JP2000223143A - Fuel-cell power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively use hydrogen energy that was wasted as unnecessary gas, and eliminate requirement of facility and power for reforming raw fuel, by supplying gas generated in an activation reaction in a manufacturing process for activated carbon and using it for power generation. SOLUTION: Activation generated gas generated in an activation furnace 11 is guided through an impurity removing device 13 and a steam concentration adjuster 14 to a CO transformer 5 for CO transformation together with adequate steam. When CO concentration in fuel gas supplied to a fuel cell 1 is high, a cell characteristic of the fuel cell 1 is reduced. Therefore, CO in the activation generated gas and the steam are reacted in the CO transformer 5, to be transformed to carbon dioxide and water, and the CO concentration is reduced to lower than about 1%, for example. Such process is applied to the activation generated gas to produce fuel gas, the fuel gas is made to flow to a fuel electrode of the fuel cell 1, air guided through a blower is made to flow to an oxidant electrode, and power generation is performed. Generated power is direct power, therefore, is converted to alternating current by an inverter 15, and supplied to a load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell power generation system using, as a fuel gas, a hydrogen-rich gas generated in a process for producing activated carbon.

[0002]

2. Description of the Related Art A fuel cell directly converts the chemical energy of fuel into electric energy. A fuel cell and an oxidant electrode sandwiching an electrolyte layer are supplied with fuel gas and oxidant from an external gas supply system. And gas, respectively,
This is a type of power generation device in which a fuel gas and an oxidizing gas are electrochemically reacted on an electrode catalyst layer of each electrode, and as a result, electric energy is taken out of the system.

[0003] As a fuel gas, a hydrocarbon gas fuel (natural gas, etc.) or a liquid fuel (methanol, naphtha, etc.), which is a raw fuel, is reformed into a hydrogen-rich fuel gas in a fuel processing system. ing.

FIG. 2 is a schematic view of a fuel processing system 10 of a general fuel cell power generation system using gaseous fuel.
In the fuel processing system 10, the raw fuel gas is first subjected to sulfur removal by the desulfurizer 2, and then sent to the reformer 3 together with steam. The reformer 3 is provided with a burner 4, and the temperature of a reforming tube (not shown) filled with a reforming catalyst is raised to about 750 ° C. The raw fuel reacts with water vapor while flowing through the reforming pipe to be reformed into a hydrogen-rich gas. afterwards,
The gas is led to the CO converter 5 to reduce the concentration of carbon monoxide in the reformed gas.

[0005] Activated carbon used as an adsorbent or a catalyst carrier is obtained by using a raw material such as charcoal or wood distillate at about 600 ° C.
After sufficient carbonization in an inert atmosphere, activated in steam or carbon dioxide in order to increase the specific surface area of the carbide and increase the adsorption capacity. FIG. 3 shows such a general activated carbon production system.

[0006] The steam activation reaction of carbide is represented by the following equation (1), and hydrogen and carbon monoxide are produced. C + H ₂ O → CO + H ₂ (1) Then, when the generated carbon monoxide further reacts with water vapor as shown in the following formula (2), a gas rich in carbon dioxide and hydrogen is obtained.

CO + H ₂ O → CO ₂ + H ₂ (2) The gas generated in the activation furnace 11 by the activation reaction of the above formula (1) or (2) is conventionally unnecessary as shown in FIG. It was released to the atmosphere by exhaust as gas.

[0008]

As described above, the conventional fuel cell power generation system has a complicated and large capacity for reforming a raw fuel gas to obtain a hydrogen-rich fuel gas used for fuel cell power generation. A large apparatus is required, and power for driving a blower 6 (FIG. 2) for supplying combustion air for the burner 4 is also required. On the other hand, in the process of producing activated carbon, fuel gas for a fuel cell is used. Exhaust gas rich in hydrogen that can be effectively used was wasted as unnecessary gas.

According to the present invention, there is provided a fuel cell power generation system capable of making effective use of the above-mentioned hydrogen energy and eliminating or reducing the power consumed for the equipment for reforming the raw fuel or the power for the equipment. The purpose is to do.

[0010]

SUMMARY OF THE INVENTION The present invention is to effectively utilize a hydrogen-rich gas produced by an activation reaction, which has been discarded as an unnecessary gas in an activated carbon production process, as a fuel gas for a fuel cell for power generation. did.

[0011]

FIG. 1 shows an embodiment of a fuel cell power generation system according to the present invention. As shown in FIG. 1, the fuel cell power generation system of the present invention effectively utilizes a hydrogen-rich activation product gas generated by an activation reaction in an activation furnace 11 in a production process of activated carbon as a fuel gas of a fuel cell 1. is there.

The activation product gas generated in the activation furnace 11 flows through the activation product gas supply path 12, passes through the impurity removing device 13 and the steam concentration controller 14, and is sent to the CO converter 5 together with an appropriate amount of water vapor for the CO conversion reaction. Be guided. If the concentration of carbon monoxide contained in the fuel gas supplied to the fuel cell 1 is high, the cell characteristics of the fuel cell are degraded.
Then, carbon monoxide and water vapor in the activation product gas are reacted with each other (formula (2)) to convert them into carbon dioxide and hydrogen, thereby reducing the carbon monoxide concentration to about 1% or less.

After the above-described treatment is performed on the activated product gas, the generated gas is used as a fuel gas to flow to the fuel electrode of the fuel cell 1 and air introduced by a blower (not shown) to the oxidant electrode to generate power. Since the power obtained by the power generation is DC power, the power is converted into AC by the inverter 15 and supplied to the load.

In the above embodiment, the supply of the fuel gas to the fuel cell relies only on the hydrogen-rich activated product gas directly supplied from the activated carbon production system through the activated product gas supply passage 12. However, the present invention is not limited to this, and other hydrogen gas supply means may be provided in addition to the case where the amount of the activated product gas is small. Alternatively, in order to cope with an increase or a decrease in the amount of the activated product gas, when the amount of the activated product gas generated is large, a cylinder for storing the activated product gas is supplied to the activation generating gas supply passage on the upper side of the impurity removing device 13. It may be configured to be provided at any position between the removing device 13 and the steam concentration controller 14 or between the CO gas converter 5 and the fuel cell 1.

[0015]

According to the present invention, the gas generated by the activation reaction in the production process of activated carbon is used as the fuel gas to be supplied to the fuel cell, so that the chemical energy of conventionally discarded hydrogen can be effectively used. To generate electricity and contribute to energy conservation. Also, it is possible to supply a hydrogen-rich gas to the fuel cell with a simple configuration without providing a reformer for reforming a gaseous fuel such as natural gas or a liquid fuel such as methanol. It is possible to provide and operate a fuel cell power generation system with small capacity and low cost.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a fuel cell power generation system according to the present invention.

FIG. 2 is a diagram showing an activated carbon production process.

FIG. 3 is a schematic diagram of a conventional fuel cell power generation system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Desulfurizer 3 Reformer 4 Burner 5 CO converter 6 Air blower 10 Fuel treatment system 11 Activation furnace 12 Activation generated gas supply channel 13 Impurity removal device 14 Steam concentration controller 15 Inverter

Claims (2)

[Claims] 1. A fuel cell power generation system, wherein a gas generated by an activation reaction in a production process of activated carbon is supplied to a fuel cell and used for power generation. 2. The fuel cell power generator according to claim 1, wherein the gas is supplied to a fuel cell after the concentration of carbon monoxide is reduced by a CO converter.