JP2003331898A - Fuel cell system - Google Patents
Fuel cell systemInfo
- Publication number
- JP2003331898A JP2003331898A JP2002140671A JP2002140671A JP2003331898A JP 2003331898 A JP2003331898 A JP 2003331898A JP 2002140671 A JP2002140671 A JP 2002140671A JP 2002140671 A JP2002140671 A JP 2002140671A JP 2003331898 A JP2003331898 A JP 2003331898A
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- reforming catalyst
- fuel cell
- ammonia
- cell system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Fuel Cell (AREA)
- Hydrogen, Water And Hydrids (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、窒素ガスを含む炭
化水素系燃料を水蒸気改質反応により水素リッチな燃料
ガスに改質させ、改質させた水素ガスに酸素ガスを反応
させて発電を行う燃料電池システムに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reforms a hydrocarbon-based fuel containing nitrogen gas into a hydrogen-rich fuel gas by a steam reforming reaction and reacts the reformed hydrogen gas with oxygen gas to generate electricity. The present invention relates to a fuel cell system.
【0002】[0002]
【従来の技術】最近の燃料電池、例えば固体高分子型燃
料電池は、形状がコンパクトであり、電気出力が高出力
密度であり、さらにシステムを簡素化させて運転を容易
にしているので、分散型の家庭住宅用電源システムとし
て、将来有望視されている。2. Description of the Related Art Recent fuel cells, such as polymer electrolyte fuel cells, have a compact shape, a high power output density, and a simplified system for easy operation. Is expected to be a promising future power supply system for homes and homes.
【0003】この燃料電池は、都市ガス等の原燃料を水
素リッチな燃料ガスに改質させる燃料処理系と、改質燃
料に酸素ガスを反応させて発電を行う電池本体とを備え
た構成になっている。This fuel cell has a structure including a fuel processing system for reforming a raw fuel such as city gas into a hydrogen-rich fuel gas, and a cell body for reacting oxygen gas with the reformed fuel to generate electricity. Has become.
【0004】電池本体は、固体高分子膜を介して燃料極
と酸化剤極とを備え、燃料極に原燃料から改質した水素
リッチな燃料ガスを、酸化剤極に空気をそれぞれ供給
し、さらに燃料ガスのうち、プロトン(H+)のみを固
体高分子膜を介して酸化剤極に通過させ、ここで化学反
応を行わせる際に発生する起電力を取り出し、この直流
電力を家庭等に供給するようになっている。The cell body is provided with a fuel electrode and an oxidant electrode through a solid polymer membrane, and hydrogen-rich fuel gas reformed from raw fuel is supplied to the fuel electrode and air is supplied to the oxidant electrode. Further, of the fuel gas, only protons (H + ) are passed through the solid polymer membrane to the oxidizer electrode, and the electromotive force generated when the chemical reaction is performed is taken out. It is supposed to be supplied.
【0005】[0005]
【発明が解決しようとする課題】ところで、原燃料とし
て用いられる炭化水素系燃料ガスには、窒素ガスを20
%程度含むものがある。例えば、原燃料として都市ガス
を用いる場合、都市ガス6B、6Cには、約10〜20
%の窒素が含まれている。By the way, as the hydrocarbon fuel gas used as a raw fuel, nitrogen gas is used.
Some include about%. For example, when city gas is used as a raw fuel, the city gas 6B and 6C contains about 10 to 20
Contains% nitrogen.
【0006】このように、比較的多くの窒素が水素リッ
チなガス中に存在すると、改質触媒層でアンモニアが生
成される。このアンモニアは、電池本体の燃料極に装着
された触媒を被毒させ、電池性能を著しく低下させる要
因になっている。As described above, when a relatively large amount of nitrogen is present in the hydrogen-rich gas, ammonia is produced in the reforming catalyst layer. This ammonia poisons the catalyst attached to the fuel electrode of the cell body and is a factor that significantly reduces cell performance.
【0007】このため、燃料極の入口側には、アンモニ
ア除去装置を設け、生成されたアンモニアを除去してい
る。しかし、充分に取り除くことができず、長年の使用
の結果、触媒の活性を著しく低下させており、何らかの
新たな改善が求められていた。For this reason, an ammonia removing device is provided on the inlet side of the fuel electrode to remove the produced ammonia. However, it could not be removed sufficiently, and as a result of long-term use, the activity of the catalyst was remarkably reduced, and some new improvement was required.
【0008】本発明は、このような事情に基づいてなさ
れたもので、電池本体を被毒させる要因となるアンモニ
アの生成を抑制し、長時間に亘って電池効率の高い、安
定運転を行わせる燃料電池システムを提供することを目
的とする。The present invention has been made under such circumstances, and suppresses the production of ammonia, which causes poisoning of the battery main body, and enables stable operation with high battery efficiency for a long time. An object is to provide a fuel cell system.
