JPH03208803A - Raw hydrogen material reformer - Google Patents

Abstract

PURPOSE:To prevent a local temp. rise, to enhance heat supply efficiency and to improve reforming efficiency in the raw hydrogen material reformer in which a fuel is burned and the heat of combustion is utilized by distributing a fuel injection pipe for introducing a fuel in the combustion chamber in plural stages. CONSTITUTION:A combustion catalyst 16 is packed in the combustion chamber 15 of the combustion cylinder 12 of a methanol reformer 11, and a fuel injection port 19 for introducing the fuel into the chamber 15 is distributed in the chamber 15 in plural stages. The fuel is sent to the fuel injection pipe 17 and air to an air injection pipe 25, and the fuel is burned in the chamber 15. The heat generated by the combustion is then supplied to a reformed gas generating tube 43 packed with a reforming catalyst 46 to reform the raw hydrogen material (e.g. methanol and water) flowing in the tube 43. The obtained reformed gas is supplied to a fuel cell from a feed pipe 50 to generate power.

Description

[Detailed Description of the Invention] <Industrial Application> The present invention provides a hydrogen raw material reforming device that efficiently generates a reformed gas containing hydrogen gas through a reforming reaction accompanying heating of a mixed gas containing hydrogen raw material. In particular, it is suitable for reforming methanol for fuel cells.

<Prior Art> It is well known that hydrogen gas, which is effective as a reducing gas for metals, etc., can also be used as a reaction gas for fuel cells. This fuel cell has excellent features such as not requiring the use of fossil fuels, which have depleted resources, generating almost no noise, and achieving extremely high energy recovery efficiency compared to other energy engines. Because of this, it is used as a relatively small power generation plant for each building or factory, for example.

In recent years, it has been considered to use this fuel cell as a power source for a motor that operates in place of an internal combustion engine in a vehicle, and to drive a vehicle or the like with the motor. What is important in this case is that it is natural to reuse the substances produced by the reaction as much as possible, and as it is clear from the fact that it is for automotive use, although a large output is not required, It is desirable to be as small as possible.

By the way, when hydrogen gas is obtained from methanol, which is commonly used as a hydrogen raw material for fuel cells, a multi-tubular fixed bed reactor is usually used as a reformer, and hydrogen gas is produced through a high temperature heat medium obtained from a heat medium boiler etc. methanol is reformed with steam through an endothermic reaction.

<Problem to be solved by the invention> Since conventional multi-tubular fixed bed reactors utilize endothermic reactions, it is important to efficiently supply heat to this fixed bed reactor in order to improve methanol. This will affect quality efficiency. For this reason, a large capital investment must be made in a heat source such as a heat medium boiler, which makes it virtually impossible to use it for vehicle use and is disadvantageous in terms of cost.

Therefore, a hydrogen raw material reforming apparatus has been proposed that employs a direct heating method using a combustion catalyst instead of a heating medium heating method.

However, with such direct heating methods, local temperature increases occur, and in some cases, the adiabatic flame temperature (1200°C or higher) may occur.
It can rise up close. Therefore, it is necessary to make the wall material of the combustion chamber that holds the combustion catalyst highly heat resistant, and the heat supply efficiency is also not sufficient.

In view of these circumstances, it is an object of the present invention to provide a hydrogen raw material reforming device that prevents a local 1 degree rise and has high heat supply efficiency (and improved reforming efficiency).

Means for Solving the Problems〉 The hydrogen raw material reforming device according to the present invention that achieves the above objects has the following features:
Hydrogen is produced by burning fuel in a combustion chamber filled with a combustion catalyst, and giving the heat from this combustion to a reformed gas generation tube filled with a reforming catalyst to reform the hydrogen raw material flowing into the reformed gas generation tube. The raw material reforming device is characterized in that fuel injection ports for introducing fuel into the combustion chamber are distributed in multiple stages within the combustion chamber.

