WO2004103555A1

WO2004103555A1 - Oxyhydrocarbon reforming catalyst, process for producing hydrogen or synthetic gas therewith and fuel cell system

Info

Publication number: WO2004103555A1
Application number: PCT/JP2004/006903
Authority: WO
Inventors: Koichi Eguchi
Original assignee: Idemitsu Kosan Co., Ltd.
Priority date: 2003-05-20
Filing date: 2004-05-14
Publication date: 2004-12-02
Also published as: KR20060009366A; KR101016891B1; TW200500138A; JP2005342543A; JP4774197B2; TWI351312B

Abstract

An oxyhydrocarbon reforming catalyst which contains copper, excels in heat resistance and is markedly improved in the activity per area; and a process for producing hydrogen or synthetic gas therewith. There is further provided a fuel cell system including a reforming unit having the excellent reforming catalyst accommodated therein and a fuel cell using hydrogen produced by the reforming unit as fuel. In particular, the oxyhydrocarbon reforming catalyst contains a metal oxide containing copper and having spinel structure, or contains the same and a solid acid substance. There is further provided a process for producing hydrogen or synthetic gas by carrying out any of steam reforming (1), self thermal reforming (2), partial oxidation reforming (3) and carbon dioxide reforming (4) of an oxyhydrocarbon with the use of the above reforming catalyst. Still further, there is provided a fuel cell system including a reforming unit having the above excellent reforming catalyst accommodated therein and a fuel cell using hydrogen produced by the reforming unit as fuel.

Description

Description Oxygen-containing hydrocarbon reforming catalyst, method for producing hydrogen or synthesis gas using the same, and fuel cell system

The present invention relates to an oxygen-containing hydrocarbon reforming catalyst, a method for producing hydrogen or synthetic gas using the same, and a fuel cell system, and more specifically, a metal oxide having a copper-containing spinel structure having excellent heat resistance, Or a reforming catalyst of an oxygen-containing hydrocarbon containing this and a solid acidic substance and having a greatly improved activity per unit surface area, and performing various reforms on the oxygen-containing hydrocarbon using the reforming catalyst, The present invention relates to a method for efficiently producing hydrogen or synthesis gas, and a fuel cell system using the reforming catalyst. Background art

Synthetic gas is composed of carbon monoxide and hydrogen, and is used as a raw material gas for methanol synthesis, oxo synthesis, Fischer-Tropsch synthesis, etc., and is also widely used as a raw material for ammonia synthesis and various chemical products.

This synthesis gas has conventionally been produced by gasification of coal or by steam reforming or partial oxidation reforming of hydrocarbons using natural gas as a raw material. However, coal gasification methods had problems such as the necessity of a complicated and expensive coal gasifier and a large-scale plant. In addition, in the hydrocarbon steam reforming method, the reaction involves a large endotherm, so a high temperature of about 700 to 120 ° C is required for the progress of the reaction, and a special reforming furnace is required. In addition, there is a problem that the catalyst used is required to have high heat resistance. In addition, high temperatures are required for partial oxidation reforming of hydrocarbons. To do so, a special partial oxidation furnace was required, and a large amount of soot was generated during the reaction, which caused problems in its treatment and deterioration of the catalyst.

In order to solve such a problem, in recent years, attempts have been made to produce a synthesis gas by using an oxygen-containing hydrocarbon such as dimethyl ether as a raw material and subjecting it to various reforming.

On the other hand, in recent years, new energy technologies have been spotlighted due to environmental issues, and fuel cells are attracting attention as one of the new energy technologies. This fuel cell converts chemical energy into electric energy by electrochemically reacting hydrogen and oxygen, and has the characteristic of high energy use efficiency. Practical research is being actively conducted on industrial and automotive applications.

Hydrogen sources for this fuel cell include liquefied natural gas mainly composed of methanol and methane, city gas mainly composed of natural gas, synthetic liquid fuel derived from natural gas, and petroleum naphtha and kerosene. Research on petroleum hydrocarbons has been conducted.

When hydrogen is produced using these petroleum hydrocarbons, the hydrocarbons are generally subjected to a steam reforming treatment or a partial oxidation reforming treatment in the presence of a catalyst. The following problems occur. Therefore, in the production of hydrogen, various methods using an oxygen-containing hydrocarbon such as dimethyl ether as a raw material have been attempted.

A variety of catalysts have been disclosed for the production of hydrogen and synthesis gas by using oxygen-containing hydrocarbons such as dimethyl ether as raw materials and subjecting them to various reforming processes. As a technology for reforming an oxygen-containing hydrocarbon using a Cu-based catalyst, for example, a catalyst for producing a synthesis gas from an oxygen-containing hydrocarbon and carbon dioxide using a Cu-containing catalyst, A method for producing a synthesis gas used (see, for example, Japanese Patent Application Laid-Open No. 10-174869), a catalyst for producing hydrogen from an oxygen-containing hydrocarbon and steam using a Cu-containing catalyst, and a catalyst using the same A method for producing hydrogen (for example, see Japanese Patent Application Laid-Open No. H10-174871), a catalyst for reforming an oxygen-containing hydrocarbon comprising a solid acid on which a metal containing Cu is supported (for example, see 200 1-96 159, Japanese Patent Application Laid-Open No. 2001-91660), to produce hydrogen from oxygen-containing hydrocarbons and steam, which consist of a mixture of a Cu-containing substance and a solid acidic substance A catalyst and a method for producing hydrogen using the same (see, for example, Japanese Patent Application Laid-Open Publication No. 2003-10684), from an oxygen-containing hydrocarbon and steam comprising a mixture of a Cu-containing substance and a solid acidic substance. Catalyst for producing synthesis gas and method for producing synthesis gas using the same (see, for example, JP-A-2003-33 No. 656) is disclosed.

