JP2002004075A - Method for decomposing chlorate in saline water - Google Patents
Method for decomposing chlorate in saline waterInfo
- Publication number
- JP2002004075A JP2002004075A JP2000185370A JP2000185370A JP2002004075A JP 2002004075 A JP2002004075 A JP 2002004075A JP 2000185370 A JP2000185370 A JP 2000185370A JP 2000185370 A JP2000185370 A JP 2000185370A JP 2002004075 A JP2002004075 A JP 2002004075A
- Authority
- JP
- Japan
- Prior art keywords
- chlorate
- salt water
- hydrogen
- ruthenium
- catalyst
- 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.)
- Pending
Links
- XTEGARKTQYYJKE-UHFFFAOYSA-M Chlorate Chemical compound [O-]Cl(=O)=O XTEGARKTQYYJKE-UHFFFAOYSA-M 0.000 title claims abstract description 122
- 238000000034 method Methods 0.000 title claims abstract description 48
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 44
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 title abstract description 10
- 239000011780 sodium chloride Substances 0.000 title abstract description 9
- 239000003054 catalyst Substances 0.000 claims abstract description 36
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 34
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 27
- 239000001257 hydrogen Substances 0.000 claims abstract description 26
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 26
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims abstract description 21
- 229910052707 ruthenium Inorganic materials 0.000 claims abstract description 21
- 229910001925 ruthenium oxide Inorganic materials 0.000 claims abstract description 12
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical compound O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 claims abstract description 12
- 239000007789 gas Substances 0.000 claims abstract description 10
- 150000003839 salts Chemical class 0.000 claims description 43
- 239000003014 ion exchange membrane Substances 0.000 claims description 8
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 4
- 238000000354 decomposition reaction Methods 0.000 abstract description 30
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 abstract description 20
- 229910052799 carbon Inorganic materials 0.000 abstract 1
- 238000006243 chemical reaction Methods 0.000 description 17
- 239000003513 alkali Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 5
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- 239000012267 brine Substances 0.000 description 4
- 238000005868 electrolysis reaction Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 238000010926 purge Methods 0.000 description 4
- 238000009825 accumulation Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 230000000737 periodic effect Effects 0.000 description 3
- 238000006722 reduction reaction Methods 0.000 description 3
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 239000003518 caustics Substances 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 101100321669 Fagopyrum esculentum FA02 gene Proteins 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- -1 and in fact Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 150000004045 organic chlorine compounds Chemical class 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 150000003303 ruthenium Chemical class 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 1
- 238000002336 sorption--desorption measurement Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は塩素酸塩を含有する
塩水中の塩素酸塩の分解方法に関し、更に詳しくは、イ
オン交換膜法塩化アルカリの電解において、循環塩水中
に蓄積してくる塩素酸塩をルテニウム系触媒を用いて水
素ガスと反応させて分解除去することにより塩素酸塩の
蓄積を防止する方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for decomposing chlorate in salt water containing chlorate, and more particularly to chlorine accumulated in circulating salt water in electrolysis of alkali chloride by an ion exchange membrane method. The present invention relates to a method for preventing the accumulation of chlorate by decomposing and removing the acid salt by reacting it with hydrogen gas using a ruthenium-based catalyst.
【０００２】[0002]
【従来の技術】イオン交換膜法塩化アルカリの電解にお
いては、陽極室より排出される濃度の低下した塩水に塩
化アルカリを飽和させ循環使用している。しかしなが
ら、この循環中に塩水中の塩素酸塩が蓄積増加してく
る。塩素酸塩の蓄積による影響はイオン交換膜の劣化、
製品苛性アルカリ中への混入による品質低下、並びに苛
性アルカリを濃縮する際の濃縮缶の腐食等が考えられる
ので、一般に塩水中の塩素酸塩濃度は２５ｇ／リットル
以下、望ましくは１０ｇ／リットル以下であることが要
求されている。2. Description of the Related Art In the electrolysis of alkali chloride by an ion exchange membrane method, alkali chloride is saturated and circulated in salt water having a reduced concentration discharged from an anode chamber. However, during this circulation, the chlorate in the salt water accumulates and increases. The effect of chlorate accumulation is degradation of ion exchange membranes,
In general, the concentration of chlorate in salt water is 25 g / liter or less, preferably 10 g / liter or less, because the quality of the product may be deteriorated due to mixing in the caustic alkali, and the concentration of the caustic alkali may be corroded. It is required to be.
