JPH07241427A - Solvent recovery method - Google Patents
Solvent recovery methodInfo
- Publication number
- JPH07241427A JPH07241427A JP6032188A JP3218894A JPH07241427A JP H07241427 A JPH07241427 A JP H07241427A JP 6032188 A JP6032188 A JP 6032188A JP 3218894 A JP3218894 A JP 3218894A JP H07241427 A JPH07241427 A JP H07241427A
- Authority
- JP
- Japan
- Prior art keywords
- solvent
- gas
- moisture
- tower
- water
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は水分と溶剤を含有するオ
フガスから溶剤を回収する方法、さらに詳しくは化学工
業、電子工業、機械工業等で広く用いられているアセト
ン、トルエン、メチルエチルケトン、エチルアルコー
ル、イソプロピルアルコール、ジメチルエチレン等の揮
発性有機溶剤（本明細書では単に溶剤という）を、圧力
スイング法（ＰＳＡ）で水分を除去した後、温度スイン
グ式（ＴＳＡ）吸着分離法で分離し、低温及び／又は高
圧条件で液化回収する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering a solvent from an off-gas containing water and a solvent, more specifically, acetone, toluene, methyl ethyl ketone, ethyl alcohol widely used in chemical industry, electronic industry, mechanical industry and the like. , A volatile organic solvent such as isopropyl alcohol, dimethyl ethylene (hereinafter simply referred to as a solvent) is removed by a pressure swing method (PSA) to remove water, and then separated by a temperature swing (TSA) adsorption separation method at a low temperature. And / or a method for liquefaction recovery under high pressure conditions.
【０００２】[0002]
【従来の技術】前記のような溶剤は排出規制が厳しく、
また、その価格が極めて高いことから、排気ガスから分
離回収して再使用することが望まれている。これらの溶
剤の回収方法としては、近年、相対的高圧条件で溶剤含
有ガスを吸着剤層に通して溶剤を吸着させ、溶剤の除去
されたオフガスを系外に放出させた後、吸着剤を相対的
低圧条件下で溶剤を脱着させて減容濃縮し、液化回収す
る圧力スイング式吸着法（ＰＳＡ）が注目を集めてい
る。この方法は完全な乾式分離法であることから、二次
汚染の心配がなく、また、分離操作が全て室温近傍で行
われるため回収溶剤が変質せず、吸着剤の劣化も少ない
という利点がある。2. Description of the Related Art The above-mentioned solvents have strict emission regulations,
Further, since the price is extremely high, it is desired to separate and collect the exhaust gas and reuse it. As a method for recovering these solvents, in recent years, the solvent-containing gas is passed through the adsorbent layer under relatively high pressure conditions to adsorb the solvent, and the off-gas from which the solvent has been removed is released to the outside of the system, and then the adsorbent is subjected to relative pressure. The pressure swing adsorption method (PSA), in which the solvent is desorbed under reduced pressure conditions to reduce the volume and then concentrated, is liquefied and collected, has attracted attention. Since this method is a complete dry separation method, there is no concern about secondary contamination, and since the separation operation is performed near room temperature, the recovered solvent does not deteriorate and the adsorbent does not deteriorate much. .
【０００３】[0003]
【発明が解決しようとする課題】前記の方法は、高濃度
の揮発性有機物の回収に対しては極めて良好な分離法で
あるが、低濃度揮発性有機物の回収に対しては消費エネ
ルギが温度スイング法（ＴＳＡ）に比較し増大する欠点
がある。一方温度スイング法は低濃度揮発性有機物の回
収に関しては圧力スイング方よりも有利な方法である
が、この方法では５０℃以上の再生では揮発性有機物及
び吸着剤の劣化が進行するという問題点を有する。ま
た、低温で処理しようとすると溶剤含有ガス中に水分が
多く含まれていると氷結してしまうため吸着処理ができ
ない。さらに０℃以上の温度で吸着させた場合でも、溶
剤が水溶性の場合には再度分離工程が必要となる。本発
明は前記従来技術の問題点を解決し、水分と溶剤とを含
有するオフガスから、溶剤のみを回収することができる
効率的な溶剤回収方法を提供するものである。The above-mentioned method is a very good separation method for recovering high-concentration volatile organic matter, but consumes less energy than temperature for recovering low-concentration volatile organic matter. It has the drawback of increasing compared to the swing method (TSA). On the other hand, the temperature swing method is more advantageous than the pressure swing method in terms of recovery of low-concentration volatile organic matter, but this method has a problem that deterioration of the volatile organic matter and the adsorbent progresses in regeneration at 50 ° C. or higher. Have. Further, when the treatment is carried out at a low temperature, if the solvent-containing gas contains a large amount of water, it freezes and the adsorption treatment cannot be performed. Further, even when the solvent is adsorbed at a temperature of 0 ° C. or higher, if the solvent is water-soluble, the separation step is required again. The present invention solves the above-mentioned problems of the prior art and provides an efficient solvent recovery method capable of recovering only a solvent from an off gas containing water and a solvent.
