Method for producing tributyl phosphate, purified tributyl phosphate obtained thereby, and extraction agent using same

Abstract

Provided is a method for efficiently removing butanol, dibutyl phosphate, and the like, which are impurities contained in tributyl phosphate. The disclosed technology is a method for producing tributyl phosphate, which is characterized by comprising a step in which crude tributyl phosphate is brought into contact with an aluminosilicate compound in which the molar ratio (SiO2 / Al203) of silica and alumina in the zeolite skeleton is 10 or more. Furthermore, disclosed is a method for producing an extractant containing tributyl phosphate and a hydrocarbon having 6 or more carbon atoms as a diluent, the method comprising bringing the tributyl phosphate into contact with an aluminosilicate compound having a molar ratio of silica to alumina of a zeolite skeleton of 10 or more, removing impurities contained in the components, and separating the tributyl phosphate from the aluminosilicate compound. And mixing with the diluent.

Description

Technical Field

[0001] The present invention relates to a method for producing tributyl phosphate, purified tributyl phosphate obtained therefrom, and an extractant using the same. In detail, the present invention relates to a method for producing tributyl phosphate from which impurities and odors are removed, purified tributyl phosphate obtained therefrom, and an extractant using the same. Background Art

[0002] Tributyl phosphate (TBP) is an organic phosphorus compound represented by the chemical formula (CH3CH2CH2CH2O)3PO, which is generally produced by the esterification reaction of phosphorus pentachloride or phosphorus oxychloride with n-butanol (see Non-Patent Document 1). Its uses include: various solvents, defoamers for papermaking / fiber processing, plasticizers for synthetic rubber, extraction solvents for rare metals (platinum, uranium), etc.

[0003] Representative impurities contained in tributyl phosphate include n-butanol, dibutyl phosphate, and odor components (hydrocarbons such as olefins). These impurities may hinder the performance of tributyl phosphate in the above-mentioned uses, resulting in reduced product quality and even reduced manufacturing efficiency, and therefore it is desirable to remove them as much as possible.

[0004] Among the impurities contained in tributyl phosphate, some solutions have been proposed in the field of radioactive material recovery as a method for removing dibutyl phosphate. That is, since tributyl phosphate has excellent performance as a recovery solvent for uranium and plutonium, it is mainly used in nuclear fuel reprocessing facilities after being diluted with hydrocarbon solvents. However, in this field, since dibutyl phosphate, which is a primary hydrolyzate of tributyl phosphate produced by the deterioration of tributyl phosphate, greatly reduces the purity of uranium and plutonium as products, attempts have been made to remove it. As a method for removing dibutyl phosphate, alkali washing has been widely known in the past, but it cannot be fully removed.

[0005] Patent document 1 discloses a method in which, after removing dibutyl phosphate generated by degradation of tributyl phosphate used in a nuclear fuel regeneration process, the tributyl phosphate containing dibutyl phosphate is brought into contact with an adsorbent comprising 40 to 60 wt % of titanium oxide and 60 to 40 wt % of zirconium oxide, so that the dibutyl phosphate is adsorbed on the adsorbent. However, this method does not remove dibutyl phosphate to a satisfactory degree.

[0006] In addition, as a method for removing n-butanol from impurities contained in tributyl phosphate, no particularly established method has been proposed in the past. Among the methods for purifying triesters of phosphate, a method widely used as a method for removing alcohols at a low boiling point is known as a vacuum distillation method, but since alkyl phosphates undergo thermal decomposition when heated, it is not preferred.

[0007] In addition, Patent Document 2 proposes a method for obtaining a high-purity phosphate ester by treating a crude phosphate ester with a crystalline hydrous aluminosilicate of an alkali metal or an alkaline earth metal. The crude phosphate ester is an ester of phosphoric acid and methanol or ethanol or an aromatic hydroxy compound, such as trimethyl phosphate, triethyl phosphate, dimethyl monoethyl phosphate, and diethyl monomethyl phosphate, and the crude phosphate ester contains a large amount of at least one polar solvent selected from water, methanol, and ethanol as an impurity; however, the phosphate ester compound that is the object of this technology does not contain tributyl phosphate. In addition, as the crystalline hydrous aluminosilicate of an alkali metal or an alkaline earth metal as a treating agent, natural and synthetic zeolite minerals, zeolites, or molecular sieves can be widely used. Moreover, as the shape of the treating agent, it is classified into spherical, columnar, powdery, etc., preferably spherical, particularly preferably a spherical treating agent having a particle size of 4 to 12 mesh (diameter of about 2.1 mm to about 6.2 mm), and more preferably 7 to 10 mesh (diameter of about 2.5 mm to about 3.6 mm). Although the above contents are described in Patent Document 2, no further mention is made.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 63-188693

[0011] Patent Document 2: Japanese Patent Application Publication No. 2000-351789

[0012] Non-patent literature

[0013] Non-patent document 1: Org. Synth. 1936, 16, 9 Summary of the invention

[0014] Problems to be solved by the invention

[0015] Therefore, the object of the present invention is to provide a method for producing high-purity tributyl phosphate by a relatively simple method that solves the above-mentioned problems in the prior art. The object of the present invention is also to provide a method for producing an extractant using the method for producing tributyl phosphate and an extractant obtained by the method.