【０００３】塩素酸塩の蓄積を防止するために、従来よ
り種々の方法が継続的に検討されてきた。例えば、晶析
法としては特開昭51-144399号が、還元法としては特公
昭55-16081号、特開昭55-123396号、特開昭60-77982
号、特公昭63-514号、特開平03-65507号、特開平03-153
890号、特開平03-294491号、特公平05-29605号、特開平
05-147928号が、塩酸法としては特開昭53-18498号、特
開昭53-110998号、特開昭54-28294号、特開昭57-19225
号、特公昭61-7478号、特開昭63-129015号、特開平01-2
5992号、特開平04-45295号、特開平04-65317号、特開平
05-4818号、特開平09-111487号が、樹脂法としては特開
平04-88183号、特開平04-88184号、特開平08-165589号
が、電解法としては特開平08-165589号が、ハ゜ーシ゛法（塩
素酸塩濃度が高くなった塩水の一部を抜き出して消費
し、新たな塩水を追加する方法）としては特開昭56-755
82号等が提案されている。In order to prevent the accumulation of chlorate, various methods have been continuously studied. For example, JP-A-51-144399 is used as a crystallization method, and JP-B-55-16081, JP-A-55-123396, and JP-A-60-77982 are used as a reduction method.
No., JP-B-63-514, JP-A-03-65507, JP-A-03-153
No. 890, JP 03-294491, JP-B 05-29605, JP
No. 05-147928, as the hydrochloric acid method JP-A-53-18498, JP-A-53-110998, JP-A-54-28294, JP-A-57-19225
No., JP-B-61-7478, JP-A-63-129015, JP-A-01-2
5992, JP 04-45295, JP 04-65317, JP
No. 05-4818, JP 09-111487, JP 04-88183, JP 04-88184, JP 08-165589 as the resin method, JP 08-165589 as the electrolysis method The Bathy method (a method of extracting and consuming a portion of salt water having an increased chlorate concentration and adding new salt water) is disclosed in JP-A-56-755.
No. 82 has been proposed.
【０００４】これらの方法の内、晶析法、還元法、電解
法および樹脂法は、効率が悪く、コスト高になり、また
電解プロセス自体に影響を及ぼす薬剤を使用する場合が
あること等の欠点を有するため、工業的には塩酸法およ
びパージ法が主流となっている。一方で、塩酸法および
パージ法においても夫々克服しなくてはならない問題は
ある。すなわち、塩酸法においては反応液中の塩素イオ
ン濃度・温度条件により反応速度が規定されるため、塩
素酸塩分解設備の操業条件が限定され、操業費用も多大
になること、副反応により爆発性のガスが発生すること
等の問題がある。パージ法においては、塩水中の塩素酸
塩、ボウ硝、食塩、有機塩素化合物他微量不純物のパー
ジ先に与える影響が無視できなくなってきていること、
操業条件によっては食塩ロスが経済的に大きな問題とな
ってこと等である。[0004] Of these methods, the crystallization method, the reduction method, the electrolytic method and the resin method are inefficient, increase the cost, and may use chemicals which affect the electrolytic process itself. Due to the disadvantages, the hydrochloric acid method and the purge method are mainly used industrially. On the other hand, there is a problem that must be overcome in each of the hydrochloric acid method and the purge method. In other words, in the hydrochloric acid method, the reaction rate is regulated by the chloride ion concentration and temperature conditions in the reaction solution, which limits the operating conditions of the chlorate decomposition equipment, increases the operating cost, and causes explosion due to side reactions. There is a problem that gas is generated. In the purging method, the effects of chlorate in salt water, bow salt, salt, organochlorine compounds and other trace impurities on the purge destination are becoming insignificant,
Depending on the operating conditions, salt loss is a major economic problem.
