JP5255886B2 - Separation accelerator and separation method for emulsion coolant wastewater - Google Patents

Description

  The present invention relates to a separation accelerator and a separation method for separating oil from an emulsion coolant waste liquid.

Conventionally, an emulsion-based water-soluble coolant waste liquid is generally composed of a water-soluble coolant mixed with a water-insoluble oil and water.
Such an emulsion-based water-soluble coolant waste liquid is partly separated into oil and moisture by standing, but the other part is generally W / O type due to the surfactant contained in the water-soluble coolant. It exists as mud oil in a state where water called an emulsion is stably dispersed in the oil to form an emulsion, or an oil called O / W type emulsion is stably dispersed in the water to form an emulsion. ing.

At present, the oil separated from the above-mentioned emulsion-based water-soluble coolant is recovered as valuables and reused, and the separated water is drained, and the remaining mud oil is disposed of as it is. ing.
However, it is preferable from the viewpoint of effective use of resources if the oil can be further separated and recovered from the portion present as mud oil.

Therefore, conventionally, oil is separated from mud oil by the following method.
For example, the oil component and moisture of the mud oil are separated by centrifugal force, or the oil component and the moisture are separated by heating the mud oil.

However, when oil and water are separated by centrifugal force, the specific gravity difference between the oil and water-soluble coolant (moisture) is small, so it cannot be completely separated, and many parts of mud oil remain. It was.
In addition, since the structure of the centrifuge is complicated, the maintenance of the equipment is complicated, the noise during operation of the centrifuge is loud, and the equipment such as the centrifuge is expensive.
In addition, when the mud oil is heated to separate the oil and moisture, the mud oil is heated to generate odor around the equipment, and the mud oil is heated using steam. Therefore, there was a problem that the cost for heating became expensive.

Moreover, as a method for treating the mud oil in the emulsion-based water-soluble coolant waste liquid, as shown in Patent Document 1, an electrolyte is added to the emulsion-based water-soluble coolant waste liquid to easily float and separate the oil component that has been stabilized. After that, a method is disclosed in which the emulsion is broken by adjusting the pH by adding an acid, and then treated by adding an inorganic flocculant while maintaining its pH.
As described above, in the processing method disclosed in Patent Document 1, it is possible to reduce the size of the processing apparatus, but it has been difficult to sufficiently separate the mud oil into oil and moisture. .
JP 11-197405 A

  Therefore, in the present invention, in order to solve the above-described problems, an emulsion coolant waste liquid separation accelerator and a separation method capable of efficiently and sufficiently separating mud oil into oil and moisture are provided. is there.

An emulsion coolant waste separation accelerator and method for solving the above-described problems have the following characteristics.
That is, as in claim 1, wherein, relative to 100 parts by weight of water, and 1-10 parts by weight of sodium hydroxide, and 10 parts by weight of potassium hydroxide, the polymeric water-soluble cationic polymer over 1-5 A separation method for separating oil from an emulsion-based coolant waste liquid using a separation accelerator containing parts by weight, the mud oil of the emulsion-based coolant waste liquid, the separation accelerator, and sodium chloride, The mixing amount is 100 parts by weight of the mud oil, 1 to 2.7 parts by weight of the separation accelerator, and 5.75 to 8.25 parts by weight of sodium chloride.

  Further, according to claim 2, the separation accelerator mixed with the emulsion coolant waste mud oil is diluted to 2 to 50 parts by weight with respect to 100 parts by weight of water, and the emulsion coolant waste liquid mud oil. The sodium chloride to be mixed in is an aqueous sodium chloride solution in which 5 to 35 parts by weight of sodium chloride is dissolved in 100 parts by weight of water.

  The polymer water-soluble cationic polymer may be any one of a polyethyleneimine polymer, a polyallylamine polymer, a diallylamine polymer, and a diallylamine-maleic acid copolymer. Composed.

According to the present invention, for example, in the case of a W / O type emulsion, the surface charge of water droplets stably dispersed in oil is neutralized, and the hydrophilic group of the surfactant is hydrophobized and emulsified. It is possible to efficiently unite the water droplets in the mud oil, so that the mud oil can be sufficiently separated into water and oil.
In the case of the O / W type emulsion, the mud oil can be sufficiently separated into water and oil by the same effect.

  Next, modes for carrying out the present invention will be described with reference to the accompanying drawings.

