TWI617340B - Method for decreasing viscosity of oil-containing scum and method for decreasing viscosity of oil-containing drainage - Google Patents

Abstract

The present invention provides a method for suppressing an increase in viscosity of an oil-containing dross or an oil-containing drain without consuming a large amount of energy or accompanying an increase in moisture. The invention relates to a method for reducing the viscosity of oily scum, which is characterized in that the oily scum is added with an alkyl diphenyl ether disulfonate, a dialkyl sulfosuccinate and a polyalkylene alkyl ether sulfate. The above sulfonate and/or sulfate salt.

Description

Method for reducing viscosity of oily scum and method for reducing viscosity of oily drainage

The invention relates to a method for reducing viscosity of oily dross and a method for reducing viscosity of oily drainage.

In the rolling treatment of metals such as cold rolling, oil for lubrication and water for cooling are required to produce oily drainage. The oil-containing drainage generated in the metal rolling treatment or the like as described above is separated into moisture and oil in the oil-water separation tank. The separated moisture can be recovered and reused in cold rolling or the like, or sent to a drainage treatment facility. The oil is floated as scum at the time of separation, and the scum containing oil (hereinafter referred to as "oily scum") is pumped from the oil-water separation tank by a pump, and is incinerated as industrial waste.

The viscosity of oily drainage and oily scum is likely to increase due to the influence of oil. The increase in viscosity is remarkable in a low temperature environment, in particular, the oily scum is highly susceptible to high viscosity due to the high concentration of oil, and has a profound influence on the liquid feeding operation by the pump in the oil-water separation tank.

The techniques of Patent Document 1 and Patent Document 2 have been proposed as the oil-water separation treatment of the oil-containing drainage.

Patent Document 1 discloses that in the oil separation tank, after the floating oil is separated from the oily wastewater, the floating oil is further separated in the pressurized floating tank without injecting the chemical, and the floating oil is removed in two stages, and thereafter The emulsion breaking is performed to add an aggregating agent, and the separated oil is agglomerated, and is floated as scum in a pressurized floating concentration tank, and concentrated and removed. However, Patent Document 1 only focuses on oil-water separation, and there is no consideration regarding the viscosity reduction of oil-containing drainage or oil-containing scum.

Patent Document 2 discloses a method of performing oil-water separation treatment using a specific oil-water separation promoter, and there is no consideration regarding the viscosity reduction of oil-containing drainage or oil-containing scum.

In order to reduce the viscosity of oily drainage or oily scum, it is effective to increase the temperature. Patent Document 3 discloses a method of increasing the operability in order to fluidize the sludge and heating the sludge.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 62-121688

[Patent Document 2] Japanese Patent Laid-Open No. Hei 8-168605

[Patent Document 3] Japanese Patent Publication No. Sho 59-38175

However, the warming process of Patent Document 3 has the following problems: The energy consumption in the steps of the column becomes larger.

Further, with regard to the oil-containing dross, the viscosity can be lowered by adding water, but the moisture of the dross increases due to the fact that a large amount of combustion improver is required at the time of incineration treatment, and oil is contained due to the presence of moisture. The heat of the scum is lowered, and the reuse of the oily scum becomes difficult.

The present invention has been made in such a situation, and an object thereof is to provide a method for reducing the viscosity of an oil-containing dross or an oil-containing drain without causing a large amount of energy consumption or accompanying an increase in moisture in the oil-containing dross.

In order to solve the above problems, the present invention provides the following [1] to [4].

[1] A method for reducing viscosity of oily dross, which comprises adding an oily dross to an alkyl diphenyl ether disulfonate, a dialkyl sulfosuccinate, and a polyalkylene alkyl ether sulfate. One or more sulfonate and/or sulfate salts of a salt.

[2] The method for reducing the viscosity of an oil-containing dross according to the above [1], wherein a dialkyl sulfosuccinate is added as the sulfonate and/or sulfate salt.

[3] A method for reducing viscosity of oily drainage, which comprises adding an alkyl diphenyl ether disulfonate, a dialkyl sulfosuccinate, and a polyalkylene alkyl ether sulfate to an oily drainage. One or more kinds of sulfonate and/or sulfate salt.

[4] The method for reducing the viscosity of an oil-containing drainage according to [3] above, wherein an alkyl diphenyl ether disulfonate is added as the sulfonate and/or sulfate salt.

Viscosity reducing method for oily dross of the present invention and viscosity of oily drainage The degree reduction method may reduce the viscosity of the oil-containing scum and the oil-containing drainage without a large amount of energy consumption or accompanied by an increase in moisture in the oil-containing scum.