【０００４】[0004]
【課題を解決するための手段】本発明は、（１）溶剤及
び水分を含有するオフガスを吸湿剤及び吸着剤で処理し
て溶剤を回収する方法において、溶剤及び水分を含有す
るオフガスを水分は吸着するが溶剤は吸着しない吸湿剤
を充填した相対的高圧条件の脱水分工程にある脱湿塔に
導いて水分を除去したのち吸着剤を充填した相対的低温
条件の吸着工程にある吸着塔を流過させて溶剤を吸着除
去し、水分及び溶剤が除去されたオフガスの一部を相対
的高温条件の脱着工程にある吸着塔に通して吸着された
溶剤を高濃度溶剤含有ガスとして採取し、この高濃度溶
剤含有ガスを凝縮器に導いて冷却及び／又は加圧して液
化させて溶剤を回収し、該凝縮器で溶剤を分離したガス
は溶剤の吸着工程に戻すようにし、水分及び溶剤が除去
されたオフガスの残部は相対的低圧条件の吸湿剤再生工
程にある脱湿塔に通して吸着水分を脱離し、脱離した水
分とともに系外に放出することを特徴とする溶剤及び水
分を含有するオフガスからの溶剤回収方法及び（２）脱
湿塔における脱水分工程を構成する相対的高圧条件が
１．０１〜１．２０気圧、吸湿剤再生工程を構成する相
対的低圧条件が０．９０〜０．８０気圧であり、溶剤の
吸着塔における吸着工程を構成する相対的低温条件が０
〜−６０℃、溶剤脱着工程を構成する相対的高温条件が
２０〜４０℃である前記（１）の溶剤回収方法である。According to the present invention, (1) in a method of recovering a solvent by treating an off gas containing a solvent and water with a hygroscopic agent and an adsorbent, the off gas containing the solvent and the water is Adsorbs but does not adsorb solvent Adsorbent in relative temperature low temperature adsorption step filled with adsorbent is introduced after dewatering tower in relative pressure high pressure dehydration step filled with hygroscopic agent The solvent is adsorbed and removed by passing it through, and a part of the off gas from which the water content and the solvent have been removed is passed through an adsorption tower in the desorption step of a relatively high temperature condition to collect the adsorbed solvent as a high-concentration solvent-containing gas, This high-concentration solvent-containing gas is introduced into a condenser, cooled and / or pressurized to be liquefied to recover the solvent, the gas separated from the solvent in the condenser is returned to the solvent adsorption step, and the water content and the solvent are Of offgas removed Part is a solvent characterized by desorbing adsorbed moisture through a dehumidifying tower in a hygroscopic agent regeneration process under relatively low pressure conditions, and releasing it out of the system together with the desorbed moisture and a solvent from off-gas containing moisture. Recovery method and (2) Relative high pressure condition constituting the dehydration step in the dehumidification tower is 1.01 to 1.20 atm, and relative low pressure condition constituting the hygroscopic agent regeneration process is 0.90 to 0.80 atm. And the relative low temperature condition constituting the adsorption step of the solvent adsorption tower is 0.
The solvent recovery method according to (1) above, wherein the relative high-temperature condition constituting the solvent desorption step is 20 to 40 ° C.
