JP4071414B2

JP4071414B2 - Waste incineration equipment

Info

Publication number: JP4071414B2
Application number: JP2000035520A
Authority: JP
Inventors: 郷紀佐々木; 直機藤原; 学山本; 和樹小林; 透千手
Original assignee: Babcock Hitachi KK
Current assignee: Mitsubishi Power Ltd
Priority date: 2000-02-14
Filing date: 2000-02-14
Publication date: 2008-04-02
Anticipated expiration: 2020-02-14
Also published as: JP2001227740A

Description

【０００１】
【発明の属する技術分野】
本発明は、排ガス中の窒素酸化物（ＮＯｘ）、及びダイオキシン（ＤＸＮｓ）などの有機塩素化合物濃度が急変しやすいごみ焼却炉などの焼却炉における排ガス中のＮＯｘ，ＤＸＮｓなどの有害成分を効率よく低減する燃焼設備に関するものである。
【０００２】
【従来の技術】
図２に示すごみ燃焼設備の概略図に基づき従来技術を説明する。従来のごみ焼却設備は、焼却炉１、給じん装置２、ガス冷却装置３、減温塔４、焼却炉排ガス用バグフィルタ２３、吸引ブロア６、煙突７、を備えている。
【０００３】
さらに、ガス冷却装置３、減温塔４、焼却炉排ガス用バグフィルタ２３から捕集される焼却飛灰８を灰クレーン９、飛灰供給装置１０を経て、灰溶融炉１１に投入して溶融し、固形分はスラグ１２として回収される。
【０００４】
一方、溶融炉排ガス１３はガス冷却装置１４で２００°Ｃ前後に冷却して、溶融炉排ガス用バグフィルタ１５上流の煙道１６において、消石灰等の酸性物質除去剤１７を吹き込み、前記バグフィルタ１５においてナトリウム（Ｎａ）、カリウム（Ｋ）等のアルカリ金属、及び塩化水素（ＨＣ１）、硫黄酸化物（ＳＯｘ）等の酸性物質を含む溶融飛灰１８として除去する。
【０００５】
処理後の溶融炉排ガス１９は、そのまま吸引ブロア２７を経由して、煙突７にて放出されていた。
【０００６】
また、図３に示すように、溶融炉排ガス用バグフィルタ１５の後流に、ガス再加熱器２４、脱硝剤投入部２５、触媒塔２６を設ける方式も考えられる。前記バグフィルタ１５上流で温度２００°Ｃ前後に冷却して、ナトリウム（Ｎａ）、カリウム（Ｋ）等のアルカリ金属、及び塩化水素（ＨＣ１）、硫黄酸化物（ＳＯｘ）等の酸性物質を含む溶融飛灰１８を除去した後、その後流のガス再加熱器２４で排ガス温度を触媒活性の高くなる２２０〜２４０°Ｃ付近に再加熱し、触媒塔２６において、窒素酸化物（ＮＯｘ）、ダイオキシン（ＤＸＮｓ）等の有機塩素化合物を除去し、そのまま吸引ブロア２７を経由して、煙突７にて放出されていた。
【０００７】
さらに、もっと簡便な方法として図４に示すように溶融炉排ガス中のＮＯｘを除去するため、溶融炉排ガス用バグフィルタに触媒を担持した触媒担持バグフィルタ２２を用い、その上流でアンモニアなどの脱硝剤２１を吹き込み、窒素酸化物（ＮＯｘ）、ダイオキシン（ＤＸＮｓ）等の有機塩素化合物を除去し、吸引ブロア２７を経由して、煙突７にて放出する方法が考えられる。
【０００８】
【発明が解決しようとする課題】
しかし、図２、図３及び図４に示したごみ焼却設備には、次に記述するような解決すべき課題がある。
【０００９】
前記灰溶融炉の溶融炉排ガス中には、焼却炉排ガスよりも高濃度のＮａ，Ｋなどのアルカリ金属、高濃度のＨＣ１，ＳＯｘ，ＮＯｘなどの酸性物質、及び前記溶融炉排ガスの冷却過程で再生成するＤＸＮｓなどが含まれている。これらの化学物質のうち、Ｎａ，Ｋなどのアルカリ金属は、ＨＣ１，ＳＯｘと容易に反応して塩化ナトリウム（ＮａＣ１）、塩化カリウム（ＫＣ１）、硫酸ナトリウム（Ｎａ_２ＳＯ_４）などの塩類となり、溶融炉排ガス用バグフィルタ上に堆積し除去できる。未反応のＨＣ１，ＳＯｘは、消石灰などの酸性物質除去剤をさらに添加することで固気反応によりバグフィルタ上で除去可能である。
【００１０】
まず、図２に示した溶融炉に溶融炉排ガス用バグフィルタのみを備えた方式においては、以上のように上記化学物質のうち、ＮＯｘ，ＤＸＮｓ以外は溶融炉排ガス用バグフィルタによって除去できるが、通過した溶融炉排ガスはそのまま煙突に放出されていたのでＮＯｘ，ＤＸＮｓについては、規則値をクリアできない可能性があった。
【００１１】
