CN-114053857-B - Exhaust gas treatment method and glass article manufacturing method

Abstract

The present invention relates to an exhaust gas treatment method and a method for manufacturing a glass article. The purpose of the present invention is to provide an exhaust gas treatment method that can significantly suppress the problem of adhesion of a neutralizing agent to the wall surface of a stabilizer. An exhaust gas treatment method for treating an exhaust gas generated during a process for producing a glass article, wherein the exhaust gas treatment method comprises a first step in which an exhaust gas generated during melting of a glass raw material is brought into contact with an aqueous cooling solution to generate a first treatment gas, a second step in which the first treatment gas is brought into contact with an alkali metal salt or an alkaline earth metal salt to generate a second treatment gas, and a third step in which the second treatment gas is brought into contact with a reducing agent for nitrogen oxides (NO x ), and the aqueous cooling solution used in the first step contains urea or ammonia.

Inventors

• Akagi Naoto
• TAIJI INOUE
• Kyotoma
• Otsuka Kangxiu
• HE XIANGWEN

Assignees

• ＡＧＣ株式会社

Dates

Publication Date

20260508

Application Date

20200731

Claims (11)

1. 1. An exhaust gas treatment method for treating an exhaust gas generated during a process for producing a glass article, wherein the exhaust gas treatment method comprises the steps of: A first step of bringing an exhaust gas generated when melting a glass raw material into contact with an aqueous cooling solution to generate a first process gas; a second step of bringing the first process gas into contact with an alkali metal salt or an alkaline earth metal salt to thereby produce a second process gas, and A third step in which the second process gas is brought into contact with a reducing agent for nitrogen oxides (NO x ), and The aqueous cooling solution used in the first step contains urea or ammonia, The temperature of the first processing gas after the first process is within the range of 200 ℃ to 220 ℃, In the first step, the urea or ammonia reacts with chlorine components contained in the exhaust gas, The concentration of urea or ammonia in the aqueous solution for cooling is 3-30 mass%.
2. 2. An exhaust gas treatment method for treating an exhaust gas generated during a process for producing a glass article, wherein the exhaust gas treatment method comprises the steps of: A first step of bringing an exhaust gas generated when melting a glass raw material into contact with an aqueous cooling solution to generate a first process gas; a second step of bringing the first process gas into contact with an alkali metal salt or an alkaline earth metal salt to thereby produce a second process gas, and A third step in which the second process gas is brought into contact with a reducing agent for nitrogen oxides (NO x ), and The aqueous cooling solution used in the first step contains urea or ammonia, In the first step, the urea or ammonia reacts with chlorine components contained in the exhaust gas, The concentration of urea or ammonia in the aqueous solution for cooling is 3-30 mass%.
3. 3. The exhaust gas treatment method according to claim 1 or 2, wherein the aqueous cooling solution further contains sodium hydroxide or magnesium hydroxide.
4. 4. The exhaust gas treatment method according to claim 3, wherein the concentration of the sodium hydroxide or magnesium hydroxide is 2.0 mass% or less.
5. 5. The exhaust gas treatment method according to claim 1 or 2, wherein a molar ratio of an amount of urea added in the aqueous cooling solution to an amount of total alkali added in the aqueous cooling solution is 20% or more.
6. 6. The exhaust gas treatment method according to claim 1 or 2, wherein the alkali metal salt is sodium bicarbonate or sodium carbonate.
7. 7. The exhaust gas treatment method according to claim 1 or 2, wherein the alkaline earth metal salt is calcium hydroxide, calcium carbonate, or a double salt of calcium carbonate and magnesium carbonate.
8. 8. The exhaust gas treatment method according to claim 1 or 2, wherein the reducing agent is ammonia, aqueous ammonia or an aqueous urea solution.
9. 9. The exhaust gas treatment method according to claim 1 or2, wherein the reaction product generated in the second step is melted together with the glass raw material.
10. 10. A production method for a glass article, comprising the steps of: a step of melting a glass raw material to form molten glass; a step of forming the molten glass to form a formed glass, and A step of slowly cooling the shaped glass to obtain a glass article, and The exhaust gas generated in the step of forming molten glass is treated by the exhaust gas treatment method according to any one of claims 1 to 9.
11. 11. The method of manufacturing according to claim 10, wherein the glass article is comprised of alkali-free glass.

