【０００１】
【発明の属する技術分野】
本発明は、少なくとも酸素及び窒素を含有する原料ガスから吸着剤を充填した吸着塔での選択的な吸着分離により、高濃度酸素と高濃度窒素を製造する圧力変動吸着装置（以下、「ＰＳＡ装置」と称す。）並びにこのＰＳＡ装置を用いた高濃度酸素及び高濃度窒素の製造方法に関する。
【０００２】
【従来の技術】
従来の高濃度ガス製造装置としては、例えば深冷分離装置、膜分離装置及びＰＳＡ装置等が用いられている。深冷分離装置は、空気を断熱膨張で冷却して液化し、窒素や酸素等の沸点の違いを利用して分離し、高濃度酸素や高濃度窒素などを製造する装置である。深冷分離装置は大容量の高濃度ガスを製造する場合に適しているが、電力等の動力費が嵩むことや設備の設置面積が大きくなる等の問題があった。また、膜分離装置は、例えば酸素を選択的に透過する高分子有機膜を用い、空気中の窒素と酸素を分離し、高濃度酸素と高濃度窒素を製造する装置である。膜分離装置は小容量の高濃度ガスを製造する場合に適しているが、工業的に大容量を製造する場合には高価な膜分離モジュールを大量に必要となるため、設備費が嵩む問題がある。また、ＰＳＡ装置は、比較的大容量の酸素や窒素等の高濃度ガスを製造する場合に適しており、設備費や動力費が低廉で、運転操作も容易であることから近年多く使用されている。
【０００３】
ＰＳＡ装置において、高濃度酸素の製造を主目的として、ゼオライト系等の酸素以外のガス成分を選択的に吸着する吸着剤を充填した吸着塔に、空気等の酸素含有ガスを供給し、窒素、炭酸ガス及び水分等のガス（以下、単に「不純物」と称す。）を吸着剤に吸着させて分離し、吸着し難い酸素を吸着塔から抜き出して高濃度酸素として回収し、吸着剤に吸着した不純物を、減圧工程及びパージ工程等の再生工程により脱着させ、オフガスとして系外に排出することにより、装置全体として連続的に高濃度酸素の製造を行うことができる装置が知られている。
【０００４】
また、主に酸素を選択的に吸着する分子篩活性炭吸着剤を充填した吸着塔に、空気等の酸素含有ガスを供給し、吸着剤に酸素を選択的に吸着させて分離し、吸着し難い窒素を吸着塔から排出して高濃度窒素ガスとして回収し、吸着剤に吸着した酸素を、減圧工程等の再生工程により脱着させ、吸着剤を再生すると共に高濃度酸素として回収し、これらの工程を複数の吸着塔間でサイクリックに繰り返されることにより、装置全体として連続的に高濃度窒素及び高濃度酸素の製造を行なうことができる装置も知られている（例えば、特許文献１参照）。
【０００５】
また、上記高濃度酸素製造における主に酸素を選択的に吸着する分子篩活性炭吸着剤を充填した吸着塔（以下、「活性炭吸着塔」と称す。）と酸素以外のガス成分を選択的に吸着するゼオライト系等の吸着剤を充填した吸着塔（以下、「ゼオライト吸着塔」と称す。）とを連結して同一装置とし、活性炭吸着塔で吸着した酸素を脱着してゼオライト吸着塔に供給し、残余の酸素以外のガス成分を選択的に吸着除去して高濃度酸素を製造するＰＳＡ装置も知られている（例えば、特許文献２及び特許文献３）。
【０００６】
【特許文献１】
特開２００１−２６９５３２号公報（特許請求の範囲）
【特許文献２】
特開昭５４−１３２４７６号公報（特許請求の範囲）
【特許文献３】
特開平７−２６７６１２号公報（特許請求の範囲）
【０００７】
【発明が解決しようとする課題】
しかしながら、従来のＰＳＡ装置として、ゼオライト系等の酸素以外のガス成分を選択的に吸着する吸着剤を用いた装置の場合には、空気から９０容量％以上の高純度酸素を得ることはできるが、被吸着物質である窒素の分圧が高いため、吸着剤充填量は膨大になるという課題があった。また、特許文献１に記載のように分子篩活性炭を吸着剤として使用し、酸素を選択的に吸着する装置の場合には、吸着剤充填量を削減することはできるが、製造される酸素の濃度が低いという課題があった。特に、空気を分離して酸素を製造する場合には、不純物となる窒素の分圧が高いため、窒素の競合吸着量が多くなり、濃縮されたとしても４０〜５０容量％程度の酸素濃度であり、酸素濃度が低下するという課題があった。
【０００８】
また、活性炭吸着塔とゼオライト吸着塔とを連結して同一装置としたＰＳＡ装置の場合には、酸素を高濃度に濃縮させるためには活性炭吸着塔において酸素が破過するまで吸着工程を継続させることが好ましく、また、窒素を高濃度に濃縮させるためには活性炭吸着塔において酸素が破過する前に脱着工程を行うことが好ましい。ところが、特許文献２、３に記載のＰＳＡ装置の場合には、これらの条件が考慮されていないため、回収される窒素の濃度が低いという課題があった。また、従来のＰＳＡ装置の場合には活性炭吸着塔とゼオライト吸着塔それぞれにおいて吸着されたガスを減圧により脱着する減圧ポンプがそれぞれの吸着塔毎に設けられているため、設備費が嵩むと共に運転が煩雑になるという課題があった。
【０００９】
本発明は、上記課題を解決するためになされたもので、吸着塔を小型化して吸着剤の充填量を削減することができると共に設備費や運転経費を低減することができ、また、高濃度酸素及び高濃度窒素を同時に製造することができる圧力変動吸着装置並びにこの装置を用いた高濃度酸素及び高濃度窒素の製造方法を提供することを目的としている。
【００１０】
【課題を解決するための手段】
本発明の請求項１に記載の圧力変動吸着装置は、主に酸素を選択的に吸着する分子篩活性炭を充填した第１吸着塔及び第２吸着塔と、主に窒素を選択的に吸着するゼオライト吸着剤を充填した第３吸着塔と、上記第１吸着塔または第２吸着塔に少なくとも酸素及び窒素を含有する原料ガスを供給する原料ガス供給経路と、上記第１吸着塔と上記第２吸着塔とを直列に接続し且つガス流通方向を切替可能に構成した直列経路と、上記第１吸着塔または上記第２吸着塔で脱着された酸素を主に含有する脱着ガスを上記第３吸着塔に供給する濃縮酸素供給路と、上記第１吸着塔または上記第２吸着塔における酸素吸着の破過を確認する酸素濃度測定手段と、を備えたことを特徴とするものである。
