KR20190028289A - Method of producing hydrogen peroxide - Google Patents

Abstract

Provided is a method of obtaining a high quality reproduction working solution by removing inactive materials from a working solution containing trioctyl phosphate (TOP). A method of preparing hydrogen peroxide of the present invention comprises: a hydrogen peroxide preparation step of producing hydrogen peroxide by oxidizing a working solution containing an aromatic hydrocarbon, TOP and anthraquinones after hydrogenation, extracting the produced hydrogen peroxide from the working solution, and returning the working solution after the extraction of the hydrogen peroxide to a hydrogenation step so as to circulate the same; a working solution reproduction step of preparing a crude reproduction working solution by removing inactive materials additionally produced as the hydrogen peroxide is produced, from the working solution; and a step of preparing a reproduction working solution for circulation by washing the crude reproduction working solution with alkaline, wherein the working solution reproduction step includes i) a primary distillation step of collecting the aromatic hydrocarbon by distillation under atmospheric pressure or a lower pressure than the atmospheric pressure, and ii) a secondary distillation step of collecting the anthraquinones and TOP by distillation at a temperature more than or equal to 160°C under a lower pressure compared to that of the primary distillation step.

Description

METHOD OF PRODUCING HYDROGEN PEROXIDE < RTI ID = 0.0 >

The present invention relates to a process for the production of hydrogen peroxide using anthraquinones, and in particular to a process for the production of hydrogen peroxide comprising a regeneration process of the working solution.

Hydrogen peroxide is used as a bleaching agent for paper, pulp, fiber and the like, a bactericide and the like in that it has an oxidizing power and a strong bleaching and sterilizing action. Since the decomposition products of hydrogen peroxide are water and oxygen, they have an important position in terms of green chemistry, and they are attracting attention as a substitute for chlorine bleaching agents. In addition, the amount of hydrogen peroxide used is also increasing in the semiconductor industry such as the cleaning of the surface of a semiconductor substrate, the chemical polishing of copper, tin and other copper alloy surfaces, and the etching of electronic circuits. Also, hydrogen peroxide is an important industrial product, widely used in oxidation reactions including epoxidation and hydroxylation.

As an industrial method for producing hydrogen peroxide, an anthraquinone method is known. In this method, an anthraquinone is dissolved in an organic solvent to obtain a working solution, and in the hydrogenation step, anthraquinones are hydrogenated in the presence of a hydrogenation catalyst to produce anthrahydroquinones. Then, in the oxidation step, the anthrahydroquinones are again recycled to the anthraquinones and at the same time hydrogen peroxide is produced. Hydrogen peroxide in the working solution is separated from the working solution by a method such as water extraction. The working solution from which hydrogen peroxide has been extracted is returned to the hydrogenation process to form a circulation process.

In the process of hydrogenating the anthraquinone contained in the working solution with an anthraquinone and oxidizing the anthraquinone with an anthraquinone to produce hydrogen peroxide, the tetrahydroanthraquinone epoxide which does not contribute to hydrogen peroxide generation, the tetraoxy Monomer side products of anthraquinones such as anthrone, anthrone, oxyanthrone, and anthrone, solvent adducts of anthraquinones, and polymers of anthraquinones are produced. Also, degradation of the solvent component is produced. Ingredients that can not participate in the production of such hydrogen peroxide are classified as " inert substances ". The increase of the inert material causes a decrease in the concentration of the anthraquinone, which is an active material, and the like, which may degrade the process capability of the circulation process. For this reason, a working solution in which the concentration of the inactive substance is low and the concentration of the active substance is kept sufficiently high is required (Patent Document 1).

WO2007 / 129769

Although the composition of the working solution differs depending on the hydrogen peroxide production plant, the aromatic hydrocarbon as the nonpolar solvent and the tris (2-ethylhexyl) phosphate (CAS No. 78-42-2, hereinafter referred to as "trioctylphosphate" or "TOP Quot;), an operation solution containing alkyl anthraquinone and alkyl tetrahydro anthraquinone as anthraquinones is widely used. However, in the working solution containing trioctyl phosphate as a polar solvent, a method of suppressing the concentration of the inactive substance and keeping the concentration of the active substance at a sufficiently high level has hitherto not been reported. Accordingly, it is an object of the present invention to provide a method for removing or removing an inert material from a working solution containing trioctyl phosphate used for preparing hydrogen peroxide by the anthraquinone method to maintain or improve the physical properties and / or activity of the working solution .

As a result of intensive studies to solve the above problems, the present inventor has found a method for removing by-products from an operation solution containing aromatic hydrocarbons, trioctyl phosphate and anthraquinones. The process comprises recovering the aromatic hydrocarbons by distillation at atmospheric pressure or below and then recovering the anthraquinones and trioctylphosphate by distillation at a temperature of 160 ° C or less under lower pressure and recovering the recovered total effluent Distillate) is reused as the working solution. As a result of further investigation by the present inventors, it has been found that the hydrogenation activity is improved by washing the regenerated working solution with alkali.

An aspect of the present invention is as follows.

[1] Hydrogen peroxide is produced by oxidizing a working solution containing an aromatic hydrocarbon, trioctyl phosphate and anthraquinone after hydrogenation, extracting the hydrogen peroxide from the working solution, extracting the hydrogen peroxide from the working solution, A working solution regeneration step of removing an inert material produced as a result of the generation of the hydrogen peroxide from the working solution to prepare a crude regeneration working solution from which the inactive material has been removed; And an alkaline cleaning solution for the crude regeneration working solution to prepare a regeneration working solution for circulation,

Wherein the working solution regeneration step comprises the steps of: i) a first distillation step for recovering aromatic hydrocarbons by distillation at atmospheric pressure or below; and ii) a second distillation step for distilling the anthraquinones and the tri And a second distillation step of recovering octyl phosphate.

[2] The method for producing hydrogen peroxide according to [1], wherein the pressure in the first distillation step is within a range of 1 to 100..

[3] The method for producing hydrogen peroxide according to [1] or [2], wherein the pressure in the second distillation step is 1 ㎪ or less.

[4] The method for producing hydrogen peroxide according to any one of [1] to [3], wherein the temperature in the second distillation step is within a range of 160 ° C to 300 ° C.

[5] The process for producing hydrogen peroxide according to any one of [1] to [4], wherein the anthraquinone comprises alkylanthraquinone and alkyltetrahydroanthraquinone.

[6] The method for producing hydrogen peroxide according to any one of [1] to [5], which comprises a step of returning the recycle working solution for circulation to the hydrogen peroxide production process.

[7] The method for producing hydrogen peroxide described in [6], wherein the solvent composition ratio of the crude regeneration working solution is within a range of ± 20% points with respect to the solvent composition ratio of the working solution circulating in the hydrogen peroxide production process.

[8] The method according to [6] or [7], wherein the concentration of the anthraquinone in the crude regeneration working solution is in a range of not more than the concentration of the anthraquinone in the working solution circulating in the hydrogen peroxide producing step, Wherein the hydrogen peroxide is hydrogen peroxide.

[9] The method for producing hydrogen peroxide according to any one of [6] to [8], wherein the regeneration working solution is adjusted to 20% to 160% of the saturated water amount in the recycling regeneration working solution preparing step.

[10] The method for producing hydrogen peroxide as described in any one of [6] to [9], further comprising a step of washing the regenerated working solution after the alkali cleaning.

[11] The method for producing hydrogen peroxide according to any one of [1] to [10], further comprising a step of separating the anthraquinones and trioctyl phosphate from the effluent of the second distillation step.

[12] The process for producing hydrogen peroxide according to [11], wherein the step of separating the anthraquinones from trioctyl phosphate is recrystallization.

