JPH08951A - Exhaust gas desulfurizing process - Google Patents
Exhaust gas desulfurizing processInfo
- Publication number
- JPH08951A JPH08951A JP6140224A JP14022494A JPH08951A JP H08951 A JPH08951 A JP H08951A JP 6140224 A JP6140224 A JP 6140224A JP 14022494 A JP14022494 A JP 14022494A JP H08951 A JPH08951 A JP H08951A
- Authority
- JP
- Japan
- Prior art keywords
- liquid
- flue
- discharged
- mist
- gas
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims description 25
- 230000003009 desulfurizing effect Effects 0.000 title 1
- 239000007788 liquid Substances 0.000 claims abstract description 69
- 239000003595 mist Substances 0.000 claims abstract description 43
- 238000010521 absorption reaction Methods 0.000 claims abstract description 36
- 150000003863 ammonium salts Chemical class 0.000 claims abstract description 25
- 230000002378 acidificating effect Effects 0.000 claims abstract description 22
- 239000002253 acid Substances 0.000 claims abstract description 9
- 239000007789 gas Substances 0.000 claims description 41
- 238000006477 desulfuration reaction Methods 0.000 claims description 28
- 230000023556 desulfurization Effects 0.000 claims description 27
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 13
- 239000003546 flue gas Substances 0.000 claims description 13
- 235000019738 Limestone Nutrition 0.000 claims description 8
- 239000006028 limestone Substances 0.000 claims description 8
- 230000002745 absorbent Effects 0.000 claims description 7
- 239000002250 absorbent Substances 0.000 claims description 7
- 239000002002 slurry Substances 0.000 claims description 5
- 238000002485 combustion reaction Methods 0.000 abstract description 5
- 239000007921 spray Substances 0.000 abstract description 5
- 238000005507 spraying Methods 0.000 abstract description 3
- 230000000717 retained effect Effects 0.000 abstract 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 34
- 229910021529 ammonia Inorganic materials 0.000 description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- 239000010440 gypsum Substances 0.000 description 7
- 229910052602 gypsum Inorganic materials 0.000 description 7
- 230000000694 effects Effects 0.000 description 5
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000006227 byproduct Substances 0.000 description 3
- 229910000019 calcium carbonate Inorganic materials 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000010494 dissociation reaction Methods 0.000 description 3
- 230000005593 dissociations Effects 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- -1 Na 2 CO 3 Chemical class 0.000 description 2
- 239000006096 absorbing agent Substances 0.000 description 2
- 239000000295 fuel oil Substances 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 239000003929 acidic solution Substances 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
- 235000011130 ammonium sulphate Nutrition 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- RSAZYXZUJROYKR-UHFFFAOYSA-N indophenol Chemical compound C1=CC(O)=CC=C1N=C1C=CC(=O)C=C1 RSAZYXZUJROYKR-UHFFFAOYSA-N 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 150000002681 magnesium compounds Chemical class 0.000 description 1
- 159000000003 magnesium salts Chemical class 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000011020 pilot scale process Methods 0.000 description 1
- 150000003388 sodium compounds Chemical class 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 1
Landscapes
- Treating Waste Gases (AREA)
Abstract
Description
【発明の詳細な説明】Detailed Description of the Invention
【０００１】[0001]
【産業上の利用分野】本発明は石炭焚き排ガスや重質油
燃焼排ガスのようなＳＯ2 を含む排ガスからＳＯ2 を除
去する排煙脱硫方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flue gas desulfurization method for removing SO 2 from exhaust gas containing SO 2 such as coal-burning exhaust gas and heavy oil combustion exhaust gas.
