CN221536703U - Production system of alpha-hydroxynitrile - Google Patents

Abstract

The utility model relates to a production system of alpha-hydroxynitrile. The production system comprises a plurality of stages of static mixers connected in series, wherein the static mixers are provided with spray assemblies. The utility model adopts a static mixer to replace a kettle type reactor in the prior art, can take hydrogen cyanide with lower purity as a raw material for reaction, and avoids the technical problems of potential safety hazard and the like caused by excessively long reaction time, severe reaction and more released heat when the kettle type reactor is adopted to take high-purity hydrogen cyanide as the raw material; meanwhile, the spraying density can be controlled through the spraying assembly, so that aldehyde substances can contact hydrogen cyanide gas to the greatest extent, the reaction can be fully and completely carried out, and the yield is improved.

Description

Production system of alpha-hydroxynitrile

Technical Field

The utility model belongs to the technical field of chemical industry, and particularly relates to a production system of alpha-hydroxynitrile.

Background

Hydrocyanic acid is also called hydrogen cyanide, has a molecular formula of HCN, a density of 0.687g/cm ³, a melting point of-13.4 ℃ (lit.) and a boiling point of 26 ℃, is colorless gas or liquid, has bitter almond flavor, and is a highly toxic chemical.

Hydrocyanic acid is an important chemical intermediate that can undergo an addition reaction with aldehyde groups to produce alpha-hydroxynitriles. Alpha-hydroxynitrile is an active compound which is easy to be converted into other compounds, so that the alpha-hydroxynitrile is an important organic synthesis intermediate, is mainly used for producing herbicides (glyphosate), dyes (indigo), nylon 66 (adiponitrile), feed additives (methionine), chelating agents (EDT A, DTPA), medical intermediates (pantothenic acid lactone, methyl 2-hydroxyvalerate), fluorescent whitening agents, pesticides and the like, and is an important fine chemical product in China at present.

Currently, in actual industrial production, the production methods of hydrogen cyanide mainly include the following methods:

1) The cracking process of light oil includes the steps of cracking light oil (or gasoline), liquid ammonia and caustic soda in an electric arc furnace, petroleum coke as carrier, sealing with nitrogen to prevent oxidation and synthesizing 20-25% hydrogen cyanide cracking gas.

2) An Andrussow method, namely methane, ammonia and air/oxygen react rapidly at a high temperature of 1000-1200 ℃ under the action of a platinum-rhodium alloy catalyst to synthesize a 7-10% hydrogen cyanide gas mixture.

3) The methanol ammoxidation method is that methanol, liquid ammonia and air react under the action of catalyst at 480-500 deg.c to produce hydrogen cyanide gas.

4) By-product of acrylonitrile, propylene, ammonia and air in certain proportion are reacted fast at 440-450 deg.c to synthesize the mixture of acrylonitrile, acetonitrile and hydrogen cyanide gas, which is absorbed and separated to obtain hydrogen cyanide gas in 2.5-11% of acrylonitrile.

The method for preparing the alpha-hydroxynitrile by taking hydrocyanic acid as a raw material is a methylolation method, and the principle is as follows: under proper acid-base condition, aldehyde solution and hydrogen cyanide are added under normal pressure to generate alpha-hydroxynitrile, and a great amount of heat is released by the reaction, and the reaction equation is as follows: hcn+hcho→hoch ₂ CNQ. The methylolation method of hydrocyanic acid can be classified into a gas phase method and a liquid phase method according to the phase state of raw material hydrocyanic acid, the hydrocyanic acid of the gas phase method being gaseous and the hydrocyanic acid of the liquid phase method being liquid.

Patent CN202111028853.2 discloses a device and a process for continuously producing hydroxy acetonitrile by using liquid-phase hydrocyanic acid, and patent CN201710313478.3 discloses an industrial preparation method of hydroxy acetonitrile. Both methods use liquid hydrocyanic acid as raw material to produce hydroxyacetonitrile with formaldehyde. However, the method has higher purity requirement on raw material hydrocyanic acid, the purity of liquid phase hydrocyanic acid needs to be more than 99%, the difficulty of removing reaction heat is large, the reaction process is not easy to control, the control requirement precision is high, the mixed gas hydrocyanic acid is purified into liquid hydrocyanic acid, the energy consumption is larger, and the production cost of the hydrocyanic acid mixed gas is only half of that of the liquid hydrocyanic acid. The latter is batch production, is not suitable for large-scale industrialized continuous production, and has higher formaldehyde content in finished products and limited application of hydroxyacetonitrile products.