[13] A system for producing hydrogen peroxide comprising a distillation column, a distillation column, a washing tank, a hydrogenation column, an oxidation column and an extraction column, wherein the distillation column has an unknown column discharge line, And the cleaning tank is connected to the cleaning tank by the alkaline solution supply line and the water supply line, and the cleaning tank is connected to the cleaning tank by the water supply line and the downstream distillation effluent supply line, Wherein the hydrogenation column and the oxidation column are communicated by a hydrogenation operation solution supply line, the hydrogenation column and the oxidation column are communicated by a hydrogenation operation solution supply line, The oxidation tower is connected to an oxidizer supply line, the oxidation tower and the extraction tower are connected by an oxidation operation solution supply line, the extraction tower is provided with a hydrogen peroxide transport line, Wherein the distillation column and the extraction column are connected by a working solution feed line after the hydrogen peroxide extraction.

The distillation column and the shear distillation effluent tank are communicated by a shear distillate effluent transport line, and the shear distillate effluent tank and coalescence are separated by a shear distillate effluent feed line And wherein the system is in communication.

The distillation column and the distillation distillation effluent tank are connected to each other by a distillation distillation effluent conveying line and the distillation distillation effluent tank is connected to a distillation distillation effluent supply line Wherein the system is in communication with the system.

The recrystallization tank is further provided with a filter and a waste liquid line. The recrystallization tank is connected to a recrystallization solvent supply line. The recrystallization tank and the distillation column are connected by a subsequent distillation effluent supply line. The system of claim 13, wherein the preparation is in communication with an anthraquinone feed line.

The present invention exhibits one or more of the following effects.

(1) the inert material can be removed from the working solution containing the trioctyl phosphate as the polar solvent in which the inert substance is accumulated.

(2) Anthraquinones, which are active substances, can be efficiently recovered from a working solution containing trioctyl phosphate as a polar solvent and reused.

(3) By reducing the inert material in the circulating working solution, the efficiency of each step of hydrogen peroxide production can be kept high.

(4) The viscosity of the circulating working solution can be kept low.

(5) The hydrogenation activity of the circulating working solution can be kept high.

(6) Since it can be applied to a working solution containing trioctyl phosphate having a high frequency of use, its application range is wide, and contribution to efficiency of hydrogen peroxide production can be expected.

1 is a schematic diagram of one embodiment of a hydrogen peroxide producing system of the present invention.
2 is a schematic diagram of an embodiment of a hydrogen peroxide producing system of the present invention with a recrystallization tank.

One aspect of the present invention is a method for producing hydrogen peroxide by oxidizing an operating solution containing an aromatic hydrocarbon, trioctyl phosphate and anthraquinone after hydrogenation (reduction), extracting the hydrogen peroxide from the working solution, Removing the inactive material produced as a result of the generation of the hydrogen peroxide from the working solution to prepare a crude recovery working solution from which the inactive material has been removed, A regeneration step, and a regeneration working solution preparation step for circulating the regeneration working solution by alkaline cleaning to prepare a regeneration working solution for circulation,

Wherein the working solution regeneration step comprises the steps of: i) a first distillation step for recovering aromatic hydrocarbons by distillation at atmospheric pressure or below; and ii) a second distillation step for distilling the anthraquinones and the tri And a second distillation step of recovering octylphosphate (hereinafter sometimes referred to as " the method for producing hydrogen peroxide of the present invention ").

The aromatic hydrocarbons contained in the working solution are not limited and include, for example, aromatic hydrocarbons substituted with at least one alkyl group, especially alkylbenzenes containing 8, 9, 10, 11 or 12 carbon atoms (e.g., Trimethylbenzene containing 9 carbon atoms, etc.), or a mixture thereof, and the like, and it is preferable that anthraquinone can be dissolved. In a specific embodiment, the aromatic hydrocarbon is selected from a mixed solvent having a carbon number of 10 and a mixed solvent having a carbon number of 9 (for example, a cumene isomer mixture). Trioctyl phosphate, a polar solvent, is a compound having the following structure.

[Chemical Formula 1]

The anthraquinones contained in the working solution include at least one of anthraquinone (9,10-anthracenedione), tetrahydroanthraquinone, and derivatives thereof capable of producing hydrogen peroxide by the anthraquinone method. The anthraquinone derivative capable of producing hydrogen peroxide is not limited, and, for example, alkyl anthraquinone can be mentioned. An alkyl anthraquinone means anthraquinone substituted with at least one alkyl group. In certain embodiments, the alkyl anthraquinone includes anthraquinone wherein the 1,2, or 3 position is at least monosubstituted by a linear or branched aliphatic substituent comprising at least one carbon atom. The alkyl substituent in the alkyl anthraquinone preferably contains 1 to 9, more preferably 1 to 6 carbon atoms. Specific examples of the alkyl anthraquinone are not limited and include, for example, methyl anthraquinone (2-methyl anthraquinone and the like), dimethyl anthraquinone (1,3-, 2,3-, 1,4-, 2,7 (2-sec-, 2-isopropylanthraquinone, etc.), propylanthraquinone (2-n-propylanthraquinone, -tert-butyl anthraquinone, etc.), amyl anthraquinone (2-sec-, 2-tert-amylanthraquinone, etc.). Preferred alkyl anthraquinones include ethyl anthraquinone, amyl anthraquinone, and mixtures thereof. The concentration of the alkyl anthraquinone in the working solution is controlled depending on the conditions of the process, and is used in a concentration range of, for example, 0.4 to 1.0 mol / l.

The derivative of tetrahydroanthraquinone capable of producing hydrogen peroxide is not limited, and examples thereof include alkyltetrahydroanthraquinone. Alkyltetrahydroanthraquinone means tetrahydroanthraquinone substituted with at least one alkyl group. In certain embodiments, the alkyltetrahydroanthraquinone comprises tetrahydroanthraquinone wherein the 1,2, or 3 position is at least monosubstituted by a linear or branched aliphatic substituent comprising at least one carbon atom. The alkyl substituent in the alkyltetrahydroanthraquinone preferably contains 1 to 9, more preferably 1 to 6 carbon atoms. Specific examples of the alkyltetrahydroanthraquinone are not limited and include, for example, methyltetrahydroanthraquinone (such as 2-methyltetrahydroanthraquinone), dimethyltetrahydroanthraquinone (such as 1,3-, 2,3-, (2-ethyltetrahydroanthraquinone, 2-n-propyltetrahydroanthraquinone, 2-ethyltetrahydrothraquinone, etc.), ethyltetrahydrothraquinone (2-sec-, 2-tert-butyltetrahydroanthraquinone, etc.), amethyltetrahydroanthraquinone (2-sec-, 2- tert- amyltetraquinone, etc.), butyltetrahydroanthraquinone Hydroanthraquinone, etc.) and the like. Preferred alkyltetrahydroanthraquinones include ethyltetrahydro anthraquinone, amyltetrahydro anthraquinone, or mixtures thereof.

In one embodiment, the working solution comprises a combination of alkyl anthraquinone and alkyl tetrahydroanthraquinone. In this combination, the molar ratio of the alkyl anthraquinone to the alkyl tetrahydroanthraquinone is not particularly limited, but it is preferably from 0.05: 1 to 100: 1 as the alkyl anthraquinone: alkyltetrahydro anthraquinone, more preferably from 0.1: 1 to 75: 1, and more preferably 0.2: 1 to 50: 1. The weight ratio of the alkyl anthraquinone to the alkyltetrahydroanthraquinone is not particularly limited, but is preferably 0.05: 1 to 100: 1, more preferably 0.1: 1 to 75: 1 as the alkyl anthraquinone: alkyltetrahydroanthraquinone More preferably 0.2: 1 to 50: 1. A particularly preferred combination of alkyl anthraquinone and alkyl tetrahydroanthraquinone is the combination of ethyl anthraquinone and ethyl tetrahydroanthraquinone.

The hydrogen peroxide production process can be carried out according to the production method of hydrogen peroxide by the known anthraquinone method. The hydrogen peroxide production process typically includes a step of hydrogenating the working solution, a step of oxidizing the working solution after hydrogenation, and a step of extracting hydrogen peroxide generated by oxidation with water. The hydrogenation of the working solution is carried out, for example, by bubbling the working solution into a gas containing hydrogen such as a hydrogen gas or a mixture of an inert gas (such as nitrogen gas) and hydrogen gas in the presence of a hydrogenation catalyst can do. Oxidation of the working solution after hydrogenation can be carried out, for example, by bubbling the working solution with a gas containing oxygen such as air or oxygen gas. The extraction of hydrogen peroxide into water phase can be carried out, for example, by mixing the working solution after oxidation with water and separating the water phase. The extracted hydrogen peroxide may then be subjected to treatment such as purification and concentration.