【0009】[0009]
【課題を解決するための手段】本発明に係る燃料電池シ
ステムは、上述の目的を達成するために、請求項1に記
載したように、窒素を含む炭化水素系燃料を水蒸気改質
反応により水素リッチな燃料ガスに改質する燃料処理系
と、水素リッチに改質した燃料ガスと空気中の酸素を電
気化学的に反応させ、その際に発生する電力を取り出す
電池本体とを備えた燃料電池システムにおいて、前記燃
料処理系の改質器に、改質触媒層を2層にして充填する
とともに、運転中の温度が250℃〜600℃以下とな
る燃料ガスの供給口側を1層目としてアンモニア生成の
活性の低い改質触媒を充填し、運転中の温度が550℃
〜750℃以上となる燃料ガスの出口側を2層目として
アンモニア分解性能の高い改質触媒層を充填したもので
ある。In order to achieve the above-mentioned object, a fuel cell system according to the present invention, as set forth in claim 1, hydrogenates a hydrocarbon fuel containing nitrogen by a steam reforming reaction. A fuel cell provided with a fuel processing system for reforming into a rich fuel gas, and a cell body for electrochemically reacting the fuel gas reformed into a hydrogen-rich gas with oxygen in the air and taking out electric power generated at that time In the system, the reformer of the fuel processing system is filled with the reforming catalyst layer in two layers, and the first side is the fuel gas supply port side where the temperature during operation is 250 ° C. to 600 ° C. or less. It is filled with a reforming catalyst with low activity of ammonia generation, and the temperature during operation is 550 ° C.
The outlet side of the fuel gas having a temperature of ˜750 ° C. or higher is used as the second layer, and the reforming catalyst layer having high ammonia decomposition performance is filled.
【0010】また、本発明に係る燃料電池システムは、
上述の目的を達成するために、請求項2に記載したよう
に、アンモニア生成の活性の低い改質触媒は、ニッケル
系改質触媒であることを特徴とするものである。Further, the fuel cell system according to the present invention is
In order to achieve the above-mentioned object, as described in claim 2, the reforming catalyst having a low activity of producing ammonia is a nickel-based reforming catalyst.
【0011】また、本発明に係る燃料電池システムは、
上述の目的を達成するために、請求項3に記載したよう
に、アンモニア生成の活性の低い改質触媒は、ロジウム
系改質触媒であることを特徴とするものである。Further, the fuel cell system according to the present invention is
In order to achieve the above-mentioned object, as described in claim 3, the reforming catalyst having a low activity of producing ammonia is a rhodium-based reforming catalyst.
【0012】また、本発明に係る燃料電池システムは、
上述の目的を達成するために、請求項4に記載したよう
に、アンモニア分解性能の高い改質触媒は、ルテニウム
系改質触媒であることを特徴とするものである。Further, the fuel cell system according to the present invention is
In order to achieve the above object, as described in claim 4, the reforming catalyst having high ammonia decomposing performance is a ruthenium-based reforming catalyst.
【0013】[0013]
【発明の実施の形態】以下、本発明に係る燃料電池シス
テムの実施形態を図面および図面に付した符号を引用し
て説明する。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a fuel cell system according to the present invention will be described below with reference to the drawings and the reference numerals attached to the drawings.
【0014】図1は、本発明に係る燃料電池システムの
概略全体を示す系統図である。FIG. 1 is a system diagram showing an overall outline of a fuel cell system according to the present invention.
【0015】なお、本発明に係る燃料電池システムは、
燃料電池本体に、例示として固体高分子型燃料電池を使
用している。The fuel cell system according to the present invention is
A polymer electrolyte fuel cell is used as an example of the fuel cell body.
【0016】本実施形態に係る燃料電池システム21
は、大別して燃料処理系(FPS;Furl Proc
essing System)1と電池本体(CSA;
Cell Stack Assembly)2とを備え
て構成されている。The fuel cell system 21 according to this embodiment
Are roughly divided into Fuel Processing Systems (FPS; Furl Proc)
essing System 1 and battery body (CSA;
Cell Stack Assembly 2).
