among the catalysts obtained in (i) to (iv), the catalyst obtained in (i) or (ii) is particularly preferable.

Examples of the silicon compound include silicon alkoxide compounds such as Si (OR) ₄ (hereinafter, R represents an alkyl group having 1 to 4 carbon atoms), silicon chloride (SiCl ₄ ), silicon bromide (SiBr ₄ ), and the like. And silicon halide alkoxide compounds such as SiCl (OR) ₃ , SiCl ₂ (OR) ₂ , and SiCl ₃ (OR). Moreover, the hydrate may be used as needed and 2 or more types thereof may be used. In the present invention, among them, a silicon alkoxide compound is preferable, and tetraethyl orthosilicate (Si (OC ₂ H ₅ ) ₄ ) is more preferable.

Examples of the raw material ruthenium compound include a halide such as RuCl ₃ and RuBr _3, a halogeno acid salt such as K ₃ RuCl ₆ and K ₂ RuCl _6, an oxo acid salt such as K ₂ RuO ₄ , Ru ₂ OCl ₄ and Ru. Oxyhalides such as ₂ OCl ₅ and Ru ₂ OCl ₆ , K ₂ [RuCl ₅ (H ₂ O) ₄ ], [RuCl ₂ (H ₂ O) ₄ ] Cl, K ₂ [Ru ₂ OCl ₁₀ ], Cs ₂ Halogeno complexes such as [Ru ₂ OCl ₄ ], [Ru (NH ₃ ) ₅ H ₂ O] Cl ₂ , [Ru (NH ₃ ) ₅ Cl] Cl ₂ , [Ru (NH ₃ ) ₆ ] Cl ₂ , [Ru Ammine complexes such as (NH ₃ ) ₆ ] Cl ₃ , [Ru (NH ₃ ) ₆ ] Br ₃ , carbonyl complexes such as Ru (CO) ₅ and Ru ₃ (CO) ₁₂ , [Ru ₃ O (OCOCH ₃ ) _{6 (H 2 O) 3] OCOCH} 3, [Ru 2 (OCOR) 4 Cl (R = alkyl group having 1 to 3 carbon atoms) such as carboxylato _{complexes, K 2 [RuCl 5 (NO} )], [Ru (NH 3) 5 (NO)] Cl 3, [Ru (OH) (NH ₃ ) ₄ (NO)] (NO ₃ ) ₂ , [Ru (NO)] (NO ₃ ) _{3 and} the like, nitrosyl complexes, phosphine complexes, amine complexes, acetylacetonato complexes and the like. Of these, halides are preferably used, and chlorides are particularly preferably used. In addition, as a raw material ruthenium compound, the hydrate may be used as needed and those 2 or more types may be used.

  In preparing the reforming catalyst, the carrier may be loaded with a silicon compound or a raw material ruthenium compound by impregnating the carrier with a solution obtained by dissolving each compound in an appropriate solvent, or by adding the carrier to the solution. Examples include a method of immersing and adsorbing each compound.

  When impregnating or dipping as described above, the temperature is usually 0 to 100 ° C., preferably 0 to 50 ° C., and the pressure is usually 0.1 to 1 MPa, preferably atmospheric pressure. Further, such impregnation or immersion can be performed in an air atmosphere or an inert gas atmosphere such as nitrogen, helium, argon, oxygen dioxide, and may contain water vapor. From the viewpoint of handling, it is preferable to carry out in the inert gas atmosphere.

  When a silicon compound is supported on a carrier, it is usually dried and then fired after impregnation or immersion as described above. As the drying method, a conventionally known method can be adopted, and the temperature is usually from room temperature to about 100 ° C., and the pressure is usually from 0.001 to 1 MPa, preferably atmospheric pressure. Such drying can be performed in an air atmosphere or an inert gas atmosphere such as nitrogen, helium, argon, or oxygen dioxide, and may contain water vapor. From the viewpoint of handling, it is preferable to carry out in the inert gas atmosphere.

  The oxidizing gas is a gas containing an oxidizing substance, and examples thereof include an oxygen-containing gas. The oxygen concentration is usually about 1 to 30% by volume. As the oxygen source, air or pure oxygen is usually used, and diluted with an inert gas or water vapor as necessary. Of these, air is preferable as the oxidizing gas. Moreover, a calcination temperature is 100-1000 degreeC normally, Preferably it is 250-450 degreeC.

