JP2007196154A - Catalyst for reforming ethanol, and method for supplying hydrogen containing gas using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst for reforming ethanol at a temperature in a range of not higher than 400°C capable of obtaining a reformed gas of a high hydrogen (H<SB>2</SB>) and carbon monoxide (CO) concentration and a low methane (CH<SB>4</SB>) concentration, and a method for supplying a hydrogen containing gas using the catalyst. <P>SOLUTION: The catalyst for reforming ethanol comprises platinum and/or rhodium supported by an inorganic oxide or oxides comprising cerium and/or niobium. Platinum in an amount of 0.5 to 6% relative to the total amount of the catalyst is supported by the oxide(s). Rhodium in an amount of 0.1 to 10% relative to the total amount of the catalyst is supported by the oxide(s). A hydrogen containing gas prepared in the presence of the catalyst for reforming ethanol by allowing ethanol to contact with the catalyst at a temperature of 200 to 600°C under the conditions of steam/carbon equal 0.1 to 3 and O<SB>2</SB>/carbon equal 0 to 0.5 is supplied to an internal combustion engine. The ethanol reforming reaction is carried out at a gas flow rate of GHSV (gas hourly space velocity) equal 10h<SP>-1</SP>or higher. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ethanol reforming catalyst and a hydrogen-containing gas supply method using the same, and more specifically, an ethanol reforming catalyst capable of reforming ethanol from a lower temperature and a hydrogen-containing gas supply using the same. Regarding the method.

In recent years, various attempts have been made for the purpose of improving the fuel efficiency of an internal combustion engine such as an automobile in consideration of the global environment.
For example, techniques for further improving the combustion efficiency in the engine have been actively developed by devising the engine system such as lean burn or direct injection.

An internal combustion engine that includes a fuel reformer and operates the engine with the reformed fuel has also been proposed.
For example, a method has been proposed in which a methanol reformer is attached to an exhaust pipe of an internal combustion engine, and reformed gas is generated by the reformer using exhaust heat (see Patent Document 1). The reformed gas obtained by this method is mainly composed of hydrogen (H ₂ ) and carbon monoxide (CO). By supplying this gas to the internal combustion engine, the lean combustion limit is high, and the engine is stable even in the lean region. Driving is possible.
JP 2002-38981 A

  On the other hand, ethanol has attracted attention as a fuel in recent years. Ethanol is expected to improve the combustibility of gasoline by mixing with gasoline, has low toxicity, and can be produced from biomass resources such as plants. Therefore, research and development using these as fuels as renewable energy sources are actively performed.

In addition, the use of a fuel cell system using a polymer electrolyte fuel cell has been proposed in the midst of increasing global environmental problems.
Hydrogen to be supplied to such a fuel cell can be obtained by reforming the fuel. For example, a method for producing hydrogen gas in which ethanol is reformed using water vapor in the presence of oxygen has been proposed (see Patent Document 2).
Special table 2003-503295 gazette

Furthermore, a reforming catalyst in which nickel or a mixture of nickel and copper is supported on α-alumina or silica has been proposed as a reforming catalyst.
In order to supply the H ₂ -containing gas to the fuel cell system using such a reforming catalyst, a reformed gas having a high H ₂ concentration and a low CO and CH ₄ concentration is desired. For this purpose, means for reducing the CO concentration is required, and water gas shift reaction and CO selective oxidation reaction are used.

  On the other hand, when supplying H2 containing gas to an internal combustion engine, CO may be contained in high concentration. On the other hand, in order to use exhaust heat, a catalyst that can reform ethanol at a lower temperature to obtain a H2-containing gas is required.

The present invention has been made in view of such problems of the prior art. The object of the present invention is to reform ethanol from a low temperature range of 400 ° C. or lower, and to have high H ₂ and CO concentrations, An object of the present invention is to provide an ethanol reforming catalyst capable of obtaining a reformed gas having a low CH ₄ concentration and a hydrogen-containing gas supply method using the same.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by supporting platinum or rhodium on an inorganic oxide containing cerium or niobium, and the present invention has been completed. It came to do.

