A method for preparing an aqueous hydroxylamine solution by bipolar membrane electrodialysis

Abstract

The present invention discloses a method for preparing hydroxylamine aqueous solution by bipolar membrane electrodialysis, belonging to the technical field of preparation of hydroxylamine aqueous solution. In this method, hydroxylamine salt and high-purity water are added to a bipolar membrane electrodialysis reactor. After dissolution, sodium salt is added to increase conductivity. The bipolar membrane electrodialysis reactor is started, and the hydroxylamine salt is electrolyzed to obtain hydroxylamine and corresponding anions. Driven by an external electric field, ions permeate through the corresponding exchange membranes to obtain a hydroxylamine aqueous solution. By surface functional modification of the bipolar membrane, the present invention enables the bipolar membrane to have stronger metal ion adsorption ability and complexation ability, thereby effectively reducing the content of metal ions in the hydroxylamine aqueous solution.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of hydroxylamine aqueous solution, and in particular to a method for preparing hydroxylamine aqueous solution by bipolar membrane electrodialysis. Background Art

[0002] Hydroxylamine is a kind of fine chemical product with very wide uses. The molecular formula of hydroxylamine is NH 2 OH. It is an unstable white crystal at room temperature, easy to deliquesce and decompose. Therefore, hydroxylamine is usually stored, transported and used in the form of aqueous solution or salt.

[0003] The published patent document PCT / EP1998 / 003714 provides a method for preparing a high-purity free hydroxylamine aqueous solution, in which a dilute hydroxylamine aqueous solution is concentrated in a tower, and the vapor containing hydroxylamine is taken out from the bottom of the tower through a side stream, and high-purity hydroxylamine is obtained by condensing the vapor.

[0004] The published patent document CN104129764B provides a preparation method of hydroxylamine salt / hydroxylamine from ketone, ammonia and hydrogen peroxide. Its basic characteristics are: using ketone as the circulating reaction medium and an organic solvent insoluble or slightly soluble in water as the circulating solvent medium, integrating the heterogeneous catalytic ammoximation technology and the hydrolysis-extraction coupling technology to realize the preparation of hydroxylamine and / or hydroxylamine salt with ammonia, hydrogen peroxide and inorganic acid as the basic raw materials.

[0005] The published patent document CN110482505B provides a method for preparing hydroxylamine using nitrogen, which is applied to a hydroxylamine preparation device. The method includes: introducing the nitrogen stored in the nitrogen storage device into the water stored in the water storage device through the first pipeline, so that the moistened nitrogen enters the discharge reaction cavity through the second pipeline; turning on the high-voltage power supply, applying a high voltage to the discharge array needle plate, so that water free radical cation clusters are generated at the tips of the discharge array needle plate, and the formed water free radical cation clusters react with nitrogen to generate hydroxylamine free radical cations and nitryl groups, and the hydroxylamine free radical cations are transferred to the cathode plate to form hydroxylamine; the hydroxylamine formed on the cathode plate is output and collected through the product output channel.

[0006] However, the existing public technologies have poor continuous production capacity for preparing hydroxylamine aqueous solution, low production efficiency and high energy consumption. In addition, the product quality of the hydroxylamine aqueous solution is poor, and the metal ion concentration cannot meet the requirements for use in the electronic industry, which limits the application. Summary of the Invention

[0007] In view of the above problems, the invention object of this patent application is to provide a method for preparing hydroxylamine aqueous solution by bipolar membrane electrodialysis, which can significantly reduce the metal ion content in the hydroxylamine aqueous solution, improve the atom economy, reduce the production cost and reduce the "three wastes" emissions.

[0008] The main technical content of the present invention is as follows:

[0009] A method for preparing an aqueous hydroxylamine solution by bipolar membrane electrodialysis, characterized in that the operation steps are as follows:

[0010] A1: By mass, add 138 - 194 parts of hydroxylamine salt into a bipolar membrane electrodialysis reactor, add 800 - 1200 parts of high-purity water for dissolution, add 30 - 60 parts of sodium salt to increase conductivity, and slowly start stirring;

[0011] A2: Start the bipolar membrane electrodialysis reactor, electrolyze the hydroxylamine salt to obtain hydroxylamine and corresponding anions, and carry out the reaction under the drive of an external electric field, so that the ions pass through the corresponding exchange membranes to obtain an aqueous hydroxylamine solution.