  The separation accelerator 2 in this example is mixed with the emulsion coolant waste liquid 1 to promote the separation of the oil and water from the emulsion coolant waste liquid 1 and enable efficient and sufficient separation.

The separation accelerator 2 contains, for example, water, sodium hydroxide, potassium hydroxide, and a high molecular weight water-soluble cationic polymer, and the content ratio of each of these components is determined based on 100 parts by weight of water. Sodium is 1 to 10 parts by weight, potassium hydroxide is 1 to 10 parts by weight, and the polymer water-soluble cationic polymer is 1 to 5 parts by weight.
The content of each component is 1 to 5 parts by weight of sodium hydroxide, 1 to 5 parts by weight of potassium hydroxide, and 1 to 3 parts by weight of the polymer water-soluble cationic polymer with respect to 100 parts by weight of water. More preferably, it is a part.

  Examples of the polymer water-soluble cationic polymer of the separation accelerator 2 include any of polyethyleneimine polymer, dicyandiamide, polyallylamine polymer, diallylamine polymer, diallylamine-maleic acid copolymer, and quaternary ammonium salt. Or one is used.

  On the other hand, the emulsion-based coolant waste liquid 1 (hereinafter simply referred to as “waste liquid 1”) to be separated into oil and water by the separation accelerator 2 is, for example, a mixture of water-soluble coolant, water-insoluble oil and water. The mixing ratio is about water-soluble coolant: water-insoluble oil: water = 5-30 parts by weight: 50-80 parts by weight: 10-50 parts by weight.

As shown in FIG. 1, when the waste liquid 1 is left standing, a part of the waste liquid 1 is naturally separated into an oil component 10 and moisture 30, but mud oil 20 remains as the other portion.
In the case of the W / O type emulsion, the mud oil 20 has a structure in which water 23 is stably dispersed in the oil 21 by the surfactant 25 contained in the water-soluble coolant, as shown in FIG. Is in a state.
When the mud oil 20 is an O / W type emulsion, as shown in FIG. 3, the oil 21 is stably dispersed in the water 23 by the surfactant 25 to form an emulsion.

The surfactant 25 is an amphiphilic substance having a lipophilic group 25a and a hydrophilic group 25b. In the mud oil 20 of the present example, the hydrophilic group 25b is oriented to the water 23 side, and the lipophilic oil The base 25a is oriented toward the oil 21 to form a water-in-oil (W / O type) emulsion or an oil-in-water (O / W type) emulsion.
The lipophilic group 25a is composed of a hydrocarbon chain, and the hydrophilic group 25b is composed of a carboxyl group, an amino group, an amide group, a hydroxyl group, and the like.

The water-soluble coolant surfactant 25 generally contains an anionic surfactant and a nonionic surfactant.
Anionic surfactants include sodium lauryl sulfate, dodecyl benzene sulfonate, sodium alkane sulfonate, sodium alkyl diphenyl ether sulfonate, sodium alkyl sulfate ester, sodium polyoxyethylene alkyl ether sulfate ester, sodium dialkyl sulfosuccinate Etc. are used.

  Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene / polyoxypropylene / block polymer, polyoxyethylene polypentylphenyl ether, polyoxyethylene stearyl ether, polyoxyethylene myristyl ether, polyoxyethylene Oxyethylene lauryl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene hydrogenated castor oil, and the like are used.

In addition, as the anionic surfactant and the nonionic surfactant, those having a molecular weight of, for example, about 100 to 1000000, more preferably about 1000 to 30000 are used.
Furthermore, each said surfactant 25 exists stably in the range of pH 5-10, for example, HLB (Hydrophile-Lipophile Balance) = about 3-20, More preferably, it sets to about HLB = 6-15. ing.

  The water-insoluble oil contained in the waste liquid 1 is a fluid oil such as a water-insoluble hydraulic oil, lubricating oil, press oil, sliding surface oil, gear oil, turbine oil, and processing oil.

Next, a method for separating the mud oil 20 of the waste liquid 1 into oil and moisture using the separation accelerator 2 will be described.
First, in the mud oil 20, the hydrophilic group 25b of the surfactant 25 is bonded (hydrated) to the polarized water 23, and the surface of the water 23 is positively charged. Accordingly, the lipophilic group 25a of the surfactant is negatively charged due to electrical repulsion.
That is, as shown in FIG. 4, in the case of the W / O type emulsion, there is a negative charge at the oil contact portion of the surfactant bonded to each water droplet (water 23) dispersed in the oil 21. Therefore, the water droplets (water 23) repel each other electrically, so that the emulsion is stably formed.
On the other hand, in the case of the O / W type emulsion, as shown in FIG. 5, a positive charge is present at the water contact portion of the surfactant bonded to each oil droplet (oil 21) dispersed in the water 23. Therefore, the oil droplets (oil 21) are electrically repelled, and the emulsion is stably formed.

