JPH092802A - Hydrogen production equipment - Google Patents

Abstract

(57) [Summary] [Objective] The reactions of a reformer, a carbon monoxide shift converter and a hydrogen purifier used in a conventional process can be collectively carried out to produce high purity hydrogen. To provide a so-called membrane reactor type hydrogen production device with high practicality. An upright burner device 1, a cylindrical radiation plate 2 surrounding the burner device, and a closed annular ceiling plate 10 are enclosed, and a reaction chamber 11 is provided between the cylindrical radiation plate and the radiation plate. An inner cylinder 3 which forms the inside of the reaction chamber 11, a raw material supply pipe 4 having an upper portion opened into the reaction chamber 11 inside the reaction chamber 11, an upright hydrogen permeation pipe 5 which is provided inside the reaction chamber 11 and has a closed upper portion, and a hydrogen permeation pipe. Sweep gas pipe 7 standing upright inside pipe 5, and inner cylinder 3
The outer cylindrical portion 6 that covers the outer periphery of the airtightly and communicates with the combustion chamber 15.
A catalytic combustion pipe 8 penetrating the hydrogen permeable pipe 5 and arranged upright; a reforming catalyst 9A inserted around the hydrogen permeable pipe 5 inside the reaction chamber 11; And the combustion catalyst 9B inserted in the.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for steam reforming hydrocarbons and / or alcohols to produce hydrogen.

[0002]

2. Description of the Related Art A method for producing hydrogen in a reformer by utilizing a steam reforming reaction from hydrocarbons and / or alcohols is widely used industrially. On the other hand, in a fuel cell that operates at about 200 ° C. or lower, the catalyst such as platinum in the electrode is poisoned by CO, so the CO concentration in the hydrogen-containing gas supplied to the fuel cell must be 1% or lower. There is.
Fuel cells that operate at a relatively low temperature of 200 ° C. or less include phosphoric acid type that operates at 150 to 230 ° C., solid polymer membrane type that operates at 100 ° C. or less, and alkaline type, but especially at 100 ° C. or less. In the working solid polymer membrane type,
The CO concentration in the hydrogen-containing gas supplied to the fuel cell is 10 pp
It is said that it must be less than m. Therefore, in order to utilize the hydrogen produced by the conventional method as the fuel gas for the above-mentioned fuel cell, the crude hydrogen is further purified by a carbon monoxide shift converter and a hydrogen purifier to obtain high purity (about C
O of 10 ppm or less), it is considered to be used for a solid polymer membrane fuel cell (polymer fuel cell). The reaction that takes place in this case is as follows in the case of methane.

[0003]

However, the above-mentioned process for purifying hydrogen in high purity has complicated steps, the entire apparatus is large, and a large amount of high-temperature heat energy is required.
In addition, the efficiency of the device is low, and the hydrogen production cost is inevitably high. It is economical to produce high-purity hydrogen that is directly supplied from a city gas or the like to a solid polymer membrane fuel cell. It is extremely difficult to consider.

For this reason, the concept of a membrane reactor that simultaneously processes a reforming reaction and hydrogen purification by allowing a hydrogen separation membrane (membrane) that selectively permeates hydrogen to coexist in the reforming reaction field has already been proposed. No. 17401 and Japanese Patent Application No. 4-321502. However, in these prior applications, only the basic principle of the reactor is proposed, and a practical reactor configuration that can be easily increased in size, in particular, a heating method and a supply / discharge method of each fluid are not shown.

FIG. 4 is a diagram showing the principle of a conventionally proposed membrane reactor type hydrogen production apparatus.

In these prior applications, as shown in FIG. 4, a hydrogen permeation tube that selectively permeates hydrogen is used as an inner tube, and a catalytic reaction tube is arranged as an outer tube in a concentric cylindrical shape outside the inner tube. It has only been shown to fill the annular space between the outer tube and the outer tube with the reforming catalyst and to heat the outer tube wall with a suitable heating medium.

