JP2021041321A - Extraction method of extraction object and liquid-liquid extraction column - Google Patents

Abstract

To provide means capable of further improving contact efficiency.SOLUTION: To provide an extraction method of an extraction object including a step of contacting a liquid containing the extraction object and an extraction solvent to move components in the liquid containing the extraction object to the extraction solvent, while feeding inert gas from an inert gas supplying device, by using a liquid-liquid extraction column having the inert gas supplying device on a tower bottom side.SELECTED DRAWING: None

Description

The present invention relates to a method for extracting an object to be extracted and a liquid-liquid extraction tower.

Liquid-liquid extraction is an operation in which a solvent is allowed to act on a stock solution of a liquid mixture to separate a specific substance in the mixture from other substances. In liquid-liquid extraction, the undiluted solution and the solvent form two phases and separate into two phases due to the difference in specific gravity, so that the desired substance, that is, the solute can be selectively transferred and separated into the solvent phase.

Examples of the liquid-liquid extraction tower used for liquid-liquid extraction include a stirring type liquid-liquid extraction tower and a non-stirring type liquid-liquid extraction tower. Although the stirring type liquid-liquid extraction tower has a high contact efficiency per unit height, it has a drawback that the equipment cost is high and maintenance is difficult because it has a mechanical driving part. On the other hand, the non-stirring type liquid-liquid extraction tower has lower contact efficiency than the stirring type, but the equipment cost is low and the maintenance is easy.

In Patent Document 1, a shelf board that occupies a part of the cross section of the tower in the horizontal direction and leaves a flow path for the liquid, and an opening extending vertically from the end of the shelf board on the flow path side to form an opening closer to the shelf board. A liquid-liquid extraction tower is disclosed in which shelves made of dam plates are alternately arranged in the tower at appropriate intervals.

Japanese Unexamined Patent Publication No. 7-80283

The liquid-liquid extraction tower disclosed in Patent Document 1 can improve the contact efficiency. However, the contact efficiency may not be sufficient, and it is desired to develop a method for further improving the contact efficiency.

Therefore, an object of the present invention is to provide a means capable of further improving the contact efficiency.

The present inventors have conducted diligent studies to solve the above problems. As a result, they have found that the above-mentioned problems can be solved by introducing the inert gas from the bottom side of the liquid-liquid extraction tower, and have completed the present invention.

That is, according to the first embodiment of the present invention, the extraction target is to be extracted while using the liquid-liquid extraction tower having the inert gas supply device on the bottom side of the column and charging the inert gas from the inert gas supply device. Provided is a method for extracting an extraction target, which comprises contacting a liquid containing the above-mentioned liquid with an extraction solvent to move a component in the liquid containing the extraction target to the extraction solvent.

According to the second aspect of the present invention, the liquid-liquid extraction tower extracts the extraction target by bringing the liquid containing the extraction target into contact with the extraction solvent, and the bottom side of the liquid-liquid extraction tower. A liquid extraction tower is provided that has an inert gas supply device.

According to the present invention, it is possible to provide a means capable of further improving the contact efficiency.

FIG. 1 is a schematic view showing a liquid-liquid extraction tower according to an embodiment of the present invention. FIG. 2 is a conceptual diagram showing an inert gas supply device provided in the liquid-liquid extraction tower according to the embodiment of the present invention. FIG. 3 is a graph showing the relationship between the boric acid concentration in the column top liquid and the amount of nitrogen gas input.

Hereinafter, embodiments according to one embodiment of the present invention will be described. The present invention is not limited to the following embodiments.

In the present specification, "X to Y" indicating a range means "X or more and Y or less". Unless otherwise specified, the operation and physical properties are measured under the conditions of room temperature (20 to 25 ° C.) / relative humidity of 40 to 50% RH.

<Liquid-liquid extraction tower>
One embodiment of the present invention is a liquid-liquid extraction tower that extracts the extraction target by bringing the liquid containing the extraction target into contact with the extraction solvent, and an inert gas is placed on the bottom side of the liquid-liquid extraction tower. A liquid extraction tower with a supply device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, these examples do not limit the scope of the present invention. The dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios.

FIG. 1 shows a schematic view of a reverse weir plate type liquid-liquid extraction tower, which is an embodiment of the liquid-liquid extraction tower according to the present invention. The reverse weir plate type liquid-liquid extraction tower 10 is provided with a heavy liquid inlet 11 and a light liquid outlet 12 at the upper part of the tower, and a light liquid inlet 13 and a heavy liquid outlet 14 at the lower part of the tower. A plurality of shelf stages 1a and 1b are arranged inside. Further, the inert gas supply device 15 is provided on the bottom side of the tower.

