JPS63298974A - Operating method for molten carbonate fuel cell - Google Patents
Operating method for molten carbonate fuel cellInfo
- Publication number
- JPS63298974A JPS63298974A JP62133007A JP13300787A JPS63298974A JP S63298974 A JPS63298974 A JP S63298974A JP 62133007 A JP62133007 A JP 62133007A JP 13300787 A JP13300787 A JP 13300787A JP S63298974 A JPS63298974 A JP S63298974A
- Authority
- JP
- Japan
- Prior art keywords
- gas
- anode
- anode electrode
- cell
- oxidation
- 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
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 title claims description 16
- 239000000446 fuel Substances 0.000 title claims description 16
- 238000011017 operating method Methods 0.000 title claims description 6
- 239000007789 gas Substances 0.000 claims abstract description 66
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000002737 fuel gas Substances 0.000 claims abstract description 23
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 17
- 239000003792 electrolyte Substances 0.000 claims description 24
- 230000001681 protective effect Effects 0.000 claims description 23
- 239000011261 inert gas Substances 0.000 claims description 19
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 6
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 4
- 239000007800 oxidant agent Substances 0.000 claims description 4
- 230000001590 oxidative effect Effects 0.000 claims description 4
- 229910052786 argon Inorganic materials 0.000 claims description 3
- 239000001569 carbon dioxide Substances 0.000 claims description 3
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 3
- 239000001307 helium Substances 0.000 claims description 3
- 229910052734 helium Inorganic materials 0.000 claims description 3
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 3
- 229910052757 nitrogen Inorganic materials 0.000 claims description 3
- 230000005611 electricity Effects 0.000 claims description 2
- 230000003647 oxidation Effects 0.000 abstract description 28
- 238000007254 oxidation reaction Methods 0.000 abstract description 28
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 17
- 239000001301 oxygen Substances 0.000 abstract description 17
- 229910052760 oxygen Inorganic materials 0.000 abstract description 17
- 229910001873 dinitrogen Inorganic materials 0.000 abstract description 11
- 239000001257 hydrogen Substances 0.000 abstract description 9
- 229910052739 hydrogen Inorganic materials 0.000 abstract description 9
- 238000010248 power generation Methods 0.000 abstract description 8
- 230000006866 deterioration Effects 0.000 abstract description 4
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 abstract 1
- 238000010438 heat treatment Methods 0.000 abstract 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 229910000480 nickel oxide Inorganic materials 0.000 description 4
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 4
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 4
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 2
- 229910052808 lithium carbonate Inorganic materials 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910000027 potassium carbonate Inorganic materials 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 239000003034 coal gas Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- YQNQTEBHHUSESQ-UHFFFAOYSA-N lithium aluminate Chemical compound [Li+].[O-][Al]=O YQNQTEBHHUSESQ-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000006748 scratching Methods 0.000 description 1
- 230000002393 scratching effect Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04223—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04223—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells
- H01M8/04225—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells during start-up
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/043—Processes for controlling fuel cells or fuel cell systems applied during specific periods
- H01M8/04302—Processes for controlling fuel cells or fuel cell systems applied during specific periods applied during start-up
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04298—Processes for controlling fuel cells or fuel cell systems
- H01M8/043—Processes for controlling fuel cells or fuel cell systems applied during specific periods
- H01M8/04303—Processes for controlling fuel cells or fuel cell systems applied during specific periods applied during shut-down
-
- 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
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、電極劣化防止、ｉｔ池時特性向上を目的と
した溶融炭酸塩型燃料電池の運転方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of operating a molten carbonate fuel cell for the purpose of preventing electrode deterioration and improving IT battery characteristics.
周知のように溶融炭酸塩型燃料電池は炭酸リチウム、炭
酸カリウム等の炭”酸塩を含浸保持した電解質板を挟ん
でその両側に多孔質のアノード電極。As is well known, molten carbonate fuel cells have porous anode electrodes on both sides of an electrolyte plate impregnated with carbonate such as lithium carbonate or potassium carbonate.
