A reaction device and a method for preparing 2,2-dinitropropanol

Abstract

This invention provides a reaction apparatus and a method for preparing 2,2-dinitropropanol. The preparation method includes the following steps: Nitroethane reacts with an alkaline solution in a series of sequential sub-static tubular reactors to obtain a dehydrogenation system; the dehydrogenation system reacts with an aqueous formaldehyde solution to obtain a hydroxymethylation intermediate system; the hydroxymethylation intermediate system reacts with a sodium nitrite solution to obtain a nitrosation intermediate system; the nitrosation intermediate system reacts with an aqueous sodium persulfate solution and an aqueous potassium ferricyanide solution to obtain a partially oxidized intermediate system; the partially oxidized intermediate system is then transferred to a dynamic tubular reactor for further oxidation to generate 2,2-dinitropropanol. This invention solves the problems of uncontrollable exothermic reactions, solid impurities causing pipeline blockage during oxidation, and high costs and environmental pollution due to excessive reliance on solvent dilution in existing 2,2-dinitropropanol preparation processes.

Description

Technical Field

[0001] This application relates to the field of chemical production, and in particular to a reaction apparatus and a method for preparing 2,2-dinitropropanol. Background Technology

[0002] 2,2-Dinitropropanol, as an important polynitro alcohol compound, has broad application prospects in the synthesis of energetic materials, fine chemicals, and pharmaceutical intermediates. The nitro and hydroxyl functional groups in its molecular structure provide diverse modification sites for subsequent derivatization reactions, making it a key precursor for the preparation of high-performance energetic plasticizers, specialty polymer monomers, and functional materials. With the development of related high-end manufacturing and specialty chemical industries, there is a continuously growing demand for efficient and green synthesis processes for this compound.

[0003] However, the synthesis of 2,2-dinitropropanol in existing technologies faces several significant technical bottlenecks and safety hazards. In the nitration reaction, due to its strong exothermic nature, heat release is concentrated and rapid; improper control can easily lead to localized overheating, exacerbating side reactions and even posing safety risks. In the subsequent oxidation process, whether using silver nitrate as the oxidant or a combination of potassium ferricyanide and sodium persulfate, a large amount of suspended solid byproducts (such as metal salt precipitates or complex complexes) insoluble in the reaction medium are generated. These solid particles are not only difficult to remove effectively through conventional filtration, but also easily accumulate in reactors, pipelines, and valves, causing severe equipment blockage and wear, affecting the continuity and stability of production. To alleviate the difficulties in mixing and mass transfer caused by excessively high solid concentrations, as well as the risk of blockage, existing processes often force a significant increase in solvent usage to dilute the reaction system. However, this directly leads to a sharp increase in organic solvent consumption and a significant expansion of the scale of subsequent wastewater treatment. This not only significantly increases the cost of raw materials and energy consumption, but also brings heavy environmental pressure and the burden of treating waste, severely restricting the large-scale production and application of this compound from both economic and environmental perspectives.

[0004] Therefore, how to solve the problems of uncontrollable exothermic reaction, pipeline blockage caused by solid impurities generated in the oxidation step, and high cost and environmental pollution caused by excessive reliance on solvent dilution in the existing 2,2-dinitropropanol preparation process has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a reaction apparatus. The core of this apparatus lies in providing precise residence time distribution and flow rate control, efficient heat transfer performance, and segmented feeding and mixing capabilities. This enables multi-step reactions to achieve spatial partitioning, stable flow, rapid heat removal, and uniform material distribution at the physical level, thereby effectively suppressing operational risks such as blockage, runaway, or accumulation and expansion of side reactions caused by unstable intermediates, instantaneous salt precipitation, or overheating of the reaction.

[0006] This application also provides a method for preparing 2,2-dinitropropanol. The core of this method lies in the precise guidance of the reaction path through segmented reaction control and condition progression strategy, which effectively suppresses problems that are difficult to avoid in traditional processes, such as side chain reactions, excessive oxidation, premature salt precipitation, and free radical chain runaway, thereby improving the selectivity, conversion rate and yield of the target product.

[0007] In a first aspect, this application provides a reaction apparatus, comprising:

[0008] The reactor comprises a static tubular reactor and a dynamic tubular reactor. The static tubular reactor includes N interconnected sub-static tubular reactors, where N ≥ 2. The outlet of the Nth sub-static tubular reactor is connected to the inlet of the dynamic tubular reactor. The first sub-static tubular reactor includes a reactant inlet, and the dynamic tubular reactor includes a product outlet.

