JPH0576729A - Nitrogen oxide removing system by ammonia catalytic reduction process for exhaust gas of glass fusion furnace or the like - Google Patents

Abstract

PURPOSE:To provide a denitrification equipment possible to execute denitration by ammonia catalytic reduction process by cooling a high temp. furnace exhaust gas of a glass fusion furnace or the like and by making vapor or solid particulate of Na, K or these compound or the like, which are catalyst poisons, solidify and enlarge to securely remove. CONSTITUTION:1. The exhaust gas is passed through the dust collector 1, is heat-exchanged in the heat exchanger 2, is introduced to the gas cooling system 3, is dust-removed again in the desulfurizing dust collector 4, is fed to the heat exchanger 2 to heat up to denitrating temp. and is brought into contact with the denitrating catalyst 8 in the denitrification equipment by ammonia catalytic reduction process 5 to remove nitrogen oxide in the exhaust gas. 2. The exhaust gas is passed through the dust collector 4, is introduced to the gas cooling system 3, is dust-removed again in the dust collector 4, is fed to the gas heating device to heat up to denitrating temp. and is brought into contact with the denitrating catalyst 8 in the denitrification equipment 5 by ammonia catalytic reduction process to remove nitrogen oxide in the exhaust gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for removing nitrogen oxides, sulfur oxides, etc. in exhaust gas generated by a glass melting furnace and a similar melting furnace by an ammonia catalytic reduction method.

[0002]

2. Description of the Related Art A denitration system (removal of nitrogen oxides in a gas) is a wet denitration method using a denitration agent in a spray tower or a spray filling tower, or an ammonia catalytic reduction in which exhaust gas is dried (dry). There is a dry denitration method such as the method. Since the denitration agent is expensive in the wet denitration method, the running cost is high, and the denitration reaction is slow and the denitration efficiency is low.

Therefore, as the denitration method for general combustion exhaust gas such as boiler exhaust gas, the ammonia catalytic reduction method denitration system which uses inexpensive ammonia and exhibits high denitration efficiency is most often adopted. However, in the exhaust gas of a glass melting furnace or the like, the catalyst in the ammonia denitration tower loses its catalytic function in a short period of time due to the influence of Na, K and compounds thereof in the exhaust gas, so-called catalyst deactivation occurs. Denitration was impossible.

That is, Nox in exhaust gas from a glass melting furnace or the like
Despite being a high concentration of several hundreds PPM, it was not possible to take sufficient measures. Since ammonia method denitration is carried out at a high temperature of around 300 ° C., a method of denitration without cooling the high temperature of the exhaust gas such as a glass melting furnace by previously removing dust with a dry dust removing device is also considered. Since the harmful substances such as K, which are harmful to the catalyst, are vaporized or fine particles, dust cannot be prevented, the ammonia denitration catalyst is adversely affected, and the denitration effect deteriorates within a short period of time, and the denitration device is not perfect.

[0005]

SUMMARY OF THE INVENTION In view of the above facts, an object of the present invention is to reliably remove catalyst poisons such as Na and K or their compounds to enable ammonia catalytic reduction denitration.

[0006]

Means for Solving the Problems (1) The exhaust gas discharged from a glass melting furnace or the like is introduced into a cooling device for cooling the exhaust gas with a cooling liquid after passing through a dust removing device, and further desulfurization. Ammonia catalytic reduction for exhaust gas such as glass melting furnace characterized by passing through a dust remover, raising the temperature of the exhaust gas to a denitration temperature by a temperature raising device, and removing nitrogen oxides in the exhaust gas by an ammonia catalytic reduction denitration device It is a system nitrogen oxide removal system.

