JP2004105864A - Method, catalyst and equipment for decomposing halogenated aromatic hydrocarbon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To decompose a halogenated aromatic hydrocarbon at one step without producing harmful by-products. <P>SOLUTION: A gaseous halogenated aromatic hydrocarbon is decomposed and converted into a hydrogen halide, carbon monoxide and/or carbon dioxide by adding hydrogen and steam to the gaseous halogenated aromatic hydrocarbon and bringing the hydrogen/steam-added hydrocarbon at a temperature of 300-600°C into contact with a catalyst obtained by depositing at least one active component selected from among Mo, W, Cr, Fe, Co, Ni, V, Pt, Pd, Rh and Ru on a carrier consisting of any of alumina, alumina-silica and mordenite. The gaseous halogenated aromatic hydrocarbon can be converted at one step into a hydrogen halide, carbon monoxide and/or carbon dioxide by adding hydrogen and steam to the gaseous halogenated aromatic hydrocarbon. <P>COPYRIGHT: (C)2004,JPO

Description

【００３８】
触媒は次のようにして調製した。
【００３９】
＜触媒４＞　Ｎｉ／Ａｌ_２Ｏ_３触媒
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１１００℃で５ｈ焼成し、αＡｌ_２Ｏ_３化させた。このアルミナ１００．００ｇ　に対し、仕込み量としてＮｉが１０ｗｔ％となるように、硝酸ニッケル６水和物（和光純薬）４９．５５ｇ　を純水に溶かして含浸した。含浸後、１２０℃で２ｈ乾燥させ、６５０℃で２ｈ焼成した。焼成後の触媒中のＮｉは酸化物となっているため、Ｈ_２　気流中で還元処理を行い、Ｎｉ酸化物をＮｉ金属に還元した。
【００４０】
結果を図５に示す。クロロベンゼン分解率に示される脱塩素反応については、反応温度４２５℃でほぼ１００％反応を達成することができた。ベンゼン分解については、反応温度４２５℃以下では分解率が低いが、５００℃で完全に分解することが判った。なお、分解生成物としては、ＨＣｌ，ＣＯ，ＣＨ_４　，Ｈ_２　，ＣＯ_２　が検出された。
【００４１】
［実施例３］
本実施例では、Ｎｉ以外の触媒活性成分の性能を調べた。実施例１と同様に、図１に示す試験装置を用いた。原料としてクロロベンゼンを用い、クロロベンゼン量を０．１１〜０．１５（ｍｏｌ／ｈ）、Ｈ_２　／クロロベンゼンモル比を１９〜２０、Ｈ_２Ｏ　／クロロベンゼンモル比を８〜１２、空間速度（ＳＶ）を２８６０〜３０５０ｈ^−１とし、この条件で反応温度４１０℃でのクロロベンゼン分解率を測定した。クロロベンゼン分解率は前述の算出式で求めた。触媒は次のようにして調製した。
【００４２】
＜触媒５＞　Ｐｔ／Ａｌ_２Ｏ_３触媒
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１２０℃で１ｈ乾燥させた。乾燥後のアルミナ５０．００ｇ　に対し、仕込み量としてＰｔがＡｌ_２Ｏ_３重量に対し１ｗｔ％となるよう１．４５９ｗｔ％　四価−アンミン溶液（田中貴金属製）３４．２７ｇ　を純水で希釈して３５ｇとしたＰｔ水溶液を含浸した。含浸後、１２０℃で２ｈ乾燥させ、６５０℃で２ｈ焼成した。
【００４３】
＜触媒６＞　Ｒｈ／シリカ−アルミナ触媒
ＳｉＯ_２／Ａｌ_２Ｏ_３（日揮化学製，Ｎ６３２Ｌ，３φ×３Ｌ）を１２０℃で１ｈ乾燥させた。乾燥後のＳｉＯ_２／Ａｌ_２Ｏ_３５０．００ｇに対し、仕込み量としてＲｈがＳｉＯ_２／Ａｌ_２Ｏ_３重量に対し１ｗｔ％となるよう４．４８５ｗｔ％Ｒｈ硝酸溶液（田中貴金属製）１１．１５ｇを純水で希釈して２８．００ｇとしたＲｈ水溶液を含浸した。含浸後、１２０℃で２ｈ乾燥させ、６５０℃で２ｈ焼成した。
【００４４】
＜触媒７＞　Ｒｕ／シリカ−アルミナ触媒
ＳｉＯ_２／Ａｌ_２Ｏ_３（日揮化学製，Ｎ６３２Ｌ，３φ×３Ｌ）を１２０℃で１ｈ乾燥させた。乾燥後のＳｉＯ_２／Ａｌ_２Ｏ_３５０．００ｇに対し、仕込み量としてＲｕがＳｉＯ_２／Ａｌ_２Ｏ_３重量に対し２ｗｔ％となるよう３．８８９ｗｔ％Ｒｕ硝酸溶液（田中貴金属製）１２．８６ｇを純水で希釈して２８．００ｇとしたＲｕ水溶液を含浸した。含浸後、１２０℃で２ｈ乾燥させ、６５０℃で２ｈ焼成した。
【００４５】
＜触媒８＞　Ｍｏ／Ａｌ_２Ｏ_３触媒
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１２０℃で１ｈ乾燥させた。乾燥後のアルミナ５０．００ｇ　に対し、仕込み量としてＭｏがＡｌ_２Ｏ_３重量に対し１０ｗｔ％となるようモリブデン酸アンモニウム（和光純薬）９．１８ｇ　を純水で溶解して３５ｇとしたＭｏ水溶液を含浸した。含浸後、１２０℃で２ｈ乾燥させ、６５０℃で２ｈ焼成した。
【００４６】
＜触媒９＞　Ｗ／Ａｌ_２Ｏ_３触媒
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１２０℃で１ｈ乾燥させた。乾燥後のアルミナ５０．００ｇ　に対し、仕込み量としてＷがＡｌ_２Ｏ_３重量に対し１０ｗｔ％となるようタングステン酸アンモニウムパラ５水和物（和光純薬）７．０５ｇ　を純水で溶解して３５ｇとしたＷ水溶液を含浸した。含浸後、１２０℃で２ｈ乾燥させ、６５０℃で２ｈ焼成した。
【００４７】
＜触媒１０＞　Ｃｒ／Ａｌ_２Ｏ_３触媒
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１２０℃で１ｈ乾燥させた。乾燥後のアルミナ５０．００ｇ　に対し、仕込み量としてＦｅがＡｌ_２Ｏ_３重量に対し５ｗｔ％となるよう硝酸クロム９水和物（和光純薬）１９．２１ｇを純水で溶解して３５ｇとしたＣｒ水溶液を含浸した。含浸後、１２０℃で２ｈ乾燥させ、６５０℃で２ｈ焼成した。
【００４８】
＜触媒１１＞　Ｆｅ／モルデナイト触媒
モルデナイト（東ソー製，６４０ＨＯＡ，１．５ｍｍペレット）を１２０℃で１ｈ乾燥させた。乾燥後のモルデナイト５０．００ｇ　に対し、仕込み量としてＦｅがモルデナイト重量に対し５ｗｔ％となるよう硝酸鉄９水和物（和光純薬）１８．１０ｇを純水で溶解して３５ｇとしたＦｅ水溶液を含浸した。含浸後、１２０℃で２ｈ乾燥させ、６５０℃で２ｈ焼成した。
【００４９】
＜触媒１２＞　Ｃｏ／モルデナイト触媒
モルデナイト（東ソー製，６４０ＨＯＡ，１．５ｍｍペレット）を１２０℃で１ｈ乾燥させた。乾燥後のモルデナイト５０．００ｇ　に対し、仕込み量としてＦｅがモルデナイト重量に対し５ｗｔ％となるよう硝酸コバルト６水和物（和光純薬）１２．３４ｇ　を純水で溶解して３５ｇとしたＣｏ水溶液を含浸した。含浸後、１２０℃で２ｈ乾燥させ、６５０℃で２ｈ焼成した。
【００５０】
結果を表２に示す。
【００５１】
【表２】

【００５２】
［実施例４］
本実施例では、Ｎｉ量の影響を調べた。触媒は触媒４，触媒４−１，触媒４−２のＮｉ／Ａｌ_２Ｏ_３触媒を用いた。実施例１と同様に、図１に示す試験装置を用いた。原料としてクロロベンゼンを用い、表３に示す条件で、クロロベンゼン及びベンゼン分解率を測定した。分解率算出式は前述のとおりである。結果を図６に示す。触媒４−２では、反応温度４１０℃でクロロベンゼン分解率が９９．９％以上、ベンゼン分解率が８９．４％　となった。また、反応温度を４５０℃で、これらの触媒を用いると、クロロベンゼン分解率，ベンゼン分解率とも向上し、触媒４−２では、いずれも９９．９％　分解した。
【００５３】
【表３】