However, the Cu-based catalysts used in these technologies all have insufficient heat resistance, so that increasing the reaction temperature in order to increase the reaction activity inevitably leads to catalyst deterioration. was there. Disclosure of the invention

The present invention has been made under such circumstances, and is intended to provide an oxygen-containing hydrocarbon reforming catalyst containing copper, having excellent heat resistance, and having greatly improved activity per unit surface area. It is an object of the present invention to provide a method for efficiently producing hydrogen or a synthesis gas by subjecting an oxygen-containing hydrocarbon to various reforming using the same. It is another object of the present invention to provide an excellent fuel cell system comprising a reformer provided with such an excellent reforming catalyst and a fuel cell using hydrogen produced by the reformer as a fuel. Things.

The present inventor has conducted intensive studies to achieve the above object, and as a result, the copper-containing catalyst has a spinel structure. By combining a catalyst and a solid acidic substance, it has been found that a catalyst having a high heat resistance and a significantly improved activity per unit surface area can be obtained, and the object can be achieved. The present invention has been completed based on such findings.

That is, the present invention

(1) An oxygen-containing hydrocarbon reforming catalyst containing copper and a metal oxide having a spinel structure (hereinafter, referred to as reforming catalyst I),

(2) an oxygen-containing hydrocarbon reforming catalyst (hereinafter, referred to as reforming catalyst II) comprising copper, a metal oxide having a spinel structure, and a solid acidic substance.

(3) The reforming catalyst for an oxygen-containing hydrocarbon according to (1) or (2), wherein the metal oxide containing copper and having a spinel structure is a 〇11- ^ 111 type spinel,

(4) The oxygen-containing hydrocarbon reforming catalyst according to (1) or (2), wherein the metal oxide containing copper and having a spinel structure is a 〇11 -6 type spinel,

(5) The oxygen-containing hydrocarbon reforming catalyst according to (1) or (2) above, wherein the metal oxide containing copper and having a spinel structure is a {11-1: 1: type spinel;

(6) The reforming catalyst for an oxygen-containing hydrocarbon according to (1) or (2), wherein the metal oxide containing copper and having a spinel structure is a Cu—Mn—Fe spinel.

(7) The reforming catalyst for an oxygen-containing hydrocarbon according to the above (2), wherein the solid acidic substance is alumina,

(8) An oxygen-containing hydrocarbon reforming catalyst obtained by reducing the reforming catalysts of (1) and (2) above,

(9) The above (1), wherein the oxygen-containing hydrocarbon is at least one selected from methanol, ethanol, dimethyl ether and methylethyl ether.

(2) an oxygen-containing hydrocarbon reforming catalyst,

(10) Using the reforming catalysts of (1) and (2) above, evaporate oxygen-containing hydrocarbons into permanent steam. A method for producing hydrogen or synthesis gas, characterized by reforming

(1 1) A method for producing hydrogen or synthesis gas, wherein the oxygen-containing hydrocarbon is autothermally reformed using the reforming catalyst according to (1) or (2).

(1 2) A method for producing hydrogen or synthesis gas, comprising partially oxidizing and reforming an oxygen-containing hydrocarbon using the reforming catalyst according to (1) or (2).

(13) A method for producing hydrogen or synthesis gas, comprising reforming oxygen-containing hydrocarbons with carbon dioxide using the reforming catalysts of (1) and (2) above, and

(14) A fuel cell system comprising: a reformer provided with the reforming catalyst according to the above (1) and (2); and a fuel cell using hydrogen produced by the reformer as a fuel. ,

Is provided. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic flowchart of the fuel cell system of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

The oxygen-containing hydrocarbon reforming catalyst of the present invention includes (1) a reforming catalyst I containing copper and a metal oxide having a subinel structure, and (2) a copper-containing reforming catalyst having a spinel structure. There are two embodiments of a reforming catalyst II containing a mixture of a metal oxide having the same and a solid acidic substance.

As the oxygen-containing hydrocarbon in the present invention, preferred are alcohols such as methanol and ethanol, and ethers such as dimethyl ether and methylethyl ether. Of these, dimethyl ether is particularly preferred.

In the present invention, the metal oxide having a spinel structure has a cubic system in one typical crystal structure type found in AB ₂ 0 ₄ type metal complex oxide. In the AB ₂ 0 _4, typically A is a divalent metal, B is Ru trivalent metal der.