【０００５】これらを改良した方法として、イオン交換
膜法塩化アルカリ電解槽に供給される循環塩水を、循環
経路中に設けられた触媒層に水素又は水素を含むガスの
存在下で流通せしめる方法が提案されており（特開昭５
６−１６３２８６号）、触媒層として、周期律表第ＶＩ
ＩＩ族にある鉄、コバルト、ニッケル、白金、ルテニウ
ム、パラジウム、ロジウム、イリジウム等の金属または
その酸化物から選ばれる触媒の使用が開示されている。
この方法によれば、電解槽に塩酸を添加しないため、電
解槽の電流効率損失分に相当する塩酸量または塩素酸塩
分解工程に添加する塩酸量を厳密に管理することはない
という特長を有する。[0005] As a method of improving these, there is a method in which circulating brine supplied to an ion-exchange membrane method alkali chloride electrolytic cell is allowed to flow through a catalyst layer provided in a circulation path in the presence of hydrogen or a gas containing hydrogen. It has been proposed (Japanese
No. 6-163286), and as the catalyst layer, Periodic Table VI
The use of a catalyst selected from the group II metals, such as iron, cobalt, nickel, platinum, ruthenium, palladium, rhodium, iridium or oxides thereof, is disclosed.
According to this method, since hydrochloric acid is not added to the electrolytic cell, the amount of hydrochloric acid corresponding to the current efficiency loss of the electrolytic cell or the amount of hydrochloric acid added to the chlorate decomposition step is not strictly controlled. .
【０００６】しかしながら、この方法では塩素酸塩の分
解効率が低く、例えば実施例１において、触媒１００ｃ
ｃと飽和塩水３００ｃｃを混合して５分間水素ガスをバ
ブリングした結果では、触媒としてＲｕＯ2系を用いた
場合では、２５℃でＣｌＯ3 -分解率が１９．８％、６０
℃においては６９．８％で、白金ブラックを用いた場合
では、２５℃で３２．０％、６０℃では７３．３％と低
いものであった。However, in this method, the efficiency of decomposing chlorate is low.
the result of bubbling five min hydrogen gas is mixed with c and saturated brine 300 cc, in the case of using the RuO 2 based as catalyst, ClO 3 at 25 ° C. - decomposition rate 19.8%, 60
At 9 ° C., it was 69.8%, and when platinum black was used, it was as low as 32.0% at 25 ° C. and 73.3% at 60 ° C.
【０００７】[0007]
【発明が解決しようとする課題】本発明の課題は、従来
の塩水中の塩素酸塩の分解方法における上記各問題を解
決し、塩酸等を使用することなく、塩素酸塩の分解効率
の高い新規な塩素酸塩の分解方法を提供することであ
る。SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the conventional method for decomposing chlorate in salt water, and to achieve a high chlorate decomposition efficiency without using hydrochloric acid or the like. It is to provide a novel chlorate decomposition method.
【０００８】[0008]
【課題を解決するための手段】本発明者等は、塩素酸塩
を含有する塩水を、触媒の存在下で水素または水素含有
ガスと接触せしめることによる塩水中の塩素酸塩の分解
方法を鋭意検討した結果、触媒としてルテニウムおよび
酸化ルテニウムが優れていることを発見すると共に、触
媒を担持する担体の種類および形状が塩素酸塩の分解に
大いに寄与するという予想外の事実を見出し、本発明を
完成するに至った。Means for Solving the Problems The present inventors have diligently developed a method for decomposing chlorate in salt water by bringing salt water containing chlorate into contact with hydrogen or a hydrogen-containing gas in the presence of a catalyst. As a result of the study, they discovered that ruthenium and ruthenium oxide were excellent as catalysts, and found the unexpected fact that the type and shape of the carrier supporting the catalyst greatly contributed to the decomposition of chlorate. It was completed.
【０００９】即ち本発明は、塩素酸塩を含有する塩水
を、粒状または粉状の活性炭に担持させたルテニウムま
たは酸化ルテニウム触媒の存在下に、水素または水素含
有ガスと接触せしめることを特徴とする塩水中の塩素酸
塩の分解方法である。That is, the present invention is characterized in that salt water containing chlorate is brought into contact with hydrogen or a hydrogen-containing gas in the presence of a ruthenium or ruthenium oxide catalyst supported on granular or powdered activated carbon. This is a method for decomposing chlorate in salt water.