【０００２】[0002]
【従来の技術】石灰石（ＣａＣＯ3 ）を吸収剤として排
ガスのＳＯ2 を吸収除去し、副生品として石膏を回収す
る湿式石灰石膏法排煙脱硫装置は広く実用化されてい
る。我が国では１９７０年代初頭に、まず重質油燃焼排
ガス処理用として実用化され、１９８２年の第２次エネ
ルギ危機以降には石炭を使用するボイラが増加し、これ
に伴って石炭焚き排ガスを処理する排煙脱硫装置が増加
したのは周知のとおりである。これらの装置を使用した
排煙脱硫プロセスにおいて吸収剤であるＣａＣＯ3 は粉
体として供給され、吸収液中で溶解しながら酸性ガスで
あるＳＯ2 を中和する。ところが一般にはＣａＣＯ3 の
溶解速度は比較的遅く、そのために高効率な脱硫を行う
ためには、次式で示す反応当量以上に吸収剤であるＣａ
ＣＯ3 を添加する必要がある。2. Description of the Related Art A wet lime gypsum method flue gas desulfurization apparatus which absorbs and removes SO 2 of exhaust gas by using limestone (CaCO 3 ) as an absorbent and recovers gypsum as a by-product is widely put into practical use. In Japan, it was first put to practical use in the early 1970s for the treatment of heavy oil combustion exhaust gas, and the number of boilers using coal increased after the second energy crisis of 1982, and coal-fired exhaust gas was processed accordingly. It is well known that the number of flue gas desulfurization equipment has increased. In the flue gas desulfurization process using these devices, the absorbent CaCO 3 is supplied as a powder, and dissolves in the absorbent to neutralize the acidic gas SO 2 . However, in general, the dissolution rate of CaCO 3 is relatively slow, and therefore, in order to perform highly efficient desulfurization, in order to carry out desulfurization with high efficiency, the amount of Ca that is an absorbent is not less than the reaction equivalent shown by the following formula.
It is necessary to add CO 3.
【化１】 ＳＯ2 ＋ＣａＣＯ3 ＋１／２Ｏ2 → ＣａＳＯ4 ＋ＣＯ2 （１） 一般には過剰にＣａＣＯ3 を入れるほど脱硫率は向上す
るが、過剰なＣａＣＯ 3 は副生物である石膏に混入し、
石膏の純度を低下させる上、ＣａＣＯ3 の消費量増大を
招く欠点があった。[Chemical 1] SO2+ CaCO3+ 1 / 2O2→ CaSOFour+ CO2 (1) Generally, excess CaCO3Desulfurization rate improves with the addition of
But excess CaCO 3Is mixed with gypsum which is a by-product,
In addition to reducing the purity of gypsum, CaCO3Increase consumption
There was a drawback to invite.
【０００３】これを解決する目的で従来の湿式脱硫方法
において、ＣａＣＯ3 溶解度を増加させ、これにより脱
硫率を向上させる各種脱硫助剤が提案されている。例え
ば、脱硫助剤として、Ｎａ2 ＳＯ4 、Ｎａ2 ＳＯ3 、Ｎ
ａＯＨ、Ｎａ2 ＣＯ3 、ＮａＨＣＯ3 、ＮａＨＳＯ3 な
どのナトリウム化合物を使用する方法は特開昭６０−８
４１３３号公報や特許第８９４７２５号明細書や特許第
９０３２７６号明細書を始め、特開昭５３−１２９１６
７号、特開昭５５−１２４５３０号、特開昭５６−６５
６１５号、及び特開昭５１−９７５９７号各公報におい
て開示されており、マグネシウム化合物を脱硫助剤とす
る方法については特開昭５３−１７５６５号公報により
開示されている。さらに、本発明者らは、従来全く触れ
られていなかったアンモニウム塩が、従来使用されてい
たナトリウム塩やマグネシウム塩の脱硫助剤としての効
果に比べて著しく高い効果を示すことを新たに見い出
し、アンモニウム塩を吸収助剤として吸収液に共存させ
る排ガスの処理方法を出願中である（特願平０５−２５
２７２３，特願平０５−２６０５６１）。In order to solve this problem, various desulfurization aids have been proposed which increase the CaCO 3 solubility and thereby improve the desulfurization rate in the conventional wet desulfurization method. For example, as desulfurization aids, Na 2 SO 4 , Na 2 SO 3 , N
NaOH, the method of using a sodium compound such as Na 2 CO 3, NaHCO 3, NaHSO 3 JP 60-8
No. 4133, Japanese Patent No. 894725 and Japanese Patent No. 903276, and Japanese Patent Laid-Open No. 53-12916.
7, JP-A-55-124530, JP-A-56-65.