カソード電極を配し、炭酸塩が溶融状態になる温度１例
えば６００〜７００℃の高温でアノード電極側に石炭ガ
ス、天然ガス等の水素ガスを含む燃料ガスを、カソード
電極側に空気、炭酸ガスを混合した酸化剤ガスを供給す
ることにより発電を行うものである。A cathode electrode is arranged, and a fuel gas containing hydrogen gas such as coal gas or natural gas is fed to the anode side at a high temperature 1, e.g. 600 to 700 degrees Celsius, at which the carbonate becomes molten, and air, carbon dioxide gas is fed to the cathode side. Electric power is generated by supplying an oxidant gas mixed with
ここで電解質仮にはりチウムアルミネート等の炭酸塩と
反応しない微細なセラミック粉末で多孔質な薄板を作り
、ここに炭酸塩を溶融して含浸保持させたものであり、
多孔質板の微細な気孔の毛細管力によって炭酸塩を保持
させる。一方、アノード電極としては一般にニッケル合
金の多孔質焼結板が、またカソード電極には酸化ニッケ
ルの多孔質焼結板が採用されている。また多孔質板で作
られたアノード、カソードｔｉはその気孔径を電解質板
の気孔径よりも大きくして電解質板がら電極側への電解
質の吸出し移行をできるだけ抑え、これにより燃料ガス
と酸化荊ガスとのクロスオーバー、電解質板のオーミッ
ク抵抗の上昇を防ぐように配慮している。この場合に通
常は気孔径が平均的に１〜２桁異なるように選定されて
いる。しかもアノード！掻材料であるニッケル合金は炭
酸塩に対する濡れ性が低い性質を有しており、このこと
も電解質板からアノード電極への電解質の移動防止に寄
与している。Here, a porous thin plate is made of fine ceramic powder that does not react with carbonates such as lithium aluminate as a temporary electrolyte, and the carbonate is melted and impregnated into this plate.
The carbonate is retained by the capillary force of the fine pores of the porous plate. On the other hand, a porous sintered nickel alloy plate is generally used as the anode electrode, and a porous sintered nickel oxide plate is used as the cathode electrode. In addition, the anode and cathode Ti made of porous plates have pore diameters larger than those of the electrolyte plate to suppress as much as possible the suction and transfer of electrolyte from the electrolyte plate to the electrode side. Care has been taken to prevent crossover with the electrolyte plate and an increase in ohmic resistance of the electrolyte plate. In this case, the pore diameters are usually selected so that they differ by 1 to 2 orders of magnitude on average. And an anode! The nickel alloy that is the scratching material has a property of having low wettability to carbonates, and this also contributes to preventing the movement of electrolyte from the electrolyte plate to the anode electrode.
ところでかかる構成に成る溶融炭酸塩型燃料電池では、
燃料ガスを供給し続けて発電を行う運転時は問題となる
ことがないが、燃料ガスの供給を停止する電池の起動時
、休止時にはアノード電極が酸化作用を受ける問題があ
る。すなわち発電中ばアノード電極へ水素ガスを多量に
含む燃料ガスが供給されるのでアノード電極に対する酸
化ポテンシャルが低い、これに対して燃料ガスの供給が
停止状態にある電池の起動時、休止時等では、電池のガ
スシール構造の不完全なこともあって外部より燃料ガス
室へ微量ながら空気が侵入するために、アノード電極に
対する酸化ポテンシャルが高くなって電極が酸化を受は
易くなる。By the way, in a molten carbonate fuel cell having such a configuration,
Although there is no problem during operation in which fuel gas is continuously supplied to generate electricity, there is a problem in that the anode electrode is subjected to oxidation when the battery is started up or stopped when the supply of fuel gas is stopped. In other words, during power generation, fuel gas containing a large amount of hydrogen gas is supplied to the anode electrode, so the oxidation potential for the anode electrode is low.On the other hand, when the fuel gas supply is stopped, such as when starting up or stopping the battery, Due to the incomplete gas sealing structure of the battery, a small amount of air enters the fuel gas chamber from the outside, which increases the oxidation potential for the anode electrode and makes the electrode more susceptible to oxidation.
しかもニッケル合金のアノード電極は酸化を受けると炭
酸塩に対する濡れ性が高まるようになる性質があるため
、電解質が電解質板よりアノード電極へ容易に吸い出さ
れて移動するようになるし、また電解質が電解質板から
アノード電極側に移動するようになると電解質機内に保
持される電解質の総保持量が減少し、この結果とてし先
記のような反応ガスのクロスオーバー、電解質板のオー
ミック抵抗の上昇が生じて電池特性の低下を引き起こす
。Moreover, when nickel alloy anode electrodes undergo oxidation, their wettability towards carbonates increases, so the electrolyte is easily sucked out and transferred from the electrolyte plate to the anode electrode. As the electrolyte moves from the electrolyte plate to the anode side, the total amount of electrolyte held in the electrolyte machine decreases, resulting in the crossover of the reactant gas as mentioned above and an increase in the ohmic resistance of the electrolyte plate. occurs, causing a decline in battery characteristics.
