JP3575914B2 - Plastic processing method and apparatus - Google Patents

Description

あるいは、下記式のように、ＨＣｌが触媒作用を有し、塩化水素分子の脱離が生じる可能性も指摘されている。
【００２７】
【化２】

一方、第２段階目の質量減少は、共役二重結合が解離し架橋が生じることによる炭化が進む反応に起因するものである。
【００２８】
しかし、日常用いられているポリ塩化ビニルの多くは樹脂の可塑性を高めるために、ＤＯＰやＤＨＰなどのフタル酸系可塑剤、あるいは、ＤＯＡなどのアジピン酸系可塑剤が配合されており、ＰＶＣの熱分解において上述の塩化水素の脱離だけでなく可塑剤の分解反応も起こり、複雑な様相を示す。このことが、リサイクル技術の確立を阻む大きな要因となっている。つまり、脱離した塩化水素と可塑剤の分解物との反応により有機ハロゲン化物が生じ、これがプラスチックの熱分解生成物に混入し、熱分解生成物の再利用を難しくする。これを解決するためには、廃プラスチックから可塑剤を予め除去する必要がある。
【００２９】
そこで、可塑剤としてＤＯＰを配合させたポリ塩化ビニル樹脂で作られたシートについて、光の当たる空気中に晒したものと地中に埋めたものとを比較したところ、地中に埋めたものからは可塑剤が溶出し、６カ月以上経過するとシートに含まれている可塑剤の約半分が溶出することが判明した。つまり、可塑剤などの添加物を吸収する性質を有する物質をシートの周りに存在させると、樹脂から添加物質を分離除去できる。吸収性の物質としては、パルプ、レーヨン等のセルロースを基調とした繊維性物質、キトサン等の天然高分子系の包接化合物、多孔性物質や土等の粒状物などの毛細管現象によって添加物をプラスチックから吸収するものや、水等の溶剤のようにプラスチック内の添加物を外に拡散するもの等が挙げられ、この様な吸収性物質を接触させて、プラスチックから添加剤、特に可塑剤を吸収除去する。吸収性物質との接触面積を大きくするに従って可塑剤の除去効率は上がるので、プラスチックをシート状あるいは細粒状に加工して吸収性物質と接触させるのが望ましい。更に、可塑剤の吸収除去はプラスチックを加熱すると進行するので、プラスチックを加熱可能な吸収性物質を使用する。加熱温度範囲は、脱ハロゲン化水素が進行しない温度、８０〜２８０℃程度が好ましい。望ましい態様としては、例えば、シート状プラスチックを土中に埋めて加熱したり、シート状あるいは細粒状のプラスチックを加熱水に浸したり高温の水蒸気を吹き付けるものが挙げられる。
【００３０】
シート状あるいはフィルム状の薄い膜として加工されているプラスチック製品は、厚い板やブロック体として加工されているいるプラスチックと性状も異なり、リサイクルの視点からも適正な処理法が求められているが、上述の処理法はこのような薄層状のプラスチックに特に適している。代表的なシート状のプラスチック製品として、例えば、農業用のポリ塩化ビニルが挙げられ、１９５１年に発売が開始されて以来その実用性が評価され、１９５３年にＪＩＳの制定の後、利用範囲も急速に拡大し、野菜などの促成栽培のハウスやトンネルの被覆材として普及している。農業用ポリ塩化ビニルシートにもっとも多く配合されているのは可塑剤であり、約３０％程度配合されている。１９９１年の農業用のプラスチックの排出量を見ても、ポリ塩化ビニルフィルムが１０５，６１６ｔ、ポリエチレンフィルムが６８，３９９ｔ、その他のフィルムが６，４６３ｔ、他のプラスチックが３，９１４ｔとなっており、フィルム加工品が９７．９％、ポリ塩化ビニルフィルムが５７．２％とかなり高い割合を占めている。また、農業用の廃プラスチックの処理は、再生利用が促進されているものの、依然として焼却処理に頼っていることは否めず、限りある資源の活用という観点から上述の処理法は有益である。更に、金属箔にプラスチックを被覆したものに本方法を適用すると、可塑剤の除去だけでなく、処理後に金属箔とプラスチックの分離が容易になるという利点もある。
【００３１】
図１に本発明に従って添加剤を除去するプラスチックの処理装置の一例を示す。このプラスチックの処理装置１は、吸着作用を持つ溶媒としての水蒸気を発生させる加熱蒸気発生装置２と、この水蒸気を噴出させる蒸気放出配管３と、添加剤が溶出している水を回収する回収ポンプ４と、この回収水を受け入れる回収水槽５と、フィルム状のプラスチックＰを巻き取る円筒状の回転体６と、溶媒としての水の保温効果を高める断熱材を被覆した容器７と、フィルムの送りを制御する円筒状の回転体８とからなる。補給水槽９から補給ポンプ１０によって水が加熱蒸気発生装置２に送られ、水蒸気が生成される。
【００３２】
加熱蒸気発生装置２を作動し、蒸気流量が安定したところで蒸気放出配管３から蒸気を噴出させる。回転体６、８をゆっくりと回転させ、フィルム状プラスチックＰが一様に水蒸気に接触するよう噴出して添加剤の溶出を促進する。一通りフィルム状プラスチックＰを水蒸気を通過させた後、回転体６、８を反転させフィルム状プラスチックＰを逆方向に走行させながら樹脂からの配合物質の溶出を継続する。この時、回転体８間を通過していくプラスチックＰが破損しないように、回転体８間に挟まれるプラスチックＰに対してかかる圧縮力が低く抑えられるように回転体８間の隙間の幅を調整する。溶出した添加剤の一部は水蒸気と共に回収口１１から回収水槽５に回収され、一部は容器７の底部に液体等として溜る。溶出回収物には可塑剤、可塑剤の加水分解物であるアルコール化合物及びカルボキシ化合物等の酸性物質等が含まれる。
【００３３】
図２に、本発明に従って添加合剤を除去するプラスチックの処理装置の第２の例を示す。このプラスチックの処理装置１２は、吸収作用を有する溶媒として水を用いており、第１の例の加熱蒸気発生装置２に代えて水を加熱するヒーター１３を、補給ポンプ１０に代えて加熱水を噴出させるための加圧ポンプ１４を、蒸気放出配管３に代えて加圧水放出口１５を備え、他の部材については第１の例と同様である。
【００３４】
ヒーター１３を作動し、加熱水の供給が安定したところで加圧水放出口１５から加熱水を噴出させる。回転体６、８をゆっくりと回転させ、フィルム状プラスチックＰが一様に加熱水に接触するようにして添加剤の溶出を促進する。一通りプラスチックを加熱水に接触させた後、回転体６、８を反転させてプラスチックＰを逆方向に走行させながら樹脂からの配合物質の溶出を継続する。この時、回転体８間を通過していくプラスチックＰが破損しないように、回転体８間に挟まれるプラスチックＰに対してかかる圧縮力が低く抑えられるように回転体８間の隙間の幅を調整する。溶出した添加剤は加熱水と共に回収口１１から回収水槽５に回収される。溶出回収物には可塑剤、可塑剤の加水分解物であるアルコール化合物及びカルボキシ化合物等の酸性物質等が含まれる。
【００３５】
上述の例において、回転体６、８にヒーターを設けて処理前にプラスチックを加熱すると、操作効率が向上する。
【００３６】
図３に本発明に従って添加合剤を除去するプラスチックの処理装置の第３の例を示す。このプラスチックの処理装置１６は、フィルム状のプラスチックＰに重ねてロール状に巻き付けた多孔性材料でできた吸収体１７と、このロール状吸収体１７を収容するための断熱材で被覆した溶出促進槽１８と、溶出促進槽１８の内部を暖めるためのヒーター１９と、溶出促進槽１８内部の圧力が一定値以上になるとガスを放出させる圧力調整弁２０と、溶出促進槽１９の下部に滞留した液化成分を取り出す排出弁２１と、圧力調整弁２０から放出されたガスを外気によって冷却凝縮して得られる液体及び排出弁２１から回収される液化成分を回収する回収槽（図示せず）とからなり、ロール状の吸収体には溶媒としての水が含浸される。
【００３７】
プラスチックＰにロール状に巻き付けた吸収体１７を複数、溶出促進槽内１８に入れ、俵積みの状態に重ねる。次に、溶出促進槽１８の内部に水を注入し、吸収体１７に滲み込ませる。最上段のロールにかぶるくらいにまで水を注入した後、静置し、水位の低下がほぼ落ちついたところで上部の蓋２２を閉め、加熱ヒーター１９を作動させる。温度は９０℃以上１００℃未満に設定するのが好ましい。この状態で温度をほぼ一定に保つことによりプラスチックＰから添加剤が除去される。
【００３８】
図４に本発明に従って添加合剤を除去するプラスチックの処理装置の第４の例を示す。このプラスチックの処理装置２３は、プラスチック中の添加剤に対して吸収作用を有する溶媒として水を用い、水を加熱するためのヒーター２４と、フィルム状のプラスチックＰを引き上げる引き上げ装置２５と、水の保温効果を高める断熱材を被覆した温水槽２６と、この温水槽２６の上部を取り囲むように形成された透光製の優れたガラス製のハウス２７と、ハウス２７の内壁に凝縮した揮発性物質を回収する回収溝２８と、処理するプラスチックＰの周りを取り囲むセルロース製の吸収体２９と、吸収体２９に水を供給する加圧ポンプ（図示せず）とからなる。吸収体２９の温度を検出する温度センサ３０が設けられ、ハウス２７内の圧力が所定圧以上に上がらないように、圧力制御弁３１が設けられており、回収槽（図示せず）に接続される。
【００３９】
フィルム状プラスチックと吸収体２９とを層状に相互に重ねて温水槽２６内に積み重ね、循環ポンプと加圧ポンプを駆動して水の循環流量が安定したところで溶媒としての水を温めるヒーター２４を作動させ、吸収体２９及びプラスチックＰを加熱する。ハウス２７は、ハウス内の加熱に必要なエネルギーを太陽光線による熱エネルギーで補う役割をする。プラスチックＰ中の添加物は吸収体２９中の水に溶出し、一部は気化する。ハウス２７の内部で気化した物質はハウス上部で凝縮し、回収路２８を通じて回収される。吸収体２９の温度を所定期間保った後、引き上げ機２５を用いてプラスチックを回収する。
【００４０】
図５に本発明に従って添加合剤を除去するプラスチックの処理装置の第５の例を示す。このプラスチックの処理装置３２は、発生させる蒸気の温度によってプラスチックから溶出させる物質を連続的に分離できるよう複数の容器から構成されることを特徴としている。即ち、この処理装置３２は、図１に示す処理装置１と同じ構造を有する第１処理装置１ａと第２処理装置１ｂとを備えており、プラスチックは第１処理装置１ａから第２処理装置１ｂへ連続的に走行させる。この構成においては、第１処理装置１ａと第２処理装置１ｂとで使用する蒸気の温度を変えることができるので、例えば、第１処理装置１ａにおいて可塑剤などの添加剤を除去し、第２処理装置１ｂにおいてプラスチックの脱ハロゲン化水素を行うことができる。この場合、有機ハロゲン化合物が生成しないように、溶出物を装置内から常に排出したり、プラスチックの温度制御を確実にするように配慮するのが望ましい。
【００４１】
以上の例に於て、溶出処理中にプラスチックに振動エネルギーを加えると、溶出を促進することができる。
【００４２】
［鉛の除去］
廃プラスチックの資源化・再利用において問題となる添加剤は、上記の可塑剤以外に、安定剤として用いられている金属系化合物がある。特に、塩化ビニル用安定剤のうち６０％と大半を占めるのは鉛系化合物で、例えば、鉛白（２ＰｂＣＯ_３ ・Ｐｂ（ＯＨ）_２ ）、塩基性亜硫酸鉛（ＰｂＯ・ＰｂＳＯ_３ ）、三塩基性硫酸鉛（３ＰｂＯ・ＰｂＳＯ_４ ・Ｈ_２ Ｏ）、二塩基性亜リン酸鉛（２ＰｂＯ・ＰｂＨＰＯ_３ ・１／２Ｈ_２ Ｏ）、二塩基性フタル酸鉛（２ＰｂＯ・Ｐｂ（Ｃ_３ Ｈ_４ Ｏ_４ ））、三塩基性マレイン酸鉛（３ＰｂＯ・Ｐｂ（Ｃ_２ Ｈ_２ Ｏ_４ ）Ｈ_２ Ｏ）、二塩基性ステアリン酸鉛（２ＰｂＯ・Ｐｂ（Ｃ_１８Ｈ_３６Ｏ_２ ）_２ ）、ステアリン酸鉛（Ｐｂ（Ｃ_１８Ｈ_３６Ｏ_２ ）_２ ）等がある。
【００４３】
この様な鉛化合物の鉛のプラスチックからの除去・回収は、酢酸及び塩化水素を用いることによって可能である。鉛を除去回収するためのプラスチックの処理方法をいかに詳細に説明する。
【００４４】
まず、プラスチックを軟化状態にし、そこに酢酸を添加しながら撹拌を行い、プラスチックと酢酸を十分接触させる。酢酸は酸化鉛を溶解することが可能であり、前述の鉛系安定剤における塩基性鉛塩に含有される酸化鉛は、酢酸によって溶解する。この時の温度は、ポリ塩化ビニルを含むプラスチックが軟化可能であり且つ、酢酸の沸点１１７．８℃以下の温度に設定する。特に９５℃前後が好ましい。酢酸によって鉛を抽出した後、この抽出液に亜鉛板を差し込む。亜鉛よりイオン化傾向の小さい鉛は亜鉛板の周りに鉛樹をつくり析出させることができる。また、塩基性鉛塩系の安定剤中の酸化鉛は約８０％と報告されているので、この方法により大半の鉛が回収される。
【００４５】
さらに、酢酸鉛以外の鉛系化合物に関しては、塩化水素により鉛の塩化物を形成した後、水蒸気の供給によって濃塩酸水溶液を生じさせ、その中に鉛の塩化物イオンとして抽出する。ポリ塩化ビニルを含むプラスチックを２８０〜４００℃、好ましくは３００〜３５０℃で加熱分解すると、塩化ビニルから塩素が脱離し塩化水素が発生する。その塩化水素と鉛系化合物を反応することにより塩化鉛が形成する。そこで、温度を９５℃程度に下げて水蒸気を添加すると、塩化水素は濃塩酸となり、塩化鉛は塩化物イオン（ＰｂＣｌ_４ ）^２−として濃塩酸中に抽出される。この後、塩化物イオンを水素と反応させて鉛に還元し、金属鉛として回収する。この方法によって、酸化鉛以外の鉛系化合物の鉛の回収も可能となる。
【００４６】
図６〜８に本発明に従って鉛を除去するためのプラスチックの処理装置の一例を示す。この装置３３は、プラスチックの時間当りの供給量を所定量に制御可能なプラスチック供給装置３４と、安定剤の酸化鉛を酢酸に溶解させるための酢酸添加槽３５と、酢酸添加槽３５において生成する酢酸鉛水溶液から鉛を回収するための鉛回収槽３９と、酸化鉛以外の鉛系化合物中の鉛を回収するためにプラスチックと塩酸を接触させる塩化鉛抽出槽４０と、塩化鉛抽出槽により塩酸中に析出する塩化鉛を水素添加によって鉛に還元し鉛のみを回収する水素添加槽４３とを備えている。酢酸添加槽３５、水素添加槽４３などは、内壁の腐食を防止するために石英加工等の耐腐食処理が施されている。
【００４７】
プラスチック供給槽３４から酢酸添加槽３５へ投入されたプラスチックには、酢酸供給装置３６から酢酸が供給され、加熱される。酢酸鉛溶液及びプラスチックは、酢酸添加槽３５に接続された酢酸鉛分離槽３７に送られて分離され、酢酸鉛溶液は真空ポンプ３８により鉛回収槽３９へ送られる。加熱により軟化したプラスチックが鉛回収槽３９に混入するのを防止するために、真空ポンプ３８と酢酸鉛分離槽３７とは多孔質のフィルターを介して接続される。プラスチックは塩化鉛抽出槽４０に投入され、加熱される。加熱温度は温度調整器４７によって塩素含有プラスチックから塩化水素が発生する温度に制御され、酸化鉛以外の鉛成分が塩化鉛に変換される。水蒸気添加装置４１から水蒸気が供給されると、塩化鉛の溶解した塩酸が生じ、プラスチックから分離され、水素添加槽４３に投入される。これに、塩酸を希釈するために水供給槽４２から水が供給され、これにより鉛成分が沈澱する。この沈澱物に水素ボンベ４４より水素が供給されることによって高純度の鉛が得られる。廃液は、切り替えバルブ４６を制御することにより、フィルターの役割をするメッシュ板４８を通過して廃液タンク４５に送られる。
【００４８】
上述の操作によって、鉛は８０％以上の回収率で回収することができ、塩化水素による処理を繰り返すことによって鉛の回収率は更に向上する。
【００４９】
図７は、上記処理装置３３の酢酸添加装置３５の構成を示す図である。酢酸添加装置３５は金属製で、円筒状の内径を有するように形成され、内部には金属製の羽が付された撹拌軸４９が設置されている。攪拌軸４９はモーター５０によって回転される。
【００５０】
塩化鉛抽出槽４０も図７の酢酸添加槽３５と同様の内部構造に構成され、さらに、水蒸気流入弁と塩化鉛を取り出すための液体流出弁（図中省略）を備える。
【００５１】
鉛回収槽３９の酢酸鉛溶液には、図８に示すような亜鉛板５１が投入され、酢酸鉛水溶液が鉛回収槽３９に移送されると、亜鉛よりイオン化傾向の小さい鉛は亜鉛板の周りに析出する。
【００５２】
１９９０年の統計によると、安定剤の年間生産量が２６、０００トンであり、その中の鉛系安定剤から鉛を８０％の回収率で回収すると、年間１３、０００トンの鉛が回収出来る。また、このようにして鉛を回収することによって、有用資源の回収だけでなく、プラスチックの熱分解による残渣に鉛が混入することもなく、安全に廃棄できる。また、熱分解によって得られる油状生成物の鉛による汚染も防止され、高品質の燃料として利用することができる。
【００５３】
［熱分解の効率向上］
プラスチックは分子構造が長いために、溶融したときの粘性が高い。従って、加熱しても対流し難く、均一に加熱する事が難しい。現状では撹拌機等を設置して、溶融プラスチックの熱の均一性を確保しながら廃プラスチックの熱分解がおこなわれているが、１０ｔ／日程度の処理規模のポリ塩化ビニル混合廃プラスチックの油化装置を例に取ると、廃プラスチックを装置に投入してから、投入したプラスチックの処理が終了するまでには４時間程度の時間を要している。このために、装置の規模はそれなりの大さを必要とし、処理に必要な時間もある時間必要になり、当然、廃プラスチックの処理費用に影響が現れる。
【００５４】
本発明においては、粘性の高い溶融プラスチックを効率よく熱分解し、処理時間を大幅に短縮するために、プラスチックを溶融させた後に厚さを２０ｍｍ以下の薄層にして熱分解する。溶融プラスチックの薄層は、赤外光、マイクロ波等の電磁波または誘電加熱法により加熱する。この様にすることによって、赤外光等で外部から加熱するときに受熱面に比べ加熱を望む体積が小さいために加熱に要する時間が短時間ですみ、また、熱分解やポリ塩化ビニール等を含む時は脱塩化水素等によって発生するガスを効率的にプラスチックから除去できる。又、赤外光、マイクロ波等の電磁波または誘電加熱法による加熱は、プラスチックに直接接触しない離れた位置から実行できる。
【００５５】
溶融プラスチックの薄層は、ベルト状又は、ディスク状又は、円柱状又は、円状又は、線状の形状のキャリア上に形成する。これにより連続的に熱分解処理行うことができる。
【００５６】
図９は、溶融プラスチックを薄層状にして熱分解を行うための処理装置の第１の例を示す。この装置５２はステンレス製のベルト５３を有し、この上に溶融プラスチックの薄層が形成される。プラスチックは破砕した後にホッパ５４に投入される。プラスチックは加熱されながらスクリュー５５ａ、５５ｂ、５５ｃにより移送され、狭搾部５６でスクリュー５５ｂ、５５ｃに押し出され、ベルト５３両面に所定の厚さに塗布される。塗布されたプラスチックは、赤外ランプ５７により加熱される。あるいは誘電加熱方法で加熱しても良い。脱塩化水素室５８で２００〜４００℃に昇温され、廃プラスチックの中にポリ塩化ビニルが含まれる場合はプラスチックから塩化水素ガスが発生する。発生したガスは塩化水素出口５９から排気される。ベルト５３上のプラスチックは、狭搾部６０を通って熱分解室６１に入る。熱分解室６１で赤外ランプ５７によりプラスチックは２５０〜５５０℃に加熱され、熱分解される。もちろん誘電加熱方法により加熱しても良い。熱分解で生成そガスは生成ガス排気口６２から排気される。生成ガス排気口６２から排出したガスは凝縮され、液体の油を回収する。狭搾部６０で溶融プラスチックは一旦溜まり、脱塩化水素室５８と熱分解室６１とは溜った溶融プラスチックによって遮断される。同様に、狭搾部５６においても脱塩化水素室５８と熱分解室６１とは遮断され、これらの部分で発生したガスは互いに気密性が保たれ混合しない構造になっている。熱分解し終わったプラスチックの残渣は掻き取り刃６３ａ、６３ｂによりベルト５３から取り除かれる。取り除かれた残渣は残渣排出部６４のスクリューにより装置の外へ排出される。ベルトは歯車６５の回転によって走行する。
【００５７】
図１０は、溶融プラスチックを薄層状にして熱分解を行うための処理装置の第２の例を示す。この装置６６は、キャリアとして環状のディスク６７を有する。プラスチックはプラスチック塗布部６８によってディスク６７に塗布され、駆動歯車６９によって回転されるディスク６７によって搬送される。塗布されたプラスチックは、赤外ランプ７０によって２５０〜５５０℃の温度に加熱される。残渣は残渣掻き取り刃７１によってディスク６７から除去される。熱分解した時に発生する分解生成物の蒸気は排気口７２より排気された後冷却・液化され、油を回収する。
【００５８】
図１１はプラスチック塗布部６８の構成を示す。
【００５９】
廃プラスチックは粉砕された後にホッパー７３に投入され、温められながらスクリュー７５ａ、７５ｂによりアーム７４内を搬送される。溶融したプラスチックはスクリュー７５ｂによってスリット７６から押し出され、ディスク６７に塗布される。アーム７４のスリット７６間の隙間ｄと押し出し圧力を調整することにより塗布されるプラスチックの厚さが調整される。
【００６０】
ディスク６７に付着した残渣は、図１２に示すように、ディスク６７の両側に先端を接している一対の掻き取り刃７１によって除去される。残渣は残渣排出部６４に溜まり、残渣を排出するためのスクリュー７７で装置の外へ排除される。排除した残渣は貯蔵用のタンク７８に貯められる。
【００６１】
回転するディスクやベルトが、線状物、円形物、円筒物であってもよい。
【００６２】
図１３は、溶融プラスチックを薄層状にして熱分解を行うための処理装置の第３の例を示す。この装置７８は、第１の例と同じベルトを用いるタイプであるが、第２の例と同様、部屋を１つしか持たない。溶融プラスチックはベルト７９に塗布されると、走行用回転体８０によって搬送され、赤外ランプ８１によって加熱される。熱分解生成物の蒸気は排気口８３から排出され、凝縮器などによって回収される。熱分解残渣は掻き取り刃８２によってベルト７９から除去される。
【００６３】
上述のような溶融プラスチックを薄層状態にして処理する方法は、前述の可塑剤の除去に応用することもできる。例えば、廃プラスチックを溶融した後に薄層状態とし、水蒸気あるいは加熱水と接触させて可塑剤を除去し、この後鉛の除去処理を経た後に、再度キャリア上に薄層状態に塗布して熱分解を行うように構成することができる。
【００６４】
［エネルギー効率の向上］
溶融プラスチックの粘性の高さは、エネルギー効率の低下にもつながる問題である。バッチ式であれ、連続工程であれ、溶融プラスチックに熱エネルギーを与える場合にはプラスチックの塊の外側から加熱するのが通常である。しかし、粘性の高いプラスチックの外側から熱を加えても、内部にまで熱が達するには時間が係る。又、脱離したハロゲン化水素や熱分解生成物のガスがプラスチックから放出される段階では、プラスチックからガスが放出される方向と外部からプラスチックに熱を与える方向が逆方向となるため、内部まで熱が伝達され難く、プラスチックの表面部分の反応は早いが内部は反応しにくい状態となる。これを解消するために攪拌が行われるが、さらに熱効率をよくする工夫として、加熱軸部材を使用する。加熱軸部材は、溶融プラスチックの塊の中央部に配置され、プラスチックを内部側から加熱するもので、攪拌装置の軸として用いるのが最も効率的である。更に、加熱軸部材を中空筒形等に構成して軸内外を連通する多数の細孔を設け、窒素、水蒸気、不活性ガスなどの等活性の低いガスを加熱してこの加熱軸部材内からプラスチック中へ吹き込むようにすると、内部側からの加熱及び熱伝導を加熱ガスによって促進することになり、攪拌効率及び熱効率がさらに向上する。
【００６５】
図１４の（ａ）及び図１５は、本発明に従って加熱軸部材を備えるプラスチックの処理装置の第１の例を示す。この処理装置８４は、外筒８５と、外筒８５内に同軸状且つ回転可能に設けられる攪拌装置８６とを備え、攪拌装置８６は加熱軸部材８７とこの外周に螺旋羽８８を有しており、モーター８９によって回転される。加熱軸部材８７は中空で多数の細孔９０が設けられており、ガス供給器９１から送られる低活性なガスは、加熱軸部材８７に設けられたヒーター９２によって加熱されて細孔９０から外筒８５内部に供給され、外筒８５に接続された配管９３を介して回収される。外筒８５は断熱材９４に覆われている。
【００６６】
プラスチックは、外筒８５一端の供給槽９５から制御弁９６が取り付けられた供給口を通じて外筒８５内に供給され、ヒーター９２を作動させると共に、プラスチックの軟化が始まる１００℃付近に到達した時点で、ガス供給器９１から弁９８介して供給される活性の低いガスを加熱軸部材８７の細孔９０を介して放出させる。加熱溶融されたプラスチックは、モーター８９による加熱軸部材８７の回転に従って他端の排出口９７へ向かって徐々に搬送される。この間、低活性なガスはヒーター９２によって加熱される。プラスチックから放出された低活性なガス、プラスチックから脱離した塩化水素及びガス状熱分解生成物は配管９３を介して回収される。加熱ガスの供給は、プラスチックの軟化を促進すると共に、プラスチック内への発泡により樹脂の高分子鎖の機械的切断にも有効に働く。更に、脱ハロゲン化水素時にハロゲン化水素の溶融プラスチックからの放出を促進する。使用される低活性なガスは、実質的にプラスチックの熱分解に有害な影響を与えないガスであればよく、アルゴン、ヘリウム、ネオン、キセノン、クリプトン等の不活性ガスや窒素、水蒸気等から適宜選択することができる。経済的には窒素が好ましい。水蒸気を用いる場合は、他の利点がある。それは、前に述べたように、プラスチックからの可塑剤の除去を促進する働きを同時にするということである。
【００６７】
加熱軸部材８７の温度は、供給口からの長手軸方向の距離に応じて、図１４の（ｂ）のグラフに示すように設定される。
【００６８】
供給口からの距離が、長手方向の全長に対して１／１０〜１／５の位置で投入したプラスチックの温度が約２５０℃に到達し（図１４（ｂ）中のａ点）、この位置から長手方向の全長に対して１／２の位置（ｂ点）まで約２５０℃に維持される。区間ａ−ｂにおいてプラスチックに含まれる可塑材の分解が進行する。
【００６９】
ｂ点までの温度設定については次のようにすると更に好ましい。まず、ａ点における温度を２００℃とし、その後、区間ａ−ｂの半分〜１／３程度の間に徐々に２５０℃まで昇温し、その後、ｂ点まで２５０℃に維持する。このように２００〜２５０℃の昇温を緩やかに行うと、可塑剤の除去効率が向上する。２００〜２５０℃の昇温区間と２５０℃での保温区間とを長くするために、２００℃までの昇温をできる限り速やかに行うのが望ましい。
【００７０】
更に、供給口からの距離が長手方向の全長に対して３／５となる位置（ｃ点）で３００℃となるように温度を上昇させ、この温度で排出口９７寸前まで保つように設定される。区間ｃ−ｄで脱ハロゲン化水素が進行する。区間ａ−ｂで回収されるガスと区間ｃ−ｄで回収されるガスとを別々に回収することにより、有機ハロゲン化合物の生成が抑制され、区間ｃ−ｄで回収されるガスを洗浄すれば、熱分解によって生じる炭化水素化合物とハロゲン化水素とは容易に分離される。前述のように、区間ａ−ｂの途中でアルカリ添加を行えば、更に可塑材の除去回収と有機ハロゲン化合物の生成防止が効率よく行われる。
【００７１】
図１６は、本発明に従って加熱軸部材を備えるプラスチックの処理装置の第２の例を示す。この処理装置９５は、加熱軸部材８７を備える複数の攪拌装置８６ａ、８６ｂを有し、互いに反対向きに回転する。この例においては、ヒーター９６は各加熱軸部材８７の内径部に設けられている。又、
２つの加熱軸部材８７の外周面に、一定間隔で断面が波形になるように溝を設けてもよい。これによって、外周面の表面積が増大し、反応効率が向上するだけでなく、不活性ガスの注入口や発生ガス排出口の目詰まりを防止することが可能となる。
【００７２】
図１７は、本発明に従って加熱軸部材を備えるプラスチックの処理装置の第３の例を示す。この処理装置９７は、第１の例と同様の加熱軸部材８７を有する攪拌装置８６を備えているが、外筒９８及び断熱材９９は直方体型に形成され、外筒９８の内径は８角柱形である。これ以外の点については第１の例と、同様である。
【００７３】
［脱ハロゲン化水素の促進］
低活性の加熱ガスを送って溶融プラスチックの内部側から加熱する上述の構成は、エネルギー効率の向上及び脱離したハロゲン化水素の除去促進に有効であることを上記で説明したが、ハロゲン化水素や可塑剤及び可塑剤の分解物などを溶融プラスチックから放出・除去するには、加熱ガスを溶融プラスチックに供給することが効果的である。この目的のために、溶融プラスチックに供給するガスのは約１５０〜４００℃に加熱する。約１５０〜３００℃の範囲は主に可塑剤などを除去する目的で、約２５０〜４００℃の範囲はハロゲン化水素の除去を目的として使用する。それを温度範囲３５０〜５００℃の加熱ガスを使用すれば、プラスチックが熱分解し、油状生成物、炭化残渣、低炭素数の燃料ガス等が生成する。ハロゲン化水素や可塑剤等の放出のためには、加熱ガスと溶融プラスチックの接触面積を大きくすることが肝要であり、プラスチック全体に均一にガスを供給できることが好ましい。従って、大量の細かい気泡を均一に供給できるようなに工夫する。この様なガスによる処理は、前に述べた可塑剤及びハロゲン化水素の除去処理と併用することによって、プラスチックに残留するこれらの量を更に低減することができる。
【００７４】
図１８は、本発明に従ってハロゲン化水素及び可塑剤を除去するプラスチックの処理装置の例である。この処理装置１００は、一般的なエクストルーダの構成を応用したもので、加熱装置を備えたエクストルーダ部１０１及びこの中に配置されたスクリュー１０２を有し、スクリュー１０２の軸及び羽は中空状に形成され、細孔１０３が多数設けられている。更に、スクリュー１０２の軸はジョイントを介してガス供給口１０４を有する管と連通されており、ガス供給口１０４から供給されたガスを加熱するヒーター１０５が設けられている。スクリュー１０２はモーター１０６によって回転する。
【００７５】
投入部１０７から投入され溶融したプラスチックは、エクストルーダ部１０１の内部のスクリュ−１０２の回転によって押し流され、ヒーター１０５で所定温度に加熱されたガスがスクリューの軸及び羽の細孔１０３からプラスチックへ泡状に放出され、プラスチックを加熱する。エクストルーダ部１０１内のプラスチックは、長手方向に沿って温度勾配が生じるように、ヒーター１０５及びエクストルーダ１０１に備えられた加熱装置を用いて調節する。この温度勾配は、投入部１０７に近い位置に形成された第１排気部付近で可塑剤及び可塑剤の分解物がプラスチックから放出され、ヒーター１０５に近い位置に形成された第２排気部付近でハロゲン化水素が発生するような、第１排気部１０８付近の温度より第２排気部１１０付近の方が高い設定である。このような温度設定をするのに加熱ガスの加熱による自然温度勾配で充分な場合には、エクストルーダ部１０１の加熱装置の作動は不要となる。プラスチックから加熱ガスと共に放出された可塑剤及び可塑剤の分解物は、第１排気部１０８からポンプ１０９によって装置外へ排出される。ハロゲン化水素は加熱ガスと共に第２排気部１１０からポンプ１１１によって排出される。エクストルーダ部１０１内で可塑剤及びその分解物が除去され、ハロゲン化水素が放出されたプラスチックは、排出口１１２から装置外に排出される。
【００７６】
上記図１８の処理装置１００を応用したプラスチックの熱分解装置の例を図１９に示す。この熱分解装置１１３は、前処理部１１４とこれに接続された熱分解槽１１５とを有しており、前処理部１１４は上述の処理装置１００と同様の構成を有している。
【００７７】
前処理部１１４によって可塑剤及びハロゲン要素を除去された溶融プラスチックは、熱分解槽１１５に供給する。熱分解槽１１５は、ヒーター１１９及び攪拌装置１２０を備え、溶融プラスチックを攪拌装置１２０で攪拌しながらヒーター１１９で熱分解温度に加熱して熱分解する。熱分解により生じたガス状低分子生成物は凝縮器１１６で冷却されて、一部は液化して油になり生成油タンク１１７に貯蔵され、凝縮器で液化されなかった成分は排ガス処理装置１１８で処理される。熱分解槽１１５の下部に残渣排出部１２１が設けられ、炭化した残渣を排出し残渣タンク１２２に貯蔵する。
【００７８】
［作業性の向上］
ＰＶＣ、ポリ塩化ビフェニル、ＰＶＣ−ポリ塩化ビニリデン共重合体のようなハロゲン含有プラスチックは、加熱溶融した際に非常に粘性が高く、ハロゲン化水素の脱離によって一旦粘性が急激に低下し流動性が増すが、この後熱分解による炭化の進行に従って粘性が増大する。従って、一般的な方法で熱分解を行うと、熱を受け易い表面において部分的に炭化による粘度上昇が起こり、プラスチック塊が分解槽壁面等に付着する。ハロゲン含有プラスチックの熱分解残渣はハロゲンを含有しないプラスチックの熱分解残渣と比べて固く、壁面等に付着した残渣を除去するのは容易ではない。又、加熱装置、反応槽、滞留槽、装置間を結ぶ配管の内面や装置内部に設置した撹拌装置の表面等に残渣や熱分解中の高粘度のプラスチックが付着すると、分解槽内のプラスチックの流動性を阻害するばかりでなく、加熱時の熱伝達の悪化ももたらす。このため、プラスチックが装置及び配送管中で付着することなく移動できることが、処理効率を上げるために重要であり、特に連続処理において熱分解中のプラスチックの流動性をできる限り保つ必要がある。
