A method for continuously and adiabatically synthesizing isopropyl nitrite

Abstract

The present invention provides a method for continuously and adiabatically synthesizing isopropyl nitrite. Under normal temperature and pressure, using sodium nitrite, isopropyl alcohol, and nitric acid as raw materials, and water as a solvent, by controlling the feed volume flow rates of the three raw materials, they are preheated or precooled to the reaction temperature in a heat exchanger, mixed in a micro-sieve pore reactor, and then reacted in an adiabatic reaction tube to finally obtain isopropyl nitrite. The synthesis process of the present invention is simple, the reaction conditions are mild, the reaction time is very short, the product yield and purity are high, the yield reaches more than 97%, the purity reaches more than 98.5%, the production cost is low, the reaction process is safe and reliable, and it is environmentally friendly, solving the technical problems of difficult reaction control, large water consumption, and high harmfulness existing in the existing preparation methods of isopropyl nitrite, and belongs to the technical field of organic synthesis.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and particularly to a method for continuously and adiabatically synthesizing isopropyl nitrite. Background Art

[0002] Isopropyl nitrite belongs to the nitrite class and is an important raw material for synthesizing products such as sodium azide, oxalate, and high-purity nitrite. As a drug, it can dilate blood vessels and is used to treat hypertension and tachycardia. It can also be used as a rocket fuel and has a wide range of applications in the military, medicine, and other fields.

[0003] Currently, there are mainly three methods for synthesizing isopropyl nitrite:

[0004] (1) Isopropanol-sodium nitrite-inorganic acid method: This method is the most widely used in industry. Patent CN108892617 discloses a method for preparing isopropyl nitrite, using isopropanol, sodium nitrite, and nitric acid as raw materials, and obtaining isopropyl nitrite through a batch reaction. The batch reaction of this method will produce highly toxic nitrogen monoxide yellow smoke, which is highly harmful. Moreover, a large amount of water solvent is required during the reaction process, resulting in high production costs. Patent CN109912421 discloses a method for continuously preparing alkyl nitrite in a pipeline. Isopropanol and hydrochloric acid are mixed to form a mixed solution, and the mixed solution and an aqueous solution of sodium nitrite are transported to a static mixer for mixing by a pump, and then reacted in a tubular reactor to obtain alkyl nitrite. In this method, it is relatively difficult for isopropanol and hydrochloric acid to be miscible. When the amount of water is small, the two phases are heterogeneous, and problems may occur in the molar ratio of the materials during the transportation process. When the amount of water is sufficient, it is a homogeneous system, which will generate a large amount of wastewater, resulting in a large pressure for the treatment of the three wastes, being unfriendly to the environment, and having high production costs;

[0005] (2) Isopropanol-benzophenone method: This method uses benzophenone to react with isopropanol to prepare isopropyl nitrite. The main disadvantage is that by-products dimethyl ketone will be generated during the reaction process, making the reaction difficult to control;

[0006] (3) Isopropanol-nitrogen oxides method: This method uses nitrogen oxides to react with isopropanol in an aqueous solution to prepare isopropyl nitrite, which has the characteristics of high selectivity and less waste acid. However, when using nitrogen oxides as reaction raw materials, waste gas will be generated during the reaction process, and there are problems of difficult waste gas treatment and great harm.

[0007] Therefore, it is necessary to explore a method for synthesizing isopropyl nitrite for industrial production. Summary of the Invention

[0008] To solve the above technical problems, the technical solution adopted in this application is to provide a method for continuously and adiabatically synthesizing isopropyl nitrite to solve the technical problems of difficult reaction control, large water consumption, and high hazard existing in the existing preparation methods of isopropyl nitrite.

[0009] The embodiment of this application provides a method for continuously and adiabatically synthesizing isopropyl nitrite, and the specific steps are as follows: Using sodium nitrite, isopropyl alcohol, and nitric acid as raw materials, first preheat or precool the raw materials to the reaction temperature, and then mix the raw materials for adiabatic reaction to obtain isopropyl nitrite.

[0010] Preferably, the preheating or precooling is carried out in a heat exchanger, the mixing is carried out in a micro-screen hole reactor, and the adiabatic reaction is carried out in an adiabatic reaction tube.

[0011] Preferably, when mixing the raw materials, it is divided into two steps: First, mix sodium nitrite with isopropyl alcohol or nitric acid to obtain a first mixed solution, and then mix the first mixed solution with nitric acid or isopropyl alcohol to obtain a second mixed solution.