The shape of the inert gas supply device 15 is not particularly limited as long as it can supply a desired amount of the inert gas. For example, as shown in FIG. 2, a cylindrical shape can be mentioned. Further, the supply direction of the inert gas is not particularly limited. The supply direction of the inert gas is preferably the tower bottom direction from the viewpoint of suppressing clogging of the inert gas supply device 15.

The positional relationship between the light liquid inlet 13 and the inert gas supply device 15 is not particularly limited. From the viewpoint of suppressing the droplets of the dispersed phase from becoming too small, it is preferable to provide the inert gas supply device 15 above the light liquid inlet 13.

The shelf stage 1a has a shelf plate 2a having a flow path 4a through which a continuous phase liquid and a dispersed phase liquid pass in a substantially central portion thereof, and vertically downward from the end of the flow path 4a of the shelf plate 2a (dispersed phase supply side). It is composed of a weir plate 3a extending to. On the side closer to the shelf board 2a, an opening serving as a flow path for the dispersed phase liquid is provided.

In the shelf stage 1b, the shelf plate 2b spreads so as to cover the flow path 4a of the shelf stage 1a, and two flow paths 4b are provided, and vertically downward from the end of the flow path 4b of each shelf plate 2b ( It is composed of a weir plate 3b extending to the dispersed phase supply side). On the side closer to the shelf board 2b, an opening serving as a flow path for the dispersed phase liquid is provided.

Below the shelf board 2a (dispersed phase supply side), the droplets of the dispersed phase accumulate and coalesce while staying to form a dispersed phase-integrated layer. The formed dispersed phase layer flows out horizontally from the opening of the weir plate 3a.

Similarly, below the shelf board 2b (dispersed phase supply side), the droplets of the dispersed phase accumulate and coalesce while staying to form a dispersed phase-integrated layer. The formed dispersed phase layer flows out horizontally from the opening of the weir plate 3b.

In the operation of the liquid-liquid contact tower, the light liquid is supplied from the light liquid inlet 13 at the lower part of the tower 10 and the heavy liquid is supplied from the heavy liquid inlet 11 at the upper part so that one is in the dispersed phase and the other is in the continuous phase. In addition, the inert gas is supplied from the inert gas supply device 15. On the other hand, the light liquid that has already been in liquid-liquid contact is withdrawn from the light liquid outlet 12 at the upper part of the tower, and the heavy liquid is continuously withdrawn from the heavy liquid outlet 14 at the lower part of the tower.

In the liquid-liquid contact tower according to the present invention, the inert gas floats by injecting the inert gas from the inert gas supply device 15. The floating inert gas can increase the flow velocity of the liquid passing through the openings of the dam plates 3a and 3b. As a result, the droplets of the dispersed phase that stay below the shelf board 2a and the shelf board 2b can be made finer, and the contact efficiency between the solute and the extraction solvent can be improved. Therefore, it is possible to simultaneously achieve a high processing amount and high contact efficiency, which cannot be expected with a conventional non-stirring liquid-liquid extraction tower that does not input an inert gas. Further, by improving the extraction efficiency, it is possible to reduce the amount of the extraction solvent and make the extraction device compact.

The above mechanism is an estimation, and the present invention is not limited by the above estimation.

<Extraction method of extraction target>
In one embodiment of the present invention, a liquid-liquid extraction tower having an inert gas supply device on the bottom side of the column is used, and a liquid containing an extraction target and an extraction solvent are used while injecting an inert gas from the inert gas supply device. This is an extraction method for an extraction target, which comprises bringing the components in the liquid containing the extraction target into contact with each other to move the components in the liquid containing the extraction target to an extraction solvent.

(Liquid-liquid extraction tower)
The liquid-liquid extraction tower used in the extraction method according to the present invention is not particularly limited as long as it has an inert gas supply device on the bottom side of the tower.

As the liquid-liquid extraction tower, a conventionally known liquid-liquid extraction tower in which an inert gas supply device is installed on the bottom side of the tower can be used. The liquid-liquid extraction tower is preferably a non-stirring type liquid-liquid extraction tower, more preferably a shelf-type liquid-liquid extraction tower, a perforated plate extraction tower, and a filling tower from the viewpoint that the effects of the present invention can be more exerted. , A baffle tower or a spray tower, more preferably a shelf-type liquid-liquid extraction tower or a perforated plate extraction tower, and particularly preferably a shelf-type liquid-liquid extraction tower.

