Preparation device and method of 2, 2-dinitropropanol

Abstract

The invention provides a preparation device and method of 2, 2-dinitropropanol, and the preparation device provides 2-nitropropanol, a sodium nitrite aqueous solution, a sodium persulfate aqueous solution and a solvent for an oxidation nitration unit through a raw material unit, and provides a potassium ferricyanide aqueous solution for the oxidation nitration unit through a catalyst unit. The oxidation and nitration unit is selected from at least one of a microchannel reactor and a tubular reactor, so that the oxidation and nitration reaction is carried out in the microchannel reactor and the tubular reactor, and the production efficiency and the product yield of synthesizing and preparing the 2, 2-dinitropropanol can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of energetic plasticizers, and particularly relates to a device and a method for preparing 2,2-dinitropropanol. Background Art

[0002] Since the 1990s, with the extensive application of high-tech in modern warfare and the increasingly harsh battlefield environment, missile development has entered a new stage of development. High energy, insensitivity, and low characteristic signals have become the main direction of solid propellant development. Using energetic plasticizers to replace inert plasticizers in the original formula can simultaneously meet the needs of low characteristic signals and maintaining higher energy. Therefore, energetic plasticizers have become one of the key components of high-energy solid propellants, generally accounting for 10% to 20% of the mass of the propellant, and directly determine the energy, mechanics, and process properties of the propellant.

[0003] Among many energetic plasticizers, geminal dinitro plasticizers are valued by researchers because of their moderate energy and outstanding stability. Among them, the mixture A3 obtained by compounding bis-2,2-dinitropropanol formal (BDNPF) and bis-2,2-dinitropropanol acetal (BDNPA) in a mass ratio of 1:1 is a typical representative of this type of compound. It has been focused on research and development and widely used because of its excellent performance in applications. 2,2-Dinitropropanol (DNPOH) is a key intermediate for the synthesis of BDNPA and BDNPF. In recent years, researchers have developed a series of synthesis methods for DNPOH, but the oxidation and nitration reactions in the synthesis methods are very exothermic.

[0004] Therefore, in actual operation, even if the reaction liquid is pre-cooled to a relatively low temperature before the raw materials are added, the temperature of the reaction liquid will rise significantly and rapidly during the addition process. The intermittent scale-up production in the workshop can be controlled by slowing down the drop rate, but this will lead to a longer reaction time. This method not only limits the production capacity, but also the product is unstable under long-term stirring under system conditions and is easy to decompose and release NO gas, which poses a safety risk and affects the product yield.

[0005] Therefore, there are still problems with heat and mass transfer when synthesizing DNPOH in the prior art, resulting in defects such as low product yield and low purity caused by slow dropwise addition of raw materials and long-term stirring. Summary of the invention

[0006] The invention provides a preparation device for 2,2-dinitropropanol, which is used to solve the problems of heat and mass transfer still existing in the prior art when synthesizing DNPOH, resulting in defects such as low product yield and low purity caused by slow dropwise addition of raw materials and long-term stirring.

[0007] The present invention also provides a method for preparing 2,2-dinitropropanol, which is performed by using the above-mentioned preparation device and can solve the heat and mass transfer problems during the synthesis of DNPOH, thereby reducing the reaction time and improving the product yield.

[0008] In one aspect, the present invention provides a 2,2-dinitropropanol preparation device, comprising a raw material unit, a catalyst unit and an oxidation nitration unit;

[0009] The outlet of the raw material unit and the outlet of the catalyst unit are respectively connected to the inlet of the oxidation nitration unit, and the outlet of the oxidation nitration unit is used to output the crude 2,2-dinitropropanol;

[0010] The raw material unit is used to provide 2-nitropropanol, sodium nitrite aqueous solution, sodium persulfate aqueous solution and solvent to the oxidation nitration unit;

[0011] The catalyst unit is used to provide potassium ferrocyanide aqueous solution to the oxidation nitration unit;

[0012] Wherein, the oxidation nitrification unit is selected from at least one of a microchannel reactor and a tubular reactor.

[0013] Further, the raw material unit includes a 2-nitropropanol unit, a sodium nitrite unit, a sodium persulfate unit and a solvent unit;

[0014] Wherein, the outlet of the 2-nitropropanol unit, the outlet of the sodium nitrite unit, the outlet of the sodium persulfate unit, and the outlet of the solvent unit are respectively connected to the inlet of the oxidative nitration unit.

[0015] Further, the raw material unit includes a first mixing unit, a 2-nitropropanol unit, a sodium nitrite unit, a sodium persulfate unit and a solvent unit;

[0016] Among them, the outlet of the solvent unit is connected to the inlet of the 2-nitropropanol unit, the outlet of the sodium nitrite unit, the outlet of the sodium persulfate unit, and the outlet of the catalyst unit are respectively connected to the inlet of the first mixing unit, and the outlet of the 2-nitropropanol unit and the outlet of the first mixing unit are respectively connected to the inlet of the oxidation nitration unit.

[0017] Further, the raw material unit includes a first mixing unit, a second mixing unit, a 2-nitropropanol unit, a sodium nitrite unit, a sodium persulfate unit and a solvent unit;

[0018] Among them, the outlet of the sodium nitrite unit, the outlet of the sodium persulfate unit, and the outlet of the solvent unit are respectively connected to the inlet of the first mixing unit, the outlet of the 2-nitropropanol unit and the outlet of the first mixing unit are respectively connected to the inlet of the second mixing unit, and the outlet of the second mixing unit is connected to the inlet of the oxidation nitration unit.

[0019] Further, it also includes: nitroethane unit, alkali liquid unit and formaldehyde unit;

[0020] The outlet of the nitroethane unit, the outlet of the alkali solution unit, and the outlet of the formaldehyde unit are respectively connected to the inlet of the 2-nitropropanol unit.

[0021] Further, it also includes: a quenching unit and a concentration and distillation unit;

[0022] The outlet of the oxidative nitration unit is communicated with the inlet of the quenching unit, and the outlet of the quenching unit is communicated with the inlet of the concentration and distillation unit. The outlet of the concentration and distillation unit is used to output the 2,2-dinitropropanol product.

