JPH07204459A - Oxidation control of calcium sulfite in absorbing solution - Google Patents
Oxidation control of calcium sulfite in absorbing solutionInfo
- Publication number
- JPH07204459A JPH07204459A JP6007014A JP701494A JPH07204459A JP H07204459 A JPH07204459 A JP H07204459A JP 6007014 A JP6007014 A JP 6007014A JP 701494 A JP701494 A JP 701494A JP H07204459 A JPH07204459 A JP H07204459A
- Authority
- JP
- Japan
- Prior art keywords
- orp
- absorbing solution
- flow rate
- absorbing
- set value
- 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
- 230000003647 oxidation Effects 0.000 title claims abstract description 21
- 238000007254 oxidation reaction Methods 0.000 title claims abstract description 21
- GBAOBIBJACZTNA-UHFFFAOYSA-L calcium sulfite Chemical compound [Ca+2].[O-]S([O-])=O GBAOBIBJACZTNA-UHFFFAOYSA-L 0.000 title claims description 13
- 235000010261 calcium sulphite Nutrition 0.000 title claims description 13
- 239000007789 gas Substances 0.000 claims abstract description 33
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 22
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 22
- 239000001301 oxygen Substances 0.000 claims abstract description 22
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical compound S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims description 22
- 229910052815 sulfur oxide Inorganic materials 0.000 claims description 9
- 238000006477 desulfuration reaction Methods 0.000 claims description 8
- 230000023556 desulfurization Effects 0.000 claims description 8
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 6
- 239000003546 flue gas Substances 0.000 claims description 6
- 238000005273 aeration Methods 0.000 claims description 5
- 229940043430 calcium compound Drugs 0.000 claims description 2
- 150000001674 calcium compounds Chemical class 0.000 claims description 2
- 238000009795 derivation Methods 0.000 claims description 2
- 239000002351 wastewater Substances 0.000 abstract description 9
- 238000001514 detection method Methods 0.000 abstract 2
- TXKMVPPZCYKFAC-UHFFFAOYSA-N disulfur monoxide Inorganic materials O=S=S TXKMVPPZCYKFAC-UHFFFAOYSA-N 0.000 abstract 1
- 230000011664 signaling Effects 0.000 abstract 1
- 239000007788 liquid Substances 0.000 description 21
- 238000010521 absorption reaction Methods 0.000 description 17
- 239000010440 gypsum Substances 0.000 description 12
- 229910052602 gypsum Inorganic materials 0.000 description 12
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 9
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 8
- 230000002745 absorbent Effects 0.000 description 7
- 239000002250 absorbent Substances 0.000 description 7
- 238000009423 ventilation Methods 0.000 description 7
- 229910000019 calcium carbonate Inorganic materials 0.000 description 4
- 238000002485 combustion reaction Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 3
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000000706 filtrate Substances 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- 239000006028 limestone Substances 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Landscapes
- Treating Waste Gases (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は排煙脱硫方法に関し、特
に吸収液中に存在する亜硫酸カルシウムの酸化制御方法
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flue gas desulfurization method, and more particularly to a method for controlling the oxidation of calcium sulfite present in an absorbent.