そこで従来では、前記したアノード電極を酸化から保護
する対策として、発電を行う定常運転時以外の起動、休
止時にアノード電極側に窒素等の不活性な保護ガスを流
し続けるような運転方法が行われている。Therefore, conventionally, as a measure to protect the anode electrode from oxidation, an operation method has been used in which an inert protective gas such as nitrogen is continuously flowed to the anode electrode side during startup and shutdown other than during steady operation for power generation. ing.
ところで前記のようにアノード電極に対し発電運転時以
外の期間中に窒素ガス等の不活性ガスを供給する方法に
よれば理論的にはアノード電極の酸化防止が可能である
が、実際には運転、停止の繰り返しにより次第にアノー
ド電極の酸化が進行するようになることが認められてい
る。By the way, as mentioned above, it is theoretically possible to prevent oxidation of the anode electrode by supplying an inert gas such as nitrogen gas to the anode electrode during periods other than during power generation operation, but in reality, during operation It has been recognized that oxidation of the anode electrode gradually progresses due to repeated stoppages.
すなわち、市販されている商業用の不活性ガスには数十
ｐｐｍ程度の微量な酸素を含んでいるのが普通であり、
この微量な酸素でも高温条件の下ではニッケル合金製の
アノード電極が酸化を受けるようになる。かかる点、ニ
ッケルは酸化自由エネルギーと酸素分圧との関係から、
温度条件６５０℃ではニッケルは酸素分圧１０−” ａ
ｔｅで酸化して酸化ニッケルが生成することが知られる
でいる。これに対し商業用として市販されている不活性
ガスは通常１０−’ａｔｍ程度の酸素分圧があので明ら
かにアノード電極が酸化を受けることになる。In other words, commercially available inert gases usually contain a trace amount of oxygen, on the order of several tens of ppm.
Even with this trace amount of oxygen, the nickel alloy anode electrode becomes oxidized under high temperature conditions. In this respect, nickel has the following relationship between oxidation free energy and oxygen partial pressure:
At a temperature of 650°C, nickel has an oxygen partial pressure of 10-” a
It is known that nickel oxide is produced by oxidation with te. On the other hand, commercially available inert gases usually have an oxygen partial pressure of about 10-'atm, which obviously causes the anode electrode to undergo oxidation.
なお、かかる点に付いて発明者は実際に起こるアノード
電極の酸化の程度、および酸化に伴う電池内部でのガス
のクロスオーバーを定量的に確カめるために次の試験を
行った。Regarding this point, the inventor conducted the following test in order to quantitatively confirm the degree of oxidation of the anode electrode that actually occurs and the crossover of gas inside the battery due to oxidation.
（試験１）
まずＮｉ−８Ｃｏ合金、厚さ１ ｍｍ、気孔率７５％の
アノード電極と、板厚が１．７ｓｕ＋の電解質板に炭酸
リチウム：炭酸カリウム−６２°鴎０１％： ３８ ｍ
ｏ１％の炭酸塩を含浸させた電解質板と、酸化ニッケル
製のカソード電極とを組合せて電解質有効面積２ｏ〇−
の単位セルを組立て、この単位セルを試験試料に電池の
運転温度： ６５０’ｔｌ：、起動時間：１３時間を
試験条件に選び、アノード電極側の燃料ガス室へ純度９
９．９９％の商業用窒素ガスをＩＪ／ｗｉｎの割合で供
給し続けた後に、単位セル内でのガスのクロスオーバー
量（アノードとカソードとの間の圧力差２００ＩＩＩｌ
水柱）を調べた。別に前記の単位セルに対し同じ温度２
時間の試験条件で商業用窒素ガスを３０１／＋ｗｉｎの
割合で流し続けた後に、アノード電極を取出してその酸
化による重量増加割合を調べた。これらの試験結果によ
れば、ガスのクロスオーバー量はＱｊ／ｗｉｎであった
が、アノード電極の酸化による重量増加割合は０．０１
０４％であり、明らかに商業用不活性ガスではガス中に
混在している微量な酸素によりアノード電極が酸化を受
けることが確かめられた。(Test 1) First, an anode electrode made of Ni-8Co alloy with a thickness of 1 mm and a porosity of 75% and an electrolyte plate with a plate thickness of 1.7su+ were coated with lithium carbonate: potassium carbonate -62° 01%: 38 m
By combining an electrolyte plate impregnated with o1% carbonate and a cathode electrode made of nickel oxide, the effective electrolyte area is 2o〇-
A unit cell was assembled, and this unit cell was used as a test sample. Operating temperature of the battery: 650'tl:, startup time: 13 hours was selected as the test condition, and purity 9 was sent to the fuel gas chamber on the anode electrode side.
