JPH0156816B2 - - Google Patents
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- Publication number
- JPH0156816B2 JPH0156816B2 JP59232507A JP23250784A JPH0156816B2 JP H0156816 B2 JPH0156816 B2 JP H0156816B2 JP 59232507 A JP59232507 A JP 59232507A JP 23250784 A JP23250784 A JP 23250784A JP H0156816 B2 JPH0156816 B2 JP H0156816B2
- Authority
- JP
- Japan
- Prior art keywords
- nox
- exhaust gas
- hcl
- absorption
- nitrogen oxides
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- Treating Waste Gases (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
ボイラー、加熱炉又は都市ごみ焼却施設等から
の排ガスから窒素酸化物及び塩化水素を除去する
方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for removing nitrogen oxides and hydrogen chloride from exhaust gas from boilers, heating furnaces, municipal waste incineration facilities, etc.
従来の技術としては、例えば河合操：熱管理と
公害、vol29、No.９（1977）51〜60頁に記載されて
いる如く脱硝法は大きく分けて「湿式吸収法」と
「乾式還元法」に分類される。
As for conventional techniques, for example, as described in Misao Kawai: Heat Management and Pollution, vol. 29, No. 9 (1977), pages 51-60, denitrification methods can be broadly divided into "wet absorption method" and "dry reduction method." are categorized.
窒素酸化物（NOx）は硫黄酸化物（SOx）と
共に大気汚染の主因として古くから精力的にその
除害対策が研究されている。これまでに商業化さ
れている排煙脱硫技術がほとんど湿式吸収法とい
うこともあり、脱硝法も初期には湿式吸収法の研
究開発が主流を占めていた。しかしながら、排ガ
ス中に含まれるNOxの95％以上が反応性の低い
一酸化窒素（NO）であるため、吸収に先だつて
使用される酸化剤のコストが高いこと（通常、オ
ゾンを用いてNO2に酸化する）、および吸収廃液
（亜硝酸塩、硝酸塩が副生される）の処理が必要
であるなどの欠点があるため、パイロツトプラン
トの規模を越えるに至つていない。 Nitrogen oxides (NOx), along with sulfur oxides (SOx), are major causes of air pollution, and measures to eliminate them have been actively researched for a long time. Most of the flue gas desulfurization technologies that have been commercialized to date are wet absorption methods, and in the early days of denitrification methods, research and development of wet absorption methods dominated. However, since more than 95% of the NOx contained in exhaust gas is nitric oxide (NO), which has low reactivity, the cost of the oxidizing agent used prior to absorption is high (usually ozone is used to However, it has not reached the scale of a pilot plant because of the drawbacks such as the need to treat the absorbed liquid (which oxidizes to oxidation) and the absorption waste liquid (nitrite and nitrate are produced as by-products).
また、アンモニア（NH3）を還元剤として用
いる乾式還元法はNOxが無害なN2となるため、
湿式吸収法のような副生物の処理を必要としない
点が大きな長所である。その反面、肥料原料等と
して貴重な資源であるNH3を消費せざるを得な
いという宿命的な欠点、および排ガス中に共存す
るSOx及びHClとNH3の反応で生成する酸性硫
安（NH4・HSO4）及び塩化アンモニウム
（NH4Cl）に起因する装置材料の腐蝕によるトラ
ブル等の問題、またNH3自体も有害ガスである
ため未反応のNH3が排ガス中に残留することに
よる二次汚染の問題もあり、更に効果的なNOx
除去法の開発が望まれている。 In addition, in the dry reduction method that uses ammonia (NH 3 ) as a reducing agent, NOx turns into harmless N 2 .
A major advantage is that it does not require treatment of by-products, as is the case with wet absorption methods. On the other hand, it has the fateful disadvantage of having to consume NH 3 , which is a valuable resource as a raw material for fertilizers, etc., and the acidic ammonium sulfate (NH 4 Problems such as corrosion of equipment materials caused by HSO 4 ) and ammonium chloride (NH 4 Cl), and secondary pollution caused by unreacted NH 3 remaining in the exhaust gas, as NH 3 itself is a harmful gas. There is also the problem of NOx, which is even more effective.
Development of a removal method is desired.
本発明が解決しようとしている問題点は前記従
来技術の欠点を排除することにある。すなわち、
吸収廃液の処理が不要でかつNH3を使用しない
NOx及びHClの乾式除去処理を可能とする。
The problem that the present invention seeks to solve is to eliminate the drawbacks of the prior art. That is,
Does not require treatment of absorption waste liquid and does not use NH 3
Enables dry removal treatment of NOx and HCl.