【０００２】[0002]
【従来の技術】硫黄酸化物を含む排ガスを対象に湿式石
灰石膏法による排煙脱硫を実施する場合、排ガス中の硫
黄酸化物は炭酸カルシウムを含有する吸収液と接触し、
以下の反応により吸収される。 ＳＯ2 ＋ＣａＣＯ3 →ＣａＳＯ3 ＋ＣＯ2 生成した亜硫酸カルシウムの一部は排ガス中の酸素によ
り酸化され石膏を生成する。 ＣａＳＯ3 ＋ 1/2Ｏ2 → ＣａＳＯ4 2. Description of the Related Art When exhaust gas containing sulfur oxides is subjected to flue gas desulfurization by the wet limestone gypsum method, the sulfur oxides in the exhaust gas come into contact with an absorbent containing calcium carbonate,
It is absorbed by the following reaction. SO 2 + CaCO 3 → CaSO 3 + CO 2 Part of the produced calcium sulfite is oxidized by oxygen in the exhaust gas to produce gypsum. CaSO 3 + 1 / 2O 2 → CaSO 4
【０００３】通常は排ガス中の酸素濃度が低く、亜硫酸
カルシウムから石膏への酸化が十分に行われないため、
系外から酸素を含む気体を吸収液中に通気している。こ
の際、酸素を含む気体の通気流量の設定が低い場合、亜
硫酸カルシウムの濃度が増加し、吸収剤である炭酸カル
シウムの溶解阻害、脱硫性能の低下、及び脱硫装置から
排出される排水中の化学的酸素要求量（以下、ＣＯＤと
称す）の増大等の不具合を生じる。一方、亜硫酸カルシ
ウムから石膏への転化率を高めに維持しようとすれば負
荷変動等を考慮して前記酸素を含む気体を過剰に供給せ
ざるを得ず、ランニングコストの増大及び排水ＣＯＤの
増大につながる。従って、酸素を含む気体を過剰に通気
せず、かつ亜硫酸カルシウムの酸化を十分に行わせるた
め、気体の通気流量を制御する必要がある。Usually, the oxygen concentration in the exhaust gas is low, and the oxidation of calcium sulfite to gypsum is not sufficiently performed.
A gas containing oxygen is ventilated from outside the system into the absorbent. At this time, if the flow rate of the gas containing oxygen is set low, the concentration of calcium sulfite increases, dissolution inhibition of calcium carbonate as an absorbent, deterioration of desulfurization performance, and chemicals in the wastewater discharged from the desulfurization equipment. This causes a problem such as an increase in dynamic oxygen demand (hereinafter referred to as COD). On the other hand, if it is attempted to maintain a high conversion rate of calcium sulfite to gypsum, the gas containing oxygen must be supplied excessively in consideration of load fluctuations and the like, which leads to an increase in running cost and an increase in wastewater COD. Connect Therefore, it is necessary to control the gas flow rate so that the gas containing oxygen is not aerated excessively and the calcium sulfite is sufficiently oxidized.
【０００４】亜硫酸カルシウムの酸化に係る酸素を含む
気体の通気流量制御方法に関しては酸化還元電位（以
下、ＯＲＰと称す）によるものが知られている。従来の
ＯＲＰによる通気流量制御方法はＯＲＰと亜硫酸濃度の
相関関係を求めた結果から予めＯＲＰ設定値を決定し、
通気流量を制御するものであった。As a method for controlling the flow rate of a gas containing oxygen related to the oxidation of calcium sulfite, a method based on a redox potential (hereinafter referred to as ORP) is known. In the conventional ventilation flow rate control method using ORP, the ORP set value is determined in advance from the result of obtaining the correlation between ORP and the sulfite concentration,
The air flow rate was controlled.
【０００５】図２はＳＯ2 ：１０００ｐｐｍを含む排ガ
スを炭酸カルシウムを含有する吸収液と接触させて湿式
石灰石膏法によって処理した場合における吸収液のＯＲ
Ｐと亜硫酸濃度の関係について一例を示したものであ
り、ＯＲＰは亜硫酸濃度以外にｐＨの影響を受ける。こ
のため、従来法による酸化制御では、負荷変動や吸収剤
原料の種類の変化などによりｐＨが変化した場合、ある
いは石炭の種類の変化などにより溶解液成分が変化した
場合にもＯＲＰは影響を受けるため、空気の過剰供給ま
たは亜硫酸濃度の増加により排水ＣＯＤが増大するなど
の不具合を生じるという問題があった。FIG. 2 shows the OR of the absorbing solution when the exhaust gas containing SO 2 : 1000 ppm is brought into contact with the absorbing solution containing calcium carbonate and treated by the wet lime gypsum method.