The removal of the inert material from the working solution in the working solution regeneration step is carried out in the following manner: i) a first distillation step (hereinafter, also referred to as a shearing distillation step) for recovering aromatic hydrocarbons by distillation under atmospheric pressure or below, And ii) a second distillation step for recovering the anthraquinone and trioctyl phosphate (hereinafter, also referred to as a post-distillation step) by distillation at 160 ° C. or higher at a lower pressure .

In the first distillation step, distillation is carried out with respect to the working solution at a pressure of atmospheric pressure or lower to recover the aromatic hydrocarbons contained in the working solution as an effluent. The distillation pressure is not particularly limited as long as it is capable of recovering aromatic hydrocarbons. For example, the distillation pressure may be 0.5 ㎪ to 100 ㎪, 0.8 ㎪ to 100 ㎪, 1 ㎪ to 100 ㎪, 1 ㎪ to 50 ㎪. Aromatic hydrocarbons are effluent, but distillation pressures in which trioctylphosphate and anthraquinone are not spilled out are preferred. The distillation temperature is not particularly limited as long as it is capable of recovering aromatic hydrocarbons. For example, the distillation temperature may be in the range of 110 to 240 ° C, 120 to 220 ° C, 130 to 200 ° C, 140 to 190 ° C, . Aromatic hydrocarbons are spilled out, but distillation temperatures at which trioctylphosphate and anthraquinone are not spilled out are preferred. The distillation in the first distillation step is preferably continued from the viewpoint of the recovery rate of aromatic hydrocarbons and the like until the outflow is eliminated. The aromatic hydrocarbons discharged in the first distillation step are reused as components of the regeneration working solution.

The working solution provided in the first distillation step is typically a working solution which is circulated in the hydrogen peroxide production process and contains an inert material as a by-product accompanied by the generation of hydrogen peroxide. Such an operation solution may be obtained at any stage of the hydrogen peroxide producing process, but may be an extraction process that does not contain hydrogen peroxide or contains very little (for example, a content of 0.35 g / liter or less) The later working solution is preferable from the viewpoint of safety. Examples of the inert material include by-products (oxides, decomposition products, etc.) derived from anthraquinones or solvents (aromatic hydrocarbons and trioctylphosphate). Examples of the byproducts derived from anthraquinones include monomer side products of anthraquinones such as tetrahydroanthraquinone epoxide, tetraoxyanthrone, oxyanthrone, and anthrone, solvent adducts of anthraquinones, And polymers of anthraquinones. As a by-product derived from a solvent, for example, carboxylic acids, polyols, phenols and the like can be given.

In the second distillation step, the residue obtained in the first distillation step is subjected to distillation at 160 ° C. or more under a pressure lower than that of the first distillation step to recover anthraquinones and trioctyl phosphate as an effluent. As a result, an anthraquinone and a by-product having a higher boiling point than trioctyl phosphate (a high-boiling component) can be removed. The distillation pressure is not particularly limited as long as it is capable of recovering anthraquinone and trioctyl phosphate. For example, the distillation pressure is 0.001 to 1, 0.002 to 0.5, 0.005 to 0.2, 0.008 to 0.1, 0.1 ㎪ to 0.3 ㎪. Although anthraquinones and trioctyl phosphate are effluent, the distillation of the by-products is preferable to a low distillation pressure. The distillation temperature is not particularly limited as long as the anthraquinone and trioctyl phosphate can be recovered. For example, the distillation temperature is in the range of 160 to 300 ° C, 165 to 280 ° C, 170 to 270 ° C, 175 to 260 ° C, 220 占 폚 to 260 占 폚. In some embodiments, the upper limit of the distillation temperature of the second distillation step may be less than 200 占 폚. Therefore, the distillation temperature range of the second distillation step in this embodiment is, for example, in the range of 160 to 199 ° C, 160 to 198 ° C, 160 to 197 ° C, 160 to 196 ° C, 160 ° C to 194 ° C, 160 ° C to 192 ° C, 160 ° C to 191 ° C, 160 ° C to 190 ° C, 160 ° C to 189 ° C, 160 ° C to 188 ° C, 160 ° C to 186 ° C, 160 ° C to 181 ° C, 160 ° C to 180 ° C, and the like. Although anthraquinones and trioctyl phosphate are effluent, the distillation of by-products is preferred at low distillation temperatures.

The distillation in the second distillation step is preferably continued from the viewpoint of recovery of the anthraquinone stream and the like until the outflow is eliminated. The average residence time in the second distillation step is not particularly limited, but may be, for example, 1 hour or more. The term " residence time " means a time from the start to the stopping of the distillation or extraction in the distillation step, and the " average residence time " It means simple arithmetic mean of stay time. The average residence time in the second distillation step may be, for example, in the range of 1 hour to 10 hours, or in the range of 6 hours to 10 hours. By setting the average residence time to 1 hour or more, the recovery rate of the anthraquinone is increased, and the anion of the anthraquinone-derived byproducts is converted into the anthraquinone having the hydrogen peroxide function, and the anthraquinone having the hydrogen peroxide- There is an advantage that the amount of the pesticide is increased. For example, the byproduct tetrahydroanthraquinone epoxide can be converted to tetrahydroanthraquinone having hydrogen peroxide function.

The anthraquinones and trioctyl phosphate exiting in the second distillation step are recycled as components of the regeneration working solution.

The apparatus used in the distillation step is not particularly limited as long as it is capable of distillation at a predetermined temperature and pressure, and examples thereof include a batch distillation apparatus, a continuous distillation apparatus, and a thin film distillation apparatus. A distillation apparatus usable in both the first distillation step and the second distillation step is preferable from the viewpoint of cost and the like.

In one embodiment, the hydrogen peroxide producing method of the present invention further comprises a step of separating the anthraquinones and trioctyl phosphate from the effluent of the second distillation step. Separation of anthraquinones and trioctylphosphate can be carried out by recrystallizing anthraquinones. Recrystallization of anthraquinones can be carried out by heating and dissolving anthraquinones in a recrystallization solvent and cooling them. After recrystallization, recrystallized anthraquinone can be recovered and reused. The trioctyl phosphate separated from the anthraquinones can be separated and recycled from the recrystallization solvent by distillation or the like. As the recrystallization solvent, it is preferable that the difference between the solubility at the time of heating and the solubility at the time of cooling of the anthraquinone is large. Examples of recrystallization solvents include alcohol solvents (e.g., lower alcohol such as methanol, ethanol, propanol, isopropanol, butanol, tert-butanol, 2-ethylhexanol and the like) Solvents (aromatic hydrocarbons, etc.) and polar solvents (TOP, diisobutylcarbinol, tetrabutylurea, methylcyclohexyl acetate, etc.). The recrystallization solvent may be a single kind of solvent or a mixture of plural kinds of solvents. The amount of the recrystallization solvent relative to the working solution is preferably such that the recrystallization of the anthraquinones is satisfactory. For example, the volume of the solvent per unit weight of the working solution (for example, g / ml) , 2 to 15 times, 3 to 10 times, 4 to 8 times, and so on. By including a step of separating anthraquinones from trioctyl phosphate, anthraquinones can be recovered in a more pure form. Therefore, the concentration of by-products contained in the regeneration working solution can be further reduced.

The crude regeneration working solution in the working solution regeneration step can be prepared by mixing the aromatic hydrocarbon recovered in the first distillation step with anthraquinones and trioctyl phosphate recovered in the second distillation step. In an embodiment involving the step of separating the anthraquinones and the trioctyl phosphate from the effluent of the second distillation step, the crude regeneration working solution is prepared by mixing the aromatic hydrocarbon recovered in the first distillation step with the aromatic hydrocarbons recovered in the second distillation step Followed by mixing separately recovered anthraquinones and trioctyl phosphate. In the present specification, the crude regeneration working solution means a regeneration working solution containing an aromatic hydrocarbon recovered in the distillation step, trioctyl phosphate, and anthraquinone, before the alkali cleaning is carried out.

