JPH1015344A - Flue gas desulfurization device - Google Patents
Flue gas desulfurization deviceInfo
- Publication number
- JPH1015344A JPH1015344A JP8173467A JP17346796A JPH1015344A JP H1015344 A JPH1015344 A JP H1015344A JP 8173467 A JP8173467 A JP 8173467A JP 17346796 A JP17346796 A JP 17346796A JP H1015344 A JPH1015344 A JP H1015344A
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- Japan
- Prior art keywords
- ammonium sulfate
- flue gas
- liquid
- tower
- gas desulfurization
- 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.)
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Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は石灰あるいは石灰石
を用いて排ガス中の亜硫酸ガス(以下SO2 と称す)を
除去する石灰石膏法排煙脱硫装置に関する。The present invention relates to relates to lime-gypsum method flue gas desulfurization apparatus for removing sulfur dioxide in the exhaust gas (hereinafter referred to as SO 2) with lime or limestone.
【0002】[0002]
【従来の技術】石灰あるいは石灰石を用いて排ガス中の
SO2 を除去する石灰石膏法排煙脱硫装置を組込んだ従
来の排ガス処理設備の系統図を図8に示す。ボイラ21
から出たSO2 、三酸化硫黄(以下SO3 と称す)、ば
いじん等を含んだ排ガスは空気予熱器22で熱回収さ
れ、ばいじん除去のため電気集じん器23に導かれる。2. Description of the Related Art FIG. 8 shows a system diagram of a conventional flue gas treatment facility incorporating a lime gypsum flue gas desulfurization apparatus for removing SO 2 in flue gas using lime or limestone. Boiler 21
Exhaust gas containing SO 2 , sulfur trioxide (hereinafter referred to as SO 3 ), dust and the like discharged from the furnace is recovered by an air preheater 22 and guided to an electric precipitator 23 for dust removal.
【0003】電気集じん器23に導入されるガスには、
SO3 が含まれるためこれを中和する目的でSO3 のモ
ル量の2倍以上のアンモニア(以下NH3 と称す)24
が注入される。2倍以上とする理由は次式で示される硫
酸アンモニウムを生成させるためである。[0003] The gas introduced into the electrostatic precipitator 23 includes:
Since it contains SO 3 , ammonia (hereinafter referred to as NH 3 ) 24 having twice or more the molar amount of SO 3 is used for the purpose of neutralizing the SO 3.
Is injected. The reason for setting it to twice or more is to generate ammonium sulfate represented by the following formula.
【0004】 2NH3 +SO3 +H2 O→(NH4 )2 SO4 仮にNH3 が2倍以下であったり、反応が十分に進行し
ないと融点の低い重硫酸アンモニウム(NH4 HS
O4 )が生成し、付着等の不具合が生じる。生成した硫
酸アンモニウムは前記電気集じん器23でばいじんとと
もに除去される。硫酸アンモニウムの生成量は明らかに
SO3 の量によってきまるが、一般に石炭焚きのボイラ
の排ガスよりも重油等の石油系燃料焚き排ガスに多い。2NH 3 + SO 3 + H 2 O → (NH 4 ) 2 SO 4 If NH 3 is twice or less or the reaction does not proceed sufficiently, ammonium bisulfate (NH 4 HS) having a low melting point will be used.
O 4 ) is generated, causing problems such as adhesion. The produced ammonium sulfate is removed together with the dust in the electric dust collector 23. Although the amount of ammonium sulfate produced is clearly determined by the amount of SO 3 , it is generally larger in the exhaust gas of petroleum fuel such as heavy oil than the exhaust gas of a coal-fired boiler.
【0005】ばいじんと硫酸アンモニウムの大部分が除
去された排ガスは脱硫装置25に導かれ、吸収剤である
石灰石26を含むスラリーと脱硫装置25の吸収塔で気
液接触して、排ガスからSO2 が取り除かれる。取り除
かれたSO2 は排ガスあるいは脱硫装置25に吹き込ま
れる酸素により、吸収液の中で酸化され、最終的には石
膏を生成する。The exhaust gas from which most of the dust and ammonium sulfate have been removed is led to a desulfurization unit 25, where it comes into gas-liquid contact with a slurry containing limestone 26 as an absorbent in an absorption tower of the desulfurization unit 25, and SO 2 is removed from the exhaust gas. Removed. The removed SO 2 is oxidized in the absorbing solution by the exhaust gas or oxygen blown into the desulfurizer 25, and finally produces gypsum.
【0006】生成された石膏は固液分離器27によって
ろ液と石膏28に分離され、石膏が回収される。ろ液は
一部排水29として系外へ排出されるが、多くは石灰石
スラリー調整用として、循環使用される。[0006] The produced gypsum is separated into a filtrate and a gypsum 28 by a solid-liquid separator 27, and the gypsum is recovered. A part of the filtrate is discharged out of the system as wastewater 29, but most of the filtrate is circulated for adjusting limestone slurry.
