JPH0446161B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application The present invention aims to provide a method for destroying O/W (oil-in-water) emulsions. That is, it destroys the relatively short-lived O/W emulsion produced by stirring and mixing water and an organic solvent that is incompatible with water,
This invention improves the separation of organic solvent and water. BACKGROUND ART Conventionally, it has been widely practiced industrially to carry out a reaction by emulsifying and contacting an organic solvent and water, which are incompatible with each other, and washing and removing unnecessary substances after the reaction. In this case, a large shear stress is applied during stirring, or an organic surfactant or the like is used as an auxiliary agent. However, in that case, there were problems such as a large amount of energy being required for stirring and a step for removing the used surfactant. In addition, oil-water separation is very often performed in the next step after oil-water contact, but it is necessary to use antifoaming agents and emulsion breakers, and even if they are used, separation takes time. There were often cases. In addition, it was naturally necessary to remove antifoaming agents and the like at that time. Such surfactants, antifoaming agents, and the like often remain in the organic solvent layer, and their contamination with useful substances in the layer has often been a fatal drawback. In addition, as a defoaming method, operations such as extremely raising or lowering the pH of the water layer are good for oil-water separation, but they often have negative effects such as condensation and decomposition of useful substances in the organic solvent layer. It was. Problems to be Solved by the Invention The present invention aims to solve the above-mentioned drawbacks of the prior art. Means for Solving the Problems As a means for solving the above-mentioned drawbacks, the present invention employs the following method. In other words, an aqueous solution that is weakly alkaline and contains trace amounts of ions that form poorly soluble colloidal precipitates and an organic solvent that contains raw materials, reactants, catalysts, etc. are strongly stirred in a weakly alkaline environment to create an O/W emulsion that has a relatively short lifespan. . After making oil-water contact in this way, Mg() ions alone or Mg() are added to the emulsion.
By adding small amounts of ions and Al() ions at the same time, or by coexisting relatively large amounts of easily water-soluble salts of alkali metals and alkaline earth metals, the emulsion disappears and oil-water separation is performed quickly and well. In particular, if the oil-water contact is only for a short time, add Mg(), Al() ions, or easily water-soluble salts to the water side in advance to eliminate the emulsion generation process, or add Mg() in the middle of the continuous line. By introducing ions and/or Al() ions, the emulsion storage step can also be omitted. In addition, the oil layer (organic solvent layer) is hydrocarbon,
The above emulsion disappearance method is also effective when a surfactant such as a higher alcohol coexists and the emulsion becomes very stable. Function Each component of the present invention will be explained below. Ions that form poorly soluble colloidal precipitates in the weakly alkaline region used in the present invention include groups b, , b, b, b of the periodic table, divalent to hexavalent ions of lanthanides and actinides, or their ions. In mixtures, e.g. Al(), Ac(),
Ti(), Zr(), V(), V(), Fe(),
Fe
( ), Cu ( ), Cr ( ), Th ( ), or a mixture thereof. In addition, counter ions for these ions include OH ^- , SO ₄ ^2- ,
It may contain Cl ^- , Br ^- , NO ₃ ^- , CO ₃ ^2- , etc.
However, in either case, it is essential to use conditions that produce a poorly soluble hydrated colloid. The organic solvents used in the present invention include aliphatic and aromatic hydrocarbons, alkyl halides, higher alcohols, phenols, ketones, aldehydes,
Esters, amines, amides, nitriles, etc., or mixtures thereof, which form a two-phase system with water, such as n-pentane, i-hexane,
i-pentane, cyclohexane, 1-hexane,
Examples include 4-methyl-1-pentene, liquid paraffin, benzene, styrene, indene, cumene, chloroform, dichloroethane, 1-octanol, and phenol. Further, these organic solvents may contain polymers, organic compounds, organometallic compounds, and inorganic compounds that are soluble therein. The compounds used to adjust the pH in the present invention include commonly used inorganic acids, alkalis, e.g.