【０００５】本発明は溶剤、水分を含有するオフガスか
ら水分のみを選択的に吸着する脱湿剤を充填した脱湿塔
により水分を除去した後、０℃以下の低温を含む相対的
低温条件下で溶剤を吸着除去し、溶剤で飽和した吸着塔
を昇温して溶剤を離脱し、離脱した溶剤は低温及び／又
は加圧条件で液化回収し、溶剤を除去された低温オフガ
スは冷熱を回収した後、水分で飽和した脱湿塔に向流に
パージして水分を離脱した後系外に放出する。通常低温
吸着による溶剤回収方法を採用する場合には塔、配管な
どで氷結が起こるという問題があるため除湿が必要とな
り、除湿に要する消費エネルギが無視できないが、本発
明では水分で飽和した脱湿塔に揮発性有機物を除去した
後の乾燥状態のオフガスを向流にパージして水分を離脱
再生することにより、除湿のために外部から供給するエ
ネルギの節減を図っている。また、水分を除去したのち
吸着塔に送るので、低温での吸着、脱着が可能となり、
脱着用の熱源としても冷熱を回収後の水分、溶剤が除去
されたオフガスを使用することができる。The present invention removes water from an off-gas containing a solvent and water by a dehumidifying tower filled with a dehumidifying agent that selectively adsorbs only the water, and then under a relatively low temperature condition including a low temperature of 0 ° C. or lower. The solvent is adsorbed and removed with, and the adsorption tower saturated with the solvent is heated to release the solvent, the separated solvent is liquefied and recovered under low temperature and / or pressure conditions, and the low temperature offgas from which the solvent is removed recovers cold heat. After that, the dehumidification tower saturated with water is countercurrently purged to remove the water and then discharged outside the system. Usually, when a solvent recovery method by low temperature adsorption is adopted, there is a problem that freezing occurs in towers, pipes, etc., so dehumidification is necessary, and energy consumption required for dehumidification cannot be ignored, but in the present invention, dehumidification saturated with water The off-gas in the dry state after removing the volatile organic substances in the tower is countercurrently purged to remove and regenerate water, thereby saving energy supplied from the outside for dehumidification. Also, after removing water, it is sent to the adsorption tower, so adsorption and desorption at low temperature becomes possible,
As a heat source for desorption, off-gas from which water and solvent have been removed after collecting cold heat can be used.
【０００６】本発明の方法において脱湿塔で使用する水
分選択型吸着剤としては小分子径である水分のみを吸着
する分子篩ゼオライトであるＫ−Ａ、Ｎｉ−Ａ等のゼオ
ライトを使用する。また、吸着塔で使用する溶剤吸着剤
としては、比較的吸着力が弱く、かつ、水分の影響を受
けにくい疎水性吸着剤が好ましい。具体的には、γ−ア
ルミナ、活性炭、シリカ／アルミナ比２５以上の高シリ
カゼオライト、Ｃａ−Ｘ、Ｎａ−Ｘ型のゼオライトなど
の低シリカ系のゼオライト、シリカ超微粒子造粒粒子
（例えば、０．１μｍ以下のシリカ超微粒子を造粒して
得た平均粒子系１．５ｍｍの粒子）、シリカゲルなどを
挙げることができる。As the water-selective adsorbent used in the dehumidifying tower in the method of the present invention, zeolites such as K-A and Ni-A which are molecular sieve zeolites which adsorb only water having a small molecular diameter are used. Further, as the solvent adsorbent used in the adsorption tower, a hydrophobic adsorbent having a relatively weak adsorbing power and being hardly influenced by moisture is preferable. Specifically, γ-alumina, activated carbon, high silica zeolite having a silica / alumina ratio of 25 or more, low silica type zeolite such as Ca-X, Na-X type zeolite, and silica ultrafine particle granulated particles (for example, 0 Examples thereof include particles having an average particle size of 1.5 mm obtained by granulating ultrafine silica particles having a particle size of 1 μm or less) and silica gel.