After continuing to supply 9.99% commercial nitrogen gas at a rate of IJ/win, the amount of gas crossover within a unit cell (pressure difference between anode and cathode of 200III
water column). Apart from the above unit cell, the same temperature 2
After continuing to flow commercial nitrogen gas at a rate of 301/+win under test conditions for hours, the anode electrode was taken out and its weight increase rate due to oxidation was examined. According to these test results, the amount of gas crossover was Qj/win, but the weight increase rate due to oxidation of the anode electrode was 0.01.
04%, and it was clearly confirmed that the anode electrode was oxidized by the trace amount of oxygen mixed in the commercial inert gas.
（試験２）
また前記の試験１とは別に、実機でのガスシール構造の
不完全さに起因する空気の侵入を想定し、保護ガスとし
て商業用窒素ガスに１％の酸素の加えた混合ガスを前記
試験１と同じ試験条件でアノード電極側の燃料ガス室に
流し続けて試験を行った。この試験結果によれば、酸化
によるアノード電極の重量増加割合は１．６２８％にも
増え、かつガスのクロスオーバー量も２Ｑｊ！／ｉ＋ｉ
ｎに達することが認められた。(Test 2) Separately from Test 1, in order to simulate the intrusion of air due to imperfections in the gas seal structure in the actual machine, a mixture of commercial nitrogen gas and 1% oxygen was used as a protective gas. The test was conducted under the same test conditions as Test 1 by continuing to flow the fuel into the fuel gas chamber on the anode electrode side. According to the test results, the weight increase rate of the anode electrode due to oxidation increased to 1.628%, and the amount of gas crossover also increased to 2Qj! /i+i
n.
なお上記のようなアノード電極の酸化を防止するには、
電池の起動、休止時に流す保護ガスとして純度のより高
い不活性ガスを使用するれば酸化防止が期待できるが、
このような純粋な不活性ガスを使用することは入手性、
経済性の面で問題があるし、仮に純粋な不活性ガスを採
用したとしても燃料電池の構造面からガスシールが不完
全であると外部からの空気侵入があるのため、このまま
ではアノード電極の酸化を完全に防止することは実用的
に不可能に近い。In order to prevent the oxidation of the anode electrode as described above,
Oxidation can be prevented by using a higher purity inert gas as a protective gas when starting and stopping the battery.
The use of pure inert gases such as
There is a problem in terms of economic efficiency, and even if pure inert gas is used, if the gas seal is incomplete due to the structure of the fuel cell, air may enter from the outside, so if it continues as it is, the anode electrode It is practically impossible to completely prevent oxidation.
この発明は上記の点にかんがみ成されたものであり、そ
の目的は発電運転時を除く燃料電池の起動、停止時に保
護ガスとしてアノード電極へ供給する商業用不活性ガス
に含まれている微量な酸素。This invention has been made in consideration of the above points, and its purpose is to eliminate trace amounts of commercial inert gas that is supplied to the anode electrode as a protective gas when starting and stopping a fuel cell, except during power generation operation. oxygen.
ないしはこの期間に電池シール構造の不完全さから侵入
する微量な空気等によって受けるアノード電極の酸化を
確実に防止して電極の保護が図れるようにした溶融炭酸
塩型燃料電池の運転方法を提供することにある。Or, to provide a method of operating a molten carbonate fuel cell that can protect the anode electrode by reliably preventing oxidation of the anode electrode caused by a small amount of air entering through imperfections in the cell seal structure during this period. There is a particular thing.
上記問題点を解決するために、この発明によれば、定常
運転時以外の起動および休止時にアノード電極側へ不活
性ガスに少量の水素ガスを混合した保護ガスを供給し続
けるようにしたものである。In order to solve the above problems, according to the present invention, a protective gas consisting of an inert gas mixed with a small amount of hydrogen gas is continuously supplied to the anode electrode side during startup and shutdown other than during steady operation. be.
