JP4318850B2 - Method for reducing moisture contained in organic solvent - Google Patents
Method for reducing moisture contained in organic solvent Download PDFInfo
- Publication number
- JP4318850B2 JP4318850B2 JP2000366242A JP2000366242A JP4318850B2 JP 4318850 B2 JP4318850 B2 JP 4318850B2 JP 2000366242 A JP2000366242 A JP 2000366242A JP 2000366242 A JP2000366242 A JP 2000366242A JP 4318850 B2 JP4318850 B2 JP 4318850B2
- Authority
- JP
- Japan
- Prior art keywords
- water
- organic solvent
- solvent
- cooling
- moisture
- 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
Description
【0001】
【産業上の利用分野】
本発明は、微量の水分を含有する有機溶剤中の水分を、さらに低減させる方法である。
特に有機溶剤を回収して再利用するような場合で、その回収工程において遠心分離等を利用して分離して得られる有機溶剤中には、水分が微細なエマルジョン状態で存在することがある。このような有機溶剤中の水分を効果的に分離・低減させるようなケースに適した方法である。
具体的に例示するならば、フイルム等の製造工程で使用される三酢酸セルロースの溶媒であるジクロロメタンあるいはジクロロメタンとアルコールの混合溶剤は、その使用過程での制限から、これらの溶媒を回収して再利用する場合には、有機溶剤中に混入する水分をできるだけ除去することが必要であり、これらの用途に本発明の方法は適用することができる。
【0002】
【従来の技術】
有機溶剤中の水分を低減させるには、蒸留や脱水剤の使用がよく行われるところであるが、水への溶解度が温度依存性を持つ溶剤について冷却して水分を析出分離する方法も有効な方法である。しかし、基本的には蒸留や脱水剤の使用は、水の含有量を極限まで低減する技術であり、蒸留の場合は過大な設備、無機塩あるいは脱水剤の使用はこれらの一部が溶剤側に混入するおそれや、薬剤使用のための経済的な負担を要することになる。これに対し、それほど水分を低濃度にまで低減させることを要しない場合には、当該溶剤を冷却することによっても、ある程度の水分量の低減が可能である。この場合、析出する水分が溶剤の冷却により生成するため非常に微細なエマルジョンとなって溶剤中に分散する。このような場合、デカンターの場合は静置時間、遠心分離器の場合は遠心分離の時間を十分に取っても、必要な分離効果が得られないことが多い。一般に均一相からある成分を析出分離する場合、析出物が元の状態と同じ状態、すなわち液相からこれに溶解しない他の液相を析出させるような場合には、エマルジョン化が起きやすく両者の分離が困難である場合が多く、前述のケースもこれに相当するものである。
【0003】
【発明が解決しようとする課題】
本発明の目的は、有機溶剤中の微量な水分を、できるだけ簡便な処理により低減する方法を提供するものである。
【0004】
【課題を解決するための手段】
本発明は、微量の水分を含有する有機溶剤に、該有機溶剤に対して2wt%以上10wt%以下の水を添加し、冷却、撹拌後静置して相分離させることを特徴とする有機溶剤中に含有されている水分の低減方法である。冷却温度としては、10℃以下とすることが望ましい。
【0005】
【発明の実施の形態】
上記課題の解決のため本発明者らは鋭意検討した結果、冷却を利用して有機溶剤中の水分除去を行う際に、冷却前あるいは冷却後に除去すべき水分を対象とする有機溶剤に逆に過剰に添加し混合することで、溶剤中に存在している水エマルジョンの会合を促進し、あるいは混合溶剤の場合には、水を有機相に溶解させる成分の一部を除去し、その後の静置で容易に目的濃度まで水分含量を低減できることを見出し本発明を完成した。
【0006】