[0009] In one possible implementation, the reaction apparatus as described above further includes: N=4.

[0010] In one possible implementation, the reaction apparatus as described above further includes a post-processor, wherein the reaction product outlet of the dynamic tubular reactor is connected to the inlet of the post-processor.

[0011] In one possible implementation, the reaction apparatus as described above further includes: the diameter of the reaction chamber of the dynamic tubular reactor is 2-3 times that of the reaction chamber of the static tubular reactor.

[0012] Secondly, this application provides a method for preparing 2,2-dinitropropanol, comprising the following steps:

[0013] Step 1) Nitroethane and alkaline solution undergo a dehydrogenation reaction in the first sub-static tubular reactor to obtain a dehydrogenation system;

[0014] Step 2) The dehydrogenation system is transported to the second sub-static tubular reactor, and formaldehyde aqueous solution is introduced into the second sub-static tubular reactor, so that the dehydrogenation system and the formaldehyde aqueous solution undergo a hydroxymethylation reaction in the second sub-static tubular reactor to generate a hydroxymethylation intermediate system;

[0015] Step 3) The hydroxymethylation intermediate system is transported to the third sub-static tubular reactor, and sodium nitrite solution is introduced into the third sub-static tubular reactor, so that the hydroxymethylation intermediate system and the sodium nitrite solution undergo a nitrosation reaction in the third sub-static tubular reactor to generate a nitrosation intermediate system;

[0016] Step 4) The nitrosation intermediate system is conveyed to the fourth sub-static tubular reactor, and sodium persulfate aqueous solution and potassium ferricyanide aqueous solution are introduced into the fourth sub-static tubular reactor. This causes the nitrosation intermediate system, the sodium persulfate aqueous solution, and the potassium ferricyanide aqueous solution to undergo a partial oxidation reaction in the fourth sub-static tubular reactor, generating a partially oxidized intermediate system.

[0017] Step 5) The partially oxidized intermediate system is transported to the dynamic tubular reactor, and the partially oxidized intermediate system continues to undergo oxidation reaction to generate 2,2-dinitropropanol system.

[0018] In one possible implementation, the preparation method described above further includes: in the partially oxidized intermediate system, the conversion rate of 2,2-dinitropropanol is 70-80%.

[0019] In one possible implementation, the preparation method described above further includes: the alkaline solution comprising at least one of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, lithium hydroxide aqueous solution, sodium carbonate aqueous solution, and ammonia solution.

[0020] In one possible embodiment, the preparation method described above further includes: the formaldehyde aqueous solution comprising formaldehyde and water; the sodium nitrite solution comprising sodium nitrite, water, and an organic solvent, wherein the mass ratio of sodium nitrite:water:organic solvent is (1:1:1) to (1:10:10); the sodium persulfate aqueous solution comprising sodium persulfate and water, wherein the mass ratio of sodium persulfate:water is (1:2) to (1:10); and the potassium ferricyanide aqueous solution comprising potassium ferricyanide and water, wherein the mass ratio of potassium ferricyanide:water is (1:2) to (1:10).

[0021] In one possible implementation, the preparation method described above further includes: the nitrosation reaction in step 3) and the oxidation reaction in step 4) are carried out at a reaction temperature of -20 to 40°C; and the reaction temperature in step 5) is carried out at a reaction temperature of 0 to 40°C.

[0022] In one possible implementation, the preparation method described above further includes, after step 5), post-treatment of the 2,2-dinitropropanol suspension system, the post-treatment including quenching, extraction and concentration drying.

