CN220969095U

CN220969095U - System for continuously producing superfine sodium azide by utilizing hypergravity bed reactor

Info

Publication number: CN220969095U
Application number: CN202322368269.2U
Authority: CN
Inventors: 刘湛; 王效峰; 李洪源; 刘林学; 李建民
Original assignee: Anhui Ruihua Pharmaceutical Technology Co ltd
Current assignee: Anhui Ruihua Pharmaceutical Technology Co ltd
Priority date: 2023-08-31
Filing date: 2023-08-31
Publication date: 2024-05-17
Anticipated expiration: 2033-08-31

Abstract

The utility model discloses a system for continuously producing superfine sodium azide by utilizing a hypergravity bed reactor, wherein a nitrite synthesis section comprises a nitrite and alcohol water solution overhead tank, a dilute acid overhead tank and a first hypergravity bed reactor; the sodium azide synthesis section comprises a nitrite high-level tank, hydrazine and sodium hydroxide solution high-level tank and a second hypergravity bed reactor; the hypergravity separation section comprises a first hypergravity bed separator. Under the action of strong centrifugal force, the mixing and the transfer of materials are effectively enhanced, so that the speed of material reaction and separation is increased, even if the phase transfer catalyst is not needed in one step of the azide reaction, the reaction time is shortened to a minute level from the traditional hours, the residence time of the materials in equipment is very short, the production period is greatly shortened, the reaction process is safer and more stable, and the production efficiency is remarkably improved.

Description

System for continuously producing superfine sodium azide by utilizing hypergravity bed reactor

Technical Field

The utility model belongs to the field of chemical industry, relates to sodium azide production, and in particular relates to a system for continuously producing superfine sodium azide by utilizing a hypergravity bed reactor.

Background

Sodium azide is an important chemical raw material, and is widely used in the fields of medicines, pesticides, electronic products, heat-resistant high polymer materials, military industry and the like in recent twenty years. The synthesis of the nitrite is commonly carried out in industry at present by a plurality of methods, namely a method of nitrite, hydrazine hydrate and sodium hydroxide, the method is divided into a sulfuric acid, nitrite and alcohol method, a dilute nitric acid, nitrite and alcohol method, an ammoxidation method, an alcohol method, an electrodialysis method, a nitric oxide, oxygen and alcohol method and the like according to the synthesis method of the raw material nitrite, and different manufacturers select technological routes according to the funds and specific working conditions, so that the method has advantages and disadvantages. The chinese patent application nos. 201510629438.0, 201310452735.3, 2015128267. X, 201721146705.X and 201310451461.6 disclose processes for synthesizing sodium azide and its raw materials, namely, nitrous acid ester, wherein the nitrous acid ester can be methyl ester, ethyl ester, propyl ester, butyl ester and isoamyl ester, more ethyl ester (boiling point of ethyl nitrite is 17 ℃) is actually used industrially, methyl ester is low in cost but is a toxic gas intermittent operation, and excessive tail gas is not well recovered, so that environmental problems are caused, propyl ester, butyl ester and isoamyl ester have high cost, and residues in mother liquor are high, so that the production environment has a pungent smell, and production wastewater is not well treated, so that the use is little. One step of azide is commonly performed using methanol as a solvent and ethanol as a second step due to the solubility problem of sodium hydroxide. The ethanol is adopted as a solvent to be matched with ethyl nitrite for easy post-treatment, but the ethanol has high cost, more importantly, the solubility of sodium azide in ethanol is 0.3 percent at 25 ℃, and impurities are easy to wrap to cause the impurity of the product to be impure and the free alkali to be high. Therefore, a plurality of industrial manufacturers can produce qualified products at one time by adopting ethyl nitrite as a raw material and methanol as a solvent, and the overall cost is lower, but the problem of separation of the methanol and the ethanol exists in the post-treatment.

The Chinese patent with the application number 201210132140.5 discloses a preparation method of sodium azide, ethyl nitrite gas is introduced into a mixture composed of hydrazine hydrate, sodium hydroxide, a catalyst and ethanol, and after the gas is introduced, the reaction is carried out for 1.5 to 2.5 hours at the temperature of 18 to 25 ℃. The catalyst is benzyl triethyl ammonium chloride, tetrabutyl ammonium bromide, tetrabutyl ammonium chloride, tetrabutyl ammonium bisulfate, trioctyl methyl ammonium chloride, dodecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium chloride and the like. The ethanol can be recycled by the technical route, but the method is a synthesis process with gas-liquid two phases, needs to be operated under pressure, has gas leakage danger, and has more strict condition control.

The chinese patent with application number 201210140899.8 discloses a water phase synthesis method of sodium azide, which comprises adding liquid ethyl nitrite into a reaction system composed of hydrazine hydrate, sodium hydroxide, a phase transfer catalyst and water, performing a closed reaction, recovering unreacted ethyl nitrite, byproduct ethanol and water after the reaction is completed, and filtering the reaction solution to obtain sodium azide. Because the reaction heat effect is relatively large, the system pressure is easily increased and exploded due to the out-of-control of one-time feeding reaction in a batch reactor by taking liquid ethyl nitrite with low boiling point as a raw material.

