JPH0776386B2 - Method for suppressing deterioration of CO gas oxidation catalyst in sintering exhaust gas treatment system - Google Patents
Method for suppressing deterioration of CO gas oxidation catalyst in sintering exhaust gas treatment systemInfo
- Publication number
- JPH0776386B2 JPH0776386B2 JP33269189A JP33269189A JPH0776386B2 JP H0776386 B2 JPH0776386 B2 JP H0776386B2 JP 33269189 A JP33269189 A JP 33269189A JP 33269189 A JP33269189 A JP 33269189A JP H0776386 B2 JPH0776386 B2 JP H0776386B2
- Authority
- JP
- Japan
- Prior art keywords
- gas
- exhaust gas
- concentration
- oxidation catalyst
- coke
- 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
- 239000003054 catalyst Substances 0.000 title claims description 35
- 230000003647 oxidation Effects 0.000 title claims description 32
- 238000007254 oxidation reaction Methods 0.000 title claims description 32
- 238000005245 sintering Methods 0.000 title claims description 19
- 238000000034 method Methods 0.000 title claims description 14
- 230000006866 deterioration Effects 0.000 title claims description 12
- 239000000571 coke Substances 0.000 claims description 23
- 239000002245 particle Substances 0.000 claims description 15
- 238000006477 desulfuration reaction Methods 0.000 claims description 10
- 230000023556 desulfurization Effects 0.000 claims description 10
- 239000000843 powder Substances 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 9
- 239000002994 raw material Substances 0.000 claims description 4
- 230000003247 decreasing effect Effects 0.000 claims description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 claims 1
- 239000011707 mineral Substances 0.000 claims 1
- 239000007789 gas Substances 0.000 description 80
- 230000007423 decrease Effects 0.000 description 11
- 238000010438 heat treatment Methods 0.000 description 10
- 230000008929 regeneration Effects 0.000 description 8
- 238000011069 regeneration method Methods 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 5
- 239000002737 fuel gas Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 230000036962 time dependent Effects 0.000 description 1
Landscapes
- Manufacture And Refinement Of Metals (AREA)
Description
【発明の詳細な説明】 ＜産業上の利用分野＞ 本発明は、焼結工場の排ガス脱硫・脱硝処理工程でのCO
ガス酸化熱回収用のCOガス酸化触媒の劣化抑制方法に関
するものである。DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to CO in the exhaust gas desulfurization / denitration process of a sintering plant.
The present invention relates to a method for suppressing deterioration of a CO gas oxidation catalyst for recovering gas oxidation heat.
＜従来の技術＞ 第３図に焼結機の排ガス脱硫・脱硝処理工程のフローの
一例を示すが、図において、１は焼結機、２は排ガスの
脱硫反応器、３は脱硝反応後の排ガスの顕熱を回収し、
これにより脱硫により温度の低下した排ガスの予熱を行
うための熱交換器、４は排ガスブロワー、５は燃料ガス
の燃焼熱により排ガスを脱硝反応に必要な温度まで加熱
する加熱炉、６は脱硝反応器、７は、脱硝後の排ガス中
のCOガスを貴金属を担持させた酸化触媒を用いて酸化さ
せ排ガスの温度を上げ、前記熱交換器３に送るCOガス酸
化触媒装置、８は排ガスを大気中へ放散するための煙突
である。<Prior Art> FIG. 3 shows an example of a flow chart of an exhaust gas desulfurization / denitration treatment process of a sintering machine. In the figure, 1 is a sintering machine, 2 is an exhaust gas desulfurization reactor, and 3 is a system after denitration reaction. Recover the sensible heat of the exhaust gas,
As a result, a heat exchanger for preheating the exhaust gas whose temperature has been lowered by desulfurization, 4 is an exhaust gas blower, 5 is a heating furnace that heats the exhaust gas to the temperature required for the denitration reaction by the combustion heat of the fuel gas, and 6 is the denitration reaction. A reactor, 7 is a CO gas oxidation catalyst device for oxidizing the CO gas in the exhaust gas after denitration using an oxidation catalyst carrying a noble metal to raise the temperature of the exhaust gas, and sending it to the heat exchanger 3, and 8 is an atmosphere for the exhaust gas. It is a chimney for dissipating inside.
