JPS62225226A - Wet stack-gas desulfurization facility - Google Patents
Wet stack-gas desulfurization facilityInfo
- Publication number
- JPS62225226A JPS62225226A JP61067480A JP6748086A JPS62225226A JP S62225226 A JPS62225226 A JP S62225226A JP 61067480 A JP61067480 A JP 61067480A JP 6748086 A JP6748086 A JP 6748086A JP S62225226 A JPS62225226 A JP S62225226A
- Authority
- JP
- Japan
- Prior art keywords
- absorption
- dust removal
- oxidation
- slurry
- tower
- 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
- 238000006477 desulfuration reaction Methods 0.000 title claims description 11
- 230000023556 desulfurization Effects 0.000 title claims description 11
- 238000010521 absorption reaction Methods 0.000 claims abstract description 81
- 239000000428 dust Substances 0.000 claims abstract description 65
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 62
- 230000003647 oxidation Effects 0.000 claims abstract description 58
- 239000002002 slurry Substances 0.000 claims abstract description 51
- 235000010261 calcium sulphite Nutrition 0.000 claims abstract description 40
- 239000010440 gypsum Substances 0.000 claims abstract description 28
- 229910052602 gypsum Inorganic materials 0.000 claims abstract description 28
- 239000007788 liquid Substances 0.000 claims abstract description 11
- GBAOBIBJACZTNA-UHFFFAOYSA-L calcium sulfite Chemical compound [Ca+2].[O-]S([O-])=O GBAOBIBJACZTNA-UHFFFAOYSA-L 0.000 claims description 38
- 239000007789 gas Substances 0.000 claims description 24
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical class S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 claims description 22
- 229910052815 sulfur oxide Inorganic materials 0.000 claims description 20
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 10
- 239000003546 flue gas Substances 0.000 claims description 10
- 239000011575 calcium Substances 0.000 claims description 9
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 7
- 229910052791 calcium Inorganic materials 0.000 claims description 7
- 238000004891 communication Methods 0.000 claims description 5
- 150000001875 compounds Chemical class 0.000 claims description 4
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims 1
- 239000000126 substance Substances 0.000 claims 1
- 239000011593 sulfur Substances 0.000 claims 1
- 229910052717 sulfur Inorganic materials 0.000 claims 1
- 239000003054 catalyst Substances 0.000 abstract description 13
- 230000002745 absorbent Effects 0.000 abstract description 8
- 239000002250 absorbent Substances 0.000 abstract description 8
- 230000001590 oxidative effect Effects 0.000 abstract description 4
- 150000001455 metallic ions Chemical class 0.000 abstract 1
- 238000001179 sorption measurement Methods 0.000 abstract 1
- 238000000034 method Methods 0.000 description 24
- 235000019738 Limestone Nutrition 0.000 description 12
- 239000006028 limestone Substances 0.000 description 12
- 238000000926 separation method Methods 0.000 description 10
- 229910021645 metal ion Inorganic materials 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000003595 mist Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 238000007664 blowing Methods 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 239000006227 byproduct Substances 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- TXKMVPPZCYKFAC-UHFFFAOYSA-N disulfur monoxide Inorganic materials O=S=S TXKMVPPZCYKFAC-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- TVEXGJYMHHTVKP-UHFFFAOYSA-N 6-oxabicyclo[3.2.1]oct-3-en-7-one Chemical compound C1C2C(=O)OC1C=CC2 TVEXGJYMHHTVKP-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 229940043430 calcium compound Drugs 0.000 description 1
- 150000001674 calcium compounds Chemical class 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000011505 plaster Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical class [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 1
- 150000003464 sulfur compounds Chemical class 0.000 description 1
- 235000011149 sulphuric acid Nutrition 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、排ガス中から硫黄酸化物を吸収除去すると共
に、その吸収により生じた亜硫酸カルシウムを石膏に酸
化して回収する湿式排煙脱硫装置に関する。[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a wet flue gas desulfurization device that absorbs and removes sulfur oxides from flue gas, and recovers calcium sulfite produced by the absorption by oxidizing it into gypsum. Regarding.
湿式排煙脱硫においては、アルカリ金属、アルカリ土類
金属、アンモニウム等の水酸化物、炭酸塩、亜硫酸塩ま
たは酸化物の溶液または懸濁液を用いて排ガス中の硫黄
酸化物を吸収・除去し、副生品として安定な硫酸塩を回
収する方法が一般的である。In wet flue gas desulfurization, sulfur oxides in flue gas are absorbed and removed using solutions or suspensions of hydroxides, carbonates, sulfites, or oxides of alkali metals, alkaline earth metals, ammonium, etc. A common method is to recover stable sulfate as a by-product.