  The reducing gas is a gas containing a reducing substance, and examples thereof include a hydrogen-containing gas, a carbon monoxide-containing gas, and a hydrocarbon-containing gas. The concentration is usually about 1 to 30% by volume, and the concentration is adjusted with, for example, an inert gas or water vapor. Among them, the reducing gas is preferably a hydrogen-containing gas or a carbon monoxide-containing gas. Moreover, a calcination temperature is 100-1000 degreeC normally, Preferably it is 200-500 degreeC.

  Examples of the inert gas include nitrogen, carbon dioxide, helium, argon, and the like, and diluted with water vapor as necessary. Among these, nitrogen and carbon dioxide are preferable as the inert gas. In (ii) above, the firing temperature when firing in an inert gas atmosphere is usually 100 to 1000 ° C, preferably 200 to 600 ° C.

In the method (ii), a method for preparing a titania carrier in which silica is supported on titania by heat-treating a titanium compound and a silicon compound is, for example, according to the method described in JP-A-2004-210586. Can do. As a specific example thereof, titanium halide and silicon halide gasified at 600 ° C. or higher are heat-treated in the presence of oxygen at 600 ° C. or higher or in the presence of oxygen and water vapor, and then the obtained powder is 300 Examples include a method of obtaining a powdery titania carrier on which silica is supported by heat treatment at ˜600 ° C. The obtained titania carrier is preferably kneaded, molded, and then fired. The calcined titania carrier can be prepared based on a known method, for example, a powdery titania carrier is kneaded with a molding aid such as an organic binder and water, extruded into noodles, dried, It can be prepared by crushing to obtain a compact, and then firing the resulting compact in an oxidizing gas atmosphere such as air. Further, titanium chloride (TiCl ₄ ) is preferably used as the titanium halide, and silicon chloride (SiCl ₄ ) is preferably used as the silicon halide.

  In the reforming catalyst, the amount of silica supported on the support is usually 0.001 to 0.3 mol, preferably 0.004 to 0.03 mol, relative to 1 mol of the support. The usage ratio of the silicon compound and the carrier is adjusted as appropriate.

  In the reforming catalyst, the content ratio (ruthenium component / support) selected from the group consisting of ruthenium and a ruthenium compound with respect to the support is usually 0.1 / 99.9 to 20/80, preferably as a weight ratio. Is 0.5 / 99.5 to 15/85, and the use ratio of the raw material ruthenium compound and the carrier is appropriately adjusted so as to be in this range. If the ruthenium component is too small, the catalytic activity may not be sufficient, and if it is too much, the cost is disadvantageous.

  In addition, the silicon compound and the raw material ruthenium compound are used so that at least one selected from the group consisting of ruthenium and a ruthenium compound in the reforming catalyst is 0.1 to 4 mol per 1 mol of supported silica. The amount is preferably adjusted, and more preferably adjusted to 0.3 to 2 mol. If the number of moles of the ruthenium component relative to 1 mole of silica is too high, the thermal stability of the resulting catalyst may be low, and if it is too low, the catalyst activity may be low.

The BET specific surface area of the reforming catalyst is usually 1 to 300 m ² / g, preferably 5 to 50 m ² / g. If the BET specific surface area is too large, the carrier and ruthenium component in the resulting catalyst are likely to sinter and thermal stability may be lowered. On the other hand, if the BET specific surface area is too small, the ruthenium component in the resulting catalyst is difficult to disperse and the catalyst activity may be lowered. The BET specific surface area is a value obtained by measurement using a specific surface area measuring device based on a nitrogen adsorption method.

  The pore volume of the reforming catalyst is usually 0.05 to 1.5 ml / g, preferably 0.1 to 1.0 ml / g. If the pore volume is too small, the pore diameter is too small, and the activity may be low. On the other hand, if the pore volume is too large, the strength of the catalyst may be reduced, which may hinder stable synthesis gas production. The pore volume is a value obtained by measurement by the Hg intrusion method.

  The catalyst may be used in the form of a spherical particle, a cylindrical pellet, an extruded shape, a ring shape, a honeycomb shape, or an appropriately sized granule that has been pulverized and classified after molding. At this time, the diameter of the catalyst is preferably 5 mm or less. If the catalyst diameter is too large, the conversion of hydrocarbons may be low. The lower limit of the diameter of the catalyst is not particularly limited, but if it becomes excessively small, pressure loss in the catalyst layer increases, and therefore, a catalyst having a diameter of 0.5 mm or more is usually used. The diameter of the catalyst here means the diameter of a sphere in the case of spherical particles, the diameter of a circular cross section in the case of a cylindrical pellet, and the maximum diameter of the cross section in other shapes.