また、図３に示した溶融炉排ガス用バグフィルタ及びその後流に触媒塔を設けた方式においては、ＮＯｘ，ＤＸＮｓ以外は溶融炉排ガス用バグフィルタによって除去でき、通過した溶融炉排ガスはその後流の触媒塔の上流においてアンモニア、尿素などの脱硝剤を添加することによりＮＯｘを、触媒作用によりＤＸＮｓを除去することができる。
【００１２】
しかし、この方式の場合、溶融炉排ガス用バグフィルタ後流に、ガス再加熱器、脱硝剤投入部、触媒塔を設ける必要があり、設備の複雑化、コストの高騰、運転制御の複雑化といった問題点があった。
【００１３】
図４に示した溶融炉排ガス用バグフィルタに触媒を担持した触媒担持バグフィルタを用い、その上流でアンモニアなどの脱硝剤を吹き込む方法が、もっと簡便な方法として考えられるが、この方式を用いた場合においても、前記脱硝剤は溶融炉排ガス中の高濃度のＨＣ１，ＳＯｘと反応して塩化アンモニウム（ＮＨ_４Ｃ１）、硫酸アンモニウム（（ＮＨ_４）_２ＳＯ_４）等の塩類となり、ＮＯｘの還元に用いられるアンモニア等の脱硝剤の実効濃度が低下するため、十分な脱硝反応が期待できない。また、生成した塩類により、前記触媒担持バグフィルタの差圧が上昇し、連続的な運転が困難になるおそれがあった。
【００１４】
また、ＤＸＮｓについては、溶融炉排ガスの冷却過程で再発生するが、溶融飛灰が主にＮａ，Ｋなどのアルカリ金属であることから、ＤＸＮｓ吸着量は焼却飛灰に比べて低く、溶融炉排ガス用バグフィルタにおいて溶融飛灰とともに除去される割合は小さいため、そのまま煙突に放出された場合、規定値をクリアできない場合も考えられる。
【００１５】
以上のように、溶融炉排ガス中のＮＯｘ，ＤＸＮｓについては、場合によっては十分に除去できず、規定値をクリアできない可能性があったり、コスト的に非常に高くつく可能性があった。
【００１６】
本発明の目的は、ごみ焼却炉、排ガス冷却設備、焼却炉排ガス除塵装置を備え、さらに前記排ガス除塵装置により分離された焼却飛灰を溶融処理する灰溶融炉、及び前記灰溶融炉後流に溶融炉排ガス除塵装置を備えたごみ焼却設備において、排ガス中の窒素酸化物、有機塩素化合物を十分処理することのできる簡易なごみ焼却設備を提供することである。
【００１７】
【課題を解決するための手段】
前記課題を解決するために、本発明は次のような構成を採用する。
【００１８】
ごみ焼却炉、前記ごみ焼却炉からの排ガスを冷却する排ガス冷却設備、前記排ガス冷却設備の排ガス後流に設けられた焼却炉排ガス除塵装置、前記焼却炉排ガス除塵装置により分離された焼却飛灰を溶融処理する灰溶融炉、前記灰溶融炉の後流に設けられた溶融炉排ガス除塵装置、を備えたごみ焼却設備において、
前記焼却炉排ガス除塵装置を触媒担持バグフィルタとし、且つ前記溶融炉排ガス除塵装置をバグフィルタとし、
前記溶融炉排ガス用バグフィルタで溶融炉排ガス中のアルカリ金属の塩化物及び硫酸塩を除去し、
前記溶融炉排ガス用バグフィルタの上流にて消石灰を一例とする酸性物質除去剤を吹き込むことにより前記溶融炉排ガス中の酸性物質を前記溶融炉排ガス用バグフィルタで溶融飛灰として除去し、
前記溶融炉排ガス用バグフィルタを通過した、窒素酸化物及び有機塩素化合物を含む排ガスを前記焼却炉排ガス用触媒担持バグフィルタの上流に戻し、前記溶融炉排ガス用バグフィルタによる除去で前記アルカリ金属及び前記酸性物質の少なくなった前記溶融炉排ガス中、及び前記焼却炉排ガス中に含まれる窒素酸化物及び有機塩素化合物を前記触媒担持フィルタによって同時処理するごみ焼却設備。
【００１９】
ごみ焼却炉、前記ごみ焼却炉からの排ガスを冷却する排ガス冷却設備、前記排ガス冷却設備の排ガス後流に設けられた焼却炉排ガス除塵装置、前記焼却炉排ガス除塵装置により分離された焼却飛灰を溶融処理する灰溶融炉、前記灰溶融炉の後流に設けられた溶融炉排ガス除塵装置、を備えたごみ焼却設備において、
前記焼却炉排ガス除塵装置を触媒担持バグフィルタとし、且つ前記溶融炉排ガス除塵装置を触媒担持バグフィルタとし、
前記溶融炉排ガス用触媒担持バグフィルタで溶融炉排ガス中のアルカリ金属の塩化物及び硫酸塩に加えて有機塩素化合物を除去し、
前記溶融炉排ガス用触媒担持バグフィルタの上流にて消石灰を一例とする酸性物質除去剤を吹き込んで前記溶融炉排ガス用触媒担持バグフィルタで酸性物質を溶融飛灰として除去し、
前記溶融炉排ガス用触媒担持バグフィルタを通過した、窒素酸化物及び有機塩素化合物を含む排ガスを前記焼却炉排ガス用触媒担持バグフィルタの上流に戻し、前記溶融炉排ガス用触媒担持バグフィルタによる除去で前記アルカリ金属及び前記酸性物質の少なくなった前記溶融炉排ガス中、及び前記焼却炉排ガス中に含まれる窒素酸化物及び有機塩素化合物を焼却炉排ガス用触媒担持フィルタによって同時処理するごみ焼却設備。