第２図により、カルシウム系吸収剤を用いて硫酸カルシ
ウム（石膏）を回収する従来技術について説明する。ボ
イラ等（図示せず）からの排ガス１は除塵塔入口ダクト
２から除塵塔３に導かれ、ここで除塵塔循環タンク４か
らのカルシウム化合物（ＣａＣＯ，等）を含む除塵用循
環スラリがスプレされることによって除塵・冷却される
。ついで飛散ミストがデミスタ５により除去された後に
吸収塔６に送られる。吸収塔６内では吸収塔循環タンク
７から抜出され、吸収塔循環ポンプ８を介して管路９か
ら供給されるカルシウム系の吸収用循環スラリがノズル
１０からスプレされ、排ガス中の硫黄酸化物が吸収除去
される。排ガス中の同伴ミストはデミスタ１１によって
除去され、清浄ガス１２がダクト１３を介して煙道へ導
かれる。A conventional technique for recovering calcium sulfate (gypsum) using a calcium-based absorbent will be explained with reference to FIG. Exhaust gas 1 from a boiler or the like (not shown) is led from a dust removal tower inlet duct 2 to a dust removal tower 3, where a circulating slurry for dust removal containing calcium compounds (CaCO, etc.) from a dust removal tower circulation tank 4 is sprayed. Dust is removed and cooled by this process. The scattered mist is then removed by a demister 5 and then sent to an absorption tower 6. Inside the absorption tower 6, a calcium-based absorption circulating slurry drawn from the absorption tower circulation tank 7 and supplied from the pipe line 9 via the absorption tower circulation pump 8 is sprayed from the nozzle 10 to remove sulfur oxides in the exhaust gas. is absorbed and removed. Entrained mist in the exhaust gas is removed by a demister 11 and clean gas 12 is led to the flue via a duct 13.
一方、硫黄酸化物を吸収したカルラム系吸収剤を含む吸
収用循環スラリは吸収塔６及び吸収塔循環タンク７内で
亜硫酸カルシウムになるが、この一部は吸収塔６内にお
いて排ガス中の酸素によって一部酸化されて石膏になる
。この吸収用循環スラリは吸収塔循環ポンプ８を介して
管路９から吸収塔内上部のノズル１０へ、またはブリー
ドポンプ１４を介して除塵塔循環タンク４会供給される
。On the other hand, the circulation slurry for absorption containing the carrum absorbent that has absorbed sulfur oxides becomes calcium sulfite in the absorption tower 6 and the absorption tower circulation tank 7, but some of this is converted into calcium sulfite in the absorption tower 6 by oxygen in the exhaust gas. It is partially oxidized and becomes gypsum. This circulation slurry for absorption is supplied from a pipe 9 via an absorption column circulation pump 8 to a nozzle 10 in the upper part of the absorption column, or via a bleed pump 14 to four dust removal column circulation tanks.
除塵塔循環タンク４内の除塵用スラリは除塵塔３内で排
ガスと気液接触し、排ガス中の硫黄酸化物を除去するこ
とによりスラリ中の未反応の石灰石の量を減じて副生石
膏回収系へ抜き出される。即ち、まず反応槽１５に抜き
出され、ここで硫酸１６を添加することによって含有さ
れる未反応ＣａＣ０１が石膏に転換され、また亜硫酸カ
ルシウムの酸化に好適なｐＨに調整される。このスラリ
は酸化塔供給ポンプ１７により酸化塔１８に供給され、
ここで亜硫酸カルシウムは空気１９によって石膏に酸化
される。得られる石膏スラリはシラフナ２０へ導かれ、
固液分離された後に遠心用分離機２１等で脱水され１石
膏２２が回収される。The slurry for dust removal in the dust removal tower circulation tank 4 comes into gas-liquid contact with the exhaust gas in the dust removal tower 3, and by removing sulfur oxides from the exhaust gas, the amount of unreacted limestone in the slurry is reduced and a by-product gypsum recovery system is created. is extracted. That is, first, it is extracted into the reaction tank 15, where the unreacted CaC01 contained therein is converted into gypsum by adding sulfuric acid 16, and the pH is adjusted to a value suitable for oxidizing calcium sulfite. This slurry is supplied to the oxidation tower 18 by the oxidation tower supply pump 17,
Here the calcium sulfite is oxidized by air 19 to gypsum. The resulting gypsum slurry is guided to Shirafuna 20,
After solid-liquid separation, it is dehydrated using a centrifugal separator 21 or the like, and one gypsum 22 is recovered.
固液分離及び脱水時の濾過水２３は石灰石スラリの調製
時に再使用される。硫黄酸化物の吸収剤である石灰石ス
ラリは石灰石スラリタンク２４において、石灰石２５、
濾過水２３及び補給水２６より調製され、ブリードポン
プ２７により吸収塔循環タンク７内に供給される。The filtered water 23 during solid-liquid separation and dewatering is reused during the preparation of limestone slurry. The limestone slurry, which is an absorbent for sulfur oxides, is stored in a limestone slurry tank 24 in which limestone 25, limestone 25,
It is prepared from filtered water 23 and make-up water 26, and is supplied into the absorption tower circulation tank 7 by a bleed pump 27.
このように、従来法では吸収塔６内での硫黄酸化物の吸
収過程で亜硫酸カルシウムを完全に石膏とすることは困
難であるため、吸収系で生ずる亜硫酸カルシウムを前記
の如く別途設けた酸化塔１８において石膏にする方法が
採用されてきた。In this way, in the conventional method, it is difficult to completely convert calcium sulfite into gypsum during the absorption process of sulfur oxides in the absorption tower 6. In 18, the method of making it into plaster has been adopted.
