JPH0235687B2 - - Google Patents
Info
- Publication number
- JPH0235687B2 JPH0235687B2 JP58244242A JP24424283A JPH0235687B2 JP H0235687 B2 JPH0235687 B2 JP H0235687B2 JP 58244242 A JP58244242 A JP 58244242A JP 24424283 A JP24424283 A JP 24424283A JP H0235687 B2 JPH0235687 B2 JP H0235687B2
- Authority
- JP
- Japan
- Prior art keywords
- chlorite
- chlorine dioxide
- section
- amount
- supply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 claims description 122
- 239000004155 Chlorine dioxide Substances 0.000 claims description 61
- 235000019398 chlorine dioxide Nutrition 0.000 claims description 61
- QBWCMBCROVPCKQ-UHFFFAOYSA-N chlorous acid Chemical compound OCl=O QBWCMBCROVPCKQ-UHFFFAOYSA-N 0.000 claims description 49
- 229910001919 chlorite Inorganic materials 0.000 claims description 48
- 229910052619 chlorite group Inorganic materials 0.000 claims description 48
- 239000002253 acid Substances 0.000 claims description 43
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical compound Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 claims description 30
- 239000012530 fluid Substances 0.000 claims description 23
- 238000005868 electrolysis reaction Methods 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 16
- 239000006185 dispersion Substances 0.000 claims description 10
- XTEGARKTQYYJKE-UHFFFAOYSA-M Chlorate Chemical compound [O-]Cl(=O)=O XTEGARKTQYYJKE-UHFFFAOYSA-M 0.000 claims description 6
- 239000007788 liquid Substances 0.000 description 19
- 239000000243 solution Substances 0.000 description 15
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 12
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 7
- 239000000460 chlorine Substances 0.000 description 7
- 229910052801 chlorine Inorganic materials 0.000 description 7
- 239000007789 gas Substances 0.000 description 7
- 235000002639 sodium chloride Nutrition 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 6
- UKLNMMHNWFDKNT-UHFFFAOYSA-M sodium chlorite Chemical compound [Na+].[O-]Cl=O UKLNMMHNWFDKNT-UHFFFAOYSA-M 0.000 description 6
- 229960002218 sodium chlorite Drugs 0.000 description 6
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- 150000003839 salts Chemical class 0.000 description 5
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 5
- 239000005708 Sodium hypochlorite Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 4
- 230000005611 electricity Effects 0.000 description 4
- 239000003792 electrolyte Substances 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- 238000007086 side reaction Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- -1 concentration Substances 0.000 description 2
- 239000003085 diluting agent Substances 0.000 description 2
- 239000003651 drinking water Substances 0.000 description 2
- 235000020188 drinking water Nutrition 0.000 description 2
- 238000012856 packing Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 239000007844 bleaching agent Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000001877 deodorizing effect Effects 0.000 description 1
- 239000000645 desinfectant Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 231100000219 mutagenic Toxicity 0.000 description 1
- 230000003505 mutagenic effect Effects 0.000 description 1
- 238000011017 operating method Methods 0.000 description 1
- 239000008213 purified water Substances 0.000 description 1
- 230000029219 regulation of pH Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