  That is, the ethanol reforming catalyst of the present invention is characterized in that platinum and / or rhodium are supported on an inorganic oxide containing cerium and / or niobium.

  The preferred embodiment of the ethanol reforming catalyst of the present invention is that the platinum is supported by 0.5 to 6% relative to the total catalyst amount, and the rhodium is 0.1 to the total catalyst amount. It is characterized by being 10% supported.

Furthermore, the hydrogen-containing gas supply method of the present invention is a method of supplying a hydrogen-containing gas to an internal combustion engine using the ethanol reforming catalyst,
Ethanol is brought into contact with the ethanol reforming catalyst under the conditions of 200 to 600 ° C., Steam / Carbon = 0.1 to 3, and O ₂ / Carbon = 0 to 0.5.

Furthermore, a preferred embodiment of the hydrogen-containing gas supply method of the present invention is characterized in that the ethanol reforming reaction is carried out with a permeate gas amount of LHSV = 10 h ⁻¹ or more.

According to the present invention, platinum or rhodium is supported on an inorganic oxide containing cerium or niobium. Therefore, ethanol is modified from a low temperature range of 400 ° C. or lower, H ₂ and CO concentrations are high, and CH ₄ A reformed gas having a low concentration can be obtained.

  Hereinafter, the ethanol reforming catalyst of the present invention will be described in detail. In the present specification and claims, “%” indicates a mass percentage unless otherwise specified.

As described above, the ethanol reforming catalyst of the present invention includes an inorganic oxide containing one or both of cerium (Ce) and niobium (Nb), platinum (Pt), rhodium (supported on the inorganic oxide). Any one or both of Rh).
With such a configuration, ethanol can be modified from a low temperature range of 400 ° C. or lower.

  Here, the inorganic oxide containing one or both of Ce and Nb exhibits oxygen ion conductivity due to the movement of lattice oxygen. Ethanol is oxidized by using this lattice oxygen. The consumed lattice oxygen can be replenished with water. It is considered that the reforming reaction can be performed from a lower temperature by efficiently rotating this cycle.

The inorganic oxide is not particularly limited as long as it contains Ce and Nb, but is preferably used as a porous oxide.
Specific examples of the porous oxide include, for example, cerium-niobium composite oxide (Ce-Nb composite oxide), cerium oxide (CeO ₂ etc.), cerium-zirconia composite oxide (Ce-Zr composite oxide). Etc.
In addition, as for the said inorganic oxide, only 1 type may be used independently and 2 or more types may be used together. There is no restriction | limiting in particular also about the shape of an inorganic oxide, etc., considering desired catalyst activity etc., it can select suitably.

Furthermore, the specific surface area (BET specific surface area by nitrogen adsorption) of the inorganic oxide is not particularly limited, but is preferably 10 m ² / g or more, more preferably 50 m ² / g or more, and still more preferably 100 m ² / g or more. It is good to be.
By adjusting the specific surface area of the inorganic support to such a range, the dispersibility of the catalyst metal can be controlled to a desired level, and the catalytic activity of the ethanol reforming catalyst can be improved.

On the other hand, the amount of Pt or Rh supported on the inorganic oxide can be appropriately adjusted in consideration of the amount of support, desired catalyst performance, cost effectiveness, and the like.
From the viewpoint of cost reduction, the supported amount of Pt is preferably 0.5 to 6% with respect to the total catalyst amount, and the supported amount of Rh is 0.1 to 10% with respect to the total catalyst amount. It is preferable that
If the supported amount of Pt or Rh is less than the lower limit, sufficient ethanol reforming catalyst activity may not be obtained. On the other hand, when the above upper limit is exceeded, an increase in catalytic activity commensurate with an increase in the amount of support may not be obtained, which tends to be disadvantageous in terms of cost.