【００７９】
本発明においては、ハロゲン含有プラスチックから可塑剤とハロゲン化水素を除去した前処理済みプラスチック及び熱分解残渣が装置壁面に付着するのを抑制するための付着抑制剤を添加して熱分解する。付着抑制剤及びこの添加方法は、２種類に分類される。
【００８０】
１つは、ハロゲンを含有しないプラスチックを添加して熱分解するもので、ＰＥやＰＰ等のハロゲンを含有しないプラスチックは加熱により低粘度の溶融物となり、熱分解残渣も柔らかく容易に装置から除去できる。従って、ハロゲンを含有しないプラスチックを混合して熱分解することにより、混合物の粘度は、前処理済みプラスチックのみのものより増加が抑制され、流動性が保持される。
【００８１】
もう１つは、脱ハロゲン化水素の温度からプラスチックの熱分解温度の範囲において低粘度の液体として存在し得る重質の油分を添加して熱分解するもので、特に、装置内壁と接触する部分付近に添加しながら熱分解を行うと効率がよい。重質の油分を添加することによって、同様に混合物の粘度が低下し、流動性が高められて装置壁面への付着が抑制される。例えば、パラフィン、高級脂肪酸、ワックス、鉱油、植物性油脂、動物性油脂などがある。
【００８２】
図２０は、可塑剤除去処理及び脱ハロゲン化水素処理をハロゲン含有プラスチックに施した後に、付着抑制剤を用いて熱分解を行う熱分解装置の一例を示す。この熱分解装置１２３は、プラスチックから可塑剤を除去するための第１前処理装置１２４と、塩化水素を脱離するための第２前処理装置１２５と、加熱溶融槽１４２と、重質油添加装置１２７と、加熱分解槽１２８とを備えている。
【００８３】
第１前処理装置１２４は、前述した図１４あるいは図１８の装置と同様の構造のエクストルーダ型装置で、保温効果を高めるための断熱材に覆われた外筒と、内部にヒーターを内蔵し外筒内径に回転可能に配置されたスクリューとを有する。第１前処理装置１２４の一端側に供給弁１３２を介してプラスチック供給槽が結合され、他端は移送弁を介して第２前処理装置１２５と接続される。更に、不活性ガス供給器１３３、ガス化成分回収槽１３４及び循環ポンプ１３５が接続され、不活性ガス供給器１３３から供給された不活性ガスは、第１前処理装置１２４内を一端側から他端側へ通過した後、ガス化成分回収槽１３４においてガス化成分が除去され、循環ポンプ１３５によって再度第１前処理装置１２４に導入される。
【００８４】
第２前処理装置１２５も第１前処理装置１２４と同様のエクストルーダ型装置で、一端は移送弁１３６に接続され、他端は加熱溶融槽１２６に接続される。更に、不活性ガス供給器１３７、ガス化成分回収槽１３８及び循環ポンプ１３９が接続される。
【００８５】
加熱溶融槽１２６には供給弁１４１を介してプラスチック供給槽１４０が接続され、第２前処理装置と加熱溶融槽１２６との間の移送配管及び供給弁１４１と加熱溶融槽１２６との間の接続管に重油添加装置１２７が接続されている。更に、蒸留装置１２９が加熱溶融槽１２６と接続されている。加熱溶融槽１２６内には攪拌器が備えられており、底部には残渣排出口が設けられている。又、加熱溶融槽１２６の下部と加熱分解槽の頂部は移送弁１４３を介して接続され、この接続配管は保温のための断熱材によって覆われている。
【００８６】
加熱分解槽１２８はヒーターを有し、内部に攪拌装置が備えられている。更に、底部には残渣排出口が設けられ、頂部は蒸留装置１３０に接続されている。
【００８７】
プラスチック供給槽１３１から第１前処理装置１２４に投入したプラスチックは、２３０〜２８０℃程度に加熱されて溶融し、フタル酸系可塑剤及びその分解物が放出され、不活性ガスに運ばれてガス化成分回収槽１３４で回収される。アルカリがプラスチックに添加されればフタル酸系以外の可塑剤の分解物も回収される。分解物溶融プラスチックは第２前処理装置１２５に送られ、第２前処理装置において３３０℃程度まで加熱され、ハロゲン含有プラスチックからハロゲン化水素が脱離して不活性ガスと共にガス化成分回収槽１３８へ送られる。
【００８８】
脱可塑剤処理及び脱ハロゲン化水素処理を経た溶融プラスチックは加熱溶融槽１２６に投入され、温度が急速に低下しない程度に保持したまま、加熱した重質性の油が添加される。加熱溶融槽１２６と接続した移送配管の内壁に沿って重質性の油を添加することによって、移送配管中でプラスチックの流動性が高まり、移送し易くなる。又、プラスチック供給槽１４０から加熱溶融槽へポリプロピレン等のハロゲンを含まないプラスチックあるいはハロゲンを含まないプラスチックを多量に含む混合物をあらかじめ投入し加熱、溶融させて、３５０〜３８０℃に保持しておく。加熱溶融槽１２６内の液面が槽の底部からおよそ５０〜８０％の位置になるように第２前処理装置１２５から溶融プラスチックを投入しながら撹拌し、底部の残渣排出口１４２から固形成分を分離する。また、一部加熱溶融槽１２６内でガス化したものについては、上部の配管から蒸留装置１２９に導き、沸点に応じて化合物を分離する。
【００８９】
加熱溶融槽１２６の溶融プラスチックは加熱分解槽１２８に投入され、攪拌しながら約４５０℃以上に加熱し熱分解する。加熱分解槽１２８から蒸留装置１３０へ導入されたガス化成分は、沸点によって分離される。加熱溶融槽１２８の下部から炭化成分等が除去される。
【００９０】
図２１は、図２０における熱分解装置１２３の加熱溶融槽２６の変形例で、連続操作に適したエクストルーダ型の装置に構成され、重質性の油を付着抑制剤として用いる。この装置１５５は、スクリュー１４５を内部に備えた中空円筒型の外筒１４７と、スクリュー１４５を回転させるモーター１４６とを備え、外筒１４７は断熱材で覆われている。外筒１４７の一端にはプラスチック投入口１５０と気流入口１４９が設けられ、他端には気流出口１５１及び排出口１５２が設けられ、重質油供給管１５４が接続されている。外筒１４７の内壁には多数の重質油注入溝１５３が形成され、重質油供給管１５４と連通している。
【００９１】
投入口１５０から投入された溶融プラスチックは、気流入口１４９から供給される加熱ガスによって所定温度に保温されながら、スクリュー１４５の回転に従って排出口１５２の方向へ搬送される。この間、重質油供給管１５４から供給される重質油は重質油注入溝１５３からプラスチックに添加される。重質油の添加によってプラスチックは外周付近の粘度が低下し、外筒１４７の内径面に付着するのが抑制され、プラスチックに浸透するに従って、プラスチック全体の粘度が低下する。
【００９２】
図２１に示されるような装置内壁に重質油注入溝を設ける構成は、図２０の前処理装置１２４、１２５に応用してもよい。
【００９３】
又、図２１に示されるような装置内壁に重質油注入溝を設ける構成は、図２０におけるバッチ式の加熱溶融槽にも適用できる。図２２はその一例を示し、この加熱溶融槽１２６’は、内部に４枚の攪拌羽１５７を有する回転軸１５６を備え、これはモーターによって回転される。加熱溶融槽１２６’の上部には重質油注入口１５８、投入口１５９、プラスチック供給口１６０及びガス排出口１６１が設けられ、重質油注入口１５８から加熱溶融槽１２６’内に重質油が供給できるように、加熱溶融槽１２６’の内壁に設けられた多数の重質油注入溝と重質油注入口１５８とが連通している。
【００９４】
この加熱溶融槽１２６’においては、重質油注入口１５８から重油を供給しながら投入口１５９から溶融プラスチックを投入することによって、内壁面への残渣等の付着が効果的に抑制される。
【００９５】
図２３は、付着抑制剤を用いて熱分解を行う熱分解装置の他の例を示す。この熱分解装置１６３は、図２０と同じ構成の第１前処理装置１２４及び第２前処理装置１２５を備えるが、加熱溶融槽１２６及び加熱分解槽１２８の役割をエクストルーダ型の加熱反応槽１６５を用いて行うことを特徴とし、第２前処理装置１２５と加熱反応槽１６５の一端とを接続する配管に重質油添加装置１６４から重質油が供給される。加熱反応槽１６５の他端には残渣回収槽１６６及び蒸留装置１６７が接続され、蒸留装置１６７はさらに加熱反応槽１６５の中央部付近とも接続されている。また、加熱反応槽１６５の内側から外側に熱が伝わるように加熱反応槽１６５内のスクリュー軸内にはヒーターが備え付けてあり、さらに重質性の油がスクリュー軸表面上に供給されるようにスクリュー軸に溝が形成されている。加熱反応槽１６５内の温度は、長手方向に沿って３つの部分に分けて制御される。
【００９６】
熱分解装置１６３において、図２０の場合と同様に可塑剤除去処理及び脱ハロゲン化水素処理を行った溶融プラスチックは、重質油が添加された後に加熱反応槽１６５で混練され、更に熱分解され、熱分解残渣は残渣回収槽１６６へ押し出される。熱分解によるガス状生成物は蒸留装置１６７で沸点によって分けられる。
【００９７】
図２４は、図２０に示した熱分解装置１２３の加熱溶融槽１２６の応用例で、加熱溶融槽１６８の下部に残渣の分離機能を有する排出口１７７を有する。更に、図２２と同様に側部壁面１７６には加熱溶融槽１２６に重質油を注入する注入口が設けられる（図中省略）。前処理装置から移送された溶融プラスチックを投入口１７２から投入するときに、加熱溶融槽１６８の壁面から重質性の油を壁面に沿わせて注入しながら攪拌羽１７０の付いた攪拌軸１６９をモーター１７１で回転し、残渣を液状物と分離して排出口１７７から排出した後、加熱溶融槽１６８内にハロゲンを含有しないプラスチックをプラスチック供給口２０５から投入し、余熱を利用し軟化させる。その後ヒーター１７５を用いて加熱し、プラスチックを溶融させ３５０〜３８０℃の範囲に保たれる。その後、プラスチックは加熱分解槽に送られ熱分解される。攪拌軸１６９及び攪拌羽１７０の内部に加熱線などの加熱手段を設けると、更に作業効率が上がり、攪拌に必要なエネルギーも減少する。
【００９８】
前述の脱ハロゲン化水素工程等の前処理工程は、ＰＶＣ等に必要なものであるので、このような前処理の必要なプラスチックと不要なプラスチックを分別できる場合には、前処理の不要なプラスチックは加熱溶融槽１６８等で添加するのがエネルギー効率上好ましく、又、ポリオレフィン等は溶融粘度が低いので、加熱溶融槽１６８において余熱などによって溶融しても作業性の面で何等問題はない。
【００９９】
［熱分解生成物のハロゲン除去］
前述において、プラスチックの熱分解で高品質の熱分解生成物を得るための対処方法について説明したが、廃プラスチックの内容を正確に把握するのは困難であるため、不測の事態として生成物が有機ハロゲン化合物によって汚染される場合が生じ得る。従って、この様な場合に対する対処も廃プラスチックの資源化再利用を広める上で重要である。
【０１００】
本発明においては、有機ハロゲン化合物による汚染に対する対処法として、熱分解生成物を１５０〜５５０℃に加熱した活性炭及びハロゲン化水素トラップ剤と接触させる。
【０１０１】
ハロゲン含有プラスチックを含む混合プラスチックを加熱したとき得られる熱分解生成物は、有機ハロゲン化合物を含んでいることがあるが、これを気体の状態で活性炭と接触させると、ラジカル反応によるハロゲン化水素の脱離反応により有機塩素化合物は分解する。この時、ハロゲン化水素トラップ剤を共存させると、発生したハロゲン化水素がトラップ剤に吸着される。従って、有機ハロゲン化物の汚染は解消される。従って、プラスチックの熱分解によって生じたガス状生成物を活性炭のカラム及びハロゲン化水素トラップ剤のカラムを通過させればよい。活性炭によるハロゲン化水素の脱離反応は１５０℃未満の温度では反応速度が遅く、５５０℃以上では副生成物を多く生成するので、１５０〜５５０℃の範囲で上記の処理を行うことが望ましい。活性炭とハロゲン化水素トラップ剤とは混在させる必要はなく、活性炭と接触させた後にハロゲン化水素トラップ剤と接触させるようにしてもよい。
【０１０２】
ハロゲン化水素トラップ剤は、ハロゲン化水素を吸着あるいは吸収できるものであればよく、例えば、アルカリ金属やアルカリ土類金属及びこれらの水酸化物のような一般的にアルカリ資材として用いられるもの、ハロゲン化水素が吸着されるような表面処理を施した担体等が挙げられる。
【０１０３】
図２５は、熱分解生成物のハロゲン除去処理を行うための処理装置の例を示す。この処理装置１７８は、熱分解する原料１８０を投入するフラスコ１７９と、フラスコ１７９を加熱するマントルヒータ１８１と、フラスコ１７９に接続されるカラム１８２と、カラム１８２を加熱するための横型炉１８３と、カラム１８２に接続される凝縮器１８５と、凝縮器１８５に接続される回収容器１８６及び排ガス容器１８７とを備える。横型炉１８３の温度はコントローラ１８４によって制御する。カラム１８２には、活性炭と表面に塩化水素を吸着する表面処理を施した活性炭との混合物が充填されている。
【０１０４】
プラスチックはフラスコ１７９に投入しマントルヒータ１８１により加熱して熱分解する。熱分解により生じるガス状生成物は、カラム１８２に達し、活性炭により有機ハロゲン化合物からハロゲン化水素が脱離し、硫酸銅及び硫酸亜鉛を表面に付着させた活性炭によってハロゲン化水素が吸着される。脱ハロゲンされたガス状熱分解生成物は、凝縮器１８５によって冷却・凝縮され、液化生成物が回収容器１８６に収容される。凝縮しなかったガスは排ガス容器１８７に導入される。
【０１０５】
図２６は、熱分解生成物のハロゲン除去処理を行うための処理装置を備えた熱分解装置の例を示す。この熱分解装置１８８は、ホッパ１８９が接続されたエクストルーダ１９０と、ヒーター１９２を有する熱分解槽１９１と、ハロゲン除去部１９３と、凝縮器１９６と回収タンク１９７とを備え、ハロゲン除去部１９３は、直列に連結された活性炭カラム１９４及びハロゲン化水素除去カラム１９５からなる。
【０１０６】
ホッパ１８９から投入されたプラスチックは、エクストルーダ１９０で加熱され、溶融、可塑剤除去及び脱塩化水素が行われる。その後、溶融プラスチックは熱分解槽１９１に搬送され、熱分解される。熱分解槽１９１から放出される熱分解生成物の蒸気はハロゲン除去部１９３に送られる。活性炭カラム１９４において有機ハロゲン化合物からハロゲン化水素が脱離し、脱離したハロゲン化水素はハロゲン化水素除去カラム１９５に吸着される。ハロゲンが除去された分解生成物蒸気は凝縮器１９６により冷却・液化され、回収タンク１９７に貯蔵される。
【０１０７】
［熱分解生成物の精製］
廃プラスチックの内容及び量は、時と場所により大きく変化するため、熱分解によって生じる生成物の組成や量の変動も大きい。このため、分解生成物の精製を行う場合、従来の精製装置ではこのような変動に充分に対応できない。本発明においては、熱分解生成物の精製においてこのような組成変化や精製量の変動に対応するために、棚段の穴の数を変更可能な棚段式蒸留装置を使用する。精製する蒸気量が増加するに従って棚段の穴数が増加するように制御することによって、各棚段に溜る液の高さを一定にすることができる。従って、精製効率を大幅に変化させることなく、取り扱う蒸気量の変化に対応することができる。
【０１０８】
図２７は、本実施例に従って熱分解生成物の精製を行う蒸留装置の一例を示す。この蒸留装置１９８は、底部のリボイラと、リボイラ上に立設され複数の棚段２００が配設さた蒸留塔１９９とを備え、熱分解槽から送られる熱分解生成物蒸気の中に混入する固体粒子を除去するためのフィルター２０３が塔に接続されている。又、２から５個程度のリフラックス２０２ａ〜ｄが蒸留塔１９９内の余分な熱を追い出すために接続されている。塔にはストリッパー２０６が接続され、塔頂及びリボイラには環流装置２０４、２０５が接続されている。
【０１０９】
棚段２００は、穴の数を増減させるために、図２８に示されるように、中心を軸としてに相対的に回転可能なように重ね合わせた２枚の円盤２０７、２０８から構成される。円盤２０７には所定の大きさの穴２０９が多数設けられ、円盤２０８には複数のスリット２１０が形成されており、２枚の円盤を回転して相対位置を変えることによってスリット２１０と重なる穴２０９の数が変化する。これにより棚段２００の実効的な穴の数を変更することができる。
【０１１０】
円盤の穴２０９の大きさは２〜８ｍｍであるのが好ましく、これ以上の大きさであると精留効果が低下する。穴の数は、棚段の直径が１０２ｍｍ程度の場合、２〜１００個／棚の範囲で変更可能なように設定すると好ましく、棚段の大きさに応じて適宜設定する。
【０１１１】
図２９は、穴数が変更可能な棚段の他の例を示し、この例においては、棚段２１１に設けられた穴２１２を開閉する弁２１３が取り付けられており、弁２１３に接続されたアームに取り付けられたバネによって弁２１３は穴２１２を閉じるように付勢され、紐２１５によってアームを操作することによって穴２１２を開閉する。
【０１１２】
図３０は、図２７の蒸留装置を組み込んだ熱分解装置の例である。この熱分解装置２１６は、ホッパを有するエクストルーダ２１７と、熱分解槽２１８と、蒸留装置１９８と、回収容器２１９〜２２２とを備える。ホッパからエクストルーダ２１７へ投入された配プラスチックは、加熱溶融と共に前述の可塑剤除去処理や脱ハロゲン化水素処理が行われた後に、熱分解槽２１８へ供給され、熱分解生成物の蒸気が固体粒子分離用フィルタ（図中省略）を介して蒸留塔１９９へ送られる。
【０１１３】
［熱分解装置の設計］
処理する廃プラスチックの内容が全く不明で回収される生成物に要求される品質が高い場合と、ある程度内容を知ることができる廃プラスチックを処理する場合とでは、熱分解生成物蒸気の脱ハロゲン処理の必要度が全く異なる。従って、上記において説明した各処理方法及び装置は、処理するプラスチックの性状及び形状、回収される熱分解生成物に必要とされる品質、経済性及び回収効率等に応じて、適宜組み合わせを変更して使用する。
【０１１４】
上述の図面を参照した例は、本発明に係るプラスチックの処理装置を具体化するための技術思想を説明する目的で例示したのもであり、本発明は上記の構造に限定されるものではない。
【０１１５】
【実施例】
以下、実施例及び比較例により、本発明をさらに詳細に説明する。尚、以下の実施例及び比較例において、特に言及がない場合、「％」、「部」は、重量よって表示するものとする。
【０１１６】
（実施例１）
図１の装置１を用いて、加熱蒸気発生装置２を作動し、水蒸気流量が安定したところで蒸気放出管３から水蒸気を噴出させた。水蒸気の温度は１５０℃以上２８０℃未満に設定して運転を続けた。巻き取り機をゆっくりと回転させ、可塑剤を３５％含む厚さ０．２ｍｍのフィルム状プラスチックＰが一様に２分以上温水の中に浸るように走行させて配合剤の溶出を促進させた。一通りフィルムを水中に通過させた後、回転装置を反転させてプラスチックＰを逆方向に走行させながら樹脂からの配合物質の溶出を継続した。この時、ローラー間を通過していくフィルムの破損を避けるため、ローラーに挟まれることによる圧縮力を低く抑えるように隙間の幅を調整した。
【０１１７】
巻き取り及び反転を２回繰り返した後、巻き取ったフィルム状プラスチックＰに配合されていた可塑剤の含有量を調べてみたところ、約１／２０に減少していた。
【０１１８】
（実施例２）
図２の装置を用いて、加圧ポンプ１４及び回収４ポンプを駆動し、水の循環流量が安定したところでヒーター１３を作動させる。水温は９０℃以上１００℃未満に設定した。回転体６、８をゆっくりと回転させ、可塑剤を３０％含む厚さ０．２ｍｍのフィルム状プラスチックＰを一様に２分以上加熱水の中に浸るように走行させて配合剤の溶出を促進させた。一通りフィルムを水中に通過させた後、回転体６、８を反転させ、プラスチックを逆方向に走行させながら樹脂からの配合物質の溶出を継続した。この時、ローラー間を通過していくプラスチックの破損を避けるため、ローラーに挟まれることによる圧縮力を低く抑えるように隙間の幅を調整した。
【０１１９】
巻き取り及び反転を２回繰り返した後、巻き取ったプラスチックに配合されていた可塑剤の含有量を調べてみたところ、約１／８に減少していることがわかった。
【０１２０】
（実施例３）
図３の装置を用いて、可塑剤を２７％含む厚さ０．１５ｍｍのＰＶＣフィルムと層状セルロース性繊維でできた吸収体１７とを重ねたものをロール状に巻き付ける。このロール状に巻き付けたものを溶出促進槽１８内に入れ、俵積みの状態に重ねておく。次に溶出促進槽１８の内部に水を注入し、吸着体１７に滲み込ませる。最上段のロールにかぶるくらいにまで水を注入した後、静置し、水位の低下がほぼ落ちついたところで上部の蓋２２を閉め、加熱ヒーター１９を作動させる。温度は９０℃以上１００℃未満に設定した。２週間以上、温度をほぼ一定に保った後、ロール状のフィルムを回収した。
【０１２１】
回収されたＰＶＣフィルムに配合されていた可塑剤の含有量を調べてみたところ、約１／１０に減少していることがわかった。
【０１２２】
（実施例４）
図４の装置を用いて、可塑剤を３３％含む厚さ０．２ｍｍのフィルム状ＰＶＣとセルロース性の繊維でできた吸収体２９とを層状に相互に重ねて温水槽２６内に積み重ねた。循環ポンプと加圧ポンプを駆動して水の循環流量が安定したところで溶媒としての水を温めるヒーター２４を作動させた。吸収体２９の温度は９０℃以上１００℃未満に設定して運転を続けた。太陽光が強い昼間の間は、太陽光線による熱エネルギーでハウス内の中心部の気温を４０℃に保つように制御することによって、ヒーター２４を弱めても吸収体２９の温度を維持することが可能であった。ハウス２７の内部で気化した物質はハウス上部で凝縮し、回収路２８を通じて回収された。また、ハウスの保温効果により温水槽内の温水の単位時間当たりの供給量は減少していった。約２週間吸収体２９の温度を保った後、引き上げ機２５を用いてゆっくりとＰＶＣを回収した。
【０１２３】
回収したＰＶＣに配合されていた可塑剤の含有量を調べてみたところ、約１／１０に減少していた。
【０１２４】
（実施例５）
図１の装置を用いて、ポリ塩化ビニルを重量比で６６％含む厚さ０．３ｍｍのフィルムをアルミニウム箔の両面に張り合わせたラミネート構造のフィルムの添加剤除去処理を以下のように行った。
【０１２５】
始めに、加熱蒸気発生装置２を作動し、蒸気流量が安定したところで蒸気放出配管３から蒸気を噴出させた。蒸気温度は、１回目の巻き取り及び反転の場合に２００℃以上２８０℃未満の蒸気が発生するようし、２回目の巻き取り及び反転の場合に２８０℃以上３５０℃未満の蒸気が発生するように設定した。これは１回目の巻き取り及び反転で可塑剤などの配合剤の溶出を促し、２回目の巻き取り及び反転で塩化水素の溶出を促すことを目的としている。回転体６、８をゆっくりと回転させ、フィルムが一様に１分以上蒸気と接するようにして、添加剤、塩化水素の溶出を促進させた。この時、回転体８間を通過していくフィルムの破損を避けるため、回転体８に挟まれることによる圧縮力を低く抑えるように隙間の幅を調整した。
【０１２６】
巻き取り及び反転を２回繰り返した後、巻き取ったフィルムに配合されていた塩素の含有量は約１／１０に、可塑剤の含有量は約１／２０に減少していた。さらに、１回目の巻き取り時に、アルミニウム箔はポリ塩化ビニルから容易に剥離できる状態であった。
【０１２７】
（実施例６）
図５の装置を用いて、ポリ塩化ビニルを重量比で６６％含む厚さ０．２ｍｍのビニルシートを以下のように処理した。
【０１２８】
始めに、加熱蒸気発生装置２を運転させ、蒸気流量が安定したところで蒸気放出配管３から蒸気を噴出させた。蒸気温度は、第１処理装置１ａで２００℃以上２８０℃未満の蒸気が発生するよう設定し、第２処理装置１ｂで２８０℃以上３５０℃未満の蒸気が発生するよう設定した。これは第１処理装置１ａで可塑剤などの添加剤の溶出を促し、第２処理装置１ｂで塩化水素の溶出を促すことを目的としている。回転体６、８をゆっくりと回転させ、フィルムが一様にそれぞれの処理装置１ａ、１ｂ内で１分以上蒸気に接するようにして、添加剤及び塩化水素の溶出を促進させた。この時回転体８間を通過していくフィルムの破損を避けるため、回転体８に挟まれることによる圧縮力を低く抑えるように隙間の幅を調整しておく。特に２段目の装置側の調整に注意を払った。
【０１２９】
フィルムの巻き取り及び反転を２回繰り返した後、巻き取ったフィルムに配合されていた塩素の含有量は約１／１０に、可塑剤の含有量は約１／１５に減少した。
【０１３０】
（実施例７）
安定剤として三塩基性硫酸鉛及び二塩基性ステアリン酸鉛を６ｐｈｒ （１００重量部中に６重量部）の割合で含んだポリ塩化ビニル樹脂１０００ｇを３〜５ｍｍのペレット状に粉砕し、図６〜８の処理装置３３のプラスチック供給装置３４に投入して毎分５０ｇの割合で酢酸添加槽３５に供給した。酢酸添加槽は９５℃に保ち、酢酸供給装置３６から毎分０．３Ｌの割合で１ ｍｏｌ／Ｌ酢酸溶液を供給した。前記撹拌軸を毎分３０回転の速度でモーター５０により回転させた。ペレット状のプラスチックは軟化しているため、酢酸と容易に混合した。酢酸と混合した軟化プラスチックは酢酸鉛分離槽３７に移送し、そこで５分間静置したところ、液相と固相に分離し、液相は分析の結果、０．０５ ｍｏｌ／Ｌ酢酸鉛水溶液であることを確認した。酢酸鉛水溶液を真空ポンプ３８を使って鉛回収槽３９に移送した。鉛回収槽３９には、５０ｃｍ間隔で並べられた３００ｍｍ×３００ｍｍの大きさの５枚の亜鉛板５１が投入され、酢酸鉛水溶液が鉛回収槽３９に移送されると、鉛が亜鉛板５１上に析出した。３０分経過後、鉛回収槽３９の水溶液の鉛濃度を分析したところ、検出限界以下であったことから鉛が亜鉛板５１上に十分析出していると判断された。亜鉛板５１に析出した鉛を取り出し、鉛純度を分析したところ、９９．９９％であった。また、鉛の回収量は約４０ｇであった。
【０１３１】
次に、酢酸鉛分離槽３７に残った軟化プラスチックを塩化鉛抽出槽４０に移送した。塩化鉛抽出槽の内部温度は３３０℃に保持した。軟化プラスチックは流動性になり、更に中から気体を発生した。この気体は検知管で測定したところ塩化水素であった。プラスチックは気体を発生しながら、徐々に流動性を有する発泡性物質に変化した。内部温度を１００℃に下げた後、水蒸気を毎分３Ｌの割合で送り込むと、水蒸気は瞬時に塩化水素と反応して濃塩酸を生成した。水蒸気を送り込んでから１分後に、塩化鉛抽出槽４０の液体流出弁から毎分３Ｌの割合で液体を取り出した。この液体（濃塩酸）を水素添加槽４３に送り、濃塩酸１Ｌに対し２Ｌの割合で水を加えて濃塩酸を希塩酸に希釈した。水を加えることにより、水素添加槽４３中には白色の沈澱が生じた。白色沈澱だけを水素添加槽４３に残し、残りの液相は廃液タンク４５に送った。この白色沈澱に水蒸気とともに水素を供給し水素添加を行った。水蒸気は毎分３Ｌの割合で添加した。水素添加槽４３に残った固体を分析したところ、純度９９．９％の鉛で、重量は４．５ｇであった。
【０１３２】
塩化鉛抽出槽４０内部を再度３３０℃に加熱したところ、プラスチックは再度気体を発生し始めた。この気体を検知管で測定したところ、前記同様塩化水素であった。この中の温度を１００℃に下げた後、水蒸気を毎分３Ｌ送り込んだところ、水蒸気は瞬時に塩化水素と反応して濃塩酸を生成した。水蒸気を送り込んでから１分後、液体流出弁から毎分３Ｌの割合で液体を取り出した。この液体を水素添加槽４３に送り、濃塩酸１Ｌに対し２Ｌの割合で水を加えて濃塩酸を希塩酸に希釈した。水を加えることにより水素添加槽４３中には白色の沈澱が生じた。白色沈澱だけを水素添加槽４３に残し、残りの液相は廃液タンク４５に送った。白色沈澱に水蒸気とともに水素を供給して水素添加を行った。水蒸気は毎分３Ｌの割合で添加した。この後、水素添加槽に残った固体を分析したところ純度９９．９％の鉛で、重量は１．５ｇであった。
【０１３３】
上記において、処理を行ったプラスチック中には６０ｇの添加剤が含まれていた。添加剤のうち約８０重量％が酸化鉛であると言われていることを考慮すると、６０ｇ×８０％＝４８ｇが酸化鉛となり、その内、鉛は４８ｇ×２０７／２２３＝４５ｇ（分子量：鉛＝２０７、酸化鉛＝２２３）となる。さらに、酸化鉛以外の鉛系化合物は６０ｇ−４８ｇ（全添加剤−酸化鉛）＝１２ｇであり、このうち鉛は平均５０重量％であるとすると、６ｇが鉛となる。つまり、４５ｇ＋６ｇ＝５１ｇがプラスチック中に含まれていた鉛の量となる。上記操作では４０ｇ＋４．５ｇ＋１．５ｇ＝４６ｇの鉛を回収したので、添加剤中の９０％の鉛が回収できたことになる。
【０１３４】
（実施例８）
安定剤としてステアリン酸鉛を１ｐｈｒ （１００重量部中に１重量部）の割合で含んだポリ塩化ビニル樹脂１０００ｇを３〜５ｍｍのペレット状に粉砕し、図６〜８の処理装置３３のプラスチック供給装置３４に投入して、毎分５０ｇの割合で塩化鉛抽出４０に供給した。
【０１３５】
塩化鉛抽出槽４０の内部温度を３３０℃に保持したところ、プラスチックは流動性になり、更に中から気体を発生した。この気体は検知管で測定したところ塩化水素であった。プラスチックは気体を発生しながら、徐々に流動性を有する発泡性物質に変化した。温度を１００ ℃に下げた後、水蒸気を毎分３Ｌの割合で送り込んだところ、水蒸気は瞬時に塩化水素と反応して濃塩酸を生成した。水蒸気を送り込んでから１分後、液体流出弁から毎分３Ｌの割合で液体を取り出した。この液体を水素添加槽４３に送り、濃塩酸１Ｌに対し２Ｌの割合で水を加えて濃塩酸を希塩酸にしたところ、水素添加槽４３中には白色の沈澱が生じた。白色沈澱だけを水素添加槽４３に残し、残りの液相は廃液タンク４５に送った。白色沈澱に水蒸気とともに水素を供給し水素添加を行った。水蒸気は毎分３Ｌの割合で添加した。この後水素添加槽４３に残った固体を分析したところ、純度９９．９％の鉛で、重量は２．８ｇであった。
【０１３６】
上記における鉛の回収率は、実施例７と同様の計算によって、８０％となる。
【０１３７】
（実施例９）
安定剤として三塩基性硫酸鉛及び二塩基性ステアリン酸鉛を６ｐｈｒ （１００重量部中に６重量部）の割合で含んだポリ塩化ビニリデン樹脂１０００ｇを３〜５ｍｍのペレット状に粉砕し、図６〜８の処理装置３３のプラスチック供給装置３４に投入して毎分５０ｇの割合で酢酸添加槽３５に供給した。酢酸添加槽は９５℃に保ち、酢酸供給装置３６から毎分０．３Ｌの割合で１ ｍｏｌ／Ｌ酢酸溶液を供給した。前記撹拌軸を毎分３０回転の速度でモーター５０により回転させた。ペレット状のプラスチックは軟化しているため、酢酸と容易に混合した。酢酸と混合した軟化プラスチックは酢酸鉛分離槽３７に移送し、そこで５分間静置したところ、液相と固相に分離し、液相は分析の結果、０．０５ ｍｏｌ／Ｌ酢酸鉛水溶液であることを確認した。酢酸鉛水溶液を真空ポンプ３８を使って鉛回収槽３９に移送した。鉛回収槽３９には、５０ｃｍ間隔で並べられた３００ｍｍ×３００ｍｍの大きさの５枚の亜鉛板５１が投入され、酢酸鉛水溶液が鉛回収槽３９に移送されると、鉛が亜鉛板５１上に析出した。３０分経過後、鉛回収槽３９の水溶液の鉛濃度を分析したところ、検出限界以下であったことから鉛が亜鉛板５１上に十分析出していると判断された。亜鉛板５１に析出した鉛を取り出し、鉛純度を分析したところ、９９．９９％であった。また、鉛の回収量は約４０ｇであった。
【０１３８】
次に、酢酸鉛分離槽３７に残った軟化プラスチックを塩化鉛抽出槽４０に移送した。塩化鉛抽出槽の内部温度は３３０℃に保持した。軟化プラスチックは流動性になり、更に中から気体を発生した。この気体は検知管で測定したところ塩化水素であった。プラスチックは気体を発生しながら、徐々に流動性を有する発泡性物質に変化した。内部温度を１００℃に下げた後、水蒸気を毎分３Ｌの割合で送り込むと、水蒸気は瞬時に塩化水素と反応して濃塩酸を生成した。水蒸気を送り込んでから１分後に、塩化鉛抽出槽４０の液体流出弁から毎分３Ｌの割合で液体を取り出した。この液体（濃塩酸）を水素添加槽４３に送り、濃塩酸１Ｌに対し２Ｌの割合で水を加えて濃塩酸を希塩酸に希釈した。水を加えることにより、水素添加槽４３中には白色の沈澱が生じた。白色沈澱だけを水素添加槽４３に残し、残りの液相は廃液タンク４５に送った。この白色沈澱に水蒸気とともに水素を供給し水素添加を行った。水蒸気は毎分３Ｌの割合で添加した。水素添加槽４３に残った固体を分析したところ、純度９９．９％の鉛で、重量は４．５ｇであった。
【０１３９】
上記における鉛の回収率は、実施例７と同様の計算によって、８０％となる。
【０１４０】
（実施例１０）
厚さ０．２ｍｍのＳＵＳ製の板をホットプレートの上で余熱しておき、ポリプロビレンを１７０℃に加熱して溶融させたものを、ＳＵＳ板の一面に厚さが２ｍｍになるように素早く塗布し、冷却した。
【０１４１】
この板を赤外光加熱式の炉に入れ、窒素雰囲気中で赤外光ランプを点灯して加熱を開始し、所定の加熱時間の後に赤外光ランプのスイッチを切り、炉内温度を冷却した。プラスチックの赤外光による加熱前後の重量を測定し、重量減少率を計算した。
【０１４２】
加熱時間を下記のように変更して上述の操作を繰り返し、加熱時間と重量減少率との関係を調べた。得られた結果を表１に示す。
【０１４３】
【表１】