Description
本発明は、亜塩素酸塩溶液と次亜塩素酸塩溶液
とを酸性下で混合することにより二酸化塩素を発
生させる方法に関し、特に、操作が簡単で経済
的、かつ立地条件に影響されない二酸化塩素の発
生方法に関する。
パルプや紙の漂白剤として工業的に広く用いら
れている二酸化塩素は、飲料水の消毒分野では一
般的に用いられる塩素に比べ、特異な臭気を与え
ず、また、トリハロメタンなどの変異原性物質を
生成しないことから、近年塩素に代わる殺菌剤と
して注目され、欧米ではすでに使用されている。
二酸化塩素の簡易な生成方法として、固体また
は溶液の亜塩素酸塩に、塩素ガス、塩素水または
次亜塩素酸塩溶液を作用させるなどの方法がある
が、塩素ガスの危険性、あるいは二酸化塩素ガス
の爆発性などを考慮して、亜塩素酸塩溶液と次亜
塩素酸塩溶液とを酸の存在下で混合することによ
り、二酸化塩素水を得ることが一般に行なわれ
る。たとえば、亜塩素酸ナトリウム、次亜塩素酸
ナトリウムおよび塩酸を使用した場合、(1)式に従
つて二酸化塩素が生成し、食塩が副生する。
2NaClO2＋NaClO＋2HCl
＝2ClO2＋3NaCl＋H2O ……(1)
(1)式に基づく二酸化塩素の生成方法は２〜３知
られているが、二酸化塩素の生成効率が低く、高
価な亜塩素酸塩を浪費する経済的犠牲をしいられ
るため、すでに本発明者らは高収率で二酸化塩素
を連続的に発生させる方法を開発している（特開
昭58−161903）。しかしながら、この方法は原料
として市販の次亜塩素酸塩溶液を使用するため問
題が残された。すなわち、次亜塩素酸塩溶液は有
効塩素濃度が10〜12％と薄く、不安定である上、
立地条件によつて供給に不安があり、また輸送等
により価格が割高になることが多々ある。一方、
長期保存も分解により好ましくない。特に、浄水
量の比較的少ない過疎地域においては、この傾向
がきわめて強い。
本発明者らは、これらの点に鑑み原料物質を安
定な食塩、塩酸、亜塩素酸塩とし、二酸化塩素の
発生収率が高く、操作が簡単で、かつ経済的に二
酸化塩素を発生させる方法を得るため、次亜塩素
酸塩の電解製造方法、原料物質の混合順序、濃
度、液性、反応終了液組成および液循環方法等を
系統的に検討し、ついに、循環液を主流路および
２つの分岐流路からなる系とし、各流路における
循環流量を規制することと、酸および亜塩素酸塩
の供給量と電解通電量を好適な範囲とすることに
より、きわめて経済的かつ容易に二酸化塩素を発
生し得ることを見い出し、その目的を達したもの
である。
すなわち、本発明は電解部、酸供給部、亜塩素
酸塩供給部、二酸化塩素発生部および放散部から
成る二酸化塩素の連続発生方法において、循環液
の主流路（F1と略す）を順に循環ポンプ、電解
部、二酸化塩素発生部、放散部および循環ポンプ
からなる循環系とし、電解槽の手前より循環液の
１部を分岐し、酸供給部を経由したのち、電解終
了後の主循環流路へ戻す酸供給分岐流路（F2と
略す）および亜塩素酸塩供給部を経由後、二酸化
塩素発生部へ戻す亜塩素酸塩供給分岐流路（F3
と略す）を設け、F1、F2、F3の循環流量をそれ
ぞれ全循環量の35〜60％、18〜48％、２〜32％に
なるように調節することを特徴とし、かつ、亜塩
素酸塩の供給量を二酸化塩素必要量の1.0〜1.2当
量とし、電解通電量を亜塩素酸塩供給量の0.5〜
0.75当量に相当する次亜塩素酸塩を発生するのに
必要な通電量とし、さらに酸供給量を電解終了後
の循環液のPHが1.0〜6.0になるようにすることを
特徴とする二酸化塩素の発生方法である。
つぎに、本発明を図面によつて説明する。本発
明の一具体例を第１図に示したが、電解部１、酸
供給部６、亜塩素酸塩供給部１１、二酸化塩素発
生部１０および放散部１５から成る。放散終了後
の循環液は放散塔１６の塔底より循環ポンプ１９
により順に電解槽２、気液分離装置５、二酸化塩
素発生部１０、放散塔１６からなる主流路F1お
よび、電解槽２の手前より分岐し酸供給部６を経
由して電解終了後のF1中へ戻る酸供給分岐流路
F2と亜塩素酸塩供給部１１を経由して二酸化塩
素発生部１０へ戻る亜塩素酸塩供給分岐流路F3
とに循環される。循環液は流量計４，９，１４に
より好適流量に調節され、電解液または希釈液と
して再使用される。電解部１は電解槽２、整流器
３、流量計４から成り、循環液には(1)式により食
塩が含まれるため、電解槽２による電解で次亜塩
素酸ナトリウムが生成される。電解槽２はいかな
る型式のものでもよいが、槽構造が簡単で比較的
製作費が安いフイルタープレス型バイポーラセル
が好適である。電極はチタンまたはチタン合金か
らなり、片面に白金族金属およびその酸化物が被
覆される。電解室を構成する絶縁パツキンは軟質
塩ビシートのようなパツキン材料を使用し、中央
部が切り抜かれる。電解を終了した循環液は気液
分離装置５へ導かれ、発生した水素ガスを系外に
排出させる。気液分離装置５は一般的な逆止弁方
式が採用される。気液分離を終了した次亜塩素酸
ナトリウムを含む循環液はａ点で酸供給部６より
供給された酸と混合される。酸供給部６は、酸貯
槽７、定量ポンプ８、流量計９から成り、循環液
のPHを1.0〜6.0に調節するのに必要な酸を定量ポ
ンプ８により供給する。この際、酸は電解槽の手
前で主流路より分岐し流量計９を経た循環液によ
り適度に希釈される。適量の酸を添加されPHを
1.0〜6.0に調整された電解終了後の循環液は、二
酸化塩素発生部１０へと導かれ、亜塩素酸塩供給
部１１からの亜塩素酸塩溶液と混合され、(1)式に
より二酸化塩素と食塩とを生成する。亜塩素酸塩
供給部１１は亜塩素酸塩溶液貯槽１２、定量ポン
プ１３、流量計１４とから成るが、二酸化塩素の
必要量に見合つた次亜塩素酸塩が定量ポンプ１３
により二酸化塩素発生部１０に供給される。この
際、亜塩素酸塩は電解槽の手前で主流路より分岐
した循環液により適度に希釈される。二酸化塩素
発生部１０で反応を終了した循環液は放散部１５
へ導かれ、流下する間に吹き込まれた空気により
二酸化塩素ガスを放散する。放散部１５は放散塔
１６、ブロワー１７、流量計１８からなるが、放
散塔１６は充填式でラツシヒリング等が充填され
る。塔底の放散終了液は循環液となり循環ポンプ
１９により電解部、各供給部へ循環され、一部は
液溜め２０を経て排出される。
本発明は二酸化塩素放散終了液を循環し、主流
路F1および分岐流路F2，F3から成る循環系とし、
原料物質の混合順序を規制し、かつ、F1，F2，
F3の流量比が好適範囲に入るように調節するこ
とを最大の特徴とするが、この好適範囲について
説明する。二酸化塩素放散終了液中には食塩が含
有されるため、次亜塩素酸塩製造用の電解液とし
て再利用することができる。しかし、単に電解部
へのみ循環すると、酸および亜塩素酸塩供給系の
流量が少なくなり、濃度も濃すぎるため、安定操
業ができず、混合不足により反応収率の低下、PH
および二酸化塩素濃度に偏りが生じ好ましくな
い。一方、酸、亜塩素酸塩を希釈して供給すると
系は安定するが、放散塔よりの排出液量が増加
し、薬品費も増大する。したがつて、電解槽経由
の主流路の他に各供給部への分岐流路が必要であ
る。また、F2，F3における循環液中に次亜塩素
酸塩が含まれると副反応が促進されるため、夫々
の分岐点は電解槽の手前でなければならないが、
F2およびF3の分岐の順はどちらが先でもよいし、
主流路からの分岐を一つにして、これを更にF2
およびF3に分岐してもよい。一方、主循環流路
F1への酸および亜塩素酸塩の供給順序は、まず
電解終了後のF1へ酸を供給し、その後亜塩素酸
塩を供給することが好ましい。供給の順序を逆に
すると塩素酸塩生成の副反応が促進される。