しかし、近年酸化塔１８を省略し、硫黄酸化物の吸収部
において硫黄化合物の硫酸カルシウムへの酸化を進めよ
うとする多くの方法が提案されている。その例として、
酸化触媒を利用する方法（特公昭５８−３６６１９号公
報）、吸収塔循環タンクや別途設けた反応槽に空気を吹
込む方法（特開昭５５−１１６４２３号公報。However, in recent years, many methods have been proposed in which the oxidation tower 18 is omitted and the oxidation of sulfur compounds to calcium sulfate proceeds in the sulfur oxide absorption section. As an example,
A method using an oxidation catalyst (Japanese Patent Publication No. 58-36619), a method of blowing air into an absorption tower circulation tank or a separately provided reaction tank (Japanese Patent Application Laid-Open No. 55-116423).
同１１６４２４号公報、 特開昭５８−９８１２６号公報。Publication No. 116424, JP-A-58-98126.
同９２４５２号公報、
同９５５４３号公報、
同１０４６１９号公報、
実開昭５８−９５２１８号公報）あるいは２段脱硫法（
特開昭５８−７４１２６号公報）を挙げることができる
。しかし、触媒を使用する方法では、これを高率で回収
しない限り経済的には成立せず、また空気吹込み法にあ
っては多量の空気を微細気泡として供給しない限り、従
来の酸イヒ塔１８に代わる程の速度で亜硫酸カルラムを
酸化することはできない。Publication No. 92452, Publication No. 95543, Publication No. 104619, Japanese Utility Model Application No. 58-95218) or two-stage desulfurization method (
JP-A-58-74126). However, the method using a catalyst is not economically viable unless it is recovered at a high rate, and the air blowing method is not economically viable unless a large amount of air is supplied as fine bubbles. It is not possible to oxidize carlum sulfite at a rate fast enough to replace 18.
これに対し、本発明者らは、先に、吸収塔６底部の吸収
塔の循環タンク７に取付けられた撹拌機２８の翼近傍に
空気を供給して微細気泡を発生させるという酸化方式を
採用すれば別途に酸化塔を用いなくても排ガス中の硫黄
酸化物を石膏として回収できることを確認している。本
方式においては吸収剤であるＣａＣＯ２を含む吸収用循
環スラリを吸収塔６内にスプレーすることによって硫黄
酸化物の吸収のみならずダストの除去をも同時に行うこ
とができる（ダスト混合方式）。ところで、亜硫酸カル
シウムの酸素酸化反応には微量の金属イオンが触媒とし
て作用することが知られているが、このダスト混合方式
においては鉄などの元素がダストに付随して吸収系に混
入することになり。In response, the present inventors first adopted an oxidation method in which air is supplied near the blades of the agitator 28 attached to the circulation tank 7 of the absorption tower at the bottom of the absorption tower 6 to generate fine bubbles. It has been confirmed that the sulfur oxides in the exhaust gas can be recovered as gypsum without using a separate oxidation tower. In this method, by spraying an absorption circulation slurry containing CaCO2 as an absorbent into the absorption tower 6, not only the absorption of sulfur oxides but also the removal of dust can be performed at the same time (dust mixing method). By the way, it is known that trace amounts of metal ions act as catalysts in the oxygen oxidation reaction of calcium sulfite, but in this dust mixing method, elements such as iron accompany the dust and get mixed into the absorption system. Become.
亜硫酸カルシウムの酸化を行う上では好ましい結果を与
える。It gives favorable results in oxidizing calcium sulfite.
これに対し、排ガス中にＣＱ、Ｆなどを多量に含有する
場合には石膏の純度を低下させるため、別途に除塵部を
設け、この除塵部と吸収部のスラリの混合を抑えるダス
ト分離方式を採用することが望ましい。しかし、このよ
うにダスト分離方式を採用するとダストに付随して吸収
系に混入して来る触媒物質の量は著しく少なくなり、従
って亜硫酸カルシウムの酸化速度も低下する結果となる
。On the other hand, if the exhaust gas contains a large amount of CQ, F, etc., the purity of the gypsum will decrease, so a separate dust removal section is installed and a dust separation method is used to prevent mixing of the slurry in the dust removal section and the absorption section. It is desirable to adopt it. However, when such a dust separation method is adopted, the amount of catalyst material that accompanies the dust and enters the absorption system is significantly reduced, resulting in a decrease in the oxidation rate of calcium sulfite.
本発明の目的は、別途に酸化塔を設置することなしに排
ガス中の硫黄酸化物を高効率で石膏として回収でき、し
かも排ガス中のダストは石膏中に混入しないようにして
高純度の石膏を得ることのできる湿式排煙脱硫装置を提
供するにある。The purpose of the present invention is to be able to recover sulfur oxides in exhaust gas as gypsum with high efficiency without installing a separate oxidation tower, and to produce high-purity gypsum by preventing dust in the exhaust gas from being mixed into the gypsum. The objective is to provide a wet flue gas desulfurization system that can be obtained.