【００１１】
また、本発明の請求項２に記載の圧力変動吸着装置は、請求項１に記載の発明において、上記第１吸着塔、上記第２吸着塔及び上記第３吸着塔にそれぞれ吸着されたガスを減圧により脱着する共通の減圧ポンプを設けたこと特徴とするものである。
【００１２】
また、本発明の請求項３に記載の圧力変動吸着装置を用いた高濃度酸素及び高濃度窒素の製造方法は、主に酸素を選択的に吸着する分子篩活性炭を充填した第１吸着塔及び第２吸着塔と、主に窒素を選択的に吸着するゼオライト吸着剤を充填した第３吸着塔と、上記第１吸着塔または第２吸着塔に少なくとも酸素及び窒素を含有する原料ガスを供給する原料ガス供給経路と、上記第１吸着塔と上記第２吸着塔に対して直列に接続し且つガス流通方向を切替可能に構成した直列経路と、上記第１吸着塔または上記第２吸着塔で脱着された酸素を主に含有する脱着ガスを第３吸着塔に供給する濃縮酸素供給路と、上記第１吸着塔または上記第２吸着塔における酸素吸着の破過を確認する酸素濃度測定手段と、を備えた圧力変動吸着装置を用いて高濃度酸素及び高濃度窒素を製造するに当たって、酸素及び窒素を含有するガスを原料ガスとして上記第１吸着塔に供給して主に酸素を吸着させる第１吸着工程と、第１吸着工程で吸着されないガスを第２吸着塔に供給して主に残余の酸素を吸着させる第２吸着工程と、第２吸着工程で吸着されないガスを高濃度窒素として回収する高濃度窒素回収工程と、上記第１吸着塔において酸素の吸着が破過したことを酸素濃度測定手段により確認した後に上記第１吸着塔における吸着ガスの脱着を行う第１脱着工程と、第１脱着工程からの脱着ガスを上記第３吸着塔に供給して主に残余の窒素を吸着させる第３吸着工程と、第３吸着工程で吸着されないガスを高濃度酸素として回収する高濃度酸素回収工程と、上記第３吸着塔における吸着ガスの脱着を行う第２脱着工程と、上記第１吸着塔と上記第２吸着塔のガス流通方向を逆向きに切り替える経路切替工程とを備え、上記第１吸着塔と上記第２吸着塔の間で上記各工程を繰り返すことを特徴とするものである。
【００１３】
【発明の実施の形態】
以下、図１及び図２に示す実施形態に基づいて本発明を説明する。尚、各図中、図１は本発明の圧力変動吸着装置の一実施形態を示す系統図、図２は図１に示す圧力変動吸着装置を用いた高濃度酸素及び高濃度窒素の製造方法の一実施形態の運転サイクルとバルブ操作を説明するための説明図である。
【００１４】
まず、本実施形態の圧力変動吸着装置（ＰＳＡ装置）について説明する。本実施形態のＰＳＡ装置は、例えば図１に示すように、主に酸素を選択的に吸着する分子篩活性炭（ＣＭＳ）を吸着剤層１Ａ、２Ａとして充填した第１、第２吸着塔１、２と、主に窒素を選択的に吸着するゼオライト吸着剤（ＺＭＳ）を吸着剤層３Ａとして充填した第３吸着塔３とを備え、後述のように第１、第２吸着塔１、２の吸着剤層１Ａ、２Ａを介して少なくとも酸素と窒素を含有する原料ガス（例えば、空気）から酸素を選択的に吸着、分離して窒素を高濃度窒素として排出し、第３吸着塔３の吸着剤層３Ａを介して第１、第２吸着塔１、２からの脱着ガスから窒素を選択的に吸着、分離して酸素を高濃度酸素として排出する。
【００１５】
また、ＰＳＡ装置は、原料ガス供給源（図示せず）に接続された原料ガス供給管４と、原料ガス供給管４に取り付けられ且つ第１吸着塔１または第２吸着塔２に空気を供給する空気ブロワ５と、第１、第２、第３吸着塔１、２、３を互いに連結する配管網と、配管網に取り付けられ且つ第１、第２、第３吸着塔１、２、３内を減圧してそれぞれの吸着ガスを脱着する減圧ポンプ６とを備え、後述するように配管網に配設された複数のバルブを開閉制御することによって空気等のガスの流通方向を適宜切り替えて空気から高濃度酸素及び高濃度酸素を製造する。
【００１６】
次に、配管網及びバルブについて説明する。原料ガス供給管４は二方向に分岐し、一方の分岐管４Ａが第１吸着塔１の底部に接続され、他方の分岐管４Ｂが第２吸着塔２の底部に接続されている。各分岐管４Ａ、４ＢにはバルブＶ１、Ｖ２がそれぞれ配設され、これらのバルブＶ１、Ｖ２を開閉制御することにより第１、第２吸着塔１、２に対して空気を選択的に供給する。第１、第２吸着塔１、２の頂部には窒素排出管７、８が接続されていると共にこれらの窒素排出管７、８にはバルブＶ３、Ｖ４が配設され、これらのバルブＶ３、Ｖ４を開閉制御することにより第１、第２吸着塔１、２から高濃度窒素を排出する。第１、第２吸着塔１、２から排出された高濃度窒素は回収タンク（図示せず）においてそれぞれ貯留される。
【００１７】
分岐管４Ａ、４Ｂは第１、第２連結管９、１０を介して互いに連結され、窒素排出管７、８は第３連結管１１を介して互いに連結されている。また、第１、第３連結管９、１１は第４連結管１２を介して互いに連結されている。第１連結管９の第４連結管１２との連結部両側にバルブＶ５、Ｖ６が配設され、第３連結部１１の第４連結管１２との連結部両側にバルブＶ７、Ｖ８が配設され、これらのバルブＶ５、Ｖ６、Ｖ７、Ｖ８を開閉制御することにより第１吸着塔１と第２吸着塔２を直列に接続すると共に第１吸着塔１と第２吸着塔２間のガスの流通方向を正逆に切り替える。つまり、バルブＶ７、Ｖ６を開くことにより第３、第４連結管１１、１２及び第１連結管９を介して第１、第２吸着塔１、２を直列に接続し、この順でガスを流通させ、また、バルブＶ５、Ｖ８を開くことにより第３、第４連結管１１、１２及び第１連結管９を介して第２、第１吸着塔２、１を直列に接続し、この順でガスを流通させる。また、第４連結管１２には酸素濃度計１３が配設され、この酸素濃度計１３は第４連結管１２を正逆方向に流れるガス中の酸素濃度を計測する。