F1への循環流量は全循環流量の35〜60％とす
るのが最適である。35％以下では極間流量の低下
により電解室内のガス含有率が高くなり槽電圧の
上昇、電流密度の増加に伴なう電極寿命の劣化が
起り好ましくない。一方、60％以上では酸および
亜塩素酸塩の希釈が不充分となり、単に電解槽の
みに循環した場合と同様の結果となる。F2への
循環流量は全循環流量の18〜48％が好適である。
18％以下では酸濃度が高すぎ、電解終了後の循環
液のPHに偏りができ、二酸化塩素ガス濃度が極部
的に高くなり自然分解の原因となる。一方、48％
以上では酸濃度が極端に薄くなり二酸化塩素発生
効率が低下し、かつ、F1，F3での流量不足に伴
なう障害が生じ好ましくない。さらに、F3への
循環流量は全循環流量の２〜32％が好適である。
２％以下では、亜塩素酸塩濃度が高すぎるため二
酸化塩素の生成反応が不安定となり、収率低化や
二酸化塩素の分解を起すことがある。一方、32％
以上では、亜塩素酸塩濃度が極端に薄くなるた
め、反応速度が遅くなり、同時に電解部、酸供給
部へ悪影響を及ぼす。また、全循環流量は25％換
算亜塩素酸塩供給流量の60〜110倍になるように
設定するのが好ましく、この範囲内の全循環流量
を好適比率に分配することにより原料系が好適濃
度となる。
次に本発明の運転方法につきさらに説明する。
酸供給部で使用する酸は塩酸が好ましく、亜塩素
酸塩としては例えば25％亜塩素酸ナトリウム溶液
が使用され、循環液により好適濃度に希釈され
る。濃度の薄い酸および亜塩素酸塩の使用は、放
散塔々底よりの排出量が大となり、かつ循環液中
の食塩濃度が低くなり電解部に悪影響を及ぼす。
また、酸消費量も大となるため好ましくない。
電解電流、酸供給量、亜塩素酸塩供給量は次の
ようにして決定される。まず、亜塩素酸塩の供給
量が二酸化塩素ガス必要量の1.0〜1.2当量となる
ように決定される。たとえば、二酸化塩素必要量
が20Kg／日の場合、25％亜塩素酸ナトリウム溶液
の供給量は90／日（62ml／分）〜107／日と
なる。次に、電解電流は亜塩素酸塩供給量の0.5
〜0.75当量に対応する次亜塩素酸塩を発生するよ
うに調節される。通電量は二酸化塩素20Kg／日で
410〜615A程度である。この通電量が小さすぎる
と二酸化塩素発生効率や亜塩素酸塩分解率が低下
し、必要とする二酸化塩素を得ることができなく
なる。一方、通電量が大きすぎると発生ガス中の
塩素ガス含有量が増加し好ましくない。酸供給量
は電解終了後の循環液のPHが1.0〜6.0の範囲にな
るように調節される。本発明においては、PH調節
も極めて重要な因子となつている。すなわち、PH
が1.0より低すぎると、電解終了後の循環液のPH
が下りすぎ溶存塩素ガスの増加により、気液分離
装置での塩素逸散が大となり不経済である。一
方、PH6.0以上になると塩素酸塩を生成する副反
応が生じ、二酸化塩素発生効率が低下する。この
ようにして通電量、酸、亜塩素酸塩供給量および
各循環流量を決定し、調節することにより安定し
た運転ができ無人化も可能である。
本発明の方法によれば、二酸化塩素ガス放散終
了液を循環し、電解液、希釈液として再利用する
ことにより、極めて経済的に二酸化塩素を製造す
ることができた。また、次亜塩素酸塩、酸、亜塩
素酸塩の混合順序、供給方法およびその供給量
（次亜塩素酸塩については通電量）を好適範囲に
することにより、反応収率の向上と安定した反応
が得られ、操作も極めて簡便なものとなり実用上
価値が高い。
本発明の方法は飲料水の消毒用に適用できるほ
か、食品類の漂白が脱臭およびスライムコントロ
ール等においても極めて有効な手段となる。
次に本発明の態様を実施例、比較例で示すが、
その主旨はこれらの例により何ら制約されるもの
ではない。
実施例 １
第１図に示したようなフローシートに基づき、
１Kg／日の二酸化塩素の発生を行なつた。供給し
た亜塩素酸塩は25％亜塩素酸ナトリウム溶液で定
量ポンプにより210ml／時の割分で供給した。一
方、電解電流は5.5Aとし、４室で通電量は総計
22Aとした。次に酸は濃塩酸を使用し、560ml／
時の割合で定量ポンプにより供給した。また、
F1の循環流量は120ml／分とし、F2の循環流量は
78ml／分さらにF3の循環流量は40ml／分とした。
この条件での運転において、放散終了後の循環
液、電解終了直後の循環液、塩酸供給後の循環液
のPHは夫々1.0〜1.4、7.0〜7.5、1.0〜1.4であり、
放散終了後の循環液中の食塩濃度は50〜55ｇ／
で電解液として充分使用可能であつた。また、放
散終了後の循環液中に亜塩素酸ナトリウムは含ま
れず、有効に二酸化塩素に転化されたことが確認
された。このときの二酸化塩素の発生効率は95％
以上で、その発生量は1.1Kg／日であつた。また、
操作は流量計、電流の監視のみで容易であつた。
比較例 １
本発明の経済的メリツトを知る目的で、亜塩素
酸塩、次亜塩素酸塩、酸を使用して二酸化塩素を
発生させる従来法により製造した場合の原単位を
求め、実施例１との比較表を第１表に示した。
The present invention relates to a method for generating chlorine dioxide by mixing a chlorite solution and a hypochlorite solution under acidic conditions, and in particular to a method for generating chlorine dioxide that is easy to operate, economical, and unaffected by location conditions. Regarding the method of occurrence. Chlorine dioxide, which is widely used industrially as a bleaching agent for pulp and paper, does not give off a peculiar odor compared to chlorine, which is commonly used in the field of drinking water disinfection, and is free from mutagenic substances such as trihalomethanes. Because it does not produce chlorine, it has recently attracted attention as a disinfectant as an alternative to chlorine, and is already in use in Europe and the United States. A simple method for producing chlorine dioxide is to react solid or solution chlorite with chlorine gas, chlorine water, or hypochlorite solution, but the dangers of chlorine gas or chlorine dioxide In consideration of the explosive nature of the gas, chlorine dioxide water is generally obtained by mixing a chlorite solution and a hypochlorite solution in the presence of an acid. For example, when sodium chlorite, sodium hypochlorite, and hydrochloric acid are used, chlorine dioxide is produced according to equation (1), and common salt is produced as a by-product. 