JPS61283309A - Process of destroying oil-in-water emulsion - Google Patents

Abstract

PURPOSE:To separate oil and water speedily and accurately by means of destroying emulsion by adding easily water-soluble salt containing ion of groups Ia, IIa and IIIa metals to oil-in-water emulsion. CONSTITUTION:A solution containing a small amount of ion which makes colloid precipitation, weakly alkaline and hard-soluble, and an organic solvent containing raw materials, reaction substance, catalyst and the like are stirred up hard to produce an oil-in-water emulsion of comparatively short life. The emulsion is destroyed by means of adding a small amount of Mg<2+> only, or Mg<2+> and Al<3+> simultaneously, or putting a comparatively large amount of easily water-soluble salt of alkali metal or alkali earth metal into the solution. Thus, oil and water separation is carried out speedily and accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention aims to provide a method for breaking O/W (oil-in-water) emulsions. In other words, relatively short-lived O/O produced by stirring and mixing water and an organic solvent that is incompatible with water
This invention breaks the W emulsion and improves the separation of organic solvent and water.

BACKGROUND OF THE INVENTION Conventionally, it has been widely practiced industrially to carry out a reaction by emulsifying an organic solvent and water, which are incompatible with each other, and bringing the emulsion into contact with each other, and to wash and remove 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, in the next step after oil-water contact, oil-water separation is very often performed, and at that time antifoaming agents,
It was often necessary to use emulsion breakers, or even if they were used, it often took time for separation. 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. Ta.

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 The present invention employs the following method as a means for solving the above drawbacks.

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 life. .

After making oil-water contact in this way, a small amount of Kg(II) ion alone, or 111%(II) ion and A11(I[I) ion are added simultaneously to the emulsion, or an alkali metal and an alkali are added to the emulsion. By coexisting a relatively large amount of easily water-soluble salts of earth metals, the emulsion disappears and oil-water separation is performed quickly and effectively.

In particular, if the oil-water contact is only for a short time, it is possible to eliminate the emulsion generation step by adding Mg (II), Al (Iff) ions or easily water-soluble salts to the water side in advance, or
Or Mg(II) ions and/or
Alternatively, the emulsion storage step can be omitted by introducing M (m) ions.

Also, 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.

action 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 Ib, II, and ■ of the periodic table.
, ■, vb, vtb, vnb, vi group and lanthanides,
Divalent to hexavalent actinide ions or mixtures thereof, for example All (m).

Ac (III), Ti (rV), Zr (
■), V (IV), V (V), Fe (I
I), Fe(m), Cu(II), 0r(
III), Th(IV), or a mixture thereof. In addition, counter ions for these ions include 0H-15042-2Cil-, Br-,
It may contain NO3-CO32-, etc. However, in either case, it is essential to use it under conditions that produce a sparingly soluble water 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. ,
It forms a two-phase system with water, for example, n-pentane,
i-hexane, i-pentane, cyclohexane, 1-hexane, 4-methyl-1-pentene, liquid paraffin,
Examples include benzene, styrene, indene, cumene, chloroform, dichloroethane, 1-octatool, 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 p)I in the present invention include commonly used inorganic acids, alkalis, such as NaOH,
Examples include KOH, HCQ, H2S0a, etc.

Furthermore, the Mg(II) and Al(m) ions used in the present invention are supplied in the form of salts that are easily soluble in water. In addition, the water-soluble group Ia and IIa of the periodic table used in the present invention may also be used in the present invention.
Group metal salts include, for example, NaBr, KCL N
a2SO4, CaCl2, BaCl2, NaN
Examples include O3.

In addition, in the present invention, using a hydrocarbon as an organic solvent -(0
/W When generating emulsion, higher alcohols,
For example, 2-hexanol, 4-methyl-2-pentanol, ethylpuenyl rubinol, stearyl alcohol, 2-octatool, etc., or hot metals thereof, may be added in trace amounts (0.1 to 1 ppm) to the oil layer side. , Mg(
When II) and Al(m) ions coexist, oil-water separation becomes good.

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°C, preferably room temperature to 20°C
0℃ (2) Pressure crab usually 0-100100O/am2. Preferably normal pressure to IQO kgf/cm2 (3) Strong stirring time (batch type) 2 Usually 10 sec m1O
hr, preferably 10 sec to lhr.

Strong stirring time (continuous type): Normally 0.1sec x 10hr
, preferably 1 sec to lhr.

(4) Amount ratio of water and organic solvent in the system: i: 1ooo to 1000:1, regardless of whether it is a batch system or a continuous system. Preferably i:ioo to 100:1 (volume ratio) (5)
The pH of the water side in the system is 7-1! Preferably 8-10 (8)
The ion concentration that forms the colloidal precipitate on the water side of the system is 0.001 to 1000 w/vppm (weight
/volume PPM; mg/l), preferably 0.1 to 100 w/vPP11 (7) Stirring may be carried out using a conventional separate type or homogenizer, etc., and is not particularly specified.

(8) When the organic solvent contains a polymer soluble in it, the solution viscosity is 0.1 to IQOOOOcP, preferably 0.
It is 1 to 1000 cp.

(8) When using a hydrocarbon as an organic solvent, the amount of higher alcohol added in a trace amount to stabilize the emulsion is 0.01 to 1000 w/vppm, preferably 0.1 to 100 w/vppm, relative to the organic solvent.