  When the reforming catalyst is used, it can be diluted with titania, alumina, zirconia, silica or the like.

  By reforming the hydrocarbon with carbon dioxide in the presence of the reforming catalyst thus produced, a synthesis gas containing hydrogen and carbon monoxide can be efficiently produced. When the reforming catalyst is supported on the support together with the ruthenium component and silica, the support or the ruthenium component supported on the support is sintered (sintered) by applying a heat load such as being used for a long-time reforming reaction. Ring) is suppressed, and a decrease in catalytic activity caused by such sintering can be suppressed.

  Examples of the hydrocarbon include hydrocarbons having 1 to 5 carbon atoms such as methane, ethane, ethylene, propane, propylene, butane, butene, isobutane, isobutylene, pentane, pentene, isopentane, isopentene, and the like. Although the above may be used, hydrocarbons mainly composed of methane and / or ethane are preferably used. The total content of methane and / or ethane in the hydrocarbon mainly composed of methane and / or ethane is usually an amount exceeding 50% by volume, preferably 90% by volume or more, more preferably 100% by volume. It is. In the present invention, natural gas containing carbon dioxide can also be used as a reaction raw material.

  The hydrocarbon may be diluted with a gas inert to the reforming reaction such as nitrogen gas or argon gas. In that case, the concentration of hydrocarbon in the diluted hydrocarbon gas is usually 1% by volume or more, preferably Is 2% by volume or more.

  The ratio of carbon dioxide to the raw material hydrocarbon is 0.1 to 20 moles, preferably 0.5 to 10 moles of carbon dioxide per mole of carbon in the raw material. If the amount of carbon dioxide is too small, the reforming reaction will hardly proceed, and synthesis gas may not be produced efficiently.

  The reaction temperature in the reforming is usually 300 to 1200 ° C, preferably 350 to 700 ° C, more preferably 450 to 650 ° C. If the reaction temperature is too low, the activity may be lowered and the equilibrium conversion rate may be lowered. On the other hand, if it is too high, the activity of the catalyst may be deteriorated.

  The reaction pressure in the reforming is usually 0.01 to 5 MPa, preferably 0.01 to 2 MPa. When the reaction pressure is lower than 0.01 MPa, productivity may be lowered, and when it is higher than 5 MPa, it may be disadvantageous in equilibrium.

As a reaction method in reforming, various methods such as a fixed bed method, a fluidized bed method, and a moving bed method can be adopted, and a fixed bed method is preferable. When the reaction is carried out in a fixed bed system, the supply rate of hydrocarbons and carbon dioxide is the gas supply rate per liter of catalyst (L / h; 0 ° C., converted to 1 atm), that is, GHSV (Gas Hourly Space Velocity). represent, 10~20000h ^-1, preferably 1000~10000h ^-1.

As mentioned above, although preferred embodiment concerning this invention was shown, it cannot be overemphasized that this invention is applicable to what was changed and improved in the range which is not limited to embodiment mentioned above and does not deviate from the summary of this invention. .

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example. In the following examples, the part representing the content or amount used is based on weight unless otherwise specified. In the following examples, the gas supply rate (ml / min) is a converted value of 0 ° C. and 1 atm unless otherwise specified.

Reference example 1
(Preparation of carrier)
First, 100 parts of titania powder [“F-1R” manufactured by Showa Titanium Co., Ltd., rutile-type titania ratio 93%] and 2 parts of organic binder [“YB-152A” manufactured by Yuken Industry Co., Ltd.] were mixed. Next, 29 parts of pure water and 12.5 parts of titania sol [“CSB” manufactured by Sakai Chemical Co., Ltd., titania content 40 wt%] were added and kneaded to obtain a mixture.

  This mixture was extruded into a noodle shape having a diameter of 3.0 mmφ, dried at 60 ° C. for 2 hours, and then a rotary non-bubbling kneader (“NBK-1” manufactured by Nippon Seiki Seisakusho Co., Ltd.) was used as a crusher. The compact was obtained by crushing to a thickness of about 3 to 5 mm. The obtained molded body was heated in air from room temperature to 600 ° C. over 1.7 hours and then calcined by holding at the same temperature for 3 hours.

