JPH059362B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a catalytic combustion reactor and its combustion method, and particularly relates to a catalytic combustion reactor and its combustion method that enable hot spot prevention and efficient heat transfer. . (Prior art) A fuel cell reformer (hereinafter sometimes referred to as a reformer) is used, for example, in a phosphoric acid fuel cell system, to convert hydrogen (H ₂ ) necessary for the battery from natural gas or other raw material. This is a device that produces _H2 by heating natural gas (the main component is _CH4 , hereinafter referred to as _CH4 ) passed through a reforming catalyst bed and steam in a reaction section. be. CH ₄ +H ₂ O → 3H ₂ +CO Figure 14 shows a system diagram of a fuel cell and a reformed gas production device attached thereto. , high and low temperature shift converters 3 and 2 and the anode 5 and cathode 6 of the fuel cell.
It consists of a compressor 7, a turbine 8, and their related piping. The important performance requirements for a fuel cell are small size, high efficiency, and low pollution, and these performance requirements are related to the performance of a rifoma that has a combustion section. In order to satisfy this performance, catalytic combustion type refurmers that use a combustion catalyst in the combustion section are attracting attention. When a combustion catalyst is used, the combustion part (catalyst packed bed)
In this method, a high heat transfer coefficient is obtained due to packed bed heat transfer, almost no NOx is generated, and the above-mentioned required performance can be satisfied. (Problems to be Solved by the Invention) However, it has been found that the catalyst-filled reformer has the following problems. That is, combustion catalysts have high activity, and fuel burns on the surface of the catalyst to generate high temperatures, but with current technology, the catalyst life is short and the catalyst quickly loses its activity. Furthermore, since the fuel is mainly combusted in the portion where it is supplied, there is a possibility that the reaction portion may be heated unevenly, resulting in uneven reaction. As a countermeasure to this problem, a catalytic burner system is currently used in which air and fuel are mixed in an excess air state and then supplied to the combustion catalyst layer. FIG. 13 is a conceptual diagram of a conventional catalytic burner type reheater. of raw materials
CH ₄ and H ₂ O are supplied from the nozzle 11 and enter the reforming catalyst layer 12 . Here, heat is received from the combustion part (filling part) filled with heat transfer particles to cause a reaction.
It becomes a reformed gas rich in _H2 . This reformed gas passes through the reaction tube inner tube 14 and is taken out of the system from the nozzle 21 while exchanging heat with the raw material gas. On the other hand, in the filling section, the anode waste gas of the fuel supplied from the nozzle 15 and the air supplied from the nozzle 16 are mixed in the premixing layer 17 and then combusted in the combustion catalyst layer 18, and the combustion gas is transferred to the heat transfer particle layer 19. After applying heat to the reaction section, it is discharged from the nozzle 20 to the outside of the system. However, in the above-mentioned catalytic burner method, the theoretical combustion temperature is set below the heat-resistant temperature of the catalyst and combustion is performed in one go, resulting in a large excess of air and an increase in the sensible heat carried out by the combustion gas. The disadvantage is that thermal efficiency decreases. In addition, the temperature control method for the reaction section measures the tube wall temperature of the reaction tube and the outlet gas temperature of the reaction section, and controls based on the safe temperature of the reaction tube and the exit temperature of the reformed gas. The control method has the disadvantage that it does not have sufficient responsiveness to sudden load changes. The purpose of the present invention is to prevent the occurrence of hot spots in the catalytic combustion layer, improve the reduction in thermal efficiency,
An object of the present invention is to provide a catalytic combustion reactor that enables effective heat transfer and a combustion method thereof. (Means for Solving the Problems) The present invention includes inserting a reaction tube into a reactor filled with a catalyst and heat transfer particles, supplying fuel gas to the portion filled with the catalyst and heat transfer particles to cause combustion, In an apparatus for heating the reaction tube to decompose and reform the raw material passing through the tube, means for supplying fuel gas to at least two locations: the lower part of the reaction tube and the catalyst and heat transfer particle filling section located at the reaction section. The present invention is characterized in that the particle size of at least the packed portion corresponding to the reaction portion is larger than that of the other portions. Furthermore, in the combustion method of the present invention, a reaction tube is inserted into a reactor filled with a catalyst and heat transfer particles in a layered manner, and fuel gas is supplied to at least two locations: the lower part of the reaction tube and the catalyst packed bed at the reaction section. In a combustion method for a catalytic combustion reactor in which the raw material passing through the tube is decomposed and reformed by heating the reaction tube and burning the fuel gas, the fuel gas is supplied to a catalyst packed bed corresponding to the reaction section of the reaction tube. The method is characterized in that the combustion gas is once supplied to the heat transfer particle layer below the catalyst packed bed, and after the combustion gas is spread over the entire packed bed, it is made to flow into the catalyst packed bed. Hereinafter, the present invention will be explained in more detail with reference to the drawings. (Example) FIG. 1 is a schematic diagram of a catalytic combustion type re-former showing an example of the present invention. This device includes a reaction tube 34 provided in a reactor 31 and an inner tube 4 thereof.