2NaClO 2 + NaClO + 2HCl = 2ClO 2 + 3NaCl + H 2 O ...(1) There are two or three known methods for producing chlorine dioxide based on equation (1), but the production efficiency of chlorine dioxide is low and expensive chlorite is not used. In order to avoid the economic sacrifice of waste, the present inventors have already developed a method for continuously generating chlorine dioxide at a high yield (Japanese Patent Application Laid-Open No. 161903/1983). However, this method still has problems because it uses a commercially available hypochlorite solution as a raw material. In other words, hypochlorite solutions have a low effective chlorine concentration of 10-12% and are unstable.
There are concerns about supply due to locational conditions, and prices are often relatively high due to transportation and other factors. on the other hand,
Long-term storage is also unfavorable due to decomposition. This tendency is particularly strong in depopulated areas where the amount of purified water is relatively small. In view of these points, the present inventors have developed a method of generating chlorine dioxide economically, with a high yield of chlorine dioxide, and with easy operation, using stable salt, hydrochloric acid, or chlorite as raw materials. In order to obtain this, we systematically investigated the electrolytic production method of hypochlorite, the mixing order of raw materials, concentration, liquid properties, reaction finished liquid composition, liquid circulation method, etc. The system consists of two branch channels, and by regulating the circulation flow rate in each channel, and by adjusting the supply amount of acid and chlorite and the amount of electrolytic energization within the appropriate range, it is extremely economical and easy to perform carbon dioxide. It was discovered that chlorine could be generated, and the objective was achieved. That is, the present invention provides a method for continuously generating chlorine dioxide, which consists of an electrolysis section, an acid supply section, a chlorite supply section, a chlorine dioxide generation section, and a dissipation section, in which the main flow path (abbreviated as F1 ) of the circulating fluid is sequentially circulated. The circulation system consists of a pump, an electrolytic section, a chlorine dioxide generation section, a dissipation section, and a circulation pump. A part of the circulating fluid is branched off before the electrolytic cell, passes through the acid supply section, and then becomes the main circulation flow after electrolysis. After passing through the acid supply branch flow path (abbreviated as F 2 ) which returns to the chlorine dioxide generation section and the chlorite supply branch flow path (abbreviated as F 2 ), which returns to the chlorine dioxide generation section
), and the circulating flow rates of F 1 , F 2 , and F 3 are adjusted to 35 to 60%, 18 to 48%, and 2 to 32% of the total circulation amount, respectively, and The amount of chlorite supplied is 1.0 to 1.2 equivalent of the required amount of chlorine dioxide, and the amount of electrolytic current is 0.5 to 0.5 of the amount of chlorite supplied.