[0023] In another aspect, the present invention provides a method for preparing 2,2-dinitropropanol, which is performed using the preparation device described in the first aspect; the preparation method comprises the following steps:

[0024] The 2-nitropropanol, sodium nitrite aqueous solution, sodium persulfate aqueous solution and solvent in the raw material unit and the potassium ferrocyanide aqueous solution in the catalyst unit are sequentially or simultaneously introduced into the oxidative nitration unit for oxidative nitration treatment to obtain crude 2,2-dinitropropanol.

[0025] Furthermore, the oxidation nitration treatment lasts for 1-30 minutes at a temperature of -25 to 50°C; and / or,

[0026] The molar ratio of potassium ferrocyanide in the potassium ferrocyanide aqueous solution to the 2-nitropropanol is 1:(0.1-10); and / or,

[0027] The introduction rate of the potassium ferrocyanide aqueous solution is 0.01 to 200 mL / min; and / or,

[0028] The mass ratio of potassium ferrocyanide to water in the potassium ferrocyanide aqueous solution is 1:(2-20).

[0029] Furthermore, the solvent includes at least one of ethyl acetate, ethylene dichloride, dichloromethane, toluene and tetrahydrofuran.

[0030] Furthermore, the method further comprises the following steps:

[0031] The nitroethane in the nitroethane unit, the sodium hydroxide aqueous solution in the alkali solution unit, and the formaldehyde aqueous solution in the formaldehyde unit are sequentially or simultaneously introduced into the 2-nitropropanol unit for condensation treatment to obtain the 2-nitropropanol;

[0032] Wherein, the condensation treatment time is 0.1 to 180 minutes, and the temperature is -10 to 50°C.

[0033] The invention provides a 2,2-dinitropropanol preparation device. 2-nitropropanol, a sodium nitrite aqueous solution, a sodium persulfate aqueous solution and a solvent are provided to an oxidative nitration unit through a raw material unit, a potassium ferrocyanide aqueous solution is provided to the oxidative nitration unit through a catalyst unit, and the oxidative nitration unit is selected from at least one of a microchannel reactor and a tubular reactor, so that the oxidative nitration reaction is carried out in the microchannel reactor and the tubular reactor, and the production efficiency and product yield of the synthetic preparation of 2,2-dinitropropanol can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of a preparation device in one embodiment of the present invention;

[0035] Figure 2 is a schematic diagram of a preparation device in one embodiment of the present invention;

[0036] Figure 3 is a schematic diagram of a preparation device in one embodiment of the present invention;

[0037] Figure 4 This is the H-NMR characterization of the 2,2-dinitropropanol product obtained in Example 1.

[0038] Description of reference numerals:

[0039] 01: Hydrogen extraction unit;

[0040] 02: 2-nitropropanol unit;

[0041] 03: Oxidation nitrification unit;

[0042] 04: Quenching unit;

[0043] 05: Concentration and distillation unit;

[0044] 06: first mixing unit;

[0045] 07: Second mixing unit;

[0046] SM1: nitroethane unit;

[0047] SM2: lye unit;

[0048] SM3: formaldehyde unit;

[0049] SM4: sodium nitrite unit;

[0050] SM5: sodium persulfate unit;

[0051] SM6: Catalyst unit;

[0052] SM7: Solvent unit. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0055] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, "plurality" means two or more, unless otherwise precisely and specifically specified.

[0056] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0057] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, fixed connection, connection through an intermediary medium, internal connection between two elements or interaction between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] On the one hand, the present invention provides a 2,2-dinitropropanol preparation device, comprising a raw material unit, a catalyst unit SM6 and an oxidation nitration unit 03;

[0059] The outlet of the raw material unit and the outlet of the catalyst unit SM6 are respectively connected to the inlet of the oxidation nitration unit 03, and the outlet of the oxidation nitration unit 03 is used to output the crude 2,2-dinitropropanol;

[0060] The raw material unit is used to provide 2-nitropropanol, sodium nitrite aqueous solution, sodium persulfate aqueous solution and solvent to the oxidation nitration unit 03;

[0061] The catalyst unit SM6 is used to provide potassium ferrocyanide aqueous solution to the oxidation nitration unit 03;

[0062] Wherein, the oxidation nitrification unit 03 is selected from at least one of a microchannel reactor and a tubular reactor.

[0063] The present invention does not limit the expression forms of the raw material unit and the catalyst unit SM6, wherein the raw material unit can provide 2-nitropropanol, sodium nitrite aqueous solution, sodium persulfate aqueous solution and solvent to the oxidation nitration unit 03, and the catalyst unit SM6 can provide potassium ferrocyanide aqueous solution to the oxidation nitration unit 03;

[0064] The oxidation nitrification unit 03 is used to provide a place for the materials from the raw material unit and the catalyst unit SM6 to undergo oxidation nitrification reaction; in the present invention, the oxidation nitrification unit 03 is selected from at least one of a microchannel reactor and a tubular reactor.

[0065] Specifically, in the oxidative nitration unit 03, the 2-nitropropanol and sodium nitrite aqueous solution entering therein are used as raw materials for the oxidative nitration reaction, the sodium persulfate aqueous solution is used as an oxidant to participate in the oxidative nitration reaction, and the potassium ferrocyanide aqueous solution is used as a catalyst to participate in the oxidative nitration reaction; therefore, when the oxidative nitration unit 03 contains only 2-nitropropanol and sodium nitrite aqueous solution, the oxidative nitration reaction does not occur, and when the oxidative nitration unit 03 contains only 2-nitropropanol, sodium nitrite aqueous solution and sodium persulfate aqueous solution, the oxidative nitration reaction proceeds very slowly, but is far from meeting the requirements of industrial production, and therefore it is necessary to add potassium ferrocyanide catalyst to promote the complete reaction of the raw materials; the oxidative nitration reaction is carried out in a microchannel reactor and a tubular reactor, which can solve the mass transfer and heat transfer problems, does not require pre-cooling of the potassium ferrocyanide solution, and also avoids the prolonged reaction time caused by intermittent production, and the unstable decomposition of the raw material system caused by long-term stirring to release nitric oxide gas, the safety of the preparation device is higher, and the product yield can be improved.

