JP3009508B2 - Method for reducing nitrous oxide in flue gas - Google Patents
Method for reducing nitrous oxide in flue gasInfo
- Publication number
- JP3009508B2 JP3009508B2 JP3168010A JP16801091A JP3009508B2 JP 3009508 B2 JP3009508 B2 JP 3009508B2 JP 3168010 A JP3168010 A JP 3168010A JP 16801091 A JP16801091 A JP 16801091A JP 3009508 B2 JP3009508 B2 JP 3009508B2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- nitrous oxide
- combustion
- flue gas
- alumina
- 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.)
- Expired - Lifetime
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
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/10—Capture or disposal of greenhouse gases of nitrous oxide (N2O)
Landscapes
- Filtering Of Dispersed Particles In Gases (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は事業用、産業用のボイ
ラ、特に燃焼温度が低い（７００〜９００℃）流動床方
式のボイラ又は都市ゴミ焼却炉等より発生する亜酸化窒
素（Ｎ2 Ｏ）を含む排ガス中の亜酸化窒素の低減方法に
関する。The present invention relates to a use business, industrial boiler, in particular a low combustion temperature (700 to 900 ° C.) nitrous oxide generated from a boiler or municipal waste incinerators fluidized bed method (N 2 O The present invention relates to a method for reducing nitrous oxide in an exhaust gas containing the same.
【０００２】[0002]
【従来の技術】亜酸化窒素（Ｎ2 Ｏ）は地球環境上問題
ある物質として注目され始めたのが比較的最近であるた
め、その低減方法については殆ど技術的な検討がなされ
ていないのが現状である。2. Description of the Related Art Nitrous oxide (N 2 O) has relatively recently begun to attract attention as a substance having a problem on the global environment, and there has been little technical study on its reduction method. It is the current situation.
【０００３】[0003]
【発明が解決しようとする課題】Ｎ2 Ｏは炭酸ガスと同
様の温室効果を有し、また、フロン（フルオロカーボ
ン）ガスと同様に成層圏のオゾン層破壊の原因物質とな
るために、近時地球規模の環境問題に関連して注目され
るようになった。このＮ2 Ｏは一般に高温度（１３００
℃以上）での燃焼方式（微粉炭燃焼、ガス燃焼、油燃焼
等）では殆ど生じないが、流動床など低温度（７００〜
９００℃）で燃焼させる方式ではかなりの濃度で発生す
ることが一般に認められつつある。Since N 2 O has a greenhouse effect similar to that of carbon dioxide gas, and also causes a destruction of the ozone layer in the stratosphere similarly to fluorocarbon (fluorocarbon) gas, N 2 O Attention has been focused on environmental issues of scale. This N 2 O is generally high temperature (1300
℃ or above) (pulverized coal combustion, gas combustion, oil combustion, etc.), but hardly occurs, but low temperature (700 ~
It is generally being recognized that combustion at 900 ° C.) produces significant concentrations.
【０００４】本発明は上記技術水準に鑑み、いったん生
成した排ガス中のＮ2 Ｏを簡単な手段によって効率的に
低減する方法を提供しようとするものである。The present invention has been made in view of the above-mentioned state of the art, and aims to provide a method for efficiently reducing N 2 O in exhaust gas once generated by simple means.
【０００５】[0005]
【課題を解決するための手段】本発明は燃焼排ガスを除
塵用多孔性セラミックスフィルタを通過させ、その後流
で該排ガス温度が５５０℃以上である領域に配置したγ
−アルミナよりなる触媒層を更に該排ガスを通過させる
ことを特徴とする燃焼排ガス中の亜酸化窒素の低減法で
ある。According to the present invention, there is provided a gamma gas which is disposed in a region where the flue gas is passed through a porous ceramic filter for dust removal and the temperature of the flue gas is 550 ° C. or higher in the subsequent flow.
-A method for reducing nitrous oxide in combustion exhaust gas, characterized by further passing the exhaust gas through a catalyst layer made of alumina.
【０００６】すなわち、本発明は燃焼排ガス中の亜酸化
窒素を５５０℃以上の比較的高い温度域で、多孔性セラ
ミックスフィルタとＮ2 Ｏ分解触媒の組み合せにより、
窒素に分解するようにした燃焼排ガス中の亜酸化窒素の
低減法である。That is, the present invention provides a method for reducing nitrous oxide in combustion exhaust gas at a relatively high temperature range of 550 ° C. or higher by combining a porous ceramic filter and an N 2 O decomposition catalyst.