[0012] Preferably, the above method for continuously and adiabatically synthesizing isopropyl nitrite specifically includes the following steps:

[0013] (1) Prepare an aqueous solution of sodium nitrite and set it aside;

[0014] (2) First, respectively transport the raw materials of aqueous sodium nitrite solution, isopropyl alcohol, and nitric acid to three heat exchangers, preheat or precool to the reaction temperature; then transport the aqueous sodium nitrite solution and isopropyl alcohol or nitric acid to the first micro-screen hole reactor for mixing to obtain a first mixed solution, and then transport the first mixed solution and nitric acid or isopropyl alcohol to the second micro-screen hole reactor for mixing to obtain a second mixed solution; transport the second mixed solution to the adiabatic reaction tube for adiabatic reaction to obtain isopropyl nitrite.

[0015] Preferably, the molar ratio of isopropyl alcohol, sodium nitrite, and nitric acid is 1:1.0:1.0 to 1:1.2:1.2.

[0016] Preferably, in step (2), the raw materials are transported by a liquid delivery pump, and the volume flow rates of the aqueous sodium nitrite solution, isopropyl alcohol, and nitric acid are 10 - 20 mL / min, 5 - 10 mL / min, and 5 - 12 mL / min respectively.

[0017] Preferably, in step (2), the mass fraction of the aqueous sodium nitrite solution is 10 - 99%, the mass fraction of isopropyl alcohol is 70 - 95%, and the mass fraction of nitric acid is 10 - 68%.

[0018] Preferably, in step (2), water is used as the solvent for the adiabatic reaction, the initial reaction temperature of the adiabatic reaction is 10 - 15 °C, and the adiabatic temperature rise of the reaction system is 25 - 38 °C.

[0019] Preferably, in step (2), the total residence time of the raw materials in the first micro-sieve pore reactor, the second micro-sieve pore reactor, and the adiabatic reaction tube is 20 to 300 s.

[0020] Preferably, in step (2), after the reaction ends, the reaction solution is collected for 10 min, and the reaction solution is phase-separated to obtain isopropyl nitrite.

[0021] The present invention provides a method for continuously and adiabatically synthesizing isopropyl nitrite. Under normal temperature and pressure, using sodium nitrite, isopropyl alcohol, and nitric acid as raw materials, water as a solvent, by controlling the feed volume flow rates of the three raw materials, preheating or precooling to the reaction temperature in a heat exchanger, mixing in a micro-sieve pore reactor, and then reacting in an adiabatic reaction tube to finally obtain isopropyl nitrite;

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) The present invention uses a micro-sieve pore reactor to achieve rapid instantaneous mixing of raw materials in a short time, realize rapid reaction in a short time, significantly shorten the reaction time, improve the reaction rate, and increase the conversion rate of the product;

[0024] (2) The present invention uses a liquid delivery pump to transport raw materials, controls the molar ratio of raw materials by controlling the volume flow rates of the three raw materials, and then uses a micro-sieve pore reactor for mixing to achieve precise control of the reaction;

[0025] (3) The present invention relies on the heat released by the adiabatic reaction to reach the reaction temperature, without additional heating, effectively reducing the safety risk caused by temperature runaway, saving energy consumption, reducing the usage amount of the water solvent, and reducing the production cost;

[0026] The synthesis process of the present invention is simple, the reaction conditions are mild, the reaction time is very short, the product yield and purity are high, the yield reaches more than 97%, the purity reaches more than 98.5%, the production cost is low, the reaction process is safe and reliable, friendly to the environment, and has high feasibility for industrial application. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a schematic structural diagram of the experimental device adopted by the present application.

[0029] Symbol description in the figure:

[0030] A, the first infusion pump; B, the second infusion pump; C, the third infusion pump; D, the first heat exchanger; E, the second heat exchanger; F, the third heat exchanger; G, the first micro - sieve - hole reactor; H, the second micro - sieve - hole reactor; I, the adiabatic reaction tube; J, the back - pressure valve; K, the collection tank. Detailed implementation manners

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the following further details the present application in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. The raw materials and devices used in the present invention are all conventional commercially available products without special regulations; the methods used in the present invention are all conventional methods without special regulations.