An example of the relationship between P and the sulfite concentration is shown, and ORP is affected by pH in addition to the sulfite concentration. Therefore, in the oxidation control by the conventional method, the ORP is affected even when the pH changes due to a load change or a change in the type of the absorbent raw material, or when the dissolved liquid component changes due to a change in the type of coal. Therefore, there is a problem in that wastewater COD increases due to excessive supply of air or an increase in sulfurous acid concentration.
【０００６】[0006]
【発明が解決しようとする課題】本発明は前記技術水準
に鑑み、硫黄酸化物を含む排ガスの湿式石灰石膏法排煙
脱硫方法を実施するに際し、従来方法におけるような不
具合のない吸収液中の亜硫酸塩の酸化制御方法を提供し
ようとするものである。In view of the above-mentioned state of the art, the present invention provides a method for carrying out a wet limestone gypsum flue gas desulfurization method for exhaust gas containing sulfur oxides in an absorbent solution having no problems as in the conventional method. It is intended to provide a method for controlling the oxidation of sulfite.
【０００７】[0007]
【課題を解決するための手段】前記のような状況におい
て、本発明者らは硫黄酸化物を含む排ガスを対象に湿式
石灰石膏法を実施するに際し、吸収液中のＯＲＰを連続
的に検知することによって酸素を含む気体の通気流量を
制御する酸化制御方法において、ＯＲＰは亜硫酸濃度以
外にｐＨの影響を受けるため、吸収液のＯＲＰ及びｐＨ
を検出した信号により既知のＯＲＰとｐＨの関係から該
吸収液のｐＨにおけるＯＲＰ設定値を導出し、該設定値
と前記吸収液のＯＲＰとの偏差信号により酸素を含む気
体の通気流量を制御する方法を見い出し、この知見に基
づいて本発明を完成するに至った。Under the above circumstances, the present inventors continuously detect the ORP in the absorbing liquid when carrying out the wet lime gypsum method for exhaust gas containing sulfur oxides. Therefore, in the oxidation control method for controlling the flow rate of the gas containing oxygen, the ORP is influenced by the pH other than the sulfurous acid concentration.
The ORP set value at the pH of the absorption liquid is derived from the known relationship between the ORP and the pH based on the detected signal, and the aeration flow rate of the gas containing oxygen is controlled by the deviation signal between the set value and the ORP of the absorption liquid. A method has been found, and the present invention has been completed based on this finding.
【０００８】すなわち、本発明は硫黄酸化物を含む排ガ
スをカルシウム化合物を含有する吸収液で処理するに際
し、該吸収液中に酸素を含む気体を通気し、該吸収液の
酸化還元電位を連続的に検知することによって前記酸素
を含む気体の通気流量を制御する排煙脱硫方法におい
て、該吸収液の酸化還元電位を検出した信号とｐＨを検
出した信号により既知酸化還元電位とｐＨの関係から該
吸収液のｐＨにおける酸化還元電位設定値を導出し、該
設定値と前記吸収液の酸化還元電位との偏差信号により
前記酸素を含む気体の通気流量を制御することを特徴と
する吸収液中の亜硫酸カルシウムの酸化制御方法であ
る。That is, according to the present invention, when the exhaust gas containing sulfur oxides is treated with the absorption liquid containing the calcium compound, a gas containing oxygen is passed through the absorption liquid to continuously adjust the redox potential of the absorption liquid. In the flue gas desulfurization method of controlling the aeration flow rate of the gas containing oxygen by detecting the above, in the relationship between the known redox potential and pH by the signal detecting the redox potential and the signal detecting the pH of the absorbing liquid, A redox potential set value at the pH of the absorbing solution is derived, and an aeration flow rate of the gas containing oxygen is controlled by a deviation signal between the set value and the redox potential of the absorbing solution. This is a method for controlling the oxidation of calcium sulfite.