Examples include NaOH, KOH, HCl, _{H2SO4 ,} etc. Additionally, Mg() and Al() used in the present invention
The ions are supplied in the form of salts that are readily soluble in water. In addition, the periodic table Ia that is easily soluble in water used in the present invention
Examples of salts of group metals and group a metals include:
NaBr, KCl, Na ₂ SO ₄ , CaCl ₂ , BaCl ₂ , NaNO ₃
etc. can be mentioned. In the present invention, when producing an O/W emulsion using a hydrocarbon as an organic solvent, higher alcohols such as 2-hexanol, 4-methyl-2-pentanol, ethyl phenyl carbinol, stearyl alcohol , 2-octanol, etc., or a mixture thereof, can be added to the oil layer side in small amounts (0.1 to 100w/vppm) to greatly stabilize the emulsion.
When () ions coexist, oil-water separation becomes better. The conditions for the O/W emulsion production operation and destructive test of the present invention are as follows. (1) Temperature: Usually 0 to 300℃, preferably room temperature to
200°C (2) Pressure: usually 0 to 1000 kgf/cm ² , preferably normal pressure to 100 kgf/cm ² (3) Strong stirring time (batch type): usually 10 sec to 10 hr, preferably 10 sec to 1 hr. Strong stirring time (continuous type): Usually 0.1sec to 10hr,
Preferably 1sec to 1hr. (4) Amount ratio of water to organic solvent in the system: 1:1000 to 1000:1, preferably 1:100 to 100:1 (volume ratio), regardless of whether it is a batch system or a continuous system. The pH on the water side of the system is 7-11, preferably 9-10 (6) The ion concentration that forms the colloidal precipitate on the water side of the system is 0.001-1000w/vppm (weight/
volume ppm; mg/), preferably 0.1~
100w/vppm (7) For stirring, there is no particular specification, such as a normal feather-shaped one or a homogenizer. (8) When the organic solvent contains a polymer soluble in it, its solution viscosity is between 0.1 and 10000 cp, preferably
It is 0.1~1000cp. (9) When using a hydrocarbon as an organic solvent, the amount of higher alcohol added in a small amount to stabilize the emulsion is 0.01 to 1000 w/w to the organic solvent.
vppm, preferably 0.1 to 100w/vppm. (10) Add it to a system containing an O/W emulsion and destroy the emulsion by stirring again, or make it coexist from the beginning to prevent the formation of an emulsion.
The concentration of Mg() is when Mg() is used alone.
0.01~1000w/vppm, preferably 0.1~100w/
vppm, when Mg() and Al() are used together, the concentration of Mg() and Al() used together is 0.01 to 1000w/vppm, preferably 0.1 to 1000w/vppm, respectively.
At 100w/vppm, the weight ratio of the two is usually Mg():Al()=1:100 to 100:1. (11) Easily water-soluble salts of Group A or Group A metals in the synchronization table that are added to the yarn containing the O/W emulsion to destroy the emulsion by re-stirring, or to coexist from the beginning to prevent the formation of an emulsion. The concentration is 10 w/vppm to 30 w/v%, preferably 100 to 10000 w/vppm. Examples of formation and destruction of short-life O/W emulsions will be described below with reference to Examples. A Reference example of short-life O/W emulsion production test using various ions that are weakly alkaline and produce poorly soluble precipitates 1 to 16 1-300 ml of water containing a specified concentration of inorganic ions and adjusted to a specified pH in a glass autoclave, and Add 300ml of liquid paraffin to each. The minimum necessary amount of NaOH or HCl was used for pH adjustment.
