JP2020078789A - Oil-water separating agent and oil-water separating method - Google Patents

Abstract

To provide an oil-water separating agent and an oil-water separating method with which water (particularly emulsified water) in waste oil can be efficiently separated.SOLUTION: An oil-water separating agent contains a nonionic surfactant which comprises one or more compounds selected from a group consisting of: (A) polyoxyethylene sorbitan mono-fatty acid ester; (B) polyoxyethylene alkyl ether; and (C) polyoxyethylene hardened castor oil. In the (A), the number of carbons in a fatty acid residue is 10-20, and the average addition molar number of ethylene oxide is 3-30 moles. The (B) is a compound represented by general formula (1): R-O-(CHO)-H (In general formula (1), Ris a 10-16C secondary alkyl group, and n is the average addition molar number of 5-12 of an ethyleneoxy group). In the (C), the average addition molar number of ethylene oxide is 3-50 moles.SELECTED DRAWING: None

Description

  The present invention relates to an oil/water separating agent and an oil/water separating method.

  As a result of continuing large-scale production, mass consumption, and large-scale waste-type economic activities, a huge amount of waste oil has been discharged in recent years, and there is concern about the tightness of the final disposal site and the impact of improperly processed waste oil on the environment. Has been done. As waste oil, lubricating oil type waste oil such as engine oil, refrigerating machine oil, cutting oil, insulating oil, etc. generated from gas stations, automobile maintenance factories, machine factories, power plants, etc.; kerosene, gasoline generated from gas stations, refineries, ships, etc. , Fuel oil waste oil such as tanker ballast water; Tar/pitch waste oil such as asphalt, pitch, wax, paraffin produced from oleochemical plants and road construction sites; Paint factory, printing factory, machine factory, chemical factory, etc. Waste solvents such as toluene, xylene, acetone, trichlorethylene, etc. generated; animal and vegetable oils such as beef tallow, soybean oil, fish oil, etc. generated from food factories, food service industries, catering facilities, general households, etc.;

  Such waste oil has been tried to be reused as much as possible, and is reused as a lubricating oil or a fuel oil. In particular, there are many fuel oils used as recycled heavy oil. Recycled heavy oil is a fuel oil produced mainly from engine oil for automobiles and used lubricating oil used for industrial purposes. Its quality is defined by JIS and it is used in direct fire industrial furnaces. Widely used as fuel for

  A wide variety of waste oils generated and collected in each industrial field are subjected to water and sludge removal at a waste oil reprocessing plant in processes such as oil-water separation by warming and standing and centrifugation. Especially for use as fuel oil, removal of water is very important from the viewpoint of preventing incomplete combustion and improving combustion efficiency.

  Generally, the difference in specific gravity is used to remove water from oil, but oil-water separation methods and oil-water separation agents have been developed that actively promote separation from the viewpoint of productivity.

  For example, in Patent Document 1, (A) HLB is a nonionic surfactant having 8 to 15 and (B) an alcohol containing 10 to 80% by mass of an oxyethylene group and having a weight average molecular weight of 1,000 to 20,000. An oil/water separating agent is described which is characterized by containing an alkylene oxide adduct as a main component.

  In Patent Document 2, a nonionic surfactant having a Griffin method HLB value of 6.5 or more and/or an anionic surfactant having a Davis method HLB value of 45 or more is used, and 1 part or less of water is added to 1 part of coal tar. A method for separating oil-water from water-containing coal tar is described in which oil-water separation is performed by adding to water-containing coal tar contained at a mass ratio of.