本発明者らは前記観点から、より経済的で簡便
な脱硝プロセスの開発を目指して鋭意検討を加え
た結果、NOxを含む排ガスを酸化剤または触媒
を用いてNO2に酸化したのち、固体状のアルカ
リと接触させることにより、該ガス中に含まれて
いるNOx及びHClを効果的に吸収除去しうるこ
とを確認して本発明を完成するに至つた。
From the above perspective, the present inventors conducted intensive studies with the aim of developing a more economical and simple denitrification process. After oxidizing NOx-containing exhaust gas to NO 2 using an oxidizing agent or catalyst, the inventors The present invention was completed by confirming that NOx and HCl contained in the gas can be effectively absorbed and removed by contacting the gas with an alkali.
本発明は、窒素酸化物と塩化水素を含有する排
ガス中の窒素酸化物を触媒の存在下又は不存在下
に酸化剤を用いて二酸化窒素に酸化したのち、固
体状のアルカリ物質に接触させることを特徴とす
る排ガスより窒素酸化物及び塩化水素を除去する
方法である。 The present invention involves oxidizing nitrogen oxides in exhaust gas containing nitrogen oxides and hydrogen chloride to nitrogen dioxide using an oxidizing agent in the presence or absence of a catalyst, and then contacting the nitrogen oxides with a solid alkaline substance. This is a method for removing nitrogen oxides and hydrogen chloride from exhaust gas.
吸収剤として固体状の物質を使用するため吸収
廃液の処理が不要となる。また従来の乾式法のよ
うにNH3を使用しないため、腐蝕のトラブル、
二次汚染のトラブルが生じない。 Since a solid substance is used as the absorbent, there is no need to treat the absorbed waste liquid. In addition, unlike the conventional dry method, NH 3 is not used, so there are no problems with corrosion.
There is no problem of secondary contamination.
なお、本発明において使用される固体状のアル
カリ金属またはアルカリ土類金属の酸化物、水酸
化物、炭酸塩（以下、アルカリという）としては
CaO、MgO、Ca（OH）2、CaCO3、MgCO3、及
び／又はNa2CO3並びにこれ等を主成分とする物
質、例えば生石灰、ドロマイト、ソーダ灰、鉄鋼
製練廃棄物である高炉スラグ等を用いうる。 The solid alkali metal or alkaline earth metal oxides, hydroxides, and carbonates (hereinafter referred to as alkali) used in the present invention include
CaO, MgO, Ca(OH) 2 , CaCO 3 , MgCO 3 , and/or Na 2 CO 3 and substances containing these as main components, such as quicklime, dolomite, soda ash, and blast furnace slag which is steel refining waste etc. can be used.
また、共存するHClも前記固体状のアルカリに
NOxと同時に吸収される。 In addition, the coexisting HCl also becomes the solid alkali.
Absorbed at the same time as NOx.
本発明における、NOxの除去機構は大略次の
如きものと考えられる。 The NOx removal mechanism in the present invention is considered to be roughly as follows.
(イ) NOからNO2への酸化
NO＋1/2O2酸化剤
―――――→
（触媒）NO2 (1)
(ロ) NO2のアルカリへの吸収
2NO2＋CaO＋1/2O2→Ca（NO3）2 (2)
2NO2＋Ca（OH）2＋1/2O2→Ca（NO3）2＋H2O
(3)
2NO2＋CaCO3＋1/2O2→Ca（NO3）2＋CO2 (4)
また、アルカリによるHClの除去機構は次の如
きものと考えられる。(a) Oxidation of NO to NO 2 NO + 1/2O 2 oxidizer --- → (catalyst) NO 2 (1) (b) Absorption of NO 2 to alkali 2NO 2 +CaO + 1/2O 2 →Ca(NO 3 ) 2 (2) 2NO 2 +Ca(OH) 2 +1/2O 2 →Ca(NO 3 ) 2 +H 2 O
(3) 2NO 2 +CaCO 3 +1/2O 2 →Ca(NO 3 ) 2 +CO 2 (4) The mechanism of HCl removal by alkali is thought to be as follows.
2HCl＋CaO→CaCl2＋H2O (5)
2HCl＋Ca（OH）2→CaCl2＋2H2O (6)
2HCl＋CaCO3→CaCl2＋H2O＋CO2 (7)
すなわち、排ガス中のNOxの大部分を占める
NOはNO2に酸化されたのち、アルカリに吸収さ
れて硝酸塩の形態で除去される。さらに、HClは
前記アルカリにより中和されて塩化物として排ガ
スから除去される。 2HCl+CaO→CaCl 2 +H 2 O (5) 2HCl+Ca(OH) 2 →CaCl 2 +2H 2 O (6) 2HCl+CaCO 3 →CaCl 2 +H 2 O+CO 2 (7) In other words, it accounts for most of the NOx in the exhaust gas.
After NO is oxidized to NO 2 , it is absorbed by alkali and removed in the form of nitrates. Furthermore, HCl is neutralized by the alkali and removed from the exhaust gas as chloride.