【０１４４】
赤外光が点灯されるとプラスチックの温度は次第に上昇し、ポリプロピレンの温度が熱分解温度である４４５℃に達すると分解してガス化し放出される。上記の結果から、重量が５０％に減少するのに要する時間は６．９分である。
【０１４５】
次に、上述の操作をプラスチックの厚さを変えて繰り返し、プラスチック厚さと重量が５０％に減少するのに必要な時間との関係を調べた。得られた結果を表２に示す。尚、参考に、プラスチックをフラスコに投入して加熱した場合の重量が５０％に減少するのに要する時間も調べた。
【０１４６】
【表２】

【０１４７】
上記の結果において、厚さが１４ｍｍ前後までは、重量が５０％減少するまでの時間は厚みにほぼ比例して長くなるが、２０ｍｍ前後よりも厚くなると、重量が５０％減少するまでの時間は急激に増加する。これは、炭化物がプラスチック表面に生成すことによる影響と考えられる。この結果から、厚さを２０ｍｍ以下にするのが熱分解効率の添加ら好ましい。この範囲においては、フラスコ中にポリプロピレンを入れて実験した場合に重量が５０％に減少するのに必要な時間の半分の時間以下で重量が５０％に減少する。
【０１４８】
（実施例１１）
図９の装置を用いて、幅１．５ｍのベルト５３を１００ｃｍ／分の速度で走行させた。ポリプロピレンを２００℃程度に加熱してスクリュー５５ａ、５５ｂ、５５ｃにより移送し、ベルト５３にポリプロピレンを２ｍｍの厚さに塗布し、脱塩化水素室５８の温度が３５０℃になり、熱分解室６１の温度が４５０℃になるように設定した。プラスチックがホッパに投入されてから、処理装置５２に投入されたプラスチックが排出されるまでに１９分の時間を要した。熱分解室６１から回収されたものは、油分が８５％、ガス分が１１％、残渣が４％であった。
【０１４９】
上記と同様の操作を繰り返して、ポリプロピレンを５０％、ポロ塩化ビニールを５０％の割合で含むプラスチックの熱分解を行った。熱分解室６１から回収されたものは、油分が４５％、ガス分が１１％、残渣が４％であった。
【０１５０】
（実施例１２）
図１０〜１２の装置を用いて、直径３ｍのディスク６７を０．１２５ｒｐｍの回転速度で回転し、ポリプロピレンを粉砕した後にホッパー７３に投入して温めながらスクリュー７５ａ、７５ｂにより搬送した。溶融したポリプロピレンはスリット７６よりディスク６７に２ｍｍの厚さで塗布された。
【０１５１】
塗布されたプラスチックは赤外ランプ７０により４５０℃に加熱した。熱分解により発生する分解ガスは排気口７２より排気された後、冷却・液化され、油状分解物を回収した。プラスチックがホッパー７３に投入されてから処理装置から排出されるまでに１４分の時間を要した。回収した生成物は、油分が８５％、ガス分が１１％、残渣が４％であった。
【０１５２】
（実施例１３）
図１４（ａ）及び図１５に記載の処理装置８４を用いて、以下の操作を行った。まず、量体数１０００のポリ塩化ビニル５０部と、可塑剤としてＤＯＰ５０部とを配合した樹脂を十分混練して、組成をできる限り均一にした後、３〜５ｍｍ径のペレットに加工した。これを処理装置８４の一端にある供給口から毎分２０ｇの割合で装置内に供給した。加熱軸部材８７の外周面には断面が波形となるように一定間隔で溝を設けてあり、回転している加熱軸部材８７の溝の面に沿って攪拌装置８６と外筒８５との間の空間を排出口９７へと樹脂を徐々に移動させた。
【０１５３】
ヒーター９２を作動させて処理装置８４内の温度を図１４（ｂ）と同様に設定すると共に、樹脂の軟化が生じる１００℃付近に到達した時点で、加熱軸部材８７の表面にある細孔９０から低活性なガスとしてヘリウムを放出させる。また、分解ガスが拡散可能な隙間、空間をヘリウムで充填するために強制的にヘリウムガスを処理装置８４内に流入させた。
【０１５４】
全長の１／２の位置で分解ガスをサンプリングしたところ、毎分平均９．９５ｇの有機化合物を回収し、芳香族系の化合物及び炭素数６〜８の鎖状炭化水素が多量に含まれており、いずれも可塑剤の分解によって生じるものであった。
【０１５５】
次に、排出口においてサンプリングを行ったところ、毎分平均５．８９ｇの刺激臭を有するガスが発生しており、塩化水素を主成分とし、０．０５ｇの炭化水素を含んでいることがわかった。また、回収されたガスを水中を通過させたところ、塩化水素は水に溶解して塩酸となり、炭化水素と塩化水素を分離することができた。
【０１５６】
（実施例１４）
図１６の装置９５を用いて、以下の操作を行った。
【０１５７】
実施例１３で用いたものと同じ樹脂を処理装置９５の供給口から毎分３０ｇの割合で装置９５内に供給した。２つの加熱軸部材８７の外周面には断面が波形となるように一定間隔で溝が設けてあり、攪拌装置８６ａ、８６ｂの回転によって樹脂を処理装置９５の排出口へと徐々に移動させた。
【０１５８】
ヒーター９６を作動させて図１４（ｂ）と同様に温度を設定すると共に、樹脂の軟化が生じる１００℃付近に到達した時点で、細孔９０から低活性なガスとして窒素を放出させた。また、分解ガスが拡散可能な隙間、空間を窒素で充填するために強制的に窒素ガスを処理装置９５内に流入させた。
【０１５９】
全長の１／２の位置で分解ガスをサンプリングしたところ、毎分平均１４．３ｇの有機化合物を回収し、芳香族系の化合物及び炭素数６〜８の鎖状炭化水素が多量に含まれており、いずれも可塑剤の分解によって生じるものであった。
【０１６０】
次に、排出口においてサンプリングを行ったところ、毎分平均８．８４ｇの刺激臭を有するガスが発生しており、塩化水素を主成分とし、０．０８ｇの炭化水素を含んでいることがわかった。また、回収されたガスを水中を通過させたところ、塩化水素は水に溶解して塩酸となり、炭化水素と塩化水素を分離することができた。
【０１６１】
（実施例１５）
図１４（ａ）に示す処理装置８４を用い、以下の操作を行った。
【０１６２】
まず、実施例１３で用いた樹脂と同じものを処理装置８４の供給口から毎分２０ｇの割合で装置８４内に供給した。加熱軸部材８７の外周面には断面が波形になるように一定間隔で溝を設けてあり、攪拌装置８６の回転によって樹脂を徐々に排出口９７の方へと移動させた。
【０１６３】
ヒーター９６を作動させて図１４（ｂ）と同様に温度を設定すると共に、樹脂の軟化が生じる１００℃付近に到達した時点で、加熱軸部材８７の細孔９０から水蒸気を放出させた。また、分解ガスが拡散可能な隙間、空間を水蒸気で充填するために強制的に水蒸気を処理装置８４内に流入させた。
【０１６４】
全長の１／２の位置で分解ガスをサンプリングしたところ、毎分平均９．９５ｇの有機化合物を回収し、０．０５ｇの酸素が含まれていた。又、芳香族系の化合物及び炭素数６〜８の鎖状炭化水素が多量に含まれており、いずれも可塑剤の分解によって生じるものであった。
【０１６５】
次に、排出口においてサンプリングを行ったところ、毎分平均５．８９ｇの刺激臭を有するガスが発生しており、塩化水素を主成分とし、０．０８ｇの炭化水素を含んでいることがわかった。また、回収されたガスを水中を通過させたところ、炭化水素と塩化水素を分離することができた。
【０１６６】
（実施例１６）
図１７の処理装置９７を用い、以下の操作を行った。
【０１６７】
まず、量体数１０００のポリ塩化ビニル７５部と、可塑剤としてＤＨＰ２５部とを配合した樹脂を十分混練して組成をできる限り均一にした後、３〜５ｍｍ径のペレットに加工した。
【０１６８】
この材料を処理装置９７の供給口から毎分２０ｇの割合で装置９７内に供給した。加熱軸部材８７の外周面には断面が波形となるように一定間隔で溝を設けてあり、攪拌装置８６の回転によって樹脂を排出口へと徐々に移動させた。
【０１６９】
ヒーター９２を作動させて図１４（ｂ）と同様に温度を設定すると共に、樹脂の軟化が生じる１００℃付近に到達した時点で、加熱軸部材８７の細孔９０から窒素を放出した。また、分解ガスが拡散可能な隙間、空間を窒素で充填するために強制的に窒素を処理装置９７内に流入させた。
【０１７０】
全長の１／２の位置で分解ガスをサンプリングしたところ、毎分平均１４．９３ｇの有機化合物を回収した。又、芳香族系の化合物及び炭素数６〜１０の鎖状炭化水素が多量に含まれており、いずれも可塑剤の分解によって生じるものであった。
【０１７１】
次に、排出口においてサンプリングを行ったところ、毎分平均２．９４ｇの刺激臭を有するガスが発生しており、塩化水素を主成分とし、０．１２ｇの炭化水素を含んでいることがわかった。また、回収されたガスを水中を通過させたところ、塩化水素は水に溶解し、炭化水素と塩化水素を分離することができた。
【０１７２】
（実施例１７）
図１８の処理装置１００を用いて以下の操作を行った。
【０１７３】
ガス供給口１０４から導入される窒素ガスをヒーター１０５で３５０℃に加熱し、長さ１ｍ、内径８ｃｍのエクストルーダ部１０１内に配置された中空のスクリュー１０２へ５Ｌ／ 分の割合で供給した。スクリュー１０２をモーター１０６によりスクリュー１０２を２０ｒｐｍの回転速度で回転させながら、可塑剤（ＤＯＰ）を３３％含有するＰＶＣを５０ｗｔ％、ポリプロピレンを５０ｗｔ％含むプラスチック５０ｋｇを投入部１０７から投入した。窒素ガスに加熱されたプラスチックは溶融し、スクリュー１０２の回転によって徐々に排出口１１２の方へ搬送された。この間、プラスチックの温度をＫタイプの熱電対で測定し、排出口１１２付近でプラスチック温度が３５０℃に達するように、必要に応じてエクストルーダの加熱装置を補助的に使用した。
【０１７４】
約４時間後にプラスチックは全て排出口１１２から排出され、３２ｋｇの溶融プラスチックが回収された。第１排気部１０８からポンプ１０９にかけてＤＯＰの分解物である無水フタル酸の付着が認められた。排出口１１２から回収されたプラスチックの塩素含有率を蛍光Ｘ線により分析したところ、脱塩素率は９９．８％以上であり、赤外分光によりプラスチックの組成を分析したところ、ポリプロビレン７８ｗｔ％とポリエン２２ｗｔ％から構成されていることを確認した。
【０１７５】
回収されたプラスチックを市販の焼却炉で燃やしたところ、燃焼ガスに塩素ガス、塩化水素ガス、タイオキシンは検出されなかった。
【０１７６】
（比較例１）
窒素ガスを供給せずにエクストルーダの加熱装置で実施例１７と同様の温度設定になるようにプラスチックを加熱し、ポンプ１０９、１１１を駆動しなかった点以外は実施例１７と同様の操作を図１８の処理装置１００を用いて行った。
【０１７７】
約４時間後にプラスチックは全て排出口１１２から排出され、３８ｋｇの溶融プラスチックが回収された。第１排気部１０８からポンプ１０９にかけてＤＯＰの分解物である無水フタル酸の付着が認められた。排出口１１２から回収されたプラスチックの塩素含有率を蛍光Ｘ線により分析したところ、脱塩素率は９５．７％であり、赤外分光によりプラスチックの組成を分析したところ、ポリプロビレン７１．２ｗｔ％とポリエン２０ｗｔ％と無水フタル酸４．５ｗｔ％とから構成されていることを確認した。
【０１７８】
回収されたプラスチックを市販の焼却炉で燃やしたところ、燃焼ガスから５３ｐｐｍの塩化水素ガス、５ｐｐｂのダイオキシンが検出された。塩素ガスは１ｐｐｍ以下であった。また、焼却後に焼却炉の内部及び排気ガス用配管の内側を調べたところ、塩化水素によると思われる腐食（変色）が認められた。
【０１７９】
（実施例１８）
窒素ガスの代わりにアルコンガスを使用した点以外は実施例１７と同様の操作を繰り返した。
【０１８０】
約４時間後にプラスチックは全て排出口１１２から排出され、３２ｋｇの溶融プラスチックが回収された。第１排気部１０８からポンプ１０９にかけてＤＯＰの分解物である無水フタル酸の付着が認められた。排出口１１２から回収されたプラスチックの塩素含有率を蛍光Ｘ線により分析したところ、脱塩素率は９９．８％以上であり、赤外分光によりプラスチックの組成を分析したところ、ポリプロビレン７８ｗｔ％とポリエン２２ｗｔ％から構成されていることを確認した。
【０１８１】
回収されたプラスチックを市販の焼却炉で燃やしたところ、燃焼ガスに塩素ガス、塩化水素ガス、タイオキシンは検出されず、目視による焼却炉の観察でも焼却を実施する上での問題は特に認められなかった。
【０１８２】
（実施例１９〜２２）
窒素ガスの加熱温度（排出口１１２付近での温度）を表３のように変えた点以外は実施例１と同様の操作を繰り返した。結果を表３に示す。
【０１８３】
【表３】