[0032] The experimental device adopted in the embodiment of the present application is as Figure 1 shown, including the first infusion pump A, the second infusion pump B, the third infusion pump C, the first heat exchanger D, the second heat exchanger E, the third heat exchanger F, the first micro - sieve - hole reactor G, the second micro - sieve - hole reactor H, the adiabatic reaction tube I, the back - pressure valve J, and the collection tank K. The first infusion pump A, the first heat exchanger D and the first micro - sieve - hole reactor G are connected in sequence. The second infusion pump B, the second heat exchanger E and the first micro - sieve - hole reactor G are connected in sequence. The third infusion pump C, the third heat exchanger F and the second micro - sieve - hole reactor H are connected in sequence. The first micro - sieve - hole reactor G, the second micro - sieve - hole reactor H, the adiabatic reaction tube I, the back - pressure valve J and the collection tank K are connected in sequence;

[0033] Among them, the first infusion pump A is used to transport the aqueous sodium nitrite solution as the raw material. The second infusion pump B and the third infusion pump C are used to transport the raw materials isopropanol or nitric acid. The first heat exchanger D, the second heat exchanger E and the third heat exchanger F are used to pre - heat or pre - cool the corresponding raw materials. The first micro - sieve - hole reactor G and the second micro - sieve - hole reactor H are used to mix the raw materials. The adiabatic reaction takes place in the adiabatic reaction tube I. The back - pressure valve J is used to apply back - pressure to the reaction system and has the functions of opening, closing and adjusting the reaction time; The collection tank K is used to collect the reaction solution after the reaction. The reaction solution is allowed to stand and phase - separate in the collection tank K to achieve the separation of the products.

[0034] Example 1

[0035] A method for continuously and adiabatically synthesizing isopropyl nitrite specifically includes the following steps:

[0036] (1) Prepare an aqueous sodium nitrite solution with a mass fraction of 30% from sodium nitrite for standby;

[0037] (2) According to the molar ratio of isopropanol, sodium nitrite, and nitric acid being 1:1.0:1.0, the raw materials, namely 30% aqueous sodium nitrite solution, 95% isopropanol, and 68% nitric acid, are respectively fed into the first infusion pump A, the second infusion pump B, and the third infusion pump C. The set volume flow rates of the raw materials are 14.3 mL / min, 6.05 mL / min, and 5 mL / min respectively. The raw materials are respectively transported to the first heat exchanger D, the second heat exchanger E, and the third heat exchanger F through the infusion pumps, preheated or precooled to the initial reaction temperature of 15 °C, and then the 30% aqueous sodium nitrite solution and 95% isopropanol are transported to the first micro-sieve pore reactor G for mixing and dispersion to obtain the first mixed solution. Then, the first mixed solution and 68% nitric acid are transported to the second micro-sieve pore reactor H for mixing and dispersion to obtain the second mixed solution;

[0038] The second mixed solution is transported to the adiabatic reaction tube I for adiabatic reaction. The initial reaction temperature is set to 15 °C, and the total residence time of the raw materials passing through the first micro-sieve pore reactor G, the second micro-sieve pore reactor H, and the adiabatic reaction tube I is 150 s. At this time, the adiabatic temperature rise of the reaction system is 31 °C. After the reaction ends, the reaction liquid flows into the collection tank K, and the reaction liquid is collected for 10 min, and the organic phase is separated to obtain 75.11 g of the product;

[0039] The product is analyzed by liquid chromatography, and the purity of isopropyl nitrite is measured to be 98.5%, and its calculated yield is 96.5%.

[0040] The reaction equation is as follows:

[0041]

[0042] Example 2

[0043] The difference between this implementation method and Example 1 is that in step (2), the feeding is carried out according to the molar ratio of isopropanol, sodium nitrite, and nitric acid being 1:1.1:1.0, and the set volume flow rates of the raw materials are 15.71 mL / min, 6.05 mL / min, and 5 mL / min respectively. The other steps are the same. At this time, the adiabatic temperature rise of the reaction system is 30 °C, and finally 74.9 g of the product is obtained. The liquid phase purity of isopropyl nitrite is measured to be 98.9%, and its calculated yield is 97.2%.

[0044] Example 3

[0045] The difference between this implementation method and Example 1 is that in step (2), the raw materials are fed in a molar ratio of isopropanol:sodium nitrite:nitric acid of 1:1.2:1.0, and the volume flow rates of the raw materials are set to 17.14 mL / min, 6.05 mL / min, and 5 mL / min respectively. Other steps are the same. At this time, the adiabatic temperature rise of the reaction system is 29 °C, and finally 75.0 g of the product is obtained. The liquid-phase purity of isopropyl nitrite is measured to be 98.6%, and its calculated yield is 97.1%.