本発明を実施するための具体的な手順を説明すると、処理対象の有機溶剤に対し2相を形成する程度の水を添加し、所定温度まで冷却し、あるいは、溶剤を所定温度まで冷却し2相を形成する程度の水を添加して、その後混合撹拌してから静置し、相分離する溶剤相を回収するようにする。最終の静置の際に、遠心分離等のように強制的に重力をかけ、分離性を向上させる方法を用いても良いことは当然である。
冷却温度としては、相分離が良好に行われ、水分の低減に効果がある10℃以下、好ましくは5℃以下、より好ましくは0℃付近である。尚、0℃付近迄冷却しても、若干の有機溶剤が水中に溶解しているため、氷結することはない。また、添加する水の量は、有機溶剤の水による溶解による逸失をできるだけ少なくし、処理量もできるだけ少ない方がよいので、有機溶剤に対して10wt%以下とする。
【0007】
本発明で対象とする有機溶剤としては、水との親和性が小さく、水難溶性で、水への溶解度が温度依存性を有するものが適している。例えば、ジクロロメタン(塩化メチレン)、クロロホルム、テトラクロロエタン等が例示でき、この中でもジクロロメタンが好ましい。また、これらの単独ではなく他の溶剤との混合溶剤であってもよい。
本発明における微量の水分を含有する有機溶剤とは、有機溶剤を回収・再利用したり、精製等の過程で、水蒸気等を用いて処理した後に冷却して得られるものが例示され、これらの有機溶剤には、高温時に平衡状態に相当する水分が含まれていたものが、凝縮したために余分となった水が存在している。この水分は有機溶剤中に分散している場合が多く、前述のごとく遠心分離等の機械的な操作では低減させることが難しい。
【0008】
【実施例】
実施例1
表1は、水分0.15wt%を含むジクロロメタン(CH2Cl299.85wt%,H2O0.15wt%)中の水分を冷却により低減するために、単に冷却による方法(比較例)と本発明による方法を比較したものである。操作方法は前述した方法に準じるが、本実施例では水を添加し軽く撹拌した後、10℃および0℃に冷却し、静置・分離した。溶剤に含有している水分が少量であるため、従来法の場合、冷却によって析出する水分が均一相を形成せず白濁し、溶剤相中ににエマルジョン状態となって分散し静置あるいは簡単な遠心操作では分離することができなかった。一方、本発明の方法では、低減すべき目的成分である水を少量添加し、混合してエマルジョン状態の水の会合を促進し、あとは単に静置することで水の十分な分離を行うことができた。
【0009】
【表1】
【0010】
【実施例2】
ジクロロメタン中にエタノールが少量溶解している混合溶剤(CH2Cl292.2wt%,C2H5OH7.0wt%,H2O0.8wt%)から水分を低減する場合の結果を、表2に示した。尚、操作手順は実施例1と同様であるが、冷却温度は10℃、7℃、O℃とした。
実施例1と比べ溶剤中の水分濃度が高いのは、エタノールが共存しているためにジクロロメタン中への水の溶解度が増加したことによると考えられる。またこの実施例での操作において、溶剤中のエタノールが一部水相側へ移行し、ジクロロメタン中のエタノール濃度が減少したために溶剤中への水分の溶解性も減少し水分の減量が大きくなっていると考えられる。
【0011】
【表2】
【0012】
溶剤中に残留する水分は、溶剤への水の溶解度あるいは実施例2のように水の溶解度を増加させる他の成分で決まるため、使用する添加水の量は多くてもよいが、多量に使用すると水へ溶剤が溶解することにより、溶剤を消費してしまうので好ましくなく、これらの例のように10wt%までの添加とする。
【0013】
【発明の効果】
有機溶剤中の水分を低減する場合、蒸留や脱水剤の使用が多く行われる。これに対し、要求される溶剤中の水分の残留量が、単に冷却等で得られる水分の溶解度程度でよい場合には、できるだけ煩雑な操作は行わず、単純な方法によることが好ましい。しかし、単に冷却による場合、もともと他の相が共存しない相からの水分の析出となるため溶剤相中にエマルジョンを形成しやすく、その結果、その後の水分を低減するための操作が煩雑になってしまったり、溶剤が混合溶剤の場合、水の有機相への溶解を増加する成分の有効な低減にはならないので、有機相が処理以前と同様の溶解度を持ち、水の析出が不充分なことも多い。
本発明の場合、低減の目的成分である水を少量添加するだけであり、設備的にも容易であり、その効果は大きい。[0001]
[Industrial application fields]
The present invention is a method for further reducing moisture in an organic solvent containing a trace amount of moisture.