Effect〉 When fuel is introduced into a combustion chamber filled with a combustion catalyst through fuel injection ports distributed in multiple stages, combustion of the fuel by the combustion catalyst starts near the injection ports, but Since combustion occurs mainly at certain locations, local temperature increases are prevented and a substantially uniform temperature distribution is achieved within the combustion chamber.

Embodiment Example The concept of an embodiment in which the hydrogen raw material reformer according to the present invention is applied to a methanol reformer for fuel cells is shown in FIG. 2, and the cross-sectional structure of the methanol reformer part is shown in FIG. As shown in the figure. As shown in both figures, at one end side of the cylindrical combustion tube 12 of the methanol reformer 11, there is a combustion gas consisting of air and methanol 13, which will be described later, or air and a fuel cell main body 1.
A combustion chamber 15 is formed to combust the combustion gas consisting of the unreacted gas from 4.
A combustion catalyst 16 for promoting combustion of combustion gas is held in this combustion chamber 15, which is set at a temperature of approximately .degree. Here, the combustion catalyst 16 includes, for example, one containing at least one element of platinum (Pt) and palladium (Pd), or one containing iron (Fs), cobalt (Go), nickel (Ni), and manganese (Mn). )
and copper (Cu).

A fuel injection pipe 17 extending through the center of the combustion chamber 15 is fixed to an end plate 18 joined to one end of the combustion cylinder 12 in a penetrating state. A large number of fuel injection ports 19 are formed in the outer peripheral surface of the fuel injection pipe 17 in the longitudinal direction, and from these fuel injection ports 19, unreacted gas or methanol from the fuel cell main body 14 is transferred to the combustion catalyst. It is scheduled to be supplied during the 16th. That is,
An unreacted gas supply pipe 21 that communicates with the hydrogen electrode 20 side of the fuel cell main body 14 and a methanol supply pipe 23 that branches off from this unreacted gas supply pipe 21 and communicates with a methanol tank 22 are connected to the fuel injection pipe 17. has been done. A starter device 24 is provided in the middle of the methanol supply pipe 23. This starting device 24 includes a starting fuel supply pump (not shown) for pressure-feeding methanol 13 in the methanol tank 22 to the fuel injection '117 side in the combustion chamber 15, and methanol 13 supplied from this starting fuel supply pump.
It is equipped with a methanol vaporizer (not shown) for evaporating and vaporizing the fuel and sending it to the fuel injection pipe 17. That is, only when starting the fuel cell, the starting device 24 forces the methanol 13 in the methanol tank 22 to an evaporator (not shown) and supplies methanol vapor to the fuel injection pipe 17.

On the other hand, air necessary for combustion is supplied into the combustion catalyst 16 via an annular air jet pipe 25 provided along the end plate 18 within the combustion chamber 17 . The air jet pipe 25, like the fuel jet pipe 17, is fixed to the end plate 18 in a penetrating state, and has a large number of air jet ports 26 formed in its annular portion. Further, one end of the air jet pipe 25 is connected to the other end of an air supply pipe 28 which communicates with the blower 27 .

Note that the fuel jet port 19 and the air jet port 26 are provided with a distributor (not shown) having a flashback prevention function.

A heat exchange tube 29 is disposed concentrically around the combustion tube 12 with a gap spaced from the outer peripheral surface of the combustion tube 12 .

The other end of the gap between the combustion tube 12 and the heat exchange tube 29 is
It communicates with the combustion chamber 15 through a notch passage 30 carved at the other end of the combustion tube 1z, and the combustion chamber 15 is connected to one end of this gap.
An exhaust pipe 31 is connected to guide the combustion exhaust gas burned inside to the outside.