【０１８４】
実施例２２では、ポリプロピレンの熱分解反応が若干進行しており、エクルトルーダ部１０１から排出されたガスからポリプロピレンの熱分解生成物である油（着色）が回収された。
【０１８５】
（実施例２３）
図１８の処理装置１００を前処理部１１４として組み込んだ図１９の熱分解装置１１３を用いて以下の操作を行った。
【０１８６】
ガス供給口１０４から導入される窒素ガスをヒーター１０５で３５０℃に加熱し、長さ１ｍ、内径８ｃｍのエクストルーダ部１０１内に配置された中空のスクリュー１０２へ５Ｌ／ 分の割合で供給した。スクリュー１０２をモーター１０６によりスクリュー１０２を２０ｒｐｍの回転速度で回転させながら、可塑剤（ＤＯＰ）を３３％含有するＰＶＣを５０ｗｔ％、ポリプロピレンを５０ｗｔ％含むプラスチック５０ｋｇを投入部１０７から１０ｋｇ／ｈの割合で投入した。窒素ガスに加熱されたプラスチックは溶融し、スクリュー１０２の回転によって徐々に排出口１１２の方へ搬送された。この間、プラスチックの温度をＫタイプの熱電対で測定し、排出口１１２付近でプラスチック温度が３５０℃に達するように、必要に応じてエクストルーダの加熱装置を補助的に使用した。
【０１８７】
排出口１１２から排出されたプラスチックは、熱分解槽１１５で熱分解された。エクストルーダ部１０１、生成油タンク１１７及び排ガス処理装置１１８において回収されたものから、投入プラスチックを１００部として物質収支を計算したところ、エクストルーダ部において、塩化水素が１９．６部、ＤＯＰの分解物である炭素数８の有機化合物が１０．２部、無水フタル酸が６．３部回収され、生成油タンク１１７において油が４２部回収され、残渣タンク１２２において分解残渣が１３．３部、排ガス処理装置１１８において低分子の有機化合物が９．４部回収された。
【０１８８】
残渣の残留塩素濃度を分析したところ、０．２％以下であった。排ガス処理装置１１８における排ガスの塩化水素濃度は１ｐｐｍ以下であり、回収油中の有機塩素化合物の濃度は１０ｐｐｍ以下であった。
【０１８９】
残渣の焼却及び回収油の重油バーナの燃料としての活用において、排ガス中に塩化水素、ダイオキシンは検出されなかった。
【０１９０】
（比較例２）
窒素ガスを供給せずにエクストルーダの加熱装置で実施例２３と同様の温度設定になるようにプラスチックを加熱し、ポンプ１０９、１１１を駆動しなかった点以外は実施例２３と同様の操作を図１９の熱分解装置１１３を用いて行った。
【０１９１】
残渣タンク１２２の残渣の残留塩素濃度を分析したところ、５．２％であった。又、排ガス処理装置における排ガスの塩化水素濃度は１２００ｐｐｍ、回収された油の有機塩素化合物の濃度は４７００ｐｐｍであった。
【０１９２】
残渣を焼却したところ、焼却炉の排ガスから塩化水素が８３ｐｐｍ検出され、燃焼炉には腐食によると思われる変色が認められた。回収油を重油バーナの燃料として使用したところ、重油バーナの排気ガスからは塩化水素が１２ｐｐｍ検出された。
【０１９３】
（実施例２４）
可塑剤を５０％含有するポリ塩化ビニル５０ｇと、ポリプロピロピレン５０ｇを混ぜ、金属製の容器に投入し、容器の外壁を取り囲むようにして設置されているヒーターを用いて投入したプラスチックを加熱した。加熱中は内部に取り付けられている撹拌羽でプラスチックを攪拌して均熱性を高めた。内部に投入した物質の温度が２３０℃に達するまでは１０℃／分の昇温速度で加熱し、２３０℃に達した時点で５℃／分の昇温速度でプラスチックの表面から発生するガスを十分放出させ、２８０℃に到達させた。この時放出したガスを冷却すると、白色の粉末が得られた。２８０℃に到達した後は、昇温速度を４℃／分にしてプラスチックから発生するガスを十分放出させ、３３０℃まで到達させた。この時発生していたガスに蒸留水で湿らせたリトマス紙をかざすと直ちに赤変し、刺激臭を有していた。
【０１９４】
加熱をさらに続け、金属製の容器の内壁に沿わせながら８ｇの重質性分の油を少量ずつ数回に分けて添加し、１０℃／分の昇温速度で４５０℃に到達させた。４５０℃に到達した後は、約１時間その温度で保持するよう加熱を制御した。この時、約５５ｇの油状物質を回収することができた。油を回収した後、黒色の炭化成分が残渣として残っていたが、容易に掻き出すことができた。
【０１９５】
（実施例２５）
図２０の熱分解装置１２３を用いて、以下の操作を行った。
【０１９６】
可塑剤を５０ｗｔ％含有する量体数１０００〜１２００のポリ塩化ビニルを混練りし組成を均一にして３〜５ｍｍの大きさに加工したペレットと、３〜５ｍｍに破砕したポリプロピロピレンのペレットとを５０部ずつ混ぜ、プラスチック供給槽１３１から単位時間当たりの供給量が一定となるよう第１前処理装置１２４に投入した。内部に投入した物質の温度が第１前処理装置１２４の長手軸方向の入口から１／３の位置までに２３０℃になるように加熱した。さらに、２３０℃に達した位置から出口付近までに２８０℃に到達するよう温度を調整した。この時、プラスチックの表面から発生するガスを十分放出させる様に不活性ガスを第１前処理装置の前方の入口から出口に向かって流し続け、ガスの拡散を促進させた。回収したガスを冷却すると白色の粉末が生じ、主な成分はフタル酸系の化合物と炭素数８のアルコール、アルデヒドを含んでいた。２８０℃に到達させた後は、第２前処理装置へ加熱処理している物質を移送し、入口から長手軸方向の１／４の位置までに物質の温度が３３０℃に到達するように温度を調整した。さらに、３３０℃に到達した後は、出口までその温度を保持した。この温度で、第１前処理装置１２４と同様に不活性ガスを入口から出口に向かって流し続け、ガスの拡散を促進させた。回収した不活性ガスは、刺激臭を有するガスを含んでおり、塩化水素を多く生じていることがわかった。又、この塩化水素を水溶液に調整してアルカリ性廃液の中和に用いることができた。
【０１９７】
第２前処理装置１２５の出口から温度が急速に低下しない程度に保持して前処理後の物質を加熱溶融槽１２６に移動させながら、加熱溶融槽１２６と接続した移送配管の内壁に沿って重質性の油を加熱したものを添加し、流動性を高めて投入した。加熱溶融槽１２６の内部にはポリプロピレンを多量に含むプラスチックをあらかじめ加熱、溶融させておき、３５０〜３８０℃に保持しておいた。この時、第２前処理装置から投入された物質の液面が加熱溶融槽の底部からおよそ５０〜８０％の位置を保つように投入をしながら撹拌を続け、底部の残渣分排出口１４２４から固形成分を分離した。また、一部加熱溶融槽内でガス化したものについては、上部の配管から蒸留装置１２９に導き、低沸点化合物と高沸点化合物を分離した。
【０１９８】
一方、加熱溶融槽１２６の液状成分を、断熱材で被覆した配管を通じて加熱分解槽１２８に移送して加熱をさらに続け、４５０℃に到達させた。その温度で保持し、加熱分解槽１２８の上部の配管から蒸留装置１３０へ導いたガス状生成物から炭素数６〜１５の炭化水素を主成分とする油状物質を回収することができた。この加熱溶融槽１２８の下部から間欠的に固形化した黒色の炭化成分を分離したが、容易に抜き取ることができた。
【０１９９】
（実施例２６）
図２０の熱分解装置１２３の加熱溶融槽１２６に代えて図２２に示す加熱溶融槽１２６’を用いた熱分解装置を用いて、以下の操作を行った。
【０２００】
投入材料と前処理の方法、加熱分解槽での乾留方法は実施例２５に示した内容と同じとしたが、加熱溶融槽１２６’の運転方法を次のようにした。
【０２０１】
第２前処理装置１２５から移送された物質を受け入れるときに加熱溶融槽１２６’の壁面から重質性の油を壁面に沿わせて注入し、加熱溶融槽の内壁面への残渣の固着を防止することができた。残渣を加熱溶融槽内の液状化物質と分離し排出した後、プラスチック供給口１６０から加熱溶融槽内に最初に投入したプラスチックの１００ｗｔ％の量のポリプロピレンのペレットを投入し、余熱を利用して軟化させた。その後、ヒーター１６２を用いて加熱し、ポリプロピレンペレットを溶融させ、３５０〜３８０℃の範囲を保つようにした。その後は実施例２５の記載に従い、加熱分解槽１２８で熱分解して回収したガス状の熱分解生成物から油状成分を得た。この時得られた油状成分は実施例２５の油状成分よりも軽質分の割合が数パーセント高かった。
【０２０２】
（実施例２７）
図２３の熱分解装置を用いて以下の操作を行った。
【０２０３】
可塑剤を３０％含有する量体数１０００〜１２００のポリ塩化ビニルを混練し組成を均一にして３〜５ｍｍに加工したペレットと、３〜５ｍｍに破砕したポリプロピロピレンのペレットとを５０部ずつ混ぜ、プラスチック供給槽１３１から単位時間当たりの供給量が一定となるよう第１前処理装置１２４に投入した。内部に投入した物質の温度が第１前処理装置の長手軸方向の入口から１／３の位置までに２３０℃になるように加熱した。更に、２３０℃に達した位置から出口付近までに２８０℃に到達するよう温度を調整した。この時、プラスチックの表面から発生するガスを十分放出させる様に不活性ガスを前処理装置の入口から出口に向かって流し続け、ガスの拡散を促進させた。回収ガスを冷却すると、白色の粉末が生じ、主な成分はフタル酸系の化合物と炭素数８のアルコール、アルデヒドを含んでいた。２８０℃に到達した後は、第２前処理装置へ加熱処理している物質を移送し、入口から長手軸方向の１／３位置までに物質の温度が３３０℃に到達するように温度を調整した。さらに３３０℃に到達した後は、出口までその温度を保持した。この温度で、同様に不活性ガスを入口から出口に向かって流し続け、ガスの拡散を促進させた。この時発生していたガスは、刺激臭を有しており、塩化水素を多く含んでいた。
【０２０４】
前処理装置から移送された物質を加熱反応装置１６５に受け入れるときに重質性の油を含むポリプロピレンを移送された物質と等量混ぜた。この混合物を受け入れた加熱反応槽１６５を、その軸の内面から外側に向かって加熱する。軸の長手方法の１／３に達するまでに物質の温度が４５０℃に到達するように温度を調整し、さらに４５０℃に到達した後は、軸の長手方法の２／３に達するまでその温度を維持した。その後、出口までに５００℃に到達させた。この間に生じたガス状回収物から油状成分を得た。この時得られた油状成分は、実施例２５の油状成分とほぼ同じであった。また、この加熱方法により加熱溶融装置内の壁面への残渣の固着はわずかであった。
【０２０５】
（実施例２８）
図２０の熱分解装置１２３の加熱溶融槽１２６に代えて図２４の加熱溶融槽１１６８を組み込んだ熱分解装置を用いて以下の操作を行った。
【０２０６】
投入材料と前処理の方法、加熱分解槽での乾留方法は実施例２５に示した内容と同じとしたが、加熱溶融槽１６８の運転方法を次のようにした。
【０２０７】
前処理装置から移送された物質を受け入れるときに、加熱溶融槽１６８の壁面から重質性のパラフィン油を壁面に沿わせて注入し、加熱溶融槽内の壁面への残渣の固着を防止することができた。残渣を溶融槽内の液状物と分離して排出口１７７から排出した後、供給口１７３から最初に投入したプラスチックの１００ｗｔ％量のポリプロピレンのペレットを加熱溶融槽１６８内に投入し、余熱を利用して軟化させた。その後、ヒーター１７５を用いて加熱し、ペレットを溶融させて温度を３５０〜３８０℃の範囲を保つようにした。その後は実施例２５の記載に従って加熱分解槽１２８で生じたガス状回収物から油状成分を得た。この時得られた油状成分は、実施例２５の油状成分よりも軽質分の割合が数パーセント高かった。
【０２０８】
（実施例２９）
図２５に示す装置１７８を用いて以下の操作を行った。
【０２０９】
比表面積１５００ｍ^２ ／ｇ、細孔径１８オングストローム、細孔容積０．５ｍｌ／ｇ、充填密度６１５ｇ／Ｌ、乾燥減量０．２％の活性炭（４〜６メッシュ）と、ハロゲン化水素トラップ剤である武田薬品工業（株）の粒状白鷺ＸＲＣ（４〜１０メッシュ）をそれぞれ５０ｗｔ％の割合で秤量混合し、軽く混ぜ合わせ、これを直径３０ｍｍ、長さ３００ｍｍのカラム１８２の中に充填した。カラム１８２を横型炉１８３により４００℃に加熱した。
【０２１０】
次に、純度９９．９％の１−クロロヘキサンを１０ｗｔ％、ｎ−オクタンを９０ｗｔ％の割合で調合した４００ｃｃの疑似油１８０を、容積５００ｃｃ用のフラスコ１７９の中へ投入した。フラスコ１７９の中の疑似油１８０はマンルヒータ１８１により沸騰するまで加熱して、油蒸気を発生させた。油蒸気は、カラム１８２へ送られ、カラム１８２を通過したガスを凝縮器１８５で冷却液化し、回収容器１８６に溜まった。液化物をＧＣ−ＭＳにより分析したところ、１−ヘキセン、３−ヘキセン等の不飽和化合物が９４．７％、ベンゼンが５．３％であり、１−クロロヘキサンは検出されなかった（０．０５％以下）。又、ｎ−オクタンは一部が芳香族化等の化学変化をしており、反応後に、３．２％がエチルベンゼン等の芳香族になり、０．９％が２，４−オクタジエン等のアルケンになり、０．３％が３−メチルヘプタン等に異性化した。
【０２１１】
更に、カラムの温度を表４のように変えて上記の操作を繰り返し行った。
【０２１２】
【表４】

【０２１３】
カラムの温度を６００℃にすると、炭素−炭素結合を切断反応が起き、成分数が極端に多くなり、正確な反応収支を計算することが不可能であった。
【０２１４】
上記の結果より、１５０〜５５０℃で副生成物の生成が少なく、且つ、有機塩素化合物の分解に効果があることが理解される。
【０２１５】
尚、上述のハロゲン化水素トラップ剤の代わに、水酸化カリウム、カセイソーダ等を使用して同じ操作を行った場合においても、上記と同様の結果が得られた。
【０２１６】
（実施例３０）
図２６の装置を用いて、以下の操作を行った。
【０２１７】
比表面積１５００ｍ^２ ／ｇ、細孔径１８オングストローム、細孔容積０．５ｍｌ／ｇ、充填密度６１５ｇ／Ｌ、乾燥減量０．２％の活性炭（４〜６メッシュ）を活性炭カラム１９４に充填し、ハロゲン化水素トラップ剤である武田薬品工業 （株）の粒状白鷺ＸＲＣ（４〜１０メッシュ）をハロゲン化水素除去カラム１９５に充填した。これらのカラム１９４、１９５を４００℃に加熱した。
【０２１８】
５０ｗｔ％のポリ塩化ビニルと５０ｗｔ％のポリプロピレンからなる廃プラスチックを破砕した後にホッパ１８９に投入した。投入したプラスチックはエクストルーダ１９０で３５０℃に加熱され、溶融、可塑剤除去及び脱塩化水素がなされた。その後、プラスチックは熱分解槽１９１に搬送され、４５０℃に加熱して熱分解された。熱分解槽１９１から放出された熱分解生成物の蒸気は、ハロゲン除去部１９３に送られた。ハロゲン除去部１９３の活性炭カラム１９４及びハロゲン化水素除去カラム１９５を通過した蒸気は、凝縮器１９６により冷却、液化され、回収タンク１９７に回収された。回収液の有機塩素化合物濃度は１０ｐｐｍ以下であった。尚、カラムから活性炭及びハロゲン化水素トラップ剤を取り除いて上記と同様の操作を行ったところ、回収液の有機塩素化合物濃度は５００ｐｐｍであった。
【０２１９】
（実施例３１）
面積が８１．７ｃｍ^２ で、直径４ｍｍの穴が設けられた図２８の棚を有する図２７の蒸留装置１９８を用いて、以下の操作を行った。
【０２２０】
蒸留装置１９８の理論段数を１２、塔頂の環流比を３に設定し、ポリプロピレンを熱分解して得られる分解生成物蒸気を蒸留塔１９９へ流入させて灯油質油の溜まる棚の油液高を測定した。
【０２２１】
プラスチックの熱分解槽の反応速度を制御して蒸気の流量を変化させ、棚段の穴数を変えて上述の操作を繰り返し行い、穴数と棚段の油液高との関係を調べた。この結果を表５に示す。
【０２２２】
【表５】

【０２２３】
蒸留塔へ流入する蒸気の流量を１０Ｌ／ｍｉｎから徐々に減少させていくと、灯油質の段の油の高さが減少した。又、流量が７Ｌ／ｍｉｎである時、棚の穴数を２４から１６にへ減少させると、油液高値が大きくなった。
【０２２４】
従って、蒸気の流量を減少した際に、棚段の穴数を減少させると、液高を一定にすることができる。上記の実施例においては、棚段の穴数を２まで減少させることによって、上記の流量が１Ｌ／ｍｉｎの場合にまで対応が可能であり、灯油質の液高を２０ｃｍ以上に維持することができた。従って、穴数を変えることによって、流入蒸気の気量が１〜１０Ｌ／ｍｉｎの範囲に適用可能である。これに対し、穴数が２４に固定されている場合、蒸気の気量が５Ｌ／ｍｉｎ以下で棚上に液が溜らず、油蒸気が蒸留塔の内部で気液接触することなく塔頂へ吹く上がり、正常な油の分離が不可能である。
【０２２５】
上記の結果から、廃プラスチックを処理する場合、投入する廃プラスチック物の内容や投入量の変動に、棚段の穴の数を制御することにより柔軟に対応できることが理解される。
【０２２６】
（実施例３２）
棚段を図２９に示した機構を有するものに変えた点以外は実施例３１と同様の操作を繰り返した。結果を表６に示す。
【０２２７】
【表６】

【０２２８】
（実施例３３）
図３０の熱分解装置２１６を用いて以下の操作を行った。
【０２２９】
エクストルーダ２１７の温度を３５０℃に設定し、ＰＶＣ（可塑剤のＤＯＰが３２ｗｔ％含まれる）５０部に対しポリプロピレン５０部の割合で混合した混合物を投入し、エクストルーダ２１７から排出された溶融プラスチックを１０ｋｇ／ｈｒ の割合で熱分解槽２１８に供給した。エクストルーダ２１７で塩化水素が発生し、熱分解槽２１８に供給された溶融プラスチックの塩素の含有量は減少してゼロ近くになった。その後は、実施例３１と同様の操作を行った。
【０２３０】
蒸留塔から排出された重中質油の分析を行ったが、有機塩素化合物の濃度は検出限界（５０ｐｐｍ）以下であった。
【０２３１】
１６８時間運転し続けた後、９６時間放置し、この後、蒸留塔内部の腐食の有無を調べたが、腐食は認められなかった。
【０２３２】
（比較例３）
エクストルーダ２１７のヒータを作動させなかったことを除いて実施例３３と同様の操作を行った。
【０２３３】
蒸留塔１９９から排出された重中質油の分析を行ったところ、炭素数が８の有機塩素化合物か３％含まれていた。
【０２３４】
１６８時間運転し続けた後に９６時間放置し、この後、蒸留塔内部の腐食の有無を調べたところ、内壁に変色が確認された。また、エクストルーダ２１７と熱分解槽２１８との間、及び、蒸留塔１９９の軽質油を排出するための配管にＤＯＰの分解物である無水フタル酸が析出しているのを確認した。
【０２３５】
（比較例４）
蒸留塔の入り口に設置してあるフィルターを取り除いた点以外は、実施例３３と同様の操作を行った。
【０２３６】
蒸留塔１９９の重質油を抜き出して目視観察すると、サスペンジョン状態の夾雑物が液面、液中及び液底にあることが認められた。
【０２３７】
【発明の効果】
本発明によれば、廃プラスチックに含まれる可塑剤や鉛化合物を除去することができ、又、ハロゲン含有プラスチックからハロゲン化水素を効率よく脱離することができるので、ハロゲン含有プラスチックを含む廃プラスチックの熱分解で得られる生成物の有機ハロゲン化合物による汚染が防止され、更に、有機ハロゲン化合物に汚染された生成物からハロゲンを除去でき、分解生成物の生成量の変化に対応して生成物の蒸留精製ができるので、産業上の利用性が極めて高い。
【図面の簡単な説明】
【図１】本発明に従ってプラスチックの添加剤を除去するための装置の第１の例を示す概略構成図。
【図２】プラスチックの添加剤を除去するための装置の第２の例を示す概略構成図。
【図３】プラスチックの添加剤を除去するための装置の第３の例を示す概略構成図。
【図４】プラスチックの添加剤を除去するための装置の第４の例を示す概略構成図。
【図５】プラスチックの添加剤を除去するための装置の第５の例を示す概略構成図。
【図６】本発明に従ってプラスチックの鉛を除去するための装置の一例を示す概略構成図。
【図７】図６の装置の酢酸添加装置の構成を示す構成図。
【図８】図６の装置の鉛回収槽に用いられる亜鉛板の構成を示す斜視図。
【図９】本発明に従ってプラスチックの熱分解を行うための装置の第１の例を示す概略構成図。
【図１０】本発明に従ってプラスチックの熱分解を行うための装置の第２の例を示す概略構成図。
【図１１】図１０の装置のプラスチック塗布部の構成を示す斜視図。
【図１２】図１０の装置の掻き取り刃の構成を説明する斜視図。
【図１３】本発明に従ってプラスチックの熱分解を行うための装置の第３の例を示す概略構成図。
【図１４】本発明に係る加熱軸部材を有するプラスチックの処理装置の第１の例を示す概略構成図（ａ）及び処理装置の温度設定を示すグラフ（ｂ）。
【図１５】図１４（ａ）の装置のｘ−ｘ’線断面図。
【図１６】本発明に係る加熱軸部材を有するプラスチックの処理装置の第２の例を示す断面図。
【図１７】本発明に係る加熱軸部材を有するプラスチックの処理装置の第３の例を示す断面図。
【図１８】本発明に従ってプラスチックの可塑剤除去及び脱ハロゲン化水素を行うための装置の一例を示す概略構成図。
【図１９】図１８の装置を適用したプラスチックの熱分解装置を示す概略構成図。
【図２０】本発明に従って、プラスチックの流動性を高めて熱分解を行うためのプラスチックの熱分解装置の第１の例を示す概略構成図。
【図２１】本発明に従って、プラスチックの流動性を高めるために用いられるプラスチックの処理装置の第１の例を示す概略構成図。
【図２２】本発明に従って、プラスチックの流動性を高めるために用いられるプラスチックの処理装置の第２の例を示す縦断面図（ａ）及び横断面図（ｂ）。
【図２３】本発明に従って、プラスチックの流動性を高めて熱分解を行うためのプラスチックの熱分解装置の第２の例を示す概略構成図。
【図２４】本発明に従って、プラスチックの流動性を高めるために用いられるプラスチックの処理装置の第３の例を示す縦断面図（ａ）及び横断面図（ｂ）。
【図２５】本発明に従って、プラスチックの熱分解生成物からハロゲンを除去するためのプラスチックの処理装置の第１の例を示す概略構成図。
【図２６】本発明に従って、プラスチックの熱分解生成物からハロゲンを除去するためのプラスチックの処理装置の第２の例を示す概略構成図。
【図２７】本発明に従って、プラスチックの熱分解生成物を生成するための蒸留装置の第１の例を示す概略構成図。
【図２８】図２７の蒸留装置の要部の説明図。
【図２９】本発明に従ってプラスチックの熱分解生成物を生成するための蒸留装置の第２の例における要部の説明図。
【図３０】図２７の蒸留装置を用いたプラスチックの熱分解装置を示す概略構成図。
【符号の説明】
Ｐ プラスチック
２ 加熱蒸気発生装置
１３、１９、９２、９６ ヒーター
１７、２９ 吸収体
３６ 酢酸供給装置
３９ 鉛回収槽
４１ 水蒸気添加装置
４２ 水供給装
４５ 水素ボンベ
５１ 亜鉛板
５７、７０、８１ 赤外ランプ
８７ 加熱軸部材
９０、１０３ 細孔
９１ ガス供給器
１２４ 第１前処理装置
１２５ 第２前処理装置
１２６ 加熱溶融槽
１２７ 重質油添加槽
１２８ 加熱分解槽
１４９ 気流入口
１５１ 気流出口
１５３ 重質油注入溝
１５４ 重質油供給管
１５８ 重質油注入口
１６０、１７３ プラスチック供給口
１６４ 重質油添加装置
１６５ 加熱反応槽
１７７ 排出口
１８２ カラム
１９４ 活性炭カラム
１９５ ハロゲン化水素除去カラム
２００、２００ａ 棚段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a treatment and an apparatus for waste plastic, and more particularly to a treatment / recovery technique for obtaining useful resources from waste plastic with high quality and a high recovery rate, and a treatment apparatus for realizing the same.
[0002]
[Prior art]
Plastic has excellent advantages as a material such as electric resistance, water resistance, and chemical resistance. For this reason, it is processed into various products and penetrates deeply into our lives, and now, without its benefits, everyday life cannot be fulfilled.
[0003]
Waste plastic after using such a plastic product is incinerated or landfilled or recycled, but both incineration and landfilling have various problems. The purpose of incineration is to recover thermal energy by actively burning high-calorie plastics, but to prevent global warming and prevent the generation of harmful organic chlorine compounds. It is not preferable to do so. Landfill disposal is a method of landfilling plastic, which is a raw material of fossil fuel, but is not preferable from the viewpoint of effective use of resources and is hardly decomposable, so that it is not naturally assimilated and remains accumulated. Furthermore, it is difficult to secure landfills as final disposal sites in various parts of Japan, and the landfills in Tokyo are already near saturation.
[0004]
Therefore, establishment of recycling technology is urgently needed to solve the garbage war as a social problem. In recent years, various laws for promoting recycling have been enacted, and plastics are also targeted. However, plastic production is on the rise, and according to 1991 data, out of 6.22 million tons of waste plastic generated in Japan, 51% is incinerated and 37% is landfilled and recycled. Only 12%.
[0005]
[Problems to be solved by the invention]
As can be understood from the above, there is a demand for the development of effective treatment and recycling technologies for plastics.
[0006]
The breakdown of consumption by raw material resin in 1994 was 28.2% by weight of polyvinyl chloride (PVC), 20.8% of polyethylene (PE), 16.6% of polystyrene (PS), and polypropylene (PP) by weight. The ratio is 18.9%, others are 15.6%, and thermoplastics account for the majority (according to the annual statistics on plastic products).
[0007]
PE, PS and PP, which are typical examples of thermoplastic polyolefins, are undergoing a transition from the demonstration stage to the practical stage from the demonstration stage to the recycling stage, such as the production of reshaped products by heating and melting, or the recovery as oil by thermal decomposition. Examples are increasing. However, in the case of PVC, which has the highest consumption breakdown by raw material resin, establishment of practical application technology for resource utilization is hampered. This is because a large amount of hydrogen chloride gas is generated at the time of heating, so that there are major problems such as high-temperature corrosion resistance of incinerators and reactors and generation of organic chlorine compounds. In fact, awareness of plastic recycling has already increased during the 1970s oil crisis, and attempts have been made to liquefy plastics. However, the range of target resins is limited to PE, PS, PP, etc., which do not contain PVC. Had been. In the 1990s, the establishment of thermal decomposition technology for PVC using a catalyst with hydrogen chloride resistance has been highlighted, but research such as designing the molecular structure of the catalyst that can withstand long-term use has not yet reached the practical stage. There are many stage tasks.
[0008]
Further, PVC, polyvinyl acetate, polyvinylidene chloride, polyurethane, cellulose and the like are widely used in paints, adhesives, rubbers, and the like, and such polymers include various types such as di (2-ethylhexyl) phthalate. A plasticizer has been added, which is also a problem. A plasticizer is a chemical used for imparting flexibility, elasticity, workability, and the like, and matching the intended use by being blended with a resin that is hard and rigid in itself. When added, the proportion may be as high as 50% or more. When a resin containing such a plasticizer is heated from room temperature, a decomposition product derived from the plasticizer is generated. At this time, if a halogen-containing plastic such as PVC coexists in the resin, it reacts with a large amount of hydrogen halide generated from PVC or the like to generate an organic halogen compound, which contaminates the thermal decomposition products and reuses them as resources. It becomes difficult.
[0009]
In addition, there are metal compounds used as stabilizers in additives of plastic products, and most of stabilizers for PVC are lead compounds, accounting for about 60%. For this reason, there is a concern that soil and groundwater may be contaminated with metals due to landfilling of waste plastics and disposal of residues generated by thermal decomposition or incineration. In particular, environmental pollution due to lead is a problem that cannot be ignored. Since lead itself has a wide variety of uses such as storage value, pigment production, soldering, etc., recovery of lead from waste plastic is very preferable from the viewpoint of effective use of resources. However, as can be understood from the fact that lead compounds are used as stabilizers to suppress the dehydrochlorination reaction of PVC due to heat or light, in practice, lead compounds are efficiently separated and recovered from plastics. To do so, advanced processing techniques are required. In addition, when a plastic containing a lead compound is thermally decomposed, lead is mixed into the resulting decomposition product, and recycling becomes difficult.
[0010]
Furthermore, in order to treat a large amount of waste plastic which increases with an increase in the production of plastic products, it is necessary to improve treatment efficiency and operability of operation. For example, if the thermal decomposition of plastics is performed in a batch system, the time required for processing and maintenance of the equipment during the thermal decomposition operation is not negligible, and the processing efficiency is not improved. Therefore, in order to improve processing efficiency and operability of operation, it is essential that continuous processing be possible. It is also important that the energy required for processing the plastic is not enormous in establishing the recycling and reuse of the plastic, and there is a demand for an energy-efficient processing method. Further, in order to increase the processing amount, it is necessary to improve workability.
[0011]
Further, since various kinds of polymers are used in the production of plastic products as described above, the contents of waste plastic vary depending on time and place, and it is difficult to accurately grasp the contents. Therefore, even when measures are taken to solve the above-described problems, there may be cases where the measures are insufficient due to extreme changes in the contents of the waste plastic. However, in order to establish the recycling and reuse of waste plastics, it is necessary to be able to cope with such cases. In particular, contamination of a thermal decomposition product due to the generation of an organic halogen compound has a great economical effect, and it is desired to take a reliable measure.
[0012]
The present invention has been made to solve such problems of the prior art, and waste plastics are efficiently converted into reusable resources, high-quality resources are recovered at a high recovery rate, economical efficiency and It is an object of the present invention to provide a waste plastic processing method and a processing apparatus which are excellent in processing reliability.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present inventors have conducted intensive studies and as a result, the removal of waste plastic additives contributes not only to the efficiency of resource recovery but also to the improvement of the quality of the recovered resources. By devising the embodiment, it is found that the energy efficiency is improved, the quality of the recovered resources is improved, and further, it is possible to remove the organic halide from the thermal decomposition product of the plastic contaminated with the organic halide. Invented a plastic processing method and apparatus according to the present invention.
[0014]
The method for treating plastic according to the present invention comprises the steps of:80-280 ° CIn a heated state, the compound contained in the plastic is brought into contact with an absorbent material toBy capillary actionElute into the material.
[0015]
Further, the method for treating plastic according to the present invention comprises the steps of adding acetic acid to the plastic, heating the plastic, and then separating the plastic from the acetic acid, and adding hydrogen vapor to the plastic after adding hydrogen chloride to convert the plastic from the generated hydrochloric acid. Separating, whereby lead contained in the plastic is removed.
[0016]
Further, in the method for treating plastic according to the present invention, the plastic is thermally decomposed by heating it into a thin layer.
[0017]
Further, in the method for treating plastic of the present invention, a lump of molten plastic is heated from the inside of the lump.
[0018]
OrThe method for treating plastic of the present invention comprises:A plastic processed so as to have a small volume to surface area ratio is brought into contact with an absorbent material in a heating state at 80 to 280 ° C., and a compound contained in the plastic is diffused or capillarized in the material. And the heating of the plastic isInject low activity gas heated to 150-400 ° C into molten plasticIncluding.
[0019]
Further, the method for treating a plastic according to the present invention is characterized in that a heavy oil or a halogen-free plastic is added to a molten plastic after removing a plasticizer from a halogen-containing plastic and subjecting to a hydrogen halide desorption treatment. Is to increase the fluidity of thermal decomposition.
[0021]
The processing apparatus for plastics of the present invention uses a plastic containing halogen.By the processing method described aboveA device for removing a plasticizer, a device for removing hydrogen halide from the halogen-containing plastic, and a plastic containing no heavy oil or halogen in the molten plastic after removing the plasticizer and removing hydrogen halide. It has an addition device for addition and a pyrolysis device for thermally decomposing the plastic to which the heavy oil or halogen-free plastic is added.
Further, the plastic processing apparatus of the present invention has a column which is loaded with activated carbon and a hydrogen halide trapping agent and is heated to 150 to 550 ° C., and the column is made to pass the vapor of the pyrolysis product. Connected to pyrolysis unit.
[0022]
The plastic processing apparatus of the present invention,Distillation apparatus for purifying pyrolysis productsToThe distillation apparatus has a distillation column having a shelf having a large number of through-holes, and an opening and closing device for opening and closing the through-holes of the shelf to adjust the number of through-holes opened.
The processed plastic is a sheet-like or film-like plastic.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
[0024]
[Removal of plasticizer]
The thermoplastic resin has the property that the composition is reversibly maintained when cooling and heating are repeated, but at high temperatures, the degradation of the polymer proceeds, and the low molecular weight and gasification easily occur. This property suggests that recycling by dissociation of chemical bonds, that is, recovery and utilization of low molecular weight compounds by thermal decomposition, can be easily performed compared to thermosetting resin, which is a representative example of a crosslinked substance having a repeated ladder structure. are doing.
[0025]
However, there are problems with halogen-containing plastics such as polyvinyl chloride (PVC), polyvinylidene chloride, vinylidene chloride-vinyl chloride copolymer, chlorinated polyethylene and the like. Generally, when PVC is heated in an inert gas, a general two-stage mass reduction occurs as shown in the following equation. The first stage of mass reduction is mainly due to the elimination of hydrogen chloride and proceeds at temperatures above about 300. It is said that in the reaction in the desorption region of hydrogen chloride, depolymerization does not occur and a radical chain reaction proceeds.
[0026]
Embedded image