〔問題点を解決するための手段及び作用〕本発明は、カ
ルシウム系化合物を含有する除塵用循環スラリと排ガス
とを気液接触させて排ガス中のダストを除去する除頭部
と、塔底部に設けた吸収塔循環タンク内に貯溜したカル
シウム系化合物を含有する吸収用循環スラリを塔上部か
らスプレして前記除頭部を通過した排ガスと気液接触さ
せて硫黄酸化物を吸収除去すると共に該吸収塔循環タン
ク内のスラリ中に微細気泡を供給して前記硫黄酸化物の
吸収によって生じる亜硫酸カルシウムを石膏に酸化する
吸収・酸化部を備えた湿式排煙脱硫装置において、除塵
用循環スラリを除塵部から吸収・酸化部に供給する連通
ラインを設けることにより、亜硫酸カルシウムの酸化触
媒になる金属イオンを除塵用循環スラリの吸収・酸化部
への一部供給により有効に利用し、生成する石膏の純度
を低下させる成分の吸収・酸化部への流入は防止するよ
うにしたものである。[Means and effects for solving the problems] The present invention provides a head removal device for removing dust from the flue gas by bringing the circulating slurry for dust removal containing a calcium-based compound into gas-liquid contact with the flue gas, and a tower bottom part. The circulating slurry for absorption containing calcium-based compounds stored in the circulation tank of the absorption tower provided is sprayed from the upper part of the tower and brought into gas-liquid contact with the exhaust gas that has passed through the head removal to absorb and remove sulfur oxides. In a wet flue gas desulfurization equipment equipped with an absorption/oxidation section that oxidizes calcium sulfite produced by the absorption of sulfur oxides into gypsum by supplying fine air bubbles into the slurry in the absorption tower circulation tank, dust is removed from the circulating slurry for dust removal. By providing a communication line to supply from the absorption and oxidation section to the absorption and oxidation section, metal ions that act as oxidation catalysts for calcium sulfite can be effectively used by partially supplying the circulating slurry for dust removal to the absorption and oxidation section. This is to prevent components that reduce purity from flowing into the absorption/oxidation section.
第１図に示した如く、ボイラ等からの排ガス１は除塵部
の除塵塔入口ダクト２から除塵塔３に導かれ、ここで除
塵塔循環タンク４からの除塵用循環スラリがスプレされ
ることによって除塵・冷却され、ついで飛散ミストがデ
ミスタ５により除去された後に吸収・酸化部の吸収塔６
に送られる。As shown in FIG. 1, exhaust gas 1 from a boiler or the like is led from a dust removal tower inlet duct 2 of a dust removal section to a dust removal tower 3, where it is sprayed with circulating slurry for dust removal from a dust removal tower circulation tank 4. After the dust is removed and cooled, and the scattered mist is removed by the demister 5, the absorption tower 6 of the absorption/oxidation section
sent to.
この吸収塔６内では吸収塔循環タンク７から抜き出され
、吸収塔循環ポンプ８を介して管路９から供給されるカ
ルシウム系吸収剤の吸収用循環スラリがノズル１ｏから
スプレされ、排ガス中の硫黄酸化物が吸収除去される。In this absorption tower 6, absorption circulation slurry of calcium-based absorbent extracted from the absorption tower circulation tank 7 and supplied from the pipe 9 via the absorption tower circulation pump 8 is sprayed from the nozzle 1o, and the absorption circulation slurry is sprayed from the nozzle 1o. Sulfur oxides are absorbed and removed.
排ガス中の同伴ミストはデミスタ１１によって除去され
、清浄ガス１２がダクト１３を介して煙道へ導かれる。Entrained mist in the exhaust gas is removed by a demister 11 and clean gas 12 is led to the flue via a duct 13.
脱硫に供された吸収用循環スラリは吸収塔循環タンク７
中に落下するが１本発明の方法においては吸収塔循環タ
ンク７中に空気よりなる微細気泡２９が供給され、排ガ
ス中の硫黄酸化物の吸収によって生じた亜硫酸カルシウ
ムが酸化されるようになっている。吸収塔循環タンク７
内における亜硫酸カルシウムの空気酸化方式としては該
タンク７中に微細気泡が発生し、スラリ中の亜硫酸カル
シウムの量が所期の値（石膏を回収する場合には、亜硫
酸カルシウム含有量は通常０．５％以下）に抑えられる
限りいかなる方法であってもよい。具体的には第１図に
示した様に吸収塔循環タンク７内に設置された撹拌機２
８の翼近傍に微細気泡２９を供給する方法が１本目的に
合致する酸化速度を与える。本酸化方式によって吸収塔
循環タンク７内における亜硫酸カルシウムの完全酸化を
達成するためには撹拌翼２８の形状、撹拌速度、空気供
給量、スラリｐＨ等を適正化する必要がある。The absorption circulation slurry subjected to desulfurization is transferred to the absorption tower circulation tank 7.