The Chinese patent with the application number 201510114085.0 discloses a sodium azide aqueous phase synthesis process for recycling n-butyl alcohol, butyl nitrite, sodium hydroxide, hydrazine hydrate, a catalyst and water are mixed to form a reaction system, after the reaction is finished, the n-butyl alcohol is recovered, the sodium azide is obtained by filtration, the recovered n-butyl alcohol is recycled, and the n-butyl ester with a higher boiling point (the boiling point of 78 ℃) is adopted relatively safely. However, the butyl nitrite has poor water solubility, so that the reaction time is as long as 12 hours, the purity of the product is low, and the produced n-butanol has bad smell and is not friendly to the production environment.

The Chinese patent with the application number 2020.1 0166694.1 discloses a continuous sodium azide aqueous phase safety production device and process by utilizing a microchannel reactor, which solve the problems of safety, automation and the like in the sodium azide production process, but have the advantages of larger equipment investment and higher energy consumption for concentrating and crystallizing reaction products from the aqueous phase. In addition, attempts have been made to solve the safety problem in the production process of sodium azide by using a microchannel reactor in an organic solvent, but the reaction cannot be smoothly performed due to the blockage of channels by the product.

The common characteristic of the above methods is that the product is crystallized from an organic phase or concentrated from an aqueous phase, the produced product particles are relatively large, sodium azide is used as a raw material in the synthesis of organic products (such as alkylsilazide, benzyl azide and acyl azide) and is carried out in organic solvents which do not contain active hydrogen, and the solvents cannot dissolve the sodium azide, so that the sodium azide is often ground into fine powder for reaction, even if the reaction time is relatively long, and a phase transfer catalyst is required, and therefore, the superfine sodium azide product is very suitable for the organic reactions.

Disclosure of Invention

Aiming at the defects existing in the prior art, the utility model aims to provide a system for continuously producing superfine sodium azide by using a hypergravity bed reactor, which solves the technical problem that the production method in the prior art is difficult to meet the practical requirements of industrial production because the product particles of the sodium azide are relatively large.

In order to solve the technical problems, the utility model adopts the following technical scheme:

A system for continuously producing superfine sodium azide by utilizing a hypergravity bed reactor comprises a nitrous acid ester synthesis section, a sodium azide synthesis section and a hypergravity separation section.

The nitrite and alcohol aqueous solution high-level tank is connected with a first feed inlet of a first hypergravity bed reactor through a first metering pump and a first preheater; the dilute acid overhead tank is connected with a second feed inlet of the first hypergravity bed reactor through a second metering pump and a second preheater.

The first hypergravity bed reactor is connected with a nitrous acid ester condenser.

The sodium azide synthesis working section comprises a nitrous acid ester high-level tank, a hydrazine and sodium hydroxide solution high-level tank, a discharge port of a nitrous acid ester condenser is connected with the nitrous acid ester high-level tank, and the nitrous acid ester high-level tank is connected with a third feed port of a second hypergravity bed reactor through a third metering pump; the hydrazine and sodium hydroxide solution overhead tank is connected with a fourth feed inlet of the second hypergravity bed reactor through a fourth metering pump.

The third discharge port of the second hypergravity bed reactor is connected with the feed inlets of a plurality of parallel crystal growing kettles, the discharge port of the crystal growing kettles is connected with the feed inlet of a centrifugal machine, and the liquid discharge port of the centrifugal machine is connected with a mother liquor storage tank.

The mother liquor storage tank is connected with a fifth feed inlet of the first hypergravity bed separator through a fifth metering pump and a third preheater.

The utility model also has the following technical characteristics:

A preferable parallel technical scheme is that a second discharge port of the first hypergravity bed reactor is connected with a nitrous acid ester condenser.

In another preferred parallel technical scheme, the first discharge port of the first hypergravity bed reactor is connected with the sixth feed port of the second hypergravity bed separator through the fourth preheater, and the second discharge port of the first hypergravity bed reactor is closed.

And the eighth discharge port of the second hypergravity bed separator is connected with a nitrous acid ester condenser.

Further, the fourth discharge port of the second hypergravity bed reactor is connected with the first condenser and the second condenser with two different cooling temperatures in a serial connection mode, condensate of the first condenser flows back to the fourth discharge port of the second hypergravity bed reactor, and the discharge port of the second condenser is used for recycling the nitrite to remove the nitrite.

Further, a sixth discharge port of the first hypergravity bed separator is connected with a solvent recovery condenser.

Preferably, the crystal growing kettle is replaced by a concentrating crystallization kettle.

