JPH0790137B2 - Refining method for high temperature reducing gas - Google Patents
Refining method for high temperature reducing gasInfo
- Publication number
- JPH0790137B2 JPH0790137B2 JP63027441A JP2744188A JPH0790137B2 JP H0790137 B2 JPH0790137 B2 JP H0790137B2 JP 63027441 A JP63027441 A JP 63027441A JP 2744188 A JP2744188 A JP 2744188A JP H0790137 B2 JPH0790137 B2 JP H0790137B2
- Authority
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- Prior art keywords
- gas
- regeneration
- reactor
- absorbent
- temperature
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Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
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- Gas Separation By Absorption (AREA)
- Industrial Gases (AREA)
- Treating Waste Gases (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は高温還元性ガスの精製方法に関し、例えば石炭
ガス化プロセスの生成ガスのような高温の還元性ガスに
含まれる硫化水素、硫化カルボニル等の硫黄化合物を合
理的に除去する方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for refining a high-temperature reducing gas, for example, hydrogen sulfide and carbonyl sulfide contained in a high-temperature reducing gas such as a product gas of a coal gasification process. Etc. to a method for rationally removing sulfur compounds.
近年、石油資源の枯渇、価格の高騰から燃料(又は原
料)の多様化が叫ばれ、石炭や重質油(タールサンド
油、オイルシエール油、大慶原油、マヤ原油あるいは減
圧残油など)の利用技術の開発が進められている。しか
し、このガス化生成ガスには原料の石炭や重質油によつ
て異なるが、数100〜数1000ppmの硫化水素(H2S)、硫
化カルボニル(COS)等の硫黄化合物を含み、公害防止
上あるいは後流機器の腐食防止のため除去する必要があ
る。この除去方法としては乾式法が熱経済的にも有利
で、プロセス構成も簡素なことから、金属酸化物を主成
分とする吸収剤を高温で硫化物として吸収除去する方法
が一般的になつている。In recent years, due to depletion of petroleum resources and soaring prices, the diversification of fuels (or raw materials) has been called for, and the use of coal and heavy oil (tar sand oil, oil shale oil, Daqing crude oil, Maya crude oil, vacuum residual oil, etc.) Technology is being developed. However, this gasification product gas contains sulfur compounds such as hydrogen sulfide (H 2 S) and carbonyl sulfide (COS) in the range of several hundreds to several thousand ppm, depending on the raw material coal or heavy oil, but it does not prevent pollution. It must be removed to prevent corrosion of the upstream or downstream equipment. As a method for removing this, the dry method is also advantageous in terms of thermo-economics, and the process configuration is simple. Therefore, the method of absorbing and removing the sorbent containing a metal oxide as the main component as a sulfide at a high temperature is generally used. There is.
吸収剤としてはFe,Zn,Mn,Cu,Mo,Wなどの金属酸化物が使
用され、250〜500℃で硫化水素(H2S)や硫化カルボニ
ル(COS)と反応させるが、H2SとFe2O3の場合を例に説
明すると、吸収反応は(1)〜(4)式に示すように進
むとされている。As the absorbent, metal oxides such as Fe, Zn, Mn, Cu, Mo, W are used, and it reacts with hydrogen sulfide (H 2 S) and carbonyl sulfide (COS) at 250 to 500 ℃, but H 2 S In the case of Fe 2 O 3 and Fe 2 O 3 , for example, it is said that the absorption reaction proceeds as shown in equations (1) to (4).
3Fe2O3+H2→2Fe3O4+H2O ……(1) 3Fe2O3+CO→2Fe3O4+CO2 ……(2) Fe3O4+H2+3H2S→3FeS+4H2O ……(3) Fe3O4+CO+3H2S→3FeS+3H2O+CO2 ……(4) 次いで、吸収反応後の吸収剤は酸素含有ガスで(5)式
に示すように元の金属酸化物に再生され、この吸収,再
生反応の繰返しで高温還元性ガス中の硫黄化合物はSO2
ガスとして回収除去される。3Fe 2 O 3 + H 2 → 2Fe 3 O 4 + H 2 O …… (1) 3Fe 2 O 3 + CO → 2Fe 3 O 4 + CO 2 …… (2) Fe 3 O 4 + H 2 + 3H 2 S → 3FeS + 4H 2 O… … (3) Fe 3 O 4 + CO + 3H 2 S → 3FeS + 3H 2 O + CO 2 …… (4) Next, the absorbent after the absorption reaction is regenerated into the original metal oxide with oxygen-containing gas as shown in equation (5). , Sulfur compounds in high temperature reducing gas are SO 2 by repeating this absorption and regeneration reaction.
It is recovered and removed as gas.
4FeS+7O2→2Fe2O3+4SO2 ……(5) このプロセスで使用される吸収剤は、前述の金属酸化物
を単独あるいは耐熱性の多孔質物質に担持したものを、
移動床方式の場合は球状や円柱状に成形したものが、固
定床方式の場合はハニカム状に形成したものが通常使用
される。石炭ガス化ガスのような還元性ガスから硫黄化
合物を除去して精製されたガスはエネルギー源として利
用されるので、CO,H2濃度を安定して製造するプロセス
が好ましく、(1)式,(2)式の反応を極力抑制しな
ければならない。流動床,移動床方式では吸収工程と再
生工程が連続的に繰返されるのでこの技術的課題は克服
しやすいが、固定床方式では吸収工程と再生工程を断続
的に繰返すので再生後の吸収反応開始時に精製ガス中の
CO,H2濃度が一時的に低下し、高温還元性ガスの精製方
法としては実用上好ましくない。4FeS + 7O 2 → 2Fe 2 O 3 + 4SO 2 (5) The absorbent used in this process is the above-mentioned metal oxide, either alone or supported on a heat-resistant porous material.
In the case of the moving bed system, those formed in a spherical shape or in a cylindrical shape are usually used, and in the case of the fixed bed system, those formed in a honeycomb shape are usually used. Since a gas purified by removing sulfur compounds from a reducing gas such as coal gasification gas is used as an energy source, a process for producing stable CO and H 2 concentrations is preferable. The reaction of equation (2) must be suppressed as much as possible. In the fluidized bed and moving bed systems, the absorption process and the regeneration process are repeated continuously, so this technical problem is easy to overcome, but in the fixed bed system, the absorption process and the regeneration process are repeated intermittently, so the absorption reaction after regeneration starts. Sometimes in the purified gas
The CO and H 2 concentrations are temporarily reduced, which is not practically preferable as a refining method for high-temperature reducing gas.
そこで本発明者らは、高温還元性ガス中に含まれるイオ
ウ化合物を、金属酸化物を主成分とする吸収剤で吸着除
去する方法において、該イオウ化合物を吸着した吸着剤
を酸素含有ガスで再生する工程、次いで再生された吸収
剤を高温還元性ガスで該吸収剤前後の精製の対象となる
還元ガス濃度が同一になるまで還元する工程、次いで該
高温還元性ガスを通気して該吸収剤で該イオウ化合物を
吸着除去する工程を連続的に繰り返すことにより精製ガ
ス中の還元性ガス濃度を安定化させることを特徴とする
高温還元性ガスの精製法を提案した(特願昭60〜85412
号)。Therefore, the present inventors have proposed a method in which a sulfur compound contained in a high-temperature reducing gas is adsorbed and removed by an adsorbent containing a metal oxide as a main component, and the adsorbent adsorbing the sulfur compound is regenerated with an oxygen-containing gas. And then reducing the regenerated absorbent with a high temperature reducing gas until the concentration of the reducing gas before and after the absorbent becomes the same, and then by aeration of the high temperature reducing gas Proposed a method for refining high-temperature reducing gas, characterized in that the reducing gas concentration in the purified gas is stabilized by continuously repeating the step of adsorbing and removing the sulfur compound (Japanese Patent Application No. 60-85412).
issue).