When the solvent composition ratio in the working solution changes, the density, viscosity, distribution coefficient, etc. of the working solution also change. When these parameters are changed, it is necessary to change operating conditions and facilities of each step, which is not preferable from the viewpoint of stable production of hydrogen peroxide. Therefore, the solvent composition ratio of the regeneration working solution is preferably adjusted to a value close to that of the working solution in the circulation process. For example, the solvent composition ratio (%) of the regeneration working solution is preferably adjusted within ± 20% points, preferably within ± 10% points, more preferably ± 5% points with respect to the working solution of the circulation process (Provided that the sum of the solvent composition ratios after the adjustment does not exceed 100%). That is, when the solvent of the working solution is composed of aromatic hydrocarbons and trioctyl phosphate and the solvent composition ratio (volume ratio) in the circulation process is aromatic hydrocarbon: trioctyl phosphate = 70%: 30% , It is preferable to adjust the amount of water to 90%: 10% to 50%: 50%, preferably 80%: 20% to 60%: 40%, more preferably 75%: 25% to 65%: 35%.

In an actual plant, since the concentration of the anthraquinone of the working solution during the circulation process decreases over time, the operation is carried out while appropriately supplementing the new anthraquinone. In order not to lower the concentration of the anthraquinone in the circulating process, the concentration of the anthraquinone in the regeneration working solution may be the same as that of the circulating process, or the concentration of the anthraquinone in the circulating process may be lower than the concentration of the anthraquinone, . For example, in a working solution containing an aromatic hydrocarbon, trioctylphosphate, ethyl anthraquinone and ethyltetrahydro anthraquinone, the total concentration of ethyl anthraquinone and ethyl tetrahydroanthraquinone in the regeneration working solution is preferably 0.1 to 1.4 mol / l, preferably 0.3 to 1.2 mol / l, and more preferably 0.5 to 1.0 mol / l.

In the preparation of the crude regeneration working solution, in addition to the components recovered in the distillation step, one or more of aromatic hydrocarbons, trioctylphosphate and anthraquinones derived from other sources may be mixed. In certain embodiments, aromatic hydrocarbons, trioctylphosphate and / or anthraquinones derived from other sources are either commercially available or newly synthesized.

In the circulating regeneration working solution preparing step, the crude regeneration working solution obtained in the working solution regeneration step is alkali-washed to prepare a regeneration working solution for circulation. The regenerating working solution for circulation means a regenerating working solution which is particularly suitable for use in a circulation process after alkaline cleaning.

The alkali washing can be carried out by washing the crude regeneration working solution with an alkaline aqueous solution or the like. The alkali to be contained in the alkali aqueous solution is preferably an alkali metal. The alkali metal used in the cleaning may be an alkali metal of Group Ia of the periodic table, but lithium, sodium or potassium is preferable. Examples of the reagent include sodium hydroxide, sodium hydroxide, sodium bicarbonate, sodium bicarbonate, sodium dibasic phosphate, sodium borate, sodium nitrite, sodium borate, sodium hydrogen phosphate, sodium silicate, Potassium carbonate, potassium hydrogen carbonate, potassium carbonate, potassium cyanide, potassium phenoxide, potassium hydrogen phosphate, potassium diphosphate, potassium tartrate and the like may be added to the aqueous solution of the organic acid such as sodium carbonate, potassium carbonate, sodium carbonate, . The component contained in the aqueous alkali solution is preferably lithium hydroxide, sodium hydroxide, sodium carbonate, sodium hydrogencarbonate or potassium hydroxide, more preferably sodium hydroxide, sodium carbonate, sodium hydrogencarbonate or potassium hydroxide, Sodium carbonate, sodium bicarbonate, and the like. The pH of the alkali aqueous solution containing an alkali metal is preferably 8 or more, more preferably 10 or more, and particularly preferably 12 or more.

The contact between the bath for regeneration working solution and the aqueous alkaline solution can be carried out, for example, by bringing it into contact with an aqueous alkali solution of 0.2 parts by volume or more with respect to 1 part by volume of the crude regeneration working solution. Preferably, the crude regeneration working solution is brought into contact with an aqueous alkali solution of 0.3 times or more by volume. As a method of bringing into contact, generally known mixing means can be used. Examples of the method include, but are not limited to, stirring, shaking, bubbling with an inert gas, cocurrent flow, and alternating current contact, but the method is not limited thereto and may be a method capable of efficiently bringing the crude regeneration working solution into contact with an aqueous alkaline solution. There is no upper limit that is important for the capacity of the aqueous alkaline solution to be brought into contact, and can be appropriately selected depending on the conditions of the apparatus and the operation to be brought into contact.

The contact time of the crude regeneration working solution and the aqueous alkali solution is, for example, at least 1 minute, more preferably at least 3 minutes, particularly preferably at least 5 minutes, but can be appropriately selected depending on the conditions of the apparatus and the operation . The contact temperature of the crude regeneration working solution and the aqueous alkali solution is, for example, in the range of 0 ° C to 70 ° C, preferably 10 ° C to 60 ° C, particularly preferably 20 ° C to 50 ° C. The pressure during the contact treatment of the bath regeneration working solution and the aqueous alkaline solution is not particularly limited, but is preferably maintained at normal pressure. The contacted aqueous alkaline solution is discharged separately from the crude regeneration working solution. The alkali washing may be carried out one or more times, for example, once, twice or three times or more.

By alkaline washing the regeneration working solution, the hydrogenation activity of the regeneration working solution can be enhanced as compared with the case of washing with water alone. In addition, when the crude regeneration working solution contains acidic impurities, there is an advantage that acidic impurities can be removed by alkali washing.

In one embodiment, in the recycling regeneration working solution preparing step, the water content of the crude regeneration working solution is adjusted to 20% to 160% of the saturated water content. In the hydrogenation process during the hydrogen peroxide production process, the water content of the working solution is considered to be preferably about 50% to about 95% of the saturation concentration at the hydrogenation temperature. The crude regeneration working solution prepared from the effluent recovered in the distillation process tends to have a low water content and a low rate of hydrogenation reaction. Therefore, it is preferable that the circulating regeneration working solution returned to the circulation process has a water content larger than that of the crude regeneration working solution. By rinsing the crude regeneration working solution with an aqueous alkali solution, the water content of the regeneration working solution can be increased to around the saturated water amount. When the desired range of water content is not reached in the alkali washing, the water content can be adjusted by dehydration treatment, addition of water, washing with water, or the like.

In the circulating regeneration working solution preparing step, in addition to the alkali washing, washing with water may be carried out. As the water used for washing, water purified by distilled water, ion-exchanged water, reverse osmosis method or the like is preferable, but purified water other than the above-mentioned method is also preferably used. In particular, pure water is preferable as the water used for washing. The cleaning with water can be carried out in the same manner as in the alkali cleaning, except that water is used as the cleaning medium. Therefore, the volume of water for the crude regeneration working solution, the contact method with the crude regeneration working solution, the contact time, the contact temperature, the contact pressure and the like are the same as those described above for the alkali cleaning. The cleaning with water may be performed before or after the alkali cleaning, or both before and after the cleaning. The washing with water may be carried out more than once, for example, once, twice or three times or more.

In the recycle working solution preparation process, in addition to the alkali washing, a treatment with a regenerating catalyst for regenerating anthraquinones from by-products derived from anthraquinones may be carried out. The treatment with the regenerated catalyst can be carried out by passing the regeneration working solution before the alkali washing or after the alkali washing through a fixed bed or a fluidized bed containing the regenerated catalyst. It is preferable to circulate and circulate the liquid because the liquid may be insufficient once. As the regenerating catalyst, activated alumina or silica alumina is preferable, and activated alumina is more preferable. The surface area and particle diameter of the regenerated catalyst are appropriately selected depending on the reaction conditions and apparatus, but are not particularly limited. The reaction temperature is preferably in the range of 0 占 폚 to 200 占 폚, more preferably 50 占 폚 to 150 占 폚. Further, as the reaction progresses, hydroquinones accumulate and the progress of the partial regeneration reaction becomes slow. Therefore, it is preferable to oxidize the hydroquinones by bringing them into contact with oxygen or air during the circulating passage. Alternatively, hydrogen peroxide generated at this time may be removed sequentially.