【００１８】
第２連結管１０は第５連結管１４を介して第３吸着塔３の底部に連結され、この第５連結管１４に減圧ポンプ６が配設されている。第２連結管１０の第５連結管１４との連結部両側にバルブＶ９、Ｖ１０が配設されている。バルブＶ９、Ｖ１０を開閉制御すると共に減圧ポンプ６を駆動することにより第１吸着塔１内または第２吸着塔２内を減圧し、それぞれの吸着剤層１Ａ、２Ａから主に酸素を含有する吸着ガス（濃縮酸素）を脱着し、濃縮酸素を第３吸着塔３に供給する。尚、以下では第５連結管１４を濃縮酸素供給管１４として説明する。また、濃縮酸素供給管１４にはバルブＶ１１が減圧ポンプ６と直列に配設され、濃縮酸素を第３吸着塔に供給する場合にはバルブＶ１１を開く。第３吸着塔３の頂部には酸素排出管１５が連結され、この酸素排出管１５にはバルブＶ１２が配設されている。そして、バルブＶ１２を開くことにより第３吸着塔３から高濃度酸素を排出する。第３吸着塔３から排出された高濃度酸素は回収タンク（図示せず）において貯留される。
【００１９】
また、濃縮酸素供給管１４には減圧ポンプ６及びバルブＶ１１を迂回するバイパス管１６が連結され、このバイパス管１６にバルブＶ１３が配設されている。更に、濃縮酸素供給管１４には減圧ポンプ６とバルブＶ１１の間に位置する排気管１７が連結され、この排気管１７にバルブＶ１４が配設されている。従って、第３吸着塔３の吸着剤層３Ａの吸着ガス（主に窒素）を脱着し、吸着剤層３Ａを再生する場合には、バルブＶ１３、Ｖ１４を開くと共に減圧ポンプ６を駆動することにより第３吸着塔３内を減圧し、吸着剤層３Ａからの脱着ガスを排気管１７から排出する。また、濃縮酸素供給管１４のバルブ１１と第３吸着塔３と間にはガス供給管１８が連結され、このガス供給管１８にはバルブＶ１５が配設されている。そして、第３吸着塔３の吸着剤層３Ａからガスを脱着した後、バルブＶ１５を開き、加圧空気、加圧高濃度酸素等を第３吸着塔３内に供給する。
【００２０】
次に、上述の圧力変動吸着装置を用いた本発明の高濃度酸素及び高濃度窒素の製造方法の一実施形態について説明する。
【００２１】
まず、高濃度窒素回収工程を行う。高濃度窒素回収工程では、バルブＶ１、Ｖ７、Ｖ６、Ｖ４を開いて第１吸着塔１と第２吸着塔２とを直列に接続し、他のバルブを閉じた状態で空気ブロワ５を駆動し、原料ガス供給管４から分岐管４Ａを介して第１吸着塔１内へ空気を供給すると、第１吸着塔１内の吸着剤層１Ａが主に酸素を選択的に吸着し、濃縮窒素が残余の酸素と一緒に第１吸着塔１から流出した後、第３、第４連結管１１、１２を経由して第２吸着塔２内へ濃縮窒素を供給する。第２吸着塔２内では吸着剤層２Ａが残余の酸素を選択的に吸着し、窒素を更に濃縮して高濃度窒素として窒素排出管８を介して排出し、回収タンク内に貯留する。第１、第２吸着塔１、２における吸着を継続し、回収タンクでの高濃度窒素の回収を継続すると、第１吸着塔１内の吸着剤層１Ａが酸素に対する吸着平衡点に達し、それ以上の酸素の吸着作用がなくなり破過する。酸素の吸着が破過したことは第４連結管１２の酸素濃度計１３によって確認することができる。尚、この時点では第２吸着塔２内の吸着剤層２Ａは酸素の破過点に到達していないため、酸素を吸着できる。このようにして高濃度窒素回収工程を終了すると、第１吸着塔１内の吸着剤層１Ａに吸着された酸素を主体とするガスを脱着し高濃度酸素回収工程に移る。
【００２２】
高濃度酸素回収工程では、バルブＶ１、Ｖ７、Ｖ６、Ｖ４を閉じると共にバルブＶ９、Ｖ１１、Ｖ１２を開き、第１吸着塔１と第３吸着塔３を連通させた状態で減圧ポンプ６を駆動すると、第１吸着塔１内を減圧して吸着剤層１Ａから酸素を主体とするガスを脱着し、濃縮酸素を残余の窒素と一緒に第１吸着塔１内から抜き出し、濃縮酸素供給管１４から第３吸着塔３に供給する。第３吸着塔３内では吸着剤層３Ａが主に窒素を選択的に吸着し、更に濃縮された高濃度酸素が第３吸着塔３から酸素排出管１５を介して高濃度酸素として排出し、回収タンク内に貯留する。このようにして高濃度酸素回収工程を終了すると、第３吸着塔３内の吸着剤層３Ａの再生工程に移る。
【００２３】
第３吸着塔３の再生工程では、バルブＶ９、Ｖ１１、Ｖ１２を閉じると共にバルブＶ１３、Ｖ１４を開いた状態で減圧ポンプ６を駆動すると、第３吸着塔３内を減圧して吸着剤層３Ａから窒素を主体とするガスを脱着し、排出管１７から排ガスとして大気中に放出し、吸着剤層３Ａを再生する。このようにして再生工程を終了すると、第３吸着塔３の昇圧工程に移る。
【００２４】
昇圧工程では、バルブＶ１３、Ｖ１４を閉じると共にバルブＶ１５を開き、加圧された空気や高濃度酸素等のガスを第３吸着塔３内に供給し、第３吸着塔３内を所定圧力まで昇圧し、バルブＶ１５を閉じて次の高濃度酸素回収工程に備える。第３吸着塔３が待機する状態で、第１、第２吸着塔１、２のガス流通方向を切り替えるガス流通方向切替工程を経由して２回目の高濃度窒素回収工程及び高濃度酸素回収工程に移る。
【００２５】