なお、酸化剤を用いて排ガス中のNOをNO2に
酸化する場合は従来一般的に用いられている酸化
剤、例えばオゾン（O3）、二酸化塩素（ClO2）を
用いて排ガス中に混入すれば良い。また、触媒を
用いる場合は一般的な酸化触媒、例えばPt、CO、
Mn、Cr−アルミナ触媒を最適温度（200℃〜400
℃）、通常の固定床、移動床等により接触させれ
ば良い。 In addition, when using an oxidizing agent to oxidize NO in exhaust gas to NO 2 , conventionally commonly used oxidizing agents such as ozone (O 3 ) and chlorine dioxide (ClO 2 ) are used and mixed into the exhaust gas. Just do it. In addition, when using a catalyst, general oxidation catalysts such as Pt, CO,
Mn, Cr-alumina catalyst at optimum temperature (200℃~400℃)
℃), contact may be made using a normal fixed bed, moving bed, etc.
吸収塔は直接噴射方式で充てん層による吸収塔
方式を採用すれば良い。 The absorption tower may be a direct injection type absorption tower type using a packed bed.
実施例 １
250ppmNO−500ppmHCl−10％O2−N2の混合
ガスに常温でO3をO3／NO＝１（モル比）の割合
で注入した結果NOの95％が酸化されてNO2に変
化し、NO含有量12.5ppm、NO2含有量237.5ppm
となつた。次いでこのガスを0.1mm〜0.25mmのCa
（OH）2を充てんした吸収塔へSV1200の割合で通
し、吸収後の排ガスをNOx計とHCl計で分析し
た。結果を第１図に示す。O3酸化によつて生成
したNO2は通気時間50時間以内では大部分吸収
され、その結果250ppmのNOxは23ppmまで減少
した（脱硝率91％）。また、500ppmのHClは
100ppm以下となり（HCl除去率80％以上）NOx
−HClの同時除去が可能であることが確認でき
た。Example 1 As a result of injecting O 3 into a mixed gas of 250 ppm NO - 500 ppm HCl - 10% O 2 - N 2 at a ratio of O 3 /NO = 1 (molar ratio) at room temperature, 95% of NO was oxidized to NO 2. Changes, NO content 12.5ppm, NO2 content 237.5ppm
It became. This gas is then converted into 0.1 mm to 0.25 mm of Ca.
It was passed through an absorption tower filled with (OH) 2 at a rate of SV1200, and the exhaust gas after absorption was analyzed using a NOx meter and an HCl meter. The results are shown in Figure 1. Most of the NO 2 generated by O 3 oxidation was absorbed within 50 hours of aeration time, and as a result, NOx from 250 ppm was reduced to 23 ppm (removal rate of 91%). Also, 500ppm HCl is
NOx becomes 100ppm or less (HCl removal rate 80% or more)
It was confirmed that simultaneous removal of -HCl was possible.
比較例
実施例１で用いたのと同じ混合ガスに、O2を
O2／NO＝１（モル比）の割合で注入しながら、
0.1mm〜0.25mmのKMnO4を充てんした吸収塔へ
SV1200の割合で通じ、吸収後の排ガスをNOx計
とHCl計で分析した。結果を第２図に示す。Comparative example O 2 was added to the same gas mixture used in Example 1.
While injecting at a ratio of O 2 /NO = 1 (molar ratio),
To the absorption tower filled with 0.1mm to 0.25mm KMnO 4
It was passed at a rate of SV1200, and the exhaust gas after absorption was analyzed using a NOx meter and an HCl meter. The results are shown in Figure 2.
NOxは通気時間50時間以内では50％程度吸収
され、その結果250ppmのNOxは125ppmまで減
少した。また、500ppmのHClは通気時間10分程
度で除去できなくなり、NOx−HClの同時除去
が不可能であることを確認した。 About 50% of NOx was absorbed within 50 hours of ventilation time, and as a result, NOx from 250ppm decreased to 125ppm. Additionally, 500 ppm HCl could no longer be removed after about 10 minutes of aeration time, confirming that simultaneous removal of NOx and HCl was impossible.
第１図は、本発明の排ガスからのNOx及び
HClの除去効果を示す図、第２図は比較例におけ
る排ガスからのNOx及びHClの除去効果を示す
図である。
Figure 1 shows NOx and
FIG. 2 is a diagram showing the effect of removing HCl from exhaust gas in a comparative example.
Claims (1)
の窒素酸化物を触媒の存在下又は不存在下に酸化
剤を用いて二酸化窒素に酸化したのち固体状のア
ルカリ金属又はアルカリ土類金属の酸化物、水酸
化物、炭酸塩及び／又は該化合物の少なくとも１
種を含有している物質と接触させることを特徴と
する排ガスの処理方法。1. Oxidation of nitrogen oxides in exhaust gas containing nitrogen oxides and hydrogen chloride to nitrogen dioxide using an oxidizing agent in the presence or absence of a catalyst, and then oxidation of solid alkali metals or alkaline earth metals. at least one of the compound, hydroxide, carbonate and/or said compound.