Description

Exhaust gas treatment method and glass article manufacturing method Technical Field The present invention relates to an exhaust gas treatment method and a method for manufacturing a glass article. Background In the process of producing glass articles, particularly in the process of forming molten glass, exhaust gas containing hydrogen chloride (HCl), sulfur oxides (SO x), nitrogen oxides (NO x), and the like may be generated. Such exhaust gases need to be properly treated before being discharged to the atmosphere. Conventionally, in order to treat such exhaust gas, an exhaust gas treatment device is used. For example, patent document 1 describes an exhaust gas treatment apparatus including a stabilizer, a bag filter, and a denitration device. The exhaust gas is cooled in a stabilization device and a part of the hydrogen chloride and sulfur oxides contained in the exhaust gas is removed. In addition, hydrogen chloride and sulfur oxides contained in the exhaust gas are also removed in the bag filter. In addition, nitrogen oxides contained in the exhaust gas are reduced and removed in the denitration device. Therefore, by using such an exhaust gas treatment apparatus, the exhaust gas can be appropriately treated. In the conventional exhaust gas treatment equipment, a neutralizing agent such as an aqueous sodium hydroxide solution for neutralizing the acid is sprayed to a stabilizer for removing the acid in the exhaust gas. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2018-184308 Disclosure of Invention Problems to be solved by the invention In recent years, with the enhancement of the productivity of glass articles, the amount of exhaust gas discharged from manufacturing facilities tends to increase. Therefore, the treatment of exhaust gas requires further improvement in efficiency. In order to increase the efficiency of the exhaust gas treatment, it is conceivable to increase the amount and/or concentration of the neutralizing agent sprayed in the stabilizing device. However, aqueous sodium hydroxide solution as a neutralizing agent has a characteristic of high viscosity. Therefore, in the case of spraying a high concentration or a large amount of the neutralizing agent (aqueous sodium hydroxide solution) in the stabilizing device, the risk of sodium hydroxide adhering to the wall surface increases. In addition, when such adhesion becomes remarkable, there is a possibility that the flow path of the exhaust gas is blocked. The present invention has been made in view of such a background, and an object of the present invention is to provide an exhaust gas treatment method capable of significantly suppressing the problem of adhesion of a neutralizing agent to a wall surface of a stabilizer. Another object of the present invention is to provide a method for producing a glass article using such an exhaust gas treatment method. Means for solving the problems The present invention provides an exhaust gas treatment method for treating an exhaust gas generated during a process for producing a glass article, wherein the exhaust gas treatment method comprises a first step in which an exhaust gas generated during melting of a glass raw material is brought into contact with an aqueous cooling solution to generate a first treatment gas, a second step in which the first treatment gas is brought into contact with an alkali metal salt or an alkaline earth metal salt to generate a second treatment gas, and a third step in which the second treatment gas is brought into contact with a nitrogen oxide (NO x) using a reducing agent, and the aqueous cooling solution used in the first step contains urea or ammonia. Effects of the invention The present invention can provide an exhaust gas treatment method capable of remarkably suppressing the problem of adhesion of a neutralizing agent to a wall surface of a stabilizer. The present invention also provides a method for producing a glass article using such an exhaust gas treatment method. Drawings Fig. 1 is a diagram schematically showing a flow of an exhaust gas treatment method according to an embodiment of the present invention. Fig. 2 is a diagram schematically showing a configuration example of an exhaust gas treatment apparatus for implementing an exhaust gas treatment method according to an embodiment of the present invention. Fig. 3 is a diagram schematically showing a flow of a method of manufacturing a glass article according to an embodiment of the present invention. Fig. 4 is a graph showing the results of measuring the amount of ammonia in the exhaust gas obtained in each example. Fig. 5 is a graph showing the amounts of chlorine measured at the outlet of the stabilizer in each example. Fig. 6 is a graph showing the total amount of sulfur dioxide measured at the outlet of the stabilizer in each example. Fig. 7 is a graph showing the total dechlorination rate in the stabilizing apparatus obtained in each example. Fig. 8 i