上記において、保護ガスの不活性ガスとしては商業用の
窒素、アルゴン、ヘリウムガス、な（為しこれらの混合
ガスを用い、かつ保護ガスの不活性ガスに対する水素ガ
スの混合割合は爆鳴気の形成限界等を考慮の上で０．５
〜２．０％に選定されている。かかる保護ガスを燃料電
池の起動、休止時にアノード電極側に供給し続けること
により、商業用不活性ガス中に混在している微量な酸素
、あるいはこの期間中に電池のガスシール部を透過して
外部から侵入した空気中の酸素は保護ガスに加えた水素
で還元され、水となって速やかに電池外に排出される。In the above, the inert gas for the protective gas is commercially available nitrogen, argon, helium gas, etc. 0.5 considering the formation limit etc.
~2.0%. By continuing to supply this protective gas to the anode side during startup and shutdown of the fuel cell, trace amounts of oxygen mixed in the commercial inert gas or penetrating the gas seal of the battery during this period can be prevented. Oxygen in the air that enters from the outside is reduced by the hydrogen added to the protective gas, turns into water, and is quickly discharged from the battery.
これによりアノード電極を酸化から完全に保護すること
ができ、併せて電池内部でのガスのクロスオーバー、電
極の劣化を抑えて電池の特性向上、長寿命化が得られる
。This allows the anode electrode to be completely protected from oxidation, and also suppresses gas crossover inside the battery and deterioration of the electrode, resulting in improved battery characteristics and longer life.
第１図はこの発明の実施例による燃料電池の運転チャー
ト、第２図は溶融炭酸塩型燃料電池の構造、並びに燃料
電池へのガス供給系統図を示す。FIG. 1 shows an operation chart of a fuel cell according to an embodiment of the present invention, and FIG. 2 shows a structure of a molten carbonate fuel cell and a gas supply system diagram to the fuel cell.
まず第２図において、１は炭酸塩を保持した電解質板、
２はニッケル合金の多孔質板で作られたアノード電極、
３は酸化ニッケルの多孔質板で作られたカソード電極、
４は電極支持板を兼ねた集電板、５は電池枠であり、電
池枠内にはアノード電極側に燃料ガス室６が、カソード
電極側には酸化剤ガス室７が画成されている。一方、前
記燃料ガス室６には石炭ガス化ブラ゛ント等に通じる燃
料ガス供給ライン８とともに、商業用窒素ガスを封入し
た窒素ガスボンベ９．および水素ガスボンベ１０が予熱
器１１．流量制御弁１２．１３．１４を介して接続され
ている。なお酸化剤ガス室７には予熱器１５゜ブロア１
６を介して空気と炭酸ガスとの混合ガスが供給される。First, in Fig. 2, 1 is an electrolyte plate holding carbonate;
2 is an anode electrode made of a porous plate of nickel alloy;
3 is a cathode electrode made of a porous plate of nickel oxide;
4 is a current collector plate that also serves as an electrode support plate, and 5 is a battery frame, in which a fuel gas chamber 6 is defined on the anode side and an oxidant gas chamber 7 is defined on the cathode side. . On the other hand, the fuel gas chamber 6 includes a fuel gas supply line 8 leading to a coal gasification branch, etc., as well as a nitrogen gas cylinder 9 filled with commercial nitrogen gas. and the hydrogen gas cylinder 10 is in the preheater 11. Connected via flow control valves 12.13.14. The oxidant gas chamber 7 is equipped with a preheater 15° blower 1.
6, a mixed gas of air and carbon dioxide is supplied.
かかるガス供給系統で、第１図のようにまず電池の起動
時には電池昇温過程から発電に移行するまでの期間に、
第２図に示した弁１２を閉、弁１３゜１４を開いて燃料
ガス室６へ窒素ガスとこれに混合割合０．５〜２．０％
の水素ガスを混合した保護ガスを加温した状態で供給す
る。なお水素ガスの混合割合を前記のように規定したの
は、商業用不活性ガス中に混在している酸素量、ないし
は電池のガスシールを透過して外部より侵入する空気中
の酸素量を想定してこれら酸素を還元できる充分な量で
あること、および水素を含む保護ガスが万一に周囲の空
気中に漏れ出た場合でも爆鳴気を形成して爆発すること
のないような安全率を考慮して定めた実用的な値である
。In such a gas supply system, as shown in Figure 1, when starting up the battery, during the period from the battery temperature rising process to the transition to power generation,
Close the valve 12 shown in Fig. 2, open the valves 13 and 14, and enter the fuel gas chamber 6 with nitrogen gas at a mixing ratio of 0.5 to 2.0%.
