JPH1047610A - Catalyst combustor of gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a catalyst have a long lifetime by constructing a catalyst combustion portion of a catalyst combustor such that a catalyst layer containing palladium is arranged as a front part thereof and a catalyst layer containing manganese and having a magnetoplumbite structure is arranged as a rear part thereof. SOLUTION: A catalyst layer 1 containing palladium which is excellent in ignitability from a low temperature is arranged at a gas inlet side as a front part of a catalyst combustion portion thus enabling a start of a catalytic action from a discharge gas temperature of a compressor. A catalyst layer 2 containing manganese which has a resistance against lowering of its catalytic activity and having a megnetoplumbite structure is arranged at a gas outlet as a rear part of the catalyst combustion portion. A mixture gas of air and fuel discharged from a compressor is fed to the catalyst layer 1 where a contact oxidation reaction proceeds. Corresponding to the progress of the reaction, the catalyst temperature and the gas temperature are elevated. The heated gas is fed to the catalyst layer 2 where the reaction is further proceeded to a temperature which enables a gas phase combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to catalytic combustor for a gas turbine for the purpose of dramatically reducing the NO _X emissions.

[0002]

2. Description of the Related Art At present, a premixed combustor is used as a combustor for a gas turbine.
al) Generation of NO _X is inevitable, and it is difficult to reduce NO _X emissions. Catalytic combustion are known as combustion technology does not produce thermal NO _X. Conventionally, this catalytic combustion
A catalyst containing a noble metal such as Pd or Pt is used, but when the gas temperature at the outlet of the catalyst layer is high as in a gas turbine combustor, volatilization and sintering of a noble metal species as an active component ( It is difficult to use the catalyst for a long time because the catalyst activity is reduced due to the decrease in the active surface area due to the heat history.

[0003]

As described above [0008] At present, premixed combustors have been used as a combustor for a gas turbine, inevitably generating the thermal NO _X NO _X
Emissions reduction is difficult, there is a catalytic combustion as the combustion technique that does not generate a thermal NO _X. In order to use catalytic combustion in a gas turbine combustor, it is necessary to have a catalytic performance capable of raising the gas temperature at the compressor outlet to a gas temperature at which gas-phase combustion is possible and a durability capable of maintaining the performance for a long period of time. Pd, Pt as catalysts satisfying this catalytic performance
Catalysts containing precious metal components such as
When the temperature is raised to a gas temperature at which gas phase combustion can be performed, the catalytic performance decreases due to volatilization and sintering of the noble metal component serving as the catalytic component, so that it is difficult to maintain the catalytic performance for a long time. This has been a serious problem in practical use. For example, a catalyst containing Pd loses its catalytic activity within a few hours after the start of combustion.

The present invention has been made in view of the above-mentioned state of the art, and an object of the present invention is to provide a catalytic combustor for a gas turbine which has the above-mentioned catalytic performance and has a durable catalyst structure which can be used for a long period of time.

[0005]

According to the present invention, as a constitution of a catalytic combustion section, a palladium-containing catalyst layer is provided in a former stage (gas inlet side), and manganese is contained in a latter stage (gas outlet side). A catalytic combustor for a gas turbine, wherein a catalyst having

[0006] In the present invention, the catalyst containing palladium, which is disposed in the preceding stage of the gas flow path, is Pd / Al ₂ O ₃
/ Cordierite (Pd catalyst component supported on Al ₂ O ₃ carrier coated on cordierite substrate:
Pd = 0.1-5 wt%), Pd / Al ₂ O ₃ -La ₂
O ₃ / cordierite (Pd catalyst component supported on Al ₂ O ₃ —La ₂ O ₃ carrier coated on cordierite substrate: Pd = 0.1 to 5 wt%) BaMn _X Al _11-X is a catalyst containing manganese to be formed and having a magnetoplumbite structure.
Assuming that the valence of O _19-a ｛1 <x ≦ 2, Mn is z, a = x
× (3-z) / 2}, particularly BaMn _1.5 Al
_10.5 O _19-a {a = 1.5 × (3-z) / 2} is preferred. The latter catalyst may use cordierite as a carrier, but it is preferable that this catalyst does not use a carrier.

The structure of the magnetoplumbite is, as schematically shown in FIG. 2, composed of a spinel block (S block) and an R block containing Ba.
However, the S block and the R block overlap by 180 ° to form a single crystal, and are thus separated into two upper and lower pieces to form a twill weave pattern. This crystal structure has high heat resistance. Is known to have

[0008]

In DETAILED DESCRIPTION OF THE INVENTION catalytic combustor for a gas turbine using catalytic combustion is a combustion technique that does not generate a thermal NO _X, and the catalyst performance can be raised from the compressor exit gas temperature to a temperature at which the vapor phase combustion occurs In addition, durability for maintaining the catalyst performance for a long time is required. However, since the catalyst containing Pd has an excellent ability to start combustion from a low temperature, it is indispensable to start the combustion from the compressor outlet gas temperature.
It is difficult to use the catalyst due to severe decrease in catalytic activity due to sintering and the like. On the other hand, a catalyst containing Mn and having a magnetoplumbite structure is inferior to a catalyst containing Pd in combustion starting ability from a low temperature. However, it is unlikely that the catalytic activity decreases due to volatilization of catalyst components and sintering under high temperature conditions, so that it can be used for a long period of time.

