JPH01143155A - Fuel cell power generator - Google Patents

Abstract

PURPOSE:To perform desulfurization at the time of a start without requiring hydrogen or performing the catalyst deoxidation operation by providing a desulfurizer operated at the ordinary temperature and using activated carbon, alkali aqueous solution or the like in addition to a desulfurizer using the desulfurizing catalyst such as ZnO. CONSTITUTION:The ordinary-temperature gas TG containing a sulfur content is utilized as fuel, a desulfurizer 7 operated at the ordinary temperature and using activated carbon or an alkali aqueous solution is provided on a line 4 guiding to a reformer 5 to perform desulfurization at the time of a start, and desulfurization is performed by the desulfurizer 7 when a power generator is started. The hydrogen gas used for desulfurization at the time of a start when only a desulfurizer using the desulfurizing catalyst such as ZnO is employed is not required, and desulfurization can be performed at the time of a start with no catalyst deoxidation operation.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is applicable to fuel cells used in the energy sector that directly converts the chemical energy of fuel*31 into electrical energy, and particularly to fuel cells that require desulfurization. The present invention relates to a power generation device.

[Prior art] Among the fuel cells proposed to date, for example,
In a molten carbonate fuel cell, an electrolyte plate (tile) made by impregnating a porous material with molten carbonate as an electrolyte is sandwiched between a cathode (oxygen electrode) and an anode (fuel electrode), and an oxidizing gas is placed on the cathode side. One cell is one cell that generates electricity by the potential difference generated between the cathode and anode by supplying fuel gas to the anode side, and each cell is stacked in multiple layers with a separator in between. It is the property of

In the power generation device using the above molten carbonate fuel cell, it has been proposed to use natural gas, city gas, coal, etc. as the fuel gas. When using city gas as fuel, the city gas is reformed, and when coal is used as fuel, it is gasified and refined.

As a molten carbonate fuel cell power generation system that utilizes a room temperature gas containing sulfur, such as city gas, as the fuel for the molten carbonate fuel cell, a configuration shown in FIG. 2 is known. That is, city gas TG to be supplied to the 7 nodes 3 of the fuel cell 1 is introduced into the reformer 5 via line 4, reformed there, and supplied to the anode 3 via line 6, and the reformed gas is Line 4 on the inlet side of the container 50
A desulfurizer 7 using a desulfurization catalyst such as Zno is installed as a desulfurizer for removing sulfur content in the gas, and natural gas preheaters 8 and 9 are installed above the desulfurizer 7. , the gas discharged from the anode 3 passes through the natural gas preheater 8.9 in order and exchanges heat with the city gas that enters the reformer 5, and then passes through the reformer 5.
The fuel is introduced into the combustion chamber of the engine. In addition, in order to supply oxidizing gas to the cathode 2 of the fuel cell 1, after compressing the air with the compressor 10, an air preheater 11 and a turbine 12 are used.
, is supplied to the cathode 2 via a line 14 via an air preheater 13, and a portion is supplied to the reformer 5 via a branch line 15.
The gas discharged from the cathode 2 is branched and one side is discharged through the air preheater 11, and the other side is discharged through the air preheater 13, the superheater 16, and the evaporator 17. Water H20
is turned into steam in the evaporator 17, superheated in the superheater 16, and supplied to the line 4, and is sent to the reformer 5 together with the gas in the line 4.
The gas containing waste acid gas discharged from the combustion chamber outlet of the reformer 5 is supplied to the cathode 2 together with the gas flowing through the line 14. 18 is a compressor.

[Problems to be Solved by the Invention] However, in the power generation system shown in FIG. Since the desulfurizer 7 is used to perform the desulfurization action even when no hydrogen is generated in the reformer at the time of startup of the device, hydrogen is required for catalytic reduction at startup, and a hydrogen cylinder is required for this purpose. There are problems such as the need to set up the catalytic reduction, etc., and the time and effort it takes to start up due to the catalytic reduction operation.