【００２０】
【発明の実施の形態】
本発明の実施形態に係るごみ焼却設備について図１を用いて以下説明する。図１はごみ焼却設備の断面概略図を示している。本実施形態は、焼却炉１、給じん装置２、ガス冷却装置３、減温塔４、焼却炉排ガス用触媒担持バグフィルタ５、吸引ブロア６、煙突７を備えている。さらに、ガス冷却装置３、減温塔４、焼却炉排ガス用触媒担持バグフィルタ５から捕集される焼却飛灰８を、灰クレーン９、飛灰供給装置１０を経て、灰溶融炉１１に投入して溶融し、固形分はスラグ１２として回収する。
【００２１】
更に、溶融炉排ガス１３はガス冷却装置１４で２００°Ｃ前後に冷却して、溶融炉排ガス用バグフィルタ１５上流の煙道１６において、消石灰等の酸性物質除去剤１７を吹き込み、前記バグフィルタ１５においてＮａ，Ｋ等のアルカリ金属、及びＨＣ１，ＳＯｘ等の酸性物質を含む溶融飛灰１８として除去する。
【００２２】
処理後の溶融炉排ガス１９中には、ＮＯｘと溶融炉排ガス１３の冷却過程で再生成したＤＸＮｓが含まれている。前記溶融炉排ガス１９は、減温塔４と焼却炉排ガス用触媒担持バグフィルタ５間の煙道２０において合流される。前記触媒担持バグフィルタ５の上流にはさらにアンモニア、尿素などの脱硝剤２１を吹き込み、前記触媒担持バグフィルタ５において、焼却炉排ガス中、及び溶融炉排ガス中のＮＯｘ，ＤＸＮｓを除去する。
【００２３】
ここにおいて、上記構成は一例であり、焼却炉１、ガス冷却装置３、減温塔４、灰溶融炉１１等の形式には、多種多様なものが考えられ、上記形状の装置に限定するものではない。さらに、触媒担持バグフィルタ５についてもその運転条件、材質、サイズなど様々なものが使用できる。
【００２４】
次に、本発明の他の実施形態に係るごみ焼却設備について図５を用いて以下説明する。本実施形態は、焼却炉１、給じん装置２、ガス冷却装置３、減温塔４、焼却炉排ガス用触媒担持バグフィルタ５、吸引ブロア６、煙突７を備えている。さらに、ガス冷却装置３、減温塔４、焼却炉排ガス用触媒担持バグフィルタ５から捕集される焼却飛灰８を、灰クレーン９、飛灰供給装置１０を経て、灰溶融炉１１に投入して溶融し、固形分はスラグ１２として回収する。
【００２５】
更に、溶融炉排ガス１３はガス冷却装置１４で２００°Ｃ前後に冷却して、溶融炉排ガス用触媒担持バグフィルタ２２上流の煙道１６において、消石灰等の酸性物質除去剤１７を吹き込み、前記触媒担持バグフィルタ２２においてＮａ，Ｋ等のアルカリ金属、及びＨＣ１，ＳＯｘ等の酸性物質を含む溶融飛灰１８として除去する。
【００２６】
さらに、前記触媒担持バグフィルタ２２内部に含まれる触媒の効果により、溶融炉排ガス用１３中のＤＸＮｓも大部分が除去される。処理後の溶融炉排ガス１９中には、ＮＯｘと、未反応のＤＸＮｓが含まれている。前記溶融炉排ガス１９は、減温塔４と焼却炉排ガス用触媒担持バグフィルタ５間の煙道２０において合流される。前記触媒担持バグフィルタ５の上流にはさらにアンモニア、尿素などの脱硝剤２１を吹き込み、さらに前記触媒担持バグフィルタ５において、焼却炉排ガス中、及び溶融炉排ガス中のＮＯｘ，ＤＸＮｓを除去することができるため、さらに高度な排ガス処理が可能となった。
【００２７】
ここにおいて、上記構成は一例であり、焼却炉１、ガス冷却装置３、減温塔４、灰溶融炉１１等の形式には、多種多様なものが考えられ、上記形状の装置に限定するものではない。さらに、触媒担持バグフィルタ５についてもその運転条件、材質、ザイズなど様々なものが使用できる。
【００２８】
以上説明したように、本発明の実施形態に係るごみ焼却設備は、次のような構成例を含むものである。
【００２９】
（１）焼却炉排ガス用バグフィルタを触媒担持バグフィルタとし、前記溶融炉排ガス用バグフィルタを通常のバグフィルタとし、前記バグフィルタで溶融炉排ガス中の高濃度のＮａ，Ｋ等のアルカリ金属を除去し、さらに前記バグフィルタの上流にて消石灰などの酸性物質除去剤を吹き込み、前記バグフィルタで溶融炉排ガス中の高濃度のＨＣ１、及びＳＯｘを除去する。前記バグフィルタを通過して上記化学物質の少なくなった排ガスを、前記焼却炉排ガス用触媒担持バグフィルタの上流に戻す。
【００３０】
したがって、溶融炉排ガス用のバグフィルタにおいて、Ｎａ，Ｋ分の多い溶融飛灰を専門的に処理でき、焼却炉排ガス用触媒担持バグフィルタの触媒劣化を軽減できる。前記焼却炉排ガス用触媒担持バグフィルタにおいて上記化学物質の少なくなった排ガス中の窒素酸化物、有機塩素化合物を同時処理する。