In the present invention, a metal oxide having a spinel structure containing copper is used. As such a metal oxide, Cu-Mn-type spinel and the like from the viewpoint of catalytic activity and heat resistance. Preferred are 11-6 type spinels and Cu-Cr type spinels. Examples of the C UMN type spinels, for example, C uMn ₂ O _4, etc. can Rukoto cited as the C u _ F e type spinel, and the like for example, C u F e ₂ 0 _4. The C u- C r type spinel, and the like for example, C u C r ₂ 〇 _4. Furthermore, and C u A 1 ₂ 0 _4, ternary C u (F e C r) 2 0 4, C u (F e A 1) 2 O 4, C u (Mn F e) 2 0 4 scan Pinel can also be used. C u (Mn F e) The ₂ O ₄ type _{spinel, C u (Mn 1 5 F} e 0. 5) 0 4, C u (Mn x. 0 F e ^ 0) 〇 _4, C u (M n _{_{2/3 F e 4/3) 0 4,}} C u (Mn 0. 5 F e ^ 5) 0 4 and the like. Such a metal oxide having a spinel structure containing copper has a higher heat resistance than a non-spinel structure metal containing copper, and has a higher catalytic activity per unit surface area when used for reforming an oxygen-containing hydrocarbon. Is much higher.

The oxygen-containing hydrocarbon reforming catalyst I of the present invention contains the above-described metal oxide having a spinel structure containing copper.On the other hand, the oxygen-containing hydrocarbon reforming catalyst I of the present invention contains And a metal oxide having a spinel structure containing copper and a solid acidic substance. The solid acidic substance in the reforming catalyst II is a solid substance exhibiting characteristics of brenstead acid or Lewis acid, and specifically, alumina, silica-alumina, silica 'titania, zeolite, aluminum silicophosphate ( S AP O). These may be used alone or in combination of two or more. Among them, alumina is preferred from the viewpoint of the activity of the obtained catalyst.

Alumina used as this solid acidic substance is commercially available, β, Any one of the crystal forms of 7, θ, and K can be used. Further, those obtained by calcining alumina hydrate such as boehmite, pyrite and gibbsite can also be used. Alternatively, aluminum hydroxide may be precipitated by adding an alkaline buffer solution of about ρΗ8 to 10 to aluminum nitrate and calcining the precipitate, or calcining aluminum chloride. Good. Also, a sol-gel method in which an alkoxide such as aluminum isopropoxide is dissolved in an alcohol such as 2-propanol and an inorganic acid such as hydrochloric acid is added as a catalyst for hydrolysis to prepare an alumina gel, which is dried and calcined. Can also be used.

The reforming catalyst II of the present invention may be a simple mixture of a metal oxide having a spinel structure containing copper and the solid acidic substance, or the solid acidic substance may be used as a carrier, and may contain 鲖. It may carry a metal oxide having a spinel structure. The content of copper in the reforming catalyst II is not particularly limited, but is usually in the range of 1 to 50% by mass, preferably 2 to 30% by mass as Cu in terms of catalytic activity and the like. .

In the reforming catalysts I and II of the present invention, a compound containing copper having a non-spinel structure is optionally contained as a metal oxide having a spinel structure containing copper as long as the object of the present invention is not impaired. Can be used. Next, an example of a method for preparing a reforming catalyst I of the present invention, will be described as an example the case of preparing a catalyst comprising C u M n ₂ 〇 ₄ spinel.

First, a water-soluble copper salt such as copper nitrate is used as a copper source, and a water-soluble manganese salt such as manganese nitrate is used as a manganese source, and these are substantially in a stoichiometric ratio, that is, Cu and Mn. Prepare an aqueous solution containing a molar ratio of substantially 1: 2. Next, a chelating agent such as citric acid is added to the aqueous solution, and the mixture is heated to evaporate the water to form a gel. Next, this gel is subjected to a heat treatment to decompose nitrate, citrate, etc. in the gel, resulting in an oxide. The fine powder is calcined in air at a temperature of about 300 to 500 ° C for about 1 to 5 hours, and then calcined at a temperature of about 500 to 1,000 ° C for about 5 to 15 hours. A catalyst comprising CuMn ₂ O ₄ spinel is obtained. Also when fired at 7 00 ° C higher temperature than is said to be Mn ₂ 0 ₃ and C u _₅ Mn ₅ 0 ₄ scan mixtures Pinel, can be used as catalysts also in this case.

In this method, a copper source can be used such that Cu is in stoichiometric excess with respect to Mn. In this case, the resulting catalyst becomes oxides of copper and (C u ₂ 0 or C u O or a mixture thereof) with a mixture of spinel-type oxides, also this one can be used as the reforming catalyst I You.

Also, when preparing a catalyst comprising C u F e ₂ 0 ₄ spinel, instead of the manganese source, it may be used iron source, such as a water-soluble iron salts such as iron nitrate. Further, by using a mixture of an iron source and a manganese source instead of the manganese source, a catalyst comprising Cu (FeMn) ₂ O ₄ spinel can be obtained. This can of course be used as the reforming catalyst I. These reforming catalysts I are usually used in the form of pellets of an appropriate size.

Next, an example of a method for preparing a reforming catalyst II of the present invention, the alumina support is a solid acidic material will be described with a case C uMn ₂ 0 ₄ spinel you preparing a catalyst comprising supported on example .