【0017】燃料処理系1は、原燃料Fの流に沿って順
に、燃料部3、脱硫器4、改質器6、改質器6に一体と
して組み込まれた燃焼部5aおよび水蒸気発生部5b、
COシフト反応器7、CO選択酸化器8、水蒸気分離器
9、改質用水タンク10、改質用水ポンプ11、排熱熱
交換器12、排熱供給水ポンプ13等を備えている。The fuel processing system 1 includes a fuel section 3, a desulfurizer 4, a reformer 6, a combustion section 5a integrally incorporated in the reformer 6 and a steam generating section 5b in order along the flow of the raw fuel F. ,
A CO shift reactor 7, a CO selective oxidizer 8, a steam separator 9, a reforming water tank 10, a reforming water pump 11, an exhaust heat heat exchanger 12, an exhaust heat supply water pump 13 and the like are provided.
【0018】なお、燃料部3から脱硫器4に供給される
原燃料Fは、炭化水素系燃料、例えば都市ガス、プロパ
ン、あるいはガス化した灯油等が適宜、選択して用いら
れる。As the raw fuel F supplied from the fuel section 3 to the desulfurizer 4, a hydrocarbon fuel such as city gas, propane, or gasified kerosene is appropriately selected and used.
【0019】一方、電池本体2は、アノード14、カソ
ード15、水冷却部16、電池冷却水ポンプ17等を備
えている。On the other hand, the battery main body 2 includes an anode 14, a cathode 15, a water cooling unit 16, a battery cooling water pump 17, and the like.
【0020】また、燃料処理系1および電池本体2に共
通な構成部品には、空気ブロア18、凝縮熱交換器19
等が設けられている。The components common to the fuel processing system 1 and the cell body 2 include an air blower 18 and a condensing heat exchanger 19.
Etc. are provided.
【0021】このような構成を備える固体高分子型燃料
電池の発電原理を簡単に説明する。The power generation principle of the polymer electrolyte fuel cell having such a structure will be briefly described.
【0022】プロパンまたは都市ガス等の原燃料Fのう
ち、例えばプロパンを選択する場合、プロパンから水素
ガスへの改質は、燃料処理系1で行われる。When, for example, propane is selected from the raw fuel F such as propane or city gas, the reforming of propane to hydrogen gas is performed in the fuel processing system 1.
【0023】まず、プロパンを選択する原燃料Fは、脱
硫器4を通る際、容器内に収容されている、例えば活性
炭やゼオライト吸着により硫黄分が取り除かれ、水蒸気
分離器9から分離されるガス状の水蒸気と合流して改質
器6に供給される。First, when the raw fuel F for selecting propane passes through the desulfurizer 4, the sulfur content is removed from the water vapor separator 9 contained in the container, for example, by activated carbon or zeolite adsorption. It is supplied to the reformer 6 by merging with the steam.
【0024】この水蒸気分離器9は、改質用水タンク1
0から改質用水ポンプ11および水供給系11aを介し
て供給される水を水蒸気発生部5bで加熱させ、ガス状
の水蒸気にして改質器6に供給し、ここで原燃料Fに合
流させるようになっている。なお、水蒸気分離器9は、
ガス状の水蒸気から分離するドレン水を水回収系11b
を介して改質用水タンク10に回収させている。This steam separator 9 is used in the reforming water tank 1
Water supplied from 0 through the reforming water pump 11 and the water supply system 11a is heated in the steam generation unit 5b to be converted into gaseous steam, which is supplied to the reformer 6 where it is merged with the raw fuel F. It is like this. The steam separator 9 is
Drain water separated from gaseous water vapor is used as a water recovery system 11b.
It is collected in the reforming water tank 10 via the.
【0025】一方、改質器6では、供給される原燃料
(プロパン)Fと水蒸気とで改質触媒により水蒸気改質
反応が行われ、水素ガスのほかにCOやCO2等も生成
される。その際、水蒸気改質は吸熱反応となる。このた
め、改質器6は、水蒸気発生部5bとともに熱源を確保
する燃焼部5aを一つの容器の内に組み込んでいる。On the other hand, in the reformer 6, the reforming catalyst causes a steam reforming reaction of the supplied raw fuel (propane) F and steam to produce CO, CO 2 and the like in addition to hydrogen gas. . At that time, the steam reforming becomes an endothermic reaction. For this reason, the reformer 6 incorporates the steam generation section 5b and the combustion section 5a that secures a heat source in one container.
【0026】ところで、固体高分子型燃料電池は、アノ
ード14に供給される燃料ガスの改質CO濃度が高い
と、電池本体2の一部を構成する電解質膜および触媒層
等からなる膜電極接合体(MEA;Membrane
Electrode Assembly、以下MEAと
記す)(図示せず)が被毒し、活性が低下し、電池性能
を著しく低下させる等の悪影響が出る。このため、CO
は事前にCO2に酸化させる必要がある。By the way, in the polymer electrolyte fuel cell, when the reforming CO concentration of the fuel gas supplied to the anode 14 is high, a membrane electrode assembly composed of an electrolyte membrane and a catalyst layer forming a part of the cell body 2 is joined. Body (MEA; Membrane
Electrode Assembly (hereinafter referred to as MEA) (not shown) is poisoned, its activity is reduced, and battery performance is significantly deteriorated. Therefore, CO
Needs to be previously oxidized to CO 2 .
