JP4228401B2

JP4228401B2 - Carbon monoxide removal equipment in reformed gas

Info

Publication number: JP4228401B2
Application number: JP06175297A
Authority: JP
Inventors: 秀明駒木
Original assignee: IHI Corp
Current assignee: IHI Corp
Priority date: 1997-03-03
Filing date: 1997-03-03
Publication date: 2009-02-25
Anticipated expiration: 2017-03-03
Also published as: JPH10245573A

Description

【０００１】
【発明の属する技術分野】
本発明は固体高分子型燃料電池発電システムにおいて、改質器で改質されて得られた改質ガス中に含まれる一酸化炭素ＣＯを選択的に除去して燃料電池の燃料極へ供給するようにするため改質ガスの供給ラインの途中に設けて用いる一酸化炭素除去装置に関するものである。
【０００２】
【従来の技術】
燃料電池のうち、固体高分子型燃料電池の場合、改質器で改質原料ガスとしてのメタノールを改質した後、改質ガス（燃料ガス）を燃料電池の燃料極へ供給するようにするが、改質ガスに一酸化炭素ＣＯが含まれていると、このＣＯによって燃料電池の電極が被毒して性能低下を来たすことから、改質ガスを燃料電池の燃料極へ供給する前に該改質ガス中のＣＯを選択的に除去する必要がある。
【０００３】
従来、かかる必要性を満足させるために改質ガス中のＣＯを除去するようにした一酸化炭素除去装置としては、図６（イ）（ロ）に示す如き長い円筒体１の内部に、該円筒体１の軸心方向と平行に延びる複数本の小径の管２を配設し、該各管２の内部にほぼ全長にわたって、ＣＯを選択的に酸化できる触媒としてロジウム（Ｒｈ）系又はルテニウム（Ｒｕ）系等の触媒３を充填して、各管２の外側を冷却媒体４を流す冷却室５とし、円筒体１の一端側に開口させた各管２の入口２ａより改質ガスＦＧとともに酸化空気又は酸素Ｏ₂を導入させると共に、円筒体１の他端より冷却室５に冷却媒体４を導入して上記各管２の入口２ａ側より取り出すようにし、改質ガスＦＧと酸化空気又は酸素Ｏ₂を各管２内の触媒３によりＣＯ＋1/2 Ｏ₂→ＣＯ₂の反応を行わせて、改質ガスＦＧ中のＣＯを選択的に除去するようにしたものがあり、又、図７に示す如く、多数のハニカム状の通路７を形成したセラミック製の触媒担持体６を、ケーシング８内に該ケーシング８の長手方向に通路７が平行となるように組み込み、該触媒担持体６の通路７に、ＣＯを選択的に酸化できる触媒３を、粉末状にして担持させ、ケーシング８の入口側から改質ガスＦＧとともに酸化空気又は酸素Ｏ₂を導入して、ＣＯ除去の反応を行わせ、ＣＯを除去した改質ガスを燃料電池の燃料極へ供給するようにしたもの、等がある。
【０００４】
【発明が解決しようとする課題】
ところが、図６に示す一酸化炭素除去装置の場合、円筒体１内に平行に配設した各管２の長さが長いため、改質ガスの流れ方向において触媒３の温度差が大きくなると共に、円筒体１の半径方向にも大きな温度差が生じ、特に、改質ガスの流れ方向に触媒温度差があると、各管２の入口２ａから導入された酸化空気又は酸素Ｏ₂がガスの流れ方向で一様に一酸化炭素と反応しないため、均一な反応温度とすることができない。ＣＯ除去率と反応温度の関係を示す図８のように、ＣＯを選択的に酸化できる触媒として、ロジウム（Ｒｈ）系触媒又はルテニウム（Ｒｕ）系触媒を充填して用いた場合のＣＯとＨ₂の除去率について見ると、Ｒｈ系触媒を用いた場合は、◇印の如く反応温度が高くなると、Ｈ₂の除去率は僅かに高くなって行く程度であるが、ＣＯの除去率は○印の如く、２００℃以上になると、低下して来るため、最適温度範囲が狭い問題があり、又、Ｒｕ系触媒を用いた場合は、反応温度が高くなっても、ＣＯ除去率は●印の如く低下しないが、◆印の如くＨ₂の除去率が１００℃を超えると急激に高くなって来てこの場合も、最適温度の範囲が狭い。水素を消費する副反応（Ｈ₂＋1/2 Ｏ₂→Ｈ₂Ｏ）が起きると、燃料電池の燃料極への燃料としてのＨ₂の量が少なくなるという問題があると共に、上記のように副反応が起るとそれだけ多くの酸素が使用されるために、酸化空気又は酸素Ｏ₂の導入量を多くしなければならず、通常は酸化空気中の酸素又は酸素を理論上必要な量の４倍程度入れなければならないとされ（酸化空気量論比４．０）、これに伴い供給機として圧縮機の能力を高めなければならない、という問題があり、更に、冷却は、管２の外側から行う構造であるため、管２の径が大きいと、該管２の中央と周囲で触媒温度に差が生じ、一方、管２の径が小さいと、ガスの流れの圧損が増大すると共に、触媒３を詰めにくくなり、更に又、平行に配設された各管２の圧損の違いから管２ごとの流量配分が異なる、等の問題がある。
【０００５】
又、図７に示す一酸化炭素除去装置の場合は、同じハニカム状の通路内では下流ほど反応温度が高くなるので、冷却に熱交換器を用いる場合はハニカム状通路と熱交換器とを交互に配置する構成とすることになり、構造が複雑になる、という問題がある。
【０００６】
そこで、本発明は、改質ガス中の一酸化炭素を選択的に除去する主反応が行われるときに水素消費反応が行われる副反応（Ｈ₂＋1/2 Ｏ₂→Ｈ₂Ｏ）が起りにくいようにして、水素の消費を少なくすると共に、酸化空気又は酸素の供給量を少なくして量論比を４．０以下にすることができるようにし、更に、触媒充填部を均一な反応温度とすることができるようにしようとするものである。
【０００７】
【課題を解決するための手段】
本発明は、上記課題を解決するために、箱形ケーシングの内部に、触媒層と、該触媒層での反応温度を調整するための冷却層とを水平の隔壁を介し冷却層で触媒層を挟むように積層させてＣＯ除去部を構成し、且つ該ＣＯ除去部の触媒層の中央部分に、一酸化炭素を選択的に酸化させる触媒を、厚さを薄くして上記ケーシングの長手方向へ長くなるように充填して触媒充填部とし、該触媒充填部の片側となる上記ケーシングの幅方向一側を改質ガス及び酸化空気又は酸素の導入部とすると共に、触媒充填部の反対側となる上記ケーシングの幅方向他側を改質ガス及び酸化空気又は酸素の導出部として、上記導入部に流量調整用の多孔板を設け、改質ガス及び酸化空気又は酸素が導入部から上記多孔板を通って触媒充填部に入り、ケーシングの幅方向へ流れるようにし、更に上記ケーシングに、上記触媒層の改質ガス及び酸化空気又は酸素の導入部と導出部、冷却層の冷却媒体導入部と導出部を各々ケーシングの外部へ開口させてなる構成とする。
