WO2015190172A1 - Oil-water separating agent for coal tar and oil-water separating method for coal tar - Google Patents

Abstract

Provided are an oil-water separating agent having an excellent oil-water separating effect for water-containing coal tar and an oil-water separating method. The oil-water separating agent for water-containing coal tar includes polyoxyalkylene alkyl sulfosuccinate and/or sulfosuccinic acid alkyl salt, and the oil-water separating method for water-containing coal tar includes a step of adding a surfactant to water-containing coal tar.

Description

Coal tar oil / water separator and coal tar oil / water separator

The present invention relates to a water-containing coal tar oil-water separation agent and an oil-water separation method.

Coal tar (hereinafter also referred to as “tar”) is a by-product generated from a coke oven and is produced as follows.
Aqueous water (ammonia water) is sprayed on the gas generated in the coke oven and cooled, and the resulting condensate is allowed to stand in a tar decanter together with the water to separate it into a water layer and a tar layer. Put in the tar tank, extract the water and put it in the water tank. Since tar in the tar tank contains sludge, the obtained tar enters tar storage by separating the sludge with a centrifuge (super decanter).
Since coal tar forms an emulsion in a water-containing state, oil-water separation is required in a tar decanter, a tar tank, a centrifuge (super decanter) or the like in the production and purification process of coal tar. However, heavy oil in coal tar has a large specific gravity, a high affinity with water, and forms a strong emulsion in a water-containing state, so that separation is not easy even with a centrifugal separation method.

In Patent Document 1, a heavy oil mainly composed of coal tar contains water-containing waste oil containing water, an alkyl allyl sulfonate, an alkane sulfonate, a higher alcohol sulfate, a polyoxyethylene alkylphenyl sulfate salt, and a polyoxyethylene alkyl. Although a method of adding one or more anionic surfactants of sulfate salt has been described, the degree of oil-water separation has not been sufficient.

Patent Document 2 describes a method for treating an emulsion in which a coal tar emulsion containing a quinoline insoluble material is mixed with a polyoxyethylene alkyl ether sulfate ester salt, but the degree of oil-water separation is not sufficient.

Patent Document 3 describes a method of separating oil and moisture by adding a cationic surfactant mainly composed of quaternary ammonium salt or imidazole derivative to tar-based hydrous waste oil. However, the oil-water separation effect was not sufficient.

JP-A 51-96785 JP-A-1-19439 JP 54-102305 A

An object of the present invention is to provide an oil / water separation agent and an oil / water separation method excellent in the oil / water separation effect of hydrous coal tar.

As a result of intensive studies to solve the above-mentioned problems, it was found that a specific sulfosuccinic acid alkyl salt is a surfactant excellent in the oil-water separation effect of hydrous coal tar, and further, a specific other surfactant is used in combination. Thus, the oil-water separation effect of hydrous coal tar was further improved and the present invention was completed.

That is, the present invention provides the following oil-water separation agent and oil-water separation method.
[1] A water-containing coal tar oil-water separator containing polyoxyalkylene alkyl sulfosuccinate and / or alkyl sulfosuccinate.
[2] The hydrous coal tar oil-water separator according to [1], further including at least one compound selected from the group consisting of dioctyl sulfosuccinate, polyoxyalkylene alkyl ether, and polyoxyethylene polyoxypropylene block polymer .
[3] An oil-water separation method of hydrous coal tar, comprising adding a polyoxyalkylene alkyl sulfosuccinate and / or alkyl sulfosuccinate to the hydrous coal tar.
[4] Further, at least one selected from the group consisting of dioctyl sulfosuccinate, polyoxyalkylene alkyl ether, and polyoxyethylene polyoxypropylene block polymer is used as the polyoxyalkylene alkyl sulfosuccinate and / or sulfosuccinic acid alkyl salt. The method for separating water-containing coal tar from oil and water according to the above [3], comprising a step of mixing with or separately adding to the water.