【0007】以上の脱硫装置での反応は以下のようにま
とめられる。[0007] The reaction in the above desulfurizer is summarized as follows.
【0008】 SO2 +CaCO3 +1/2 O2 →CaSO4 +CO2 一方、脱硫装置25で脱硫処理された排ガスは必要あれ
ば、加熱器30で加熱され、煙突31より大気へ放出さ
れる。SO 2 + CaCO 3 + 1 / 2O 2 → CaSO 4 + CO 2 On the other hand, if necessary, the exhaust gas desulfurized by the desulfurization device 25 is heated by the heater 30 and released from the chimney 31 to the atmosphere.
【0009】[0009]
【発明が解決しようとする課題】前述の如く、従来の技
術では排ガス中で生成した硫酸アンモニウムは大部分電
気集じん器23で除去され、ばいじんと混合された形で
回収される。石油系燃料の排ガスの場合、ばいじんは未
燃焼のカーボンが主体であるため、カーボンと硫酸アン
モニウムを主成分とする混合物となる。As described above, in the prior art, most of the ammonium sulfate generated in the exhaust gas is removed by the electric precipitator 23 and recovered in a form mixed with the dust. In the case of petroleum-based fuel exhaust gas, since dust is mainly composed of unburned carbon, it is a mixture mainly composed of carbon and ammonium sulfate.
【0010】この混合物はこれ自体では有効利用するこ
とは現実的には難しく、仮に硫酸アンモニウムのみを回
収しようとすれば混合物を液体に再溶解させ、分離する
などの新たな装置が必要となり、経済的な方法とは言え
ない。[0010] It is actually difficult to effectively use this mixture by itself, and if it is intended to recover only ammonium sulfate, a new apparatus such as re-dissolving the mixture in a liquid and separating it is necessary, which is economical. It's not an easy way.
【0011】本発明は、排ガス中にNH3 を注入して脱
硫する場合に生成する硫酸アンモニウムを経済的に回収
可能に構成した排煙脱硫装置を提供することを課題とし
ている。An object of the present invention is to provide a flue gas desulfurization apparatus configured to economically recover ammonium sulfate produced when desulfurizing by injecting NH 3 into exhaust gas.
【0012】また本発明は、上記に加え、回収した硫酸
アンモニウムから脱硫用に再利用可能な気体状のNH3
を回収可能な排煙脱硫装置を提供することを課題として
いる。The present invention also provides, in addition to the above, gaseous NH 3 which can be reused for desulfurization from recovered ammonium sulfate.
It is an object of the present invention to provide a flue gas desulfurization device capable of recovering waste gas.
【0013】更に、本発明は脱硫装置の吸収塔における
SO2 吸収能力を高め、また、純度の高い石膏を生成可
能な排煙脱硫装置を提供することもその課題としてい
る。Another object of the present invention is to provide a flue gas desulfurization apparatus capable of increasing the SO 2 absorption capacity in an absorption tower of a desulfurization apparatus and producing gypsum of high purity.
【0014】[0014]
【課題を解決するための手段】本発明は、アンモニアを
注入された排ガスを吸収塔で脱硫処理する湿式石灰石膏
法排煙脱硫装置における前記課題を解決するため、脱硫
装置の吸収塔前流に気液接触型の硫酸アンモニウム回収
塔を設けたもので、これによって従来型のように電気集
じん器を設けずに、排ガス中のばいじんおよび硫酸アン
モニウムを回収できるようにしたものである。SUMMARY OF THE INVENTION The present invention is directed to a wet lime-gypsum method flue gas desulfurization apparatus for desulfurizing an exhaust gas injected with ammonia in an absorption tower. A gas-liquid contact type ammonium sulfate recovery tower is provided, whereby dust and ammonium sulfate in exhaust gas can be recovered without providing an electric precipitator unlike the conventional type.
【0015】このように構成した本発明の排煙脱硫装置
において、気液接触型の硫酸アンモニウム回収塔のばい
じん除去率がばいじんの性状によって満足できない場合
には、硫酸アンモニウム回収塔の上部に簡易電気集じん
器を設置し、簡易電気集じん器で捕捉されたばいじんを
硫酸アンモニウム回収塔循環液に回収し、ばいじん除去
率を高めるのが効果的である。In the flue gas desulfurization apparatus of the present invention thus constructed, if the dust removal rate of the gas-liquid contact type ammonium sulfate recovery tower is not satisfactory due to the properties of the dust, a simple electric dust collector is provided above the ammonium sulfate recovery tower. It is effective to install a vessel and collect the soot and dust trapped by the simple electric precipitator into the circulating liquid of the ammonium sulfate recovery tower to increase the soot removal rate.