【００５４】
使用した触媒は次のようにして調製した。
【００５５】
＜触媒４−１＞
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１１００℃で５ｈ焼成し、αＡｌ_２Ｏ_３化させた。このアルミナ６５．０５ｇ　に対し、仕込み量としてＮｉが２０ｗｔ％となるように、硝酸ニッケル６水和物（和光純薬）６４．４１ｇを純水２１．６２ｇに溶かして含浸した。含浸後、１２０℃で１ｈ乾燥させ、６５０℃で２ｈ焼成した。焼成後の触媒中のＮｉは酸化物となっているため、Ｈ_２　気流中で還元処理を行い、Ｎｉ酸化物をＮｉ金属に還元した。
【００５６】
＜触媒４−２＞
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１１００℃で５ｈ焼成し、αＡｌ_２Ｏ_３化させた。このアルミナ６５．０８ｇ　に対し、仕込み量としてＮｉが４０ｗｔ％となるように、硝酸ニッケル６水和物（和光純薬）１２８．８０ｇを純水４３．２０ｇに溶かして含浸した。含浸は、数回に分けて行った。まず、ニッケル溶液５５ｍｌを含浸し、１２０℃で１ｈ乾燥した。その後、ニッケル溶液２８ｍｌを含浸、１２０℃で３ｈ乾燥して６５０℃で１ｈ焼成した。焼成後、残りのニッケル溶液２７ｍｌを含浸し、１２０℃で１ｈ乾燥して６５０℃で２ｈ焼成した。この触媒中のＮｉは酸化物となっているため、Ｈ_２　気流中で還元処理を行い、Ｎｉ酸化物をＮｉ金属に還元した。
【００５７】
［実施例５］
本実施例では、３成分系触媒の影響を調べた。実施例１と同様に、図１に示す試験装置を用いた。原料としてクロロベンゼンを用い、表４に示す条件でクロロベンゼン及びベンゼン分解率を測定した。クロロベンゼン及びベンゼン分解率は前述の算出式で求めた。分解率の結果を表５に示す。
【００５８】
【表４】

【００５９】
【表５】

【００６０】
Ｎｉ／Ａｌ触媒にＰｔ，Ｐｄ，Ｖ，Ｃｏ，Ｌａ，Ｋをそれぞれ添加した触媒も高い分解率を示した。ただし、触媒２４のＬａ添加触媒，触媒２５のＫ添加触媒は、試験後の触媒中にＣｌが検出された。
【００６１】
触媒２０−２５は次のようにして調製した。
【００６２】
＜触媒２０＞　Ｐｔ／Ｎｉ／Ａｌ_２Ｏ_３
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１１００℃で５ｈ焼成し、αＡｌ_２Ｏ_３化させた。このアルミナ６５．００ｇ　に対し、仕込み量としてＮｉが２０ｗｔ％となるように、硝酸ニッケル６水和物（和光純薬）６４．４１ｇ　を純水２１．５８ｇ　に溶かして含浸した。含浸後、１２０℃で１ｈ乾燥させ、６５０℃で２ｈ焼成した。焼成後の触媒６５．００ｇ　に３０８ｍｇ／ｇ塩化白金酸２．０９７ｇ　を純水を添加して２９．２６ｇ　とした。これを含浸し、１２０℃で１ｈ乾燥し、６５０℃で２ｈ焼成した。焼成後の触媒中のＮｉは酸化物となっているため、Ｈ_２　気流中で還元処理を行い、Ｎｉ酸化物をＮｉ金属に還元した。
【００６３】
＜触媒２１＞　Ｐｄ／Ｎｉ／Ａｌ_２Ｏ_３
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１１００℃で５ｈ焼成し、αＡｌ_２Ｏ_３化させた。このアルミナ６５．００ｇ　に対し、仕込み量としてＮｉが２０ｗｔ％となるように、硝酸ニッケル６水和物（和光純薬）６４．４１ｇを純水２１．５８ｇに溶かして含浸した。含浸後、１２０℃で１ｈ乾燥させ、６５０℃で２ｈ焼成した。焼成後の触媒６５．０２ｇに４．４２２ｗｔ％Ｐｄ硝酸溶液１４．６９９ｇを純水を添加して２９．２６ｇとした。これを含浸し、１２０℃で１ｈ乾燥し、６５０℃で２ｈ焼成した。焼成後の触媒中のＮｉは酸化物となっているため、Ｈ_２　気流中で還元処理を行い、Ｎｉ酸化物をＮｉ金属に還元した。
【００６４】
＜触媒２２＞　Ｖ／Ｎｉ／Ａｌ_２Ｏ_３
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１１００℃で５ｈ焼成し、αＡｌ_２Ｏ_３化させた。このアルミナ６５．０５ｇに対し、仕込み量としてＮｉが２０ｗｔ％となるように、硝酸ニッケル６水和物（和光純薬）６４．４１ｇを純水２１．６２ｇに溶かして含浸した。含浸後、１２０℃で１ｈ乾燥させ、６５０℃で２ｈ焼成した。焼成後の触媒６５．７５ｇ　に対し、仕込み量としてＶが１ｗｔ％となるように、バナジン酸アンモニウム（和光純薬）１．４９ｇを３０％過酸化水素水５ｍｌに溶かし、さらに３０ｇの純水を添加した後に含浸した。含浸後、１２０℃で１ｈ乾燥させ、５００で２ｈ焼成した。焼成後の触媒中のＮｉは酸化物となっているため、Ｈ_２　気流中で還元処理を行い、Ｎｉ酸化物をＮｉ金属に還元した。
【００６５】
＜触媒２３＞　Ｃｏ／Ｎｉ／Ａｌ_２Ｏ_３
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１１００℃で５ｈ焼成し、αＡｌ_２Ｏ_３化させた。このアルミナ６５．０５ｇ　に対し、仕込み量としてＮｉが２０ｗｔ％となるように、硝酸ニッケル６水和物（和光純薬）６４．４１ｇを純水２１．６２ｇに溶かして含浸した。含浸後、１２０℃で１ｈ乾燥させ、６５０℃で２ｈ焼成した。焼成後の触媒６５．１３ｇ　に対し、仕込み量としてＣｏが５ｗｔ％となるように、硝酸コバルト６水和物（和光純薬）１６．０４ｇを純水２９．９５ｇ　に溶かして含浸した。含浸後、１２０℃で１ｈ乾燥させ、６５０℃で２ｈ焼成した。焼成後の触媒中のＮｉは酸化物となっているため、Ｈ_２　気流中で還元処理を行い、Ｎｉ酸化物をＮｉ金属に還元した。
【００６６】
＜触媒２４＞　Ｌａ／Ｎｉ／Ａｌ_２Ｏ_３
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１１００℃で５ｈ焼成し、αＡｌ_２Ｏ_３化させた。このアルミナ６５．００ｇ　に対し、仕込み量としてＮｉが２０ｗｔ％、Ｌａが６ｗｔ％となるように、硝酸ニッケル６水和物（和光純薬）６４．５５ｇと硝酸ランタン６水和物１２．１７ｇを純水２７．９５ｇに溶かして含浸した。なお、含浸は２回に分けて行い、１回目の含浸後、１２０℃で１ｈ乾燥し、再度含浸した。含浸後、１２０℃で１．５ｈ　乾燥させ、６５０℃で２ｈ焼成した。焼成後の触媒中のＮｉは酸化物となっているため、Ｈ_２　気流中で還元処理を行い、Ｎｉ酸化物をＮｉ金属に還元した。
【００６７】
＜触媒２５＞　Ｋ／Ｎｉ／Ａｌ_２Ｏ_３
活性アルミナ（住友科学製，ＮＫＨＤ−２４，粒径２−４ｍｍ）を１１００℃で５ｈ焼成し、αＡｌ_２Ｏ_３化させた。このアルミナ６４．５５ｇ　に対し、仕込み量としてＮｉが２０ｗｔ％、Ｋが６ｗｔ％となるように、硝酸ニッケル６水和物
（和光純薬）６４．５５ｇと硝酸カリウム１０．０８ｇを純水２７．９５ｇに溶かして含浸した。なお、含浸は２回に分けて行い、１回目の含浸後、１２０℃で１ｈ乾燥し、再度含浸した。含浸後、１２０℃で１．５ｈ　乾燥させ、６５０℃で２ｈ焼成した。焼成後の触媒中のＮｉは酸化物となっているため、Ｈ_２　気流中で還元処理を行い、Ｎｉ酸化物をＮｉ金属に還元した。
【００６８】
［実施例６］
本実施例は、Ｐｄ／Ａｌ_２Ｏ_３触媒を外径１．２ｍｍφのアルミナ棒にコートし、図２に示す反応器内に設置し、図３に示す試験装置で分解を行った結果である。触媒は次のようにして調製した。
【００６９】
＜触媒１３＞　Ｐｄ／Ａｌ_２Ｏ_３触媒
アルミナゾル（日産化学製，アルミナゾル−５２０）をマイクロチューブポンプで吸引し、外径１．２ｍｍφ，内径１．０ｍｍφのＡｌ_２Ｏ_３棒内部を通過させ、内表面をアルミナゾルコートした。１２０℃で０．５ｈ　乾燥し、６５０℃で１ｈ焼成した。Ａｌ_２Ｏ_３ゾルをコートしたＡｌ_２Ｏ_３棒に、Ａｌ_２Ｏ_３スラリをコートした。Ａｌ_２Ｏ_３スラリは、前述のＡｌ_２Ｏ_３ゾル１０ｇにベーマイト（ＣＯＮＤＥＡ製　ＰＵＲＡＬＳＢ１）１．５ｇを攪拌しながら混合して調製した。このスラリをマイクロチューブポンプを用いてＡｌ_２Ｏ_３棒内表面にコートした。コート後、１２０℃で０．５ｈ乾燥させ、６５０℃で１ｈ焼成した。このＡｌ_２Ｏ_３棒に４．４２２ｗｔ％Ｐｄ硝酸溶液（田中貴金属製）をマイクロチューブポンプで通過させて、内表面にコートされたＡｌ_２Ｏ_３層に含浸した。Ｐｄ硝酸溶液をコートしたＡｌ_２Ｏ_３棒を１２０℃で０．５ｈ乾燥させ、６５０℃で２ｈ焼成した。
【００７０】
＜触媒１４＞　Ｎｉ／Ａｌ_２Ｏ_３触媒
アルミナゾル（日産化学製，アルミナゾル−５２０）をマイクロチューブポンプで吸引し、外径１．２ｍｍφ，内径１．０ｍｍφのＡｌ_２Ｏ_３棒内部を通過させ、内表面をコートした。さらに、外表面にもアルミナゾルをコートし、１２０℃で０．５ｈ乾燥し、６５０℃で１ｈ焼成した。Ａｌ_２Ｏ_３ゾルをコートしたＡｌ_２Ｏ_３棒に、次にＡｌ_２Ｏ_３スラリをコートした。Ａｌ_２Ｏ_３スラリは、前述のＡｌ_２Ｏ_３ゾル１０ｇにベーマイト（ＣＯＮＤＥＡ製　ＰＵＲＡＬＳＢ１）１．５ｇを攪拌しながら混合して調製した。このスラリをマイクロチューブポンプを用いてＡｌ_２Ｏ_３棒内表面にコートした。ゾルコートと同様に、外表面にもアルミナスラリをコートした。コート後、１２０℃で０．５ｈ　乾燥させ、１１００℃で１ｈ焼成した。このＡｌ_２Ｏ_３棒に４．４２２ｗｔ％Ｐｄ硝酸溶液（田中貴金属製）をマイクロチューブポンプで通過させて、内表面にコートされたＡｌ_２Ｏ_３層に含浸した。外表面にもコートした。Ｐｄ硝酸溶液をコートしたＡｌ_２Ｏ_３棒を１２０℃で０．５ｈ　乾燥させ、６５０℃で２ｈ焼成した。
【００７１】
分解率はクロロベンゼン（ＣＢ）量，ベンゼン（Ｂ）量から算出した。
【００７２】
分解率（％）＝（１−（出口ＣＢ＋出口Ｂ量（ｍｏｌ／ｈ））／入口ＣＢ量（ｍｏｌ／ｈ））×１００
出口ＣＢ量（ｍｏｌ／ｈ）＝排ガス中のＣＢ量＋第一吸収槽及び第二吸収槽のＣＢ量出口Ｂ量（ｍｏｌ／ｈ）＝排ガス中のＢ量＋第一吸収槽及び第二吸収槽のＢ量
結果を表６に示す。
【００７３】
【表６】