Examples of the shelf-stage type liquid-liquid extraction tower include a weir plate type liquid-liquid extraction tower, a reverse weir plate type liquid-liquid extraction tower, and the like. Therefore, in the extraction method according to the present invention, it is preferable that the liquid-liquid extraction tower is a weir plate type liquid-liquid extraction tower or a reverse weir plate type liquid-liquid extraction tower. By using the shelf-type liquid-liquid extraction tower, the contact efficiency and the extraction efficiency can be further improved.

(Contact between the liquid containing the extraction target and the extraction solvent)
In the extraction method according to the present invention, the liquid containing the extraction target is brought into contact with the extraction solvent while the inert gas is introduced from the inert gas supply device of the liquid-liquid extraction tower, and the liquid contains the extraction target. Ingredients are transferred to the extraction solvent. By contacting the liquid containing the extraction target with the extraction solvent, a specific component in the liquid containing the extraction target is moved to the extraction solvent through the liquid-liquid interface. The component (solute) to be transferred to the extraction solvent may be an extraction target or a component other than the extraction target.

That is, in one embodiment of the extraction method according to the present invention, the liquid containing the extraction target is brought into contact with the extraction solvent, the extraction target is moved into the extraction solvent, and the extraction target is separated and recovered. In this case, the extraction target is a solute, and the extraction target is contained in the extract.

Further, in another embodiment of the extraction method according to the present invention, the liquid containing the extraction target is brought into contact with the extraction solvent, substances other than the extraction target are moved into the extraction solvent, and the liquid containing the extraction target is contained. Remove substances other than the extraction target from the extract. In this case, the substance other than the extraction target is the solute, and the extraction target is contained in the extraction residue.

A liquid-liquid extraction tower such as a conventional perforated plate extraction tower or a shelf-type liquid-liquid extraction tower has a two-phase separation portion at the top of the column due to its structure. Therefore, when the inert gas is charged, the two-phase separation portion is agitated by the inert gas, and it is considered that the two-phase separation is difficult.

However, surprisingly, the present inventor is capable of two-phase separation even if the inert gas is introduced from the bottom side of the liquid-liquid extraction tower, and the extraction target is further introduced by introducing the inert gas. It has been found that the contact efficiency between the liquid containing the above and the extraction solvent can be improved, and the extraction efficiency of the components in the liquid containing the extraction target can be improved.

As described above, the extraction method according to the present invention can improve the contact efficiency and the extraction efficiency. The presumed mechanism will be described with reference to FIG. By charging the inert gas from the inert gas supply device 15, the inert gas floats. The floating inert gas can increase the flow velocity of the liquid passing through the openings of the dam plates 3a and 3b. As a result, the droplets of the dispersed phase that stay below the shelf board 2a and the shelf board 2b can be made finer, and the contact efficiency between the solute and the extraction solvent can be improved. Therefore, it is possible to simultaneously achieve a high processing amount and high contact efficiency, which cannot be expected with a conventional non-stirring liquid-liquid extraction tower that does not input an inert gas. Further, by improving the extraction efficiency, it is possible to reduce the amount of the extraction solvent and make the extraction device compact.

The above mechanism is an estimation, and the present invention is not limited by the above estimation.

The inert gas to be charged is not particularly limited and can be appropriately selected depending on the type of solute. Examples of the inert gas include nitrogen, argon, methane, ethane and the like. The inert gas is preferably nitrogen.

The amount of the inert gas input can be adjusted as appropriate. ^{The amount of the inert gas input is preferably 0.1 to 2.5 m 3} / m ² / h, more preferably 0.3, per cross-sectional area of the liquid-liquid extraction tower from the viewpoint of further improving the contact efficiency. It is ~ 1.0 ^{m 3} / m ² / h, more preferably 0.4 to 0.9 ^{m 3} / m ² / h.

It is known that in liquid-liquid extraction using a liquid-liquid extraction tower, the contact efficiency and the extraction efficiency may decrease when the flow rate (supply amount) of the heavy liquid and the light liquid decreases. In particular, when the total flux (volume flux) is 0.005 m ³ / m ² / h or less, the contact efficiency and the extraction efficiency may decrease.

Here, the total flux (volume flux) is the total superficial velocity of the heavy liquid and the light liquid.