【０００７】[0007]
【作用】図１は本発明の１実施態様を示すフローシート
の概略図である。このプロセスはそれぞれ２個の脱湿塔
５ａ及び５ｂ（Ａ塔及びＢ塔）、吸着塔１５ａ及び１５
ｂ（Ａ塔及びＢ塔）を有しており、以下の説明は脱湿塔
５ａが脱水分工程、５ｂが吸湿剤再生工程にあり、吸着
塔１５ａが吸着工程、吸着塔１５ｂが脱着工程にある状
態について述べる。脱湿塔、吸着塔とも一方の塔で水分
及び溶剤の吸着が行われている間、他方の塔では脱着再
生が進行し、吸着が飽和になった時点でバルブを切替え
ることにより連続運転を行うことができる。図１におい
て主プラント１から放出された溶剤及び水分を含有する
オフガスはブロア２で１．０１〜１．２気圧程度に圧縮
されてバルブ３ａを通って脱湿塔５ａの下部から、水分
のみを選択的に吸着する吸湿剤４に供給され、脱湿塔５
ａの上部から乾燥溶剤含有ガスとしてバルブ６ａを通じ
て流出する。脱水分工程にある脱湿塔内の温度はほぼ室
温域である。一方吸湿剤再生工程にある脱湿塔５ｂでは
後流側で溶剤を除去され、冷熱を回収されたほぼ室温域
の乾燥オフガスがバルブ７ｂを通じて脱湿塔５ｂ上部か
ら供給され、減圧条件下に水分が飽和した吸湿剤から水
分を離脱しながら塔内を流過し、脱湿塔５ｂ下部からバ
ルブ８ａを通じて真空ポンプ９から溶剤を除去された湿
オフガスとして系外に放出される。1 is a schematic view of a flow sheet showing one embodiment of the present invention. This process consists of two dehumidifying towers 5a and 5b (A tower and B tower) and adsorption towers 15a and 15b, respectively.
b (A tower and B tower), the dehumidification tower 5a is in the dehydration step, 5b is in the hygroscopic agent regeneration step, the adsorption tower 15a is in the adsorption step, and the adsorption tower 15b is in the desorption step. Describe a state. While both the dehumidifying tower and the adsorption tower are adsorbing moisture and solvent in one tower, the desorption regeneration is progressing in the other tower and continuous operation is performed by switching the valve when the adsorption is saturated. be able to. In FIG. 1, the off-gas containing the solvent and water discharged from the main plant 1 is compressed to about 1.01 to 1.2 atm by the blower 2 and passes through the valve 3a to remove only water from the lower part of the dehumidification tower 5a. The dehumidifying tower 5 is supplied with the hygroscopic agent 4 that selectively adsorbs it.
The dry solvent-containing gas is discharged from the upper part of a through the valve 6a. The temperature in the dehumidification tower in the dehydration step is almost room temperature. On the other hand, in the dehumidifying tower 5b in the hygroscopic agent regeneration step, the solvent is removed on the downstream side, and the dry off-gas in the approximately room temperature range, from which cold heat has been recovered, is supplied from the upper part of the dehumidifying tower 5b through the valve 7b, and the moisture is reduced under reduced pressure. While passing through the tower while removing water from the saturated hygroscopic agent, the solvent is removed from the lower part of the dehumidifying tower 5b through the valve 8a as a wet off-gas from the vacuum pump 9 to the outside of the system.
【０００８】脱湿塔５ａで水分を除去されたほぼ室温域
の乾燥状態の溶剤含有オフガスは流路１０を通り、熱交
換器１１において流路１２から供給される０〜−６０℃
の乾燥脱溶剤オフガスと熱交換して０〜−６０℃の低温
に冷却されバルブ１３ａから溶剤吸着剤１４が充填され
た吸着塔１５ａに流入する。吸着工程にある吸着塔に入
ったガスは０〜−６０℃で吸着塔内を通り溶剤が吸着さ
れて吸着塔上部からバルブ１６ａ、流路１２を通じて０
〜−６０℃で熱交換器１１に戻り冷熱が回収される。吸
着工程の温度が０℃を超えると溶剤の蒸気圧が高くな
り、また、−６０℃未満では固化しやすくなるので好ま
しくない。溶剤で飽和した溶剤吸着剤１４が充填された
脱着工程にある吸着塔１５ｂには、流路１７からブロア
１８、バルブ１９ｂを通じてほぼ室温域の乾燥オフガス
が流入し、吸着されている溶剤は吸着剤の昇温に伴い離
脱してバルブ２０ｂから凝縮器２１に入る。凝縮器２１
は０〜−６０℃の低温に保たれており、過飽和状態にあ
る溶剤は凝縮して流路２２から液化溶剤として取り出さ
れる。未凝縮の溶剤を含む脱着ガスは流路２３から溶剤
回収前のオフガス中に戻される。The dry solvent-containing off-gas in the substantially room temperature range, from which water has been removed by the dehumidifying tower 5a, passes through the channel 10 and is supplied from the channel 12 in the heat exchanger 11 at 0 to -60 ° C.