[0016] Means for solving problems

[0017] In order to solve the above-mentioned problems, the present technicians have repeatedly conducted in-depth research and exploration, and as a result, they have found that as a method for removing n-butanol, dibutyl phosphate and odor components contained as impurities in tributyl phosphate, by using a hydrophobic aluminosilicate compound with a molar ratio of silica to alumina (SiO2 / Al2O3) of 10 or more in the zeolite framework, i.e., so-called high-silicon zeolite, n-butanol, dibutyl phosphate and odor components can be removed very effectively compared with other adsorbents such as activated carbon and ordinary zeolite, thereby completing the present technology.

[0018] In addition, tributyl phosphate is suitable as an extractant for radioactive elements, rare earth metals, carboxylic acids, etc., and is used after being diluted with hydrocarbons. When preparing such an extractant, the presence of n-butanol, dibutyl phosphate, and odor components contained as impurities in tributyl phosphate will cause adverse effects such as reduced extraction efficiency and reduced quality of the final product, so it is desirable to remove them. Here, the following insight is obtained: in a state where tributyl phosphate, which is the main component of the extractant, exists together with hydrocarbons as a diluent, even if it is in contact with the above-mentioned high-silicon zeolite, n-butanol and the like cannot be fully adsorbed and removed. Therefore, the technicians of the present invention have found that as a method for producing an extractant containing tributyl phosphate as a main component and hydrocarbons with a carbon number of 6 or more as a diluent, the tributyl phosphate is brought into contact with an aluminosilicate compound having a molar ratio of silica to alumina (SiO2 / Al2O3) of 10 or more in the zeolite framework to remove impurities contained in the components, and then mixed with the diluent to provide an extractant with excellent characteristics, thereby completing the present technology.

[0019] That is, the first aspect of the present technology for solving the above-mentioned problems is a method for producing tributyl phosphate, characterized in that it comprises a step of bringing crude tributyl phosphate into contact with a hydrophobic aluminosilicate compound having a molar ratio (SiO2 / Al2O3) of silica and alumina in a zeolite framework of 10 or more.

[0020] In one embodiment of the method for producing tributyl phosphate of the present technology, the step of contacting crude tributyl phosphate with a hydrophobic aluminosilicate compound is shown at a space velocity SV = 1h -1 The method is carried out by passing the liquid through the reaction mixture, or by contacting the mixture in a batch or circulating manner for at least 10 hours.

[0021] In one embodiment of the method for producing tributyl phosphate of the present technology, there is shown a method characterized in that the butanol concentration is reduced to 0.02 mass % or less and the dibutyl phosphate concentration is reduced to 0.01 mass % or less by a step of contacting crude tributyl phosphate with a hydrophobic aluminosilicate compound.

[0022] In another embodiment of the method for producing tributyl phosphate of the present technology, there is shown a method in which the hydrophobic aluminosilicate compound is a ZSM-5 (Zeolite Socony Mobil-5) type or Beta type zeolite.

[0023] In another embodiment of the method for producing tributyl phosphate of the present technology, a method in which the molar ratio of silica to alumina in the zeolite framework of the hydrophobic aluminosilicate compound is 10 to 500 is shown.

[0024] In addition, the second aspect of the present technology for solving the above-mentioned problems is a method for producing an extractant containing tributyl phosphate and a hydrocarbon having 6 or more carbon atoms as a diluent, wherein the tributyl phosphate is brought into contact with an aluminosilicate compound having a molar ratio of silica to alumina of a zeolite framework of 10 or more, and impurities contained in the components are removed before mixing with the diluent.

[0025] In one embodiment of the method for producing an extractant of the present technology, it is shown that: the step of contacting the tributyl phosphate with a hydrophobic aluminosilicate compound is carried out at a space velocity SV = 1h -1 The method is carried out by passing the liquid through the reaction mixture, or by contacting the mixture in a batch or circulating manner for at least 10 hours.

[0026] In addition, a third aspect of the present technology for solving the above-mentioned problems comprises tributyl phosphate as a main component and a hydrocarbon having 6 or more carbon atoms as a diluent, wherein the concentration of butanol as an impurity is 0.02 mass % or less, and the concentration of dibutyl phosphate as an impurity is 0.01 mass % or less.

