JPH06279001A - Production of hydrogen-containing gas - Google Patents

Abstract

PURPOSE:To provide a process for the production of a hydrogen-containing gas in high efficiency at a low cost while keeping high methanol conversion and suppressing the production of CO and suitable for the production of a fuel for solid polymer fuel cell, phosphate-type fuel cell, etc. CONSTITUTION:A hydrogen-containing gas is produced by mixing methanol with oxygen and water to obtain a mixture containing 0.01-0.5mol of oxygen based on 1mol of methanol, introducing the mixture into a catalyst layer heated at >=100 deg.C to effect the reaction of the components and adjusting the outlet temperature of the catalyst layer to <=200 deg.C when the above reaction teaches a stationary state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing hydrogen-containing gas, and more particularly, it is suitable for producing fuels such as polymer electrolyte fuel cells and phosphoric acid fuel cells, and maintains a high methanol conversion rate. In addition, the present invention relates to a method for producing a hydrogen-containing gas, which can suppress the production of CO to a low level and can economically and efficiently produce a hydrogen-containing gas.

[0002]

2. Description of the Related Art Conventionally, a method for producing a hydrogen-containing gas using methanol and water as raw materials has been known. This method is used in fuel cell fuel production, on-site hydrogen production, and other processes. In the process such as fuel production of the fuel cell,
It is required to minimize the production of inhibitors in the process and keep the efficiency high.

It is known that CO becomes an inhibitory substance of the reaction in the process such as fuel production of the fuel cell. However, since CO is produced by the method for producing the hydrogen-containing gas, it is necessary to suppress the production of CO as low as possible when using this method for producing the fuel of the fuel cell. Specifically, for example, in the fuel production of a phosphoric acid fuel cell, C
It is necessary to suppress the production of O to 1% or less, and in the fuel production of a polymer electrolyte fuel cell, the production of CO is tens of p
It is necessary to keep it below pm.

By the way, as a conventional method for producing such a hydrogen-containing gas, methanol and water are used as raw materials,
A method for producing a hydrogen-containing gas using a copper-based catalyst is known. The reaction of this method is represented by the following formula (1), and its elementary reaction is represented by formula (2) and formula (3).

CH ₃ OH + H ₂ O → CO ₂ + 2H ₂・ ・ ・ (1) CH ₃ OH → CO + 2H ₂・ ・ ・ ・ ・ ・ (2) CO + H ₂ O → CO ₂ + 2H ₂・ ・ ・ ・ ・(3) In the above reaction, since the reaction of the formula (2) is an endothermic reaction, it is necessary to raise the reaction temperature in order to improve the conversion rate of methanol. On the other hand, the reaction of the formula (3) is an exothermic reaction, so that the reaction does not proceed under high temperature conditions and CO
Will remain a lot. Therefore, in order to reduce the CO concentration in this reaction, it is necessary to increase the water / methanol ratio or carry out the reaction under low temperature conditions.

However, in the method of increasing the water / methanol ratio, water as a raw material has to be vaporized, so that there is a problem in that the cost and energy for that purpose increase and it is not economical.

Therefore, a method for producing a hydrogen-containing gas at a low reaction temperature by using a catalyst having a high activity even under the low temperature condition has been studied. For example, in Japanese Unexamined Patent Publication No. Hei 4-139001, low temperature and high activity copper,
230 materials using zinc, chromium, iron, etc. as catalysts and having a water-methanol ratio (water / methanol) of 1.2
It is shown that when the reaction is carried out at 0 ° C., the methanol conversion rate can be maintained as high as 98.3% and the CO concentration can be suppressed as low as 1.3%.

However, at present, the above-mentioned results described in the above-mentioned publication are limited, and it is the actual situation that the concentration of CO produced cannot be suppressed to a lower level. Therefore, even in the method described in the above publication, which uses a low-temperature and high-activity catalyst, there is a problem in that it is not possible to expect a significant reduction in CO concentration while maintaining a high methanol conversion rate.

On the other hand, a method of producing hydrogen-containing gas by reacting oxygen in the presence of a copper-based or noble metal-based catalyst at the time of methanol steam reforming is disclosed in, for example, JP-A-61-161.
No. 127601 and Japanese Patent Laid-Open No. 2-116603. However, these publications do not describe reduction of CO concentration or high methanol conversion rate, and these methods have a problem that CO generation cannot be suppressed low while maintaining high methanol conversion rate. is there.