[0023] This application provides a reaction apparatus and a method for preparing 2,2-dinitropropanol, which achieves efficient management of staged release of reaction heat and solid precipitation through a combination of static and dynamic reactors. First, the static tubular reactor, with its long pipeline design, extends the reaction time and controls the release of reaction heat in stages, rapidly completing partial conversion in the early stages. At this point, a small amount of by-product inorganic salts precipitate, but the static tubular reactor can still flow smoothly. Subsequently, the reaction liquid enters the dynamic tubular reactor, where stirring enhances mass transfer, ensuring uniform dispersion of solid precipitates in the high-concentration reaction system, avoiding pipeline blockage, reducing dependence on solvent dilution, and improving the overall conversion rate. Compared with traditional batch processes, this process solves the problems of uncontrollable exothermic reactions, pipeline blockage caused by solid impurities generated in the oxidation step, and high costs and environmental pollution caused by excessive reliance on solvent dilution in existing 2,2-dinitropropanol preparation processes. It achieves green and continuous production, balancing safety and economy. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0025] Figure 1 This is a schematic diagram of the structure of the reaction apparatus provided in the embodiments of this application;

[0026] Figure 2 A schematic flowchart illustrating the preparation method of 2,2-dinitropropanol provided in the embodiments of this application;

[0027] Figure 3 A schematic diagram of the structure of a dynamic tubular reactor is provided for an embodiment of this application.

[0028] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] As mentioned above, in order to solve the problems of uncontrollable exothermic reaction, pipeline blockage caused by solid impurities generated in the oxidation step, and high cost and environmental pollution caused by excessive reliance on solvent dilution in the existing 2,2-dinitropropanol preparation process, the inventors have proposed the reaction apparatus and the preparation method of 2,2-dinitropropanol of this application.

[0031] In a first aspect, this application provides a reaction apparatus, comprising:

[0032] Static tubular reactors and dynamic tubular reactors are defined as follows: a static tubular reactor consists of N interconnected sub-static tubular reactors, where N ≥ 2. The outlet of the Nth sub-static tubular reactor is connected to the inlet of the dynamic tubular reactor. The first sub-static tubular reactor includes a raw material inlet, and the dynamic tubular reactor includes a product outlet.

[0033] In one possible embodiment, the reaction apparatus described above, wherein a static tubular reactor is a device for staged and mild reaction of reactants. The internal fluid flows primarily by pressure difference or gravity, without mechanical stirring, reducing shear forces and dead zones, thus allowing the reaction to proceed under mild conditions. This helps reduce byproduct formation, avoids intermediate product accumulation, and lowers the risk of thermal runaway. A dynamic tubular reactor is a device for accelerating reaction completion and homogenizing products. Through forced mixing or fluidization, it achieves rapid heat transfer, thorough mixing of the reaction liquid, and ensures continuous product output, thereby increasing product yield, reducing the risk of clogging, and decreasing solvent dilution.

[0034] In this embodiment, N secondary static tubular reactors (i.e., sub-static tubular reactors, N≥2) are connected end-to-end to form a complete static tubular reactor. Here, "end-to-end connection" means that the outlet of each sub-static tubular reactor is fixedly connected to the inlet of the next sub-static tubular reactor, ensuring continuous flow of reactants without intermittent production and improving production efficiency.

[0035] Furthermore, the first sub-static tubular reactor includes a reactant inlet, and the outlet of the Nth sub-static tubular reactor is connected to the inlet of the dynamic tubular reactor, which includes a product outlet. This configuration ensures unidirectional flow of reactants within the reactor, enabling segmented temperature control and segmented feeding based on each sub-static tubular reactor. This allows for control of the release of heat of reaction and regulation of the reaction progress. It also allows for the continuous discharge of the fully mixed and reacted liquid from the dynamic tubular sections, achieving continuous production and reducing the risk of side reactions or degradation caused by residence time.

[0036] This device achieves the gradual release of reaction heat and the step-by-step conversion of intermediates through segmented static tubular reactors, and enhances mass transfer and solid dispersion in dynamic tubular reactors, thereby effectively controlling the exothermic process, avoiding pipeline blockage, and reducing solvent use, thus realizing continuous and green production.

[0037] To illustrate the composition and effect of the reaction apparatus more specifically, in one embodiment, the static tubular reactor described above can be made of 316L stainless steel straight pipe, spiral pipe, or glass-lined pipe. The diameter of the reaction chamber can be 10-50 mm, and the length can be 1-5 m. Furthermore, the reactor can be divided into multiple interconnected sub-sections according to the reaction time and required segmented temperature control. Each section can be independently equipped with a thermostatic jacket or spiral cold / heat medium pipe to achieve precise local temperature control.