This is a method for reducing nitrous oxide in combustion exhaust gas which is decomposed into nitrogen.
【０００７】一般に工業用触媒はペレット、粒状、ある
いはハニカム状に整形して用いるが、燃焼排ガス中に固
形分が多量に含まれていると運転中に目詰りを生じる不
具合がある。本発明にいう多孔性セラミックスフィルタ
とは、排ガス中の未燃カーボン、灰分などの固形物を微
細な孔に付着させて除くもので、従来の電気集塵機ある
いはスクラバ等の方式より、高い温度で適用可能なもの
である。Generally, industrial catalysts are used after being shaped into pellets, granules, or honeycombs. However, if the combustion exhaust gas contains a large amount of solids, there is a problem that clogging occurs during operation. The porous ceramic filter referred to in the present invention is a filter that removes solid substances such as unburned carbon and ash in exhaust gas by adhering to fine pores, and is applied at a higher temperature than conventional methods such as an electric dust collector or a scrubber. It is possible.
【０００８】多孔性セラミックスの材料としては、アル
ミナ、マグネシア等の耐高温性のものが用いられる。ま
たフィルタの形状としては、ハニカム状のエレメントを
充填したものあるいは円筒状で円筒内側を固形分を含ん
だ燃焼排ガスが流通し円筒材中で固形分を吸着した後、
円筒外側へ清浄な排ガスが流出する型式のものなど燃焼
排ガスの流量や固形分濃度に応じて適宜選択して使用さ
れる。As the material of the porous ceramic, a high temperature resistant material such as alumina and magnesia is used. Also, as the shape of the filter, a honeycomb-filled element or a cylindrical exhaust gas containing solid content inside the cylinder and flowing through the cylinder and adsorbing the solid content in the cylindrical material,
It is appropriately selected and used depending on the flow rate of the combustion exhaust gas and the solid content concentration, such as a type in which clean exhaust gas flows out of the cylinder.
【０００９】また、Ｎ2 Ｏ分解触媒としては、本発明者
らの試験によれば、γ（ガンマ）アルミナが５５０℃以
上の温度域でＮ2 Ｏの分解性能を有しており、セラミッ
クスフィルタとの組み合せに適している。ここでγ−ア
ルミナとは酸化アルミニウムの結晶形の一つであり、最
も安定なα型とは異なり、スピネル型に近い結晶構造を
有するもので、工業的には脱水触媒などとして用いられ
ているものである。[0009] Also, as the N 2 O decomposition catalyst, according to our studies, it has a performance of decomposing N 2 O in gamma (gamma) temperature range of not lower than 550 ° C. alumina, ceramics filters Suitable for combination with Here, γ-alumina is one of the crystal forms of aluminum oxide and, unlike the most stable α form, has a crystal structure close to a spinel form, and is industrially used as a dehydration catalyst or the like. Things.
【００１０】すなわち、本発明は、高温度でダスト除去
可能な多孔性セラミックスフィルタと、高温度でＮ2 Ｏ
分解性能を有する触媒の組み合せにより排ガス中のＮ2
Ｏを有効に低減するものである。That is, the present invention provides a porous ceramic filter capable of removing dust at a high temperature and a N 2 O filter at a high temperature.
N 2 in exhaust gas by combination of catalysts having decomposition performance
O is effectively reduced.
【００１１】以上の趣旨から本発明は多孔性セラミック
スフィルタの後流にＮ2 Ｏ分解用の触媒層を分離して設
置すること、あるいは両者を一体化して設置すること、
或いはフィルタの排ガス出口側にＮ2 Ｏ分解触媒を塗布
・焼結させること等も可能である。In view of the above, the present invention is to separate and install a catalyst layer for decomposing N 2 O in the downstream of a porous ceramics filter, or to install both in an integrated manner.
Alternatively, it is also possible to apply and sinter an N 2 O decomposition catalyst to the exhaust gas outlet side of the filter.
【００１２】[0012]
【作用】Ｎ2 Ｏは５５０℃以上でのγ−アルミナの作用
により、実用的な速度及び耐久性を維持してＮ2 とＯ2
に分解することが本発明者らの実験によって判明した。The action of N 2 O is maintained at a practical speed and durability by the action of γ-alumina at 550 ° C. or higher, and N 2 and O 2 are maintained.
It was found by the experiments of the present inventors that the decomposition was carried out.
【００１３】以下にＮ2 Ｏ分解触媒に関する本発明者ら
の実験結果について述べる。The results of experiments conducted by the present inventors on the N 2 O decomposition catalyst will be described below.