焼結工場の排ガス処理・脱硝処理工程では、所定の脱硝
反応温度を得るために、排ガスの加熱炉５を用いて昇温
し、かつ脱硝反応後の排ガス中に含まれるCOガスをCOガ
ス酸化触媒装置７で触媒を通して酸化させ潜熱を回収
し、この熱を脱硫後の排ガスの加熱用熱源として利用し
ている。ところが排ガス中COガスが一定濃度以下になる
と、COガス酸化触媒装置７のCOガス酸化触媒が急激に劣
化し、酸化熱回収量が減少しそれを補償するために排ガ
スの加熱炉で大量に燃料ガスを燃焼させ所定の温度に保
たねばならないという問題がある。In the exhaust gas treatment / denitrification treatment process of the sintering plant, in order to obtain a predetermined denitrification reaction temperature, the exhaust gas heating furnace 5 is used to raise the temperature, and the CO gas contained in the exhaust gas after the denitrification reaction is oxidized to CO gas. The catalyst device 7 oxidizes the latent heat through the catalyst to recover the latent heat, and uses this heat as a heat source for heating the exhaust gas after desulfurization. However, when the CO gas in the exhaust gas falls below a certain concentration, the CO gas oxidation catalyst of the CO gas oxidation catalyst device 7 deteriorates rapidly, the amount of oxidation heat recovery decreases, and a large amount of fuel is burned in the exhaust gas heating furnace to compensate for it. There is a problem that the gas must be burned and kept at a predetermined temperature.
さらに一度劣化したCOガス酸化触媒を再生するために
は、触媒担体に担持された貴金属触媒の表面に付着した
錯塩を昇華させなければならず、かなりの加熱時間を要
するという問題がある。Furthermore, in order to regenerate the once deteriorated CO gas oxidation catalyst, the complex salt adhering to the surface of the noble metal catalyst carried on the catalyst carrier must be sublimated, which requires a considerable heating time.
＜発明が解決しようとする課題＞ 本発明は、前述のような問題点を解決し、焼結排ガス中
のCOガスの濃度低下によるCOガス酸化触媒の劣化を抑制
する方法を提供することを課題とする。<Problems to be Solved by the Invention> It is an object of the present invention to provide a method for solving the above-mentioned problems and suppressing deterioration of a CO gas oxidation catalyst due to a decrease in the concentration of CO gas in a sintering exhaust gas. And
＜課題を解決するための手段＞ 本発明は、焼結工場の排ガス脱硫・脱硝処理系統のCOガ
スの潜熱回収用のCOガス酸化触媒の劣化抑制方法におい
て、COガス酸化前の排ガス中CO濃度を連続的に分析し、
COガス濃度が所定の下限値を超えて低下した場合は、焼
結鉱原料中の粉コークスの平均粒径を低下させおよび／
またはコークス配合比を上昇させ、COガス濃度が前記下
限値以上になるように調整することにより焼結排ガス処
理系内のCOガス酸化触媒の劣化を抑制し、前記課題を解
決したものである。<Means for Solving the Problems> The present invention relates to a method for suppressing deterioration of a CO gas oxidation catalyst for recovering latent heat of CO gas in an exhaust gas desulfurization / denitration processing system of a sintering plant, in which CO concentration in exhaust gas before CO gas oxidation Continuously analyzed,
When the CO gas concentration falls below a predetermined lower limit value, the average particle size of the powder coke in the sintered ore raw material is reduced and / or
Alternatively, the coke mixing ratio is increased and the CO gas concentration is adjusted to be equal to or higher than the lower limit value to suppress the deterioration of the CO gas oxidation catalyst in the sintering exhaust gas treatment system, thereby solving the above problem.
＜作用＞ 本発明は、COガス酸化前の排ガス中のCOガス濃度を排ガ
スの連続ガス分析装置で測定し、所定の下限値を下回っ
た場合は、例えば焼結原料コークス配合比をパラメータ
ーとして粉コークス粒径と排ガス中のCOガス濃度との関
係を模式的に示す第２図から、COガス濃度が所定の下限
値以上になるように、粉コークス平均粒径を低下させる
か、および／または粉コークス配合比を上昇させる。<Operation> The present invention measures the CO gas concentration in exhaust gas before CO gas oxidation with a continuous gas analyzer for exhaust gas, and when it falls below a predetermined lower limit value, for example, a sintering raw material coke mixing ratio is used as a parameter for powder. From FIG. 2 schematically showing the relationship between the coke particle size and the CO gas concentration in the exhaust gas, the average coke powder particle size is reduced so that the CO gas concentration is equal to or higher than a predetermined lower limit value, and / or Increase the powder coke blending ratio.