[0012] As a further supplement to the above technical solution, the hydroxylamine salt is selected from at least one of hydroxylamine sulfate, hydroxylamine hydrochloride, hydroxylamine nitrate or hydroxylamine phosphate.

[0013] As a further supplement to the above technical solution, the sodium salt is selected from at least one of sodium sulfate, sodium chloride, sodium nitrate or sodium phosphate.

[0014] As a further supplement to the above technical solution, the bipolar membrane electrodialysis reactor is set with a current of 0.1 A to 2.0 A.

[0015] As a further supplement to the above technical solution, the bipolar membrane electrodialysis reactor is set with a voltage of 5 V to 30 V.

[0016] As a further supplement to the above technical solution, the flow rate of the circulation pump of the bipolar membrane electrodialysis reactor is set to 5 - 30 L / h

[0017] As a further supplement to the above technical solution, the reaction temperature is set to 0 °C to 20 °C.

[0018] As a further supplement to the above technical solution, the bipolar membrane is a modified bipolar membrane, and its modification method is as follows:

[0019] By mass, irradiate 50 - 70 parts of the bipolar membrane with an electron beam using an electron accelerator. Immediately after completion, put the bipolar membrane into 500 - 700 parts of cyclohexane, add 0.3 - 0.6 parts of polyvinyl alcohol, 0.01 - 0.3 parts of tetrakis(4-boronic acid phenyl)ethylene, 0.05 - 0.5 parts of vinyltriphenylphosphonium bromide, and 2 - 4 parts of 2,2'-azobis(2-methylbutyronitrile). Control the temperature at 60 - 75 °C and stir and react for 80 - 150 min. After completion, take out the bipolar membrane, wash it 3 - 6 times with deionized water, and dry it to obtain the modified bipolar membrane.

[0020] For further supplement of the above technical solution, the irradiation voltage range is 2 - 5 MeV, the current rate range is 10 - 20 mA, and the irradiation dose range is 40 kGy - 100 kGy.

[0021] The modification mechanism of the bipolar membrane in the present invention is as follows:

[0022] The bipolar membrane uses an electron accelerator to generate free radicals by electron beam radiation, and undergoes surface graft polymerization with tetrakis(4-boronic acid phenyl)ethylene and vinyltriphenylphosphonium bromide, resulting in boronic acid groups and triphenylphosphine functional groups on the surface of the bipolar membrane, which can reduce the metal ion content in the hydroxylamine aqueous solution.

[0023] The technical effects of the present invention are as follows:

[0024] After surface graft polymerization, the bipolar membrane has boronic acid groups and triphenylphosphine functional groups. The boronic acid groups on the surface of the bipolar membrane can form complexes with metal ions, and the triphenylphosphine functional groups can also undergo coordination reactions with metal ions, thereby removing metal ions from the solution. This reaction mechanism is based on the surface functionalization modification of the bipolar membrane, enabling the bipolar membrane to have stronger metal ion adsorption and complexation abilities, and thus effectively reducing the metal ion content in the hydroxylamine aqueous solution. Specific implementation manners

[0025] The essential features and remarkable effects of the present invention can be reflected from the following embodiments, but they do not impose any limitations on the present invention. Those skilled in the art can make some non-essential improvements and adjustments based on the content of the present invention. The present invention will be further described below through specific implementation manners.

[0026] In the examples, the concentration of the free hydroxylamine solution is analyzed by the potassium permanganate redox titration method.