  In Patent Document 3, a first step of collecting a mixture of (water/heavy oil-type emulsion) and (heavy oil/water-type emulsion) in which water is incorporated and agglomerated, and the above-mentioned recovery ( By adding a surfactant to the mixture of (water/heavy oil type emulsion) and (heavy oil/water type emulsion) and stirring, (water/heavy oil type emulsion) and (heavy oil type emulsion) A second step of destroying the mixture (quality oil/water emulsion) (water/heavy oil emulsion) and (heavy oil/water emulsion). A method for separating oil/water of a mixture of

  In Patent Document 4, according to the viscosity of the oil-containing scum, the following (a) viscosity at 20° C. is less than 1000 mPa·s: polyoxyalkylene alkyl ether having an HLB value of 10 to 13.5, (b) 20° C. Viscosity is 1000 mPa·s or more and less than 2000 mPa·s: polyoxyalkylene alkyl ether having an HLB value of 10 to 13.5 and/or a polyoxyalkylene alkyl ether having an alkyl group derived from a secondary alcohol, (c) at 20° C. Viscosity of 2000 mPa·s or more: polyoxyalkylene alkyl ether in which the alkyl group is derived from a secondary alcohol, a polyoxyalkylene alkyl ether is selected, and the selected polyoxyalkylene alkyl ether is added to the oil-containing scum. A method of separating oil-water from an oil-containing scum is described.

JP 2001-162107 A JP, 2016-130284, A JP, 2005-87841, A JP, 2005-171689, A

  The waste oil is collected as a collected waste oil in which various waste oils are mixed, and various additives (for example, sulfonate, phenate, salicylate contained as a metal-based detergent) according to the purpose and deterioration products generated by deterioration ( For example, in the case of oils and fats, a large amount of fatty acid produced by hydrolysis forms a salt with a metal and the like). Further, the waste oil contains water due to water being mixed in at the time of collection or originally mixed in at the time of use. Therefore, normally, the waste oil (and the recovered waste oil) contains the emulsified water (about several%) because the oil-water interface is stabilized by the above-mentioned various additives and deterioration products.

  On the other hand, the oil-water separating agent and the oil-water separating method described in Patent Documents 1 to 4 are not satisfactory in removing water (especially emulsified water) in waste oil, and thus have an oil-water separating effect for use as fuel oil as recycled heavy oil. It was insufficient.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an oil-water separator and an oil-water separation method that can efficiently separate water (especially emulsified water) in waste oil.

The present invention is an oil-water separating agent containing a nonionic surfactant, wherein the nonionic surfactant is polyoxyethylene sorbitan monofatty acid ester (A), polyoxyethylene alkyl ether (B), and One or more compounds selected from the group consisting of polyoxyethylene hydrogenated castor oil (C), wherein the polyoxyethylene sorbitan monofatty acid ester (A) has a carbon number of a fatty acid residue of 10 or more and 20 or less, The average addition mole number of ethylene oxide is 3 moles or more and 30 moles or less, and the polyoxyethylene alkyl ether (B) has the general formula (1): R ¹ -O-(C ₂ H ₄ O) _n -H( In the general formula (1), R ¹ is a secondary alkyl group having 10 to 16 carbon atoms, and n is an average addition mole number of ethyleneoxy groups having 5 to 12 carbon atoms.) The polyoxyethylene hydrogenated castor oil (C) relates to an oil/water separating agent, characterized in that the average addition mole number of ethylene oxide is 3 moles or more and 50 moles or less.

  The present invention also relates to an oil/water separation method, which comprises a step of adding the oil/water separation agent to an oil containing water.

  The details of the mechanism of action of the effects of the oil-water separating agent and the oil-water separating method according to the present invention are unclear, but it is presumed as follows. However, the present invention may not be construed as being limited to this mechanism of action.

  The oil-water separating agent of the present invention has a well-balanced hydrophilic/hydrophobic and bulky structure, and therefore acts on the oil-water interface to disturb the orientation of the oil-water interface and can destabilize the emulsification (demulsification). It is presumed that the water content can be efficiently reduced. In particular, the oil-water separating agent of the present invention can efficiently demulsify waste oil (particularly recovered waste oil) with a small addition amount, so that the waste oil after being treated with the oil-water separating agent is fuel oil (particularly recycled heavy oil). ) Is suitable.

<Oil water separator>
The oil-water separator of the present invention is an oil-water separator containing a nonionic surfactant, and the nonionic surfactant is a polyoxyethylene sorbitan monofatty acid ester (A) or a polyoxyethylene alkyl ether ( B) and one or more compounds selected from the group consisting of polyoxyethylene hydrogenated castor oil (C).

