A process for purifying hydrogen bromide by-product containing organic acids

Abstract

The application provides a purification method of hydrogen bromide by-product containing organic acid, and belongs to the field of purification. The application provides a purification method of hydrogen bromide by-product containing organic acid, which comprises the following steps: mixing the hydrogen bromide by-product containing organic acid and monohydric alcohol, and then performing esterification reaction to obtain a mixture containing organic acid ester; and performing distillation or liquid separation on the mixture containing organic acid ester to obtain organic acid ester and hydrogen bromide. The application utilizes hydrogen bromide as a catalyst, adds monohydric alcohol to react with organic acid to generate organic acid ester which has a large difference in boiling point with hydrogen bromide or has poor compatibility with hydrogen bromide, and then the hydrogen bromide by-product containing organic acid can be purified through simple distillation or liquid separation, thereby improving the utilization rate of the hydrogen bromide by-product containing organic acid, maximizing the utilization of the hydrogen bromide by-product containing organic acid, achieving the goal of green production, and reducing the pollution to the environment. Moreover, the purification method is suitable for industrial production, and improves the production value of enterprises.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of purification, in particular to a purification method of by-product hydrogen bromide containing organic acid. BACKGROUND

[0002] In recent years, China attaches great importance to the development of green chemical industry and puts forward higher requirements for the rational use of resources. Hydrogen bromide, as an important chemical raw material, is widely used in petroleum chemical industry, fine chemical industry, medicine and other fields.

[0003] A large amount of hydrogen bromide gas is by-produced in the synthesis process of organic bromide using bromine as raw material, but the by-product hydrogen bromide contains many impurities and cannot be directly used in industrial production, so different treatment methods need to be taken for by-product hydrogen bromide from different sources to meet different industrial production needs. Among them, the by-product hydrogen bromide containing organic acid is relatively difficult to purify and utilize due to the presence of organic acid. How to purify this kind of hydrogen bromide so as to make rational use of resources is a difficult problem to be solved.

[0004] At present, the refining process of by-product hydrogen bromide is: filtration, adsorption, bromine removal, distillation and adjustment, so as to obtain the required hydrogen bromide. However, the by-product hydrogen bromide containing organic acid has the problems of difficult distillation purification and difficult separation when treated according to the process. SUMMARY

[0005] The purpose of the present application is to provide a purification method of by-product hydrogen bromide containing organic acid. The method of the present application can realize the separation of hydrogen bromide by simple distillation or liquid separation method, and realize the utilization of organic acid and hydrogen bromide in by-product hydrogen bromide containing organic acid.

[0006] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical scheme:

[0007] The present application provides a purification method of by-product hydrogen bromide containing organic acid, comprising the following steps:

[0008] The by-product hydrogen bromide containing organic acid and monohydric alcohol are mixed to carry out esterification reaction, and a mixture containing organic acid ester is obtained;

[0009] The mixture containing organic acid ester is subjected to distillation or liquid separation to obtain organic acid ester and hydrogen bromide.

[0010] Preferably, the organic acid includes one or more of acetic acid, propionic acid, butyric acid and valeric acid.

[0011] Preferably, the molar ratio of the organic acid to monohydric alcohol is 0.8-1.1:1.

[0012] The content of hydrogen bromide in the by-product hydrogen bromide containing organic acid is 20-48wt%.

[0013] Preferably, the monohydric alcohol includes one or more of methanol, ethanol, propanol, butanol, pentanol and hexanol.

[0014] Preferably, the esterification reaction is performed at a temperature of 70-100℃ for 2-10h.

[0015] Preferably, the distillation is performed at a temperature of 70-90℃.

[0016] Preferably, the separation is performed at room temperature.

[0017] Preferably, the method further comprises: adsorbing and filtering the hydrobromic acid to obtain a pure product of the hydrobromic acid.

[0018] The present application provides a purification method for by-product hydrobromic acid containing organic acid, comprising the following steps: mixing the by-product hydrobromic acid containing organic acid with monohydric alcohol and performing esterification reaction to obtain a mixture containing organic acid ester; distilling or separating the mixture containing organic acid ester to obtain organic acid ester and hydrobromic acid.

[0019] The purification method of the present application is simple in process, easy to control in production process, high in production safety, and clean in separation and purification. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The gas chromatogram and analysis results of the butyl acetate product of Example 1 are shown in Table 1.

[0021] Figure 2 The gas chromatogram and analysis results of the butyl acetate product of Example 2 are shown in Table 2.

[0022] Figure 3 The gas chromatogram and analysis results of the butyl acetate product of Example 3 are shown in Table 3.

[0023] Figure 4 The purification flowchart of the present application is shown in Figure 1. DETAILED DESCRIPTION

[0024] The present application provides a purification method for by-product hydrobromic acid containing organic acid, comprising the following steps:

[0025] mixing the by-product hydrobromic acid containing organic acid with monohydric alcohol and performing esterification reaction to obtain a mixture containing organic acid ester;

[0026] The mixture containing organic acid ester is subjected to distillation or liquid separation to obtain organic acid ester and hydrobromic acid.