[0046] As can be seen from Examples 1-3, as the molar ratio of raw material isopropanol to sodium nitrite increases from 1:1.0 to 1:1.1, the calculated yield of the product isopropyl nitrite increases accordingly. When the molar ratio of raw material isopropanol to sodium nitrite increases from 1:1.1 to 1:1.2, the calculated yield of the product isopropyl nitrite decreases slightly, but the decrease is not obvious. Therefore, from an economic perspective, the molar ratio of raw material isopropanol to sodium nitrite is preferably 1:1.1.

[0047] Example 4

[0048] The difference between this implementation method and Example 2 is that in step (2), the raw materials are fed in a molar ratio of isopropanol:sodium nitrite:nitric acid of 1:1.1:1.1, and the volume flow rates of the raw materials are set to 14.29 mL / min, 5.5 mL / min, and 5 mL / min respectively. Other steps are the same. At this time, the adiabatic temperature rise of the reaction system is 31 °C, and finally 68.2 g of the product is obtained. The liquid-phase purity of isopropyl nitrite is measured to be 98.7%, and its calculated yield is 97.5%.

[0049] Example 5

[0050] The difference between this implementation method and Example 2 is that in step (2), the raw materials are fed in a molar ratio of isopropanol:sodium nitrite:nitric acid of 1:1.1:1.2, and the volume flow rates of the raw materials are set to 13.09 mL / min, 5.05 mL / min, and 5 mL / min respectively. Other steps are the same. At this time, the adiabatic temperature rise of the reaction system is 29.7 °C, and finally 62.4 g of the product is obtained. The liquid-phase purity of isopropyl nitrite is measured to be 98.8%, and its calculated yield is 97.4%.

[0051] As can be seen from Examples 2, 4-5, as the molar ratio of raw material isopropanol to nitric acid increases from 1:1.0 to 1:1.1, the calculated yield of the product isopropyl nitrite increases accordingly. When the molar ratio of raw material isopropanol to nitric acid increases from 1:1.1 to 1:1.2, the calculated yield of the product isopropyl nitrite decreases slightly, but the decrease is not obvious. Therefore, from an economic perspective, the molar ratio of raw material isopropanol to nitric acid is preferably 1:1.1.

[0052] Example 6

[0053] The difference between this implementation method and Example 4 is that in step (2), the total residence time of the raw materials passing through the first micro-sieve pore reactor G, the second micro-sieve pore reactor H, and the adiabatic reaction tube I is set to 20 s, and the other steps are the same. At this time, the adiabatic temperature rise of the reaction system is 31 °C, and finally 68.1 g of the product is obtained. The measured liquid-phase purity of isopropyl nitrite is 97.1%, and its calculated yield is 96.1%.

[0054] Example 7

[0055] The difference between this implementation method and Example 4 is that in step (2), the total residence time of the raw materials passing through the first micro-sieve pore reactor G, the second micro-sieve pore reactor H, and the adiabatic reaction tube I is set to 90 s, and the other steps are the same. At this time, the adiabatic temperature rise of the reaction system is 30.4 °C, and finally 68.4 g of the product is obtained. The measured liquid-phase purity of isopropyl nitrite is 98.9%, and its calculated yield is 97.5%.

[0056] Example 8

[0057] The difference between this implementation method and Example 4 is that in step (2), the total residence time of the raw materials passing through the first micro-sieve pore reactor G, the second micro-sieve pore reactor H, and the adiabatic reaction tube I is set to 120 s, and the other steps are the same. At this time, the adiabatic temperature rise of the reaction system is 29.7 °C, and finally 68.3 g of the product is obtained. The measured liquid-phase purity of isopropyl nitrite is 98.6%, and its calculated yield is 97.3%.

[0058] Example 9

[0059] The difference between this implementation method and Example 4 is that in step (2), the total residence time of the raw materials passing through the first micro-sieve pore reactor G, the second micro-sieve pore reactor H, and the adiabatic reaction tube I is set to 300 s, and the other steps are the same. At this time, the adiabatic temperature rise of the reaction system is 29.6 °C, and finally 68.2 g of the product is obtained. The measured liquid-phase purity of isopropyl nitrite is 98.6%, and its calculated yield is 97.5%.