[0027] Example 1

[0028] A method for preparing hydroxylamine aqueous solution by bipolar membrane electrodialysis, characterized in that its operation steps are as follows:

[0029] A1: Add 138 kg of hydroxylamine salt into the bipolar membrane electrodialysis reactor, add 800 kg of high-purity water for dissolution, add 30 kg of sodium salt to increase conductivity, and slowly start stirring;

[0030] A2: Start the bipolar membrane electrodialysis reactor, electrolyze the hydroxylamine salt to obtain hydroxylamine and corresponding anions, and carry out reactions under the drive of an external electric field, so that the ions pass through the corresponding exchange membranes to obtain a hydroxylamine aqueous solution.

[0031] The hydroxylamine salt is selected from hydroxylamine sulfate.

[0032] The sodium salt is selected as sodium sulfate.

[0033] The bipolar membrane electrodialysis reactor is set with a current of 0.5 A.

[0034] The bipolar membrane electrodialysis reactor is set with a current of 5 V.

[0035] The flow rate of the circulation pump of the bipolar membrane electrodialysis reactor is set to 5 L / h.

[0036] The reaction temperature is set to 0 °C.

[0037] The bipolar membrane is a modified bipolar membrane, and its modification method is as follows:

[0038] 500 g of the bipolar membrane is irradiated with an electron beam using an electron accelerator. Immediately after completion, the bipolar membrane is placed into 5000 g of cyclohexane, and 3 g of polyvinyl alcohol, 1 g of tetrakis(4-boronic acid phenyl)ethylene, 1 g of vinyltriphenylphosphonium bromide, and 20 g of 2,2'-azobis(2-methylbutyronitrile) are added. The temperature is controlled at 60 °C, and the mixture is stirred and reacted for 80 min. After completion, the bipolar membrane is taken out, washed 3 times with deionized water, and dried to obtain the modified bipolar membrane.

[0039] After analysis and calculation, the concentration of the hydroxylamine solution in this example is 15.6%, and the concentration of Na + is not higher than 0.1 ppm.

[0040] Example 2

[0041] A method for preparing an aqueous hydroxylamine solution by bipolar membrane electrodialysis, characterized in that its operating steps are as follows:

[0042] A1: Add 152 kg of hydroxylamine salt to the bipolar membrane electrodialysis reactor, dissolve it in 1000 kg of high-purity water, add 40 kg of sodium salt to increase conductivity, and slowly start stirring;

[0043] A2: Start the bipolar membrane electrodialysis reactor, electrolyze the hydroxylamine salt to obtain hydroxylamine and corresponding anions, and carry out the reaction under the drive of an external electric field, so that the ions pass through the corresponding exchange membrane to obtain an aqueous hydroxylamine solution.

[0044] The hydroxylamine salt is selected from hydroxylamine hydrochloride.

[0045] The sodium salt is selected as sodium chloride.

[0046] The bipolar membrane electrodialysis reactor is set with a current of 1.0 A.

[0047] The bipolar membrane electrodialysis reactor is set with a current of 15 V.

[0048] The flow rate of the circulation pump of the bipolar membrane electrodialysis reactor is set to 10 L / h.

[0049] The reaction temperature is set to 5 °C.

[0050] The bipolar membrane is a modified bipolar membrane, and its modification method is as follows:

[0051] 600 g of the bipolar membrane is irradiated with an electron beam using an electron accelerator. Immediately after completion, the bipolar membrane is placed in 6000 g of cyclohexane, and 4 g of polyvinyl alcohol, 2 g of tetrakis(4-boronic acid phenyl)ethylene, 2.5 g of vinyltriphenylphosphonium bromide, and 30 g of azobisisobutyronitrile are added. The temperature is controlled at 65 °C, and the mixture is stirred and reacted for 100 min. After completion, the bipolar membrane is taken out, washed 4 times with deionized water, and dried to obtain the modified bipolar membrane.

[0052] Through analysis and calculation, the concentration of the hydroxylamine solution in this example is 17.4%, and the concentration of Na + is not higher than 0.1 ppm.