また本発明者らは、高温還元性ガス中に含まれる硫化水
素、硫化カルボニル等の硫黄化合物を吸収剤で吸収除去
する方法で、再生された吸収剤を高温還元性ガスで該吸
収剤前後の対象となる還元性ガス濃度が一定となるまで
還元後、該硫黄化合物を吸収除去する工程を連続的に繰
返す高温還元性ガスの精製方法において、吸収剤を充填
した反応器を少なくとも三塔使用し、吸収、予備再生、
再生および還元の四工程より構成し、該高温還元性ガス
を通気して該吸収剤で該硫黄化合物を吸収除去すること
により、吸収、再生の性能を安定化させることを特徴と
する高温還元性ガスの精製方法(特願昭62〜167814号)
や、高温還元性ガスに含まれる硫化水素,硫化カルボニ
ル等の硫黄化合物を吸収除去する方法において、該硫黄
化合物を吸収剤で吸収除去する工程、該硫黄化合物を吸
収した該吸収剤を再生反応に必要な温度に達するまで昇
温させる予備再生工程、再生反応温度に到達した該吸収
剤を酸素含有ガスで再生する工程、再生された該吸収剤
を高温還元性ガスで該吸収剤前後の還元性ガス濃度が同
一になるまで還元する工程の四工程で構成すると共に、
前記再生工程に循環させるガス量を調節するか、又はこ
の再生循環ガス量の調節と再生工程に供給される高温還
元性ガスの燃焼熱の利用とにより、低負荷時の吸収,再
生の性能を安定化させることを特徴とする高温還元性ガ
スの精製法(特願昭62〜167815号)などを提案してき
た。In addition, the inventors of the present invention have a method of absorbing and removing a sulfur compound such as hydrogen sulfide and carbonyl sulfide contained in a high-temperature reducing gas with an absorbent, thereby recovering a regenerated absorbent with a high-temperature reducing gas before and after the absorbent. After reducing until the target reducing gas concentration becomes constant, in a method for refining a high-temperature reducing gas in which the step of absorbing and removing the sulfur compound is continuously repeated, at least three reactors packed with an absorbent are used. Absorption, pre-regeneration,
A high-temperature reducing property characterized by comprising four steps of regeneration and reduction and stabilizing the absorption and regeneration performance by aerating the high-temperature reducing gas and absorbing and removing the sulfur compound with the absorbent. Gas purification method (Japanese Patent Application No. 62-167814)
Or a method of absorbing and removing a sulfur compound such as hydrogen sulfide and carbonyl sulfide contained in a high-temperature reducing gas in a step of absorbing and removing the sulfur compound with an absorbent, and absorbing the sulfur compound into a regeneration reaction. Preliminary regeneration step of raising the temperature to reach the required temperature, step of regenerating the absorbent that has reached the regeneration reaction temperature with an oxygen-containing gas, reducing the regenerated absorbent with a high temperature reducing gas before and after the absorbent It consists of four steps of reducing until the gas concentration becomes the same,
By adjusting the amount of gas circulated in the regeneration process, or by adjusting the amount of the recycle gas and utilizing the combustion heat of the high-temperature reducing gas supplied to the regeneration process, absorption and regeneration performance at low load can be improved. We have proposed a refining method for high-temperature reducing gas, which is characterized by stabilization (Japanese Patent Application No. 62-167815).
吸収工程における通常の処理ガス温度は300〜500℃であ
るが、再生工程の場合再生用ガス中の酸素ガス(O2)が
吸収工程で硫化された吸収剤中の硫化鉄と前記(5)式
で反応し、その際発生する反応熱によつて500〜900℃に
も達する。高温ガスに接触した吸収剤は蓄熱現象を生じ
て、異常高温となり、その結果吸収剤の破壊に至ること
もあることから、吸収剤への異常蓄積を緩和するような
再生システムの導入が期待されている。反応熱の大小と
関係する再生反応器入口ガス中のO2濃度は固定床方式の
場合通常1〜3%であり、ガス中O2濃度を上げると、再
生循環ガス量はそれに逆比例して少なくなるので、再生
系内の設備及び電力消費は経済的となる利点があるが、
反面所定濃度以上になると前述のような吸収剤にとつて
好ましくない現象が起こることとなり、再生反応器入口
ガス中のO2濃度を単に制御するだけでは経済的かつ効果
的な方法とは言い難い。吸収,再生,還元の各工程から
なる脱硫再生サイクルが連続的にかつスムーズに行わ
れ、その上安定した吸収,再生の性能が得られると共に
後段のS回収系の負荷変動が最も小さい塔切替えシステ
ムを採用した高温還元性ガスの精製方法とする必要があ
る。The normal process gas temperature in the absorption process is 300 to 500 ° C, but in the case of the regeneration process, the oxygen gas (O 2 ) in the regeneration gas is sulfided in the absorption process and the iron sulfide in the absorbent and the above (5). The reaction takes place according to the formula, and due to the heat of reaction generated at that time, it reaches 500 to 900 ° C. Since the absorbent that comes into contact with high-temperature gas causes a heat storage phenomenon and becomes an abnormally high temperature, which may result in the destruction of the absorbent, it is expected to introduce a regeneration system that alleviates the abnormal accumulation in the absorbent. ing. O 2 concentration in the regeneration reactor inlet gases associated with the magnitude of the reaction heat in the case of a fixed bed system is usually 1-3%, increasing the O 2 concentration in the gas, regeneration recycle gas volume is inversely proportional to it Since there is less, there is an advantage that the equipment and power consumption in the regeneration system become economical,
On the other hand, if the concentration exceeds a certain level, the above-mentioned unfavorable phenomenon will occur with the absorbent, and it is difficult to say that it is an economical and effective method simply by controlling the O 2 concentration in the gas at the inlet of the regeneration reactor. . A tower switching system in which the desulfurization regeneration cycle consisting of absorption, regeneration, and reduction steps is continuously and smoothly performed, and moreover stable absorption and regeneration performance is obtained and the load fluctuation of the S recovery system in the latter stage is the smallest. It is necessary to adopt a method of refining a high-temperature reducing gas that adopts.
本発明は、吸収,再生,還元の各工程を一塔ずつ操作す
るシステムにおいて、高温還元性ガスの精製方法がかか
える前述の欠点を解消しうる方法を提供するものであ
り、特に再生工程で生じる再生反応熱に起因する吸収剤
への異常蓄熱を緩和し、結果的には吸収剤の寿命を保護
するとともに安定した吸収,再生の性能が得られる方法
を提供するものである。The present invention provides a method capable of eliminating the above-mentioned drawbacks associated with a method for purifying a high-temperature reducing gas in a system in which absorption, regeneration, and reduction steps are operated one tower at a time, particularly in the regeneration step. It is intended to provide a method for alleviating abnormal heat storage in an absorbent due to heat of regeneration reaction, eventually protecting the life of the absorbent and obtaining stable absorption and regeneration performance.
〔課題を解決するための手段〕 本発明は高温還元性ガス中に含まれる硫化水素、硫化カ
ルボニル等の硫黄化合物を吸収剤で吸収除去する方法に
おいて、吸収剤を充填した反応器を少なくとも四塔使用
し、該硫黄化合物を吸収剤で吸収除去する吸収工程、該
吸収剤を酸素含有ガスで再生する再生工程、再生工程完
了後の冷却工程、再生された該吸収剤を高温還元性ガス
で該吸収剤前後の還元性ガス濃度が同一になるまで還元
する還元工程の四工程より構成し、再生工程にある反応
器における再生が終了する前に次に再生工程を開始する
反応器との一部並列再生を行うようにすると共に、再生
終了後の冷却工程にある反応器の出口ガスを再生工程に
ある反応器に導入して再生ガスの一部とし、かつ、前記
再生工程において、再生反応器出口高温ガスから連続的
に熱回収を行い吸収、再生の性能を安定化させることを
特徴とする高温還元性ガスの精製方法である。[Means for Solving the Problems] The present invention is a method of absorbing and removing a sulfur compound such as hydrogen sulfide and carbonyl sulfide contained in a high-temperature reducing gas with an absorbent, in which at least four reactors are filled with the absorbent. An absorption step of absorbing and removing the sulfur compound with an absorbent, a regeneration step of regenerating the absorbent with an oxygen-containing gas, a cooling step after completion of the regeneration step, a regeneration step of the regenerated absorbent with a high-temperature reducing gas. Part of the reactor that consists of four steps of reduction process that reduces until the reducing gas concentration before and after the absorbent becomes the same and starts the next regeneration process before the regeneration in the reactor in the regeneration process is completed In addition to performing parallel regeneration, the outlet gas of the reactor in the cooling step after the regeneration is introduced into the reactor in the regeneration step to be a part of the regeneration gas, and in the regeneration step, the regeneration reactor High temperature outlet It is a method for refining a high-temperature reducing gas, characterized in that heat is continuously recovered from the gas to stabilize absorption and regeneration performance.
吸収反応後の吸収剤を再生して、硫黄化合物を吸収でき
る状態にする場合再生反応温度が低い程下記(6)〜
(9)式のような硫酸塩生成反応が起こりやすくなる。
これらの硫酸塩が吸収剤内部に残留し、細孔を閉塞させ
ると、高温で再生させても完全に脱離させることができ
ず、吸収剤の性能低下をきたす。When the absorbent after the absorption reaction is regenerated so that the sulfur compound can be absorbed, the following (6) to
The sulfate-forming reaction as in the formula (9) is likely to occur.