<Polyoxyethylene sorbitan monofatty acid ester (A)>
In the polyoxyethylene sorbitan monofatty acid ester (A) of the present invention, the fatty acid residue has 10 to 20 carbon atoms, and the average number of moles of ethylene oxide added is 3 to 30 moles. The polyoxyethylene sorbitan monofatty acid ester (A) is usually obtained by adding ethylene oxide in an amount of 3 mol or more and 30 mol or less to a sorbitan monofatty acid ester obtained by condensing a sorbitol with a fatty acid having 10 or more and 20 or less carbon atoms. .. The polyoxyethylene sorbitan monofatty acid ester (A) may be used alone or in combination of two or more kinds.

  Examples of the fatty acid having 10 to 20 carbon atoms include saturated fatty acids such as decanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, eicosanoic acid; decenoic acid, dodecenoic acid, tetradecenoic acid, hexadecenoic acid. And unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid. The fatty acid having 10 or more and 20 or less carbon atoms is preferably lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, more preferably lauric acid and oleic acid, and olein from the viewpoint of efficiently reducing the water content in waste oil. Acids are more preferred. The number of carbon atoms of the fatty acid residue is preferably 12 or more and preferably 18 or less from the viewpoint of efficiently reducing the water content in the waste oil.

  Further, the average added mole number of ethylene oxide is preferably 5 moles or more, more preferably 10 moles or more, and further preferably 15 moles or more, from the viewpoint of efficiently reducing the water content in the waste oil. It is more preferably 18 mol or more, still more preferably 28 mol or less, more preferably 25 mol or less, and further preferably 23 mol or less.

<Polyoxyethylene alkyl ether (B)>
The polyoxyethylene alkyl ether (B) of the present invention is a compound represented by the following general formula (1).
Formula ^{_{(1): R 1 -O- (}} C 2 H 4 O) n -H
(In the general formula (1), R ¹ is a secondary alkyl group having 10 or more and 16 or less carbon atoms, and n is the average added mole number of ethyleneoxy groups of 5 or more and 12 or less.)

In the general formula (1), R ¹ is a secondary alkyl group having 10 to 16 carbon atoms. Here, the secondary alkyl group is a residue obtained by removing a hydroxyl group from a secondary alcohol, and in R ¹ —O— in the general formula (1), the carbon atom of R ¹ bonded to O is It means a secondary carbon atom.

  The polyoxyethylene alkyl ether (B) is usually obtained by adding 5 to 12 mol of ethylene oxide to a secondary alcohol having 10 to 16 carbon atoms. The polyoxyethylene alkyl ether (B) may be used alone or in combination of two or more kinds.

In the general formula (1), R ¹ preferably has 12 or more carbon atoms, and preferably 14 or less carbon atoms, from the viewpoint of efficiently reducing the water content in the waste oil. Further, in the general formula (1), n is preferably 10 or less from the viewpoint of efficiently reducing the water content in the waste oil.

<Polyoxyethylene hydrogenated castor oil (C)>
The polyoxyethylene hydrogenated castor oil (C) of the present invention has an average addition mole number of ethylene oxide of 3 to 50 moles. The polyoxyethylene hydrogenated castor oil (C) is usually obtained by adding 3 to 50 mol of ethylene oxide to hydrogenated castor oil. The polyoxyethylene hydrogenated castor oil (C) may be used alone or in combination of two or more kinds.

  The average addition mole number of ethylene oxide is preferably 5 moles or more, more preferably 10 moles or more, and further preferably 15 moles or more, from the viewpoint of efficiently reducing the water content in the waste oil. The amount is more preferably 20 mol or more, still more preferably 25 mol or more, further preferably 45 mol or less, more preferably 40 mol or less, and 35 mol or less. More preferable.

  The nonionic surfactant of the present invention may contain a nonionic surfactant other than the one or more compounds (the components (A) to (C)), but the one or more compounds (the above It is preferable that the ratio of (A) to (C) is 80% by mass or more in the nonionic surfactant. The ratio of the one or more compounds (the total of the components (A) to (C)) in the nonionic surfactant is 85% by mass or more from the viewpoint of efficiently reducing the water content in the waste oil. The amount is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 98% by mass or more.