【0027】本実施形態は、このような点を考慮したも
ので、改質器6の下流側にCOシフト反応器7とCO選
択酸化器8を備えるとともに、CO選択酸化器8に空気
ブロア18からの空気を供給し、改質器6で生成される
改質ガスのうち、COがCOシフト反応器7およびCO
選択酸化器8を流れる間に触媒とともに酸化促進させる
ようにしている。In the present embodiment, in consideration of such a point, the CO shift reactor 7 and the CO selective oxidizer 8 are provided on the downstream side of the reformer 6, and the air blower 18 is provided in the CO selective oxidizer 8. Of the reformed gas produced in the reformer 6 by supplying air from the CO 2 to the CO shift reactor 7 and CO.
While flowing through the selective oxidizer 8, the oxidation is promoted together with the catalyst.
【0028】また、図示しないが、改質器6、CO選択
酸化器8の触媒反応温度は、それぞれ異なり、改質器6
の数百度からCO選択酸化器8の百数十度と、改質ガス
の上流と下流の温度差が大きいため、実際には下流側温
度を下げるための水熱交換器が必要となり、例えば、C
Oシフト反応器7とCO選択酸化器8との間に水熱交換
器を設ける構成にしてもよい。Although not shown, the catalytic reaction temperatures of the reformer 6 and the CO selective oxidizer 8 are different from each other and are different from each other.
Since the temperature difference between the upstream side and the downstream side of the reformed gas is large, from several hundred degrees to several hundred degrees of the CO selective oxidizer 8, a water heat exchanger for lowering the downstream temperature is actually required. C
A water heat exchanger may be provided between the O shift reactor 7 and the CO selective oxidizer 8.
【0029】また、例えば、原燃料Fのプロパンを改質
させる場合、COからCO2への酸化反応を省略し、全
体をスルーする水蒸気改質は、以下の(1)式による。Further, for example, when propane of the raw fuel F is reformed, steam reforming by omitting the oxidation reaction of CO to CO 2 and passing through the whole is according to the following equation (1).
【0030】[0030]
【化1】 [Chemical 1]
【0031】また、CO選択酸化器8を通過する改質ガ
スは、主として水素、炭酸ガス、水蒸気等の成分からな
る。これらのガスが電池本体2のアノード14に供給さ
れると、水素ガスは膜電極接合体MEAの触媒層(図示
せず)を経てプロトンH+が電解質膜(図示せず)を流
れ、空気ブロア18からカソード15に流れる空気中の
酸素および電子と結び付いて水を生成する。The reformed gas passing through the CO selective oxidizer 8 is mainly composed of components such as hydrogen, carbon dioxide and steam. When these gases are supplied to the anode 14 of the battery main body 2, hydrogen gas passes through the catalyst layer (not shown) of the membrane electrode assembly MEA, the protons H + flow through the electrolyte membrane (not shown), and the air blower. It combines with oxygen and electrons in the air flowing from 18 to the cathode 15 to generate water.
【0032】したがって、アノード14はマイナス
(−)極、カソード15はプラス(+)極になり、電位
を持って直流電力を発電する。この電位間に電気負荷を
存在させると、電源としての機能を持たせることができ
る。Therefore, the anode 14 becomes a minus (-) pole and the cathode 15 becomes a plus (+) pole, and DC electric power is generated with a potential. When an electric load is present between these potentials, it can function as a power source.
【0033】他方、発電に寄与しないまま残ったアノー
ド14の出口から出るガスは、未燃ガス系20を介して
燃焼部5aおよび水蒸気発生部5b等の加熱用燃焼ガス
として使用される。On the other hand, the gas remaining from the outlet of the anode 14 that does not contribute to power generation is used as a combustion gas for heating the combustion section 5a and the steam generation section 5b via the unburned gas system 20.
【0034】また、カソード15の出口から出る水蒸気
および燃焼排ガス中の水蒸気は、水蒸気発生部5bの燃
焼ガスと合流し、凝縮熱交換器19を介して改質用水タ
ンク10に回収され、燃料電池システム21での水自立
を図っている。Further, the water vapor emitted from the outlet of the cathode 15 and the water vapor in the combustion exhaust gas merge with the combustion gas in the water vapor generating section 5b and are recovered in the reforming water tank 10 via the condensation heat exchanger 19 to be supplied to the fuel cell. Water independence in the system 21 is aimed at.