According to the oil-water separation agent and oil-water separation method of the hydrous coal tar of the present invention, the oil-water separation effect of the hydrous coal tar is excellent, the moisture of the coal tar is sufficiently reduced, and a stable quality tar product can be obtained. It becomes.

The present invention relates to a water-containing coal tar oil-water separation agent and an oil-water separation method.
The hydrous coal tar oil / water separating agent of the present invention contains a polyoxyalkylene alkyl sulfosuccinate and / or an alkyl sulfosuccinate, and exhibits a sufficient oil / water separation effect on hydrous coal tar.

In the polyoxyalkylene alkyl sulfosuccinate, the polyoxyalkylene of the polyoxyalkylene alkyl group is polyoxyethylene or polyoxypropylene, and the average addition mole number thereof is preferably about 1 to 2, and the polyoxyalkylene alkyl group alkyl Has a carbon number of 10 to 18, preferably 12 to 14, and the sulfosuccinic acid salt is a sulfosuccinic acid dialkali metal salt or a sulfosuccinic acid diammonium salt.
Specific examples include polyoxyethylene (about 2) alkyl (12-14) disodium sulfosuccinate (commercially available product name “Bulight ESS” manufactured by Sanyo Chemical Industries, Ltd.), polyoxyethylene (about 1 ) Disodium lauryl sulfosuccinate (commercial name “Bulight LSS”, manufactured by Sanyo Chemical Industries, Ltd.) may be mentioned.

In the sulfosuccinic acid alkyl salt, the alkyl group has 10 to 18, preferably 12 to 14 carbon atoms, and the sulfosuccinic acid salt is a sulfosuccinic acid dialkali metal salt or a sulfosuccinic acid diammonium salt.
Specific examples include disodium lauryl sulfosuccinate (commercial name “Bulight SSS” manufactured by Sanyo Chemical Industries, Ltd.).

The addition amount of polyoxyalkylene alkyl sulfosuccinate and / or alkyl sulfosuccinate is 0.005 to 1% by mass, preferably 0.01 to 0.1% by mass, based on the pure tar content.

The hydrous coal tar oil / water separating agent of the present invention includes the polyoxyalkylene alkyl sulfosuccinate and / or the sulfosuccinic acid alkyl salt (hereinafter also referred to as “main surfactant”), and other specific compounds. These surfactants (hereinafter also referred to as “auxiliary surfactants”) may be used in combination.

The specific other surfactant (co-surfactant) used in the present invention is at least one surfactant selected from the group consisting of dioctyl sulfosuccinate, polyoxyalkylene alkyl ether, and polyoxyethylene polyoxypropylene block polymer. It is an agent. The dioctylsulfosuccinate is an alkali metal dioctylsulfosuccinate or ammonium dioctylsulfosuccinate, and sodium dioctylsulfosuccinate is preferred because it is readily available.
These co-surfactants have good permeability to coal tar and improve the oil-water separation effect of the main surfactant. In particular, dioctyl sulfosuccinate is preferred because of its high permeability.

When a main surfactant such as polyoxyalkylene alkyl sulfosuccinate and a co-surfactant such as dioctyl sulfosuccinate are mixed, the mixing ratio is not particularly limited. For example, disodium polyoxyethylene alkyl sulfosuccinate and dioctyl sulfosuccinate are mixed. The mass ratio of sodium acid is preferably about 1: 0.1 to 1: 2, more preferably about 1: 0.5 to 1: 1.

The above surfactants may be added as they are, such as disodium polyoxyethylene sulfosuccinate or disodium lauryl sulfosuccinate. However, in consideration of mixing and homogenization with the target hydrous coal tar, It is desirable to dilute and add as a liquid.

The oil / water separating agent of the present invention is mainly used in the production and refining process of coal tar, and the addition site may be any location where coal tar and the oil / water separating agent can be brought into contact with each other. It may be added when returning to the tar decanter to separate the oil and water in the tar decanter, and it may be added to the aqueduct (circulated aquatic water) sent from the tar decanter to reduce the oil adhesion to the flushing nozzle. Further, it may be added to tar separated by a tar decanter to promote dehydration in a tar tank or a super decanter (centrifuge).