【０００９】[0009]
【作用】本発明はＯＲＰによる酸化制御が安定に維持で
きるように鋭意検討の結果得られたものであり、ＯＲＰ
が亜硫酸濃度以外にｐＨの影響を受けるという知見に基
づき、吸収液中のＯＲＰ及びｐＨを連続的に検出した信
号により既知ＯＲＰとｐＨの関係から該吸収液のｐＨに
おけるＯＲＰ設定値を導出し、該設定値と前記吸収液の
ＯＲＰとの偏差信号により酸素を含む気体の通気流量を
制御することで、ｐＨの変動に対しても安定した酸化制
御を維持でき、排水ＣＯＤ低減が可能となる。The present invention was obtained as a result of extensive studies so that the oxidation control by ORP could be stably maintained.
Based on the finding that is influenced by pH other than the sulfite concentration, the ORP set value at the pH of the absorbing solution is derived from the relationship between the known ORP and the pH by the signal that continuously detects the ORP and pH in the absorbing solution, By controlling the flow rate of the gas containing oxygen based on the deviation signal between the set value and the ORP of the absorbing liquid, stable oxidation control can be maintained even when the pH changes, and wastewater COD can be reduced.
【００１０】[0010]
【実施例】本発明の一実施例を図１によって説明する。
燃焼排ガス２と吸収塔１を循環する吸収液３とを気液接
触させ、燃焼排ガス２中の硫黄酸化物を吸収・分離す
る。硫黄酸化物が除去された燃焼排ガスは洗浄ガス４と
なって排出される。吸収液３に吸収された硫黄酸化物は
亜硫酸カルシウムとなり、一部は燃焼排ガス中の酸素に
より酸化されて石膏を生成する。吸収液中に存在する未
酸化の亜硫酸カルシウムは吸収塔液室５に通気される空
気６によって酸化され石膏となる。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.
The combustion exhaust gas 2 and the absorption liquid 3 circulating in the absorption tower 1 are brought into gas-liquid contact to absorb and separate the sulfur oxides in the combustion exhaust gas 2. The combustion exhaust gas from which sulfur oxides have been removed is discharged as the cleaning gas 4. The sulfur oxides absorbed by the absorption liquid 3 become calcium sulfite, and a part thereof is oxidized by oxygen in the combustion exhaust gas to generate gypsum. The unoxidized calcium sulfite existing in the absorption liquid is oxidized by the air 6 aerated in the absorption tower liquid chamber 5 to become gypsum.
【００１１】前記酸化の制御は、溶解液成分組成の変動
などに対しても安定な制御が可能となるように２値信号
を出力する関数演算器（２種類の信号のいずれかを入力
信号に応じて出力する演算器）９を使用し、以下の方法
を適用する。ＯＲＰ検出器７及びｐＨ検出器８からの出
力信号を関数演算器９に入力する。関数演算器９は所定
ｐＨにおけるＯＲＰ設定値を既知ＯＲＰとｐＨの関係か
ら吸収液ｐＨにおけるＯＲＰ設定値に演算し、導出され
た設定値と吸収液のＯＲＰとの偏差に応じて２値信号を
出力する。関数演算器９からの出力信号を通気流量調節
器１０に入力し、導出されたＯＲＰ設定値との偏差によ
りコントロールバルブ開閉信号を出力する。コントロー
ルバルブ１１により空気の通気流量を調節することによ
って酸化を制御する。In the control of the oxidation, a function calculator outputting a binary signal (either one of two kinds of signals as an input signal is output so that stable control can be performed even when the composition of the solution is changed. And the following method is applied. The output signals from the ORP detector 7 and the pH detector 8 are input to the function calculator 9. The function calculator 9 calculates an ORP set value at a predetermined pH into an ORP set value at the absorbing solution pH based on the relationship between the known ORP and the pH, and outputs a binary signal according to the deviation between the derived set value and the ORP of the absorbing solution. Output. An output signal from the function calculator 9 is input to the ventilation flow rate controller 10, and a control valve opening / closing signal is output according to a deviation from the derived ORP set value. Oxidation is controlled by adjusting the ventilation flow rate of air by the control valve 11.