【0016】なお、本発明による排煙脱硫装置の構成は
従来型の電気集じん器が設置されている場合にも電気集
じん器前流に注入された過剰のNH3 (一般的には、硫
酸アンモニウムの生成を十分行わせるため反応当量以上
のNH3 が注入される)をこの硫酸アンモニウム回収塔
で回収することもできる。The structure of the flue gas desulfurization apparatus according to the present invention is such that even when a conventional electric precipitator is installed, excess NH 3 injected into the upstream of the precipitator (generally, NH 3 at a reaction equivalent or more is injected to sufficiently produce ammonium sulfate).
【0017】硫酸アンモニウム回収塔の循環液中には当
然硫酸アンモニウムが大量に溶解しているため、この液
を抜き出し、水酸化カルシウムあるいは水酸化ナトリウ
ム等のアルカリを添加し、加熱および/または減圧する
ことによって、気体状のNH 3 を回収することも可能で
ある。この回収したNH3 は排ガス中に注入するNH 3
として利用可能であり、NH3 の有効利用も図れる。In the circulating liquid of the ammonium sulfate recovery tower,
However, since ammonium sulfate is dissolved in a large amount,
And then use calcium hydroxide or sodium hydroxide
Heat and / or reduce the pressure by adding alkali such as
Thus, the gaseous NH ThreeIt is also possible to collect
is there. This recovered NHThreeIs NH to be injected into exhaust gas Three
Available as NHThreeCan also be used effectively.
【0018】本発明による排煙脱硫装置において、硫酸
アンモニウム回収塔の循環液には大量の硫酸アンモニウ
ムが溶解していることは前述の通りである。詳細は実施
形態において後述するが、本発明者らの研究によって、
前記脱硫装置吸収塔の吸収液の吸収能力が硫酸アンモニ
ウムからもたらされるアンモニウム塩の添加によって、
飛躍的に向上することが見出された。本発明者らはこの
現象に着目し、硫酸アンモニウム回収塔の抜き出し液を
吸収塔に送液し、吸収塔の性能向上を実現した。As described above, in the flue gas desulfurization apparatus according to the present invention, a large amount of ammonium sulfate is dissolved in the circulating liquid of the ammonium sulfate recovery tower. Although details will be described later in the embodiment, according to the study of the present inventors,
The absorption capacity of the absorption liquid of the desulfurization unit absorption tower is obtained by adding an ammonium salt derived from ammonium sulfate.
It was found to be dramatically improved. The present inventors have paid attention to this phenomenon, and have pumped the liquid extracted from the ammonium sulfate recovery tower to the absorption tower to improve the performance of the absorption tower.
【0019】硫酸アンモニウム回収塔からの抜き出し液
には硫酸アンモニウムとともにばいじんが含まれる。一
方、前記脱硫装置吸収塔の吸収液からは直接石膏が回収
される。したがって、硫酸アンモニウム回収塔で除去さ
れるばいじん量が多い場合、直接、硫酸アンモニウム回
収塔抜き出し液を吸収塔に送液すると、吸収液に大量の
ばいじんが混入し、所望の石膏の純度が得られないこと
がある。The liquid extracted from the ammonium sulfate recovery tower contains soot and dust together with ammonium sulfate. On the other hand, gypsum is directly recovered from the absorbent in the desulfurizer absorption tower. Therefore, when the amount of dust removed in the ammonium sulfate recovery tower is large, if the liquid extracted from the ammonium sulfate recovery tower is directly sent to the absorption tower, a large amount of dust is mixed into the absorption liquid, and the desired gypsum purity cannot be obtained. There is.
【0020】その場合、硫酸アンモニウム回収塔からの
抜き出し液から固液分離操作によりばいじんを除去し、
吸収塔へ送液するように構成すると石膏純度を向上させ
るのに有効である。硫酸アンモニウムは溶解しているの
でこの操作による損失は少ない。In that case, soot and dust is removed from the liquid extracted from the ammonium sulfate recovery tower by a solid-liquid separation operation,
It is effective to improve the purity of gypsum when the liquid is sent to the absorption tower. Since the ammonium sulfate is dissolved, the loss due to this operation is small.
【0021】吸収塔に送液された抜き出し液に含まれる
硫酸アンモニウムは前記したように脱硫装置の吸収塔に
おいて、吸収液の性能向上効果を発現するが、一部は排
水として、系外へ排出する必要がある。As described above, ammonium sulfate contained in the withdrawn liquid sent to the absorption tower exerts an effect of improving the performance of the absorption liquid in the absorption tower of the desulfurization apparatus, but part of the liquid is discharged to the outside as wastewater. There is a need.
【0022】これを排水処理し、放流することも可能で
あるが、前述したと同様に、この液に水酸化カルシウム
あるいは水酸化ナトリウム等のアルカリを添加し、加熱
および/または減圧することによって、気体状のNH3
を回収することも可能である。この回収したNH3 は排
ガス中に注入するNH3 として利用可能であり、NH 3
の有効利用も図れる。This can be drained and discharged.