(2) Soot and dust in the high temperature exhaust gas discharged from the glass melting furnace and the like are removed by a dust remover for removing in advance, and then heat exchange is performed with the low temperature exhaust gas passing through the wet desulfurization dust remover by a heat exchanger. By cooling the gas by passing through an exhaust gas cooling device, solidification or solid fine particles are increased to facilitate removal of gaseous or particulate denitration catalyst harmful substances generated in a glass melting furnace etc., and exhaust gas cooling After removing sulfur oxides with a desulfurization / dust removal device provided on the gas downstream side of the device, and removing the denitrification catalyst harmful substances in which the solidified or solid fine particles have been increased, the denitrification reaction temperature is passed through a heat exchanger. It is a system that removes the nitrogen oxides in the exhaust gas by heating the exhaust gas to the ammonia catalytic reduction denitration reactor and generating it in a conventional glass melting furnace. a, the denitration catalyst poisons K etc., the ammonia catalytic reduction method, a denitration which was difficult exhaust gas,
By cooling the exhaust gas in front of the denitration device, the solidification or fine particles are increased to facilitate removal of the gaseous or particulate denitration catalyst poison, and after removing the denitration catalyst poison by the dust remover, It is a denitration system, and
It is an energy-saving type system designed to raise the exhaust gas cooled by the high-temperature gas discharged from the glass melting furnace etc. to the denitration reaction temperature using a heat exchanger, and also uses alkaline chemicals in the desulfurization dust remover. By doing so, it is also possible to remove the sulfur oxides in the exhaust gas, and this is a system for removing nitrogen oxides by the ammonia catalytic reduction method for a glass melting furnace.

[0008]

[Operation] Exhaust gas discharged from a glass melting furnace, etc. is passed through a dust remover and led to an exhaust gas cooler that cools the exhaust gas. Further, a desulfurizing dust remover removes catalyst harmful substances from the exhaust gas, and then catalytic reduction with ammonia. Nitrogen oxides in the exhaust gas are removed by the method denitration device.

[0009]

Embodiments of the present invention will be described with reference to the accompanying drawings. The system of the present invention was invented to completely remove the catalyst poisons of sodium, potassium or their compounds and enable denitrification by ammonia catalytic reduction method. After removing the high-concentration soot dust in the exhaust gas generated in the glass melting furnace 6 etc. to some extent to reduce the absolute amount of soot dust, eliminate the blockage accident due to the soot dust of each equipment after the dust remover 1 and facilitate the operation The exhaust gas is guided to the exhaust gas cooling device 3 via the heat exchanger 2. During the process of passing the exhaust gas through the exhaust gas cooling device 3, the denitration catalyst harmful substances such as sodium, potassium or their compounds are solidified from a gaseous state, or fine particles which have already become a solid content are subjected to temperature cooling and gas disturbance. It becomes larger and can be easily removed. By removing the exhaust gas that has passed through the gas cooling device 3 by removing the denitration catalyst harmful substances solidified and increased by the dust removing device 4 of any method such as a wet dust removing device, a dry dust removing device, or an electrostatic precipitator,
The denitration reaction of the ammonia catalytic reduction method denitration device 5 provided on the gas downstream side is made possible.

In the exhaust gas, sulfur oxide (SO
Since x) is also included, it is possible to remove the sulfur oxides (SOx) by adopting a wet method for the desulfurization dust remover 4 and introducing an alkaline chemical into the desulfurization dust remover 4.

It is necessary to raise the temperature of the exhaust gas discharged from the desulfurization / dust removal device 4 to a temperature effective for the denitration reaction, and in order to save the fuel when a new combustion furnace is installed, the low-temperature exhaust gas that has passed through the desulfurization / dust removal device 4 Through the heat exchanger 2 or the temperature raising device 2'to exchange heat with the high temperature exhaust gas discharged from the dust removing device 1 to save energy, and then guide the exhaust gas to the ammonia catalytic reduction method denitration device 5 to remove the denitration catalyst 8 To remove nitrogen oxides in the exhaust gas.

After soot, sulfur oxides and nitrogen oxides in the exhaust gas are almost completely removed to form a clean exhaust gas, the exhaust gas is guided to the chimney 7 by the blower 9 connected to the pipe and is discharged into the atmosphere from the chimney 7. It is a thing. In addition, with respect to the dust remover 1, the heat exchanger 2 or the temperature raising device 2 ′ on the upstream side of the gas cooling device,
In order to prevent dust from adhering to the inside of the equipment, cleaning equipment is attached to these equipment.