In particular, when the organic solvent is recovered and reused, moisture may be present in a fine emulsion state in the organic solvent obtained by separation using centrifugation or the like in the recovery step. This is a method suitable for a case where water in the organic solvent is effectively separated and reduced.
Specifically, dichloromethane or a mixed solvent of dichloromethane and alcohol, which is a solvent of cellulose triacetate used in the production process of film or the like, is recovered by recovering these solvents due to limitations in the process of use. When using, it is necessary to remove the water | moisture content mixed in an organic solvent as much as possible, and the method of this invention is applicable to these uses.
[0002]
[Prior art]
In order to reduce moisture in organic solvents, distillation and the use of dehydrating agents are often used, but it is also an effective method to precipitate and separate moisture by cooling a solvent whose solubility in water is temperature dependent It is. However, basically, distillation and the use of dehydrating agents are technologies that reduce the water content to the utmost. In the case of distillation, excessive equipment, use of inorganic salts or dehydrating agents, some of which are solvent-side There is a risk that it will be mixed in and the economic burden for using the drug will be required. On the other hand, when it is not necessary to reduce the moisture to a low concentration, the amount of moisture can be reduced to some extent by cooling the solvent. In this case, the precipitated water is generated by cooling the solvent, so that it becomes a very fine emulsion and is dispersed in the solvent. In such a case, in many cases, the required separation effect cannot be obtained even when sufficient time is taken for the decanter and for the centrifuge. In general, when a certain component is precipitated and separated from a homogeneous phase, when the precipitate is in the same state as the original state, that is, when another liquid phase that does not dissolve in the liquid phase is precipitated, emulsification easily occurs. Separation is often difficult, and the above-mentioned case corresponds to this.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for reducing a very small amount of water in an organic solvent by a treatment as simple as possible.
[0004]
[Means for Solving the Problems]
The present invention is an organic solvent characterized by adding 2 wt% or more and 10 wt% or less of water to an organic solvent containing a trace amount of water, allowing to cool and stirring and allowing to stand after phase separation. This is a method for reducing the moisture contained therein. The cooling temperature is desirably 10 ° C. or lower.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
In order to solve the above problems, the present inventors have intensively studied. As a result, when water is removed from the organic solvent by using cooling, the water to be removed before or after cooling is changed to the target organic solvent. Addition and mixing in excess promotes the association of the water emulsion present in the solvent, or, in the case of a mixed solvent, removes some of the components that dissolve the water in the organic phase, followed by static As a result, the present inventors have found that the water content can be easily reduced to the target concentration.
[0006]
The specific procedure for carrying out the present invention will be described. Water to such an extent that two phases are formed is added to the organic solvent to be treated and cooled to a predetermined temperature, or the solvent is cooled to a predetermined temperature. Add enough water to form a phase, then mix and stir and let stand to recover the solvent phase that separates. Of course, a method of improving the separability by forcibly applying gravity, such as centrifugation, at the time of final standing may be used.
The cooling temperature is 10 ° C. or lower, preferably 5 ° C. or lower, more preferably around 0 ° C., in which phase separation is performed satisfactorily and is effective in reducing moisture. In addition, even if it cools to about 0 degreeC, since some organic solvents are melt | dissolving in water, it does not freeze. Further, the amount of water to be added is set to 10 wt% or less with respect to the organic solvent since it is preferable that the loss due to the dissolution of the organic solvent by water is as small as possible and the processing amount is as small as possible .