Chlorine dioxide, characterized in that the amount of current is required to generate hypochlorite equivalent to 0.75 equivalent, and the amount of acid supplied is such that the pH of the circulating fluid after electrolysis is 1.0 to 6.0. This is how it occurs. Next, the present invention will be explained with reference to the drawings. A specific example of the present invention is shown in FIG. 1, and consists of an electrolytic section 1, an acid supply section 6, a chlorite supply section 11, a chlorine dioxide generation section 10, and a dissipation section 15. After the dispersion is completed, the circulating liquid is transferred from the bottom of the dispersion tower 16 to the circulation pump 19.
The main flow path F1 consists of the electrolytic cell 2, the gas-liquid separator 5, the chlorine dioxide generating section 10, and the stripping tower 16 in this order, and the main channel F1 which branches from before the electrolytic cell 2 and passes through the acid supply section 6 after the electrolysis is completed. 1 Acid supply branch flow path returning to inside
A chlorite supply branch flow path F 3 that returns to the chlorine dioxide generation unit 10 via F 2 and the chlorite supply unit 11
It is circulated between The circulating fluid is adjusted to a suitable flow rate by flowmeters 4, 9, and 14, and is reused as an electrolyte or diluent. The electrolytic section 1 consists of an electrolytic cell 2, a rectifier 3, and a flow meter 4. Since the circulating fluid contains salt according to equation (1), sodium hypochlorite is produced by electrolysis in the electrolytic cell 2. The electrolytic cell 2 may be of any type, but a filter press type bipolar cell is preferred because it has a simple cell structure and is relatively inexpensive to manufacture. The electrodes are made of titanium or titanium alloys, coated on one side with platinum group metals and their oxides. The insulating packing that makes up the electrolytic chamber is made of a packing material such as a soft PVC sheet, and the center part is cut out. The circulating liquid that has undergone electrolysis is led to the gas-liquid separator 5, and the generated hydrogen gas is discharged out of the system. The gas-liquid separation device 5 employs a general check valve type. The circulating liquid containing sodium hypochlorite that has undergone gas-liquid separation is mixed with the acid supplied from the acid supply section 6 at point a. The acid supply section 6 includes an acid storage tank 7, a metering pump 8, and a flow meter 9, and the metering pump 8 supplies the acid necessary to adjust the pH of the circulating fluid to 1.0 to 6.0. At this time, the acid is diluted appropriately by the circulating fluid that branches from the main flow path before the electrolytic cell and passes through the flow meter 9. An appropriate amount of acid is added to adjust the pH.
After the completion of electrolysis, the circulating fluid adjusted to 1.0 to 6.0 is led to the chlorine dioxide generation section 10, mixed with the chlorite solution from the chlorite supply section 11, and converted to chlorine dioxide according to equation (1). and table salt. The chlorite supply unit 11 consists of a chlorite solution storage tank 12, a metering pump 13, and a flow meter 14. The metering pump 13 supplies hypochlorite corresponding to the required amount of chlorine dioxide.
The chlorine dioxide is supplied to the chlorine dioxide generating section 10 by the chlorine dioxide generating section 10. At this time, the chlorite is appropriately diluted by the circulating fluid that branches from the main flow path before the electrolytic cell. The circulating fluid that has completed the reaction in the chlorine dioxide generation section 10 is disposed of in the dispersion section 15.
The chlorine dioxide gas is dissipated by the air blown in while flowing down. The dispersion section 15 includes a dispersion tower 16, a blower 17, and a flow meter 18, and the dispersion tower 16 is of a filling type and is filled with Raschig rings and the like. The dispersion-completed liquid at the bottom of the column becomes a circulating liquid and is circulated to the electrolytic section and each supply section by a circulation pump 19, and a portion is discharged through a liquid reservoir 20. The present invention circulates the chlorine dioxide emission finished liquid, and has a circulation system consisting of a main channel F 1 and branch channels F 2 and F 3 ,
The mixing order of raw materials is regulated, and F 1 , F 2 ,
The main feature is that the flow rate ratio of F 3 is adjusted to fall within a preferred range, and this preferred range will be explained below. Since the chlorine dioxide diffusion finished solution contains salt, it can be reused as an electrolyte for producing hypochlorite. However, if the acid and chlorite are simply circulated to the electrolytic section, the flow rate of the acid and chlorite supply system will be low and the concentration will be too high, making stable operation impossible.