[0038] Dynamic tubular reactors can employ turbine agitators (e.g., at 300-600 rpm), helical reactors, continuous stirred tubular reactors, or pump-driven fluidized bed reactors. Continuous fluidized bed reactors can also utilize internal heat exchange pipes, external circulating oil tanks, or electric heating mantles, equipped with temperature sensors and PID controllers to achieve rapid response and uniform temperature. Dynamic tubular reactors can rapidly homogenize and efficiently transfer heat to the reactants after the initial reaction in the static tubular section, ensuring complete reaction and improving the yield and purity of the target product.

[0039] In one possible embodiment, such as Figure 3 The diagram shows the structure of a dynamic tubular reactor. In this embodiment, the diameter of the reaction chamber can be 50-60 mm, the diameter of the axial stirring shaft inside can be 40-50 mm, and the length of the axial stirring shaft blades can be 3-9 mm. To ensure sufficient stirring effect for systems with high solids content and avoid solids accumulation and blockage, it is preferable that the distance between the blades of the axial stirring shaft and the inner wall of the reaction chamber is 1-3 mm.

[0040] Each sub-static tubular reactor, and between the sub-static tubular reactor and the dynamic tubular reactor, can be connected end to end by standard flanges (e.g., DN25-DN50 flanges), high-pressure quick couplings, or welding, ensuring that the reactants can flow continuously without leakage, while also facilitating the disassembly, cleaning, and maintenance of the equipment.

[0041] In addition, the reactants can be introduced from the feed inlet of the first sub-static tubular reactor via a pump or gravity feed system. Specifically, a precision metering pump (such as a peristaltic pump, gear pump, or diaphragm pump) can be used to continuously deliver the reactants, or a gravity feed system can be used with a regulating valve to control the flow rate. For multi-component reactants, multiple feed inlets can be set up, and the proportion of each component can be precisely controlled by a flow meter or mass flow controller (MFC).

[0042] The dynamic tubular reactor is equipped with a product outlet for continuously outputting the reaction liquid that has been fully mixed and reacted through the dynamic tubing section. Specifically, the product outlet can be connected to a downstream collection device or the next process reactor via a flange interface, quick-connect fitting, or threaded connection pipe, ensuring sealing and continuous flow.

[0043] In one possible embodiment, in the reaction apparatus described above, N could be 4. Figure 1 As shown, the static tubular reactor includes four sub-static tubular reactors connected end to end, denoted as R1, R2, R3 and R4 respectively; the dynamic tubular reactor is denoted as R0.

[0044] In this embodiment, the reactants flow sequentially through four sub-static tubular reactors R1, R2, R3, and R4. Each sub-static tubular reactor R1, R2, R3, and R4 can be independently equipped with a thermostatic jacket, a spiral refrigerant pipe, or a heat pipe to achieve segmented temperature control within the target range, thereby more precisely controlling the heat release of the reaction and reducing the risk of thermal runaway. Each sub-static tubular reactor R1, R2, R3, and R4 is equipped with a lateral feeding port, allowing for the segmented feeding of catalyst solution, regulator, or supplementary raw materials according to reaction kinetic requirements, thus precisely controlling the reactant concentration and reaction progress in each segment. By implementing segmented temperature control and segmented feeding in the four static tubular sections, and further achieving efficient agitation mixing in the subsequent dynamic tubular reactor R0, a designable temperature and concentration gradient can be formed throughout the system. This significantly improves the selectivity of the target product, reduces the probability of by-product formation, and enhances the performance of the continuous reaction process in terms of safety, controllability, and operational stability.

[0045] In one possible embodiment, the reaction apparatus described above may further include a post-processor F1, such as... Figure 1As shown, the product fed from the dynamic tubular reactor R0 to the post-processor F1 for further processing can be a target product that meets different requirements. The dynamic tubular reactor R0 and the post-processor F1 can be connected by a pipeline.

[0046] In one possible embodiment, the post-processor may include a quenching unit for rapidly cooling or terminating reactants or intermediates in the chemical reaction system. The quenching unit may include a quenching reactor, a flow control device, and piping. The outlet of the dynamic tubular reactor R0 is connected to the inlet of the quenching reactor via piping. The quenching reactor may be a static mixer, a spiral mixing tube, or a spray device to enhance the thorough mixing of the reaction solution and the quenching solution. It may also be equipped with a quenching solution storage tank connected via piping, which may store water, low-temperature organic solvents, buffer solutions, or other quenching agents suitable for a specific reaction. The flow control device is located in the piping connecting the outlet of the dynamic tubular reactor R0 to the inlet of the quenching reactor, or in the piping connecting the quenching reactor to the quenching solution storage tank, or both. The flow control device may be a regulating valve, a metering pump, or a mass flow controller to achieve precise proportional mixing of the quenching solution and the reaction solution. The piping may be made of stainless steel or glass-lined tubing, depending on the properties of the reactants.