【００１０】[0010]
【発明の実施の形態】本発明の具体的手段は次のとおり
である。本発明で用いる触媒はルテニウムまたは酸化ル
テニウムである。塩素酸塩の分解は、触媒に吸蔵された
水素ガスが触媒表面に存在する塩素酸塩と、例えば式
（１）のように反応して起こる。 ＮａＣｌＯ3 ＋３Ｈ2 → ＮａＣｌ ＋ ３Ｈ2Ｏ （１） この反応速度は、触媒の吸蔵水素ガス量および反応温度
に依存する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific means of the present invention are as follows. The catalyst used in the present invention is ruthenium or ruthenium oxide. The decomposition of chlorate occurs when the hydrogen gas stored in the catalyst reacts with the chlorate present on the surface of the catalyst, for example, as in formula (1). NaClO 3 + 3H 2 → NaCl + 3H 2 O (1) The reaction rate depends on the amount of hydrogen gas stored in the catalyst and the reaction temperature.
【００１１】水素ガスを吸蔵する金属としては、ルテニ
ウム以外に、ニッケル、白金、パラジウム等の周期律表
第ＶＩＩＩ族の金属が挙げられる。しかしながら、本発
明者等が検討した結果、塩水中の塩素酸塩の分解に関し
ては、ルテニウムが著しく優れた効果を有していること
を見出した。Examples of the metal that stores hydrogen gas include metals of Group VIII of the periodic table, such as nickel, platinum, and palladium, in addition to ruthenium. However, as a result of the study by the present inventors, it has been found that ruthenium has a remarkably excellent effect on the decomposition of chlorate in salt water.
【００１２】本発明では、ルテニウムとして金属ルテニ
ウム以外に酸化ルテニウムも使用できる。しかしながら
酸化ルテニウムは結局のところ、水素により還元されて
金属ルテニウムとなり、塩素酸塩の分解反応に寄与する
ものであるから、敢えて酸化ルテニウムを使用しなくと
も良く、実際金属ルテニウムの方が分解効率が高く好ま
しい。In the present invention, ruthenium oxide can be used in addition to metal ruthenium as ruthenium. However, ruthenium oxide is ultimately reduced by hydrogen to metal ruthenium and contributes to the decomposition reaction of chlorate.Therefore, it is not necessary to use ruthenium oxide, and in fact, metal ruthenium has a higher decomposition efficiency. High and preferred.
【００１３】本発明は、ルテニウムまたは酸化ルテニウ
ム触媒を、特定形状の活性炭に担持させた点に特徴を有
する。即ち、粒状または粉末状のものが、不定形や板状
のものに比べ、塩素酸塩の分解速度が大きいため使用す
るものである。粒径は６００μｍ以下のものが塩素酸塩
の分解速度が大きいので好ましく、より好ましくは４０
０μｍ以下、特に好ましくは１００〜４００μｍの範囲
の粒状のものである。前述の特開昭５６−１６３２８６
号では、周期律第ＶＩＩＩ族にある金属及びその酸化物
から選ばれる１種又は２種以上からなる触媒を使用する
ものであるが、これら触媒が担体との組合わせにより反
応効率が異なる点についての開示はない。本発明者等
は、これらのうち、ルテニウム系触媒と活性炭との組み
合わせが、著しく反応効率が高くなることを見出し、加
えて、担持する活性炭が粒径３００μｍ程度の粒状のも
のがより広い範囲の条件で効率が高いことを発見した。The present invention is characterized in that a ruthenium or ruthenium oxide catalyst is supported on activated carbon having a specific shape. That is, a granular or powdery material is used because it has a higher chlorate decomposition rate than an amorphous or plate-like material. Particles having a particle size of not more than 600 μm are preferred because the decomposition rate of chlorate is high, and more preferably 40 μm or less.
Granules having a size of 0 μm or less, particularly preferably in the range of 100 to 400 μm. The aforementioned JP-A-56-163286.