Next, the temperature is raised to a predetermined temperature while stirring at about 100 rpm. While keeping the temperature constant, stir at 1000 rpm for 10 minutes, and after stopping, measure the time required for oil/water separation and the amount of remaining emulsion. The criteria for determining separation are as follows. (1) Oil and water separate in a relatively short time (within 20 minutes),
If the emulsion layer also disappears. Time → Time required for the aqueous layer to recover to approximately 300 ml Amount of trace emulsion → Amount of emulsion when the aqueous layer recovers to 300 ml. (2) Most of the oil and water are separated in a relatively short time (5 to 20 minutes), but it takes time for the emulsion to disappear. Time → 240ml or more (approximately 80% or more) Time for the aqueous layer to recover (however, the emulsion must not decrease much in the next 1 minute) Emulsion amount → Emulsion amount at the above time (3) Oil-water separation is slow (20 minutes or more) In such case). Time → 20 minutes or more Amount of emulsion → Amount 20 minutes after stopping stirring As a result of conducting an oil-water separation experiment using this method, the results shown in Table 1 were obtained. Note that Fe ³⁺ is FeCl ₃ , Ti ⁴⁺ is TiCl ₄ , and Al ³⁺ is
_AlCl3 was used. Comparative Reference Examples 1 to 4 The results shown in Table 1 were obtained by performing the same operations as in Reference Examples 1 to 16, except that nothing was added to the aqueous layer other than inorganic ions for pH adjustment. B Emulsion destruction by Mg() ions Examples 1 to 3, Comparative Example 1 The results shown in Table 2 were obtained in exactly the same manner as in Reference Examples 1 to 16. _MgCl2 was used as Mg2 ⁺ . Examples 4 to 7 of destruction of emulsions due to the combined effect of C Mg() and Al() ions The results shown in Table 3 were obtained in exactly the same manner as in Reference Examples 1 to 16. Examples 8 to 9 After carrying out exactly the same operations as in Reference Example 3 and Reference Example 13, respectively, Al () and Mg () were added to readjust the pH, and the mixture was stirred again to obtain the results shown in Table 3. D System in which polymer is dissolved Example 10, Reference Example 17 Ethylene propylene rubber (MFR (230
The results shown in Table 4 were obtained by performing the same operations as in Reference Examples 1 to 16, except for using an isohexane solution (40 g/10 min, ethylene content: 80 mol%). E Higher alcohol coexistence system Example 11, Reference Example 18, Comparative Reference Example 5 The results shown in Table 4 were obtained by performing the same operations as in Reference Examples 1 to 16, except that a predetermined amount of higher alcohol was added to the oil layer in advance. . F Example 12 Effect of adding a large amount of easily water-soluble salt Reference example 1 except for adding a large amount of NaCl to the aquarium
The results shown in Table 4 were obtained by performing the same operations as those in 16 to 16. Comparative Example 2 The results shown in Table 4 were obtained in the same manner as in Example 12 except for adding NaCl.

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[Table] Effects of the invention Emulsified states caused by the coexistence of oil/water layers, especially cases where colloidal solids are generated and phase separation becomes difficult, sometimes occur in various industrial facilities, and conventional countermeasures have been desired. However, according to the present invention, the emulsion disappears and phase separation becomes easy.

Claims (1)

[Scope of Claims] 1. A short-lived oil-in-water obtained by strongly stirring an aqueous solution containing a small amount of ions that are weakly alkaline and poorly soluble and form colloidal precipitates and an organic solution that is incompatible with water in a weakly alkaline condition. periodic table a in type emulsion
A method of separating oil and water by breaking the emulsion by adding a readily water-soluble salt containing ions of group metals and/or group a metals. 2. The method according to claim 1, wherein the easily water-soluble salt further contains an ion of a group A metal in addition to an ion of a group a metal of the periodic table. 3 The added ions are Mg() ions or
The method according to claim 1 or 2, which is a coexistence system of Mg() ions and Al() ions. 4. The method according to claim 1 or 2, wherein the metal salt added is one or more easily water-soluble salts selected from chlorides, sulfates, and nitrates of Group A metals of the Periodic Table.