[0060] It can be seen from Examples 4, 6 - 9 that as the total residence time of the raw materials passing through the first micro-sieve pore reactor, the second micro-sieve pore reactor, and the adiabatic reaction tube increases from 20 s to 90 s, the calculated yield of the product isopropyl nitrite increases accordingly. When the total residence time of the raw materials passing through the first micro-sieve pore reactor, the second micro-sieve pore reactor, and the adiabatic reaction tube increases from 90 s to 300 s, the change in the calculated yield of the product isopropyl nitrite is not obvious. Therefore, from an economic perspective, the total residence time of the raw materials passing through the first micro-sieve pore reactor, the second micro-sieve pore reactor, and the adiabatic reaction tube is preferably 90 s.

[0061] Example 10

[0062] The difference between this implementation method and Example 7 is that in step (2), the raw materials are preheated or precooled to the initial reaction temperature of 10°C, and the initial reaction temperature in the adiabatic reaction tube is set to 10°C. The other steps are the same. At this time, the adiabatic temperature rise of the reaction system is 29°C, and finally 68.3 g of the product is obtained. The measured liquid-phase purity of isopropyl nitrite is 98.8%, and its calculated yield is 97.5%.

[0063] It can be seen from Examples 7 and 10 that as the initial reaction temperature increases from 10°C to 15°C, the change in the calculated yield of the product isopropyl nitrite is not obvious. Therefore, as long as the initial reaction temperature of the adiabatic reaction is within the range of 10 - 15°C, isopropyl nitrite can be synthesized with a high yield.

[0064] Example 11

[0065] The difference between this implementation method and Example 7 is that in step (2), the 30% aqueous sodium nitrite solution and 68% nitric acid are first transported to the first micro-sieve pore reactor G for mixing and dispersion to obtain a first mixed solution, and then the first mixed solution and 95% isopropyl alcohol are transported to the second micro-sieve pore reactor H for mixing and dispersion to obtain a second mixed solution. The other steps are the same. At this time, the adiabatic temperature rise of the reaction system is 30°C, and finally 68.2 g of the product is obtained. The measured liquid-phase purity of isopropyl nitrite is 98.9%, and its calculated yield is 97.4%.

[0066] It can be seen from Examples 7 and 11 that whether the raw material aqueous sodium nitrite solution is first mixed with isopropyl alcohol and then with nitric acid, or the raw material aqueous sodium nitrite solution is first mixed with nitric acid and then with isopropyl alcohol, the change in the calculated yield of the product isopropyl nitrite is not obvious, that is, changing the mixing order has no obvious effect on the calculated yield of the product isopropyl nitrite. Therefore, both mixing methods can be implemented.

[0067] The experimental data and experimental results of Examples 1 - 11 are summarized, and the results are shown in Table 1.

[0068] Table 1 Summary of experimental data and experimental results of Examples 1 - 11

[0069]

[0070] It can be seen from Table 1 that when the molar ratio of isopropyl alcohol, sodium nitrite, and nitric acid is 1:1.0:1.0 - 1:1.2:1.2, the initial reaction temperature of the adiabatic reaction is 10 - 15°C, and the total residence time of the raw materials in the first micro-sieve pore reactor, the second micro-sieve pore reactor, and the adiabatic reaction tube is 20 - 300 s, the adiabatic temperature rise of the reaction system is 25 - 38°C. At this time, high yield and high purity of isopropyl nitrite can be obtained, thus realizing the high-yield and high-purity synthesis of isopropyl nitrite in the present invention.

[0071] It should be noted that:

[0072] (1) The synthesis process of the present invention is a continuous process and requires continuous feeding. Therefore, an infusion pump is used to transport the raw materials. During the transportation process, the molar ratio of the raw materials is controlled by controlling the volume flow rates of the three raw materials. Therefore, when the molar ratio of the raw materials changes, the volume flow rates of the raw materials will also change. As long as the volume flow rates of the aqueous sodium nitrite solution, isopropanol, and nitric acid are within the ranges of 10 - 20 mL / min, 5 - 10 mL / min, and 5 - 12 mL / min respectively, during actual operation, adjustments are made according to the actual situation.

[0073] (2) The adiabatic reaction of the present invention uses water as a solvent. Therefore, each raw material needs to be configured into an aqueous solution. Among them, the mass fraction of the aqueous sodium nitrite solution is 10 - 99%, the mass fraction of isopropanol is 70 - 95%, and the mass fraction of nitric acid is 10 - 68%. As long as it is within the above ranges, during actual operation, adjustments are made according to the actual situation.

