JP5326193B2 - Power generation method and power generation apparatus using exhaust gas, and exhaust gas oxidation treatment method and oxidation treatment apparatus - Google Patents

Description

The present invention relates to a power generation method and a power generation apparatus using an exhaust gas containing a predetermined amount or more of H ₂ or CO, such as converter gas and coke oven gas of a steel mill, and an oxidation treatment method and an oxidation treatment apparatus for the exhaust gas. is there.

In general, large amounts of high-temperature exhaust gas containing H ₂ or CO at a predetermined concentration or more are generated from converters and coke ovens in steelworks. Conventionally, such exhaust gas burns H ₂ or CO by oxygen addition thereafter. (Oxidation) treated to detoxify and then discharged to the atmosphere (2H ₂ + O ₂ → 2H ₂ O, 2CO + O ₂ → 2CO ₂ )
In the combustion treatment of the exhaust gas containing H ₂ or CO having a predetermined concentration or more, attempts have been made to effectively use the combustion heat, and the location where the combustion heat is generated is a converter, coke oven, etc. It is difficult to use and the collection efficiency is not good because of the furnace bottom and flue.

That is, as one of the reasons why the thermal energy generated during the combustion process cannot be used effectively, the thermal energy has a lot of loss due to the transfer, and it is necessary to change its energy form except for use near the generation source. Can be mentioned. Furthermore, there is a problem that a large amount of investment is required for equipment that converts the thermal energy form into electrical energy. Furthermore, the combustion process results in a large amount of CO ₂ being generated.

Therefore, for example, in Patent Documents 1 and 2 below, a method of using high-temperature exhaust gas containing H ₂ or CO generated in a converter or coke oven as fuel gas of a high-temperature fuel cell and recovering it as electric energy Has proposed.
JP-A-60-177571 Japanese Unexamined Patent Publication No. 63-62160

By the way, in Patent Documents 1 and 2, high-temperature exhaust gas generated in a converter or coke oven is once stored in a gas holder or the like, subjected to refining treatment or post-heat treatment, and then supplied to a fuel cell to generate power. Therefore, there is a problem that a dedicated facility for that purpose is newly required and a huge amount of money is required for its construction and processing.
Accordingly, the present invention has been devised to effectively solve such problems, and its purpose is to utilize H ₂ or CO in high-temperature exhaust gas generated in a converter or coke oven at a low cost. Alternatively, the present invention provides a power generation method and power generation apparatus using a novel exhaust gas that can be oxidized, and an exhaust gas oxidation treatment method and oxidation treatment apparatus.

In order to solve the above problems, the first invention is:
A power generation method using exhaust gas containing H ₂ and / or CO having a predetermined concentration or more, generated from a converter or coke oven, and burned for detoxification and discharged to the atmosphere. In addition, the exhaust gas at 700 to 1000 ° C. generated in a converter or coke oven is directly used as it is, and instead of the combustion treatment, a fuel having an ion conductive oxide as a solid electrolyte in a flue or furnace through which the exhaust gas passes An exhaust gas characterized in that a fuel electrode of a battery is positioned and brought into contact with the exhaust gas passing through the flue or furnace, and oxygen is supplied to the oxygen electrode side of the fuel cell to generate electric power. This is the power generation method used.

In addition, the second invention,
One specific concentration or more of H ₂ and CO or either only contains, and, a power generation apparatus using the exhaust gas is discharged to the atmosphere from the combustion process for detoxifying generated from a converter furnace or the coke oven The fuel electrode of the fuel cell is provided in a flue or furnace through which the exhaust gas passes, and the ion conductive oxide is used as a solid electrolyte so as to be in contact with the exhaust gas passing through the flue or furnace. In addition, there is provided a power generation apparatus using exhaust gas, characterized in that oxygen supply means for supplying oxygen to the oxygen electrode side of the fuel cell is provided.

In addition, the third invention,
A method of oxidizing an exhaust gas containing H ₂ and / or CO having a predetermined concentration or more and being emitted from a converter or a coke oven and burned for detoxification and discharged into the atmosphere. In addition, the exhaust gas at 700 to 1000 ° C. generated in a converter or coke oven is directly used as it is, and instead of the combustion treatment, a fuel having an ion conductive oxide as a solid electrolyte in a flue or furnace through which the exhaust gas passes A fuel electrode of the battery is positioned and brought into contact with the exhaust gas passing through the flue or the furnace, and oxygen is supplied to the oxygen electrode side of the fuel cell so that H ₂ and / or CO in the exhaust gas is supplied. This is an exhaust gas oxidation method for oxidizing treatment.