After being heat-exchanged with the dry desolventized off-gas of (1) and cooled to a low temperature of 0 to -60 ° C, it flows into the adsorption tower 15a filled with the solvent adsorbent 14 from the valve 13a. The gas entering the adsorption tower in the adsorption step passes through the inside of the adsorption tower at 0 to −60 ° C. and the solvent is adsorbed to the gas from the upper part of the adsorption tower through the valve 16a and the flow path 12
At -60 ° C, the cold heat is returned to the heat exchanger 11 to recover the cold heat. If the temperature of the adsorption step is higher than 0 ° C, the vapor pressure of the solvent will be high, and if it is lower than -60 ° C, solidification is likely to occur, which is not preferable. Dry off-gas in a room temperature range flows from the flow path 17 through the blower 18 and the valve 19b into the adsorption tower 15b in the desorption process, which is filled with the solvent adsorbent 14 saturated with the solvent, and the adsorbed solvent is adsorbent. When the temperature rises, the valve 20b separates and enters the condenser 21 through the valve 20b. Condenser 21
Is kept at a low temperature of 0 to −60 ° C., and the solvent in a supersaturated state is condensed and taken out from the flow path 22 as a liquefied solvent. The desorption gas containing uncondensed solvent is returned from the flow path 23 to the off-gas before solvent recovery.
【０００９】本発明において脱湿塔５ａ、５ｂの吸湿剤
４の水分離脱については、ブロア２からの入口ガス量Ｇ
0 （ｍ3 Ｎ／ｈｒ）、流路１２からのリーンガス量Ｇ1
（ｍ 3 Ｎ／ｈｒ）、吸着圧力Ｐa （ａｔｍ）、再生圧力
Ｐd （ａｔｍ）とすると、真空ポンプ９の再生圧力Ｐd
（ａｔｍ）は Ｐd ＝（Ｇ0 ・Ｐa ）／（ｋ・Ｇ1 ）、ｋ＝１．１〜
１．２ で表される。従ってここではＧ0 ≒Ｇ1 なのでＰa が１
ａｔｍとするとＰd は０．８〜０．９ａｔｍ程度であ
る。また、バルブ２０ａ、２０ｂからの離脱溶剤濃度に
ついては爆発性の回避のため１容量％以下に設定する必
要があり、このため凝縮器２１の温度は−３０〜−６０
℃に設定し、かつブロア１８からのパージガス量Ｇp に
ついても一定の流量を確保することが必要である。In the present invention, the moisture absorbent of the dehumidifying towers 5a and 5b
For the water release of No. 4, the inlet gas amount G from the blower 2
0(M3N / hr), the amount G of lean gas from the flow path 121
(M 3N / hr), adsorption pressure Pa(Atm), regeneration pressure
Pd(Atm), the regeneration pressure P of the vacuum pump 9d
(Atm) is Pd= (G0・ Pa) / (K ・ G1), K = 1.1-
It is represented by 1.2. Therefore here G0≒ G1So PaIs 1
If atm is PdIs about 0.8 to 0.9 atm
It In addition, the concentration of the solvent released from the valves 20a and 20b
Therefore, it is necessary to set it to 1% by volume or less to avoid explosiveness.
Therefore, the temperature of the condenser 21 is -30 to -60.
C. and purge gas amount G from the blower 18pTo
Even then, it is necessary to secure a constant flow rate.
【００１０】[0010]
【実施例】以下実施例により本発明の方法をさらに具体
的に説明する。 （実施例１）接着剤や印刷工程などから放出される可燃
性有機溶剤であるメチルエチルケトン、シクロヘキサノ
ンを各々２５００ｐｐｍ含有する雰囲気空気を、図１の
構成の装置を用いて処理し溶剤回収を行った。なお、各
ステップの時間は、表１のシーケンスの表に示したとお
りである。ガス分離操作の諸元は、表２のとおりであ
る。EXAMPLES The method of the present invention will be described in more detail with reference to the following examples. (Example 1) Atmospheric air containing 2500 ppm each of methyl ethyl ketone and cyclohexanone, which are flammable organic solvents released from adhesives and printing processes, was treated using the apparatus having the configuration shown in FIG. 1 to recover the solvent. The time of each step is as shown in the sequence table of Table 1. Table 2 shows the specifications of the gas separation operation.