In the gap between the combustion tube 12 and the heat exchange tube 29, a reforming material preheating tube 32 is spirally arranged. One end of this reforming material preheating tube 32 passes through the heat exchange cylinder 29 and is connected to the methanol tank 22 via the reforming methanol supply pipe 33, while the other end of the reforming material preheating tube 32 It is connected to one end side of a reforming material heating pipe 34 that is spirally piped along the inner circumferential surface of the combustion chamber 15 . In the middle of the methanol supply %F33 for reforming between the methanol reformer 11 and the methanol tank 22, a motor 35 drives a motor 35 that pumps the methanol 13 in the methanol tank 22, which is a hydrogen raw material, to the methanol & reformer [1161]. A pump 36 is attached. Further, in the middle of this methanol supply pipe 33 for reforming, the other end side of a water supply pipe 38 whose one end side communicates with a water tank 37 is connected, and in the middle of this water supply pipe 38, methanol 13 and reforming A methanol supply pipe 33 for reforming water 39 in a water tank 37 serving as a raw material
A pump 41 driven by a motor 40 is attached separately for pumping the inside.

Therefore, while the reformed raw material consisting of methanol 13 and water 39 moves through the reformed raw material preheating pipe 32 to the reformed raw material heating pipe 34, the combustion W! Heat exchange is performed between the high-temperature combustion exhaust gas flowing toward the exhaust pipe 31 through the gap between the i12 and the heat exchange cylinder 29, and the reformed raw material is
It is designed to be preheated to about 500°C to 500°C.

In this case, it is desirable to set the mixing ratio of methanol 13 and water 39 to approximately 0.05 to 5 moles of water per 1 mole of methanol, and further, in order to completely burn the combustion exhaust gas, It is also effective to fill the gap between the heat exchange cylinder 29 and the combustion catalyst 16 described above.

A reforming header 42 connected to the other end of the reforming material heating pipe 34 is provided at the center of the combustion tube 12. One end sides of a plurality of mutually extending reformed gas generation pipes 43 are connected to each other via a rectifying orifice 44 . On the other end side of these reformed gas generation pipes 43, a large number of communication ports 4 are provided.
A single sealing plate 46 made of punched metal with 5
The reformed gas generation pipes 43 are each filled with a reforming catalyst 47 for promoting the reforming reaction of the raw material gas heated by the reformed raw material heating w34. The mixed gas of methanol 13 and water 39 is CH30H+nH2O-(1-n)CO+nCO□+(
2+n)H2 is heated, a reforming reaction occurs where 0<n<1, and the reformed gas shown on the right side of the above chemical formula is produced. In this case, in order to efficiently carry out the reforming reaction of the raw material gas, the pressure inside the reformed gas generation pipe 43 is set to about 0 kg to 20 kg per square centimeter. Temperature inside 2
It is desirable to set the temperature to about 00°C to 600°C. Note that this reforming catalyst 47 is made of, for example, platinum (Pt
) and at least one element among palladium (Pd), rhodium (Rh), and nickel (N1), or copper (Cu), zinc (Zn), and chromium (C
Examples include those containing at least one element of r).

It is made of stainless steel such as Nao, nE combustion rR12rx, 5US301S material, and a heat insulating layer made of heat-resistant brick or the like is formed on its outer peripheral surface to keep the inside of the combustion chamber 15 warm. Prevents temperature drop.

On the other end side of such methanol reformer 11, a first
A CO reduction device 48 is attached adjacent to the sealing plate 46, and the reformed gas generation pipe 43 and this first CO reduction device 48 communicate through the communication port 45 of the sealing plate 46. . The first CO reduction device 48 reduces carbon monoxide (CO) in the reformed gas generated by the reforming reaction of the raw material gas in the reformed gas generation pipe 43 by reacting it with water. Although the Go shift catalyst 49 is filled,
The purpose of removing carbon monoxide from this reformed gas is to prevent the hydrogen electrode 20 of the fuel cell body 14 from being poisoned by carbon monoxide, which would lead to an extreme drop in battery performance. It's for a reason. Note that the CO shift catalyst 4
Examples of 9 include those containing at least one of the following elements: copper (Cu) and zinc (Zn).