[0053] Example 3

[0054] A method for preparing an aqueous hydroxylamine solution by bipolar membrane electrodialysis, characterized in that its operating steps are as follows:

[0055] A1: Add 174 kg of hydroxylamine salt to the bipolar membrane electrodialysis reactor, dissolve it in 1100 kg of high-purity water, add 50 kg of sodium salt to increase conductivity, and slowly start stirring;

[0056] A2: Start the bipolar membrane electrodialysis reactor, electrolyze the hydroxylamine salt to obtain hydroxylamine and the corresponding anions, and react under the drive of an external electric field to allow the ions to pass through the corresponding exchange membranes to obtain an aqueous hydroxylamine solution.

[0057] The hydroxylamine salt is selected from hydroxylamine nitrate.

[0058] The sodium salt is selected as sodium phosphate.

[0059] The bipolar membrane electrodialysis reactor is set with a current of 1.5 A.

[0060] The bipolar membrane electrodialysis reactor is set with a voltage of 25 V.

[0061] The flow rate of the circulation pump of the bipolar membrane electrodialysis reactor is set to 25 / h

[0062] The reaction temperature is set to 15 °C.

[0063] The bipolar membrane is a modified bipolar membrane, and its modification method is as follows:

[0064] Radiate 600 g of bipolar membrane with an electron beam using an electron accelerator. Immediately after completion, place the bipolar membrane into 600 g of cyclohexane, add 5 g of polyvinyl alcohol, 2 g of tetrakis(4-boronic acid phenyl)ethylene, 4 g of vinyltriphenylphosphonium bromide, and 30 g of 2,2'-azobis(2-methylbutyronitrile). Control the temperature at 70 °C and stir for 120 min. After completion, take out the bipolar membrane, wash it 5 times with deionized water, and dry it to obtain the modified bipolar membrane.

[0065] After analysis and calculation, the concentration of hydroxylamine solution in this example is 17.0%, and the concentration of Na + is not higher than 0.1 ppm.

[0066] Example 4

[0067] A method for preparing an aqueous hydroxylamine solution by bipolar membrane electrodialysis, characterized in that: the operating steps are as follows:

[0068] A1: Add 194 kg of hydroxylamine salt to a bipolar membrane electrodialysis reactor, add 1200 kg of high-purity water to dissolve it, add 60 kg of sodium salt to increase conductivity, and slowly start stirring;

[0069] A2: Start the bipolar membrane electrodialysis reactor, electrolyze the hydroxylamine salt to obtain hydroxylamine and the corresponding anions, and carry out the reaction under the drive of an external electric field to make the ions pass through the corresponding exchange membrane to obtain an aqueous hydroxylamine solution.

[0070] The hydroxylamine salt is selected from hydroxylamine phosphate.

[0071] The sodium salt is selected as sodium phosphate.

[0072] The bipolar membrane electrodialysis reactor is set with a current of 2.0 A.

[0073] The bipolar membrane electrodialysis reactor is set with a current of 30 V

[0074] The flow rate of the circulation pump of the bipolar membrane electrodialysis reactor is set to 30 L / h

[0075] The reaction temperature is set to 20 °C.

[0076] The bipolar membrane is a modified bipolar membrane, and its modification method is as follows:

[0077] Radiate 700 g of bipolar membrane with an electron beam using an electron accelerator. Immediately after completion, place the bipolar membrane into 7000 g of cyclohexane, add 6 g of polyvinyl alcohol, 3 g of tetrakis(4-boronic acid phenyl)ethylene, 5 g of vinyltriphenylphosphonium bromide, and 40 g of 2,2'-azobis(2-methylbutyronitrile). Control the temperature at 75 °C and stir for 150 min. After completion, take out the bipolar membrane, wash it 6 times with deionized water, and dry it to obtain the modified bipolar membrane.

[0078] After analysis and calculation, in this example, the concentration of the hydroxylamine solution is 19.1%, and the concentration of Na + is not higher than 0.1 ppm.

