Method for continuous preparation of sodium azide

[0037] Example 1:

[0038] This example provides a method for continuously preparing sodium azide, the method adopts such as figure 1 The continuous reaction device shown to realize the continuous preparation of sodium azide, the continuous reaction device includes an ammoxidation furnace A, the top of the ammoxidation furnace A is connected to the feed port of the heat exchanger B, and the heat exchanger B The discharge port is communicated with the bottom of the tower body of the tower type esterification reactor C. The tower kettle of the tower type esterification reactor C pumps the tower kettle liquid to the top of the tower body, and the top of the tower type esterification reactor C tower body Connected with the bottom of condenser D1, the bottom of condenser D1 is connected with the top of heater D2, the top of heater D2 is connected with the feed port of the three-way valve, and one outlet of the three-way valve is connected with the first tower reactor E1 The bottom of the tower body is connected, the other outlet of the three-way valve is connected to the bottom of the tower body of the second tower reactor E2, the bottom of the first tower reactor E1 and the tower of the second tower reactor E2 The kettle is used to pump the tower kettle liquid to the top of the tower body. The tower kettle of the first tower reactor E1 and the tower kettle bottom of the second tower reactor E2 are respectively connected to the filter F, which is connected to the post-treatment system Connected; the top of the condenser D1, the top of the tower of the first tower reactor E1, and the top of the tower of the second tower reactor E2 are all connected to the tail gas treatment system.

[0039] The method for continuously preparing sodium azide specifically includes the following steps:

[0040] Step 1: Pass ammonia gas and air into the bottom of ammonia oxidation furnace A to carry out catalytic oxidation reaction. The nitrogen oxides produced are passed into the bottom of heat exchanger B for heat exchange, and the temperature of nitrogen oxides is reduced to 30℃~40. ℃, where: the reaction temperature of ammoxidation is controlled in the range of 700℃~720℃, the pressure is in the range of 0.1~0.15Mpa, the molar ratio of ammonia to oxygen is 1:1.5, and the catalyst is a platinum-rhodium catalyst;

[0041] Step 2: The nitrogen oxides cooled by the heat exchanger B are passed into the bottom of the tower body of the tower esterification reactor C in a countercurrent direction and pumped from the tower kettle of the tower esterification reactor C to the tower esterification reactor C. The methanol flowing down from the top of the tower body undergoes an esterification reaction, and the methyl nitrite produced is discharged from the top of the tower body of the tower esterification reactor C. The temperature of the tower esterification reaction is controlled at 40°C and the pressure is constant. Pressure

[0042] Step 3: The methyl nitrite discharged from the top of the tower body of the tower type esterification reactor C enters the condenser D1, and the unreacted nitrogen oxide is separated from the methyl nitrite through the condenser D1, and the unreacted nitrogen oxide passes through The exhaust gas treatment system is recycled and reused, and the condensed methyl nitrite enters the heater D2 for vaporization, in which the temperature of the condenser is controlled within the range of -16℃~-10℃, and the temperature of the heater is controlled at 20℃;

[0043] Step 4: The vaporized methyl nitrite enters the bottom of the E1 tower body of the first tower reactor through the three-way valve, and the methanol solution containing hydrazine hydrate/sodium hydroxide is sent to the E1 tower of the first tower reactor through the tower The circulation pump at the bottom of the kettle is circulated to the top of the first tower reactor E1 tower body to react with methyl nitrite in the countercurrent flow and up to produce sodium azide, and the sodium azide produced enters the first tower reactor E1 tower In the kettle, the unreacted methyl nitrite is recovered and reused through the tail gas treatment system. The mass concentration of the methanol solution of sodium hydroxide is 20%, and the molar ratio of hydrazine hydrate to sodium hydroxide is 1:1.05. The reaction temperature of the E1 tower body of the reactor is 45°C;