【００１２】ここで、関数演算器９におけるＯＲＰ偏差
と２値信号出力の関係の一例を図３に示す。吸収液のＯ
ＲＰが吸収液のｐＨにおけるＯＲＰ設定値に対して低下
し、ＯＲＰ偏差が所定ｐＨにて予め設定されたしきい値
を既知ＯＲＰとｐＨの関係から吸収液ｐＨにおけるしき
い値に演算した値（図３におけるβ）より大きくなる
と、出力信号が吸収液のｐＨにおけるＯＲＰ設定値（図
３におけるαH ）から該ＯＲＰ設定値よりＯＲＰ偏差し
きい値を減じた値（図３におけるαL ）まで変化し、Ｏ
ＲＰ偏差が０になるまで保持する。この際、ｐＨの変動
が少ない場合には、所定ｐＨにおけるしきい値をそのま
ゝ用いることも可能である。An example of the relationship between the ORP deviation and the binary signal output in the function calculator 9 is shown in FIG. Absorbing liquid O
RP decreases with respect to the ORP set value at the pH of the absorbing solution, and the ORP deviation is a threshold value preset at a predetermined pH calculated as a threshold value at the absorbing solution pH from the relationship between the known ORP and the pH ( When it becomes larger than β) in FIG. 3, the output signal is from the ORP set value (α H in FIG. 3) at the pH of the absorbing solution to a value (α L in FIG. 3) obtained by subtracting the ORP deviation threshold from the ORP set value. Change, O
Hold until the RP deviation becomes zero. At this time, when the fluctuation of the pH is small, it is possible to use the threshold value at the predetermined pH as it is.
【００１３】前記関数演算器９の出力特性を踏まえ酸化
制御方法を具体的に説明する。亜硫酸が所定濃度となる
ように予め所定ｐＨにてＯＲＰ設定値を決定したうえ、
吸収液ｐＨにおけるＯＲＰ設定値を導出し通気酸化の停
止による吸収液ＯＲＰの低下によりＯＲＰ偏差がしきい
値βよりも大きくなると、コントロールバルブ１１が開
き空気の通気を開始する。通気の開始によりＯＲＰが上
昇し、ＯＲＰ偏差が０となった時点でコントロールバル
ブ１１が閉じ空気の通気を停止する。この際、空気の通
気流量を減じる方法も可能である。以上の如くコントロ
ールバルブ１１の開閉を繰り返すことによって酸化を制
御する。The oxidation control method will be specifically described based on the output characteristics of the function calculator 9. After setting the ORP set value in advance at a predetermined pH so that the sulfurous acid has a predetermined concentration,
When the ORP deviation becomes larger than the threshold value β due to the decrease of the absorbing solution ORP due to the derivation of the ORP set value at the absorbing solution pH and the stop of the ventilation oxidation, the control valve 11 opens to start the ventilation of air. The ORP rises due to the start of ventilation, and when the ORP deviation becomes 0, the control valve 11 closes and ventilation of air is stopped. At this time, a method of reducing the air flow rate of air is also possible. Oxidation is controlled by repeating opening and closing of the control valve 11 as described above.
【００１４】前記酸化制御により生成した石膏は溶解度
が小さいため吸収液中で析出して固体となる。石膏を含
んだ吸収液の一部は抜き出しライン１２を介して吸収塔
１から排出され、固液分離機１３で石膏１４とろ液１５
に分離され、ろ液の一部は原料調整槽１６へ送られ残部
は排水１７として系外に排出される。原料調整槽１６で
炭酸カルシウム１８が供給され再び吸収塔１へ戻され
る。Since the gypsum produced by the above-mentioned oxidation control has a low solubility, it precipitates in the absorbent and becomes a solid. A part of the absorption liquid containing gypsum is discharged from the absorption tower 1 through the extraction line 12, and the gypsum 14 and the filtrate 15 are separated by the solid-liquid separator 13.