In the above item, a catalyst consisting of one or more selected from metals and oxides thereof belonging to Group VIII of the periodic system is used. However, these catalysts differ in the reaction efficiency depending on the combination with the support. Is not disclosed. The present inventors have found that, among these, a combination of a ruthenium-based catalyst and activated carbon significantly increases the reaction efficiency, and in addition, the activated carbon to be supported has a granular form having a particle size of about 300 μm in a wider range. It was found that the efficiency was high under the conditions.
【００１４】ルテニウムを活性炭に担持させる方法とし
ては、ルテニウム塩の溶液に活性炭を浸漬した後、乾燥
させて加熱還元する方法等が挙げられる。ルテニウムま
たは酸化ルテニウムの活性炭に対する好ましい担持率
は、２質量％以上で、より好ましくは４質量％以上であ
る。２質量％未満では、分解反応が遅く実用的ではな
い。As a method for supporting ruthenium on activated carbon, there is a method in which activated carbon is immersed in a ruthenium salt solution, dried, and then reduced by heating. The preferable loading of ruthenium or ruthenium oxide on activated carbon is 2% by mass or more, more preferably 4% by mass or more. If it is less than 2% by mass, the decomposition reaction is slow and not practical.
【００１５】塩素酸塩の分解反応は、水素を用いるが純
粋な水素でなく、工業的に副生されたような水素含有ガ
スでも使用可能である。In the chlorate decomposition reaction, hydrogen is used, but not pure hydrogen, but also a hydrogen-containing gas which is industrially produced as a by-product.
【００１６】分解反応は２５℃以上で行えば良いが、本
発明によれば、後述の実施例にもあるように、５０℃で
６０％以上の反応率が得られる。電解槽からの戻り塩水
は概ね６５〜９５℃であるので、特に加熱することなく
高効率で塩素酸塩の分解が実施できることになる。分解
反応はｐＨが低い方が早く進行し、ｐＨ２．５以下とす
るのが好ましい。但し、ｐＨが１以下では、活性炭に担
持したルテニウムが溶出する恐れがあるので、好ましく
ない。The decomposition reaction may be carried out at 25 ° C. or higher. According to the present invention, a reaction rate of 60% or more can be obtained at 50 ° C., as described in Examples described later. Since the salt water returned from the electrolytic cell is approximately 65 to 95 ° C., the chlorate can be decomposed with high efficiency without particularly heating. The decomposition reaction proceeds faster when the pH is low, and is preferably adjusted to pH 2.5 or less. However, if the pH is 1 or less, ruthenium supported on activated carbon may elute, which is not preferable.
【００１７】なお、ルテニウムは塩酸酸性・酸素存在条
件でゆっくりと溶出する。このため、水素還元雰囲気下
で反応させることが必要である。また、活性炭自体も酸
性又は中性、６０℃以上でクロレートとの反応をおこ
し、塩素の存在下で反応が促進されるが、この反応は水
素還元反応に比べ非常に遅く、反応効率の向上には寄与
していない。Note that ruthenium elutes slowly under conditions of hydrochloric acid and oxygen. For this reason, it is necessary to carry out the reaction in a hydrogen reducing atmosphere. Activated carbon itself also reacts with chlorate at 60 ° C or higher in acidic or neutral conditions, and the reaction is promoted in the presence of chlorine. This reaction is much slower than the hydrogen reduction reaction, and the reaction efficiency is improved. Has not contributed.
【００１８】分解反応はバッチ式でも連続式でも可能だ
が、生産性の点から連続式が好ましい。連続式の場合、
塩水中の塩素酸塩濃度を一定に保つためには、イオン交
換膜法電解槽の陽極室での塩素酸塩生成量と分解反応に
よる分解量が等しくなるように負荷を決定することが好
ましい。このため、循環塩水のうち一部を抜き出しし、
分解装置で塩素酸塩を分解した後、塩水を循環系に戻す
方法が好ましい。抜き出しの比率は循環塩水に対して２
〜３０％、好ましくは２〜１０％の範囲である。The decomposition reaction can be performed in a batch system or a continuous system, but a continuous system is preferred from the viewpoint of productivity. In the case of continuous type,
In order to keep the chlorate concentration in the salt water constant, it is preferable to determine the load so that the amount of chlorate generated in the anode chamber of the ion exchange membrane electrolytic cell and the amount of decomposition by the decomposition reaction are equal. For this reason, a part of the circulating saline is extracted,
After the chlorate is decomposed by the decomposer, it is preferable to return the salt water to the circulation system. The extraction ratio is 2 for the circulating saline
-30%, preferably 2-10%.
