A kind of preparation method of peracetic acid

Abstract

The invention discloses a method for preparing peracetic acid, which comprises contact reaction of acetic acid and hydrogen peroxide in the presence of a catalyst, wherein the catalyst is a modified multi-walled carbon nanotube loaded with copper oxide. The invention adopts a multi-walled carbon nanotube loaded with copper oxide after modification, a chromium-modified multi-walled carbon nanotube, and imparts a certain acidity to the surface of the multi-walled carbon nanotube, and then loads copper oxide to promote the reaction of acetic acid and hydrogen peroxide on the one hand, reduce the reaction time, and on the other hand, have a certain activation effect on the generated peracetic acid, so that the finally obtained peracetic acid has a good degradation effect on bisphenol A, a water source pollutant, and can be used as a disinfectant.

Description

Technical Field

[0001] The invention relates to the field of peroxide preparation, and in particular to a method for preparing peracetic acid. Background Art

[0002] Peracetic acid is a peroxide with the chemical formula CH3COOOH. It has a strong pungent smell and is soluble in water, alcohol, ether, and sulfuric acid. It is a strong oxidant and extremely unstable. It will explode at -20°C. It is explosive when the concentration is greater than 45%. It will explode when exposed to high heat, reducing agents, or metal ions. It is mainly used as a bleaching agent for paper, paraffin, wood, fabrics, grease, and starch. At the same time, peracetic acid is a green ecological fungicide.

[0003] With the development of industry, water pollution is becoming increasingly serious. Endocrine disruptors are a new type of pollutants often detected in water. They have obvious three-hazard properties, and the existing peracetic acid disinfectants cannot effectively remove endocrine disruptors.

[0004] The principle of preparing peracetic acid is generally to oxidize acetic acid through an acid-catalyzed ion reaction to obtain peracetic acid. The traditional industrial method for producing peracetic acid is to use glacial acetic acid and high-concentration hydrogen peroxide as substrates and sulfuric acid as a catalyst to react at room temperature to obtain peracetic acid, and then dilute the obtained peracetic acid according to the application scenario. However, in the above production method, the hydrogen peroxide is generally 300g / L, and the obtained peracetic acid is generally 150-200g / L. The above raw materials are extremely sensitive to heat. At a relatively low temperature, the reaction may be out of control, resulting in high temperature and high pressure, and the obtained peracetic acid will have more sulfuric acid residues. On the one hand, during the transportation of peracetic acid, sulfuric acid may react with residual hydrogen peroxide, increasing safety hazards; on the other hand, due to the corrosiveness of sulfuric acid itself, the application scenarios of peracetic acid containing sulfuric acid are limited, such as the disinfection of some processing machinery. That is, the above method has great safety hazards in the production process of peracetic acid and the transportation process of peracetic acid, and the application scenarios of the obtained peracetic acid are limited.

[0005] In summary, it is particularly important to design a method for preparing peracetic acid without sulfuric acid, simplify the preparation method, and improve the yield and performance of peracetic acid. Summary of the invention

[0006] Based on this, the present invention provides a method for preparing peracetic acid, using modified multi-walled carbon nanotubes loaded with copper oxide as a catalyst to obtain peracetic acid. This method has a mild reaction and safe production, does not contain sulfuric acid, and the obtained peracetic acid can effectively degrade the endocrine disruptor bisphenol A.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A method for preparing peracetic acid comprises the following steps: acetic acid and hydrogen peroxide are contacted and reacted in the presence of a catalyst, wherein the catalyst is a modified multi-walled carbon nanotube loaded with copper oxide.

[0009] Hydrogen peroxide can oxidize acetic acid to form peracetic acid. The method of the present invention is particularly suitable for the occasion of using hydrogen peroxide as an oxidant to oxidize acetic acid to produce peracetic acid, which can significantly improve the effective utilization rate of hydrogen peroxide and reduce the cost of acetic acid oxidation. Compared with other peroxides, hydrogen peroxide can further reduce the separation cost, and hydrogen peroxide is added in the form of an aqueous solution.