Compared with the prior art, the utility model has the following technical effects:

the super gravity bed (1000 times gravity) continuous reactor used in the utility model effectively strengthens the mixing and transferring of materials under the action of strong centrifugal force, thereby accelerating the reaction and separation speed of the materials, even the phase transfer catalyst is not needed in one step of the azide reaction, the reaction time is shortened to the minute level from the traditional hours, the residence time of the materials in the equipment is very short, the production period is greatly shortened, the reaction process is safer and more stable, and the production efficiency is obviously improved.

The super-gravity bed reactor used in the utility model has the structural characteristics of small reaction space and large specific surface area, can strengthen mass transfer in the reaction process, and has small occupied area of the whole reaction system and reduced equipment investment.

The utility model adopts two temperature conditions of reaction and separation in the preparation process of the ester, effectively avoids the decomposition of nitrous acid as an intermediate product, and further avoids the side reaction of nitrogen oxides as a decomposition product and hydrazine hydrate.

And (IV) the whole system adopts continuous and airtight operation, so that the loss of solvent and the pollution of VOCs are avoided.

The reaction and crystallization process can be effectively controlled on molecular scale by adopting a spiral channel type rotating bed and other reactors in the sodium azide generation reaction, so that the high-quality nano powder with small granularity and uniform distribution is obtained, and the method has the characteristics of small amplification effect, no raw material wrapping, difficult blockage and the like.

The utility model can increase the production scale or flexibly arrange the production capacity through the design of the number of the super-gravity bed continuous reactors and the like, thereby completely realizing the automation.

Drawings

Fig. 1 is a schematic diagram of the overall connection relationship of the a system in embodiment 1.

FIG. 2 is a schematic diagram showing the connection of the nitrite synthesis section of the A system in example 1.

FIG. 3 is a schematic diagram of the connection of the sodium azide synthesis section of the A system in example 1.

FIG. 4 is a schematic diagram showing the connection of the hypergravity separation section of the A system in example 1.

Fig. 5 is a schematic diagram of the overall connection relationship of the B system in embodiment 2.

FIG. 6 is a schematic diagram showing the connection of the nitrite synthesis section of the B system in example 2.

The meaning of each reference numeral in the figures is: a-nitrous acid ester synthesis section, b-sodium azide synthesis section and c-hypergravity separation section.

1-Nitrite and alcohol water solution overhead tank, 2-dilute acid overhead tank, 3-first metering pump, 4-second metering pump, 5-first preheater, 6-second preheater, 7-first hypergravity bed reactor, 8-second feed port, 9-first feed port, 10-first discharge port, 11-waste brine tank, 12-waste brine pump, 13-second discharge port, 14-nitrite condenser, 15-nitrite overhead tank, 16-sodium hydroxide solution overhead tank, 17-third metering pump, 18-fourth metering pump, 19-second hypergravity bed reactor, 20-fourth feed port, 21-third feed port, 22-third discharge port, 23-crystal growing kettle, 24-centrifuge, 25-mother liquor storage tank, 26-fifth metering pump, 27-fourth discharge port, 28-first condenser, 29-second condenser, 30-third preheater, 31-first hypergravity bed separator, 32-fifth feed port, 33-sixth feed port, 33-third condenser, 35-sixth condenser, water recovery tank, and alcohol recovery tank, and water recovery pump, and water tank, and the like.

101-Fourth preheater, 102-second hypergravity bed separator, 103-sixth feed inlet, 104-seventh discharge outlet, 105-eighth discharge outlet.

In the figure, FE denotes a flowmeter, and T denotes a thermometer.

The following examples illustrate the utility model in further detail.

Detailed Description

All the components and devices of the present utility model are known in the art unless otherwise specified. For example, a hypergravity bed reactor is used as the hypergravity bed reactor known in the prior art, and a hypergravity bed separator is used as the hypergravity bed separator known in the prior art; the wastewater treatment system employs a wastewater treatment system known in the art. The material drying system adopts a material drying system known in the prior art, and the solvent recovery system adopts a solvent recovery system known in the prior art.

As can be seen from analysis of the prior art in the background art, the sodium azide production process mainly has four problems, namely, the safety problem is firstly that the prior art for synthesizing the ester by simultaneously synthesizing and separating the nitrite at room temperature or above comprises three reactions (nitrite reacts with acid to generate nitrous acid, nitrous acid reacts with alcohol to generate nitrous acid ester, nitrous acid is decomposed into nitric oxide and nitrogen dioxide, the nitrous acid and the alcohol react to generate nitrous acid ester, the nitrous acid and the nitrogen dioxide can escape from a reaction system and are not reacted with alcohol), the escaped nitric oxide and air are all oxidized into nitrogen dioxide when contacted, if the nitrogen dioxide enters the next section to react with hydrazine hydrate, potential safety hazards exist, and only at lower temperature, preferably-5 ℃ to 5 ℃, the nitrous acid is not easy to decompose. In addition, the reaction heat effect of the azide reaction is relatively large, and the nitrous acid ester is inflammable, explosive and toxic, can not be stored in a large quantity and is required to be generated and utilized simultaneously; secondly, the reaction speed, the conversion rate and the product purity are affected by the different solubilities of sodium hydroxide, sodium azide and nitrous acid ester in water and alcohol; the third aspect is the problem of product granularity, and the large-scale use of the kettle type organic solvent for reaction in the current production has the disadvantages of poor control of product granularity, large size and adverse subsequent application; the fourth aspect is the problem commonly existing in the reported process, namely the problem of continuity and automation of the reaction process, and solves the problems of safety, cost, production efficiency and the like.