However, as described above, this solution contains calcium hydroxide.
Alternatively, add an alkali such as sodium hydroxide and heat
And / or by reducing the pressure, the gaseous NHThree
Can also be recovered. This recovered NHThreeIs exhaust
NH injected into gasThreeAvailable as NH Three
Can also be used effectively.
【0023】[0023]
【発明の実施の形態】以下、本発明による排煙脱硫装置
について図1〜図6に示した実施の形態に基づいて具体
的に説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a flue gas desulfurization apparatus according to the present invention will be described in detail with reference to the embodiments shown in FIGS.
【0024】(第1実施形態)図1に本発明の第1実施
形態による排煙脱硫装置の系統図を示す。本第1実施形
態は重油焚き排ガスの処理に係わるものである。ボイラ
1からの燃焼排ガスは空気予熱器2を経て、硫酸アンモ
ニウム回収塔3に導かれる。空気予熱器2と硫酸アンモ
ニウム回収塔3の間には、NH3 タンク4から供給され
るNH3 が注入されている。(First Embodiment) FIG. 1 shows a system diagram of a flue gas desulfurization apparatus according to a first embodiment of the present invention. The first embodiment relates to the processing of heavy oil fired exhaust gas. The combustion exhaust gas from the boiler 1 is led to the ammonium sulfate recovery tower 3 via the air preheater 2. During the air preheater 2 and the ammonium sulfate recovery column 3, the NH 3 supplied from the NH 3 tank 4 is injected.
【0025】硫酸アンモニウム回収塔3でばいじんと硫
酸アンモニウムが大部分除去された排ガスは、石灰石膏
法に基づいた脱硫装置の吸収塔5に導かれ、ここで大部
分のSO2 が除去される。ばいじん、硫酸アンモニウ
ム、SO2 が取り除かれた排ガスは煙突6を介して、大
気へ放出される。表1及び表2に本装置のテスト条件を
示す。The exhaust gas from which most of the dust and ammonium sulfate have been removed in the ammonium sulfate recovery tower 3 is led to an absorption tower 5 of a desulfurization unit based on the lime-gypsum method, where most SO 2 is removed. The exhaust gas from which soot, ammonium sulfate and SO 2 have been removed is discharged to the atmosphere via a chimney 6. Tables 1 and 2 show the test conditions of this apparatus.
【0026】[0026]
【表1】 [Table 1]
【0027】[0027]
【表2】 [Table 2]
【0028】表1、表2の条件のもとで運転した結果、
硫酸アンモニウム回収塔3出口において、ばいじん濃度
はばいじん成分と硫酸アンモニウム成分あわせて210
mg/m3Nとなり、ばいじん成分、硫酸アンモニウム成分
ともに、80%程度が硫酸アンモニウム回収塔3で除去
できた。As a result of operating under the conditions of Tables 1 and 2,
At the outlet of the ammonium sulfate recovery tower 3, the soot concentration is 210 parts in total for the soot and ammonium sulfate components.
mg / m 3 N, and about 80% of both dust and ammonium sulfate components could be removed by the ammonium sulfate recovery tower 3.
【0029】その結果、硫酸アンモニウム回収塔3の抜
き出し液からは75g/hの硫酸アンモニウムが回収で
きた。また、この抜き出し液のなかにはガス状のNH3
も一部回収され、NH3 の回収率としてはさらに向上し
た。As a result, 75 g / h of ammonium sulfate could be recovered from the withdrawn liquid of the ammonium sulfate recovery tower 3. Also, in this withdrawn liquid, gaseous NH 3
Was also partially recovered, and the recovery rate of NH 3 was further improved.
【0030】(第2実施形態)第2実施形態による排煙
脱硫装置の系統図を図2に示す。本第2実施形態は第1
実施形態による装置における硫酸アンモニウム回収塔3
のばいじん除去率を高めることを目的にしたものであ
り、硫酸アンモニウム回収塔3の上部に簡易電気集じん
器7を設置し、簡易電気集じん器7で捕捉されたばいじ
んを硫酸アンモニウム回収塔3の循環液に回収するよう
に構成したものである。(Second Embodiment) FIG. 2 is a system diagram of a flue gas desulfurization apparatus according to a second embodiment. The second embodiment is the first embodiment.
Ammonium sulfate recovery tower 3 in the apparatus according to the embodiment
The purpose of the present invention is to increase the removal rate of soot and dust. A simple electric dust collector 7 is installed above the ammonium sulfate collecting tower 3, and the dust collected by the simple electric dust collector 7 is circulated through the ammonium sulfate collecting tower 3. It is configured to be collected in a liquid.