(Impregnation of silicon compound into support)
A solution prepared by dissolving 3.55 g of tetraethyl orthosilicate [Si (OC ₂ H ₅ ) ₄ ] manufactured by Wako Pure Chemical Industries, Ltd. in 14.6 g of ethanol in 100.0 g of the obtained fired product. Impregnated.

  The same operation as the above (impregnation of the silicon compound into the carrier) was repeated a total of 8 times to obtain a total of 934 g of a white solid. This white solid was allowed to stand at 20 to 30 ° C. for 20 hours in an air atmosphere. 808 g of the obtained solid was heated from room temperature to 300 ° C. over 0.8 hours in an air atmosphere and then calcined by holding at the same temperature for 2 hours. The silica content was 1.0% by weight. A white titania carrier was obtained. This carrier contains titania in a ratio of 99% with respect to the total amount of the carrier. Further, in the titania contained in the carrier, the ratio of the rutile type titania is 90% or more.

(Production of supported ruthenium oxide)
To 100.0 g of the titania carrier obtained above, 2.43 g of ruthenium chloride hydrate (RuCl ₃ · nH ₂ O manufactured by NE Chemcat Co., Ltd., Ru content 40.0 wt%) was added to 22.1 g of pure water. It was impregnated with an aqueous solution prepared by dissolving in, and allowed to stand at 20 to 33 ° C. in an air atmosphere for 15 hours or more and air-dried. The obtained solid (103.3 g) was heated from room temperature to 250 ° C. over 1.3 hours under air flow, and then held at the same temperature for 2 hours and calcined. As a result, 100.7 g of supported ruthenium oxide having a ruthenium oxide content of 1.25% by weight, that is, a supported ruthenium oxide in which ruthenium oxide and silica are supported on a support was obtained.

  Then, the same operation as the above (manufacture of supported ruthenium oxide) was repeated a total of 8 times to obtain a total of 806 g of supported ruthenium oxide.

Example 1
<Catalyst filling>
The lower part of a 14 mm inner diameter SUS reaction tube provided with a thermometer sheath tube with an outer diameter of 3 mm was filled with quartz wool as a partition material, and then a 2 mmφ α-alumina ball [“SSA995” manufactured by Nikkato Corporation, BET specific surface area of less than 0.1 m ² / g] was charged from the top of the reaction tube. Further, 1 g (0.74 ml) of the supported ruthenium oxide obtained above was charged from the upper part of the reaction tube. Next, 20 g of α-alumina balls having a diameter of 2 mm (“SSA995” manufactured by Nikkato Co., Ltd., BET specific surface area of less than 0.1 m ² / g) were charged from the upper part of the reaction tube.

<Manufacture of synthesis gas>
While supplying nitrogen gas at a rate of 143 ml / min from the inlet of the reaction tube filled with the catalyst, the reaction tube was heated in an electric furnace to bring the temperature of the catalyst layer to 600 ° C. Then, the supply of nitrogen gas was stopped, carbon dioxide gas from the inlet of the reaction tube was 25 ml / min (0.067 mol / h), and methane gas diluted to 3.5% by volume with nitrogen was 143 ml / min (0 as methane). .013 mol / h), and the reaction was started at a reaction pressure of 0.1 MPa.

After the start of the reaction, the temperature of the catalyst layer was maintained at 581 to 585 ° C. by endotherm. When 5 minutes, 30 minutes, and 60 minutes have elapsed from the start of the reaction, the reaction tube outlet gas is collected with a gas syringe, analyzed by gas chromatography having a TCD detector, and each component contained in the reaction tube outlet gas Was quantified. The components in the reaction tube outlet gas were confirmed to be carbon monoxide, hydrogen, methane, carbon dioxide and nitrogen. From the methane supply flow rate (mol / h) and the methane flow rate (mol / h) in the reaction tube outlet gas, the conversion rate (%) of methane was calculated by the following equation (I). Further, the H ₂ / CO ratio (molar ratio) was calculated from the following formula (II) from the hydrogen production rate (mol / h) and the carbon monoxide production rate (mol / h) in the reaction tube outlet gas. . The results are shown in Table 1.