[0007]
As the organic solvent to be used in the present invention, an organic solvent having a low affinity for water, poorly water-soluble, and water-soluble solubility is suitable. For example, dichloromethane (methylene chloride), chloroform, tetrachloroethane and the like can be exemplified, and among these, dichloromethane is preferable. In addition, these solvents may be mixed with other solvents.
Examples of the organic solvent containing a trace amount of water in the present invention include those obtained by cooling after treatment with water vapor or the like in the process of recovering or reusing the organic solvent or purification. The organic solvent contains water corresponding to an equilibrium state at a high temperature, but there is excess water due to condensation. This water is often dispersed in an organic solvent, and as described above, it is difficult to reduce it by mechanical operation such as centrifugation.
[0008]
【Example】
Example 1
Table 1 shows only a method (comparative example) by cooling and this method in order to reduce moisture in dichloromethane (CH 2 Cl 2 99.85 wt%, H 2 O 0.15 wt%) containing 0.15 wt% of moisture by cooling. The method according to the invention is compared. The operating method is the same as described above. In this example, water was added and the mixture was stirred gently, then cooled to 10 ° C. and 0 ° C., and allowed to stand and separate. Because of the small amount of water contained in the solvent, in the case of the conventional method, the water precipitated by cooling does not form a uniform phase and becomes cloudy and is dispersed in an emulsion state in the solvent phase. Separation was not possible by centrifugation. On the other hand, in the method of the present invention, a small amount of water, which is the target component to be reduced, is added and mixed to promote the association of the water in the emulsion state. I was able to.
[0009]
[Table 1]
[0010]
[Example 2]
Table 2 shows the results when water is reduced from a mixed solvent (CH 2 Cl 2 92.2 wt%, C 2 H 5 OH 7.0 wt%, H 2 O 0.8 wt%) in which a small amount of ethanol is dissolved in dichloromethane. It was shown to. The operating procedure was the same as in Example 1, but the cooling temperatures were 10 ° C., 7 ° C., and O ° C.
The reason why the water concentration in the solvent is higher than that in Example 1 is considered to be due to the increased solubility of water in dichloromethane due to the coexistence of ethanol. In the operation in this example, part of the ethanol in the solvent moved to the aqueous phase side, and the ethanol concentration in dichloromethane decreased, so the solubility of water in the solvent also decreased and the water loss increased. It is thought that there is.
[0011]
[Table 2]
[0012]
Since the water remaining in the solvent is determined by the solubility of water in the solvent or other components that increase the solubility of water as in Example 2, the amount of added water used may be large, but a large amount is used. Then, since a solvent will be consumed by melt | dissolving in water, it is unpreferable , and it is set as addition to 10 wt% like these examples .
[0013]
【The invention's effect】
In order to reduce the moisture in the organic solvent, distillation or a dehydrating agent is often used. On the other hand, when the required residual amount of water in the solvent is only about the solubility of water obtained by cooling or the like, it is preferable to use a simple method without performing complicated operations as much as possible. However, in the case of simple cooling, water is precipitated from the phase in which no other phases coexist originally, so it is easy to form an emulsion in the solvent phase, and as a result, the subsequent operation for reducing the water becomes complicated. If the solvent is a mixed solvent, it will not effectively reduce the components that increase the dissolution of water in the organic phase, so the organic phase will have the same solubility as before treatment and water precipitation will be insufficient. There are also many.
In the case of the present invention, only a small amount of water, which is the target component for reduction, is added, which is easy in terms of equipment, and the effect is great.