粉コークス平均粒径の低下は、コークス破砕系への原料
コークス供給速度を変えることによって達成することが
できる。The reduction of the average particle size of the powder coke can be achieved by changing the feed coke feed rate to the coke crushing system.
なお、粉コークス粒径の低下によるCOガス利用率の低下
に伴う焼結熱量の低減を補償するため、COガス利用率の
低下分に相当する粉コークスの増量を行うことが望まし
い。In order to compensate for the decrease in the calorific value of sintering due to the decrease in the CO gas utilization rate due to the decrease in the coke particle size, it is desirable to increase the amount of the coke powder corresponding to the decrease in the CO gas utilization rate.
また、粉コークス粒径を変化させずに粉コークス配合比
を上昇させるだけでもよい。Alternatively, the powder coke blending ratio may be increased without changing the powder coke particle size.
このようにして、COガス濃度が所定の下限値以上になる
よう調整され、COガス酸化触媒の劣化が抑制される。In this way, the CO gas concentration is adjusted to be equal to or higher than the predetermined lower limit value, and deterioration of the CO gas oxidation catalyst is suppressed.
逆に排ガス中のCO濃度が所定値より高すぎる場合には、
エネルギーの過大な消費を生じるので、粉コークス平均
粒径を上昇させるか粉コークス粒径の調整（粒径アッ
プ）をせずに省エネルギーを図るために粉コークスの配
合比を低下させてもよい。これらの方法でCOガス酸化触
媒が劣化する前に焼結排ガス中のCOガス濃度を所定の目
標範囲に調整することによって、触媒性能劣化と再生処
理に伴う酸化熱回収の減少を抑制することができ、また
エネルギーの過大な消費をも防止できる。On the contrary, if the CO concentration in the exhaust gas is too high than the specified value,
Since excessive consumption of energy occurs, the blending ratio of the powder coke may be reduced in order to save energy without increasing the powder coke average particle size or adjusting the powder coke particle size (particle size increase). By adjusting the CO gas concentration in the sintering exhaust gas to a predetermined target range before the CO gas oxidation catalyst is deteriorated by these methods, it is possible to suppress deterioration of catalyst performance and reduction of oxidation heat recovery due to regeneration treatment. It is also possible to prevent excessive consumption of energy.
＜実施例＞ 第４図は、第３図のような焼結機排ガスの脱硫・脱硝処
理フローに於ける本発明方法を適用しない従来の排ガス
中CO濃度、COガス酸化率、触媒出側排ガス温度及び加熱
炉投入熱量等の経時変化の一例を示す特性図である。<Example> FIG. 4 is a conventional exhaust gas CO concentration, CO gas oxidation rate, catalyst outlet exhaust gas to which the method of the present invention is not applied in the desulfurization / denitration processing flow of the exhaust gas of the sintering machine as shown in FIG. It is a characteristic view which shows an example of a time-dependent change of temperature, a heating furnace input heat quantity, etc.