In one embodiment, the hydrogen peroxide manufacturing method of the present invention includes a step of returning the recycle working solution for circulation to the hydrogen peroxide manufacturing process. The recycle working solution for circulation can be returned to any one or more of the hydrogenation process, the oxidation process, and the extraction process included in the hydrogen peroxide production process. Here, returning to a certain process means returning to an arbitrary step from the step from the end of the process before the process to the step before the end of the process. For example, returning the recycle regeneration working solution to the hydrogenation process means that the recycle regeneration working solution is removed from the regeneration process at any stage from the end of the extraction process until the end of the hydrogenation process (e.g., The outlet of the extraction device or the inlet of the hydrogenation device). In certain embodiments, the recycle regeneration working solution is returned to the hydrogenation process. This embodiment is advantageous in that it can utilize the high hydrogenating activity of the recycle working solution for circulation. As a concrete example of this embodiment, there can be mentioned, for example, mixing a regeneration working solution for circulation and a working solution in circulation immediately before a hydrogenation apparatus (hydrogenation tower), and introducing the resulting mixed solution into a hydrogenation apparatus. In another specific embodiment, the recycle working solution for circulation is returned to the oxidation and / or extraction processes. This aspect is advantageous when the water content of the recycling regeneration working solution is low.

Another aspect of the present invention is a method for removing hydrogen peroxide from an operating solution for producing hydrogen peroxide comprising an aromatic hydrocarbon, trioctyl phosphate, anthraquinones, and an inert material produced as a result of generation of hydrogen peroxide, An operation solution regeneration step of regenerating the crude regeneration working solution from which the crude regeneration working solution has been removed; and an alkaline regeneration step of regenerating the regeneration regeneration working solution to prepare a regeneration working solution for circulation,

Wherein the working solution regeneration step comprises the steps of: i) a first distillation step for recovering aromatic hydrocarbons by distillation at atmospheric pressure or below; and ii) a second distillation step for distilling the anthraquinones and the tri And a second distillation step of recovering octylphosphate (hereinafter sometimes referred to as " the method for producing a recycle working solution for circulation of the present invention ").

The characteristics of each step of the recycling regeneration working solution manufacturing method of the present invention are the same as the corresponding steps in the hydrogen peroxide producing method of the present invention.

Another aspect of the present invention is a process for producing hydrogen peroxide by oxidizing a working solution containing an aromatic hydrocarbon, trioctyl phosphate and anthraquinones after hydrogenation, extracting the hydrogen peroxide from the working solution, A hydrogen peroxide production process for circulating the solution back to the hydrogenation process, an operation solution regeneration process for removing the inactive substance produced as a result of the generation of the hydrogen peroxide from the operation solution to prepare a regeneration operation solution, Water or an alkali to prepare a recycle working solution for circulation,

Wherein the working solution regeneration step comprises the steps of: i) a first distillation step for recovering aromatic hydrocarbons by distillation at atmospheric pressure or below; and ii) a second distillation step for distilling the anthraquinones and the tri And a second distillation step of recovering octyl phosphate (hereinafter sometimes referred to as " hydrogen peroxide production method A of the present invention "). This embodiment is the same except that the method for producing hydrogen peroxide of the present invention and the alkaline cleaning of the crude regeneration working solution are not essential and that they can be replaced by washing with water. As shown in Example 4, even if the crude regeneration working solution is washed with water, the hydrogenation activity of the regeneration working solution containing trioctyl phosphate can be improved as compared with the working solution in circulation. The above description related to the hydrogen peroxide producing method of the present invention also applies to the hydrogen peroxide producing method A of the present invention under the condition that the alkali washing is not essential.

Another aspect of the present invention is a method for removing hydrogen peroxide from an operating solution for producing hydrogen peroxide comprising an aromatic hydrocarbon, trioctyl phosphate, anthraquinones, and an inert material produced as a result of generation of hydrogen peroxide, A recovering working solution for circulation is prepared by washing the crude recovery working solution with water or an alkali to prepare a recovery working solution for circulation,

Wherein the working solution regeneration step comprises the steps of: i) a first distillation step for recovering aromatic hydrocarbons by distillation at atmospheric pressure or below; and ii) a second distillation step for distilling the anthraquinones and the tri (Hereinafter sometimes referred to as " recycling regeneration working solution preparation method A of the present invention "), characterized by having a second distillation step for recovering octyl phosphate.

The features of each step of the recycling working solution preparation method A of the present invention are the same as those of corresponding steps in the hydrogen peroxide producing method A of the present invention.

Another aspect of the present invention is a method for producing hydrogen peroxide by oxidizing a working solution containing an aromatic hydrocarbon, a polar solvent and an anthraquinone after hydrogenation, extracting the hydrogen peroxide from the working solution, extracting the hydrogen peroxide from the working solution An operation solution regeneration step of removing an inert material produced as a result of the generation of hydrogen peroxide from the working solution to prepare a regeneration working solution; To prepare a recycle working solution for circulation,

Wherein the working solution regeneration step comprises the steps of: i) a first distillation step for recovering the aromatic hydrocarbons by distillation at atmospheric pressure or below; and ii) a second step for distilling the anthraquinones And a polar solvent is recovered in a first distillation step or a second distillation step (hereinafter referred to as " hydrogen peroxide producing method B of the present invention " have). This embodiment differs from the hydrogen peroxide producing method of the present invention in that the polar solvent contained in the working solution is not specified by trioctyl phosphate and that the polar solvent is recovered in the first distillation step or the second distillation step same. As shown in Example 4, by alkaline washing the crude regeneration working solution, it is possible to improve the hydrogenating activity of the resulting regeneration working solution, as compared with the case of washing with water, but this is because the operation including the polar solvent other than trioctylphosphate Solution. The above description related to the hydrogen peroxide production method of the present invention is based on the assumption that the polar solvent is not specified in trioctyl phosphate and the polar solvent is recovered in either the first distillation step or the second distillation step, Method B also applies.

The polar solvent in the hydrogen peroxide producing method B of the present invention is not particularly limited as long as it can dissolve anthrahydroquinones, and examples thereof include alcohols (for example, diisobutylcarbinol (DIBC), 2- Octanoyl), 4-substituted ureas (e.g., tetrabutylurea (TBU), phosphoric acid esters (e.g., trioctylphosphate), 2-pyrrolidone or alkylcyclohexylacetates (e.g., methylcyclohexyl Acetate (MCHA)) and the like. The distillation step in which the polar solvent is recovered can be appropriately determined depending on the kind of the polar solvent. For example, DIBC or 2-octanol can be recovered in the first distillation process, and TOP or TBU can be recovered in the second distillation process.

Another aspect of the present invention is a method for removing hydrogen peroxide from an operating solution for producing hydrogen peroxide comprising an aromatic hydrocarbon, a polar solvent, an anthraquinone, and an inert material produced as a result of generation of hydrogen peroxide, A regeneration working solution preparation process for preparing a regeneration working solution which has been removed, and an alkaline cleaning process for the above-mentioned regeneration working solution to prepare a regeneration working solution for circulation,

Wherein the working solution regeneration step comprises the steps of: i) a first distillation step for recovering the aromatic hydrocarbons by distillation at atmospheric pressure or below; and ii) a second step for distilling the anthraquinones And a polar solvent is recovered in a first distillation step or a second distillation step (hereinafter referred to as " recycling regeneration operation of the present invention Solution manufacturing method B ").

The characteristics of each step of the recycling working solution preparation method B of the present invention are the same as those of corresponding steps in the hydrogen peroxide production method B of the present invention.