即ち、第１吸着塔１から第２吸着塔２へ空気を流した時にはバルブＶ１、Ｖ７、Ｖ６、Ｖ４を開いたが、ガス流通方向切替工程では、バルブＶ２、Ｖ８、Ｖ５、Ｖ３を開き、空気の流通方向を第２吸着塔２から第１」吸着塔１の方向へ逆転させる。ガス流通方向切替工程を終了すると、２回目の高濃度窒素回収工程に移る。この高濃度窒素回収工程では、バルブＶ２、Ｖ８、Ｖ５、Ｖ３を開いて第２吸着塔２と第１吸着塔１とを直列に接続し、空気ブロワ５の駆動により原料ガス供給管４から分岐管４Ｂを介して第２吸着塔２内へ空気を供給する。これにより第２吸着塔２内の吸着剤層２Ａが主に酸素を選択的に吸着し、濃縮窒素が残余の酸素と一緒に第２吸着塔２から流出した後、第３、第４連結管１１、１２を経由して第１吸着塔１内へ濃縮窒素を供給する。第１吸着塔１内では吸着剤層１Ａが残余の酸素を選択的に吸着し、窒素を更に濃縮して高濃度窒素として窒素排出管７を介して排出し、回収タンク内に貯留する。第１、第２吸着塔１、２における吸着を継続し、回収タンクでの高濃度窒素の回収を継続すると、前述したように第２吸着塔２内の吸着剤層２Ａにおける酸素の吸着作用がなくなり破過する。酸素の吸着が破過したことは第４連結管１２の酸素濃度計１３によって確認することができる。このようにして高濃度窒素回収工程を終了すると、第２吸着塔２内の吸着剤層２Ａに吸着された酸素を主体とするガスを脱着し２回目の高濃度酸素回収工程に移る。
【００２６】
２回目の高濃度酸素回収工程では、バルブＶ２、Ｖ８、Ｖ５、Ｖ３を閉じると共にバルブＶ１０、Ｖ１１、Ｖ１２を開き、第２吸着塔２と第３吸着塔３を連通させた状態で減圧ポンプ６を駆動すると、第２吸着塔２内を減圧して吸着剤層２Ａから酸素を主体とするガスを脱着し、濃縮酸素を残余の窒素と一緒に第２吸着塔２内から抜き出し、濃縮酸素を残余の窒素と一緒に濃縮酸素供給管１４から第３吸着塔３に供給する。第３吸着塔３内では吸着剤層３Ａが主に窒素を選択的に吸着し、更に濃縮された高濃度酸素が第３吸着塔３から酸素排出管１５を介して高濃度酸素として排出し、回収タンク内に貯留する。このようにして２回目の高濃度酸素回収工程を終了すると、上述の場合と同様に第３吸着塔３内の吸着剤層３Ａの再生工程に移る。
【００２７】
上述の各工程は、図２に示す運転サイクルとバルブ操作を繰り返し行って高濃度窒素及び高濃度酸素の製造を行う。
【００２８】
【実施例】
以下、具体的な実施例に基づいて本発明を更に説明する。
実施例１
本実施例では下記仕様のＰＳＡ装置を用い、下記製造条件で空気を供給して高濃度酸素及び高濃度窒素を製造した結果、下記に示す結果が得られた。下記結果によれば、極めて効率的に高濃度窒素及び高濃度酸素を製造することができた。［ＰＳＡ装置の仕様］
第１吸着塔の容量：５００ｃｍ３
分子篩活性炭の充填量：２７５ｇ
第２吸着塔の容量：５００ｃｍ３
分子篩活性炭の充填量：２７５ｇ
第３吸着塔の容量：５００ｃｍ３
ゼオライトの充填量：３８０ｇ
［製造条件］
原料空気流量：１０８３Ｎｃｍ３／サイクル
吸着圧力：０．０５ＭＰａＧ
脱着圧力：２５０Ｔｏｒｒ
サイクル時間：１３０秒
［製品］
窒素量：４３３Ｎｃｍ３／サイクル（窒素：９９．１モル％）
酸素量：４３６Ｎｃｍ３／サイクル（酸素：９３．５モル％）
【００２９】
以上説明したように本実施形態によれば、ＰＳＡ装置は、第１、第２、第３吸着塔１、２、３と、第１、第２、第３吸着塔１、２、３を連結する配管網と、配管網に配設された一台ずつの空気ブロワ５及び減圧ポンプ６を備えて構成されているため、ＰＳＡ装置自体がコンパクトで設備費を低減することができる。また、コンパクトなＰＳＡ装置を用いる場合には、運転操作としては、高濃度窒素回収工程、高濃度酸素回収工程、第３吸着塔３の再生、昇圧工程、第１、第２吸着塔１、２間のガス流通方向の切替工程、切替工程後の２回目の高濃度窒素回収工程及び２回目の高濃度酸素回収工程からなる運転サイクルを繰り返して行うだけ、空気から高濃度酸素及び高濃度窒素を同時に製造することができ、しかも、その他の複雑な操作工程がないため、運転経費を削減することができる。
【００３０】
尚、本発明は上記実施形態に何等制限されるものではないことは云うまでもない。
【００３１】
【発明の効果】
本発明の請求項１〜請求項３に記載の発明によれば、吸着塔を小型化して吸着剤の充填量を削減することができると共に設備費や運転経費を低減することができ、また、高濃度酸素及び高濃度窒素を同時に製造することができる圧力変動吸着装置並びにこの装置を用いた高濃度酸素及び高濃度窒素の製造方法を提供することができる。
【図面の簡単な説明】
【図１】本発明の圧力変動吸着装置の一実施形態を示す系統図である。
【図２】図１に示す圧力変動吸着装置を用いた高濃度酸素及び高濃度窒素の製造方法の一実施形態の運転サイクルとバルブ操作を説明するための説明図である。
【符号の説明】
１ 第１吸着塔
１Ａ 吸着剤層（分子篩活性炭）
２ 第２吸着塔
２Ａ 吸着剤層（分子篩活性炭）
３ 第３吸着塔
３Ａ 吸着剤層（ゼオライト吸着剤）
４ 原料ガス供給管（原料ガス供給経路）
５ 空気ブロワ
６ 減圧ポンプ
１３ 酸素濃度計（酸素濃度測定手段）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pressure fluctuation adsorption apparatus (hereinafter, referred to as “PSA apparatus”) for producing high-concentration oxygen and high-concentration nitrogen by selective adsorption separation in an adsorption tower filled with an adsorbent from a raw material gas containing at least oxygen and nitrogen. And a method for producing high-concentration oxygen and high-concentration nitrogen using the PSA apparatus.