【００１４】Ｎ2 Ｏ：４９ppm 、Ｏ2 ：３％、残部：Ｎ
2 よりなる供試ガスを標準ガスボンベと浮遊式流量計に
て調整し、磁製反応管（アルミナ製内径２０mm、有効加
熱長１５０mm）と電気炉よりなる流動式反応装置を用い
てＮ2 Ｏの分解挙動を調査した。反応時間は０．４秒、
ガス流量は２Ｎｌ／分、またＮ2 Ｏ濃度の分析はＥＣＤ
検出器ガスクロマトグラフによった。なお、触媒は球の
γ−アルミナ（球径４mm）２０ｇを充填した。なお、比
較のため、安定なα−アルミナ及び無充填の試験も併せ
実施した。N 2 O: 49 ppm, O 2 : 3%, balance: N
The test gas consisting of 2 was adjusted with a standard gas cylinder and a floating flow meter, and N 2 O was measured using a fluidized reactor consisting of a porcelain reaction tube (alumina inner diameter 20 mm, effective heating length 150 mm) and an electric furnace. The decomposition behavior was investigated. The reaction time is 0.4 seconds,
The gas flow rate was 2Nl / min, and the analysis of N 2 O concentration was ECD
Detector gas chromatography was used. The catalyst was filled with 20 g of spherical γ-alumina (sphere diameter 4 mm). Note that, for comparison, stable α-alumina and an unfilled test were also performed.
【００１５】結果を表１に示す。表１に示したように、
Ｎ2 Ｏはγ−アルミナの存在下では５５０℃以上で有効
に低減されることが判明した。なお、出口ガス中のＮ
Ｏ、Ｎ 2 Ｏ濃度は、いずれの条件でも１ppm 以下であ
り、Ｎ2 Ｏは無害なＮ2 とＯ2 に分解されている。The results are shown in Table 1. As shown in Table 1,
NTwoO is effective at 550 ° C or higher in the presence of γ-alumina
Was found to be reduced. Note that N in the outlet gas
O, N TwoO concentration is 1 ppm or less under any condition.
, NTwoO is harmless NTwoAnd OTwoHas been broken down.
【表１】 [Table 1]
【００１６】[0016]
【実施例】本発明の一実施例を図１によって説明する。
図１において、１は燃焼炉本体、２は同燃焼炉本体１内
に設けられた流動床燃焼部、３は燃焼用空気の供給ライ
ン、４は流動床燃焼部２へ供給される主燃料である石炭
の供給ライン、５は燃焼炉本体１の上部に接続された未
燃炭素回収用の多孔性セラミックスフィルタ、６はＮ2
Ｏ分解触媒の充填層であり、５，６が本発明の主要構成
要素である。FIG. 1 shows an embodiment of the present invention.
In FIG. 1, 1 is a combustion furnace main body, 2 is a fluidized bed combustion section provided in the combustion furnace main body 1, 3 is a supply line of combustion air, and 4 is a main fuel supplied to the fluidized bed combustion section 2. A certain coal supply line, 5 is a porous ceramic filter connected to the upper part of the combustion furnace main body 1 for recovering unburned carbon, and 6 is N 2
This is a packed bed of the O decomposition catalyst, and 5 and 6 are main components of the present invention.
【００１７】一般に多孔性セラミックスフィルタ５及び
触媒充填層６は５５０〜９００℃で運転される。Generally, the porous ceramics filter 5 and the catalyst packed layer 6 are operated at 550 to 900 ° C.
【００１８】前記の流動床燃焼部２においては、石炭
（豪州炭）を８５０℃の温度、残留酸素濃度３．５％で
燃焼した。石炭供給量は１００kg／時間であり、触媒と
して球径５mmのγ−アルミナを空間速度（ＳＶ）＝１
０，０００ｈｒ-1になるように充填した。図１で８，９
はＮ2 Ｏ濃度の第１及び第２計測点であり、７は後流へ
のＮ2 Ｏ除去後排ガスの流路である。In the fluidized bed combustion section 2, coal (Australian coal) was burned at a temperature of 850 ° C. and a residual oxygen concentration of 3.5%. The amount of coal supplied was 100 kg / hour, and γ-alumina having a sphere diameter of 5 mm was used as a catalyst with a space velocity (SV) = 1
The filling was performed so as to be 000 hr -1 . 8, 9 in FIG.