In the extraction method according to the present invention, by adding an inert gas, the droplets of the dispersed phase can be made finer, and the contact efficiency between the solute and the extraction solvent can be improved. Therefore, excellent contact efficiency and extraction efficiency can be obtained even in a system having a small total flux.

In the extraction method according to the present invention, the solute is not particularly limited as long as it is a substance that can be separated by liquid-liquid extraction. As described above, the solute may be an extraction target or a substance other than the extraction target. Further, the extraction solvent can be appropriately selected depending on the solute. Depending on the solute and extraction solvent used, one of the liquid containing the extraction target and the extraction solvent becomes a heavy liquid, and the other becomes a light liquid. Similarly, one of the heavy and light liquids is the dispersed phase and the other is the continuous phase.

Examples of the extraction target include alcohol, acetic acid, acrylic acid, methacrylic acid, saturated aliphatic hydrocarbons, alcohol alkoxylate and the like.

In one embodiment of the extraction method according to the present invention, the extraction target is any one selected from a secondary alcohol, a saturated aliphatic hydrocarbon and a secondary alcohol alkoxylate, and a secondary alcohol is preferable. Is. The carbon number of the secondary alcohol, the saturated aliphatic hydrocarbon and the secondary alcohol alkoxylate is, for example, 8 or more and 30 or less.

A liquid containing a secondary alcohol, a saturated aliphatic hydrocarbon or a secondary alcohol alkoxylate can be obtained by a conventionally known method, and for example, JP-A-48-34807 and JP-A-56-131531. And the contents described in Japanese Patent Application Laid-Open No. 50-159595 can be obtained by referring to the contents as appropriate.

The liquid containing a secondary alcohol contains, for example, a corresponding secondary alcohol by partially oxidizing a saturated aliphatic hydrocarbon having 8 to 30 carbon atoms with a molecular oxygen-containing gas in the presence of a boron compound. Liquid can be obtained.

The saturated aliphatic hydrocarbon having 8 to 30 carbon atoms may be one kind or a mixture of two or more kinds.

Examples of saturated aliphatic hydrocarbons having 8 to 30 carbon atoms include octane, decane, dodecane, tridecane, tetradecane, hexadecane, octadecane, icosane, docosane, tetracosane, hexacosane, octacosane, and tridecane. Of these, the saturated aliphatic hydrocarbon is preferably a saturated aliphatic hydrocarbon having 10 to 20 carbon atoms, and is more preferably selected from the group consisting of decane, dodecane, tridecane, tetradecane, hexadecane, octadecane and icosane. ..

Examples of the boron compound include metaboric acid, orthoboric acid, and anhydrous boric acid.

The amount of the boron compound used is, for example, 1 to 20 wt% with respect to the saturated aliphatic hydrocarbon.

The oxygen concentration in the molecular oxygen-containing gas is, for example, 1 to 20% by volume.

The amount of the molecular oxygen-containing gas used is, for example, 100 to 1000 L / h per 1 kg of saturated aliphatic hydrocarbon.

The reaction temperature in the liquid phase partial oxidation is, for example, 100 to 200 ° C.

Since the liquid containing the secondary alcohol thus obtained contains the boric acid ester of the secondary alcohol, it is preferable to appropriately hydrolyze the boric acid ester of the secondary alcohol.

The liquid containing the saturated aliphatic hydrocarbon can be obtained from the liquid containing the secondary alcohol as described later.

A liquid containing a secondary alcohol alkoxylate can be obtained by adding an alkylene oxide to the secondary alcohol as described later.

The extraction solvent has low mutual solubility with the extraction target (secondary alcohol, saturated aliphatic hydrocarbon or secondary alcohol alkoxylate), and is distributed to solutes (boron compounds, organic compounds, organic salts, inorganic salts, etc.). It is not particularly limited as long as it has a large coefficient and separation coefficient. The extraction solvent preferably contains water.

When the extraction solvent contains water, the liquid containing the secondary alcohol, the saturated aliphatic hydrocarbon or the secondary alcohol ethoxylate is a light liquid, and the extraction solvent is a heavy liquid. The light liquid is the dispersed phase and the heavy liquid is the continuous phase. The secondary alcohol is contained in the extraction residual liquid and is recovered from the light liquid outlet. The boron compound is contained in the extract and is recovered from the heavy liquid outlet.

When the object to be extracted is a secondary alcohol, a saturated aliphatic hydrocarbon or a secondary alcohol alkoxylate, the liquid-liquid extraction tower used is preferably a reverse dam plate from the viewpoint of further improving contact efficiency. It is a mold liquid extraction tower.