【００７４】
触媒１３は分解率５６．２４％、触媒１４では約７０％分解できることが判った。これは、図２に示す反応器の触媒充填部分が直方体であるため、触媒５では触媒がコートされていない外表面部分を反応ガスの一部が通過してしまうためと考えられた。外表面にも触媒をコートした触媒１４では分解率が向上したことから、反応器の触媒充填部分の構造を改良すればさらに高い分解率が得られると考えられる。
【００７５】
［実施例７］
本実施例では、Ｎｉ／Ａｌ_２Ｏ_３触媒を外径１．２ｍｍφ　のアルミナ棒にコートし、図２に示す反応器内に設置し、図３に示す試験装置で分解を行った。触媒は次のようにして調製した。分解率はクロロベンゼン（ＣＢ）量，ベンゼン（Ｂ）量から算出した。
【００７６】
分解率（％）＝（１−（出口ＣＢ＋出口Ｂ量（ｍｏｌ／ｈ））／入口ＣＢ量（ｍｏｌ／ｈ））×１００
出口ＣＢ量（ｍｏｌ／ｈ）＝排ガス中のＣＢ量＋第一吸収槽及び第二吸収槽のＣＢ量
出口Ｂ量（ｍｏｌ／ｈ）＝排ガス中のＢ量＋第一吸収槽及び第二吸収槽のＢ量
＜触媒１５＞　Ｎｉ／Ａｌ_２Ｏ_３触媒
アルミナゾル（日産化学製，アルミナゾル−５２０）をマイクロチューブポンプで吸引し、外径１．２ｍｍφ，内径１．０ｍｍφのＡｌ_２Ｏ_３棒内部を通過させ、内表面をアルミナゾルコートした。１２０℃で０．５ｈ　乾燥し、６５０℃で１ｈ焼成した。Ａｌ_２Ｏ_３ゾルをコートしたＡｌ_２Ｏ_３棒に、Ａｌ_２Ｏ_３スラリをコートした。Ａｌ_２Ｏ_３スラリは、前述のＡｌ_２Ｏ_３ゾル１０ｇにベーマイト（ＣＯＮＤＥＡ製　ＰＵＲＡＬＳＢ１）１．５ｇを攪拌しながら混合して調製した。このスラリをマイクロチューブポンプを用いてＡｌ_２Ｏ_３棒内表面にコートした。コート後、１２０℃で０．５ｈ　乾燥させ、１１００℃で１ｈ焼成した。このＡｌ_２Ｏ_３棒に硝酸ニッケル水溶液をマイクロチューブポンプで通過させて、内表面にコートされたＡｌ_２Ｏ_３層に含浸した。硝酸ニッケル水溶液は、硝酸ニッケル６水和物６３．３９ｇを純水５０ｍｌに溶かして調製した。仕込み量から算出したＮｉ量はＮｉ／Ａｌ_２Ｏ_３触媒中１１．３ｗｔ％　となる。Ｎｉ水溶液をコートしたＡｌ_２Ｏ_３棒を１２０℃で０．５ｈ　乾燥させ、６５０℃で２ｈ焼成した。
【００７７】
＜触媒１６＞　Ｎｉ／Ａｌ_２Ｏ_３触媒
アルミナゾル（日産化学製，アルミナゾル−５２０）をマイクロチューブポンプで吸引し、外径１．２ｍｍφ　，内径１．０ｍｍφのＡｌ_２Ｏ_３棒内部を通過させ、内表面をコートした。さらに、外表面にもアルミナゾルをコートし、１２０℃で０．５ｈ　乾燥し、６５０℃で１ｈ焼成した。Ａｌ_２Ｏ_３ゾルをコートしたＡｌ_２Ｏ_３棒に、次にＡｌ_２Ｏ_３スラリをコートした。Ａｌ_２Ｏ_３スラリは、前述のＡｌ_２Ｏ_３ゾル１０ｇにベーマイト（ＣＯＮＤＥＡ製　ＰＵＲＡＬＳＢ１）１．５ｇを攪拌しながら混合して調製した。このスラリをマイクロチューブポンプを用いてＡｌ_２Ｏ_３棒内表面にコートした。ゾルコートと同様に、外表面にもアルミナスラリをコートした。コート後、１２０℃で０．５ｈ　乾燥させ、１１００℃で１ｈ焼成した。このＡｌ_２Ｏ_３棒に硝酸ニッケル水溶液をマイクロチューブポンプで通過させて、内表面にコートされたＡｌ_２Ｏ_３層に含浸した。外表面にもコートした。硝酸ニッケル水溶液は、硝酸ニッケル６水和物６３．３９ｇ　を純水５０ｍｌに溶かして調製した。仕込み量から算出したＮｉ量はＮｉ／Ａｌ_２Ｏ_３触媒中１１．３ｗｔ％　となる。Ｎｉ水溶液をコートしたＡｌ_２Ｏ_３棒を１２０℃で０．５ｈ乾燥させ、６５０℃で２ｈ焼成した。
【００７８】
触媒１５は分解率６０％、触媒１６は９０％分解できることが判った。これは、実施例５と同様に触媒１５では触媒がコートされていない外表面部分を反応ガスの一部が通過してしまうためと考えられた。外表面にも触媒をコートした触媒１６では分解率が向上したことから、反応器の触媒充填部分の構造を改良すればさらに高い分解率が得られると考えられる。
【００７９】
【発明の効果】
本発明によれば、ＰＣＢ等のハロゲン化芳香族炭化水素を一段の処理にて有害な副生物を生ずることなく分解することができる。
【図面の簡単な説明】
【図１】本発明の一実施例を示す処理装置のシステム構成図。
【図２】本発明で使用されるマイクロリアクタの一実施例を示す上面図と側面図。
【図３】本発明の他の実施例を示す処理装置のシステム構成図。
【図４】本発明の触媒の性能を示す図。
【図５】本発明の触媒の性能を示す図。
【図６】本発明の触媒の性能を示す図。
【符号の説明】
１…ハロゲン化芳香族炭化水素、２…純水、３…水素、４…窒素、５…加熱器、６…触媒反応器、７…触媒、８…電気炉、９…分解ガス吸収槽、１０…ミストキャッチャ、１１…活性炭槽、１２…反応ガス入口、１３…分解ガス出口、１４…冷却媒体入口、１５…冷却媒体出口、１６…アルミナ棒、１７…触媒層、１８…バッファスペース、１９…加熱装置。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method, a catalyst and a cracking device for cracking a halogenated aromatic hydrocarbon by contacting the catalyst with a catalyst.
[0002]
[Prior art]
The treatment of halogenated aromatic hydrocarbons as an environmental pollutant has been studied in various ways. To date, a sodium metal dispersion method, a chemical extraction decomposition method, an organic alkali metal decomposition method, a catalytic hydrogen reduction method, and the like have been known.
[0003]
JP-A-6-226046 discloses that a volatile organic halogen compound is once adsorbed on an adsorbent, a saturated adsorbent is regenerated with steam, and then a regenerated waste liquid obtained by condensation is directly used or an aerated gas is used in the presence of a metal catalyst. Describes a method of contacting with a reducing agent at room temperature. This method is a dehalogenation cracking that removes only halogen from a halogenated aromatic hydrocarbon.
[0004]
In addition, JP-A-9-880 discloses a method for decomposing an organic halogen compound using a catalyst.
[0005]
[Problems to be solved by the invention]
In the method described in JP-A-6-226046, it is necessary to treat a dehalogenated aromatic hydrocarbon.
[0006]
An object of the present invention is to provide a method, a catalyst and a decomposition apparatus for decomposing halogenated aromatic hydrocarbons without generating harmful by-products.
[0007]
[Means for Solving the Problems]
The process of the present invention comprises adding hydrogen and steam to a gaseous halogenated aromatic hydrocarbon and contacting the gas stream with a catalyst to convert the halogenated aromatic hydrocarbon to hydrogen halide, carbon monoxide and carbon dioxide. At least one of the following.
[0008]
The catalyst of the present invention uses a carrier selected from alumina, alumina-silica, and mordenite as a support, and further comprises a carrier selected from Mo, W, Cr, Fe, Co, Ni, V, Pt, Pd, Rh, and Ru. At least one of a metal or an oxide containing at least one of Mo, W, Cr, Fe, Co, Ni and V in a total amount of 0.5 to 50 wt%, and at least one of Pt, Pd, Rh and Ru The total content is 0.1 to 3 wt%. A carrier selected from the group consisting of alumina, alumina-silica, and mordenite is used as a carrier, and at least one selected from the group consisting of Mo, W, Cr, Fe, Co, Ni, and V is used as a metal or oxide. The total content is 0.5% to 50% by weight (% by weight), and at least one selected from the group consisting of Pt, Pd, Rh and Ru is 0.1% to 3% by weight as a metal or oxide.
[0009]
The cracking device of the present invention includes a hydrogen supplier for adding hydrogen to a gaseous halogenated aromatic hydrocarbon, a steam supplier for adding steam, and a halogenated aromatic hydrocarbon to which the hydrogen and steam are added. The present invention has a catalyst reactor for decomposing by contacting with a catalyst, and an exhaust gas cleaning device for cleaning decomposition products generated in the catalyst reactor with water or an alkaline aqueous solution.
[0010]
Initially, we will use normal pressure, reaction temperature 500 ° C, H₂The decomposition of halogenated aromatic hydrocarbons was examined using with 18 to 22 times the amount of halogen in the halogenated aromatic hydrocarbon and steam with 1 to 3 times the carbon amount in chlorobenzene. In this case, although the halogenated aromatic hydrocarbon was dehalogenated, the decomposition rate of the aromatic hydrocarbon was found to be low. Various catalysts were evaluated. Dehalogenation was easy, but aromatic hydrocarbons hardly decomposed. However, it has been found that by supplying a predetermined amount of steam together with hydrogen during the decomposition reaction, benzene and the like, which are intermediate products of the halogenated aromatic hydrocarbon decomposition reaction, can be simultaneously decomposed. The amount of water vapor to be added is extremely important, and if the amount is small, the decomposition rate decreases.
[0011]
The effect of adding steam is considered as follows. The following is an example of a chlorobenzene decomposition reaction. H₂If only, only equation (1) proceeds and H₂When the amount of O is small
C generated without sufficiently progressing the equation (2)₆H₆Causes cracking. But H₂It is considered that by adding O in an optimal amount, the equations (1) to (3) occur, and complete decomposition is achieved. Depending on the reaction conditions, as shown in equation (4), some CH₄In some cases, such hydrocarbons are generated.
[0012]
C₆H₅Cl + H₂→ C₆H₆{+} HCl} ... (1)
C₆H₆+ 6H₂O →→ 6CO + 9H₂… (2)
CO + H₂O → CO₂+ H₂… (3)
CO₂+ 2H₂→ CH₄+ O₂… (4)
In the present invention, it is desirable that the catalyst and the reaction gas be brought into contact at 300 to 600 ° C. When the temperature is lower than 300 ° C., sufficient decomposition performance cannot be obtained. If the temperature is 600 ° C. or higher, cracking is likely to occur, and carbon and the like are deposited.
[0013]
H₂The amount is preferably from 10 mol% to 30 mol%, more preferably from 15 mol% to 25 mol%, based on the halogen amount in the halogenated aromatic hydrocarbon. As for the amount of water vapor, the S / C (water vapor / carbon) ratio is desirably 5 mol% or more and 50 mol% or less, preferably 7 mol% or more and 15 mol% or less, based on the carbon amount in the halogenated aromatic hydrocarbon. A large amount of water vapor does not affect the decomposition, but requires energy to raise the temperature to the reaction temperature.
[0014]
Halogenated aromatic hydrocarbons that are targeted in the present invention include chlorobenzene, dichlorobenzene, trichlorobenzene, biphenyl chloride, polychlorinated biphenyls, dioxins, furans, and the like. In addition, halogenated aromatic hydrocarbons used as electrical insulating oil from transformers, capacitors, and the like are also targeted.
[0015]
In the catalyst of the present invention, the catalytically active component supported on the carrier is desirably a metal. It is desirable that the carrier component be crystallized so that the carrier component and the carrier component do not react to form a compound. The crystallization of the carrier component can be performed by firing at a high temperature. Ir, Os, etc., as catalytically active components, also have some effects, but are inferior to Pt, Pd, Rh and Ru.
[0016]
At least one of Mo, W, Cr, Fe, Co, Ni and V as a catalytically active component is desirably contained in a total amount of 0.5 to 50 wt%, and particularly preferably 10 to 40 wt%. Further, at least one of Pt, Pd, Rh and Ru is preferably in the range of 5 wt% to 50 wt% in total, and more preferably 0.5% to 2 wt%.
[0017]
A preferred catalyst is one in which Ni is supported on an alumina carrier, and Ni is supported on an alumina carrier.
A carrier carrying Co, a carrier carrying Ni and V on an alumina carrier, and a carrier carrying Ni and at least one of Pt, Pd, Rh and Ru on a alumina carrier.
[0018]
As the Al raw material for preparing the catalyst of the present invention, γ-alumina, a mixture of γ-alumina and δ-alumina, and the like can be used. In particular, using boehmite or the like as an Al material,₂O₃Is also a preferred method.
[0019]
As raw materials of various metal components for preparing the catalyst of the present invention, nitrates, sulfates, ammonium salts, chlorides and the like can be used.
[0020]
As the method for producing the catalyst of the present invention, any of a precipitation method, an impregnation method, and the like, which are usually used for producing a catalyst, can be used.