[0027] In one embodiment of the extractant disclosed in the present invention, there is shown: an extractant, characterized in that the diluent of the prepared extractant is selected from at least one of hexane, benzene, toluene, octane, isooctane, nonane, decane, undecane, dodecane, o-xylene, m-xylene, p-xylene and ethylbenzene.

[0028] Effects of the Invention

[0029] In the present technology, when removing impurities from crude tributyl phosphate, the crude tributyl phosphate is brought into contact with a hydrophobic aluminosilicate compound having a zeolite framework in which the molar ratio of silica to alumina is 10 or more, thereby enabling n-butanol, dibutyl phosphate, and odor components contained as impurities to be efficiently removed by a simple method, and can be efficiently recovered as highly purified tributyl phosphate. DETAILED DESCRIPTION

[0030] Hereinafter, the present technology will be described in detail based on embodiments.

[0031] (Method for producing tributyl phosphate)

[0032] The first aspect of the present technology is a method for producing tributyl phosphate, characterized in that it comprises a step of contacting crude tributyl phosphate with a hydrophobic aluminosilicate compound having a molar ratio (SiO2 / Al2O3) of silica to alumina in a zeolite framework of 10 or more.

[0033] Crude tributyl phosphate

[0034] In the method for producing tributyl phosphate of the first aspect of the present technology, the method for synthesizing crude tributyl phosphate as the treated product is not particularly limited. In addition, for example, in the process of separating and purifying tributyl phosphate from waste liquid which is a primary hydrolyzate of tributyl phosphate and has accumulated impurities such as dibutyl phosphate or butanol, which is used for some extractants, etc., and then reusing it, the crude tributyl phosphate may be used as the treated product.

[0035] Although not particularly limited, the crude tributyl phosphate to be treated may contain, as impurities, for example, 0.1 mass % or more of butanol in a concentration (mass fraction), typically 0.1 to 0.3 mass %, and / or 0.03 mass % or more of dibutyl phosphate in a concentration (mass fraction), typically 0.03 to 0.2 mass %, and in addition, about 30 ml of the sample may be added to a 70 ml sample bottle, and odor components such as butene may be contained as other trace components in a concentration (mass fraction) of about 0.1 mass % in the gas phase in a state covered with a septum.

[0036] Aluminosilicate compounds

[0037] On the other hand, in the method for producing tributyl phosphate of the first aspect of the present technology, as an adsorbent for contacting with the crude tributyl phosphate as described above to adsorb and remove impurities, a hydrophobic aluminosilicate compound having a molar ratio of silica to alumina (SiO2 / Al2O3) of 10 or more, more preferably 10 to 500, and further preferably 40 to 300 in the zeolite framework is used.

[0038] Furthermore, as the hydrophobic aluminosilicate compound, its crystalline framework structure preferably uses ZSM-5 (Zeolite Socony Mobil-5) type or Beta type, wherein ZSM-5 type is a code defined by the International Zeolite Society using three capital letters and has an MFI type topological structure as shown in "Zeolite Framework Type Atlas, Sixth Revised Edition, Elsevier, Amsterdam, 2007". By using ZSM-5 type or Beta type zeolite, impurities such as butanol and dibutyl phosphate can be more efficiently adsorbed and removed.

[0039] The average pore size of the hydrophobic aluminosilicate compound, so-called high silica zeolite, is not particularly limited, but is preferably The following are more preferably More preferably The pore diameter of high-silica zeolite can be measured as follows.

[0040] <Method for measuring average pore diameter>

[0041] The average pore size can generally be obtained by a gas adsorption method such as a nitrogen adsorption method, and can be measured using a commercially available specific surface area / pore distribution measuring device (e.g., Tristar II 3020 series manufactured by Shimadzu Corporation). The values ​​shown in this specification are average pore sizes measured by the nitrogen adsorption method using the above-mentioned device.

[0042] In the present technology, when the average pore size of the hydrophobic aluminosilicate compound as an adsorbent is the preferred size as described above, since this is the size that the molecules of n-butanol, one of the impurities contained in crude tributyl phosphate, enter, it is believed that the adsorption and removal of n-butanol is also a corresponding result to a certain extent, but surprisingly, in addition to n-butanol, dibutyl phosphate, whose molecular size is larger than the average pore size, can also be adsorbed at the same time. Regarding this point, the clear mechanism of action is not yet clear, but it is believed that since dibutyl phosphate is hydrophilic and has a butanol skeleton, it is also removed by the above-mentioned hydrophobic aluminosilicate compound, although not to the same extent as n-butanol.