The temperature at which the liquid containing the secondary alcohol, saturated aliphatic hydrocarbon or secondary alcohol alkoxylate is brought into contact with the extraction solvent is, for example, 50 ° C. or higher, preferably 85 to 95 ° C., and more preferably about. It is 90 ° C.

Further, in one embodiment of the present invention, a step of partially oxidizing a saturated aliphatic hydrocarbon with a molecular oxygen-containing gas in the presence of a boron compound to prepare a liquid containing a corresponding secondary alcohol, and the above-mentioned A step of contacting a liquid containing a secondary alcohol with an extraction solvent by an extraction method, moving the boron compound in the liquid containing the secondary alcohol to the extraction solvent, and separating and recovering the secondary alcohol. A method for producing a secondary alcohol having is provided.

In the method for producing a secondary alcohol of the present embodiment, the extraction solvent preferably contains water.

In the method for producing a secondary alcohol of the present embodiment, the boron compound can be efficiently removed, so that the boron compound contained in the waste water can be reduced.

The method for producing a secondary alcohol of the present embodiment contains an unreacted saturated aliphatic hydrocarbon by distilling an unreacted saturated aliphatic hydrocarbon from a liquid containing the secondary alcohol before the separation and recovery step. It can further have a step of recovering the liquid. At this time, the liquid containing the secondary alcohol after recovering the liquid containing the saturated aliphatic hydrocarbon is used for the above extraction method.

The liquid containing the secondary alcohol may contain unreacted saturated aliphatic hydrocarbons and by-products of the oxidation reaction. Examples of by-products of the oxidation reaction include lower fatty acids and fatty acid esters.

Therefore, the unreacted saturated aliphatic hydrocarbon is distilled by distilling the liquid containing the secondary alcohol by a method close to simple distillation such as flash distillation to obtain a liquid containing the saturated aliphatic hydrocarbon. be able to. In addition, since the by-product is distilled together with the unreacted saturated aliphatic hydrocarbon, the liquid containing the saturated aliphatic hydrocarbon may contain the by-product.

Further, when the method for producing a secondary alcohol of the present embodiment has a step of recovering the liquid containing the saturated aliphatic hydrocarbon, the following separation recovery step and reuse step can be further provided:
By the above extraction method, the liquid containing the saturated aliphatic hydrocarbon is brought into contact with the extraction solvent, and at least one of the components other than the saturated aliphatic hydrocarbon in the liquid containing the saturated aliphatic hydrocarbon is moved to the extraction solvent. , A step of separating and recovering the saturated aliphatic hydrocarbon; and a step of reusing the extracted saturated aliphatic hydrocarbon as the saturated aliphatic hydrocarbon in the preparation step.

Since the method for producing a secondary alcohol of the present embodiment includes the above-mentioned separation and recovery step and the reuse step, components other than the saturated aliphatic hydrocarbon in the liquid containing the saturated aliphatic hydrocarbon can be efficiently removed. It facilitates the recovery of saturated aliphatic hydrocarbons and their reuse as raw materials. Therefore, the production efficiency of the secondary alcohol can be improved.

As described above, the liquid containing the saturated aliphatic hydrocarbon obtained by distillation may contain components other than the saturated aliphatic hydrocarbon such as by-products of the oxidation reaction. Therefore, by using the extraction method according to the present invention, components other than the saturated aliphatic hydrocarbon can be removed from the liquid containing the saturated aliphatic hydrocarbon.

The components removed from the liquid containing saturated aliphatic hydrocarbons include lower fatty acids, organic compounds such as fatty acid esters; organic salts such as sodium fatty acid and potassium fatty acid; and inorganic salts such as sodium hydroxide and potassium hydroxide. Can be mentioned.

Since the liquid obtained by separating and recovering the saturated aliphatic hydrocarbon may contain unseparated ketones, alcohols, etc., the saturated aliphatic hydrocarbon in the liquid is distilled after reducing it with hydrogen to obtain a saturated aliphatic hydrocarbon. Can be separated and recovered. The separated and recovered saturated aliphatic hydrocarbon can be reused as a saturated aliphatic hydrocarbon (raw material) in the preparation step of the liquid containing the secondary alcohol.

Further, in one embodiment of the present invention, an alkylene oxide is added to the secondary alcohol extracted by the extraction method or the secondary alcohol produced by the production method to obtain a secondary alcohol alkoxylate. A method for producing a secondary alcohol alkoxylate is provided, which comprises a step of preparing a liquid to be contained.