  Thus, in order to separate the mud oil 20 that is stably dispersed as a W / O emulsion or an O / W emulsion into oil and moisture, as shown in FIGS. 6 and 7, In this example, the separation accelerator 2 and the sodium chloride aqueous solution 3 as an electrolyte are added to the mud oil 20 to mix the mud oil 20, the separation accelerator 2 and the sodium chloride aqueous solution 3 (FIG. / O type emulsion, FIG. 7 shows the case of O / W type emulsion).

The separation accelerator 2 mixed with the mud oil 20 is added to the mud oil 20 in a state diluted with water.
In this case, the dilution ratio of the separation accelerator 2 with water is, for example, 2 to 50 parts by weight of the separation accelerator 2 with respect to 100 parts by weight of water, and more preferably the separation accelerator 2 with respect to 100 parts by weight of water. 5 to 20 parts by weight.

  Moreover, the sodium chloride aqueous solution 3 mixed with the mud oil 20 uses what melt | dissolved 5-35 weight part sodium chloride with respect to 100 weight part of water, for example, More preferably with respect to 100 weight part of water What dissolved 20-30 weight part sodium chloride is used.

By mixing the sodium chloride aqueous solution 3 prepared in such a concentration with the mud oil 20, the surface of the surfactant 25, particularly the water 23 to which the anionic surfactant is bound, is electrically neutralized. (That is, the positive charge on the surface of the water 23 is reduced).
As a result, the negative charge charged on the lipophilic group 25a of the surfactant 25 bonded to the water 23 is similarly reduced.

Moreover, in the said surfactant 25, especially a nonionic surfactant, since the circumference | surroundings become a basic atmosphere by sodium hydroxide or potassium hydroxide contained in the mixed separation accelerator 2, the lipophilic group 25a and The balance with the hydrophilic group 25 b is lost, the hydrophilic group 25 b does not act, and the hydrophilic group 25 b is separated from the water 23.
Note that the sodium hydroxide and potassium hydroxide of the separation accelerator 2 also have an effect of electrically neutralizing the surface of the water 23.

  As described above, the surface of the water droplet (water 23) or the oil droplet (oil 21) is electrically neutralized, and the hydration state of the hydrophilic group 25b of the surfactant 25 with respect to the water 23 is inhibited. Since the repulsive force between water droplets (water 23) or between oil droplets (oil 21) becomes weak, as shown in FIGS. 8 and 9, dispersed water droplets (water 23) or between oil droplets (oil 21) As shown in FIG. 10 and FIG. 11, the water droplets (water 23) or the oil droplets (oil 21) become larger as a result of coalescence.

  Then, when the water droplet (water 23) or the oil droplet (oil 21) has a certain size or more, the water 23 falls due to the difference in specific gravity between the water 23 and the oil 21 or the oil 21 floats. As shown, the water 23 and the oil 21 are separated.

Thus, by mixing the sodium chloride aqueous solution 3 and the separation accelerator 2 in the mud oil 20, the sodium chloride aqueous solution 3 and the sodium hydroxide and potassium hydroxide in the separation accelerator 2 are stably present. The emulsion thus formed is broken and the salting-out reaction proceeds to separate the mud oil 20 into water 23 and oil 21.
That is, by mixing the aqueous sodium chloride solution 3 and the separation accelerator 2 in the mud oil 20, the surface charge of the water 23 dispersed in the oil 21 is neutralized, and the hydrophilic groups 25b of the surfactant 25 are eliminated. The function is inhibited and hydrophobized, and the water droplets (water 23) or the oil droplets (oil 21) constituting the emulsion are efficiently united, so that the mud oil 20 is sufficient for the water 23 and the oil 21. Can be separated.

Further, in this case, since the separation process is only to add the sodium chloride aqueous solution 3 and the separation accelerator 2 to the mud oil 20 and stir, the treatment equipment can be configured simply and inexpensively and easily. Can be separated by work.
The water 23 separated from the mud oil 20 can be drained to a wastewater treatment plant or the like, and the separated oil 21 can be recovered and reused as fuel.