[0066] The invention provides a 2,2-dinitropropanol preparation device. 2-nitropropanol, a sodium nitrite aqueous solution, a sodium persulfate aqueous solution and a solvent are provided to an oxidative nitration unit through a raw material unit, a potassium ferrocyanide aqueous solution is provided to the oxidative nitration unit through a catalyst unit, and the oxidative nitration unit is selected from at least one of a microchannel reactor and a tubular reactor, so that the oxidative nitration reaction is carried out in the microchannel reactor and the tubular reactor, and the production efficiency and product yield of the synthetic preparation of 2,2-dinitropropanol can be improved.

[0067] It can be understood that in practical applications, microchannel reactors and tubular reactors can be freely selected according to the needs of actual production volume. For reference, when the feed amount reaches kilograms or above, a tubular reactor can be selected; at the same time, according to the characteristics of the equipment, it should be noted that the microchannel reactor requires the solid material to be completely dissolved before it can be passed in, while in the tubular reactor, the material does not need to be completely dissolved, that is, the solid material and the solvent can be passed in a solid-liquid mixed state.

[0068] In a specific embodiment, Figure 1 Schematic diagram of a preparation device in one embodiment of the present invention; Figure 1 As shown, the raw material unit includes 2-nitropropanol unit 02, sodium nitrite unit SM4, sodium persulfate unit SM5 and solvent unit SM7;

[0069] Among them, the outlet of the 2-nitropropanol unit 02, the outlet of the sodium nitrite unit SM4, the outlet of the sodium persulfate unit SM5, and the outlet of the solvent unit SM7 are respectively connected to the inlet of the oxidation nitration unit 03.

[0070] The present invention does not limit the specific form of each unit; wherein, the 2-nitropropanol unit 02 is used to output 2-nitropropanol; the sodium nitrite unit SM4 is used to output a sodium nitrite aqueous solution; the solvent unit SM7 is used to output a solvent;

[0071] Specifically, the 2-nitropropanol in the 2-nitropropanol unit 02, the sodium nitrite aqueous solution in the sodium nitrite unit SM4, and the solvent in the solvent unit SM7 leave through the outlets of their respective units, and then pass into the oxidative nitration unit 03 through the inlet of the oxidative nitration unit 03. The potassium ferrocyanide aqueous solution leaves through the outlet of the catalyst unit SM6 and also passes into the oxidative nitration unit 03 through the inlet of the oxidative nitration unit 03, and jointly participates in the oxidative nitration reaction; by controlling the co-addition of 2-nitropropanol, the sodium nitrite aqueous solution and the solvent into the oxidative nitration unit 03, and passing the potassium ferrocyanide aqueous solution alone into the oxidative nitration unit 03, the mass transfer and heat transfer problems of the reaction occurring in the oxidative nitration unit 03 can be controlled, thereby further improving the reaction efficiency and the yield of the product.

[0072] In a specific embodiment, Figure 2 Schematic diagram of a preparation device in one embodiment of the present invention; Figure 2 As shown, the raw material unit includes a first mixing unit 06, a 2-nitropropanol unit 02, a sodium nitrite unit SM4, a sodium persulfate unit SM5 and a solvent unit SM7;

[0073] Among them, the outlet of the solvent unit SM7 is connected to the inlet of the 2-nitropropanol unit 02, the outlet of the sodium nitrite unit SM4, the outlet of the sodium persulfate unit SM5, and the outlet of the catalyst unit SM6 are respectively connected to the inlet of the first mixing unit 06, and the outlet of the 2-nitropropanol unit 02 and the outlet of the first mixing unit 06 are respectively connected to the inlet of the oxidation nitration unit 03.

[0074] The present invention does not limit the specific form of each unit; wherein the first mixing unit 06 is used to pre-mix and cool the materials entering therein; the 2-nitropropanol unit 02 is used to output 2-nitropropanol; the sodium nitrite unit SM4 is used to output a sodium nitrite aqueous solution; the solvent unit SM7 is used to output a solvent;

[0075] Specifically, the solvent leaves through the outlet of the solvent unit SM7 and then enters the 2-nitropropanol unit 02 through the inlet of the 2-nitropropanol unit 02, and the 2-nitropropanol is first mixed and dissolved. The material after the mixed and dissolved treatment leaves through the outlet of the 2-nitropropanol unit 02 and then enters the oxidation nitration unit 03 through the inlet of the oxidation nitration unit 03;

[0076] The sodium nitrite aqueous solution leaves through the outlet of the sodium nitrite unit SM4 and then enters the first mixing unit 06 through the inlet of the first mixing unit 06, the sodium persulfate aqueous solution leaves through the outlet of the sodium persulfate unit SM5 and then enters the first mixing unit 06 through the inlet of the first mixing unit 06, and the potassium ferrocyanide aqueous solution leaves through the outlet of the catalyst unit SM6 and then enters the first mixing unit 06 through the inlet of the first mixing unit 06. After the sodium nitrite aqueous solution, the ammonium persulfate aqueous solution and the potassium ferrocyanide aqueous solution are pre-mixed and cooled in the first mixing unit 06, the mixed solution is then taken out through the outlet of the first mixing unit 06 and enters the oxidation nitration unit 03 through the inlet of the oxidation nitration unit 03;

[0077] In this embodiment, the solvent is first mixed and dissolved with 2-nitropropanol and then introduced into the oxidative nitration unit 03. In addition, the sodium nitrite aqueous solution, the ammonium persulfate aqueous solution and the potassium ferrocyanide aqueous solution are mixed in advance and then introduced into the oxidative nitration unit 03 together. This can further control the mass transfer and heat transfer problems of the oxidative nitration reaction in the oxidative nitration unit 03, further improve the reaction efficiency, and improve the yield of the product.