【０００８】
改質ガス及び酸化空気又は酸素が導入部をケーシングの長手方向へ流れてから直角方向に向きを変えて触媒充填部を通過するようにしてあるので、ガスの流れ方向で触媒は短かく、したがって、触媒の温度差は小さく、又、触媒充填部の両面が全面にわたり冷却されるので、均一冷却ができ、更に、触媒は薄くしてあることから、反応温度の均一化が図れる。これにより、酸化空気又は酸素の供給量を減少できて量論比を下げることができ、改質ガス中の水素の消費量が減少する。
【０００９】
又、ＣＯ除去部を、ケーシング内の幅方向に区画して複数構成し、各ＣＯ除去部の各改質ガス及び酸化空気又は酸素の導入部同士及び導出部同士をそれぞれ連通させ、且つ各冷却層の入口側同士及び出口側同士をそれぞれ連通させた構成とすると、効率よく一酸化炭素を除去できる。
【００１０】
更に、ＣＯ除去部の触媒充填部にケーシングの長手方向へ多数の小空間を区画形成するようにケーシングの長手方向と直交する方向へ延びる多数の仕切壁で触媒充填部を仕切るようにした構成とすると、触媒を小さいブロックとして詰めることができると共に、改質ガスの流れを均一化できる。
【００１１】
【発明の実施の形態】
以下、本発明の実施の形態を図面を参照して説明する。
【００１２】
図１（イ）（ロ）（ハ）は本発明の実施の一形態として、プレート型のＣＯ除去部１０ａと１０ｂを１つの箱形ケーシング１１の内部に左右別々に形成し、ケーシング１１の一端側から導入した改質ガスＦＧ及び酸化空気又は酸素Ｏ₂を同時に２つのＣＯ除去部１０ａと１０ｂに流して改質ガスＦＧ中の一酸化炭素ＣＯを除去するようにしたものについて示す。
【００１３】
詳述すると、箱形に形成したケーシング１１内の中央部に、中央仕切壁１２を設けて左右に仕切ると共に、該中央仕切壁１２を挟んで左右対称的に水平の隔壁１３を多段に配設して、１つ置きに内部に触媒を充填するためのプレート型の触媒層１４と該触媒層１４での反応温度を調整するために冷却媒体を流すようにするプレート型の冷却層１５を積層して形成するようにして触媒層１４が両面より冷却層１５で挟まれているようにし、且つ上記各触媒層１４と冷却層１５の各中央部分にのみ左右方向へ延びる仕切壁１６を所要間隔で配設して多数の小空間を形成させ、更に、該触媒層１４中央部の小空間形成部の片側をケーシング１１の長手方向に沿うガス導入部１７とし、又、反対側をガス導出部１８とし、同様に上記冷却層１５中央部の小空間形成部の片側を冷却媒体導入部１９とし、反対側を冷却媒体導出部２０とするようにして、ガスや冷却媒体の入口側となるケーシング１１の一端側では、各触媒層１４のガス導入部１７と各冷却層１５の冷却媒体導入部１９のみを残して閉塞板２１で閉塞すると共に、ケーシング１１の反対側では、各触媒層１４のガス導入部１７と各冷却層１５の冷却媒体導入部１９を除いて閉塞板２２で閉塞して、上記触媒層１４の隣接する仕切壁１６の間又は両端の仕切壁１６と閉塞板２１，２２との間で形成された各小空間には、一酸化炭素を選択的に酸化できる触媒２３を厚さを薄くして詰めて触媒充填部２４を形成することにより、左右別々のＣＯ除去部１０ａと１０ｂを構成するようにする。
【００１４】
２５は触媒充填部２４のガス導入部１７側に設けたガスの流量調整用の多孔板、２６は酸化空気又は酸素Ｏ₂を各小空間に均一に流すようにするために触媒層１４のガス導入部１７に設けた流量調整用の多孔板で、該多孔板２６とケーシング１１の内壁又は中央仕切壁１２との間に形成される流路２７に、ケーシング１１の外部から酸化空気又は酸素Ｏ₂を供給できるようにしてある。２８は２つのＣＯ除去部１０ａ，１０ｂの各触媒層１４のガス導入部１７へ改質ガスＦＧを導くようにするため、各触媒層１４に対応させてケーシング１１に設けた改質ガス入口、２９はケーシング１１の反対側に各触媒層１４に対応させて設けた改質ガス出口、３０は冷却媒体４を各冷却層１５へ導入するため、ケーシング１１の一端側に設けた冷却媒体入口、３１はケーシング１１の反対側に設けた冷却媒体出口である。
【００１５】
なお、冷却媒体４は図１（ハ）において、流れ方向を逆にして冷却媒体出口３１から導入して冷却媒体入口３０から排出するようにしてもよく、又、１つのケーシング１１の内部に中央の仕切壁１２にて左右に別々のＣＯ除去部１０ａ，１０ｂを構成した場合を示しているが、ケーシング１１内に１つのＣＯ除去部を構成したものでもよい。
【００１６】
したがって、改質ガスＦＧがケーシング１１の入口２８から導入されると、該改質ガスＦＧはケーシング１１内の各層の触媒層１４のガス導入部１７から流量調整用多孔板２５を通って触媒充填部２４へ入る。一方、酸化空気又は酸素Ｏ₂は、ケーシング１１の外部から流路２７へと導かれた後、該流路２７を仕切る流量調整用多孔板２６を通り、上記改質ガスＦＧとともに均一に触媒充填部２４へ入り、触媒２３の存在下で主反応（ＣＯ＋1/2 Ｏ₂→ＣＯ₂）が行われることになる。この間、冷却層１５には冷却媒体４が流されているので、上記発熱反応による一酸化炭素の除去時に冷却作用を行うことができる。
【００１７】
上記において、本発明では、上述したように、ケーシング１１の長手方向に長くなるように形成したプレート型触媒層１４の反応部となる幅方向中央部分に、触媒２３を充填して触媒充填部２４として、改質ガスＦＧと酸化空気又は酸素Ｏ₂がケーシング１１の長手方向と直交する方向へ流れて触媒充填部２４を通過するようにしてあり、又、上記触媒充填部２４は、多数の仕切壁１６で小さな区画に仕切られていて、触媒充填部２４の触媒２３は厚さが薄く且つガスの流れ方向に短かくなっており、しかもガスは触媒充填部２４を全域にわたって均一に流れ、更に、触媒充填部２４は両面から冷却層１５で挟まれていて、全面にわたって均一な冷却が行われるようになっているので、ガスの流れ方向や厚み方向での温度差は小さく、且つ冷却面積は円管の場合より大きくできるので触媒全体にわたり均一に冷却を行うことができる。これにより、触媒充填部２４での反応温度を均一化することができ、図８に示したＣＯの除去率が高く且つＨ₂の除去率が低い最適値の反応温度に保つことができ、ＣＯ＋1/2 Ｏ₂→ＣＯ₂の主反応のほかに起るＨ₂＋1/2 Ｏ₂→Ｈ₂ＯやＣＯ＋３Ｈ₂→ＣＨ₄＋Ｈ₂Ｏの如き副反応が少なくなり、これに伴い酸化空気又は酸素Ｏ₂の供給量を予め少なくすることが可能となり、従来、前記したように酸化空気量論比を４．０としていたものを、酸化空気量論比を４．０以下とすることができる。