Alternatively, it has been pointed out that HCl has a catalytic action as shown in the following formula, and the elimination of hydrogen chloride molecules may occur.
[0027]
Embedded image

On the other hand, the mass reduction in the second stage is caused by a reaction in which carbonization proceeds due to dissociation of a conjugated double bond and generation of crosslinking.
[0028]
However, many of the polyvinyl chlorides that are used daily contain a phthalic acid-based plasticizer such as DOP or DHP or an adipic acid-based plasticizer such as DOA in order to increase the plasticity of the resin. In the thermal decomposition, not only the above-mentioned elimination of hydrogen chloride but also the decomposition reaction of the plasticizer occur, and the composition shows a complicated aspect. This is a major factor that hinders the establishment of recycling technology. That is, the reaction between the desorbed hydrogen chloride and the decomposition product of the plasticizer produces an organic halide, which is mixed into the thermal decomposition product of the plastic, making it difficult to reuse the thermal decomposition product. In order to solve this, it is necessary to remove the plasticizer from the waste plastic in advance.
[0029]
A comparison was made between a sheet made of polyvinyl chloride resin containing DOP as a plasticizer and a sheet buried in the ground, which was exposed to light and exposed to the air. It was found that the plasticizer eluted, and after 6 months or more, about half of the plasticizer contained in the sheet was eluted. That is, when a substance having a property of absorbing an additive such as a plasticizer is present around the sheet, the additive can be separated and removed from the resin. Examples of the absorbent material include additives such as fibrous materials based on cellulose such as pulp and rayon, natural polymer-based inclusion compounds such as chitosan, and porous materials and granular materials such as soil. Examples include those that absorb from plastics and those that diffuse additives in plastics out of the water, such as solvents such as water.By contacting such an absorbent substance, additives, especially plasticizers, are removed from plastics. Absorb and remove. Since the removal efficiency of the plasticizer increases as the contact area with the absorbent material increases, it is desirable to process the plastic into a sheet or fine granules and contact the plastic with the absorbent material. Further, since the absorption and removal of the plasticizer proceeds when the plastic is heated, an absorbent material capable of heating the plastic is used. The heating temperature range is a temperature at which dehydrohalogenation does not proceed, preferably about 80 to 280 ° C. Desirable embodiments include, for example, those in which a sheet-shaped plastic is buried in soil and heated, or a sheet-shaped or fine-grained plastic is immersed in heated water or sprayed with high-temperature steam.
[0030]
Plastic products processed as thin sheets or films have different properties from plastic processed as thick plates or blocks, and proper processing methods are required from the viewpoint of recycling. The process described above is particularly suitable for such laminar plastics. A typical sheet-like plastic product is, for example, polyvinyl chloride for agricultural use. Its practicality has been evaluated since its launch in 1951, and its application range has been established since the establishment of JIS in 1953. It is expanding rapidly and is widely used as a covering material for greenhouses and tunnels for forcing cultivation of vegetables. A plasticizer is most frequently blended in the agricultural polyvinyl chloride sheet, and is blended at about 30%. Looking at the emissions of agricultural plastics in 1991, 105,616 t for polyvinyl chloride film, 68,399 t for polyethylene film, 6,463 t for other films, and 3,914 t for other plastics. 97.9% of processed film products and 57.2% of polyvinyl chloride film, which are quite high. In addition, although the recycling of waste plastic for agriculture has been promoted, it cannot be denied that it is still dependent on incineration, and the above-mentioned treatment method is useful from the viewpoint of utilizing limited resources. Furthermore, applying this method to a metal foil coated with plastic has the advantage that not only the removal of the plasticizer but also the separation of the metal foil and the plastic after the treatment is facilitated.
[0031]
FIG. 1 shows an example of a plastic processing apparatus for removing additives according to the present invention. The plastic processing apparatus 1 includes a heated steam generator 2 for generating steam as a solvent having an adsorption function, a steam discharge pipe 3 for ejecting the steam, and a recovery pump for recovering water in which the additive is eluted. 4, a collecting water tank 5 for receiving the collected water, a cylindrical rotator 6 for winding the film-like plastic P, a container 7 coated with a heat insulating material for increasing the heat retaining effect of water as a solvent, and a film feeder. And a cylindrical rotating body 8 for controlling Water is sent from the makeup water tank 9 to the heating steam generator 2 by the makeup pump 10 to generate steam.
[0032]
The heating steam generator 2 is operated, and steam is ejected from the steam discharge pipe 3 when the steam flow rate is stabilized. The rotating bodies 6 and 8 are slowly rotated to spout the film-shaped plastic P so as to uniformly contact the water vapor to promote the elution of the additive. After passing the water vapor through the film-shaped plastic P, the rotators 6 and 8 are reversed, and the elution of the compounded substance from the resin is continued while the film-shaped plastic P runs in the reverse direction. At this time, the width of the gap between the rotating bodies 8 is reduced so that the compressive force applied to the plastic P sandwiched between the rotating bodies 8 is suppressed low so that the plastic P passing between the rotating bodies 8 is not damaged. adjust. A part of the eluted additive is recovered from the recovery port 11 together with the water vapor into the recovery water tank 5, and a part of the additive is collected as a liquid or the like at the bottom of the container 7. The eluted and recovered product contains a plasticizer, an acidic compound such as an alcohol compound and a carboxy compound which are hydrolysates of the plasticizer, and the like.
[0033]
FIG. 2 shows a second example of a plastic processing apparatus for removing an additive according to the present invention. The plastic processing apparatus 12 uses water as a solvent having an absorbing action, and uses a heater 13 for heating water in place of the heating steam generator 2 of the first example and heating water in place of the replenishing pump 10. The pressurizing pump 14 for jetting is provided with a pressurized water discharge port 15 instead of the steam discharge pipe 3, and other members are the same as those in the first example.
[0034]
The heater 13 is operated, and when the supply of the heating water is stabilized, the heating water is ejected from the pressurized water discharge port 15. The rotating bodies 6 and 8 are slowly rotated to promote the elution of the additive by making the film-shaped plastic P uniformly contact the heated water. After the plastic is brought into contact with the heated water, the rotating bodies 6 and 8 are turned over, and the plastic P is run in the opposite direction, and the elution of the compounded substance from the resin is continued. At this time, the width of the gap between the rotating bodies 8 is reduced so that the compressive force applied to the plastic P sandwiched between the rotating bodies 8 is suppressed low so that the plastic P passing between the rotating bodies 8 is not damaged. adjust. The eluted additive is recovered in the recovery water tank 5 from the recovery port 11 together with the heated water. The eluted and recovered product contains a plasticizer, an acidic compound such as an alcohol compound and a carboxy compound which are hydrolysates of the plasticizer, and the like.
[0035]
In the above-mentioned example, if the plastic is heated before the processing by providing a heater to the rotating bodies 6 and 8, the operation efficiency is improved.
[0036]
FIG. 3 shows a third example of a plastic processing apparatus for removing an additive according to the present invention. The plastic processing device 16 includes an absorber 17 made of a porous material wound on a film of plastic P and wound in a roll shape, and an elution accelerator coated with a heat insulating material for accommodating the roll-shaped absorber 17. The tank 18, a heater 19 for warming the inside of the elution accelerating tank 18, a pressure regulating valve 20 for releasing gas when the pressure inside the elution accelerating tank 18 becomes equal to or more than a certain value, and accumulated in the lower part of the elution accelerating tank 19. A discharge valve 21 for taking out the liquefied component, and a recovery tank (not shown) for collecting a liquid obtained by cooling and condensing the gas discharged from the pressure regulating valve 20 with the outside air and a liquefied component recovered from the discharge valve 21. Thus, the roll-shaped absorber is impregnated with water as a solvent.
[0037]
A plurality of absorbers 17 wound in a roll around plastic P are put into the dissolution accelerating tank 18 and are stacked in a bale stack. Next, water is injected into the elution accelerating tank 18 to allow it to permeate the absorber 17. After injecting water so as to cover the uppermost roll, the water is allowed to stand, and when the water level has almost completely dropped, the upper lid 22 is closed and the heater 19 is operated. The temperature is preferably set to 90 ° C. or higher and lower than 100 ° C. By keeping the temperature substantially constant in this state, the additives are removed from the plastic P.
[0038]
FIG. 4 shows a fourth example of a plastic processing apparatus for removing an additive according to the present invention. The plastic processing device 23 uses water as a solvent having an absorbing effect on additives in the plastic, and uses a heater 24 for heating the water, a pulling device 25 for pulling up the film-shaped plastic P, A hot water tank 26 coated with a heat insulating material that enhances the heat retaining effect, an excellent light-transmitting glass house 27 formed so as to surround the upper part of the hot water tank 26, and a volatile substance condensed on the inner wall of the house 27 A collecting groove 28 for collecting the water, an absorbent 29 made of cellulose surrounding the plastic P to be treated, and a pressure pump (not shown) for supplying water to the absorbent 29. A temperature sensor 30 for detecting the temperature of the absorber 29 is provided, and a pressure control valve 31 is provided so that the pressure in the house 27 does not rise above a predetermined pressure, and is connected to a collection tank (not shown). You.
[0039]
The film plastic and the absorber 29 are layered on top of each other and stacked in a hot water tank 26, and the circulation pump and the pressure pump are driven to operate the heater 24 for heating water as a solvent when the circulation flow rate of water is stabilized. Then, the absorber 29 and the plastic P are heated. The house 27 plays a role of supplementing the energy required for heating the inside of the house with the heat energy by the sun rays. The additives in the plastic P are eluted in the water in the absorber 29, and a part is vaporized. The substance vaporized inside the house 27 is condensed at the upper part of the house and is recovered through the recovery path 28. After maintaining the temperature of the absorber 29 for a predetermined period, the plastic is recovered using the lifting machine 25.
[0040]
FIG. 5 shows a fifth example of a plastic processing apparatus for removing an additive according to the present invention. The plastic processing apparatus 32 is characterized by comprising a plurality of containers so that substances eluted from the plastic can be continuously separated according to the temperature of the generated steam. That is, the processing apparatus 32 includes a first processing apparatus 1a and a second processing apparatus 1b having the same structure as that of the processing apparatus 1 shown in FIG. 1, and plastic is transferred from the first processing apparatus 1a to the second processing apparatus 1b. To run continuously. In this configuration, since the temperature of the steam used in the first processing device 1a and the second processing device 1b can be changed, for example, an additive such as a plasticizer is removed in the first processing device 1a, In the processing apparatus 1b, dehydrohalogenation of plastic can be performed. In this case, it is desirable to always discharge the eluate from the inside of the apparatus or to ensure the temperature control of the plastic so that the organic halogen compound is not generated.
[0041]
In the above example, the dissolution can be promoted by applying vibrational energy to the plastic during the dissolution treatment.
[0042]
[Removal of lead]
Additives that pose a problem in recycling and recycling waste plastics include metal compounds used as stabilizers in addition to the above-mentioned plasticizers. In particular, lead-based compounds account for the majority of the stabilizers for vinyl chloride at 60%, for example, lead white (2PbCO2).₃・ Pb (OH)₂), Basic lead sulfite (PbO.PbSO)₃), Tribasic lead sulfate (3PbO.PbSO)₄・ H₂O), dibasic lead phosphite (2PbO.PbHPO)₃・ 1 / 2H₂O), dibasic lead phthalate (2PbO.Pb (C₃H₄O₄)), Tribasic lead maleate (3PbO.Pb (C₂H₂O₄) H₂O), dibasic lead stearate (2PbO.Pb (C₁₈H₃₆O₂)₂), Lead stearate (Pb (C₁₈H₃₆O₂)₂).
[0043]
The removal and recovery of such lead compounds from plastics can be achieved by using acetic acid and hydrogen chloride. A detailed description will be given of a plastic processing method for removing and recovering lead.
[0044]
First, the plastic is brought into a softened state, and the mixture is stirred while adding acetic acid to bring the plastic and acetic acid into sufficient contact. Acetic acid can dissolve lead oxide, and the lead oxide contained in the basic lead salt in the above-mentioned lead-based stabilizer is dissolved by acetic acid. The temperature at this time is set to a temperature at which the plastic containing polyvinyl chloride can be softened and the boiling point of acetic acid is 117.8 ° C. or less. Especially around 95 ° C. is preferred. After extracting lead with acetic acid, a zinc plate is inserted into the extract. Lead, which has a lower ionization tendency than zinc, can form a lead tree around the zinc plate and precipitate. In addition, since about 80% of lead oxide is reported in the basic lead salt-based stabilizer, most of the lead is recovered by this method.
[0045]
Further, with respect to lead compounds other than lead acetate, after chloride of lead is formed by hydrogen chloride, a concentrated hydrochloric acid aqueous solution is generated by supplying steam, and extracted as lead chloride ions therein. When a plastic containing polyvinyl chloride is thermally decomposed at 280 to 400 ° C., preferably 300 to 350 ° C., chlorine is eliminated from vinyl chloride to generate hydrogen chloride. Lead chloride is formed by reacting the hydrogen chloride with the lead compound. When the temperature is lowered to about 95 ° C. and steam is added, hydrogen chloride becomes concentrated hydrochloric acid, and lead chloride becomes chloride ion (PbCl 2).₄)^2-As concentrated in concentrated hydrochloric acid. Thereafter, chloride ions are reacted with hydrogen to reduce them to lead, and are recovered as metallic lead. By this method, it is also possible to recover lead of a lead compound other than lead oxide.
[0046]
6 to 8 show an example of a plastic processing apparatus for removing lead according to the present invention. This device 33 is formed in a plastic supply device 34 capable of controlling a supply amount of plastic per hour to a predetermined amount, an acetic acid addition tank 35 for dissolving lead oxide as a stabilizer in acetic acid, and an acetic acid addition tank 35. A lead recovery tank 39 for recovering lead from an aqueous lead acetate solution, a lead chloride extraction tank 40 for bringing plastic into contact with hydrochloric acid to recover lead in a lead-based compound other than lead oxide, A hydrogenation tank 43 is provided that reduces lead chloride precipitated therein to lead by hydrogenation and recovers only lead. The acetic acid addition tank 35, the hydrogen addition tank 43, and the like are subjected to a corrosion-resistant treatment such as quartz processing in order to prevent corrosion of the inner wall.
[0047]
Acetic acid is supplied from the acetic acid supply device 36 to the plastic charged into the acetic acid addition tank 35 from the plastic supply tank 34 and heated. The lead acetate solution and the plastic are sent to and separated from a lead acetate separation tank 37 connected to an acetic acid addition tank 35, and the lead acetate solution is sent to a lead recovery tank 39 by a vacuum pump 38. The vacuum pump 38 and the lead acetate separation tank 37 are connected via a porous filter in order to prevent the plastic softened by heating from entering the lead recovery tank 39. The plastic is put into the lead chloride extraction tank 40 and heated. The heating temperature is controlled by the temperature controller 47 to a temperature at which hydrogen chloride is generated from the chlorine-containing plastic, and lead components other than lead oxide are converted to lead chloride. When steam is supplied from the steam addition device 41, hydrochloric acid in which lead chloride is dissolved is generated, separated from plastic, and put into the hydrogenation tank 43. To this, water is supplied from the water supply tank 42 to dilute the hydrochloric acid, whereby the lead component precipitates. By supplying hydrogen to the precipitate from a hydrogen cylinder 44, high-purity lead is obtained. The waste liquid is sent to a waste liquid tank 45 through a mesh plate 48 serving as a filter by controlling the switching valve 46.
[0048]
By the above-described operation, lead can be recovered at a recovery rate of 80% or more, and the lead recovery rate is further improved by repeating the treatment with hydrogen chloride.
[0049]
FIG. 7 is a diagram showing the configuration of the acetic acid addition device 35 of the processing device 33. The acetic acid addition device 35 is made of metal and is formed to have a cylindrical inner diameter, and a stirring shaft 49 with metal wings is installed inside. The stirring shaft 49 is rotated by a motor 50.
[0050]
The lead chloride extraction tank 40 has the same internal structure as the acetic acid addition tank 35 of FIG. 7, and further includes a steam inflow valve and a liquid outflow valve (not shown) for extracting lead chloride.
[0051]
A zinc plate 51 as shown in FIG. 8 is put into the lead acetate solution in the lead recovery tank 39, and when the aqueous lead acetate solution is transferred to the lead recovery tank 39, lead having a smaller ionization tendency than zinc is deposited around the zinc plate. Precipitates out.
[0052]
According to the statistics of 1990, the annual production of stabilizer is 26,000 tons, and when 80% of lead is recovered from lead-based stabilizer in it, 13,000 tons of lead can be recovered per year. . In addition, by recovering lead in this way, not only can useful resources be recovered, but also lead can be safely disposed without being mixed into the residue due to thermal decomposition of plastic. In addition, contamination of the oily product obtained by thermal decomposition with lead is prevented, and it can be used as a high quality fuel.
[0053]
[Improvement of thermal decomposition efficiency]
Plastic has a high viscosity when melted due to its long molecular structure. Therefore, convection is difficult even when heated, and it is difficult to heat uniformly. At present, waste plastics are thermally decomposed while installing a stirrer, etc., while ensuring the uniformity of heat of the molten plastic. Taking the apparatus as an example, it takes about 4 hours from the input of the waste plastic to the apparatus to the end of the processing of the input plastic. For this reason, the scale of the apparatus needs to be relatively large, and the time required for the treatment is also required for a certain period of time, which naturally affects the disposal cost of the waste plastic.
[0054]
In the present invention, in order to efficiently pyrolyze a molten plastic having high viscosity and greatly reduce the processing time, the plastic is melted and then pyrolyzed into a thin layer having a thickness of 20 mm or less. The thin layer of the molten plastic is heated by an electromagnetic wave such as infrared light or microwave or a dielectric heating method. In this way, when heating from the outside with infrared light or the like, the volume required to be heated is smaller than that of the heat receiving surface, so the time required for heating is short, and thermal decomposition and polyvinyl chloride When included, gas generated by dehydrochlorination or the like can be efficiently removed from the plastic. Heating by infrared light, electromagnetic waves such as microwaves, or the dielectric heating method can be performed from a remote position that does not directly contact the plastic.
[0055]
The thin layer of the molten plastic is formed on a carrier having a belt shape, a disk shape, a column shape, a circular shape, or a linear shape. Thereby, the thermal decomposition treatment can be continuously performed.
[0056]
FIG. 9 shows a first example of a processing apparatus for performing pyrolysis in a thin layer of molten plastic. This device 52 has a stainless steel belt 53 on which a thin layer of molten plastic is formed. After the plastic is crushed, it is put into the hopper 54. The plastic is transported by the screws 55a, 55b, 55c while being heated, extruded by the screws 55b, 55c at the squeezing section 56, and applied to both surfaces of the belt 53 to a predetermined thickness. The applied plastic is heated by the infrared lamp 57. Alternatively, heating may be performed by a dielectric heating method. The temperature is raised to 200 to 400 ° C. in the dehydrochlorination chamber 58, and when the waste plastic contains polyvinyl chloride, hydrogen chloride gas is generated from the plastic. The generated gas is exhausted from the hydrogen chloride outlet 59. The plastic on belt 53 enters pyrolysis chamber 61 through squeezing section 60. The plastic is heated to 250 to 550 ° C. by the infrared lamp 57 in the pyrolysis chamber 61 and pyrolyzed. Of course, heating may be performed by a dielectric heating method. The gas generated by the thermal decomposition is exhausted from a product gas exhaust port 62. The gas discharged from the generated gas exhaust port 62 is condensed and recovers liquid oil. The molten plastic is once accumulated in the squeezing section 60, and the dehydrochlorination chamber 58 and the thermal decomposition chamber 61 are shut off by the accumulated molten plastic. Similarly, the dehydrochlorination chamber 58 and the thermal decomposition chamber 61 are also shut off in the squeezing section 56, and the gas generated in these sections is kept airtight and does not mix. The residue of the plastic that has been thermally decomposed is removed from the belt 53 by the scraping blades 63a and 63b. The removed residue is discharged out of the apparatus by the screw of the residue discharge section 64. The belt runs by the rotation of the gear 65.
[0057]
FIG. 10 shows a second example of a processing apparatus for performing pyrolysis in a thin layer of molten plastic. This device 66 has an annular disk 67 as a carrier. The plastic is applied to the disk 67 by a plastic application section 68 and is conveyed by the disk 67 rotated by a drive gear 69. The applied plastic is heated to a temperature of 250 to 550 ° C. by the infrared lamp 70. Residue is removed from the disk 67 by the residue scraping blade 71. The vapor of the decomposition product generated during the thermal decomposition is exhausted from the exhaust port 72 and then cooled and liquefied to recover the oil.
[0058]
FIG. 11 shows the configuration of the plastic application section 68.
[0059]
After the waste plastic is pulverized, it is put into a hopper 73, and is conveyed in an arm 74 by screws 75a and 75b while being heated. The molten plastic is extruded from the slit 76 by the screw 75b and applied to the disk 67. By adjusting the gap d between the slits 76 of the arm 74 and the extrusion pressure, the thickness of the applied plastic is adjusted.
[0060]
As shown in FIG. 12, the residue attached to the disk 67 is removed by a pair of scraping blades 71 whose tips contact both sides of the disk 67. The residue accumulates in the residue discharge section 64 and is discharged out of the apparatus by a screw 77 for discharging the residue. The removed residue is stored in a storage tank 78.
[0061]
The rotating disk or belt may be a linear object, a circular object, or a cylindrical object.
[0062]
FIG. 13 shows a third example of a processing apparatus for performing pyrolysis in a thin layer of molten plastic. This device 78 is of the type using the same belt as in the first example, but has only one room, as in the second example. When the molten plastic is applied to the belt 79, it is conveyed by the traveling rotating body 80 and heated by the infrared lamp 81. The vapor of the pyrolysis product is discharged from the exhaust port 83 and collected by a condenser or the like. The pyrolysis residue is removed from the belt 79 by the scraping blade 82.
[0063]
The method of treating the molten plastic in a thin layer state as described above can also be applied to the removal of the plasticizer described above. For example, waste plastics are melted to form a thin layer, and the plasticizer is removed by contacting with steam or heated water.After removing lead, the thin layer is applied again to the carrier and pyrolyzed. Can be configured.
[0064]
[Improvement of energy efficiency]
The high viscosity of molten plastic is a problem that also leads to a decrease in energy efficiency. When applying thermal energy to molten plastic, whether in a batch or continuous process, it is common to heat the plastic from outside the mass. However, even if heat is applied from outside the viscous plastic, it takes time for the heat to reach the inside. In addition, at the stage where desorbed hydrogen halide or pyrolysis product gas is released from the plastic, the direction in which the gas is released from the plastic is opposite to the direction in which heat is applied to the plastic from the outside. It is difficult for heat to be transmitted, and the reaction on the surface of the plastic is fast, but the inside is difficult to react. Stirring is performed to eliminate this, but a heating shaft member is used as a device for further improving the thermal efficiency. The heating shaft member is disposed at the center of the lump of molten plastic and heats the plastic from the inside, and is most efficiently used as a shaft of the stirring device. Further, the heating shaft member is formed into a hollow cylindrical shape or the like, and a large number of pores communicating between the inside and outside of the shaft are provided, and a gas having a low activity such as nitrogen, water vapor, and an inert gas is heated, and the inside of the heating shaft member is heated. When the plastic is blown into the plastic, the heating and heat conduction from the inside are promoted by the heated gas, and the stirring efficiency and the heat efficiency are further improved.
[0065]
FIGS. 14A and 15 show a first example of a plastic processing apparatus having a heating shaft member according to the present invention. The processing device 84 includes an outer cylinder 85 and a stirrer 86 provided coaxially and rotatably in the outer cylinder 85. The stirrer 86 has a heating shaft member 87 and a spiral blade 88 on the outer periphery thereof. And is rotated by a motor 89. The heating shaft member 87 is hollow and provided with a large number of pores 90, and the low-activity gas sent from the gas supply device 91 is heated by a heater 92 provided on the heating shaft member 87 to be outside the pores 90. It is supplied to the inside of the cylinder 85 and is collected via a pipe 93 connected to the outer cylinder 85. The outer cylinder 85 is covered with a heat insulating material 94.
[0066]
The plastic is supplied from the supply tank 95 at one end of the outer cylinder 85 into the outer cylinder 85 through a supply port provided with a control valve 96, and when the heater 92 is operated and the temperature reaches around 100 ° C. at which plastic softening starts. The low-activity gas supplied from the gas supply device 91 via the valve 98 is discharged through the fine holes 90 of the heating shaft member 87. The heated and melted plastic is gradually conveyed toward the discharge port 97 at the other end according to the rotation of the heating shaft member 87 by the motor 89. During this time, the low-activity gas is heated by the heater 92. The low-activity gas released from the plastic, the hydrogen chloride desorbed from the plastic, and the gaseous pyrolysis products are recovered via a pipe 93. The supply of the heating gas promotes the softening of the plastic, and also works effectively for mechanical cutting of the polymer chains of the resin by foaming into the plastic. Further, it promotes the release of hydrogen halide from molten plastic during dehydrohalogenation. The low-activity gas used may be any gas that does not substantially have a detrimental effect on the thermal decomposition of plastic, and may be appropriately selected from inert gases such as argon, helium, neon, xenon, and krypton, nitrogen, and steam. You can choose. Economically, nitrogen is preferred. There are other advantages when using steam. That is, as mentioned earlier, it also serves to facilitate the removal of the plasticizer from the plastic.
[0067]
The temperature of the heating shaft member 87 is set according to the distance in the longitudinal axis direction from the supply port, as shown in the graph of FIG.
[0068]
When the distance from the supply port is 1/10 to 1/5 of the total length in the longitudinal direction, the temperature of the injected plastic reaches about 250 ° C. (point a in FIG. 14B). From about to a position (point b) with respect to the entire length in the longitudinal direction (point b). In the section ab, the decomposition of the plastic material contained in the plastic proceeds.
[0069]
It is more preferable to set the temperature up to the point b as follows. First, the temperature at point a is set to 200 ° C., and then gradually raised to 250 ° C. during about half to ３ of the section ab, and then maintained at 250 ° C. to point b. When the temperature is slowly increased from 200 to 250 ° C., the efficiency of removing the plasticizer is improved. In order to lengthen the heating section at 200 to 250 ° C. and the heating section at 250 ° C., it is desirable to raise the temperature to 200 ° C. as quickly as possible.
[0070]
Further, at a position (point c) where the distance from the supply port is 3/5 of the entire length in the longitudinal direction, the temperature is raised so as to be 300 ° C., and the temperature is set to be maintained at just before 97 at the discharge port. You. The dehydrohalogenation proceeds in the section cd. By separately collecting the gas collected in the section ab and the gas collected in the section cd, the production of the organic halogen compound is suppressed, and the gas collected in the section cd is washed. Hydrocarbon compounds and hydrogen halides generated by thermal decomposition are easily separated. As described above, if the alkali is added in the middle of the section ab, the removal and recovery of the plasticizer and the prevention of the generation of the organic halogen compound can be performed more efficiently.
[0071]
FIG. 16 shows a second example of a plastic processing apparatus provided with a heating shaft member according to the present invention. The processing device 95 has a plurality of stirring devices 86a and 86b having a heating shaft member 87, and rotates in opposite directions. In this example, the heater 96 is provided at the inner diameter of each heating shaft member 87. or,
Grooves may be provided on the outer peripheral surfaces of the two heating shaft members 87 at regular intervals so that the cross section has a waveform. This not only increases the surface area of the outer peripheral surface and improves the reaction efficiency, but also makes it possible to prevent clogging of the inlet for the inert gas and the outlet for the generated gas.
[0072]
FIG. 17 shows a third example of a plastic processing apparatus provided with a heating shaft member according to the present invention. This processing device 97 includes a stirring device 86 having a heating shaft member 87 similar to that of the first example, but the outer cylinder 98 and the heat insulating material 99 are formed in a rectangular parallelepiped shape, and the inner diameter of the outer cylinder 98 is an octagonal prism. Shape. The other points are the same as in the first example.
[0073]
[Promotion of dehydrohalogenation]
As described above, the above-described configuration in which a low-activity heating gas is supplied to heat the molten plastic from the inner side is effective in improving energy efficiency and accelerating the removal of desorbed hydrogen halide. Supplying a heated gas to the molten plastic is effective for releasing and removing plasticizers and decomposition products of the plasticizer from the molten plastic. For this purpose, the gas supplied to the molten plastic is heated to about 150-400 ° C. The range of about 150 to 300 ° C is mainly used for removing plasticizers and the like, and the range of about 250 to 400 ° C is used for removing hydrogen halide. If a heating gas having a temperature range of 350 to 500 ° C. is used, the plastic is thermally decomposed, and oily products, carbonized residues, low carbon fuel gas and the like are generated. In order to release hydrogen halide, plasticizer, and the like, it is important to increase the contact area between the heating gas and the molten plastic, and it is preferable that the gas can be uniformly supplied to the entire plastic. Therefore, it is devised so that a large amount of fine bubbles can be supplied uniformly. By using such a gas treatment together with the above-described removal treatment of the plasticizer and the hydrogen halide, the amount of these remaining in the plastic can be further reduced.
[0074]
FIG. 18 is an example of a plastic processing apparatus for removing hydrogen halide and a plasticizer according to the present invention. This processing apparatus 100 is an application of a general extruder configuration, and has an extruder section 101 provided with a heating device and a screw 102 disposed therein, and the shaft and wings of the screw 102 are formed in a hollow shape. In this case, many pores 103 are provided. Further, the axis of the screw 102 is connected to a pipe having a gas supply port 104 through a joint, and a heater 105 for heating the gas supplied from the gas supply port 104 is provided. The screw 102 is rotated by a motor 106.
[0075]
The molten plastic injected from the charging section 107 is swept away by the rotation of the screw 102 inside the extruder section 101, and gas heated to a predetermined temperature by the heater 105 is bubbled into the plastic from the screw shaft and the fine holes 103 of the blades. Released in a shape, heating the plastic. The plastic in the extruder unit 101 is adjusted using a heater 105 and a heating device provided in the extruder 101 so that a temperature gradient is generated along the longitudinal direction. This temperature gradient is such that the plasticizer and the decomposition product of the plasticizer are released from the plastic near the first exhaust unit formed near the input unit 107, and near the second exhaust unit formed near the heater 105. The setting near the second exhaust unit 110 is higher than the temperature near the first exhaust unit 108 such that hydrogen halide is generated. If a natural temperature gradient due to heating of the heating gas is sufficient to set such a temperature, the operation of the heating device of the extruder unit 101 becomes unnecessary. The plasticizer and the decomposition product of the plasticizer released from the plastic together with the heating gas are discharged from the first exhaust unit 108 to the outside of the apparatus by the pump 109. The hydrogen halide is discharged from the second exhaust unit 110 together with the heating gas by the pump 111. The plasticizer from which the plasticizer and its decomposition products have been removed in the extruder section 101 and the hydrogen halide has been released is discharged from the discharge port 112 to the outside of the apparatus.
[0076]
FIG. 19 shows an example of a plastic pyrolysis apparatus to which the processing apparatus 100 shown in FIG. 18 is applied. The thermal decomposition apparatus 113 has a pre-processing unit 114 and a thermal decomposition tank 115 connected to the pre-processing unit 114. The pre-processing unit 114 has the same configuration as the processing apparatus 100 described above.
[0077]
The molten plastic from which the plasticizer and the halogen element have been removed by the pretreatment unit 114 is supplied to a pyrolysis tank 115. The thermal decomposition tank 115 is provided with a heater 119 and a stirring device 120, and heats the molten plastic to a thermal decomposition temperature with the heater 119 while stirring with the stirring device 120 to thermally decompose. The gaseous low-molecular product generated by the thermal decomposition is cooled in the condenser 116, and partly liquefied into oil to be stored in the generated oil tank 117, and components not liquefied in the condenser are exhaust gas treatment equipment 118. Is processed. A residue discharge unit 121 is provided below the thermal decomposition tank 115 to discharge the carbonized residue and store it in a residue tank 122.
[0078]
[Improvement of workability]
Halogen-containing plastics such as PVC, polychlorinated biphenyls, and PVC-polyvinylidene chloride copolymers have a very high viscosity when melted by heating, and once the viscosity drops rapidly due to desorption of hydrogen halide, the fluidity decreases. After that, the viscosity increases with the progress of carbonization by thermal decomposition. Therefore, when thermal decomposition is performed by a general method, the viscosity is partially increased due to carbonization on a surface that is easily subjected to heat, and the plastic mass adheres to the wall surface of the decomposition tank. The thermal decomposition residue of a halogen-containing plastic is harder than the thermal decomposition residue of a halogen-free plastic, and it is not easy to remove the residue attached to a wall or the like. In addition, if residue or high-viscosity plastic during pyrolysis adheres to the inner surface of the heating device, reaction tank, residence tank, piping connecting the devices, or the surface of the stirrer installed inside the device, the plastic in the decomposition tank is removed. Not only does it impair fluidity, but it also results in poor heat transfer during heating. For this reason, it is important to increase the processing efficiency that the plastic can move in the apparatus and the delivery pipe without adhering. In particular, it is necessary to maintain the fluidity of the plastic during thermal decomposition as much as possible in continuous processing.
[0079]
In the present invention, the pre-treated plastic obtained by removing the plasticizer and hydrogen halide from the halogen-containing plastic and an adhesion inhibitor for suppressing the adhesion of the thermal decomposition residue to the wall of the apparatus are added to thermally decompose. The adhesion inhibitor and the method of adding the same are classified into two types.