[0021]
Further, the catalyst in the present invention can be used as it is formed into granules, honeycombs or the like. As the molding method, any method such as an extrusion molding method, a tablet molding method, and a tumbling granulation method can be adopted according to the purpose. Further, it can be used after being coated on a ceramic, metal honeycomb, pipe or plate. In particular, it is preferable to use a catalyst coated on the inside of a ceramic pipe having an inner diameter of 1 mm or less, because the apparatus can be reduced in size and the reaction temperature can be easily controlled. This is because layers (several hundred square meters) contributing to the promotion of the chemical reaction on the catalyst surface can be arranged. It is also preferable that a groove having a length, width, and height of 1 mm or less is formed by etching or the like, a catalyst is coated on the inner wall, and a gas flow containing a halogenated aromatic hydrocarbon is caused to flow through the groove. When used as a granular catalyst, a particle size of 2 to 4 mm is desirable, but this particle size may be changed depending on the treatment amount and conditions.
[0022]
Al₂O₃The firing temperature of the raw material is desirably 900 to 1100 ° C. The purpose of firing is
αAl₂O₃The firing temperature may be changed depending on the raw material used.
[0023]
The space velocity (SV) for performing the reaction is 500 to 10,000 hours.^-1Is preferred, and particularly preferably 1,000 to 5,000 h^-1It is.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
The disassembly flow will be described in detail using the experimental apparatus shown in FIG. The minimum configuration of the present apparatus is a reaction gas heater 5, a catalyst reactor 6, and a decomposition gas absorption tank 9. A halogenated aromatic hydrocarbon 1, pure water 2, and hydrogen 3 are supplied to the heater 5, and heated to a predetermined temperature. The heated gas is introduced into the catalyst reactor 6 heated in the electric furnace 8 and comes into contact with the catalyst 7. The decomposed gas is bubbled into water in the decomposed gas absorption tank 9 to
After removing acid components such as HCl and further removing water with a mist catcher 10, the gas is exhausted through an activated carbon tank 11. Before performing the decomposition test, the catalytic reactor 6 and the piping leading to the reactor are replaced with an inert gas such as nitrogen 4.
[0025]
FIG. 2 shows a small catalytic reactor (microreactor). The size is a cubic structure of about 40 mm square. The reaction gas flows in from the reaction gas inlet 12 in the top view and flows out from the decomposition gas outlet 13. Here, the reaction gas is a halogenated aromatic hydrocarbon, hydrogen, or steam. A cooling medium flows from the cooling medium inlet 14 to control a rise in temperature during the reaction. The cooling medium flows out of the cooling medium outlet 15. A circle having an outer diameter of 1.2 mmφ in the side view is an alumina rod 16 coated with a catalyst. The portion where the alumina rod is placed is a groove having a height of 1.5 mm (catalyst layer 17). These are arranged in three rows. The reaction gas flows through this part. The reaction gas enters the buffer space 18 in the top view, where the gas is once reduced in linear velocity and then passed through the catalyst layer. This allows the gas to flow uniformly through the three catalyst layers.
[0026]
FIG. 3 shows a decomposition apparatus using the small reactor shown in FIG. The apparatus includes a water supply line, a halogenated aromatic hydrocarbon supply line, a hydrogen gas supply line, an inert gas supply line such as nitrogen, a heater 5, a catalyst reactor 6, a cracked gas absorption tank 9, a mist catcher 10, It is composed of an activated carbon tank 11. First, before flowing the reaction gas, the inside of the system is replaced with an inert gas such as nitrogen. After that, hydrogen is replaced with H₂。 From the cylinder, supply through a pressure reducing valve with a mass flow controller to control the flow rate. Further, pure water is sucked from a tank by a micro tube pump, introduced into the heater 5, and vaporized into steam. When the flow rates of hydrogen and water vapor are stabilized, the halogenated aromatic hydrocarbon 1 is sucked by a micro tube pump and supplied. The gas heated to a predetermined temperature by the heater 5 is introduced from outside into the small catalytic reactor 6 heated by the heating device 19. In the catalytic reactor, the reaction gas comes into contact with the catalyst as shown in FIG. The decomposed gas is exhausted after passing through a mist catcher 10 and an activated carbon tank 11 after removing acid components such as HCl in a decomposed gas absorption tank 9. These disassembly devices are housed in a housing, and the inside of the housing is sucked and evacuated. In addition, H₂Install gas sensors such as and benzene. The temperature of various metering pumps, gas flow meters, heaters, catalytic reactors, etc. are controlled collectively by a controller.
[0027]
As the step of removing HCl, washing by spraying water or an alkaline aqueous solution is preferable because it is highly efficient and blockage of the pipe due to crystal precipitation or the like hardly occurs. A method of bubbling the decomposition product gas in water or an aqueous alkaline solution or a method of washing using a packed tower may be used. Further, an alkaline solid may be used.
[0028]
The reactor used for carrying out the treatment method of the present invention may be of a usual fixed bed, moving bed or fluidized bed type, but corrosive gas such as HCl is generated as a decomposition product gas. The reactor should be made of materials that are not easily damaged by these corrosive gases.
[0029]
The processing apparatus of the present invention may be connected to a removing apparatus for extracting halogenated aromatic hydrocarbons from a transformer, a condenser, or the like. Halogenated aromatic hydrocarbons extracted from transformers, condensers, etc. contain impurities such as solids precipitated in oil or catalyst. Therefore, once the impurities are removed in the refining process, the halogenated aromatics after removing the impurities are removed. Preferably, the aromatic hydrocarbon is supplied to the cracking device. At this time, the piping connecting the removal device for extracting the halogenated aromatic hydrocarbon and the decomposition device is kept warm by a ribbon heater or the like. By keeping the temperature, condensation of halogenated aromatic hydrocarbons on the way can be suppressed.
[0030]
[Example 1]
In this example, the influence of the catalyst carrier was examined. In the test device shown in FIG. 1, chlorobenzene was used as a raw material, and the amount of chlorobenzene was 0.11 to 0.15 (mol / h).
H₂/ Chlorobenzene molar ratio of 19 to 20, H₂O / chlorobenzene molar ratio 8-12, space velocity (SV) 2860-3050h^-1Under these conditions, the generated CH at various reaction temperatures₄Measure the amount of CH₄Generated CH per volume₄The ratio of the amount (wt%) was calculated. The catalyst was prepared as follows.
[0031]
<Catalyst 1> @ Pd / Al₂O₃catalyst
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size: 2-4 mm) was dried at 120 ° C. for 1 hour. To 50.02 g of the dried alumina, 11.31 g of a 4.422 wt% Pd nitric acid solution (manufactured by Tanaka Kikinzoku) was diluted with pure water to make 34.99 g of a Pd aqueous solution, which was then impregnated. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0032]
<Catalyst 2> Pd / silica-alumina catalyst
SiO₂/ Al₂O₃(Manufactured by JGC Chemicals, N632L, 3φ × 3L) was dried at 120 ° C. for 1 hour. SiO after drying₂/ Al₂O₃To 50.35 g, 11.33 g of a 4.422 wt% Pd nitric acid solution (manufactured by Tanaka Kikinzoku) was diluted with pure water to make a 28.00 g Pd aqueous solution, and the resultant was impregnated. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0033]
<Catalyst 3> Pd / mordenite catalyst
Mordenite (Tosoh, 640HOA, 1.5 mm pellet) was dried at 120 ° C. for 1 h. To 50.42 g of the dried mordenite, 11.32 g of a 4.422 wt% Pd nitric acid solution (manufactured by Tanaka Kikinzoku) was diluted with pure water to make a 29.89 g Pd aqueous solution, and impregnated. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0034]
FIG. 4 shows the results. CH from reaction temperature around 400 ° C₄The generation of has begun. At 400 ° C., the difference between the catalysts is small, but at 550 ° C., Pd / Al₂O₃CH₄The amount of production is the largest, and among these three types of carriers, Al₂O₃Was found to be most preferred.
[0035]
[Example 2]
In this embodiment, Ni is used as the catalytically active component.₂O₃Was prepared to decompose chlorobenzene. As in Example 1, the test apparatus shown in FIG. 1 was used. Using chlorobenzene as a raw material, the decomposition rates of chlorobenzene and benzene at various reaction temperatures were measured under the conditions shown in Table 1. The chlorobenzene (CB) decomposition rate and the benzene (B) decomposition rate were calculated by the following equations.
[0036]
Chlorobenzene (CB) decomposition rate (%) = (1-outlet CB amount (mol / h) / inlet CB amount (mol / h)) × 100
Outlet CB amount (mol / h) = CB amount in exhaust gas + CB amount in first absorption tank and second absorption tank
Benzene (B) decomposition rate (%) = (1-outlet B amount (mol / h) / inlet B amount (mol / h)) × 100
Outlet B amount (mol / h) = B amount in exhaust gas + B amount in first and second absorption tanks
[0037]
[Table 1]