[0079] Comparative Example 1

[0080] A method for preparing an aqueous hydroxylamine solution by bipolar membrane electrodialysis, characterized in that the operating steps are as follows:

[0081] A1: Add 138 kg of hydroxylamine salt to the bipolar membrane electrodialysis reactor, add 800 kg of high-purity water to dissolve it, add 30 kg of sodium salt to increase conductivity, and slowly start stirring;

[0082] A2: Start the bipolar membrane electrodialysis reactor, electrolyze the hydroxylamine salt to obtain hydroxylamine and the corresponding anions, and carry out the reaction under the drive of an external electric field to make the ions pass through the corresponding exchange membrane to obtain an aqueous hydroxylamine solution.

[0083] The hydroxylamine salt is selected from hydroxylamine sulfate.

[0084] The sodium salt is selected as sodium sulfate.

[0085] The bipolar membrane electrodialysis reactor is set with a current of 0.5 A.

[0086] The bipolar membrane electrodialysis reactor is set with a current of 5 V.

[0087] The flow rate of the circulation pump of the bipolar membrane electrodialysis reactor is set to 5 L / h.

[0088] The reaction temperature is set to 0 °C.

[0089] After analysis and calculation, in this example, the concentration of the hydroxylamine solution is 14.3%, and the concentration of Na + is 0.6 ppm.

[0090] Comparative Example 2

[0091] A method for preparing an aqueous hydroxylamine solution by bipolar membrane electrodialysis, characterized in that the operating steps are as follows:

[0092] A1: Add 138 kg of hydroxylamine salt to the bipolar membrane electrodialysis reactor, add 800 kg of high-purity water to dissolve it, add 30 kg of sodium salt to increase conductivity, and slowly start stirring;

[0093] A2: Start the bipolar membrane electrodialysis reactor, electrolyze the hydroxylamine salt to obtain hydroxylamine and the corresponding anions, and carry out the reaction under the drive of an external electric field to make the ions pass through the corresponding exchange membrane to obtain an aqueous hydroxylamine solution.

[0094] The hydroxylamine salt is selected from hydroxylamine sulfate.

[0095] The sodium salt is selected as sodium sulfate.

[0096] The bipolar membrane electrodialysis reactor is set with a current of 0.5 A.

[0097] The bipolar membrane electrodialysis reactor is set with a current of 5 V.

[0098] The flow rate of the circulation pump of the bipolar membrane electrodialysis reactor is set to 5 L / h.

[0099] The reaction temperature is set to 0 °C.

[0100] The bipolar membrane is a modified bipolar membrane, and its modification method is as follows:

[0101] Irradiate 500 g of the bipolar membrane with an electron beam using an electron accelerator. Immediately after completion, put the bipolar membrane into 5000 g of cyclohexane, add 3 g of polyvinyl alcohol, 1 g of vinyltriphenylphosphonium bromide, and 20 g of 2,2'-azobis(2-methylbutyronitrile). Control the temperature at 60 °C and stir for 80 min. After completion, take out the bipolar membrane, wash it 3 times with deionized water, and dry it to obtain the modified bipolar membrane.

[0102] After analysis and calculation, the concentration of the hydroxylamine solution in this example is 14.9%, and the concentration of Na + is 0.3 ppm.

[0103] Comparative Example 3

[0104] A method for preparing an aqueous hydroxylamine solution by bipolar membrane electrodialysis, characterized in that its operating steps are as follows:

[0105] A1: Add 138 kg of hydroxylamine salt to the bipolar membrane electrodialysis reactor, add 800 kg of high-purity water to dissolve it, add 30 kg of sodium salt to increase conductivity, and slowly start stirring;

[0106] A2: Start the bipolar membrane electrodialysis reactor, electrolyze the hydroxylamine salt to obtain hydroxylamine and the corresponding anions, and react under the drive of an external electric field to allow the ions to pass through the corresponding exchange membranes to obtain an aqueous hydroxylamine solution.

[0107] The hydroxylamine salt is selected from hydroxylamine sulfate.

[0108] The sodium salt is selected as sodium sulfate.

[0109] The bipolar membrane electrodialysis reactor is set with a current of 0.5 A.

[0110] The bipolar membrane electrodialysis reactor is set with a current of 5 V.