  In the oil-water separator of the present invention, the content of the nonionic surfactant in the oil-water separator is preferably 90% by mass or more, more preferably 95% by mass or more, and 98% by mass or more. More preferable.

<Other ingredients>
The oil-water separator of the present invention may contain additives (other components) generally used as an oil-water separator within a range that does not affect the performance. Examples of the additives include solvents such as water and solvents, aggregating agents, viscosity reducing agents, defoaming agents, preservatives, reducing agents, antioxidants, decolorizing agents, and coloring agents.

  In the oil/water separating agent of the present invention, the oil is preferably waste oil. Examples of the waste oil include lubricating oil waste oil such as engine oil, refrigerating machine oil, cutting oil, insulating oil, etc. generated from a gas station, automobile maintenance factory, machine factory, power plant, etc.; generated from a gas station, refinery, ship, etc. Fuel oil waste oil such as kerosene, gasoline, ballast water of tanker; tar/pitch waste oil such as asphalt, pitch, wax, paraffin generated from oleochemical factory and road construction site; paint factory, printing factory, machine factory, chemical Waste solvents such as toluene, xylene, acetone, and trichloroethylene produced from factories; beef tallow, soybean oil, animal and vegetable oils such as fish oil produced from food factories, restaurants, food service facilities, general households, etc. In particular, the oil/water separating agent of the present invention is suitable for the above-mentioned lubricating oil waste oil.

  The waste oil preferably has an acid value (AV) of 20 mg·KOH/g or less from the viewpoint of sufficiently exerting the oil-water separation effect of the oil-water separator. The acid value is an index of deterioration. The acid value is preferably 0.1 mg·KOH/g or more, more preferably 0.5 mg·KOH/g or more, further preferably 1 mg·KOH/g or more, and 10 mg. -KOH/g or less is more preferable, and 5 mgKOH/g or less is further preferable.

  The waste oil preferably has a hydroxyl value (OHV) of 0.1 mg·KOH/g or more, and is 0.5 mg·KOH/g or more, from the viewpoint of sufficiently exerting the oil-water separating effect of the oil-water separating agent. More preferably, it is 1 mg·KOH/g or more, further preferably 100 mg·KOH/g or less, more preferably 50 mg·KOH/g or less, 10 mg·KOH/g The following is more preferable.

The waste oil preferably has an iodine value (IV) of 0.1 gI ₂ /g or more, and preferably 0.5 gI ₂ /g or more, from the viewpoint that the oil-water separating effect of the oil-water separating agent can be sufficiently exhibited. more preferably, further preferably _{1 gI} 2 / g or more, and is preferably from 100gI ₂ / g, more preferably at most 50gI ₂ / g, further not more than 10gI ₂ / g preferable.

  The waste oil has a viscosity at 40° C. of preferably 20 mPa·s or more, more preferably 30 mPa·s or more, and further preferably 40 mPa· s or more is more preferable, and from the viewpoint of improving the separation efficiency, it is preferably 150 mPa·s or less, more preferably 100 mPa·s or less, and further preferably 70 mPa·s or less. Further, the waste oil has a viscosity at 100° C. of preferably 1 mPa·s or more, more preferably 2 mPa·s or more, from the viewpoint of sufficiently exerting the oil-water separating effect of the oil-water separating agent. It is more preferably 3 mPa·s or more, and from the viewpoint of improving the separation efficiency, it is preferably 20 mPa·s or less, more preferably 15 mPa·s or less, and further preferably 10 mPa·s or less. preferable.

  From the viewpoint of improving the efficiency of reducing the amount of water in the oil, the waste oil preferably has a water content of 20 mass% or less, more preferably 15 mass% or less, and further preferably 10 mass% or less. ..

<Oil water separation method>
The oil-water separating method of the present invention includes a step of adding the oil-water separating agent to an oil containing water. The method for adding the oil-water separating agent to the oil is not particularly limited, and it may be added to the oil by a general method, followed by mixing and mixing the oil-water by a general separation method such as static separation and centrifugation. Should be done. From the viewpoint of reducing the amount of water in oil and improving productivity, the oil-water separation method preferably includes a step of stationary separation and centrifugation, and more preferably centrifugation after stationary separation. Although the production efficiency is inferior, the stationary separation is preferable from the viewpoint of not requiring a large-scale device.