First, a water-soluble copper salt such as copper nitrate is used as a copper source, and a water-soluble manganese salt such as manganese nitrate is used as a manganese source, and these are used in a substantially stoichiometric ratio, that is, Cu and Mn. Prepare an aqueous solution containing a molar ratio of substantially 1: 2. Next, a predetermined amount of alumina powder is added to the aqueous solution, uniformly dispersed, and then heated to evaporate water to obtain a powder. Then this The powder is calcined in air at a temperature of about 300 to 500 ° C for about 1 to 5 hours, and then calcined at a temperature of about 500 to 1,000 ° C for about 5 to 15 hours. Thus, a spinel-supported alumina catalyst containing Cu and Mn is obtained.

Further, by using an iron source instead of the manganese source, a CuFe ₂ O ₄ spinel-supported alumina catalyst can be obtained, and by using a mixture of an iron source and a manganese source instead of the manganese source. , it can be obtained Cu (F eMn) ₂ O ₄ spinel on alumina catalyst.

These reforming catalysts II are usually used in the form of pellets of an appropriate size.

Furthermore, when a mixture of a metal oxide and alumina spinel structure containing reforming catalyst II 1S copper of the present invention, for example, C UMN ₂ 〇 ₄ spinel, C u F e ₂ 0 ₄ spinel及Pi C Even if the reforming catalyst II is prepared by mixing an appropriate-sized pellet made of at least one selected from u (F e Mn) ₂ O ₄ spinel and the like and an appropriate-sized alumina pellet. good to, C UMN ₂ 0 ₄ spinel, C u F e ₂ 0 ₄ spinel及Pi C u (F eMn) ₂ 〇 ₄ and at least one powder selected from the group consisting of spinel Le, homogeneously mixed-and alumina powder After that, the reforming catalyst II may be prepared by molding into a pellet of an appropriate size.

In the present invention, the activity can be further improved by reducing the reforming catalyst. The reduction treatment includes a gas phase reduction method in which the treatment is performed in an air stream containing hydrogen and a wet reduction method in which the treatment is performed with a reducing agent. The former reduction treatment is usually carried out at a temperature of 150 to 500 ° C, preferably 200 to 300 ° C, for 30 minutes to 24 hours, preferably 1 to 10 hours, under a stream of hydrogen. An inert gas such as nitrogen, helium, or argon may coexist in addition to hydrogen gas. The latter wet reduction method includes Birch reduction using liquid ammonia Z alcohol / Na, liquid ammonia alcohol ZLi, Benkeser reduction using methyl amiso / Li, Zn / HCl, A1 / NaOH. _{/ H 2 0, N a H} , L i a 1 H 4 , or a substitution product thereof, human Doroshiran acids, hydrogen coercive © containing sodium or derivatives thereof, diborane, formic acid, formalin, with a reducing agent such as human Doraji down There is a way to handle it. In this case, the reaction is usually carried out at room temperature to 1 oo ° C for 10 minutes to 24 hours, preferably for 30 minutes to 10 hours.

In addition, by flowing the reaction raw materials, the catalyst is reduced by the generated hydrogen and CO during the reaction.

In the present invention, the catalyst is reduced by the pretreatment for reduction or by the generated gas, so that Cu or other elements are desorbed from the spinel structure, and the spinel structure is in a state where some or all of the spinel structure is not retained. However, it is an important point of the present invention to first use a Cu catalyst having a spinel structure. In the method for producing hydrogen or synthesis gas according to the present invention, the reforming catalyst I and / or the reforming catalyst II according to the present invention is used to convert an oxygen-containing hydrocarbon such as dimethyl ether into (1) steam reforming, 2) Autothermal reforming, (3) partial oxidation reforming, or (4) carbon dioxide reforming to produce hydrogen or synthesis gas. Next, each reforming method will be described with reference to an example in which dimethyl ether is used.

[Steam reforming]

When the reforming catalyst of the present invention is used, the reaction of steam reforming of dimethyl ether is considered to proceed according to the following reaction formula.

CH ₃ OCH ₃ + H ₂ 0 → 2 CH ₃ OH

2 CH ₃ OH + 2 H ₂ O → 2 CO 2 + 6 H ₂ --(2) 2 C 0 ₂ + 2 H ₂ 2 2 CO + 2 H ₂ 0 In this case, the reaction (3) is difficult to proceed. So, that is,

CH ₃ OCH ₃ + 3 H ₂ O → 2 C0 ₂ + 6 Η ₂ · ·-The reaction conditions may be selected so that the reaction (4) occurs.

On the other hand, in the case of producing synthesis gas, the reactions (1), (2) and (3) are performed so that

CH ₃ O CH ₃ + H ₂ 0 → 2 CO + 4 H ₂ ··· The reaction condition may be selected so that the reaction (5) occurs.

In the case of producing hydrogen, the molar ratio of water vapor / dimethyl ether is theoretically 3, but is preferably about 3 to 6.On the other hand, in the case of producing synthesis gas, the molar ratio of water vapor / dimethyl ether is theoretically 1, but preferably about 1-2.