[0044] Step 5, take a sample from the E1 tower of the first tower reactor for testing. When the mass content of sodium hydroxide in the residue after the sample is concentrated under reduced pressure to a volatile-free solid is less than 5%, switch the three-way valve to the second Two-tower reactor E2, the first tower reactor E1 is discharged from the tower, and the sodium azide suspension produced enters the filter F, and then enters the post-treatment system after passing through the filter F; the second tower reactor E2 The reaction conditions are the same as the reaction conditions of the first tower reactor E1. The unreacted methyl nitrite is recovered and reused through the tail gas treatment system. A sample is taken from the second tower reactor E2 tower for testing. When the sample is concentrated under reduced pressure to no When the mass content of sodium hydroxide in the residue after the solid of the volatiles is less than 5%, switch the three-way valve to the first tower reactor E1, and the second tower reactor E2 will discharge the tower to produce azide The sodium chloride suspension enters the filter F, and then enters the post-processing system after passing through the filter F; the first tower reactor E1 and the second tower reactor E2 are switched to each other to realize the continuous preparation of sodium azide. The sodium azide continuously prepared in this example is based on hydrazine hydrate, and the yield reaches more than 95%.

[0045] Example 2:

[0046] This example provides a method for continuously preparing sodium azide, the method adopts such as figure 1 The continuous reaction device shown realizes the continuous preparation of sodium azide, and the continuous reaction device is the same as in Example 1.

[0047] The method for continuously preparing sodium azide specifically includes the following steps:

[0048] Step 1: Pass ammonia gas and air into the bottom of ammonia oxidation furnace A to carry out catalytic oxidation reaction. The nitrogen oxides produced are passed into the bottom of heat exchanger B for heat exchange, and the temperature of nitrogen oxides is reduced to 30℃~40. ℃, where: the reaction temperature of ammoxidation is controlled within the range of 700℃~720℃, the pressure is within the range of 0.1~0.15Mpa, the molar ratio of ammonia to oxygen is 1:1.5, and the catalyst is a platinum-rhodium catalyst;

[0049] Step 2: The nitrogen oxides cooled by the heat exchanger B are passed into the bottom of the tower body of the tower esterification reactor C in a countercurrent direction and pumped from the tower kettle of the tower esterification reactor C to the tower esterification reactor C. The ethanol flowing downstream from the top of the tower body undergoes an esterification reaction, and the produced ethyl nitrite is discharged from the top of the tower body of the tower esterification reactor C. The temperature of the tower esterification reaction is controlled at 45°C and the pressure is constant. Pressure

[0050] Step 3: The ethyl nitrite discharged from the top of the tower body of the tower esterification reactor C enters the condenser D1, and the unreacted nitrogen oxide is separated from the ethyl nitrite through the condenser D1, and the unreacted nitrogen oxide passes through The exhaust gas treatment system is recycled and reused, and the condensed ethyl nitrite enters the heater D2 for vaporization, in which the temperature of the condenser is controlled within the range of -10℃~0℃, and the temperature of the heater is controlled at 30℃;

[0051] Step 4. The vaporized ethyl nitrite enters the bottom of the E1 tower of the first tower reactor through the three-way valve, and the ethanol solution containing hydrazine hydrate/sodium hydroxide is sent to the E1 tower of the first tower reactor through the tower The circulating pump at the bottom of the kettle is circulated to the top of the first tower reactor E1, which reacts with ethyl nitrite in the countercurrent flow to form sodium azide, and the sodium azide produced enters the E1 tower of the first tower reactor In the kettle, the unreacted ethyl nitrite is recovered and reused through the tail gas treatment system, where the mass concentration of the sodium hydroxide ethanol solution is 15%, and the molar ratio of hydrazine hydrate to sodium hydroxide is 1:1.05, the first tower type The reaction temperature of the E1 tower body of the reactor is 50°C;

[0052] Step 5, take a sample from the E1 tower of the first tower reactor for testing. When the mass content of sodium hydroxide in the residue after the sample is concentrated under reduced pressure to a volatile-free solid is less than 5%, switch the three-way valve to the second Two-tower reactor E2, the first tower reactor E1 is discharged from the tower, and the sodium azide suspension produced enters the filter F, and then enters the post-treatment system after passing through the filter F; the second tower reactor E2 The reaction conditions are the same as the reaction conditions of the first tower reactor E1. The unreacted ethyl nitrite is recovered and reused through the tail gas treatment system. A sample is taken from the second tower reactor E2 tower kettle for testing. When the sample is concentrated under reduced pressure to no When the mass content of sodium hydroxide in the residue after the solid of the volatiles is less than 5%, switch the three-way valve to the first tower reactor E1, and the second tower reactor E2 will discharge the tower to produce azide The sodium sulfide suspension enters the filter F, and then enters the post-processing system after passing through the filter F; the first tower reactor E1 and the second tower reactor E2 are switched to each other to realize the continuous preparation of sodium azide. The sodium azide continuously prepared in this example is based on hydrazine hydrate, and the yield reaches more than 95%.