【００１８】
すなわち、図２及び図３は酸化空気量論比と出口ＣＯ濃度との関係及び酸化空気量論比と水素濃度との関係を示すもので、酸化空気の量論比を多くすると、一酸化炭素除去装置出口のＣＯ濃度は、図２に△印で示す如く低くなるが、副反応が起きて図３に▽印で示す如く一酸化炭素除去装置出口の水素濃度も低くなるという関係にある。
【００１９】
本発明では、上述した如き構成としてあることから、酸化空気又は酸素Ｏ₂の供給量を減らすことができるので、図２における一酸化炭素除去装置出口のＣＯ濃度（△印）を図上左方へシフトさせて酸化空気量論比を４．０より少くしても十分なＣＯ除去効果が得られ、同時に、出口における水素濃度は図３に破線で示す一酸化炭素除去装置入口水素濃度ａとほとんど変らずに水素消費量を少なくすることができる。これに伴い燃料電池の効率を向上させることができる。
【００２０】
本発明の一酸化炭素除去装置は、たとえば、船舶推進用燃料電池発電装置に用いるようにする。
【００２１】
図４は、船舶推進用燃料電池として固体高分子型燃料電池による発電装置を示すもので、本発明の一酸化炭素除去装置Ｉは、改質器３２で改質され、ＣＯコンバータ３３を経由した改質ガス中のＣＯを除去するようＣＯコンバータ３３の下流側に設置して用いられる。
【００２２】
固体高分子電解質型燃料電池発電装置について説明すると、固体高分子電解質膜３４を酸素極（カソード）３５と燃料極（アノード）３６の両電極で両面から挟んでなるセルをセパレータを介して積層し且つ任意のセルに冷却部３７を有してスタックとしてなる固体高分子電解質型燃料電池ＦＣの外側に、改質器３２を設置し、燃料としてのメタノールをメタノールタンク３８からメタノールポンプ３９で加圧して蒸発器４０、予熱器４１を経て改質器３２の改質室に供給するようにし、該改質器３２で改質されたガス（燃料ガス）ＦＧを、上記予熱器４１、ＣＯコンバータ３３、熱交換器４２を通した後、本発明の一酸化炭素除去装置ＩでＣＯを除去した後、熱交換器４３を経て１００℃以下にし、更に、改質ガスリザーバ４４を通し、加湿器４５を経て燃料極３６に供給するようにし、且つ該燃料極３６から排出されたアノード排ガスＡＧを、気水分離器４６で水分を除去した後、アノード排ガスライン４７により改質器３２の燃焼室に供給し燃焼させるようにすると共に、アノード排ガスＡＧの一部を、アノード排ガスライン４７より分岐したバイパスライン４８によりバイパスさせて触媒燃焼器４９に導入するようにし、更に、上記アノード排ガスライン４７とバイパスライン４８に流量調節弁５０と５１を設け、改質器３２の燃焼室の温度を検出する温度計５２からの検出温度に応じてアノード排ガス流量を調節するよう流量調節弁５０，５１をコントロールする制御部５３を設けた構成としてある。又、上記触媒燃焼器４９には、改質器３２から排出された燃焼ガスを燃焼ガスラインを通して導入するようにすると共に、排ガスタービン５４で駆動させられる圧縮機５５で圧縮された空気の一部を導入して、ここでアノード排ガス中の未反応分を燃焼させるようにし、触媒燃焼器４９へ入るバイパスライン４８からのアノード排ガス量が少ないときは、メタノールタンク３８内からメタノールの一部をポンプ５６で加圧して触媒燃焼器４９へ導入して燃焼させるようにしてある。
【００２３】
５７は蒸気発生器、５８は蒸気ライン、５９は酸素極３５への酸化剤ガスＯＧとしての空気Ａの供給ライン、６０と６１は酸素極３５から排出されたカソード排ガスＣＧを改質器３２の燃焼室に供給するラインに設けた熱交換器と気水分離器である。
【００２４】
本発明の一酸化炭素除去装置Ｉを、かかる固体高分子型燃料電池発電装置に用いる場合、改質器３２及びＣＯコンバータ３３をともにプレート型として、本発明の一酸化炭素除去装置Ｉと組み合わせて積層することができる。
【００２５】
図５はその一例として、本発明の一酸化炭素除去装置Ｉを、ＣＯコンバータ３３と改質器３２の上に重ねた場合を示すもので、改質器３２は、中央部分の反応部に改質用触媒６２を充填したプレート型の改質室６３と燃焼用触媒６４を充填した燃焼室６５とを隔壁６６を介し積層して、改質室６３を燃焼室６５で挟むようにし、改質室６３には入口側から改質原料（メタノール）と水蒸気６７供給ラインより供給すると共に、燃焼室６５には入口側から燃焼ガス６８を供給ラインより供給して、燃焼室６５で燃焼させ、燃焼により生じた熱を隔壁６６を通して改質室６３で吸熱して改質反応を行わせ、改質ガスＦＧを改質室６３出口側の改質ガスライン６９に排出させ、燃焼室６５の出口側より燃焼排ガスを排出させるようにしてある。又、ＣＯコンバータ３３は、触媒７０を充填したプレート型の変成室７１を、隔壁７２を介してプレート型の冷却室７３で両面より挟むようにして積層し、改質器３２で改質された改質ガスＦＧをＣＯコンバータ３３の変成室７１で変成して排出するようにしてある。
【００２６】
上記３つの機器をプレート型にして積層し、改質器３２の出口側とＣＯコンバータ３３の入口側とを改質ガスライン６９で接続すると共に、各冷却室７３には冷却媒体供給ライン７４より冷却媒体を供給するようにし、該ＣＯコンバータ３３の変成室７１から排出された改質ガスを改質ガスライン６９にて本発明の一酸化炭素除去装置Ｉの触媒層１４へ導入させるようにする。
【００２７】
なお、図５は一例であり、改質器３２とＣＯコンバータ３３を入れ替える等、組み合わせ方は任意である。
【００２８】
このように、本発明の一酸化炭素除去装置Ｉをプレート型の改質器３２とプレート型のＣＯコンバータ３３と積層させて一体化させることにより、コンパクト化を図ることができ、発電装置のシステム構成を簡略化することができる。
【００２９】
なお、触媒充填部２４はハニカム状にして触媒２３を担持させるようにしてもよい。ハニカム状触媒の場合、振動等によっても触媒が動きにくいので、仕切壁１６はなくすこともできる。
【００３０】
【実施例】
本発明者が行った実験結果について説明する。
【００３１】
１０ＫＷ級メタノール改質ガス中一酸化炭素除去装置において、