The present invention solves the above problems and
It is suitable for producing fuels such as polymer electrolyte fuel cells and phosphoric acid fuel cells, and can keep CO production low while maintaining high methanol conversion rate, and produce hydrogen-containing gas economically and efficiently. An object of the present invention is to provide a method for producing a hydrogen-containing gas that can be used.

[0011]

In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that the catalyst layer previously heated to 100 ° C. or higher contains methanol and 0.01 to 1 mol of methanol. The reaction is carried out by introducing 0.5 mol of oxygen and water, and after the reaction has reached a steady state, the temperature of the outlet part of the catalyst layer is adjusted to 200 ° C. or lower. It is a manufacturing method, and the invention described in claim 2 is the method for manufacturing a hydrogen-containing gas according to claim 1, wherein oxygen introduced into the catalyst layer is in a ratio of 0.25 to 0.5 mol per mol of methanol. Is the way.

The method for producing the hydrogen-containing gas according to the present invention will be described in detail below.

In the present invention, first, methanol 1
A raw material containing methanol, oxygen, and water is prepared so that oxygen has a predetermined ratio with respect to moles.

As the methanol and water, pure products may be used, or an aqueous methanol solution may be used. As oxygen, pure oxygen gas may be used, or oxygen-containing gas obtained by mixing oxygen with an inert gas such as nitrogen or argon, or air may be used.

The ratio of oxygen to methanol is
Usually, oxygen is 0.01 to 0.5 per mol of methanol.
The amount of oxygen is 0.25 to 0.5 mol, preferably 1 mol of methanol. When the ratio of oxygen to 1 mol of the methanol is within the above range, CO generation can be suppressed to a low level, and a decrease in hydrogen generation amount can be suppressed.

The proportion of water is usually 1.0 to 2.5 mol per 1 mol of methanol, and preferably 1.2 to 2.0 mol per 1 mol of methanol. When the proportion of water is within the above range, the production of CO can be reduced. The ratio of water is 1 mol of methanol,
If it is less than 1.0 mol, CO may not be removed sufficiently, while if it exceeds 2.5 mol, the energy used for vaporizing water increases, which is not economical and reduces efficiency. Sometimes.

The method of supplying methanol, oxygen and water to the catalyst layer may be any method as long as these three coexist in the catalyst layer. For example, methanol and water may be supplied together or separately. In addition, a method of supplying a raw material gas obtained by supplying oxygen to vapor which is heated and vaporized by an appropriate method to the catalyst layer can be mentioned. Specifically, for example, methanol and water are gasified using different evaporators, respectively, and then a raw material gas is obtained by mixing this with air, and the raw material gas is supplied to the catalyst layer by a method such as methanol. A method of gasifying an aqueous solution using an evaporator to prepare a mixed gas containing methanol and water, mixing the mixed gas with an oxygen-containing gas to prepare a raw material gas, and supplying the raw material gas to a catalyst layer. Can be mentioned. In addition to this, a method of separately supplying vaporized methanol, water vapor, oxygen gas or oxygen-containing gas to the catalyst layer, a vapor obtained by vaporizing a methanol aqueous solution and oxygen or oxygen-containing gas are supplied to the catalyst layer. The method of doing can also be mentioned.

In the present invention, next, the methanol, oxygen and water are introduced into the catalyst layer which has been heated to 100 ° C. or more in advance, and these are reacted with each other, and after the reaction reaches a steady state, the catalyst layer Temperature of the outlet is 200 ℃
A hydrogen-containing gas is produced by the following.

The catalyst layer is, for example, a catalyst layer filled in a properly selected reactor such as a reformer known per se, a catalyst layer supported on a honeycomb, or a catalyst layer supported on a tube wall inside the reaction tube. The catalyst layer etc. which were formed can be mentioned.

The catalyst constituting the catalyst layer is not particularly limited as long as it is a catalyst which can be generally used in a methanol steam reforming reaction, and examples thereof include a copper-containing catalyst and VI.
Examples thereof include Group II metal-supported catalysts.