Aiming at the defects of the prior art, the utility model provides a process for producing sodium azide by adopting a hypergravity bed reactor in the whole process of ester synthesis, ester separation, sodium azide synthesis and mother liquor recovery. The method can strictly control the temperature and the residence time in the reaction process, prevent the reaction from being out of control and improve the safety of the production process. The utility model can continuously, safely and efficiently carry out the reaction and realize the automatic production due to the strong mass transfer effect of the hypergravity bed reactor.

The utility model adopts a continuous hypergravity bed reactor to quickly react the prepared acid with nitrite and alcohol water solution, and quickly separates the generated ester (the residue of the ester in the mother liquor is less than 50 ppm) by using the hypergravity bed, so that the selectivity of the acid is more flexible, and the dilute sulfuric acid, the dilute hydrochloric acid and the dilute nitric acid can be selected by the traditional process.

According to the utility model, nitrous acid ester, prepared hydrazine hydrate and sodium hydroxide solution are respectively metered and introduced into a super-gravity bed reactor according to a certain proportion, and react at a certain temperature to obtain superfine sodium azide dispersion liquid, the dispersion liquid is subjected to crystal growth through a crystal growing kettle (a concentrating and crystallizing kettle) to generate uniform superfine sodium azide particles, and then the superfine sodium azide particles are subjected to solid-liquid separation to obtain a product, and are dried to obtain a superfine sodium azide finished product. The mother liquor is distilled by a hypergravity bed to recover the solvent for reuse.

In the utility model, the condenser adopts cooling liquid of-20 to room temperature, the generated mother liquor is directly concentrated to crystallize the corresponding inorganic salt as a byproduct, and the waste gas of the synthesized ester tail gas is treated.

The tail gas of the synthesized sodium azide is subjected to two-stage condensation, the cooling liquid of the 1 st stage is cooling water at room temperature, and the cooling liquid of the 2 nd stage is cooling liquid of minus 20 to room temperature.

In the utility model, mother liquor in the centrifugal machine returns to the batching section after being treated, and the product goes to the finished product drying section.

In the present utility model, the ultrafine sodium azide means sodium azide having a particle size of 50 to 5000nm, and preferably, the ultrafine sodium azide means sodium azide having a particle size of 50 to 500 nm.

In the utility model, all the devices are connected through pipelines, and valves are arranged on all the pipelines according to the requirements.

The following specific embodiments of the present utility model are provided, and it should be noted that the present utility model is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical scheme of the present utility model fall within the protection scope of the present utility model.

Example 1:

The embodiment provides a system for continuously producing superfine sodium azide by utilizing a hypergravity bed reactor, wherein the system is an A system.

As shown in fig. 1, the a system comprises a nitrite synthesis section a, a sodium azide synthesis section b and a supergravity separation section c.

As shown in fig. 2, the nitrite synthesis section a of the system A comprises a nitrite and alcohol water solution overhead tank 1 and a dilute acid overhead tank 2, wherein the nitrite and alcohol water solution overhead tank 1 is connected with a first feed inlet 9 of a first hypergravity bed reactor 7 through a first metering pump 3 and a first preheater 5; the dilute acid overhead tank 2 is connected with a second feed inlet 8 of the first hypergravity bed reactor 7 through a second metering pump 4 and a second preheater 6;

the second discharge port 13 of the first hypergravity bed reactor 7 is connected with a nitrous acid ester condenser 14.

As shown in fig. 3, the sodium azide synthesis section b of the system a comprises a nitrite high tank 15 and a hydrazine and sodium hydroxide solution high tank 16, the discharge port of a nitrite condenser 14 is connected with the nitrite high tank 15, and the nitrite high tank 15 is connected with a third feed port 21 of a second hypergravity bed reactor 19 through a third metering pump 17; the hydrazine and sodium hydroxide solution overhead tank 16 is connected to a fourth feed port 20 of a second hypergravity bed reactor 19 by a fourth metering pump 18.

The third discharge port 22 of the second hypergravity bed reactor 19 is connected with the feed ports of a plurality of parallel crystal growing kettles 23, the discharge port of the crystal growing kettles 23 is connected with the feed port of a centrifugal machine 24, and the liquid discharge port of the centrifugal machine 24 is connected with a mother liquor storage tank 25.