The alkylene oxide to be added is, for example, an alkylene oxide having 2 to 10 carbon atoms, preferably an alkylene oxide having 2 to 4 carbon atoms. Examples of alkylene oxides include ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, styrene oxide and the like. Of these, ethylene oxide, propylene oxide and butylene oxide are preferably selected.

The added alkylene oxide may be a compound in the form of 1 to 50 bonds. Further, the alkylene oxide contained in the compound may be used alone or in combination of two or more. The number of additions / bonds of the alkylene oxide is preferably 2 to 45, more preferably 5 to 40.

The method for adding / binding the alkylene oxide to the secondary alcohol is not particularly limited, and a known method can be used. Examples of such a method include a method using an acid catalyst or an alkali catalyst. The acid catalyst is not particularly limited, and examples thereof include halogen compounds of metals that are Lewis acid catalysts such as boron trifluoride; mineral acids such as hydrogen chloride, hydrogen bromine, and sulfuric acid. The alkali catalyst is not particularly limited, and examples thereof include potassium hydroxide, sodium hydroxide, and sodium hydride.

The reaction conditions are not particularly limited as long as the reaction proceeds and a sufficient secondary alcohol alkoxylate can be obtained. The reaction temperature is, for example, 50 to 200 ° C, preferably 100 to 200 ° C, and more preferably 100 to 150 ° C. The reaction time is, for example, 1 to 48 hours, preferably 1 to 40 hours, and more preferably 2 to 36 hours. The reaction may be under normal pressure or under pressure.

The secondary alcohol alkoxylate is preferably a compound represented by the following formula (1).

In the formula (1), R ¹ and R ² are alkyl groups, ^{the total number of carbon atoms of R 1 and} the number of carbon atoms of R ² is 7 to 29, and the number of carbon atoms of ^{R 2 is R 1} . More than or equal to the number ^{of carbon atoms (the number of carbon atoms in R 1} ≤ the number of carbon atoms in R ² ); A is an alkylene group having 2 to 8 carbon atoms; B is a hydrogen atom; n is an integer of 1 to 50. is there.

In the formula (1), ^{the total number of carbon atoms of R 1 and} the number of carbon atoms of R ² is preferably 9 to 19, and more preferably 11 to 13.

In the formula (1), A is preferably an alkylene group of 2 to 4, and more preferably an ethylene group.

In formula (1), n is preferably an integer of 2 to 45, more preferably an integer of 5 to 40.

In the formula (1), the additional structure (AO) n may be a random structure or a block structure.

In the method for producing a secondary alcohol alkoxylate of the present embodiment, the liquid containing the secondary alcohol alkoxyrate is brought into contact with the extraction solvent by the above extraction method, and the liquid containing the secondary alcohol alkoxylate is the second. It is possible to further have a step of moving at least one of the components other than the secondary alcohol alkoxyrate to the extraction solvent to separate and recover the secondary alcohol alkoxylate.

Since the method for producing a secondary alcohol alkoxylate of the present embodiment has the above-mentioned separation and recovery step, components other than the secondary alcohol alkoxylate in the liquid containing the secondary alcohol alkoxylate can be efficiently removed. The production efficiency of the secondary alcohol alkoxylate can be improved.

Examples of the component removed from the liquid containing the secondary alcohol alkoxylate include organic compounds such as lower alcohols, ethylene glycol, propylene glycol and polyethylene glycol; and inorganic salts such as sodium sulfate and sodium fluoride.

In the above-mentioned production method, the amount of the organic salt contained in the liquid containing the secondary alcohol, the saturated aliphatic hydrocarbon or the secondary alcohol alkoxylate is determined by the secondary alcohol, the saturated aliphatic hydrocarbon or the secondary alcohol. For example, 0.1 to 10 wt% with respect to the weight of the alkoxyrate.

In the above-mentioned production method, the amount of the inorganic salt contained in the liquid containing the secondary alcohol, the saturated aliphatic hydrocarbon or the secondary alcohol alkoxylate is determined by the secondary alcohol, the saturated aliphatic hydrocarbon or the secondary alcohol. For example, 0.1 to 10 wt% with respect to the weight of the alkoxyrate.

Examples of the use of the secondary alcohol alkoxylate produced in the present embodiment include raw materials for producing nonionic surfactants, anionic surfactants and cationic surfactants, cleaning agents, emulsifiers and the like.

The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.

