CN109205571B

CN109205571B - Method for separating and purifying hydrogen peroxide

Info

Publication number: CN109205571B
Application number: CN201710521631.1A
Authority: CN
Inventors: 霍稳周; 吕清林; 刘野; 李花伊
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2017-06-30
Filing date: 2017-06-30
Publication date: 2020-10-27
Anticipated expiration: 2037-06-30
Also published as: CN109205571A

Abstract

A method for separating and purifying hydrogen peroxide comprises the following steps: condensing hydrogen peroxide to be purified to 10-30 ℃, introducing the hydrogen peroxide into a membrane separator for membrane separation, removing organic carbon in the hydrogen peroxide, and purifying hydrogen peroxide; the membrane in the membrane reactor is a hollow fiber composite organic membrane, the aperture of the membrane is 0.01 um-1.5 um, the inner diameter is 0.1 mm-1.5 mm, and the wall thickness is 0.5 mm-1.0 mm; before use, the mixture is soaked in aqueous solution of low-carbon alcohol at 60-200 ℃ for 12-24 h. In the hydrogen peroxide purification method, the membrane reactor for special treatment is utilized, so that micromolecular polymer impurities in the membrane component are removed, the pore size distribution of the membrane component is more uniform, and the organic carbon in the hydrogen peroxide is more favorably removed; the invention also has the advantages of low equipment investment cost, long service cycle, simple operation and low energy consumption.

Description

Method for separating and purifying hydrogen peroxide

Technical Field

The invention relates to a method for separating and purifying hydrogen peroxide, in particular to a method for removing organic carbon in hydrogen peroxide.

Background

Caprolactam is an important raw material for fibers and engineering plastics. The production of the caprolactam adopts a ketone-oxime process route, and in the traditional oximation and Beckmann rearrangement reaction, cyclohexanone, ammonia and hydrogen peroxide are placed in the same reactor to synthesize the cyclohexanone oxime in one step, so that the hydrogen peroxide is a main raw material for synthesizing caprolactam, and the concentration of organic carbon in the reaction to the hydrogen peroxide needs to be reduced to below 50 ppm.

At present, almost all hydrogen peroxide produced at home and abroad adopts an anthraquinone method, a small amount of anthraquinone organic matters are generated in the hydrogen peroxide production process, the content of the anthraquinone organic matters is increased along with the increase of the running time of a device, and is converted into the content of organic carbon which is generally below 300PPm, but the content of the anthraquinone organic matters sometimes reaches 400PPm or even higher along with the extension of the running time of the device. If hydrogen peroxide containing organic carbon is used for cyclohexanone oxime production, the organic matters can be brought into caprolactam which is a final product, and the product purity is influenced.

Therefore, hydrogen peroxide needs to be purified, and since the 50 th century of the 20 th century, many purification methods, including rectification, adsorption, ion exchange, extraction, crystallization, membrane separation, and a combination of these methods, have been developed in succession in order to remove these organic impurities from hydrogen peroxide products.

Rectification and ion exchange resin purification are now common in industrial applications. The rectification method is generally used for concentrating hydrogen peroxide, and because organic matters have higher boiling points, the organic matters are enriched in unvaporized liquid and are removed, so that the hydrogen peroxide is purified. However, because the gas-liquid separation is incomplete and the mist liquid is carried, volatile organic matters enter a rectification system along with hydrogen peroxide steam, and the purity is generally not very high. The patents on the membrane separation and purification method of hydrogen peroxide which are disclosed at present mainly include: CN203079688U discloses a be applied to device of hydrogen peroxide purification, the device includes stock solution jar, filter, phase separator, membrane separation system, one set of chemical cleaning system, one set of conventional cleaning system, the stock solution jar is connected with the filter through the feed liquor pump, and two sets of filters are connected with the phase separator, and the phase separator passes through the high-pressure pump and connects membrane separation system, is connected with chemical cleaning device and conventional cleaning device on the membrane separation system, the filter is two sets, membrane separation system also is two sets.