The fourth discharge port 27 of the second hypergravity bed reactor 19 is connected with the first condenser 28 and the second condenser 29 with two different cooling temperatures in series, and condensate of the first condenser 28 flows back to the fourth discharge port 27 of the second hypergravity bed reactor 19, and the discharge port of the second condenser 29 is used for recycling the nitrite to the nitrite removing high tank 15.

As shown in fig. 4, the hypergravity separation section c of the a system comprises a first hypergravity bed separator 31, and the mother liquor storage tank 25 is connected to a fifth feed inlet 32 of the first hypergravity bed separator 31 by a fifth metering pump 26, a third preheater 30.

The sixth outlet 34 of the first hypergravity bed separator 31 is connected to a solvent recovery condenser 35.

In this embodiment, the first discharge port 10 of the first hypergravity bed reactor 7 in the nitrite synthesis section a is connected to a wastewater brine tank 11 and to a wastewater treatment system via a wastewater brine pump 12.

In this embodiment, the solid discharge port of the centrifuge 24 in the sodium azide synthesis section b is discharged to a material drying system.

In this embodiment, the discharge port of the solvent recovery condenser 35 in the hypergravity separation section c is connected to a solvent recovery system.

In this embodiment, the fifth discharge port 33 of the first hypergravity bed separator 31 in the hypergravity separation section c is connected to a wastewater treatment system,

In the embodiment, the hypergravity bed reactor and the hypergravity bed separator can select a single-drive hypergravity bed rotary packed bed, a double-drive hypergravity bed rotary packed bed, a spiral channel type rotary bed and a multi-layer baffled hypergravity bed rotary bed according to requirements.

In this embodiment, the nitrite tank 15 is provided with a coolant inlet and outlet.

In this embodiment, the number of the crystal growing kettles 23 is two or more. The crystal growing kettle 23 is provided with a heating or cooling liquid inlet and a heating or cooling liquid outlet.

Example 2:

the embodiment provides a system for continuously producing superfine sodium azide by utilizing a hypergravity bed reactor, wherein the system is a B system.

As shown in fig. 5, the B system also includes a nitrite synthesis section a, a sodium azide synthesis section B, and a supergravity separation section c.

As shown in fig. 6, the nitrite synthesis section a of the system B comprises a nitrite and alcohol water solution overhead tank 1 and a dilute acid overhead tank 2, wherein the nitrite and alcohol water solution overhead tank 1 is connected with a first feed inlet 9 of a first hypergravity bed reactor 7 through a first metering pump 3 and a first preheater 5; the dilute acid overhead tank 2 is connected with a second feed inlet 8 of the first hypergravity bed reactor 7 through a second metering pump 4 and a second preheater 6;

The first discharge port 10 of the first hypergravity bed reactor 7 is connected with the sixth feed port 103 of the second hypergravity bed separator 102 through the fourth preheater 101, and the second discharge port 13 of the first hypergravity bed reactor 7 is closed.

The eighth outlet 105 of the second hypergravity bed separator 102 is connected to the nitrite condenser 14.

The sodium azide synthesis section B of the system B is identical to the sodium azide synthesis section B of the system a.

The hypergravity separation section c of the B system is the same as the hypergravity separation section c of the A system.

In the embodiment, a seventh discharge port 104 of the second hypergravity bed separator 102 in the nitrite synthesis section a is connected with a waste brine tank 11 and is connected with a waste water treatment system through a waste brine pump 12,

Example 3:

this example shows a process for continuously producing ultrafine sodium azide using a hypergravity bed reactor, which employs the system for continuously producing ultrafine sodium azide using a hypergravity bed reactor shown in example 1.

And (3) batching:

1. The concentration of sodium nitrite in the aqueous solution of sodium nitrite and methanol is 4.6mol/L, and the concentration of methanol is 4.83mol/L.

2. The concentration of the dilute sulfuric acid is 2.6mol/L.

3. The concentration of hydrazine hydrate in the methanol solution of hydrazine and sodium hydroxide is 5.25mol/L, and the concentration of sodium hydroxide is 5.0mol/L.

Firstly, pumping the prepared sodium nitrite and methanol aqueous solution into a nitrite and alcohol aqueous solution overhead tank 1 with a weighing module, pumping dilute sulfuric acid into a dilute acid overhead tank 2 with the weighing module, starting a first hypergravity bed reactor 7, and mixing the two according to a volume ratio of 1:1 is pumped into a first hypergravity bed reactor 7 from a first feed inlet 9 and a second feed inlet 8 through a first metering pump 3, a second metering pump 4, a first preheater 5 and a second preheater 6, the temperature of feed liquid is controlled to be-5-0 ℃, and the jacket temperature of a nitrite condenser 14 and a nitrite overhead tank 15 is controlled to be lower than-15 ℃. At this time, the molar ratio of sodium nitrite, methanol and sulfuric acid was 1:1.05:0.565.