In addition, the oil / water separator of the present invention can be used for oil / water separation of hydrated waste oil from a tar factory or treatment of waste oil when oil extracted from coal tar distillation comes into contact with water, waste oil generated when washing a storage tank, etc. It can also be used.

Since tar retains moisture as a W / O type emulsion, it is necessary to break the emulsion in order to separate tar and water. When a main surfactant such as polyoxyalkylene alkyl sulfosuccinate, which is an oil / water separating agent of the present invention, is added, it acts on the interface forming the emulsion so that the emulsion cannot be maintained. It is thought to separate into water and tar.
In addition, when an auxiliary surfactant such as dioctylsulfosuccinate is used in combination with the main surfactant, the auxiliary surfactant penetrates into the sludge gaps present at the emulsion interface, which cannot be penetrated by the main surfactant, and the properties of the interface. It is considered that the oil / water separation effect is improved by making the main surfactant easier to act.

The oil / water separation method of the present invention includes a step of adding the oil / water separation agent to the hydrous coal tar. In the case of an oil / water separator containing a main surfactant and a co-surfactant, a mixture of the main surfactant and co-surfactant may be added to the hydrous coal tar, or each of them may be added separately. It may be added to tar.

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

Examples 1-7, Comparative Examples 1-15
(Tar): Tar (moisture content of 15%) at the exit of the tar decanter was used.
(Addition amount of oil / water separating agent): Various surfactants which are oil / water separating agents were added so that the total amount of the surfactant was 0.020% by mass with respect to the pure tar content.
(Test procedure): Tar was allowed to stand in a constant temperature bath at 70 ° C., the temperature was raised, 100 g of tar was dispensed into a 100 ml test tube, and a predetermined amount of surfactant was added with a micropipette. The mixture was stirred for 1 minute with a spatula and allowed to stand for 3 hours in a constant temperature bath at 70 ° C. Then, the external appearance was observed visually, the amount of separated water was measured, and the oil-water separation effect was evaluated.
(Evaluation): From the amount of water in the aqueous phase after standing, it was confirmed what percentage of the water present in the tar was separated.
○ ... 35% or more of separated water amount Δ ... 20% or more of separated water amount of less than 35% × ... separated water amount of less than 20% The test results are shown in Table 1.

 

 

The polyoxyethylene alkylsulfosuccinate disodium or the disodium lauryl sulfosuccinate showed a high oil / water separation effect with respect to the surfactant of the comparative example.
Further, when polyoxyethylene alkyl sulfosuccinate disodium is used in combination with dioctyl sulfosuccinic acid, polyoxyalkylene alkyl ether (HLB 10.5 product, HLB 13.2 product) or polyoxyethylene polyoxypropylene block polymer, a small amount of main surfactant The oil / water separation effect was high even in the amount.

Claims (4)

An oil-water separator for hydrous coal tar containing polyoxyalkylene alkyl sulfosuccinate and / or alkyl sulfosuccinate. The hydrous coal tar oil-water separator according to claim 1, further comprising at least one compound selected from the group consisting of dioctyl sulfosuccinate, polyoxyalkylene alkyl ether, and polyoxyethylene polyoxypropylene block polymer. An oil-water separation method of hydrous coal tar, comprising a step of adding polyoxyalkylene alkyl sulfosuccinate and / or alkyl sulfosuccinate to hydrous coal tar. Further, one or more selected from the group consisting of dioctyl sulfosuccinate, polyoxyalkylene alkyl ether, and polyoxyethylene polyoxypropylene block polymer is mixed with the polyoxyalkylene alkyl sulfosuccinate and / or alkyl sulfosulfosuccinate. The method for oil-water separation of hydrous coal tar according to claim 3, comprising the step of adding them separately or separately.