The invention discloses a device and a process applied to hydrogen peroxide purification, and the device comprises a raw liquid tank, a filter, a phase separator, a membrane separation system, a set of chemical cleaning system and a set of conventional cleaning system, wherein the raw liquid tank is connected with the filter through a liquid inlet pump, the two sets of filters are connected with the phase separator, the phase separator is connected with the membrane separation system through a high-pressure pump, the membrane separation system is connected with the chemical cleaning device and the conventional cleaning device, the number of the filters is two, and the number of the membrane separation system is also two.

In conclusion, the method for purifying hydrogen peroxide by membrane separation generally has the problems of high operating cost, complex flow, high energy consumption, unsatisfactory purification treatment effect, even incapability of meeting the requirements of downstream production on raw materials and the like.

Disclosure of Invention

In order to solve the problems of complex purification process, high cost and poor hydrogen peroxide purification effect in the existing hydrogen peroxide purification technology, the invention aims to provide a method for separating and purifying hydrogen peroxide.

In order to achieve the technical purpose, the invention adopts the following technical means:

a method for separating and purifying hydrogen peroxide comprises the following steps: condensing hydrogen peroxide to be purified to 10-30 ℃, introducing the hydrogen peroxide into a membrane separator for membrane separation, removing organic carbon in the hydrogen peroxide, and purifying hydrogen peroxide;

wherein, the membrane in the membrane separator is a hollow fiber composite organic membrane, the aperture of the membrane is 0.01 um-1.5 um, the inner diameter is 0.1 mm-1.5 mm, and the wall thickness is 0.5 mm-1.0 mm;

the membrane separator is treated prior to use by:

firstly removing oxygen in low-carbon alcohol and deionized water, and soaking the membrane component in a low-carbon alcohol aqueous solution at 60-200 ℃ for 12-24 h; the lower alcohol is at least one of C1-C4 alcohols.

In the above treatment method, it should be understood by those skilled in the art that the hydrogen peroxide to be purified is hydrogen peroxide produced by anthraquinone process, and is hydrogen peroxide with organic carbon content of 1500PPm or less, preferably 1500PPm or less, and more preferably 1000PPm or less. .

In the above treatment method, the hollow fiber composite organic membrane is preferably a silicone rubber/polysulfone composite membrane. Preferably, the membrane aperture of the silicone rubber/maple composite membrane is 0.01um to 1.0um, more preferably 0.01um to 0.5 um; the inner diameter is 0.1 mm-1.0 mm, and the membrane aperture is more preferably 0.1 mm-0.8 mm; the thickness of the wall is 0.5mm to 0.8mm, and more preferably 0.5mm to 0.7 mm.

In the above treatment method, as a further preferable aspect, the lower alcohol is at least one selected from the group consisting of methanol, ethanol, propanol, isopropanol, n-butanol, t-butanol, sec-butanol and isobutanol; most preferred is at least one of methanol, ethanol, isopropanol, and sec-butanol.

In the treatment method, the volume concentration of the alcohol in the low-carbon alcohol aqueous solution is 0.5-20%, preferably 1-10%.

It should be noted that in the membrane module treatment process, the solution used must be deoxygenated and the treatment solution should be free of mechanical dust.

In the treatment method, the soaking temperature of the aqueous solution of the low-carbon alcohol is 80-150 ℃, more preferably 100-150 ℃, and the soaking time is preferably 12-18 h.

When the membrane module is treated, a closed container is adopted, and the closed container is a reactor which is suitable for various inert material linings of hydrothermal reaction, such as an enamel, glass, ceramic or tetrafluoroethylene lined container.

In the above treatment method, the soaking according to the present invention is based on the condition that the membrane module is completely submerged by the liquid.