[0010] In some embodiments, the method for preparing the catalyst comprises the following steps:

[0011] (1) Purification of multi-walled carbon nanotubes: MWCNTs are added to a nitric acid solution for ultrasonic treatment, and then placed in a water bath after the ultrasonic treatment. After the water bath, the mixture is filtered and washed with water until neutral, and then dried for later use;

[0012] (2) Modification of multi-walled carbon nanotubes: Weigh chromium tungstate according to the mass ratio and add it to the purified MWCNTs obtained in step (1), add an appropriate amount of solvent to dissolve, stir for 30-40 minutes, ultrasonically treat for 10-30 minutes, let stand for 1-3 hours, dry at 80-85°C, and calcine in a tube furnace at 300-400°C in an inert gas atmosphere for 2-5 hours to obtain MWCNTs-CrOx, which is set aside;

[0013] (3) Loading of active ingredients: The MWCNTs-CrOx prepared in step (2) is dissolved in a solvent, copper oxide is added, stirred for 20-30 min, subjected to ultrasonic treatment, dried, and calcined in a tube furnace under an inert gas atmosphere to obtain a catalyst CuO / MWCNTs-CrOx.

[0014] In some embodiments, the step (1) is specifically as follows: placing MWCNTs in nitric acid, with a solid-liquid ratio of 1: (150-200) g / mL, and a nitric acid concentration of 1-3 mol·L -1 ; Ultrasonic treatment for 10-30 minutes, then water bath for 2-4 hours, the water bath temperature is 90-100℃; filter after water bath and use water to wash until neutral; after water washing, dry at 90-100℃ for 12-24 hours for use.

[0015] In some of the embodiments, the step (2) is specifically as follows: adding chromium tungstate to the MWCNTs treated in step (1), adding a solvent to dissolve, stirring for 20-30 minutes, then ultrasonically treating for 20-30 minutes, standing for 1-3 hours, drying at 80-85°C, and after drying, calcining in a tube furnace at 300-400°C in a N2 atmosphere for 2-5 hours to obtain MWCNTs-CrOx for later use.

[0016] In some of the embodiments, the step (3) is specifically as follows: dissolving the MWCNTs-CrOx obtained in step (2) in a solvent, adding copper oxide, stirring for 30-40 minutes, ultrasonically treating for 30-40 minutes, drying at 80-90°C, and calcining in a tube furnace at 300-400°C in a N2 atmosphere for 2-5 hours to obtain the catalyst CuO / MWCNTs-WOx.

[0017] In some of the embodiments, the mass ratio of copper oxide to MWCNTs is (1-2):10.

[0018] In some embodiments, the step (3) is specifically as follows: dissolving the MWCNTs-CrOx obtained in step (2) in a solvent, adding copper oxide and iron oxide, stirring for 20-30 minutes, performing ultrasonic treatment, drying, and calcining in a tube furnace under an inert gas atmosphere to obtain a catalyst CuO / MWCNTs-CrOx, wherein the mass ratio of copper oxide to MWCNTs is (2-3):10, and the mass ratio of iron oxide to MWCNTs is (1-1.5):10.

[0019] In some embodiments, the solvent is at least one of water, acetone, butanone and acetophenone.

[0020] In some embodiments, the molar ratio of acetic acid to hydrogen peroxide is 1:(0.5-3); the weight ratio of acetic acid to catalyst is (30-70):1; the reaction conditions include: temperature of 20-40°C and pressure of 0.1-3MPa.

[0021] In some embodiments, the mass concentration of hydrogen peroxide is greater than 60%.

[0022] Compared with the prior art, the method for preparing peracetic acid of the present invention has the following beneficial effects:

[0023] The invention discloses a method for preparing peracetic acid. The method adopts a multi-walled carbon nanotube loaded with copper oxide after modification, and chromium-modified multi-walled carbon nanotubes to give the surface of the multi-walled carbon nanotubes certain acidity. The copper oxide is then loaded on the multi-walled carbon nanotubes to promote the reaction between acetic acid and hydrogen peroxide and reduce the reaction time. The copper oxide also has a certain activation effect on the generated peracetic acid. Therefore, the finally obtained peracetic acid has a good degradation effect on bisphenol A, a water source pollutant, and can be used as a disinfectant.

[0024] The acetic acid obtained by the preparation method of the present invention has a high conversion rate, good selectivity of the product peracetic acid, high yield and good quality, and can be stably stored for a long time at a relatively high concentration under normal temperature conditions. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the embodiments of the present invention are summarized below to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0026] A method for preparing peracetic acid comprises the following steps: putting acetic acid, a 50 wt% hydrogen peroxide aqueous solution and a catalyst into a reaction kettle, wherein the molar ratio of acetic acid to hydrogen peroxide is 1:0.5, and the weight ratio of acetic acid to the catalyst is 30:1, and reacting at a temperature of 10°C and a pressure of 0.1 MPa. The results of reacting for 2 hours and 12 hours are shown in Table 1.