No. 615 and JP-A-51-97597, and a method of using a magnesium compound as a desulfurization aid is disclosed in JP-A-53-17565. Furthermore, the present inventors have newly found that the ammonium salt, which has not been touched at all in the past, exhibits a remarkably high effect as compared with the effect of the desulfurization aid of the sodium salt or the magnesium salt which has been conventionally used, A method for treating exhaust gas in which an ammonium salt coexists as an absorption aid in an absorption liquid is being applied (Japanese Patent Application No. 05-25
2723, Japanese Patent Application No. 05-260561).
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、アンモ
ニウム塩を吸収助剤、ＣａＣＯ3 を吸収剤として使用す
るプロセスにおいては、新たに吸収液からのアンモニア
ガスの放散という技術課題が浮上してきた。通常石灰石
膏方法で使用する吸収液は酸性であるため次の解離平衡
式によってアンモニウム塩の大部分は吸収液中でアンモ
ニウムイオン（ＮＨ4 + ）として存在し、吸収液中より
ガス中に放散する恐れのあるアンモニアガス（ＮＨ3 ）
の存在量はごく僅かである。However, in the process of using ammonium salt as the absorption aid and CaCO 3 as the absorption agent, a new technical problem has emerged, namely the emission of ammonia gas from the absorption liquid. Usually, the absorption liquid used in the limestone gypsum method is acidic, so most of the ammonium salts exist as ammonium ions (NH 4 + ) in the absorption liquid according to the following dissociation equilibrium equation, and are diffused into the gas from the absorption liquid. Ammonia gas (NH 3 )
Is present in a very small amount.
【化２】 ところが、吸収助剤としてのアンモニウム塩の効果は、
その濃度が高いほど大きいため、高い脱硫効率を得るた
めには、吸収液中のアンモニウム塩濃度を高めることが
望ましい。アンモニウム塩濃度が高くなると、前記解離
平衡式からわかるように、ほぼそれに比例して吸収液中
に存在するＮＨ3 量が増大し、吸収液中からガス中に放
散するアンモニアガスが増大することとなる。アンモニ
アガスがＳＯ2 除去後の浄化ガスに同伴されると、アン
モニウム塩の過剰消費を招く上に、その量次第では、臭
気など二次的な環境問題を引き起こす恐れも出てくる。
本発明は前記従来技術の問題点を解消し、アンモニウム
塩の吸収助剤効果を向上させるため吸収液中に高濃度の
アンモニウム塩を溶存させた条件下でも、処理ガス中へ
のアンモニアガスの拡散が無い排煙脱硫方法を提供しよ
うとするものである。[Chemical 2] However, the effect of ammonium salt as an absorption aid is
Since the higher the concentration, the greater the concentration, it is desirable to increase the concentration of ammonium salt in the absorption liquid in order to obtain high desulfurization efficiency. As can be seen from the dissociation equilibrium equation, when the ammonium salt concentration increases, the amount of NH 3 present in the absorbing solution increases almost in proportion to that, and the ammonia gas released from the absorbing solution into the gas increases. Become. When ammonia gas is entrained in the purified gas after SO 2 is removed, it causes excessive consumption of ammonium salt, and depending on the amount thereof, may cause secondary environmental problems such as odor.
The present invention solves the above-mentioned problems of the prior art, and in order to improve the absorption aid effect of ammonium salt, the diffusion of ammonia gas into the process gas even under the condition that a high concentration of ammonium salt is dissolved in the absorption liquid. There is no flue gas desulfurization method.