Further, since the surfactant 25 and other impurities contained in the mud oil 20 are aggregated by the polymer water-soluble cationic polymer contained in the separation accelerator 2, and become a precipitate in the water 23, The clarity of the separated water 23 can be improved.
Note that the separated water 23 contains sodium and potassium components resulting from the sodium chloride aqueous solution 3 and the separation accelerator 2 added to the mud oil 20, so that the separated water 23 is not subjected to the separation treatment. By adding to the mud oil 20, it is possible to reduce the amount of the sodium chloride aqueous solution 3 and the separation accelerator 2 to be added to the mud oil 20 during the separation process.

  Next, as a result of the separation state of the oil 21 and the water 23 when the separation process of the oil 21 and the water 23 is actually performed by mixing the mud oil 20 with the sodium chloride aqueous solution 3 and the separation accelerator 2. Will be described with reference to Example 1 and Example 2 below.

The separation process of this example is performed by adding a predetermined amount of sodium chloride aqueous solution 3 and a predetermined amount of separation accelerator 2 to the mud oil 20 and stirring for a predetermined time, and then allowing to stand for a predetermined time. The state of separation from the water 23 was performed by confirming the separation rate between the oil 21 and the water 23.
As the sodium chloride aqueous solution 3 and the separation accelerator 2 to be mixed with the mud oil 20, a 25 wt% sodium chloride aqueous solution 3 and a separation accelerator 2 having a dilution rate of 10% were used.

  Further, in this example, as in the samples a to d shown in (Table 1), the amounts of the sodium chloride aqueous solution 3 and the separation accelerator 2 to be mixed with the mud oil 20 are changed, respectively. The separation rate of was confirmed.

  The mixing amount of the sodium chloride aqueous solution 3 and the separation accelerator 2 in each of the samples a to d is 33 parts by weight of the sodium chloride aqueous solution 3 and 23 parts by weight of the separation accelerator 2 with respect to 100 parts by weight of the mud oil 20 of the sample a. 27 parts by weight of the sodium chloride aqueous solution 3 and 27 parts by weight of the separation accelerator 2 are mixed with 100 parts by weight of the mud oil 20 in which the sample b is 100 parts by weight, and the sample a is 100 parts by weight of mud. 33 parts by weight of sodium chloride aqueous solution 3 and 17 parts by weight of separation accelerator 2 are mixed with oil 20, and 23 parts by weight of sodium chloride aqueous solution 3 with respect to mud oil 20 in which sample a is 100 parts by weight, In addition, 23 parts by weight of the separation accelerator 2 is mixed.

According to Table 1, the separation rate of sample a was the highest at 94%, and samples b to d were both 88%.
From this, for the mud oil 20 in this example, among the samples a to d, the mixing ratio of the sodium chloride aqueous solution 3 and the separation accelerator 2 in the sample a is the most suitable ratio for oil-water separation. However, the mud oil 20 can be almost completely separated into the oil 21 and the water 23 by the sample a.

The separation process of this example is performed by adding a predetermined amount of sodium chloride aqueous solution 3 and a predetermined amount of separation accelerator 2 to the mud oil 20 and stirring for a predetermined time, and then allowing to stand for a predetermined time. The state of separation from the water 23 was confirmed by a three-stage evaluation of “separation”, “slight separation”, and “not separated”.
As the sodium chloride aqueous solution 3 and the separation accelerator 2 to be mixed with the mud oil 20, a 25 wt% sodium chloride aqueous solution 3 and a separation accelerator 2 having a dilution rate of 10% were used.

  Further, in this example, as in each sample A to H shown in (Table 2), the amounts of the sodium chloride aqueous solution 3 and the separation accelerator 2 to be mixed with the mud oil 20 are changed, respectively. The separation state of was confirmed.