[0038]
The catalyst was prepared as follows.
[0039]
<Catalyst 4> @ Ni / Al₂O₃catalyst
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size 2-4 mm) is calcined at 1100 ° C. for 5 hours, and αAl₂O₃It was made. To 100.00 g of this alumina, 49.55 g of nickel nitrate hexahydrate (Wako Pure Chemical Industries, Ltd.) was dissolved in pure water and impregnated so that the charged amount of Ni was 10 wt%. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours. Since Ni in the catalyst after calcination is an oxide, H₂還 元 Reduction treatment was performed in an air stream to reduce Ni oxide to Ni metal.
[0040]
FIG. 5 shows the results. As for the dechlorination reaction indicated by the chlorobenzene decomposition rate, almost 100% reaction could be achieved at a reaction temperature of 425 ° C. Regarding benzene decomposition, it was found that the decomposition rate was low at a reaction temperature of 425 ° C or lower, but it was completely decomposed at 500 ° C. The decomposition products include HCl, CO, CH₄, H₂ＣＯ, CO₂Was detected.
[0041]
[Example 3]
In this example, the performance of catalytically active components other than Ni was examined. As in Example 1, the test apparatus shown in FIG. 1 was used. Using chlorobenzene as a raw material, the amount of chlorobenzene is 0.11 to 0.15 (mol / h),₂/ Chlorobenzene molar ratio of 19 to 20, H₂O / chlorobenzene molar ratio 8-12, space velocity (SV) 2860-3050h^-1Under these conditions, the decomposition rate of chlorobenzene at a reaction temperature of 410 ° C. was measured. The chlorobenzene decomposition rate was determined by the above-mentioned calculation formula. The catalyst was prepared as follows.
[0042]
<Catalyst 5> @ Pt / Al₂O₃catalyst
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size: 2-4 mm) was dried at 120 ° C. for 1 hour. 50.00 g of alumina after drying, Pt was added as Al₂O₃A 1.459 wt% {34.27 g of tetravalent-ammine solution (manufactured by Tanaka Kikinzoku)} was diluted with pure water to 35 g so as to be 1 wt% to the weight to impregnate with a Pt aqueous solution. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0043]
<Catalyst 6> @ Rh / silica-alumina catalyst
SiO₂/ Al₂O₃(Manufactured by JGC Chemicals, N632L, 3φ × 3L) was dried at 120 ° C. for 1 hour. SiO after drying₂/ Al₂O₃For 50.00 g, Rh was SiO₂/ Al₂O₃11.15 g of a 4.485 wt% Rh nitric acid solution (manufactured by Tanaka Kikinzoku) was diluted with pure water to 28 wt. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0044]
<Catalyst 7> @ Ru / silica-alumina catalyst
SiO₂/ Al₂O₃(Manufactured by JGC Chemicals, N632L, 3φ × 3L) was dried at 120 ° C. for 1 hour. SiO after drying₂/ Al₂O₃For 50.00 g, the charged amount of Ru is SiO₂/ Al₂O₃12.86 g of a 3.889 wt% Ru nitric acid solution (manufactured by Tanaka Kikinzoku) was diluted with pure water to 28 wt. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0045]
<Catalyst 8> Mo / Al₂O₃catalyst
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size: 2-4 mm) was dried at 120 ° C. for 1 hour. 50.00 g of alumina after drying, Mo was added to Al₂O₃9.18 g of ammonium molybdate (Wako Pure Chemical Industries, Ltd.) was dissolved in pure water to make 10 wt% with respect to the weight, and the resultant was impregnated with a 35 g of Mo aqueous solution. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0046]
<Catalyst 9> @ W / Al₂O₃catalyst
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size: 2-4 mm) was dried at 120 ° C. for 1 hour. 50.00 g of alumina after drying, W was charged as Al₂O₃7.05 g of ammonium tungstate para-pentahydrate (Wako Pure Chemical Industries, Ltd.) was dissolved in pure water to make the amount 35 wt. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0047]
<Catalyst 10> Cr / Al₂O₃catalyst
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size: 2-4 mm) was dried at 120 ° C. for 1 hour. 50.00 g of alumina after drying, Fe₂O₃A Cr aqueous solution was prepared by dissolving 19.21 g of chromium nitrate nonahydrate (Wako Pure Chemical Industries, Ltd.) with pure water to 35 g so as to be 5 wt% based on the weight. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0048]
<Catalyst 11> @ Fe / mordenite catalyst
Mordenite (Tosoh, 640HOA, 1.5 mm pellet) was dried at 120 ° C. for 1 h. With respect to 50.00 g of mordenite after drying, 18.10 g of iron nitrate nonahydrate (Wako Pure Chemical) was dissolved in pure water to 35 g so that the amount of Fe was 5 wt% based on the weight of mordenite. Was impregnated. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0049]
<Catalyst 12> Co / mordenite catalyst
Mordenite (Tosoh, 640HOA, 1.5 mm pellet) was dried at 120 ° C. for 1 h. To 50.00 g of the mordenite after drying, 12.34 g of cobalt nitrate hexahydrate (Wako Pure Chemical Industries, Ltd.) was dissolved in pure water to make 35 g so that the charged amount of Fe was 5 wt% based on the weight of the mordenite. Was impregnated. After impregnation, it was dried at 120 ° C. for 2 hours and calcined at 650 ° C. for 2 hours.
[0050]
Table 2 shows the results.
[0051]
[Table 2]