(10) The concentration of Mg (n), which is added to a system containing an O/W emulsion to destroy the emulsion by stirring again, or to prevent the formation of an emulsion by allowing it to coexist from the beginning, is the same when Mg (II) is used alone. 0.01~1000w
/vppm, preferably Q, 1-100w/mappp■,
When Mg (■) and Al (m) are used together, the concentrations of Mg (II) and M (III) used together are 0.01 to 1000 w/vPpm, preferably 0.1 to 1000 w/vPpm, respectively.
The ratio of both is usually Mg by weight at 100 cm/ppm.
(II) :AQ (III) = 1 : 109
~100:1.

(11) Easy water solubility of group Ia or group IIa metals that can be added to a system containing O/W emulsion to destroy the emulsion by stirring again, or cause them to coexist from the beginning to prevent the formation of an emulsion. The concentration of salt is 10w/vppm
~30 w/v%, preferably 100-~10000 quality/
Mappps.

Examples of generation and failure of short-life O/W emulsions will be explained below with reference to Examples.

Test examples 1 to 1B for the production of short-lived 0/W emulsions using various ions that are weakly alkaline and produce poorly soluble precipitates. Insert 300-layer history of liquid paraffin and 300-layer history of liquid paraffin. To adjust the pHW, use the minimum amount of NaOH or HCl to adjust the pH.
The temperature is raised to a predetermined temperature while stirring at about 00 rpm. While keeping the temperature constant, stir at 11,000 rpm for 10 minutes, and after stopping, measure the time required for oil/water separation and the amount of residual emulsion. The standard for determining 0 separation is as follows.

(1) When oil and water separate in a relatively short time (within 20 minutes) and the emulsion layer also disappears.

Time required for the aqueous layer to recover to approximately 300 ml Amount of emulsion → Amount of emulsion when the aqueous layer recovers to 300 ml Partial separation occurs, but it takes time for the emulsion to disappear.

Time → 240s + IL or more (approximately 80% or more) Time for the aqueous layer to recover (however, the emulsion should hardly decrease in 1 minute after that) Emulsion amount → Emulsion amount at the above time (3) Oil-water separation is slow ( (takes more than 20 minutes).

Time→20 minutes or more Emulsion amount→20 minutes after stopping stirring An oil/water separation experiment was conducted using the water method, and the results shown in Table 1 were obtained.

In addition, Fe3+ is FeC13, Ti4◆ is TiC1,...
MCQ 3 was used for Ai3+.

Comparative Examples 1 to 4 The results shown in Table 1 were obtained by performing the same operations as in Examples 1 to 1B, except that nothing was added to the aqueous layer other than inorganic ions for pH adjustment.

B.) Emulsion destruction by Ig(II) ions Examples 17 to 20, Comparative Examples 5 to 8 The results shown in Table 2 were obtained in exactly the same manner as in Examples 1 to 1B.* Gci2 was used for Kg2+. .

Destruction of emulsions due to the combined effect of C, Mg (IT) and Al (III) ions Examples 21 to 24, Comparative Examples 9 to 1G The results shown in Table 3 were obtained in exactly the same manner as in Examples 1 to 1B. . Comparative Example 9 is Example 1B, Comparative Example 10 is Example 20
is the same as

Examples 25-28 Example 3. After carrying out exactly the same operation as in Example 13, the pH was readjusted by adding M (m) and Mg (■), and the mixture was stirred again to obtain the results shown in Table 3.

Comparative examples 11-12 Example 3, respectively. This is the same as Example 13.

D. System in which polymer was dissolved Example 27, Comparative Example 13 Ethylene propylene rubber (M F R (230
°C) = Ig/lo min, ethylene content 80 mo, le%)
The results shown in Table 4 were obtained by carrying out exactly the same operations as in Examples 1 to IB except for using an isohexane solution (40 g/l) of .

E. Higher alcohol coexistence system Example 28, Comparative Examples 14 to 1B The results shown in Table 4 were obtained by performing the same operations as in Examples 1 to 10, except that a predetermined amount of higher alcohol was added to the oil layer in advance.

F. Effect of adding a large amount of easily water-soluble salt Example 28 Examples 1 to 1 except for adding a large amount of NaC11 to the aqueous layer
The results shown in Table 4 were obtained by performing the same operation as in 6.

Comparative Example 17 The results shown in Table 4 were obtained by performing the same operations as in Examples 1 to 1B. Effects of the Invention There are various cases in which the emulsified state caused by the coexistence of oil and water, especially when colloidal solids are generated and phase separation becomes difficult. However, according to the present invention, the emulsion can be easily eliminated and the phases can be separated.

Claims (1)

[Claims] 1. A method for separating oil and water by breaking the emulsion by adding to the oil-in-water emulsion a readily water-soluble salt containing ions of metals of groups Ia, IIa, and IIIa of the periodic table. 2. A short-lived oil-in-water emulsion obtained by strongly stirring an aqueous solution containing trace amounts of ions that form colloidal precipitates that are weakly alkaline and poorly soluble, and an organic solution that is incompatible with water. 2. The method of claim 1, which is a mold emulsion. 3. The ions added are Mg(II) ions or Mg(
The method according to claim 1 or 2, which is a coexistence system of II) ions and Al(III) ions. 4. The metal salt added is one or more easily water-soluble salts selected from chlorides, sulfates, and nitrates of Group Ia and Group IIa metals of the Periodic Table, according to claim 1 or 2. Method.