[0043] Furthermore, if the average pore diameter of the hydrophobic aluminosilicate compound reaches the above-mentioned preferred size, the odor components contained in the crude tributyl phosphate are adsorbed and removed well. It is believed that this is because the odor components contained in the crude tributyl phosphate are presumed to be, for example, butene gases generated when tributyl phosphate is thermally decomposed, and these butene molecules also have a size consistent with the above-mentioned average pore diameter.

[0044] The shape of the hydrophobic aluminosilicate compound as the adsorbent is not particularly limited, but generally, from the viewpoint of contact efficiency, it is preferably in a granular, cylindrical, spherical or other shape, and is preferably packed in a predetermined chromatographic column or the like to contact with crude tributyl phosphate.

[0045] When the hydrophobic aluminosilicate compound is a granular compound, its average particle size is preferably about 1 to 5 mm, more preferably about 1 to 2 mm; in addition, when it is spherical, its average particle size is preferably about 1 to 5 mm, more preferably about 2 to 3 mm. In addition, the average particle size of the hydrophobic aluminosilicate compound can be obtained using a laser diffraction / scattering particle size analyzer.

[0046] Contact process

[0047] As long as the hydrophobic aluminosilicate compound can be brought into sufficient contact with the crude tributyl phosphate so that the impurities contained in the crude tributyl phosphate are adsorbed and removed by the hydrophobic aluminosilicate compound, the step of bringing the crude tributyl phosphate into contact with the hydrophobic aluminosilicate compound can be carried out in a continuous liquid flow method, or in a batch process method or even in a circulation method.

[0048] Since it is also affected by the amount and ratio of impurities such as butanol, dibutyl phosphate, and odor components contained in the crude tributyl phosphate, there is no particular limitation. However, in the case of a continuous liquid flow type, the space velocity SV is 1h -1 Below, more preferably SV is 0.1~0.6h -1 or, in the case of batch or circulation, it is desirable to contact for at least 10 hours, more preferably 17 to 75 hours.

[0049] Here, the "space velocity" in this specification means the speed at which crude tributyl phosphate as the liquid to be treated is charged into the adsorbent filled in the adsorption tower, and is represented by the following formula.

[0050] Space velocity SV = Q / V (1 / Hr)

[0051] Where, Q: flow rate (m 3 / Hr), V: adsorbent dosage in the adsorption tower (m 3 ).

[0052] In addition, in the method for producing tributyl phosphate of the present technology, when crude tributyl phosphate is brought into contact with a hydrophobic aluminosilicate compound, as shown in the examples described below, it is clear that the hydrophobic aluminosilicate compound adsorbs the various impurities contained in the crude tributyl phosphate in a manner that butanol among the impurities is preferentially adsorbed over dibutyl phosphate.

[0053] Therefore, for example, as a production method of the present technology, a method can be adopted in which the contact process between crude tributyl phosphate and a hydrophobic aluminosilicate compound is divided into two or more stages, butanol is mainly removed from impurities in the first stage, and dibutyl phosphate is mainly removed from impurities in the second stage. In this way, these adsorbed components can be efficiently separated from the hydrophobic aluminosilicate compound used and the hydrophobic aluminosilicate compound can be regenerated.

[0054] The environmental conditions of the step of contacting the crude tributyl phosphate with the hydrophobic aluminosilicate compound are not particularly limited, and the contact can be preferably carried out under conditions of, for example, a temperature of about 10 to 40° C. and a pressure of about 101325±20 Pa.

[0055] In addition, the contact process of the crude tributyl phosphate and the hydrophobic aluminosilicate compound is not particularly limited, but for example, in order to improve the contact efficiency, it is preferred that after the adsorption tower is filled with liquid, the pressure is reduced (about 2666.45 to 13332.2 Pa), for example, after the bubble removal in the adsorbent is performed for about 10 minutes, the pressure is reduced for a predetermined time or SV is 1h. -1 The liquid flow or batch treatment is performed under the following conditions. In addition, since the treatment liquid after the contact treatment contains fine powder of the hydrophobic aluminosilicate compound, it is preferable to provide a filter for removing the fine powder to remove it.

[0056] The filter to be used is not particularly limited, and for example, a depth filter, a surface filter, a membrane filter, etc. can be used.

[0057] In the method for producing tributyl phosphate of the present technology, after the above-mentioned contact step, by simply performing solid-liquid separation of the treated liquid and the hydrophobic aluminosilicate compound, high-purity tributyl phosphate with extremely low impurity concentration, specifically, for example, a butanol concentration of 0.02 mass % or less, more preferably 0.01 mass % or less, and a dibutyl phosphate concentration of 0.01 mass % or less, more preferably 0.005 mass % or less, can be obtained.