Representative examples of the ethanol reforming catalyst of the present invention include a catalyst in which platinum is supported on a complex oxide of cerium and niobium (Pt / Ce-Nb complex oxide), and a catalyst in which rhodium is supported on ceria (Rh / CeO ₂ ). Etc.

Next, an example of a method for producing the above-described ethanol reforming catalyst will be described.
Needless to say, the method for producing the ethanol reforming catalyst is not limited to the following preferred embodiments, and can be produced by other methods.

Such an ethanol reforming catalyst can be produced without using a special technique, for example, the following steps:
(1) preparing an inorganic oxide;
(2) a step of preparing a catalyst preparation solution in which catalytic metal atoms (Pt and Rh) are dissolved,
(3) a step of supporting a catalyst metal atom dissolved in the catalyst preparation solution on an inorganic oxide;
(4) a step of firing an inorganic oxide carrying a catalytic metal atom;
It can manufacture by performing.

Here, each said process is demonstrated.
First, in the step (1), as described above, an inorganic oxide containing one or both of Ce and Nb is prepared.
In order to obtain such an inorganic oxide, it may be purchased when it is commercially available, but it may be obtained by synthesis from a commercially available raw material.
In order to synthesize an inorganic oxide containing Ce or Nb, a compound serving as a metal supply source to be contained in the inorganic carrier raw material may be mixed with other compounds as necessary, and then fired. At this time, if necessary, further pulverization treatment and classification treatment may be performed.
Examples of the compound serving as a supply source of Ce and Nb include hydroxides, sulfates, nitrates, chlorides, inorganic oxide sols, and organic metal salts of the metals.

Specific methods and firing conditions at the time of firing are not particularly limited, and may be adjusted as appropriate by appropriately referring to conventionally known knowledge in the catalyst preparation field in consideration of a desired particle diameter and specific surface area.
As an example of the specific surface area of the inorganic oxide, generally, when firing is performed at a low firing temperature, an inorganic oxide having a relatively large specific surface area can be obtained. On the other hand, when the firing temperature is set high, an inorganic oxide having a relatively small specific surface area is obtained.
As typical firing conditions, the firing temperature is about 300 to 600 ° C., and the firing time is about 0.5 to 10 hours.

  Next, in step (2), a catalyst preparation solution in which one or both of Pt and Rh are dissolved is prepared. This catalyst preparation solution is used in the supporting step described later for the purpose of supporting the dissolved catalytic metal atoms on the inorganic support prepared above. This catalytic metal atom finally functions as a catalytic metal involved in the ethanol reforming reaction.

A Pt compound and a Rh compound as a supply source of Pt and Rh are prepared. Moreover, the solvent for dissolving these compounds is prepared.
Thereafter, the compound is added to the prepared solvent, and stirred if necessary to prepare a catalyst preparation solution.
The catalyst preparation solution in which the Pt compound and Rh compound are dissolved may be prepared separately, or both may be dissolved at the same time. For example, when the co-impregnation method is employed in the supporting stage described later, a catalyst preparation solution in which both the Pt compound and the Rh compound are dissolved simultaneously may be prepared.

  Although it does not restrict | limit especially as a Pt compound and a Rh compound, For example, compounds, such as a hydroxide, a sulfate, nitrate, a chloride, an inorganic oxide sol, and an organic metal salt, of Pt atom, Rh atom, and a co-catalyst atom are mentioned. It can be illustrated. These compounds are easily available, are widely used as raw materials for catalyst preparation, and are easy to handle when supported on inorganic oxides.

Examples of the solvent used in the preparation of the catalyst preparation solution include water and ethanol, but are not limited thereto.
The concentration of Pt and Rh in the catalyst preparation solution is not particularly limited, and can be adjusted as appropriate in consideration of the amount of inorganic oxide used in the supporting stage, which will be described later, a desired supporting amount, a supporting method, cost effectiveness, and the like.