Therefore, in the present invention, as shown in FIG. 1, a catalyst layer 1 containing Pd, which is excellent in ignition performance from low temperatures, is disposed at the front stage (gas inlet side), whereby the catalytic reaction from the gas temperature at the compressor outlet is performed. M can be started, and M is less susceptible to reduction in catalyst activity due to high temperature in the subsequent stage (gas outlet side).
n-containing catalyst layer having magnetoplumbite structure 2
Is arranged so that the outlet gas temperature at which gas phase combustion is possible can be maintained for a long period of time.

A mixed gas of air discharged from a compressor (not shown) and fuel gas (natural gas) is Pd / Al
_The catalyst is introduced into the catalyst layer 1 made of ₂ O ₃ / cordierite (Pd = 1 wt%), and the catalytic oxidation reaction proceeds. As the reaction proceeds, the catalyst temperature and gas temperature increase. The gas heated on the catalyst layer 1 is BaMn _1.5 Al _10.5 O
_19-a {a = 1.5 × (3-z) / 2} is introduced into the catalyst layer 2 (without carrier) having a magnetoplumbite structure,
Further, the catalytic oxidation reaction proceeds, and the temperature rises to a temperature at which gas phase combustion can be performed. By adopting this catalyst configuration, it has a catalyst performance that can raise the compressor outlet gas temperature to a temperature at which gas phase combustion can be performed, and a durability that can maintain this catalyst performance for a long time. Have.

[0011]

EXAMPLES Hereinafter, specific examples of the present invention will be described to clarify the effects of the present invention. FIG. 3 shows an example of incorporation of a catalyst into a catalytic combustor for a gas turbine, and FIG. 4 is a table showing test results of catalyst performance of a catalyst layer under atmospheric pressure conditions.

In FIG. 3, reference numeral 1 denotes Pd / Al ₂ O ₃ / cordierite (Pd content relative to the carrier Al ₂ O ₃ : 1 wt.
%, Cordierite: Pd-supported Al ₂ per 100 g
Pd-containing catalyst layer composed of O ₃ content: 5 g);
Mn _1.5 Al _10.5 O _19-a ｛a = 1.5 × (3-z) /
A catalyst layer containing Mn of 2% and having a magnetoplumbite structure, 3 is a catalyst pilot, 4 is a fuel inlet,
5 is an air inlet, 6 is a (fuel + air) inlet, 7 is a catalyst pilot outlet, 8 is a catalytic combustor, and points A and B are shown in FIG.
The catalyst layer inlet position and the catalyst layer outlet position shown in FIG. Here, the volume ratio of the catalyst layer 1 to the catalyst layer 2 is set to 3: 2.

Assuming that the fuel (LNG) / air ratio is 2.6% by weight, fuel and air are introduced into the catalytic combustor 8, and 5 to 10% of the gas amount thereof is introduced into the catalytic pilot 3, and other fuel and air are introduced. Air is introduced from the fuel inlet 4 and the air inlet 5. When the gas temperature at the catalyst layer inlet position A of the catalyst pilot 3 is about 400 ° C., the gas temperature at the catalyst layer outlet position B reaches 900 ° C. or more, for example, about 1000 ° C. And becomes an ignition source of the fuel and the air mixture gas introduced from the fuel inlet 4 and the air inlet 5 to burn all the fuel almost completely (99% or more). At the outlet of the catalytic combustor 8, about 1350 ° C. Also reach. At this time, the combustion gas burned in the catalyst pilot 3,
Combustion gas combusted in the catalytic combustor 8 generates of the NO _X together was confirmed that almost no in 1ppm or less.

FIG. 4 is a table showing the test results of the catalyst performance described above. The mixed gas of fuel (LNG) and air (fuel / air ratio = 2.6 wt%) is 400 ° C. and the catalyst described with reference to FIG. The gas supplied to the bed and passing through both catalyst layers has a temperature of about 1000 ° C. immediately after exiting the catalyst layer. As a result of the continuous operation for 1000 hours, it was confirmed that the catalyst performance did not decrease as shown in FIG.

[0015] From these test results, in the catalytic combustor for the purpose of NO _X emissions reduction, by employing the catalyst structure according to the present invention, a 400 ° C. of about gas corresponding to the compressor outlet temperature vapor phase combustion It was found that the temperature could be higher than the possible temperature, and that this performance could be maintained for a long time.

[0016]

As described above, in the catalytic combustor for a gas turbine, by employing the catalyst structure according to the present invention, the catalytic performance capable of increasing the gas at the compressor outlet temperature to a temperature at which the gas phase combustion can be performed is maintained for a long time. It becomes possible. Therefore, according to the present invention, in using the catalytic combustor for gas turbine, the catalyst can be used for a long time.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an example of the structure and temperature distribution of a catalyst according to the present invention.

FIG. 2 is a schematic diagram showing a magnetoplumbite structure.

FIG. 3 is an explanatory view showing an example of incorporating a catalyst into a catalytic combustor according to one embodiment of the present invention.

FIG. 4 is a chart showing an example of test results regarding durability of catalytic combustion.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigetomi Bandai 2-1-1, Shinhama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Kuniaki Aoyama 2-1-1, Araimachi, Takarai City, Hyogo Prefecture No. 1 Inside Mitsubishi Heavy Industries, Ltd. Takasago Works (72) Inventor Koichi Nishida 2-1-1, Shinhama, Araimachi, Takasago City, Hyogo Prefecture Inside Mitsubishi Heavy Industries, Ltd. Takasago Works

Claims (1)

[Claims] As a configuration of a catalytic combustion section, a catalyst layer containing palladium is arranged at a former stage (gas inlet side), and a catalyst containing manganese and having a magnetoplumbite structure is arranged at a latter stage (gas outlet side). A catalytic combustor for a gas turbine.