[0027] The present application carries out esterification reaction on the by-product hydrobromic acid containing organic acid and monohydric alcohol to obtain a mixture containing organic acid ester. In the present application, the content of hydrobromic acid in the by-product hydrobromic acid containing organic acid is preferably 20-48wt%, more preferably 25-40wt%, and further preferably 30-35wt%; the organic acid preferably includes one or more of acetic acid, propionic acid and butyric acid. In the present application, the molar ratio of organic acid to monohydric alcohol is preferably 0.8-1.1:1. In the present application, the monohydric alcohol preferably includes one or more of methanol, ethanol, propanol, butanol, pentanol and hexanol.

[0028] In the present application, the temperature of the esterification reaction is preferably 70-100℃, more preferably 80-90℃; the time is preferably 2-10h, more preferably 3-8h, and further preferably 4-6h. In the present application, the esterification reaction is preferably carried out in a three-necked flask. The time of the esterification reaction is preferably counted from the beginning of obvious reflux phenomenon.

[0029] After obtaining the mixture containing ester, the present application subjects the mixture containing organic acid ester to distillation or liquid separation to obtain organic acid ester and hydrobromic acid. The organic acid ester can be obtained in pure form by rectification, and the hydrobromic acid can be obtained in pure form by filtration. In the present application, the temperature of the distillation is preferably 70-90℃, and the temperature of the liquid separation is preferably room temperature.

[0030] After obtaining the hydrobromic acid, the present application preferably subjects the hydrobromic acid to adsorption and filtration to obtain pure hydrobromic acid. In the present application, the adsorption is preferably carried out using montmorillonite activated carbon. The adsorption and filtration can remove the impurities carried by the by-product hydrobromic acid.

[0031] The present application uses hydrobromic acid as a catalyst, adds monohydric alcohol to react with organic acid to generate organic acid ester which has a large difference in boiling point with hydrobromic acid or has poor compatibility with hydrobromic acid, and then the by-product hydrobromic acid containing organic acid can be purified by simple distillation or liquid separation, thereby improving the utilization rate of the by-product hydrobromic acid containing organic acid, maximizing the utilization of the by-product hydrobromic acid containing organic acid, achieving the goal of green production, and reducing the pollution to the environment. Moreover, the purification method of the present application is suitable for industrial production, and improves the production value of enterprises.

[0032] Moreover, the purification method of the present application has simple process, easy-to-control production process, high production safety, and clean separation and purification.

[0033] The purification flowchart of the embodiment of the present application is as shown in Figure 4The organic acid-containing by-product hydrobromic acid is heated with a monohydric alcohol, and then distilled or separated to obtain an organic ester. The obtained crude hydrobromic acid is subjected to adsorption and filtration to obtain hydrobromic acid.

[0034] The purification method of the organic acid-containing by-product hydrobromic acid provided by the present application is described in detail below in combination with examples, but they should not be understood as limiting the protection scope of the present application.

[0035] Example 1

[0036] 30.00 g of C3H7OH (0.5 mol) and 105.63 g of by-product hydrobromic acid containing 27 wt% of HBr and 24.1 wt% of acetic acid are added into a three-necked flask, 10.03 g of concentrated sulfuric acid with a mass concentration of 98% is slowly added and stirred, 6.65 g of concentrated sulfuric acid with a mass concentration of 98% is slowly added and stirred when the reaction temperature is heated to 80°C, and the heating is continued. The reaction temperature is measured by a thermometer, and the reaction temperature is controlled to be not higher than 90°C and not lower than 75°C. After obvious reflux phenomenon appears, the liquid in the device is fully refluxed for 2 hours without obvious phenomenon, the distillation device is changed, and the 70°C fraction is collected. After the collection is completed, the mass of the organic acid ester is weighed as 37.25 g.

[0037] The organic acid ester product collected in Example 1 is subjected to gas chromatography analysis, and the results are shown in Table 1. Figure 1 Table 1 Figure 1 a is a gas chromatogram, Figure 1 b is a gas chromatography analysis result. It can be known from Table 1 that the content of propyl acetate is 83.5%. Figure 1

[0038] Example 2

[0039] 126.61 g of by-product hydrobromic acid containing 0.75 mol of HBr and 24.1 wt% of acetic acid is added into a three-necked flask, 3.25 g (0.05 mol) of zinc powder is slowly added until complete reaction, and the reaction temperature is slowly heated to 70°C. A thermometer is used to measure the reaction temperature, and the reaction temperature is controlled to be not higher than 70°C and not lower than 65°C. After obvious reflux phenomenon appears, the liquid in the device is fully reacted and refluxed for 2 hours without obvious phenomenon, the distillation device is changed, and the 70°C fraction is collected. After the collection is completed, the mass of the organic acid ester is weighed as 42.14 g.