3, a combustion catalyst 42 filled around the reaction tube 34, and fuel gas supply ports 32 and 41.
, an air supply port 33 for combustion, an inlet 36 for raw material gas, an outlet 37 for generated gas, and an outlet 35 for combustion exhaust gas. In the figure, while fuel gas is supplied from the lower part of the packed bed of the reactor, it is also simultaneously supplied from the gas supply port 41 in the center of the column. The fuel gas supplied from the supply ports 32 and 41 is first combusted at the large particle size catalyst 42 to generate high temperature gas, and is then transferred to the high temperature zone 4.
form 0. In this vicinity, heat transfer to the reaction tube 34 is dominated by radiation heat transfer, so it is preferable to fill the catalyst with a particle size as large as possible. On the other hand, methane and steam, which are raw material gases, are supplied into the reaction tube from the raw material inlet 36, and when the temperature reaches 700° C., hydrogen-rich gas is produced by a reforming reaction. The generated hydrogen-rich gas is taken out of the system from the generated gas outlet 37 through the inner tube 43 of the reaction tube. As the combustion gas goes to the top of the reactor, heat is taken away by the reaction tube and the temperature decreases, and in the low temperature zone 39, the heat is efficiently transferred to the reactor 34 by contact with the normal catalyst particles 38, and it exits as combustion exhaust gas. 35
is discharged from the system. Note that Fig. 1-A and Fig. 1-B show an example of a method for supplying fuel gas to the center of the column, but Fig. 1-A shows cases in which fuel is supplied perpendicularly to the reactor, and FIG. 1-B shows the case of feeding in the tangential direction. In each case, a case is shown in which there are four supply ports, but one or more supply ports may be provided, and it is also possible to provide two or more supply ports in the height direction of the tower. Figure 2 shows the reaction tube surface temperature distribution of a conventional catalytic combustion reactor that supplies fuel gas only from the bottom of the tower without providing a fuel supply port in the center of the tower in Figure 1, and the reactor of the present invention. It is a diagram shown in comparison. In this case, the case where the same amount of raw material gas and fuel gas are supplied is compared, but in Invention A, the length of the reaction tube in the reforming zone of 700°C or higher is longer and more uniform than in Conventional Method B. You can see that From this, it is understood that in the present invention, local heat spots are less likely to occur and the reforming reaction is carried out more smoothly. In addition, in the low temperature zone below 700℃, heat exchange of combustion waste gas is easily carried out through convective heat transfer with ordinary small catalyst particles.
It becomes possible to shorten the length of the reaction tube in this zone. In the embodiment shown in Fig. 1, the diameter of the catalyst particles packed in the reaction tower is 2 to 7 mm in areas other than the part where the fuel gas is supplied, but the diameter of the catalyst particles near the fuel gas supply port is 2 to 7 mm. It is preferable to fill the particles with particles that are twice the size or more. The reason for this is that, as shown in Figure 3, the overall heat transfer coefficient in the catalyst packed bed is
In the high temperature range of 1000°C or higher, radiation becomes more dominant than convection. Therefore, in the high temperature range where endothermic reactions occur, it is desirable to increase the catalyst particle size and increase the radiation heat transfer coefficient (catalyst particle size 5 mm in Figure 3). , gas passing speed 0.3 m/s). Figure 4 shows the effect of particle size on the radiant heat transfer coefficient.
At 800℃, the radiation heat transfer coefficient does not increase much even if the particle size is increased, but at 1200℃, increasing the particle size to 10mm increases it to more than twice that of 5mm, which makes it difficult to increase the particle size. Therefore, it is clear that the radiation heat transfer coefficient is increased (gas passage velocity in Figure 4).