【０００５】[0005]
【課題を解決するための手段】本発明はＳＯ2 を含む排
ガスを石灰石とアンモニウム塩を含む吸収液スラリと接
触させてＳＯ2 を湿式除去する排煙脱硫方法において、
吸収塔の後段の煙道内に設置したミストエリミネータの
ガス入口側の煙道内に酸性液を連続的に噴霧し、該ミス
トエリミネータから排出される補集ミスト排出液のｐＨ
値を５以下に維持するようにすると共に、該酸性液とし
て前記補集ミスト排出液の一部に酸を加えた液を循環使
用することを特徴とする排煙脱硫方法及びＳＯ2 を含む
排ガスを石灰石とアンモニウム塩を含む吸収液スラリと
接触させてＳＯ2 を湿式除去する排煙脱硫方法におい
て、吸収塔の後段の煙道内に設置したミストエリミネー
タのガス入口側の煙道内に酸性液を連続的に噴霧し、該
ミストエリミネータから排出される補集ミスト排出液の
ｐＨ値を５以下に維持するようにすると共に、該酸性液
として前記補集ミスト排出液の一部に酸を加えた液を循
環使用し、補集ミスト排出液の残部は前記吸収液に添加
することを特徴とする排煙脱硫方法である。The present invention SUMMARY OF] In flue gas desulfurization process for wet removal of SO 2 and the exhaust gas is contacted with the absorption liquid slurry containing limestone and ammonium salts containing SO 2,
The acidic liquid is continuously sprayed into the gas inlet side flue of the mist eliminator installed in the flue of the latter stage of the absorption tower, and the pH of the collected mist effluent discharged from the mist eliminator
A flue gas desulfurization method and an exhaust gas containing SO 2 , characterized in that the value is maintained at 5 or less, and a solution obtained by adding an acid to a part of the collected mist discharge solution is circulated as the acidic solution. In a flue gas desulfurization method in which SO 2 is wet-removed by contacting with an absorbent slurry containing limestone and ammonium salt, the acidic liquid is continuously fed into the flue of the gas inlet side of the mist eliminator installed in the flue of the latter stage of the absorption tower. To maintain the pH value of the collected mist discharged liquid discharged from the mist eliminator at 5 or less, and add an acid to a part of the collected mist discharged liquid as the acidic liquid. Is circulated and the rest of the collected mist discharge liquid is added to the absorption liquid in the flue gas desulfurization method.
【０００６】[0006]
【作用】以下図面を参照して本発明の方法を詳細に説明
する。図１は本発明の実施態様の１例を示す説明図であ
る。図１のプロセスにおいて、燃焼排ガスは煙道１より
吸収塔２に導かれ、ＳＯ2を除去された後、ミストエリ
ミネータ３を通って浄化ガスとして煙道４より系外に排
出される。吸収塔２内では、排ガスは循環ポンプ５によ
りラインａを通して送液された吸収液と接触し、ＳＯ2
が吸収除去される。塔底タンク６中の吸収液中にはライ
ンｂより石灰石粉体、ラインｃより吸収助剤であるアン
モニウム塩が供給され、ＳＯ2 を高効率で脱硫除去す
る。石灰石粉体供給量は吸収液のｐＨが設定値（通常、
ｐＨ４．５〜６．５）となるよう調整される。また塔底
タンク６にはタンク底部にラインｅより空気が供給さ
れ、ＳＯ2 吸収により生成した亜硫酸イオンを酸化して
石膏とする。ラインｄからは補給水が加えられ、吸収液
中のスラリー濃度が一定に維持される。The method of the present invention will now be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing an example of an embodiment of the present invention. In the process of FIG. 1, the combustion exhaust gas is guided from the flue 1 to the absorption tower 2, and after SO 2 is removed, it passes through the mist eliminator 3 and is discharged from the flue 4 to the outside of the system as purified gas. In the absorption tower 2, the exhaust gas comes into contact with the absorption liquid sent through the line a by the circulation pump 5, and the SO 2
Are absorbed and removed. Limestone powder is supplied from the line b to the absorption liquid in the bottom tank 6 and ammonium salt as an absorption aid is supplied from the line c to desulfurize SO 2 with high efficiency. The pH of the absorbing liquid is set to the limestone powder supply amount (usually
The pH is adjusted to 4.5 to 6.5). Air is supplied to the tower bottom tank 6 from a line e at the bottom of the tank to oxidize sulfite ions generated by SO 2 absorption to form gypsum. Make-up water is added from the line d, and the slurry concentration in the absorbing liquid is maintained constant.