【００３１】
（２）前記焼却炉ガス用バグフィルタ及び、前記溶融炉排ガス用バグフィルタをともに触媒担持バグフィルタとし、前記溶融炉排ガス用触媒担持バグフィルタにおいて、溶融炉排ガス中の高濃度のＮａ，Ｋ等のアルカリ金属、ＨＣ１，ＳＯｘ等の酸性物質、加えて有機塩素化合物を除去し、前記触媒担持バグフィルタを通過して上記化学物質の少なくなった排ガスを、前記焼却炉排ガス用触媒担持バグフィルタの上流に戻す。前記焼却炉排ガス用触媒担持バグフィルタにおいて上記化学物質の少なくなった排ガス中の窒素酸化物、有機塩酸化合物を同時処理する。
【００３２】
【発明の効果】
本発明によれば、次のような作用並びに効果を奏することができる。
【００３３】
（１）灰溶融炉の溶融炉排ガス中には、焼却炉排ガスよりも高濃度のＮａ，Ｋなどのアルカリ金属、また、高濃度のＨＣ１，ＳＯｘ，ＮＯｘなどの酸性物質、及び溶融炉排ガスの冷却過程で再生成するＤＸＮｓなどが含まれている。
【００３４】
溶融炉排ガス用バグフィルタにおいては、Ｎａ，Ｋなどのアルカリ金属、ＨＣ１，ＳＯｘ等の酸性物質など、脱硝剤への阻害成分となる化学物質のみを除去し、残ったＮＯｘ，ＤＸＮｓは、前記バグフィルタ通過後に、焼却炉排ガス用触媒担持バグフィルタ上流に戻し、前記焼却炉排ガス用触媒担持バグフィルタ上流において、アンモニア、尿素などの脱硝剤を投入しながら、脱硝剤の阻害成分が少ない条件で脱硝及びＤＸＮｓ除去を行うことができ、脱硝剤の使用量の低減が可能となる。
【００３５】
（２）溶融炉排ガス用バグフィルタに触媒を担持した触媒担持バグフィルタを用いる場合、Ｎａ，Ｋなどのアルカリ金属、ＨＣ１，ＳＯｘ等の酸性物質など脱硝剤への阻害成分となる化学物質、及びＤＸＮｓが除去できる。残ったＮＯｘは、前記バグフィルタ通過後に、焼却炉排ガス用触媒担持バグフィルタ上流に戻し、前記焼却炉排ガス用触媒担持バグフィルタ上流において、アンモニア、尿素などの脱硝剤を投入しながら、脱硝剤の阻害成分が少ない条件で脱硝、及び焼却炉排ガス中のＤＸＮｓ除去を行うことができ、脱硝剤の使用量の低減が可能となる。
【００３６】
また、溶融炉排ガス用触媒担持バグフィルタ上流においては、脱硝剤を吹き込まないので、塩類が生成することなく、触媒の活性点が閉塞し、触媒活性が低下したり、ろ布の差圧が上昇するのを抑えることができる。
【００３７】
（３）溶融飛灰は主にＮａ，Ｋなどのアルカリ金属であることから、ＤＸＮｓ吸着量は焼却飛灰に比べて低く、溶融炉排ガス用バグフィルタにおいては、溶融炉排ガス中のＤＸＮｓが溶融飛灰とともに除去される割合は小さいが、溶融炉排ガス用触媒担持バグフィルタにおいては触媒効果により、溶融炉排ガス中のＤＸＮｓも除去可能である。前記溶融炉排ガスの量は焼却炉排ガスに比べ１／３〜１／１０程度であり、前記触媒担持バグフィルタは焼却炉排ガス用バグフィルタよりも小容量で済み、経済的効果も大きい。
【図面の簡単な説明】
【図１】本発明の実施形態に係るごみ焼却設備を示す図である。
【図２】従来のごみ焼却設備の概略図である。
【図３】従来の別のごみ焼却設備の概略図である。
【図４】従来のさらに別のごみ焼却設備の概略図である。
【図５】本発明の他の実施形態に係るごみ焼却設備を示す図である。
【符号の説明】
１焼却炉
２給じん装置
３ガス冷却装置
４減温塔
５焼却炉排ガス用触媒担持バグフィルタ
６吸引ブロア
７煙突
８焼却飛灰
９灰クレーン
１０飛灰供給装置
１１灰溶融炉
１２スラグ
１３溶融炉排ガス
１４ガス冷却装置
１５溶融炉排ガス用バグフィルタ
１６煙道
１７酸性物質除去剤
１８溶融飛灰
１９溶融炉排ガス
２０煙道
２１脱硝剤
２２溶融炉排ガス用触媒担持バグフィルタ
２３焼却炉排ガス用バグフィルタ
２４ガス再加熱器
２５脱硝剤投入部
２６触媒塔
２７吸引ブロア[0001]
BACKGROUND OF THE INVENTION
The present invention efficiently removes harmful components such as NOx and DXNs in exhaust gas in an incinerator such as a waste incinerator in which the concentration of organic chlorine compounds such as nitrogen oxides (NOx) and dioxins (DXNs) in exhaust gas easily changes. It relates to a combustion facility to be reduced.