時刻T1以後の排ガス中のCO濃度の低下に伴ない、時刻T2
以後酸化触媒のCOガス酸化率および排ガス温度が急に低
下しているのがわかる。この場合、系内に熱を加えない
と熱バランスがとれないため、時刻T2以後加熱炉に投入
する燃料ガスを増して系内温度を上げ、触媒の酸化率の
低下は防げたが、酸化率の回復がないため、触媒出側温
度は450〜460℃付近で平衡している。その後CO濃度の上
昇も、酸化率の回復もないため、時刻T3で触媒再生を図
るため更に加熱炉の投入熱量を増加させ、それに伴い時
刻T4で触媒の酸化率が上昇し始め触媒は再生を開始し
た。その後触媒は酸化率を回復し、触媒出側排ガス温度
は定常運転温度域（490〜500℃）に達した。定常運転状
況を確認の上、時刻T6で触媒再生は完了したと判断し
て、加熱炉投入熱量を定常レベルに減じた。As the CO concentration in the exhaust gas decreases after time T 1 , time T 2
After that, it can be seen that the CO gas oxidation rate of the oxidation catalyst and the exhaust gas temperature suddenly dropped. In this case, since it is not possible to heat balance unless adding heat to the system, increasing the fuel gas to be introduced into the time T 2, after the furnace increases the temperature in the system, but prevented the decrease in the oxidation rate of the catalyst, oxidation Since there is no rate recovery, the catalyst outlet temperature is in equilibrium around 450-460 ° C. After that, since the CO concentration does not increase and the oxidation rate does not recover, the amount of heat input to the heating furnace is further increased in order to regenerate the catalyst at time T 3 , and the oxidation rate of the catalyst begins to increase at time T 4 , and the catalyst Playback started. After that, the catalyst recovered its oxidation rate and the exhaust gas temperature on the catalyst exit side reached the steady operating temperature range (490 to 500 ° C). After confirming the steady operation status, it was judged that the catalyst regeneration was completed at time T 6 , and the heating furnace input heat quantity was reduced to a steady level.
このように触媒再生に要する時間は触媒再生開始時の判
断にもよるが、再生完了まで約半日程度を要し、再生終
了に多大なエネルギーを要した。As described above, the time required for catalyst regeneration depends on the judgment at the start of catalyst regeneration, but it takes about half a day until the regeneration is completed, and much energy is required to finish the regeneration.
第１図は、本発明を適用した場合の前記第４図と同様の
各数値の経時変化を示す。図示省略した排ガス分析装置
により焼結機出側排ガスのCO濃度が所定の下限値1.5％
を下回るまで低下したのを検知したら（時刻T1）、直ち
にコークス平均粒径をそれ以前の1.6mmから1.4mmまで低
下させ、排ガス中CO濃度を下限値の1.5％以上に上昇さ
せ、触媒によるCO酸化率の低下、排ガス温度低下を抑制
し、触媒の劣化を最小限に抑えることができた。FIG. 1 shows the changes over time in the same numerical values as in FIG. 4 when the present invention is applied. The CO concentration of the exhaust gas on the outlet side of the sintering machine was set to a predetermined lower limit of 1.5% by an exhaust gas analyzer not shown.
When it is detected that the temperature has fallen below the value (time T 1 ), the coke average particle size is immediately reduced from the previous 1.6 mm to 1.4 mm, the CO concentration in the exhaust gas is increased to 1.5% or more of the lower limit, and The deterioration of the catalyst could be minimized by suppressing the decrease of CO oxidation rate and the decrease of exhaust gas temperature.
なお、排ガス中CO濃度が低下した時点で、コークスの平
均粒径を低下させても、原料配合から焼結機出側に至る
トラッキングタイム（時刻T2からT3まで）の間は、排ガ
ス系内の温度低下を防止するために必要な量だけの燃料
ガスを加熱炉で増量し熱補償した。Even if the average particle size of coke is reduced at the time when the CO concentration in the exhaust gas decreases, the exhaust gas system is still present during the tracking time (from time T 2 to T 3 ) from the raw material blending to the sintering machine exit side. The amount of fuel gas required to prevent the temperature drop in the interior was increased in the heating furnace for thermal compensation.
前記実施例では粉コークス平均粒径を低下させることに
よって排ガス中CO濃度を下限値1.5％以上に調整する方
法について述べたが、本発明は、これに限るものでな
く、コークス比を増加させてもよく、またコークス平均
粒径の低下とコークス配合比の増加を同時に行ってもよ
い。In the above-mentioned example, the method of adjusting the CO concentration in the exhaust gas to the lower limit value of 1.5% or more by reducing the average particle size of the coke powder was described, but the present invention is not limited to this, and the coke ratio can be increased. Alternatively, the average coke particle size may be decreased and the coke blending ratio may be increased at the same time.
このように、本発明によって排ガス中のCOガス酸化触媒
の劣化が抑制され、再生に要する時間が大幅に短縮、も
しくは不必要となった。As described above, according to the present invention, the deterioration of the CO gas oxidation catalyst in the exhaust gas is suppressed, and the time required for regeneration is significantly shortened or made unnecessary.