[0078] In a specific embodiment, Figure 3 Schematic diagram of a preparation device in one embodiment of the present invention; Figure 3 As shown, the raw material unit includes a first mixing unit 06, a second mixing unit 07, a 2-nitropropanol unit 02, a sodium nitrite unit SM4, a sodium persulfate unit SM5 and a solvent unit SM7;

[0079] Among them, the outlet of sodium nitrite unit SM4, the outlet of sodium persulfate unit SM5, and the outlet of solvent unit SM7 are respectively connected to the inlet of the first mixing unit 06, the outlet of 2-nitropropanol unit 02 and the outlet of the first mixing unit 06 are respectively connected to the inlet of the second mixing unit 07, and the outlet of the second mixing unit 07 is connected to the inlet of the oxidation nitrification unit 03.

[0080] The present invention does not limit the specific form of each unit; wherein the first mixing unit 06 is used to pre-mix and cool the materials entering therein; the 2-nitropropanol unit 02 is used to output 2-nitropropanol; the sodium nitrite unit SM4 is used to output a sodium nitrite aqueous solution; the solvent unit SM7 is used to output a solvent;

[0081] Specifically, the sodium nitrite aqueous solution leaves through the outlet of the sodium nitrite unit SM4 and then enters the first mixing unit 06 through the inlet of the first mixing unit 06, the sodium persulfate aqueous solution leaves through the outlet of the sodium persulfate unit SM5 and then enters the first mixing unit 06 through the inlet of the first mixing unit 06, the solvent leaves through the outlet of the solvent unit SM7 and then enters the first mixing unit 06 through the inlet of the first mixing unit 06, the sodium nitrite aqueous solution, the sodium persulfate aqueous solution and the solvent are pre-mixed and cooled to obtain a mixed solution, the mixed solution is then extracted through the outlet of the first mixing unit 06 and enters the second mixing unit 07 through the inlet of the second mixing unit 07; 2-nitropropanol is extracted through the outlet of the 2-nitropropanol unit 02 and then enters the second mixing unit 07 through the inlet of the second mixing unit 07, and is mixed with the mixed solution for a second time to obtain a second mixed solution;

[0082] The second mixed liquid is taken out through the outlet of the second mixing unit 07, the potassium ferrocyanide aqueous solution is taken out through the outlet of the catalyst unit SM6, and then enters the oxidation nitrification unit 03 through the inlet of the oxidation nitrification unit 03;

[0083] In this embodiment, the sodium nitrite aqueous solution, the sodium persulfate aqueous solution and the solvent are pre-mixed and cooled to obtain a mixed solution, 2-nitropropanol is then mixed with the mixed solution to obtain a second mixed solution, and the second mixed solution is then introduced into the oxidative nitration unit 03 together with the potassium ferrocyanide aqueous solution to carry out an oxidative nitration reaction, which can further control the mass transfer and heat transfer problems of the oxidative nitration reaction in the oxidative nitration unit 03, further improve the reaction efficiency, and improve the yield of the product.

[0084] The following are Figure 1 Take this as an example to illustrate.

[0085] Optionally, it further comprises: a nitroethane unit SM1, an alkali solution unit SM2 and a formaldehyde unit SM3;

[0086] The outlet of the nitroethane unit SM1, the outlet of the alkali solution unit SM2, and the outlet of the formaldehyde unit SM3 are connected to the inlet of the 2-nitropropanol unit 02, respectively.

[0087] The present invention does not limit the specific forms of each unit; wherein, the nitroethane unit SM1 is used to output nitroethane; the alkali solution unit SM2 is used to output sodium hydroxide aqueous solution; and the formaldehyde unit SM3 is used to output formaldehyde aqueous solution.

[0088] Specifically, nitroethane is produced through the outlet of nitroethane unit SM1, sodium hydroxide aqueous solution is produced through the outlet of alkali solution unit SM2, and formaldehyde aqueous solution is produced through the outlet of formaldehyde unit SM3, and then they are respectively introduced into 2-nitropropanol unit 02 through the inlet of 2-nitropropanol unit 02, where condensation reaction is carried out to obtain 2-nitropropanol, which is then produced through the outlet of 2-nitropropanol unit 02.

[0089] Furthermore, it also includes a hydrogenation unit; the outlet of the nitroethane unit SM1 and the outlet of the alkali solution unit SM2 are respectively connected to the inlet of the hydrogenation unit, the outlet of the hydrogenation unit is connected to the inlet of the 2-nitropropanol unit 02, and the outlet of the formaldehyde unit SM3 is connected to the inlet of the 2-nitropropanol unit 02;

[0090] Specifically, nitroethane and an aqueous sodium hydroxide solution are first introduced into a hydrogenation unit, where a hydrogenation treatment is performed, and the hydrogenated material is extracted through the outlet of the hydrogenation unit and then introduced into the 2-nitropropanol unit 02 through the inlet of the 2-nitropropanol unit 02. The formaldehyde aqueous solution is extracted through the outlet of the formaldehyde unit SM3 and then introduced into the 2-nitropropanol unit 02 through the inlet of the 2-nitropropanol unit 02. In the 2-nitropropanol unit 02, the formaldehyde aqueous solution undergoes a condensation reaction with the hydrogenated material to obtain 2-nitropropanol, which is extracted through the outlet of the 2-nitropropanol unit 02.

[0091] Optionally, the 2-nitropropanol unit 02 may be selected from at least one of a reaction kettle, a microchannel reactor and a tubular reactor.

[0092] Furthermore, it also includes: a quenching unit 04 and a concentration and distillation unit 05;

[0093] The outlet of the oxidative nitration unit 03 is connected to the inlet of the quenching unit 04, and the outlet of the quenching unit 04 is connected to the inlet of the concentration and distillation unit 05. The outlet of the concentration and distillation unit 05 is used to output the 2,2-dinitropropanol product.

[0094] The present invention does not limit the specific form of each unit; wherein, the quenching unit 04 is used to quench the crude 2,2-dinitropropanol to obtain a quenched material; the concentration and distillation unit 05 is used to concentrate and distill the quenched material, including separation treatment to remove the water phase of the quenched material, vacuum concentration treatment to remove the solvent, and vacuum distillation treatment to obtain a purified 2,2-dinitropropanol product.