【0035】電池本体2の膜電極接合体MEAにおける
触媒での反応温度は、通常、百度以下が適当であるか
ら、電池本体2の温度がそれ以下になるように、電池冷
却水ポンプ17で冷却水を循環させ、排熱熱交換器12
で放熱させ、電池本体2の入口側冷却水温度が一定にな
るように電気制御部(図示せず)で制御している。The reaction temperature of the catalyst in the membrane electrode assembly MEA of the battery body 2 is usually suitable to be 100 degrees Celsius or less. Therefore, the battery cooling pump 17 cools the battery body 2 so that the temperature falls below that temperature. Circulate water to exhaust heat exchanger 12
The heat is dissipated and the temperature of the cooling water on the inlet side of the battery body 2 is controlled by an electric control unit (not shown) so as to be constant.
【0036】また、排熱熱交換器12で電池本体2の水
冷却部16からの高温水として熱交換して温められる不
凍液等の媒体または温水は、排熱供給水ポンプ13の駆
動により、例えば温水器等に供給され、給湯やお風呂の
温水として使われる。The medium or hot water such as antifreeze solution which is heated by exchanging heat as high temperature water from the water cooling unit 16 of the battery body 2 in the exhaust heat heat exchanger 12 is driven by the exhaust heat supply water pump 13, for example. It is supplied to water heaters and used as hot water for hot water and baths.
【0037】図2は、本発明に係る燃料電池システムに
適用する改質器6の実施形態を示す概念図である。FIG. 2 is a conceptual diagram showing an embodiment of the reformer 6 applied to the fuel cell system according to the present invention.
【0038】本実施形態に係る改質器6は、器内に充填
する改質触媒22のうち、図1で示した燃料部3からの
原燃料Fに水蒸気分離器9からの水蒸気を混合させ、そ
の混合燃料ガスの供給口23側にニッケル系改質触媒2
2aを、さらに、このニッケル系改質触媒22aの下流
側にルテニウム系改質触媒22bをそれぞれ充填させた
ものである。The reformer 6 according to the present embodiment mixes the raw fuel F from the fuel section 3 shown in FIG. 1 with the steam from the steam separator 9 in the reforming catalyst 22 filled in the reactor. , The nickel-based reforming catalyst 2 on the side of the mixed fuel gas supply port 23.
2a, and the ruthenium-based reforming catalyst 22b is further filled on the downstream side of the nickel-based reforming catalyst 22a.
【0039】このような構成を備える改質器6におい
て、原燃料Fに水蒸気を混合させた、その混合燃料ガス
は、供給口23に案内され、ニッケル系改質触媒22
a、ルテニウム系改質触媒22bのそれぞれで水素リッ
チな燃料ガスに改質される。In the reformer 6 having such a configuration, the raw fuel F is mixed with steam, and the mixed fuel gas is guided to the supply port 23 and the nickel-based reforming catalyst 22.
Each of a and the ruthenium-based reforming catalyst 22b is reformed into hydrogen-rich fuel gas.
【0040】その際、ニッケル系改質触媒22aの温度
は、約250℃〜600℃であり、ルテニウム系改質触
媒22bの温度は、約550℃〜750℃である。At this time, the temperature of the nickel-based reforming catalyst 22a is about 250 ° C to 600 ° C, and the temperature of the ruthenium-based reforming catalyst 22b is about 550 ° C to 750 ° C.
【0041】このような高温のため、ニッケル系改質触
媒22aでは、水蒸気改質反応と同時に、原燃料Fに含
まれている窒素は改質により生成される水素と反応し、
アンモニアを生成する。Due to such a high temperature, in the nickel-based reforming catalyst 22a, at the same time as the steam reforming reaction, the nitrogen contained in the raw fuel F reacts with the hydrogen produced by the reforming,
It produces ammonia.
【0042】また、ルテニウム系改質触媒22bでは、
ニッケル系改質触媒22aで生成されたアンモニアを分
解する。In the ruthenium-based reforming catalyst 22b,
Ammonia generated by the nickel-based reforming catalyst 22a is decomposed.
【0043】なお、本実施形態では、改質器6の混合燃
料ガスの供給口23側に、ニッケル系改質触媒22a
を、この下流側に、ルテニウム系改質触媒22bをそれ
ぞれ充填させたが、この例に限らず、混合燃料ガスの供
給口23側に、ニッケル系改質触媒に替えてロジウム系
改質触媒22cを充填させてもよい。ロジウム系改質触
媒22cの場合も、温度範囲が約250℃〜600℃で
あり、上述の混合燃料ガスに含まれる窒素と改質により
生成される水素とが反応し、アンモニアが生成される。
その発生量は、ニッケル系改質触媒22aと同程度であ
る。そして、生成されたアンモニアは、上述と同様に、
ルテニウム系改質触媒22bで分解される。In this embodiment, the nickel-based reforming catalyst 22a is provided on the mixed fuel gas supply port 23 side of the reformer 6.