The present invention has been made in consideration of the above points, and the reactions of the reformer, the carbon monoxide shift converter and the hydrogen purifier used in the conventional process are collectively carried out,
An object of the present invention is to provide a so-called membrane reactor type highly practical hydrogen production apparatus capable of producing high-purity hydrogen.

[0008]

In order to solve the above-mentioned problems, the present invention is an apparatus for producing hydrogen from hydrocarbons and / or alcohols by a steam reforming reaction. In the apparatus, an upright burner apparatus and the burner apparatus are surrounded. And a cylindrical radiating plate forming a combustion chamber having an open upper end, and an inner cylinder that surrounds the outer periphery of the radiating plate and forms an annular ceiling plate and a sealed reaction chamber between the radiating plate and the reaction chamber. A raw material supply pipe that surrounds the radiation plate inside and has an upper portion opened into the reaction chamber, and a plurality of upright hydrogen permeation pipes that are provided outside the radiation plate inside the reaction chamber and that seal the upper portion, A plurality of sweep gas pipes provided upright inside the hydrogen permeation pipe and having an open upper end, and the outer periphery of the inner cylinder is hermetically covered with a space therebetween and communicates with a combustion chamber inside the radiation plate. Outer tube part and the water A plurality of catalytic combustion tubes penetrating the permeation tube and arranged upright inside the reaction chamber and having an upper end opened into the outer cylinder portion, and inserted inside the reaction chamber around the hydrogen permeation tube. The reforming catalyst and the combustion catalyst inserted inside the catalytic combustion tube are included.

The present invention is also characterized in that the catalytic combustion pipe passes through the sweep gas pipe.

Further, the present invention is characterized in that the catalytic combustion tube passes through the reforming catalyst in the reaction chamber.

[0011]

The hydrogen producing apparatus of the present invention includes a reforming catalyst, a combustion catalyst,
A hydrogen permeable membrane type reformer consisting of a hydrogen permeation tube (such as a thin film made of palladium or a palladium alloy), a catalytic combustion tube, and a heating burner. It is a high-purity hydrogen directly from hydrocarbons and / or alcohols. Can be built.
That is, high-purity hydrogen can be easily obtained by providing a hydrogen permeation tube through the catalyst layer in the reaction chamber. By providing a burner in the center and a radiant plate around the burner, the radiant heat is efficiently and evenly transmitted to the reforming catalyst layer around the radiant plate, and the hot combustion exhaust gas of the burner is located above and around the reaction chamber. Convection heat and conduction heat are evenly transferred to the reforming catalyst layer by pouring from the bottom. A catalytic combustion tube is installed inside the hydrogen permeation tube, and fuel gas such as city gas and air are allowed to pass through it.
The reforming catalyst layer is also heated from the inside to improve the non-uniformity of the temperature distribution in the reforming catalyst layer, and the sweep gas is supplied as an upflow and becomes a counterflow to the downflow of gas in the catalyst layer, Transmission is efficient. Also, since the chemical equilibrium shifts by using a hydrogen permeation tube, the reforming temperature (700
˜800 ° C.) can be reduced by 150-200 ° C.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical cross-sectional view showing a schematic structure of the hydrogen production apparatus of the present invention.

The hydrogen production apparatus of FIG. 1 is shown with the auxiliary tools, heat insulating material layer and protective cover material attached to the outer periphery thereof removed.

In FIG. 1, an upright cylindrical burner device 1 for burning a fuel such as city gas or natural gas blown from a central hole of a bottom burner tile 12 constructed of an annular refractory material to generate a high temperature combustion gas. Is installed at the center of the hydrogen production equipment.

A cylindrical radiation plate 2 surrounds the outer periphery of the burner device 1 around the central axis of the burner device 1 to form a combustion chamber 15. The high temperature combustion gas generated in the combustion chamber 15 by the burner device 1 is configured to give radiant heat to the radiant plate 2 and to flow from the upper opening 13 of the radiant plate 2 into the outer cylinder part 6 in the direction of arrow A. .