[0027] The preparation method of the catalyst comprises the following steps:

[0028] (1) Purification of multi-walled carbon nanotubes: MWCNTs were placed in nitric acid with a solid-liquid ratio of 1:200 g / mL and a nitric acid concentration of 1 mol·L -1 ; Ultrasonic treatment for 30 minutes, then water bath for 2 hours, the water bath temperature is 100℃; filter after water bath and use water to wash until neutral; after water washing, dry at 90℃ for 24 hours for use.

[0029] (2) adding chromium tungstate to the MWCNTs treated in step (1), adding acetone to dissolve, stirring for 20 min, then subjecting to ultrasonic treatment for 20 min, standing for 3 hours, drying at 80° C., and then calcining in a tube furnace at 400° C. in a N2 atmosphere for 5 h to obtain MWCNTs-CrOx for later use;

[0030] (3) Loading of active ingredients: The MWCNTs-CrOx prepared in step (2) was dissolved in acetone, copper oxide was added, stirred for 40 min, ultrasonically treated for 30 min, dried at 80 °C, and calcined in a tube furnace at 400 °C in a N2 atmosphere for 2 h to obtain a catalyst CuO / MWCNTs-WOx; the mass ratio of copper oxide to MWCNTs was 1:10. Example 2

[0031] A method for preparing peracetic acid comprises the following steps: putting acetic acid, a 50 wt% hydrogen peroxide aqueous solution and a catalyst into a reaction kettle, wherein the molar ratio of acetic acid to hydrogen peroxide is 1:3, and the weight ratio of acetic acid to the catalyst is 70:1, and reacting at a temperature of 40°C and a pressure of 3 MPa. The results of reacting for 2 hours and 12 hours are shown in Table 1.

[0032] The preparation method of the catalyst comprises the following steps:

[0033] (1) Purification of multi-walled carbon nanotubes: MWCNTs were placed in nitric acid with a solid-liquid ratio of 1:150 g / mL and a nitric acid concentration of 3 mol·L -1 ; Ultrasonic treatment for 10 minutes, then water bath for 4 hours, the water bath temperature is 90℃; filter after water bath and use water to wash until neutral; after water washing, dry at 100℃ for 12 hours for use.

[0034] (2) adding chromium tungstate to the MWCNTs treated in step (1), adding butanone to dissolve, stirring for 30 minutes, then subjecting to ultrasonic treatment for 30 minutes, standing for 1 hour, drying at 85°C, and after drying, calcining in a tube furnace at 300°C in a N2 atmosphere for 2 hours to obtain MWCNTs-CrOx, which is set aside;

[0035] (3) Loading of active ingredients: The MWCNTs-CrOx prepared in step (2) was dissolved in butanone, copper oxide was added, stirred for 30 min, ultrasonically treated for 40 min, dried at 90 °C, and calcined in a tube furnace at 300 °C in a N2 atmosphere for 5 h to obtain a catalyst CuO / MWCNTs-WOx; the mass ratio of copper oxide to MWCNTs was 2:10. Example 3

[0036] A method for preparing peracetic acid comprises the following steps: putting acetic acid, a 50 wt% hydrogen peroxide aqueous solution and a catalyst into a reaction kettle, wherein the molar ratio of acetic acid to hydrogen peroxide is 1:2, and the weight ratio of acetic acid to the catalyst is 50:1, and reacting at a temperature of 30°C and a pressure of 2 MPa. The results of reacting for 2 hours and 12 hours are shown in Table 1.

[0037] The preparation method of the catalyst comprises the following steps:

[0038] (1) Purification of multi-walled carbon nanotubes: MWCNTs were placed in nitric acid with a solid-liquid ratio of 1:180 g / mL and a nitric acid concentration of 2 mol·L -1 ; Ultrasonic treatment for 20 minutes, then water bath for 3 hours, the water bath temperature is 95°C; filter after water bath and use water to wash until neutral; after water washing, dry at 95°C for 18 hours for use.

[0039] (2) adding chromium tungstate to the MWCNTs treated in step (1), adding acetone to dissolve, stirring for 25 minutes, then subjecting to ultrasonic treatment for 25 minutes, standing for 2 hours, drying at 83°C, and then calcining in a tube furnace at 350°C in a N2 atmosphere for 4 hours to obtain MWCNTs-CrOx for later use;

[0040] (3) Loading of active ingredients: The MWCNTs-CrOx prepared in step (2) was dissolved in acetone, copper oxide was added, stirred for 35 min, ultrasonically treated for 35 min, dried at 85 °C, and calcined in a tube furnace at 350 °C in a N2 atmosphere for 3 h to obtain a catalyst CuO / MWCNTs-WOx; the mass ratio of copper oxide to MWCNTs was 1.5:10. Example 4

[0041] A method for preparing peracetic acid comprises the following steps: putting acetic acid, a 50 wt% hydrogen peroxide aqueous solution and a catalyst into a reaction kettle, wherein the molar ratio of acetic acid to hydrogen peroxide is 1:1.5, and the weight ratio of acetic acid to the catalyst is 60:1, and reacting at a temperature of 35°C and a pressure of 1 MPa. The results of reacting for 2 hours and 12 hours are shown in Table 1.