改質ガス流量：０．４５８Ｋmol ／Ｈ（１０．２５Ｎｍ³／Ｈ）
触媒容積：４３０cm³
発熱量（量論比４）：８６８Ｋcal ／Ｈ
酸化空気量（量論比４）：１１．４Ｎｌ／min
の条件で図６に示す従来装置を円筒体１の径を１００mm、各管２の長さを１５００mmとして実施したとき、触媒温度差は、ガス流れ方向に約５０℃、半径方向に約５０℃で、冷却媒体を入れたところが多く冷却されている。
【００３２】
これに対し、本発明の場合は、触媒層１４及び冷却層１５を積層して収納したケーシング１１の幅を４５０mm、長さを６００mm、高さを１５mmとし、冷却媒体として水と空気を用いた場合の流量Ｑと温度上昇（入口、出口の温度差）ΔＴを求めたところ、
水冷却の場合：Ｑ＝１．４４ｌ／min ΔＴ＝１０℃（量論比４．０のとき）
空気冷却の場合：Ｑ＝９６０Ｎｌ／min ΔＴ＝６０℃（量論比４．０のとき）
であった。空気冷却の場合は、ΔＴが大きいので、このΔＴを下げるためには、酸化空気量論比を４．０以下に下げる必要がある。水冷却の場合はΔＴは１０℃であるから、図８においてＣＯの除去率が高く水素の除去率が低いところの最適温度に触媒反応温度を保つことができる。
【００３３】
【発明の効果】
以上述べた如く、本発明の改質ガス中の一酸化炭素除去装置によれば、箱形ケーシングの内部に、触媒層と、該触媒層での反応温度を調整するための冷却層とを水平の隔壁を介し冷却層で触媒層を挟むように積層させてＣＯ除去部を構成し、且つ該ＣＯ除去部の触媒層の中央部分に、一酸化炭素を選択的に酸化させる触媒を、厚さを薄くして上記ケーシングの長手方向へ長くなるように充填して触媒充填部とし、該触媒充填部の片側となる上記ケーシングの幅方向一側を改質ガス及び酸化空気又は酸素の導入部とすると共に、触媒充填部の反対側となる上記ケーシングの幅方向他側を改質ガス及び酸化空気又は酸素の導出部として、上記導入部に流量調整用の多孔板を設け、改質ガス及び酸化空気又は酸素が導入部から上記多孔板を通って触媒充填部に入り、ケーシングの幅方向へ流れるようにし、更に上記ケーシングに、上記触媒層の改質ガス及び酸化空気又は酸素の導入部と導出部、冷却層の冷却媒体導入部と導出部を各々ケーシングの外部へ開口させてなる構成としてあるので、触媒の温度差が極めて少なく且つ触媒充填部は全体にわたって均一に冷却を行うことができて、反応温度の均一化を図ることができると共に、酸化空気又は酸素の供給量を少なくすることができて量論比を従来より下げることができ、これに伴い改質ガス中の水素の消費量をより少なくすることができて燃料電池の効率向上を図ることができ、又、温度分布の均一化が図れて反応の安定化が向上し、更に、酸化空気供給量の減少から圧縮機による供給動力を大幅に減少できる、等の優れた効果を奏し得られる。
【図面の簡単な説明】
【図１】本発明の一酸化炭素除去装置の実施の一形態を示すもので、（イ）は切断側面図、（ロ）は（イ）のＸ−Ｘ矢視図、（ハ）は（イ）のＹ−Ｙ矢視図である。
【図２】酸化空気量論比と一酸化炭素除去装置出口ＣＯ濃度の関係を示す図である。
【図３】酸化空気量論比と一酸化炭素除去装置出口水素濃度の関係を示す図である。
【図４】固体高分子型燃料電池発電装置の一例を示すシステム系統構成図である。
【図５】本発明の一酸化炭素除去装置をプレート型の改質器、ＣＯコンバータと積層して一体とした場合を示す概略図である。
【図６】従来の一酸化炭素除去装置の一例を示すもので、（イ）は切断側面図、（ロ）は（イ）のＺ−Ｚ矢視図である。
【図７】従来の一酸化炭素除去装置の他の例を示す断面図である。
【図８】触媒の反応温度とＣＯ、Ｈ₂の除去率の関係を示す図である。
【符号の説明】
４冷却媒体
１０ａ，１０ｂＣＯ除去部
１１ケーシング
１２中央仕切壁
１３隔壁
１４触媒層
１５冷却層
１６仕切壁
１７ガス導入部
１８ガス導出部
１９冷却媒体導入部
２０冷却媒体導出部
２３触媒
２４触媒充填部
２５流量調整用の多孔板
２６流量調整用の多孔板
３２改質器
３３ＣＯコンバータ
６３改質室
６５燃焼室
７１変成室
ＦＧ改質ガス
Ｏ_２酸化空気又は酸素[0001]
BACKGROUND OF THE INVENTION
The present invention provides a polymer electrolyte fuel cell power generation system that selectively removes carbon monoxide CO contained in a reformed gas obtained by reforming by a reformer and supplies the carbon monoxide CO to a fuel electrode of a fuel cell. Therefore, the present invention relates to a carbon monoxide removing apparatus that is provided and used in the middle of a reformed gas supply line.
[0002]
[Prior art]
In the case of a polymer electrolyte fuel cell among fuel cells, after reforming methanol as a reforming raw material gas with a reformer, the reformed gas (fuel gas) is supplied to the fuel electrode of the fuel cell. However, if carbon monoxide CO is included in the reformed gas, the fuel cell electrode is poisoned by this CO, resulting in a decrease in performance. Therefore, before supplying the reformed gas to the fuel electrode of the fuel cell, It is necessary to selectively remove CO in the reformed gas.