Next, in step (3), Pt atoms and Rh atoms dissolved in the catalyst preparation solution are supported on the inorganic oxide prepared in step (1).
As a specific supporting method, for example, a conventionally known method in the catalyst preparation field such as an impregnation method, a coprecipitation method, or a competitive adsorption method can be employed.
The treatment conditions can be appropriately selected according to the method employed, but usually the inorganic oxide and the catalyst preparation solution may be contacted at room temperature for about 0.5 to 10 hours. At this time, there is no particular limitation on the order in which Pt atoms and Rh atoms are supported, and after supporting one of them, the other may be supported. Moreover, you may carry | support both components simultaneously (co-impregnation method). From the viewpoint of improving the catalytic activity, it is preferable to employ a co-impregnation method.

After carrying | supporting a catalyst metal atom on an inorganic oxide, this is dried as needed.
As a specific drying method, for example, natural drying, evaporation to dryness, drying using a rotary evaporator, an air dryer, or the like can be employed. The drying time can be appropriately set according to the method employed. In some cases, this drying step may be omitted, and drying may be performed in the firing step described below.

Next, in step (4), the inorganic oxide carrying Pt atoms and Rh atoms is baked.
The apparatus and conditions (calcination atmosphere, calcination temperature, calcination time) used for calcination are not particularly limited, and conventionally known knowledge can be appropriately referred to in the catalyst preparation field.
Specifically, for example, the firing conditions are 0.5 to 10 hours at 200 ° C. to 600 ° C. in an air or humidified air atmosphere. Through this firing step, the ethanol reforming catalyst of the present invention is obtained.

Further, the ethanol reforming catalyst obtained by the above-described method may be further subjected to processing such as pulverization and sieving according to the use.
Furthermore, in order to process the ethanol reforming catalyst into the form of a monolith catalyst, for example, an appropriate solvent or binder (for example, alumina sol) is added to and mixed with the manufactured ethanol reforming catalyst, and the monolith support is coated. A coating slurry is prepared. Thereafter, the coating slurry may be coated on the inner surface of the monolith carrier, and dried and fired as necessary. The form of the monolith carrier is not particularly limited, but a foam molded body made of a similar material can be used as the carrier of the monolith catalyst in addition to the honeycomb carrier made of ceramics or metal.

Next, the hydrogen-containing gas supply method of the present invention will be described in detail.
In the present invention, when ethanol is brought into contact with the above-described ethanol reforming catalyst, control is performed under conditions of 200 to 600 ° C., Steam / Carbon = 0.1 to 3, and O ₂ / Carbon = 0 to 0.5. Supply the hydrogen-containing gas to the internal combustion engine.
More preferably, the control conditions are 300 to 450 ° C., Steam / Carbon = 0.3 to 1.5, and O ₂ / Carbon = 0 to 0.3.

Thereby, the reformed gas having a high H ₂ concentration can be supplied to the internal combustion engine by utilizing the exhaust heat of the internal combustion engine. The internal combustion engine has a high lean combustion limit and can perform stable combustion.
Moreover, the thermal efficiency of an internal combustion engine can be improved by utilizing the exhaust heat which was not utilized conventionally.

  FIG. 1 shows a combustion system including a hydrogen-containing gas supply device 1 to which the present method can be applied. In this system, ethanol supplied from the fuel tank 2 can be reformed to supply hydrogen-containing gas to the combustion chamber 3.

Here, in the hydrogen-containing gas supply method of the present invention, how much the exhaust heat of the internal combustion engine can be used is a point for improving the thermal efficiency.
For this purpose, it is desirable to use an ethanol steam reforming reaction which is an endothermic reaction. Further, if the amount of water vapor used in the steam reforming reaction is too small, the catalyst performance is reduced due to carbon deposition, but if it is too large, the amount of heat for evaporating water is insufficient.

That is, in the hydrogen-containing gas supply method of the present invention, the reformed gas supplied to the internal combustion engine is preferably a reformed gas having a high H ₂ and CO concentration and a low CH ₄ and CO ₂ concentration.
Specifically, the hydrogen-containing gas to be supplied is preferably controlled to have a H ₂ concentration of 10% or more. In this case, the lean combustion limit can be increased and stable engine operation can be performed. Further, it is preferable to control the CO concentration by 5% or more. At this time, the combustion rate can be increased, and it is not necessary to reduce the CO concentration in the reformed gas. .
Note that if the CO ₂ concentration is high, the combustion efficiency tends to decrease.