Another aspect of the present invention relates to a hydrogen peroxide producing system comprising a distillation column, a preparation bath, a washing tank, a hydrogenation column, an oxidation column and an extraction column (hereinafter sometimes referred to as "hydrogen peroxide production system of the present invention"). The hydrogen peroxide producing system of the present invention may further comprise a shear distillate effluent tank and / or a rear end distillate effluent tank in addition to the above. One embodiment of the hydrogen peroxide producing system of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic view of a distillation tower 1, a preparation 2, a washing tank 3, a hydrogenation tower 4, an oxidation tower 5, an extraction tower 6, a shear distillation effluent tank 9, A hydrogen peroxide production system A of the present invention having an effluent tank 10 is described. The distillation column 1 has an unknown waste discharge line 8 and an effluent transport line 7 and the effluent transport line 7 and the shear distillate effluent tank 9 are connected to a shear distillation effluent transport line 7a The distillation effluent transport line 7 and the after-distillation effluent effluent tank 10 are communicated by the after-distillation effluent transport line 7b, 2 is communicated by a shear distillation effluent feed line 11 and the latter distillation effluent tank 10 and preparation 2 are communicated by a latter distillation effluent feed line 12, And the washing tub 3 are communicated by the bath regeneration working solution supply line 13. The alkaline solution supply line 14 and the water supply line 15 are connected to the washing tub 3, 3 has a waste liquid line 17 and the cleaning tank 3 and the hydrogenation tower 4 are communicated by the circulating regeneration working solution supply line 16 , The hydrogenation column 4 is provided with the hydrogenating agent supply line 19 and the hydrogenating agent circulation line 18 and the hydrogenation column 4 and the oxidation column 5 are communicated by the hydrogenation working solution supply line 20 And the oxidation tower 5 has an oxidant supply line 21 and an exhaust line 22. The oxidation tower 5 and the extraction tower 6 are communicated by the oxidation operation solution supply line 23, The distillation column 1 and the extraction column 6 are connected to each other by the working solution supply line 26 after the hydrogen peroxide extraction and the circulation regeneration The working solution supply line 16 and the working solution supply line 26 after the hydrogen peroxide extraction are communicated by the working solution circulation line 27 after the hydrogen peroxide extraction. The shear distillation effluent transport line 7a, the downstream distillation effluent transport line 7b, the unknown effluent discharge line 8, the shear distillation effluent supply line 11, the downstream distillation effluent supply line 12, A valve V is provided in the tank regeneration operation solution supply line 13, the alkaline solution supply line 14, the water supply line 15, the circulating regeneration working solution supply line 16 and the waste liquid line 17 have. The distillation column 1 can be subjected to reduced pressure distillation at various temperatures (for example, 120 ° C to 260 ° C) (for example, 0.1 to 15 ° C).

The working solution is supplied from the hydrogenation column 4 to the hydrogenating agent 32 (for example, a mixture of hydrogen gas, inert gas (nitrogen gas, etc.) and hydrogen gas) containing hydrogen from the hydrogenating agent supply line 19, And anthraquinones are generated from anthraquinones. The unreacted hydrogenating agent is supplied repeatedly to the hydrogenation column 4 via the hydrogenating agent circulation line 18. [ The hydrogenated working solution enters the oxidation column 5 through the hydrogenation working solution feed line 20 and is fed to the oxidizing agent 33 containing oxygen sent from the oxidant feed line 21 Air, oxygen gas, etc.) to generate anthraquinones and hydrogen peroxide. The unreacted oxidizing agent 34 is exhausted from the exhaust line 22. And the working solution containing hydrogen peroxide enters the extraction tower 6 through the oxidation working solution supply line 23 and the generated hydrogen peroxide is oxidized by the water 35 supplied from the water supply line 24 (36), and is recovered from the hydrogen peroxide transport line (25). After the hydrogen peroxide is extracted, a portion of the working solution enters the distillation column 1 after passing through the working solution feed line 26 after the extraction of hydrogen peroxide and the rest passes through the working solution circulation line 27 after the hydrogen peroxide extraction, (16) and returns to the hydrogenation tower (4).

The working solution after extraction of hydrogen peroxide into the distillation column 1 is provided for shear distillation at atmospheric pressure or lower. The shear distillation effluent containing aromatic hydrocarbons, which is effluent by shear distillation, passes through the effluent transport line 7 and the shear distillate effluent transport line 7a and is received in the shear distillate effluent tank 9. The residue remaining in the distillation column (1) is fed to a post-distillation at 160 ° C or higher at a pressure lower than the shear distillation. The anthraquinones and the late distillation effluent, which is distilled by the latter distillation and contains trioctyl phosphate, passes through the effluent transport line 7 and the latter distillate effluent transport line 7b and is fed to the latter distillation effluent tank 10 . Unknown fractions 28, which are residues after the latter distillation, are discharged from the unknown discharge line 8. The shear distillation effluent received in the shear distillation effluent tank 9 and the latter distillation effluent received in the latter distillation effluent tank 10 are fed to the shear distillation effluent feed line 11 and the downstream distillate effluent feed line 12, Respectively, and then enters the preparation tank 2 and mixed to prepare a crude regeneration working solution. The prepared crude regeneration working solution enters the washing tub 3 through the crude regeneration working solution supply line 13. The crude regeneration working solution is cleaned by the alkali solution 29 supplied from the alkali solution supply line 14 and then further washed by the water 30 supplied from the water supply line 15, And becomes a recycle working solution for circulation. The alkali solution or water used for washing is discharged from the waste liquid line 17 as waste liquid 31. [ The regeneration working solution for circulation passes through the circulating regeneration working solution supply line 16, merges with the working solution from the working solution circulation line 27 after the hydrogen peroxide is extracted on the way, and enters the hydrogenation column 4.

The hydrogen peroxide producing system of the present invention may further comprise a recrystallization tank. An outline of a hydrogen peroxide producing system B of the present invention having a recrystallization tank will be described with reference to Fig. In the hydrogen peroxide producing system B, the same constituents as those of the hydrogen peroxide producing system A shown in Fig. 1 are denoted by the same reference numerals, and a description thereof will be omitted.

In the present embodiment, the rear distillation effluent supply line 12 connected to the rear distillation effluent tank 10 is connected to the recrystallization tank 37 and connected to the anthraquinone supply line 12 connected to the recrystallization tank 37, (40) is connected to the preparation tank (2). A recrystallization solvent supply line 39, a waste solution line 41 and a filtrate transport line 42 are additionally connected to the recrystallization tank 37. The recrystallization solvent supply line 39 is connected to the recrystallization solvent tank 38, And the filtrate transport line 42 communicates the recrystallization tank 37 and the distillation column 1. In this case, The recrystallization solvent tank 38 is communicated with the effluent transport line 7 by the outflow recrystallization solvent transport line 7d and the preparatory production 2 is connected to the effluent transport line 7c by the effluent TOP transport line 7c. 7). The recrystallization tank 37 is provided with a temperature regulating device so that heating and dissolution of an anthraquinone in a recrystallization solvent and subsequent cooling can recrystallize anthraquinone. The recrystallization tank 37 is further provided with a filter so that the recrystallized anthraquinone can be separated by filtration.

In the present embodiment, the downstream distillation effluent received in the downstream distillation effluent tank 10 enters the recrystallization tank 37 through the downstream distillation effluent feed line 12. A recrystallization solvent is supplied from the recrystallization solvent supply line 39 to the recrystallization tank 37, and the anthraquinones contained in the subsequent distillation effluent are recrystallized by heating and dissolving the anthraquinones. The recrystallized anthraquinone is recovered by a filter provided in the recrystallization tank 37, passed through the anthraquinone supply line 40, and sent to the preparation tank 2. The filtrate containing the trioctyl phosphate and the recrystallization solvent which has passed through the filter is sent to the distillation column 1 through the filtrate transport line 42 or discarded from the waste liquid line 41. From the filtrate sent to the distillation column 1, the recrystallization solvent and the trioctyl phosphate are distilled separately by distillation. The recrystallized solvent flows through the effluent transport line 7 and the outflow recrystallization solvent transport line 7d, Is received in the solvent tank 38 and the effluent trioctyl phosphate is sent to the crude preparation 2 through the effluent transport line 7 and the effluent TOP transport line 7c.