Claims (3)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000366242A JP4318850B2 (en) | 2000-10-26 | 2000-10-26 | Method for reducing moisture contained in organic solvent |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000366242A JP4318850B2 (en) | 2000-10-26 | 2000-10-26 | Method for reducing moisture contained in organic solvent |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2002126402A JP2002126402A (en) | 2002-05-08 |
JP4318850B2 true JP4318850B2 (en) | 2009-08-26 |
Family
ID=18836895
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2000366242A Expired - Lifetime JP4318850B2 (en) | 2000-10-26 | 2000-10-26 | Method for reducing moisture contained in organic solvent |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP4318850B2 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5368131B2 (en) * | 2009-02-20 | 2013-12-18 | 大日本スクリーン製造株式会社 | Solvent regenerating apparatus and method |
JP5747684B2 (en) | 2010-09-14 | 2015-07-15 | セントラル硝子株式会社 | Method for dehydrating hydrofluorocarbon or hydrochlorofluorocarbon, and method for producing 1,3,3,3-tetrafluoropropene using the dehydration method |
CN103664500B (en) * | 2013-12-11 | 2015-09-02 | 甘肃大禹节水集团股份有限公司 | A kind of method processing PVC dichloromethane impregnating experiment waste liquid |
CN111995492A (en) * | 2020-09-26 | 2020-11-27 | 安徽金禾实业股份有限公司 | Method for recovering solvent dichloromethane in acesulfame potassium production |
-
2000
- 2000-10-26 JP JP2000366242A patent/JP4318850B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JP2002126402A (en) | 2002-05-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JPS5939488B2 (en) | Method for extracting metal valuables from an aqueous solution of metal salts | |
JP4318850B2 (en) | Method for reducing moisture contained in organic solvent | |
US11623909B2 (en) | Water-based extraction and purification processes for cannabinoid acids | |
De Jong et al. | Lanthanum (III) and gadolinium (III) separation by cloud point extraction | |
JPS6058171B2 (en) | Method for extracting gallium using substituted hydroxyquinoline and organic compound containing sulfate or sulfonate groups | |
Hano et al. | Extraction of penicillin with liquid surfactant membrane | |
ID29951A (en) | METHODS AND TOOLS TO PURE THE INGREDIENTS IN CRYSTALLIZATION | |
JP2000507306A (en) | Recovery of valuable metals from solids by digestion in sulfuric acid medium containing reducing agent | |
JP2008513559A (en) | Method for treating a mixture of ABS and PS | |
JPS63230659A (en) | Recovery of polymerization inhibitor | |
JP3290960B2 (en) | Reprocessing method of lost wax compound | |
US2877276A (en) | Removal of water from halogenated hydrocarbons | |
EP0410990B1 (en) | Multistep method for separating organic compounds from a solution | |
KR20050037994A (en) | Application of scrubbing process for “method for treating of etching waste acid or waste acid” | |
JPS60166224A (en) | Method of recovery of gallium from dust of aluminum smelting | |
JPH02235863A (en) | Recovery of n-methyl-2-pyprolidone | |
EP0209470B1 (en) | Process for separating by precipitation molybdenum contained in sulfuric or nitric solutions of uranium | |
US4767854A (en) | Separation of RDX and HMX | |
JPS5943984B2 (en) | Treatment method for nickel and cobalt-containing liquids containing zinc | |
JP2000128531A (en) | Separation of indium | |
JPS60132948A (en) | Isolation of low alkali sulfate content paraffin sulfonate and sulfuric acid from paraffin sulfo oxidation reactant mixture | |
JP3012085B2 (en) | Method for removing organic solvent embedded in tissue of solid material | |
JPS62216609A (en) | Treatment of used filter medium | |
JPS5829936B2 (en) | How to remove organic acid polymer | |
GB2308358A (en) | Recovering metal values by solvent extraction |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050927 |
|
RD03 | Notification of appointment of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7423 Effective date: 20061222 |
|
RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20070130 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20081118 |
|
A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20090115 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20090210 |
|
A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20090406 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20090519 |
|
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20090527 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120605 Year of fee payment: 3 |
|
R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 Ref document number: 4318850 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120605 Year of fee payment: 3 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130605 Year of fee payment: 4 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130605 Year of fee payment: 4 |
|
R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140605 Year of fee payment: 5 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
EXPY | Cancellation because of completion of term |