Moreover, a partial oxidation reaction can also be utilized as one method for reducing the CH ₄ concentration and increasing the CO concentration. The introduction of a large amount of air causes a reduction in combustion efficiency, but the combustion efficiency can be improved if CH ₄ production is significantly suppressed by introduction of a small amount.

As described above, in the hydrogen-containing gas supply method of the present invention, the ethanol reforming reaction is performed under the conditions of 200 to 600 ° C., Steam / Carbon = 0.1 to 3, and O ₂ / Carbon = 0 to 0.5. However, if the reformer is large, the installation location and the heat capacity of the reformer itself become a problem.
Therefore, it is desirable that the reformer is as small as possible, and it is preferable that the ethanol reforming reaction can be performed with a permeate gas amount of LHSV = 10 h ⁻¹ or more, more preferably 20 h ⁻¹ or more.
In this case, the CH ₄ concentration can be lowered, and the apparatus can be used as a small and efficient hydrogen-containing gas supply device.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in full detail, this invention is not limited to these Examples.

Example 1
Using a catalyst prepared solution of rhodium nitrate (11.4%) were impregnated with Rh in CeO _2. Rh was impregnated so as to be 4% (in metal conversion) with respect to the obtained catalyst powder. After drying at 150 ° C. for 4 hours, calcination was performed at 500 ° C. for 1 hour to obtain 4% Rh / CeO ₂ catalyst powder.
The 4% Rh / CeO ₂ catalyst powder, alumina sol, and water were put into a magnetic ball mill pot and mixed and pulverized for 2 hours to form a slurry. The slurry was applied to the honeycomb, dried by ventilation at 130 ° C., and fired at 400 ° C. for 1 hour to obtain Catalyst 1. Catalyst 1 was applied at 60 g / L.

(Example 2)
Using a catalyst prepared solution of di-Nin Toro diamine platinum solution (8.5%) were impregnated with Pt to CeO _2. Pt was impregnated so as to be 4% (in metal conversion) with respect to the obtained catalyst powder. After drying at 150 ° C. for 4 hours, calcination was performed at 500 ° C. for 1 hour to obtain 4% Pt / CeO ₂ catalyst powder.
The 4% Pt / CeO ₂ catalyst powder, alumina sol, and water were put into a magnetic ball mill pot and mixed and pulverized for 2 hours to form a slurry. The slurry was applied to the honeycomb, dried by ventilation at 130 ° C., and fired at 400 ° C. for 1 hour to obtain Catalyst 2. The catalyst 2 was applied so as to be 60 g / L.

(Example 3)
Using a catalyst prepared solution of rhodium nitrate solution (11.4%) and di nin Toro diamine platinum solution (8.5%) was impregnated with Rh and Pt in CeO _2. Rh and Pt were impregnated so as to be 2% (metal conversion) with respect to the obtained catalyst powder. After drying at 150 ° C. for 4 hours, calcination was performed at 500 ° C. for 1 hour to obtain 2% Rh-2% Pt / CeO ₂ catalyst powder.
The 2% Rh-2% Pt / CeO ₂ catalyst powder, alumina sol, and water were placed in a magnetic ball mill pot and mixed and pulverized for 2 hours to form a slurry. The slurry was applied to the honeycomb, dried by ventilation at 130 ° C., and fired at 400 ° C. for 1 hour to obtain Catalyst 3. Catalyst 3 was applied so as to be 60 g / L.