The reaction temperature is usually selected in the range of 200 to 500 ° C, preferably 250 to 450 ° C. If the temperature is lower than 200 ° C, the conversion of dimethyl ether may be low. If the temperature is higher than 500 ° C, the activity of the catalyst may be deteriorated. GHSV (gas hourly space velocity) is a dimethyl ether reference 1 0 0: 1 0, the range of 000 h ¹ are preferred. The GHSV is 1 00 h ¹ less than the production efficiency is low, 'to not practically preferred, 1 0, 000 if h ¹ a exceeds too low dimethyl ether conversion, practically undesirable. The reaction pressure is usually from normal pressure to IMPa. If the pressure is too high, the conversion of dimethyl ether tends to decrease.

[Autothermal reforming]

In the autothermal reforming reaction, the oxidation reaction of dimethyl ether and the reaction with steam occur in the same reactor or in continuous reactors. In this case, the reaction conditions for hydrogen production and synthesis gas production are slightly different, but in general, the oxygen Z dimethyl ether molar ratio is preferably selected from the range of 0.1 to ι, and the steam dimethyl ether molar ratio is , Preferably in the range of 0.5-3 Selected. If the oxygen dimethyl ether molar ratio is less than 0.1, the heat of reaction may not be sufficiently supplied due to heat generation, while if it exceeds 1, complete oxidation may occur and the hydrogen concentration may decrease. If the steam / dimethyl ether molar ratio is less than 0.5, the hydrogen concentration may decrease. On the other hand, if it exceeds 3, the supply of heat may be insufficient.

The reaction temperature is usually selected in the range of 200 to 800 ° C, preferably 250 to 500 ° C. The GHSV and the reaction pressure are the same as in the case of the steam reforming.

[Partial oxidation reforming]

In the partial oxidation reforming reaction, a partial oxidation reaction of dimethyl ether occurs, and the reaction conditions are slightly different between hydrogen production and synthesis gas production.In general, the oxygen-to-dimethyl ether molar ratio is preferably 0.3 to 1. It is selected in the range of 5. If the oxygen / dimethyl ether molar ratio is less than 0.3, the conversion of dimethyl ether may not be sufficiently high, while if it exceeds 1.5, complete oxidation occurs, causing a reduction in the hydrogen concentration. The reaction temperature is usually selected in the range of 200 to 900 ° C, preferably 250 to 600 ° C. The GHSV and the reaction pressure are the same as in the case of the steam reforming.

[Carbon dioxide reforming].

In the carbon dioxide reforming reaction, a reaction between dimethyl ether and carbon dioxide occurs.The reaction conditions are slightly different between hydrogen production and synthesis gas production, but in general, the molar ratio of CO ₂ Z dimethyl ether is preferably 0.8. To 2, more preferably 0.9 to 1.5. If the CO ₂ dimethyl ether mole ratio is less than 0.8, the conversion of dimethyl ether may not be sufficiently high, while if it exceeds ₂ , a large amount of C02 remains in the product and the hydrogen partial pressure decreases. on the, may remove the C_〇 ₂ is required, it has an unwanted. In this reaction, steam can be introduced, and the introduction of hydrogen It is possible to increase the degree. Further, the reaction temperature, GHSV and reaction pressure are the same as in the case of the steam reforming.

A third invention of the present application is a fuel cell system comprising: a reformer including the above-described reforming catalyst; and a fuel cell using hydrogen produced by the reformer as fuel. This will be described with reference to FIG.

The fuel in the fuel tank 21 is introduced into the desulfurizer 23 via the fuel pump 22. The desulfurizer 23 can be filled with, for example, activated carbon, zeolite or a metal-based adsorbent. The fuel desulfurized in the desulfurizer 23 is mixed with water from the water tank through the water pump 24, introduced into the vaporizer 1 and vaporized, and then mixed with the air sent out from the air blower 135. It is sent to the reformer 31. The reformer 31 is filled with the above-mentioned reforming catalyst, and is converted from the fuel mixture (a mixture containing oxygen-containing hydrocarbon, steam and oxygen) fed into the reformer 31 as described above. Hydrogen is produced by either of the reactions.

The hydrogen produced in this way is reduced through the CO 2 converter 32 and the CO 2 selective oxidizer 3 3 to such an extent that the CO concentration does not affect the characteristics of the fuel cell. Examples of catalysts used in these reactors include an iron-chromium catalyst, a copper-zinc catalyst or a noble metal catalyst in the CO converter 32, and a ruthenium catalyst in the CO selective oxidizer 33. Catalysts, platinum catalysts or mixed catalysts thereof. When the C 2 O concentration in the hydrogen produced by the reforming reaction is low, it is not necessary to attach the C 2 O 3 converter 32.

The fuel cell 34 is a polymer electrolyte fuel cell having a polymer electrolyte 34 C between a negative electrode 34 A and a positive electrode 34 B. The hydrogen-rich gas obtained by the above method is applied to the negative electrode side, and the air sent from the air blower 135 is applied to the positive electrode side. (Not shown) Introduced.