[0003]
Conventionally, as a carbon monoxide removal apparatus that removes CO in the reformed gas in order to satisfy such a need, the long cylindrical body 1 as shown in FIGS. A plurality of small-diameter pipes 2 extending in parallel with the axial direction of the cylindrical body 1 are disposed, and a rhodium (Rh) -based or ruthenium is used as a catalyst capable of selectively oxidizing CO over substantially the entire length inside each pipe 2. A catalyst 3 such as a (Ru) system is filled, and the outside of each pipe 2 serves as a cooling chamber 5 through which the cooling medium 4 flows, and the reformed gas FG is introduced from the inlet 2a of each pipe 2 opened to one end side of the cylindrical body 1. At the same time, oxidizing air or oxygen O ₂ is introduced, and the cooling medium 4 is introduced into the cooling chamber 5 from the other end of the cylindrical body 1 so as to be taken out from the inlet 2a side of each of the pipes 2 so that the reformed gas FG and the oxidizing air Alternatively, oxygen O ₂ is converted into CO + 1/2 O ₂ → CO ₂ by the catalyst 3 in each pipe 2. There is a catalyst in which CO in the reformed gas FG is selectively removed, and a ceramic catalyst carrier having a number of honeycomb-shaped passages 7 as shown in FIG. 6 is incorporated in the casing 8 so that the passage 7 is parallel to the longitudinal direction of the casing 8, and the catalyst 3 capable of selectively oxidizing CO is supported in powder form in the passage 7 of the catalyst carrier 6. Then, oxidized air or oxygen O ₂ is introduced from the inlet side of the casing 8 together with the reformed gas FG to cause a CO removal reaction, and the reformed gas from which the CO has been removed is supplied to the fuel electrode of the fuel cell. There are things.
[0004]
[Problems to be solved by the invention]
However, in the case of the carbon monoxide removing apparatus shown in FIG. 6, the length of each pipe 2 arranged in parallel in the cylindrical body 1 is long, so that the temperature difference of the catalyst 3 increases in the flow direction of the reformed gas. A large temperature difference also occurs in the radial direction of the cylindrical body 1, and in particular, if there is a catalyst temperature difference in the flow direction of the reformed gas, the oxidized air or oxygen O ₂ introduced from the inlet 2 a of each pipe 2 Since it does not react with carbon monoxide uniformly in the flow direction, a uniform reaction temperature cannot be achieved. As shown in FIG. 8 showing the relationship between the CO removal rate and the reaction temperature, CO and H when a rhodium (Rh) catalyst or a ruthenium (Ru) catalyst is used as a catalyst capable of selectively oxidizing CO. _{As for} the removal rate of ₂ , when the Rh-based catalyst was used, the removal rate of H ₂ increased slightly as the reaction temperature increased as indicated by ◇, but the removal rate of CO was ○ As indicated by the mark, when the temperature exceeds 200 ° C., there is a problem that the optimum temperature range is narrow, and when using a Ru-based catalyst, the CO removal rate is marked even if the reaction temperature increases. However, when the H ₂ removal rate exceeds 100 ° C. as indicated by ◆, it rapidly increases, and in this case, the optimum temperature range is narrow. When a side reaction (H ₂ +1/2 O ₂ → H ₂ O) that consumes hydrogen occurs, there is a problem that the amount of H ₂ as a fuel to the fuel electrode of the fuel cell decreases, as described above. Since a large amount of oxygen is used when a side reaction occurs, the amount of oxidized air or oxygen O ₂ to be introduced must be increased. Usually, oxygen or oxygen in the oxidized air is reduced to a theoretically necessary amount. About four times as much must be added (oxidized air stoichiometric ratio 4.0), and accordingly, there is a problem that the capacity of the compressor as a feeder must be increased. Further, cooling is performed outside the pipe 2. Therefore, if the diameter of the pipe 2 is large, a difference in catalyst temperature occurs between the center and the periphery of the pipe 2. On the other hand, if the diameter of the pipe 2 is small, the pressure loss of the gas flow increases. It becomes difficult to pack the catalyst 3, and furthermore, the difference in pressure loss between the pipes 2 arranged in parallel Flow distribution per al pipe 2 are different, there are problems such.
[0005]
Further, in the case of the carbon monoxide removing apparatus shown in FIG. 7, the reaction temperature becomes higher in the downstream in the same honeycomb-shaped passage. Therefore, when a heat exchanger is used for cooling, the honeycomb-shaped passage and the heat exchanger are alternately arranged. Therefore, there is a problem that the structure becomes complicated.
[0006]
Therefore, in the present invention, when a main reaction for selectively removing carbon monoxide in the reformed gas is performed, a side reaction (H ₂ +1/2 O ₂ → H ₂ O) in which a hydrogen consumption reaction is performed occurs. In order to reduce the consumption of hydrogen and reduce the supply amount of oxidizing air or oxygen, the stoichiometric ratio can be reduced to 4.0 or less. Is to try to be able to.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a catalyst layer and a cooling layer for adjusting a reaction temperature in the catalyst layer in a box-shaped casing, and the catalyst layer is formed by a cooling layer via a horizontal partition wall. A CO removing section is formed by stacking the sandwiched layers, and a catalyst that selectively oxidizes carbon monoxide is formed in the central portion of the catalyst layer of the CO removing section in the longitudinal direction of the casing with a reduced thickness. The catalyst filling portion is filled so as to be long, and one side in the width direction of the casing, which is one side of the catalyst filling portion, is an introduction portion for reformed gas and oxidized air or oxygen, and the opposite side of the catalyst filling portion The other side in the width direction of the casing is used as a reformed gas and oxidized air or oxygen lead-out portion, and a flow rate adjusting porous plate is provided in the introduction portion, and the reformed gas and oxidized air or oxygen are introduced from the introduction portion into the porous plate. through enters the catalyst-filled portion, the casing Further, the reformed gas and the oxidized air or oxygen introduction part and the lead-out part of the catalyst layer and the cooling medium introduction part and the lead-out part of the cooling layer are respectively opened to the outside of the casing. The configuration.
[0008]
Since the reformed gas and the oxidized air or oxygen flow through the introduction portion in the longitudinal direction of the casing and then turn in the direction perpendicular to the catalyst filling portion, the catalyst is short in the gas flow direction. The temperature difference of the catalyst is small, and both surfaces of the catalyst filling portion are cooled over the entire surface, so that uniform cooling can be achieved. Further, since the catalyst is thinned, the reaction temperature can be made uniform. As a result, the supply amount of oxidized air or oxygen can be reduced, the stoichiometric ratio can be lowered, and the consumption of hydrogen in the reformed gas is reduced.
[0009]
In addition, a plurality of CO removal units are configured by partitioning in the width direction in the casing, and each reformed gas and oxidized air or oxygen introduction unit and each derived unit of each CO removal unit communicate with each other, and each cooling unit Carbon monoxide can be efficiently removed by adopting a configuration in which the inlet sides and the outlet sides of the layers are communicated with each other.