Patent CN201410671537.0 discloses a process method for jointly preparing liquid hydrocyanic acid and hydroxyacetonitrile, which adopts a cryogenic process to cool a part of hydrocyanic acid gas mixture into liquid to obtain liquid hydrocyanic acid, and the other part of hydrocyanic acid gas is tail gas containing hydrocyanic acid and is absorbed by formaldehyde aqueous solution containing a catalyst to prepare hydroxyacetonitrile aqueous solution, and the tail gas after being absorbed by the formaldehyde aqueous solution directly enters an incinerator for incineration. However, the hydrocyanic acid content in the tail gas is low, the hydroxy acetonitrile content obtained by absorption is 30-40%, and the product content is low, so that the application range of the product is limited.

Patent CN201310722698.3 utilizes hydrocyanic acid mixed gas to prepare 2-hydroxy-4-methylthiobutyronitrile, and adopts hydrocyanic acid mixed gas multistage series kettle type reactor to realize industrialized large-scale continuous production. However, the hydrocyanic acid gas is introduced into the kettle type reaction, the contact surface with the reaction liquid is small, the reaction time is long, the generated product is easy to polymerize or decompose, the product quality is low, and the energy consumption is high; in addition, the kettle type reaction condition is strictly controlled, the reaction process is accompanied by intense heat release, the danger coefficient is high, and safety accidents are easy to occur.

Patent CN202110480384.1 discloses a falling film reactor for uniformly splitting hydroxyacetonitrile by using hydrocyanic acid as a raw material, which is characterized in that an annular distribution plate is fixed on a tube plate to ensure that gas and split flow enter the falling film reactor, but in the actual use process, mixed liquid flows down from a falling film pipe close to a liquid inlet after entering a tower body through the liquid inlet, so that other falling film pipes have a phenomenon of dry pipe. The dry pipe can influence the contact reaction of hydrocyanic acid gas and the mixed solution, and further can influence the production efficiency of hydroxyacetonitrile.

In conclusion, the methylolation method is adopted to produce the alpha-hydroxynitrile, the liquid phase method has higher purity requirement on hydrocyanic acid raw materials, the purity of liquid phase hydrocyanic acid needs to be more than 99%, the difficulty of removing reaction heat is high, the reaction process is not easy to control, the precision of reaction control requirement is high, and the hydrocyanic acid mixed gas is purified into liquid hydrocyanic acid, so that the energy consumption is high. The contact surface of the gas phase kettle type reaction or falling film reaction and the reaction liquid is small, the reaction time is long, the generated product is easy to polymerize or decompose, the product quality is low, the energy consumption is high, the kettle type reaction condition is strictly controlled, the reaction process is accompanied by intense heat release, the danger coefficient is high, safety accidents are easy to occur, the falling film reaction falling film pipe also has the phenomenon of 'dry pipe', the contact reaction of hydrocyanic acid gas and the mixed solution is influenced, the production efficiency of alpha-hydroxynitrile is further influenced, the equipment size of the falling film reactor is large, and the occupied area of multi-stage absorption equipment is large.

Disclosure of utility model

Therefore, the utility model aims to provide a production system of alpha-hydroxynitrile, which solves the problems that in the prior art, the production of alpha-hydroxynitrile by a methylolation method has higher purity requirement on hydrocyanic acid raw materials by a liquid phase method, the purity of liquid phase hydrocyanic acid needs to be more than 99 percent, the difficulty of removing reaction heat is large, the reaction process is not easy to control, the reaction control requirement precision is high, and the hydrocyanic acid mixed gas is purified into liquid hydrocyanic acid, so that the energy consumption is large. The contact surface of the gas phase kettle type reaction or falling film reaction and the reaction liquid is small, the reaction time is long, the generated product is easy to polymerize or decompose, the product quality is low, the energy consumption is high, the kettle type reaction condition is strictly controlled, the reaction process is accompanied by intense heat release, the danger coefficient is high, safety accidents are easy to occur, the falling film reaction falling film pipe also has the phenomenon of a dry pipe, the contact reaction of hydrocyanic acid gas and the mixed solution is influenced, the production efficiency of alpha-hydroxynitrile is further influenced, the equipment size of the falling film reactor is large, the occupied area of multi-stage absorption equipment is large, and the like.