[0053] Example 3:

[0054] This example provides a method for continuously preparing sodium azide, the method adopts such as figure 1 The continuous reaction device shown realizes the continuous preparation of sodium azide, and the continuous reaction device is the same as in Example 1.

[0055] The method for continuously preparing sodium azide specifically includes the following steps:

[0056] Step 1: Pass ammonia gas and air into the bottom of ammonia oxidation furnace A to carry out catalytic oxidation reaction. The nitrogen oxides produced are passed into the bottom of heat exchanger B for heat exchange, and the temperature of nitrogen oxides is reduced to 30℃~40. ℃, where: the reaction temperature of ammoxidation is controlled in the range of 700℃~720℃, the pressure is in the range of 0.1~0.15Mpa, the molar ratio of ammonia to oxygen is 1:1.5, and the catalyst is a platinum-rhodium catalyst;

[0057] Step 2: The nitrogen oxides cooled by the heat exchanger B are passed into the bottom of the tower body of the tower esterification reactor C in a countercurrent direction and pumped from the tower kettle of the tower esterification reactor C to the tower esterification reactor C. The isopropanol flowing downstream from the top of the tower body undergoes an esterification reaction, and the produced isopropyl nitrite is discharged from the top of the tower body of the tower esterification reactor C. The temperature of the tower esterification reaction is controlled at 50°C. The pressure is normal pressure;

[0058] Step 3: The isopropyl nitrite discharged from the top of the tower body of the tower esterification reactor C enters the condenser D1, and the unreacted nitrogen oxide is separated from the isopropyl nitrite through the condenser D1, and the unreacted nitrogen is oxidized The waste gas is recovered and reused through the exhaust gas treatment system, and the condensed isopropyl nitrite enters the heater D2 for vaporization, where the temperature of the condenser is controlled within the range of 0℃~10℃, and the temperature of the heater is controlled at 50℃;

[0059] Step 4, the vaporized isopropyl nitrite enters the bottom of the E1 tower body of the first tower reactor through the three-way valve, and the methanol solution containing hydrazine hydrate/sodium hydroxide is sent to the E1 tower kettle of the first tower reactor. The circulation pump at the bottom of the bottom of the tower is circulated to the top of the first tower reactor E1. The top of the tower body reacts with isopropyl nitrite in the countercurrent flow and up to produce sodium azide, and the sodium azide produced enters the first tower reactor In the E1 tower, the unreacted isopropyl nitrite is recovered and reused through the tail gas treatment system. The mass concentration of the methanol solution of sodium hydroxide is 20%, and the molar ratio of hydrazine hydrate to sodium hydroxide is 1:1.05. The reaction temperature of the E1 tower body of a tower reactor is 55°C;

[0060] Step 5, take a sample from the E1 tower of the first tower reactor for testing. When the mass content of sodium hydroxide in the residue after the sample is concentrated under reduced pressure to a volatile-free solid is less than 5%, switch the three-way valve to the second Two-tower reactor E2, the first tower reactor E1 is discharged from the tower, and the sodium azide suspension produced enters the filter F, and then enters the post-treatment system after passing through the filter F; the second tower reactor E2 The reaction conditions are the same as the reaction conditions of the first tower reactor E1. The unreacted isopropyl nitrite is recovered and reused through the tail gas treatment system. A sample is taken from the second tower reactor E2 tower for testing. When the sample is concentrated under reduced pressure to When the mass content of sodium hydroxide in the residue after volatile solids is less than 5%, the three-way valve is switched to the first tower reactor E1, and the second tower reactor E2 is discharged, and the resulting stack The sodium nitride suspension enters the filter F, and then enters the post-processing system after passing through the filter F; the first tower reactor E1 and the second tower reactor E2 are switched to each other to realize the continuous preparation of sodium azide. The sodium azide continuously prepared in this example is based on hydrazine hydrate, and the yield reaches more than 95%.