Examples of the copper-containing catalyst include CuO-
MeO _x (in the Formula, MeO _x represents a metal oxide, Me represents Mn, represents a metal such as Si.) Copper oxide kneaded catalyst represented by, Cu ion exchange MeO _x (where
In the formula, MeO _x represents a metal oxide such as SiO ₂ , ZnO ₂ , and Al ₂ O ₃ . ) Copper ion exchange catalyst, Cu / Al ₂ O ₃ , Cu / SiO _{2 and} other copper oxide-supported catalysts, CuO.ZnO, CuO.ZnO.Al ₂ O ₃ ,
CuO / Cr ₂ O ₃ , CuO / NiO, CuO / NiO
A copper-containing coprecipitation catalyst such as ZnO may be mentioned.

Examples of the Group VIII metal-supported catalyst include metals such as Co, Ni, Pt and Pd, and SiO ₂ and Z.
A catalyst having a metal oxide such as rO ₂ or Al ₂ O ₃ can be mentioned.

Of these, the copper-containing catalyst is preferable, and the copper-containing coprecipitation catalyst is particularly preferable. These are preferable because they have high activity at low temperatures and can reduce by-products such as aldehyde and formic acid.

The copper-containing catalyst is, for example, a copper-nickel-zinc combination, and the copper-containing coprecipitation catalyst is, for example, a copper-cobalt-zinc combination or copper-nickel-lanthanum. A copper-containing coprecipitation catalyst consisting of a combination of

As the copper-containing catalyst composed of the combination of copper-nickel-zinc, for example, copper is 5 to 30% by weight, nickel is 5 to 50% by weight, and zinc is 30 to 90% by weight.
A copper-containing catalyst obtained by eluting inactive zinc with an alkali can be mentioned as a catalyst by expanding the alloys contained therein. The zinc elution amount is usually 10 to 90% by weight of the zinc content in the alloy. The development is usually carried out at a temperature of 20 to 100 ° C. by
For example, it can be carried out according to a usual developing method of treating with an alkaline solution such as an aqueous solution of caustic soda, an aqueous solution of caustic potash, and an aqueous solution of potassium carbonate.

In the expanded alloy obtained by the above expansion,
The content ratio of copper, nickel and zinc is 10 to 50 for copper.
% By weight, 20-80% by weight nickel and 10% zinc
-60% by weight. When the contents of copper, nickel and zinc are within the above ranges, the activity can be maintained for a long time and the production of by-products can be suppressed to a low level, which is preferable.

This copper-containing catalyst can be prepared, for example, by separating the spread alloy, washing with water, drying, shaping, and reducing.

The separation can be carried out by a usual solid-liquid separation method such as filtration, centrifugation, decantation and the like. The washing with water is performed for the purpose of removing the alkaline solution, and can be performed by, for example, a gradient method using distilled water or ion-exchanged water. The drying can be performed by air-drying for 3 to 12 hours. The molding may be performed in various shapes such as a tablet shape, a pellet shape, a granular shape, a strip shape, and a plate shape by adding graphite as a lubricant to the spread alloy by, for example, a press molding method, a tablet molding method, or the like. You can The reduction can be usually performed in a hydrogen atmosphere at 200 to 500 ° C., or can be performed by diluting with an inert gas such as helium gas, neon gas, argon gas or nitrogen gas.

As the copper-containing coprecipitation catalyst comprising the combination of copper-cobalt-zinc, for example, the ratio of each element, that is, the atomic ratio is Cu: Co: Zn = 1: 0.01-5.
0: 0.1 to 1,000, preferably Cu: Co: Zn
A copper-containing coprecipitation catalyst having a ratio of 1: 1 to 10: 1 to 20 can be mentioned. When the atomic ratio is within the above range, a copper-containing coprecipitated catalyst having desired performance can be obtained, which is preferable.

As the copper-containing coprecipitation catalyst comprising the combination of copper-nickel-lanthanum, for example, the ratio of each element, that is, the atomic ratio is Cu: Ni: La = 1: 1.
0.01-50: 0.1-1,000, preferably C
Mention may be made of a copper-containing coprecipitation catalyst in which u: Ni: La = 1: 1 to 10: 1 to 20. When the atomic ratio is within the above range, a copper-containing coprecipitated catalyst having desired performance can be obtained, which is preferable.