[0040] The organic acid ester product collected in Example 2 is subjected to gas chromatography analysis, and the results are shown in Table 2. Figure 2 Table 2 Figure 2 a is a gas chromatogram, Figure 2 b is a gas chromatography analysis result. It can be known from Table 2 that the content of propyl acetate is 83.7%. Figure 2 ​​

[0041] Example 3

[0042] Take 126.61 g of by-product hydrobromic acid containing 0.75 mol of HBr and 24.1 wt% of acetic acid, and add it into a three-necked flask, and slowly heat it to a reaction temperature of 70°C. Add 30.00 g of C3H7OH (0.5 mol), and measure the reaction temperature with a thermometer, and control the reaction temperature at 70°C, and not lower than 65°C. After obvious reflux phenomenon occurs, make the liquid in the device fully react and reflux for 2 h without obvious phenomenon, and then change the distillation device, and collect the 70°C fraction. After the collection is completed, the mass of the organic acid ester is measured to be 41.14 g.

[0043] The organic acid ester product collected in Example 3 is analyzed by gas chromatography, and the results are shown in Table 1. Figure 3 Figure 3 a is a gas chromatogram, Figure 3 b is a gas chromatography analysis result. It can be seen from Table 1 that the content of propyl acetate is 82.6%. Figure 3

[0044] The remaining aqueous solution is a hydrobromic acid solution without acetic acid. The solution is adsorbed by montmorillonite activated carbon, filtered, and a pure hydrobromic acid solution is obtained, and the mass content of HBr is 21.7%.

[0045] Example 4

[0046] Take 126.61 g of by-product hydrobromic acid containing 0.75 mol of HBr and 24.1 wt% of acetic acid, and add it into a three-necked flask, and slowly heat it to a reaction temperature of 70°C. Add 30.00 g of C3H7OH (0.5 mol), and measure the reaction temperature with a thermometer, and control the reaction temperature at 70°C, and not lower than 65°C. After obvious reflux phenomenon occurs, make the liquid in the device fully react and reflux for 2 h without obvious phenomenon, and then change the distillation device, and collect the 70°C fraction. After the collection is completed, the mass of the organic acid ester is measured to be 41.14 g.

[0047] The remaining aqueous solution is a hydrobromic acid solution without acetic acid. The solution is adsorbed by montmorillonite activated carbon, filtered, and a pure hydrobromic acid solution is obtained, and the mass content of HBr is 21.7%.

[0048] Example 5

[0049] ​​Take 126.61 g of the by-product hydrobromic acid containing 0.75 mol of HBr and 24.1 wt% of acetic acid into a three-necked flask, and slowly heat to the reaction temperature of 80°C. Add 30.00 g of ethanol (0.5 mol) drop by drop, and measure the reaction temperature with a thermometer to control the reaction temperature at 80°C. After obvious refluxing occurs, make the liquid in the device fully react and reflux for 2 h without obvious phenomenon, and then change the distillation device to collect the 70°C fraction. After the collection is completed, the mass of the organic acid ester is 37.14 g, and the purity is 82.4%.

[0050] The remaining aqueous solution is a hydrobromic acid solution without acetic acid. The solution is adsorbed by montmorillonite activated carbon, filtered, and a pure hydrobromic acid solution is obtained. The mass content of HBr is 21.7%.

[0051] Example 6

[0052] Take 126.61 g of the by-product hydrobromic acid containing 0.75 mol of HBr and 24.1 wt% of acetic acid into a three-necked flask, and slowly heat to the reaction temperature of 80°C. Add 30.00 g of ethanol (0.5 mol) drop by drop, and measure the reaction temperature with a thermometer to control the reaction temperature at 80°C. After obvious refluxing occurs, make the liquid in the device fully react and reflux for 2 h without obvious phenomenon, and then change the distillation device to collect the 70°C fraction. After the collection is completed, the mass of the organic acid ester is 37.14 g, and the purity is 82.4%.

[0053] The remaining aqueous solution is a hydrobromic acid solution without acetic acid. The solution is adsorbed by montmorillonite activated carbon, filtered, and a pure hydrobromic acid solution is obtained. The mass content of HBr is 21.7%.

[0054] The above only describes the preferred embodiments of the present application. It should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A process for purifying a by-product hydrobromic acid containing organic acids, characterized in that, The steps are: The by-product hydrogen bromide containing organic acid and monohydric alcohol are mixed to perform esterification reaction to obtain a mixture containing organic acid ester; the temperature of the esterification reaction is 70-90℃; The mixture containing organic acid ester is subjected to distillation or liquid separation to obtain organic acid ester and hydrogen bromide.

2. The purification method of claim 1, wherein, The organic acid includes one or more of acetic acid, propionic acid, butyric acid and valeric acid.

3. The purification method according to claim 1 or 2, characterized in that, The molar ratio of the organic acid to monohydric alcohol is 0.8-1.1:1; The content of hydrogen bromide in the by-product hydrogen bromide containing organic acid is 20-48wt%.

4. The purification method according to claim 1 or 2, characterized by, The monohydric alcohol includes one or more of methanol, ethanol, propanol, butanol, pentanol and hexanol.

5. The purification method of claim 3, wherein, The time of the esterification reaction is 2-10h.

6. The purification method of claim 1, wherein, The temperature of the distillation is 70-90℃.

7. The purification method of claim 1, wherein, The temperature of the liquid separation is room temperature.

8. The purification method of claim 1, wherein, Further comprising: The hydrogen bromide is subjected to adsorption and filtration to obtain pure hydrogen bromide.

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