[0002]
[Prior art]
The prior art will be described based on the schematic diagram of the waste combustion facility shown in FIG. The conventional waste incineration equipment includes an incinerator 1, a dust feeder 2, a gas cooling device 3, a temperature reducing tower 4, an incinerator exhaust gas bag filter 23, a suction blower 6, and a chimney 7.
[0003]
Further, the incineration fly ash 8 collected from the gas cooling device 3, the temperature reducing tower 4, and the incinerator exhaust gas bag filter 23 is introduced into the ash melting furnace 11 through the ash crane 9 and the fly ash supply device 10 to be melted. The solid content is recovered as slag 12.
[0004]
On the other hand, the melting furnace exhaust gas 13 is cooled to about 200 ° C. by the gas cooling device 14, and an acidic substance removing agent 17 such as slaked lime is blown into the flue 16 upstream of the melting furnace exhaust gas bag filter 15. , The molten fly ash 18 containing an alkali metal such as sodium (Na) or potassium (K) and an acidic substance such as hydrogen chloride (HC1) or sulfur oxide (SOx) is removed.
[0005]
The treated melting furnace exhaust gas 19 was discharged as it was through the suction blower 27 at the chimney 7.
[0006]
In addition, as shown in FIG. 3, a system in which a gas reheater 24, a denitration agent charging unit 25, and a catalyst tower 26 are provided downstream of the melting furnace exhaust gas bag filter 15 is also conceivable. Cooled to a temperature of about 200 ° C. upstream of the bag filter 15 and melted containing an alkali metal such as sodium (Na) or potassium (K), and an acidic substance such as hydrogen chloride (HC1) or sulfur oxide (SOx). After the fly ash 18 is removed, the exhaust gas temperature is reheated to around 220 to 240 ° C. where the catalytic activity becomes high by the downstream gas reheater 24, and in the catalyst tower 26, nitrogen oxide (NOx), dioxin ( The organochlorine compound such as DXNs) was removed, and was discharged as it was through the suction blower 27 at the chimney 7.
[0007]
Furthermore, as a simpler method, as shown in FIG. 4, in order to remove NOx in the melting furnace exhaust gas, a catalyst-carrying bag filter 22 having a catalyst supported on the melting furnace exhaust gas bag filter is used, and denitration such as ammonia is performed upstream thereof. A method of blowing the agent 21 and removing organic chlorine compounds such as nitrogen oxides (NOx) and dioxins (DXNs) and discharging them at the chimney 7 through the suction blower 27 is conceivable.
[0008]
[Problems to be solved by the invention]
However, the waste incineration facilities shown in FIGS. 2, 3 and 4 have problems to be solved as described below.
[0009]
In the melting furnace exhaust gas of the ash melting furnace, alkali metals such as Na and K having a higher concentration than incinerator exhaust gas, acidic substances such as high concentrations of HC1, SOx, and NOx, and the cooling process of the melting furnace exhaust gas. DXNs to be regenerated are included. Among these chemical substances, alkali metals such as Na and K easily react with HC1 and SOx to form salts such as sodium chloride (NaC1), potassium chloride (KC1), and sodium sulfate (Na ₂ SO ₄ ). It can be deposited and removed on the melting furnace exhaust gas bag filter. Unreacted HC1 and SOx can be removed on the bag filter by solid-gas reaction by further adding an acidic substance removing agent such as slaked lime.
[0010]
First, in the system provided with only the melting furnace exhaust gas bag filter in the melting furnace shown in FIG. 2, among the above chemical substances, except NOx and DXNs can be removed by the melting furnace exhaust gas bag filter. Since the melting furnace exhaust gas that passed through was directly discharged to the chimney, there was a possibility that the regulation values of NOx and DXNs could not be cleared.
[0011]
Further, in the melting furnace exhaust gas bag filter shown in FIG. 3 and a system in which a catalyst tower is provided in the subsequent stream, NOx and DXNs can be removed by the melting furnace exhaust gas bag filter. By adding a denitration agent such as ammonia or urea upstream of the catalyst tower, NOx can be removed and DXNs can be removed by catalytic action.
[0012]
However, in this system, it is necessary to provide a gas reheater, a denitration agent charging section, and a catalyst tower in the downstream of the bag filter for the melting furnace exhaust gas, which complicates equipment, increases costs, and complicates operation control. There was a problem.
[0013]
A method of using a catalyst-carrying bag filter carrying a catalyst in the melting furnace exhaust gas bag filter shown in FIG. 4 and blowing a denitration agent such as ammonia upstream thereof is considered as a simpler method. Even in this case, the denitration agent reacts with high-concentration HC1 and SOx in the melting furnace exhaust gas to become salts such as ammonium chloride (NH ₄ C1) and ammonium sulfate ((NH ₄ ) ₂ SO ₄ ). Since the effective concentration of the denitration agent such as ammonia used is lowered, a sufficient denitration reaction cannot be expected. Further, the generated salts may increase the differential pressure of the catalyst-carrying bag filter, which may make continuous operation difficult.
[0014]
DXNs are regenerated during the cooling process of the melting furnace exhaust gas. Since the molten fly ash is mainly an alkali metal such as Na and K, the adsorption amount of DXNs is lower than that of the incinerated fly ash. Since the rate of removal with molten fly ash in the exhaust gas bag filter is small, there may be a case where the specified value cannot be cleared if it is released as it is into the chimney.
