JP2002284502A - Method for manufacturing hydrogen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate hydrogen from 2-propanol that can stably be supplied to a fuel cell. SOLUTION: 2-propanol is heated to a higher temperature than the boiling point and subjected to catalytic steam reforming to generate hydrogen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing hydrogen from 2-propanol by steam reforming.

[0002]

2. Description of the Related Art Methanol, which is relatively low-cost and easily reformable to hydrogen, has been used as a fuel for a fuel cell for remote islands. Recently, methanol has also attracted attention as a fuel for vehicles.

[0003] The steam reforming reaction of methanol is as follows, and is carried out at about 450 ° C using a Cn-Zn catalyst.
A high-temperature reforming method of reforming at about 700 ° C. using a Ni-based catalyst is generally widely used.

CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ On the other hand, 2-propanol (IPA) has a low toxicity and is easy to handle as compared with methanol. It is being used. Since the waste 2-propanol after washing contains a large amount of water and a small amount of impurities, it has been reused as a heating heat source by combustion or by distillation.

Since all of these uses involve combustion,
Exhaust gas containing CO ₂ will be released to the atmosphere.

[0006]

As a method for producing hydrogen from 2-propanol, there is an invention in which an alkali is added to 2-propanol as disclosed in Japanese Patent No. 2976032. Is a production method at a boiling point or lower, which contains acetone produced by a dehydration reaction, and cannot be directly applied to a fuel cell.

In the reforming with a Ni catalyst or a Ru catalyst used for steam reforming of methanol or city gas, 2-
Decomposition of propanol occurs, and unsaturated hydrocarbons (C ₂
H ₄ and C ₃ H ₆ ) generate carbon precipitation,
At present, it has not been put to practical use.

CH ₃ CH (OH) CH ₃ → C ₃ H ₆ + H ₂ O The present invention has been made to solve the above-mentioned problems, and is intended to reduce the amount of hydrogen that can be supplied from 2-propanol to a fuel cell. An object of the present invention is to provide a method for producing hydrogen that can be produced.

[0009]

In order to achieve the above object, the present invention is to produce hydrogen by the following method.

[0010] The invention corresponding to claim 1 produces carbon by heating 2-propanol to a temperature higher than the boiling point and performing steam reforming without depositing carbon using a catalyst.

According to a second aspect of the present invention, in the method for producing hydrogen according to the first aspect, the catalyst comprises:
Rhodium of 8 wt% or more is supported on a carrier.

According to a third aspect of the present invention, in the hydrogen production method according to the second aspect of the present invention, the carrier uses at least one kind selected from alumina, ceria, and zirconia. .

According to a fourth aspect of the present invention, in the hydrogen production method according to the second aspect, steam reforming is performed at a catalyst layer temperature of 350 ° C. or more using the catalyst.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, 2-propanol is heated to a temperature higher than the boiling point and steam reformed using a catalyst. In this case, at least one selected from rhodium as a catalyst and alumina or zirconia as a carrier is used. Among the above carriers, alumina and ceria are preferred. The amount of the metal or oxide supported was preferably 3.6 wt% or more.

Hereinafter, the present invention will be described specifically with reference to examples.

Example 1 The catalysts of Ni, Ru and Rh used in the test were prepared from each nitrate aqueous solution by an impregnation method, and were subjected to a reduction treatment in a stream of steam immediately before the test.

In the test, 1.5 ml / min of 2-propanol and 13.5 ml / min of water were heated using an atmospheric pressure fixed bed flow type reactor, and a carrier gas (helium gas) containing the vapor was heated at 60 ml / min. The min was sent to the catalyst layer and reacted for 30 minutes.
When the generated gas was measured by gas chromatography, a reforming result at a temperature of 400 ° C. as shown in Table 1 was obtained. However, the concentration of the produced gas is indicated by vol%.

[0018]

[Table 1]

As is clear from Table 1, only Rh as a catalyst can stably produce hydrogen gas without producing acetone or propylene which causes carbon deposition.

That is, in the case of the Rh catalyst, since steam reforming proceeds stably via acetone, carbon deposition does not occur.

[0021] The _{CH 3 CH (OH) CH 3} → CH 3 COCH 3 + H 2 CH 3 COCH 3 + H 2 O → 3CO + H 2 O Example 2 then catalyst was changed rhodium supporting amount of the test under the same conditions as above As a result, the modification results as shown in Table 2 were obtained.

[0022]

[Table 2]

As is clear from Table 2, when the supported amount of rhodium is 1.8 wt%, the production of acetone and propylene is suppressed, and when the supported amount is 3.6 wt% or more, hydrogen gas can be obtained stably.

Example 3 Next, a test was conducted on a catalyst using Al2O3, CeO2, ZrO2, TiO2 or the like as a carrier under the same conditions as described above, and the results of reforming as shown in Table 3 were obtained.

[0025]

[Table 3]

As is clear from Table 3, in the catalyst using alumina, ceria, zirconia alone or at least two kinds selected from these, formation of acetone and propylene is suppressed, and hydrogen gas is stably produced. You can see that it is obtained.

Example 4 A test was carried out under the same conditions as above by changing the reforming temperature using 5 wt% Rh / Al 2 O 3 as a catalyst, and the reforming results as shown in Table 4 were obtained.

[0028]

[Table 4]

As apparent from Table 3 above, the reforming temperature was 35
At 0 ° C, the production of acetone and propylene is suppressed,
It is understood that hydrogen gas can be stably obtained at a temperature of not less than ° C.

[0030]

As described above, according to the present invention, 35
A hydrogen production method capable of stably producing hydrogen from 2-propanol by steam reforming at a temperature condition of 0 ° C. and thus effectively utilizing waste 2-propanol containing water as fuel for a fuel cell. Can be provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 23/755 H01M 8/06 G H01M 8/06 B01J 23/74 321M (72) Inventor Tsuyoshi Nakajima Nagano Prefecture 4-17-1 Wakasato, Nagano City Faculty of Engineering, Shinshu University (72) Inventor Takayoshi Mizuno 4-17-1, Wakasato, Nagano City, Nagano Prefecture F-term (Reference) 4G040 EA02 EA06 EC03 4G069 AA03 AA08 BA01A BA01B BA05A BA05B BB04A BB04B BB12C BC43A BC43B BC70B BC71A BC71B BC72B BC75B CC25 DA06 FB14 4G140 EA02 EA06 EC03 5H027 AA02 BA01 KK31 KK42

Claims (4)

[Claims] 1. A method for producing hydrogen, comprising heating 2-propanol to a temperature higher than the boiling point and producing hydrogen by steam reforming using a catalyst. 2. The method for producing hydrogen according to claim 1, wherein
The method for producing hydrogen, wherein the catalyst has 1.8 wt% or more of rhodium supported on a carrier. 3. The method for producing hydrogen according to claim 2, wherein
The method for producing hydrogen, wherein the carrier uses at least one selected from alumina, ceria, and zirconia oxide. 4. The method for producing hydrogen according to claim 2, wherein
A method for producing hydrogen, wherein steam reforming is performed at a catalyst layer temperature of 350 ° C. or higher using the catalyst.