In addition, the fourth invention is
One specific concentration or more of H ₂ and CO or either only contains, and, there in apparatus for oxidizing the exhaust gas is discharged to the atmosphere from the combustion process for generated from the converter or coke oven harmless The fuel electrode of the fuel cell is provided in a flue or furnace through which the exhaust gas passes, and the ion conductive oxide is used as a solid electrolyte so as to be in contact with the exhaust gas passing through the flue or furnace. In addition, an exhaust gas oxidation apparatus comprising oxygen supply means for supplying oxygen to the oxygen electrode side of the fuel cell.

According to the first and second inventions, since the fuel cell is installed in a flue or furnace through which the exhaust gas passes, H ₂ and / or CO having a predetermined concentration or more and either one contained in the exhaust gas and air Electricity can be generated by efficiently reacting (oxygen) with the high temperature of the exhaust gas. In addition, since a large dedicated facility for using the exhaust gas is not required, H ₂ or CO in the exhaust gas can be effectively used at a low cost.

According to the third and fourth inventions, as in the first or second invention , since the fuel cell is installed in a flue or furnace through which the exhaust gas passes, it is included in the exhaust gas. H ₂ and / or CO having a predetermined concentration or higher and air (oxygen) can be efficiently reacted using the high temperature of the exhaust gas and removed from the exhaust gas. In addition, since a large dedicated facility for removing H ₂ or CO in the exhaust gas is not necessary, H ₂ or CO in the exhaust gas can be oxidized at a low cost.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows an embodiment of a power generator 100 according to the present invention.
As shown in the figure, the power generation apparatus 100 includes a fuel cell unit 10 provided in a flue S through which a high-temperature (for example, 700 to 1000 ° C.) exhaust gas containing H ₂ and / or CO having a predetermined concentration or higher passes. The oxygen supply fan 20 that supplies air (oxygen) to the fuel cell unit 10 and a load unit 30 that uses or stores electricity generated by the fuel cell unit 10 are mainly configured.

  As shown in FIG. 2, the fuel cell unit 10 has a configuration similar to that of a known one, and a header (not shown) for guiding gas to a cell stack 50 in which a plurality of cells 40 having a power generation function are stacked. And the exhaust gas and the air in the atmosphere are alternately passed through the slit-like flow paths of the separators 41 that partition the cells 40 to generate power.

That is, as shown in FIG. 3, each cell 40 constituting the cell stack 50 is made of a solid electrolyte that is active at a high temperature, for example, yttria stabilized zirconia (YSZ), which is a typical ion conductive oxide. The solid electrolyte layer 42 used as the electrolyte includes a sheet or plate-shaped fuel electrode (cathode: for example, Ni-YSZ cermet) 43 through which gas can pass, and a sheet or plate-shaped oxygen electrode (cathode) through which gas can also pass. : La (Sr) MnO ₃ or the like) 44, and the upper and lower sides are sandwiched between a pair of separators 41a and 41b, respectively. Note that catalyst layers 45 and 45 for promoting a reaction (power generation) in the solid electrolyte layer 42 are formed on the solid electrolyte layer 42 of the fuel electrode 43 and the oxygen electrode 44, respectively.

Then, as shown in the figure, high-temperature exhaust gas containing H ₂ and / or CO having a predetermined concentration or higher or one of them is passed to one separator 41a side, and air (oxygen) is passed to the other separator 41b side as described above. As shown in FIG. 4, when the fuel is hydrogen (H ₂ ) on the fuel electrode 43 side as shown in FIG. 4, the H ₂ separates electrons by the action of the catalyst 45 on the fuel electrode 43 side to generate hydrogen ions (2H ⁺ ) (H ₂ → 2H ⁺ + 2e ⁻ ). Since the solid electrolyte layer 42 has a property of allowing only ions to pass therethrough, the separated electrons flow out from the electric wire 30a and flow to the load portion 30 side.

Thereafter, the hydrogen ions (2H ⁺ ) move in the solid electrolyte layer 42 and reach the opposite oxygen electrode 44, where they return to the oxygen (O ₂ ) that has entered the oxygen electrode 44 and the load portion 30. It reacts (oxidizes) with the incoming electrons to form water (H ₂ O) (1 / 2O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O), and is discharged to the outside together with the remaining air.
When the fuel supplied to the fuel electrode 43 side is carbon monoxide (CO), it reacts (oxidizes) with oxygen (O ₂ ) on the oxygen electrode 44 side and remains as carbon dioxide (CO ₂ ). It will be discharged to the outside along with the air.