[0042] The preparation method of the catalyst comprises the following steps:

[0043] (1) Purification of multi-walled carbon nanotubes: MWCNTs were placed in nitric acid with a solid-liquid ratio of 1:160 g / mL and a nitric acid concentration of 2 mol·L -1 ; Ultrasonic treatment for 15 minutes, then water bath for 2 hours, the water bath temperature is 90℃; filter after water bath and use water to wash until neutral; after water washing, dry at 100℃ for 18 hours for use.

[0044] (2) adding chromium tungstate to the MWCNTs treated in step (1), adding acetone to dissolve, stirring for 20 minutes, then subjecting to ultrasonic treatment for 25 minutes, standing for 2 hours, drying at 85°C, and then calcining in a tube furnace at 400°C in a N2 atmosphere for 2 hours to obtain MWCNTs-CrOx for later use;

[0045] (3) The MWCNTs-CrOx prepared in step (2) was dissolved in acetone, copper oxide and iron oxide were added, stirred for 30 min, ultrasonically treated for 30 min, dried, and calcined in a tubular furnace under a nitrogen atmosphere for 2 h to obtain a catalyst CuO / MWCNTs-CrOx, wherein the mass ratio of copper oxide to MWCNTs was 2.5:10, and the mass ratio of iron oxide to MWCNTs was 1.3:10.

[0046] Comparative Example 1

[0047] A method for preparing peracetic acid comprises the following steps: putting acetic acid, a 50 wt% hydrogen peroxide aqueous solution and a catalyst into a reaction kettle, wherein the molar ratio of acetic acid to hydrogen peroxide is 1:2, and the weight ratio of acetic acid to the catalyst is 50:1, and reacting at a temperature of 30°C and a pressure of 2 MPa. The results of reacting for 2 hours and 12 hours are shown in Table 1.

[0048] Comparative Example 2

[0049] A method for preparing peracetic acid comprises the following steps: putting acetic acid, a 50 wt% hydrogen peroxide aqueous solution and a catalyst into a reaction kettle, wherein the molar ratio of acetic acid to hydrogen peroxide is 1:2, and the weight ratio of acetic acid to the catalyst is 50:1, and reacting at a temperature of 30°C and a pressure of 2 MPa. The results of reacting for 2 hours and 12 hours are shown in Table 1.

[0050] The preparation method of the catalyst is:

[0051] MWCNTs were dissolved in acetone, copper oxide was added, stirred for 35 minutes, ultrasonically treated for 35 minutes, dried at 85°C, and calcined in a tube furnace at 350°C for 3 hours in a N2 atmosphere to obtain a catalyst; the mass ratio of copper oxide to MWCNTs was 1.5:10.

[0052] Comparative Example 3

[0053] A method for preparing peracetic acid comprises the following steps: putting acetic acid, a 50 wt% hydrogen peroxide aqueous solution and a catalyst into a reaction kettle, wherein the molar ratio of acetic acid to hydrogen peroxide is 1:2, and the weight ratio of acetic acid to the catalyst is 50:1, and reacting at a temperature of 30°C and a pressure of 2 MPa. The results of reacting for 2 hours and 12 hours are shown in Table 1.

[0054] The preparation method of the catalyst comprises the following steps:

[0055] (1) Purification of multi-walled carbon nanotubes: MWCNTs were placed in nitric acid with a solid-liquid ratio of 1:180 g / mL and a nitric acid concentration of 2 mol·L -1; Ultrasonic treatment for 20 minutes, then water bath for 3 hours, the water bath temperature is 95°C; filter after water bath and use water to wash until neutral; after water washing, dry at 95°C for 18 hours for use.