In the treatment method, the membrane separator comprises a shell and a membrane component, the membrane component is arranged in the shell, one end of the shell and the membrane component are provided with a hydrogen peroxide inlet to be purified in parallel, the other end of the shell and the membrane component are provided with a purified hydrogen peroxide outlet in parallel, and the side surface of the shell is provided with an outlet for recovering organic carbon compounds. The organic carbon compound of the hydrogen peroxide flows outside the membrane module, and the hydrogen peroxide after the organic carbon is removed flows inside the membrane module.

Compared with the prior art, the method for separating and purifying hydrogen peroxide has the following advantages:

1. the membrane separator is soaked in the aqueous solution of low-carbon alcohol under specific conditions, so that small-molecule polymer impurities in the membrane component are removed, the pore size distribution of the membrane component is more uniform, and the separation of organic carbon components is facilitated.

2. Compared with other processes, the hydrogen peroxide purification method has the advantages of low equipment investment cost, long service cycle, simple operation and low energy consumption; the membrane separator after special treatment has good separation selectivity and high separation efficiency, effectively separates the organic carbon components in the hydrogen peroxide, obviously improves the recovery efficiency compared with a membrane component without treatment, realizes more effective separation of the organic carbon components, and does not generate secondary pollution in the whole process.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

FIG. 1 is a specific process flow diagram of hydrogen peroxide separation and purification;

FIG. 2 is a schematic diagram of the structure of a membrane separator.

Detailed Description

The following examples further illustrate the process of the present invention but are not intended to limit the invention in any way.

The invention adopts the process flow chart shown in figure 1 to purify hydrogen peroxide, the hydrogen peroxide to be purified is cooled to 10-30 ℃ by a condenser 1 and enters the upper part of a membrane separator 2 through a valve 4, as shown in figure 2, the membrane separator is provided with a shell 22, a membrane assembly 23 is arranged in the shell, one end of the shell 22 is provided with an inlet 24 in parallel with the membrane assembly 23, the other end of the shell 22 is provided with a non-osmotic component outlet 21 in parallel with the membrane assembly 23, and the side surface of the shell is provided with an osmotic component outlet 25. Hydrogen peroxide enters the membrane component from the inlet 25, the purified hydrogen peroxide is discharged from the non-permeable component outlet 21 at the lower part, the separated organic carbon compound contains a small amount of water and enters the oil-water separator 3 through the valve 5, and a partition plate is arranged in the oil-water separator 3 to separate the organic carbon compound for recycling.

The membrane module is made of a silicon rubber/poly-maple composite membrane. The film parameters are shown in Table 1.

TABLE 1

Example 1

The membrane module is subjected to the following treatments: firstly, carrying out deoxygenation treatment on isopropanol, sec-butyl alcohol and deionized water in advance, preparing a low-carbon alcohol mixed solution with the volume fractions of the isopropanol and the sec-butyl alcohol being 5%, placing a membrane assembly in the low-carbon alcohol mixed solution, placing the membrane assembly in a container, heating to 100 ℃, and treating for 12 hours at the temperature. And drying after the treatment to obtain the membrane component for purifying the hydrogen peroxide oxidized tail gas. According to the process flow shown in fig. 1 and fig. 2, hydrogen peroxide water with different organic carbon contents, numbered 1-10, was condensed to 10 ℃, and introduced into a membrane separator for purification, and the results are shown in table 2.

Example 2

Purification was carried out by following the procedure of example 1, except that isopropanol and sec-butanol were replaced with ethanol and sec-butanol, and hydrogen peroxide was condensed to 15 ℃ and the results are shown in Table 2.

Example 3

The hydrogen peroxide purification was carried out by condensing hydrogen peroxide to 20 ℃ according to the procedure of example 1 except that ethanol and isopropanol were used instead of isopropanol and sec-butanol, and the results are shown in Table 2.

Example 4

The hydrogen peroxide purification was carried out by condensing hydrogen peroxide to 25 ℃ according to the procedure of example 1 except that isopropyl alcohol and sec-butyl alcohol were replaced by sec-butyl alcohol, and the results are shown in Table 2.