A protective gas mixed with hydrogen gas is supplied in a heated state. The mixing ratio of hydrogen gas was specified above based on the assumption that the amount of oxygen mixed in commercial inert gas, or the amount of oxygen in the air that penetrates from the outside through the gas seal of the battery. The amount of hydrogen contained in the protective gas must be sufficient to reduce these oxygens, and there must be a safety factor to ensure that even if the protective gas containing hydrogen leaks into the surrounding air, it will not form explosive gas and cause an explosion. This is a practical value determined by considering the following.
一方、前記のように保護ガスを供給しながら電池本体を
加温し、ここで電池本体が規定の運転温度に昇温するよ
うになると、次に弁１３．１４を閉。On the other hand, the battery body is heated while supplying the protective gas as described above, and when the battery body reaches the specified operating temperature, the valves 13 and 14 are then closed.
弁１２を開に切換えて燃料ガス室６へ燃料ガスを供給し
て発電に移行する。また発電を停止する場合は、発電停
止とともに前記した弁１１．１２を起動時と同じように
切換えて燃料ガス室６への供給ガスを燃料ガスから保護
ガスに切替え、かつ休止期間中はこの保護ガスを流し続
ける。The valve 12 is switched to open, fuel gas is supplied to the fuel gas chamber 6, and power generation begins. In addition, when power generation is to be stopped, the aforementioned valves 11 and 12 are switched in the same way as at the time of startup, and the gas supplied to the fuel gas chamber 6 is switched from fuel gas to protective gas. Keep the gas flowing.
なお図示実施例では、保護ガスに加える水素を別に用意
した水素ガスボンベ１０より供給する方式を述べたが、
水素ガスボンベ１０の代わりに燃料ガス供給ライン８の
供給ガス量を微量に流量制御し、水素を多く含む燃料ガ
スを不活性ガスに加えた混合ガスを保護ガスとして使用
することも可能である。In the illustrated embodiment, a method is described in which hydrogen to be added to the protective gas is supplied from a separately prepared hydrogen gas cylinder 10.
Instead of the hydrogen gas cylinder 10, it is also possible to control the amount of gas supplied in the fuel gas supply line 8 to a very small flow rate, and to use a mixed gas in which a fuel gas containing a large amount of hydrogen is added to an inert gas as the protective gas.
また前記運転方法によるアノード電極に対する保護効果
をｉ認するために、本発明者は先記した試験１．２と同
様な単位セルを用い、起動試験の期間中に保護ガスとし
て純°度が９９．９９％の商業用窒素ガスに１％の酸素
と０．５％の水素を加えた混合ガス供給し続けた後に、
ガスのクロスオーバー量、アノード電極の酸化による重
量増加割合を調べた。この試験結果によれば、ガスのク
ロスオーバー量はＯｍ ｌ ／分く圧力差２００１水柱
）、酸化によるアノード電極の重量増加割合は−０，０
０８６％となる結果が得られた。なお重量増加割合がマ
イナスを示したのはアノード電極の表面に僅かに存在し
ていた酸化物が水素によって還元された結果である。こ
の試験結果を先記した試験１．２と較べると、明らかに
アノード電極の酸化が阻止され、かつガスのクロスオー
バーでも改善効果のあることが確認された。In addition, in order to confirm the protective effect on the anode electrode by the above operating method, the present inventor used a unit cell similar to the test 1.2 described above, and used a protective gas of 99% purity during the start-up test. After continuing to feed a mixture of .99% commercial nitrogen gas with 1% oxygen and 0.5% hydrogen,
The amount of gas crossover and the weight increase rate due to oxidation of the anode were investigated. According to the test results, the amount of gas crossover is Oml/min (pressure difference 2001 water columns), and the weight increase rate of the anode electrode due to oxidation is -0.0.
A result of 0.086% was obtained. Note that the reason why the weight increase rate showed a negative value was due to the reduction of the oxide slightly present on the surface of the anode electrode by hydrogen. Comparing this test result with Test 1.2 described above, it was confirmed that oxidation of the anode electrode was clearly prevented and that there was also an improvement effect on gas crossover.
なお保護ガスに用いる不活性ガスとして実施例の商業用
窒素ガスの他に商業用アルゴン、ヘリウムガス、および
これらガスの混合ガスを用いた場合も同様な効果が得ら
れる。Note that similar effects can be obtained when commercial argon, helium gas, or a mixed gas of these gases is used in addition to the commercial nitrogen gas of the embodiment as the inert gas used as the protective gas.
以上述べたようにこの発明によれば、定常運転時以外の
起動および休止時゛にアノード電極側へ不活性ガスに少
量の水素ガスを混合した保護ガスを供給し続けることに
より、保護ガスとして使用する商業用不活性ガス中に含
まれている微量な酸素、あるいはガスシール構造の不完
全さから外部より侵入する空気中の酸素を保護ガスに加
えた水素で還元してニッケル合金であるアノード電極の
酸化を確実に防止することができ、これによりアノード
電極劣化、電解質板からアノード電解質への電解質の吸
出し移動、ガスクロスオーバーを改善して電池特性の向
上、長寿命化を図ることができる。As described above, according to the present invention, the protective gas, which is a mixture of an inert gas and a small amount of hydrogen gas, is continuously supplied to the anode electrode side during startup and shutdown other than during steady operation, so that it can be used as a protective gas. The anode electrode is made of a nickel alloy by reducing trace amounts of oxygen contained in commercial inert gas, or oxygen in the air that enters from the outside due to imperfections in the gas seal structure, with hydrogen added to the protective gas. It is possible to reliably prevent oxidation of the anode electrode, thereby improving the deterioration of the anode electrode, the suction and movement of the electrolyte from the electrolyte plate to the anode electrolyte, and the gas crossover, thereby improving battery characteristics and extending the lifespan.
第１図は本発明の運転方法を示す運転チャート、第２図
は第１図の運転方法を実施するための燃料電池のガス供
給系統図である０図において、１：電解質板、２ニアノ
ード電極、３：カソードｉｕｉ、５：電池枠、６：燃料
ガス室、７：酸化側ガス室、８：燃料ガス供給ライン、
９：窒素ガスボンベ、１０：水素ガスボンベ。
Ｘ ′・Fig. 1 is an operation chart showing the operating method of the present invention, and Fig. 2 is a gas supply system diagram of a fuel cell for carrying out the operating method of Fig. 1. , 3: cathode IUI, 5: battery frame, 6: fuel gas chamber, 7: oxidation side gas chamber, 8: fuel gas supply line,
9: Nitrogen gas cylinder, 10: Hydrogen gas cylinder. X'・
Claims (1)
ード電極、カソード電極を配し、アノード電極側に水素
ガスを含む燃料ガス、カソード電極側に空気と炭酸ガス
を混合した酸化剤ガスを供給して発電を行う溶融炭酸塩
型燃料電池に対し、定常運転時以外の起動および休止時
にアノード電極側へ不活性ガスに少量の水素ガスを混合
した保護ガスを供給し続けることを特徴とする溶融炭酸
塩型燃料電池の運転方法。 ２）特許請求の範囲第１項記載の運転方法において、保
護ガスの不活性ガスに対する水素ガスの混合割合が０．
５〜２．０％であることを特徴とする溶融炭酸塩型燃料
電池の運転方法。 ３）特許請求の範囲第１項記載の運転方法において、不
活性ガスが商業用の窒素、アルゴン、ヘリウムガス単独
、ないしその混合ガスのいずれかであることを特徴とす
る溶融炭酸塩型燃料電池の運転方法。[Claims] 1) An anode electrode and a cathode electrode are arranged on both sides of an electrolyte plate holding carbonate, and a fuel gas containing hydrogen gas is supplied to the anode electrode side, and air and carbon dioxide gas is supplied to the cathode electrode side. For molten carbonate fuel cells that generate electricity by supplying a mixed oxidant gas, a protective gas containing a small amount of hydrogen gas mixed with an inert gas is supplied to the anode side during startup and shutdown other than during steady operation. A method of operating a molten carbonate fuel cell characterized by: 2) In the operating method according to claim 1, the mixing ratio of hydrogen gas to the inert gas of the protective gas is 0.