The above elements contained in the copper-containing coprecipitation catalyst are
Usually, it can be obtained from a water-soluble salt. Examples of such salts include nitrates, acetates, sulfates, oxalates, formates and the like. More specifically,
Copper nitrate, copper acetate, copper sulfate, copper oxalate, copper formate, cobalt nitrate, cobalt acetate, cobalt sulfate, cobalt oxalate, cobalt formate, zinc nitrate, zinc acetate, zinc sulfate, zinc oxalate, zinc formate, nickel nitrate , Nickel acetate,
Examples thereof include nickel sulfate, nickel oxalate, nickel formate, lanthanum nitrate, lanthanum acetate, lanthanum sulfate, lanthanum oxalate, and lanthanum formate.

For the preparation of these copper-containing coprecipitated catalysts,
This will be described below.

First, a mixture of a water-soluble salt of copper, a water-soluble salt of cobalt and a water-soluble salt of zinc, or a mixture of a water-soluble salt of copper, a water-soluble salt of nickel and a water-soluble salt of lanthanum and a precipitant. A precipitate is formed by mixing with an aqueous solution of (sodium carbonate, potassium carbonate, caustic soda, caustic potash, etc.).

The concentration of the water-soluble salt in the mixed solution is usually 0.1 to 10 mol / L, preferably 0.5 to 5 mol / L. The precipitating agent is not particularly limited, but sodium carbonate is preferred. The concentration of the precipitating agent in the aqueous solution is preferably 0.05 to 5 mol / L. The liquid amount ratio (volume ratio) of the mixed liquid and the precipitant aqueous solution is preferably 0.1 to 10. When the mixed solution and the precipitant aqueous solution are mixed, the temperature of both solutions is usually 50 to 50.
The temperature is 90 ° C, preferably 60 to 85 ° C. The mixing of the mixed solution and the aqueous precipitant solution is preferably carried out rapidly.

After mixing, the mixed solution is aged. It is known that when the new precipitate immediately after co-precipitation is formed, it is allowed to contact with the mother liquor, and the precipitated particles grow and grow, and the sharp parts and edges of the precipitate disappear and become smooth. Precipitation of various particles will be obtained. Further, since the pH of the solution changes during the aging, it is considered that the crystal structure and the chemical composition are changed, and the aging operation is necessary to obtain a catalyst with good reproducibility. As the aging conditions, the temperature is 50 to 90 ° C., the aging time is 1 to 10 hours, and p
H is preferably 8 to 11.

The copper-containing coprecipitated catalyst can be obtained by washing the coprecipitate obtained as described above with water, drying it, and calcining it sufficiently. The drying temperature is usually 100 to 120 ° C., and the drying time is
It is usually 5 to 20 hours. The firing temperature is usually 300 to 600 ° C., and the firing time is usually 1 to 10 hours.

The length and cross-sectional area of the catalyst layer can be appropriately selected depending on the conditions such as heat transfer in the reactor, feed rate of raw materials and reaction pressure.

In the present invention, before introducing the methanol, oxygen and water into the catalyst layer, the catalyst layer is preheated to 100 ° C. or higher. 1 for the catalyst layer in advance
For heating to a temperature of 00 ° C. or higher, for example, the reformer or reaction tube as a catalyst layer is placed inside a heating device such as an electric furnace with an automatic control function capable of automatically heating to a set temperature. A method of supplying heat from the heating device to the catalyst layer can be adopted. The heating is preferably performed in an N ₂ gas atmosphere. The temperature of the catalyst layer is
For example, it can be measured by inserting a thermocouple protection tube into the catalyst layer and inserting a thermocouple into the protection tube.

In the present invention, the catalyst layer is 100
After heating to a temperature of not lower than 0 ° C., the catalyst layer can be appropriately subjected to a treatment such as hydrogen reduction.

The introduction of the raw material gas into the catalyst layer can be carried out, for example, by pressure feeding, blower or the like.

The pressure for reacting the raw material gas in the catalyst layer is usually from atmospheric pressure to 30 Kg / cm ^2.
G, preferably normal pressure to 10 Kg / cm ² G. When the pressure is within the above range, the conversion rate of methanol can be kept high, which is preferable. The feed rate of the raw material (gas space velocity) is usually 100 to
100,000 (h ^-1 ), preferably 1,000
˜10,000 (h ⁻¹ ).