  Methane conversion rate (%) = [(ab) / a] × 100 (I)

a: Supply flow rate of methane (mol / h)
b: Methane flow rate in reaction tube outlet gas (mol / h)

H ₂ / CO ratio (molar ratio) = c / d (II)

c: Hydrogen production rate (mol / h)
d: Carbon monoxide production rate (mol / h)

Example 2
In <Production of synthesis gas>, the reaction tube was heated in an electric furnace while supplying nitrogen gas at a rate of 143 ml / min from the inlet of the catalyst-filled reaction tube, and the temperature of the catalyst layer was 410 ° C. The synthesis gas was produced in the same manner as in Example 1. After the start of the reaction, the temperature of the catalyst layer was maintained at 404 ° C. by endotherm. Table 2 shows the results of calculating the conversion rate (%) of methane and the H ₂ / CO ratio (molar ratio).

Example 3
In <Production of synthesis gas>, except that nitrogen gas was supplied from the inlet of the reaction tube filled with catalyst at a rate of 143 ml / min, the reaction tube was heated in an electric furnace, and the temperature of the catalyst layer was changed to 510 ° C. The reaction was performed in the same manner as in Example 1. After the start of the reaction, the temperature of the catalyst layer was maintained at 502 to 503 ° C. by endotherm. Table 3 shows the results of calculating the conversion rate (%) of methane and the H ₂ / CO ratio (molar ratio).

Example 4
<Catalyst filling>
Catalyst filling was carried out in the same manner as in Example 1.
<Manufacture of synthesis gas>
While supplying nitrogen gas at a rate of 100 ml / min from the inlet of the reaction tube filled with the catalyst, the reaction tube was heated in an electric furnace to bring the temperature of the catalyst layer to 620 ° C. Then, the supply of nitrogen gas was stopped, carbon dioxide gas was supplied from the inlet of the reaction tube at 90 ml / min (0.24 mol / h), and ethane gas was supplied at 10 ml / min (ethane as 0.027 mol / h), and the reaction pressure was 0 The reaction was started at 1 MPa.

After the start of the reaction, the temperature of the catalyst layer was maintained at 600 ° C. by endotherm. When 15 minutes and 131 minutes had elapsed from the start of the reaction, the reaction tube outlet gas was collected with a gas syringe and analyzed by gas chromatography having a TCD detector to quantify each component contained in the reaction tube outlet gas. . The components in the reaction tube outlet gas were confirmed to be carbon monoxide, hydrogen, methane and carbon dioxide. The reaction tube outlet gas composition is shown in Table 4. From the ethane supply flow rate (mol / h) and the ethane flow rate (mol / h) in the reaction tube outlet gas, the conversion rate (%) of ethane was calculated by the following formula (III). Further, the H ₂ / CO ratio (molar ratio) was calculated from the above formula (II) from the hydrogen production rate (mol / h) and the carbon monoxide production rate (mol / h) in the reaction tube outlet gas. . The results are shown in Table 4.

  Conversion of ethane (%) = [(e−f) / e] × 100 (III)

e: Supply flow rate of ethane (mol / h)
f: Flow rate of ethane in the reaction tube outlet gas (mol / h)

Example 5
Following Example 4, the reaction was carried out. When 140 minutes passed from the start of the reaction in Example 4, the temperature of the electric furnace was adjusted, the temperature of the catalyst layer was lowered to 500 ° C. over 30 minutes, and when 25 minutes passed, the reaction tube outlet gas was changed to Each component contained in the reaction tube outlet gas was quantified by collecting with a gas syringe and analyzing with a gas chromatography having a TCD detector. The components in the reaction tube outlet gas were confirmed to be carbon monoxide, hydrogen, methane and carbon dioxide. Table 5 shows the results of calculating the ethane conversion rate (%) and H ₂ / CO ratio (molar ratio) in the same manner as in Example 4 together with the reaction tube outlet gas composition.

Example 6
Subsequent to Example 5, the reaction was performed. When 215 minutes have passed since the start of the reaction in Example 4, the temperature of the electric furnace was adjusted, the temperature of the catalyst layer was lowered to 400 ° C. over 30 minutes, and when 25 minutes passed, the reaction tube outlet gas was changed to Each component contained in the reaction tube outlet gas was quantified by collecting with a gas syringe and analyzing with a gas chromatography having a TCD detector. The components in the reaction tube outlet gas were confirmed to be carbon monoxide, hydrogen, methane, carbon dioxide and ethane. Table 5 shows the results of calculating the ethane conversion rate (%) and H ₂ / CO ratio (molar ratio) in the same manner as in Example 4 together with the reaction tube outlet gas composition.