【0031】簡易電気集じん器7は15cm角、高さ1m
であり、37kVの電圧を与え、3mAの電流を通じる
ようにした。なお、簡易電気集じん器7の電極上に捕捉
されたばいじんは定期的なハンマリングにより、硫酸ア
ンモニウム回収塔3へ落下させた。The simple electric dust collector 7 is 15 cm square and 1 m high.
And a voltage of 37 kV was applied to allow a current of 3 mA to pass. The dust trapped on the electrode of the simple dust collector 7 was dropped into the ammonium sulfate recovery tower 3 by regular hammering.
【0032】この結果、硫酸アンモニウム回収塔3の出
口においてばいじん濃度はばいじん成分と硫酸アンモニ
ウム成分あわせて110mg/m3Nとなり、ばいじん成
分、硫酸アンモニウム成分ともに、90%程度が硫酸ア
ンモニウム回収塔3で除去でき、硫酸アンモニウム回収
塔3のばいじん除去率が改善された。As a result, the dust concentration at the outlet of the ammonium sulfate recovery tower 3 is 110 mg / m 3 N in total, including the dust component and the ammonium sulfate component. The dust removal rate of the recovery tower 3 was improved.
【0033】(第3実施形態)第3実施形態による排煙
脱硫装置の系統図を図3に示す。本第3実施形態は第1
実施形態における硫酸アンモニウム回収塔3の抜き出し
液から気体のNH3 の回収を行った試験である。硫酸ア
ンモニウム回収塔3の循環液の一部を抜き出し、pH調
整槽14へ導く。(Third Embodiment) FIG. 3 shows a system diagram of a flue gas desulfurization apparatus according to a third embodiment. The third embodiment is the first embodiment.
This is a test in which gaseous NH 3 was recovered from the withdrawn liquid of the ammonium sulfate recovery tower 3 in the embodiment. A part of the circulating liquid in the ammonium sulfate recovery tower 3 is withdrawn and led to the pH adjusting tank 14.
【0034】pH調整槽14で水酸化カルシウムを添加
してpHを11に調整後、加熱器8へ送液する。加熱器
8で放散したNH3 は蒸留器9へ送られ、NH3 が濃縮
される。After the pH is adjusted to 11 by adding calcium hydroxide in the pH adjusting tank 14, the solution is sent to the heater 8. The NH 3 emitted by the heater 8 is sent to the still 9 to concentrate the NH 3 .
【0035】本実施形態では20重量%のアンモニア水
溶液が回収できた。この回収されたアンモニア水は返送
ライン10を介して、NH3 タンク4へ送られ、NH3
注入用としてリサイクルできた。In this embodiment, a 20% by weight aqueous ammonia solution could be recovered. The recovered ammonia water through a return line 10, is sent to NH 3 tank 4, NH 3
It could be recycled for injection.
【0036】(第4実施形態)第4実施形態による排煙
脱硫装置の系統図を図4に示す。本第4実施形態は第1
実施形態における硫酸アンモニウム回収塔3の抜き出し
液を脱硫装置の吸収塔5へ送液を行った試験である。(Fourth Embodiment) FIG. 4 is a system diagram of a flue gas desulfurization apparatus according to a fourth embodiment. The fourth embodiment is the first embodiment.
This is a test in which the extracted liquid of the ammonium sulfate recovery tower 3 in the embodiment was sent to the absorption tower 5 of the desulfurization device.
【0037】硫酸アンモニウム回収塔3の液の一部を抜
き出し、送液ライン11を介して、吸収塔5へ送液し
た。この結果、吸収塔循環液中のアンモニウム塩の濃度
が上昇し、図7に示すように、吸収塔5でSO2 除去率
を飛躍的に向上させることができた。A part of the liquid in the ammonium sulfate recovery tower 3 was withdrawn and sent to the absorption tower 5 via the liquid sending line 11. As a result, the concentration of ammonium salt in the absorption tower circulating fluid rises, as shown in FIG. 7, it was possible to dramatically improve the SO 2 removal rate in the absorption tower 5.
【0038】(第5実施形態)第5実施形態による排煙
脱硫装置の系統図を図5に示す。本第5実施形態は第1
実施形態における硫酸アンモニウム回収塔3の抜き出し
液を固液分離処理し、抜き出し液中のばいじん成分を除
去し、脱硫装置の吸収塔へ送液を行った試験である。(Fifth Embodiment) FIG. 5 shows a system diagram of a flue gas desulfurization apparatus according to a fifth embodiment. The fifth embodiment is the first embodiment.
This is a test in which the liquid discharged from the ammonium sulfate recovery tower 3 in the embodiment is subjected to solid-liquid separation treatment, soot and dust components in the liquid discharged are removed, and the liquid is sent to an absorption tower of a desulfurizer.