[0015]
As described above, NOx and DXNs in the melting furnace exhaust gas cannot be sufficiently removed in some cases, and there is a possibility that the specified value cannot be cleared, and there is a possibility that the cost is very high.
[0016]
An object of the present invention is to provide a waste incinerator, an exhaust gas cooling facility, an incinerator exhaust gas dust removing device, an ash melting furnace for melting the incinerated fly ash separated by the exhaust gas dust removing device, and a downstream of the ash melting furnace In a waste incineration facility equipped with a melting furnace exhaust gas dust removal device, a simple waste incineration facility capable of sufficiently treating nitrogen oxides and organochlorine compounds in exhaust gas is provided.
[0017]
[Means for Solving the Problems]
In order to solve the above problems, the present invention adopts the following configuration.
[0018]
A waste incinerator, an exhaust gas cooling facility for cooling exhaust gas from the waste incinerator, an incinerator exhaust gas dust removal device provided in the exhaust gas downstream of the exhaust gas cooling facility, and an incineration fly ash separated by the incinerator exhaust gas dust removal device In a refuse incineration facility comprising an ash melting furnace for melting treatment, a melting furnace exhaust gas dust removing device provided in the downstream of the ash melting furnace,
The incinerator exhaust gas dust removal device is a catalyst-supporting bag filter, and the melting furnace exhaust gas dust removal device is a bag filter,
The alkali metal chloride and sulfate in the melting furnace exhaust gas are removed by the melting furnace exhaust gas bag filter,
By removing an acidic substance removing agent as an example of slaked lime upstream of the melting furnace exhaust gas bag filter, the acidic substance in the melting furnace exhaust gas is removed as molten fly ash with the melting furnace exhaust gas bag filter,
The exhaust gas containing nitrogen oxides and organic chlorine compounds that has passed through the melting furnace exhaust gas bag filter is returned upstream of the incinerator exhaust gas catalyst-supporting bag filter, and the alkali metal and the exhaust gas are removed by the melting furnace exhaust gas bag filter. A waste incineration facility that simultaneously treats nitrogen oxides and organochlorine compounds contained in the melting furnace exhaust gas and the incinerator exhaust gas in which the acidic substance is reduced by the catalyst supporting filter .
[0019]
A waste incinerator, an exhaust gas cooling facility for cooling exhaust gas from the waste incinerator, an incinerator exhaust gas dust removal device provided in the exhaust gas downstream of the exhaust gas cooling facility, and an incineration fly ash separated by the incinerator exhaust gas dust removal device In a refuse incineration facility comprising an ash melting furnace for melting treatment, a melting furnace exhaust gas dust removing device provided in the downstream of the ash melting furnace,
The incinerator exhaust gas dust removal device is a catalyst-carrying bag filter, and the melting furnace exhaust gas dust removal device is a catalyst-carrying bag filter,
In addition to the alkali metal chlorides and sulfates in the melting furnace exhaust gas with the catalyst-supporting bag filter for melting furnace exhaust gas, the organic chlorine compound is removed,
Blowing an acidic substance remover as an example of slaked lime upstream of the melting furnace exhaust gas catalyst-carrying bag filter to remove acidic substances as molten fly ash with the melting furnace exhaust gas catalyst carrying bag filter,
The exhaust gas containing nitrogen oxides and organochlorine compounds that has passed through the melting furnace exhaust gas catalyst-carrying bag filter is returned to the upstream side of the incinerator exhaust gas catalyst carrying bag filter, and removed by the melting furnace exhaust gas catalyst carrying bag filter. A waste incineration facility for simultaneously treating nitrogen oxides and organic chlorine compounds contained in the melting furnace exhaust gas reduced in the alkali metal and the acidic substance and in the incinerator exhaust gas with a catalyst-carrying filter for incinerator exhaust gas .
[0020]
DETAILED DESCRIPTION OF THE INVENTION
A waste incineration facility according to an embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows a schematic cross-sectional view of a waste incineration facility. The present embodiment includes an incinerator 1, a dust supply device 2, a gas cooling device 3, a temperature reducing tower 4, an incinerator exhaust gas catalyst-carrying bag filter 5, a suction blower 6, and a chimney 7. Further, the incineration fly ash 8 collected from the gas cooling device 3, the temperature reducing tower 4, and the incinerator exhaust gas catalyst-carrying bag filter 5 is input to the ash melting furnace 11 through the ash crane 9 and the fly ash supply device 10. The solid content is recovered as slag 12.
[0021]
Further, the melting furnace exhaust gas 13 is cooled to about 200 ° C. by the gas cooling device 14, and an acidic substance removing agent 17 such as slaked lime is blown into the flue 16 upstream of the melting furnace exhaust gas bag filter 15. , The molten fly ash 18 containing an alkali metal such as Na and K and an acidic substance such as HC1 and SOx is removed.
[0022]
The treated melting furnace exhaust gas 19 contains NOx and DXNs regenerated during the cooling process of the melting furnace exhaust gas 13. The melting furnace exhaust gas 19 is merged in a flue 20 between the temperature reducing tower 4 and the incinerator exhaust gas catalyst-carrying bag filter 5. A denitration agent 21 such as ammonia or urea is further blown upstream of the catalyst-carrying bag filter 5, and the catalyst-carrying bag filter 5 removes NOx and DXNs in the incinerator exhaust gas and the melting furnace exhaust gas.