[0080]
One is to add a halogen-free plastic and thermally decompose it. A halogen-free plastic such as PE or PP becomes a low-viscosity melt by heating, and the pyrolysis residue is soft and easily removed from the apparatus. . Therefore, by mixing and thermally decomposing a halogen-free plastic, the viscosity of the mixture is suppressed from increasing more than that of the pretreated plastic alone, and the fluidity is maintained.
[0081]
The other is to add a heavy oil which can exist as a low-viscosity liquid in the range of the temperature of dehydrohalogenation to the thermal decomposition temperature of plastics and to thermally decompose it. It is efficient to carry out thermal decomposition while adding to the vicinity. By adding a heavy oil component, the viscosity of the mixture is similarly reduced, the fluidity is increased, and the adhesion to the apparatus wall is suppressed. For example, there are paraffin, higher fatty acids, waxes, mineral oils, vegetable oils, animal oils and the like.
[0082]
FIG. 20 shows an example of a thermal decomposition apparatus that performs a plasticizer removal treatment and a dehydrohalogenation treatment on a halogen-containing plastic, and then performs thermal decomposition using an adhesion inhibitor. The pyrolysis device 123 includes a first pretreatment device 124 for removing a plasticizer from plastic, a second pretreatment device 125 for desorbing hydrogen chloride, a heating / melting tank 142, An apparatus 127 and a pyrolysis tank 128 are provided.
[0083]
The first pretreatment device 124 is an extruder-type device having a structure similar to that of the above-described device in FIG. 14 or FIG. 18, and includes an outer cylinder covered with a heat insulating material for enhancing a heat retaining effect, and a built-in heater inside. And a screw rotatably arranged on the inner diameter of the cylinder. A plastic supply tank is connected to one end of the first pretreatment device 124 via a supply valve 132, and the other end is connected to the second pretreatment device 125 via a transfer valve. Further, the inert gas supply 133, the gasification component recovery tank 134, and the circulation pump 135 are connected, and the inert gas supplied from the inert gas supply 133 flows through the first pretreatment device 124 from one end to the other. After passing to the end side, gasification components are removed in the gasification component recovery tank 134, and the gasification components are again introduced into the first pretreatment device 124 by the circulation pump 135.
[0084]
The second pretreatment device 125 is also an extruder-type device similar to the first pretreatment device 124, and has one end connected to the transfer valve 136 and the other end connected to the heating and melting tank 126. Further, an inert gas supply device 137, a gasification component recovery tank 138, and a circulation pump 139 are connected.
[0085]
A plastic supply tank 140 is connected to the heating and melting tank 126 via a supply valve 141, and a transfer pipe between the second pretreatment device and the heating and melting tank 126 and a connection between the supply valve 141 and the heating and melting tank 126. The heavy oil adding device 127 is connected to the pipe. Further, a distillation device 129 is connected to the heating and melting tank 126. A stirrer is provided in the heating and melting tank 126, and a residue discharge port is provided at the bottom. Further, the lower part of the heating and melting tank 126 and the top of the thermal decomposition tank are connected via a transfer valve 143, and this connection pipe is covered with a heat insulating material for keeping heat.
[0086]
The thermal decomposition tank 128 has a heater and has a stirring device inside. Furthermore, a residue outlet is provided at the bottom, and the top is connected to the distillation apparatus 130.
[0087]
The plastic put into the first pretreatment device 124 from the plastic supply tank 131 is heated to about 230 to 280 ° C. to be melted, the phthalic acid-based plasticizer and its decomposed product are released, carried to the inert gas, and It is collected in the chemical component recovery tank 134. If the alkali is added to the plastic, the decomposition products of the plasticizers other than phthalic acid are also recovered. The decomposed product molten plastic is sent to the second pretreatment device 125 and heated to about 330 ° C. in the second pretreatment device, where hydrogen halide is desorbed from the halogen-containing plastic and is sent to the gasification component recovery tank 138 together with the inert gas. Sent.
[0088]
The molten plastic that has been subjected to the deplasticizing treatment and the dehydrohalogenation treatment is charged into a heating and melting tank 126, and a heated heavy oil is added while maintaining the temperature so that the temperature does not drop rapidly. By adding heavy oil along the inner wall of the transfer pipe connected to the heating and melting tank 126, the flowability of the plastic in the transfer pipe is increased, and the transfer becomes easier. Further, a plastic containing no halogen such as polypropylene or a mixture containing a large amount of a plastic containing no halogen such as polypropylene is charged in advance from the plastic supply tank 140 to the heating and melting tank, heated and melted, and kept at 350 to 380 ° C. The molten plastic is stirred from the second pretreatment device 125 while the molten plastic is being supplied from the second pretreatment device 125 such that the liquid level in the heating and melting tank 126 is approximately 50 to 80% from the bottom of the tank. To separate. In addition, the gasified gas partially in the heating and melting tank 126 is led to the distillation apparatus 129 from the upper pipe, and the compound is separated according to the boiling point.
[0089]
The molten plastic in the heating and melting tank 126 is put into a pyrolysis tank 128, and is heated to about 450 ° C. or higher while being stirred and thermally decomposed. The gasification components introduced from the pyrolysis tank 128 to the distillation apparatus 130 are separated by the boiling point. Carbonized components and the like are removed from the lower part of the heating and melting tank 128.
[0090]
FIG. 21 is a modified example of the heating and melting tank 26 of the thermal decomposition apparatus 123 in FIG. 20, which is configured as an extruder type apparatus suitable for continuous operation, and uses heavy oil as an adhesion inhibitor. The device 155 includes a hollow cylindrical outer cylinder 147 having a screw 145 therein, and a motor 146 for rotating the screw 145, and the outer cylinder 147 is covered with a heat insulating material. At one end of the outer cylinder 147, a plastic inlet 150 and an air inlet 149 are provided, and at the other end, an air outlet 151 and an outlet 152 are provided, and a heavy oil supply pipe 154 is connected. A number of heavy oil injection grooves 153 are formed on the inner wall of the outer cylinder 147, and communicate with the heavy oil supply pipe 154.
[0091]
The molten plastic introduced from the inlet 150 is conveyed in the direction of the outlet 152 according to the rotation of the screw 145 while being kept at a predetermined temperature by the heating gas supplied from the air inlet 149. During this time, heavy oil supplied from the heavy oil supply pipe 154 is added to the plastic from the heavy oil injection groove 153. The addition of heavy oil reduces the viscosity of the plastic in the vicinity of the outer periphery, suppresses adhesion to the inner surface of the outer cylinder 147, and reduces the viscosity of the entire plastic as it permeates the plastic.
[0092]
The structure in which the heavy oil injection groove is provided on the inner wall of the device as shown in FIG. 21 may be applied to the pretreatment devices 124 and 125 in FIG.
[0093]
The configuration in which the heavy oil injection groove is provided on the inner wall of the apparatus as shown in FIG. 21 can be applied to the batch type heating and melting tank in FIG. FIG. 22 shows an example thereof. This heating / melting tank 126 'includes a rotating shaft 156 having four stirring blades 157 therein, which is rotated by a motor. A heavy oil injection port 158, an input port 159, a plastic supply port 160, and a gas discharge port 161 are provided at an upper portion of the heating and melting tank 126 ', and the heavy oil is injected into the heating and melting tank 126' from the heavy oil injection port 158. A number of heavy oil injection grooves provided on the inner wall of the heating and melting tank 126 'communicate with the heavy oil injection port 158 so as to supply the heavy oil.
[0094]
In this heating / melting tank 126 ', by admitting molten plastic from the inlet 159 while supplying heavy oil from the heavy oil inlet 158, adhesion of residues and the like to the inner wall surface is effectively suppressed.
[0095]
FIG. 23 shows another example of a thermal decomposition apparatus that performs thermal decomposition using an adhesion inhibitor. The thermal decomposition device 163 includes a first pretreatment device 124 and a second pretreatment device 125 having the same configuration as that of FIG. 20, but the extruder-type heating reaction tank 165 plays the role of the heat melting tank 126 and the heat decomposition tank 128. The heavy oil is supplied from the heavy oil adding device 164 to a pipe connecting the second pretreatment device 125 and one end of the heating reaction tank 165. A residue recovery tank 166 and a distillation apparatus 167 are connected to the other end of the heating reaction tank 165, and the distillation apparatus 167 is further connected to the vicinity of the center of the heating reaction tank 165. In addition, a heater is provided in the screw shaft in the heating reaction tank 165 so that heat is transmitted from the inside to the outside of the heating reaction tank 165, so that heavy oil is supplied onto the screw shaft surface. A groove is formed in the screw shaft. The temperature in the heating reaction tank 165 is controlled in three parts along the longitudinal direction.
[0096]
In the pyrolysis device 163, the molten plastic that has been subjected to the plasticizer removal treatment and the dehydrohalogenation treatment in the same manner as in FIG. 20 is kneaded in a heating reaction tank 165 after heavy oil is added, and further thermally decomposed. Then, the pyrolysis residue is pushed out to a residue recovery tank 166. The gaseous products from the pyrolysis are separated by boiling point in distillation apparatus 167.
[0097]
FIG. 24 shows an application example of the heating and melting tank 126 of the thermal decomposition apparatus 123 shown in FIG. Further, an injection port for injecting heavy oil into the heating and melting tank 126 is provided on the side wall surface 176 as in FIG. 22 (omitted in the figure). When the molten plastic transferred from the pretreatment device is introduced from the inlet 172, the stirring shaft 169 provided with the stirring blade 170 is injected while heavy oil is injected from the wall surface of the heating and melting tank 168 along the wall surface. After rotating by a motor 171, the residue is separated from the liquid material and discharged from a discharge port 177. Then, a plastic containing no halogen is introduced into the heating and melting tank 168 from a plastic supply port 205, and is softened by using residual heat. Thereafter, heating is performed using a heater 175 to melt the plastic, and the temperature is maintained at 350 to 380 ° C. Thereafter, the plastic is sent to a pyrolysis tank and pyrolyzed. When a heating means such as a heating wire is provided inside the stirring shaft 169 and the stirring blade 170, the working efficiency is further increased and the energy required for stirring is reduced.
[0098]
The pretreatment step such as the above-mentioned dehydrohalogenation step is necessary for PVC and the like. Therefore, if such a plastic that requires pretreatment and an unnecessary plastic can be separated, a plastic that does not require pretreatment is used. Is preferably added in a heating and melting tank 168 and the like from the viewpoint of energy efficiency, and since polyolefin and the like have a low melt viscosity, there is no problem in terms of workability even if the polyolefin or the like is melted in the heating and melting tank 168 by residual heat or the like.
[0099]
[Halogen removal of pyrolysis products]
In the above, measures for obtaining high-quality pyrolysis products by pyrolysis of plastics have been described.However, it is difficult to accurately grasp the contents of waste plastics, so the unexpected There may be cases where contamination by halogen compounds occurs. Therefore, measures to deal with such cases are also important in promoting the recycling of waste plastics as resources.
[0100]
In the present invention, the thermal decomposition product is brought into contact with activated carbon heated to 150 to 550 ° C. and a hydrogen halide trapping agent as a measure against contamination by the organic halogen compound.
[0101]
Pyrolysis products obtained when heating mixed plastics containing halogen-containing plastics may contain organic halogen compounds, but when this is brought into contact with activated carbon in a gaseous state, the formation of hydrogen halide by radical reaction The organic chlorine compound is decomposed by the elimination reaction. At this time, when a hydrogen halide trapping agent coexists, the generated hydrogen halide is adsorbed by the trapping agent. Accordingly, contamination of the organic halide is eliminated. Therefore, the gaseous product generated by the thermal decomposition of the plastic may be passed through a column of activated carbon and a column of a hydrogen halide trapping agent. Since the reaction rate of the elimination reaction of hydrogen halide by activated carbon is slow at a temperature lower than 150 ° C. and a large amount of by-products are generated at a temperature of 550 ° C. or higher, it is desirable to perform the above-mentioned treatment in the range of 150 to 550 ° C. The activated carbon and the hydrogen halide trapping agent need not be mixed, and may be brought into contact with the activated carbon and then with the hydrogen halide trapping agent.
[0102]
The hydrogen halide trapping agent is not particularly limited as long as it can adsorb or absorb hydrogen halide. Examples thereof include those commonly used as alkali materials such as alkali metals, alkaline earth metals and hydroxides thereof, and halogens. Carriers and the like that have been subjected to a surface treatment such that hydrogen chloride is adsorbed can be used.
[0103]
FIG. 25 shows an example of a processing apparatus for performing a halogen removal treatment on a pyrolysis product. The processing device 178 includes a flask 179 into which the raw material 180 to be thermally decomposed is charged, a mantle heater 181 to heat the flask 179, a column 182 connected to the flask 179, a horizontal furnace 183 to heat the column 182, The condenser 185 includes a condenser 185 connected to the column 182, and a collection container 186 and an exhaust gas container 187 connected to the condenser 185. The temperature of the horizontal furnace 183 is controlled by the controller 184. The column 182 is filled with a mixture of activated carbon and activated carbon whose surface has been subjected to a surface treatment of adsorbing hydrogen chloride.
[0104]
The plastic is put into a flask 179 and heated by a mantle heater 181 to be thermally decomposed. The gaseous product generated by the thermal decomposition reaches the column 182, where the activated carbon removes hydrogen halide from the organic halogen compound, and the activated carbon having copper sulfate and zinc sulfate attached to the surface adsorbs the hydrogen halide. The dehalogenated gaseous pyrolysis product is cooled and condensed by the condenser 185, and the liquefied product is stored in the recovery container 186. The gas that has not been condensed is introduced into the exhaust gas container 187.
[0105]
FIG. 26 shows an example of a thermal decomposition apparatus provided with a processing apparatus for performing a halogen removal treatment of a thermal decomposition product. The thermal decomposition device 188 includes an extruder 190 to which a hopper 189 is connected, a thermal decomposition tank 191 having a heater 192, a halogen removing unit 193, a condenser 196, and a recovery tank 197. It comprises an activated carbon column 194 and a hydrogen halide removal column 195 connected in series.
[0106]
The plastic introduced from the hopper 189 is heated by the extruder 190 to perform melting, plasticizer removal, and dehydrochlorination. After that, the molten plastic is transported to the thermal decomposition tank 191 and thermally decomposed. The vapor of the pyrolysis product released from the pyrolysis tank 191 is sent to the halogen removing unit 193. Hydrogen halide is desorbed from the organic halogen compound in the activated carbon column 194, and the desorbed hydrogen halide is adsorbed on the hydrogen halide removal column 195. The decomposition product vapor from which the halogen has been removed is cooled and liquefied by the condenser 196 and stored in the recovery tank 197.
[0107]
[Purification of pyrolysis products]
Since the content and amount of waste plastic vary greatly with time and place, the composition and amount of products generated by thermal decomposition also vary greatly. Therefore, when purifying the decomposition product, the conventional purification apparatus cannot sufficiently cope with such fluctuation. In the present invention, in order to cope with such a change in composition or a change in the amount of purification in the purification of a pyrolysis product, a plate distillation apparatus capable of changing the number of holes in the plate is used. By controlling so that the number of holes in the tray increases as the amount of steam to be purified increases, the height of the liquid accumulated in each tray can be made constant. Therefore, it is possible to cope with a change in the amount of steam to be handled without significantly changing the purification efficiency.
[0108]
FIG. 27 shows an example of a distillation apparatus for purifying a pyrolysis product according to this embodiment. The distillation apparatus 198 includes a bottom reboiler and a distillation column 199 erected on the reboiler and provided with a plurality of trays 200, and is mixed into the pyrolysis product vapor sent from the pyrolysis tank. A filter 203 for removing solid particles is connected to the tower. Also, about 2 to 5 refluxes 202a to 202d are connected to drive off excess heat in the distillation column 199. A stripper 206 is connected to the tower, and reflux devices 204 and 205 are connected to the top and the reboiler.
[0109]
As shown in FIG. 28, the shelf 200 is composed of two disks 207 and 208 which are superimposed so as to be relatively rotatable about a center in order to increase or decrease the number of holes. The disk 207 is provided with a large number of holes 209 of a predetermined size, and the disk 208 is provided with a plurality of slits 210. The holes 209 overlapping the slit 210 by rotating two disks to change the relative position. The number changes. Thereby, the effective number of holes in the shelf 200 can be changed.
[0110]
The size of the hole 209 of the disk is preferably 2 to 8 mm, and if it is larger than this, the rectification effect is reduced. The number of holes is preferably set so that it can be changed in the range of 2 to 100 / shelf when the diameter of the shelf is about 102 mm, and is set appropriately according to the size of the shelf.
[0111]
FIG. 29 shows another example of a shelf in which the number of holes can be changed. In this example, a valve 213 that opens and closes a hole 212 provided in the shelf 211 is attached and connected to the valve 213. The valve 213 is urged to close the hole 212 by a spring attached to the arm, and the hole 212 is opened and closed by operating the arm with the cord 215.
[0112]
FIG. 30 shows an example of a pyrolysis apparatus incorporating the distillation apparatus of FIG. The thermal decomposition device 216 includes an extruder 217 having a hopper, a thermal decomposition tank 218, a distillation device 198, and recovery containers 219 to 222. The plastic dispensed into the extruder 217 from the hopper is heated and melted, and after the plasticizer removal treatment and the dehydrohalogenation treatment described above are performed, is supplied to the thermal decomposition tank 218, where the vapor of the thermal decomposition product is converted into solid particles. It is sent to the distillation column 199 via a separation filter (omitted in the figure).
[0113]
[Design of thermal decomposition equipment]
The dehalogenation treatment of pyrolysis product vapor depends on whether the content of the waste plastic to be treated is completely unknown and the quality required of the product to be recovered is high, and when the waste plastic whose content can be known to some extent is treated. The degree of necessity is completely different. Accordingly, each of the processing methods and apparatuses described above may be appropriately changed in combination according to the properties and shape of the plastic to be processed, the quality, economy, and recovery efficiency required for the recovered pyrolysis products. To use.
[0114]
The example with reference to the above-described drawings has been described for the purpose of explaining the technical idea for embodying the plastic processing apparatus according to the present invention, and the present invention is not limited to the above structure. .
[0115]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following Examples and Comparative Examples, “%” and “parts” are indicated by weight unless otherwise specified.
[0116]
(Example 1)
Using the apparatus 1 of FIG. 1, the heating steam generator 2 was operated, and steam was ejected from the steam discharge pipe 3 when the steam flow rate became stable. The operation was continued with the temperature of steam set at 150 ° C. or more and less than 280 ° C. The winding machine was slowly rotated to allow the 0.2-mm-thick film-form plastic P containing 35% of the plasticizer to uniformly immerse in the warm water for 2 minutes or more to promote the dissolution of the compounding agent. . After allowing the film to pass through the water, the rotating device was inverted to allow the plastic P to run in the opposite direction, and the elution of the compounding substance from the resin was continued. At this time, in order to avoid breakage of the film passing between the rollers, the width of the gap was adjusted so as to suppress the compression force caused by being caught by the rollers.
[0117]
After repeating the winding and reversing twice, the content of the plasticizer contained in the wound film-form plastic P was examined and found to be reduced to about 1/20.
[0118]
(Example 2)
By using the apparatus shown in FIG. 2, the pressurizing pump 14 and the recovery 4 pump are driven, and the heater 13 is operated when the circulating flow rate of water is stabilized. The water temperature was set at 90 ° C or higher and lower than 100 ° C. The rotating bodies 6 and 8 are slowly rotated, and a 0.2 mm-thick film-shaped plastic P containing 30% of a plasticizer is uniformly immersed in heated water for 2 minutes or more to elute the compounding agent. Promoted. After passing the film through the water, the rotating bodies 6 and 8 were inverted, and the elution of the compound from the resin was continued while the plastic was running in the reverse direction. At this time, in order to avoid breakage of the plastic passing between the rollers, the width of the gap was adjusted so as to suppress the compression force caused by being caught between the rollers.
[0119]
After the winding and reversing were repeated twice, the content of the plasticizer contained in the wound plastic was examined, and it was found that the content was reduced to about 1/8.
[0120]
(Example 3)
Using an apparatus shown in FIG. 3, a laminate of a PVC film having a thickness of 0.15 mm containing 27% of a plasticizer and an absorbent body 17 made of layered cellulosic fibers is wound into a roll. The material wound in the form of a roll is put into the elution promoting tank 18 and is stacked in a bale stack. Next, water is injected into the elution accelerating tank 18 so as to seep into the adsorbent 17. After injecting water so as to cover the uppermost roll, the water is allowed to stand, and when the water level has almost completely dropped, the upper lid 22 is closed and the heater 19 is operated. The temperature was set between 90 ° C. and less than 100 ° C. After keeping the temperature substantially constant for more than two weeks, the rolled film was recovered.
[0121]
Examination of the content of the plasticizer contained in the recovered PVC film revealed that the content was reduced to about 1/10.
[0122]
(Example 4)
Using the apparatus shown in FIG. 4, a 0.2-mm thick film-like PVC containing 33% of a plasticizer and an absorbent body 29 made of cellulosic fibers were layered on top of each other in layers and stacked in a hot water tank 26. When the circulation flow rate of the water was stabilized by driving the circulation pump and the pressure pump, the heater 24 for heating water as a solvent was operated. The operation was continued with the temperature of the absorber 29 set at 90 ° C or higher and lower than 100 ° C. During the daytime when sunlight is strong, the temperature of the absorber 29 can be maintained even if the heater 24 is weakened by controlling the temperature in the center of the house at 40 ° C. by the heat energy of the sun rays. It was possible. The substance vaporized inside the house 27 was condensed at the upper part of the house and was recovered through the recovery path 28. Also, the amount of hot water supplied per unit time in the hot water tank was reduced due to the heat retaining effect of the house. After maintaining the temperature of the absorber 29 for about two weeks, the PVC was slowly recovered using the lifting machine 25.
[0123]
When the content of the plasticizer contained in the recovered PVC was examined, it was found to be reduced to about 1/10.
[0124]
(Example 5)
Using the apparatus shown in FIG. 1, additive removal treatment was performed on a film having a laminate structure in which a 0.3 mm-thick film containing 66% by weight of polyvinyl chloride was adhered to both sides of an aluminum foil as follows.
[0125]
First, the heating steam generator 2 was operated, and when the steam flow was stabilized, steam was ejected from the steam discharge pipe 3. The steam temperature is set so that steam of 200 ° C or more and less than 280 ° C is generated in the first winding and reversing, and steam of 280 ° C or more and less than 350 ° C is generated in the second winding and reversing. Set to. The purpose is to promote elution of a compounding agent such as a plasticizer in the first winding and reversing, and to promote elution of hydrogen chloride in the second winding and reversing. The rotating bodies 6 and 8 were slowly rotated so that the film uniformly contacted the vapor for 1 minute or more to promote the elution of the additive and hydrogen chloride. At this time, in order to avoid breakage of the film passing between the rotating bodies 8, the width of the gap was adjusted so as to suppress the compressive force caused by being sandwiched by the rotating bodies 8 low.
[0126]
After repeating the winding and reversing twice, the content of chlorine contained in the wound film was reduced to about 1/10, and the content of the plasticizer was reduced to about 1/20. Furthermore, at the time of the first winding, the aluminum foil was in a state where it could be easily peeled off from polyvinyl chloride.
[0127]
(Example 6)
Using the apparatus shown in FIG. 5, a vinyl sheet having a thickness of 0.2 mm and containing 66% by weight of polyvinyl chloride was treated as follows.
[0128]
First, the heating steam generator 2 was operated, and steam was ejected from the steam discharge pipe 3 when the steam flow rate became stable. The steam temperature was set so that steam having a temperature of 200 ° C. or more and less than 280 ° C. was generated in the first processing device 1a, and was set such that steam having a temperature of 280 ° C. or more and less than 350 ° C. was generated in the second processing device 1b. This aims at promoting the elution of additives such as a plasticizer in the first processing apparatus 1a and promoting the elution of hydrogen chloride in the second processing apparatus 1b. The rotating bodies 6 and 8 were slowly rotated so that the film uniformly came into contact with the steam in each of the processing apparatuses 1a and 1b for 1 minute or more to promote the elution of the additive and the hydrogen chloride. At this time, in order to avoid breakage of the film passing between the rotating bodies 8, the width of the gap is adjusted so as to suppress the compression force caused by being sandwiched by the rotating bodies 8 low. Particular attention was paid to the adjustment of the second-stage device side.
[0129]
After repeating the winding and reversing of the film twice, the content of chlorine contained in the wound film was reduced to about 1/10 and the content of the plasticizer was reduced to about 1/15.
[0130]
(Example 7)
As a stabilizer, 1000 g of polyvinyl chloride resin containing 6 phr (6 parts by weight per 100 parts by weight) of tribasic lead sulfate and dibasic lead stearate was pulverized into pellets of 3 to 5 mm. And then fed to the acetic acid addition tank 35 at a rate of 50 g / min. The acetic acid addition tank was maintained at 95 ° C., and a 1 mol / L acetic acid solution was supplied from the acetic acid supply device at a rate of 0.3 L / min. The stirring shaft was rotated by the motor 50 at a speed of 30 revolutions per minute. The plastic in pellet form was softened and easily mixed with acetic acid. The softened plastic mixed with acetic acid was transferred to a lead acetate separation tank 37, where it was allowed to stand for 5 minutes, whereupon it was separated into a liquid phase and a solid phase. As a result of analysis, the liquid phase was analyzed using a 0.05 mol / L aqueous lead acetate solution. I confirmed that there is. The aqueous lead acetate solution was transferred to a lead recovery tank 39 using a vacuum pump 38. Five zinc plates 51 having a size of 300 mm × 300 mm arranged at intervals of 50 cm are put into the lead recovery tank 39, and when the aqueous lead acetate solution is transferred to the lead recovery tank 39, the lead is deposited on the zinc plate 51. Was precipitated. After a lapse of 30 minutes, when the lead concentration of the aqueous solution in the lead recovery tank 39 was analyzed, it was determined that the lead was sufficiently deposited on the zinc plate 51 because it was below the detection limit. When the lead precipitated on the zinc plate 51 was taken out and analyzed for lead purity, it was 99.99%. Also, the recovered amount of lead was about 40 g.
[0131]
Next, the softened plastic remaining in the lead acetate separation tank 37 was transferred to the lead chloride extraction tank 40. The internal temperature of the lead chloride extraction tank was maintained at 330 ° C. The softened plastic became flowable and evolved gas from inside. This gas was hydrogen chloride as measured by a detector tube. The plastic gradually changed into a foamable substance having fluidity while generating gas. After lowering the internal temperature to 100 ° C., when steam was fed at a rate of 3 L / min, the steam instantaneously reacted with hydrogen chloride to generate concentrated hydrochloric acid. One minute after feeding the steam, the liquid was taken out from the liquid outflow valve of the lead chloride extraction tank 40 at a rate of 3 L / min. This liquid (concentrated hydrochloric acid) was sent to the hydrogenation tank 43, and 2 L of water was added to 1 L of concentrated hydrochloric acid to dilute the concentrated hydrochloric acid to dilute hydrochloric acid. By adding water, a white precipitate was formed in the hydrogenation tank 43. Only the white precipitate was left in the hydrogenation tank 43, and the remaining liquid phase was sent to the waste liquid tank 45. Hydrogen was supplied to this white precipitate together with steam to supply hydrogen. Steam was added at a rate of 3 L per minute. When the solid remaining in the hydrogenation tank 43 was analyzed, it was 99.9% pure lead and weighed 4.5 g.
[0132]
When the inside of the lead chloride extraction tank 40 was heated again to 330 ° C., the plastic began to generate gas again. When this gas was measured with a detector tube, it was hydrogen chloride as described above. After the temperature was lowered to 100 ° C., steam was fed at a rate of 3 L / min. The steam instantaneously reacted with hydrogen chloride to produce concentrated hydrochloric acid. One minute after feeding the steam, the liquid was taken out of the liquid outflow valve at a rate of 3 L / min. This liquid was sent to the hydrogenation tank 43, and water was added at a ratio of 2 L to 1 L of concentrated hydrochloric acid to dilute the concentrated hydrochloric acid to dilute hydrochloric acid. By adding water, a white precipitate was formed in the hydrogenation tank 43. Only the white precipitate was left in the hydrogenation tank 43, and the remaining liquid phase was sent to the waste liquid tank 45. Hydrogen was supplied by supplying hydrogen to the white precipitate together with water vapor. Steam was added at a rate of 3 L per minute. After that, when the solid remaining in the hydrogenation tank was analyzed, it was 99.9% pure lead and weighed 1.5 g.
[0133]
In the above, the treated plastic contained 60 g of additives. Considering that it is said that about 80% by weight of the additive is lead oxide, 60 g × 80% = 48 g is lead oxide, of which 48 g × 207/223 = 45 g (molecular weight: lead) = 207, lead oxide = 223). Further, the lead-based compound other than lead oxide is 60 g-48 g (all additives-lead oxide) = 12 g. If the average of lead is 50% by weight, 6 g is lead. That is, 45 g + 6 g = 51 g is the amount of lead contained in the plastic. In the above operation, 40 g + 4.5 g + 1.5 g = 46 g of lead was recovered, which means that 90% of the lead in the additive could be recovered.
[0134]
(Example 8)
1000 g of a polyvinyl chloride resin containing 1 phr (1 part by weight per 100 parts by weight) of lead stearate as a stabilizer is pulverized into pellets of 3 to 5 mm, and supplied to the processing apparatus 33 shown in FIGS. It was charged into the apparatus 34 and fed to the lead chloride extraction 40 at a rate of 50 g per minute.
[0135]
When the internal temperature of the lead chloride extraction tank 40 was maintained at 330 ° C., the plastic became fluid and generated gas from inside. This gas was hydrogen chloride as measured by a detector tube. The plastic gradually changed into a foamable substance having fluidity while generating gas. After the temperature was lowered to 100 ° C., steam was fed at a rate of 3 L / min. The steam instantaneously reacted with hydrogen chloride to generate concentrated hydrochloric acid. One minute after feeding the steam, the liquid was taken out of the liquid outflow valve at a rate of 3 L / min. This liquid was sent to the hydrogenation tank 43, and water was added at a ratio of 2 L to 1 L of concentrated hydrochloric acid to dilute the concentrated hydrochloric acid. As a result, a white precipitate was formed in the hydrogenation tank 43. Only the white precipitate was left in the hydrogenation tank 43, and the remaining liquid phase was sent to the waste liquid tank 45. Hydrogen was supplied to the white precipitate together with steam to supply hydrogen. Steam was added at a rate of 3 L per minute. After that, when the solid remaining in the hydrogenation tank 43 was analyzed, it was 99.9% pure lead and weighed 2.8 g.
[0136]
The lead recovery rate in the above becomes 80% by the same calculation as in Example 7.
[0137]
(Example 9)
As a stabilizer, 1000 g of a polyvinylidene chloride resin containing 6 phr (6 parts by weight per 100 parts by weight) of tribasic lead sulfate and dibasic lead stearate was pulverized into pellets of 3 to 5 mm. And then fed to the acetic acid addition tank 35 at a rate of 50 g / min. The acetic acid addition tank was maintained at 95 ° C., and a 1 mol / L acetic acid solution was supplied from the acetic acid supply device at a rate of 0.3 L / min. The stirring shaft was rotated by the motor 50 at a speed of 30 revolutions per minute. The plastic in pellet form was softened and easily mixed with acetic acid. The softened plastic mixed with acetic acid was transferred to a lead acetate separation tank 37, where it was allowed to stand for 5 minutes, whereupon it was separated into a liquid phase and a solid phase. As a result of analysis, the liquid phase was analyzed using a 0.05 mol / L aqueous lead acetate solution. I confirmed that there is. The aqueous lead acetate solution was transferred to a lead recovery tank 39 using a vacuum pump 38. Five zinc plates 51 having a size of 300 mm × 300 mm arranged at intervals of 50 cm are put into the lead recovery tank 39, and when the aqueous lead acetate solution is transferred to the lead recovery tank 39, the lead is deposited on the zinc plate 51. Was precipitated. After a lapse of 30 minutes, when the lead concentration of the aqueous solution in the lead recovery tank 39 was analyzed, it was determined that the lead was sufficiently deposited on the zinc plate 51 because it was below the detection limit. When the lead precipitated on the zinc plate 51 was taken out and analyzed for lead purity, it was 99.99%. Also, the recovered amount of lead was about 40 g.
[0138]
Next, the softened plastic remaining in the lead acetate separation tank 37 was transferred to the lead chloride extraction tank 40. The internal temperature of the lead chloride extraction tank was maintained at 330 ° C. The softened plastic became flowable and evolved gas from inside. This gas was hydrogen chloride as measured by a detector tube. The plastic gradually changed into a foamable substance having fluidity while generating gas. After lowering the internal temperature to 100 ° C., when steam was fed at a rate of 3 L / min, the steam instantaneously reacted with hydrogen chloride to generate concentrated hydrochloric acid. One minute after feeding the steam, the liquid was taken out from the liquid outflow valve of the lead chloride extraction tank 40 at a rate of 3 L / min. This liquid (concentrated hydrochloric acid) was sent to the hydrogenation tank 43, and 2 L of water was added to 1 L of concentrated hydrochloric acid to dilute the concentrated hydrochloric acid to dilute hydrochloric acid. By adding water, a white precipitate was formed in the hydrogenation tank 43. Only the white precipitate was left in the hydrogenation tank 43, and the remaining liquid phase was sent to the waste liquid tank 45. Hydrogen was supplied to this white precipitate together with steam to supply hydrogen. Steam was added at a rate of 3 L per minute. When the solid remaining in the hydrogenation tank 43 was analyzed, it was 99.9% pure lead and weighed 4.5 g.
[0139]
The lead recovery rate in the above becomes 80% by the same calculation as in Example 7.
[0140]
(Example 10)
Preliminarily heat a 0.2 mm thick SUS plate on a hot plate and heat and melt the polypropylene at 170 ° C to quickly apply one surface of the SUS plate to a thickness of 2 mm. And cooled.
[0141]
Put this plate in an infrared heating furnace, turn on the infrared lamp in a nitrogen atmosphere to start heating, switch off the infrared lamp after a predetermined heating time, and cool down the furnace temperature. did. The weight of the plastic before and after heating by infrared light was measured, and the weight loss rate was calculated.
[0142]
The above operation was repeated while changing the heating time as described below, and the relationship between the heating time and the weight loss rate was examined. Table 1 shows the obtained results.
[0143]
[Table 1]