In some embodiments of the utility model, the utility model provides a production system for an α -hydroxynitrile, the production system comprising: a plurality of stages of static mixers in series, wherein the static mixers are provided with spray assemblies.

The principle of the production system of the utility model is as follows: the static mixer is adopted to replace a kettle type reactor in the prior art, so that the reaction can be carried out by taking hydrogen cyanide with lower purity as a raw material, and the technical problems of potential safety hazard and the like caused by excessively long reaction time, severe reaction and more heat release of the kettle type reactor by taking high-purity hydrogen cyanide as the raw material are avoided; meanwhile, the spraying density can be controlled through the spraying assembly, so that aldehyde substances can contact hydrogen cyanide gas to the greatest extent, the reaction can be fully and completely carried out, and the yield is improved.

In some embodiments of the utility model, the static mixer is provided with a feed inlet and a discharge outlet, a circulating tank is arranged on a communication pipeline between the adjacent upstream static mixer and the adjacent downstream static mixer, the circulating tank is provided with a liquid inlet, a gas outlet, a liquid outlet and a mixed liquid outlet, and the mixed liquid outlet is communicated with the feed inlet of the adjacent upstream static mixer.

In some embodiments of the utility model, a heat exchanger is arranged on the communication pipeline between the mixed liquor outlet and the feed inlet.

According to the utility model, the heat exchanger on the communication pipeline between the mixed liquid outlet of the circulating tank and the feed inlet of the adjacent upstream static mixer is additionally arranged, so that the heat of raw materials can be reduced, polymerization or decomposition or side reaction caused by overhigh heat is avoided, the heat released in the reaction process is further rapidly taken away, hydrocyanic acid gas decomposition and ammonia release caused by overhigh temperature in the reaction process are avoided, and the purity and yield of products are ensured.

In some embodiments of the utility model, a circulating pump is arranged on a communication pipeline between the mixed liquor outlet and the heat exchanger.

In some embodiments of the utility model, the production system further comprises a gas-liquid separator in communication with the last stage recycle tank.

In some embodiments of the utility model, the gas-liquid separator is provided with a liquid outlet which communicates with the liquid inlet of the last stage recycle tank.

In some embodiments of the utility model, the production system further comprises a mixer for adding the mixed liquor to the final stage static mixer, the mixer being in communication with the feed inlet of the final stage static mixer.

According to the utility model, by additionally arranging the mixer and connecting the mixer with the feed inlet of the static mixer at the last stage, new raw materials can be added into the production system through the mixer after the raw materials are reacted, so that the production stability is improved.

Drawings

Fig. 1 is a schematic diagram of the structure of the production system of embodiment 1.

Reference numerals

1-A static mixer, 11-a spray assembly;

2-a heater;

3-heat exchanger;

4-a circulation pump;

5-a gas-liquid separator;

6-mixer.

Detailed Description

The present utility model will be further described with reference to the following specific examples, but it should be noted that the specific material ratios, process conditions, results, etc. described in the embodiments of the present utility model are only for illustrating the present utility model, and are not intended to limit the scope of the present utility model, and all equivalent changes or modifications according to the spirit of the present utility model should be included in the scope of the present utility model.

It should be noted that all directional indicators (such as up, down, top, bottom, inner, outer … …) in the embodiments of the present application are merely used to explain the relative positional relationship, movement conditions, etc. between the components in a particular gesture (as shown in the drawings), and if the particular gesture changes, the directional indicators correspondingly change.

Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the present application, unless explicitly specified and defined otherwise, the term "connected" and the like should be construed broadly, for example, "connected" may be either direct or indirect through intermediaries, unless explicitly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

The present utility model will be described in detail with reference to specific exemplary examples. It is also to be understood that the following examples are given solely for the purpose of illustration and are not to be construed as limitations upon the scope of the utility model, as many insubstantial modifications and variations are within the scope of the utility model as would be apparent to those skilled in the art in light of the foregoing disclosure.