【０００７】吸収塔２でＳＯ2 を除去された排ガスはミ
ストエリミネータ３を備えた煙道４から排出されるが、
ミストエリミネータ３のガス入口側煙道内にはミストエ
リミネータに向かって複数の噴霧ノズル７が配置され、
これにより送液ポンプ８によりラインｆを介して供給さ
れた酸性液が連続的にガス中に噴霧される。噴霧された
酸性液は、ガスに同伴されてミストエリミネータ３に達
し、ここで、吸収塔から飛沫同伴された吸収液の一部と
共に捕集される。通常ミストエリミネータ３は２段とな
っているため、その捕集効率は極めて高く、噴霧された
酸性液と飛沫同伴された吸収液のほとんど全部が捕集さ
れ、ラインｇより捕集ミスト排出液として排出される。
ＳＯ2 除去後の排ガス中に一部放散されたアンモニアガ
スは噴霧された酸性液と接触し吸収除去されるため捕集
ミスト排出液中にはアンモニウム塩が含有される。The exhaust gas from which SO 2 has been removed in the absorption tower 2 is discharged from the flue 4 equipped with the mist eliminator 3,
A plurality of spray nozzles 7 are arranged toward the mist eliminator in the gas inlet side flue of the mist eliminator 3,
As a result, the acidic liquid supplied by the liquid feed pump 8 via the line f is continuously sprayed into the gas. The sprayed acidic liquid reaches the mist eliminator 3 by being entrained by the gas, and is collected here together with part of the entrained absorbing liquid from the absorption tower. Since the normal mist eliminator 3 has two stages, its collection efficiency is extremely high, and almost all of the sprayed acidic liquid and the entrained absorbing liquid are collected, and the collected mist discharged liquid is discharged from the line g. Is discharged.
Ammonia gas partially released in the exhaust gas after SO 2 removal comes into contact with the sprayed acidic liquid and is absorbed and removed, so that the collected mist discharge liquid contains an ammonium salt.
【０００８】ここでアンモニウム塩を含んだ捕集ミスト
排出液のｐＨが高いと、前述の（２）式で示した解離平
衡関係により排出液のアンモニア分圧が高くなるため、
酸性液噴霧によるアンモニアガスの吸収が不可能とな
る。本発明者らは図２に１例を示した捕集ミスト排出液
のｐＨとアンモニアガスの平衡分圧測定結果、及び吸収
速度の実測等により鋭意検討した結果、ラインｇより抜
き出される捕集ミスト排出液のｐＨを５以下に保持する
ことで、極く低濃度、例えば１ｐｐｍ以下までアンモニ
アガス濃度を低減できることを見出し、この事実に基づ
いて本発明を完成するに至った。すなわち捕集ミスト排
出液のｐＨ値をｐＨメータ９で検出し、このｐＨ値が５
以下となるよう、ラインｈより硫酸または塩酸等の酸を
酸性液タンク１０に加える量を調整し、噴霧ノズル７か
ら排ガス中に噴霧する酸性液のｐＨを調整する。ここで
ラインｇより抜き出される捕集ミスト排出液の一部を循
環使用することで噴霧ノズル７から噴霧する酸性液量を
増大し排ガスからのアンモニアガスの除去効率の向上を
はかることができる。捕集ミスト排出液の残部はライン
ｉを介して塔底タンク６に供給して吸収液として使用
し、アンモニウム塩を有効利用することができる。な
お、固液分離装置１１において吸収液より副生石膏１２
が分離された後のアンモニウム塩を含むろ液の大部分は
ラインｊを介して塔底タンク６に循環され、一部はライ
ンｋにより系外に排出される。When the pH of the collected mist discharge liquid containing ammonium salt is high, the ammonia partial pressure of the discharge liquid becomes high due to the dissociation equilibrium relationship shown in the above formula (2).
Absorption of ammonia gas by acid solution spraying becomes impossible. The inventors of the present invention have made an intensive study by measuring the pH of the collected mist discharged liquid and the equilibrium partial pressure of ammonia gas, which is shown in FIG. By keeping the pH of the mist discharge liquid at 5 or less, it was found that the ammonia gas concentration can be reduced to an extremely low concentration, for example, 1 ppm or less, and based on this fact, the present invention has been completed. That is, the pH value of the collected mist discharge liquid is detected by the pH meter 9, and this pH value is 5
The amount of acid such as sulfuric acid or hydrochloric acid added to the acidic liquid tank 10 is adjusted from the line h so as to be as follows, and the pH of the acidic liquid sprayed from the spray nozzle 7 into the exhaust gas is adjusted. By circulating and using a part of the collected mist discharge liquid extracted from the line g, the amount of acidic liquid sprayed from the spray nozzle 7 can be increased and the efficiency of removing ammonia gas from the exhaust gas can be improved. The rest of the collected mist discharge liquid is supplied to the column bottom tank 6 through the line i and used as an absorption liquid, and the ammonium salt can be effectively used. Incidentally, in the solid-liquid separation device 11, by-product gypsum 12 from the absorption liquid
Most of the ammonium salt-containing filtrate after the separation of the above is circulated to the bottom tank 6 via the line j, and a part thereof is discharged to the outside of the system by the line k.