Also, the concentration of chlorine dioxide is unbalanced, which is undesirable. On the other hand, if the acid or chlorite is diluted and supplied, the system will be stabilized, but the amount of liquid discharged from the stripping tower will increase, and the cost of chemicals will also increase. Therefore, in addition to the main flow path via the electrolytic cell, branch flow paths to each supply section are required. In addition, if hypochlorite is included in the circulating fluid in F 2 and F 3 , side reactions will be promoted, so the branch point for each must be before the electrolytic cell.
The order of branching F 2 and F 3 can be either first,
Combine the branches from the main flow path and connect this further to F 2
and may branch to F 3 . On the other hand, the main circulation flow path
Regarding the order of supplying acid and chlorite to F 1 , it is preferable to first supply acid to F 1 after completion of electrolysis, and then supply chlorite. Reversing the order of feeding accelerates the side reaction of chlorate formation. Optimally, the recirculation flow rate to F 1 should be 35-60% of the total recirculation flow rate. If it is less than 35%, the gas content in the electrolytic chamber increases due to a decrease in the interelectrode flow rate, which is undesirable because the cell voltage increases and the electrode life deteriorates due to an increase in current density. On the other hand, if it exceeds 60%, the acid and chlorite will not be sufficiently diluted, resulting in the same result as when they are simply circulated to the electrolytic cell. The circulating flow rate to F2 is preferably 18 to 48% of the total circulating flow rate.
If it is less than 18%, the acid concentration is too high and the pH of the circulating fluid after electrolysis is uneven, causing the chlorine dioxide gas concentration to become extremely high and causing natural decomposition. On the other hand, 48%
In the above case, the acid concentration becomes extremely thin, the chlorine dioxide generation efficiency decreases, and troubles due to insufficient flow rates at F 1 and F 3 occur, which is undesirable. Furthermore, the circulating flow rate to F3 is preferably 2 to 32% of the total circulating flow rate.
If it is less than 2%, the chlorite concentration is too high and the reaction for producing chlorine dioxide becomes unstable, which may result in a lower yield or decomposition of chlorine dioxide. On the other hand, 32%
In this case, the chlorite concentration becomes extremely low, which slows down the reaction rate, and at the same time adversely affects the electrolytic section and the acid supply section. In addition, it is preferable to set the total circulation flow rate to be 60 to 110 times the 25% equivalent chlorite supply flow rate, and by distributing the total circulation flow rate within this range at a suitable ratio, the raw material system can be adjusted to a suitable concentration. becomes. Next, the operating method of the present invention will be further explained.
The acid used in the acid supply section is preferably hydrochloric acid, and the chlorite used is, for example, a 25% sodium chlorite solution, which is diluted to a suitable concentration with the circulating fluid. The use of acids and chlorites with low concentrations increases the amount discharged from the bottoms of the stripping towers, lowers the salt concentration in the circulating fluid, and adversely affects the electrolytic section.
Further, the amount of acid consumed is also large, which is not preferable. The electrolysis current, acid supply amount, and chlorite supply amount are determined as follows. First, the amount of chlorite supplied is determined to be 1.0 to 1.2 equivalents of the required amount of chlorine dioxide gas. For example, if the required amount of chlorine dioxide is 20 kg/day, the supply amount of 25% sodium chlorite solution will be 90/day (62 ml/min) to 107/day. Then the electrolysis current is 0.5 of the chlorite supply
Adjusted to generate hypochlorite corresponding to ~0.75 equivalents. The amount of current is 20 kg of chlorine dioxide/day.
It is about 410-615A. If this amount of current is too small, the chlorine dioxide generation efficiency and chlorite decomposition rate will decrease, making it impossible to obtain the required chlorine dioxide. On the other hand, if the amount of current applied is too large, the chlorine gas content in the generated gas will increase, which is not preferable. The amount of acid supplied is adjusted so that the pH of the circulating fluid after electrolysis is in the range of 1.0 to 6.0. In the present invention, PH regulation is also an extremely important factor. That is, P.H.
is too low than 1.0, the pH of the circulating fluid after electrolysis is
The amount of dissolved chlorine gas decreases too much and the amount of dissolved chlorine gas increases, resulting in a large amount of chlorine dissipating in the gas-liquid separator, which is uneconomical. On the other hand, when the pH is higher than 6.0, a side reaction that produces chlorate occurs, and the efficiency of chlorine dioxide generation decreases. By determining and adjusting the amount of electricity, the amount of acid and chlorite supplied, and each circulation flow rate in this way, stable operation can be achieved and unmanned operation is also possible. According to the method of the present invention, chlorine dioxide can be produced extremely economically by circulating the liquid after chlorine dioxide gas diffusion and reusing it as an electrolytic solution and a diluent. In addition, by adjusting the mixing order of hypochlorite, acid, and chlorite, the supply method, and the supply amount (the amount of electricity for hypochlorite) within the appropriate range, the reaction yield can be improved and stabilized. This method is highly valuable in practical terms because it allows a reaction to be obtained and the operation is extremely simple. The method of the present invention can be applied to disinfect drinking water, and is also an extremely effective means for bleaching foods, deodorizing them, controlling slime, and the like. Next, aspects of the present invention will be illustrated by Examples and Comparative Examples.