【００１９】分解反応の反応器としては、槽型反応器・
充填層型反応器いずれも使用可能である。塩素酸塩分解
工程に供する塩水中の塩素酸塩の濃度は、あまり高いと
分解に時間を要し、分解しきれずに残る塩素酸塩が出て
くるため、２５ｇ／リットル以下が好ましく、更に１８
ｇ／リットル以下である。塩水に対する触媒の割合は多
い方が、塩素酸塩の分解速度が早くて好ましいが、多す
ぎると経済的でないので、分解の装置・条件等を加味し
て適宜定めるのが良い。As a reactor for the decomposition reaction, a tank-type reactor
Any packed bed type reactor can be used. If the concentration of chlorate in the salt water to be subjected to the chlorate decomposition step is too high, it takes time to decompose and chlorate remaining without being completely decomposed comes out.
g / liter or less. It is preferable that the ratio of the catalyst to the salt water be high, since the decomposition rate of the chlorate is high. However, if it is too high, it is not economical.
【００２０】本発明による塩素酸塩の分解方法の工程を
図１および２に示す。図１は、塩素酸塩の分解方法の工
程図の一例で、例えば主塩水循環系より一部を抜き出さ
れた塩水および水素を、触媒が必要量投入されている分
解装置１に供給する。内部温度は２５℃以上であれば特
に加熱しなくて良い。分解装置１で塩素酸塩が低減した
塩水/触媒混合液は触媒分離装置２に導入される。触媒
分離はデカンター・液体サイクロン等を使用することで
容易に実施できる。触媒分離装置２より分離された触媒
は分解装置１にリサイクルする。塩水は主塩水循環系に
返送する。分解装置１より放出される未反応の水素はリ
サイクル使用してもよいし、そのままパージしても良
い。The steps of the method for decomposing chlorate according to the present invention are shown in FIGS. FIG. 1 is an example of a process diagram of a method for decomposing chlorate. For example, salt water and hydrogen partially extracted from a main salt water circulation system are supplied to a decomposer 1 in which a required amount of a catalyst is charged. If the internal temperature is 25 ° C. or higher, there is no particular need for heating. The salt water / catalyst mixture having reduced chlorate in the cracker 1 is introduced into the catalyst separator 2. The catalyst can be easily separated by using a decanter, a liquid cyclone or the like. The catalyst separated from the catalyst separation device 2 is recycled to the decomposition device 1. Brine is returned to the main brine circulation system. Unreacted hydrogen released from the decomposition apparatus 1 may be recycled or may be purged as it is.
【００２１】図２は塩素酸塩分解装置１における塩水お
よび水素の流れを詳細に示した工程図である。塩水、水
素の供給方法は、共に下降流（Ａ）でも、上昇流（Ｂ）
でも、ガス液向流（Ｃ）でも良い。しかし、ガス液向流の
場合はガスは上昇流であるので分解効率が良く好まし
い。分解装置１内では触媒が保持されており、そこを塩
水と水素が互いに触媒と接触しながら通過するようにな
っている。FIG. 2 is a process diagram showing the flow of salt water and hydrogen in the chlorate decomposing apparatus 1 in detail. The method of supplying the salt water and hydrogen is either downward flow (A) or upward flow (B).
However, the gas liquid countercurrent (C) may be used. However, in the case of a gas liquid countercurrent, the gas is an upward flow, so that the decomposition efficiency is good and preferable. The catalyst is held in the cracking device 1, and the salt water and the hydrogen pass through the catalyst while being in contact with each other.