【０００９】[0009]
【実施例】以下実施例により本発明の方法をさらに具体
的に説明する。 （実施例１）石炭焚き排ガスを図１の形式の吸収装置で
処理した。吸収装置はパイロット規模とし、テスト条件
を表１に示す。ミストエリミネータの型式は折れ板式
で、２段設置とした。吸収液中のアンモニウム塩濃度は
０．１８〔ｍｏｌ／ｌ ａｓＮＨ4 + 〕となるようライ
ンｃからの供給硫酸アンモニウム量を調整した。またラ
インｇより排出される捕集ミスト排出液のｐＨ値は４．
０となるよう酸性液タンク１０に硫酸を加えて調整し
た。定常状態での浄化ガス中のアンモニアガス濃度及び
脱硫率を測定した結果、浄化ガス中のアンモニア濃度は
０．２ｐｐｍ、脱硫率は９８．８％であった。なお、ア
ンモニア濃度の測定は０．５％ホウ酸水によるアンモニ
アガスの吸収後、インドフェノール法によって定量する
ＪＩＳＫ００９９法によった。後述する比較例に比べ、
浄化ガス中のアンモニア濃度は顕著に低減した。EXAMPLES The method of the present invention will be described in more detail with reference to the following examples. Example 1 Coal-fired exhaust gas was treated with an absorber of the type shown in FIG. The absorber is of pilot scale and the test conditions are shown in Table 1. The model of the mist eliminator is a bent plate type, and it was installed in two stages. The amount of ammonium sulfate supplied from the line c was adjusted so that the ammonium salt concentration in the absorbing solution was 0.18 [mol / l asNH 4 + ]. The pH value of the collected mist discharged liquid discharged from the line g is 4.
The acid solution was adjusted to 0 by adding sulfuric acid to the acid solution tank 10. As a result of measuring the ammonia gas concentration in the purified gas and the desulfurization rate in a steady state, the ammonia concentration in the purified gas was 0.2 ppm and the desulfurization rate was 98.8%. In addition, the measurement of the ammonia concentration was performed by the JISK0099 method in which the ammonia gas was absorbed by 0.5% boric acid water, and then quantified by the indophenol method. Compared to the comparative example described later,
The ammonia concentration in the purified gas was remarkably reduced.
【００１０】[0010]
【表１】 [Table 1]
【００１１】（実施例２）実施例１のパイロットプラン
トテスト運転条件のうち、硫酸添加後の捕集ミスト排出
液のｐＨ値を５．０とし、他は実施例１と全く同一条件
で運転した。定常状態での浄化ガス中のアンモニアガス
濃度は０．３ｐｐｍ、脱硫率は９８．８％であった。実
施例１と比較し、同オーダーまで浄化ガス中のアンモニ
ア濃度が低減されていることがわかった。(Example 2) Of the pilot plant test operation conditions of Example 1, the pH value of the collected mist discharge liquid after addition of sulfuric acid was 5.0, and the other conditions were exactly the same as those of Example 1. . The ammonia gas concentration in the purified gas in the steady state was 0.3 ppm, and the desulfurization rate was 98.8%. As compared with Example 1, it was found that the ammonia concentration in the purified gas was reduced to the same order.