A method for treating exhaust gas, characterized by bringing it into contact with a substance containing seeds.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59232507A JPS61111127A (en) | 1984-11-06 | 1984-11-06 | Method for removing nitrogen oxide from waste gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59232507A JPS61111127A (en) | 1984-11-06 | 1984-11-06 | Method for removing nitrogen oxide from waste gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61111127A JPS61111127A (en) | 1986-05-29 |
| JPH0156816B2 true JPH0156816B2 (en) | 1989-12-01 |
Family
ID=16940409
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59232507A Granted JPS61111127A (en) | 1984-11-06 | 1984-11-06 | Method for removing nitrogen oxide from waste gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61111127A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993008383A1 (en) * | 1991-10-14 | 1993-04-29 | Toyota Jidosha Kabushiki Kaisha | Exhaust and purification device for internal combustion engine |
| WO1993025805A1 (en) * | 1992-06-12 | 1993-12-23 | Toyota Jidosha Kabushiki Kaisha | Exhaust emission control system for internal combustion engine |
| WO1993025806A1 (en) * | 1992-06-12 | 1993-12-23 | Toyota Jidosha Kabushiki Kaisha | Exhaust emission control system for internal combustion engine |
| WO1994012778A1 (en) * | 1992-12-03 | 1994-06-09 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas cleaning apparatus for internal combustion engines |
| US5483795A (en) * | 1993-01-19 | 1996-01-16 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5447703A (en) * | 1992-06-30 | 1995-09-05 | Novacon Energy Systems, Inc. | Process for combustion of sulfur-containing carbonaceous materials |
| JP2605586B2 (en) * | 1992-07-24 | 1997-04-30 | トヨタ自動車株式会社 | Exhaust gas purification device for internal combustion engine |
| JP2605553B2 (en) * | 1992-08-04 | 1997-04-30 | トヨタ自動車株式会社 | Exhaust gas purification device for internal combustion engine |
| US6010673A (en) * | 1992-09-21 | 2000-01-04 | Toyota Jidosha Kabushiki Kaisha | Method for purifying exhaust gas |
| JP3291086B2 (en) * | 1993-09-24 | 2002-06-10 | トヨタ自動車株式会社 | Exhaust gas purification catalyst and exhaust gas purification method |
| US5750082A (en) * | 1995-09-21 | 1998-05-12 | Ford Global Technologies, Inc. | Nox trap with improved performance |
| US5837212A (en) * | 1995-09-21 | 1998-11-17 | Ford Global Technologies, Inc. | Potassium/manganese nitrogen oxide traps for lean-burn engine operation |
| KR100622990B1 (en) | 2005-04-25 | 2006-09-13 | 한국에너지기술연구원 | Removal Method of Sulfur Dioxide and Nitrogen Oxide in Combustion Flue Gas Using Chlorine Dioxide |
| US9308496B2 (en) * | 2010-04-23 | 2016-04-12 | General Electric Company | System and method for controlling and reducing NOx emissions |
| JP6062463B2 (en) * | 2015-02-16 | 2017-01-18 | 公立大学法人大阪府立大学 | Exhaust gas treatment method and exhaust gas treatment apparatus |
| CN113117482A (en) * | 2019-12-30 | 2021-07-16 | 中晶环境科技股份有限公司 | Method for desulfurization and denitrification by using gas-phase oxidant |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS495877A (en) * | 1972-05-04 | 1974-01-19 | ||
| JPS5687418A (en) * | 1979-12-14 | 1981-07-16 | Babcock Hitachi Kk | Method and apparatus for treating waste gas of incinerator of urban garbage and sludge |
-
1984
- 1984-11-06 JP JP59232507A patent/JPS61111127A/en active Granted
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993008383A1 (en) * | 1991-10-14 | 1993-04-29 | Toyota Jidosha Kabushiki Kaisha | Exhaust and purification device for internal combustion engine |
| WO1993025805A1 (en) * | 1992-06-12 | 1993-12-23 | Toyota Jidosha Kabushiki Kaisha | Exhaust emission control system for internal combustion engine |
| WO1993025806A1 (en) * | 1992-06-12 | 1993-12-23 | Toyota Jidosha Kabushiki Kaisha | Exhaust emission control system for internal combustion engine |
| WO1994012778A1 (en) * | 1992-12-03 | 1994-06-09 | Toyota Jidosha Kabushiki Kaisha | Exhaust gas cleaning apparatus for internal combustion engines |
| US5483795A (en) * | 1993-01-19 | 1996-01-16 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification device of internal combustion engine |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61111127A (en) | 1986-05-29 |
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