KR100204259B1 - A purification method of hydrogen peroxide - Google Patents

Abstract

The present invention relates to a method for purifying a working solution for the production of hydrogen peroxide, and more particularly to a method for purifying an operating solution for producing hydrogen peroxide using anthraquinone as an active material, And then extracting the polar and nonpolar inerts contained in the distillation residue with a mixture of acyclic hydrocarbons and alcohols. The present invention also relates to an improved method of purifying anthraquinone functional solutions for the production of hydrogen peroxide.

Description

Method for purifying the working solution for the production of hydrogen peroxide

The present invention relates to a method for purifying a working solution for hydrogen peroxide and more particularly to a method for purifying a working solution for hydrogen peroxide, the present invention relates to a method for purifying a working solution for producing hydrogen peroxide which can improve the productivity of hydrogen peroxide and improve the purity of the produced hydrogen peroxide.

The production of hydrogen peroxide using 2-alkyl anthraquinone is generally carried out in an organic solution called the working solution. That is, in the presence of a catalyst, the 2-alkyl anthraquinone reacts with hydrogen to produce the corresponding hydroquinone, and when the catalyst is removed, the hydroquinone is reacted with oxygen to produce quinone and hydrogen soxide.

Since the working solvent and some of the working materials constituting the working solution deteriorate due to the repeated reduction / oxidation process, over time, the working solution decreases in productivity due to the decrease of the active quinone and the increase of the process inhibitor. Accordingly. In order to maintain the composition of the working solution within the set limits, the inert material should be removed and the working solution should be supplemented in small increments.

A study on the purification of the working solution for the production of hydrogen peroxide which removes the inactive substance includes Canadian Patent No. 664, 876 which extracts water-soluble inactive substance by using pure water, and Patent No. 4 , 668 and 436. However, these extraction methods have a problem that the removal efficiency is low and it is impossible to simultaneously remove the polar and non-polar materials. U.S. Pat. Nos. 3,179,672, 1,335,700 and 1,667,476 disclose that an inert substance for the production of hydrogen peroxide is distilled and then an inert material is extracted using various solvents or recycled after recrystallization from methanol However, these methods also have limitations in the removal of nonpolar materials.

Also, British Patent Nos. 1,228,494 and 1,252,822 and German Patent 2,012,988 disclose a method in which an active material is reduced or distilled with hydroquinone and then the residue is recrystallized using various organic solvents, and a method in which an ion- However, these methods have a disadvantage in that the purification process is complicated and the recovery cost is high.

It is therefore an object of the present invention to provide a process for the preparation of hydrogen peroxide by removing all of the polar and nonpolar inert materials in the working solution for hydrogen peroxide and distilling the working solution to increase the recovery of the active substance and the working solvent and then mixing the distillation residue with a mixture of a polar solvent and a non- And a method for purifying an action solution for hydrogen peroxide production that can be extracted by using the method of the present invention.

In order to accomplish the above object, the present invention provides a method for purifying a working solution for hydrogen peroxide production using anthraquinone as an active material, comprising the steps of: distilling the working solution used to recover the working solvent; Characterized by the extraction of polar and nonpolar inerts contained in the distillation residue with a mixture of acyclic hydrocarbons and alcohols.

FIG. 1 is a diagram for explaining a purification method of the present invention in which an active solution used in an anthraquinone process is purified and reused.

DESCRIPTION OF THE REFERENCE NUMERALS

1: extractor

2, 4, 6, 8, 10, 12, 15, 17, 18, 20, 24, 25,

3, 16: Retortor 5: Vacuum pump

7, 19: condenser 9: mixer

11: cooler 13: filter

14: air 21: extract liquid storage tank

22, 23: Extraction solvent storage tank 27: Working solution storage tank

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to the accompanying drawings. As a result of analyzing the components of the working solution for the production of hydrogen peroxide using 2-ethylcyclohexyl acetate and an alkylbenzene mixture having 9-10 carbon atoms as the working solvent, Are known to be composed of the benzyl alcohols represented by the formula (1) produced by the oxidation of alkylbenzene as the working solvent, the tetrahydronaphthol represented by the formula (2), and various kinds of 2-ethyl anthraquinone derivatives oxidized or reduced I got it.