【００１２】（比較例１）実施例１のパイロットプラン
トテスト運転条件のうち、硫酸添加後の捕集ミスト排出
液のｐＨ値を６．０とし、他は実施例１と全く同一条件
で運転した。定常状態での浄化ガス中のアンモニアガス
濃度は３ｐｐｍ、脱硫率は９８．９％であった。実施例
１及び２と比較すると、浄化ガス中のアンモニア濃度が
著しく上昇していることが判明した。これは捕集ミスト
排出液のｐＨが、実施例１及び２より高いため、酸性液
によるアンモニア吸収除去効率が低下したためと推定さ
れ、捕集ミスト排出液のｐＨが本発明の範囲である５以
下となるよう酸性液を噴霧する必要があることが明らか
となった。(Comparative Example 1) Of the pilot plant test operating conditions of Example 1, the pH value of the collected mist discharged liquid after the addition of sulfuric acid was 6.0, and the other conditions were exactly the same as those of Example 1. . The ammonia gas concentration in the purified gas in the steady state was 3 ppm, and the desulfurization rate was 98.9%. As compared with Examples 1 and 2, it was found that the ammonia concentration in the purified gas was significantly increased. It is presumed that this is because the pH of the collected mist discharged liquid was higher than that in Examples 1 and 2, and therefore the efficiency of ammonia absorption and removal by the acidic liquid was lowered, and the pH of the collected mist discharged liquid was 5 or less, which is within the range of the present invention. It became clear that it was necessary to spray the acidic liquid so that
【００１３】（比較例２）実施例１と同一装置を使用
し、酸性液の噴霧を停止した以外は、実施例１と同一条
件で運転を行った。定常状態での浄化ガス中のアンモニ
ア濃度は５ｐｐｍ、脱硫率は９８．８％であった。(Comparative Example 2) The same apparatus as in Example 1 was used, and the operation was carried out under the same conditions as in Example 1 except that the spraying of the acidic liquid was stopped. The ammonia concentration in the purified gas in the steady state was 5 ppm, and the desulfurization rate was 98.8%.
【００１４】[0014]
【発明の効果】本発明の適用によりアンモニウム塩の吸
収助剤としての顕著な効果を損ねることなく、吸収助剤
として添加されたアンモニウム塩がアンモニアガスとし
て浄化ガス中に放散されるのを防止することができる。
また、捕集されたアンモニウム塩は、吸収助剤として再
使用できるのでアンモニウム塩の過剰消費の問題も解消
でき、アンモニアガスの放出による臭気問題も解決され
る。The application of the present invention prevents the ammonium salt added as an absorption aid from being emitted as ammonia gas into the purified gas without impairing the remarkable effect of the ammonium salt as an absorption aid. be able to.
Further, since the collected ammonium salt can be reused as an absorption aid, the problem of excessive consumption of ammonium salt can be solved and the odor problem due to the release of ammonia gas can be solved.
【図１】本発明の１実施態様を示す概略断面図。FIG. 1 is a schematic sectional view showing an embodiment of the present invention.
【図２】補集ミスト排出液のｐＨ値と平衡ガス中のアン
モニア濃度との関係を示すグラフ。FIG. 2 is a graph showing the relationship between the pH value of the collected mist discharge liquid and the concentration of ammonia in the equilibrium gas.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｂ０１Ｄ 53/34 １２５ Ｂ １２５ Ｇ (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 菱重工業株式会社本社内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Internal reference number FI Technical indication location B01D 53/34 125 B 125 G (72) Inventor Koichiro Iwashita 2-5-1 Marunouchi, Chiyoda-ku, Tokyo No. Sanryo Heavy Industries Co., Ltd.
Claims (2)
ウム塩を含む吸収液スラリと接触させてＳＯ2 を湿式除
去する排煙脱硫方法において、吸収塔の後段の煙道内に
設置したミストエリミネータのガス入口側の煙道内に酸
性液を連続的に噴霧し、該ミストエリミネータから排出
される補集ミスト排出液のｐＨ値を５以下に維持するよ
うにすると共に、該酸性液として前記補集ミスト排出液
の一部に酸を加えた液を循環使用することを特徴とする
排煙脱硫方法。1. A flue gas desulfurization method in which exhaust gas containing SO 2 is brought into contact with an absorbent slurry containing limestone and an ammonium salt to remove SO 2 in a wet manner, and a gas of a mist eliminator installed in a flue of a latter stage of an absorption tower. The acidic liquid is continuously sprayed into the flue on the inlet side so that the pH value of the collected mist discharged liquid discharged from the mist eliminator is maintained at 5 or less, and the collected mist discharged as the acidic liquid is discharged. A flue gas desulfurization method characterized in that a liquid obtained by adding an acid to a part of the liquid is circulated and used.