The ruthenium-based reforming catalysts 22b were respectively filled on the downstream side, but not limited to this example, the rhodium-based reforming catalysts 22c instead of the nickel-based reforming catalysts are provided on the mixed fuel gas supply port 23 side. May be filled. Also in the case of the rhodium-based reforming catalyst 22c, the temperature range is about 250 ° C. to 600 ° C., and the nitrogen contained in the mixed fuel gas described above reacts with the hydrogen produced by the reforming to produce ammonia.
The amount thereof is about the same as that of the nickel-based reforming catalyst 22a. And the produced ammonia is the same as above.
It is decomposed by the ruthenium-based reforming catalyst 22b.
【0044】図3は、本実施形態に係る改質器6に充填
されるニッケル系改質触媒22a、ルテニウム系触媒2
2b、およびロジウム系改質触媒22cのアンモニア生
成特性を示すグラフである。FIG. 3 shows a nickel-based reforming catalyst 22a and a ruthenium-based catalyst 2 packed in the reformer 6 according to this embodiment.
It is a graph which shows the ammonia formation characteristic of 2b and the rhodium type | system | group reforming catalyst 22c.
【0045】図3は、それぞれの単一触媒を充填し、窒
素と水素を含む燃料ガスを流したときの入口温度が25
0℃、出口温度が750℃となるように触媒層を模擬し
た反応管に、燃料ガス流れ方向に等間隔に設置したサン
プリングポートから得られた温度を横軸に、最大濃度を
1としたときの相対アンモニア濃度を縦軸に示してい
る。FIG. 3 shows that the inlet temperature is 25 when the fuel gas containing nitrogen and hydrogen is filled with each single catalyst.
When the maximum concentration is 1 with the horizontal axis representing the temperature obtained from the sampling ports installed at equal intervals in the fuel gas flow direction in a reaction tube simulating a catalyst layer so that the outlet temperature is 0 ° C and the outlet temperature is 750 ° C. The relative ammonia concentration of is shown on the vertical axis.
【0046】このグラフから、温度600℃以下ではニ
ッケル系改質触媒22aおよびロジウム系改質触媒22
cのアンモニア生成量が少なく、ルテニウム系改質触媒
22bのアンモニア生成量が最も多いことがわかった。From this graph, at a temperature of 600 ° C. or lower, the nickel-based reforming catalyst 22a and the rhodium-based reforming catalyst 22
It was found that the amount of ammonia produced in c was small and the amount of ammonia produced in the ruthenium-based reforming catalyst 22b was the largest.
【0047】しかし、温度550℃以上においては、ニ
ッケル系改質触媒22aおよびロジウム系改質触媒22
cで、アンモニアの減少は見られなかったが、ルテニウ
ム系改質触媒22bではアンモニアの分解による減少が
見られた。However, at temperatures above 550 ° C., the nickel-based reforming catalyst 22a and the rhodium-based reforming catalyst 22
In c, no decrease in ammonia was observed, but in the ruthenium-based reforming catalyst 22b, a decrease due to decomposition of ammonia was observed.
【0048】このような事象から、窒素を含む炭化水素
燃料を水蒸気改質反応により水素リッチな燃料ガスに改
質する改質器6の改質触媒22において、改質触媒22
を2層に構成し、温度550℃〜600℃以下となる改
質触媒22の1層目をアンモニア生成の活性が低く、か
つコストの安いニッケル系改質触媒22aを選択し、温
度550℃〜600℃以上となる2層目を、アンモニア
分解の活性が高いルテニウム系改質触媒22bを組み合
せることが効果的である。From such an event, in the reforming catalyst 22 of the reformer 6 for reforming the hydrocarbon fuel containing nitrogen into the hydrogen-rich fuel gas by the steam reforming reaction, the reforming catalyst 22
Is composed of two layers, and the nickel-based reforming catalyst 22a having low ammonia production activity and low cost is selected for the first layer of the reforming catalyst 22 having a temperature of 550 ° C. to 600 ° C. It is effective to combine the second layer having a temperature of 600 ° C. or higher with the ruthenium-based reforming catalyst 22b having a high activity of decomposing ammonia.