[0023]
Here, the above-described configuration is an example, and there are various types of incinerator 1, gas cooling device 3, temperature-decreasing tower 4, ash melting furnace 11, and the like. is not. Further, various types of catalyst-carrying bag filters 5 such as operating conditions, materials, and sizes can be used.
[0024]
Next, a waste incineration facility according to another embodiment of the present invention will be described with reference to FIG. The present embodiment includes an incinerator 1, a dust supply device 2, a gas cooling device 3, a temperature reducing tower 4, an incinerator exhaust gas catalyst-carrying bag filter 5, a suction blower 6, and a chimney 7. Further, the incineration fly ash 8 collected from the gas cooling device 3, the temperature reducing tower 4, and the incinerator exhaust gas catalyst-carrying bag filter 5 is input to the ash melting furnace 11 through the ash crane 9 and the fly ash supply device 10. The solid content is recovered as slag 12.
[0025]
Further, the melting furnace exhaust gas 13 is cooled to about 200 ° C. by the gas cooling device 14, and an acidic substance removing agent 17 such as slaked lime is blown into the flue 16 upstream of the melting furnace exhaust gas catalyst-carrying bag filter 22. It is removed as molten fly ash 18 containing alkali metals such as Na and K and acidic substances such as HC1 and SOx in the supporting bag filter 22.
[0026]
Furthermore, most of the DXNs in the melting furnace exhaust gas 13 are also removed by the effect of the catalyst contained in the catalyst-carrying bag filter 22. The melting furnace exhaust gas 19 after the treatment contains NOx and unreacted DXNs. The melting furnace exhaust gas 19 is merged in a flue 20 between the temperature reducing tower 4 and the incinerator exhaust gas catalyst-carrying bag filter 5. A denitration agent 21 such as ammonia or urea is further blown upstream of the catalyst-carrying bag filter 5, and NOx and DXNs in the incinerator exhaust gas and the melting furnace exhaust gas are further removed in the catalyst-carrying bag filter 5. As a result, more advanced exhaust gas treatment has become possible.
[0027]
Here, the above-described configuration is an example, and there are various types of incinerator 1, gas cooling device 3, temperature-decreasing tower 4, ash melting furnace 11, and the like. is not. Furthermore, various types of catalyst-carrying bag filters 5 such as operating conditions, materials, and sizes can be used.
[0028]
As described above, the waste incineration facility according to the embodiment of the present invention includes the following configuration example.
[0029]
(1) The incinerator exhaust gas bag filter is a catalyst-supported bag filter, the melting furnace exhaust gas bag filter is an ordinary bag filter, and the bag filter is used to remove alkali metals such as Na and K at high concentrations in the melting furnace exhaust gas. Further, an acidic substance removing agent such as slaked lime is blown upstream of the bag filter, and the bag filter removes high-concentration HC1 and SOx in the melting furnace exhaust gas. The exhaust gas in which the chemical substance is reduced through the bag filter is returned upstream of the incinerator exhaust gas catalyst-carrying bag filter.
[0030]
Therefore, in the bag filter for melting furnace exhaust gas, molten fly ash with a large amount of Na and K can be treated professionally, and the catalyst deterioration of the catalyst-supporting bag filter for incinerator exhaust gas can be reduced. In the incinerator exhaust gas catalyst-supporting bag filter, nitrogen oxides and organochlorine compounds in the exhaust gas in which the chemical substances are reduced are simultaneously processed.
[0031]
(2) Both the incinerator gas bag filter and the melting furnace exhaust gas bag filter are used as catalyst-supporting bag filters. In the melting furnace exhaust gas catalyst-supporting bag filter, high concentrations of Na, K, etc. in the melting furnace exhaust gas In addition to removing acidic substances such as alkali metals, HC1, and SOx, in addition to organic chlorine compounds, the exhaust gas with reduced chemical substances passing through the catalyst-carrying bag filter is converted into the catalyst-carrying bag filter for incinerator exhaust gas. Return upstream. In the incinerator exhaust gas catalyst-carrying bag filter, nitrogen oxides and organic hydrochloric acid compounds in the exhaust gas in which the chemical substances are reduced are simultaneously processed.
[0032]
【The invention's effect】
According to the present invention, the following operations and effects can be achieved.
[0033]
(1) In the melting furnace exhaust gas of the ash melting furnace, alkali metals such as Na and K having a higher concentration than incinerator exhaust gas, acidic substances such as HC1, SOx and NOx having a higher concentration, and melting furnace exhaust gas DXNs that are regenerated during the cooling process are included.
[0034]
In the melting furnace exhaust gas bag filter, only the chemical substances that inhibit the denitration agent such as alkali metals such as Na and K, and acidic substances such as HC1 and SOx are removed, and the remaining NOx and DXNs After passing through the filter, return to the upstream side of the incinerator exhaust gas catalyst-carrying bag filter, and in the upstream side of the incinerator exhaust gas catalyst-carrying bag filter, add denitration agents such as ammonia and urea while denitrating the denitration agent with less inhibitory components. And DXNs can be removed, and the amount of denitration agent used can be reduced.
[0035]
(2) When a catalyst-carrying bag filter carrying a catalyst is used in the melting furnace exhaust gas bag filter, a chemical substance that becomes an inhibitory component to the denitration agent such as an alkali metal such as Na or K, or an acidic substance such as HC1 or SOx, and DXNs can be removed. The remaining NOx is returned to the upstream of the incinerator exhaust gas catalyst-carrying bag filter upstream after passing through the bag filter, and while the denitration agent such as ammonia and urea is introduced upstream of the incinerator exhaust gas catalyst support bag filter, Denitration and DXNs removal from the incinerator exhaust gas can be performed under conditions where there are few inhibitory components, and the amount of denitration agent used can be reduced.