[Method for reducing viscosity of oily scum]

The method for reducing the viscosity of the oil-containing dross of the present invention is to add an oil-containing dross to the salt selected from the group consisting of alkyl diphenyl ether disulfonate, dialkyl sulfosuccinate and polyoxyalkylene alkyl ether sulfate. The above sulfonate and/or sulfate salt (hereinafter sometimes referred to as "the sulfonate and/or sulfate salt of the present invention").

In addition, the "oil-containing scum" in the present invention includes at least an oil component (floating oil) separated by the oil-water separation tank, and further contains a component other than the oil component such as moisture which is taken out together with the oil component at the time of oil-water separation. And the components added after the separation of the oil and water, such as water dispersed in the oily scum.

The oil-containing dross which can be applied in the viscosity reduction method of the oil-containing dross of the present invention is not particularly limited. Examples of the source of the oil-containing dross include oil-containing drainage water generated in a rolling treatment of a metal such as cold rolling.

The oil content in the oil-containing dross is not particularly limited, but is usually 20% by mass to 80% by mass.

As the sulfonate and/or sulfate salt, one or more selected from the group consisting of alkyl diphenyl ether disulfonate, dialkyl sulfosuccinate, and polyoxyalkylene alkyl sulfate can be used. Excellent in viscosity reduction in systems with a large oil content such as oily scum In terms of aspects, dialkyl sulfosuccinates are suitable among these.

It is considered that the sulfonate and/or sulfate salt of the present invention contributes to a decrease in viscosity of the oil-containing dross due to inhibition of crystallization of the wax component contained in the oil component. Further, it is considered that the viscosity of the oil-containing dross is lowered by promoting the dispersion of the oil droplets in the oil-containing dross.

As described above, the sulfonate and/or sulfate salt of the present invention has an effect of lowering the viscosity of the oil-containing dross, so that the amount of water dispersed in the oil-containing dross can be reduced. Thereby, the water content in the oil-containing dross is reduced, and the amount of the combustion improver added to the incineration of the oil-containing dross can be reduced. Moreover, by reducing the moisture in the oily scum, the heat of the oily scum can be increased, and the recovered oily scum can be reused.

Further, it is not necessary to heat the oil-containing dross to lower the viscosity, and it is possible to reduce the amount of energy such as steam.

The sulfonate and/or sulfate salt of the present invention serves to reduce the viscosity of the oil-containing dross. By this action, the water enclosed in the hard oil film easily escapes to the outside of the oil film, and the oil-water separation effect can be promoted. In particular, the alkyl diphenyl ether disulfonate and the dialkyl sulfosuccinic acid are suitable in terms of excellent oil-water separation. Due to the oil-water separation effect of the oil-containing scum, the moisture of the oil-containing scum can be reduced at each stage of the oil-water separation.

The amount of the sulfonate and/or sulfate salt of the present invention to be added to the oil-containing dross is preferably from 3 g/L to 30 g/L with respect to the oil content in the oil-containing dross.

The position at which the sulfonate and/or sulfate salt of the present invention is added is not particularly limited. From the viewpoint of reducing the moisture in the oily dross, it is preferred to obtain the oily dross. The front position, specifically, the position before the oil-water separation tank or the oil-water separation tank is added. In addition, from the viewpoint of reducing the amount of addition, it is preferable to add it to a pipe or the like after the oil-water separation tank.

The alkyl diphenyl ether disulfonate can be represented by the following formula (1).

In the formula (1), R ¹ represents an alkyl group having a carbon number of 8 to 15, and X ¹ and X ² each independently represent any selected from the group consisting of Na, NH(CH ₂ CH ₂ OH) ₃ , K, and NH ₄ . One]

The dialkyl sulfosuccinate is exemplified by the following formula (2).

In the formula (2), R ² and R ³ each independently represent an alkyl group having 1 to 13 carbon atoms, and X ³ represents any one selected from the group consisting of Na and NH(CH ₂ CH ₂ OH) ₃ .

The sulfonate of the formula (2) preferably has an alkyl group of R ² and R ³ independently having a carbon number of 6 to 9. Further, it is preferred that the alkyl groups of R ² and R ^{3 have} the same carbon number, and more preferably, the carbon number of both is 8. Moreover, it is preferred that X ³ is Na.

The polyoxyalkylene alkyl ether sulfate can be represented by the following formula (3).

[In the formula (3), R ⁴ represents an alkyl group having a carbon number of 12 to 15, R ⁵ represents an alkylene group having a carbon number of 2 to 3, n represents a number of 2 to 4, and X ⁴ represents a selected from Na, Any of NH(CH ₂ CH ₂ OH) ₃ ]

[Method for reducing viscosity of oily drainage]

The viscosity reduction method of the oil-containing drainage of the present invention is one or more selected from the group consisting of alkyl diphenyl ether disulfonate, dialkyl sulfosuccinate, and polyoxyalkylene alkyl ether sulfate. Sulfonate and/or sulfate salt.