Further, a hydrogen inlet 51 of the fuel cell main body 14 is connected to a reformed gas supply pipe 50 communicating with the first CO reduction device 48 via a humidifier 52 . And the first C
In the middle of the reformed gas supply pipe 50 between the O reduction device 48 and this humidifying device 52, there is an exhaust turbine 53, which removes carbon monoxide in the reformed gas by reacting it with oxygen.
A second CO reduction device 54 (select oxo) is provided in order from the methanol reformer 11 side, and this second CO reduction device 54 is
The reformed gas purified by the reduction device 54 is humidified and sent to the hydrogen inlet 51 side of the fuel cell main body 14. Of the reformed gas sent from this hydrogen inlet 51 to the hydrogen electrode 20 of the fuel cell main body 14, surplus unreacted gas is removed from the fuel cell main body 14 as described above.
The unreacted gas is supplied to the fuel jet W17 via an unreacted gas supply pipe 21 that communicates the unreacted gas W17 with the fuel jet pipe 17.

Note that a generator 55 is connected to the exhaust turbine 53, and the electricity generated by the generator 55 is transferred to the MTt pond 5.
6 can be stored. The blower 27 is driven by a blower drive motor 57 to which electricity is supplied from the storage battery 56. Further, the motors 35 and 40 are also the blower drive motor 57 and v1.
It is designed to be operated by electricity supplied from a storage battery 56.

Further, the blower 27 and an air inlet 58 formed in the fuel cell main body 14 are connected via an air supply pipe 59, and the pressurized air from the blower 27 driven by electricity from the storage battery 56 is The fuel is fed under pressure to an oxygen electrode 57 connected to an air inlet 58 of the fuel cell main body 14. The air fed into the fuel cell main body 14 from this air inlet 58 (contains reaction product water in the fuel cell main body 14), and the fuel cell main body 14
Supplied to air and water power @M61 connected to m industry 60 of 4,
The moisture in this water is collected into the water tank 36 via the water recovery pipe 62, and the gas force is discharged to the outside from the exhaust pipe 63.

On the other hand, the water tank 37, the fuel cell main body 14, and the humidifier 52 are connected via a cooling water circulation pipe 64. In this step, water 39 in the water tank 37 is supplied to the fuel cell main body 14 to cool the fuel cell main body 14, and a humidifying group W152 is used to cool the reformed gas flowing through the reformed gas supply w50. A pump 66 driven by a motor 65 is provided. In addition, in the humidifier 52, the reformed gas flowing in the reformed gas supply pipe 31 and the heated cooling water are in contact with each other via a gas diffusion membrane, and water vapor corresponding to one degree of the heated cooling water is Steam is added to the reformed gas at partial pressure. Further, the motor 65 is designed to be driven by electricity from the storage battery 56.

In such an apparatus, at the time of startup, the methanol 13 in the methanol tank 22 is pumped by the starter 24, the methanol vapor obtained by the evaporator (not shown) is sent to the fuel injection pipe 17, and the air from the blower 27 is sent to the air supply pipe. 2
8 to the air jet pipe 25. As a result, combustion chamber 1
The nimethanol vapor and air in the combustion catalyst 16 filled in the combustion catalyst 16 are ejected, and combustion is started. Along with this, methanol for reforming is supplied 1! When methanol 13 and water 28 are supplied through I33, the methanol 13 is reformed in the reformed gas generation pipe 43. Further, when this reformed gas is supplied to the hydrogen electrode 20 of the fuel cell main body 14 and air is supplied to the oxygen electrode 57, power generation is started. After the unreacted gas is discharged from the hydrogen electrode 20 of the fuel cell main body 14 and the temperature inside the combustion chamber 15 has risen sufficiently, the starter 124 is stopped and the unreacted gas is replaced with methanol. The reforming reaction is maintained by supplying the reaction gas to the fuel jet pipe 17 and sending air from the blower 27 to the air jet pipe 25 via the air supply W2B.