[0002]
[Prior art]
As a conventional high-concentration gas production apparatus, for example, a cryogenic separation apparatus, a membrane separation apparatus, a PSA apparatus, and the like are used. A cryogenic separation device is a device that cools and liquefies air by adiabatic expansion, separates the air using the difference in boiling points of nitrogen, oxygen, and the like, and produces high-concentration oxygen, high-concentration nitrogen, and the like. Although the cryogenic separation device is suitable for producing a large-capacity, high-concentration gas, it has problems such as an increase in power costs such as electric power and an increase in the installation area of the equipment. The membrane separation device is a device that uses a polymer organic membrane that selectively transmits oxygen, separates nitrogen and oxygen in the air, and produces high-concentration oxygen and high-concentration nitrogen. Membrane separation equipment is suitable for producing small-volume, high-concentration gas.However, when producing large-capacity industrially, a large amount of expensive membrane separation modules are required. is there. In addition, PSA devices are suitable for producing relatively large volumes of high-concentration gases such as oxygen and nitrogen, and have been widely used in recent years because of their low equipment and power costs and easy operation. I have.
[0003]
In a PSA apparatus, an oxygen-containing gas such as air is supplied to an adsorption tower filled with an adsorbent for selectively adsorbing a gas component other than oxygen, such as zeolite, for the purpose of producing high-concentration oxygen. Gases such as carbon dioxide gas and moisture (hereinafter simply referred to as "impurities") are adsorbed and separated by an adsorbent, and oxygen that is hardly adsorbed is extracted from the adsorption tower, recovered as high-concentration oxygen, and adsorbed by the adsorbent. There is known an apparatus capable of continuously producing high-concentration oxygen as a whole apparatus by desorbing impurities by a regeneration step such as a pressure reduction step and a purge step and discharging the impurities as an off-gas outside the system.
[0004]
In addition, an oxygen-containing gas such as air is supplied to an adsorption tower filled with a molecular sieve activated carbon adsorbent that mainly adsorbs oxygen selectively. Is discharged from the adsorption tower and recovered as high-concentration nitrogen gas, and the oxygen adsorbed on the adsorbent is desorbed by a regeneration step such as a decompression step, and the adsorbent is regenerated and recovered as high-concentration oxygen. There is also known an apparatus capable of continuously producing high-concentration nitrogen and high-concentration oxygen as a whole by repeating cyclically between a plurality of adsorption towers (for example, see Patent Document 1).
[0005]
Further, in the high-concentration oxygen production, an adsorption tower (hereinafter, referred to as an “activated carbon adsorption tower”) packed with a molecular sieve activated carbon adsorbent that mainly adsorbs oxygen selectively and a gas component other than oxygen are selectively adsorbed. An adsorption tower filled with a zeolite-based adsorbent (hereinafter referred to as a "zeolite adsorption tower") is connected to the same apparatus, and oxygen adsorbed by the activated carbon adsorption tower is desorbed and supplied to the zeolite adsorption tower. There are also known PSA apparatuses that selectively adsorb and remove the remaining gas components other than oxygen to produce high-concentration oxygen (for example, Patent Documents 2 and 3).
[0006]
[Patent Document 1]
JP 2001-269532 A (Claims)
[Patent Document 2]
JP-A-54-132476 (Claims)
[Patent Document 3]
JP-A-7-267612 (Claims)
[0007]
[Problems to be solved by the invention]
However, in the case of a conventional PSA device using an adsorbent such as zeolite, which selectively adsorbs gas components other than oxygen, high-purity oxygen of 90% by volume or more can be obtained from air. However, since the partial pressure of nitrogen as the substance to be adsorbed is high, there has been a problem that the amount of adsorbent charged becomes enormous. Also, in the case of an apparatus that selectively adsorbs oxygen using molecular sieve activated carbon as an adsorbent as described in Patent Document 1, although the amount of adsorbent charged can be reduced, the concentration of oxygen produced Was low. In particular, when oxygen is produced by separating air, the partial pressure of nitrogen, which is an impurity, is high, so that the amount of competitive adsorption of nitrogen increases, and even when the oxygen is concentrated, the oxygen concentration is about 40 to 50% by volume. There is a problem that the oxygen concentration decreases.
[0008]
In the case of a PSA apparatus in which the activated carbon adsorption tower and the zeolite adsorption tower are connected to each other to form the same apparatus, in order to concentrate oxygen to a high concentration, the adsorption step is continued until oxygen breaks down in the activated carbon adsorption tower. In order to concentrate nitrogen at a high concentration, it is preferable to perform a desorption step before oxygen breaks through in the activated carbon adsorption tower. However, in the case of the PSA devices described in Patent Documents 2 and 3, since these conditions are not taken into consideration, there is a problem that the concentration of the recovered nitrogen is low. Further, in the case of the conventional PSA apparatus, a decompression pump for desorbing the gas adsorbed in each of the activated carbon adsorption tower and the zeolite adsorption tower by decompression is provided for each of the adsorption towers. There was a problem that it became complicated.
[0009]
The present invention has been made in order to solve the above-mentioned problems, and it is possible to reduce the amount of adsorbent by reducing the size of an adsorption tower, reduce equipment costs and operating costs, An object of the present invention is to provide a pressure fluctuation adsorption apparatus capable of simultaneously producing oxygen and high-concentration nitrogen, and a method for producing high-concentration oxygen and high-concentration nitrogen using this apparatus.
[0010]
[Means for Solving the Problems]
The pressure fluctuation adsorption apparatus according to claim 1 of the present invention comprises a first adsorption tower and a second adsorption tower packed with a molecular sieve activated carbon mainly for selectively adsorbing oxygen, and a zeolite mainly for selectively adsorbing nitrogen. A third adsorption tower filled with an adsorbent, a source gas supply path for supplying a source gas containing at least oxygen and nitrogen to the first adsorption tower or the second adsorption tower, the first adsorption tower and the second adsorption tower, And a series path configured to connect the towers in series and to switch the gas flow direction, and a desorption gas mainly containing oxygen desorbed in the first adsorption tower or the second adsorption tower to the third adsorption tower. And an oxygen concentration measuring means for confirming breakthrough of oxygen adsorption in the first adsorption tower or the second adsorption tower.