If these sulfates remain inside the absorbent and block the pores, they cannot be completely desorbed even when they are regenerated at a high temperature, resulting in deterioration of the performance of the absorbent.
FeS+2O2→FeSO4 ……(6) 2FeS+SO2+5O2→Fe2(SO4)3 ……(7) 2Fe2O3+4SO2+O2→4FeSO2 ……(8) 2Fe2O3+6SO2+3O2→2Fe2(SO4)3 ……(9) 従つて上記硫酸塩を副生させないようにするために、再
生反応温度はある程度高くする必要がある。しかし必要
以上に高温になり過ぎると吸収剤の破壊を招くこととな
り、再生温度や再生用ガス中のO2ガス濃度の選択と共に
再生システムが重要となつてくる。FeS + 2O 2 → FeSO 4 …… (6) 2FeS + SO 2 + 5O 2 → Fe 2 (SO 4 ) 3 …… (7) 2Fe 2 O 3 + 4SO 2 + O 2 → 4FeSO 2 …… (8) 2Fe 2 O 3 + 6SO 2 + 3O 2 → 2Fe 2 (SO 4 ) 3 (9) Therefore, the regeneration reaction temperature must be raised to some extent in order to prevent the above-mentioned sulfate from being produced as a by-product. However, if the temperature becomes too high than necessary, the absorbent will be destroyed, and the regeneration system becomes important together with the selection of the regeneration temperature and the O 2 gas concentration in the regeneration gas.
吸収,再生,還元からなる連続脱硫再生システムにおい
て、塔の数に応じて種々の塔切替えパターンが考えら
れ、その再生システムも異なるが、吸収工程を完了した
反応器の再生処理を1塔毎に、独立して行うケースが多
い。その際再生用ガスの導入は吸収操作と並流か向流で
あるので、出口側になるほど反応熱の移動や吸収剤の蓄
熱現象によりガスは高温となりやすく、吸収剤にとつて
可酷な雰囲気となる。かと言つて例えばガスを再生反応
器の中段から導入する分割再生操作も再生塔が一塔の場
合採用し難い。吸収剤の再生が進むにつれて、反応器出
口ガス中にO2ガスが出やすくなるが、このO2ガスが後段
のSO2還元反応器に混入しないようにしなければなら
ず、再生反応器の再生時の管理や吸収,還元を含めた全
体の塔切替えタイムシステムを考慮した場合実用生に乏
しいと言える。In a continuous desulfurization regeneration system consisting of absorption, regeneration, and reduction, various tower switching patterns are conceivable depending on the number of towers, and the regeneration system also differs, but the regeneration treatment of the reactor that completed the absorption process is performed for each tower. , In many cases, it is done independently. At that time, since the introduction of the regeneration gas is either co-current or countercurrent with the absorption operation, the gas tends to reach a higher temperature due to the transfer of reaction heat and the heat storage phenomenon of the absorbent toward the outlet side, and the atmosphere is harsh for the absorbent. Becomes On the other hand, it is difficult to adopt the split regeneration operation in which gas is introduced from the middle stage of the regeneration reactor when the regeneration tower is one. As the absorbent is regenerated, O 2 gas tends to come out in the reactor outlet gas, but it is necessary to prevent this O 2 gas from mixing with the SO 2 reduction reactor in the subsequent stage. Considering the entire tower switching time system including time management, absorption, and reduction, it can be said that it is poor for practical use.
そこで再生反応器を二塔設置し、前述のような技術的課
題を解消したのが本発明方法である。本発明方法は再生
反応熱に由来する吸収剤への異常蓄熱を緩和し、結果的
には吸収剤の寿命保護を行うと共に再生反応器での生成
SO2ガスの濃度変動を抑制し得る利点を有している。Therefore, the method of the present invention is one in which two regeneration reactors are installed to solve the above technical problems. The method of the present invention alleviates the abnormal heat storage in the absorbent due to the heat of the regeneration reaction, and consequently protects the life of the absorbent and produces it in the regeneration reactor.
It has the advantage of suppressing fluctuations in the concentration of SO 2 gas.
本発明方法では吸収剤を充填した反応器を少なくとも四
塔使用し、吸収,再生,冷却,還元の各工程を例えば4,
6,2,4の時間配分からなるサイクルで行わさせ、特に冷
却工程を含めた再生工程では再生反応器を二塔設置し
て、一部並列再生を行うようにした点に特徴がある。す
なわち、吸収工程を完了した吸収剤の再生を十分に行わ
せるために、再生終了後の冷却工程時でも該反応器へO2
含有ガスを通気する。しかし再生を終えた吸収剤にはO2
ガスを必要としないので、再生反応器出口からO2ガスが
出ることとなるが、このガスをもう一方の再生反応器の
中段に導入し、S回収系ガス中にO2ガスが混入しないよ
うにする。In the method of the present invention, at least four reactors packed with an absorbent are used, and the steps of absorption, regeneration, cooling, and reduction are carried out by, for example, 4,
It is characterized in that it is carried out in a cycle consisting of 6,2,4 time distribution, and particularly in the regeneration process including the cooling process, two regeneration reactors are installed and partial regeneration is performed. That is, in order to sufficiently perform the regeneration of the absorbent that has completed the absorption step, O 2 is supplied to the reactor even during the cooling step after the completion of the regeneration.
Aerate the contained gas. However, O 2 is not
Since no gas is required, O 2 gas will come out from the outlet of the regeneration reactor, but introduce this gas into the middle stage of the other regeneration reactor so that O 2 gas will not be mixed in the S recovery system gas. To
このように、再生終了後の冷却工程出口ガスはもう一方
の再生反応器の中段に導入するが、それ以前からその再
生反応器には入口から再生用ガスが導入されており、冷
却工程出口ガスと再生用ガスが相待つて、それらの一連
の操作によつて再生操作が進む。もう一方の再生反応器
の中段に導入する再生終了後の冷却工程出口ガスの温度
は再生反応器入口ガス温度より高いので、再生反応器入
口温度程度まで熱交換器で冷却後もう一方の再生反応器
に導入する。このように分割再生方法を一部採用するこ
とにより、吸収剤の反応熱に由来する異常高温を避け、
吸収剤を破壊から保護できる。In this way, the cooling process outlet gas after the regeneration is introduced to the middle stage of the other regeneration reactor, but the regeneration gas is introduced from the inlet to the regeneration reactor before that, and the cooling process outlet gas is introduced. And the regeneration gas waits for a while, and the regeneration operation proceeds by a series of these operations. Since the temperature of the outlet gas of the cooling process after the completion of regeneration introduced into the middle stage of the other regeneration reactor is higher than the temperature of the gas at the inlet of the regeneration reactor, the temperature of the gas at the inlet of the regeneration reactor is about the same as the temperature at the inlet of the regeneration reactor. Introduce into the vessel By partially adopting the divisional regeneration method in this way, avoiding abnormally high temperatures resulting from the reaction heat of the absorbent,
Can protect the absorbent from destruction.
なお以上の方法によつて、再生反応器出口高温ガスから
は連続的に有効に熱回収を行うことができ、それに伴い
吸収,再生に関する全体システムの熱バランスを保つこ
とができるので、吸収性能、再生性能の安定化に役立
つ。According to the above method, heat can be continuously and effectively recovered from the hot gas at the outlet of the regeneration reactor, and the heat balance of the entire system regarding absorption and regeneration can be maintained accordingly. It helps stabilize the playback performance.
第1図は本発明方法の一実施態様を示すである。 FIG. 1 shows an embodiment of the method of the present invention.