(Preparation of liquid containing secondary alcohol)
The liquid containing the secondary alcohol was prepared based on Example 1 described in JP-A-56-131531. Specifically, hydrolyzing a canned out liquid containing a boric acid ester of a secondary alcohol having 12 to 14 carbon atoms obtained in Example 1 described in JP-A-56-131531 at 200 ° C. Prepared a solution containing a secondary alcohol. The concentration of secondary alcohol was 50 wt%. The concentration of boric acid in the liquid containing the secondary alcohol was 3 wt%.

(Liquid-liquid extraction tower)
The liquid-liquid extraction tower having the structure shown in FIG. 1 was used in the following examples, comparative examples and reference examples. The details of the liquid-liquid extraction tower are shown in Table 1.

(Comparative Example 1)
The extraction solvent was a heavy liquid (continuous phase), and the liquid containing a secondary alcohol was a light liquid (dispersed phase). Water was used as the extraction solvent. The temperature at which the liquid containing the extraction solvent and the secondary alcohol was supplied was set to 90 ° C. Here, the object to be extracted was a secondary alcohol, and the extract was boric acid.

The extraction solvent was supplied at 30 L / min, and a liquid containing a secondary alcohol was supplied at 142 L / min to carry out liquid-liquid contact. No nitrogen gas (inert gas) was added.

The column top liquid was recovered to obtain a liquid containing purified secondary alcohol. The concentration of boric acid contained in the column top liquid was 0.89 wt%.

(Example 1)
Liquid-liquid contact was performed in the same manner as in Comparative Example 1 except that nitrogen gas was charged at 0.33 m ^{3 / h (0.42 m 3} / m ² / h per cross-sectional area), and the top liquid was recovered. A liquid containing a purified secondary alcohol was obtained. The concentration of boric acid contained in the column top liquid was 0.78 wt%.

(Example 2)
Liquid-liquid contact was performed in the same manner as in Comparative Example 1 except that nitrogen gas was ^{charged at 0.49 m 3 / h (0.63 m 3} / m ² / h per cross-sectional area), and the top liquid was recovered. A liquid containing a purified secondary alcohol was obtained. The concentration of boric acid contained in the column top liquid was 0.66 wt%.

(Example 3)
Liquid-liquid contact was performed in the same manner as in Comparative Example 1 except that nitrogen gas was charged at 0.66 m ³ / h (0.84 m ³ / m ^{2 / h per cross-sectional area), and the top liquid was recovered.} A liquid containing a purified secondary alcohol was obtained. The concentration of boric acid contained in the column top liquid was 0.53 wt%.

(Reference example)
Liquid-liquid contact was carried out in the same manner as in Comparative Example 1 except that nitrogen gas was ^{charged at 2.10 m 3 / h (2.67 m 3} / m ² / h per cross-sectional area). The operation was stopped because an emulsion was generated inside the tower.

The results are shown in Table 2 and FIG.

As shown in Table 2 and FIG. 3, in Examples 1 to 3, the boric acid concentration in the column top liquid can be reduced by adding nitrogen gas as compared with Comparative Example 1. Therefore, it can be seen that the extraction efficiency of boric acid can be improved, so that the extraction efficiency of the secondary alcohol, which is the extraction target, can be improved.

(Manufacturing of secondary alcohol ethoxylate)
The liquid containing the secondary alcohol obtained above was an oil phase. The oil phase was fractionated at 7 hPa and the first fraction (boiling point range 95-120 ° C. fraction) was a mixture of small amounts of saturated aliphatic hydrocarbons, carbonyl compounds and monovalent primary alcohols. As the secondary fraction (boiling point range 120 to 150 ° C. fraction), a trace amount of carbonyl compound and a polyhydric secondary alcohol were obtained, but most of them were monohydric secondary alcohols. As this second fraction, a monohydric secondary alcohol was obtained. As described above, a secondary alcohol mixture was obtained.

1 kg of the obtained secondary alcohol mixture was placed in a SUS 3L autoclave equipped with a stirrer, a thermometer, and an ethylene oxide (EO) inlet tube, and the mixture was replaced with nitrogen. Then, 1.68 g of a BF3-Et catalyst (BF3: 46-49%) was charged, and 1.7 mol of ethylene oxide (EO) was fed to 1 mol of hydroxyl groups at an initial nitrogen pressure of 0.05 MPa and 55 ± 5 ° C. Added. Then, NaOH solution was added, the reaction solution was washed at 90 ° C., and further washed with water until the pH became 7 or less. Next, the oil phase was placed in a 3 L glass three-necked flask, a distillation column (filling Dixon packing inner diameter 40 mm, length 200 mm, theoretical plate number 3 stages) was attached, and distillation was performed to obtain 3 moles per 1 mole of hydroxyl groups. Ethoxylate adduct was obtained. Next, 558 g of the obtained ethoxylate adduct and 1 g of potassium hydroxide were charged into an autoclave similar to the above, and after nitrogen substitution, the pressure in the reactor was adjusted to 15 kPa with nitrogen and heated to 150 ° C. to obtain 442 g of ethylene oxide. It was reacted. After the reaction, it was neutralized with acetic acid to obtain a secondary alcohol ethoxylate.