＜発明の効果＞ 本発明によると、コークスの平均粒径および／もしくは
コークス配合比を変化させ排ガス中CO濃度を下限値以上
に管理することによってCO酸化触媒の劣化を抑制し、そ
の再生に要する時間を短縮、もしくは必要としなくする
ことができた。<Effects of the Invention> According to the present invention, deterioration of the CO oxidation catalyst is suppressed by changing the average particle size of the coke and / or the coke mixing ratio to control the CO concentration in the exhaust gas to be not less than the lower limit value, and it is necessary for regeneration. We were able to save time or eliminate it.
第１図は本発明方法を適用したときの排ガス中CO濃度な
どの各数値の経時変化の例を示す特性図、第２図は、コ
ークス配合比をパラメーターとした粉コークス平均粒径
と排ガス中のCOガス濃度との関係を模式的に示す特性
図、第３図は、焼結機の排ガス脱硫・脱硝処理工程
（例）を示すフロー図、第４図は、従来例における排ガ
ス中CO濃度などの各数値の経時変化の１例を示す特性図
である。 １……焼結機、２……脱硫反応器、 ３……熱交換器、４……排ガスブロワー、 ５……加熱炉、６……脱硝反応器、 ７……COガス酸化触媒装置、８……煙突、 ９……燃料ガス、10……排ガス。FIG. 1 is a characteristic diagram showing an example of changes with time of various numerical values such as CO concentration in exhaust gas when the method of the present invention is applied, and FIG. Fig. 3 is a characteristic diagram that schematically shows the relationship with the CO gas concentration, Fig. 3 is a flow chart showing the exhaust gas desulfurization / denitration treatment process (example) of the sintering machine, and Fig. 4 is the CO concentration in exhaust gas in the conventional example. It is a characteristic view showing an example of a change with time of each numerical value such as. 1 ... Sintering machine, 2 ... Desulfurization reactor, 3 ... Heat exchanger, 4 ... Exhaust gas blower, 5 ... Heating furnace, 6 ... Denitration reactor, 7 ... CO gas oxidation catalyst device, 8 ...... Chimney, 9 ... Fuel gas, 10 ... Exhaust gas.
Claims (1)
ガスの潜熱回収用のCOガス酸化触媒の劣化抑制方法にお
いて、 COガス酸化前の排ガス中CO濃度を連続的に分析し、COガ
ス濃度が所定の下限値を超えて低下した場合は、焼結鉱
原料中の粉コークスの平均粒径を低下させおよび／また
はコークス配合比を上昇させ、COガス濃度が前記下限値
以上になるように調整することを特徴とする焼結排ガス
処理系内のCOガス酸化触媒の劣化抑制方法。[Claim 1] CO in an exhaust gas desulfurization / denitration treatment system at a sintering plant
In the method for suppressing the deterioration of the CO gas oxidation catalyst for recovering latent heat of gas, the CO concentration in the exhaust gas before CO gas oxidation is continuously analyzed, and if the CO gas concentration falls below the specified lower limit, sintering is performed. CO in a sintering exhaust gas treatment system characterized by decreasing the average particle size of powder coke in a mineral raw material and / or increasing the coke blending ratio so that the CO gas concentration is equal to or higher than the lower limit value. A method for suppressing deterioration of a gas oxidation catalyst.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33269189A JPH0776386B2 (en) | 1989-12-25 | 1989-12-25 | Method for suppressing deterioration of CO gas oxidation catalyst in sintering exhaust gas treatment system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33269189A JPH0776386B2 (en) | 1989-12-25 | 1989-12-25 | Method for suppressing deterioration of CO gas oxidation catalyst in sintering exhaust gas treatment system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03193831A JPH03193831A (en) | 1991-08-23 |
| JPH0776386B2 true JPH0776386B2 (en) | 1995-08-16 |
Family
ID=18257804
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33269189A Expired - Lifetime JPH0776386B2 (en) | 1989-12-25 | 1989-12-25 | Method for suppressing deterioration of CO gas oxidation catalyst in sintering exhaust gas treatment system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0776386B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7700527B2 (en) * | 2021-06-17 | 2025-07-01 | 住友金属鉱山株式会社 | Reduction treatment method and reduction treatment device |
-
1989
- 1989-12-25 JP JP33269189A patent/JPH0776386B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03193831A (en) | 1991-08-23 |
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