[0058] (Method for producing extraction agent)

[0059] The method for producing an extractant of the present technology is a method for producing an extractant containing tributyl phosphate and a hydrocarbon having 6 or more carbon atoms as a diluent, characterized in that the tributyl phosphate is brought into contact with an aluminosilicate compound having a zeolite skeleton with a molar ratio of silica to alumina of 10 or more, and impurities contained in the components are removed before mixing with the diluent.

[0060] In the method for producing an extractant of the present technology, basically the same as the method for producing tributyl phosphate described above, the tributyl phosphate used is first brought into contact with an aluminosilicate compound having a molar ratio of silica to alumina of zeolite framework of 10 or more, and after removing impurities contained in the components, the extractant is mixed with a diluent, thereby obtaining an extractant with extremely few impurities. This is because in the presence of the diluent, the aluminosilicate compound tends not to effectively adsorb impurities such as butanol and dibutyl phosphate, and therefore the adsorption treatment is performed before mixing with the diluent.

[0061] In the method for producing the extractant of the present technology, the step of contacting the tributyl phosphate used with the aluminosilicate compound is the same as the step of contacting crude tributyl phosphate with the aluminosilicate compound in the above-mentioned method for producing tributyl phosphate, in terms of treatment conditions, preferred ranges, etc., and therefore the description thereof is omitted here.

[0062] In addition, the hydrocarbon having 6 or more carbon atoms used as a diluent mixed with tributyl phosphate is appropriately determined according to the purpose of the diluent, and is not particularly limited as long as the above conditions are met. For example, it includes saturated or even unsaturated aliphatic, aromatic, etc. hydrocarbons. Among them, preferably, hexane, benzene, toluene, octane, isooctane, nonane, decane, undecane, dodecane, o-xylene, m-xylene, p-xylene and ethylbenzene, especially toluene, octane and decane.

[0063] When the tributyl phosphate is mixed with the diluent as described above after the step of contacting the tributyl phosphate with the aluminosilicate compound, the mixing ratio and mixing method are not particularly limited and can be appropriately selected according to the application of the extractant to be obtained.

[0064] (Extraction Agent)

[0065] The extractant of the present technology is characterized in that it can be manufactured by the manufacturing method of the extractant as described above, the extractant contains tributyl phosphate as a main component and a hydrocarbon with a carbon number of 6 or more as a diluent, the concentration of butanol as an impurity is 0.02 mass% or less, more preferably 0.014 mass% or less; and the concentration of dibutyl phosphate as an impurity is 0.01 mass% or less, more preferably 0.007 mass% or less.

[0066] Such an extractant with an extremely low impurity content can be used for various known purposes without particular limitation, and can be suitably used as an extraction solvent for various metals such as rare metals, rare earth metals, and radioactive metals, or an extraction solvent for specific carboxylic acids in a mixed solution.

[0067] Example

[0068] Hereinafter, the present technology will be described in more detail based on examples.

[0069] In the following examples, each component was analyzed by the following method.

[0070] (Dibutyl Phosphate)

[0071] The amount of dibutyl phosphate components was measured by gas chromatography after derivatization treatment using a silylating agent under the following conditions.

[0072] A BSTFA solution to which 1 g of bis(trimethylsilyl)trifluoroacetamide (manufactured by Kanto Chemical Co., Ltd., hereinafter referred to as BSTFA) and 9 g of n-decane (manufactured by Kanto Chemical Co., Ltd.) were added was used as a preparative silanization reagent. About 0.5 g of the preparative silanization reagent was added to about 2 g of the sample solution, and the mixture was heated in a thermostatic bath at 80° C. for 1 hour, and then analyzed by gas chromatography. The amount of dibutyl phosphate was quantified using a calibration curve method.

[0073] Device: GC-2014 (manufactured by Shimadzu Corporation)

[0074] Detector: Flame ionization detector (FID)

[0075] Chromatographic column: G-100 (inner diameter: 1.2mm, length: 40m, film thickness: 3.0μm)

[0076] Column heating conditions: 80℃→10℃ / min→240℃ (maintained for 44 minutes)

[0077] Injection conditions: 250℃, carrier gas flow rate: 15ml / min

[0078] (Moisture)

[0079] The water content was determined using a Karl Fischer titrator.

[0080] (Butanol)

[0081] The butanol content was quantified using an absolute calibration curve method. The gas chromatography analysis conditions were as follows.