【００１１】[0011]
【表１】 [Table 1]
【００１２】[0012]
【表２】 注） ＵＳＹ： Ultra Stable Ｙ型ゼオライト[Table 2] Note) USY: Ultra Stable Y type zeolite
【００１３】前記の操作条件で溶剤回収を行ったとこ
ろ、吸着工程から流出した処理ガスの溶剤濃度は５０ｐ
ｐｍであり、脱着工程からの脱着ガス中の溶剤濃度は１
容量％で、凝縮器から約２０ｋｇ／ｈで溶剤を回収する
ことができた。脱湿塔での溶剤の損失は１％以下であ
り、脱湿用吸湿剤Ｎａ−Ａの分子篩効果が確認された。
また、脱湿塔から溶剤吸着塔に供給される乾燥オフガス
の露点は−５０℃以下である。露点は真空圧力を高真空
に設定する程低温に移行するが、消費電力の増大を伴う
ため、本実施例では比較的高圧の０．９気圧としてい
る。When solvent recovery was carried out under the above operating conditions, the solvent concentration of the processing gas flowing out from the adsorption step was 50 p.
pm, and the solvent concentration in the desorption gas from the desorption process is 1
In volume%, it was possible to recover the solvent from the condenser at about 20 kg / h. The solvent loss in the dehumidification tower was 1% or less, and the molecular sieve effect of the dehumidifying hygroscopic agent Na-A was confirmed.
Further, the dew point of the dry off-gas supplied from the dehumidification tower to the solvent adsorption tower is -50 ° C or lower. The dew point shifts to a lower temperature as the vacuum pressure is set to a higher vacuum, but since power consumption increases, the dew point is set to a relatively high pressure of 0.9 atm.
【００１４】前記の操作条件のうち、溶剤脱着工程へ供
給する乾燥オフガス温度を可変とし、脱着温度と溶剤濃
縮倍率の関係を調べた。その結果は図２に示したとおり
である。なお、溶剤吸着剤を前記のＵＳＹの他に、シリ
カライト、γ−アルミナ、活性炭、シリカ超微粒子の造
粒粒子（２０００℃以上の高温気相ＳｉＯ2 を急冷して
得られる０．１μｍ以下の超微粒子を造粒した平均粒径
１．５ｍｍの成形品）を用いて同様に溶剤回収を行った
結果も合わせて示した。図２中、◎印はγ−アルミナ、
○印は活性炭、×印はＵＳＹ、△印はシリカライト、●
印はシリカ超微粒子の造粒粒子である。図２から明らか
なように、脱着温度が高い程、溶剤の濃縮倍率は増大す
る。なお、参考のため図２のグラフにおける０℃と４０
℃での濃縮倍率の値を表３に示す。Among the above operating conditions, the temperature of the drying off gas supplied to the solvent desorption process was made variable, and the relationship between the desorption temperature and the solvent concentration factor was investigated. The result is as shown in FIG. In addition to the above USY solvent adsorbents, granulated particles of silicalite, γ-alumina, activated carbon, and silica ultrafine particles (0.1 μm or less obtained by rapidly cooling high temperature gas phase SiO 2 at 2000 ° C. or higher) The results of similarly performing solvent recovery using a molded product obtained by granulating ultrafine particles and having an average particle size of 1.5 mm are also shown. In FIG. 2, ◎ indicates γ-alumina,
○ indicates activated carbon, × indicates USY, Δ indicates silicalite, ●
The mark is a granulated particle of ultrafine silica particles. As is clear from FIG. 2, the higher the desorption temperature, the higher the concentration ratio of the solvent. For reference, 0 ° C and 40 ° C in the graph of Fig. 2
Table 3 shows the values of the concentration ratio at ° C.
【００１５】[0015]
【表３】 [Table 3]
【００１６】ただし、５０℃以上ではシクロヘキサノ
ン、ＭＥＫ等の溶剤では劣化が顕著となるので、これ以
下の温度で実施する必要がある。However, if the temperature is 50 ° C. or higher, the deterioration becomes remarkable with a solvent such as cyclohexanone or MEK, so it is necessary to carry out at a temperature lower than this.