At this time, on the negative electrode side, the reaction of hydrogen gas becoming protons and releasing electrons proceeds. On the positive electrode side, oxygen gas obtains electrons and protons and the reaction of turning into water progresses, and a DC current is generated between both electrodes 34A and 34B. In that case, a platinum black or activated carbon-supported Pt catalyst or a Pt-Ru alloy catalyst is used for the negative electrode, and a platinum black or activated carbon-supported Pt catalyst or the like is used for the positive electrode. By connecting the parner 31 A of the reformer 31 to the negative electrode 34 A side, excess hydrogen can be used as fuel. In addition, a water-water separator 36 is connected to the positive electrode 34B side to separate water and exhaust gas generated by the combination of oxygen and hydrogen in the air supplied to the positive electrode 34B side, and to separate the water. It can be used to generate steam. In the fuel cell 34, heat is generated as a result of power generation. Therefore, an exhaust heat recovery device 37 can be provided to recover and effectively use this heat. The exhaust heat recovery device 37 is provided with a heat exchanger 37 A attached to the fuel cell 34 for removing heat generated during the reaction, and a heat exchanger for exchanging the heat taken by the heat exchanger 37 A with water. Heat exchanger 37 B, a heat exchanger 37 B, a cooler 37 C, a pump 37 D for circulating the refrigerant to the heat exchangers 37 A, 37 B and the cooler 37 C. The hot water obtained in can be used effectively in other facilities.

In FIG. 1, 11 is a water supply pipe, 12 is a fuel introduction pipe, and 15 is a connection pipe. Example

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1)

1 Li Tsu Torubika, copper nitrate [Nacalai tester manufactured, 9 9. 5% C u ( N0 3) 2 · 3 Η 2 θ] 1 3. 2 8 g (5 5 Mi Rimoru)及Pi manganese nitrate [sigma Aldrich Japan, 9 8. a _{_{0% Mn (N0 3) 2}} · 6 H 2 O] 3 1. 5 5 g (1 08 Mi Rimoru), distilled water 300 millimeters liters pressurized Then, the mixture was stirred at 60 ° C for 2 hours. Next, 34.65 g (165 mmol) of citrate monohydrate [manufactured by Sigma-Aldrich Japan] was added to the solution, and the mixture was stirred at 60 ° C for 1 hour, and then stirred at 80 ° C. And the water was evaporated.

The gel thus formed is continuously heated at 140 ° C. to decompose nitrate and citric acid to obtain an oxide fine powder, which is then temporarily put in air at 400 ° C. for 2 hours. Baking, and then further baking in air at 900 ° C for 10 hours in a baking furnace

There was thus obtained the ς u- Mn spinel type oxide catalyst _{_{_{(CUL 5 Mn x. 5 0}}} 4 mixture of spinel and Mn ₂ 0 _3).

(Comparative Example 1)

1 Li Tsu Torubika ^, copper nitrate [Nacalai tester manufactured, 9 9. 5% C u ( NO 3) 2 · 3 Η 2 0] 2 2. 9 3 g (9 5 Mi Rimoru) and aluminum nitrate two © arm [manufactured by Wako Pure Chemical Industries, Ltd., 9 8. 0% a 1 ( N0 3) 3 · 9H 2 0] 1 0 5. 1 4 g (2 7 5 Mi Rimoru) and distilled water 3 0 0 millimeter Li Tsu The mixture was stirred at 60 for 2 hours. Then, to this solution was added 114.04 g (557 mmol) of citrate monohydrate [manufactured by Sigma-Aldrich Co., Ltd.], and the mixture was added with 60%. The mixture was stirred at C for 1 hour, and then heated to 80 ° C to evaporate water.

The gel thus formed is continuously heated at 140 ° C. to decompose nitrate and citric acid to obtain an oxide fine powder, and then temporarily set at 400 ° C. in air for 2 hours. After baking, further baking was performed at 500 ° C. for 3 hours in air in a baking furnace.

Thus, a 30 mass ⁰ / oCu supported alumina catalyst (non-spinel) was obtained.

(Example 2)

1 In a little beaker, add copper nitrate [Nacalai Tesque, 99.5% Cu (NO ₃ ) ₂ · 3H ₂₀ ] 6.40 g (26 mimol) and manganese nitrate [Sigma-Aldrich Japan K.K., 9 8. 0% Μη (Ν0 3) 2 · 6Η 2 Ο] and 7. 7 3 2 g (26 mmol), distilled water 300 millimeter rate torr addition, 2 60 ° C Stirred for hours. Then, this solution A 1 ₂ 0 ₃ [manufactured by Sumitomo Chemical Co., Ltd., "AKP_G0 1 5"] added 30. O g, water is evaporated at 80 ° C, to obtain a powder flour.

Next, the obtained powder was calcined in air at 400 ° C. for 2 hours, and then further calcined in air at 900 ° C. for 10 hours in a firing furnace.

, Was thus obtained the _{_{_{C u 5 Mn x. 5 0}}} 4 spinel on alumina catalyst to 5 mass ^_0/0 containing C u.

(Example 3)

1 Li Ttorubika, copper nitrate [Nacalai tester manufactured, 9 9. 5% C u ( NO 3) 2 '3H 2 O] 4. 3 70 g (1 8 mmol) and ferric nitrate port light Pure Chemical Industries, Ltd. Ltd., 9 9. and _{0% F e (N0 3)} 3 · 9H 2 0] 1 4. 6 5 g (3 6 mmol), distilled water 3 00 milli liters, and the mixture was stirred for 2 hours at 60 ° C. Then, this solution A 1 ₂ 0 ₃ [manufactured by Sumitomo Chemical Co., Ltd., "AKP- GO 1 5"] 30. O g was added, water is evaporated at 80 ° C, to obtain a powder.