Wherein Rn is _{R = CH 3, n = 2} , 3.

U.S. Pat. No. 3,767,779 describes that such inactive agents can be present up to 15% in the working solution because they can increase the solubility of the agent, but U.S. Pat. No. 4,668,436 discloses that inactive materials Accumulation increases specific gravity and viscosity and causes problems in oxidation / reduction reaction and extraction.

In addition to the above-mentioned problems, the increase of the inert active substances and the benzyl alcohols leads to an increase in the total organic matter content in the extracted hydrogen peroxide as well as an increase in the interfacial formation time between water and the working solution by forming an emulsion upon extraction, Purity is lowered. Accordingly, the present invention relates to a purification process for removing an inert material during a hydrogen peroxide production process, and it is an object of the present invention to provide a purification process capable of removing both polar and non- Benzyl alcohol and an operating solvent for reducing the production of an inert solvent which is converted to tetrahydronaphthol. In the present invention, in order to remove both the polar and non-polar inert substances in the working solution for hydrogen peroxide production and distillation of the working solution to increase the recovery rate of the working substance and the working solvent, the distillation residue is extracted using a mixture of a polar solvent and a non- ≪ / RTI > Meanwhile, the mixing ratio of the polar and non-polar extraction solvent used here depends on the polarity of the working solution and the composition ratio of the non-polar inactive material. As a method for increasing the purity of the recovered solvent and reducing the generation of inert solvent, The temperature and distillation pressure are controlled to minimize the recovery of the working solvent, which is highly likely to be converted to the inert working solvent and the inert working solvent.

Briefly, the method for purifying the working solution for the production of hydrogen peroxide according to the present invention is characterized in that in the method for purifying the working solution for the production of hydrogen peroxide using anthraquinone as the working substance, the working solution is distilled under reduced pressure to recover the working solvent, It is characterized by the extraction and re-use of polar and non-polar inert materials contained with a mixture of acyclic hydrocarbons and alcohols.

The process for purifying the working solution for hydrogen peroxide according to the present invention will now be described in more detail. First, an anthraquinone is reacted with an active substance, 2-methylcyclohexyl acetate and an alkylbenzene mixture having 9 to 10 carbon atoms as an action solvent When a solvent is used to produce hydrogen peroxide, the working solution used is first distilled under reduced pressure to recover the working solvent. At this time, the pressure during the vacuum distillation is 15 mmHg and the temperature is 130 to 150 ° C, but preferably the pressure is 15 mmHg and the temperature is 140 ° C.

The polar and nonpolar inerts contained in the distillation residue are then extracted using a mixture of acyclic hydrocarbons and alcohol and reused. At this time, the acyclic hydrocarbons used in the extraction are preferably aliphatic hydrocarbons having 5 to 7 carbon atoms, such as n-hexane or n-heptane. The alcohol used is preferably 1 to 4 carbon atoms, preferably methanol or ethanol. On the other hand, the amount of the acyclic hydrocarbon-alcohol mixed solution used in the extraction is 3 to 5 times, preferably 4 times, the mass of the working solution distillation residue. At the time of extraction, the temperature of the mixture is about 5 to 10 占 폚 before filtration, preferably about 7 to 8 占 폚. The mixing mass ratio of the polar / nonpolar mixed extraction solvent at the time of extraction is preferably such that the phase separation does not occur at 5 캜. After extraction, the filtrate used can be generally re-used after simple classification.

As described above, the present invention provides a method for purifying and reusing an active solution used in a known anthraquinone process, and the method of the present invention will be described with reference to the accompanying drawings.