【0049】そのときの改質触媒22の各温度域におけ
るアンモニア生成濃度を図3のグラフで示す。このグラ
フでの相対アンモニア濃度は、図2で示したときと同様
に、最大濃度を1としている。The ammonia production concentration in each temperature range of the reforming catalyst 22 at that time is shown in the graph of FIG. As for the relative ammonia concentration in this graph, the maximum concentration is 1 as in the case shown in FIG.
【0050】図3から、アンモニア濃度は、温度600
℃付近で最も高いデータを示し、その後、減少し、改質
器6の出口側で、ニッケル系改質触媒22aの単独およ
びルテニウム系改質触媒22bの単独のときよりも低く
なることがわかった。From FIG. 3, the ammonia concentration is the temperature 600.
It was found that the highest data was obtained at around 0 ° C., then decreased, and became lower at the outlet side of the reformer 6 than when the nickel-based reforming catalyst 22a alone and the ruthenium-based reforming catalyst 22b alone were used. .
【0051】なお、いずれの改質触媒22a,22bも
充分な水蒸気改質反応特性を維持させていることは言う
までもない。Needless to say, both reforming catalysts 22a and 22b maintain sufficient steam reforming reaction characteristics.
【0052】[0052]
【発明の効果】以上の説明のとおり、本発明に係る燃料
電池システムによれば、窒素ガスを含む炭化水素系燃料
を水蒸気改質反応により、水素リッチな燃料ガスに改質
する際、温度が550℃〜600℃以下の領域で、第1
層目で、例えばニッケル系改質触媒、またはロジウム系
改質触媒を配置するので、アンモニアの生成量を抑制す
ることができ、温度が550℃〜600℃以上の領域
で、第2層目に、例えばルテニウム系改質触媒を配置す
るので、生成したアンモニアを分解することができ、ト
ータルとして燃料電池を被毒させるアンモニアの生成を
抑制し、長時間に亘って電池効率の高い、安定運転を実
現することができる。As described above, according to the fuel cell system of the present invention, when the hydrocarbon-based fuel containing nitrogen gas is reformed into the hydrogen-rich fuel gas by the steam reforming reaction, the temperature is In the range of 550 ° C to 600 ° C or less, the first
Since, for example, a nickel-based reforming catalyst or a rhodium-based reforming catalyst is arranged in the second layer, it is possible to suppress the production amount of ammonia, and in the region where the temperature is 550 ° C to 600 ° C or higher, the second layer is formed. Since, for example, a ruthenium-based reforming catalyst is arranged, the produced ammonia can be decomposed, the production of ammonia that poisons the fuel cell as a whole is suppressed, and a high cell efficiency and stable operation can be achieved for a long time. Can be realized.
【図1】本発明に係る燃料電池システムの概略全体を示
す系統図。FIG. 1 is a system diagram showing an overall outline of a fuel cell system according to the present invention.
【図2】本発明に係る燃料電池システムに適用する改質
器の実施形態を示す概念図。FIG. 2 is a conceptual diagram showing an embodiment of a reformer applied to the fuel cell system according to the present invention.
【図3】改質触媒を単一層とした場合のアンモニア生成
特性を示すグラフ。FIG. 3 is a graph showing ammonia generation characteristics when the reforming catalyst is a single layer.
【図4】改質触媒を二層にした場合のアンモニア生成特
性を示すグラフ。FIG. 4 is a graph showing ammonia generation characteristics when the reforming catalyst has two layers.