第1図において、1,2はH2S,COS等の硫黄化合物を含有す
る脱塵高温還元性ガスライン、3,4,5,6,7,8,10,12及び1
4は同ガス流路切替バルブ、9,11,13及び15は再生工程の
反応器から出る高濃度硫黄化合物を含有するガスの切替
バルブ、16,17,18及び19は吸着剤を充填した反応器、20
は吸着剤、21,22,23及び24は冷却工程にある反応器の出
口ガスに比較的低温の循環ガスの一部を混合したガスを
再生工程を行つている反応器の中段に供給するための流
路切替バルブ、25,26,27及び28は還元工程にある反応器
の出口ガスを吸収工程にある反応器の中段に供給するた
めの流路切替バルブ、29,32,35及び38は還元工程にある
反応器の出口ガスの流路切替バルブ、30,33,36及び39は
吸収工程にある反応器からの精製ガスの流路切替バル
ブ、31,34,37及び40は再生工程にある反応器への再生ガ
ス供給のための流路切替バルブ、41は再生ガス循環ライ
ン、42は精製ガス取出ライン、43は還元性ガスの流路切
替バルブ、44は還元性ガスライン、45は後述のライン50
の分岐ライン、46は同流路切替バルブ、47は空気又は酸
素含有ガス供給ライン、48は熱交換器、49は後述のライ
ン50の分岐ライン、50は高濃度硫黄化合物含有ガスから
硫黄を分離した残りのガスライン、51は50の分岐ライ
ン、52は降温された高濃度硫黄化合物含有ガスライン、
53は硫黄回収装置、54は熱交換器、55はガスライン、56
は熱交換器、57は硫黄回収装置、58,59はガスライン、6
0はブロワーである。In FIG. 1, 1 and 2 are dedusting high-temperature reducing gas lines containing sulfur compounds such as H 2 S and COS, 3,4,5,6,7,8,10,12 and 1
4 is the same gas flow path switching valve, 9, 11, 13 and 15 are gas switching valves containing high-concentration sulfur compounds from the reactor of the regeneration process, 16, 17, 18 and 19 are reactions filled with adsorbent Bowl, 20
Is an adsorbent, and 21, 22, 23 and 24 are for supplying a gas obtained by mixing a part of a relatively low-temperature circulating gas to the outlet gas of the reactor in the cooling process to the middle stage of the reactor performing the regeneration process. The flow path switching valves of 25, 26, 27 and 28 are flow path switching valves for supplying the outlet gas of the reactor in the reduction step to the middle stage of the reactor in the absorption step, and 29, 32, 35 and 38 are Reactor outlet gas flow path switching valve in the reduction step, 30, 33, 36 and 39 are purified gas flow path switching valve from the absorption step reactor, 31, 34, 37 and 40 are in the regeneration step A flow passage switching valve for supplying a regeneration gas to a certain reactor, 41 is a regeneration gas circulation line, 42 is a purified gas extraction line, 43 is a reducing gas flow passage switching valve, 44 is a reducing gas line, and 45 is Line 50 below
A branch line, 46 is the same flow path switching valve, 47 is an air or oxygen-containing gas supply line, 48 is a heat exchanger, 49 is a branch line of a line 50 described below, 50 is sulfur from the high-concentration sulfur compound-containing gas. The remaining gas line, 51 is a branch line of 50, 52 is a cooled high-concentration sulfur compound-containing gas line,
53 is a sulfur recovery device, 54 is a heat exchanger, 55 is a gas line, 56
Is a heat exchanger, 57 is a sulfur recovery device, 58 and 59 are gas lines, 6
0 is a blower.
なお*1,*2,*3はライン51と相当するラインである。Note that * 1, * 2, and * 3 are lines corresponding to the line 51.
第1図では吸収剤20が充填された同一構造の反応器16〜
19を(1)式,(2)式による還元工程、(3)式、
(4)式による吸収工程、(5)式による再生工程と順
次切替えていく実施態様を示しているが、本発明は固定
床式に限定されるものではなく、還元ガス中のH2S,COS
等の硫黄化合物を吸収剤で吸収除去後、(5)式による
再生を繰返すプロセスなら流動床式,移動床式を問わず
適用できる。また、四塔以上の固定床式にも適用できる
のはいうまでもない。さらに、吸収剤の組成,形状に何
ら限定されるものではないが、ここではFe2O3を吸収剤
とする場合につき説明する。In FIG. 1, the reactor 16 of the same structure filled with the absorbent 20
19 is the reduction step according to the equations (1) and (2), the equation (3),
An embodiment in which the absorption step according to the formula (4) and the regeneration step according to the formula (5) are sequentially switched is shown, but the present invention is not limited to the fixed bed type, and H 2 S, COS
A process of repeating regeneration by the formula (5) after absorbing and removing sulfur compounds such as the above can be applied to both the fluidized bed system and the moving bed system. Needless to say, it can be applied to a fixed bed type with four or more towers. Further, although the composition and shape of the absorbent are not particularly limited, here, the case where Fe 2 O 3 is used as the absorbent will be described.
H2S,COS等の硫黄化合物を含有する高温還元性ガス1
は、例えば石炭のガス化ガスを集塵装置でダスト濃度10
mg/Nm3程度まで脱塵したものであり、石炭の種類やガス
化条件で異なるがダスト以外に数10〜数1000ppmのH2S,C
OS,NH3及びハロゲン等が含まれており、ガス温度はガス
化炉出口部での燃回収により250〜500℃、圧力はガス化
炉の形式により異なるが常圧〜25kg/cm2Gである。High temperature reducing gas containing sulfur compounds such as H 2 S and COS 1
For example, if the coal gasification gas has a dust concentration of 10
mg / Nm 3 about to is obtained by dedusting, of different but several tens to several hundreds of 1000ppm besides dust coal types and gasification conditions H 2 S, C
It contains OS, NH 3, halogen, etc., the gas temperature is 250 to 500 ° C due to the fuel recovery at the gasifier outlet, and the pressure varies from atmospheric pressure to 25 kg / cm 2 G depending on the type of gasifier. is there.
第1は反応器16で吸収工程を、反応器17で還元工程を、
反応器18,19で再生工程を行つている状態を示してい
る。The first is the absorption step in the reactor 16 and the reduction step in the reactor 17,
The state in which the regeneration process is being performed in the reactors 18 and 19 is shown.
第2図は本発明実施時の吸収,再生,冷却,還元サイク
ルのタイムスケジユールを第3図は吸収ガス温度を450
℃、再生入口ガス温度を500℃とした場合の再生塔出口
ガス温度の時間的変化の一例を示している。FIG. 2 shows the time schedule of the absorption, regeneration, cooling, and reduction cycles when the present invention is carried out, and FIG. 3 shows the absorption gas temperature of 450.
The graph shows an example of the temporal change of the regeneration tower outlet gas temperature when the regeneration inlet gas temperature is 500 ° C and the regeneration inlet gas temperature is 500 ° C.
第1図において脱塵ガス化ガス1は流路切替バルブ4を
介して反応器16に吸収され、該ガス中の硫黄化合物が通
常300〜500℃で(3)式,(4)式によつて吸収剤20に
吸収除去され、流路切替バルブ30を介して精製ガス42と
なり、後流のガスタービンに供給される。In FIG. 1, the dedusted gasified gas 1 is absorbed by the reactor 16 via the flow path switching valve 4, and the sulfur compound in the gas is usually 300 to 500 ° C. according to the formulas (3) and (4). Then, it is absorbed and removed by the absorbent 20, becomes purified gas 42 through the flow path switching valve 30, and is supplied to the gas turbine in the downstream.
第2図のタイムスケジユールにおいて、反応器18は反応
器19の4時間前に再生を開始しているという前提で以下
説明する。In the time schedule of FIG. 2, the explanation will be given below on the assumption that the reactor 18 starts regeneration 4 hours before the reactor 19.
吸収工程を完了した反応器19は再生工程に移るが、ライ
ン47より空気又は酸素含有ガスがライン50に供給され、
ライン49、熱交換器48、ライン41を経て流路切替バルブ
37及び40を介して反応器18及び19に導入される。吸収剤
の再生に用いられたガスは流路切替バルブ13及び15を介
し、熱交換器48、ライン52を介してSO2還元及び硫黄回
収装置53、熱交換器54、ライン55、熱交換器56を通つて
硫黄分離器57に導かれ、ライン64を経て硫黄が回収され
る。その後、硫黄を分離したガスはブロワー60を経てラ
イン47より空気又は酸素含有ガスの供給を受け、ライン
50、ライン49を通して熱交換器48で再生反応の必要温度
まで昇温された後、循環ガスライン41に戻される。The reactor 19 that has completed the absorption step moves to the regeneration step, but air or oxygen-containing gas is supplied to the line 50 from the line 47,
Flow path switching valve via line 49, heat exchanger 48, line 41
It is introduced into reactors 18 and 19 via 37 and 40. The gas used to regenerate the absorbent is passed through the flow path switching valves 13 and 15 and the SO 2 reduction and sulfur recovery device 53, the heat exchanger 54, the line 55, and the heat exchanger 48 and the line 52 through the line 52. It is led to the sulfur separator 57 via 56 and the sulfur is recovered via the line 64. After that, the gas from which sulfur has been separated is supplied with air or an oxygen-containing gas from a line 47 through a blower 60, and the line is supplied.
After being heated to the required temperature for the regeneration reaction in the heat exchanger 48 through the line 50 and the line 49, it is returned to the circulating gas line 41.
ガスライン41に戻されたガスは流路切替バルブ37及び40
を経て、再生中の反応器18及び19に導入され、再生反応
の促進に寄与した後、流路切替バルブ13及び15を介して
前述したように循環ガスとなる。The gas returned to the gas line 41 flows through the flow path switching valves 37 and 40.