1 is a diagram for explaining a purification method of the present invention for purifying and reusing an action solution used in an anthraquinone process. In the figure, reference numeral 1 denotes an extractor, 2, 4, 6, 8, 10, 12, 15, 18, 20, 24, 25 and 26 are tubes; 3 and 16 are distillers; 5 is a vacuum pump; 7 and 19 are condensers; 9 is a mixer; 11 is a cooler; 22 and 23 are extraction solvent storage tanks, and 27 are working solution storage tanks.

1, a part of the working solution from the extractor 1 is passed through the tube 2 to the vacuum pump 5 and to the distiller 3 in which the stirrer is installed . Simultaneously with the stirring, the vacuum pump 5 is operated to lower the pressure inside the distiller to about 15 mmHg, and then the reduced pressure distillation is started while increasing the temperature of the still 3. The distilled working solvent is liquefied in the condenser 7 via the pipe 6 and stored in the mixer 9 for reuse. When the temperature of the distiller 3 reaches about 130-150 DEG C, this temperature is maintained until the working solvent is no longer distilled.

When the distillation is finished, the temperature of the still 3 is lowered to about 50 C and the extraction solvent is supplied from the extraction solution recovery tank 21 to the still 3. The mixture is stirred until the distillation residue in the still 3 is not agglomerated. The mixture is conveyed through the pipe 10 to the filter 13 while being kept at about 5-10 캜 through the cooler 11. The filtration residue is purged with air 14 for one hour and then sent to mixer 9 where it is dissolved in the recovered working solvent and then sent to working solution storage tank 27 for reuse. The filtrate is sent to the extractive distiller 16, distilled, and then sent to the extractive liquid storage tank 21 for reuse via the condenser 19.

For the analysis of working solutions and recovered agonists, tube chromatography, high performance liquid chromatography (HPLC) or gas chromatography-mass spectrometry (CG-MSD) are generally used.

Hereinafter, the present invention will be described in more detail by way of examples, which should not be construed as limiting the scope of the present invention.

[Example 1]

The hydrogen peroxide solution used in the purification was 2-ethyl anthraquinone: 2-methylcyclohexyl acetate in the form of 2-methylcyclohexyl acetate, and the initial composition ratio was 1: 4: 4. The composition ratio of the working solution used in the purification is as follows, and it can be divided into active quinone which can produce hydrogen peroxide, a working solvent and other substances to be removed.

Working solution Component composition ratio (% by weight)

Working solvent 79.5

Active quinone 15.3

Moisture 0.1

Other Polarities 4.6

Nonpolar 0.5

Active quinones include 2-ethyltetrahydroanthraquinone, which is a reducing substance of 2-ethyl anthraquinone, 2-ethyl anthraquinone, and 2-ethyltetrahydrofuran, which can be converted into a substance capable of directly producing hydrogen peroxide, Anthraquinone epoxide. The working solvent was distilled at 140 ° C with a pressure of 15 mmHg, and the other substances were classified as polar and nonpolar to compare the effect of the extraction solvent.

Distribution of components of distillation residue (%)

Active quinone 78.12

Polar inactive substance 17.70

Non-polar Inert Materials and Working Solvents 4.18

80 g of a mixed solution of normal hexane and methanol (1: 3 by mass) was added to 22.25 g of distillation residue obtained by distilling 100 g of the working solution at 140 DEG C under a pressure of 15 mmHg. The mixture was stirred for about 5 minutes until it was not lumpy, And then filtered. The filtration residue was purged with air for 1 hour to obtain 12.62 g of filtration residue. The composition of the filtration residue was 96.74% active quinone, 3.25% polar inactive material, 0.01% nonpolar inert material and the recovery rate was 82.46%.

[Example 2]

100 g of the working solution was distilled in the same manner as in Example 1, and the distillation residue was extracted with a mixture of normal hexane-ethyl alcohol (1: 5 by mass ratio) to obtain 12.180 g of filtration residue. The composition of the filtration residue was 97.07% of active quinone, 2.91% of polar inert material, 0.02% of nonpolar inert material, and the recovery rate was 77.27%.