【0039】すなわち、硫酸アンモニウム回収塔3の液
の一部を抜き出し、送液ライン11を介して、固液分離
器12に導く。固液分離器12では固形分のばいじん成
分が除去されるが、硫酸アンモニウムは可溶成分である
ため、固液分離器12を通過し吸収塔5へ送られる。That is, a part of the liquid in the ammonium sulfate recovery tower 3 is withdrawn and led to the solid-liquid separator 12 through the liquid feed line 11. The solid-liquid separator 12 removes the solid soot and dust components. However, since ammonium sulfate is a soluble component, it passes through the solid-liquid separator 12 and is sent to the absorption tower 5.
【0040】この結果、吸収塔5でのSO2 除去率の向
上効果を維持した上で、ばいじん成分が除去できたた
め、吸収塔5で回収される石膏の純度が向上した。固液
分離器12を設置しない場合の第4実施形態の場合と比
較し、石膏純度は以下の通りであった。第4実施形態に
おける石膏純度:94%、第5実施形態における石膏純
度:97%。As a result, while the effect of improving the SO 2 removal rate in the absorption tower 5 was maintained, soot and dust components could be removed, so that the purity of the gypsum recovered in the absorption tower 5 was improved. The gypsum purity was as follows as compared with the case of the fourth embodiment in which the solid-liquid separator 12 was not installed. Gypsum purity in the fourth embodiment: 94%, gypsum purity in the fifth embodiment: 97%.
【0041】(第6実施形態)第6実施形態による排煙
脱硫装置の系統図を図6に示す。本第6実施形態は第4
実施形態あるいは第5実施形態における吸収塔抜き出し
液を固液分離後アルカリを添加して、気体のNH3 を回
収した試験である。(Sixth Embodiment) FIG. 6 is a system diagram of a flue gas desulfurization apparatus according to a sixth embodiment. The sixth embodiment is a fourth embodiment.
This is a test in which the liquid extracted from the absorption tower in the embodiment or the fifth embodiment is solid-liquid separated and then alkali is added to recover gaseous NH 3 .
【0042】すなわち、吸収塔抜き出しライン13を介
して、脱硫装置の吸収塔5を循環する液を一部抜き出
し、固液分離器12へ送液し、吸収液中の石膏を主体と
する固形分を除去する。固液分離処理した液をpH調整
槽14に送り、水酸化カルシウムを添加してpHを11
に調整後、加熱器15へ送液する。That is, a part of the liquid circulating in the absorption tower 5 of the desulfurization unit is withdrawn through the absorption tower withdrawal line 13 and sent to the solid-liquid separator 12, where the solid content mainly composed of gypsum in the absorption liquid is extracted. Is removed. The liquid subjected to the solid-liquid separation treatment is sent to a pH adjusting tank 14 and calcium hydroxide is added to adjust the pH to 11.
Then, the solution is sent to the heater 15.
【0043】加熱器15で放散したNH3 は蒸留器16
へ送られ、NH3 が濃縮される。本実施形態では20重
量%のアンモニア水溶液が回収できた。この回収された
アンモニア水はNH3 返送ライン17を介して、NH3
タンク4へ送られる。The NH 3 released by the heater 15 is supplied to the still 16
To concentrate NH 3 . In this embodiment, a 20% by weight aqueous ammonia solution could be recovered. The recovered ammonia water is passed through an NH 3 return line 17 to pass through the NH 3
It is sent to the tank 4.
【0044】一方、蒸留器16の底部より排出されるろ
液はろ液返送ライン18を介して石灰石調整槽19へ送
られ、SO2 吸収剤である石灰石を添加し、再び吸収塔
5へリサイクルする。この結果、吸収塔5でのSO2 除
去率の向上効果を維持した上で、NH3 のリサイクルも
可能となった。On the other hand, the filtrate discharged from the bottom of the still 16 is sent to the limestone adjusting tank 19 through the filtrate return line 18, to which limestone as an SO 2 absorbent is added, and is recycled to the absorption tower 5 again. . As a result, it was possible to recycle NH 3 while maintaining the effect of improving the SO 2 removal rate in the absorption tower 5.
【0045】[0045]
【発明の効果】以上、実施形態でも詳細に説明したよう
に、本発明による排煙脱硫装置では、脱硫装置の吸収塔
前流に気液接触型の硫酸アンモニウム回収塔を設け、要
すれば硫酸アンモニウム回収塔の上部に簡易電気集じん
器を備え、簡易電気集じん器で捕捉されたばいじんを硫
酸アンモニウム回収塔循環液に回収し、ばいじん除去率
を高める手段を用い、従来型の電気集じん器を設けず
に、排ガス中の硫酸アンモニウムを回収できる。As described above in detail in the embodiment, in the flue gas desulfurization apparatus according to the present invention, a gas-liquid contact type ammonium sulfate recovery tower is provided upstream of the absorption tower of the desulfurization apparatus, and if necessary, ammonium sulfate recovery is performed. A simple electric precipitator is installed at the top of the tower, and a conventional electric precipitator is installed using a means to increase the dust removal rate by collecting the dust captured by the simple electric precipitator in the circulating liquid of the ammonium sulfate recovery tower. Without recovering ammonium sulfate in the exhaust gas.