[0010]
Furthermore, configuration in which the partition so that the catalyst-packed portion in a number of partition walls extending in a direction orthogonal to the longitudinal direction of the casing so as to define a large number of small spaces in the catalyst filled portion of the CO removal unit in the longitudinal direction of the casing Then, the catalyst can be packed as a small block and the flow of the reformed gas can be made uniform.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
1 (a), (b), and (c), as one embodiment of the present invention, plate-type CO removing sections 10a and 10b are separately formed in one box-shaped casing 11, and one end of the casing 11 is formed. The reformed gas FG and oxidized air or oxygen O ₂ introduced from the side are simultaneously caused to flow through two CO removing sections 10a and 10b to remove carbon monoxide CO in the reformed gas FG.
[0013]
More specifically, a central partition wall 12 is provided at the center of the box-shaped casing 11 to divide it left and right, and horizontal partitions 13 are arranged in multiple stages symmetrically across the center partition wall 12. Then, every other plate type catalyst layer 14 for filling the inside of the catalyst and a plate type cooling layer 15 for allowing a cooling medium to flow in order to adjust the reaction temperature in the catalyst layer 14 are laminated. Thus, the catalyst layer 14 is sandwiched between the cooling layers 15 from both sides, and the partition walls 16 extending in the left-right direction only at the central portions of the catalyst layers 14 and the cooling layers 15 are provided at a necessary interval. To form a large number of small spaces, and one side of the small space forming portion at the central portion of the catalyst layer 14 is a gas introducing portion 17 along the longitudinal direction of the casing 11, and the opposite side is a gas outlet portion. 18 and similarly, the cooling layer 15 central portion One side of the small space forming part is a cooling medium introduction part 19 and the other side is a cooling medium lead-out part 20, and the gas of each catalyst layer 14 is formed at one end side of the casing 11 serving as an inlet side of the gas or the cooling medium. Only the introduction part 17 and the cooling medium introduction part 19 of each cooling layer 15 are left closed by the closing plate 21, and on the opposite side of the casing 11, the gas introduction part 17 of each catalyst layer 14 and the cooling medium of each cooling layer 15. Each small space formed between the adjacent partition walls 16 of the catalyst layer 14 or between the partition walls 16 at both ends and the closing plates 21 and 22 is closed by the closing plate 22 except for the introduction portion 19. The catalyst filling unit 24 is formed by reducing the thickness of the catalyst 23 that can selectively oxidize carbon monoxide, thereby forming the left and right CO removing units 10a and 10b.
[0014]
25 is a perforated plate for adjusting the gas flow rate provided on the gas introduction part 17 side of the catalyst filling part 24, and 26 is a gas in the catalyst layer 14 in order to allow the oxidant air or oxygen O ₂ to flow uniformly in each small space. A perforated plate for adjusting the flow rate provided in the introduction portion 17, and a flow path 27 formed between the perforated plate 26 and the inner wall or the central partition wall 12 of the casing 11 oxidizes air or oxygen O from the outside of the casing 11. ₂ can be supplied. Reference numeral 28 denotes a reformed gas inlet provided in the casing 11 corresponding to each catalyst layer 14 so as to guide the reformed gas FG to the gas introduction section 17 of each catalyst layer 14 of the two CO removing sections 10a and 10b. 29 is a reformed gas outlet provided on the opposite side of the casing 11 so as to correspond to each catalyst layer 14, and 30 is a cooling medium inlet provided on one end side of the casing 11 for introducing the cooling medium 4 into each cooling layer 15. Reference numeral 31 denotes a cooling medium outlet provided on the opposite side of the casing 11.
[0015]
Note that the cooling medium 4 may be introduced from the cooling medium outlet 31 and discharged from the cooling medium inlet 30 with the flow direction reversed in FIG. Although the case where separate CO removing units 10a and 10b are configured on the left and right sides of the partition wall 12 is shown, one CO removing unit may be configured in the casing 11.
[0016]
Therefore, when the reformed gas FG is introduced from the inlet 28 of the casing 11, the reformed gas FG is filled with the catalyst from the gas introduction portion 17 of the catalyst layer 14 of each layer in the casing 11 through the perforated plate 25 for flow rate adjustment. Enter part 24. On the other hand, the oxidized air or oxygen O ₂ is led from the outside of the casing 11 to the flow path 27, and then passes through the flow rate adjusting porous plate 26 that partitions the flow path 27, and is uniformly charged with the reformed gas FG. The main reaction (CO + 1/2 O ₂ → CO ₂ ) is performed in the presence of the catalyst 23. During this time, since the cooling medium 4 is flowing through the cooling layer 15, a cooling action can be performed when carbon monoxide is removed by the exothermic reaction.
[0017]
In the above, in the present invention, as described above, the catalyst 23 is filled by filling the catalyst 23 in the central portion in the width direction which becomes the reaction portion of the plate-type catalyst layer 14 formed to be long in the longitudinal direction of the casing 11. As described above, the reformed gas FG and oxidized air or oxygen O ₂ flow in a direction perpendicular to the longitudinal direction of the casing 11 and pass through the catalyst filling portion 24. The catalyst filling portion 24 includes a number of partitions. The catalyst is divided into small sections by the wall 16, the catalyst 23 of the catalyst filling portion 24 is thin and short in the gas flow direction, and the gas flows uniformly through the catalyst filling portion 24 over the entire area. The catalyst filling unit 24 is sandwiched between the cooling layers 15 from both sides, so that uniform cooling is performed over the entire surface. Therefore, the temperature difference in the gas flow direction and the thickness direction is small, and the cooling is performed. Since the area can be larger than in the case of a circular pipe can be uniformly cooled throughout catalyst. As a result, the reaction temperature in the catalyst filling unit 24 can be made uniform, the CO removal rate shown in FIG. 8 can be kept high, and the H ₂ removal rate can be kept at the optimum reaction temperature, so that CO + 1 / 2 O ₂ → CO ₂ in addition to the main reaction H ₂ +1/2 O ₂ → H ₂ O and CO + 3H ₂ → CH ₄ + H ₂ O, and side reactions such as oxidation air or oxygen It is possible to reduce the supply amount of O ₂ in advance, and it is possible to reduce the oxidative air stoichiometric ratio to 4.0 or less from the conventional oxidative air stoichiometric ratio of 4.0 as described above.
[0018]
That is, FIGS. 2 and 3 show the relationship between the oxidized air stoichiometric ratio and the outlet CO concentration and the relationship between the oxidized air stoichiometric ratio and the hydrogen concentration. When the stoichiometric ratio of oxidized air is increased, carbon monoxide is increased. The CO concentration at the outlet of the removing device is low as indicated by Δ in FIG. 2, but the side reaction occurs, and the hydrogen concentration at the outlet of the carbon monoxide removing device is also reduced as indicated by ▽ in FIG.