Part of the filtrate is sent to the raw material adjusting tank 16 and the rest is discharged as drainage 17 to the outside of the system. Calcium carbonate 18 is supplied from the raw material adjusting tank 16 and returned to the absorption tower 1 again.
【００１５】以下に一実施例の運転状態の一例を示す。 （１）排ガス性状 入口ガス量 ： ２００ｍ3 Ｎ／ｈ（ｄｒｙ） 入口ＳＯ2 濃度 ： １０００ｐｐｍ（ｄｒｙ） （２）吸収塔 吸収液循環流量 ： ３．９ｍ3 ／ｈ 吸収塔液室容量 ： ０．２ｍ3 ＯＲＰ設定値 ： ４８０ｍＶ（ｐＨ＝５） 前記の装置及び運転状態においてＯＲＰ偏差しきい値を
１００ｍＶ（ｐＨ＝５）に設定した場合、ｐＨが５から
６の間で変動したにもかかわらず吸収液中の亜硫酸濃度
は０．５ｍｍｏｌ／リットル以下で安定な酸化制御を維
持でき、排水のＣＯＤは６．８ｍｇ／リットルであっ
た。An example of the operating state of one embodiment will be shown below. (1) Exhaust gas properties Inlet gas amount: 200 m 3 N / h (dry) Inlet SO 2 concentration: 1000 ppm (dry) (2) Absorption tower absorption liquid circulation flow rate: 3.9 m 3 / h Absorption tower liquid chamber capacity: 0. 2 m 3 ORP set value: 480 mV (pH = 5) When the ORP deviation threshold value was set to 100 mV (pH = 5) in the above equipment and operating conditions, the pH fluctuated between 5 and 6 The sulfur dioxide concentration in the absorption liquid was 0.5 mmol / liter or less, and stable oxidation control could be maintained, and the COD of the wastewater was 6.8 mg / liter.
【００１６】（比較例）関数演算器を使用せず、吸収液
のＯＲＰを検出した信号のみによる空気通気流量の調節
によって酸化制御を実施した場合、装置及びその他の運
転状態は実施例と同一の条件において、ｐＨが５から６
の間で変動したことにより空気の供給が過剰となること
もあったため、排水のＣＯＤは２３ｍｇ／リットルとな
り、実施例に比較して著しく高かった。(Comparative example) When the oxidation control is carried out by adjusting the air flow rate of the air only by the signal which detects the ORP of the absorbing liquid without using the function calculator, the apparatus and other operating conditions are the same as those of the embodiment. PH of 5 to 6 depending on conditions
The COD of the wastewater was 23 mg / liter, which was remarkably higher than that of the example, because the air supply was sometimes excessive due to the fluctuation between the two.
【００１７】[0017]
【発明の効果】以上、説明したように、本発明によれ
ば、排煙脱硫方法における吸収液中に存在する亜硫酸カ
ルシウムの合目的な酸化制御方法が提供され、排水中の
ＣＯＤの低減が可能となる。As described above, according to the present invention, a purposeful oxidation control method for calcium sulfite present in an absorbing solution in a flue gas desulfurization method is provided, and COD in waste water can be reduced. Becomes
【図１】本発明の一実施例の説明図。FIG. 1 is an explanatory diagram of an embodiment of the present invention.
【図２】吸収液の亜硫酸濃度と酸化還元電位の関係を示
す図表。FIG. 2 is a chart showing the relationship between the sulfurous acid concentration of an absorbing solution and the redox potential.
【図３】本発明の関数演算器の出力特性図表。FIG. 3 is an output characteristic chart of a function calculator according to the present invention.