Example 7
The reaction was carried out following Example 6. When 270 minutes passed from the start of the reaction in Example 4, the temperature of the electric furnace was adjusted, the temperature of the catalyst layer was raised to 600 ° C. over 10 minutes, and when 5 minutes passed, the reaction tube outlet gas was changed to Each component contained in the reaction tube outlet gas was quantified by collecting with a gas syringe and analyzing with a gas chromatography having a TCD detector. The components in the reaction tube outlet gas were confirmed to be carbon monoxide, hydrogen, methane and carbon dioxide. Table 6 shows the results of calculating the ethane conversion rate (%) and the H ₂ / CO ratio (molar ratio) in the same manner as in Example 4 together with the reaction tube outlet gas composition.

Example 8
The reaction was carried out following Example 7. When 335 minutes have elapsed since the start of the reaction in Example 4, the reaction pressure was adjusted to 0.5 MPa, and when 16 minutes had elapsed, the reaction tube outlet gas was collected with a gas syringe and had a TCD detector. Each component contained in the reaction tube outlet gas was quantitatively analyzed by gas chromatography. The components in the reaction tube outlet gas were confirmed to be carbon monoxide, hydrogen, methane and carbon dioxide. Table 6 shows the results of calculating the ethane conversion rate (%) and the H ₂ / CO ratio (molar ratio) in the same manner as in Example 4 together with the reaction tube outlet gas composition.

Example 9
Subsequent to Example 8, the reaction was performed. When 360 minutes have elapsed since the start of the reaction in Example 4, the reaction pressure was adjusted to 0.25 MPa, and when 18 minutes had elapsed, the reaction tube outlet gas was sampled with a gas syringe and had a TCD detector. Each component contained in the reaction tube outlet gas was quantitatively analyzed by gas chromatography. The components in the reaction tube outlet gas were confirmed to be carbon monoxide, hydrogen, methane and carbon dioxide. Table 6 shows the results of calculating the ethane conversion rate (%) and the H ₂ / CO ratio (molar ratio) in the same manner as in Example 4 together with the reaction tube outlet gas composition.

Example 10
Following Example 9, the reaction was carried out. When 380 minutes passed from the start of the reaction in Example 4, the temperature of the electric furnace was adjusted, the temperature of the catalyst layer was lowered to 500 ° C. over 20 minutes, and the supply amount of carbon dioxide gas was 30 ml / minute (0. The reaction tube outlet gas was sampled with a gas syringe at the time when another 60 minutes had passed, and analyzed by gas chromatography having a TCD detector, and each contained in the reaction tube outlet gas. Ingredients were quantified. The components in the reaction tube outlet gas were confirmed to be carbon monoxide, hydrogen, methane, carbon dioxide and ethane. Table 7 shows the results of calculating the ethane conversion rate (%) and the H ₂ / CO ratio (molar ratio) in the same manner as in Example 4 together with the reaction tube outlet gas composition.

Example 11
Subsequent to Example 10, the reaction was performed. When 460 minutes have elapsed from the start of the reaction in Example 4, the supply amount of carbon dioxide gas was adjusted to 10 ml / min (0.03 mol / h), and when 46 minutes had elapsed, the reaction tube outlet gas was gas. It collected with the syringe and analyzed with the gas chromatography which has a TCD detector, and quantified each component contained in reaction tube exit gas. The components in the reaction tube outlet gas were confirmed to be carbon monoxide, hydrogen, methane, carbon dioxide and ethane. Table 7 shows the results of calculating the ethane conversion rate (%) and the H ₂ / CO ratio (molar ratio) in the same manner as in Example 4 together with the reaction tube outlet gas composition.

Claims (6)

  A synthesis gas containing hydrogen and carbon monoxide that reforms hydrocarbons with carbon dioxide in the presence of a reforming catalyst in which at least one selected from the group consisting of ruthenium and ruthenium compounds and silica are supported on a carrier. Production method.   The manufacturing method according to claim 1, wherein the carrier is titania.   The method of claim 2, wherein the titania contains rutile crystalline titania.   The production method according to claim 3, wherein a ratio of the rutile crystal titania in the titania measured by X-ray diffraction method is 20% or more with respect to the total of the rutile crystal titania and the anatase crystal titania.   The production method according to claim 1, wherein the hydrocarbon is at least one selected from the group consisting of methane and ethane.   The reforming temperature is 350 to 700 ° C. The production method according to any one of claims 1 to 5.