In the present invention, after the reaction of the raw material gas in the catalyst layer reaches a steady state, the temperature at the outlet of the catalyst layer is set to 200 ° C. or lower. The steady state is a state in which the change in temperature distribution in the catalyst layer is stable. The temperature at the outlet of the catalyst layer is set to 200
In order to reduce the temperature to not higher than 0 ° C, for example, a method of reducing the heat supply amount of a heating device that houses the catalyst layer or a method of stopping the heat supply, a method of using cooling water, and the like can be appropriately selected. it can. Among these, the method of reducing the heat supply amount of the heating device and the method of stopping the heat supply are preferable because it is not necessary to provide a cooling device or the like.

Next, the mechanism of the reaction for producing the hydrogen-containing gas in the present invention will be described.

First, when a raw material gas containing the raw materials methanol, oxygen and water is introduced into the catalyst layer which has been heated to 100 ° C. or higher in advance, the vicinity of the inlet of the catalyst layer (hereinafter referred to as the inlet portion of the catalyst layer). On the catalyst, methanol and oxygen react as in formula (4) shown below.

CH ₃ OH + 3 / 2O ₂ → CO ₂ + 2H ₂ O (4) Since the reaction of the above formula (4) is a large exothermic reaction, the temperature of the inlet portion of the catalyst layer rises due to this reaction. . Due to the heat generated by this exothermic reaction, the above formula (2)
The endothermic reaction represented by is promoted, and the methanol introduced into the catalyst layer is almost completely converted.

At this time, if the heating temperature of the catalyst layer is lower than 100 ° C., the reaction represented by the formula (4) does not proceed sufficiently, and the heat generated by this reaction is absorbed by the formula (2). Since it cannot supply enough for the reaction,
The reaction represented by the formula (2) cannot be promoted, and the conversion rate of methanol cannot be increased. Further, if the proportion of oxygen is less than 0.01 mol with respect to 1 mol of methanol, the exothermic reaction represented by the above formula (4) does not sufficiently occur, so the heat generated by the exothermic reaction represented by the above formula (4) is generated. May not be sufficiently supplied to the endothermic reaction represented by the above formula (2), and the conversion of methanol to hydrogen may not be sufficient. On the other hand, if it exceeds 0.5 mol, a large amount of methanol is consumed in the exothermic reaction represented by the above formula (4), and the amount of hydrogen generated from the endothermic reaction represented by the above formula (2) is greatly reduced. However, this is not preferable because the hydrogen generation efficiency may be reduced.

Thereafter, the heat generation due to the reaction represented by the above formula (4) and the heat absorption due to the reaction represented by the above formula (2) are balanced, the temperature distribution of the catalyst layer is stabilized, and the catalyst layer is in a steady state. .

Then, in the vicinity of the outlet of the catalyst layer whose temperature is maintained at 200 ° C. or lower by an appropriate method (hereinafter referred to as the outlet of the catalyst layer), it is mainly represented by the above formula (3). The reaction proceeds and a hydrogen-containing gas is produced.

At this time, if the temperature at the outlet of the catalyst layer is higher than 200 ° C., the exothermic reaction represented by the above (3) becomes difficult to proceed, and the by-product CO is converted to CO _2. In some cases, the amount of CO cannot be reduced. The lower limit of the temperature at the outlet of the catalyst layer matches the lower limit of the temperature at which the endothermic reaction represented by the above formula (2) can proceed.

In the present invention, the hydrogen-containing gas can be produced economically when the temperature at the outlet of the catalyst layer is set to 200 ° C. or lower, the heat supply from the heating device is stopped and the electric power is reduced. This is a mode in which the hydrogen-containing gas generation reaction proceeds while suppressing the consumption.

In this case, since heat is not supplied to the catalyst layer from the outside and the heat of the catalyst layer is consumed by the endothermic reaction represented by the above formula (2), the heat is continuously consumed as it is and the temperature of the catalyst layer is increased. When it decreases, the reaction represented by the above formula (2), which is an endothermic reaction, does not proceed, the conversion of methanol decreases, and the amount of hydrogen-containing gas produced decreases.
However, even if the heat supply from the outside is stopped, the above equation (4)
If the amount of heat (a) generated by the exothermic reaction represented by the formula (2) can be maintained in a state (a ≧ b) larger than the amount of heat (b) consumed by the endothermic reaction of the formula (2), A hydrogen-containing gas can be produced without impeding the progress of the reaction shown and without lowering the conversion of methanol. The proportion of oxygen in the raw material gas for a ≧ b is 0.25 to 0.5 with respect to 1 mol of methanol.
It is a mole.