  The amount of the oil-water separating agent added to the oil is preferably 0.05 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the oil containing water. From the viewpoint of reducing the amount of water in the oil and improving the separation efficiency, the amount of the oil-water separating agent added to the oil is more preferably 0.08 parts by mass or more, relative to 100 parts by mass of the oil containing water. It is more preferably 0.1 part by mass or more, and more preferably 3 parts by mass or less, and further preferably 1 part by mass or less, from the viewpoint of reducing the amount of water in oil and economical efficiency.

  In the oil-water separation method, it is preferable to heat the oil from the viewpoint of reducing the viscosity of the oil and improving the separation efficiency. The temperature in the separation method is preferably 20° C. or higher, more preferably 30° C. or higher, further preferably 40° C. or higher, from the viewpoint of reducing the amount of water in the oil and improving the separation efficiency. From the viewpoint of reducing energy cost, the temperature is preferably 100° C. or lower, more preferably 95° C. or lower, and further preferably 90° C. or lower.

  When the stationary separation is performed, the stationary time is preferably 0.5 hours or more, more preferably 1 hour or more, and further preferably 5 hours or more, from the viewpoint of reducing the amount of water in the oil. Is more preferable, 10 hours or more is more preferable, 100 hours or less is preferable, 50 hours or less is more preferable, 30 hours or less is further preferable from the viewpoint of productivity improvement. .

  When performing the centrifugation, the centrifugal force is preferably 500 G or more, more preferably 1,000 G, and more preferably 2,000 G or more from the viewpoint of reducing the amount of water in the oil and improving productivity. Is more preferable, and from the viewpoint of economy, it is preferably 20,000 G or less, and more preferably 10,000 G or less. The centrifugation time is preferably 1 minute or more, more preferably 2 minutes or more, and further preferably 5 minutes or more, from the viewpoint of reducing the amount of water in the oil and improving productivity. And from the viewpoint of improving productivity, it is preferably 60 minutes or less, more preferably 30 minutes or less, and further preferably 20 minutes or less.

  Since the oil-water separating agent of the present invention can efficiently demulsify waste oil (particularly recovered waste oil) with a small addition amount, the waste oil after being treated with the oil-water separating agent is used as fuel oil (particularly recycled heavy oil). It is suitable.

  Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Waste oil>
The following was used as waste oil. Table 1 shows the physical properties of waste oil obtained by the following measuring methods.
Waste oil A: Massimo motor oil SN/CF (manufactured by Fuji Kosan Co., Ltd., SAE: 10W-30) that has deteriorated after running for 5000 km was added with ion-exchanged water so that the water concentration was 20% by mass, and after mixing, static for 1 week. Upper phase after placing (there is a visually emulsified component)
Waste oil B: Waste oil collected in the Hokkaido area (there are visual emulsified components)
Waste oil C: Waste oil collected in the Niigata area (visually emulsified components are present)

<Measurement of acid value (AV), hydroxyl value (OHV), and iodine value (IV)>
It was measured by a method according to JIS K0070.

<Measurement of viscosity>
After standing in a constant temperature bath set at the measurement temperature for 1 hour, measurement was performed at a rotation speed of 100/s using an Anton Paar Rheometer (MCR-302 type) and an attachment (CP50-1) (measurement time: 5 seconds, measurement temperature: 40° C. or 100° C.), and the shear viscosity was measured.

<Measurement of water content (water content)>
The water content was measured by the Karl Fischer method (JIS K2275).

<Examples 1 to 17 and Comparative Examples 1 to 6>
<Oil water separation test (1)>
10 g of waste oil was added to a Laboran screw tube bottle (manufactured by AS ONE Corporation, No. 5 20 mL). Then, oil-water separators of the types shown in Table 2 were added so that the ratio (% by mass) shown in Table 2 was reached, the lid was closed, and the mixture was shaken up and down by hand 100 times for 30 seconds. It was left to stand in a constant temperature bath set to the temperature shown. After 12 hours, 5 g of the supernatant was collected, and the water content was measured by the Karl Fischer method (JIS K2275). The results are shown in Table 2.