[0011]
Further, the pressure fluctuation adsorption device according to claim 2 of the present invention is the pressure fluctuation adsorption device according to claim 1, wherein the gas adsorbed by the first adsorption tower, the second adsorption tower, and the third adsorption tower respectively is used. It is characterized in that a common decompression pump is provided which is detached by decompression.
[0012]
In addition, the method for producing high-concentration oxygen and high-concentration nitrogen using the pressure fluctuation adsorption apparatus according to claim 3 of the present invention is characterized in that the first adsorption tower and the first adsorption tower packed with molecular sieve activated carbon that mainly selectively adsorbs oxygen are provided. (2) an adsorption tower, a third adsorption tower filled with a zeolite adsorbent mainly for selectively adsorbing nitrogen, and a raw material for supplying a raw material gas containing at least oxygen and nitrogen to the first adsorption tower or the second adsorption tower A gas supply path, a series path connected in series to the first adsorption tower and the second adsorption tower and configured to switch the gas flow direction, and desorption by the first adsorption tower or the second adsorption tower. A concentrated oxygen supply path for supplying a desorbed gas mainly containing the supplied oxygen to the third adsorption tower, an oxygen concentration measuring means for confirming breakthrough of oxygen adsorption in the first adsorption tower or the second adsorption tower, Using a pressure fluctuation adsorption device equipped with In producing oxygen and high-concentration nitrogen, a gas containing oxygen and nitrogen is supplied as a raw material gas to the first adsorption tower to mainly adsorb oxygen, and is not adsorbed in the first adsorption step. A second adsorption step of supplying gas to the second adsorption tower to mainly adsorb residual oxygen, a high-concentration nitrogen recovery step of recovering gas not adsorbed in the second adsorption step as high-concentration nitrogen; A first desorption step of desorbing the adsorbed gas in the first adsorption tower after confirming that oxygen adsorption in the tower has passed through the oxygen concentration measuring means, and a third adsorption step of desorbing gas from the first desorption step in the third adsorption tower. A third adsorption step in which the remaining nitrogen is mainly adsorbed by supplying the gas to the tower, a high-concentration oxygen recovery step in which gas not adsorbed in the third adsorption step is recovered as high-concentration oxygen, Desorption Performing a second desorption step, and a path switching step of switching a gas flow direction of the first adsorption tower and the second adsorption tower in opposite directions. It is characterized by repeating the steps.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described based on the embodiment shown in FIGS. In each of the drawings, FIG. 1 is a system diagram showing an embodiment of the pressure fluctuation adsorption apparatus of the present invention, and FIG. 2 is a diagram of a method for producing high concentration oxygen and high concentration nitrogen using the pressure fluctuation adsorption apparatus shown in FIG. It is an explanatory view for explaining an operation cycle and valve operation of one embodiment.
[0014]
First, a pressure fluctuation adsorption device (PSA device) of the present embodiment will be described. As shown in FIG. 1, for example, the PSA apparatus of the present embodiment includes first and second adsorption towers 1 and 2 in which molecular sieve activated carbon (CMS) mainly for selectively adsorbing oxygen is packed as adsorbent layers 1A and 2A. And a third adsorption tower 3 filled with a zeolite adsorbent (ZMS) for selectively adsorbing nitrogen as an adsorbent layer 3A, and adsorb the first and second adsorption towers 1 and 2 as described later. Oxygen is selectively adsorbed and separated from a raw material gas (for example, air) containing at least oxygen and nitrogen through the agent layers 1A and 2A, and nitrogen is discharged as high-concentration nitrogen. Nitrogen is selectively adsorbed and separated from the desorbed gas from the first and second adsorption towers 1 and 2 through the layer 3A, and oxygen is discharged as high-concentration oxygen.
[0015]
The PSA apparatus supplies air to the source gas supply pipe 4 connected to the source gas supply source (not shown) and the first adsorption tower 1 or the second adsorption tower 2 attached to the source gas supply pipe 4. An air blower 5, a piping network connecting the first, second, and third adsorption towers 1, 2, and 3 to each other; a first, second, and third adsorption towers 1, 2, and 3 attached to the piping network. A decompression pump 6 for depressurizing the inside and desorbing each adsorbed gas, and by appropriately controlling the opening and closing of a plurality of valves arranged in a piping network as described later, appropriately switching the flow direction of gas such as air. Produce high concentration oxygen and high concentration oxygen from air.
[0016]
Next, the piping network and the valve will be described. The source gas supply pipe 4 branches in two directions, one branch pipe 4A is connected to the bottom of the first adsorption tower 1, and the other branch pipe 4B is connected to the bottom of the second adsorption tower 2. Valves V1 and V2 are provided in the branch pipes 4A and 4B, respectively, and air is selectively supplied to the first and second adsorption towers 1 and 2 by opening and closing these valves V1 and V2. . Nitrogen discharge pipes 7 and 8 are connected to the tops of the first and second adsorption towers 1 and 2, and valves V3 and V4 are arranged in these nitrogen discharge pipes 7 and 8, respectively. High-concentration nitrogen is discharged from the first and second adsorption towers 1 and 2 by controlling the opening and closing of V4. The high-concentration nitrogen discharged from the first and second adsorption towers 1 and 2 is stored in a recovery tank (not shown).
[0017]
The branch pipes 4A and 4B are connected to each other via first and second connection pipes 9 and 10, and the nitrogen discharge pipes 7 and 8 are connected to each other via a third connection pipe 11. The first and third connecting pipes 9 and 11 are connected to each other via a fourth connecting pipe 12. Valves V5 and V6 are provided on both sides of the first connecting pipe 9 connected to the fourth connecting pipe 12, and valves V7 and V8 are provided on both sides of the connecting part of the third connecting section 11 and the fourth connecting pipe 12. By controlling the opening and closing of these valves V5, V6, V7, V8, the first adsorption tower 1 and the second adsorption tower 2 are connected in series, and the gas between the first adsorption tower 1 and the second adsorption tower 2 is exchanged. Switch the distribution direction to forward or reverse. That is, by opening the valves V7 and V6, the first and second adsorption towers 1 and 2 are connected in series via the third and fourth connection pipes 11 and 12 and the first connection pipe 9, and the gas is supplied in this order. The second and first adsorption towers 2 and 1 are connected in series via the third and fourth connection pipes 11 and 12 and the first connection pipe 9 by flowing the valves and opening the valves V5 and V8. To distribute gas. Further, an oxygen concentration meter 13 is provided in the fourth connection pipe 12, and the oxygen concentration meter 13 measures the oxygen concentration in the gas flowing in the forward and reverse directions through the fourth connection pipe 12.