0.3m/s). According to the above embodiment, in the catalyst-packed bed type re-former, fuel gas is supplied from at least two locations in the reactor, one at the bottom of the packed bed and the other at the center, and the particle size of the catalyst layer in the fuel supply section is increased. ,
The heat transfer effect in the reforming reaction zone can be enhanced and the reaction tube temperature can be made uniform. In the embodiment shown in Fig. 1, the same fuel gas is supplied to the lower part and the center of the reactor, but it is possible to supply different fuel gases depending on the reaction characteristics inside the reaction tube. The surrounding catalyst filling portion may be provided with a filling portion of heat transfer particles having no combustion activity, if necessary. Particularly, as will be described later, if the combustion gas supplied to the reaction section is diffused through the heat transfer particle layer and then passed through the catalyst particle layer, local temperature increases can be prevented. Figure 5 shows an example in which different fuel gases were supplied to the lower part and center of the reactor depending on the reaction characteristics, with fuel cell anode waste gas being supplied to the lower part of the reactor and natural gas (mainly
CH ₄ ) is supplied, and the fuel (CH ₄ ) supplying part _in the center of the reactor is filled only with heat transfer particles. This uses filled particles with a diameter larger than that of the part. That is, in the embodiment shown in FIG. 5, different types of fuel are supplied to two locations in the reactor, and the difference in combustion characteristics of these fuels is utilized to prevent the occurrence of hot spots in the heating section of the reaction tube. In addition, the reduction in thermal efficiency caused by a large excess of air when using the same fuel is improved, and effective heat transfer is achieved. The fuel supplied to the reactor is anode waste gas (mainly hydrogen) recycled from the fuel cell anode and natural gas for auxiliary combustion (hereinafter referred to as
CH ₄ ) is preferably used. The main combustion component of the anode waste gas is _H2 , but _H2 and
There are considerable differences in the combustion characteristics of CH ₄ as shown in Table 1.

[Table] As is clear from Table 1, the energy required for ignition of H ₂ is 1/10 of that of CH ₄ , and if a catalyst is used, it can be ignited even at room temperature. It is the fastest and requires the least amount of air for combustion. On the other hand, CH ₄ has a high ignition temperature, a slow combustion speed, and the amount of air required for combustion is three times that of H ₂ . The present inventors used the above two types of fuel, and the fifth
Various experiments were carried out using the catalytic burner type reformer shown in the figure, and the following results were clarified. (1) When the amount of air was constant and only the amount of H ₂ was increased (H ₂ concentration relative to air from 1.2 to 1.5%), the temperature only in the catalytic burner section increased (see Figure 6). In the diagram, C
indicates the case where the amount of _H2 is small, and D indicates the case where the amount of _H2 is large. (2) When only the amount of CH ₄ was increased (CH ₄ concentration relative to air from 1.5% to 2.3%) while the amount of air remained constant, the temperature in the catalytic burner part did not rise much, and the highest temperature part moved to the heat transfer particle layer ( (See Figure 7). In the figure, E
indicates the case where the amount of CH ₄ is small, and F indicates the case where the amount of CH ₄ is maximum. (3) When the flow velocity of the combustion section was increased by adjusting the amount of combustion air (from about 0.2 m/s to 0.3 m/s superficial velocity of the combustion section), the maximum temperature range increased as the flow velocity increased. The trend was shown (see Figure 8). In the figure, G indicates a case where the flow velocity (air amount) is low, and H indicates a case where the flow velocity is high. In addition, the reaction part is an endothermic reaction, but when we investigated the distribution of the amount of heat absorbed, we found that the reaction part temperature was 650.