[Example 3]

100 g of the working solution was distilled in the same manner as in Example 1, and the distillation residue was extracted with a mixture of normal hexane-isopropyl alcohol (5: 1 by mass ratio) to obtain 10.812 g of filtration residue. The composition of the filtration residue was 95.75% active quinone, 4.25% polar inactive material, 0% nonpolar inert material and the recovery rate was 67.66%.

[Example 4]

100 g of the working solution was distilled in the same manner as in Example 1, and the distillation residue was extracted with a mixture of normal hexane-n-propyl alcohol (1: 1 by mass ratio) to obtain 12.128 g of filtration residue. The composition of the filtration residue was 96.13% active quinone, 3.86% polar inactive material, 0.01% non-polar inert material and 76.20% recovery.

[Example 5]

100 g of the working solution was distilled by a method similar to that of Example 1, and the distillation residue was extracted with a mixture of normal heptane-ethanol (1: 4 by mass ratio) to obtain 11.835 g of filtration residue. The composition of the filtration residue was 96.60% active quinone, 3.39% polar inactive material, 0.01% non-polar inert material and 74.72% recovery.

[Example 6]

100 g of the working solution was distilled in the same manner as in Example 1, and the distillation residue was extracted with a mixture of normal heptane-isopropyl alcohol (5: 1 by mass ratio) to obtain 10.653 g of filtration residue. The composition of the filtration residue was 94.13% active quinone, 5.87% polar inactive material, 0% nonpolar inert material and 65.54% recovery.

[Example 7]

100 g of the working solution was distilled in the same manner as in Example 1, and the distillation residue was extracted with a mixture of normal heptane-n-propyl alcohol (1: 3 by mass ratio) to obtain 11.457 g of filtration residue. The composition of the filtration residue was 92.34% active quinone, 7.65% polar inactive material, 0.01% nonpolar inert material and 69.15% recovery.

Table 1 is a table showing the recovery and purity of the recovered active materials in the purification method in the same manner as in Example 1.

*: Based on active quinone

In the present invention, the purity and yield of the recovered functional solvent and the active material were improved by purifying the working solution for hydrogen peroxide by the conventional method, and the hydrogen peroxide produced in the purified working solution had a significantly higher total organic content .

Claims (13)

A method for purifying an active solution for the production of hydrogen peroxide using anthraquinone as an active substance, characterized in that the working solution used is subjected to vacuum distillation to recover the working solvent, and then the polar and nonpolar inert substances contained in the distillation residue are reacted with acyclic hydrocarbons and alcohols Wherein the hydrogen peroxide solution is extracted with a mixture. The method according to claim 1, wherein the pressure during the vacuum distillation is 15 mmHg and the temperature is 130 to 150 ° C. The method according to claim 2, wherein the pressure during the vacuum distillation is 15 mmHg and the temperature is 140 ° C The method according to claim 1, wherein the acyclic hydrocarbons used in the extraction are aliphatic hydrocarbons having 5 to 7 carbon atoms The method according to claim 4, wherein the aliphatic hydrocarbon is n-hexane or n-heptane. The method according to claim 1, wherein the alcohols used in the extraction have 1 to 4 carbon atoms. 7. A process according to claim 6, characterized in that the alcohol is methanol or ethanol, The method according to claim 1, wherein the amount of the acyclic hydrocarbon-alcohol mixed solution used in the extraction is 3 to 5 times the mass of the distillation residue of the working solution. 9. The method according to claim 8, wherein the amount of the acyclic hydrocarbon-alcohol mixed solution used in the extraction is 4 times the mass of the working solution distillation residue. The process according to claim 1, wherein the temperature of the mixture at the time of extraction is from 5 to 10 ° C before filtration. 11. The process according to claim 10, wherein the temperature of the mixture at the time of extraction is from 7 to 8 before filtration. The method according to claim 1, wherein the mixing mass ratio of the polar / nonpolar mixed extraction solvent during extraction is such that phase separation does not occur at 5 캜. The method according to claim 1, wherein the filtrate after extraction is simply distilled and then reused.