[0144]
When the infrared light is turned on, the temperature of the plastic gradually increases, and when the temperature of the polypropylene reaches the pyrolysis temperature of 445 ° C., the plastic is decomposed and gasified and released. From the above results, the time required for the weight to decrease to 50% is 6.9 minutes.
[0145]
Next, the above operation was repeated while changing the thickness of the plastic, and the relationship between the plastic thickness and the time required for the weight to decrease to 50% was examined. Table 2 shows the obtained results. For reference, the time required for the weight of the plastic to be reduced to 50% when the plastic was charged into the flask and heated was also examined.
[0146]
[Table 2]

[0147]
In the above results, the time until the weight is reduced by 50% increases almost in proportion to the thickness until the thickness is about 14 mm, but the time until the weight decreases by 50% when the thickness is more than about 20 mm. Increase rapidly. This is thought to be the effect of the formation of carbides on the plastic surface. From these results, it is preferable to reduce the thickness to 20 mm or less in view of the addition of thermal decomposition efficiency. In this range, the weight is reduced to 50% in less than half the time required for the weight to be reduced to 50% when polypropylene is placed in the flask and tested.
[0148]
(Example 11)
Using the apparatus shown in FIG. 9, a belt 53 having a width of 1.5 m was run at a speed of 100 cm / min. The polypropylene is heated to about 200 ° C. and transported by screws 55a, 55b, and 55c, and the belt 53 is coated with polypropylene to a thickness of 2 mm. The temperature was set to 450 ° C. It took 19 minutes from when the plastic was put into the hopper to when the plastic put into the processing device 52 was discharged. The oil recovered from the pyrolysis chamber 61 had an oil content of 85%, a gas content of 11%, and a residue of 4%.
[0149]
The same operation as above was repeated to thermally decompose a plastic containing 50% of polypropylene and 50% of polyvinyl chloride. The oil recovered from the pyrolysis chamber 61 had an oil content of 45%, a gas content of 11%, and a residue of 4%.
[0150]
(Example 12)
Using the apparatus shown in FIGS. 10 to 12, a disk 67 having a diameter of 3 m was rotated at a rotation speed of 0.125 rpm, and polypropylene was pulverized, then fed into a hopper 73 and conveyed by screws 75a and 75b while warming. The melted polypropylene was applied to the disk 67 from the slit 76 at a thickness of 2 mm.
[0151]
The applied plastic was heated to 450 ° C. by the infrared lamp 70. The decomposition gas generated by the thermal decomposition was exhausted from the exhaust port 72, then cooled and liquefied, and an oily decomposition product was recovered. It took 14 minutes from when the plastic was put into the hopper 73 to when it was discharged from the processing apparatus. The recovered product was 85% oil, 11% gas, and 4% residue.
[0152]
(Example 13)
The following operations were performed using the processing device 84 shown in FIG. 14A and FIG. First, a resin prepared by mixing 50 parts of polyvinyl chloride having a number of monomers of 1000 and 50 parts of DOP as a plasticizer was sufficiently kneaded to make the composition as uniform as possible, and then processed into pellets having a diameter of 3 to 5 mm. This was supplied into the apparatus from a supply port at one end of the processing apparatus 84 at a rate of 20 g / min. Grooves are provided at regular intervals on the outer peripheral surface of the heating shaft member 87 so that the cross section has a wavy shape, and between the stirring device 86 and the outer cylinder 85 along the groove surface of the rotating heating shaft member 87. The resin was gradually moved from the space to the outlet 97.
[0153]
The heater 92 is operated to set the temperature inside the processing device 84 in the same manner as in FIG. 14B, and when the temperature reaches around 100 ° C. where the softening of the resin occurs, the pores 90 on the surface of the heating shaft member 87 are reduced. Releases helium as a low-activity gas. Also, helium gas was forcibly flowed into the processing device 84 in order to fill the gaps and spaces in which the decomposition gas could diffuse with helium.
[0154]
When the cracked gas was sampled at one half of the total length, an average of 9.95 g of organic compound was recovered every minute, and a large amount of aromatic compounds and chain hydrocarbons having 6 to 8 carbon atoms were contained. All of these were caused by decomposition of the plasticizer.
[0155]
Next, when sampling was performed at the outlet, it was found that an average of 5.89 g of gas having an irritating odor was generated per minute, which was mainly composed of hydrogen chloride and contained 0.05 g of hydrocarbon. Was. When the recovered gas was passed through water, hydrogen chloride was dissolved in water to form hydrochloric acid, and hydrocarbons and hydrogen chloride could be separated.
[0156]
(Example 14)
The following operation was performed using the device 95 of FIG.
[0157]
The same resin as that used in Example 13 was supplied into the apparatus 95 from the supply port of the processing apparatus 95 at a rate of 30 g / min. Grooves are provided at regular intervals on the outer peripheral surfaces of the two heating shaft members 87 so that the cross section becomes wavy, and the resin is gradually moved to the discharge port of the processing device 95 by rotation of the stirring devices 86a and 86b. .
[0158]
The heater 96 was operated to set the temperature in the same manner as in FIG. 14B, and when the temperature reached around 100 ° C. where the softening of the resin occurred, nitrogen was released from the pores 90 as a low-activity gas. Nitrogen gas was forcibly flowed into the processing apparatus 95 in order to fill gaps and spaces in which the decomposition gas could diffuse with nitrogen.
[0159]
When the cracked gas was sampled at one half of the total length, an average of 14.3 g of organic compound was recovered per minute, and a large amount of aromatic compounds and chain hydrocarbons having 6 to 8 carbon atoms were contained. All of these were caused by decomposition of the plasticizer.
[0160]
Next, when sampling was performed at the outlet, it was found that a gas having an irritating odor of 8.84 g per minute was generated, which was mainly composed of hydrogen chloride and contained 0.08 g of hydrocarbon. Was. When the recovered gas was passed through water, hydrogen chloride was dissolved in water to form hydrochloric acid, and hydrocarbons and hydrogen chloride could be separated.
[0161]
(Example 15)
The following operation was performed using the processing device 84 shown in FIG.
[0162]
First, the same resin as that used in Example 13 was supplied into the apparatus 84 from the supply port of the processing apparatus 84 at a rate of 20 g / min. Grooves were provided at regular intervals on the outer peripheral surface of the heating shaft member 87 so that the cross section became wavy, and the resin was gradually moved toward the discharge port 97 by the rotation of the stirring device 86.
[0163]
The temperature was set in the same manner as in FIG. 14B by operating the heater 96, and water vapor was released from the pores 90 of the heating shaft member 87 when the temperature reached around 100 ° C. where the softening of the resin occurred. In addition, steam was forced to flow into the processing device 84 in order to fill gaps and spaces in which the decomposition gas could diffuse with steam.
[0164]
When the cracked gas was sampled at one half of the total length, 9.95 g of organic compound was recovered every minute on average and contained 0.05 g of oxygen. In addition, a large amount of an aromatic compound and a chain hydrocarbon having 6 to 8 carbon atoms were contained, all of which were generated by decomposition of a plasticizer.
[0165]
Next, when sampling was performed at the outlet, it was found that an average of 5.89 g of gas having an irritating odor was generated per minute, which was mainly composed of hydrogen chloride and contained 0.08 g of hydrocarbon. Was. When the recovered gas was passed through water, hydrocarbons and hydrogen chloride could be separated.
[0166]
(Example 16)
The following operation was performed using the processing apparatus 97 of FIG.
[0167]
First, a resin obtained by mixing 75 parts of polyvinyl chloride having 1000 parts and 25 parts of DHP as a plasticizer was sufficiently kneaded to make the composition as uniform as possible, and then processed into pellets having a diameter of 3 to 5 mm.
[0168]
This material was supplied into the apparatus 97 from the supply port of the processing apparatus 97 at a rate of 20 g / min. Grooves were provided at regular intervals on the outer peripheral surface of the heating shaft member 87 so that the cross section was corrugated, and the resin was gradually moved to the discharge port by rotation of the stirring device 86.
[0169]
The heater 92 was operated to set the temperature in the same manner as in FIG. 14B, and when the temperature reached around 100 ° C. where the softening of the resin occurred, nitrogen was released from the pores 90 of the heating shaft member 87. Nitrogen was forcibly flowed into the processing device 97 to fill the gaps and spaces through which the decomposition gas could diffuse with nitrogen.
[0170]
When the cracked gas was sampled at a position of the full length, an average of 14.93 g of organic compound was recovered per minute. Further, a large amount of an aromatic compound and a chain hydrocarbon having 6 to 10 carbon atoms were contained, all of which were generated by decomposition of a plasticizer.
[0171]
Next, when sampling was performed at the outlet, it was found that an average of 2.94 g of gas having an irritating odor per minute was generated, and the main component was hydrogen chloride and contained 0.12 g of hydrocarbon. Was. When the recovered gas was passed through water, hydrogen chloride was dissolved in the water, and hydrocarbons and hydrogen chloride could be separated.
[0172]
(Example 17)
The following operation was performed using the processing apparatus 100 of FIG.
[0173]
The nitrogen gas introduced from the gas supply port 104 was heated to 350 ° C. by the heater 105 and supplied at a rate of 5 L / min to the hollow screw 102 disposed in the extruder section 101 having a length of 1 m and an inner diameter of 8 cm. While rotating the screw 102 at a rotation speed of 20 rpm by the motor 106, 50 kg of plastic containing 50% by weight of PVC containing 33% of plasticizer (DOP) and 50% by weight of polypropylene was charged from the charging section 107. The plastic heated by the nitrogen gas melted and was gradually conveyed toward the outlet 112 by the rotation of the screw 102. During this time, the temperature of the plastic was measured with a K-type thermocouple, and an extruder heating device was used as necessary so that the plastic temperature reached 350 ° C. near the outlet 112.
[0174]
After about 4 hours, all the plastic was discharged from the outlet 112, and 32 kg of molten plastic was recovered. Adhesion of phthalic anhydride, which is a decomposition product of DOP, was observed from the first exhaust part 108 to the pump 109. When the chlorine content of the plastic recovered from the outlet 112 was analyzed by X-ray fluorescence, the dechlorination rate was 99.8% or more. When the composition of the plastic was analyzed by infrared spectroscopy, 78% by weight of polypropylene and polyene were obtained. It was confirmed that it was composed of 22 wt%.
[0175]
When the recovered plastic was burned in a commercial incinerator, chlorine gas, hydrogen chloride gas, and tyoxin were not detected in the combustion gas.
[0176]
(Comparative Example 1)
The same operation as in Example 17 was performed except that the plastic was heated to the same temperature setting as in Example 17 by using a heating device of the extruder without supplying nitrogen gas, and the pumps 109 and 111 were not driven. 18 using the processing apparatus 100.
[0177]
After about 4 hours, all the plastic was discharged from the outlet 112, and 38 kg of molten plastic was recovered. Adhesion of phthalic anhydride, which is a decomposition product of DOP, was observed from the first exhaust part 108 to the pump 109. When the chlorine content of the plastic recovered from the outlet 112 was analyzed by X-ray fluorescence, the dechlorination rate was 95.7%, and the composition of the plastic was analyzed by infrared spectroscopy. It was confirmed that it was composed of 20 wt% of polyene and 4.5 wt% of phthalic anhydride.
[0178]
When the recovered plastic was burned in a commercially available incinerator, 53 ppm of hydrogen chloride gas and 5 ppb of dioxin were detected from the combustion gas. Chlorine gas was 1 ppm or less. When the inside of the incinerator and the inside of the exhaust gas pipe were examined after incineration, corrosion (discoloration) considered to be caused by hydrogen chloride was found.
[0179]
(Example 18)
The same operation as in Example 17 was repeated except that alcon gas was used instead of nitrogen gas.
[0180]
After about 4 hours, all the plastic was discharged from the outlet 112, and 32 kg of molten plastic was recovered. Adhesion of phthalic anhydride, which is a decomposition product of DOP, was observed from the first exhaust part 108 to the pump 109. When the chlorine content of the plastic recovered from the outlet 112 was analyzed by X-ray fluorescence, the dechlorination rate was 99.8% or more. When the composition of the plastic was analyzed by infrared spectroscopy, 78% by weight of polypropylene and polyene were obtained. It was confirmed that it was composed of 22 wt%.
[0181]
When the recovered plastic was burned in a commercial incinerator, chlorine gas, hydrogen chloride gas, and tyoxin were not detected in the combustion gas, and the visual observation of the incinerator showed no particular problem in incineration. Did not.
[0182]
(Examples 19 to 22)
The same operation as in Example 1 was repeated except that the heating temperature of the nitrogen gas (the temperature near the outlet 112) was changed as shown in Table 3. Table 3 shows the results.
[0183]
[Table 3]