Secondly, pumping the prepared hydrazine and sodium hydroxide methanol solution into a sodium hydroxide solution high-level tank 16 with a weighing module, starting a second hypergravity reactor 19, and when the ester collected by the sodium nitrite high-level tank 15 exceeds 1/3 of the tank capacity, mixing the materials according to the volume of 1:0.3234 (methyl nitrite density 0.991g/cm ³, at this time, the molar ratio of sodium hydroxide, hydrazine and nitrous acid ester is 1:1.05:1.05) respectively enters the second hypergravity bed reactor 19 from the third feed inlet 21 and the fourth feed inlet 20 at the same time, 1 crystal growing kettle 23 is opened at the same time, the temperature in the crystal growing kettles 23 is kept at 35-40 ℃, and when the liquid level of one crystal growing kettle 23 reaches the control liquid level, the crystal growing kettle 23 is switched to the other crystal growing kettle 23. The residence time in the crystal growing kettle 23 is not more than 1 hour from the time when the control liquid level is reached. And cooling to room temperature after crystal growth, centrifuging to obtain sodium azide solid powder, drying to obtain superfine powder, and analyzing the powder to obtain powder with particle size of 50-500 nm, main content of 99.5% and free alkali content of 0.3%.

And thirdly, heating the centrifugal mother liquor to 70 ℃ through a fifth metering pump 26 and a third preheater 30, and feeding the centrifugal mother liquor into a first hypergravity bed separator 31 from a fifth feed inlet 32, recovering solvent methanol, and dehydrating the wastewater.

Example 4:

And (3) batching:

1. The concentration of nitrite in the aqueous solution of sodium nitrite and ethanol is 4.6mol/L, and the concentration of ethanol is 4.83mol/L.

2. The concentration of the dilute sulfuric acid is 2.6mol/L.

3. The concentration of hydrazine hydrate in the hydrazine and sodium hydroxide ethanol solution is 5.25mol/L, and the concentration of sodium hydroxide is 5.0mol/L.

Firstly, pumping the prepared sodium nitrite and ethanol aqueous solution into a nitrite and ethanol aqueous solution overhead tank 1 with a weighing module, pumping dilute sulfuric acid into a dilute acid overhead tank 2 with the weighing module, starting a first hypergravity bed reactor 7, and mixing the two according to a volume ratio of 1:1 is pumped into a first hypergravity bed reactor 7 from a first feed inlet 9 and a second feed inlet 8 through a first metering pump 3, a second metering pump 4, a first preheater 5 and a second preheater 6, the temperature of feed liquid is controlled to be room temperature, and the jacket temperature of a nitrite condenser 14 and a nitrite high level tank 15 is controlled to be lower than 0 ℃. At this time, the molar ratio of sodium nitrite, ethanol and sulfuric acid was 1:1.05:0.565.

Secondly, pumping the prepared hydrazine and sodium hydroxide ethanol solution into a sodium hydroxide solution high-level tank 16 with a weighing module, and opening a second hypergravity reactor 19, wherein when the ester collected by the sodium nitrite high-level tank 15 exceeds 1/3 of the tank capacity, the volume ratio is 1:0.3289 (the density of ethyl nitrite is 1.05g/cm ³, at the moment, the molar ratio of sodium hydroxide, hydrazine and nitrous acid ester is 1:1.05:1.05) respectively enters the second hypergravity bed reactor 19 from the third feed inlet 21 and the fourth feed inlet 20 at the same time, 1 crystal growing kettle 23 is opened at the same time, the temperature in the crystal growing kettles 23 is kept at 35-40 ℃, and when the liquid level of one crystal growing kettle 23 reaches the control liquid level, the crystal growing kettle 23 is switched to the other crystal growing kettle 23. The residence time in the crystal growing kettle 23 is not more than 1 hour from the time when the control liquid level is reached. After crystal growth, cooling to room temperature, centrifuging to obtain sodium azide solid powder, drying to obtain superfine powder, and analyzing the powder to obtain powder with particle size of 50-500 nm and main content of 99.6% and free alkali content of 0.2%.

And thirdly, heating the centrifugal mother liquor to 90 ℃ through a fifth metering pump 26 and a third preheater 30, and feeding the centrifugal mother liquor into a first hypergravity bed separator 31 from a fifth feed inlet 32, recovering solvent ethanol and dehydrating the wastewater.

Example 5:

This example is essentially the same as example 3, except that the raw dilute acid is replaced with 5.2mol/L dilute nitric acid and the sodium nitrate-containing wastewater is produced in the synthetic ester section.

Example 6:

This example is essentially the same as example 3, except that the nitrite is potassium nitrite and the raw dilute acid is 5.2mol/L dilute hydrochloric acid, and the potassium chloride-containing wastewater is produced in the synthesis of the ester section.

Example 7:

This example is basically the same as example 3, except that hydrazine and sodium hydroxide solution are changed to aqueous solution, the crystallization kettle 23 is changed to a concentration crystallization kettle, the centrifugal mother liquor is returned to the concentration crystallization kettle to be combined with a new reaction mixture to be concentrated and crystallized, and the recovered methanol is returned to the ester synthesis section for batching and the wastewater is dehydrated.