[0013]

As described above, according to the present invention, the high-concentration soot smoke in the exhaust gas generated in the glass melting furnace or the like is removed by the dust removing device 1 provided in the upstream portion of the present system, and the absolute amount of soot smoke is reduced. Eliminate blockage accidents caused by soot and smoke in downstream equipment. The exhaust gas from which high-concentration soot has been removed can be easily removed by solidifying denitration catalyst harmful substances in the gas cooling device from the gaseous state or increasing fine particles that have already become solid in the gas cooling device. The solidified and increased denitration catalyst harmful substances are removed by a desulfurization dust remover. Sulfur oxides are removed by introducing alkaline chemicals into the desulfurization dust remover. Energy can be saved because the exhaust gas discharged from the desulfurization dust remover is heat-exchanged with the high temperature exhaust gas discharged from the dust remover by the heat exchanger. The exhaust gas discharged from the heat exchanger can be completely removed of nitrogen oxides in the exhaust gas by an ammonia catalytic reduction denitrification device, guided to a chimney by a blower, and released into the atmosphere.

[Brief description of drawings]

FIG. 1 is a system diagram of an embodiment of the system of the present invention.

FIG. 2 is a system diagram of another embodiment of the system of the present invention.

[Explanation of symbols]

 1 Dust removal device 2 Heat exchanger 2'Gas temperature raising device 3 Exhaust gas cooling device 4 Desulfurization dust removal device 4'Wet desulfurization dust removal device 5 Ammonia catalytic reduction method denitration reaction device 6 Glass melting furnace 7 Chimney 8 Ammonia catalytic reduction method denitration device DeNOx catalyst used 9 Blower

[Procedure amendment]

[Submission date] September 26, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

[0013]

The present invention according to the present invention is to remove the high concentration of soot dust in the exhaust gas generated in the glass melting furnace or the like in the filtration apparatus 1 provided on the upstream portion of the system as described above, the absolute amount of soot dust It reduced eliminate the blockage accidents caused by soot dust of each equipment of downstream. High concentration soot
The exhaust gas from which dust has been removed can be easily removed by solidifying the NOx removal catalyst harmful substances in the gas cooling device from the gaseous state or increasing the already solid particles in the gas cooling device. The solidified and increased denitration catalyst harmful substances are removed by a desulfurization dust remover. Sulfur oxides are removed by introducing alkaline chemicals into the desulfurization dust remover. Energy can be saved because the exhaust gas discharged from the desulfurization dust remover is heat-exchanged with the high temperature exhaust gas discharged from the dust remover by the heat exchanger. The exhaust gas discharged from the heat exchanger can be completely removed of nitrogen oxides in the exhaust gas by an ammonia catalytic reduction denitrification device, guided to a chimney by a blower, and released into the atmosphere.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1] ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 15, 1991

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (2)

[Claims] 1. Exhaust gas discharged from a glass melting furnace or the like 6 is passed through a dust remover 1 and then led to an exhaust gas cooler 3 for cooling the exhaust gas with a cooling liquid, and further desulfurization dust remover 4
After the gas has passed through, the temperature of the exhaust gas is raised to the temperature required for the denitration reaction by the gas temperature raising device 2 ', and the nitrogen oxides in the exhaust gas of the glass melting furnace 6 etc. are removed by the ammonia catalytic reduction method denitration device 5. Ammonia catalytic reduction method nitrogen oxide removal system for exhaust gas such as glass melting furnace. 2. A low-temperature exhaust gas that has passed through a wet desulfurization dust-removing device 4'of this system after being removed by a dust removing device 1 that removes soot and dust in high-temperature exhaust gas discharged from a glass melting furnace or the like, and a heat exchanger 2. To remove the gaseous or particulate denitration catalyst harmful substances generated in the glass melting furnace or the like by facilitating solidification or solid particulates by exchanging heat with the exhaust gas cooling device 3 and cooling the exhaust gas. And removing the sulfur oxides by the wet desulfurization dust remover 4'provided on the gas downstream side of the exhaust gas cooling device 3 and removing the denitration catalyst harmful substances having the solidified or increased solid particles, After passing through the exchanger 2, the temperature of the gas is raised to the denitration reaction temperature, and the exhaust gas is guided to the ammonia catalytic reduction method denitration device 5 to remove nitrogen oxides in the exhaust gas and to perform wet desulfurization dust removal. Glass melting furnace as ammonia catalytic reduction method nitrogen oxides removal system for exhaust gas, characterized in that also the removal of sulfur oxides in the exhaust gas using an alkaline agent in location 4 '.