[0018]
The second connection pipe 10 is connected to the bottom of the third adsorption tower 3 via the fifth connection pipe 14, and the decompression pump 6 is provided in the fifth connection pipe 14. Valves V9 and V10 are arranged on both sides of the connection portion of the second connection tube 10 with the fifth connection tube 14. By controlling the opening and closing of the valves V9 and V10 and driving the decompression pump 6, the pressure in the first adsorption tower 1 or the second adsorption tower 2 is reduced, and the adsorption mainly containing oxygen from the respective adsorbent layers 1A and 2A. The gas (concentrated oxygen) is desorbed and the concentrated oxygen is supplied to the third adsorption tower 3. Hereinafter, the fifth connection pipe 14 will be described as the concentrated oxygen supply pipe 14. Further, a valve V11 is disposed in series with the decompression pump 6 in the concentrated oxygen supply pipe 14, and when supplying concentrated oxygen to the third adsorption tower, the valve V11 is opened. An oxygen discharge pipe 15 is connected to the top of the third adsorption tower 3, and a valve V12 is provided in the oxygen discharge pipe 15. Then, high-concentration oxygen is discharged from the third adsorption tower 3 by opening the valve V12. The high-concentration oxygen discharged from the third adsorption tower 3 is stored in a recovery tank (not shown).
[0019]
The concentrated oxygen supply pipe 14 is connected to a decompression pump 6 and a bypass pipe 16 that bypasses the valve V11. The bypass pipe 16 is provided with a valve V13. Further, an exhaust pipe 17 located between the decompression pump 6 and the valve V11 is connected to the concentrated oxygen supply pipe 14, and the exhaust pipe 17 is provided with a valve V14. Therefore, when the adsorbent gas (mainly nitrogen) of the adsorbent layer 3A of the third adsorption tower 3 is desorbed and the adsorbent layer 3A is regenerated, the valves V13 and V14 are opened and the decompression pump 6 is driven. The pressure inside the third adsorption tower 3 is reduced, and the desorbed gas from the adsorbent layer 3A is discharged from the exhaust pipe 17. Further, a gas supply pipe 18 is connected between the valve 11 of the concentrated oxygen supply pipe 14 and the third adsorption tower 3, and a valve V15 is provided in the gas supply pipe 18. Then, after the gas is desorbed from the adsorbent layer 3A of the third adsorption tower 3, the valve V15 is opened, and pressurized air, pressurized high-concentration oxygen and the like are supplied into the third adsorption tower 3.
[0020]
Next, an embodiment of the method for producing high-concentration oxygen and high-concentration nitrogen of the present invention using the above-described pressure fluctuation adsorption apparatus will be described.
[0021]
First, a high-concentration nitrogen recovery step is performed. In the high-concentration nitrogen recovery step, the valves V1, V7, V6, and V4 are opened to connect the first adsorption tower 1 and the second adsorption tower 2 in series, and the air blower 5 is driven with the other valves closed. When air is supplied from the raw material gas supply pipe 4 into the first adsorption tower 1 through the branch pipe 4A, the adsorbent layer 1A in the first adsorption tower 1 mainly selectively adsorbs oxygen, and the concentrated nitrogen is removed. After flowing out of the first adsorption tower 1 together with the remaining oxygen, concentrated nitrogen is supplied into the second adsorption tower 2 via the third and fourth connection pipes 11 and 12. In the second adsorption tower 2, the adsorbent layer 2A selectively adsorbs the remaining oxygen, further concentrates nitrogen, discharges it as high-concentration nitrogen through the nitrogen discharge pipe 8, and stores it in the recovery tank. When the adsorption in the first and second adsorption towers 1 and 2 is continued and the high concentration nitrogen is continuously collected in the collection tank, the adsorbent layer 1A in the first adsorption tower 1 reaches the adsorption equilibrium point for oxygen. The oxygen adsorbing action described above is lost, and breakthrough occurs. The breakthrough of the adsorption of oxygen can be confirmed by the oxygen concentration meter 13 of the fourth connection pipe 12. At this time, since the adsorbent layer 2A in the second adsorption tower 2 has not reached the oxygen breakthrough point, it can adsorb oxygen. When the high-concentration nitrogen recovery step is completed in this way, the gas mainly containing oxygen adsorbed on the adsorbent layer 1A in the first adsorption tower 1 is desorbed, and the process proceeds to the high-concentration oxygen recovery step.
[0022]
In the high-concentration oxygen recovery step, when the valves V1, V7, V6, and V4 are closed and the valves V9, V11, and V12 are opened, and the decompression pump 6 is driven in a state where the first adsorption tower 1 and the third adsorption tower 3 are communicated with each other. The pressure in the first adsorption tower 1 is reduced to desorb a gas mainly composed of oxygen from the adsorbent layer 1A, and the concentrated oxygen is extracted from the first adsorption tower 1 together with the remaining nitrogen from the first adsorption tower 1; It is supplied to the third adsorption tower 3. In the third adsorption tower 3, the adsorbent layer 3A mainly selectively adsorbs nitrogen, and further concentrated high-concentration oxygen is discharged from the third adsorption tower 3 as high-concentration oxygen through the oxygen discharge pipe 15, Store in collection tank. When the high-concentration oxygen recovery step is completed in this way, the process proceeds to the step of regenerating the adsorbent layer 3A in the third adsorption tower 3.
[0023]
In the regeneration step of the third adsorption tower 3, when the decompression pump 6 is driven with the valves V9, V11, V12 closed and the valves V13, V14 open, the pressure in the third adsorption tower 3 is reduced and the adsorbent layer 3A is discharged. The gas mainly composed of nitrogen is desorbed and released into the atmosphere as exhaust gas from the discharge pipe 17 to regenerate the adsorbent layer 3A. When the regeneration step is completed in this way, the process proceeds to the pressure increasing step of the third adsorption tower 3.