In the method of the present invention, fine air bubbles 29 made of air are supplied into the absorption tower circulation tank 7, and calcium sulfite produced by absorption of sulfur oxides in the exhaust gas is oxidized. There is. Absorption tower circulation tank 7
In the air oxidation method of calcium sulfite in the tank 7, fine bubbles are generated in the tank 7, and the amount of calcium sulfite in the slurry reaches the desired value (when recovering gypsum, the calcium sulfite content is usually 0. Any method may be used as long as it can be suppressed to (5% or less). Specifically, as shown in FIG. 1, the stirrer 2 installed in the absorption tower circulation tank 7
One method of supplying microbubbles 29 near the blades 8 provides an oxidation rate that meets the objective. In order to achieve complete oxidation of calcium sulfite in the absorption tower circulation tank 7 by this oxidation method, it is necessary to optimize the shape of the stirring blade 28, stirring speed, air supply amount, slurry pH, etc.
このうち、スラリｐ Ｈについては硫黄酸化物の吸収と
生成する亜硫酸カルシウムの酸化が所期の速度で進行す
る条件でなければならない。硫黄酸化物の吸収及び亜硫
酸カルシウムの酸化に対する適正ｐＨはそれぞれ５．５
以上及び４．０〜５．５とされており１両反応に共通な
適正ｐＨは５．５付近に限定されることになる。これに
対し、本発明者らは、吸収塔循環タンク７中に落下して
来るスラリ中の亜硫酸カルシウムは溶液状態にあり、こ
のタンク７内における酸化手段が適切ならばｐＨ６付近
においても亜硫酸カルシウムの酸化は充分に進行するこ
と、また、この酸化手段としては上記の撹拌翼２８に空
気を吹き付ける方法が好結果を与えることを確認してい
る。本発明は、これを更に改良したものである。Among these, the conditions for the slurry pH must be such that the absorption of sulfur oxides and the oxidation of the produced calcium sulfite proceed at a desired rate. The appropriate pH for absorption of sulfur oxides and oxidation of calcium sulfite is 5.5, respectively.
Above, the appropriate pH common to both reactions is limited to around 5.5. On the other hand, the present inventors have discovered that calcium sulfite in the slurry falling into the absorption tower circulation tank 7 is in a solution state, and if the oxidation means in this tank 7 is appropriate, calcium sulfite can be dissolved even at a pH of around 6. It has been confirmed that the oxidation proceeds sufficiently and that the method of blowing air onto the stirring blades 28 described above gives good results as the oxidation means. The present invention further improves this.
亜硫酸カルシウムの酸素酸化反応に対してはＦ ｅ”、
Ｍｎ”、 Ｃｏ”、 Ｃｕ”＋等の金属イオンが触媒
作用をすることがよく知られている。ここで、まずこの
金属イオンの働きについて説明する。For the oxygen oxidation reaction of calcium sulfite, F e”,
It is well known that metal ions such as Mn", Co", and Cu"+ act as catalysts. First, the function of these metal ions will be explained.
通常の湿式脱硫においては、使用する水、石灰石のほか
排ガス中のダストに伴なわれて、これら金属元素が吸収
系に混入してくるために、特に触媒イオンを意図的に添
加しなくても亜硫酸カルシウムの酸化は純水系における
よりも速やかに進行する、特にダスト混合方式において
は、従来、除塵部から抜き出された除塵用循環スラリか
酸化塔１８に導かれるために、Ｆｅ”＋を主体とするイ
オンの触媒効果が現われる。一方、ダスト分離方式の場
合にも、一部のダストは除塵部を通過して吸収部に混入
するほか、石灰石に起因する金属イオンも触媒として作
用する。また、いずれの方式においても亜硫酸カルシウ
ムを酸化塔１８において酸化すると次式に従って硫酸が
遊離してｐＨが低Ｃａ（ＨＳＯ，）、＋０１＋ＣａＳＯ
４＋Ｈ２Ｓｏ。In normal wet desulfurization, these metal elements are mixed into the absorption system along with the water and limestone used, as well as dust in the exhaust gas, so it is not necessary to intentionally add catalyst ions. The oxidation of calcium sulfite proceeds more quickly than in a pure water system.Especially in the dust mixing method, conventionally, the circulating slurry for dust removal extracted from the dust removal section is led to the oxidation tower 18, so that the oxidation of calcium sulfite is mainly Fe"+. On the other hand, in the case of the dust separation method, some dust passes through the dust removal section and enters the absorption section, and metal ions originating from limestone also act as a catalyst. In either method, when calcium sulfite is oxidized in the oxidation tower 18, sulfuric acid is liberated according to the following formula, and the pH becomes low Ca (HSO, ), +01+CaSO,
4+H2So.
下するために、スラリ中に固体として存在していた触媒
イオンは酸化塔内で溶解することになる。In order to remove the oxidation, the catalyst ions that were present as solids in the slurry are dissolved in the oxidation tower.
従って１石膏の分離母液は吸収剤の調製用に循環使用さ
れるので専用酸化塔を持つ限り、ダスト分離、ダスト混
合、いずれの方式においても酸化塔１８においては金属
イオンの触媒効果は発現することになる。Therefore, since the separated mother liquor of 1 gypsum is recycled for use in preparing the absorbent, as long as a dedicated oxidation tower is provided, the catalytic effect of metal ions will be exerted in the oxidation tower 18 regardless of whether it is dust separation or dust mixing. become.