After being introduced into the reactors 18 and 19 during regeneration and contributing to promotion of the regeneration reaction, it becomes a circulating gas through the flow path switching valves 13 and 15 as described above.
第2図に示すタイムスケジユールで連続脱硫再生サイク
ルを形成したとすれば反応器18は前述の流路でガスを8
時間循環通気し、吸収剤の再生を完全に完了させるが、
最初の6時間で再生はほぼ完了し、残こり2時間は再生
の完遂と冷却する役目をなす。この冷却工程の出口ガス
は再生反応器入口ガス温度より高いので、このガスにブ
ロアー60からの比較的低温(200〜300℃)の再生循環ガ
スの一部をライン50,51を経て、混合しその混合ガスを
反応器18及び19の入口ガス温度程度まで冷却後、流路切
替バルブ24を経て、もう一方の反応器19の中段に導入す
る。Assuming that a continuous desulfurization regeneration cycle is formed by the time schedule shown in FIG.
Circulate and vent for a period of time to complete the regeneration of the absorbent,
Regeneration is almost complete within the first 6 hours, and the remaining 2 hours serve to complete regeneration and cool down. Since the outlet gas of this cooling step is higher than the inlet gas temperature of the regeneration reactor, a part of the relatively low temperature (200-300 ° C) regeneration circulation gas from the blower 60 is mixed with this gas via lines 50 and 51. The mixed gas is cooled to about the inlet gas temperature of the reactors 18 and 19, and then introduced into the middle stage of the other reactor 19 via the flow path switching valve 24.
反応器19はその中段に反応器18の冷却工程のガスが導入
される2時間前から再生用ガスが導入されており、その
ガスはS回収系を経たガスにライン47からの空気又は酸
素含有ガスがライン50に供給され前述したようにライン
49、熱交換器48、ライン41を経て、流路切替バルブ40を
介する流路で導入される。反応器19は反応器18のそれと
同様の操作で再生される。即ち反応器入口から流路切替
バルブ40を介して、ライン47からの空気又は酸素含有ガ
スを供給した循環ライン41のガスが8時間導入される
が、導入開始2時間後からは再生反応器18の冷却工程の
ガスが流路切替バルブ24を通して2時間導入されること
となる。反応器19入口は8時間通ガスするが、最後の2
時間は前述したように反応器の冷却を目的とする冷却工
程となり、熱交換器48の低温側入口ライン49のガスを混
合し、反応器入口とほぼ同程度の温度となつたガスはす
でに2時間前から再生工程に移つている反応器16の中段
に流路切替バルブ21を介して導入され、一連の再生,冷
却工程を終了する。Regeneration gas is introduced into the reactor 19 from 2 hours before the gas in the cooling step of the reactor 18 is introduced into the middle stage thereof, and the gas is the gas that has passed through the S recovery system and contains air or oxygen from the line 47. Gas is supplied to line 50 and line as described above.
It is introduced through the flow path 49, the heat exchanger 48, and the line 41 through the flow path switching valve 40. Reactor 19 is regenerated in a similar manner to that of reactor 18. That is, the gas in the circulation line 41 supplied with the air or the oxygen-containing gas from the line 47 is introduced from the reactor inlet through the flow path switching valve 40 for 8 hours, but the regeneration reactor 18 is introduced 2 hours after the introduction is started. The gas in the cooling step of 2 is introduced through the flow path switching valve 24 for 2 hours. Gas is passed through the reactor 19 inlet for 8 hours, but the last 2
As described above, the cooling process is aimed at cooling the reactor, the gas in the low temperature side inlet line 49 of the heat exchanger 48 is mixed, and the gas that has reached a temperature almost the same as the reactor inlet is already 2 times. It is introduced through the flow path switching valve 21 into the middle stage of the reactor 16 which has been moved to the regeneration process from the time before, and a series of regeneration and cooling processes is completed.
この間の再生反応器出口ガス温度の挙動の一例を第3図
に示す。An example of the behavior of the gas temperature at the outlet of the regeneration reactor during this period is shown in FIG.
再生反応器を一塔毎独立して操作する場合再生工程開示
時の出口ガス温度はAの温度を示し、ほぼ入口ガス温度
に近いが、再生が進むにつれて、硫化鉄と酸素との発熱
反応の進行と熱と移動に伴つて出口ガス温度は徐々に高
温となり、Bの温度を示す。この場合のAとBの温度差
は約200℃となる。When the regeneration reactor is operated independently for each tower, the outlet gas temperature at the time of disclosure of the regeneration step shows the temperature of A and is almost close to the inlet gas temperature, but as the regeneration proceeds, the exothermic reaction of iron sulfide and oxygen The outlet gas temperature gradually increases with the progress, heat, and movement, and shows the temperature of B. In this case, the temperature difference between A and B is about 200 ° C.
これに対して本発明方法の場合は再生反応器を二塔シリ
ーズ運転をするので、出口ガス温度は次のような挙動を
示す。すなわち、再生反応器19において、その出口ガス
温度はDからEの挙動を示す。反応器19が再生を開始す
るDの点においては反応器18はすでに再生操作の開始後
4時間を経過しており、反応器18の出口ガス温度はエの
点に達していることが計算される。従つて熱交換器48の
高温側入口には反応器19と18の出口ガスが合流したガス
が導入されるため、熱交換器48の高温側入口ガス温度は
エとDの平均温度オを示すこととなる。反応器18と19の
再生操作の進行と共に各反応器の出口ガス温度は上昇
し、それと共に熱交換器48の高温側入口ガス温度も上昇
する。反応器18の再生操作が完了するBの点が最も高く
なりカの温度を示すこととなるが、反応器18が冷却工程
に移り反応器19の中段には入口ガス温度程度まで冷却さ
れたガスを導入するので、反応器18が冷却操作開始と同
時に反応器19の出口ガスはキの温度となり、そのまま他
のガスが混合されることなく、熱交換器48に入ることと
なる。その後反応器19の再生操作が進むにつれて、出口
ガス温度はキからクまで上昇し、そのまま熱交換器48に
入る。反応器19の出口ガスがクの温度を示す時点で反応
器16の再生が開始されるため、熱交換器48の高温側入口
ガス温度はクとGの平均温度ケを示すこととなる。以下
上述の操作を繰り返すにつれて、熱交換器48高温側入口
ガス温度はケ〜コ〜サ〜シと変化する。On the other hand, in the case of the method of the present invention, since the regeneration reactor is operated in a two-column series, the outlet gas temperature exhibits the following behavior. That is, in the regeneration reactor 19, the outlet gas temperature exhibits the behavior of D to E. It is calculated that at the point D where the reactor 19 starts regeneration, the reactor 18 has already passed 4 hours after the start of the regeneration operation, and the outlet gas temperature of the reactor 18 has reached point D. It Therefore, since the gas in which the outlet gases of the reactors 19 and 18 merge is introduced into the high temperature side inlet of the heat exchanger 48, the high temperature side inlet gas temperature of the heat exchanger 48 shows the average temperature of D and D. It will be. As the regeneration operation of the reactors 18 and 19 progresses, the outlet gas temperature of each reactor rises, and the hot side inlet gas temperature of the heat exchanger 48 rises accordingly. The point B at which the regeneration operation of the reactor 18 is completed becomes the highest and indicates the temperature of the gas. However, the reactor 18 moves to the cooling step, and the middle stage of the reactor 19 is a gas cooled to about the inlet gas temperature. Since the reactor 18 is introduced, the temperature of the outlet gas of the reactor 19 reaches a temperature of K when the cooling operation is started, and the other gas enters the heat exchanger 48 without being mixed. Thereafter, as the regeneration operation of the reactor 19 progresses, the outlet gas temperature rises from K to K and enters the heat exchanger 48 as it is. Since the regeneration of the reactor 16 is started at the time when the outlet gas of the reactor 19 shows the temperature of K, the temperature of the gas on the high temperature side of the heat exchanger 48 shows the average temperature of K and G. As the above-described operation is repeated, the temperature of the gas at the high temperature side inlet of the heat exchanger 48 changes from one to another.
このように本発明方法の場合の熱交換器48の高温側入口
ガス温度(=図3中の出口ガス平均温度)の高低差は約
120℃と一塔毎の独立再生の場合に比べて格段に小さく
なり、安定した運転が可能となる。Thus, in the case of the method of the present invention, the difference in height of the high temperature side inlet gas temperature (= outlet gas average temperature in FIG. 3) of the heat exchanger 48 is about
Compared to the case of 120 ° C and independent regeneration of each tower, it is much smaller and stable operation is possible.