[0111] The flow rate of the circulation pump of the bipolar membrane electrodialysis reactor is set to 5 L / h.

[0112] The reaction temperature is set to 0 °C.

[0113] The bipolar membrane is a modified bipolar membrane, and its modification method is as follows:

[0114] Radiate 500 g of the bipolar membrane with an electron beam using an electron accelerator. Immediately after completion, put the bipolar membrane into 5000 g of cyclohexane, add 3 g of polyvinyl alcohol, 1 g of tetrakis(4-boronic acid phenyl)ethylene, and 20 g of azobisisobutyronitrile. Control the temperature at 60 °C and stir for 80 min. After completion, take out the bipolar membrane, wash it 3 times with deionized water, and dry it to obtain the modified bipolar membrane.

[0115] Through analysis and calculation, the concentration of the hydroxylamine solution in this example is 14.7%, and the concentration of Na + is 0.4 ppm.

[0116] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should fall within the protection scope determined by the claims.

Claims

1. A method for preparing a hydroxylamine aqueous solution by bipolar membrane electrodialysis, characterized in that: The operation steps are: A1: Add 138-194 parts of hydroxylamine salt, 800-1200 parts of high-purity water to a bipolar membrane electrodialysis reactor by mass, add 30-60 parts of sodium salt to increase conductivity, and slowly start stirring; A2: Start the bipolar membrane electrodialysis reactor, electrolyze the hydroxylamine salt to obtain hydroxylamine and the corresponding anion, and react under the drive of the external electric field, so that the ions pass through the corresponding exchange membrane to obtain a hydroxylamine aqueous solution; The bipolar membrane is a modified bipolar membrane, and the modification method is as follows: According to the mass fraction, 50-70 parts of the bipolar membrane are subjected to electron beam irradiation using an electron accelerator. After completion, the bipolar membrane is immediately placed in 500-700 parts of cyclohexane, 0.3-0.6 parts of polyvinyl alcohol and 0.01-0.3 parts of tetrakis(4-boric acid phenyl)ethylene, 0.05-0.5 parts of vinyl triphenylphosphine bromide, 2-4 parts of azobisisoheptanenitrile are added, the temperature is controlled at 60-75° C., the reaction is stirred for 80-150 minutes, and after completion, the bipolar membrane is taken out, washed with deionized water for 3-6 times, and dried to obtain a modified bipolar membrane.

2. The method for preparing a hydroxylamine aqueous solution by bipolar membrane electrodialysis according to claim 1, characterized in that: The hydroxylamine salt is selected from at least one of hydroxylamine sulfate, hydroxylamine hydrochloride, hydroxylamine nitrate or hydroxylamine phosphate.

3. The method for preparing hydroxylamine aqueous solution by bipolar membrane electrodialysis according to claim 1, characterized in that: The sodium salt is selected from at least one of sodium sulfate, sodium chloride, sodium nitrate or sodium phosphate.

4. The method for preparing a hydroxylamine aqueous solution by bipolar membrane electrodialysis according to claim 1, characterized in that: The bipolar membrane electrodialysis reactor is set with a current of 0.1A to 2.0A.

5. The method for preparing hydroxylamine aqueous solution by bipolar membrane electrodialysis according to claim 1, characterized in that: The bipolar membrane electrodialysis reactor is set at a voltage of 5V to 30V.

6. The method for preparing hydroxylamine aqueous solution by bipolar membrane electrodialysis according to claim 1, characterized in that: The flow rate of the circulation pump of the bipolar membrane electrodialysis reactor is set to 5-30 L / h.

7. The method for preparing hydroxylamine aqueous solution by bipolar membrane electrodialysis according to claim 1, characterized in that: The reaction temperature is set at 0°C to 20°C.

8. The method for preparing hydroxylamine aqueous solution by bipolar membrane electrodialysis according to claim 1, characterized in that: The irradiation voltage range is 2-5 MeV, the rate range is 10-20 mA, and the irradiation dose range is 40 kGy-100 kGy.