[0095] Specifically, the crude 2,2-dinitropropanol is taken out from the outlet of the oxidation nitration unit 03, and then passed into the quenching unit 04 through the inlet of the quenching unit 04 for quenching treatment to obtain the quenched material; the quenched material is taken out from the outlet of the quenching unit 04, and then passed into the concentration distillation unit 05 through the inlet of the concentration distillation unit 05, where it is subjected to separation treatment, reduced pressure concentration treatment and reduced pressure distillation treatment, etc. to obtain the 2,2-dinitropropanol product, which is taken out from the outlet of the concentration distillation unit 05.

[0096] Through the quenching unit 04 and the concentration distillation unit 05, the 2,2-dinitropropanol product can be subsequently treated and purified to obtain the 2,2-dinitropropanol product, thereby further improving the yield and purity of the product obtained by the preparation device.

[0097] Optionally, the quenching unit 04 can be selected from at least one of a reactor, a microchannel reactor and a tubular reactor; the concentration distillation unit 05 can be selected from at least one of a vacuum distillation reactor, a thin film evaporator, a scraped surface evaporator, etc.

[0098] On the other hand, the present invention also provides a method for preparing 2,2-dinitropropanol, which is performed using the above-mentioned preparation device; the preparation method comprises the following steps:

[0099] The 2-nitropropanol, sodium nitrite aqueous solution, sodium persulfate aqueous solution and solvent in the raw material unit and the potassium ferrocyanide aqueous solution in the catalyst unit SM6 are sequentially or simultaneously introduced into the oxidative nitration unit 03 for oxidative nitration treatment to obtain crude 2,2-dinitropropanol.

[0100] In the oxidative nitration unit 03, 2-nitropropanol and sodium nitrite aqueous solution are used as raw materials for oxidative nitration reaction, sodium persulfate aqueous solution is used as oxidant, and potassium ferrocyanide aqueous solution is used as catalyst to participate in oxidative nitration treatment, and oxidative nitration reaction occurs. The oxidative nitration reaction is carried out in the oxidative nitration unit 03 including a microchannel reactor and a tubular reactor, which can solve the mass transfer and heat transfer problems, does not require pre-cooling of the potassium ferrocyanide solution, and also avoids the extension of reaction time caused by intermittent production, and the unstable decomposition and release of nitric oxide gas caused by long-term stirring of the raw material system. The preparation method is safer and can improve the product yield.

[0101] The present invention provides a method for preparing 2,2-dinitropropanol. The method comprises the following steps: introducing 2-nitropropanol, a sodium nitrite aqueous solution, a sodium persulfate aqueous solution and a solvent into at least one oxidative nitration unit 03 selected from a microchannel reactor and a tubular reactor, and introducing a potassium ferrocyanide aqueous solution into the oxidative nitration unit 03, so that the oxidative nitration reaction is carried out in the microchannel reactor and the tubular reactor, thereby improving the production efficiency and product yield of the synthetic preparation of 2,2-dinitropropanol.

[0102] Specifically, when the content of 2-nitropropanol during the oxidative nitration treatment in the oxidative nitration unit 03 is not higher than 2%, the oxidative nitration treatment is completed to obtain a crude 2,2-dinitropropanol, which is subsequently treated.

[0103] In one specific embodiment, the oxidation nitration treatment time is 1 to 30 minutes, and the temperature is -25 to 50°C;

[0104] The molar ratio of 2-nitropropanol to potassium ferrocyanide in the potassium ferrocyanide aqueous solution is 1:(0.1-10);

[0105] The rate of introduction of potassium ferrocyanide aqueous solution is 0.01-200 mL / min;

[0106] The mass ratio of potassium ferrocyanide to water in the potassium ferrocyanide aqueous solution is 1:(2-20).

[0107] The inventors have found that by further controlling the time of the oxidation nitration treatment, that is, the residence time of the material in the oxidation nitration unit 03, the reaction process can be better controlled, the reaction efficiency can be further improved, and the product yield can be increased;

[0108] By limiting the molar ratio of the potassium ferrocyanide aqueous solution to 2-nitropropanol, the product yield of the preparation method can be further improved, and the reaction efficiency can be improved;

[0109] By further controlling the introduction rate of the potassium ferrocyanide aqueous solution, the mass transfer and heat transfer problems of the oxidative nitration treatment can be better improved, the safety of the reaction can be improved, and the product yield and preparation efficiency of the preparation method can be further improved;

[0110] Further, the solvent includes at least one of ethyl acetate, ethylene dichloride, dichloromethane, toluene and tetrahydrofuran.

[0111] It can be understood that a suitable solvent has a crucial influence on the progress of the reaction. The inventors have found that when the solvent includes at least one of ethyl acetate, dichloroethane, dichloromethane, toluene and tetrahydrofuran, the product yield of the preparation method and the reaction efficiency can be further improved; the solvent can also be further limited to tetrahydrofuran.

[0112] Optionally, the method further comprises the following steps:

[0113] The nitroethane in the nitroethane unit SM1, the sodium hydroxide aqueous solution in the alkali solution unit SM2, and the formaldehyde aqueous solution in the formaldehyde unit SM3 are sequentially or simultaneously introduced into the 2-nitropropanol unit 02 for condensation treatment to obtain 2-nitropropanol;

[0114] The condensation treatment time is 1 to 30 minutes, and the temperature is -10 to 50°C.

[0115] The feed rate of the formaldehyde aqueous solution is 0.01-200 mL / min, the molar ratio of the material after hydrogenation to the formaldehyde aqueous solution is 0.01-100; the condensation treatment time is 0.1-180 min, further refined to 1-20 min; the temperature is -10-50°C;

[0116] By subjecting nitroethane to a condensation treatment with an aqueous sodium hydroxide solution and an aqueous formaldehyde solution, a condensation reaction can be performed to obtain 2-nitropropanol, which can be used as an intermediate for preparing 2,2-dinitropropanol.

[0117] By specifically limiting the time and temperature of the condensation treatment, the condensation reaction can be better controlled and the purity and yield of the obtained product can be improved.

[0118] Specifically, when the condensation treatment is carried out in the 2-nitropropanol unit 02, when the content of nitroethane is not higher than 2%, it is judged that the condensation treatment is completed and 2-nitropropanol is obtained, and the 2-nitropropanol can be output.