As described above, according to the present invention, the production of CO can be suppressed to a low level while maintaining a high methanol conversion rate, and the amount of heat supplied from the outside can be reduced, which is economical and efficient. A hydrogen-containing gas can be produced well.

[0053]

Embodiments of the present invention will be described below. The present invention is not limited to the following embodiments.

(Preparation of catalyst) An aqueous sodium carbonate solution was added to an aqueous solution containing copper nitrate (trihydrate), zinc nitrate (hexahydrate) and aluminum nitrate (decahydrate) to form a precipitate. . Then, this precipitate was filtered and washed with water. The obtained precipitate was dried at a temperature of 120 ° C. for about 12 hours and then calcined at 450 ° C. for 2 hours to prepare a copper-containing coprecipitation catalyst composed of a combination of copper-zinc-aluminum.

The ratio of each element in this copper-containing coprecipitation catalyst was Cu: Zn: Al = 1: 2: 0.5 (molar ratio). This catalyst was used in the following examples and comparative examples.

(Example 1) 5 cc of the copper-containing coprecipitated catalyst molded into 16 to 32 mesh and 10 cc of inactive silicon carbide (SiC) were mixed and filled in a reaction tube made of quartz glass to form a catalyst layer. Formed. At this time, the length of the catalyst layer was about 8 cm. Then, the quartz glass reaction tube was placed in an electric furnace capable of being automatically controlled to a predetermined temperature.

After the hydrogen reduction was carried out at 300 ° C. for 2 hours before using the catalyst layer, the temperature inside the furnace set to heat the reaction tube in N ₂ gas (hereinafter referred to as the furnace heating temperature) Was maintained at 220 ° C.

Next, by inserting a thermocouple protection tube into the center of the catalyst layer formed in the quartz glass reaction tube, and inserting the thermocouple into the protection tube and moving it up and down, the catalyst 1c from the catalyst layer inlet in the bed
The temperature at each point of m (inlet in catalyst layer), 4 cm, and 7 cm (outlet in catalyst layer) was measured. The average value of the temperatures at the three points was taken as the average catalyst temperature.

Then, a raw material gas consisting of methanol, oxygen and water, in which 1.6 mol of water is 1 mol to 1 mol of methanol and 0.3 mol of oxygen is 1 mol of methanol, a feed rate of methanol ( LHSV) is 4.3 h ^-1 ,
It was introduced into the catalyst layer and reacted under the condition that the reaction pressure was normal pressure. Then, the furnace heating temperature was maintained at 220 ° C. for about 5 minutes until the temperature distribution in the catalyst layer became stable.

Thereafter, the furnace heating temperature is lowered to 200 ° C., and 1
After a lapse of time, the temperature distribution in the catalyst layer during the reaction was measured, and then the produced gas was analyzed. The results are shown in Table 1. As a result, a hydrogen-containing gas containing hydrogen gas at a high rate of 70.0% was obtained, while maintaining a high methanol conversion rate of 100%, the CO concentration in the dry gas was as low as 0.5%. I was able to suppress it.

Example 2 The furnace heating temperature was changed from 220 ° C. to 2
A hydrogen-containing gas was produced in the same manner as in Example 1 except that the temperature was lowered to 00 ° C. and 220 ° C. to 150 ° C. The results are shown in Table 1. As a result, a hydrogen-containing gas containing hydrogen gas at a high ratio of 70.0% was obtained, and while maintaining a high methanol conversion rate of 99.5%, the CO concentration in the dry gas was 0.4%. We were able to keep it low.

(Example 3) The furnace heating temperature was changed from 220 ° C to 2
A hydrogen-containing gas was produced in the same manner as in Example 1 except that the temperature was lowered to 00 ° C. and 220 ° C. to 120 ° C. The results are shown in Table 1. As a result, a hydrogen-containing gas containing hydrogen gas at a high rate of 69.8% was obtained, and while maintaining a high methanol conversion rate of 99.4%, the CO concentration in the dry gas was 0.4%. We were able to keep it low.