The hydrogen peroxide producing system of the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, in the hydrogen peroxide producing system A shown in FIG. 1, (A1) the sheathed distillation effluent tank 9 and the shear distillation effluent transport line 7a connected thereto are not formed, and the effluent transport line (A2) the downstream distillation effluent tank (10) and the downstream distillation effluent transport line (7b) connected to the downstream distillation effluent effluent tank (10) (A3) the shear distillation effluent tank (9) and the front end connected to the distillation effluent outlet line (12) The distillation effluent transport line 7 and the crude distillation effluent transport line 7b without forming the distillation effluent transport line 7a and the downstream distillation effluent tank 10 and the downstream distillation effluent transport line 7b connected thereto, By a shear distillation effluent feed line (11) and a downstream distillation effluent feed line (12) (A4) an effluent transport line 7, a shear distillate effluent tank 9 and a shear distillate effluent transport line 7a connected thereto, a rear distillation effluent tank 10, The distillation column 1 and the crude product 2 are connected to each other by the shear distillation effluent supply line 11 and the subsequent distillation effluent supply line 12 without forming the downstream distillation effluent transport line 7b to be connected, , And so on.

In addition, in the hydrogen peroxide producing system B shown in FIG. 2, the hydrogen peroxide producing system A is provided with, for example, a (B1) filtrate transporting line 42 and an outflow recrystallization solvent (B2) an outflow TOP tank is formed, the effluent transport line (7) and the outflow TOP tank are communicated by the outflow TOP transport line (7c), and the outflow TOP tank and the outflow TOP tank (B3) the filter is not formed in the recrystallization tank 37, and the filter is formed in the middle of the anthraquinone supply line 40, or the like.

It is also possible to remove the valve from the line provided with the valve or to form a pump, an additional valve, or a branch line in at least one of the lines, if necessary, in any of the hydrogen peroxide producing systems A and B.

Hereinafter, the present invention will be described concretely with reference to examples, but the present invention is not limited thereto.

Example

<Analysis method>

Using a gas chromatograph analyzer, aromatic hydrocarbons, trioctylphosphate, 2-ethyl anthraquinone and 2-ethyltetrahydro anthraquinone in the working solution and the sample obtained by each operation were quantified. A gas chromatograph GC-2014 manufactured by Shimadzu Corporation was used as the gas chromatograph analyzer. As the column, a capillary column DB-5MS manufactured by Agilent was used. In addition, all substances other than the above-mentioned components are represented as &quot; unknown substances &quot;. Most of "unknown substances" are assumed to be inert substances.

The density of the initial working solution and the regenerating working solution for circulation was measured using a density ratio meter DA-640 manufactured by Kyoto Electronics Industrial Co., Ltd., and the viscosity was measured using a B-type viscometer manufactured by Tokyo Chemical Industry Co., Ltd.

The hydrogenation activity of the initial working solution and the recycle working solution for circulation was evaluated in the following manner. A hydrogenation catalyst and working solution were placed in a 100 ml two-necked flask. A stirrer was connected to one of the flasks, and the other was connected to the hydrogen supply part. The flask is sealed. The hydrogen supply section consisted of a hydrogen metering tube, a U-tube manometer, and a water-holding section. During the hydrogenation reaction, the flask pressure and the atmospheric pressure were kept the same by adjusting the height of the water storage section in accordance with the change of the liquid level of the U- The amount of hydrogen absorption was measured as a difference in liquid surface height in the hydrogen metering tube. The flask was immersed in a water bath at 30 캜 and allowed to stand for 10 minutes. After the exhaust and hydrogen introduction in the flask were repeated three times, the stirrer was operated. The amount of hydrogen absorption from the start of hydrogen absorption to the end of 30 minutes was measured. The amount of hydrogen absorption was converted to a value at 0 ° C and 1 atm. The activity value of the hydrogenation catalyst was expressed as a standard hydrogen absorption rate per unit weight of the hydrogenation catalyst [Nml / (min x g)]. For the hydrogenation catalyst, 0.05 g of 2 wt% Pd / silica dried at 120 캜 or 0.1 g of 1 wt% Pd / silica alumina dried at 120 캜 was used.

Example 1

The first distillation step and the second distillation step in the present invention were carried out on a small scale, and the initial working solution and the circulating regeneration working solution were compared.

&Lt; First Distillation Process &gt;

400 g of working solution was injected into a 500 ml flask equipped with a distillation apparatus. The distillation was carried out under reduced pressure, and the degree of vacuum was controlled at 1.3 시. The temperature in the flask was raised from room temperature to 182 ° C. Finally, the distillation was continued under the conditions of 1.3 ㎪ and 182 캜 until the effluent disappeared.

&Lt; Second Distillation Process &gt;

The residue obtained in the first distillation step was distilled at a lower pressure than the first distillation step. The degree of vacuum fluctuated between 0.03 ㎪ and 0.15 얼마 for some time from the start of distillation, but finally stabilized at 0.08.. The temperature in the flask was raised from room temperature to 202 占 폚. Finally, the distillation was continued until the effluent disappeared under the conditions of 0.08 ㎪ and 202 캜.

<Distillation result>

The composition of the initial working solution and the effluent and residues recovered by each distillation process are shown in Table 1. As aromatic hydrocarbons, high boiling point aromatic naphtha (Swazol 1500, CAS No. 64742-94-5, manufactured by Maruzen Petrochemical Co., Ltd.) was used (the same applies to Examples 2 to 4). Further, during distillation, various reactions occur, including dialysis to tetrahydroanthraquinone anthraquinone, so that some of the components have an increased weight than the initial working solution. In addition, &quot; loss minute &quot; indicates the amount of loss during the experiment (it is possible to consider a cold trap or a loss to the pump as a cause).

&Lt; Evaluation of circulating regeneration working solution >

A regeneration working solution was prepared from the effluent recovered in each distillation step. The oil of the first distillation step was added to the distillate of the second distillation step so as to have a solvent composition ratio close to that of the initial working solution to prepare a crude regeneration working solution. The composition of the initial working solution and crude recovery working solution was shown below.

The crude regeneration working solution was sequentially washed with twice the volume of a 30 wt% aqueous solution of sodium hydroxide and twice the volume of pure water to obtain a regenerated working solution for circulation. The results of comparing the density, viscosity and hydrogenation activity of the initial working solution and the recycle working solution for circulation are shown below. In addition, when evaluating the hydrogenation activity, 0.05 wt% of 2 wt% Pd / silica dried at 120 ° C was used as the hydrogenation catalyst.

<Isolation of Anthraquinones>

Approximately 200 ml of ethanol was added to 32 g of the effluent from the second distillation step, dissolved by heating, and then cooled to room temperature (recrystallization). The crystals were separated by filtration and dried. The composition of the effluent from the second distillation step and the crystal recovered by recrystallization are shown below. Anthraquinones could be separated from the trioctyl phosphate and the unknown at a recovery of 64%. In this way, the recovered anthraquinone can be reused as a component of the working solution.

Example 2

The first distillation step and the second distillation step in the present invention were carried out under conditions different from those in Example 1, and the initial working solution and the circulating regeneration working solution were compared.

&Lt; First Distillation Process &gt;

351 g of working solution was injected into a 500 ml flask equipped with a distillation apparatus. Distillation was carried out under reduced pressure, and the degree of vacuum was controlled at 1.3 시. The temperature in the flask was raised from room temperature to 157 占 폚. Finally, the distillation was continued under the conditions of 1.3 ㎪ and 157 캜 until the effluent disappeared.

&Lt; Second Distillation Process &gt;

The residue obtained in the first distillation step was distilled at a lower pressure than the first distillation step. The degree of vacuum fluctuated between 10 Pa and 150 Pa for a while from the start of distillation, but finally stabilized at 0.01 to 0.04 Pa. The temperature in the flask was raised from room temperature to 181 ° C. Finally, the distillation was continued under the conditions of 0.01 ㎪ and 181 캜 until the effluent disappeared.

<Distillation result>

The composition of the initial working solution and the effluent and the residue recovered by each distillation process are shown in Table 5. &lt; tb &gt; &lt; TABLE &gt;

In the same manner as in Example 1, a crude regeneration working solution was prepared. Table 6 shows the composition of the initial working solution and crude recovery working solution.