[0082] Device: GC-2014 (manufactured by Shimadzu Corporation)

[0083] Detector: Flame ionization detector (FID)

[0084] Chromatographic column: G-100 (inner diameter: 1.2mm, length: 40m, film thickness: 3.0μm)

[0085] Column heating conditions: 80℃→10℃ / min→240℃ (maintained for 44 minutes)

[0086] Injection conditions: 250℃, carrier gas flow rate: 15ml / min

[0087] (Other volatile components including odorous components)

[0088] Regarding other volatile components including odor components, add about 30 ml of sample to a 70 ml sample bottle, insert the injection needle into the sample bottle covered with a septum, collect 50 ml of the gas phase with a 100 ml syringe attached with NEEDLex (manufactured by Shinwa Chemical Co., Ltd., for organic solvents), replace NEEDLex with a gas phase syringe, inject 0.5 ml into the gas chromatograph, and concentrate the headspace (gas phase) to 100 times for analysis. Then, quantitative determination is performed by gas chromatograph under the following conditions.

[0089] Device: GC-2014 (manufactured by Shimadzu Corporation)

[0090] Detector: Flame ionization detector (FID)

[0091] Chromatographic column: DB-WAX (inner diameter: 0.25mm, length: 60m, film thickness: 0.5μm)

[0092] Column heating conditions: 80℃→10℃ / min→220℃ (maintained for 44 minutes)

[0093] Injection conditions: 250℃, carrier gas flow rate: 100ml / min

[0094] (Dibutyl Phosphate)

[0095] In gas chromatography, the remainder after subtracting the amounts of other components was taken as the amount of tributyl phosphate.

[0096] Examples 1 to 4 and Comparative Examples 1 to 6

[0097] As the crude tributyl phosphate to be treated, crude tributyl phosphate provided by a cooperative company was prepared. The crude tributyl phosphate was analyzed by the above method, and the result was that the concentration of butanol as an impurity contained 0.1214 mass%. Furthermore, about 30 ml of the sample was added to a 70 ml sample bottle, and the concentration of the volatile components in the gas phase covered with a septum was 0.022 mass% of butene, 0.038 mass% of chlorobutane, and 0.009 mass% of butyl ether (hereinafter, the crude tributyl phosphate is represented as "treated liquid 1").

[0098] 5 mass % of the adsorbent shown in Table 1 was added to the sample solution 1, and after shaking for 18 hours using a shaker (manufactured by Thomas Scientific Instruments, T-25), the supernatant was collected, and the concentration of each component was measured according to the above-mentioned analysis conditions, and the adsorption amount of each component was compared. The results are shown in Table 1.

[0099] In addition, as the adsorbent, Example 1 and Comparative Example 5 used high-silicon zeolite Na + Examples 2 to 4 and Comparative Example 6 use high silicon zeolite H + Type, Comparative Example 1 uses WH2C (manufactured by Osaka Gas Chemicals, activated carbon from coconut shells), Comparative Example 2 uses WH5C (manufactured by Osaka Gas Chemicals, activated carbon from coal), and Comparative Example 3 uses KL (manufactured by Osaka Gas Chemicals, activated carbon from charcoal).

[0100] Embodiment 5-6

[0101] The crude tributyl phosphate used as the treatment object was crude tributyl phosphate from another batch provided by a cooperative company. The crude tributyl phosphate was analyzed by the above method, and the result was that the concentration of butanol as an impurity contained 0.1691 mass % (hereinafter, the crude tributyl phosphate is referred to as "treatment liquid 2").

[0102] 5 mass % of the adsorbent shown in Table 1 was added to the sample solution 2, and after shaking for 18 hours using a shaker in the same manner as in Examples 1 to 4, the supernatant was collected, and the concentration of each component was measured according to the above-mentioned analysis conditions, and the adsorption amount of each component was compared. The results are shown in Table 1.

[0103] In addition, as the adsorbent, high silica zeolite Na + Type, Example 6 uses high silicon zeolite H + type.

[0104] Comparative Example 7

[0105] The crude tributyl phosphate used as the treatment object was crude tributyl phosphate from another batch provided by a cooperative company. The crude tributyl phosphate was analyzed by the above method, and the result was that the concentration of butanol as an impurity contained 0.0826 mass % (hereinafter, the crude tributyl phosphate is referred to as "treatment liquid 3").

[0106] 5 mass % of the adsorbent shown in Table 1 was added to the sample solution 3, and after shaking for 18 hours using a shaker in the same manner as in Examples 1 to 4, the supernatant was collected, and the concentration of each component was measured according to the above-mentioned analysis conditions, and the adsorption amount of each component was compared. The results are shown in Table 1. As the adsorbent, Molecular Sieve 5A (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used in Comparative Example 7.