【0046】また、本発明による排煙脱硫装置では、前
記した構成に加え、硫酸アンモニウム回収塔の液を抜き
出し、それに水酸化カルシウムあるいは水酸化ナトリウ
ム等のアルカリを添加し、加熱および/または減圧する
ことによって、気体状のNH 3 を回収することも可能と
なった。この回収したNH3 は排ガス中に注入するNH
3 として利用可能であり、NH3 の有効利用も図れた。In the flue gas desulfurization apparatus according to the present invention,
In addition to the configuration described above, drain the liquid from the ammonium sulfate recovery tower.
And calcium hydroxide or sodium hydroxide
Heat and / or reduce the pressure by adding alkali such as
Thus, the gaseous NH ThreeIt is also possible to collect
became. This recovered NHThreeIs NH to be injected into exhaust gas
ThreeAvailable as NHThreeWas also effectively used.
【0047】また、吸収液のSO2 吸収能力が硫酸アン
モニウムの添加によって、飛躍的に向上することが見出
されたため、本発明による排煙脱硫装置では、硫酸アン
モニウム回収塔の抜き出し液を吸収塔に送液し、吸収塔
の性能向上を実現できた。Further, it has been found that the SO 2 absorption capacity of the absorbing solution is drastically improved by the addition of ammonium sulfate. Therefore, in the flue gas desulfurization apparatus according to the present invention, the liquid extracted from the ammonium sulfate recovering tower is sent to the absorbing tower. Liquefaction and improved performance of the absorption tower were realized.
【0048】また、所望の石膏純度が得られない場合に
は、抜き出し液から固液分離操作によりばいじんを除去
するように構成して石膏純度を向上させることも可能と
なった。Further, when the desired gypsum purity cannot be obtained, it is possible to improve the gypsum purity by removing soot and dust from the extracted liquid by a solid-liquid separation operation.
【0049】吸収塔に送液された抜き出し液に含まれる
硫酸アンモニウムは吸収塔の吸収液に溶解しているが、
この液に水酸化カルシウムあるいは水酸化ナトリウム等
のアルカリを添加するように構成した本発明の装置にお
いては、アルカリ添加後の液を加熱および/または減圧
することによって、気体状のNH3 を回収することも可
能となった。The ammonium sulfate contained in the withdrawn liquid sent to the absorption tower is dissolved in the absorption liquid in the absorption tower.
In the apparatus of the present invention in which an alkali such as calcium hydroxide or sodium hydroxide is added to this liquid, gaseous NH 3 is recovered by heating and / or reducing the pressure of the liquid after the addition of the alkali. It became possible.
【図1】本発明の第1実施形態による排煙脱硫装置を示
す系統図。FIG. 1 is a system diagram showing a flue gas desulfurization device according to a first embodiment of the present invention.
【図2】本発明の第2実施形態による排煙脱硫装置を示
す系統図。FIG. 2 is a system diagram showing a flue gas desulfurization device according to a second embodiment of the present invention.
【図3】本発明の第3実施形態による排煙脱硫装置を示
す系統図。FIG. 3 is a system diagram showing a flue gas desulfurization device according to a third embodiment of the present invention.
【図4】本発明の第4実施形態による排煙脱硫装置を示
す系統図。FIG. 4 is a system diagram showing a flue gas desulfurization device according to a fourth embodiment of the present invention.
【図5】本発明の第5実施形態による排煙脱硫装置を示
す系統図。FIG. 5 is a system diagram showing a flue gas desulfurization device according to a fifth embodiment of the present invention.
【図6】本発明の第6実施形態による排煙脱硫装置を示
す系統図。FIG. 6 is a system diagram showing a flue gas desulfurization device according to a sixth embodiment of the present invention.
【図7】アンモニウム塩のSO2 性能向上効果を示す
図。FIG. 7 is a graph showing the effect of improving the SO 2 performance of an ammonium salt.
【図8】従来技術による排煙脱硫装置を示す系統図。FIG. 8 is a system diagram showing a flue gas desulfurization device according to a conventional technique.