【００１７】（実施例２）溶剤の種類及び濃度、溶剤の
吸着剤の種類を変えて実施例１と同様の溶剤回収を行っ
たところ、表４に示すように良好な結果が得られた。Example 2 The same solvent recovery as in Example 1 was carried out by changing the kind and concentration of the solvent and the kind of the adsorbent of the solvent, and good results were obtained as shown in Table 4.
【００１８】[0018]
【表４】 [Table 4]
【００１９】[0019]
【発明の効果】本発明は、低濃度の溶剤含有ガスについ
ても溶剤及び吸着剤の劣化を生ずることなく、高い濃縮
倍率で溶剤を回収することができ、かつ、氷結の恐れが
ないので液化凝縮も効率的に行うことができる。すなわ
ち、先ず圧力スイング法により水分のみを除去した後、
温度スイング法により溶剤を回収するようにすることに
より、水分と溶剤の両方を含むガスから低エネルギかつ
低い温度で溶剤を回収できるようになった。また、低温
で回収できるようになったことにより溶剤や吸着剤の劣
化が少ない。さらに、水分及び溶剤を除去した乾燥オフ
ガスを吸湿剤、吸着剤の再生工程で使用するので極めて
効率的なプロセスが構成できる。INDUSTRIAL APPLICABILITY The present invention is capable of recovering a solvent at a high concentration ratio without degrading the solvent and the adsorbent even with a low-concentration solvent-containing gas, and since there is no fear of freezing, liquefaction condensation Can also be done efficiently. That is, after first removing only water by the pressure swing method,
By recovering the solvent by the temperature swing method, it has become possible to recover the solvent from a gas containing both water and solvent at low energy and low temperature. In addition, the solvent and the adsorbent are less deteriorated because they can be collected at a low temperature. Furthermore, since the dry off-gas from which water and solvent have been removed is used in the step of regenerating the hygroscopic agent and adsorbent, an extremely efficient process can be constructed.
【図１】本発明の１実施態様を示すフローシートの概略
図。FIG. 1 is a schematic view of a flow sheet showing one embodiment of the present invention.
【図２】実施例１における脱着温度と溶剤濃縮倍率との
関係を示すグラフ。FIG. 2 is a graph showing the relationship between the desorption temperature and the solvent concentration ratio in Example 1.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 篠田 正治 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 (72)発明者 原田 孝幸 山口県下関市彦島江の浦町六丁目16番１号 三菱重工業株式会社下関造船所内 (72)発明者 石崎 安良 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 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shoji Shinoda 2-5-1, Marunouchi, Chiyoda-ku, Tokyo Sanryo Heavy Industries Co., Ltd. (72) Inventor Takayuki Harada 6-16, Hikoshimaenoura-cho, Shimonoseki, Yamaguchi Prefecture No. 1 Mitsubishi Heavy Industries, Ltd. Shimonoseki Shipyard (72) Inventor Akira Ishizaki 1-1, Atsunoura-cho, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries Ltd. Nagasaki Shipyard
Claims (2)
剤及び吸着剤で処理して溶剤を回収する方法において、
溶剤及び水分を含有するオフガスを水分は吸着するが溶
剤は吸着しない吸湿剤を充填した相対的高圧条件の脱水
分工程にある脱湿塔に導いて水分を除去したのち吸着剤
を充填した相対的低温条件の吸着工程にある吸着塔を流
過させて溶剤を吸着除去し、水分及び溶剤が除去された
オフガスの一部を相対的高温条件の脱着工程にある吸着
塔に通して吸着された溶剤を高濃度溶剤含有ガスとして
採取し、この高濃度溶剤含有ガスを凝縮器に導いて冷却
及び／又は加圧して液化させて溶剤を回収し、該凝縮器
で溶剤を分離したガスは溶剤の吸着工程に戻すように
し、水分及び溶剤が除去されたオフガスの残部は相対的
低圧条件の吸湿剤再生工程にある脱湿塔に通して吸着水
分を脱離し、脱離した水分とともに系外に放出すること
を特徴とする溶剤及び水分を含有するオフガスからの溶
剤回収方法。1. A method for recovering a solvent by treating an off-gas containing a solvent and water with a hygroscopic agent and an adsorbent,
Off-gas containing solvent and water adsorbs water but does not adsorb solvent Relative filled with hygroscopic agent Dehydration tower in dehydration process under high pressure conditions to remove water and then adsorbed relative The solvent adsorbed and removed by adsorbing and removing the solvent by passing through the adsorption tower in the adsorption step under the low temperature condition, and adsorbing the solvent and a part of the off-gas from which the solvent has been removed through the adsorption tower in the desorption step under the relative high temperature condition. Is collected as a high-concentration solvent-containing gas, and the high-concentration solvent-containing gas is introduced into a condenser to be cooled and / or pressurized to liquefy it to recover the solvent, and the gas separated from the solvent is adsorbed by the solvent. The remaining off-gas from which water and solvent have been removed is passed through a dehumidifying tower in the hygroscopic agent regeneration process under relatively low pressure conditions to desorb adsorbed moisture and release it to the outside of the system along with the desorbed moisture. Solvents characterized by Solvent recovery process from the off-gas containing moisture.