[0052]
[Example 4]
In this example, the effect of the amount of Ni was examined. The catalyst was Ni / Al of catalyst 4, catalyst 4-1, and catalyst 4-2.₂O₃A catalyst was used. As in Example 1, the test apparatus shown in FIG. 1 was used. Using chlorobenzene as a raw material, the decomposition rate of chlorobenzene and benzene was measured under the conditions shown in Table 3. The decomposition rate calculation formula is as described above. FIG. 6 shows the results. With the catalyst 4-2, the chlorobenzene decomposition rate was 99.9% or more and the benzene decomposition rate was 89.4% ８９ at a reaction temperature of 410 ° C. When these catalysts were used at a reaction temperature of 450 ° C., both the chlorobenzene decomposition rate and the benzene decomposition rate were improved, and the catalyst 4-2 decomposed 99.9%.
[0053]
[Table 3]

[0054]
The catalyst used was prepared as follows.
[0055]
<Catalyst 4-1>
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size 2-4 mm) is calcined at 1100 ° C. for 5 hours, and αAl₂O₃It was made. With respect to 65.05 g of this alumina, 64.41 g of nickel nitrate hexahydrate (Wako Pure Chemical Industries) was dissolved in 21.62 g of pure water and impregnated so that the charged amount of Ni was 20 wt%. After impregnation, it was dried at 120 ° C. for 1 hour and calcined at 650 ° C. for 2 hours. Since Ni in the catalyst after calcination is an oxide, H₂還 元 Reduction treatment was performed in an air stream to reduce Ni oxide to Ni metal.
[0056]
<Catalyst 4-2>
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size 2-4 mm) is calcined at 1100 ° C. for 5 hours, and αAl₂O₃It was made. With respect to 65.08 g of this alumina, 128.80 g of nickel nitrate hexahydrate (Wako Pure Chemical) was dissolved in 43.20 g of pure water and impregnated so that the charged amount of Ni was 40 wt%. The impregnation was performed several times. First, 55 ml of a nickel solution was impregnated and dried at 120 ° C. for 1 hour. Then, it was impregnated with 28 ml of a nickel solution, dried at 120 ° C. for 3 hours, and fired at 650 ° C. for 1 hour. After firing, the remaining nickel solution (27 ml) was impregnated, dried at 120 ° C. for 1 hour, and fired at 650 ° C. for 2 hours. Since Ni in this catalyst is an oxide, H₂還 元 Reduction treatment was performed in an air stream to reduce Ni oxide to Ni metal.
[0057]
[Example 5]
In this example, the influence of a three-component catalyst was examined. As in Example 1, the test apparatus shown in FIG. 1 was used. Using chlorobenzene as a raw material, the decomposition rate of chlorobenzene and benzene was measured under the conditions shown in Table 4. Chlorobenzene and benzene decomposition rates were determined by the above-mentioned calculation formula. Table 5 shows the results of the decomposition rates.
[0058]
[Table 4]

[0059]
[Table 5]