[0056] (2) adding chromium tungstate to the MWCNTs treated in step (1), adding acetone to dissolve, stirring for 25 minutes, then subjecting to ultrasonic treatment for 25 minutes, standing for 2 hours, drying at 83°C, and then calcining in a tube furnace at 350°C in a N2 atmosphere for 4 hours to obtain MWCNTs-CrOx for later use;

[0057] (3) Loading of active ingredients: The MWCNTs-CrOx prepared in step (2) was dissolved in acetone, iron oxide was added, stirred for 35 min, ultrasonically treated for 35 min, dried at 85 °C, and calcined in a tube furnace at 350 °C for 3 h in a N2 atmosphere to obtain a catalyst CuO / MWCNTs-WOx; the mass ratio of copper oxide to MWCNTs was 1.5:10.

[0058] The results of Examples 1-4 and Comparative Examples 1-3 after reacting for 2 hours and 12 hours are shown in Table 1.

[0059] Table 1

[0060]

[0061] The peracetic acid obtained after reacting for 2 hours was tested, and the concentration of peracetic acid is shown in Table 2.

[0062] Table 2

[0063]

[0064] The peracetic acid obtained by reacting for 2 hours in Example 1-4 and Comparative Example 1-3 was tested for bisphenol A degradation.

[0065] The bisphenol A degradation detection method is:

[0066] The bisphenol A content was tested in the water source, and then 200 mL of water sample was taken out, 2 mL of ascorbic acid aqueous solution (100 mg / L) was added for fixation, and then 10 ml of hydrogen peroxide solution was added. The bisphenol A content was tested after 30 minutes and 40 minutes, and the degradation rate was calculated. The results are shown in Table 3.

[0067] Table 3

[0068]

[0069] As can be seen from Table 1-Table 3, the peracetic acid prepared in Examples 1-4 of the present invention can obtain a higher acetic acid conversion rate, peracetic acid selectivity and relative effective utilization rate of hydrogen peroxide. By comparing Example 3 with Comparative Example 1, it can be seen that compared with not using a catalyst, the preparation method of the present invention can greatly improve the relative conversion rate of acetic acid, the relative effective utilization rate of the oxidant, the selectivity of peracetic acid, the concentration of peracetic acid and the degradation rate of bisphenol A. By comparing Comparative Example 2 with Example 3, it can be seen that the catalyst prepared by using carbon nanotubes that are not modified by chromium cannot be completely reacted within the same time. As can be seen from Table 2, its peracetic acid concentration is only 3.2%, and the concentration should be above 4% after sufficient reaction. By comparing Comparative Example 4 with Example 3, it can be seen that although the use of iron oxide to replace copper oxide loaded on MWCNTs-CrOx also obtains a better acetic acid conversion rate, peracetic acid selectivity, relative effective utilization rate of hydrogen peroxide and peracetic acid concentration, its effect of degrading bisphenol A is significantly lower than that of Example 3. By comparing Example 4 with Example 3, it can be seen that the use of iron oxide and copper oxide in combination can obtain better relative conversion rate of acetic acid, relative effective utilization rate of oxidant, selectivity of peracetic acid, peracetic acid concentration and bisphenol A degradation rate than using only copper oxide.

[0070] In the absence of conflict, the above-mentioned embodiments and features thereof may be combined with each other.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing peracetic acid, characterized in that: The method comprises the following steps: putting acetic acid, a 50 wt% hydrogen peroxide aqueous solution and a catalyst into a reaction kettle, wherein the molar ratio of acetic acid to hydrogen peroxide is 1:1.5, and the weight ratio of acetic acid to the catalyst is 60:1, and reacting at a temperature of 35°C and a pressure of 1 MPa; The preparation method of the catalyst comprises the following steps: (1) Purification of multi-walled carbon nanotubes: MWCNTs were placed in nitric acid with a solid-liquid ratio of 1:160 g / mL and a nitric acid concentration of 2 mol·L -1 ; Ultrasonic treatment for 15 minutes, then water bath for 2 hours, the water bath temperature is 90°C; filter after water bath and use water to wash until neutral; after water washing, dry at 100°C for 18 hours for use; (2) adding chromium tungstate to the MWCNTs treated in step (1), adding acetone to dissolve, stirring for 20 minutes, then subjecting to ultrasonic treatment for 25 minutes, standing for 2 hours, drying at 85°C, and then calcining in a tube furnace at 400°C in a N2 atmosphere for 2 hours to obtain MWCNTs-CrOx for later use; (3) The MWCNTs-CrOx prepared in step (2) was dissolved in acetone, copper oxide and iron oxide were added, stirred for 30 min, ultrasonically treated for 30 min, dried, and calcined in a tubular furnace under a nitrogen atmosphere for 2 h to obtain a catalyst CuO / MWCNTs-CrOx, wherein the mass ratio of copper oxide to MWCNTs was 2.5:10, and the mass ratio of iron oxide to MWCNTs was 1.3:10.

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