Example 5

The hydrogen peroxide purification was carried out by condensing hydrogen peroxide to 30 ℃ according to the procedure of example 1 except that isopropanol and sec-butanol were replaced with isopropanol, and the results are shown in Table 2.

Example 6

The hydrogen peroxide purification was carried out by condensing hydrogen peroxide to 30 ℃ according to the method of example 1, replacing isopropanol and sec-butanol with methanol and isopropanol, and the results are shown in table 2.

Example 7

The purification with hydrogen peroxide was carried out by condensing hydrogen peroxide to 20 ℃ according to the procedure of example 1, replacing isopropanol and sec-butanol with methanol and sec-butanol, and the results are shown in table 2.

Example 8

The purification results of hydrogen peroxide are shown in Table 2, except that the method of example 1 is followed and 5% methanol is used as the lower alcohol mixed solution, and the conditions are the same as those of example 1.

Example 9

The process of example 1 was followed to change the concentrations of isopropanol and sec-butanol to 0.5% and 9.5%, respectively, under the same conditions as in example 1, and the results of the hydrogen peroxide purification are shown in table 2.

Example 10

The process of example 1 was followed to change the concentrations of isopropanol and sec-butanol to 9.5% and 0.5%, respectively, under the same conditions as in example 1, and the results of the hydrogen peroxide purification are shown in table 2.

Example 11

The process of example 1 was followed to change the concentrations of isopropanol and sec-butanol to 0.5% and 0.5%, respectively, under the same conditions as in example 1, and the results of the hydrogen peroxide purification are shown in table 2.

Comparative example 1

According to the method disclosed in patent CN203079688U, 10 hydrogen peroxide solutions with different organic carbon contents, which are numbered 1-10, are purified, and the results are shown in Table 2.

Table 2.

As can be seen from Table 2, the content of organic carbon in hydrogen peroxide after being purified by an untreated membrane filter is far higher than that after being purified by a treated membrane separator in the invention, which indicates that the method of the invention achieves the purpose of purifying organic carbon in hydrogen peroxide more ideally.

Claims

1. A method for separating and purifying hydrogen peroxide comprises the following steps: condensing hydrogen peroxide to be purified to 10-30 ℃, introducing the hydrogen peroxide into a membrane separator for membrane separation, removing organic carbon in the hydrogen peroxide, and purifying hydrogen peroxide;

wherein, the membrane in the membrane separator is a hollow fiber composite organic membrane, in particular to a silicon rubber/polysulfone composite membrane, the aperture of the membrane is 0.01-0.5 μm, the inner diameter is 0.1-1.5 mm, and the wall thickness is 0.5-1.0 mm;

the membrane separator is treated prior to use by:

removing oxygen in low-carbon alcohol and deionized water, and soaking the membrane module in a low-carbon alcohol aqueous solution at 80-150 ℃ for 12-24 h, wherein the treatment is a hydrothermal reaction in a closed container; the lower alcohol is at least one of C1-C4 alcohol; the volume concentration of the alcohol in the low-carbon alcohol aqueous solution is 0.5-20%.

2. The process according to claim 1, wherein the hydrogen peroxide to be purified has an organic carbon content of 2000ppm or less.

3. The method according to claim 2, wherein the hydrogen peroxide to be purified has an organic carbon content of 1500ppm or less.

4. The method according to claim 3, wherein the hydrogen peroxide to be purified has an organic carbon content of 1000ppm or less.

5. The method of claim 1, wherein the inner diameter is 0.1mm to 1.0mm and the wall thickness is 0.5mm to 0.8 mm.

6. The method of claim 5, wherein the inner diameter is 0.1mm to 0.8mm and the wall thickness is 0.5mm to 0.7 mm.

7. The method according to claim 1, wherein the lower alcohol is at least one selected from the group consisting of methanol, ethanol, propanol, isopropanol, n-butanol, t-butanol, sec-butanol, and isobutanol.

8. The method of claim 1, wherein the soaking time with the lower alcohol aqueous solution is 12-18 h.