Therefore, the present invention aims to enable desulfurization at startup to be performed without requiring hydrogen at startup or performing catalytic reduction.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a fuel cell power generation device that uses a room temperature gas containing sulfur as a fuel to be supplied to the anode of a fuel cell. ZnO was added to the room temperature gas supply line containing sulfur to be introduced into the reformer.
In addition to the desulfurizer using a desulfurization catalyst such as the above, a desulfurizer that operates at room temperature using activated carbon, alkaline aqueous solution, etc. is installed for desulfurization at startup, and the above-mentioned two desulfurizers are used by switching. do.

[Function] When starting up the power generation equipment, a desulfurization action is performed to remove the sulfur content in the introduced gas using a desulfurizer that operates at room temperature using activated carbon, alkaline aqueous solution, etc., and each equipment is warmed up and the equipment is renovated. When hydrogen starts to be generated by the hydrogen generator, etc., the use of the desulfurizer for startup is stopped and the desulfurization is switched to a desulfurizer using a desulfurization catalyst such as ZnO. This eliminates the need to place a hydrogen cylinder required for catalytic reduction at startup, and also eliminates the need for operations for catalytic reduction.

[Example] Hereinafter, an example of the present invention will be explained with reference to the drawings. Figure 1 shows an example of the present invention, and Figure 2 shows a conventional city gas reforming melting method. In the same configuration as the carbonate fuel cell power generation device, on the inlet side of the compressor 18 in the line 4 that leads the room temperature gas containing sulfur to the reformer 5,
A desulfurizer 19 that operates at room temperature using activated carbon, aqueous alkaline solution, etc. is provided for desulfurization at startup, and the desulfurizer 19 and the desulfurizer 7 that uses a desulfurization catalyst such as ZnO located in the middle of the line 4 are as follows: Switch to enable driving.

The activated carbon or alkaline aqueous solution (chemical solution) in the desulfurizer 19 for desulfurization at startup is of a cartridge type so that it can be easily replaced, and can be replaced during periodic inspection. The other configurations are the same as those in FIG. 2, and the same components are given the same reference numerals.

At startup, a newly installed desulfurizer 19 using activated carbon, alkaline aqueous solution, etc. is used to desulfurize the gas supplied to the line 4. After a certain period of time has passed after startup, each device is warmed up and hydrogen H2 is generated by the reformer 5 and the like. When hydrogen is generated, the generated hydrogen is used to reduce the desulfurization catalyst such as ZnO, so the use of the desulfurizer 19 for starting is stopped and the desulfurizer 7 using the desulfurization catalyst such as ZnO is started. Let it be used. In this case, the line 20 connected to the line 4 from the outlet side of the reformer 5 is opened, and a part of the hydrogen obtained by reforming in the reformer 5 is transferred from the line 6 into the line 4. and used for catalytic reduction in the desulfurizer 7.

In addition, at the time of startup mentioned above, the fuel flow rate may be small, so
The startup desulfurizer 19 may be small.

In addition, although the case of a molten carbonate fuel cell was shown as an example,
It is not limited to this.

[Effects of the Invention] As described above, according to the fuel cell power generation device of the present invention,
To use room temperature gas containing sulfur as fuel, a desulfurizer that operates at room temperature and uses activated carbon or aqueous alkaline solution is installed in the line leading to the reformer to perform desulfurization at startup. Since the above-mentioned desulfurizer is used to desulfurize when the equipment is started, hydrogen for catalytic reduction is not used even when the desulfurizer is used for desulfurization using the conventional desulfurizer such as Zno. No gas is required, and a catalyst reduction operation is not required at the time of start-up, and the start-up does not take much time and effort, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention, and FIG. 2 is a system configuration diagram of a conventional power generation system. DESCRIPTION OF SYMBOLS 1... Fuel cell, 2... Cathode, 3... Anode, 4... Line, 5... Reformer, 7... Desulfurizer, 19... Desulfurizer for startup.

Claims (1)

[Claims] 1) In a fuel cell power generation device in which a room temperature gas containing sulfur is supplied to the anode of the fuel cell after being reformed, and an oxidizing gas is supplied to the cathode, the room temperature gas containing sulfur is supplied to the anode of the fuel cell. In addition to a desulfurizer that uses a desulfurization catalyst such as ZnO, a desulfurizer that uses activated carbon or a chemical solution is installed in the line that introduces the gaseous body into the reformer to perform desulfurization only at startup. A fuel cell power generation device characterized by: