JP3211513B2 - Ammonia measuring device - Google Patents
Ammonia measuring deviceInfo
- Publication number
- JP3211513B2 JP3211513B2 JP24224193A JP24224193A JP3211513B2 JP 3211513 B2 JP3211513 B2 JP 3211513B2 JP 24224193 A JP24224193 A JP 24224193A JP 24224193 A JP24224193 A JP 24224193A JP 3211513 B2 JP3211513 B2 JP 3211513B2
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- JP
- Japan
- Prior art keywords
- sample gas
- cell
- solid electrolyte
- electrode
- ammonia
- Prior art date
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- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、煙道等を通って排出さ
れるガス中のアンモニアの濃度を測定する装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the concentration of ammonia in a gas discharged through a flue or the like.
【０００２】[0002]
【従来の技術】従来、乾式によるアンモニア濃度の測定
技術としては、化学発光法や赤外線吸収法が知られてい
る。2. Description of the Related Art Conventionally, a chemiluminescence method and an infrared absorption method are known as techniques for measuring ammonia concentration by a dry method.
【０００３】前者の化学発光法は、アンモニア（Ｎ
Ｈ3 ）を酸化して一旦一酸化窒素（ＮＯ）とし、このＮ
Ｏをオゾン（Ｏ3 ）と反応させて化学発光させ、その発
光量からＮＯを定量してアンモニアの濃度を求めるもの
である。[0003] The former chemiluminescence method uses ammonia (N
H 3 ) is oxidized to nitrogen monoxide (NO), and this N 3
O is reacted with ozone (O 3 ) to cause chemiluminescence, and NO is quantified from the amount of luminescence to determine the concentration of ammonia.
【０００４】一方、後者の赤外線吸収法は、試料ガスに
赤外線を照射し、その試料ガス中のアンモニアによる赤
外線吸収スペクトルの強度からアンモニアを定量するも
のである。On the other hand, in the latter infrared absorption method, a sample gas is irradiated with infrared rays, and ammonia is quantified from the intensity of an infrared absorption spectrum of ammonia in the sample gas.
【０００５】[0005]
【発明が解決しようとする課題】上記の化学発光法は現
在主流となっているものであるが、この化学発光法によ
るＮＨ3 の測定では、試料ガス中のＮＨ3 を一度ＮＯに
酸化し、そのＮＯをＯ3との化学発光で定量するため、
試料ガス用の流路のみらずＯ3 用の流路等を要するとと
もに、それらの流路をカラム等で適宜切り換える必要が
あった。このため、操作が比較的煩雑で装置も大規模に
なってしまうという問題があった。しかも、当初から試
料ガス中にＮＯが含まれていると、そのＮＯの量も測定
されるため、当初のＮＯ量を別途測定する必要があっ
た。The above chemiluminescent [0008] Although those which are the current mainstream, in the measurement of the NH 3 by the chemiluminescence method, oxidizing the NH 3 in the sample gas once NO, To quantify the NO by chemiluminescence with O 3 ,
Not only a flow path for O 3 but also a flow path for O 3 was required in addition to a flow path for the sample gas, and these flow paths had to be appropriately switched by a column or the like. For this reason, there has been a problem that the operation is relatively complicated and the device becomes large-scale. In addition, if NO is included in the sample gas from the beginning, the amount of NO is also measured, so that it was necessary to separately measure the initial NO amount.
【０００６】一方、赤外線吸収法によるＮＨ3 の測定で
は、試料ガス中に水分やＮＯが存在していた場合に、そ
れらによる赤外吸収スペクトルがＮＨ3 による赤外吸収
スペクトルの近くに現れるため吸収スペクトルの干渉が
生じ、その結果、ＮＨ3 濃度の測定値が不明瞭となるお
それがあった。また同測定に使用される装置も大掛かり
なものであった。On the other hand, in the measurement of NH 3 by the infrared absorption method, when moisture or NO is present in the sample gas, the infrared absorption spectrum due to these appears near the infrared absorption spectrum by NH 3 , so that absorption is not possible. The interference of the spectrum occurred, and as a result, the measured value of the NH 3 concentration might be unclear. The equipment used for the measurement was also large.
【０００７】本発明は、アンモニア測定における上記の
ような問題を解消するもので、酸素イオン伝導性を有す
る固体電解質を利用することにより、流路を切換えるこ
となく簡便な方法でアンモニアを定量でき、しかも小型
化が可能なアンモニア測定装置を提供することを目的と
する。The present invention solves the above-mentioned problems in ammonia measurement. By using a solid electrolyte having oxygen ion conductivity, ammonia can be quantified by a simple method without switching a flow path. Moreover, it is an object of the present invention to provide an ammonia measuring device that can be reduced in size.
【０００８】[0008]
【課題を解決するための手段】上記目的達成のため、本
発明は、共存成分として酸素を含むガス中のアンモニア
の濃度を測定するアンモニア測定装置において、次のよ
うに構成したことを特徴とする。To achieve the above object, the present invention provides an ammonia measuring apparatus for measuring the concentration of ammonia in a gas containing oxygen as a coexisting component, which is characterized in that it is constituted as follows. .
【０００９】すなわち、一対の電極間に酸素イオン伝導
性を有する固体電解質を設けてなる固体電解質セルを、
その一方の電極側に試料ガスが接触する状態で試料ガス
の流路の前段および後段にそれぞれ配置する。そして、
そのうちの前段の固体電解質セルについては、同セルの
両電極間に一定電圧を印加した時に試料ガスと接触する
側の電極が還元電極となって試料ガス中の酸素を同セル
により除去されるように電圧源に接続する。また、後段
の固体電解質セルについては、同セルの両電極間に一定
電圧を印加した時に試料ガスと接触する側の電極が酸化
電極となって同電極側の固体電解質表面で試料ガス中の
アンモニアが酸化され且つその酸化反応に伴って同セル
に流れる電流の量からアンモニア濃度が測定されるよう
に電圧源に接続する。That is, a solid electrolyte cell in which a solid electrolyte having oxygen ion conductivity is provided between a pair of electrodes,
The sample gas is arranged at the front and rear stages of the sample gas flow path in a state where the sample gas is in contact with one of the electrodes. And
Of the solid electrolyte cells in the former stage, when a constant voltage is applied between both electrodes of the cell, the electrode in contact with the sample gas serves as a reduction electrode so that oxygen in the sample gas is removed by the cell. To the voltage source. Also, in the latter solid electrolyte cell, when a constant voltage is applied between both electrodes of the cell, the electrode in contact with the sample gas becomes an oxidation electrode and the ammonia in the sample gas on the surface of the solid electrolyte on the same electrode side. Is connected to a voltage source so that the ammonia concentration can be measured from the amount of current flowing through the cell along with the oxidation reaction.
【００１０】ここで、固体電解質としては、例えばＯ2
検出器などに使用されているＺｒＯ 2 （酸化ジルコニウ
ムないしジルコニア）が挙げられるが、酸素イオン伝導
性を有する固体電解質であれば、それ以外のものであっ
てもよい。Here, as the solid electrolyte, for example, O 2Two
ZrO used for detectors, etc. Two(Zirconium oxide
Or zirconia), but oxygen ion conduction
Other than the solid electrolyte
You may.
【００１１】また、固体電解質の表面に白金等のペース
トを塗布するか溶射して電極として使用する。Further, a paste of platinum or the like is applied to the surface of the solid electrolyte or sprayed and used as an electrode.
【００１２】[0012]
【作用】上記の構成によれば、次のようにしてアンモニ
アの濃度を測定することができる。According to the above arrangement, the concentration of ammonia can be measured as follows.
【００１３】前段および後段の固体電解質セルの電極に
一定の電圧を印加した状態で、酸素（Ｏ2 ）およびアン
モニア（ＮＨ3 ）を含む試料ガスを流路中に流すと、試
料ガスは先ず前段の固体電解質セルの還元電極側に接触
する。その結果、試料ガス中のＯ2 は同電極側の固体電
解質表面で還元されてＯ2-となり、そのＯ2-状態で固体
電解質中を反対の電極（酸化電極）側まで移動し、そこ
で再びＯ2 となって流路外に放出される。こうして、前
段のセルにおける固体電解質のＯ2 に対するポンプ作用
により、試料ガス中のＯ2 が除去される。When a sample gas containing oxygen (O 2 ) and ammonia (NH 3 ) is caused to flow through the flow path while a constant voltage is applied to the electrodes of the solid electrolyte cells of the former and latter stages, the sample gas is firstly placed in the former stage. To the reduction electrode side of the solid electrolyte cell. As a result, O 2 in the sample gas is reduced on the surface of the solid electrolyte on the same electrode side to O 2− , and moves in the solid electrolyte to the opposite electrode (oxidation electrode) side in the O 2− state, where it is again formed. O 2 is released out of the channel. Thus, the pumping action for O 2 solid electrolyte in the preceding stage of the cell, O 2 in the sample gas are removed.
【００１４】次に、Ｏ2 が除去された試料ガスは流路の
下流側に流れて後段の固体電解質セルの酸化電極側に接
触する。その結果、試料ガス中のＮＨ3 は、同電極側の
固体電解質表面で酸化されて一酸化窒素（ＮＯ）とな
る。この時、同セルの両電極間には一定の電位差が与え
られているから、その酸化反応に応じた電流が同セルに
流れる。したがって、その一定電位差の下、同セルを通
過した電子ないし負電荷の数、つまり電流量からＮＨ3
の濃度が定量できることとなる。Next, the sample gas from which O 2 has been removed flows downstream of the flow path and comes into contact with the oxidation electrode side of the subsequent solid electrolyte cell. As a result, NH 3 in the sample gas is oxidized on the surface of the solid electrolyte on the same electrode side as nitrogen monoxide (NO). At this time, since a certain potential difference is given between both electrodes of the cell, a current corresponding to the oxidation reaction flows through the cell. Accordingly, under that constant potential difference, electron or the number of negative charges that have passed through the same cell, i.e. NH 3 from the current amount
Can be quantified.
【００１５】[0015]
【実施例】以下、本発明の実施例を説明する。まず、図
１および図２を使用して本発明による測定の原理につい
て説明する。Embodiments of the present invention will be described below. First, the principle of measurement according to the present invention will be described with reference to FIGS.
【００１６】ＺｒＯ2 （酸化ジルコニウムあるいはジル
コニア）等の固体電解質は、高温において高い酸素イオ
ン伝導性を示す。そこで、図１に示すように、上記のよ
うな固体電解質１表面に例えば白金（Ｐｔ）製の電極２
ａ、２ｂを塗布し、一方の電極２ａが＋で他方の電極２
ｂが−となるように両電極間に一定電圧を印加した状態
で、＋側の酸化電極２ａ側にＮＨ3 を含む試料ガスを導
入すると、ＮＨ3 は同電極２側の固体電解質表面でＮＯ
に酸化される。すなわち、２ＮＨ3 ＋５Ｏ2-→２ＮＯ＋
Ｈ2 Ｏ＋１０ｅ- となる。この反応は酸化電極２ａ側に
Ｃｏ2 Ｏ3 等をコーティングすることにより、その選択
性は極めて高くなる（Ｊｏｕｒｎａｌｏｆ Ｍａｔｅｒ
ｉａｌ Ｓｃｉｅｎｃｅ １１（１９９２） ｐｐ１６
２〜１６３参照）。A solid electrolyte such as ZrO 2 (zirconium oxide or zirconia) exhibits high oxygen ion conductivity at high temperatures. Therefore, as shown in FIG. 1, an electrode 2 made of, for example, platinum (Pt) is formed on the surface of the solid electrolyte 1 as described above.
a, 2b, one electrode 2a is positive and the other electrode 2a is positive.
b is - become so in the state where a constant voltage is applied between the electrodes, the + in the oxidation electrode 2a of the side for introducing a sample gas including NH 3, NH 3 in the solid electrolyte surface of the electrode 2 side NO
Is oxidized. That is, 2NH 3 + 5O 2- → 2NO +
H 2 O + 10 e − is obtained. In this reaction, the selectivity becomes extremely high by coating Co 2 O 3 or the like on the oxidation electrode 2a side (Journalof Mater).
ial Science 11 (1992) pp16
2-163).
【００１７】なお、図１の状態では、−側の電極２ｂは
還元電極となるから、同電極２ｂ側にＯ2 を含むガスが
接触すると、そのガス中のＯ2 がＯ2-となって酸化電極
２ａ側に移動する。[0017] In the state of FIG. 1, - from the side of the electrode 2b is the reduction electrode, the gas containing O 2 in the electrode 2b side is in contact, is O 2 in the gas is an O 2- It moves to the oxidation electrode 2a side.
【００１８】また、固体電解質は、温度を下げることに
より、イオン輸送率が低下する。したがって、低温にお
いてＮＨ3 と接触させることにより、電解質表面でのＮ
Ｈ3との反応を律速状態にしておけば、一定電位差の
下、通過した電子の数、すなわち電流量からＮＨ3 の濃
度が定量可能となる。The ion transport rate of the solid electrolyte is reduced by lowering the temperature. Therefore, by contact with NH 3 at a low temperature, N 3 on the electrolyte surface
If the reaction with H 3 is controlled, the NH 3 concentration can be quantified from the number of passed electrons, that is, the amount of current, under a constant potential difference.
【００１９】しかし、試料ガス中にＯ2 が存在すると、
そのＯ2 が酸化電極２ａ側でＮＨ3と反応を生じるため
に、試料ガス中のＯ2 をあらかじめ除去しておく必要が
ある。However, if O 2 is present in the sample gas,
Since the O 2 reacts with NH 3 on the oxidation electrode 2a side, it is necessary to remove O 2 in the sample gas in advance.
【００２０】そこで、図２に示すように、円筒状ないし
管状の固体電解質（ＺｒＯ2 ）の内周面および外周面に
一対の電極をそれぞれ設けてなる固体電解質セル３、４
を前段および後段の２段に配置し、前段のセル３につい
てはその内側３ａが還元電極（−側電極）となるように
電圧源５に接続する一方、後段のセル４についてはその
内側４ａが酸化電極（＋電極）となるように電圧源６に
接続した上で電流計７をセットしておく。なお、図示の
状態では前段セル３と後段のセル４との間は空間となっ
ているが、実際には、流路側に試料ガスが漏出しないよ
うに、両セル３、４間には気密性を有する流路形成用の
管等が配管される。Therefore, as shown in FIG. 2, solid electrolyte cells 3, 4 in which a pair of electrodes are provided on the inner and outer peripheral surfaces of a cylindrical or tubular solid electrolyte (ZrO 2 ), respectively.
Are arranged in two stages, the former stage and the latter stage. The cell 3 of the former stage is connected to the voltage source 5 so that the inner side 3a becomes a reduction electrode (− side electrode), while the inner side 4a of the latter cell 4 is The ammeter 7 is set before connecting to the voltage source 6 so as to be an oxidation electrode (+ electrode). In the state shown in the figure, a space is provided between the former cell 3 and the latter cell 4, but in reality, airtightness is provided between the two cells 3 and 4 so that the sample gas does not leak to the flow path side. And a pipe for forming a flow path having the above.
【００２１】そして、この状態で、図示の矢印方向に試
料ガスを流して前段セル３および後段セル４の順にそれ
らのセル内を通過させると、前段のセル３では内側３ａ
が還元電極となるように電位が印加されているから、同
セル３によるＯ2 ポンプ作用で試料ガス中からＯ2 が除
去される。こうして後段セル４にはＯ2 を含まない試料
ガスが供給されるが、同セル４では試料ガスに接触する
内側４ａが酸化電極となるように電位が印加されている
ので、試料ガス中のＮＨ3 がその酸化電極側の固体電解
質表面で酸化されて一酸化窒素（ＮＯ）となる。この
時、同セルの両電極間には一定の電位差が与えられてい
ることにより、その酸化反応に応じた電流が同セルに流
れるので、その一定電位差の下、同セルを通過した電子
ないし負電荷の数、つまり電流量を電流計７から読み取
れば、その電流量からＮＨ3 の濃度が定量できることと
なる。In this state, when the sample gas is flowed in the direction of the arrow shown in the drawing and passed through these cells in the order of the pre-stage cell 3 and the post-stage cell 4, the pre-stage cell 3 has an inside 3a.
Is applied as a reducing electrode, so that O 2 is removed from the sample gas by the O 2 pumping action of the cell 3. In this way, the sample gas containing no O 2 is supplied to the subsequent cell 4, but in the same cell 4, the potential is applied so that the inner side 4 a in contact with the sample gas becomes an oxidation electrode, so that NH 4 in the sample gas is 3 is oxidized to nitrogen monoxide (NO) on the surface of the solid electrolyte on the oxidation electrode side. At this time, since a certain potential difference is given between the two electrodes of the cell, a current corresponding to the oxidation reaction flows through the same cell. If the number of electric charges, that is, the current amount is read from the ammeter 7, the NH 3 concentration can be determined from the current amount.
【００２２】ここで、１秒当たりに流れるＮＨ3 分子の
量を［ＮＨ3 ］（単位：ｍｏｌ／ｓ）とすると、 ［ＮＨ3 ］＝Ｉ／５Ｆ ・・・（１） ただし、Ｉ：電流値、Ｆ：ファラデー定数である。Here, assuming that the amount of NH 3 molecules flowing per second is [NH 3 ] (unit: mol / s), [NH 3 ] = I / 5F (1) where I: current Value, F: Faraday constant.
【００２３】次に、以上の原理に基づく本発明実施例に
ついて説明する。図３に、同実施例に係るアンモニア測
定装置のブロック図を示す。この図に示すように、アン
モニア測定装置１１は、同図の矢印方向に導入される試
料ガスの流路に沿って上流側から順番に、一定量の試料
ガスを下流側に流すための流量制御部１２と、Ｏ2 除去
用の前段の固体電解質セル１３と、ＮＨ3 酸化測定用の
後段の固体電解質セル１４とを直列に配置した構成であ
る。Next, an embodiment of the present invention based on the above principle will be described. FIG. 3 shows a block diagram of the ammonia measuring device according to the embodiment. As shown in this figure, the ammonia measuring apparatus 11 controls a flow rate for flowing a certain amount of sample gas to the downstream side in order from the upstream side along the flow path of the sample gas introduced in the direction of the arrow in FIG. This is a configuration in which a section 12, a solid electrolyte cell 13 at a preceding stage for removing O 2 , and a solid electrolyte cell 14 at a later stage for measuring NH 3 oxidation are arranged in series.
【００２４】このうち前段および後段の固体電解質セル
１３、１４は、図２に示した前段および後段の各セル
３、４のように、円筒状もしくは管状に形成された例え
ばＺｒＯ2 からなる固体電解質の内周面および外周面に
それぞれ電極（例えば、Ｐｔ製のもの）を設けた構造と
されている。したがって、この図３の実施例において
も、前段の固体電解質セル１３については内側の電極が
還元電極となるように電圧源１５に接続され、後段の固
体電解質セル１４については内側の電極が酸化電極とな
るよう電圧源１６に接続され且つその回路中に電流計１
７が設けられている。The solid electrolyte cells 13 and 14 of the former and latter stages are made of a solid or cylindrical solid electrolyte made of, for example, ZrO 2 , like the cells 3 and 4 of the former and latter stages shown in FIG. Are provided with electrodes (for example, those made of Pt) on the inner peripheral surface and the outer peripheral surface, respectively. Therefore, also in the embodiment of FIG. 3, the inner electrode of the former solid electrolyte cell 13 is connected to the voltage source 15 so as to be a reduction electrode, and the inner electrode of the latter solid electrolyte cell 14 is an oxidation electrode. And connected to the voltage source 16 so that
7 are provided.
【００２５】ここで、特に後段の固体電解質セル１４に
おいては、図示しないが、その内側の酸化電極の表面に
Ｃｏ2 Ｏ3 がコーティングされている。その理由は、上
述したように、ＮＨ3 酸化反応における選択性を高める
ためである。Here, especially in the latter solid electrolyte cell 14, although not shown, the inner surface of the oxidation electrode is coated with Co 2 O 3 . The reason is, as described above, to enhance the selectivity in the NH 3 oxidation reaction.
【００２６】また、図例では、上記各セル１３、１４
は、それぞれ電気炉１８、１９内に設けられている。こ
れは、上述したように各セル１３、１４における固体電
解質によるイオン輸送率が温度に依存することから、電
気炉１８、１９によって同セル１３、１４を適切な温度
に保つためである。In the example shown in FIG.
Are provided in electric furnaces 18 and 19, respectively. This is because the electric furnaces 18 and 19 maintain the cells 13 and 14 at an appropriate temperature because the ion transport rate of the solid electrolyte in each cell 13 and 14 depends on the temperature as described above.
【００２７】次に、この実施例の作用を説明する。図３
に示す状態で、同図のアンモニア測定装置１１における
流路の左側からＯ 2 およびＮＨ3 を含む試料ガスを導入
すると、この流路中に導入された試料ガスは先ず流量制
御部１２を通過する。この時、その流量制御部１２によ
って試料ガスの流量が制御されることにより、下流側に
は一定の割合で試料ガスが流れるようになる。Next, the operation of this embodiment will be described. FIG.
In the state shown in FIG.
O from the left side of the channel TwoAnd NHThreeIntroduce sample gas containing
Then, the sample gas introduced into this flow path is first flow-controlled.
It passes through the control unit 12. At this time, the flow control unit 12
By controlling the flow rate of the sample gas,
Causes the sample gas to flow at a constant rate.
【００２８】こうして流量制御部１２を通過した試料ガ
スは、次に前段の固体電解質セル１３内を通過する。こ
の時、同セル１３においては、内側の電極が還元電極と
なるように電位が印加されているから、同セル１３内を
通過する試料ガス中の試料ガス中のＯ2 は同電極側の固
体電解質表面に接触してＯ2-となり、そのＯ2-となった
状態で同セル１３の固体電解質中を外側の電極側まで移
動し、そこで再びＯ2となって流路外に放出される。こ
うして、前段の固体電解質セル１３のＯ2 ポンプ作用に
より、試料ガス中のＯ2 が流路側に排出されて除去され
る。The sample gas that has passed through the flow control unit 12 in this manner passes through the solid electrolyte cell 13 in the preceding stage. At this time, in the cell 13, since a potential is applied so that the inner electrode becomes a reduction electrode, O 2 in the sample gas in the sample gas passing through the cell 13 becomes solid on the electrode side. O 2- next in contact with the electrolyte surface, is released to the cells 13 of the solid electrolyte in a condition that the O 2- moved to the outer electrode side, where again the flow path outside of a O 2 . Thus, the O 2 pumping action of the front of the solid electrolyte cell 13 are removed is discharged to the O 2 the flow path side in the sample gas.
【００２９】次に、Ｏ2 が除去された試料ガスは、下流
側に配置されている後段の固体電解質セル１４内を通過
する。この時、同セル１４においては、内側の電極が酸
化電極となるように電位が印加されているから、同セル
１４内を通過する試料ガス中のＮＨ3 は、同電極側の固
体電解質表面で酸化されてＮＯとなり、これに伴ってそ
の酸化反応に応じた電流が同セルに流れる。この電流量
は、同セル１４に接続された電流計によって読み取られ
るが、この時の電流量とＮＨ3 の量との間には、上記
（１）式に示したような関係にある。したがって、この
後段の固体電解質セル１４に通電している電流量からＮ
Ｈ3 濃度がわかる。Next, the sample gas from which O 2 has been removed passes through the solid electrolyte cell 14 in the latter stage, which is arranged on the downstream side. At this time, in the cell 14, since a potential is applied so that the inner electrode becomes an oxidation electrode, NH 3 in the sample gas passing through the cell 14 is deposited on the surface of the solid electrolyte on the electrode side. It is oxidized to NO, and accordingly, a current corresponding to the oxidation reaction flows through the cell. This current amount is read by an ammeter connected to the cell 14, and the current amount and the amount of NH 3 at this time have a relationship as shown in the above equation (1). Therefore, the amount of current flowing through the subsequent solid electrolyte cell 14
The H 3 concentration is known.
【００３０】このように、このアンモニア測定装置によ
れば、一つの流路内に一定量の試料ガスを流して、直列
に配置された前段および後段の各固体電解質セル１３、
１４内を順次通過させるだけで、ＮＨ3 の濃度を正確に
定量することができる。したがって、複数の流路を必要
としないから、装置の構成が簡素となり、それだけ小型
化される。また、流路等の切換え操作も不要となるか
ら、それだけ測定作業が簡便化されることになる。As described above, according to this ammonia measuring apparatus, a fixed amount of sample gas is flowed into one flow path, and the solid electrolyte cells 13 in the front and rear stages, which are arranged in series,
The NH 3 concentration can be accurately quantified only by sequentially passing through the inside of the sample. Therefore, since a plurality of flow paths are not required, the configuration of the device is simplified, and the size is reduced accordingly. In addition, since the switching operation of the flow path and the like becomes unnecessary, the measuring operation is simplified accordingly.
【００３１】なお、上記実施例では、後段に配置したＮ
Ｈ3 酸化測定用固体電解質セル１４の酸化電極側にＣｏ
2 Ｏ3 をコーティングしたが、それ以外でＮＯ選択性が
高いものを使用してもよい。In the above embodiment, the N
Co on the oxidation electrode side of the solid electrolyte cell 14 for measuring H 3 oxidation
Although coated with 2 O 3 , other materials having high NO selectivity may be used.
【００３２】[0032]
【発明の効果】以上のように、本発明のアンモニア測定
装置によれば、Ｏ2 除去用の固体電解質セルとＮＨ3 酸
化測定用の固体電解質セルとを直列に２段に配置しただ
けの極めて簡素な構成で、共存成分としてＯ2 を含む試
料ガス中のＮＨ3 の濃度を定量することができるので、
複数の流路やその切換え操作が不要となる。これによ
り、小型で、しかも操作の簡単なアンモニア測定装置が
実現できることになる。As described above, according to the ammonia measuring apparatus of the present invention, it is extremely difficult to arrange a solid electrolyte cell for removing O 2 and a solid electrolyte cell for measuring NH 3 oxidation in two stages in series. With a simple configuration, the concentration of NH 3 in the sample gas containing O 2 as a coexisting component can be determined,
A plurality of flow paths and a switching operation thereof are not required. As a result, a small-sized and easy-to-operate ammonia measuring device can be realized.
【図１】固体電解質セルによるアンモニア酸化反応の原
理を説明するために使用した同セルの概略構造説明図FIG. 1 is a schematic structural explanatory view of a solid electrolyte cell used to explain the principle of an ammonia oxidation reaction of the cell.
【図２】本発明実施例によるアンモニア濃度測定の原理
を説明するために使用した説明図FIG. 2 is an explanatory diagram used to explain the principle of ammonia concentration measurement according to an embodiment of the present invention.
【図３】本発明実施例に係るアンモニア測定装置の構成
を示すブロック図FIG. 3 is a block diagram showing a configuration of an ammonia measuring device according to an embodiment of the present invention.
１・・・固体電解質 ２ａ、２ｂ・・・電極 １１・・・アンモニア測定装置 ３、１３・・・前段の固体電解質セル ４、１４・・・後段の固体電解質セル ５、６、１５、１６・・・電圧源 DESCRIPTION OF SYMBOLS 1 ... Solid electrolyte 2a, 2b ... Electrode 11 ... Ammonia measuring device 3, 13 ... Solid electrolyte cell of the former stage 4, 14 ... Solid electrolyte cell of the latter stage 5, 6, 15, 16 ..Voltage sources
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平４−62466（ＪＰ，Ａ) 特開 昭63−6454（ＪＰ，Ａ) 特開 平５−281186（ＪＰ，Ａ) 特開 平２−195247（ＪＰ，Ａ) 特開 平１−223339（ＪＰ，Ａ) 特開 昭63−42460（ＪＰ，Ａ) 特開 昭55−132947（ＪＰ，Ａ) 特開 昭56−16864（ＪＰ，Ａ) 特開 平５−264501（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G01N 27/42 G01N 27/26 G01N 27/41 G01N 27/416 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-62466 (JP, A) JP-A-63-6454 (JP, A) JP-A-5-281186 (JP, A) JP-A-2- 195247 (JP, A) JP-A-1-223339 (JP, A) JP-A-63-42460 (JP, A) JP-A-55-132947 (JP, A) JP-A-56-16864 (JP, A) JP-A-5-264501 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) G01N 27/42 G01N 27/26 G01N 27/41 G01N 27/416
Claims (1)
アンモニアの濃度を測定する装置であって、一対の電極
間に酸素イオン伝導性を有する固体電解質を設けてなる
固体電解質セルが、その一方の電極側に試料ガスが接触
する状態で試料ガスの流路の前段および後段にそれぞれ
配置されており、そのうちの前段の固体電解質セルは、
同セルの両電極間に一定電圧を印加した時に試料ガスと
接触する側の電極が還元電極となって試料ガス中の酸素
が同セルにより除去されるように電圧源に接続されてい
る一方、後段の固体電解質セルは、同セルの両電極間に
一定電圧を印加した時に試料ガスと接触する側の電極が
酸化電極となって同電極側の固体電解質表面で試料ガス
中のアンモニアが酸化され且つその酸化反応に伴って同
セルに流れる電流の量からアンモニア濃度が測定される
ように電圧源に接続されていることを特徴とするアンモ
ニア測定装置。1. An apparatus for measuring the concentration of ammonia in a sample gas containing oxygen as a co-existing component, wherein a solid electrolyte cell having a solid electrolyte having oxygen ion conductivity provided between a pair of electrodes is provided. The sample gas flow path of the sample gas is arranged in the former stage and the latter stage, respectively, in a state where the sample gas is in contact with the electrode side of the solid electrolyte cell of the former stage,
The electrode on the side that comes into contact with the sample gas when a constant voltage is applied between both electrodes of the cell is connected to a voltage source so that oxygen in the sample gas is removed by the cell as a reduction electrode, In the latter solid electrolyte cell, when a constant voltage is applied between both electrodes of the cell, the electrode in contact with the sample gas becomes an oxidation electrode, and ammonia in the sample gas is oxidized on the surface of the solid electrolyte on the same electrode side. An ammonia measuring device, which is connected to a voltage source so that the ammonia concentration is measured from the amount of current flowing through the cell following the oxidation reaction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24224193A JP3211513B2 (en) | 1993-09-29 | 1993-09-29 | Ammonia measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24224193A JP3211513B2 (en) | 1993-09-29 | 1993-09-29 | Ammonia measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0798297A JPH0798297A (en) | 1995-04-11 |
| JP3211513B2 true JP3211513B2 (en) | 2001-09-25 |
Family
ID=17086346
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24224193A Expired - Fee Related JP3211513B2 (en) | 1993-09-29 | 1993-09-29 | Ammonia measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3211513B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5479409B2 (en) * | 2010-07-16 | 2014-04-23 | 日本特殊陶業株式会社 | Ammonia gas sensor |
-
1993
- 1993-09-29 JP JP24224193A patent/JP3211513B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0798297A (en) | 1995-04-11 |
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