Example 4
While stirring the 30% nitric acid solution, cerium carbonate, niobium sol (Nb ₂ O ₅ , 10.2% sol) and Hi-Metroze were gradually added and dissolved to prepare a Ce—Nb mixed solution.
Then, it dried at 150 degreeC for 4 hours, baked at 500 degreeC for 2 hours, and obtained Ce-Nb complex oxide (80:20 (mol%)). Moreover, Hi-Metroze was made into 1% of the used cerium carbonate.
Next, a catalyst preparation solution in which rhodium nitrate (11.4%) was dissolved in the obtained Ce—Nb composite oxide (80:20 (mol%)) was used, and Rh was converted into Ce—Nb composite oxide (80: 20 (mol%)). Rh was impregnated so as to be 4% (in metal conversion) with respect to the obtained catalyst powder. After drying at 150 ° C. for 4 hours, calcination was performed at 500 ° C. for 1 hour to obtain a 4% Rh / Ce—Nb composite oxide (80:20 (mol%)) catalyst powder.
The 4% Rh / Ce—Nb composite oxide (80:20 (mol%)) catalyst powder, alumina sol, and water were placed in a magnetic ball mill pot and mixed and ground for 2 hours to form a slurry. The slurry was applied to the honeycomb, dried by ventilation at 130 ° C., and fired at 400 ° C. for 1 hour to obtain a catalyst 4. The catalyst 4 was applied so as to be 60 g / L.

(Example 5)
The same operation as in Example 4 was repeated to obtain a Ce—Nb composite oxide (80:20 (mol%)).
Next, using a catalyst preparation solution in which dinintrodiamine platinum solution (8.5%) was dissolved, Pt was impregnated with Ce-Nb composite oxide (80:20 (mol%)). Pt was impregnated so as to be 4% (in metal conversion) with respect to the obtained catalyst powder. After drying at 150 ° C. for 4 hours, calcination was performed at 500 ° C. for 1 hour to obtain 4% Pt / Ce—Nb composite oxide (80:20 (mol%)) catalyst powder.
The 4% Pt / Ce—Nb composite oxide (80:20 (mol%)) catalyst powder, alumina sol, and water were placed in a magnetic ball mill pot and mixed and ground for 2 hours to form a slurry. The slurry was applied to the honeycomb, dried by ventilation at 130 ° C., and fired at 400 ° C. for 1 hour to obtain catalyst 5. The catalyst 5 was applied so as to be 60 g / L.

(Example 6)
The same operation as in Example 4 was repeated to obtain a Ce—Nb composite oxide (80:20 (mol%)).
Next, a catalyst preparation solution in which rhodium nitrate (11.4%) and dinintrodiamine platinum solution (8.5%) were dissolved was used, and Rh and Pt were converted into Ce—Nb composite oxide (80:20 (mol%)). ). Rh and Pt were impregnated so as to be 2% (metal conversion) with respect to the obtained catalyst powder. After drying at 150 ° C. for 4 hours, calcination was performed at 500 ° C. for 1 hour to obtain 2% Rh-2% Pt / Ce—Nb composite oxide (80:20 (mol%)) catalyst powder.
The 2% Rh-2% Pt / Ce—Nb composite oxide (80:20 (mol%)) catalyst powder, alumina sol, and water were placed in a magnetic ball mill pot and mixed and ground for 2 hours to form a slurry. The slurry was applied to the honeycomb, dried by ventilation at 130 ° C., and fired at 400 ° C. for 1 hour to obtain catalyst 6. The catalyst 6 was applied so as to be 60 g / L.

(Comparative Example 1)
Using a catalyst preparation solution in which rhodium nitrate (11.4%) was dissolved, Rh was impregnated in Al ₂ O ₃ . Rh was impregnated so as to be 4% (in metal conversion) with respect to the obtained catalyst powder. After drying at 150 ° C. for 4 hours, calcination was performed at 500 ° C. for 1 hour to obtain 4% Rh / Al ₂ O ₃ catalyst powder.
The 4% Rh / Al2O3 catalyst powder, alumina sol, and water were put into a magnetic ball mill pot and mixed and pulverized for 2 hours to form a slurry. The slurry was applied to the honeycomb, dried by ventilation at 130 ° C., and fired at 400 ° C. for 1 hour to obtain catalyst 7. Catalyst 7 was applied at 60 g / L.