[0036]
In addition, the NOx removal agent is not blown upstream of the melting furnace exhaust gas catalyst-carrying bag filter, so that no salt is formed, the active site of the catalyst is blocked, the catalytic activity is reduced, and the differential pressure of the filter cloth is increased. Can be suppressed.
[0037]
(3) Since molten fly ash is mainly alkali metals such as Na and K, the amount of DXNs adsorbed is lower than that of incinerated fly ash, and DXNs in melting furnace exhaust gas melt in the melting furnace exhaust gas bag filter. Although the proportion removed together with fly ash is small, DXNs in the melting furnace exhaust gas can also be removed by the catalytic effect in the catalyst-carrying bag filter for melting furnace exhaust gas. The amount of the melting furnace exhaust gas is about 1/3 to 1/10 of the incinerator exhaust gas, and the catalyst-carrying bag filter has a smaller capacity than the incinerator exhaust gas bag filter, and has a large economic effect.
[Brief description of the drawings]
FIG. 1 is a diagram showing a waste incineration facility according to an embodiment of the present invention.
FIG. 2 is a schematic view of a conventional waste incineration facility.
FIG. 3 is a schematic view of another conventional waste incineration facility.
FIG. 4 is a schematic view of still another conventional waste incineration facility.
FIG. 5 is a view showing a waste incineration facility according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Incinerator 2 Dust supply device 3 Gas cooling device 4 Temperature reduction tower 5 Catalyst carrying bag filter 6 for incinerator exhaust gas Suction blower 7 Chimney 8 Incineration fly ash 9 Ash crane 10 Fly ash supply device 11 Ash melting furnace 12 Slag 13 Melting furnace Exhaust gas 14 Gas cooling device 15 Bag filter 16 for melting furnace exhaust gas Flue 17 Acidic substance removing agent 18 Molten fly ash 19 Melting furnace exhaust gas 20 Flue 21 Denitration agent 22 Catalyst carrying bag filter 23 for melting furnace exhaust gas Bag filter for incinerator exhaust gas 24 Gas reheater 25 Denitration agent charging unit 26 Catalyst tower 27 Suction blower

Claims

A waste incinerator, an exhaust gas cooling facility for cooling exhaust gas from the waste incinerator, an incinerator exhaust gas dust removal device provided in the exhaust gas downstream of the exhaust gas cooling facility, and an incineration fly ash separated by the incinerator exhaust gas dust removal device In a refuse incineration facility comprising an ash melting furnace for melting treatment, a melting furnace exhaust gas dust removing device provided in the downstream of the ash melting furnace,
The incinerator exhaust gas dust removal device is a catalyst-supporting bag filter, and the melting furnace exhaust gas dust removal device is a bag filter,
The alkali metal chloride and sulfate in the melting furnace exhaust gas are removed by the melting furnace exhaust gas bag filter,
By removing an acidic substance removing agent as an example of slaked lime upstream of the melting furnace exhaust gas bag filter, the acidic substance in the melting furnace exhaust gas is removed as molten fly ash with the melting furnace exhaust gas bag filter,
The exhaust gas containing nitrogen oxides and organic chlorine compounds that has passed through the melting furnace exhaust gas bag filter is returned upstream of the incinerator exhaust gas catalyst-supporting bag filter, and the alkali metal and the exhaust gas are removed by the melting furnace exhaust gas bag filter. A waste incineration facility, wherein the catalyst-supporting filter simultaneously treats nitrogen oxides and organochlorine compounds contained in the melting furnace exhaust gas and the incinerator exhaust gas in which the acidic substance is reduced .

A waste incinerator, an exhaust gas cooling facility for cooling exhaust gas from the waste incinerator, an incinerator exhaust gas dust removal device provided in the exhaust gas downstream of the exhaust gas cooling facility, and an incineration fly ash separated by the incinerator exhaust gas dust removal device In a refuse incineration facility comprising an ash melting furnace for melting treatment, a melting furnace exhaust gas dust removing device provided in the downstream of the ash melting furnace,
The incinerator exhaust gas dust removal device is a catalyst-carrying bag filter, and the melting furnace exhaust gas dust removal device is a catalyst-carrying bag filter,
In addition to the alkali metal chlorides and sulfates in the melting furnace exhaust gas with the catalyst-supporting bag filter for melting furnace exhaust gas, the organic chlorine compound is removed,
Blowing an acidic substance remover as an example of slaked lime upstream of the melting furnace exhaust gas catalyst-carrying bag filter to remove acidic substances as molten fly ash with the melting furnace exhaust gas catalyst carrying bag filter,
The exhaust gas containing nitrogen oxides and organochlorine compounds that has passed through the melting furnace exhaust gas catalyst-carrying bag filter is returned to the upstream side of the incinerator exhaust gas catalyst carrying bag filter, and removed by the melting furnace exhaust gas catalyst carrying bag filter. Nitrogen oxides and organic chlorine compounds contained in the melting furnace exhaust gas reduced in the alkali metal and the acidic substance and in the incinerator exhaust gas are simultaneously processed by a catalyst supporting filter for incinerator exhaust gas. Waste incineration equipment.