[0019]
In the present invention, since it is configured as described above, the supply amount of oxidized air or oxygen O ₂ can be reduced. Therefore, the CO concentration (Δ mark) at the outlet of the carbon monoxide removal apparatus in FIG. Even if the stoichiometric ratio is reduced to less than 4.0, a sufficient CO removal effect can be obtained. At the same time, the hydrogen concentration at the outlet is the same as the hydrogen concentration a at the inlet of the carbon monoxide removal apparatus indicated by the broken line in FIG. Hydrogen consumption can be reduced with almost no change. Accordingly, the efficiency of the fuel cell can be improved.
[0020]
The carbon monoxide removal apparatus of the present invention is used for, for example, a marine propulsion fuel cell power generation apparatus.
[0021]
FIG. 4 shows a power generation apparatus using a polymer electrolyte fuel cell as a marine propulsion fuel cell. The carbon monoxide removal apparatus I of the present invention is reformed by a reformer 32 and passes through a CO converter 33. It is installed and used on the downstream side of the CO converter 33 so as to remove CO in the reformed gas.
[0022]
A solid polymer electrolyte fuel cell power generator will be described. A cell in which a solid polymer electrolyte membrane 34 is sandwiched between both electrodes of an oxygen electrode (cathode) 35 and a fuel electrode (anode) 36 is laminated via a separator. In addition, a reformer 32 is installed outside a solid polymer electrolyte fuel cell FC having a cooling unit 37 in an arbitrary cell as a stack, and methanol as fuel is pressurized from a methanol tank 38 by a methanol pump 39. Then, the gas is supplied to the reforming chamber of the reformer 32 through the evaporator 40 and the preheater 41, and the gas (fuel gas) FG reformed by the reformer 32 is supplied to the preheater 41 and the CO converter 33. Then, after passing through the heat exchanger 42, CO is removed by the carbon monoxide removing apparatus I of the present invention, then the temperature is reduced to 100 ° C. or less through the heat exchanger 43, and further, the reformed gas reservoir 44 is passed through. Then, the anode exhaust gas AG discharged from the fuel electrode 36 is supplied to the fuel electrode 36 and the moisture is removed by the steam separator 46. Then, the anode exhaust gas line 47 combusts the reformer 32. A portion of the anode exhaust gas AG is bypassed by a bypass line 48 branched from the anode exhaust gas line 47 and introduced into the catalyst combustor 49, and the anode exhaust gas line 47 is further combusted. The flow rate adjusting valves 50 and 51 are provided in the bypass line 48, and the flow rate adjusting valves 50 and 51 are adjusted so as to adjust the anode exhaust gas flow rate according to the detected temperature from the thermometer 52 that detects the temperature of the combustion chamber of the reformer 32. A control unit 53 for control is provided. Further, the combustion gas discharged from the reformer 32 is introduced into the catalytic combustor 49 through the combustion gas line, and a part of the air compressed by the compressor 55 driven by the exhaust gas turbine 54 is introduced. Here, unreacted components in the anode exhaust gas are burned, and when the amount of anode exhaust gas from the bypass line 48 entering the catalyst combustor 49 is small, a part of methanol is pumped from the methanol tank 38. The pressure is applied at 56 and introduced into the catalytic combustor 49 for combustion.
[0023]
57 is a steam generator, 58 is a steam line, 59 is a supply line of air A as oxidant gas OG to the oxygen electrode 35, and 60 and 61 are cathode exhaust gas CG discharged from the oxygen electrode 35 of the reformer 32. It is a heat exchanger and a steam separator provided in the line supplied to the combustion chamber.
[0024]
When the carbon monoxide removal apparatus I of the present invention is used in such a polymer electrolyte fuel cell power generation apparatus, the reformer 32 and the CO converter 33 are both plate-shaped and combined with the carbon monoxide removal apparatus I of the present invention. Can be stacked.
[0025]
FIG. 5 shows, as an example, a case where the carbon monoxide removal apparatus I of the present invention is overlaid on a CO converter 33 and a reformer 32. The reformer 32 is modified to a reaction part in the center portion. The plate-type reforming chamber 63 filled with the quality catalyst 62 and the combustion chamber 65 filled with the combustion catalyst 64 are stacked via the partition wall 66 so that the reforming chamber 63 is sandwiched by the combustion chamber 65, and reforming is performed. The reforming material (methanol) and water vapor 67 are supplied to the chamber 63 from the inlet side, and the combustion gas 68 is supplied from the inlet side to the combustion chamber 65 from the supply line. The heat generated by the heat is absorbed in the reforming chamber 63 through the partition wall 66 to cause a reforming reaction, the reformed gas FG is discharged to the reformed gas line 69 on the outlet side of the reforming chamber 63, and the outlet side of the combustion chamber 65 More exhaust gas of combustion is discharged. The CO converter 33 also stacks the plate-type shift chamber 71 filled with the catalyst 70 so as to be sandwiched from both sides by the plate-type cooling chamber 73 via the partition wall 72, and the reformer reformed by the reformer 32. The gas FG is transformed in the transformation chamber 71 of the CO converter 33 and discharged.
[0026]
The above three devices are stacked in a plate shape, the outlet side of the reformer 32 and the inlet side of the CO converter 33 are connected by a reformed gas line 69, and each cooling chamber 73 is connected to a cooling medium supply line 74. A cooling medium is supplied, and the reformed gas discharged from the shift chamber 71 of the CO converter 33 is introduced into the catalyst layer 14 of the carbon monoxide removal apparatus I of the present invention through the reformed gas line 69. .
[0027]
Note that FIG. 5 is an example, and the combination method is arbitrary, such as replacing the reformer 32 and the CO converter 33.
[0028]
Thus, the carbon monoxide removal apparatus I of the present invention can be made compact by stacking and integrating the plate-type reformer 32 and the plate-type CO converter 33, and the system of the power generation apparatus The configuration can be simplified.
[0029]
The catalyst filling portion 24 may be formed in a honeycomb shape to carry the catalyst 23. In the case of a honeycomb catalyst, the partition wall 16 can be eliminated because the catalyst is difficult to move due to vibration or the like.
[0030]
【Example】
The results of experiments conducted by the inventor will be described.
[0031]
In the carbon monoxide removal apparatus in 10KW class methanol reformed gas,
Reforming gas flow rate: 0.458 Kmol / H (10.25 Nm ³ / H)
Catalyst volume: 430cm ³
Calorific value (stoichiometric ratio 4): 868 Kcal / H
Oxidized air volume (4 stoichiometric ratio): 11.4 Nl / min
6 is carried out with the diameter of the cylindrical body 1 being 100 mm and the length of each tube 2 being 1500 mm, the catalyst temperature difference is about 50 ° C. in the gas flow direction and about 50 ° C. in the radial direction. And many places where the cooling medium is put are cooled.