───────────────────────────────────────────────────── 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 Ｑ (72)発明者 田中 裕士 広島県広島市西区観音新町四丁目６番22号 三菱重工業株式会社広島研究所内─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Reference number within the agency FI Technical indication location B01D 53/34 125 Q (72) Inventor Hiroshi Tanaka 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima No. Mitsubishi Heavy Industries, Ltd. Hiroshima Research Institute
Claims (1)
合物を含有する吸収液で処理するに際し、該吸収液中に
酸素を含む気体を通気し、該吸収液の酸化還元電位を連
続的に検知することによって前記酸素を含む気体の通気
流量を制御する排煙脱硫方法において、該吸収液の酸化
還元電位を検出した信号とｐＨを検出した信号により既
知酸化還元電位とｐＨの関係から該吸収液のｐＨにおけ
る酸化還元電位設定値を導出し、該設定値と前記吸収液
の酸化還元電位との偏差信号により前記酸素を含む気体
の通気流量を制御することを特徴とする吸収液中の亜硫
酸カルシウムの酸化制御方法。1. When treating an exhaust gas containing sulfur oxides with an absorbing solution containing a calcium compound, a gas containing oxygen is passed through the absorbing solution to continuously detect the redox potential of the absorbing solution. In the flue gas desulfurization method for controlling the aeration flow rate of the gas containing oxygen by the above, the signal of detecting the redox potential of the absorbing solution and the signal of detecting the pH of the absorbing solution from the relationship between the known redox potential and the pH of the absorbing solution. Derivation of a redox potential setting value at pH, and controlling the aeration flow rate of the gas containing oxygen by a deviation signal between the setting value and the redox potential of the absorbing solution, of calcium sulfite in the absorbing solution. Oxidation control method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00701494A JP3241197B2 (en) | 1994-01-26 | 1994-01-26 | Method for controlling the oxidation of calcium sulfite in absorption solution |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP00701494A JP3241197B2 (en) | 1994-01-26 | 1994-01-26 | Method for controlling the oxidation of calcium sulfite in absorption solution |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07204459A true JPH07204459A (en) | 1995-08-08 |
| JP3241197B2 JP3241197B2 (en) | 2001-12-25 |
Family
ID=11654192
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP00701494A Expired - Fee Related JP3241197B2 (en) | 1994-01-26 | 1994-01-26 | Method for controlling the oxidation of calcium sulfite in absorption solution |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3241197B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0780151A1 (en) * | 1995-12-19 | 1997-06-25 | Mitsubishi Jukogyo Kabushiki Kaisha | Method for controlling the oxidation of sulfites in a flue gas desulfurization process |
| EP0824953A1 (en) * | 1996-08-23 | 1998-02-25 | Mitsubishi Heavy Industries, Ltd. | Method for measuring oxidation-reduction potential in a flue gas desulfurization process |
-
1994
- 1994-01-26 JP JP00701494A patent/JP3241197B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0780151A1 (en) * | 1995-12-19 | 1997-06-25 | Mitsubishi Jukogyo Kabushiki Kaisha | Method for controlling the oxidation of sulfites in a flue gas desulfurization process |
| US5766563A (en) * | 1995-12-19 | 1998-06-16 | Mitsubishi Jukogyo Kabushiki Kaisha | Method for controlling the oxidation of sulfites in a flue gas desulfurization process |
| CN1090045C (en) * | 1995-12-19 | 2002-09-04 | 三菱重工业株式会社 | Method for controlling oxidation of sulfite in flue gas devulcanizing method |
| EP0824953A1 (en) * | 1996-08-23 | 1998-02-25 | Mitsubishi Heavy Industries, Ltd. | Method for measuring oxidation-reduction potential in a flue gas desulfurization process |
| US5879945A (en) * | 1996-08-23 | 1999-03-09 | Mitsubishi Heavy Industries, Ltd. | Method for measuring oxidation-reduction potential in a flue gas desulfurization process |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3241197B2 (en) | 2001-12-25 |
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