[0074] In summary, the present invention provides a method for continuously and adiabatically synthesizing isopropyl nitrite. Under normal temperature and pressure, using sodium nitrite, isopropanol, and nitric acid as raw materials, water as a solvent, by controlling the feed volume flow rates of the three raw materials, preheating or precooling to the reaction temperature in a heat exchanger, mixing in a micro - sieve - pore reactor, and then reacting in an adiabatic reaction tube, finally obtaining isopropyl nitrite;

[0075] Compared with the prior art, (1) the present invention uses a micro - sieve - pore reactor to achieve rapid instantaneous mixing of raw materials in a short time, realize rapid reaction in a short time, significantly shorten the reaction time, improve the reaction rate, and increase the conversion rate of the product; (2) the present invention uses an infusion pump to transport raw materials, controls the molar ratio of raw materials by controlling the volume flow rates of the three raw materials, and then uses a micro - sieve - pore reactor for mixing to achieve precise control of the reaction; (3) the present invention relies on the heat released by the adiabatic reaction to reach the reaction temperature, without additional heating, effectively reducing the safety risk caused by runaway temperature, saving energy consumption, reducing the usage amount of the water solvent, and reducing the production cost. The synthesis process of the present invention is simple, the reaction conditions are mild, the reaction time is very short, the product yield and purity are high, the yield reaches more than 97%, the purity reaches more than 98.5%, the production cost is low, the reaction process is safe and reliable, environmentally friendly, and has high feasibility for industrial application, and can be widely applied in the field of organic synthesis technology.

[0076] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for continuously and adiabatically synthesizing isopropyl nitrite, characterized in that, The specific steps are as follows: Using sodium nitrite, isopropyl alcohol, and nitric acid as raw materials, first preheat or precool the raw materials to the reaction temperature, and then mix the raw materials for an adiabatic reaction to obtain isopropyl nitrite; Specifically, it includes the following steps: (1) Prepare an aqueous solution of sodium nitrite and set it aside; (2) First, separately transport the aqueous solution of sodium nitrite, isopropyl alcohol, and nitric acid to three heat exchangers to preheat or precool to the reaction temperature; then transport the aqueous solution of sodium nitrite and isopropyl alcohol or nitric acid to the first micro-sieve pore reactor for mixing to obtain a first mixed solution, and then transport the first mixed solution and nitric acid or isopropyl alcohol to the second micro-sieve pore reactor for mixing to obtain a second mixed solution; transport the second mixed solution to an adiabatic reaction tube for an adiabatic reaction to obtain isopropyl nitrite; In step (2), the molar ratio of isopropyl alcohol, sodium nitrite, and nitric acid is 1:1.0:1.0 to 1:1.2:1.2; Use a liquid infusion pump to transport the raw materials. The volume flow rates of the aqueous solution of sodium nitrite, isopropyl alcohol, and nitric acid are 10 - 20 mL / min, 5 - 10 mL / min, and 5 - 12 mL / min respectively; The mass fraction of the aqueous solution of sodium nitrite is 10 - 99%, the mass fraction of isopropyl alcohol is 70 - 95%, and the mass fraction of nitric acid is 10 - 68%; The initial reaction temperature of the adiabatic reaction is 10 - 15 °C, the adiabatic temperature rise of the reaction system is 25 - 38 °C, and the total residence time of the raw materials passing through the first micro-sieve pore reactor, the second micro-sieve pore reactor, and the adiabatic reaction tube is 20 - 300 s.

2. The method for continuously and adiabatically synthesizing isopropyl nitrite according to claim 1, characterized in that, Preheating or precooling is carried out in a heat exchanger, mixing is carried out in a micro-sieve pore reactor, and the adiabatic reaction is carried out in an adiabatic reaction tube.

3. The method for continuously and adiabatically synthesizing isopropyl nitrite according to claim 1, characterized in that, When mixing the raw materials, it is divided into two steps: First, mix sodium nitrite and isopropyl alcohol or nitric acid to obtain a first mixed solution, and then mix the first mixed solution and nitric acid or isopropyl alcohol to obtain a second mixed solution.

4. The method for continuously and adiabatically synthesizing isopropyl nitrite according to claim 1, characterized in that, In step (2), water is used as the solvent for the adiabatic reaction.

5. The method for continuously and adiabatically synthesizing isopropyl nitrite according to claim 1, wherein In step (2), after the reaction ends, collect the reaction solution for 10 min. After phase separation of the reaction solution, isopropyl nitrite can be obtained.

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