Next, the obtained powder was calcined at 400 ° C for 2 hours in the air, and then further calcined in a firing furnace at 900 ° C for 10 hours in the air.

There was thus obtained the C u F e ₂ 0 ₄ spinel supported § alumina catalyst to 5 mass ^_0/0 containing C u.

(Example 4)

It was prepared in the same manner as in Example 1 Cu- Mn spinel type oxide catalyst _{(Cu!. 5 Mn!.} 5 0 4 mixture of spinel and Mn ₂ 0 ₃₎ 1 0 g of alumina (Sumitomo Chemical Co., Ltd., " resulting AKP- G 0 1 5 ") 4. by mixing in a mortar 445 g, 20 weight ^_0/0 containing C u, the C u- Mn mixed catalyst of the spinel oxide catalyst and a 1 ₂ 0 ₃ Was. (Example 5)

In a 1-liter beaker, add 26.56 g (109 mmol) of copper nitrate [Nacalai Tester, 99.5% Cu (NO ₃ ) ₂ · 3H ₂₀ ] and manganese nitrate [Sigma Aldrich Japan, 98. _{_{0% Mn (N0 3) 2}} · 6 H 2 0] 3 1. 55 g (54 mmol), and ferric nitrate [manufactured by Wako Pure Chemical Industries, Ltd., 99. 0% F e (Ν0 3) 3 · 9Η ₂₀ ] 67.33 g (165 millimoles) of distilled water and 3 リ 0 milliliters of distilled water were mixed and stirred at 60 ° C for 2 hours. Next, 85.84 g (409 mimol) of citrate monohydrate [manufactured by Sigma-Aldrich Japan] was added to this solution, and the mixture was stirred at 60 ° C for 1 hour, and then heated to 80 ° C to remove water. Evaporated.

The gel thus formed is heated at 140 ° C for 7 hours to decompose nitrate and citric acid to obtain fine oxide powder, and then calcined in air at 400 ° C for 2 hours. Thereafter, firing was further performed at 900 ° C for 10 hours in air in a firing furnace.

After calcination, the obtained Cu—Mn—Fe spinel oxide catalyst (CuMn ₀ .

_{_{5 F e 5 0 4) 10}} g of alumina (manufactured by Sumitomo Chemical Co., Ltd. "AKP _G 0 1 5 j) 4. Rei_11 containing 20 wt% of Cu by mixing in a mortar 445 g Mn _0. ₅ F e!. ₅ 0 ₄ to obtain a mixed catalyst of the spinel and a 1 ₂ 0 _3.,

(Example 6)

1 In a little beaker, add copper nitrate [99.5% Cu (NO ₃ ) ₂ · 3Η ₂₀ ] manufactured by Nacalai Tester, Inc. 20.30 g (84 mmol) and ferric nitrate [Wako Pure Chemical Industries, Ltd. 99.0% F e (Ν0 ₃ ) ₃ · 9Η ₂₀ ] 68.24 g (1

68 millimoles) and 300 milliliters of distilled water were added and stirred at 60 ° C for 2 hours. Then, 70.56 g (336 mimol) of citrate monohydrate [manufactured by Sigma-Aldrich Japan] was added to the solution, and the mixture was stirred at 60 ° C for 1 hour. Was evaporated. The gel thus formed is heated at 140 ° C for 7 hours to decompose nitrate and citric acid to obtain an oxide fine powder, and then temporarily in air at 400 ° C for 2 hours. After baking, it was further fired in a firing furnace at 900 ° C for 10 hours in air.

After calcination, the resulting C u- F e spinel type oxide catalyst _{_{(Cu F e 2 0 4)}} 1 0 g of alumina (manufactured by Sumitomo Chemical Co., Ltd., "AKP- GO 1 5") 4. 2 3 5 g to obtain a mixed catalyst of C u F e ₂ 0 ₄ spinel and a 1 ₂ 0 ₃ of the C u containing 20 wt% by mixing in a mortar.

(Example 7)

1 Li Tsu Torubika, copper nitrate [Nacalai tester manufactured, 9 9. 5% C u ( NO 3) 2 · 3 Η 2 θ] 20. 98 g (8 7 Mi Rimoru) and chromium nitrate [Na force Raitesuta Inc. Ltd., 9 9. a _{5% C r (Ν0 3)} 3 · 9Η 2 0] 70. 5 6 g (1 74 Mi Rimoru), distilled water 300 millimeter Li Tsu torr addition, between 2:00 at 60 ° C Stirred. Next, 73.08 g (348 mmol) of citrate monohydrate [manufactured by Sigma-Aldrich Japan] was added to the solution, and the mixture was stirred at 60 ° C for 1 hour, and heated to 80 ° C to remove water. Evaporated.

The thus produced gel was heated for 7 hours at 1 40 ^D C, after the yield of the oxide powder by decomposing the nitrate Ne及Piku E phosphate, between 2:00 at 400 ° C in air It was calcined and then further fired in a firing furnace at 900 ° C. for 10 hours in air.