一方再生反応器二塔を一部シリーズ運転にしたことによ
り、吸収剤の再生を十分に完遂できる上に、再生完了後
の反応器出口ガス中のO2ガスを後段のS回収系に混入さ
せる懸念もなく、そのメリツトは大きいと言える。On the other hand, by operating the two columns of the regeneration reactor in a part of series operation, regeneration of the absorbent can be sufficiently completed, and O 2 gas in the reactor outlet gas after the regeneration is completed is mixed with the S recovery system in the subsequent stage. There is no concern and it can be said that the merits are great.
再生反応で生成するSO2ガスの除去にはSO2還元反応の単
独、SO2還元反応及びクラウス反応との組合せによる単
体硫黄としての回収除去並びに湿式における石灰との反
応による石膏としての回収除去などがあるが方式の制限
はない。For removal of SO 2 gas generated by regeneration reaction, SO 2 reduction reaction alone, recovery and removal as elemental sulfur by combination with SO 2 reduction reaction and Claus reaction, recovery and removal as gypsum by reaction with wet lime, etc. There is no limitation on the method.
ここでは(10)〜(13)式のSO2還元反応、(14)式の
クラウス反応と(15)式の加水分解反応との組合せによ
る単体硫黄としての回収除去法で説明する。Here, a method for recovering and removing SO as a simple substance by combining the SO 2 reduction reaction of the formulas (10) to (13), the Claus reaction of the formula (14) and the hydrolysis reaction of the formula (15) will be described.
SO2+3H2→H2S+2H2O ……(10) SO2+3CO→COS+2CO2 ……(11) 2SO2+4H2→S2+4H2O ……(12) 2SO2+4CO→S2+4H2O ……(13) 2H2S+SO2→3/xSX+2H2O(x=2〜8) ……(14) COS+H2O→H2S+CO2 ……(15) SO2還元反応に必要なライン2の還元ガスは、流路切替
バルブ3を介して、ライン1の脱塵ガス比ガスの一部が
SO2還元及び硫黄回収装置53に供給され、ライン52の再
生工程後のガスに含まれるSO2ガスは、(10)〜(13)
式によりH2S,COS,単体硫黄となる。次いで、(14),
(15)式の反応後に、130〜250℃に冷却し、単体硫黄64
を系外に回収除去することによつて、再生反応で生成す
るSO2ガスの大部分を除去した処理ガス(ライン58中の
ガス)となる。なお、ここで使用する還元ガスは、精製
後のライン42のガス化ガスならばより好ましいのは当然
である。SO 2 + 3H 2 → H 2 S + 2H 2 O …… (10) SO 2 + 3CO → COS + 2CO 2 …… (11) 2SO 2 + 4H 2 → S 2 + 4H 2 O …… (12) 2SO 2 + 4CO → S 2 + 4H 2 O …… (13) 2H 2 S + SO 2 → 3 / xS X + 2H 2 O (x = 2-8) …… (14) COS + H 2 O → H 2 S + CO 2 …… (15) Line required for SO 2 reduction reaction The reducing gas of No. 2 is a part of the dedusting gas ratio gas of the line 1 via the flow path switching valve 3.
Is supplied to the SO 2 reduction and sulfur recovery device 53, SO 2 gas contained in the gas after the regeneration step of the line 52, (10) - (13)
According to the formula, it becomes H 2 S, COS, and elemental sulfur. Then, (14),
After the reaction of the formula (15), it was cooled to 130 to 250 ° C and the sulfur content of 64
By recovering and removing the SO3 out of the system, a processing gas (gas in line 58) is obtained by removing most of SO 2 gas generated in the regeneration reaction. It is a matter of course that the reducing gas used here is more preferably a gasified gas in the line 42 after purification.
ブロワー60の出口のライン50のガスの一部45は、ライン
2の還元ガスの量、ライン47の再生反応の酸素源として
供給される空気又は酸素含有ガスの供給量と、系外に回
収除去される単体硫黄64の量などを考慮に入れて、吸収
工程中の反応器16に供給される。A part 45 of the gas in the line 50 at the outlet of the blower 60 is recovered and removed outside the system together with the amount of the reducing gas in the line 2, the supply amount of air or oxygen-containing gas supplied as an oxygen source for the regeneration reaction in the line 47. Taking into account the amount of elemental sulfur 64 that is generated and the like, it is supplied to the reactor 16 during the absorption step.
すなわち、SO2還元及び硫黄回収工程でSO2回収除去した
ライン59(=45)のガスは未反応のSO2,H2O,COS並びに
ガス状硫黄を若干含有しているので、流路切替バルブ46
を介して、吸収工程を行つている反応器16に導入して吸
収反応させて、系内のバランスとガス精製を両立させ
る。In other words, the gas in line 59 (= 45) that has been SO 2 recovered and removed in the SO 2 reduction and sulfur recovery process contains a small amount of unreacted SO 2 , H 2 O, COS and gaseous sulfur. Valve 46
The gas is introduced into the reactor 16 through which the absorption step is performed to cause an absorption reaction, thereby achieving both balance in the system and gas purification.
一方熱バランスの観点から言えば第3図からわかるよう
に再生開始時再生反応器2塔分の出口混合ガスは再生サ
イクル中最低温度になつているが、それでも550℃程度
もあり、平均してSO2還元反応に必要な所定温度(例え
ば300℃)よりも高目に保持されることとなり、ガス切
替時の再生系内の熱バランスの点で利点がある。On the other hand, from the viewpoint of heat balance, as can be seen from Fig. 3, the mixed gas at the outlet of the two regeneration reactors at the start of regeneration has the lowest temperature during the regeneration cycle, but it is still around 550 ° C, and on average. The temperature is kept higher than the predetermined temperature (for example, 300 ° C.) required for the SO 2 reduction reaction, which is advantageous in terms of heat balance in the regeneration system during gas switching.
また低負荷でライン1の高温還元性ガスの流量が減少し
たりあるいは低硫黄炭を使用する場合には(3)式,
(4)式の吸収反応で生成する吸収剤中のFeS量が通常
より少なくなり、再生反応熱量が減少し、再生系の熱収
支をとることが次第に困難になつてくる。負荷が所定以
下(例えば50%以下)になつて熱収支をとるのが難しく
なつた場合はクラウス反応系を一部バイパスして対応す
る方法を採用することもできる。その際SO2還元反応系
だけでも単体硫黄生成反応が一部生起し、硫黄が50〜70
%程度生成し、該反応系出口ガス中の残留H2S,硫黄ベー
パーは再生反応器入口又は器内で燃焼するために再生系
内の補熱に寄与するととなる。なおSO2還元反応系のみ
(クラウス反応系なし)でもS回収システムとして十分
成り立つ。この際ガス中に残留H2Sや硫黄ペーパーが若
干増加し、O2ガスを消費して燃焼するために、再生用必
要空気量がクラウス反応系有りの場合に比べて10%程度
増加することとなるがシステム上大きな問題となること
はない。If the flow rate of the high-temperature reducing gas in line 1 is reduced under low load or low-sulfur coal is used, formula (3),
The amount of FeS in the absorbent produced by the absorption reaction of the equation (4) becomes smaller than usual, the heat of the regeneration reaction decreases, and it becomes gradually difficult to obtain the heat balance of the regeneration system. When it becomes difficult to obtain the heat balance due to the load being below a predetermined value (for example, 50% or less), it is possible to adopt a method in which the Claus reaction system is partially bypassed. At this time, a single sulfur-producing reaction occurs only in the SO 2 reduction reaction system, and the sulfur content is 50 to 70%.
%, And the residual H 2 S and sulfur vapor in the reaction system outlet gas are combusted at the inlet or inside the regeneration reactor, and thus contribute to the supplementary heat in the regeneration system. It should be noted that only the SO 2 reduction reaction system (without Claus reaction system) is sufficient as an S recovery system. At this time, residual H 2 S and sulfur paper slightly increase in the gas, and O 2 gas is consumed and burned, so the amount of air required for regeneration increases by about 10% compared to the case with the Claus reaction system. However, it does not cause a big problem in the system.