The gist is not limited in any way by these examples. Example 1 Based on the flow sheet shown in Figure 1,
1 kg/day of chlorine dioxide was generated. The supplied chlorite was a 25% sodium chlorite solution, which was supplied at a rate of 210 ml/hour using a metering pump. On the other hand, the electrolytic current was 5.5A, and the total amount of electricity was applied in the four chambers.
It was set to 22A. Next, use concentrated hydrochloric acid as the acid, 560ml/
It was supplied by a metering pump at a rate of 100 hrs. Also,
The circulation flow rate of F 1 is 120ml/min, and the circulation flow rate of F 2 is
The circulation flow rate of F 3 was 78 ml/min and 40 ml/min.
In operation under these conditions, the PH values of the circulating fluid after dispersion, immediately after electrolysis, and after hydrochloric acid supply are 1.0 to 1.4, 7.0 to 7.5, and 1.0 to 1.4, respectively.
The salt concentration in the circulating fluid after dissipation is 50 to 55 g/
It could be used satisfactorily as an electrolyte. Furthermore, it was confirmed that sodium chlorite was not contained in the circulating fluid after completion of the dispersion, and that it was effectively converted to chlorine dioxide. The generation efficiency of chlorine dioxide at this time is 95%
As described above, the amount generated was 1.1Kg/day. Also,
Operation was easy with only a flowmeter and current monitoring. Comparative Example 1 In order to understand the economic merits of the present invention, the basic unit of production when chlorine dioxide is produced using a conventional method of generating chlorine dioxide using chlorite, hypochlorite, and acid was determined. A comparison table is shown in Table 1.
【表】
次亜塩素酸ナトリウムおよび電力単価は400
円／Kg、25円／kwhとし、両者のランニングコス
トを計算したところ、実施例１の方法で行なうと
約12％の製造費が削除される。
実施例 ２
25％亜塩素酸ナトリウムの供給量を65ml／分、
濃塩酸供給量を23ml／分、電解電流44A（10室、
440A）とし、更にF1，F2，F3への循環流量を
夫々4.0／分、2.0／分、1.0／分として20
Kg／日の二酸化塩素を発生させた。運転実績を第
２図に示したが、亜塩素酸塩の分解率、二酸化塩
素発生効率共に良好であつた。この際、電解電
流、各流量を調整するのみでほとんど無人運転が
可能で、安定操業ができた。
比較例 ２
本発明の各流路への循環流量規制の有効性を確
認するため、実施例１で使用した装置を用い実験
Ａ〜Ｅを行なつた。
実験Ａ：放散終了後の循環液をF1のみに供給し
て運転
Ｂ：F1：F2：F3＝80：10：10として運転
Ｃ：F1：F2：F3＝10：70：20として運転
Ｄ：F1：F2：F3＝10：60：30として運転
Ｅ：F1：F2：F3＝40：10：50として運転
二酸化塩素発生効率、反応の安定性、操作性等
について検討し、各運転条件における実験結果を
第２表に示した。[Table] Sodium hypochlorite and electricity unit price is 400
When the running costs for both were calculated as yen/Kg and 25 yen/kwh, it was found that if the method of Example 1 is used, about 12% of the manufacturing cost will be eliminated. Example 2 Supply amount of 25% sodium chlorite at 65 ml/min,
Concentrated hydrochloric acid supply rate: 23ml/min, electrolytic current: 44A (10 rooms,
440A), and the circulation flow rates to F 1 , F 2 , and F 3 are set to 4.0/min, 2.0/min, and 1.0/min, respectively.
Kg/day of chlorine dioxide was generated. The operational results are shown in Figure 2, and both the chlorite decomposition rate and chlorine dioxide generation efficiency were good. At this time, almost unmanned operation was possible by simply adjusting the electrolytic current and each flow rate, and stable operation was achieved. Comparative Example 2 In order to confirm the effectiveness of regulating the circulation flow rate to each channel of the present invention, experiments A to E were conducted using the apparatus used in Example 1. Experiment A: Operation with circulating fluid supplied only to F 1 after dispersion B: Operation with F 1 :F 2 :F 3 = 80:10:10 C: F 1 :F 2 :F 3 = 10:70 :20 operation D:F 1 :F 2 :F 3 = 10:60:30 operation E:F 1 :F 2 :F 3 = 40:10:50 operation Chlorine dioxide generation efficiency, reaction stability, The operability etc. were studied and the experimental results under each operating condition are shown in Table 2.
【表】【table】
【表】
比較例 ３
実施例１と同条件ではあるが、亜塩素酸塩供給
量、電解通電量、酸供給流量を本発明の好適範囲
の有効性を検討するため、実験Ｆ〜Ｋを行ない第
３表を得た。[Table] Comparative Example 3 Although the conditions were the same as in Example 1, experiments F to K were conducted in order to examine the effectiveness of the preferred ranges of the present invention for the amount of chlorite supplied, the amount of electrolytic energization, and the amount of acid supplied. Table 3 was obtained.