After calcination, the resulting Cu- C r spinel type oxide catalyst _{_{(Cu C r 2 0 4)}} 1 0 g of alumina (manufactured by Sumitomo Chemical Co., Ltd., "AKP- GO 1 5") 4. mortar 74 g mixed to obtain a mixed catalyst of C u C r ₂ 0 ₄ spinel and a 1 ₂ O ₃ containing C u 2 0 wt% by.

(Test Example 1)

The catalysts obtained in Examples 1 to 7 and Comparative Example 1 were formed to a size of 6 to 14 mesh. The reactor was filled with 1 milliliter each.

The catalysts of Examples 2, 3, 6, 7 and Comparative Example 1 were heated at 250 ° C. for 1 hour in a mixed gas of hydrogen and nitrogen having a hydrogen content of 10% by volume to reduce hydrogen reduction. went. The catalysts of Examples 1, 4 and 5 were not subjected to hydrogen reduction.

Dimethyl ether (DME), steam and nitrogen were supplied to the reactor at a rate of 15 milliliters Z, 45 milliliters, and 40 milliliters / minute, respectively, and the DME steam was reformed at 400 ° C or 450 ° C. The quality went. At this time, the GH SV (gas hourly space velocity) based on the total gas amount was 6, OOO h- ¹ and the GHS V based on DME was 900 h- ¹ .

The DME reaction rate and DME conversion were calculated according to the following equations, and the performance of the catalyst was evaluated. The results are shown in Table 1.

DME reaction rate (ΐΆ θ 1 / s-m ² -cat)>

DME reaction rate = DME flow rate mo 1 / s) X 0.01 DME conversion (%) Surface area of catalyst in reactor (m ² )

However,

Surface area of catalyst in reactor-catalyst volume used (m 1) X specific gravity of catalyst (gZm 1) X BET specific surface area (m ² / g)

DME conversion rate (%)>

DME conversion rate = [(Inlet DME flow rate-Outlet DME flow rate) Inlet DME flow rate] X 100

As can be seen from Table 1, the catalyst of Example 1 containing spinel has a higher reaction rate than the catalyst of Comparative Example 1 containing no spinel. In addition, the catalyst of Example 27 containing spinel has a higher conversion of DME than the catalyst of Comparative Example 1 containing no spinel. Industrial applicability

According to the present invention, a metal oxide having a copper-containing spinel structure having excellent heat resistance, or an oxygen-containing hydrocarbon reforming catalyst containing this and a solid acidic substance and having a greatly improved activity per unit surface is provided. It is possible to provide a method for efficiently producing hydrogen or synthesis gas by subjecting an oxygen-containing hydrocarbon to various reforming using the reforming catalyst. Further, it is possible to manufacture an excellent fuel cell system having a reformer provided with such an excellent reforming catalyst and a fuel cell using hydrogen produced by the reformer as a fuel. .

Claims

The scope of the claims

1. An oxygen-containing hydrocarbon reforming catalyst containing copper and a metal oxide having a spinel structure.

2. An oxygen-containing hydrocarbon reforming catalyst comprising copper, a metal oxide having a spinel structure, and a solid acidic substance.

3. The oxygen-containing hydrocarbon reforming catalyst according to claim 1, wherein the metal oxide containing copper and having a spinel structure is a Cu—Mn spinel.

4. Metal oxides containing copper and having a spinel structure 3. The reforming catalyst for an oxygen-containing hydrocarbon according to claim 1, which is a 6-type spinel.

5. The oxygen-containing hydrocarbon reforming catalyst according to claim 1 or 2, wherein the metal oxide containing copper and having a spinel structure is a spinel of type 11-01.

6. The reforming catalyst for an oxygen-containing hydrocarbon according to claim 1, wherein the metal oxide containing copper and having a spinel structure is a Cu_Mn-Fe type spinel.

7. The reforming catalyst for an oxygen-containing hydrocarbon according to claim 2, wherein the solid acidic substance is alumina. '

8. An oxygen-containing hydrocarbon reforming catalyst obtained by reducing the reforming catalyst according to claim 1 or 2.

9. The reforming catalyst for an oxygen-containing hydrocarbon according to claim 1, wherein the oxygen-containing hydrocarbon is at least one selected from methanol, ethanol, dimethyl ether, and methylethyl ether.

10. A method for producing hydrogen or synthesis gas, comprising reforming an oxygen-containing hydrocarbon with steam using the reforming catalyst according to claim 1 or 2.

11. A method for producing hydrogen or synthesis gas, wherein the reforming catalyst according to claim 1 or 2 is used for autothermal reforming of an oxygen-containing hydrocarbon.

12. A method for producing hydrogen or synthesis gas, comprising subjecting an oxygen-containing hydrocarbon to partial oxidation reforming using the reforming catalyst according to claim 1 or 2.

13. A method for producing hydrogen or synthesis gas, comprising reforming an oxygen-containing hydrocarbon with carbon dioxide using the reforming catalyst according to claim 1 or 2.

14. A fuel cell system comprising: a reformer provided with the reforming catalyst according to claim 1 or 2; and a fuel cell using hydrogen produced by the reformer as a fuel. .