1 燃料処理系 2 電池本体 3 燃料部 4 脱硫器 5a 燃焼部 5b 水蒸気発生部 6 改質器 7 COシフト反応器 8 CO選択酸化器 9 水蒸気分離器 10 改質用水タンク 11 改質用水ポンプ 11a 水供給系 11b 水回収系 12 排熱熱交換器 13 排熱供給水ポンプ 14 アノード 15 カソード 16 水冷却部 17 電池冷却水ポンプ 18 空気ブロア 19 凝縮熱交換器 20 未燃ガス系 21 燃料電池システム 22 改質触媒 22a ニッケル系改質触媒 22b ルテニウム系改質触媒 22c ロジウム系改質触媒 23 供給口 1 Fuel processing system 2 Battery body 3 Fuel Department 4 desulfurizer 5a Combustion section 5b Steam generator 6 reformer 7 CO shift reactor 8 CO selective oxidizer 9 Water vapor separator 10 Reforming water tank 11 Reforming water pump 11a Water supply system 11b Water recovery system 12 Exhaust heat heat exchanger 13 Waste heat supply water pump 14 Anode 15 cathode 16 Water cooling unit 17 Battery cooling water pump 18 air blower 19 Condensation heat exchanger 20 unburned gas system 21 Fuel cell system 22 Reforming catalyst 22a Nickel-based reforming catalyst 22b Ruthenium-based reforming catalyst 22c Rhodium-based reforming catalyst 23 Supply port
───────────────────────────────────────────────────── フロントページの続き Fターム(参考) 4G140 EA03 EA06 EB16 EB23 EC02 EC03 5H026 AA06 HH08 5H027 AA06 BA01 BA16 KK42 ─────────────────────────────────────────────────── ─── Continued front page F-term (reference) 4G140 EA03 EA06 EB16 EB23 EC02 EC03 5H026 AA06 HH08 5H027 AA06 BA01 BA16 KK42
Claims (4)
反応により水素リッチな燃料ガスに改質する燃料処理系
と、水素リッチに改質した燃料ガスと空気中の酸素を電
気化学的に反応させ、その際に発生する電力を取り出す
電池本体とを備えた燃料電池システムにおいて、前記燃
料処理系の改質器に、改質触媒層を2層にして充填する
とともに、運転中の温度が250℃〜600℃以下とな
る燃料ガスの供給口側を1層目としてアンモニア生成の
活性の低い改質触媒を充填し、運転中の温度が550℃
〜750℃以上となる燃料ガスの出口側を2層目として
アンモニア分解性能の高い改質触媒層を充填したことを
特徴とする燃料電池システム。1. A fuel processing system for reforming a nitrogen-containing hydrocarbon fuel into a hydrogen-rich fuel gas by a steam reforming reaction, and an electrochemical reaction between the hydrogen-rich reformed fuel gas and oxygen in the air. In a fuel cell system including a cell body for reacting and extracting electric power generated at that time, the reformer of the fuel processing system is filled with two layers of reforming catalyst layers, and the temperature during operation is The reforming catalyst having a low activity of generating ammonia is filled with the supply port side of the fuel gas of 250 ° C to 600 ° C or less as the first layer, and the temperature during operation is 550 ° C.
A fuel cell system characterized in that a reforming catalyst layer having high ammonia decomposing performance is filled with a second layer on the outlet side of the fuel gas at 750 ° C or higher.
は、ニッケル系改質触媒であることを特徴とする請求項
1記載の燃料電池システム。2. The fuel cell system according to claim 1, wherein the reforming catalyst having a low activity of producing ammonia is a nickel-based reforming catalyst.
は、ロジウム系改質触媒であることを特徴とする請求項
1記載の燃料電池システム。3. The fuel cell system according to claim 1, wherein the reforming catalyst having a low activity of producing ammonia is a rhodium-based reforming catalyst.
ルテニウム系改質触媒であることを特徴とする請求項1
記載の燃料電池システム。4. A reforming catalyst having a high ammonia decomposing performance,
A ruthenium-based reforming catalyst, characterized in that
The fuel cell system described.
Priority Applications (1)
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JP2002140671A JP2003331898A (en) | 2002-05-15 | 2002-05-15 | Fuel cell system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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JP2002140671A JP2003331898A (en) | 2002-05-15 | 2002-05-15 | Fuel cell system |
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JP2003331898A true JP2003331898A (en) | 2003-11-21 |
Family
ID=29701494
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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JP2002140671A Pending JP2003331898A (en) | 2002-05-15 | 2002-05-15 | Fuel cell system |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006244873A (en) * | 2005-03-03 | 2006-09-14 | Cosmo Oil Co Ltd | Manufacturing method of hydrogen for fuel cell |
JP2011210626A (en) * | 2010-03-30 | 2011-10-20 | Jx Nippon Oil & Energy Corp | Fuel cell system |
JP2011210634A (en) * | 2010-03-30 | 2011-10-20 | Jx Nippon Oil & Energy Corp | Fuel cell system |
JP5586809B2 (en) * | 2012-04-06 | 2014-09-10 | パナソニック株式会社 | Hydrogen purification apparatus, hydrogen generation apparatus, and fuel cell system |
-
2002
- 2002-05-15 JP JP2002140671A patent/JP2003331898A/en active Pending
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006244873A (en) * | 2005-03-03 | 2006-09-14 | Cosmo Oil Co Ltd | Manufacturing method of hydrogen for fuel cell |
JP2011210626A (en) * | 2010-03-30 | 2011-10-20 | Jx Nippon Oil & Energy Corp | Fuel cell system |
JP2011210634A (en) * | 2010-03-30 | 2011-10-20 | Jx Nippon Oil & Energy Corp | Fuel cell system |
JP5586809B2 (en) * | 2012-04-06 | 2014-09-10 | パナソニック株式会社 | Hydrogen purification apparatus, hydrogen generation apparatus, and fuel cell system |
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