[0119] Furthermore, the nitroethane in the nitroethane unit SM1 and the sodium hydroxide aqueous solution in the alkali solution unit SM2 may be first introduced into the hydrogenation unit for hydrogenation treatment to carry out hydrogenation reaction to obtain the hydrogenation-extracted material; and the hydrogenation-extracted material and the formaldehyde aqueous solution in the formaldehyde unit SM3 are introduced into the 2-nitropropanol unit 02 for condensation treatment to obtain 2-nitropropanol.

[0120] In a specific embodiment, the mass ratio of sodium hydroxide to water in the sodium hydroxide aqueous solution is 1:(2-20), further refined to 1:(3-5);

[0121] The mass ratio of formaldehyde to water in the formaldehyde aqueous solution is 1:(1.5-20), further refined to 1:(1.5-4);

[0122] The mass ratio of sodium nitrite to water in the sodium nitrite aqueous solution is 1:(0.5-20), further refined to 1:(1-5);

[0123] The mass ratio of sodium persulfate to water in the sodium persulfate aqueous solution is 1:(2-20), further refined to 1:(2.5-5);

[0124] The mass ratio of potassium ferrocyanide to water in the potassium ferrocyanide aqueous solution is 1:(2-20), further refined to 1:(2.5-5);

[0125] The feed rate of nitroethane and sodium hydroxide aqueous solution is 0.01-200 mL / min, further refined to 10-120 mL / min; the molar ratio of nitroethane to sodium hydroxide in the sodium hydroxide aqueous solution is 0.01:100, and the parameter is further refined to 1:10; the time of hydrogenation treatment is 1-30 min, further refined to 3-15 min; the temperature of hydrogenation treatment is -10-50° C., further refined to 10-25° C.;

[0126] The feeding rate of the solvent is 0.01 to 200 mL / min, the mass ratio of 2-nitropropanol to the solvent is 1:(1 to 10), further refined to 1:(1.5 to 5); the time for the dilution and mixing treatment is 1 to 80 min, further refined to 1 to 10 min; the temperature is -10 to 50° C., further refined to 5 to 20° C.;

[0127] The feeding rate of the sodium nitrite aqueous solution is 0.01-200 mL / min, the molar ratio of 2-nitropropanol to the sodium nitrite in the sodium nitrite aqueous solution is 1:(1-20); the mixing treatment time is 0.1-180 min, and the temperature is -25-50° C.;

[0128] The feeding rate of the sodium persulfate aqueous solution is 0.01-200 mL / min, the molar ratio of 2-nitropropanol to the sodium persulfate aqueous solution is 1:(0.1-10); the oxidation nitration treatment time is 1-30 min, and the temperature is -25-50° C.;

[0129] The feed rate of potassium ferrocyanide aqueous solution is 0.01-200 mL / min, the molar ratio of 2-nitropropanol to potassium perferrocyanide aqueous solution is 1:(0.1-10); the time of oxidation nitration treatment is 1-30 min, and the temperature is -25-50° C.;

[0130] When the crude 2,2-nitropropanol in the quenching unit 04 is quenched, cold water is introduced at a flow rate of 0.01 to 200 mL / min, the mass ratio of the crude 2,2-nitropropanol to water is 1:(1-20), the quenching time is 0.1 to 180 min, and the temperature is -15 to 30° C.;

[0131] Hereinafter, a method for preparing 2,2-dinitropropanol provided by the present invention is described in detail through specific examples.

[0132] Example 1

[0133] Use Figure 1 The preparation device shown is carried out, the oxidation nitration unit 03 is selected from a tubular reactor, comprising the following steps:

[0134] (1) First, the nitroethane in the nitroethane unit SM1 and the sodium hydroxide aqueous solution in the alkali solution unit SM2 are introduced into the hydrogenation unit for hydrogenation treatment to obtain the hydrogenation-extracted material, which is introduced into the 2-nitropropanol unit 02; wherein the mass ratio of sodium hydroxide to water in the sodium hydroxide aqueous solution is 1:3, the feed rate is 38 mL / min, the molar ratio of nitroethane to sodium hydroxide in the sodium hydroxide aqueous solution is 1:2, the hydrogenation treatment time is 1.5 min, and the temperature is 20°C;

[0135] (2) passing the formaldehyde aqueous solution in the formaldehyde unit SM3 into the 2-nitropropanol unit 02, and condensing it with the material after hydrogenation to obtain 2-nitropropanol. When the nitroethane content in the system is 2%, passing it into the oxidative nitration unit 03; wherein the mass ratio of formaldehyde to water in the formaldehyde aqueous solution is 1:4, the feed rate of the formaldehyde aqueous solution is 28.1 mL / min, and the molar ratio of the material after hydrogenation to the formaldehyde aqueous solution is 1:1.5; the condensation treatment time is 3 min, and the temperature is 20°C;

[0136] (3) The tetrahydrofuran solvent in the solvent unit SM7 is passed into the oxidative nitration unit 03 for dilution and mixing treatment; wherein the solvent feed rate is 38 mL / min, and the mass ratio of 2-nitropropanol to the solvent is 1:8; the dilution and mixing treatment time is 1.5 min, and the temperature is 15° C.;

[0137] (4) passing the sodium nitrite aqueous solution in the sodium nitrite unit SM4 into the oxidation nitration unit 03 for mixing treatment; wherein the mass ratio of sodium nitrite to water in the sodium nitrite aqueous solution is 1:3, the feed rate of the sodium nitrite aqueous solution is 76 mL / min, the molar ratio of 2-nitropropanol to the sodium nitrite aqueous solution is 1:4, the mixing treatment time is 4.5 min, and the temperature is 22° C.;

[0138] (5) passing the sodium persulfate aqueous solution in the sodium persulfate unit SM5 into the oxidative nitration unit 03 for oxidative nitration treatment; wherein the mass ratio of sodium persulfate to water in the sodium persulfate aqueous solution is 1:3, the feed rate of the sodium persulfate aqueous solution is 38 mL / min, and the molar ratio of 2-nitropropanol to the sodium persulfate aqueous solution is 1:2; the oxidative nitration treatment time is 6 min, and the temperature is 22° C.;