As shown in FIG. 3, when water is used as the solvent for the azide reaction, the crystal growing kettle 23 is changed into a concentrated crystallization kettle, the mother liquor storage tank 25 is also connected with a feed inlet of the concentrated crystallization kettle through a fifth metering pump 26, a condensate outlet of the concentrated crystallization kettle is respectively connected with a low boiling point alcohol receiving tank 36 and a water receiving tank 38, the alcohol receiving tank 36 is connected with an alcohol batching system of an ester production section through an alcohol delivery pump 37, and the water receiving tank 38 is connected with a water treatment system through a water delivery pump 39.

The final product has a particle size of 1000-5000 nm, a main content of 99.4% and free alkali content of 0.4%.

Example 8:

this example shows a process for continuously producing ultrafine sodium azide using a hypergravity bed reactor, which employs the system for continuously producing ultrafine sodium azide using a hypergravity bed reactor as shown in example 2.

And (3) batching:

1. The concentration of sodium nitrite in the aqueous solution of sodium nitrite and ethanol is 4.6mol/L, and the concentration of ethanol is 4.83mol/L.

2. The concentration of the dilute sulfuric acid is 2.6mol/L.

Firstly, pumping the prepared sodium nitrite and ethanol water solution into a nitrite and ethanol water solution overhead tank 1 with a weighing module, pumping dilute sulfuric acid into a dilute acid overhead tank 2 with the weighing module, starting a first hypergravity bed reactor 7 and a first hypergravity bed separator 102, and mixing the two according to a volume ratio of 1:1 is pumped into a first hypergravity bed reactor 7 from a first feed inlet 9 and a second feed inlet 8 through a first metering pump 3, a second metering pump 4, a first preheater 5 and a second preheater 6, the temperature of feed liquid is controlled to be 0-5 ℃, the mixed liquid generated by reaction enters a second hypergravity bed separator 102 from a sixth feed inlet 103 through a fourth preheater 101, the temperature of feed liquid is controlled to be 20-25 ℃, and the jacket temperature of a nitrite condenser 14 and a nitrite high level tank 15 is controlled to be lower than 0 ℃. At this time, the molar ratio of sodium nitrite, ethanol and sulfuric acid was 1:1.05:0.565.

Secondly, pumping the prepared hydrazine and sodium hydroxide ethanol solution into a sodium hydroxide solution high-level tank 16 with a weighing module, starting a second hypergravity reactor 19, and when the ester collected by the sodium nitrite high-level tank 15 exceeds 1/3 of the tank capacity, mixing the materials according to the volume ratio of 1:0.3289 (the density of ethyl nitrite is 1.05g/cm ³, at the moment, the molar ratio of sodium hydroxide, hydrazine and nitrous acid ester is 1:1.05:1.05) respectively enters the second hypergravity bed reactor 19 from the third feed inlet 21 and the fourth feed inlet 20 at the same time, 1 crystal growing kettle 23 is opened at the same time, the temperature in the crystal growing kettles 23 is kept at 35-40 ℃, and when the liquid level of one crystal growing kettle 23 reaches the control liquid level, the crystal growing kettle 23 is switched to the other crystal growing kettle 23. The residence time in the crystal growing kettle 23 is not more than 1 hour from the time when the control liquid level is reached. After crystal growth, cooling to room temperature, centrifuging to obtain sodium azide solid powder, drying to obtain superfine powder, and analyzing the powder to obtain powder with particle size of 50-500 nm and main content of 99.6% and free alkali content of 0.2%.

Example 9:

This example is essentially the same as example 8, except that the nitrite is potassium nitrite and the raw dilute acid is 5.2mol/L dilute hydrochloric acid, and the potassium chloride-containing wastewater is produced in the synthesis of the ester section.

Example 10:

This example is essentially the same as example 8, except that the raw dilute acid is 5.2mol/L dilute nitric acid and the sodium nitrate-containing wastewater is produced in the synthetic ester section.

Example 11:

This example is substantially the same as example 8 except that the feed alcohol is isopropyl alcohol, the temperature of the feed liquid entering the first super gravity bed separator 12 through the preheater 11 is 45 to 50 ℃, the jacket temperature of the nitrite condenser 14, the nitrite overhead tank 15 is lower than 20 ℃, and the temperature of the feed liquid entering the second super gravity bed separator through the preheater 34 is 95 ℃. The one-step feeding of the azide reaction is carried out according to the volume ratio of 1:0.4098 (the density of isopropyl nitrite is 1.02g/cm ³).

Example 12:

This example is essentially the same as example 8, except that the hydrazine and sodium hydroxide in ethanol solution has a hydrazine hydrate concentration of 3.15mol/L and sodium hydroxide concentration of 3.0mol/L. The one-step feeding of the azide reaction is carried out according to the volume ratio of 1:0.1973, the final product is analyzed to have a powder particle size of 50-300 nm, a main content of 99.4%, and a free alkali content of 0.2%.