It was found that the largest amount of heat absorption was observed at a temperature of ~700°C, resulting in a large heat flux. Based on the above results, it was conventionally thought that hot spots occur when fuel is directly supplied to the catalyst layer, but this is caused by the combustion of H ₂ with a high burning rate, and it takes time for CH ₄ to be completely burned. It was found that the mixture spreads into the packed bed and then combusts. In addition, the combustion gas in a conventional re-former is flowed in a countercurrent flow to the gas in the reaction section, but the outlet temperature of the reaction section is
Since the temperature is 750-800℃, there is a sensible heat rise from the 650-700℃ range forming a significant endothermic zone to the outlet temperature, and the sensible heat of the combustion gas is used for this sensible heat increase. ), the temperature of the combustion gas decreases, making it impossible to maintain a large enough temperature difference between the zone and the reaction zone, and it was therefore found that the heat transfer surface must be increased. The re-former shown in FIG. 5 is provided with a supply pipe 15A for high-calorie fuel gas (for example, natural gas, CH ₄ ) in the combustion part (filling part) corresponding to the heat absorption part (reaction part) of the reaction tube, and also in the combustion part. From the bottom, the packed beds are: combustion catalyst first layer 18A, heat transfer particle layer first layer 19
A, heat transfer particle layer second layer 19B, combustion catalyst second layer 1
8B, a third heat transfer particle layer 19C and a metal particle layer 19M, anode waste gas (hydrogen gas) is supplied from the low calorie fuel gas supply pipe 15 at the bottom of the reactor, and from the high calorie fuel supply pipe 15A at the top. No. 13 in that it started supplying natural gas (CH ₄ ).
This is different from the conventional device shown in the figure. In an apparatus with such a configuration, H ₂ having a high combustion rate is introduced from the gas supply pipe 15 into the fuel/air premixing zone 17, where it is mixed with the air supplied from the air supply pipe 16, and the combustion catalyst first It enters the layer (catalytic burner) 18A and is burned here,
The combustion heat is used for heat transfer to the tip of the reaction tube 14. Heat transfer at the tip of the reaction tube 14 is mainly used to increase the sensible heat of the reaction fluid past the heat absorption zone. The combustion gas in the combustion catalyst first layer 18A gives heat to the reaction section of the reaction tube in the heat transfer particle layer first layer 19A, and its temperature is lowered. The combustion gas whose temperature has been lowered then enters the endothermic zone and is heated by the combustion heat of the high-calorie fuel supplied from the fuel supply pipe 15A at the center of the reaction tube. That is, the fuel supply pipe 15 is used to heat the reaction section (endothermic zone) of the reaction tube.
CH ₄ supplied from A and having a slow burning rate is used. The part to which this CH ₄ is supplied has a packed bed of heat transfer particles with no combustion activity (heat transfer particle layer 2 layer 19).
Since B) is filled, it is sufficiently diffused into the filled part before being completely combusted in the combustion catalyst part on the upstream side. The filling material of this second heat transfer particle layer 19B is
It is preferable to make the diameter larger so that CH ₄ can easily diffuse. The CH ₄ thus diffused into the filling part enters the combustion catalyst second layer 18B on the downstream side thereof and is combusted all at once. The position of the second layer of combustion catalyst is set so that the temperature of the reaction section is around 650°C during normal operation. A third heat transfer particle layer is further provided on the second combustion catalyst layer 18B, and a metal particle layer 19M is further provided thereon.
The position where the metal particle layer 19M is switched is preferably such that the combustion gas temperature decreases to about 700°C. The metal particles of the metal particle layer 19M have lower heat resistance than the heat transfer particle layer 19C made of a refractory material such as alumina, and also lead to an increase in weight, but as shown in FIG. 9, the metal particles have a high thermal conductivity. , the heat transfer coefficient can be improved. Furthermore, since metal particles have a high density, they also have the effect of preventing light refractory particles from scattering when the flow rate increases. Note that the heat transfer coefficient of the packed bed exhibits a larger value as the particle size becomes larger in a high temperature region where radiation is large.
Therefore, the heat transfer particle layers 19A and 19 at the bottom of the reactor
It is preferable that the particles of B have a larger diameter than the particles of the upper heat transfer particle layer 19C. Next, temperature control of the reaction section and combustion section of the catalytic combustion reactor will be explained using FIG. 10 and FIG. 11. A plurality of thermocouples are used to measure the temperature inside the reaction column at equal intervals in the axial direction of the reaction tube (in this case, thermocouples A, B,
Thermocouples A', B', C', D' and E' are attached to the surrounding combustion section (filling section) at the same height as the reaction section. Furthermore, a thermocouple F for protecting the reaction tube is attached to the surface of the reaction tube in the reaction tube return section. Each dimension is determined at the time of design so that the heat absorption zone of the reaction section is located between the thermocouples C and D, and the fuel supply pipe 15A is arranged so as to be approximately at the same height as the thermocouple D. The air supply pipe 16 has an air flow control valve 47.