In the related art, the methylolation method is used for producing the alpha-hydroxynitrile, the liquid phase method requires that the purity of hydrocyanic acid raw material is high, the purity of liquid phase hydrocyanic acid is more than 99 percent, the difficulty of removing reaction heat is large, the reaction process is difficult to control, the reaction control requires high precision, and the hydrocyanic acid mixed gas is purified into liquid hydrocyanic acid, so that the energy consumption is large. The contact surface of the gas phase kettle type reaction or falling film reaction and the reaction liquid is small, the product generated by long reaction time is easy to polymerize or decompose, the product quality is low, the energy consumption is high, the kettle type reaction condition is strictly controlled, the reaction process is accompanied by intense heat release, the danger coefficient is high, safety accidents are easy to occur, the falling film reaction falling film pipe also has the phenomenon of 'dry pipe', the contact reaction of hydrocyanic acid gas and the mixed solution is influenced, the production efficiency of alpha-hydroxynitrile is further influenced, the size of the falling film reactor equipment is large, and the occupied area of the multistage absorption equipment is large. In order to solve the technical problems, the application provides a production system of alpha-hydroxynitrile.

Example 1

As shown in fig. 1, the present embodiment provides a production system of α -hydroxynitrile, which includes a plurality of stages of static mixers 1 connected in series, the number of stages of the static mixers 1 is at least 2, for example, may be 2, may be 3, may be 4, etc., and a circulation tank 2 is provided on a communication pipe between adjacent upstream and downstream static mixers 1.

With continued reference to fig. 1, the static mixer 1 is used as a reaction site for reacting aldehyde substances (such as formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, etc.) with hydrogen cyanide under the action of a base catalyst (such as at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium carbonate, potassium bicarbonate, organic base, triethylamine, pyridine, and diethanolamine), to generate α -hydroxynitrile, the static mixer 1 is provided with a spray assembly 11, a hydrogen cyanide gas inlet, a feed inlet, and a discharge outlet, the outside of the static mixer 1 is provided with a jacket, the jacket is provided with an opening for adding a cooling medium into the jacket, the hydrogen cyanide gas inlet is located at the top of the static mixer 1, the feed inlet is located at the upper portion of the static mixer 1, the discharge outlet is located at the bottom of the static mixer 1, the spray assembly 11 is fixed on the upper inner wall of the static mixer 1, and the spray assembly 11 may be a nozzle.

The principle of this embodiment is: the static mixer is adopted to replace a kettle type reactor in the prior art, so that the reaction can be carried out by taking hydrogen cyanide with lower purity as a raw material, and the technical problems of potential safety hazard and the like caused by excessively long reaction time, severe reaction and more heat release of the kettle type reactor by taking high-purity hydrogen cyanide as the raw material are avoided; meanwhile, the spraying density can be controlled through the spraying assembly 11, so that the liquid material can be contacted with the hydrogen cyanide gas to the maximum extent, the reaction can be fully and completely carried out, and the yield is improved.

With continued reference to fig. 1, the circulation tank 2 is located in the communication pipeline between adjacent upstream and downstream static mixers 1, and the circulation tank 2 is also disposed downstream of the last stage static mixer 1. The circulation tank 2 is provided with a liquid inlet, a gas outlet, a liquid outlet, a mixed liquid outlet, a sampling port and a liquid level meter (not shown), and the bottom of the circulation tank 2 is provided with a switch valve. The liquid inlet of the circulating tank 2 is communicated with the discharge outlet of the adjacent upstream static mixer 1, and the liquid outlet of the circulating tank 2 is communicated with the discharge outlet of the adjacent upstream static mixer 1. The liquid outlet of the first-stage circulating tank 2 is communicated with the feed inlet of the first-stage static mixer 1.

With continued reference to fig. 1, the production system of the present embodiment further includes a plurality of heat exchangers 3 and a plurality of circulation pumps 4, where the heat exchangers 3 and the circulation pumps 4 are located on a communication pipeline between the mixed liquor outlet of the circulation tank 2 and the feed inlet of the static mixer 1, and the heat exchangers 3 are also located on a communication pipeline between the mixed liquor outlet of the circulation tank 2 and the feed inlet of an adjacent upstream static mixer 1. The heat exchanger 3 is used for cooling raw materials, avoiding polymerization or decomposition or side reaction caused by overhigh temperature, further rapidly taking away heat released in the reaction process, avoiding decomposition of hydrocyanic acid gas to release ammonia caused by overhigh temperature in the reaction process, and further ensuring the purity and yield of the product. The heat exchanger 3 may be a tube-in-tube heat exchanger, a plate heat exchanger, or the like.