With such a device, hydrogen-containing gas is supplied from the fuel injection pipe 17 at a rate of 4Nm' per hour, and air is supplied from the air jet jW25 at a rate of 28Nm' per hour.
While supplying methanol for reforming [33, the molar ratio of methanol and water is 1:1.5].
methanol 13 per hour 6.5 kg 5 water 35
When the methanol 13 was supplied at a rate of 5.4 kg/hour, 99.8% of the supplied methanol 13 was converted to reformed gas. or,
The carbon monoxide concentration in the reformed gas at the outlet of the first CO reduction device 48 in a dry state was 1.0%.

In addition, in this test device, 10/Pb was used as the combustion catalyst 16.
The containing catalyst is filled into the combustion chamber 15, and 31 ZnO-containing catalysts are used as the methanol reforming catalyst 46 to generate reformed gas W43.
Furthermore, a 0.51 ZnO-containing catalyst was filled into the first CO reduction device 48 as a CO shift catalyst 47.

Further, when the temperature distribution inside the combustion IE 15 at this time was measured from the center to the end in FIG. 1, it was as shown in FIG. 3. That is, the temperature was distributed almost uniformly throughout the combustion chamber 15, and no local temperature increase was observed.

Here, for comparison, as shown in FIG. 4, the embodiment was carried out except that a fuel/air injection pipe 100 was provided at the end of the combustion chamber 15 in place of the fuel injection pipe 17 and the air injection pipe 25 of the previous embodiment. A methanol reformer similar to that in the example was prepared. The temperature distribution in the combustion chamber 15 was measured from A' to B' in Fig. 4 under the same conditions except that a mixed gas of hydrogen-containing gas and air was injected from the fuel/air injection pipe 100. , the results are shown in FIG. That is, the result was that only the area near the outlet of the fuel/air ejection pipe 100 became locally high temperature.

In the embodiment described above, the air jet pipe 25 is provided separately from the fuel jet pipe 17, but the air may be jetted out from the fuel jet pipe 17 together. However, by separately introducing air as described above, it is possible to prevent a local increase in the ai degree near the fuel injection port 19.

Further, the fuel injection pipe 17 does not necessarily have to be provided in the center of the combustion chamber 15, but may be provided in the vicinity of the inner wall in a spiral shape, for example, so that the fuel injection port is formed inward.

<Effects of the Invention> As explained above, in the hydrogen raw material reforming device according to the present invention, fuel is introduced into the combustion chamber filled with the combustion catalyst from the fuel injection ports distributed in multiple stages. This has the effect of preventing local temperature rises, increasing heat supply efficiency, and improving reforming efficiency.

[Brief explanation of drawings]

FIG. 1 shows one example of the present invention. A cross-sectional view of the hydrogen raw material reformer according to the example, FIG. 2 is a conceptual diagram showing a fuel cell to which it is applied, and 3rd FI! J is a graph showing the temperature distribution in the combustion chamber, FIG. 4 is a sectional view showing the reformer of the comparative example, and FIG. 5 is a graph showing the concentration distribution in the combustion chamber. In the drawing, 11 is a methanol reformer, 12 is a combustion tube, 13 is methanol, 14 is a fuel cell main body, 15 is a combustion chamber, 16 is a combustion catalyst, 17 is a fuel injection pipe, 18 is an end plate, and 19 is a fuel injection Outlet, 22, methanol tank 1, 25, air jet pipe, 26, air jet port, 2, reforming material preheating pipe, 3, methanol supply pipe for reforming, 4, reforming material heating pipe, 7, water tank, 8 9 is a water supply pipe, 2 is a reforming header, 3 is a reformed gas generation pipe, 6 is a reforming catalyst, 8 is a first CO reduction device, and 0 is a reformed gas supply pipe. 7

Claims (1)

[Claims] Hydrogen is produced by burning fuel in a combustion chamber filled with a combustion catalyst, and giving the heat from this combustion to a reformed gas generation tube filled with a reforming catalyst to reform the hydrogen raw material flowing into the reformed gas generation tube. A hydrogen raw material reforming device characterized in that fuel injection ports for introducing fuel into the combustion chamber are distributed in multiple stages within the combustion chamber.