対的高圧条件が１．０１〜１．２０気圧、吸湿剤再生工
程を構成する相対的低圧条件が０．９０〜０．８０気圧
であり、溶剤の吸着塔における吸着工程を構成する相対
的低温条件が０〜−６０℃、溶剤脱着工程を構成する相
対的高温条件が２０〜４０℃である請求項１に記載の溶
剤回収方法。2. The relative high pressure condition constituting the dehydration step in the dehumidification tower is 1.01 to 1.20 atm, and the relative low pressure condition constituting the moisture absorbent regenerating step is 0.90 to 0.80 atm. The solvent recovery method according to claim 1, wherein the relative low temperature condition constituting the adsorption step in the solvent adsorption tower is 0 to -60 ° C, and the relative high temperature condition constituting the solvent desorption step is 20 to 40 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03218894A JP3363986B2 (en) | 1994-03-02 | 1994-03-02 | Solvent recovery method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03218894A JP3363986B2 (en) | 1994-03-02 | 1994-03-02 | Solvent recovery method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07241427A true JPH07241427A (en) | 1995-09-19 |
| JP3363986B2 JP3363986B2 (en) | 2003-01-08 |
Family
ID=12351937
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03218894A Expired - Fee Related JP3363986B2 (en) | 1994-03-02 | 1994-03-02 | Solvent recovery method |
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| Country | Link |
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| JP (1) | JP3363986B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100698764B1 (en) * | 2005-10-17 | 2007-03-26 | 세계화학공업(주) | Method for recovery of volatile organic compounds by adsorption-condensation and apparatus therefor |
| KR100926764B1 (en) * | 2009-01-05 | 2009-11-16 | 가스파워 주식회사 | Absorption type gas dryer |
| CN103990358A (en) * | 2014-06-05 | 2014-08-20 | 广东省肇庆化工机械厂 | Emission-free finished gas cold blowing heat regenerative drying process |
| CN108096977A (en) * | 2017-12-28 | 2018-06-01 | 杭州捷瑞空气处理设备有限公司 | The processing method and system for the exhaust gas that lithium battery recovery processing generates in the process |
| JPWO2023042302A1 (en) * | 2021-09-15 | 2023-03-23 |
-
1994
- 1994-03-02 JP JP03218894A patent/JP3363986B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100698764B1 (en) * | 2005-10-17 | 2007-03-26 | 세계화학공업(주) | Method for recovery of volatile organic compounds by adsorption-condensation and apparatus therefor |
| KR100926764B1 (en) * | 2009-01-05 | 2009-11-16 | 가스파워 주식회사 | Absorption type gas dryer |
| CN103990358A (en) * | 2014-06-05 | 2014-08-20 | 广东省肇庆化工机械厂 | Emission-free finished gas cold blowing heat regenerative drying process |
| CN108096977A (en) * | 2017-12-28 | 2018-06-01 | 杭州捷瑞空气处理设备有限公司 | The processing method and system for the exhaust gas that lithium battery recovery processing generates in the process |
| JPWO2023042302A1 (en) * | 2021-09-15 | 2023-03-23 | ||
| WO2023042302A1 (en) * | 2021-09-15 | 2023-03-23 | カンケンテクノ株式会社 | Ethylene oxide gas removal method, and ethylene oxide gas removal system using same |
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| Publication number | Publication date |
|---|---|
| JP3363986B2 (en) | 2003-01-08 |
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