ウム塩を含む吸収液スラリと接触させてＳＯ2 を湿式除
去する排煙脱硫方法において、吸収塔の後段の煙道内に
設置したミストエリミネータのガス入口側の煙道内に酸
性液を連続的に噴霧し、該ミストエリミネータから排出
される補集ミスト排出液のｐＨ値を５以下に維持するよ
うにすると共に、該酸性液として前記補集ミスト排出液
の一部に酸を加えた液を循環使用し、補集ミスト排出液
の残部は前記吸収液に添加することを特徴とする排煙脱
硫方法。2. A flue gas desulfurization method in which SO 2 is wet-removed by contacting exhaust gas containing SO 2 with an absorbent slurry containing limestone and ammonium salt, and a gas of a mist eliminator installed in a flue of a latter stage of an absorption tower. The acidic liquid is continuously sprayed into the flue on the inlet side so that the pH value of the collected mist discharged liquid discharged from the mist eliminator is maintained at 5 or less, and the collected mist discharged as the acidic liquid is discharged. A flue gas desulfurization method characterized in that a liquid obtained by adding an acid to a part of the liquid is circulated and used, and the rest of the collected mist discharge liquid is added to the absorption liquid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14022494A JP3241209B2 (en) | 1994-06-22 | 1994-06-22 | Flue gas desulfurization method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14022494A JP3241209B2 (en) | 1994-06-22 | 1994-06-22 | Flue gas desulfurization method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08951A true JPH08951A (en) | 1996-01-09 |
| JP3241209B2 JP3241209B2 (en) | 2001-12-25 |
Family
ID=15263799
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14022494A Expired - Fee Related JP3241209B2 (en) | 1994-06-22 | 1994-06-22 | Flue gas desulfurization method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3241209B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6863875B1 (en) | 1998-04-13 | 2005-03-08 | Mitsubishi Heavy Industries, Ltd. | Flue gas treating system and process |
| US7326284B2 (en) * | 2003-07-03 | 2008-02-05 | Samsung Electronics Co., Ltd. | Contamination control system and air-conditioning system of a substrate processing apparatus using the same |
| JP2009154099A (en) * | 2007-12-27 | 2009-07-16 | Ihi Corp | Mercury removing apparatus and mercury removing method |
| JP2012035153A (en) * | 2010-08-03 | 2012-02-23 | Hitachi Plant Technologies Ltd | Method for treating exhaust gas, and equipment |
| CN103041682A (en) * | 2012-10-02 | 2013-04-17 | 云南云天化国际化工股份有限公司 | Application method of fine desulfurization in sulfuric acid exhaust absorption |
-
1994
- 1994-06-22 JP JP14022494A patent/JP3241209B2/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6863875B1 (en) | 1998-04-13 | 2005-03-08 | Mitsubishi Heavy Industries, Ltd. | Flue gas treating system and process |
| US7326284B2 (en) * | 2003-07-03 | 2008-02-05 | Samsung Electronics Co., Ltd. | Contamination control system and air-conditioning system of a substrate processing apparatus using the same |
| JP2009154099A (en) * | 2007-12-27 | 2009-07-16 | Ihi Corp | Mercury removing apparatus and mercury removing method |
| JP2012035153A (en) * | 2010-08-03 | 2012-02-23 | Hitachi Plant Technologies Ltd | Method for treating exhaust gas, and equipment |
| US8968691B2 (en) | 2010-08-03 | 2015-03-03 | Hitachi, Ltd. | Treatment method and treatment facilities of exhaust gas |
| CN103041682A (en) * | 2012-10-02 | 2013-04-17 | 云南云天化国际化工股份有限公司 | Application method of fine desulfurization in sulfuric acid exhaust absorption |
| CN103041682B (en) * | 2012-10-02 | 2016-05-11 | 云南云天化国际化工股份有限公司 | The application process of a kind of smart desulfurization in sulfuric acid tail is inhaled |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3241209B2 (en) | 2001-12-25 |
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