これに対し、同一塔内で硫黄酸化物の吸収と亜硫酸カル
シウムの酸化を行う方式のうちダスト混合方式の場合に
はダストに起因する金属元素が吸収−酸化系に混入する
ことになるが、ダスト分離方式の場合にはダストに起因
しての金属元素の混入量は極めて少量となる。また、吸
収と酸化が同一のＰＨ（５，５〜６．０）で行われ、専
用酸化塔を設置する場合のように酸が遊離する過程が含
まれないために、吸収塔循環タンク７内の吸収用循環ス
ラリ中の触媒イオンの濃度は他の方式よりも著しく低い
ものとなり、場合によっては亜硫酸カルシウムの酸化速
度が所期の値以下になる場合が現われる。On the other hand, in the case of the dust mixing method, which absorbs sulfur oxides and oxidizes calcium sulfite in the same tower, metal elements originating from dust will mix into the absorption-oxidation system. In the case of the separation method, the amount of metal elements mixed in due to dust is extremely small. In addition, since absorption and oxidation are performed at the same pH (5.5 to 6.0), and the process of acid liberation is not included, unlike when installing a dedicated oxidation tower, the absorption tower circulation tank 7 The concentration of catalyst ions in the circulating slurry for absorption is significantly lower than in other methods, and in some cases, the oxidation rate of calcium sulfite may be lower than the desired value.
本発明は、このダスト分離方式の一塔式脱硫システムに
おける亜硫酸カルシウムの酸化速度を高める装置に関す
るものであり、吸収塔循環タンク７中の吸収用循環スラ
リを管路３０から除塵塔循環タンク４に供給する一方、
除塵用循環スラリの一部を連通ラインとなる管路３１を
通して除塵部から吸収・酸化部の吸収塔循環タンク７中
に供給することをその特徴とする。３２はブリードポン
プを示す。これにより、亜硫酸カルシウムの酸化触媒と
なる金属イオンが吸収・酸化部に供給されることになる
。この除塵用循環スラリの供給量は亜硫酸カルシウムに
対する酸化触媒能によって決定されるが、必要以上に多
量に供給すると吸収系のＣＱ等の濃度が増大することに
なるので好ましくない、吸収塔循環タンク７から抜出さ
れたスラリの一部は管路３３よりシラフナ２０へ導かれ
。The present invention relates to a device for increasing the oxidation rate of calcium sulfite in this dust separation type one-column desulfurization system, in which the circulation slurry for absorption in the absorption column circulation tank 7 is transferred from the pipe 30 to the dust removal column circulation tank 4. While supplying
Its feature is that a part of the circulation slurry for dust removal is supplied from the dust removal section to the absorption tower circulation tank 7 of the absorption/oxidation section through a pipe 31 serving as a communication line. 32 indicates a bleed pump. As a result, metal ions that act as an oxidation catalyst for calcium sulfite are supplied to the absorption/oxidation section. The supply amount of this circulation slurry for dust removal is determined by the oxidation catalytic ability for calcium sulfite, but if it is supplied in an amount larger than necessary, the concentration of CQ, etc. in the absorption system will increase, which is undesirable. A part of the slurry extracted from the pipe is guided to the Shirafuna 20 through the pipe line 33.
固液分離された後、遠心分離機２１等で脱水され。After solid-liquid separation, it is dehydrated using a centrifuge 21 or the like.
石膏２２が回収される。固液分離及び脱水時の濾液２３
は石灰石スラリの調製等に使用される。なお、硫黄酸化
物の吸収剤である石灰石２５は石灰石スラリ調製タンク
２４中に添加され、濾過水２３及び補給水２６と混合さ
れて石灰石スラリとなってブリードポンプ２７を介して
吸収塔循環タンク７へ導かれる。Gypsum 22 is collected. Filtrate 23 during solid-liquid separation and dehydration
is used for preparing limestone slurry, etc. Note that limestone 25, which is an absorbent for sulfur oxides, is added to a limestone slurry preparation tank 24, mixed with filtered water 23 and make-up water 26, and turned into limestone slurry, which is then sent to the absorption tower circulation tank 7 via a bleed pump 27. be led to.
失産透エエ
直径８０ａａのポリ塩化ビニル製タンクに１０％の石膏
スラリを２５０Ｑを入れ、これにＣａ（ＨＳＯ，）、を
０．３５ｍｏ Ｑ／Ｑ、Ｆａ ： １．７ｐｐｍ、ｖ：
１００ｐｐｂ、Ｃｕ ： ２０ｐｐｂｔＮｉ：２０ｐ
ｐｂ、Ｍｎ：４０ｐｐｂを含む溶液を１６．７Ｑ／ｈの
流量で供給した。このスラリのＰＨをＣａＣ０，粉末あ
るいは（１＋３）Ｈ２ＳＯ４を添加することによって５
．５に維持し、またタンク側面に取付けられた４台の撹
拌機（羽根径１２（１ｍ）に空気を１．２Ｎｒｒｌ’／
ｈ一台（合計４．８Ｎｎｉ’／ｈ）で供給するとともに
速度１．ＯＯＯｒｐｍで撹拌し、この人ラリを１６．７
Ｑ／ｈの流量で抜き出した＜８Ｆ留時間１５ｈに相当
する）。Put 250Q of 10% gypsum slurry into a polyvinyl chloride tank with a diameter of 80 aa, and add Ca (HSO,), 0.35 mo Q/Q, Fa: 1.7 ppm, v:
100ppb, Cu: 20ppbtNi: 20p
A solution containing 40 ppb of pb and Mn was supplied at a flow rate of 16.7 Q/h. The pH of this slurry can be increased to 5 by adding CaC0, powder or (1+3)H2SO4.