Denotes the first and second measurement points of the N 2 O concentration, and 7 denotes a flow path of the exhaust gas after removing the N 2 O to the downstream.
【００１９】以上の方法により、多孔性フィルタ５の入
口濃度６９ppm のＮ2 Ｏを１．２ppm まで低減させるこ
とができた。また排ガス中に含まれるＳＯ2 の濃度は約
３０ppm であったが、これに被毒されることなく、７５
０時間後の性能は初期と殆ど差がなく、耐久性にも問題
がないことが確認された。According to the above method, N 2 O having an inlet concentration of 69 ppm in the porous filter 5 could be reduced to 1.2 ppm. Also, the concentration of SO 2 contained in the exhaust gas was about 30 ppm, but without being poisoned, the concentration was 75 ppm.
The performance after 0 hours was almost the same as the initial performance, and it was confirmed that there was no problem in durability.
【００２０】また多孔性セラミックスフィルタ５を設置
したことにより、排ガス中に含まれる未燃カーボンや灰
分が除去され、Ｎ2 Ｏ分解触媒充填層の目詰りや触媒性
能の劣化が防止でき、長期間の連続運転が可能になっ
た。By installing the porous ceramics filter 5, unburned carbon and ash contained in the exhaust gas are removed, and clogging of the N 2 O decomposition catalyst packed layer and deterioration of the catalyst performance can be prevented. Can be operated continuously.
【００２１】[0021]
【発明の効果】以上説明したように、本発明は、未燃カ
ーボンや灰分等のダスト及びＮ2 Ｏを含む燃焼排ガスの
高温部に、多孔性セラミックスフィルタ及びＮ2 Ｏの分
解触媒を設置するという簡単な手段によって、地球温室
効果および成層圏オゾン層破壊の原因物質の一であるＮ
2 Ｏを容易、低廉、かつ効果的に低減することができ
る。As described above, according to the present invention, the high-temperature portion of the combustion exhaust gas containing dust and N 2 O, such as unburned carbon and ash, to install a catalyst for decomposing the porous ceramic filter and N 2 O N, one of the causative agents of the global greenhouse effect and stratospheric ozone depletion,
2 O can be easily, inexpensively and effectively reduced.
【図１】本発明の一実施例の説明図。FIG. 1 is an explanatory diagram of one embodiment of the present invention.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 内田 聡 長崎県長崎市飽の浦町１番１号 三菱重 工業株式会社長崎造船所内 (72)発明者 小林 敬古 東京都千代田区丸の内二丁目５番１号 三菱重工業株式会社 本社内 (58)調査した分野(Int.Cl.7，ＤＢ名) B01D 53/86,53/94 B01J 21/00 - 38/74 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoshi Uchida 1-1, Akunouracho, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (72) Inventor Takako Kobayashi 2-5-1 Marunouchi, Chiyoda-ku, Tokyo No. Mitsubishi Heavy Industries, Ltd. Headquarters (58) Field surveyed (Int. Cl. 7 , DB name) B01D 53 / 86,53 / 94 B01J 21/00-38/74
Claims (1)
フィルタを通過させ、その後流で該排ガス温度が５５０
℃以上である領域に配置したγ−アルミナよりなる触媒
層を更に該排ガスを通過させることを特徴とする燃焼排
ガス中の亜酸化窒素の低減法。1. A combustion exhaust gas is passed through a porous ceramic filter for dust removal, and the temperature of the exhaust gas is reduced to 550 in the subsequent flow.
A method for reducing nitrous oxide in combustion exhaust gas, which further comprises passing the exhaust gas through a catalyst layer made of γ-alumina disposed in a region where the temperature is at least ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3168010A JP3009508B2 (en) | 1991-07-09 | 1991-07-09 | Method for reducing nitrous oxide in flue gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3168010A JP3009508B2 (en) | 1991-07-09 | 1991-07-09 | Method for reducing nitrous oxide in flue gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0515742A JPH0515742A (en) | 1993-01-26 |
| JP3009508B2 true JP3009508B2 (en) | 2000-02-14 |
Family
ID=15860136
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3168010A Expired - Lifetime JP3009508B2 (en) | 1991-07-09 | 1991-07-09 | Method for reducing nitrous oxide in flue gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3009508B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5555913B2 (en) * | 2009-12-08 | 2014-07-23 | 出光興産株式会社 | N2O and NOx emission suppression method in combustion apparatus |
-
1991
- 1991-07-09 JP JP3168010A patent/JP3009508B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0515742A (en) | 1993-01-26 |
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