5 to 2.0%. 3) A molten carbonate fuel cell according to the operating method according to claim 1, wherein the inert gas is commercially available nitrogen, argon, or helium gas alone, or a mixture thereof. How to drive.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62133007A JPS63298974A (en) | 1987-05-28 | 1987-05-28 | Operating method for molten carbonate fuel cell |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62133007A JPS63298974A (en) | 1987-05-28 | 1987-05-28 | Operating method for molten carbonate fuel cell |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63298974A true JPS63298974A (en) | 1988-12-06 |
Family
ID=15094604
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62133007A Pending JPS63298974A (en) | 1987-05-28 | 1987-05-28 | Operating method for molten carbonate fuel cell |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63298974A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02230664A (en) * | 1989-03-03 | 1990-09-13 | Hitachi Ltd | Operation of molten carbonate fuel cell |
| EP0433681A2 (en) * | 1989-12-18 | 1991-06-26 | Institute of Gas Technology | Molten carbonate fuel cell start-up process |
| EP1227532A2 (en) * | 2001-01-25 | 2002-07-31 | Delphi Technologies, Inc. | Gas control valve for a solid oxide fuel cell |
| EP1263071A2 (en) * | 2001-05-09 | 2002-12-04 | Delphi Technologies, Inc. | Methods for preventing anode oxidation in a fuel cell |
| WO2004012288A2 (en) * | 2002-07-31 | 2004-02-05 | Fuel Cell Technologies Ltd. | Fuel cell system with degradation protected anode |
| WO2003075381A3 (en) * | 2002-03-02 | 2004-02-05 | Mtu Cfc Solutions Gmbh | Method for inerting the anodes of fuel cells |
| WO2005053075A1 (en) * | 2003-11-27 | 2005-06-09 | Nissan Motor Co., Ltd. | Fuel cell system and method of starting it |
| JP2005190854A (en) * | 2003-12-25 | 2005-07-14 | Toshiba Fuel Cell Power Systems Corp | Fuel cell system and its starting method |
| JP2009505356A (en) * | 2005-08-11 | 2009-02-05 | フュエルセル エナジー， インコーポレイテッド | Control assembly that controls the fuel cell system during shutdown and restart |
-
1987
- 1987-05-28 JP JP62133007A patent/JPS63298974A/en active Pending
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02230664A (en) * | 1989-03-03 | 1990-09-13 | Hitachi Ltd | Operation of molten carbonate fuel cell |
| EP0433681A2 (en) * | 1989-12-18 | 1991-06-26 | Institute of Gas Technology | Molten carbonate fuel cell start-up process |
| EP1227532A3 (en) * | 2001-01-25 | 2004-06-16 | Delphi Technologies, Inc. | Gas control valve for a solid oxide fuel cell |
| EP1227532A2 (en) * | 2001-01-25 | 2002-07-31 | Delphi Technologies, Inc. | Gas control valve for a solid oxide fuel cell |
| EP1263071A2 (en) * | 2001-05-09 | 2002-12-04 | Delphi Technologies, Inc. | Methods for preventing anode oxidation in a fuel cell |
| EP1263071A3 (en) * | 2001-05-09 | 2005-04-27 | Delphi Technologies, Inc. | Methods for preventing anode oxidation in a fuel cell |
| WO2003075381A3 (en) * | 2002-03-02 | 2004-02-05 | Mtu Cfc Solutions Gmbh | Method for inerting the anodes of fuel cells |
| US7972739B2 (en) | 2002-03-02 | 2011-07-05 | Mtu Cfc Solutions Gmbh | Method for inerting the anodes of fuel cells |
| WO2004012288A2 (en) * | 2002-07-31 | 2004-02-05 | Fuel Cell Technologies Ltd. | Fuel cell system with degradation protected anode |
| WO2004012288A3 (en) * | 2002-07-31 | 2005-02-03 | Fuel Cell Technologies Ltd | Fuel cell system with degradation protected anode |
| US7226679B2 (en) | 2002-07-31 | 2007-06-05 | Siemens Power Generation, Inc. | Fuel cell system with degradation protected anode |
| US7465509B2 (en) | 2002-07-31 | 2008-12-16 | Siemens Energy, Inc. | Fuel cell system with degradation protected anode |
| WO2005053075A1 (en) * | 2003-11-27 | 2005-06-09 | Nissan Motor Co., Ltd. | Fuel cell system and method of starting it |
| JP2005190854A (en) * | 2003-12-25 | 2005-07-14 | Toshiba Fuel Cell Power Systems Corp | Fuel cell system and its starting method |
| JP2009505356A (en) * | 2005-08-11 | 2009-02-05 | フュエルセル エナジー， インコーポレイテッド | Control assembly that controls the fuel cell system during shutdown and restart |
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