1 ボイラ 2 空気予熱器 3 硫酸アンモニウム回収塔 4 NH3 タンク 5 吸収塔 7 簡易電気集じん器 8 加熱器 9 蒸留器 10 返送ライン 11 送液ライン 12 固液分離器 13 吸収塔抜き出しライン 14 pH調整槽 15 加熱器 16 蒸留器 17 NH3 返送ライン 18 ろ液返送ライン 19 石灰石調整槽1 Boiler 2 air preheater 3 ammonium sulfate recovery tower 4 NH 3 tank 5 absorption tower 7 simple electrostatic precipitator 8 heater 9 distiller 10 return line 11 feed line 12 the solid-liquid separator 13 absorption column extraction line 14 pH adjustment tank 15 Heater 16 Distiller 17 NH 3 return line 18 Filtrate return line 19 Limestone adjustment tank
───────────────────────────────────────────────────── フロントページの続き (72)発明者 岡添 清 東京都千代田区丸の内二丁目5番1号 三 菱重工業株式会社内 (72)発明者 岩下 浩一郎 東京都千代田区丸の内二丁目5番1号 三 菱重工業株式会社内 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyoshi Okazoe 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Sansei Heavy Industries Co., Ltd. (72) Inventor Koichiro Iwashita 2-5-1 Marunouchi, Chiyoda-ku, Tokyo 3 Hishi Heavy Industries Co., Ltd.
Claims (6)
で脱硫処理する湿式石灰石膏法排煙脱硫装置において、
前記吸収塔前流に気液接触型の硫酸アンモニウム回収塔
を備えたことを特徴とする排煙脱硫装置。1. A wet lime gypsum method flue gas desulfurization apparatus for desulfurizing an exhaust gas injected with ammonia in an absorption tower,
A flue gas desulfurization apparatus comprising a gas-liquid contact type ammonium sulfate recovery tower upstream of the absorption tower.
易電気集じん器を備え、同簡易電気集じん器で捕捉され
たばいじんを前記硫酸アンモニウム回収塔循環液に回収
するよう構成したことを特徴とする請求項1記載の排煙
脱硫装置。2. A simple electric precipitator is provided on the upper part of said ammonium sulfate collecting tower, and the dust collected by said simple electric precipitator is collected in said circulating liquid of said ammonium sulfate collecting tower. Item 2. The flue gas desulfurization device according to Item 1.
液にアルカリを添加し、気体のアンモニアを回収する装
置を備えたことを特徴とする請求項1または請求項2記
載の排煙脱硫装置。3. The flue gas desulfurization apparatus according to claim 1, further comprising an apparatus for recovering gaseous ammonia by adding an alkali to an extraction liquid of the ammonium sulfate recovery tower.
液を前記吸収塔に送液するよう構成したことを特徴とす
る請求項1または請求項2記載の排煙脱硫装置。4. The flue gas desulfurization apparatus according to claim 1, wherein the liquid extracted from the ammonium sulfate recovery tower is sent to the absorption tower.
液を固液分離処理し、前記吸収塔に送液するよう構成し
たことを特徴とする請求項1または請求項2記載の排煙
脱硫装置。5. The flue gas desulfurization apparatus according to claim 1, wherein the liquid discharged from the ammonium sulfate recovery tower is subjected to solid-liquid separation treatment and sent to the absorption tower.
し、アルカリを添加し、気体のアンモニアを回収する装
置を備えたことを特徴とする請求項4または請求項5記
載の排煙脱硫装置。6. The flue gas desulfurization according to claim 4 or 5, further comprising a device for subjecting the liquid discharged from the absorption tower to a solid-liquid separation treatment, adding an alkali, and recovering gaseous ammonia. apparatus.
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JP17346796A JP3411755B2 (en) | 1996-07-03 | 1996-07-03 | Flue gas desulfurization equipment |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002009851A1 (en) * | 2000-07-31 | 2002-02-07 | Showa Denko K. K. | Method of treating combustion gas and treating apparatus |
JP2010501332A (en) * | 2006-08-25 | 2010-01-21 | エクソンモービル リサーチ アンド エンジニアリング カンパニー | Wet gas cleaning process |
CN103638695A (en) * | 2013-12-27 | 2014-03-19 | 云南铝业股份有限公司 | Method for removing metal impurities in ammonia desulfurization process of petroleum coke calcination flue gas |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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KR102669039B1 (en) * | 2023-09-12 | 2024-05-27 | 현대제철 주식회사 | Integrated system for regenerating sodium bicarbonate and recovering ammonia |
-
1996
- 1996-07-03 JP JP17346796A patent/JP3411755B2/en not_active Expired - Lifetime
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002009851A1 (en) * | 2000-07-31 | 2002-02-07 | Showa Denko K. K. | Method of treating combustion gas and treating apparatus |
US6752975B2 (en) | 2000-07-31 | 2004-06-22 | Showa Denko K.K. | Combustion exhaust gas treatment process and treatment apparatus |
JP2010501332A (en) * | 2006-08-25 | 2010-01-21 | エクソンモービル リサーチ アンド エンジニアリング カンパニー | Wet gas cleaning process |
CN103638695A (en) * | 2013-12-27 | 2014-03-19 | 云南铝业股份有限公司 | Method for removing metal impurities in ammonia desulfurization process of petroleum coke calcination flue gas |
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