[0024]
In the pressure increasing step, the valves V13 and V14 are closed and the valve V15 is opened to supply a gas such as pressurized air or high-concentration oxygen into the third adsorption tower 3, and to increase the pressure in the third adsorption tower 3 to a predetermined pressure. Then, the valve V15 is closed to prepare for the next high-concentration oxygen recovery step. In a state where the third adsorption tower 3 is on standby, a second high-concentration nitrogen recovery step and a high-concentration oxygen recovery step via a gas flow direction switching step of switching the gas flow direction of the first and second adsorption towers 1 and 2 Move on to
[0025]
That is, when air was flowed from the first adsorption tower 1 to the second adsorption tower 2, the valves V1, V7, V6, and V4 were opened. In the gas flow direction switching step, the valves V2, V8, V5, and V3 were opened. The direction of air flow is reversed from the second adsorption tower 2 to the first "first adsorption tower 1". When the gas flow direction switching step is completed, the process proceeds to the second high concentration nitrogen recovery step. In this high-concentration nitrogen recovery step, the valves V2, V8, V5 and V3 are opened to connect the second adsorption tower 2 and the first adsorption tower 1 in series, and the air blower 5 is driven to branch off from the raw material gas supply pipe 4. Air is supplied into the second adsorption tower 2 via the pipe 4B. Thereby, the adsorbent layer 2A in the second adsorption tower 2 mainly selectively adsorbs oxygen, and after the concentrated nitrogen flows out of the second adsorption tower 2 together with the remaining oxygen, the third and fourth connection pipes Concentrated nitrogen is supplied into the first adsorption tower 1 via 11 and 12. In the first adsorption tower 1, the adsorbent layer 1A selectively adsorbs the remaining oxygen, further concentrates the nitrogen, discharges it as high-concentration nitrogen through the nitrogen discharge pipe 7, and stores it in the recovery tank. When the adsorption in the first and second adsorption towers 1 and 2 is continued and the recovery of high-concentration nitrogen in the recovery tank is continued, the adsorbing action of oxygen in the adsorbent layer 2A in the second adsorption tower 2 is increased as described above. It breaks through. The breakthrough of the adsorption of oxygen can be confirmed by the oxygen concentration meter 13 of the fourth connection pipe 12. When the high-concentration nitrogen recovery step is completed as described above, the gas mainly containing oxygen adsorbed on the adsorbent layer 2A in the second adsorption tower 2 is desorbed, and the process proceeds to the second high-concentration oxygen recovery step.
[0026]
In the second high-concentration oxygen recovery step, the valves V2, V8, V5, and V3 are closed, and the valves V10, V11, and V12 are opened, and the decompression pump 6 is connected with the second adsorption tower 2 and the third adsorption tower 3 in communication. Is driven, the inside of the second adsorption tower 2 is depressurized to desorb a gas mainly composed of oxygen from the adsorbent layer 2A, and the concentrated oxygen is extracted from the second adsorption tower 2 together with the remaining nitrogen to remove the concentrated oxygen. The remaining nitrogen is supplied to the third adsorption tower 3 from the concentrated oxygen supply pipe 14 together with the remaining nitrogen. In the third adsorption tower 3, the adsorbent layer 3A mainly selectively adsorbs nitrogen, and further concentrated high-concentration oxygen is discharged from the third adsorption tower 3 as high-concentration oxygen through the oxygen discharge pipe 15, Store in collection tank. When the second high-concentration oxygen recovery step is completed in this manner, the process proceeds to the step of regenerating the adsorbent layer 3A in the third adsorption tower 3 as in the case described above.
[0027]
In each of the above steps, the operation cycle and valve operation shown in FIG. 2 are repeated to produce high-concentration nitrogen and high-concentration oxygen.
[0028]
【Example】
Hereinafter, the present invention will be further described based on specific examples.
Example 1
In this example, high-concentration oxygen and high-concentration nitrogen were produced by using a PSA apparatus having the following specifications and supplying air under the following production conditions. As a result, the following results were obtained. According to the following results, highly concentrated nitrogen and highly concentrated oxygen could be produced very efficiently. [Specification of PSA device]
Capacity of the first adsorption tower: 500 cm 3
Filling amount of molecular sieve activated carbon: 275 g
Capacity of the second adsorption tower: 500 cm 3
Filling amount of molecular sieve activated carbon: 275 g
Capacity of the third adsorption tower: 500 cm 3
Zeolite filling amount: 380 g
[Manufacturing conditions]
Raw material air flow rate: 1083 Ncm 3 / cycle adsorption pressure: 0.05 MPaG
Desorption pressure: 250 Torr
Cycle time: 130 seconds [product]
Nitrogen amount: 433 Ncm 3 / cycle (nitrogen: 99.1 mol%)
Oxygen amount: 436 Ncm 3 / cycle (oxygen: 93.5 mol%)
[0029]
As described above, according to the present embodiment, the PSA device connects the first, second, and third adsorption towers 1, 2, and 3 with the first, second, and third adsorption towers 1, 2, and 3. Since it is configured to include a piping network to be provided and one air blower 5 and one decompression pump 6 disposed in the piping network, the PSA device itself is compact and the equipment cost can be reduced. When a compact PSA device is used, the high-concentration nitrogen recovery step, the high-concentration oxygen recovery step, the regeneration of the third adsorption tower 3, the pressure increase step, the first and second adsorption towers 1, 2 The high-concentration oxygen and high-concentration nitrogen are removed from the air only by repeating the operation cycle consisting of the switching step of the gas flow direction between the second step and the second high-concentration nitrogen recovery step after the switching step and the second high-concentration oxygen recovery step. Since it can be manufactured at the same time and there are no other complicated operation steps, the operating cost can be reduced.
[0030]
Needless to say, the present invention is not limited to the above embodiment.
[0031]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the invention as described in claim 1 to claim 3 of the present invention, the adsorption tower can be reduced in size, the amount of adsorbent to be charged can be reduced, and equipment costs and operation costs can be reduced. A pressure fluctuation adsorption device capable of simultaneously producing high-concentration oxygen and high-concentration nitrogen and a method for producing high-concentration oxygen and high-concentration nitrogen using this device can be provided.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an embodiment of a pressure fluctuation adsorption device of the present invention.
FIG. 2 is an explanatory diagram for explaining an operation cycle and a valve operation of one embodiment of a method for producing high-concentration oxygen and high-concentration nitrogen using the pressure fluctuation adsorption apparatus shown in FIG.
[Explanation of symbols]
1 1A adsorption tower 1A adsorbent layer (molecular sieve activated carbon)
2 Second adsorption tower 2A Adsorbent layer (molecular sieve activated carbon)
3 3rd adsorption tower 3A adsorbent layer (zeolite adsorbent)
4 Source gas supply pipe (source gas supply path)
5 Air blower 6 Pressure reducing pump 13 Oxygen concentration meter (Oxygen concentration measuring means)