The outer cylinder portion 6 constitutes the outermost side wall of the hydrogen production apparatus, and hermetically seals the side portion and the upper portion of the inner cylinder 3,
The upper opening 13 is provided inside the radiation plate 2, that is, in the combustion chamber 15.
In communication. High-temperature combustion gas flows between the outer cylinder portion 6 and the inner cylinder 3, and a combustion gas outlet 23 is provided in the lower manifold of the outer cylinder portion 6.

The inner cylinder 3 serves as a side wall surrounding the outer circumference of the radiation plate 2, and an annular ceiling plate 10 and a closed reaction chamber 11 are formed between the inner cylinder 3 and the radiation plate 2. The lower manifold of the inner cylinder 3 is provided with an inlet 20 for raw city gas and water vapor.
Further, an outlet 24 for process off gas is provided in the lower manifold of the inner cylinder 3. The process off gas is the remaining gas obtained by permeating and removing hydrogen from the generated gas.

The raw material supply pipe 4 concentrically surrounds the radiation plate 2 inside the reaction chamber 11, forms a raw material supply passage between the radiation plate 2 and the radiation plate 2, and opens the upper part inside the reaction chamber 11. .

A plurality of hydrogen permeation tubes 5 are provided inside the reaction chamber 11 outside the radiation plate 2 in an upright manner on a circumference centered on the burner device 1 at appropriate intervals. The top of the tube 5 is sealed. The hydrogen permeation tube 5 is capable of selectively permeating hydrogen, such as one prepared by depositing palladium on a porous carrier by an electroless plating method, and 50
Those having a heat resistance of 0 to 600 ° C. can be used. The other components are mainly made of stainless steel. A sweep gas inlet 21 is provided in the lower manifold of the hydrogen permeation tube 5. The sweep gas is a gas for scavenging hydrogen generated in the hydrogen permeation tube 5.

A plurality of sweep gas pipes 7 are hydrogen permeation pipes 5.
Are provided in an upright shape inside, and their upper ends are open. The lower manifold of the sweep gas pipe 7 is provided with a hydrogen and sweep gas outlet 22.

A plurality of catalytic combustion tubes 8 are provided inside the reaction chamber 11 upright on a circumference centered on the burner device 1 at appropriate intervals, and their upper ends 16 are provided at the ceiling plate 10 of the inner cylinder 3. And is communicated with the outer tubular portion 6. Catalytic combustion tube 8
A combustion catalyst 9B is inserted inside the. Further, a lower manifold of the catalytic combustion pipe 8 is provided with an inlet 25 for city gas and air for combustion. In the embodiment of FIG. 1, a catalytic combustion pipe 8 is installed inside the hydrogen permeation pipe 5, city gas and air are passed therethrough, and the reforming catalyst layer 9A is also heated from the inside to make the temperature distribution uniform. I am trying.

The reforming catalyst 9A is inserted inside the reaction chamber 11 around the hydrogen permeation pipe 5. The reforming catalyst 9A is also inserted inside the raw material supply pipe 4. The reforming catalyst is a Group VIII metal (Fe, Co, Ni, Ru, Rh, P
d, Pt, etc.) are preferred, and Ni, Ru,
A catalyst carrying Rh or a NiO-containing catalyst is particularly preferred.

The hydrogen production apparatus of the present invention having the above-mentioned structure operates as follows.

By burning the fuel supplied from below in the burner device 1, high-temperature combustion gas is generated and filled inside the radiation plate 2. This combustion gas flows from the upper peripheral edge of the radiation plate 2 into the outer cylinder portion 6 in the direction of arrow A, heats the reaction chamber 11 from the inside and the outside, and from the combustion gas discharge port 23 of the outer cylinder portion 6 to the outside. Is discharged to. Thus, the reaction chamber 11
The reforming catalyst 9A and the reforming gas as the reaction fluid in the hydrogen permeation pipe 5 are heated.