The oil-containing drainage which can be applied to the viscosity reduction method of the oil-containing drainage of the present invention is not particularly limited and can be applied to any oil-containing drainage. The oil-containing drainage can be referred to as drainage generated in a rolling treatment of a metal such as cold rolling.

The oil content in the oily drainage is not particularly limited, and in the case of the metal rolling treatment, the oil is usually 50 ppm to 500 ppm.

As the sulfonate and/or sulfate salt, one or more selected from the group consisting of alkyl diphenyl ether disulfonate, dialkyl sulfosuccinate, and polyoxyalkylene alkyl sulfate can be used. Viscosity in systems with less oil (such as oily systems) Among the preferable ones, an alkyl diphenyl ether disulfonate is suitable among them.

It is considered that these sulfonate and/or sulfate salts contribute to a decrease in viscosity of the oil-containing drainage due to hindering the crystallization of the wax component contained in the oil component. Further, it is considered that the viscosity of the oil-containing drainage is lowered by promoting the dispersion of the oil droplets in the oil-containing drainage.

The sulfonate and/or sulfate salt of the present invention serves to reduce the viscosity of the oil-containing drainage. By this action, the water enclosed in the hard oil film easily escapes to the outside of the oil film, and the oil-water separation effect can be promoted. In particular, the alkyl diphenyl ether disulfonate and the dialkyl sulfosuccinic acid are suitable in terms of excellent oil-water separation. Due to the oil-water separation effect, the moisture of the oil-containing drainage obtained in the oil-water separation tank can be reduced.

The amount of the sulfonate and/or sulfate salt added to the oily drainage is preferably from 3 g/L to 30 g/L with respect to the oil content in the drainage.

Suitable embodiments of the alkyl diphenyl ether disulfonate, dialkyl sulfosuccinate and polyoxyalkylene alkyl ether sulfate used in the method for reducing viscosity of oil-containing drainage of the present invention Suitable embodiments of the alkyl diphenyl ether disulfonate, dialkyl sulfosuccinate and polyoxyalkylene alkyl ether sulfate used in the method for reducing the viscosity of the oil-containing dross of the invention are the same.

<arbitrarily added ingredients>

In the method for reducing the viscosity of the oil-containing dross of the present invention and the method for reducing the viscosity of the oil-containing drainage, various additives such as a nonionic surfactant and a cationic surfactant may be added to the extent that the object of the present invention is not impaired. Wait. These additional components may be used alone or in combination of two or more.

[Examples]

Next, the present invention will be described in more detail by way of examples, but the invention is not limited by the examples.

1. Verification of viscosity reduction of oily dross

[Example 1]

The tank containing oil-containing scum (water content: 52% by mass, oil content: 48% by mass, viscosity: 7.6 Pa.s) collected by the oil-water separation tank with cold-rolled oil-containing drainage was carried out 30 to 40 times. Mix and mix. 50 ml of the oily scum which was stirred was poured into a 100 ml test tube, and a drug corresponding to the general formula (3) (polyoxyalkylene alkyl ether sulfate triethanolamine; R ⁴ having a carbon number of 12 and R ⁵ was added thereto). The carbon number was 2, n≒4; manufactured by Sanyo Chemical Industry Co., Ltd., Sandet ET), and oily scum was reinjected to adjust the concentration of the agent to 10 g/L (20.8 g/L with respect to the oil content). The sample in the test tube was stirred with a spatula for 120 seconds, and the oily dross was mixed with the drug, and the viscosity was measured at a sample temperature of 20 °C.

[Example 2 to Example 5], [Comparative Example 1 to Comparative Example 8]

The viscosity of the oil-containing dross was measured in the same manner as in Example 1 except that the chemical was changed to the following.

(Pharmaceutical of Example 2)

A drug corresponding to the general formula (3) (polyoxyethylene lauryl ether sulfate; R ^{4 has} a carbon number of 12, R ^{5 has} a carbon number of 2, n≒2; manufactured by Sanyo Chemical Industries, Inc., Sandet EN)

(Pharmaceutical of Example 3)

An agent corresponding to the general formula (3) (sodium polyalkylene alkyl ether sulfate; R ^{4 has} a carbon number of 12-15, R ^{5 has} a carbon number of 2, n≒3; manufactured by Sanyo Chemical Industry Co., Ltd., Sandet END)

(Pharmaceutical of Example 4)

An agent corresponding to the formula (1) (sodium alkyl diphenyl ether disulfonate; R ^{1 has} a carbon number of 8 to 15; manufactured by Sanyo Chemical Industries, Inc., Sandet ALH)

(Pharmaceutical of Example 5)

A drug corresponding to the formula (2) (sodium dioctylsulfosuccinate; R ^{2 has} a carbon number of 8 and R ^{3 has} a carbon number of 8; Sanyo Chemical Industries, Inc., Sanmorin OT-70)