By the same cleaning step as in Example 1, a recycle working solution for circulation was prepared. Table 7 shows the comparison of the density, viscosity and hydrogenation activity of the initial working solution and the recycle working solution for circulation. In addition, when evaluating the hydrogenation activity, 0.1 g of 1 wt% Pd / silica alumina dried at 120 캜 was used as the hydrogenation catalyst.

Example 3

The first distillation step and the second distillation step in the present invention were conducted under different conditions from those of Examples 1 and 2, and the initial working solution and the recycle working solution for circulation were compared.

&Lt; First Distillation Process &gt;

351 g of the same working solution as in Example 2 was injected into a 500 ml flask equipped with a distillation apparatus. The distillation was carried out under reduced pressure, and the degree of vacuum was controlled at 1.3 시. The temperature in the flask was raised from room temperature to 180 占 폚. Finally, the distillation was continued under the conditions of 1.3 ㎪ and 180 캜 until the effluent disappeared.

&Lt; Second Distillation Process &gt;

The residue obtained in the first distillation step was distilled at a lower pressure than the first distillation step. The degree of vacuum was controlled to 0.13 시 at the start. The temperature in the flask was raised from room temperature to 250 &lt; 0 &gt; C. Finally, the distillation was continued until the effluent disappeared under the conditions of 0.13 ㎪ and 250 캜.

<Distillation result>

The composition of the initial working solution and the effluent and residues recovered by each distillation process are shown in Table 8. &lt; tb &gt; &lt; TABLE &gt;

In the same manner as in Example 1, a crude regeneration working solution was prepared. Table 9 shows the composition of the initial working solution and crude recovery working solution.

By the same cleaning step as in Example 1, a recycle working solution for circulation was prepared. Table 10 shows the comparison of density, viscosity and hydrogenation activity. In addition, when evaluating the hydrogenation activity, 0.1 g of 1 wt% Pd / silica alumina dried at 120 캜 was used as the hydrogenation catalyst.

Example 4

The crude regeneration working solution prepared in Example 2 was washed twice with pure water twice the volume of volume to obtain a regeneration working solution for circulation (pure washing). A hydrogenation activity test was conducted in the same manner as in Example 2. For the hydrogenation catalyst, 0.1 g of 1 wt% Pd / silica alumina dried at 120 &lt; 0 &gt; C was used. Table 11 shows the results of the hydrogenation activity test. The hydrogenation activity of the recycled working solution for pure recycling only was higher than that of the initial working solution, but the activity of hydrogenation was higher for the alkaline cleaned recycle working solution (Example 2).

1: Distillation tower
2: Manufacturing
3: Cleaning tank
4: hydrogenation tower
5: Oxidation tower
6: Extraction tower
7: Spillway transport line
7a: shear distillation effluent transport line
7b: downstream distillation effluent transport line
7c: Spill TOP transport line
7d: Outflow recrystallization solvent transport line
8: Unknown discharge line
9: Shear distillate effluent tank
10: distillation effluent tank
11: Shear distillation effluent supply line
12: Later-stage distillation effluent feed line
13: regeneration operation liquid supply line
14: alkali solution supply line
15: Water supply line
16: regeneration working solution supply line for circulation
17: waste liquid line
18: Hydrogenating agent circulation line
19: Hydrogenating agent supply line
20: hydrogenation working solution supply line
21: oxidant supply line
22: Exhaust line
23: Oxidation working solution supply line
24: Water supply line
25: hydrogen peroxide transport line
26: Operation solution supply line after hydrogen peroxide extraction
27: Working solution circulation line after hydrogen peroxide extraction
28: Unknown person
29: Alkali solution
30: water
31: Waste solution
32: hydrogenating agent
33: oxidizing agent
34: Unreacted oxidizing agent
35: water
36: hydrogen peroxide water
37: Recrystallization tank
38: Recrystallization solvent tank
39: Recrystallization solvent supply line
40: Anthraquinone supply line
41: waste liquid line
42: filtrate transport line
V: Valve

Claims (16)

Hydrogen peroxide is produced by oxidizing the working solution containing aromatic hydrocarbons, trioctyl phosphate and anthraquinones after hydrogenation, the hydrogen peroxide is extracted from the working solution, and the working solution after extracting the hydrogen peroxide is returned to the hydrogenation process and circulated An operation solution regeneration step of removing an inert material produced as a result of the generation of hydrogen peroxide from the working solution to prepare a crude regeneration working solution from which the inactive material has been removed; Alkaline cleaning to prepare a recycle working solution for circulation,
Wherein the working solution regeneration step comprises the steps of: i) a first distillation step for recovering aromatic hydrocarbons by distillation at atmospheric pressure or below; and ii) a second distillation step for distilling the anthraquinones and the tri And a second distillation step for recovering octyl phosphate. The method according to claim 1,
Wherein the pressure in the first distillation step is within a range of 1 to 100 mu m. 3. The method according to claim 1 or 2,
Wherein the pressure in the second distillation step is 1 GPa or less. 4. The method according to any one of claims 1 to 3,
Wherein the temperature in the second distillation step is within a range of 160 占 폚 to 300 占 폚. 5. The method according to any one of claims 1 to 4,
Wherein the anthraquinone comprises alkyl anthraquinone and alkyltetrahydro anthraquinone. 6. The method according to any one of claims 1 to 5,
And returning the recycle working solution for circulation to the hydrogen peroxide production process. The method according to claim 6,
Wherein the solvent composition ratio of the crude regeneration working solution is within a range of 20% with respect to the solvent composition ratio of the working solution circulating in the hydrogen peroxide production process. 8. The method according to claim 6 or 7,
Wherein the concentration of the anthraquinone in the crude regeneration working solution is within a range of not more than the concentration of the anthraquinone in the working solution circulating in the hydrogen peroxide producing process and not more than the saturation concentration of the anthraquinone. 9. The method according to any one of claims 6 to 8,
Wherein the regeneration working solution is adjusted to 20% to 160% of the saturated water content in the recycling regeneration working solution preparing step. 10. The method according to any one of claims 6 to 9,
Wherein the recycling regeneration working solution preparing step further comprises washing the regeneration working solution after the alkali washing. 11. The method according to any one of claims 1 to 10,
Further comprising the step of separating the anthraquinones and the trioctyl phosphate from the effluent of the second distillation step. 12. The method of claim 11,
Wherein the step of separating the anthraquinones from the trioctyl phosphate is carried out by recrystallization. A system for producing hydrogen peroxide comprising a distillation column, a distillation column, a scrubber, a hydrogenation column, an oxidation column and an extraction column, wherein the distillation column has an unknown column discharge line and the distillation column is combined with a shear distillation effluent feed line, And the cleaning tank is connected to the alkaline solution supply line and the water supply line, the cleaning tank is provided with a waste solution line, and the cleaning solution is supplied to the cleaning solution supply line, The hydrogenation column and the oxidation column are communicated by the hydrogenation operation solution supply line and the oxidation column is connected to the oxidizing agent supply line And the oxidation column and the extraction column are connected by an oxidation operation solution supply line, the extraction column is provided with a hydrogen peroxide transport line, Wherein the tower is communicated by a working solution feed line after hydrogen peroxide extraction. 14. The method of claim 13,
Wherein the distillation column and the shear distillation effluent tank are communicated by a shear distillate effluent transport line and the shear distillate effluent tank and the preparation are communicated by a shear distillate effluent feed line , Hydrogen peroxide manufacturing system. 14. The method of claim 13,
The distillation column and the distillation distillation effluent tank are communicated by a subsequent distillation effluent transport line and the latter distillation effluent tank and the preparation are communicated by a latter distillation effluent feed line , Hydrogen peroxide manufacturing system. 14. The method of claim 13,
Wherein the recrystallization tank and the distillation column are connected to each other by a downstream distillation effluent supply line, the recrystallization tank and the refining column are connected to each other by an anthra Wherein the hydrogen peroxide production system is in communication with the quinone supply line.

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