The city gas for combustion and air are supplied to the catalytic combustion pipe 8 from the inlet 25 at the lower part thereof to generate a high temperature in the combustion catalyst 9B, and the reforming catalyst layer 9A is heated from the inside to make its temperature distribution uniform. Turn into.

The sweep gas is supplied from the sweep gas inlet 21 into the hydrogen permeation pipe 5, rises, descends in the sweep gas pipe 7, and is discharged from the hydrogen and the sweep gas outlet 22 to the outside.

A mixture of city gas and steam as a raw material gas is supplied from the raw material gas inlet 20 in the direction of the arrow and enters the reforming catalyst 9A in the reaction chamber 11 through the raw material supply pipe 4. While the raw material gas passes through the inside of the reforming catalyst 9A, the raw material gas is steam-reformed with heat generated by the combustion of the fuel gas and the fuel catalyst to generate hydrogen. The reaction formula at this time is as follows, when an example of methane is shown. The generated hydrogen permeates into the hydrogen permeation pipe 5 in the direction of arrow B, where it rides on the sweep gas and descends through the sweep gas pipe 7, and is pushed out from the hydrogen and sweep gas outlet 22 in the direction of the arrow.

Further, the off gas such as carbon dioxide gas in the reaction chamber 11 is discharged from the outlet 24 in the direction of the arrow.
At this time, the discharge direction (downward) of the off gas in the packed bed of the reforming catalyst 9A is opposite to the inflow direction (upward) of the sweep gas in the hydrogen permeation pipe 5, so the packed bed of the reforming catalyst 9A is Hydrogen can be efficiently permeated to the hydrogen permeation pipe 5 from the reformed gas flowing therein. It is also possible to increase or decrease the number of annular rows of the hydrogen permeation tubes 5 used in the apparatus of the above embodiment.
It is also possible to increase or decrease the number of hydrogen permeation tubes 5 in one annular row.

The apparatus of the above embodiment is turned upside down so that fuel is blown into the burner apparatus from above for combustion, and sweep gas, raw material gas, and steam are introduced from above and hydrogen and off-gas are discharged from above. You can also

FIG. 2 is a vertical sectional view showing the schematic construction of another embodiment of the hydrogen producing apparatus of the present invention. The hydrogen production apparatus of FIG. 2 has the same structure as that of the embodiment of FIG. 1 except that the catalytic combustion pipe 8 is arranged in the sweep gas pipe 7, and the operation is similar. Omit it.

FIG. 3 is a vertical cross-sectional view showing the schematic construction of another embodiment of the hydrogen producing apparatus of the present invention.

In the hydrogen production apparatus of FIG. 3, the catalytic combustion tube 8 is arranged inside the reaction chamber, outside the hydrogen permeation tube 5 and inside the reforming catalyst 9A, except that the temperature distribution is made uniform. The configuration is the same as that of the first embodiment and the operation is similar, and thus the description thereof is omitted.

[0034]

As described above, according to the present invention, the following excellent effects can be obtained. (1) High-purity hydrogen can be directly produced from hydrocarbons and / or alcohols. (2) The burner device, the radiation plate, the inner cylinder, the raw material supply pipe, the hydrogen permeation pipe, the outer cylinder part, the catalytic combustion pipe, the reforming catalyst and the combustion catalyst are efficiently arranged, the heat transfer property is improved, and the generated heat energy is generated. Is effectively used, an energy-saving process is realized, hydrogen production capacity is improved, and the configuration of the entire device is simplified and made compact. (3) Since the furnace is provided in the central portion, the heat transfer rate in the radial direction due to radiation is increased, and the heat flux distribution is easily made uniform. Therefore, it is possible to prevent the occurrence of hot spots that exceed the heat resistant temperatures of the hydrogen permeation tube and the reforming catalyst. (4) Since the sweep gas flowing in the hydrogen permeable pipe and the reformed gas flowing in the reforming catalyst layer are mass-transferred by countercurrent contact through the hydrogen permeable pipe wall, It is possible to increase the recovery rate and increase the hydrogen concentration in the permeated gas. (5) The separation and purification steps after the reaction are omitted. (6) The chemical equilibrium is shifted by the hydrogen permeation tube, the reforming temperature is lowered by 150 to 200 ° C compared with the conventional method, the selection range of materials used for manufacturing the device is expanded, the cost is reduced, and the durability of the device is improved. Let (7) A catalytic combustion tube is installed inside the hydrogen permeation tube or inside the reforming catalyst layer, the combustion catalyst is arranged in this, and the reforming catalyst layer is heated from the inside by passing city gas and air. Therefore, the temperature distribution is made uniform. (8) The improvement of the temperature distribution improves the conversion rate of hydrocarbons and increases the amount of hydrogen produced. (9) By improving the temperature distribution, the hydrogen permeation tube can be prevented from being deformed such as stretched or bent, and the hydrogen separation membrane can be prevented from being broken or the hydrogen permeation tube can be prevented from being broken. Therefore, the durability of the hydrogen production device is improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a schematic configuration of a hydrogen production device of the present invention.