一方、冷却工程が終了した反応器18を還元工程に切替え
るために、流路切替バルブ13,24,37を閉に、12,35を開
にして、ライン1の脱塵ガス化ガスの一部を通気させ
る。なお、還元工程開始時は、反応器18内に残存する微
量のSO2ガスをSO2還元及び硫黄回収装置53で処理するた
めに、流路切替バルブ26を開にする前に、短時間流路切
替バルブ43を開にして、SO2ガスが無くなつたことを確
認後、流路切替バルブ26を開に、43を閉にして、反応器
18の出口ガスを吸収工程に入つた反応器17の中間に導入
する。ここで、還元反応後のガスを、そのまま流路切替
バルブ33を介して、精製ガス42に混合させないのは、以
下の理由による。On the other hand, in order to switch the reactor 18 that has completed the cooling process to the reduction process, the flow path switching valves 13, 24, 37 are closed and 12, 35 are opened, and a part of the dedusting gasified gas in line 1 To ventilate. At the start of the reduction step, in order to treat the trace amount of SO 2 gas remaining in the reactor 18 with the SO 2 reduction and sulfur recovery device 53, a short time flow is performed before opening the flow path switching valve 26. After confirming that the SO 2 gas has been exhausted by opening the flow switching valve 43, open the flow switching valve 26 and close 43 to the reactor.
The outlet gas of 18 is introduced into the middle of the reactor 17 which has entered the absorption step. The reason why the gas after the reduction reaction is not directly mixed with the purified gas 42 via the flow path switching valve 33 is as follows.
即ち、再生工程での運転管理ミス等による反応器18内部
の温度低下で再生が不十分であつたり、あるいは経時的
な性能低下現象で吸収剤20に硫酸塩が蓄積すると、該硫
酸塩が還元ガス中のH2,COと(16)〜(22)式のような
反応を起し、SO2,H2S等の硫黄化合物が発生する。That is, when regeneration is insufficient due to a temperature decrease inside the reactor 18 due to operation management error in the regeneration process, or when sulfate is accumulated in the absorbent 20 due to a performance deterioration phenomenon over time, the sulfate is reduced. Reaction with H 2 and CO in the gas occurs as shown in formulas (16) to (22), and sulfur compounds such as SO 2 and H 2 S are generated.
FeSO4+2/3H2→1/3Fe3O4+SO2+2/3H2O ……(16) Fe2(SO4)3+10/3H2→2/3Fe3O4+3SO2+10/3H2O ……
(17) Fe2(SO4)3+10H2→2FeS+SO2+10H2O ……(18) FeSO4+2/3CO→1/3Fe3O4+SO2+2/3CO2 ……(19) Fe2(SO4)3+10/3CO→2/3Fe3O4+3SO2+10/3CO2 ……
(20) Fe2(SO4)3+10CO→2FeS+SO2+2H2O ……(21) SO2+3H2O→H2S+2H2O ……(22) この硫黄化合物のかなりの部分は、還元工程で吸収除去
されるが、一部は還元処理後のガスに含有され、その硫
黄化合物濃度は吸収剤20に蓄積している硫酸塩の量によ
つては無視できない程高い場合もあるので、還元処理後
のガスを吸収工程出口のライン42の精製ガスに混合させ
るのは好ましくないからである。FeSO 4 + 2 / 3H 2 → 1 / 3Fe 3 O 4 + SO 2 + 2 / 3H 2 O …… (16) Fe 2 (SO 4 ) 3 + 10 / 3H 2 → 2 / 3Fe 3 O 4 + 3SO 2 + 10 / 3H 2 O ......
(17) Fe 2 (SO 4 ) 3 + 10H 2 → 2FeS + SO 2 + 10H 2 O …… (18) FeSO 4 + 2 / 3CO → 1 / 3Fe 3 O 4 + SO 2 + 2 / 3CO 2 …… (19) Fe 2 (SO 4 ) 3 + 10 / 3CO → 2 / 3Fe 3 O 4 + 3SO 2 + 10 / 3CO 2 ……
(20) Fe 2 (SO 4 ) 3 + 10CO → 2FeS + SO 2 + 2H 2 O …… (21) SO 2 + 3H 2 O → H 2 S + 2H 2 O …… (22) A considerable part of this sulfur compound is generated in the reduction process. It is absorbed and removed, but part of it is contained in the gas after the reduction treatment, and the concentration of its sulfur compounds may be too high to be ignored depending on the amount of sulfate accumulated in the absorbent 20. This is because it is not preferable to mix the latter gas with the purified gas in the line 42 at the outlet of the absorption process.
還元工程に移行する際、該反応器内の吸収剤の温度は蓄
積現象のため高温還元性ガスの温度より50〜300℃程度
高くなつているが、このことは通常の吸収剤の還元性能
には悪影響することはなくむしろ吸収剤の一部が最生時
再生不十分で硫酸塩が生成している場合、吸収剤の温度
が高い程該高温還元性ガスによつて硫酸塩の分解が前述
の(16)〜(23)式に従つて促進されることとなり好ま
しいと言える。When moving to the reduction step, the temperature of the absorbent in the reactor is higher than the temperature of the high-temperature reducing gas by about 50 to 300 ° C. due to an accumulation phenomenon, but this is due to the reduction performance of ordinary absorbents. Does not adversely affect, but rather, when a part of the absorbent is not sufficiently regenerated at the time of life and sulfate is generated, the higher the temperature of the absorbent is, the higher the temperature of the absorbent is, so that the decomposition of the sulfate is caused by the above-mentioned reduction. It can be said that it is preferable because it is promoted according to the equations (16) to (23).
一方、ガス化炉の負荷変動,炭種変更などにより精製の
対象となる処理ガス量、硫黄化合物の含有量が変動して
も、吸収性能と再生性能を安定化させることが実用上強
く要求される。On the other hand, even if the amount of processing gas to be refined and the content of sulfur compounds change due to changes in the load of the gasification furnace, changes in coal type, etc., it is strongly required in practice to stabilize the absorption performance and regeneration performance. It
例えば、H2S,COS等の硫黄化合物を含有する高温還元性
ガス1の流量が減少したり、あるいは低硫黄炭を使用す
る場合には、吸収反応で生成する吸収剤中のFeS量が通
常より少なくなり、再生工程の負荷が低減される。従つ
て、再生反応を通常の負荷と同じ循環ガス流量で行う
と、短時間で反応が終了し、再生工程の時間経過に伴な
い再生反応熱量が減少する。そのため、再生工程中の反
応器内部温度及び出口ガス温度が、通常負荷時より相対
的に低くなるので、安定した再生運転を維持するには補
熱が必要となる。For example, when the flow rate of the high-temperature reducing gas 1 containing a sulfur compound such as H 2 S, COS decreases, or when low-sulfur coal is used, the amount of FeS in the absorbent produced by the absorption reaction is usually This reduces the load on the regeneration process. Therefore, when the regeneration reaction is performed at the same circulating gas flow rate as the normal load, the reaction is completed in a short time, and the heat of the regeneration reaction decreases with the passage of time in the regeneration process. Therefore, the internal temperature of the reactor and the outlet gas temperature during the regeneration process are relatively lower than those under normal load, so supplementary heat is required to maintain stable regeneration operation.
この補熱方法としては、系外からCO,H2などの可燃性ガ
スを含有するライン1のガス化ガスを供給し、該ガスと
酸素との燃焼反応による燃焼熱の利用が考えられる。し
かし、ガス化ガスのこのような使用は、ガス精製の後流
側で使用すべきCO,H2などを消費することになり、ガス
精製システムの経済性を高める観点からは極力避けるこ
とが好ましい。As a method for supplementing this heat, it is conceivable to supply the gasification gas in line 1 containing a combustible gas such as CO or H 2 from outside the system and utilize the combustion heat by the combustion reaction between the gas and oxygen. However, such use of the gasified gas consumes CO, H 2 and the like to be used on the downstream side of the gas purification, and it is preferable to avoid it as much as possible from the viewpoint of increasing the economical efficiency of the gas purification system. .
従つて、低負荷時も安定した連続運転を維持するため
に、再生ガス循環量を減少させて、再生反応時間を延長
させることで対処し得る。低負荷時の再生ガス循環ライ
ンは、前述の通常負荷時と同じであるが、ブロワ60の保
護のために次の手段を講じる。すなわち、通常、ブロワ
は吸引ガス量が減少すると冷却不足となり過昇温の状態
になるので、ブロワの吸引ガス量は一定にすることが好
ましい。従つて、再生ガス循環流量の減少に伴い、流路
切替バルブ61を介して、硫黄回収除去後のライン59のガ
スの一部をライン62を経て最終硫黄コンデンサ56の前に
戻して、ブロワ60では通常負荷時とほぼ同一のガス量を
確保するようにする。Therefore, in order to maintain stable continuous operation even under a low load, it is possible to deal with the problem by reducing the recycle gas circulation amount and extending the regeneration reaction time. The regeneration gas circulation line at low load is the same as that at normal load described above, but the following measures are taken to protect the blower 60. That is, in general, when the suction gas amount of the blower decreases, the cooling becomes insufficient and the temperature rises excessively. Therefore, it is preferable that the suction gas amount of the blower be constant. Therefore, as the regeneration gas circulation flow rate decreases, a part of the gas in the line 59 after the sulfur recovery and removal is returned to the front of the final sulfur condenser 56 via the line 62 via the flow path switching valve 61, and the blower 60 Then, make sure to secure almost the same amount of gas as under normal load.
