JPS5934404B2 - How to separate water and oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for separating oil as an r-liquid by passing an oil-water mixture through a f-filtration.

Conventionally, for the separation of water and oil, a natural phase separation method or a centrifugation method that utilizes the difference in specific gravity has been adopted or used on a trial basis.

However, when the difference in specific gravity between the water layer and the oil layer is small, or when the oil layer is emulsified, phase separation takes a long time and has the disadvantage of requiring great skill and labor.

Therefore, a separation method that does not rely on the specific gravity difference method, which has the above-mentioned drawbacks, was proposed.

That is, a separation method has been devised in which oil and water mixtures are passed through a porous membrane made of a non-polar polymer such as polytetrafluoroethylene, polyvinylidene fluoride, polypropylene, or polyethylene to obtain only oil as an r-liquid.

However, when making porous membranes from these non-polar polymers, it is difficult to mold them into membranes with the desired pore size and porosity due to the non-adhesive nature of the polymers, which makes porous membranes extremely expensive. There are drawbacks.

Another disadvantage is that separation is difficult when the oil is a polar organic liquid.

In order to eliminate the above-mentioned drawbacks, the present inventors have focused on organic compounds containing perfluoroalkyl groups and have conducted extensive research into improving the technology, and as a result, have accomplished the present invention.

That is, the present invention is directed to the use of "F-material itself or its pre-wetted material with oil, which is coated with 0.1-10% by weight of a surface-active compound containing a perfluoroalkyl group having 4 to 12 carbon atoms. A method for separating a polar organic liquid as an r-liquid by filtering a polar organic liquid-water mixture using

The "surfactant compound containing a perfluoroalkyl group" used in the present invention is one that can be physically or chemically bonded to the surface of a polar solid (P material), and has at least one perfluoroalkyl group in its molecule. It contains an alkyl group and at least one polar group, preferably has a molecular weight of 300 to 200,000, and particularly contains a perfluoroalkyl group having 4 to 12 carbon atoms.

Examples of such compounds include the following.

■ Polymers with perfluoroalkyl groups in their side chains (b) Surfactants containing perfluoroalkyl groups
~7° Such surface-active compounds can be produced by known methods, and some are commercially available.

For example, the product names manufactured by Dainippon Ink and Chemicals Co., Ltd. [Megafac JF-305, F-310, F-320, etc.], and the product names manufactured by 3M Co., Ltd.
gard J FC-214, FC-218, FC-4
52, FC-453 etc., and Allied's product name rAcTJ2100.2300 etc. are also available.C1
ba Geigy product name IT 1ntop J
T-10 is available, as well as Asahi Glass's product name "Asahi Guard" AG-710, AG-720, AG-620, etc., and Sumitomo Chemical's product name "Sumifroil" 5M-
Commercially available products such as 1,5M-2 and the like can also be used.

For the f material, f'' paper (made of cellulose, glass fiber, etc.), sawn cloth (made of cotton, tetron, nylon, vinylon, etc.), or a packed bed or aggregate of alumina, silica gel, sand, activated carbon, etc. can be used. can.

The amount of surface active compound containing perfluoroalkyl group to be attached to the f-material is in the range of 0.1-to4 weight coefficient.

As a method of attachment, for example, the swamp material may be immersed in a solution or emulsion of the above-mentioned compound and then air-dried or squeezed with a roller and then dried.

After drying, heat treatment may be performed subsequently.

The obtained "F material to which a surface-active compound containing a perfluoroalkyl group is attached" (hereinafter abbreviated as F-treated P material) may be used as it is, but the separation of oil and water may be slightly poor. Therefore, it is preferable to wet the F-treated lumber with oil in advance.

As a method for pre-wetting the F-treated material with oil, the F-treated material may be immersed in heated oil or immersed in oil under reduced pressure.

Additionally, organic liquids with a low surface tension of 18 dynes/cIIl or less, such as ethyl ether and n-pentane,
It is also possible to adopt a method of wetting the treated P material with oil having a higher surface tension.

Next, the heated oil-water mixture is passed through a conventional method with or without creating a pressure difference across the material.

Oils that can be separated by the method of the present invention are all organic liquids that are immiscible with water, such as gasoline, kerosene, light oil, heavy oil,
n-hexane, cyclohexane, decalin, benzene,
In addition to non-polar organic liquids such as toluene, polar organic liquids that form emulsions with water and are characterized by having polar groups in their molecules, such as alcohols (n-
butanol, higher alcohols, etc.], esters (ethyl acetate, methyl acrylate, ethyl acrylate, methyl methacrylate, etc.), ketones (methyl ethyl ketone, methyl isobutyl ketone, etc.), ethers (ethyl ether, isopropyl ether, etc.), etc. This includes reeds and non-polar organic liquids containing these alone or containing them.

According to the present invention, since f-material, which is inexpensive and easily available, is used as a base material, it is possible to select a material with a shape, pore size, and porosity suitable for various purposes, and also to It requires only a small amount and is cheaper than polytetrafluoroethylene membranes.

The method of the present invention improves the efficiency of the aqueous phase and oil phase in analytical operations.
Not only is it useful as a continuous separation means, but it can also be applied to industrial production, waste water and oil treatment, etc.

Examples are shown below.

Example 1 1 paper (Toyo 1 paper A
5B) was immersed, squeezed with a roller, and dried at 135° C. for 5 minutes to produce F-treated P paper with a coating weight of 1, which was wetted with the oil to be separated.

A mixed solution of equal amounts of water and oil was poured onto F-treated paper without stirring, and then filtered to observe the state of separation of the water and oil layers.

The results are shown in Table 2.

× indicates that the oil layer and water layer both pass through one sheet of paper and cannot be separated; ○ indicates that the oil layer passes through completely and the paper retains the water layer for 10 to 30 minutes after separation from the water layer is completed. Similarly, cases in which the water layer is retained by the paper for more than 2 hours after separation is completed are expressed as ◎.

Example 2 A piece of paper (A5C manufactured by Toyosawa Paper) was immersed in a 1 part diluted solution of a copolymer emulsion of 2-(N-methylperfluorooctyl sulfonamide) ethyl acrylate and n-butyl acrylate, and the paper was soaked with a roller. It is dried for 10 minutes at 135° C. to produce F-treated F paper with a coating weight of 1, and is wetted with the organic liquid to be separated.

A mixture of equal amounts of water and organic liquid was added to this mixture with vigorous stirring, and the state of separation of the aqueous layer and organic layer was observed.

The results are shown in Table 2. In the case where both the organic liquid layer and water pass through the f material and cannot be separated, ×, the organic liquid layer is completely removed. After the separation from the water layer is completed, the water layer is separated by 10 to 3
○ when holding for 0 minutes, f after separation is completed in the same way
A case where the weekly holiday retains the water layer for more than 2 hours is expressed as ◎.

Example 3 A 1-part solution of a copolymer of 2-(N-propyl perfluorooctyl sulfonamide) ethyl methacrylate and stearyl methacrylate in methyl chloroform was passed through a glass filter in room 3, air-dried, and wetted with the organic liquid to be separated. Then, an isostatic mixture of water and organic liquid was added to this mixture while stirring, and the state of separation was observed.

The results are shown in Table 3.

The same symbols as in Example 2 were used to represent the separation state.

Claims (1)

[Claims] i P material itself to which 0.1-10% by weight of a surface-active compound containing a perfluoroalkyl group containing carbon atoms of 4 to 12 carbon atoms is attached or a material pre-wetted with oil is used as the f material to A method of separating a polar organic liquid as an r-liquid by filtering a mixed liquid of an organic liquid and water.