(Comparative Example 2)
Using a catalyst prepared solution of cobalt nitrate was impregnated with Co in CeO _2. Co was impregnated so as to be 4% (metal conversion) with respect to the obtained catalyst powder. After drying at 150 ° C. for 4 hours, calcination was performed at 500 ° C. for 1 hour to obtain 4% Co / CeO ₂ catalyst powder.
The 4% Co / CeO ₂ catalyst powder, alumina sol, and water were put into a magnetic ball mill pot and mixed and ground for 2 hours to form a slurry. The slurry was applied to the honeycomb, dried by ventilation at 130 ° C., and fired at 400 ° C. for 1 hour to obtain catalyst 8. The catalyst 8 was applied so as to be 60 g / L.

(Comparative Example 3)
Using a catalyst prepared solution of nickel nitrate was impregnated with Ni to CeO _2. Ni was impregnated so as to be 4% (metal conversion) with respect to the obtained catalyst powder. After drying at 150 ° C. for 4 hours, calcination was performed at 500 ° C. for 1 hour to obtain 4% Ni / CeO ₂ catalyst powder.
The 4% Ni / CeO ₂ catalyst powder, alumina sol, and water were put into a magnetic ball mill pot and mixed and pulverized for 2 hours to form a slurry. The slurry was applied to the honeycomb, dried by ventilation at 130 ° C., and fired at 400 ° C. for 1 hour to obtain a catalyst 9. The catalyst 9 was applied so as to be 60 g / L.

Each catalyst was evaluated by adjusting ethanol and water so that Steam / Carbon = 1.5 and LHSV = 20 h ⁻¹ , changing the reaction temperature, and measuring the ethanol conversion and outlet concentration.
In addition, as a pretreatment of the catalyst, it was treated with a 10% H ₂ / N ₂ balance gas in an H ₂ stream at 500 ° C. for 1 hour.
The results at the inlet gas temperature of 380 ° C. are shown in Table 1.

  From Table 1, it can be seen that the ethanol reforming catalyst which is a preferred embodiment of the present invention is excellent in reforming performance.

It is the schematic which shows an example of the combustion system provided with the hydrogen containing gas supply apparatus.

Explanation of symbols

1 Hydrogen-containing gas supply device 2 Fuel tank 3 Combustion chamber

Claims (9)

  An ethanol reforming catalyst, wherein platinum and / or rhodium are supported on an inorganic oxide containing cerium and / or niobium.   2. The ethanol reforming catalyst according to claim 1, wherein the platinum is supported by 0.5 to 6% with respect to the total amount of catalyst.   The ethanol reforming catalyst according to claim 1 or 2, wherein the rhodium is supported in an amount of 0.1 to 10% based on the total catalyst amount.   The ethanol reforming catalyst according to claim 1 or 2, wherein platinum is supported on a complex oxide of cerium and niobium.   4. The ethanol reforming catalyst according to claim 1, wherein rhodium is supported on ceria. A method for supplying a hydrogen-containing gas to an internal combustion engine using the ethanol reforming catalyst according to any one of claims 1 to 5,
A method for supplying a hydrogen-containing gas, characterized in that ethanol is brought into contact with the ethanol reforming catalyst under the conditions of 200 to 600 ° C., Steam / Carbon = 0.1 to 3, and O ₂ / Carbon = 0 to 0.5. .   The method for supplying a hydrogen-containing gas according to claim 6, wherein a hydrogen-containing gas containing 10% or more of hydrogen is supplied to the internal combustion engine.   The hydrogen-containing gas supply method according to claim 6 or 7, wherein a hydrogen-containing gas containing 5% or more of carbon monoxide is supplied to the internal combustion engine. The method for supplying a hydrogen-containing gas according to any one of claims 6 to 8, wherein the ethanol reforming reaction is performed with a permeate gas amount of LHSV = 10h ^-1 or more.

Images