  The mixing amount of the sodium chloride aqueous solution 3 and the separation accelerator 2 in each sample A to H is 30 parts by weight of the sodium chloride aqueous solution 3 and 10 parts by weight of the separation accelerator 2 with respect to the mud oil 20 in which the sample A is 100 parts by weight. 30 parts by weight of the sodium chloride aqueous solution 3 and 0 part by weight of the separation accelerator 2 are mixed with 100 parts by weight of the mud oil 20 in which the sample B is 100 parts by weight, and the sample C is 100 parts by weight of mud. 50 parts by weight of sodium chloride aqueous solution 3 and 0 part by weight of separation accelerator 2 are mixed with oil 20, and 0 part by weight of sodium chloride aqueous solution 3 with respect to mud oil 20 in which sample D is 100 parts by weight, 10 parts by weight of the separation accelerator 2 is mixed, 0 parts by weight of the sodium chloride aqueous solution 3 is mixed with 20 parts by weight of the separation accelerator 2 with respect to 100 parts by weight of the mud oil 20 of the sample E, Trial F is mixed with 15 parts by weight of sodium chloride aqueous solution 3 and 5 parts by weight of separation accelerator 2 with respect to 100 parts by weight of mud oil 20, and sample G is sodium chloride with respect to 100 parts by weight of mud oil 20. 50 parts by weight of the aqueous solution 3 and 20 parts by weight of the separation accelerator 2 are mixed, and 10 parts by weight of the sodium chloride aqueous solution 3 and 3 parts of the separation accelerator 2 are added to the mud oil 20 of 100 parts by weight of the sample H. Part by weight is mixed.

According to Table 1, the separation state of the sample A is “separation”, the separation state of the sample F and the sample G is “partial separation”, and the separation states of the other materials B to E · H are “ “No separation”.
From this, it can be said that the mixing ratio of the sodium chloride aqueous solution 3 and the separation accelerator 2 in the sample A is the most suitable ratio for oil-water separation with respect to the mud oil 20 in the present embodiment. The oil 21 and the water 23 can be separated almost completely.

It is a figure which shows the emulsion type coolant waste liquid of the state isolate | separated into oil, mud oil, and water by standing still. It is a figure which shows the mud oil of the state which has comprised the emulsion by disperse | distributing water in oil. It is a figure which shows the mud oil of the state which oil has disperse | distributed in water and has comprised the emulsion. It is a figure which shows a mode that the water droplets disperse | distributed in oil repel by the electric charge of a mutual surface. It is a figure which shows a mode that the oil droplets disperse | distributed in water repel by the electric charge of a mutual surface. It is a figure which shows a mode that sodium chloride aqueous solution and a separation promoter are added to the emulsion type coolant waste liquid comprised by the W / O type | mold emulsion. It is a figure which shows a mode that sodium chloride aqueous solution and a separation promoter are added to the emulsion type coolant waste liquid comprised by the O / W type | mold emulsion. It is a figure which shows a mode that the water droplet currently disperse | distributed in oil mutually approaches. It is a figure which shows a mode that the oil droplets disperse | distributed in water mutually approach. It is a figure which shows a mode that the water droplets currently disperse | distributed in oil are united. It is a figure which shows a mode that the oil droplets disperse | distributed in water are united. It is a figure which shows the mud oil isolate | separated into oil and water.

DESCRIPTION OF SYMBOLS 1 Emulsion-type coolant waste liquid 2 Separation promoter 3 Sodium chloride 10 Oil 20 Mud oil 21 Oil 23 Water 25 Surfactant 25a Lipophilic group 25b Hydrophilic group 30 Water

Claims (3)

Relative to 100 parts by weight of water, and 1 to 10 parts by weight of sodium hydroxide, and 1 to 10 parts by weight of potassium hydroxide, separated promoter containing a 1 to 5 parts by weight of the polymer water-soluble cationic polymer over Is a separation method for separating oil from an emulsion-based coolant waste liquid,
The emulsion-based coolant waste liquid mud oil, the separation accelerator, and sodium chloride are mixed in an amount of 100 parts by weight of the mud oil, 1 to 2.7 parts by weight of the separation accelerator, and sodium chloride. To be 5.75-8.25 parts by weight,
A method for separating an emulsion-based coolant waste liquid. The separation accelerator mixed with the emulsion coolant waste liquid is diluted to 2 to 50 parts by weight with respect to 100 parts by weight of water.
The sodium chloride to be mixed with the mud oil of the emulsion coolant waste liquid is a sodium chloride aqueous solution in which 5 to 35 parts by weight of sodium chloride is dissolved with respect to 100 parts by weight of water.
The method for separating an emulsion-based coolant waste liquid according to claim 1. The polymer water-soluble cationic polymer is composed of any one of a polyethyleneimine polymer, a polyallylamine polymer, a diallylamine polymer, and a diallylamine-maleic acid copolymer.
The method for separating an emulsion-based coolant waste liquid according to claim 1 or 2, wherein

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