[0060]
The catalyst in which Pt, Pd, V, Co, La, and K were respectively added to the Ni / Al catalyst also showed a high decomposition rate. However, for the La-added catalyst of the catalyst 24 and the K-added catalyst of the catalyst 25, Cl was detected in the catalyst after the test.
[0061]
Catalysts 20-25 were prepared as follows.
[0062]
<Catalyst 20> @ Pt / Ni / Al₂O₃
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size 2-4 mm) is calcined at 1100 ° C. for 5 hours, and αAl₂O₃It was made. To 65.00 g of this alumina, 64.41 g of nickel nitrate hexahydrate (Wako Pure Chemical Industries, Ltd.) was dissolved and impregnated in 21.58 g of pure water so that the charged amount of Ni was 20 wt%. After impregnation, it was dried at 120 ° C. for 1 hour and calcined at 650 ° C. for 2 hours. To 65.00 g of the calcined catalyst, 298 mg / g of chloroplatinic acid 2.097 g of pure water was added to make 29.26 g of pure catalyst. This was impregnated, dried at 120 ° C. for 1 hour, and fired at 650 ° C. for 2 hours. Since Ni in the catalyst after calcination is an oxide, H₂還 元 Reduction treatment was performed in an air stream to reduce Ni oxide to Ni metal.
[0063]
<Catalyst 21> @ Pd / Ni / Al₂O₃
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size 2-4 mm) is calcined at 1100 ° C. for 5 hours, and αAl₂O₃It was made. To 65.00 g of this alumina, 64.41 g of nickel nitrate hexahydrate (Wako Pure Chemical) was dissolved in 21.58 g of pure water and impregnated so that the amount of Ni to be charged was 20 wt%. After impregnation, it was dried at 120 ° C. for 1 hour and calcined at 650 ° C. for 2 hours. 14.699 g of a 4.422 wt% Pd nitric acid solution was added to 65.02 g of the calcined catalyst to give 29.26 g by adding pure water. This was impregnated, dried at 120 ° C. for 1 hour, and fired at 650 ° C. for 2 hours. Since Ni in the catalyst after calcination is an oxide, H₂還 元 Reduction treatment was performed in an air stream to reduce Ni oxide to Ni metal.
[0064]
<Catalyst 22> @ V / Ni / Al₂O₃
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size 2-4 mm) is calcined at 1100 ° C. for 5 hours, and αAl₂O₃It was made. To 65.05 g of this alumina, 64.41 g of nickel nitrate hexahydrate (Wako Pure Chemical Industries, Ltd.) was dissolved in 21.62 g of pure water and impregnated so that the charged amount of Ni was 20 wt%. After impregnation, it was dried at 120 ° C. for 1 hour and calcined at 650 ° C. for 2 hours. With respect to 65.75 g of the calcined catalyst, 1.49 g of ammonium vanadate (Wako Pure Chemical Industries) was dissolved in 5 ml of 30% hydrogen peroxide solution so that the charged amount would be 1 wt%, and 30 g of pure water was further added. Impregnation was performed after the addition. After impregnation, it was dried at 120 ° C. for 1 hour and calcined at 500 for 2 hours. Since Ni in the catalyst after calcination is an oxide, H₂還 元 Reduction treatment was performed in an air stream to reduce Ni oxide to Ni metal.
[0065]
<Catalyst 23> @ Co / Ni / Al₂O₃
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size 2-4 mm) is calcined at 1100 ° C. for 5 hours, and αAl₂O₃It was made. With respect to 65.05 g of this alumina, 64.41 g of nickel nitrate hexahydrate (Wako Pure Chemical Industries) was dissolved in 21.62 g of pure water and impregnated so that the charged amount of Ni was 20 wt%. After impregnation, it was dried at 120 ° C. for 1 hour and calcined at 650 ° C. for 2 hours. With respect to 65.13 g of the calcined catalyst, 16.04 g of cobalt nitrate hexahydrate (Wako Pure Chemical Industries) was dissolved in 29.95 g of pure water and impregnated so that the charged amount of Co became 5 wt%. After impregnation, it was dried at 120 ° C. for 1 hour and calcined at 650 ° C. for 2 hours. Since Ni in the catalyst after calcination is an oxide, H₂還 元 Reduction treatment was performed in an air stream to reduce Ni oxide to Ni metal.
[0066]
<Catalyst 24> @ La / Ni / Al₂O₃
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size 2-4 mm) is calcined at 1100 ° C. for 5 hours, and αAl₂O₃It was made. With respect to 65.00 g of this alumina, 64.55 g of nickel nitrate hexahydrate (Wako Pure Chemical Industries, Ltd.) and 12.17 g of lanthanum nitrate hexahydrate were prepared so that the charged amounts of Ni and La were 20 wt% and 6 wt%, respectively. It was dissolved in 27.95 g of pure water and impregnated. In addition, impregnation was divided into two times, and after the first impregnation, drying was performed at 120 ° C. for 1 hour, and impregnation was performed again. After impregnation, it was dried at 120 ° C. for 1.5 hours and calcined at 650 ° C. for 2 hours. Since Ni in the catalyst after calcination is an oxide, H₂還 元 Reduction treatment was performed in an air stream to reduce Ni oxide to Ni metal.
[0067]
<Catalyst 25> @ K / Ni / Al₂O₃
Activated alumina (manufactured by Sumitomo Kagaku, NKHD-24, particle size 2-4 mm) is calcined at 1100 ° C. for 5 hours, and αAl₂O₃It was made. Nickel nitrate hexahydrate was added to 64.55 g of alumina so that Ni was 20 wt% and K was 6 wt%.
(Wako Pure Chemical Industries) 64.55 g and potassium nitrate (10.08 g) were dissolved in pure water (27.95 g) and impregnated. In addition, impregnation was divided into two times, and after the first impregnation, drying was performed at 120 ° C. for 1 hour, and impregnation was performed again. After impregnation, it was dried at 120 ° C. for 1.5 hours and calcined at 650 ° C. for 2 hours. Since Ni in the catalyst after calcination is an oxide, H₂還 元 Reduction treatment was performed in an air stream to reduce Ni oxide to Ni metal.
[0068]
[Example 6]
In this embodiment, Pd / Al₂O₃This is the result of coating the catalyst on an alumina rod having an outer diameter of 1.2 mmφ, placing the catalyst in the reactor shown in FIG. 2, and decomposing it with the test device shown in FIG. The catalyst was prepared as follows.
[0069]
<Catalyst 13> Pd / Al₂O₃catalyst
Alumina sol (alumina sol-520, manufactured by Nissan Chemical Co., Ltd.) is sucked by a micro tube pump, and Al with an outer diameter of 1.2 mmφ and an inner diameter of 1.0 mmφ₂O₃After passing through the inside of the rod, the inner surface was coated with alumina sol. It was dried at 120 ° C. for 0.5 h and calcined at 650 ° C. for 1 h. Al₂O₃Al coated with sol₂O₃Al on the rod₂O₃The slurry was coated. Al₂O₃The slurry is Al₂O₃1.5 g of boehmite (PURALSB1 manufactured by CONDEA) was mixed with 10 g of the sol while stirring. This slurry was converted to Al using a micro tube pump.₂O₃The inner surface of the bar was coated. After the coating, the coating was dried at 120 ° C. for 0.5 h and baked at 650 ° C. for 1 h. This Al₂O₃4.422 wt% Pd nitric acid solution (manufactured by Tanaka Kikinzoku) was passed through a rod with a microtube pump, and the Al coated on the inner surface was₂O₃The layer was impregnated. Al coated with Pd nitric acid solution₂O₃The rod was dried at 120 ° C. for 0.5 h and calcined at 650 ° C. for 2 h.
[0070]
<Catalyst 14> @ Ni / Al₂O₃catalyst
Alumina sol (alumina sol-520, manufactured by Nissan Chemical Co., Ltd.) is sucked by a micro tube pump, and Al having an outer diameter of 1.2 mmφ and an inner diameter of 1.0 mmφ is drawn.₂O₃The rod was passed through the inside of the rod to coat the inner surface. Further, the outer surface was coated with alumina sol, dried at 120 ° C. for 0.5 hour, and fired at 650 ° C. for 1 hour. Al₂O₃Al coated with sol₂O₃To the rod, then Al₂O₃The slurry was coated. Al₂O₃The slurry is Al₂O₃1.5 g of boehmite (PURALSB1 manufactured by CONDEA) was mixed with 10 g of the sol while stirring. This slurry was converted to Al using a micro tube pump.₂O₃The inner surface of the bar was coated. Similarly to the sol coat, the outer surface was coated with alumina slurry. After the coating, the coating was dried at 120 ° C. for 0.5 hours and baked at 1100 ° C. for 1 hour. This Al₂O₃A 4.422 wt% Pd nitric acid solution (manufactured by Tanaka Kikinzoku) was passed through a rod with a microtube pump, and Al coated on the inner surface was coated.₂O₃The layer was impregnated. The outer surface was also coated. Al coated with Pd nitric acid solution₂O₃The bar was dried at 120 ° C. for 0.5 h and calcined at 650 ° C. for 2 h.
[0071]
The decomposition rate was calculated from the amounts of chlorobenzene (CB) and benzene (B).
[0072]
Decomposition rate (%) = (1− (outlet CB + outlet B amount (mol / h)) / inlet CB amount (mol / h)) × 100
Outlet CB amount (mol / h) = CB amount in exhaust gas + CB amount in first and second absorption tanks Outlet B amount (mol / h) = B amount in exhaust gas + First absorption tank and second absorption B amount of tank
Table 6 shows the results.
[0073]
[Table 6]