[0107] [Table 1]

[0108]

[0109] As shown in Table 1, Examples 1 to 6 of the present technology obtained a higher butanol adsorption rate than Comparative Examples 1 to 7. In addition, the odor of the treated liquid after the adsorbent treatment was significantly improved in Examples 1 to 6 compared with the treated liquid before the treatment. In fact, when the gas phase was analyzed by gas chromatography under the above conditions, the peak area of ​​the odor component was reduced. Table 2 shows the concentration of odor components in the treated liquid 1 before the adsorption treatment obtained from the results of the above gas chromatography and the concentration of odor components in the treated liquid after the adsorption treatment in Examples 1, 2 and Comparative Example 2.

[0110] [Table 2]

[0111]

[0112] Example 7

[0113] In order to study the removal rate of dibutyl phosphate by the adsorbent of this technology, n-butanol (manufactured by Kanto Chemical Co., Ltd.) and dibutyl phosphate (manufactured by Sigma-Aldrich Corporation) were added to reagent grade n-butyl phosphate (manufactured by Kanto Chemical Co., Ltd.) in the proportions shown below to simulate the preparation of various treated liquids.

[0114] Treated liquid 4: Add 0.1% by mass of n-butanol and dibutyl phosphate to reagent grade tributyl phosphate

[0115] Treated liquid 5: Add 0.1% by mass of n-butanol and 0.05% by mass of dibutyl phosphate to reagent grade tributyl phosphate

[0116] Treated liquid 6: 0.02 mass % of n-butanol and 0.1 mass % of dibutyl phosphate were added to reagent grade tributyl phosphate.

[0117] 5 mass % of the same high-silicon zeolite as used in Example 5 was added to these treated liquids, and after shaking for 18 hours using a shaker (manufactured by Thomas Scientific Instruments, T-25), the supernatant was collected, and the concentration of each component was measured according to the above-mentioned analysis conditions, and the adsorption amount of each component was compared. The results are shown in Table 3.

[0118] [Table 3]

[0119]

[0120] As shown in Table 3, it can be seen that in Example 7 of the present technology, even if the concentrations of dibutyl phosphate and butanol as impurities contained in tributyl phosphate are different, both impurity components can be adsorbed and removed. In the adsorption treatment of the ZSM-5 type high-silica zeolite used in Example 7, although a tendency to preferentially remove butanol was found, even when either butanol or dibutyl phosphate was contained in excess, a tendency that one of them was not adsorbed at all was not found.

[0121] Examples 8 and 9

[0122] In order to investigate the removal rate of dibutyl phosphate when the crystal structure of the adsorbent of the present technology is different, the same high-silicon zeolite used in Example 3 was added as an adsorbent (Example 8), or the same high-silicon zeolite used in Example 4 was added (Example 9) at 5 mass % to the treated liquid 6 prepared in Example 7, and after shaking for 18 hours with an oscillator (manufactured by Thomas Scientific Instruments, T-25), the supernatant was collected, and the concentration of each component was measured according to the above-mentioned analysis conditions, and the adsorption amount of each component was compared. The results are shown in Table 4.

[0123] [Table 4]

[0124]

[0125] As shown in Table 4, the adsorption amount of dibutyl phosphate in tributyl phosphate is higher in Example 9. As described above, the adsorption amounts of butanol and dibutyl phosphate are different due to the difference in the crystal structure of the adsorbent of the present technology, but in both the Beta type and the ZSM-5 type, butanol and dibutyl phosphate are adsorbed.

[0126] Reference Example 1

[0127] In order to confirm the adsorption efficiency of the adsorbent of the present technology on an extractant containing tributyl phosphate and a diluent, the same treated liquid 2 as used in Examples 5 to 6 and a simulated extractant (hereinafter referred to as "treated liquid 7") prepared by mixing the treated liquid 2 and reagent grade decane (manufactured by Kanto Chemical Co., Ltd.) in a mass ratio of 75:25 were prepared.

[0128] Then, the same adsorbent as used in Example 1 was added to these sample solutions 2 and 7 in the proportions shown in Table 5, and after shaking for 18 hours using a shaker in the same manner as in Examples 1 to 4, the supernatant was collected, and the concentration of each component was measured under the above-mentioned analysis conditions, and the adsorption amount of each component was compared. The results are shown in Table 5.

[0129] [Table 5]

[0130]

[0131] As shown in Table 5, in the case where decane as a diluent coexists, the amount of butanol adsorbed from tributyl phosphate tends to decrease by about 60%.

[0132] Examples 10 and 11

[0133] In order to investigate the effect of different flow rates on the adsorption efficiency of butanol and dibutyl phosphate, adsorption treatment was carried out under the following conditions.