In this embodiment, by adding the heat exchanger 3 on the communication pipeline between the mixed liquid outlet of the circulation tank 2 and the feed inlet of the static mixer 1, the raw materials can be cooled, and polymerization or decomposition or side reaction caused by overhigh temperature is avoided, so as to ensure the purity of the product.

With continued reference to fig. 1, the production system of the present embodiment further includes a gas-liquid separator 5 and a mixer 6, where the gas-liquid separator 5 is provided with a feed inlet, a gas outlet and a liquid outlet, the gas-liquid separator 5 is circularly communicated with the last-stage circulation tank 2, specifically, the feed inlet of the gas-liquid separator 5 is communicated with the liquid outlet of the last-stage circulation tank 2, the liquid outlet of the gas-liquid separator 5 is communicated with the liquid inlet of the last-stage circulation tank 2, and the gas outlet of the gas-liquid separator 5 is communicated with the tail gas treatment system. The mixer 6 is communicated with the feed inlet of the static mixer 1 of the last stage, and a heat exchanger 3 is arranged on a communication pipeline between the mixer 6 and the feed inlet of the static mixer 1 of the last stage. The mixer 6 is provided with a raw material inlet through which fresh aldehyde substances and catalyst can be added to the mixer 6. The mixer 6 may be a liquid-liquid mixer.

In this embodiment, by adding the mixer 6 and communicating the mixer 6 with the feed inlet of the static mixer 1 at the last stage, new raw materials can be added into the production system through the mixer 6 after the raw materials react, so as to improve the stability of production.

It should be understood that in the present application, all the communication pipes are provided with on-off valves.

The working procedure of the production system of this embodiment is as follows:

S1, deaminizing a hydrogen cyanide mixed gas obtained in an industrial reaction device for synthesizing hydrocyanic acid by an Ann method to obtain hydrogen cyanide synthetic gas with the temperature reduced to 20 ℃ and the content of hydrogen cyanide of 3-11 wt%;

Adding aldehyde substances (such as formaldehyde, acetaldehyde and the like) and alkali catalysts (the alkali catalysts are at least one of sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium carbonate, potassium bicarbonate, organic alkali, triethylamine, pyridine or diethanolamine) into all the circulating tanks 2, obtaining mixed liquid, ensuring that the liquid of all the circulating tanks 2 can normally start the circulating pumps 4, respectively opening the switching valves at the bottoms of the circulating tanks 2, starting the circulating pumps 4 for circulation, and allowing the mixed liquid to enter the static mixer 1 after heat exchange of the circulating liquid by the heat exchanger 3;

s2, controlling the temperature of the first static mixing to be 10-20 ℃;

Hydrogen cyanide synthesis gas is fed into a first-stage static mixer 1, and in the process that mixed liquid enters the first static mixer 1, the mixed liquid is precooled to 10-18 ℃ by cold water with the temperature of 8-15 ℃ in a first-stage heat exchanger 3;

The hydrogen cyanide is mixed and contacted with the mixed solution which enters the first static mixer 1 according to the spray density of 20-110m ³/(m² h) and reacts under the action of a catalyst to generate alpha-hydroxynitrile, and the molar ratio of the hydrogen cyanide to aldehyde substances in the hydrogen cyanide synthesis gas is 0.9-1.1:1, obtaining a reaction solution;

In the process, the spray assembly 11 enables aldehyde substances to contact the hydrogen cyanide synthesis gas to the greatest extent so as to fully and completely carry out the reaction, thereby improving the yield;

The reaction liquid enters a first-stage circulation tank 2 from a first-stage static mixer 1, a sampling port is used for sampling, the pH value, the aldehyde substance content, the hydrogen cyanide content and the hydrogen cyanide yield of the reaction liquid are detected, if the pH value is between 5 and 7, the aldehyde substance content is less than or equal to the preset aldehyde substance content threshold value of 0.5wt%, the hydrogen cyanide content is less than or equal to the preset hydrogen cyanide content threshold value of 0.5wt%, the hydrogen cyanide yield is more than or equal to the preset yield threshold value of 98 percent, namely the reaction end point is reached, and the reaction liquid is continuously and stably extracted into an alpha-hydroxynitrile solution through a first-stage circulation pump 2;

If the reaction end point is not reached, the reaction liquid is sent into the first-stage static mixer 1 by the first-stage circulating pump 2 to continue the reaction until the reaction end point is reached