【００２２】[0022]
【作用】本発明の特定の活性炭に担持させたルテニウム
または酸化ルテニウム触媒が、単なるルテニウムまたは
酸化ルテニウムより、塩素酸塩の分解効率が遥かに高い
理由は定かではないが、当該活性炭による水素の高速吸
脱着・表面拡散現象により触媒に速やかに水素が供給さ
れるため、水素供給量が、前記式（１）で示される反応
に要する当量分となっているためと推定される。The reason why the ruthenium or ruthenium oxide catalyst supported on the specific activated carbon of the present invention has a much higher chlorate decomposition efficiency than simple ruthenium or ruthenium oxide is not clear, but it is not clear why the activated carbon converts hydrogen at a high rate. It is presumed that because hydrogen is quickly supplied to the catalyst due to the adsorption / desorption / surface diffusion phenomenon, the amount of hydrogen supplied is equivalent to the equivalent required for the reaction represented by the above formula (1).
【００２３】[0023]
【実施例】以下実施例により本発明を具体的に説明す
る。但し、本発明は実施例のみに限定されるものではな
い。The present invention will be described in detail with reference to the following examples. However, the present invention is not limited only to the examples.
【００２４】実施例１ 表１に示す種類の触媒各５．８ｇを容器に入れた。イオ
ン交換膜法電解の戻り塩水を脱塩素した、ＣｌＯ3 -濃度
６.４ｇ/リットルの食塩水５００ｍｌ（ｐＨ４〜５）を
入れ、攪拌して８０℃に安定させた。水素ガスを２リッ
トル／分吹き込んで２時間反応させた。塩水中の塩素酸
塩の濃度を測定し、反応率を表１に示した。Example 1 5.8 g of each of the catalysts of the type shown in Table 1 were placed in a container. The return water of the ion exchange membrane method electrolysis was dechlorinated, ClO 3 - Put concentration 6.4 g / l saline 500 ml (pH 4-5), were stabilized into stirred to 80 ° C.. Hydrogen gas was blown in at a rate of 2 liters / minute to react for 2 hours. The concentration of chlorate in the salt water was measured, and the reaction rates are shown in Table 1.
【００２５】[0025]
【表１】 [Table 1]
【００２６】実施例２ ＣｌＯ3 -濃度５ｇ/リットルの塩水１，０００ｍｌを容
器に入れ、触媒を4ｇ（但し、Ｒｕ／ジルコニア担体のみ
９ｇ）を添加した。液をｐＨ２に調整の後、攪拌して８
０℃に保ち、水素ガスを２リットル/分吹き込んで２時
間反応させた。塩水中の塩素酸塩の濃度を測定し、反応
率を表２に示した。[0026] Example 2 ClO 3 - concentration 5 g / l of saline 1,000ml placed in a container, the catalyst 4g (However, only 9 g Ru / zirconia support) was added. The solution was adjusted to pH 2 and stirred to 8
While maintaining the temperature at 0 ° C., hydrogen gas was blown in at a rate of 2 liters / minute to react for 2 hours. The chlorate concentration in the salt water was measured, and the reaction rates are shown in Table 2.
【００２７】[0027]
【表２】 [Table 2]
【００２８】実施例３ 表３記載の濃度の塩素酸塩を含む塩水３００ｍｌ（ｐＨ
＝２）と表３記載の触媒１００ｍｌ（担持率５質量％）
を混合し、２５℃または６０℃で水素を吹き込み５分間
反応させた。塩水中の塩素酸塩の濃度を測定し、反応率
を表３に示した。Example 3 300 ml of salt water containing chlorate at the concentration shown in Table 3 (pH
= 2) and 100 ml of the catalyst described in Table 3 (loading ratio 5% by mass)
Were mixed, and hydrogen was blown at 25 ° C. or 60 ° C. to cause a reaction for 5 minutes. The concentration of chlorate in the salt water was measured, and the reaction rates are shown in Table 3.
【００２９】[0029]
【表３】 [Table 3]
【００３０】実施例４ ＣｌＯ3 -濃度６ｇ/リットルの塩水を１，０００ｍｌ取
り、表４記載の触媒を混合し、液をｐＨ２に調整後、５
０℃に保ち、水素ガスを２リットル/分で吹込み２時間
反応させた。塩水中の塩素酸塩の濃度を測定し、反応率
を表４に示した。[0030] Example 4 ClO 3 - concentration 6 g / l of brine 1,000ml up by mixing the catalyst described in Table 4, after adjusting the liquid to pH 2, 5
While maintaining the temperature at 0 ° C., hydrogen gas was blown at a rate of 2 liters / minute and reacted for 2 hours. The concentration of chlorate in the salt water was measured, and the conversion was shown in Table 4.