[0032]
On the other hand, in the case of the present invention, the casing 11 in which the catalyst layer 14 and the cooling layer 15 are stacked and accommodated has a width of 450 mm, a length of 600 mm, and a height of 15 mm, and water and air are used as the cooling medium. When the flow rate Q and temperature rise (temperature difference between the inlet and outlet) ΔT were obtained,
In the case of water cooling: Q = 1.44 l / min ΔT = 10 ° C. (when the stoichiometric ratio is 4.0)
In the case of air cooling: Q = 960 Nl / min ΔT = 60 ° C. (when the stoichiometric ratio is 4.0)
Met. In the case of air cooling, since ΔT is large, to reduce this ΔT, it is necessary to lower the oxidative air stoichiometric ratio to 4.0 or less. In the case of water cooling, ΔT is 10 ° C., so that the catalyst reaction temperature can be maintained at the optimum temperature at which the CO removal rate is high and the hydrogen removal rate is low in FIG.
[0033]
【The invention's effect】
As described above, according to the apparatus for removing carbon monoxide in the reformed gas of the present invention , the catalyst layer and the cooling layer for adjusting the reaction temperature in the catalyst layer are horizontally disposed inside the box-shaped casing. A catalyst removal layer is formed by laminating a catalyst layer with a cooling layer interposed between the partition walls of the catalyst, and a CO removal portion is configured, and a catalyst that selectively oxidizes carbon monoxide is formed in the central portion of the catalyst layer of the CO removal portion. The catalyst filling portion is formed by thinning and filling the casing so as to be longer in the longitudinal direction of the casing, and one side in the width direction of the casing, which is one side of the catalyst filling portion, is an introduction portion of reformed gas and oxidized air or oxygen. In addition, the other side in the width direction of the casing, which is the opposite side of the catalyst filling part, is used as a reforming gas and oxidizing air or oxygen outlet part, and a perforated plate for adjusting the flow rate is provided in the introducing part, so that the reforming gas and oxidation are provided. Air or oxygen touches through the perforated plate from the inlet. It enters the filling part and flows in the width direction of the casing, and the casing is further provided with a reformed gas and oxidized air or oxygen introducing part and a leading part for the catalyst layer, and a cooling medium introducing part and a leading part for the cooling layer, respectively. since then opens into the casing of the outer are a structure comprising very small and the catalyst packed portion temperature difference of the catalyst is able to perform uniform cooling throughout, it is possible to achieve uniform reaction temperature The amount of oxidized air or oxygen can be reduced, the stoichiometric ratio can be lowered, and the consumption of hydrogen in the reformed gas can be reduced accordingly. Excellent effects such as the ability to improve the temperature distribution, improve the stability of the reaction by improving the temperature distribution, and greatly reduce the supply power from the compressor due to the decrease in the supply amount of oxidized air Play The resulting Ru.
[Brief description of the drawings]
FIG. 1 shows an embodiment of a carbon monoxide removing apparatus of the present invention, where (A) is a cut side view, (B) is a view taken along the line XX of (A), and (C) is ( It is a YY arrow line view of a).
FIG. 2 is a diagram showing the relationship between the oxidative air stoichiometric ratio and the carbon monoxide removal device outlet CO concentration.
FIG. 3 is a graph showing the relationship between the oxidative air stoichiometric ratio and the carbon monoxide removal device outlet hydrogen concentration.
FIG. 4 is a system configuration diagram showing an example of a polymer electrolyte fuel cell power generator.
FIG. 5 is a schematic view showing a case where the carbon monoxide removing apparatus of the present invention is laminated and integrated with a plate type reformer and a CO converter.
FIGS. 6A and 6B show an example of a conventional carbon monoxide removal apparatus, where FIG. 6A is a cut side view, and FIG. 6B is a view taken along the line ZZ of FIG.
FIG. 7 is a cross-sectional view showing another example of a conventional carbon monoxide removing apparatus.
FIG. 8 is a graph showing the relationship between the reaction temperature of the catalyst and the removal rate of CO and H ₂ .
[Explanation of symbols]
4 Cooling medium 10a, 10b CO removing section 11 Casing 12 Central partition wall 13 Partition wall 14 Catalyst layer 15 Cooling layer 16 Partition wall 17 Gas introducing section 18 Gas outlet section 19 Cooling medium introducing section 20 Cooling medium outlet section 23 Catalyst 24 Catalyst filling section
25 Perforated plate for flow rate adjustment
26 flow rate adjustment of the porous plate 32 reformer 33 CO converter 63 reforming chamber 65 combustion chamber 71 transformer chamber FG reformed gas O ₂ oxidation air or oxygen

Claims

A CO removal unit is configured by laminating a catalyst layer and a cooling layer for adjusting a reaction temperature in the catalyst layer inside a box-shaped casing so that the catalyst layer is sandwiched between cooling layers through horizontal partition walls. In addition, a catalyst that selectively oxidizes carbon monoxide in the central portion of the catalyst layer of the CO removal unit is filled so as to be thin in the longitudinal direction of the casing to be a catalyst filling unit, One side in the width direction of the casing, which is one side of the catalyst filling portion, is used as a reformed gas and oxidized air or oxygen introduction portion, and the other side in the width direction of the casing, which is the opposite side of the catalyst filling portion, is a reformed gas. As a lead-out portion for the oxidized air or oxygen, a porous plate for adjusting the flow rate is provided in the introduction portion, and the reformed gas and the oxidized air or oxygen enter the catalyst filling portion through the porous plate from the introduction portion, and the width of the casing. In the direction of the The reformed gas is characterized in that the reformed gas and the oxidized air or oxygen introducing section and the leading section of the catalyst layer and the cooling medium introducing section and the leading section of the cooling layer are respectively opened to the outside of the casing. Carbon monoxide removal device inside.

A plurality of CO removal units are configured by partitioning in the width direction in the casing, each reformed gas of each CO removal unit and each of the introduction portions and outflow portions of oxidized air or oxygen communicate with each other, and each cooling layer The apparatus for removing carbon monoxide in the reformed gas according to claim 1, wherein the inlet sides and the outlet sides communicate with each other.

Claim to the catalyst packed portion to the partition so that a number of partition walls in the catalyst packed portion of the CO removal unit extending in a direction perpendicular to the longitudinal direction of the casing so as to define a plurality of small spaces in the longitudinal direction of the casing 1 Or the carbon monoxide removal apparatus in the reformed gas of 2.

The carbon monoxide removal apparatus in the reformed gas according to claim 1, 2 or 3, wherein a plurality of layers are formed by laminating the catalyst layer of the CO removal unit so as to be sandwiched between cooling layers.