上記の再生循環ガス量の調節だけで再生反応系内の補熱
ができない場合には、さらに再生工程中の反応器入口ラ
イン41に流路切替バルブ63を介して高温還元性ガスを供
給してH2,CO可燃性ガスの燃焼反応による燃焼熱の利用
による補熱を行うことができる。If the heat in the regeneration reaction system cannot be supplemented simply by adjusting the amount of the recycle gas, a high-temperature reducing gas is further supplied to the reactor inlet line 41 during the regeneration process via the flow path switching valve 63. It is possible to supplement the heat by utilizing the combustion heat from the combustion reaction of H 2 and CO combustible gas.
なお、第1図では、反応器で吸収と再生操作を向流(逆
流)にして行うフローの例を示しているが、その操作を
並流にして行うこともできる。Note that, although FIG. 1 shows an example of a flow in which the absorption and regeneration operations are carried out in a countercurrent (backflow) in the reactor, the operations may be carried out in parallel.
本発明方法によれば吸収剤を充填した反応器を少なくと
も四塔使用しそのうち再生反応器を二塔設置して、一部
シリーズ運転で再生操作を行うことにより、再生反応熱
に由来する吸収剤への異常蓄熱を緩和し、吸収剤の寿命
保護を行うとともに再生反応器での生成SO2ガスの濃度
変動を抑制しかつ後段のS回収系へのO2ガスの混入をも
たらすことなく再生を十分に行わせることができるの
で、該吸収剤によつて連続的に安定した硫黄化合物の吸
収除去ができる。According to the method of the present invention, at least four reactors packed with an absorbent are used, and two regeneration reactors are installed among them, and a regeneration operation is performed in a part of series operation, whereby the absorbent derived from the heat of regeneration reaction is absorbed. The abnormal heat storage in the regeneration reactor is mitigated, the life of the absorbent is protected, the fluctuation of the concentration of SO 2 gas produced in the regeneration reactor is suppressed, and regeneration is performed without introducing O 2 gas into the subsequent S recovery system. Since it can be sufficiently carried out, the absorbent can continuously and stably absorb and remove the sulfur compound.
第1図は本発明方法の一実施態様例を説明するためのフ
ローを示す図、第2図は本発明実施時の吸収再生サイク
ルのタイムスケジユールを示す図、第3図は再生反応器
出口ガス温度の時間的変化の一例を示す図である。FIG. 1 is a diagram showing a flow for explaining an embodiment of the method of the present invention, FIG. 2 is a diagram showing a time schedule of an absorption regeneration cycle when the present invention is carried out, and FIG. 3 is a regenerator outlet gas. It is a figure which shows an example of the time change of temperature.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 瀬戸 徹 広島県広島市西区観音新町4丁目6番22号 三菱重工業株式会社広島研究所内 (72)発明者 光岡 薫明 広島県広島市西区観音新町4丁目6番22号 三菱重工業株式会社広島研究所内 (72)発明者 井上 健治 広島県広島市西区観音新町4丁目6番22号 三菱重工業株式会社広島研究所内 (56)参考文献 特開 昭61−245819(JP,A) 特表 昭62−502815(JP,A) ─────────────────────────────────────────────────── ─── Continuation of front page (72) Toru Seto 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Hiroshima Research Laboratory (72) Kaoru Mitsuoka 4 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture 6-22 22 Mitsubishi Heavy Industries, Ltd. Hiroshima Research Institute (72) Inventor Kenji Inoue 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Research Institute (56) Reference JP-A-61-245819 (JP, A) Special table Sho 62-502815 (JP, A)
Claims (1)
化カルボニル等の硫黄化合物を吸収剤で吸収除去する方
法において、吸収剤を充填した反応器を少なくとも四塔
使用し、該硫黄化合物を吸収剤で吸収除去する吸収工
程、該吸収剤を酸素含有ガスで再生する再生工程、再生
工程完了後の冷却工程、再生された該吸収剤を高温還元
性ガスで該吸収剤前後の還元性ガス濃度が同一になるま
で還元する還元工程の四工程より構成し、再生工程にあ
る反応器における再生が終了する前に次に再生工程を開
始する反応器との一部並列再生を行うようにすると共
に、再生終了後の冷却工程にある反応器の出口ガスを再
生工程にある反応器に導入して再生ガスの一部として使
用し、かつ、前記再生工程において、再生反応器出口高
温ガスから連続的に熱回収を行い吸収、再生の性能を安
定化させることを特徴とする高温還元性ガスの精製方
法。1. A method for absorbing and removing a sulfur compound such as hydrogen sulfide and carbonyl sulfide contained in a high-temperature reducing gas with an absorbent, wherein at least four reactors filled with the absorbent are used to remove the sulfur compound. Absorption step of absorbing and removing with an absorbent, regeneration step of regenerating the absorbent with an oxygen-containing gas, cooling step after completion of the regeneration step, reducing gas of the regenerated absorbent with a high-temperature reducing gas before and after the absorbing agent It consists of four steps of reduction process to reduce to the same concentration, and performs partial parallel regeneration with the reactor which starts the next regeneration process before the regeneration in the reactor in the regeneration process is completed. Along with this, the outlet gas of the reactor in the cooling step after the regeneration is introduced into the reactor in the regeneration step and used as a part of the regeneration gas, and in the regeneration step, the high temperature gas from the regeneration reactor outlet is continuously supplied. Heat Absorbing perform yield method for purifying a high-temperature reducing gas which is characterized in that to stabilize the performance of the playback.
Priority Applications (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63027441A JPH0790137B2 (en) | 1988-02-10 | 1988-02-10 | Refining method for high temperature reducing gas |
DE68921905T DE68921905T2 (en) | 1988-02-10 | 1989-02-03 | Method of cleaning hot reducing gas. |
AT89730023T ATE120480T1 (en) | 1988-02-10 | 1989-02-03 | METHOD FOR PURIFYING HOT REDUCTION GAS. |
EP89730023A EP0328479B1 (en) | 1988-02-10 | 1989-02-03 | Method for purifying high-temperature reducing gas |
AU29641/89A AU610337B2 (en) | 1988-02-10 | 1989-02-06 | Method for purifying high-temperature reducing gas |
CA000590569A CA1324875C (en) | 1988-02-10 | 1989-02-09 | Method for purifying high-temperature reducing gas |
CN89101997.9A CN1010379B (en) | 1988-02-10 | 1989-02-10 | Process for purification of reducing gases under high temp. |
US07/721,912 US5154900A (en) | 1988-02-10 | 1991-06-20 | Method for purifying high-temperature reducing gas |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63027441A JPH0790137B2 (en) | 1988-02-10 | 1988-02-10 | Refining method for high temperature reducing gas |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH01203020A JPH01203020A (en) | 1989-08-15 |
JPH0790137B2 true JPH0790137B2 (en) | 1995-10-04 |
Family
ID=12221200
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP63027441A Expired - Lifetime JPH0790137B2 (en) | 1988-02-10 | 1988-02-10 | Refining method for high temperature reducing gas |
Country Status (1)
Country | Link |
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JP (1) | JPH0790137B2 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2865845B2 (en) * | 1990-10-08 | 1999-03-08 | 三菱重工業株式会社 | Purification method of high-temperature reducing gas |
WO2012063253A1 (en) * | 2010-11-09 | 2012-05-18 | Digambar Pande Dhananjay | A novel system for adsorbing and separating suspended gaseous impurities from effluent gases and thereby recovery of value added products |
JP2015010211A (en) * | 2013-07-01 | 2015-01-19 | 一般財団法人電力中央研究所 | Impurity removal method and desulfurization method |
JP6161064B2 (en) * | 2013-07-01 | 2017-07-12 | 一般財団法人電力中央研究所 | Desulfurization equipment and coal gasification combined power generation facility |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0659377B2 (en) * | 1985-04-23 | 1994-08-10 | 三菱重工業株式会社 | Refining method for high temperature reducing gas |
FR2581560B1 (en) * | 1985-05-10 | 1987-06-05 | Elf Aquitaine | REGENERATIVE PROCESS FOR THE REMOVAL OF MERCAPTANS CONTAINED IN A GAS |
-
1988
- 1988-02-10 JP JP63027441A patent/JPH0790137B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPH01203020A (en) | 1989-08-15 |
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