Example 13:

This example is essentially the same as example 8, except that the concentration of sodium nitrite in the aqueous solution of sodium nitrite and ethanol is 2.3mol/L, the concentration of ethanol is 2.76mol/L, the concentration of dilute sulfuric acid is 1.3mol/L, and the final product has a particle size of 100 to 400nm, a major content of 99.5% and a free base of 0.15% as analyzed.

Example 14:

The example is basically the same as example 8, except that the mixed solution of sodium hydroxide and hydrazine is changed into aqueous solution, the crystal growing kettle is changed into a concentrated crystallization kettle, the centrifugal mother liquor is returned to the concentrated crystallization kettle to be combined with the new reaction mixed solution for concentration and crystallization, the recovered ethanol is returned to the ester synthesis section for batching, the wastewater is dehydrated, the particle size of the final product is 1000-5000 nm, the main content is 99.4%, and the free alkali is 0.4%.

Example 15:

The example is basically the same as example 8, except that the hydrazine and sodium hydroxide solution is methanol solution, the alcohol separated by the second super gravity bed separator is a mixture of methanol and ethanol, the mixture cannot be directly returned to the system for reuse, the mixture is further separated and then returned to the system, and the final product has a particle size of 100-500 nm after analysis, a main content of 99.3%, and free alkali content of 0.2%.

Claims

1. A system for continuously producing superfine sodium azide by utilizing a hypergravity bed reactor is characterized by comprising a nitrous acid ester synthesis working section (a), a sodium azide synthesis working section (b) and a hypergravity separation working section (c);

the nitrite synthesis section (a) comprises a nitrite and alcohol water solution high-level tank (1) and a dilute acid high-level tank (2), wherein the nitrite and alcohol water solution high-level tank (1) is connected with a first feed inlet (9) of a first hypergravity bed reactor (7) through a first metering pump (3) and a first preheater (5); the dilute acid high-level tank (2) is connected with a second feed inlet (8) of the first hypergravity bed reactor (7) through a second metering pump (4) and a second preheater (6);

the first hypergravity bed reactor (7) is connected with a nitrous acid ester condenser (14);

The sodium azide synthesis section (b) comprises a nitrous acid ester high-level tank (15) and a hydrazine and sodium hydroxide solution high-level tank (16), a discharge hole of a nitrous acid ester condenser (14) is connected with the nitrous acid ester high-level tank (15), and the nitrous acid ester high-level tank (15) is connected with a third feed inlet (21) of a second hypergravity bed reactor (19) through a third metering pump (17); the hydrazine and sodium hydroxide solution overhead tank (16) is connected with a fourth feed inlet (20) of the second hypergravity bed reactor (19) through a fourth metering pump (18);

The third discharge port (22) of the second hypergravity bed reactor (19) is connected with the feed inlets of a plurality of parallel crystal growing kettles (23), the discharge port of the crystal growing kettles (23) is connected with the feed inlet of a centrifugal machine (24), and the liquid discharge port of the centrifugal machine (24) is connected with a mother liquor storage tank (25);

The hypergravity separation working section (c) comprises a first hypergravity bed separator (31), and the mother liquor storage tank (25) is connected with a fifth feed inlet (32) of the first hypergravity bed separator (31) through a fifth metering pump (26) and a third preheater (30).

2. The system for continuously producing superfine sodium azide by utilizing the hypergravity bed reactor according to claim 1, wherein the second discharging port (13) of the first hypergravity bed reactor (7) is connected with a nitrous acid ester condenser (14).

3. The system for continuously producing superfine sodium azide by utilizing the hypergravity bed reactor according to claim 1, wherein a first discharge port (10) of the first hypergravity bed reactor (7) is connected with a sixth feed port (103) of a second hypergravity bed separator (102) through a fourth preheater (101), and a second discharge port (13) of the first hypergravity bed reactor (7) is closed;

The eighth discharge port (105) of the second super-gravity bed separator (102) is connected with the nitrous acid ester condenser (14).

4. The system for continuously producing superfine sodium azide by utilizing the hypergravity bed reactor according to claim 1, wherein a fourth discharge port (27) of the second hypergravity bed reactor (19) is connected with a first condenser (28) and a second condenser (29) with two different cooling temperatures in a serial connection mode, condensate of the first condenser (28) flows back to the fourth discharge port (27) of the second hypergravity bed reactor (19), and nitrite is removed from a high-level tank (15) of nitrite recovered from the discharge port of the second condenser (29).

5. The continuous production system of superfine sodium azide using super gravity bed reactor according to claim 1, wherein the sixth discharge port (34) of the first super gravity bed separator (31) is connected with a solvent recovery condenser (35).

6. The system for continuously producing superfine sodium azide by utilizing the hypergravity bed reactor according to claim 1, wherein the crystal growing kettle (23) is replaced by a concentrated crystallization kettle.