．． 5, and four agitators (blade diameter 12 (1 m)) installed on the side of the tank pumped air at 1.2Nrrl'/
h (total 4.8Nni'/h) and at a speed of 1. Stir at OOOrpm, this person's rari is 16.7
<8F extracted at a flow rate of Q/h, corresponding to a residence time of 15 h).
反応開始５，１０及び２０ｈ後の亜硫酸カルシウムの酸
化率はいずれも９９％以上であった。The oxidation rates of calcium sulfite 5, 10, and 20 hours after the start of the reaction were all 99% or higher.
尖嵐亘又工
実施例１の実験終了後にタンク内のスラリのＰＨを６．
０に調整したところ、５及び１０ｈ後の亜硫酸カルシウ
ムの酸化率はそれぞれ９９．１及び９８．８％であった
。After completing the experiment of Tsugaran Watamata Example 1, the pH of the slurry in the tank was set to 6.
When adjusted to 0, the oxidation rates of calcium sulfite after 5 and 10 hours were 99.1% and 98.8%, respectively.
崖豊且１工 実施例１．においてＦｅ、Ｖ、Ｃｕ、Ｎｉ。Cliff Toyotaka and 1 construction Example 1. In Fe, V, Cu, Ni.
Ｍｎの供給を省略したところ、５及び１０ｈ後の亜硫酸
カルシウムの酸化率はそれぞれ９７．０及び９５．１％
であった。When the supply of Mn was omitted, the oxidation rates of calcium sulfite after 5 and 10 h were 97.0 and 95.1%, respectively.
Met.
共ＪＬｌ＝
実施例１．において亜硫酸カルシウムを溶液でなく Ｃ
ａ Ｓ Ｏ３・１／２Ｈ，Ｏ粉末を用いて供給したとこ
ろ、５ｈ後の亜硫酸カルシウムの酸化率は６０％であっ
た。Co-JLl = Example 1. Calcium sulfite is not in solution at C
When aS O3.1/2H,O powder was used, the oxidation rate of calcium sulfite after 5 hours was 60%.
且笠且ユニ
実施例１．においてスラリのｐＨを６．０、また亜硫酸
カルシウムの添加をＣａＣ０，・１／２Ｈ，０によって
行ったところ、５ｈ後の亜硫酸カルシウムの酸化率は１
０％であった。Kasa and Uni Example 1. When the pH of the slurry was set to 6.0 and calcium sulfite was added using CaC0,·1/2H,0, the oxidation rate of calcium sulfite after 5 hours was 1.
It was 0%.
本発明によれば、除塵用循環スラリを除塵部から吸収・
酸化部に供給する連通ラインを設けることにより、排ガ
ス中に含まれていた亜硫酸カルシウムの酸化触媒となる
金属イオンを除塵用循環スラリの吸収・酸化部への一部
供給により有効に利用でき、それでいて生成する石膏の
純度を低下させる成分の吸収・酸化部への流入は防止す
ることができる。従って、別途に酸化塔を設置すること
なしに排ガス中の硫黄酸化物を高効率で石膏として回収
でき、しかも排ガス中のダストは石膏中に混入しないよ
うにして高純度の石膏を得ることができる。According to the present invention, the circulating slurry for dust removal is absorbed from the dust removal section.
By providing a communication line to supply the oxidation section, the metal ions that act as oxidation catalysts for calcium sulfite contained in the exhaust gas can be effectively used by absorbing the circulating slurry for dust removal and partially supplying it to the oxidation section. Components that reduce the purity of the produced gypsum can be prevented from flowing into the absorption/oxidation section. Therefore, sulfur oxides in the exhaust gas can be recovered as gypsum with high efficiency without installing a separate oxidation tower, and high-purity gypsum can be obtained by preventing the dust in the exhaust gas from being mixed into the gypsum. .
すなわち、従来別々に行われてきた硫黄酸化物の吸収・
酸化の反応を同一塔内で実施でき、しかも高純度の石膏
を得ることができる。In other words, sulfur oxide absorption and
The oxidation reaction can be carried out in the same column, and high purity gypsum can be obtained.
第１図は本発明に係る装置の構成図を示し、第２図は従
来例の構成図を示す。
１・・・排ガス、 ４・・・除塵塔循環タンク、
６・・・吸収塔、 ７・・・吸収塔循環タンク
、２２・・・石膏、 ２９・・・微細気泡、３１
・・・連通ライン。FIG. 1 shows a configuration diagram of an apparatus according to the present invention, and FIG. 2 shows a configuration diagram of a conventional example. 1... Exhaust gas, 4... Dust removal tower circulation tank,
6...Absorption tower, 7...Absorption tower circulation tank, 22...Gypsum, 29...Fine bubbles, 31
...Communication line.