[0139] (6) Passing the potassium ferrocyanide aqueous solution in the catalyst unit SM6 into the oxidation nitration unit 03 for oxidation nitration treatment to obtain a crude 2,2-nitropropanol. When the 2-nitropropanol content in the system is 2%, passing it into the quenching unit 04; wherein the mass ratio of potassium ferrocyanide to water in the potassium ferrocyanide aqueous solution is 1:3, the feed rate of the potassium ferrocyanide aqueous solution is 19 mL / min, and the molar ratio of 2-nitropropanol to the potassium ferrocyanide aqueous solution is 1:1; the temperature of the oxidation nitration treatment is 22°C;

[0140] (7) quenching the crude 2,2-nitropropanol in the quenching unit 04, passing cold water at a flow rate of 76 mL / min to obtain a quenched material, and passing it into the concentration distillation unit 05; the mass ratio of the crude 2,2-nitropropanol to water is 1:3.7, the quenching time is 1.5 min, and the temperature is 20° C.;

[0141] (8) The quenched material in the concentration and distillation unit 05 is separated to remove the water phase, the organic phase is concentrated under reduced pressure to remove the solvent, and purified by high vacuum and reduced pressure distillation to obtain a 2,2-dinitropropanol product.

[0142] Example 2

[0143] Use Figure 2 The preparation device shown is carried out, the oxidation nitration unit 03 is selected from a tubular reactor, comprising the following steps:

[0144] (1) and (2) are the same as in Example 1;

[0145] (3) passing the tetrahydrofuran solvent in the solvent unit SM7 into the 2-nitropropanol unit 02 for dilution and mixing to obtain a first mixed material, which is then passed into the oxidation nitration unit 03;

[0146] (4) The sodium nitrite aqueous solution in the sodium nitrite unit SM4, the sodium persulfate aqueous solution in the sodium persulfate unit SM5, and the potassium ferrocyanide aqueous solution in the catalyst unit SM6 are respectively introduced into the first mixing unit 06 for mixing to obtain a second mixed material, which is then introduced into the oxidation nitration unit 03;

[0147] (5) In the oxidation nitration unit 03, the first mixed material and the second mixed material are subjected to oxidation nitration treatment to obtain a crude 2,2-nitropropanol. When the nitroethane content in the system is 2%, the crude 2,2-nitropropanol is passed into the quenching unit 04;

[0148] (6) and (7) are the same as steps (7) and (8) of the embodiment;

[0149] The remaining parameters are the same as those in Example 1.

[0150] Example 3

[0151] Use Figure 3 The preparation device shown is carried out in the oxidation nitration unit 03 tubular reactor, comprising the following steps:

[0152] (1) Same as Example 1;

[0153] (2) passing the formaldehyde aqueous solution in the formaldehyde unit SM3 into the 2-nitropropanol unit 02, and condensing it with the material after hydrogen extraction to obtain 2-nitropropanol. When the nitroethane content in the system is 2%, passing it into the second mixing unit 07;

[0154] (3) introducing the tetrahydrofuran solvent in the solvent unit SM7, the sodium nitrite aqueous solution in the sodium nitrite unit SM4, and the sodium persulfate aqueous solution in the sodium persulfate unit SM5 into the first mixing unit 06, respectively, for a first mixing treatment to obtain a first mixed material, which is introduced into the second mixing unit 07;

[0155] (4) performing a second mixing treatment on the 2-nitropropanol in the second mixing unit 07 and the first mixed material to obtain a second mixed material, which is then introduced into the oxidation nitration unit 03;

[0156] (5) Passing the potassium ferricyanide aqueous solution in the catalyst unit SM6 into the oxidation nitration unit 03 for oxidation nitration treatment to obtain a crude 2,2-nitropropanol product. When the 2-nitropropanol content in the system is 2%, passing it into the quenching unit 04;

[0157] (6) and (7) are the same as steps (7) and (8) of the embodiment;

[0158] The remaining parameters are the same as those in Example 1.

[0159] Example 4

[0160] The difference between this embodiment and embodiment 1 is that in step (6), the feed rate of the potassium ferrocyanide aqueous solution is 210 mL / min.

[0161] Example 5

[0162] The difference between this embodiment and embodiment 1 is that in step (6), the molar ratio of 2-nitropropanol to potassium ferrocyanide is 1:0.05.

[0163] Example 6

[0164] The difference between this embodiment and embodiment 1 is that in step (6), the time of oxidation nitration treatment is 20 minutes.

[0165] Example 7

[0166] The difference between this embodiment and embodiment 1 is that in step (6), the temperature is 15°C.

[0167] Example 8

[0168] The difference between this embodiment and embodiment 1 is that the solvent is selected from ethyl acetate.

[0169] Example 9

[0170] The difference between this embodiment and embodiment 1 is that in step (6), the time of oxidation nitration treatment is 1 minute.

[0171] Example 10

[0172] The difference between this embodiment and embodiment 1 is that in step (6), the time of oxidation nitration treatment is 3 minutes.

[0173] Embodiment 11

[0174] The difference between this embodiment and embodiment 1 is that in step (6), the time of oxidation nitration treatment is 9 minutes.

[0175] Example 12

[0176] The difference between this embodiment and embodiment 1 is that in step (6), the time of oxidation nitration treatment is 12 minutes.

[0177] Example 13

[0178] The difference between this embodiment and embodiment 1 is that in step (6), the time of oxidation nitration treatment is 15 minutes.

[0179] Embodiment 14

[0180] The difference between this embodiment and embodiment 1 is that in step (6), the time of oxidation nitration treatment is 18 minutes.

[0181] Embodiment 15

[0182] The difference between this embodiment and embodiment 1 is that in step (6), the time of oxidation nitration treatment is 21 minutes.

[0183] Example 16

[0184] The difference between this embodiment and embodiment 1 is that in step (6), the time of oxidation nitration treatment is 24 minutes.

[0185] Test Example 1

[0186] The yield of the 2,2-dinitropropanol product obtained in the above examples and comparative examples was calculated by formula (1);

[0187] Yield = (mass of 2,2-dinitropropanol / molecular weight of 2,2-dinitropropanol) / (mass of nitroethane / molecular weight of nitroethane)*2*100%

[0188] The results are shown in Table 1.