(Pharmaceutical of Comparative Example 1)

Cationic surfactant (stearyl dimethyl benzyl ammonium chloride; manufactured by Sanyo Chemical Industry Co., Ltd., Cation S)

(Comparative Example 2)

Cationic surfactant (cetyltrimethylammonium chloride; manufactured by Sanyo Chemical Industry Co., Ltd., ECONOL TM-22)

(Comparative Example 3)

Non-ionic surfactant (poly(ethylene glycol monostearate; manufactured by Sanyo Chemical Industry Co., Ltd., IONET MS-1000)

(Comparative Example 4)

Non-ionic surfactant (polyoxyethylene polyoxypropylene glycol; manufactured by Sanyo Chemical Industry Co., Ltd., NEWPOL PE-68)

(Comparative Example 5)

Anionic surfactant (sodium polyoxyethylene lauryl ether acetate; manufactured by Sanyo Chemical Co., Ltd., BEAULIGHT LCA-25N)

(Comparative Example 6)

Anionic surfactant (polyoxyethylene tridecyl ether acetate; manufactured by Sanyo Chemical Co., Ltd., BEAULIGHT ECA)

(Pharmaceutical of Comparative Example 7)

Anionic surfactant (sodium lauryl glycol acetate; manufactured by Sanyo Chemical Co., Ltd., BEAULIGHT SHAA)

(Comparative Example 8)

Blank (not used)

2. Verification of oil-water separation of oily dross

In Examples 1 to 5 and Comparative Examples 1 to 8, the sample of the test tube was stirred with a spatula for 120 seconds after the viscosity measurement, and the oil-containing dross was mixed with the drug at 20 ° C. The environment was allowed to stand for 18 hours under the environment, and the state of oil-water separation was visually observed. As a result, the case where the water layer is observed as 1/5 to 1/4 of the whole is regarded as "○", and the case where the water layer is less than 1/5 is observed as "△", and the oil and water are not separated and the water layer cannot be observed. The situation is "X". The results are shown in Table 1.

According to the results of Table 1, it is known that a sulfonate and/or a sulfate selected from the group consisting of alkyl diphenyl ether disulfonate, dialkyl sulfosuccinate and polyoxyalkylene alkyl sulfate is added. Examples 1 to 5 of the salt can greatly reduce the viscosity (7.6 Pa.s) of the initial oil-containing dross. Further, the sulfonate and/or sulfate salt of Example 1, Example 3 to Example 5 was also excellent in oil-water separation effect.

Claims (8)

A method for reducing viscosity of oily dross, which comprises adding at least one sulfonate and/or sulfate selected from the group consisting of alkyl diphenyl ether disulfonate and dialkyl sulfosuccinate to oily dross. A salt containing the floating oil of the oil-water separation tank of the oil-containing drain produced in the rolling process of the metal. The method for reducing the viscosity of an oily dross according to the first aspect of the invention, wherein a dialkyl sulfosuccinate represented by the following formula (2) is added as the sulfonate and/or sulfate. salt; In the formula (2), R ² and R ³ each independently represent an alkyl group having 6 to 9 carbon atoms, and X ³ represents any one selected from the group consisting of Na and NH(CH ₂ CH ₂ OH) ₃ . The method for reducing the viscosity of an oily dross according to claim 1, wherein an alkyl diphenyl ether disulfonate is added as the sulfonate and/or sulfate salt. The method for reducing the viscosity of an oily dross according to any one of claims 1 to 3, wherein the sulfonate is added in an amount of from 3 g/L to 30 g/L with respect to the oil in the oil-containing dross. And / or sulfate salt. A method for reducing the viscosity of an oil-containing drainage, which comprises adding one or more selected from the group consisting of alkyl diphenyl ether disulfonate and dialkyl sulfosuccinate to the oily drainage produced in the metal rolling treatment. Sulfonate and/or sulfate salt. A method for reducing the viscosity of an oil-containing drainage according to claim 5, wherein an alkyl diphenyl ether disulfonate is added as the sulfonate and/or sulfate salt. The method for reducing the viscosity of the oil-containing drainage according to the fifth aspect of the invention, wherein the dialkyl sulfosuccinate represented by the following formula (2) is added as the sulfonate and/or sulfate salt. ; In the formula (2), R ² and R ³ each independently represent an alkyl group having 6 to 9 carbon atoms, and X ³ represents any one selected from the group consisting of Na and NH(CH ₂ CH ₂ OH) ₃ . The method for reducing the viscosity of an oil-containing drainage according to any one of the items 5 to 7, wherein the sulfonate is added in an amount of 3 g/L to 30 g/L with respect to the oil in the oil-containing drainage. Or a sulfate salt.