[0134] As the crude tributyl phosphate to be treated, crude tributyl phosphate from another batch provided by a cooperative company was used. The crude tributyl phosphate was analyzed by the above method, and the result was that the concentration of butanol as an impurity contained 0.1930 mass%. A liquid prepared by adding 0.1 mass% of the reagent dibutyl phosphate to the crude tributyl phosphate was used as the treated liquid 8, and 12.0 g of the adsorbent shown in Example 5 was added to a PFA adsorption column with an inner diameter of 17.5 mm and a length of 120 mm. After the adsorption column was filled with the treated liquid 8, the pressure was reduced to 13332.2 Pa and the liquid was sent to the adsorption column at a flow rate of 0.08 g / min (SV=0.3) (Example 10) and at a flow rate of 0.91 g / min (SV=3.2) (Example 11) using a quantitative pump (manufactured by Iwasaki Co., Ltd., EHN-R). The concentrations of butanol and dibutyl phosphate were measured under the above analysis conditions, and the relationship between the flow rate and the adsorption amount was compared. The results are shown in Table 6.

[0135] [Table 6]

[0136]

[0137] Example 12

[0138] In order to investigate the relationship between the contact time of the adsorbent and the amount of butanol adsorbed, an adsorption treatment was performed under the following conditions. 60.0 g of the adsorbent shown in Example 5 was added to an adsorption chromatographic column made of SUS304 with an inner diameter of 28.4 mm and a length of 200 mm, and filled into the adsorption chromatographic column. 1000 g of the sample liquid 2 was placed in a conical flask, and while stirring with a stirrer, the sample liquid 2 was sent to the adsorption chromatographic column with a metering pump (manufactured by Iwasaki Co., Ltd., EHN-R) at a liquid flow rate of 7.1 g / min. The liquid after being sent to the adsorption chromatographic column was mixed with the conical flask containing the sample liquid 2. The liquid in the conical flask was collected every certain period of time, and the butanol concentration was determined according to the above-mentioned analysis conditions, and the relationship between the liquid circulation time and the butanol adsorption amount was compared. The results are shown in Table 7.

[0139] [Table 7]

[0140]

[0141] As shown in Table 7, a tendency was observed that the amount of butanol adsorbed increased in proportion to the contact time with the adsorbent.

Claims

1. A method for producing tributyl phosphate, characterized in that: A process for bringing crude tributyl phosphate into contact with a hydrophobic aluminosilicate compound having a molar ratio (SiO2 / Al2O3) of silica to alumina in a zeolite framework of 10 or more.

2. The method for producing tributyl phosphate according to claim 1, wherein the step of contacting the crude tributyl phosphate with the hydrophobic aluminosilicate compound is carried out at a space velocity SV = 1 h -1 The reaction is carried out by passing the liquid through the reaction mixture, or by contacting the mixture in a batch or circulating manner for at least 10 hours.

3. The method for producing tributyl phosphate according to claim 1 or 2, characterized in that: By the step of contacting crude tributyl phosphate with a hydrophobic aluminosilicate compound, the butanol concentration and the dibutyl phosphate concentration of butanol and dibutyl phosphate as impurities contained in the crude tributyl phosphate are controlled to be 0.02 mass % or less and 0.01 mass % or less.

4. The method for producing tributyl phosphate according to claim 1 or 2, wherein the hydrophobic aluminosilicate compound is ZSM-5 (Zeolite Socony Mobil-5) type or Beta type zeolite. 5 . The method for producing tributyl phosphate according to claim 1 , wherein the molar ratio of silicon dioxide to aluminum oxide in the zeolite framework of the hydrophobic aluminosilicate compound is 10 to 500.

6. A method for producing an extractant, which is a method for producing an extractant containing tributyl phosphate and a hydrocarbon having 6 or more carbon atoms as a diluent, wherein the tributyl phosphate is brought into contact with an aluminosilicate compound having a zeolite skeleton with a molar ratio of silica to alumina of 10 or more, and after removing impurities contained in the components, the extractant is mixed with the diluent.

7. The method for producing an extractant according to claim 6, wherein the step of contacting the tributyl phosphate with the hydrophobic aluminosilicate compound is carried out at a space velocity SV = 1 h -1 The reaction is carried out by passing the liquid through the reaction mixture, or by contacting the mixture in a batch or circulating manner for at least 10 hours.

8. An extractant comprising tributyl phosphate as a main component and a hydrocarbon having 6 or more carbon atoms as a diluent, characterized in that: The concentration of butanol as an impurity was 0.02 mass % or less, and the concentration of dibutyl phosphate as an impurity was 0.01 mass % or less.

9. The extractant according to claim 8, characterized in that The diluent is selected from at least one of hexane, benzene, toluene, octane, isooctane, nonane, decane, undecane, dodecane, o-xylene, m-xylene, p-xylene and ethylbenzene.

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