[0189] Table 1

[0190] Serial number Oxidation nitrification treatment time (min) Product yield (%) Example 1 6 80.09 Example 2 6 83.76 Example 3 6 81.35 Example 4 6 80.01 Example 5 6 82.21 Example 6 20 75.13 Example 7 6 70.13 Example 8 6 62.17 Example 9 1 68.11 Example 10 3 75.02 Embodiment 11 9 80.26 Example 12 12 78.53 Example 13 15 77.00 Embodiment 14 18 75.83 Embodiment 15 21 74.22 Example 16 24 72.16

[0191] The invention provides a 2,2-dinitropropanol preparation device. 2-nitropropanol, a sodium nitrite aqueous solution, a sodium persulfate aqueous solution and a solvent are provided to an oxidative nitration unit through a raw material unit, a potassium ferrocyanide aqueous solution is provided to the oxidative nitration unit through a catalyst unit, and the oxidative nitration unit is selected from at least one of a microchannel reactor and a tubular reactor, so that the oxidative nitration reaction is carried out in the microchannel reactor and the tubular reactor, and the production efficiency and product yield of the synthetic preparation of 2,2-dinitropropanol can be improved.

[0192] Test Example 2

[0193] The 2,2-dinitropropanol product obtained in Example 1 was characterized by H-NMR. Figure 4 As shown by Figure 4 It can be seen that the product obtained in Example 1 is 2,2-dinitropropanol.

[0194] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for preparing 2,2-dinitropropanol, characterized in that: It includes a raw material unit, a catalyst unit and an oxidation nitration unit; The outlet of the raw material unit and the outlet of the catalyst unit are respectively connected to the inlet of the oxidation nitration unit, and the outlet of the oxidation nitration unit is used to output the crude 2,2-dinitropropanol; The raw material unit is used to provide 2-nitropropanol, sodium nitrite aqueous solution, sodium persulfate aqueous solution and solvent to the oxidation nitration unit; The catalyst unit is used to provide potassium ferrocyanide aqueous solution to the oxidation nitration unit; Wherein, the oxidation nitrification unit is selected from at least one of a microchannel reactor and a tubular reactor.

2. The preparation device according to claim 1, characterized in that: The raw material unit includes a 2-nitropropanol unit, a sodium nitrite unit, a sodium persulfate unit and a solvent unit; Wherein, the outlet of the 2-nitropropanol unit, the outlet of the sodium nitrite unit, the outlet of the sodium persulfate unit, and the outlet of the solvent unit are respectively connected to the inlet of the oxidative nitration unit.

3. The preparation device according to claim 1, characterized in that: The raw material unit includes a first mixing unit, a 2-nitropropanol unit, a sodium nitrite unit, a sodium persulfate unit and a solvent unit; Among them, the outlet of the solvent unit is connected to the inlet of the 2-nitropropanol unit, the outlet of the sodium nitrite unit, the outlet of the sodium persulfate unit, and the outlet of the catalyst unit are respectively connected to the inlet of the first mixing unit, and the outlet of the 2-nitropropanol unit and the outlet of the first mixing unit are respectively connected to the inlet of the oxidation nitration unit.

4. The preparation device according to claim 1, characterized in that: The raw material unit includes a first mixing unit, a second mixing unit, a 2-nitropropanol unit, a sodium nitrite unit, a sodium persulfate unit and a solvent unit; Among them, the outlet of the sodium nitrite unit, the outlet of the sodium persulfate unit, and the outlet of the solvent unit are respectively connected to the inlet of the first mixing unit, the outlet of the 2-nitropropanol unit and the outlet of the first mixing unit are respectively connected to the inlet of the second mixing unit, and the outlet of the second mixing unit is connected to the inlet of the oxidation nitration unit.

5. The preparation device according to any one of claims 2 to 4, characterized in that: Also includes: Nitroethane units, lye units and formaldehyde units; The outlet of the nitroethane unit, the outlet of the alkali solution unit, and the outlet of the formaldehyde unit are respectively connected to the inlet of the 2-nitropropanol unit.

6. The preparation device according to any one of claims 1 to 5, characterized in that: Also includes: Quenching unit and concentrating distillation unit; The outlet of the oxidative nitration unit is communicated with the inlet of the quenching unit, and the outlet of the quenching unit is communicated with the inlet of the concentration and distillation unit. The outlet of the concentration and distillation unit is used to output the 2,2-dinitropropanol product.

7. A method for preparing 2,2-dinitropropanol, characterized in that: The preparation method is performed by using the preparation device according to any one of claims 1 to 6; the preparation method comprises the following steps: The 2-nitropropanol, sodium nitrite aqueous solution, sodium persulfate aqueous solution and solvent in the raw material unit and the potassium ferrocyanide aqueous solution in the catalyst unit are sequentially or simultaneously introduced into the oxidative nitration unit for oxidative nitration treatment to obtain crude 2,2-dinitropropanol.

8. The preparation method according to claim 7, characterized in that: The oxidation nitration treatment lasts for 1-30 minutes at a temperature of -25 to 50°C; and / or, The molar ratio of potassium ferrocyanide in the potassium ferrocyanide aqueous solution to the 2-nitropropanol is 1:(0.1-10); and / or, The introduction rate of the potassium ferrocyanide aqueous solution is 0.01 to 200 mL / min; and / or, The mass ratio of potassium ferrocyanide to water in the potassium ferrocyanide aqueous solution is 1:(2-20).

9. The preparation method according to claim 7 or 8, characterized in that: The solvent includes at least one of ethyl acetate, ethylene dichloride, dichloromethane, toluene and tetrahydrofuran.

10. The preparation method according to any one of claims 7 to 9, characterized in that: The following steps are also included: The nitroethane in the nitroethane unit, the sodium hydroxide aqueous solution in the alkali solution unit, and the formaldehyde aqueous solution in the formaldehyde unit are sequentially or simultaneously introduced into the 2-nitropropanol unit for condensation treatment to obtain the 2-nitropropanol; Wherein, the condensation treatment time is 0.1 to 180 minutes, and the temperature is -10 to 50°C.

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