第１図は本発明の二酸化塩素発生時のフローシ
ートの一具体例で、第２図は運転状況を示す図で
ある。
１……電解部、２……電解槽、３……整流器、
４……流量計、５……気液分離装置、６……酸供
給部、７……酸貯槽、８……定量ポンプ、９……
流量計、１０……二酸化塩素発生部、１１……亜
塩素酸塩供給部、１２……亜塩素酸塩溶液貯槽、
１３……定量ポンプ、１４……流量計、１５……
放散部、１６……放散塔、１７……ブロワー、１
８……流量計、１９……循環ポンプ、２０……液
溜め、F1……主流路、F2……酸供給分岐流路、
F3……亜塩素酸塩供給分岐流路。
FIG. 1 is a specific example of a flow sheet for generating chlorine dioxide according to the present invention, and FIG. 2 is a diagram showing the operating conditions. 1... Electrolytic section, 2... Electrolytic tank, 3... Rectifier,
4... Flow meter, 5... Gas-liquid separator, 6... Acid supply section, 7... Acid storage tank, 8... Metering pump, 9...
Flowmeter, 10... Chlorine dioxide generating section, 11... Chlorite supply section, 12... Chlorite solution storage tank,
13...metering pump, 14...flow meter, 15...
Diffusion section, 16...Diffusion tower, 17...Blower, 1
8...Flowmeter, 19...Circulation pump, 20...Liquid reservoir, F1 ...Main flow path, F2 ...Acid supply branch flow path,
F 3 ... Chlorite supply branch flow path.
Claims (1)
化塩素発生部および放散部から成る二酸化塩素の
連続発生方法において、 (1) 循環液の主流路を、順に循環ポンプ、電解
部、二酸化塩素発生部、放散部および循環ポン
プからなる循環系とし、該電解部の手前より循
環液の１部を分岐し、酸供給部を経由して電解
終了後の主循環流路へ戻す酸供給分岐流路およ
び亜塩素酸塩供給部を経由して二酸化塩素発生
部へ戻す亜塩素酸塩供給分岐流路を設け、 (2) 前記主流路、酸供給分岐流路および亜塩素酸
塩供給分岐流路の流量をそれぞれ全循環流量の
35〜60％、18〜48％、２〜32％になるように調
節し、 (3) 亜塩素酸塩の供給量を二酸化塩素必要量の
1.0〜1.2当量とし、電解通電量を亜塩素酸塩供
給量の0.5〜0.75当量に相当する次亜塩素酸塩
を発生するのに必要な通電量とし、かつ、酸供
給量を電解終了後の循環液のPHが1.0〜6.0にな
るようにし、 (4) 全循環流量を25％換算亜塩素酸塩供給流量の
60〜110倍になるように設定することを特徴と
する二酸化塩素の連続発生方法。[Scope of Claims] 1. A method for continuously generating chlorine dioxide comprising an electrolytic section, an acid supply section, a chlorite supply section, a chlorine dioxide generation section, and a dissipation section, including: (1) circulating a circulating fluid in the main channel in order; The circulation system consists of a pump, an electrolysis section, a chlorine dioxide generation section, a dispersion section, and a circulation pump, and a part of the circulating fluid is branched off before the electrolysis section, and the main circulation flow after the electrolysis is completed via the acid supply section. (2) providing a branch passage for supplying acid to the main passage, a branch passage for supplying chlorite, and a branch passage for supplying chlorite to the chlorine dioxide generation unit via the chlorite supply unit; The flow rate of each chlorate supply branch flow path is the total circulation flow rate.
(3) Adjust the supply amount of chlorite to the required amount of chlorine dioxide.
1.0 to 1.2 equivalents, the amount of electrolytic current applied is the amount of current necessary to generate hypochlorite equivalent to 0.5 to 0.75 equivalents of the amount of chlorite supplied, and the amount of acid supplied is set to Adjust the pH of the circulating fluid to 1.0 to 6.0, and (4) convert the total circulation flow rate to 25% of the chlorite supply flow rate.
A method for continuously generating chlorine dioxide, which is characterized by setting the amount to increase by 60 to 110 times.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58244242A JPS60137804A (en) | 1983-12-26 | 1983-12-26 | Continuous generation of chlorine dioxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58244242A JPS60137804A (en) | 1983-12-26 | 1983-12-26 | Continuous generation of chlorine dioxide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60137804A JPS60137804A (en) | 1985-07-22 |
| JPH0235687B2 true JPH0235687B2 (en) | 1990-08-13 |
Family
ID=17115845
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58244242A Granted JPS60137804A (en) | 1983-12-26 | 1983-12-26 | Continuous generation of chlorine dioxide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60137804A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100956516B1 (en) | 2009-01-21 | 2010-05-06 | 대한민국(농촌진흥청장) | The continuous chlorine dixide generation system |
| JP6283551B2 (en) * | 2014-01-20 | 2018-02-21 | 高砂熱学工業株式会社 | Chlorine dioxide gas generator and method |
| CN107059013A (en) * | 2017-05-17 | 2017-08-18 | 宁波东盛集成电路元件有限公司 | A kind of cyclic electrolysis device regenerated for ferric trichloride etching liquid |
| CN107254681A (en) * | 2017-05-17 | 2017-10-17 | 宁波东盛集成电路元件有限公司 | A kind of cyclic electrolysis method regenerated for ferric trichloride etching liquid and its device |
-
1983
- 1983-12-26 JP JP58244242A patent/JPS60137804A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60137804A (en) | 1985-07-22 |
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