FIG. 2 is a longitudinal sectional view showing a schematic configuration of another embodiment of the hydrogen production device of the present invention.

FIG. 3 is a vertical cross-sectional view showing a schematic configuration of another embodiment of the hydrogen production device of the present invention.

FIG. 4 is a diagram showing the principle of a conventionally proposed membrane reactor type hydrogen production apparatus.

[Explanation of symbols]

 1 Burner Device 2 Radiant Plate 3 Inner Cylinder 4 Raw Material Supply Pipe 5 Hydrogen Permeation Pipe 6 Outer Cylinder 7 Sweep Gas Pipe 8 Catalyst Combustion Pipe 9A Reforming Catalyst 9B Combustion Catalyst 10 Ceiling Plate 11 Reaction Chamber 12 Bottom Burner Tile 13 Upper Opening 15 Combustion chamber 16 Upper end 20 Raw material gas inlet 21 Sweep inlet 23 Combustion gas outlet 24 Off gas outlet 25 City gas and air inlet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kyoichi Inoue 1-3-25-504 Kishitani, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture (72) Kennosuke Kuroda 2-5-1, Marunouchi, Chiyoda-ku, Tokyo Sanryo Heavy Industries Co., Ltd. In-company (72) Inventor Kazuto Kobayashi 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Hiroshima Research Laboratory (72) Inventor Shinsuke Ota 4-6-22 Kannon-shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Inside Mitsubishi Heavy Industries Hiroshima Works

Claims (3)

[Claims] 1. An apparatus for producing hydrogen from a hydrocarbon and / or alcohol by a steam reforming reaction,
An upright burner device, a cylindrical radiation plate that surrounds the burner device and forms a combustion chamber with an open upper end, and an annular ceiling plate and a closed reaction chamber that surrounds the outer periphery of the radiation plate and the radiation plate. Forming an inner cylinder, a raw material supply pipe that surrounds the radiation plate inside the reaction chamber and has an upper portion opened into the reaction chamber, and an upper portion that is provided outside the radiation plate inside the reaction chamber and seals the upper portion. A plurality of upright hydrogen permeation pipes, a plurality of sweep gas pipes provided upright inside the hydrogen permeation pipe and having an open upper end, and the outer circumference of the inner cylinder is hermetically covered by a space and An outer cylinder part communicating with a combustion chamber inside the radiation plate, and a plurality of catalytic combustions penetrating the hydrogen permeation tube and arranged upright inside the reaction chamber and having an upper end opened into the outer cylinder part. A tube and the hydrogen permeation tube inside the reaction chamber. Hydrogen production apparatus characterized in that it comprises a reforming catalyst inserted in the enclosed, and a combustion catalyst that is inserted inside the catalytic combustion tube. 2. The hydrogen production apparatus according to claim 1, wherein the catalytic combustion pipe passes through the sweep gas pipe. 3. The hydrogen generating apparatus according to claim 1, wherein the catalytic combustion pipe passes through a reforming catalyst in the reaction chamber.