However, the upper and lower fuel supply pipes 15A and 1
5 each has a natural gas (CH ₄ ) flow rate control valve 48.
and a lower natural gas flow rate control valve 49 are provided, respectively, and these are respectively connected to the electric circuits of the thermocouples that are electrically connected to the air flow rate control valve 47. In such a configuration, the fuel and air control method is as follows. First, read the indicated values of thermocouples A to E and write the temperature profile of the reaction section in the computer. Next, read the readings from the thermocouples A' to D' and write the temperature profile of the combustion section into the computer. Next, overlap the temperature profiles of both sides,
The CH ₄ valves 48 and 49 and the air valve 47 are adjusted so that the endothermic zone of the reaction section and the maximum combustion temperature due to CH ₄ combustion overlap. The amount of air at this time is
The theoretical combustion temperature of 18B and 18B does not exceed the heat-resistant limit temperature of the catalyst, and the amount to suppress the excess air ratio as much as possible is calculated in advance, and an appropriate amount of air is supplied through the valve 47 according to the amount of CH ₄ supplied. supply
Valves 48 and 49 are used to raise and lower the maximum temperature of the combustion section. That is, when raising the maximum part, valve 49 is closed and valve 48 is opened, while when lowering the maximum part, valve 49 is closed and valve 48 is opened.
9 and close valve 48. Further, during load fluctuation operation, the heat absorption zone may be separated from between thermocouples C and D, but the combustion section is similarly controlled by opening and closing valves 48 and 49. By controlling the temperature of such two-stage combustion, a large amount of heat can be effectively provided to the endothermic zone where heat is required, and the heat transfer area can be minimized. FIG. 12 shows an example of a specific control program for the computer. Among these, the endothermic zone is determined by using the indicated values of thermocouples A to E.
The values on both sides of 650℃ and 700℃ are detected, and the space between them is defined as the endothermic zone. For example, C is 620℃,
When D is 710°C, zone 3 sandwiched between CD is an endothermic zone. Also, the temperature maximum value Tp of the combustion zone
To find out, determine the maximum temperature value from A' to D' excluding E', and set it as the maximum temperature value Tp. For example, if C' is the maximum value, C' becomes Tp. Next, to determine whether Tp is below the endothermic zone, in this case, C′ is Tp
Therefore, Tp is above the endothermic zone. The operation is to squeeze the valve 48 and open the valve 49. As a result, the catalytic burner (first stage combustion catalyst) side is heated, and Tp decreases. Tube temperature F
The set value of is determined based on the design temperature of the reaction tube. This program is run at appropriate intervals (for example, 1 minute)
Let it be an infinite loop that repeats with . For example, if Tp drops to D' at the next time, then valve 4
8 is opened, valve 49 is squeezed, and Tp rises. In other words, Tp slowly moves back and forth between the upper and lower ends of the endothermic zone. According to the above embodiment, by effectively heating the endothermic zone of the reaction section, the heat transfer area can be made smaller by, for example, 20 to 40% than in conventional re-formers, and the amount of combustion air can be suppressed. Therefore, the sensible heat taken out of the exhaust gas decreases, and the thermal efficiency improves, for example.