Claims (1)
スとを気液接触させて排ガス中のダストを除去する除塵
部と、塔底部に設けた吸収塔循環タンク内に貯溜したカ
ルシウム系化合物を含有する吸収用循環スラリを塔上部
からスプレして前記除塵部を通過した排ガスと気液接触
させて硫黄酸化物を吸収除去する共に該吸収塔循環タン
ク内のスラリ中に微細気泡を供給して前記硫黄酸化物の
吸収によって生じる亜硫酸カルシウムを石膏に酸化する
吸収・酸化部を備えた湿式排煙脱硫装置において、除塵
用循環スラリを除塵部から吸収・酸化部に供給する連通
ラインを設けたことを特徴とする湿式排煙脱硫装置。A dust removal section that removes dust from the exhaust gas by bringing the circulating slurry for dust removal containing calcium-based compounds into gas-liquid contact with the exhaust gas, and an absorption unit that contains calcium-based compounds stored in the absorption tower circulation tank installed at the bottom of the tower. The circulating slurry is sprayed from the upper part of the tower and brought into gas-liquid contact with the exhaust gas that has passed through the dust removal section to absorb and remove sulfur oxides, and at the same time, fine bubbles are supplied into the slurry in the absorption tower circulation tank to remove the sulfur oxidation. A wet flue gas desulfurization device equipped with an absorption and oxidation section that oxidizes calcium sulfite produced by absorption of substances into gypsum, characterized in that a communication line is provided to supply circulation slurry for dust removal from the dust removal section to the absorption and oxidation section. Wet flue gas desulfurization equipment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61067480A JPH0722675B2 (en) | 1986-03-26 | 1986-03-26 | Wet flue gas desulfurization equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61067480A JPH0722675B2 (en) | 1986-03-26 | 1986-03-26 | Wet flue gas desulfurization equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62225226A true JPS62225226A (en) | 1987-10-03 |
| JPH0722675B2 JPH0722675B2 (en) | 1995-03-15 |
Family
ID=13346176
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61067480A Expired - Lifetime JPH0722675B2 (en) | 1986-03-26 | 1986-03-26 | Wet flue gas desulfurization equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0722675B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5693301A (en) * | 1994-03-31 | 1997-12-02 | Abb Flakt Ab | Method for removing sulphur dioxide from a gas |
| US6254843B1 (en) * | 1999-11-19 | 2001-07-03 | Marsulex Environmental Technologies, Llc | Process for the reclamation of calcium sulfite produced by a calcium-based FGD system |
| US7819959B2 (en) * | 2006-05-03 | 2010-10-26 | S.A. Snc-Lavalin Europe N.V. | Gas quench and scrubber draw-off system |
| JP2010269277A (en) * | 2009-05-25 | 2010-12-02 | Babcock Hitachi Kk | Method and apparatus of suppressing mercury re-release in desulfurization apparatus |
| CN106390707A (en) * | 2016-11-30 | 2017-02-15 | 合肥亿福自动化科技有限公司 | Flue gas wet-desulfurization system |
| CN107469609A (en) * | 2017-09-06 | 2017-12-15 | 杭州小橙工业设计有限公司 | A kind of full-automatic desulphurization system |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN208553709U (en) * | 2017-11-07 | 2019-03-01 | 中国石油化工股份有限公司 | Flue gas washing system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS531171A (en) * | 1976-06-10 | 1978-01-07 | Chiyoda Chem Eng & Constr Co Ltd | Removal of sulfur oxides in exhaust gas |
-
1986
- 1986-03-26 JP JP61067480A patent/JPH0722675B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS531171A (en) * | 1976-06-10 | 1978-01-07 | Chiyoda Chem Eng & Constr Co Ltd | Removal of sulfur oxides in exhaust gas |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5693301A (en) * | 1994-03-31 | 1997-12-02 | Abb Flakt Ab | Method for removing sulphur dioxide from a gas |
| US6254843B1 (en) * | 1999-11-19 | 2001-07-03 | Marsulex Environmental Technologies, Llc | Process for the reclamation of calcium sulfite produced by a calcium-based FGD system |
| US7819959B2 (en) * | 2006-05-03 | 2010-10-26 | S.A. Snc-Lavalin Europe N.V. | Gas quench and scrubber draw-off system |
| JP2010269277A (en) * | 2009-05-25 | 2010-12-02 | Babcock Hitachi Kk | Method and apparatus of suppressing mercury re-release in desulfurization apparatus |
| CN106390707A (en) * | 2016-11-30 | 2017-02-15 | 合肥亿福自动化科技有限公司 | Flue gas wet-desulfurization system |
| CN107469609A (en) * | 2017-09-06 | 2017-12-15 | 杭州小橙工业设计有限公司 | A kind of full-automatic desulphurization system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0722675B2 (en) | 1995-03-15 |
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