【００３１】[0031]
【表４】 [Table 4]
【００３２】[0032]
【発明の効果】本発明によれば、イオン交換膜法電解槽
の戻り塩水等の塩素酸塩を含有する塩水から高効率で塩
素酸塩を除去することができ、イオン交換膜法電解の生
産性の向上に大いに寄与するものである。According to the present invention, it is possible to remove chlorate from chlorate-containing salt water such as return salt water of an ion exchange membrane method electrolytic cell with high efficiency. It greatly contributes to the improvement of performance.
【図１】 本発明の塩素酸塩の分解方法の工程の一例を
示す工程図である。FIG. 1 is a process chart showing an example of steps of a chlorate decomposition method of the present invention.
【図２】 塩素酸塩分解装置における塩水および水素の
流れを詳細に示した工程図である。FIG. 2 is a process diagram showing in detail the flows of salt water and hydrogen in the chlorate decomposition apparatus.
１ 塩素酸塩分解装置 ２ 触媒分離装置 ３ 塩水 ４ 水素ガス ５ 触媒 DESCRIPTION OF SYMBOLS 1 Chlorate decomposition apparatus 2 Catalyst separation apparatus 3 Salt water 4 Hydrogen gas 5 Catalyst
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 4G069 AA03 AA08 BA08A BA08B BB02A BB02B BB04A BB04B BC70A BC70B CB81 DA06 EB18X EB18Y FA02 FB44 4K021 BA03 BC02 BC03 CA15 DB31 EA09 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G069 AA03 AA08 BA08A BA08B BB02A BB02B BB04A BB04B BC70A BC70B CB81 DA06 EB18X EB18Y FA02 FB44 4K021 BA03 BC02 BC03 CA15 DB31 EA09
Claims (3)
粉状の活性炭に担持させたルテニウムまたは酸化ルテニ
ウム触媒の存在下に、水素または水素含有ガスと接触せ
しめることを特徴とする塩水中の塩素酸塩の分解方法。Claims: 1. A method of bringing a chlorate-containing salt water into contact with hydrogen or a hydrogen-containing gas in the presence of a ruthenium or ruthenium oxide catalyst supported on granular or powdered activated carbon. How to decompose chlorate.
のである請求項１の塩水中の塩素酸塩の分解方法。2. The method for decomposing chlorate in salt water according to claim 1, wherein the granular activated carbon has a particle size of 600 μm or less.
膜法塩化アルカリ電解槽に供給される塩水である請求項
１または２の塩水中の塩素酸塩の分解方法。3. The method for decomposing chlorate in salt water according to claim 1 or 2, wherein the salt water containing chlorate is salt water supplied to an ion-exchange membrane method alkaline chloride electrolytic cell.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000185370A JP2002004075A (en) | 2000-06-20 | 2000-06-20 | Method for decomposing chlorate in saline water |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000185370A JP2002004075A (en) | 2000-06-20 | 2000-06-20 | Method for decomposing chlorate in saline water |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002004075A true JP2002004075A (en) | 2002-01-09 |
Family
ID=18685698
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000185370A Pending JP2002004075A (en) | 2000-06-20 | 2000-06-20 | Method for decomposing chlorate in saline water |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102634813A (en) * | 2012-03-19 | 2012-08-15 | 山东东岳氟硅材料有限公司 | Method for increasing chlorate decomposition efficiency |
| CN104651878A (en) * | 2014-11-20 | 2015-05-27 | 新疆中泰化学股份有限公司 | Alkali liquor deoxidizing device, alkali liquor continuous deoxidizing device and using methods of devices |
-
2000
- 2000-06-20 JP JP2000185370A patent/JP2002004075A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102634813A (en) * | 2012-03-19 | 2012-08-15 | 山东东岳氟硅材料有限公司 | Method for increasing chlorate decomposition efficiency |
| CN104651878A (en) * | 2014-11-20 | 2015-05-27 | 新疆中泰化学股份有限公司 | Alkali liquor deoxidizing device, alkali liquor continuous deoxidizing device and using methods of devices |
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