<Examples 18 to 20 and Comparative Example 7>
<Oil water separation test (2)>
10 g of waste oil was added to a Laboran screw tube bottle (manufactured by AS ONE Corporation, No. 5 20 mL). Then, oil-water separators of the types shown in Table 2 were added so that the ratio (% by mass) shown in Table 2 was reached, the lid was closed, and the mixture was shaken up and down by hand 100 times for 30 seconds. It was left to stand in a constant temperature bath set to the temperature shown. After 1 hour, centrifugation was performed using a centrifugal separator at a centrifugal force of 1,500 G for 10 minutes, 5 g of the supernatant was collected, and the water content was measured by the Karl Fischer method (JIS K2275). The results are shown in Table 2.

In Table 2, compound 1A is polyoxyethylene (20) sorbitan monooleate (manufactured by Kao Corporation, Leodol TW-O120V);
Compound 1B is polyoxyethylene (20) sorbitan monolauric acid ester (manufactured by Kao Corporation, Leodol TW-L120);
Compound 2A is polyethylene glycol (7) alkyl (mixed with secondary dodecyl and secondary tetradecyl) ether (manufactured by Nippon Shokubai Co., Ltd., Softanol 70);
Compound 2B is polyethylene glycol (5) alkyl (mixed secondary dodecyl and secondary tetradecyl) ether (Nippon Shokubai Co., Ltd., Softanol 50);
Compound 2C is a polyethylene glycol (9) alkyl (mixed secondary dodecyl and secondary tetradecyl) ether (manufactured by Nippon Shokubai Co., Softanol 90);
Compound 3A is polyoxyethylene (25) hydrogenated castor oil (manufactured by Kao Corporation, Emanone CH-25);
Compound 3B is polyoxyethylene (40) hydrogenated castor oil (manufactured by Kao Corporation, Emanone CH-40);
Compound 4 is hydrogenated castor oil;
Compound 5 is polyethylene glycol (3) alkyl (mixed secondary dodecyl and secondary tetradecyl) ether (Nippon Shokubai Co., Ltd., Softanol 30);
Compound 6 represents sorbitan monooleate (Emazole O10V, manufactured by Kao Corporation).

Claims (7)

An oil-water separating agent containing a nonionic surfactant,
The nonionic surfactant is
One or more compounds selected from the group consisting of polyoxyethylene sorbitan monofatty acid ester (A), polyoxyethylene alkyl ether (B), and polyoxyethylene hydrogenated castor oil (C),
In the polyoxyethylene sorbitan monofatty acid ester (A), the fatty acid residue has 10 to 20 carbon atoms, and the average number of moles of ethylene oxide added is 3 to 30 moles.
The polyoxyethylene alkyl ether (B) is
Formula ^{_{(1): R 1 -O- (}} C 2 H 4 O) n -H
(In the general formula (1), R ¹ is a secondary alkyl group having 10 or more and 16 or less carbon atoms, and n is an average number of moles of ethyleneoxy groups having 5 or more and 12 or less.). Is a compound,
The oil-water separating agent, wherein the polyoxyethylene hydrogenated castor oil (C) has an average addition mole number of ethylene oxide of 3 to 50 moles.   The oil-water separating agent according to claim 1, wherein the ratio of the one or more compounds is 80% by mass or more in the nonionic surfactant.   The oil-water separating agent according to claim 1 or 2, wherein the oil is waste oil.   The oil-water separating agent according to claim 3, wherein the waste oil has an acid value of 20 mg·KOH/g or less.   The oil-water separator according to claim 3 or 4, wherein the waste oil has a water content of 20% by mass or less.   An oil/water separation method comprising a step of adding the oil/water separation agent according to any one of claims 1 to 5 to an oil containing water. The oil-water separation method according to claim 6, which is a step of adding 0.05 part by mass or more and 5 parts by mass or less of the oil-water separating agent to 100 parts by mass of the oil containing water.