(Example 4) The furnace heating temperature was changed from 220 ° C to 2
A hydrogen-containing gas was produced in the same manner as in Example 1 except that the temperature was lowered to 00 ° C. and 220 ° C. to 100 ° C. The results are shown in Table 1. As a result, a hydrogen-containing gas containing hydrogen gas at a high rate of 69.9% was obtained, and while maintaining a high methanol conversion rate of 92.5%, the CO concentration in the dry gas was 0.3%. We were able to keep it low.

(Embodiment 5) The furnace heating temperature is changed from 220 ° C. to 2
When the temperature was lowered to 00 ℃, the heat supply from the outside was stopped,
A hydrogen-containing gas was produced in the same manner as in Example 1 except that the temperature was naturally decreased from 220 ° C. The results are shown in Table 1. As a result, a hydrogen-containing gas containing hydrogen gas at a high ratio of 69.9% was obtained, and
While maintaining a high methanol conversion rate of 2.6%, the CO concentration in the dry gas could be suppressed to a low value of 0.3%.

(Comparative Example 1) The furnace heating temperature was changed from 220 ° C to 2
Example 1 except that the temperature was lowered to 00 ° C. and maintained at 220 ° C.
A hydrogen-containing gas was produced in the same manner as in. The results are shown in Table 1.
It was shown to. As a result, only a hydrogen-containing gas containing hydrogen gas at a low ratio of 69.5% was obtained, and although the methanol conversion rate was as high as 100%, the CO concentration in the dry gas was 1.0. It became a high value of%.

From the results of Examples 1 to 5 and Comparative Example 1, when the furnace heating temperature is not lowered and the temperature of the outlet of the catalyst layer is not lower than 200 ° C., the hydrogen gas production efficiency is poor and It can be seen that the production of CO, which is a living organism, cannot be suppressed low.

Example 6 A hydrogen-containing gas was produced in the same manner as in Example 1 except that the furnace heating temperature of 220 ° C. when introducing the source gas was changed to 110 ° C. As a result, the average catalyst temperature before the reaction was 108 ° C, but when the reaction started, the temperature at the inlet of the catalyst layer reached about 300 ° C after 3 to 4 minutes. After that, the reaction became a steady state, and the hydrogen-containing gas could be efficiently produced.

(Comparative Example 2) The furnace heating temperature was changed from 110 ° C to 9 ° C.
A hydrogen-containing gas was produced in the same manner as in Example 6 except that the temperature was changed to 5 ° C. As a result, even if the raw material gas was introduced, no rise in the temperature of the catalyst layer and generation of the hydrogen-containing gas were observed.

From the results of Example 6 and Comparative Example 2, the furnace heating temperature was set to 100 ° C. before introducing the raw material gas into the catalyst layer.
It can be seen that when the heating is not performed above, the hydrogen-containing gas generation reaction does not start even if the raw material gas is introduced into the catalyst layer.

When the reaction is carried out under the conditions of the present invention,
It is possible to economically and efficiently produce a hydrogen-containing gas having a high hydrogen gas concentration while keeping the methanol conversion rate at a high value and suppressing the CO concentration to be low.

[0071]

[Table 1]

[0072]

According to the present invention, it is suitable for producing fuels such as polymer electrolyte fuel cells and phosphoric acid fuel cells, and it is possible to keep CO generation low while maintaining a high methanol conversion rate. Since the amount of heat supplied from the outside can be reduced, it is possible to provide a method for producing a hydrogen-containing gas that can produce a hydrogen-containing gas economically and efficiently.

Claims (2)

[Claims] 1. Methanol and 0.0 mol per 1 mol of methanol are added to a catalyst layer previously heated to 100 ° C. or higher.
1-0.5 mol of oxygen and water are introduced to carry out a reaction, and after the reaction has reached a steady state, the temperature of the outlet of the catalyst layer is adjusted to 200 ° C. or lower. Gas production method. 2. The method for producing a hydrogen-containing gas according to claim 1, wherein the amount of oxygen introduced into the catalyst layer is 0.25 to 0.5 mol with respect to 1 mol of methanol.