[0074]
It was found that the decomposition rate of catalyst 13 was 56.24%, and that of catalyst 14 was about 70%. It is considered that this is because the catalyst-filled portion of the reactor shown in FIG. 2 is a rectangular parallelepiped, so that a part of the reaction gas passes through the outer surface portion of the catalyst 5 where the catalyst is not coated. Since the decomposition rate of the catalyst 14 having the outer surface coated with the catalyst was improved, it is considered that a higher decomposition rate can be obtained by improving the structure of the catalyst-filled portion of the reactor.
[0075]
[Example 7]
In this embodiment, Ni / Al₂O₃The catalyst was coated on an alumina rod having an outer diameter of 1.2 mmφ, placed in a reactor shown in FIG. 2, and decomposed by a test apparatus shown in FIG. The catalyst was prepared as follows. The decomposition rate was calculated from the amounts of chlorobenzene (CB) and benzene (B).
[0076]
Decomposition rate (%) = (1− (outlet CB + outlet B amount (mol / h)) / inlet CB amount (mol / h)) × 100
Outlet CB amount (mol / h) = CB amount in exhaust gas + CB amount in first absorption tank and second absorption tank
Outlet B amount (mol / h) = B amount in exhaust gas + B amount in first and second absorption tanks
<Catalyst 15> @ Ni / Al₂O₃catalyst
Alumina sol (alumina sol-520, manufactured by Nissan Chemical Co., Ltd.) is sucked by a micro tube pump, and Al having an outer diameter of 1.2 mmφ and an inner diameter of 1.0 mmφ is drawn.₂O₃After passing through the inside of the rod, the inner surface was coated with alumina sol. It was dried at 120 ° C. for 0.5 h and calcined at 650 ° C. for 1 h. Al₂O₃Al coated with sol₂O₃Al on the rod₂O₃The slurry was coated. Al₂O₃The slurry is Al₂O₃1.5 g of boehmite (PURALSB1 manufactured by CONDEA) was mixed with 10 g of the sol while stirring. This slurry was converted to Al using a micro tube pump.₂O₃The inner surface of the bar was coated. After the coating, the coating was dried at 120 ° C. for 0.5 hours and baked at 1100 ° C. for 1 hour. This Al₂O₃An aqueous solution of nickel nitrate was passed through a rod with a microtube pump, and the Al₂O₃The layer was impregnated. The nickel nitrate aqueous solution was prepared by dissolving 63.39 g of nickel nitrate hexahydrate in 50 ml of pure water. Ni amount calculated from the charged amount is Ni / Al₂O₃11.3 wt%} in the catalyst. Al coated with Ni aqueous solution₂O₃The bar was dried at 120 ° C. for 0.5 h and calcined at 650 ° C. for 2 h.
[0077]
<Catalyst 16> @ Ni / Al₂O₃catalyst
Alumina sol (alumina sol-520, manufactured by Nissan Chemical Co., Ltd.) is sucked by a micro tube pump, and an Al with an outer diameter of 1.2 mmφ and an inner diameter of 1.0 mmφ is used.₂O₃The rod was passed through the inside of the rod to coat the inner surface. Further, the outer surface was coated with alumina sol, dried at 120 ° C. for 0.5 hours, and fired at 650 ° C. for 1 hour. Al₂O₃Al coated with sol₂O₃To the rod, then Al₂O₃The slurry was coated. Al₂O₃The slurry is Al₂O₃1.5 g of boehmite (PURALSB1 manufactured by CONDEA) was mixed with 10 g of the sol while stirring. This slurry was converted to Al using a micro tube pump.₂O₃The inner surface of the bar was coated. Similarly to the sol coat, the outer surface was coated with alumina slurry. After the coating, the coating was dried at 120 ° C. for 0.5 hours and baked at 1100 ° C. for 1 hour. This Al₂O₃An aqueous solution of nickel nitrate was passed through a rod with a microtube pump, and the Al₂O₃The layer was impregnated. The outer surface was also coated. The aqueous nickel nitrate solution was prepared by dissolving 63.39 g of nickel nitrate hexahydrate in 50 ml of pure water. Ni amount calculated from the charged amount is Ni / Al₂O₃11.3 wt%} in the catalyst. Al coated with Ni aqueous solution₂O₃The rod was dried at 120 ° C. for 0.5 h and calcined at 650 ° C. for 2 h.
[0078]
It was found that the catalyst 15 could decompose 60% and the catalyst 16 could decompose 90%. It is considered that this is because a part of the reaction gas passes through the outer surface portion of the catalyst 15 where the catalyst is not coated as in the case of the fifth embodiment. Since the decomposition rate of the catalyst 16 whose outer surface was coated with the catalyst was improved, it is considered that a higher decomposition rate can be obtained by improving the structure of the catalyst-filled portion of the reactor.
[0079]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, halogenated aromatic hydrocarbons, such as PCB, can be decomposed | disassembled without producing harmful by-products by one process.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a processing apparatus according to an embodiment of the present invention.
FIG. 2 is a top view and a side view showing one embodiment of a microreactor used in the present invention.
FIG. 3 is a system configuration diagram of a processing apparatus showing another embodiment of the present invention.
FIG. 4 is a graph showing the performance of the catalyst of the present invention.
FIG. 5 is a graph showing the performance of the catalyst of the present invention.
FIG. 6 is a graph showing the performance of the catalyst of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Halogenated aromatic hydrocarbon, 2 ... pure water, 3 ... hydrogen, 4 ... nitrogen, 5 ... heater, 6 ... catalyst reactor, 7 ... catalyst, 8 ... electric furnace, 9 ... cracked gas absorption tank, 10 ... Mist catcher, 11 ... Activated carbon tank, 12 ... Reaction gas inlet, 13 ... Decomposition gas outlet, 14 ... Cooling medium inlet, 15 ... Cooling medium outlet, 16 ... Alumina rod, 17 ... Catalyst layer, 18 ... Buffer space, 19 ... Heating equipment.

Claims (18)

A method for decomposing a halogenated aromatic hydrocarbon with a catalyst, comprising contacting a gaseous gas stream containing the halogenated aromatic hydrocarbon with hydrogen and water vapor with a catalyst to halogenate the halogenated aromatic hydrocarbon. A method for decomposing halogenated aromatic hydrocarbons, which decomposes into hydrogen, at least one of carbon monoxide and carbon dioxide. The gas stream containing halogenated aromatic hydrocarbons according to claim 1,
A method for decomposing a halogenated aromatic hydrocarbon, which is brought into contact with a catalyst at a temperature of 600 ° C. 2. The catalyst according to claim 1, wherein the catalyst support contains at least one selected from the group consisting of Mo, W, Cr, Fe, Co, Ni, V, Pt, Pd, Rh and Ru. A method for decomposing a halogenated aromatic hydrocarbon. 4. A method for decomposing a halogenated aromatic hydrocarbon, wherein the catalyst carrier according to claim 3 contains at least one selected from alumina, alumina-silica, and mordenite. 4. The decomposition of a halogenated aromatic hydrocarbon according to claim 3, wherein at least one selected from Mo, W, Cr, Fe, Co, Ni, V, Pt, Pd, Rh and Ru is contained as a metal. Method. 2. The method according to claim 1, wherein the amount of hydrogen is 15-25 mol% based on the amount of halogen in the halogenated aromatic hydrocarbon, and the amount of water vapor is 5-50 mol% based on the amount of carbon in the halogenated aromatic hydrocarbon. A method for decomposing halogenated aromatic hydrocarbons, comprising steam. The method for cracking a halogenated aromatic hydrocarbon according to claim 1, wherein the catalyst is coated on the inside of a tubular pipe having an inner diameter of 1 mm or less to decompose the halogenated aromatic hydrocarbon. 2. The method according to claim 1, wherein a sheet having a large number of grooves having a width and a depth of 1 mm or less is coated with a catalyst coated in the grooves, and is used to decompose the halogenated aromatic hydrocarbon. A method for decomposing a halogenated aromatic hydrocarbon. A catalyst for decomposing halogenated aromatic hydrocarbons, wherein a carrier selected from alumina, alumina-silica, and mordenite is used as a carrier, and Mo, W, Cr, Fe, Co, Ni, V, Pt, At least one selected from Pd, Rh, and Ru is used as a metal or an oxide, and at least one of Mo, W, Cr, Fe, Co, Ni, and V contains 0.5 to 50 wt% in total, and Pt, Pd, A halogenated aromatic hydrocarbon cracking catalyst characterized by containing at least one of Rh and Ru in a total amount of 0.1% to 3% by weight. A catalyst for decomposing halogenated aromatic hydrocarbons, comprising a carrier selected from the group consisting of alumina, alumina-silica and mordenite, and a group consisting of Mo, W, Cr, Fe, Co, Ni and V And at least one selected from the group consisting of Pt, Pd, Rh and Ru in a total amount of 0.1 to 50 wt% as a metal or oxide. A halogenated aromatic hydrocarbon cracking catalyst characterized by containing about 3% by weight. The halogenated aromatic hydrocarbon cracking catalyst according to claim 9 or 10, wherein αAl ₂ O ₃ is contained as a main component as a crystal form of alumina. The halogenated aromatic hydrocarbon decomposition catalyst according to claim 9, wherein Ni is supported on an alumina carrier. 10. The halogenated aromatic hydrocarbon cracking catalyst according to claim 9, wherein Ni and Co are supported on an alumina carrier. 10. The halogenated aromatic hydrocarbon cracking catalyst according to claim 9, wherein Ni and V are supported on an alumina carrier. The halogenated aromatic hydrocarbon cracking catalyst according to claim 10, wherein Ni and at least one selected from Pt, Pd, Rh, and Ru are supported on the alumina carrier. An apparatus for decomposing a halogenated aromatic hydrocarbon with a catalyst, comprising: a hydrogen supplier for adding hydrogen to a gaseous halogenated aromatic hydrocarbon; a steam supplier for adding steam; and the hydrogen and steam being added. A catalyst reactor that decomposes the halogenated aromatic hydrocarbon by contact with the catalyst, and an exhaust gas cleaning device that cleans decomposition products generated in the catalyst reactor with water or an aqueous alkaline solution. Halogenated aromatic hydrocarbon cracking equipment. 17. The catalyst reactor according to claim 16, wherein the catalyst reactor comprises a tubular pipe having an inner diameter of 1 mm or less, a catalyst coated on an inner surface of the pipe, and a gas flow containing a halogenated aromatic hydrocarbon flows through the pipe. A halogenated aromatic hydrocarbon decomposer characterized by being performed. 17. The catalyst reactor according to claim 16, wherein the catalytic reactor has a number of grooves, each of which has a width and depth of 1 mm or less, and a plurality of sheets in which the catalyst is coated on the inner surface of the grooves. A halogenated aromatic hydrocarbon decomposer characterized in that:

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