[0184]
In Example 22, the thermal decomposition reaction of polypropylene proceeded slightly, and oil (coloring), which is a thermal decomposition product of polypropylene, was recovered from the gas discharged from the ecrutruder unit 101.
[0185]
(Example 23)
The following operation was performed using the thermal decomposition apparatus 113 of FIG. 19 incorporating the processing apparatus 100 of FIG. 18 as the pre-processing unit 114.
[0186]
The nitrogen gas introduced from the gas supply port 104 was heated to 350 ° C. by the heater 105 and supplied at a rate of 5 L / min to the hollow screw 102 disposed in the extruder section 101 having a length of 1 m and an inner diameter of 8 cm. While the screw 102 is rotated at a rotation speed of 20 rpm by the motor 106, 50 kg of PVC containing 33% of a plasticizer (DOP) and 50 kg of plastic containing 50 wt% of polypropylene are fed from the input unit 107 at a rate of 10 kg / h. It was put in. The plastic heated by the nitrogen gas melted and was gradually conveyed toward the outlet 112 by the rotation of the screw 102. During this time, the temperature of the plastic was measured with a K-type thermocouple, and an extruder heating device was used as necessary so that the plastic temperature reached 350 ° C. near the outlet 112.
[0187]
The plastic discharged from the outlet 112 was pyrolyzed in the pyrolysis tank 115. From the material collected in the extruder section 101, the generated oil tank 117, and the exhaust gas treatment apparatus 118, the material balance was calculated by assuming that the input plastic was 100 parts. In the extruder section, hydrogen chloride was 19.6 parts, and DOP was a decomposition product of DOP. 10.2 parts of an organic compound having 8 carbon atoms, 6.3 parts of phthalic anhydride are recovered, 42 parts of oil are recovered in the generated oil tank 117, 13.3 parts of decomposition residue in the residue tank 122, and exhaust gas treatment. In the apparatus 118, 9.4 parts of a low molecular organic compound was recovered.
[0188]
When the residual chlorine concentration of the residue was analyzed, it was 0.2% or less. The concentration of hydrogen chloride in the exhaust gas in the exhaust gas treatment device 118 was 1 ppm or less, and the concentration of the organic chlorine compound in the recovered oil was 10 ppm or less.
[0189]
Hydrogen chloride and dioxin were not detected in the exhaust gas when the residue was incinerated and the recovered oil was used as fuel for heavy oil burners.
[0190]
(Comparative Example 2)
The same operation as in Example 23 was performed except that the plastic was heated to the same temperature setting as in Example 23 by using the heating device of the extruder without supplying nitrogen gas, and the pumps 109 and 111 were not driven. This was performed using 19 thermal decomposition apparatuses 113.
[0191]
When the residual chlorine concentration of the residue in the residue tank 122 was analyzed, it was 5.2%. The concentration of hydrogen chloride in the exhaust gas in the exhaust gas treatment device was 1200 ppm, and the concentration of the organic chlorine compound in the recovered oil was 4700 ppm.
[0192]
When the residue was incinerated, 83 ppm of hydrogen chloride was detected from the exhaust gas of the incinerator, and the discoloration considered to be due to corrosion was observed in the combustion furnace. When the recovered oil was used as fuel for a heavy oil burner, 12 ppm of hydrogen chloride was detected from the exhaust gas of the heavy oil burner.
[0193]
(Example 24)
50 g of polyvinyl chloride containing 50% of a plasticizer and 50 g of polypropylene were mixed and charged into a metal container, and the input plastic was heated using a heater installed so as to surround the outer wall of the container. During heating, the plastic was agitated by the agitating blades installed inside to increase the uniformity of heat. Until the temperature of the substance put into the inside reaches 230 ° C., the material is heated at a rate of 10 ° C./min, and when the temperature reaches 230 ° C., gas generated from the surface of the plastic at a rate of 5 ° C./min. Full release was allowed to reach 280 ° C. When the gas released at this time was cooled, a white powder was obtained. After the temperature reached 280 ° C., the temperature was raised at a rate of 4 ° C./min to sufficiently release the gas generated from the plastic, and the temperature reached 330 ° C. When the litmus paper moistened with distilled water was held over the gas generated at this time, it immediately turned red and had a pungent odor.
[0194]
Heating was further continued and 8 g of heavy oil was added in small portions in several portions along the inner wall of the metal container, and the temperature was raised to 450 ° C. at a rate of 10 ° C./min. After reaching 450 ° C., the heating was controlled to maintain that temperature for about one hour. At this time, about 55 g of an oily substance could be recovered. After the oil was collected, a black carbonized component remained as a residue, but could be easily scraped off.
[0195]
(Example 25)
The following operation was performed using the thermal decomposition apparatus 123 of FIG.
[0196]
A pellet obtained by kneading a polyvinyl chloride having a number of 1000 to 1200 containing a plasticizer in an amount of 1000 to 1200 and having a uniform composition and working to a size of 3 to 5 mm, and a pellet of polypropylene having a size of 3 to 5 mm and crushed to 3 to 5 mm. Fifty parts were mixed and charged into the first pretreatment device 124 so that the supply amount per unit time from the plastic supply tank 131 was constant. Heating was performed so that the temperature of the substance charged into the inside became 230 ° C. from the entrance in the longitudinal axis direction of the first pretreatment device 124 to 位置 of the position. Further, the temperature was adjusted so as to reach 280 ° C. from the position where the temperature reached 230 ° C. to the vicinity of the outlet. At this time, an inert gas was continuously flowed from the inlet in front of the first pretreatment device to the outlet so as to sufficiently release the gas generated from the surface of the plastic, thereby promoting gas diffusion. When the recovered gas was cooled, a white powder was formed, and the main components contained a phthalic acid-based compound and an alcohol or aldehyde having 8 carbon atoms. After the temperature reaches 280 ° C., the heat-treated substance is transferred to the second pretreatment device, and the temperature is set so that the temperature of the substance reaches 330 ° C. from the inlet to a position の of the longitudinal axis. Was adjusted. After the temperature reached 330 ° C., the temperature was maintained until the outlet. At this temperature, as in the first pretreatment device 124, the inert gas continued to flow from the inlet to the outlet to promote gas diffusion. The recovered inert gas contained a gas having a pungent odor, and it was found that a large amount of hydrogen chloride was generated. Also, this hydrogen chloride was adjusted to an aqueous solution and used for neutralizing the alkaline waste liquid.
[0197]
While moving the pretreated substance to the heating and melting tank 126 while maintaining the temperature from the outlet of the second pretreatment device 125 to such an extent that the temperature does not rapidly drop, the weight may be reduced along the inner wall of the transfer pipe connected to the heating and melting tank 126. Heated quality oil was added, and the fluid was added with increased fluidity. A plastic containing a large amount of polypropylene was heated and melted in advance in the heating and melting tank 126, and kept at 350 to 380 ° C. At this time, stirring is continued while charging so that the liquid level of the substance supplied from the second pretreatment device is maintained at a position of about 50 to 80% from the bottom of the heating and melting tank, and the residue is discharged from the residue discharge port 1424 at the bottom. The solid component was separated. In addition, a part of the gas which was gasified in the heating and melting tank was led to the distillation apparatus 129 from the upper pipe to separate the low-boiling compound and the high-boiling compound.
[0198]
On the other hand, the liquid component in the heating and melting tank 126 was transferred to the pyrolysis tank 128 through a pipe covered with a heat insulating material, and heating was further continued to reach 450 ° C. The oil was maintained at that temperature, and an oil containing a hydrocarbon having 6 to 15 carbon atoms as a main component was able to be recovered from the gaseous product led to the distillation apparatus 130 from the pipe above the pyrolysis tank 128. The black carbon component intermittently solidified was separated from the lower portion of the heating and melting tank 128, but could be easily extracted.
[0199]
(Example 26)
The following operation was performed using a thermal decomposition apparatus using a heating and melting tank 126 'shown in FIG. 22 instead of the heating and melting tank 126 of the thermal decomposition apparatus 123 in FIG.
[0200]
The materials to be charged, the method of pretreatment, and the method of dry distillation in the pyrolysis tank were the same as those described in Example 25, but the operation method of the heating and melting tank 126 'was as follows.
[0201]
When receiving the substance transferred from the second pretreatment device 125, heavy oil is injected from the wall surface of the heating and melting tank 126 'along the wall surface to prevent the residue from adhering to the inner wall surface of the heating and melting tank. We were able to. After the residue is separated from the liquefied substance in the heating / melting tank and discharged, 100% by weight of the plastic pellets initially introduced into the heating / melting tank are fed into the heating / melting tank with polypropylene pellets, and the residual heat is used. Softened. Thereafter, heating was performed using the heater 162 to melt the polypropylene pellets, so that the temperature was kept in the range of 350 to 380 ° C. Thereafter, as described in Example 25, an oily component was obtained from a gaseous pyrolysis product recovered by pyrolysis in the pyrolysis tank 128. The oily component obtained at this time had a lighter content of several percent higher than the oily component of Example 25.
[0202]
(Example 27)
The following operation was performed using the thermal decomposition apparatus of FIG.
[0203]
Mix 50 parts of pellets of 3 to 5 mm, which is made by kneading polyvinyl chloride having a quantity of 1000 to 1200 and containing 30% of a plasticizer to make the composition uniform, and pellets of polypropylene crushed to 3 to 5 mm. Then, it was charged into the first pretreatment device 124 so that the supply amount per unit time from the plastic supply tank 131 was constant. Heating was performed so that the temperature of the substance charged into the inside became 230 ° C. from the inlet in the longitudinal axis direction of the first pretreatment device to a position １ ／. Further, the temperature was adjusted so as to reach 280 ° C. from the position where the temperature reached 230 ° C. to the vicinity of the outlet. At this time, an inert gas was continuously flowed from the inlet to the outlet of the pretreatment device so as to sufficiently release the gas generated from the surface of the plastic, thereby promoting the gas diffusion. When the recovered gas was cooled, a white powder was formed, and the main components contained a phthalic acid-based compound and an alcohol or aldehyde having 8 carbon atoms. After the temperature reaches 280 ° C, the heat-treated substance is transferred to the second pretreatment device, and the temperature is adjusted so that the temperature of the substance reaches 330 ° C from the inlet to 1/3 position in the longitudinal axis direction. did. After the temperature reached 330 ° C., the temperature was maintained until the outlet. At this temperature, an inert gas was also continued to flow from the inlet to the outlet to promote gas diffusion. The gas generated at this time had a pungent odor and contained a large amount of hydrogen chloride.
[0204]
When the material transferred from the pretreatment device was received into the heating reactor 165, the heavy oil-containing polypropylene was mixed with the transferred material in an equal amount. The heating reaction tank 165 receiving the mixture is heated from the inner surface of the shaft to the outer side. The temperature is adjusted so that the temperature of the substance reaches 450 ° C. until it reaches 1/3 of the length of the shaft, and after reaching 450 ° C., the temperature reaches 2/3 of the length of the shaft. Was maintained. Thereafter, the temperature reached 500 ° C. by the outlet. An oily component was obtained from the gaseous recovered product generated during this time. The oily component obtained at this time was almost the same as the oily component of Example 25. In addition, the residue of the residue on the wall surface in the heating and melting device was slightly fixed by this heating method.
[0205]
(Example 28)
The following operation was performed using a thermal decomposition apparatus in which the heating and melting tank 1168 of FIG. 24 was incorporated instead of the heating and melting tank 126 of the thermal decomposition apparatus 123 of FIG.
[0206]
The materials to be charged, the method of pretreatment, and the method of dry distillation in the thermal decomposition tank were the same as those described in Example 25, but the operation method of the heating and melting tank 168 was as follows.
[0207]
When receiving the substance transferred from the pretreatment device, heavy paraffin oil is injected along the wall surface from the wall of the heating and melting tank 168 to prevent the residue from adhering to the wall in the heating and melting tank. Was completed. After the residue is separated from the liquid material in the melting tank and discharged from the discharge port 177, 100% by weight of polypropylene pellets of the plastic initially charged from the supply port 173 are charged into the heating and melting tank 168, and the residual heat is used. And softened. Thereafter, heating was performed using a heater 175 to melt the pellets so that the temperature was maintained in the range of 350 to 380 ° C. Thereafter, an oily component was obtained from the gaseous recovered product generated in the pyrolysis tank 128 as described in Example 25. The oily component obtained at this time had a lighter content of several percent higher than the oily component of Example 25.
[0208]
(Example 29)
The following operation was performed using the device 178 shown in FIG.
[0209]
Specific surface area 1500m²/ G, pore size 18 angstrom, pore volume 0.5 ml / g, packing density 615 g / L, dry loss 0.2% activated carbon (4 to 6 mesh), and hydrogen halide trapping agent Takeda Pharmaceutical ( Granular Shirasagi XRC (4 to 10 mesh) was weighed and mixed at a ratio of 50% by weight, and gently mixed, and packed into a column 182 having a diameter of 30 mm and a length of 300 mm. Column 182 was heated to 400 ° C. by horizontal furnace 183.
[0210]
Next, 400 cc of the pseudo oil 180 prepared by mixing 1-chlorohexane having a purity of 99.9% at a ratio of 10 wt% and n-octane at a ratio of 90 wt% was charged into a flask 179 having a volume of 500 cc. The pseudo oil 180 in the flask 179 was heated to boiling by the mantle heater 181 to generate oil vapor. The oil vapor was sent to the column 182, and the gas that passed through the column 182 was cooled and liquefied by the condenser 185 and accumulated in the recovery container 186. When the liquefied product was analyzed by GC-MS, unsaturated compounds such as 1-hexene and 3-hexene were 94.7% and benzene were 5.3%, and 1-chlorohexane was not detected (0. 05% or less). In addition, n-octane has undergone a chemical change such as partial aromatization, and after the reaction, 3.2% becomes aromatic such as ethylbenzene and 0.9% represents alkene such as 2,4-octadiene. And 0.3% was isomerized to 3-methylheptane and the like.
[0211]
Further, the above operation was repeated while changing the column temperature as shown in Table 4.
[0212]
[Table 4]

[0213]
When the temperature of the column was set to 600 ° C., a carbon-carbon bond cleavage reaction occurred, the number of components became extremely large, and it was impossible to calculate an accurate reaction balance.
[0214]
From the above results, it is understood that the generation of by-products is small at 150 to 550 ° C., and it is effective in decomposing the organic chlorine compound.
[0215]
The same results were obtained when the same operation was performed using potassium hydroxide, caustic soda, or the like instead of the above-described hydrogen halide trapping agent.
[0216]
(Example 30)
The following operation was performed using the apparatus of FIG.
[0217]
Specific surface area 1500m²/ G, pore size 18 angstrom, pore volume 0.5 ml / g, packing density 615 g / L, activated carbon (4 to 6 mesh) having a drying loss of 0.2%, packed in an activated carbon column 194, and a hydrogen halide trapping agent. Granular Shirasagi XRC (4-10 mesh) manufactured by Takeda Pharmaceutical Co., Ltd. was packed in a hydrogen halide removal column 195. These columns 194, 195 were heated to 400 ° C.
[0218]
Waste plastic consisting of 50% by weight of polyvinyl chloride and 50% by weight of polypropylene was crushed and charged into a hopper 189. The injected plastic was heated to 350 ° C. by an extruder 190, and was subjected to melting, plasticizer removal, and dehydrochlorination. Thereafter, the plastic was transported to a pyrolysis tank 191 and heated to 450 ° C. to be pyrolyzed. The vapor of the pyrolysis product released from the pyrolysis tank 191 was sent to the halogen removing unit 193. The steam that passed through the activated carbon column 194 and the hydrogen halide removal column 195 of the halogen removal unit 193 was cooled and liquefied by the condenser 196, and was recovered in the recovery tank 197. The concentration of the organic chlorine compound in the recovered liquid was 10 ppm or less. When the same operation as above was performed with the activated carbon and the hydrogen halide trapping agent removed from the column, the concentration of the organic chlorine compound in the recovered liquid was 500 ppm.
[0219]
(Example 31)
Area is 81.7cm²The following operation was performed using the distillation apparatus 198 of FIG. 27 having the shelf of FIG. 28 provided with a hole having a diameter of 4 mm.
[0220]
The number of theoretical stages of the distillation apparatus 198 was set to 12, the reflux ratio at the top of the column was set to 3, and the decomposition product vapor obtained by pyrolyzing the polypropylene was allowed to flow into the distillation column 199, and the oil liquid height of the shelf where kerosene oil was stored was set. Was measured.
[0221]
The above-mentioned operation was repeated by changing the steam flow rate by controlling the reaction rate of the plastic pyrolysis tank, changing the number of holes in the plate, and examining the relationship between the number of holes and the oil liquid height in the plate. Table 5 shows the results.
[0222]
[Table 5]

[0223]
As the flow rate of the steam flowing into the distillation column was gradually decreased from 10 L / min, the height of the oil in the kerosene-like stage decreased. When the number of holes in the shelf was reduced from 24 to 16 when the flow rate was 7 L / min, the oil liquid height increased.
[0224]
Therefore, when the number of holes in the shelf is reduced when the flow rate of the steam is reduced, the liquid level can be kept constant. In the above embodiment, it is possible to cope with the above flow rate of 1 L / min by reducing the number of holes in the shelf to 2 and to maintain the kerosene liquid height at 20 cm or more. did it. Therefore, by changing the number of holes, the flow rate of the inflow steam can be applied to a range of 1 to 10 L / min. On the other hand, when the number of holes is fixed to 24, the liquid does not accumulate on the shelf when the vapor volume is 5 L / min or less, and the oil vapor reaches the top without gas-liquid contact inside the distillation column. Blows up and normal oil separation is not possible.
[0225]
From the above results, it is understood that when processing waste plastic, it is possible to flexibly cope with fluctuations in the contents and the amount of waste plastic to be charged by controlling the number of holes in the shelf.
[0226]
(Example 32)
The same operation as in Example 31 was repeated, except that the shelf was changed to one having the mechanism shown in FIG. Table 6 shows the results.
[0227]
[Table 6]

[0228]
(Example 33)
The following operation was performed using the thermal decomposition apparatus 216 of FIG.
[0229]
The temperature of the extruder 217 was set to 350 ° C., and a mixture obtained by mixing 50 parts of PVC (containing 32 wt% of plasticizer DOP) at a ratio of 50 parts of polypropylene was charged, and 10 kg of molten plastic discharged from the extruder 217 was added. / Hr to the pyrolysis tank 218. Hydrogen chloride was generated in the extruder 217, and the chlorine content of the molten plastic supplied to the pyrolysis tank 218 decreased to almost zero. Thereafter, the same operation as in Example 31 was performed.
[0230]
The analysis of heavy medium oil discharged from the distillation column showed that the concentration of the organic chlorine compound was below the detection limit (50 ppm).
[0231]
After the operation was continued for 168 hours, the system was allowed to stand for 96 hours. Thereafter, the presence or absence of corrosion inside the distillation column was examined, but no corrosion was found.
[0232]
(Comparative Example 3)
The same operation as in Example 33 was performed except that the heater of the extruder 217 was not operated.
[0233]
The analysis of the heavy and medium oil discharged from the distillation column 199 revealed that it contained 3% of an organochlorine compound having 8 carbon atoms.
[0234]
After the operation was continued for 168 hours, the apparatus was left for 96 hours, and thereafter, the inside of the distillation column was examined for corrosion. As a result, discoloration was confirmed on the inner wall. In addition, it was confirmed that phthalic anhydride, which is a decomposition product of DOP, was precipitated between the extruder 217 and the pyrolysis tank 218 and in the piping for discharging the light oil of the distillation column 199.
[0235]
(Comparative Example 4)
The same operation as in Example 33 was performed except that the filter provided at the entrance of the distillation column was removed.
[0236]
When the heavy oil in the distillation column 199 was extracted and visually observed, it was confirmed that impurities in the suspension state were present on the liquid surface, in the liquid, and on the liquid bottom.
[0237]
【The invention's effect】
According to the present invention, the plasticizer and the lead compound contained in the waste plastic can be removed, and the hydrogen halide can be efficiently desorbed from the halogen-containing plastic. The contamination of the product obtained by thermal decomposition of the organic halogen compound with the organic halogen compound is prevented, and the halogen can be removed from the product contaminated with the organic halogen compound. Since it can be purified by distillation, it has extremely high industrial utility.
[Brief description of the drawings]
FIG. 1 is a schematic structural view showing a first example of an apparatus for removing a plastic additive according to the present invention.
FIG. 2 is a schematic configuration diagram showing a second example of an apparatus for removing a plastic additive.
FIG. 3 is a schematic configuration diagram showing a third example of an apparatus for removing a plastic additive.
FIG. 4 is a schematic configuration diagram showing a fourth example of an apparatus for removing a plastic additive.
FIG. 5 is a schematic configuration diagram showing a fifth example of an apparatus for removing a plastic additive.
FIG. 6 is a schematic diagram showing an example of an apparatus for removing lead from plastics according to the present invention.
FIG. 7 is a configuration diagram showing a configuration of an acetic acid addition device of the device of FIG. 6;
FIG. 8 is a perspective view showing a configuration of a zinc plate used for a lead recovery tank of the apparatus of FIG.
FIG. 9 is a schematic configuration diagram showing a first example of an apparatus for performing pyrolysis of plastic according to the present invention.
FIG. 10 is a schematic configuration diagram showing a second example of an apparatus for performing pyrolysis of plastic according to the present invention.
FIG. 11 is a perspective view showing the configuration of a plastic coating unit of the apparatus shown in FIG.
FIG. 12 is a perspective view illustrating a configuration of a scraping blade of the apparatus of FIG. 10;
FIG. 13 is a schematic configuration diagram showing a third example of an apparatus for performing pyrolysis of plastic according to the present invention.
14A is a schematic configuration diagram illustrating a first example of a plastic processing apparatus having a heating shaft member according to the present invention, and FIG. 14B is a graph illustrating temperature settings of the processing apparatus.
FIG. 15 is a cross-sectional view of the device of FIG.
FIG. 16 is a cross-sectional view showing a second example of a plastic processing apparatus having a heating shaft member according to the present invention.
FIG. 17 is a cross-sectional view showing a third example of the plastic processing apparatus having the heating shaft member according to the present invention.
FIG. 18 is a schematic structural view showing an example of an apparatus for removing a plasticizer and dehydrohalogenating a plastic according to the present invention.
FIG. 19 is a schematic configuration diagram showing a plastic pyrolysis apparatus to which the apparatus shown in FIG. 18 is applied.
FIG. 20 is a schematic configuration diagram showing a first example of a plastic pyrolysis apparatus for performing pyrolysis by increasing the fluidity of plastic according to the present invention.
FIG. 21 is a schematic configuration diagram showing a first example of a plastic processing apparatus used to increase the fluidity of plastic according to the present invention.
FIG. 22 is a longitudinal sectional view (a) and a transverse sectional view (b) showing a second example of a plastic processing apparatus used for increasing the fluidity of plastic according to the present invention.
FIG. 23 is a schematic configuration diagram showing a second example of a plastic pyrolysis apparatus for performing pyrolysis by increasing the fluidity of plastic according to the present invention.
FIG. 24 is a longitudinal sectional view (a) and a transverse sectional view (b) showing a third example of a plastic processing apparatus used to increase the fluidity of plastic according to the present invention.
FIG. 25 is a schematic structural view showing a first example of a plastic processing apparatus for removing halogen from a pyrolysis product of plastic according to the present invention.
FIG. 26 is a schematic structural view showing a second example of a plastic processing apparatus for removing halogen from a pyrolysis product of plastic according to the present invention.
FIG. 27 is a schematic structural diagram showing a first example of a distillation apparatus for producing a pyrolysis product of a plastic according to the present invention.
FIG. 28 is an explanatory view of a main part of the distillation apparatus in FIG. 27.
FIG. 29 is an explanatory diagram of a main part of a second example of a distillation apparatus for producing a pyrolysis product of plastics according to the present invention.
FIG. 30 is a schematic configuration diagram showing a plastic pyrolysis apparatus using the distillation apparatus of FIG. 27.
[Explanation of symbols]
P plastic
2 Heating steam generator
13, 19, 92, 96 heater
17, 29 absorber
36 Acetic acid supply device
39 Lead recovery tank
41 Steam addition device
42 Water supply equipment
45 hydrogen cylinder
51 zinc plate
57, 70, 81 Infrared lamp
87 Heating shaft member
90,103 pores
91 gas supply
124 first pretreatment device
125 second pretreatment device
126 Heating and melting tank
127 Heavy oil addition tank
128 Pyrolysis tank
149 Air inlet
151 air outlet
153 Heavy oil injection groove
154 heavy oil supply pipe
158 Heavy oil filler
160, 173 Plastic supply port
164 heavy oil addition equipment
165 heating reaction tank
177 outlet
182 column
194 activated carbon column
195 Hydrogen halide removal column
200, 200a shelf

Claims (10)

The processed plastic so that the ratio of the volume is reduced to the surface area, in a heated state of eighty to two hundred eighty ° C., in contact with substances having absorption properties, the formulation contained in the plastic by the hair capillary phenomenon into the substance A plastic processing method characterized by being eluted. A step of separating the plastic from the acetic acid after adding acetic acid to the plastic and heating, and a step of adding water vapor after applying hydrogen chloride to the plastic and separating the plastic from the generated hydrochloric acid, whereby the plastic A method for treating plastic, comprising removing lead contained in a plastic. The method according to claim 1 or 2, further comprising a step of decomposing the plastic by heating the plastic in a thin layer state. The method for treating plastic according to any one of claims 1 to 3, wherein the heating of the plastic includes heating a lump of molten plastic from the inside of the lump. The plastic processed so that the ratio of the volume to the surface area is reduced is brought into contact with an absorbent material in a heating state of 80 to 280 ° C., and the compound contained in the plastic is diffused or capillary action occurs in the material. To elute
Heating of the plastic, it features and to pulp plastic processing methods in that it comprises blowing a plastic melt having a low activity which had been heated to 150 to 400 ° C. gas. A heavy oil or a halogen-free plastic is added to the molten plastic after the plasticizer has been removed from the halogen-containing plastic by the plastic processing method according to claim 1 and the hydrogen halide has been eliminated. A plastic processing method characterized by enhancing the flowability of thermal decomposition. Halogen-containing plastic processed to reduce the volume to surface area ratio is brought into contact with an absorptive substance in a heated state at 80 to 280 ° C to diffuse or capillarize the plasticizer contained in the halogen-containing plastic. A device for eluting and removing hydrogen halide from the halogen-containing plastic, a device for desorbing hydrogen halide from the halogen-containing plastic, and a heavy oil or halogen for molten plastic after removing the plasticizer and desorbing hydrogen halide. An apparatus for treating plastics, comprising: an adding device for adding a plastic containing no plastic; and a pyrolysis device for thermally decomposing the plastic to which the plastic containing no heavy oil or halogen is added. Further, it has a column in which activated carbon and a hydrogen halide trapping agent are mounted and heated to 150 to 550 ° C., and the column is provided with the heat so as to pass the vapor of a pyrolysis product generated by the pyrolysis apparatus. The plastic processing apparatus according to claim 7, which is connected to a decomposition apparatus. Further, there is provided a distillation apparatus for purifying a pyrolysis product generated by the pyrolysis apparatus, wherein the distillation apparatus has a distillation column having a plate having a large number of through holes; 8. A plastic processing apparatus according to claim 7, further comprising an opening / closing device for adjusting the number of through-holes opened and closed by opening and closing the opening. The plastic processing method according to claim 1, wherein the processed plastic is a sheet-like or film-like plastic.

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