Improve by 10-20%. Furthermore, high efficiency operation is possible under any load condition by controlling the temperature profiles of the reaction section and combustion section. (Effects of the Invention) According to the present invention, in a catalyst-filled reformer, fuel gas is supplied from at least two locations, one at the bottom of the packed bed of the reactor and the other at the top thereof, and the diameter of the packed particles in the fuel supply section is increased. This makes it possible to improve heat transfer performance and make the temperature of the reaction tube in the reforming reaction zone uniform. In addition, for example, low-calorie and high-calorie fuels can be supplied from the two fuel supply sections mentioned above, and the catalyst filling By alternately providing the combustion catalyst layer and the heat transfer particle layer, the reforming reaction zone, that is, the endothermic zone, can be effectively heated, the heat transfer area can be reduced, and the amount of combustion air can be reduced. It is possible to reduce sensible heat taken out of exhaust gas and improve thermal efficiency.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a reforming reactor showing one embodiment of the present invention, and FIGS. 1-A and 1-B are respectively taken in the direction of the arrow along line A-A' in FIG. cross section,
FIG. 2 is a diagram showing the surface temperature of the reaction tube with respect to the reaction tube height in the apparatus of FIG. 1, and FIGS. 3 and 4 are diagrams showing the relationship between temperature and particle size on the heat transfer coefficient, respectively. FIG. 5 is a sectional view of a reforming reactor showing another embodiment of the present invention, and FIGS. 6, 7, and 8 show H ₂ , CH ₄ , FIG. 9 shows the relationship between the thermal conductivity of heat transfer particles in the reforming reactor and the overall heat transfer coefficient of the packed bed. 11 is an explanatory diagram showing the control pattern in the temperature control of FIG. 10, and FIG. 12 is a diagram showing the temperature control system of the reforming reactor of the fuel split supply system of the present invention. FIG. 13 is an explanatory diagram showing a typical example of a conventional reforming reactor, and FIG. 14 is a flowchart of a control program for temperature control. FIG. 2 is an apparatus system diagram of a quality reactor. 31... Reforming reactor, 32... Fuel gas supply port, 33... Air supply port, 34... Reaction tube, 35
... Combustion waste gas discharge port, 36 ... Raw material gas supply port, 37 ... Produced gas discharge port, 38 ... Catalyst particles, 39 ... Low temperature zone, 40 ... High temperature zone,
41... Tower central fuel gas supply port, 42... Large particle size catalyst, 43... Reaction tube inner tube, 47... Air flow rate control valve, 48, 49... Natural gas flow rate control valve, 1
1... Raw material supply pipe, 12... Reforming catalyst layer, 13...
...Reaction tube (outer tube), 14...Reaction tube (inner tube), 15
... Fuel gas supply pipe, 16 ... Air supply pipe, 17
... Fuel, air premixing zone, 18A ... Combustion catalyst first layer, 19A ... Heat transfer particle layer first layer, 20 ...
...Combustion waste gas outlet, 15A...CH ₄ supply pipe, 1
8B...Combustion catalyst second layer, 21...Reformed gas outlet, 19B...Second heat transfer particle layer, 19C...Third heat transfer particle layer, 19M...Metal particle layer.

Claims (1)

[Claims] 1. A reaction tube is inserted into a reactor filled with a catalyst and heat transfer particles, and fuel gas is supplied to the portion filled with the catalyst and heat transfer particles to cause combustion, thereby heating the reaction tube. In the apparatus for decomposing and reforming the raw material passing through the tube, means is provided for supplying fuel gas to at least two locations: a lower part of the reaction tube and a catalyst and heat transfer particle filling section located at the reaction section; 1. A catalytic combustion reactor characterized in that the particle size of the packed part corresponding to 2 is larger than that of other parts. 2. In claim 1, the packed section has a layered structure of a combustion catalyst and heat transfer particles, and the catalyst particle diameter of at least the catalyst packed section corresponding to the reaction section is larger than that of other parts. A catalytic combustion reactor characterized by: 3. A reaction tube is inserted into a reactor filled with a catalyst and heat transfer particles in a layered manner, and fuel gas is supplied to at least two places, the lower part of the reaction tube and the catalyst packed bed at the reaction part, to be combusted, and the reaction is started. In a combustion method for a catalytic combustion reactor in which a tube is heated to decompose and reform the raw material passing through the tube, the fuel gas supplied to the catalyst packed bed corresponding to the reaction section of the reaction tube is temporarily transferred to the lower layer of the catalyst packed bed. A combustion method for a catalytic combustion reactor, characterized in that the combustion gas is supplied to a heat transfer particle bed, and after spreading the combustion gas throughout the packed bed, it flows into the catalyst packed bed. 4. In claim 3, the catalyst packed bed is arranged such that the combustion gas velocity is maintained in a constant relationship with the amount of combustion gas supplied to the catalyst packed bed at the reaction section of the reaction tube. A combustion method for a catalytic combustion reactor characterized by adjusting the amount of air. 5 In claim 3, a temperature sensor is provided in the reaction part and a filling part at the position of the reaction part, and the temperature of the filling part reaches a maximum value at a position where the temperature of the reaction part becomes 650 to 700°C. A combustion method for a catalytic combustion reactor, characterized in that the amount of fuel supplied to the filling section is adjusted so as to increase the amount of fuel supplied to the filling section.