S3, controlling the temperature of other static mixers except the first-stage static mixer 1 to be 10-20 ℃;

The unreacted complete hydrogen cyanide synthesis gas in the first-stage static mixer 1 enters the next-stage static mixer 1, and is precooled to 10-18 ℃ by cold water with the temperature of 8-15 ℃ in the second-stage heat exchanger 3 in the process that the mixer enters the next-stage static mixer 1;

Hydrogen cyanide is mixed and contacted with the mixed solution which enters the next-stage static mixer 1 according to the spray density of 20-110m ³/(m² & h), and the mixed solution reacts under the action of a catalyst to generate alpha-hydroxynitrile, so as to obtain a reaction solution;

In the process, the spray assembly 11 enables aldehydes to contact hydrogen cyanide synthesis gas to the greatest extent so as to enable the reaction to be fully and completely carried out, and further improves the yield;

After the reaction, the reaction liquid is sent into a static mixer 1 at the next stage through a second-stage circulating tank 2, a heat exchanger at the next stage is opened, and the temperature of the mixed liquid is 10-18 ℃ after heat exchange;

When the material level of the liquid in the second-stage circulating tank 2 reaches about 60%, the reaction liquid is sent to the first-stage heat exchanger 3 from the bottom of the second-stage circulating tank 2 through the second-stage circulating pump 4 according to the metering part, and the other part is sent to the second-stage heat exchanger 3 for continuous circulating reaction;

the reaction liquid is circulated until being sent into the last-stage static mixer 1, when the material level of the liquid in the last-stage circulating tank 2 reaches about 60%, the reaction liquid is sent into the adjacent last-stage heat exchanger 3 from the bottom of the last-stage circulating tank 2 through the last-stage circulating pump 4 according to the metering part, and the other part is sent into the last-stage heat exchanger 3 for continuous circulation reaction;

The liquid of the little unreacted hydrogen cyanide synthesis gas separated by the gas-liquid separator 5 returns to the last-stage circulating tank 2, and the obtained tail gas enters a tail gas treatment system;

Mixing fresh aldehyde substances with alkali catalysts of sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium carbonate, potassium bicarbonate, organic alkali, triethylamine, pyridine or diethanolamine according to a mass ratio of 100:0.5 to 1.5 is mixed by a mixer 6 and then is continuously introduced into a third-stage heat exchanger 3 after being metered, so that the whole reaction system can stably and continuously react.

In the production process, a static mixer is adopted for absorption reaction at low temperature, hydrocyanic acid is not easy to decompose or polymerize, the reaction condition is mild, the conditions of kettle type reaction are prevented from being strictly controlled, heat is severely released in the reaction process, the danger coefficient is high, and safety accidents are easy to occur; solves the problems that the falling film reaction falling film pipe can generate a phenomenon of 'dry pipe', the contact reaction of hydrocyanic acid gas and mixed solution is influenced, the equipment size of the falling film reactor is relatively large, the occupied area of the equipment is wide, and the like. Finally, the absorption efficiency of the product is greatly improved, the energy consumption is reduced, and the operation is simpler.

The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. Accordingly, it is intended that all equivalent modifications and variations of the utility model be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims (6)

1. A production system for α -hydroxynitrile, the production system comprising: the static mixer is provided with a spraying assembly, the static mixer is provided with a feed inlet and a discharge outlet, a circulating tank is arranged on a communication pipeline between the static mixers at the adjacent upstream and downstream, the circulating tank is provided with a liquid inlet, a gas outlet, a liquid outlet and a mixed liquid outlet, and the mixed liquid outlet is communicated with the feed inlet of the static mixer at the adjacent upstream.

2. The production system of claim 1, wherein a heat exchanger is provided on the communication conduit between the mixed liquor outlet and the feed inlet.

3. The production system of claim 1, wherein a circulation pump is provided in the communication conduit between the mixed liquor outlet and the heat exchanger.

4. The production system of claim 3, further comprising a gas-liquid separator in communication with the last stage recycle tank.

5. The production system of claim 4, wherein the gas-liquid separator is provided with a liquid outlet which is communicated with the liquid inlet of the last-stage circulation tank.

6. The production system of claim 1, further comprising a mixer for adding the mixed liquor to the final stage static mixer, the mixer being in communication with the feed inlet of the final stage static mixer.