Therefore, in the present invention, as shown in FIG. 1, the fuel cell unit 10 of the power generation apparatus 100 is disposed on the fuel electrode 43 side of the cell stack 50 with high-temperature exhaust gas containing H ₂ and / or CO having a predetermined concentration or higher. It is installed in the flue S so that it is always in contact, and sufficient oxygen is always supplied to the oxygen electrode 44 of the cell stack 50 by the oxygen supply fan 20. It is possible to reliably oxidize and remove H ₂ and CO in the exhaust gas passing through the gas and to supply sufficient electricity.

  The solid electrolyte layer 42 is made of an ion conductive oxide such as yttria-stabilized zirconia that exhibits the highest activity around 1000 ° C., and can be used at high temperatures. Since the high-temperature exhaust gas immediately after generation can be directly processed, dedicated processing equipment and handling become unnecessary, and the present invention can be realized at a low cost.

In the present embodiment, the fuel cell unit 10 of the power generation apparatus 100 has been described as an example in which the fuel cell unit 10 is provided in the flue S through which high-temperature exhaust gas containing H ₂ and / or CO having a predetermined concentration or more flows. For example, in a case (equipment) in which the heat in the exhaust gas is recovered (after cooling) and flows into the flue S, the exhaust gas temperature is low and the reaction is not good. Therefore, in such a case, the fuel cell unit 10 of the power generation apparatus 100 may be provided directly in the furnace where the high-temperature exhaust gas is generated instead of the flue S.

It is explanatory drawing which shows one Embodiment of the electric power generating apparatus 100 which concerns on this invention. It is a perspective view which shows the fuel cell unit 10 which comprises a part of electric power generating apparatus 100 which concerns on this invention. 3 is an exploded perspective view showing a structure of a cell 40 constituting the fuel cell unit 10. FIG. 3 is an explanatory diagram showing the principle of power generation by a cell 40. FIG.

Explanation of symbols

100 ... Power generation device (oxidation treatment device)
DESCRIPTION OF SYMBOLS 10 ... Fuel cell unit 20 ... Oxygen supply fan (oxygen supply means)
DESCRIPTION OF SYMBOLS 30 ... Load part 30a ... Electric wire 40 ... Cell 41 ... Separator 42 ... Solid electrolyte layer 43 ... Fuel electrode 44 ... Oxygen electrode 45 ... Catalyst 50 ... Cell stack S ... Flue

Claims (4)

A power generation method using exhaust gas containing H ₂ and / or CO having a predetermined concentration or more, generated from a converter or coke oven, and burned for detoxification and discharged to the atmosphere. ,
A fuel cell in which an exhaust gas of 700 to 1000 ° C. generated in a converter or a coke oven is directly used as it is, and instead of the combustion treatment, an ion conductive oxide is used as a solid electrolyte in a flue or furnace through which the exhaust gas passes. The exhaust gas is characterized in that the fuel electrode is positioned and brought into contact with the exhaust gas passing through the flue or furnace and oxygen is supplied to the oxygen electrode side of the fuel cell to generate power. Was the power generation method. A power generator using exhaust gas containing H ₂ and / or CO having a predetermined concentration or more, and generated from a converter or a coke oven and subjected to combustion treatment for detoxification and then discharged to the atmosphere ,
The fuel electrode of the fuel cell is provided in a flue or furnace through which the exhaust gas passes, and an ion conductive oxide is used as a solid electrolyte so as to be in contact with the exhaust gas passing through the flue or furnace, and A power generator using exhaust gas, characterized by comprising oxygen supply means for supplying oxygen to the oxygen electrode side of the fuel cell. A method of oxidizing an exhaust gas containing H ₂ and / or CO having a predetermined concentration or more and being emitted from a converter or a coke oven and burned for detoxification and discharged into the atmosphere. ,
A fuel cell in which an exhaust gas of 700 to 1000 ° C. generated in a converter or a coke oven is directly used as it is, and instead of the combustion treatment, an ion conductive oxide is used as a solid electrolyte in a flue or furnace through which the exhaust gas passes. The fuel electrode is placed in contact with the exhaust gas passing through the flue or furnace, and oxygen is supplied to the oxygen electrode side of the fuel cell to oxidize H ₂ and / or CO in the exhaust gas. An exhaust gas oxidation method for treating exhaust gas. An apparatus for oxidizing exhaust gas that contains H ₂ and / or CO at a predetermined concentration or any one of them and that is generated from a converter or coke oven and burned for detoxification and then discharged to the atmosphere. ,
The fuel electrode of the fuel cell is provided in a flue or furnace through which the exhaust gas passes, and an ion conductive oxide is used as a solid electrolyte so as to be in contact with the exhaust gas passing through the flue or furnace, and An exhaust gas oxidation apparatus comprising oxygen supply means for supplying oxygen to the oxygen electrode side of the fuel cell.

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