1a, 1b shelves,
2a, 2b shelves,
3a, 3b weir board,
4a, 4b flow path,
10 Reverse weir plate type liquid-liquid extraction tower,
11 Heavy liquid inlet,
12 Light liquid outlet,
13 Light liquid inlet,
14 Heavy liquid outlet,
15 Inert gas supply device.

Claims (13)

Using a liquid-liquid extraction tower having an inert gas supply device on the bottom side of the column, the liquid containing the extraction target and the extraction solvent are brought into contact with each other while the inert gas is introduced from the inert gas supply device. A method for extracting an extraction target, which comprises moving a component in a liquid containing the extraction target to an extraction solvent. The extraction method according to claim 1, wherein the amount of the inert gas input per cross-sectional area of the liquid-liquid extraction tower ^{is less than 0.1 to 2.5 m 3} / m ^{2 / h.} The extraction method according to claim 1 or 2, wherein the inert gas is nitrogen gas. The extraction method according to any one of claims 1 to 3, wherein the liquid-liquid extraction tower is a weir plate type liquid-liquid extraction tower or a reverse weir plate type liquid-liquid extraction tower. The extraction method according to any one of claims 1 to 4, wherein the extraction target is any one selected from a secondary alcohol, a saturated aliphatic hydrocarbon and a secondary alcohol alkoxylate. The extraction method according to claim 5, wherein the secondary alcohol, the saturated aliphatic hydrocarbon and the secondary alcohol alkoxylate have 8 or more and 30 or less carbon atoms. The extraction method according to any one of claims 1 to 6, wherein the extraction solvent contains water. A step of partially oxidizing a saturated aliphatic hydrocarbon with a gas containing molecular oxygen in the presence of a boron compound to prepare a liquid containing a corresponding secondary alcohol.
The liquid containing the secondary alcohol is brought into contact with the extraction solvent by the extraction method according to claim 5 or 6, and the boron compound in the liquid containing the secondary alcohol is moved to the extraction solvent to cause the secondary alcohol. A method for producing a secondary alcohol, which comprises a step of separating and recovering the alcohol. The eighth aspect of the present invention further comprises a step of distilling an unreacted saturated aliphatic hydrocarbon from the liquid containing the secondary alcohol and recovering the liquid containing the saturated aliphatic hydrocarbon before the separation and recovery step. The method for producing a secondary alcohol according to the above. At least one of the components other than the saturated aliphatic hydrocarbon in the liquid containing the saturated aliphatic hydrocarbon by contacting the liquid containing the saturated aliphatic hydrocarbon with the extraction solvent by the extraction method according to claim 5 or 6. To separate and recover saturated aliphatic hydrocarbons by moving
The method for producing a secondary alcohol according to claim 9, further comprising a step of reusing the extracted saturated aliphatic hydrocarbon as the saturated aliphatic hydrocarbon in the preparation step. An alkylene oxide is added to the secondary alcohol extracted by the extraction method according to claim 5 or 6 or the secondary alcohol produced by the production method according to any one of claims 8 to 10. A method for producing a secondary alcohol alkoxylate, which comprises a step of preparing a liquid containing the secondary alcohol alkoxylate. The liquid containing the secondary alcohol alkoxylate is brought into contact with the extraction solvent by the extraction method according to claim 5 or 6, and the components other than the secondary alcohol alkoxyrate in the liquid containing the secondary alcohol alkoxyrate are brought into contact with each other. The method for producing a secondary alcohol alkoxylate according to claim 11, further comprising a step of moving at least one of the above to an extraction solvent to separate and recover the secondary alcohol alkoxylate. A liquid-liquid extraction tower that extracts the extraction target by bringing the liquid containing the extraction target into contact with the extraction solvent.
A liquid-liquid extraction tower having an inert gas supply device on the bottom side of the liquid-liquid extraction tower.

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