[0047] This quenching unit enables rapid cooling of reaction products or termination of the reaction, reduces the generation of by-products, and improves product stability and safety. It is also compatible with various static tubular reactors, dynamic tubular reactors, and other continuous reaction devices, making it suitable for a variety of industrial continuous production processes.

[0048] In one possible embodiment, the post-processor may further include a solid-liquid separation unit for separating the target product and the precipitated solid salts. For example, a plate and frame filter press, a horizontal screw centrifuge, or a continuous vacuum belt filter can be used. This embodiment uses a continuous vacuum belt filter for solid-liquid separation, enabling continuous feeding, filtration, desliming, and slag discharge. During operation, a filter cloth (such as a corrosion-resistant polyester mesh) is laid on a rubber belt and runs synchronously with it. After the material slurry is evenly distributed on the filter cloth, the vacuum system draws suction from the bottom of the rubber belt, causing the filtrate to pass through the filter cloth and be discharged through the drain holes on the rubber belt. Solid particles form a filter cake on the filter cloth. Continuous belt filtration efficiently separates the solid and liquid phases, facilitating subsequent processing.

[0049] In one possible embodiment, the post-processor may further include an extraction unit for transferring organic products from the aqueous phase to the organic phase for subsequent recovery. The aqueous phase material containing organic products enters the extraction device from the upstream unit via a first conveying pipeline. The extraction device may be an extraction tower, a stirred extraction vessel, or a continuous extractor. The organic solvent is fed into the extraction device from a solvent storage tank via a second conveying pipeline and comes into full contact with the aqueous phase material within the extraction device. Mass transfer and distribution of the organic products between the aqueous and organic phases are achieved through stirring, spraying, or countercurrent flow.

[0050] After extraction, the mixture enters a phase separation device via a third conveying pipeline from the bottom or side of the extraction equipment. This phase separation device can be a gravity settling tank, a phase separation tank, or a centrifuge, used to separate the aqueous and organic phases. The separated organic phase, enriched with organic products, is conveyed downstream via a fourth conveying pipeline from the organic phase outlet of the phase separation device. The separated aqueous phase is discharged via a fifth conveying pipeline from the aqueous phase outlet and can be recycled or sent to subsequent processing units as needed.

[0051] In one possible embodiment, the post-processor may also include a concentration and drying unit. The concentration and drying unit is used for solvent recovery and product acquisition from the organic phase containing the target product. The organic phase containing the target product is fed into a concentration device via a fourth delivery line and a pumping device. The concentration device may be an evaporator, a thin-film evaporator, or a vacuum concentrator, used to evaporate the organic solvent under heating or vacuum conditions to achieve preliminary concentration of the material.

[0052] The evaporated organic solvent vapor enters the condensation and recovery system from the top of the concentration equipment via the sixth conveying pipeline. The condensation and recovery system includes a condenser and a solvent recovery tank, used to condense the solvent vapor into liquid organic solvent and collect it. The recovered organic solvent can be returned to the solvent storage tank or recycled to the extraction unit via the seventh conveying pipeline. The concentrated material enters the drying equipment from the bottom of the concentration equipment via the eighth conveying pipeline. The drying equipment can be a vacuum dryer, a belt dryer, or a fluidized bed dryer, used to further remove residual organic solvent, so that the target product reaches the required solvent content.

[0053] Solvent vapors generated during the drying process are fed into the condensation and recovery system via the ninth conveying pipeline from the drying equipment, achieving secondary solvent recovery. The dried solid product is discharged from the outlet of the drying equipment via the tenth conveying pipeline and enters the product collection or packaging section. Through the aforementioned equipment connections and material flow, the concentration and drying unit achieves the recycling of organic solvents and the continuous and stable acquisition of the target product.

[0054] It should be noted that the post-processor in this application embodiment may include one or more of the above-mentioned processing units, or may only use a combination of any of these units. The configuration and combination order of the above-mentioned processing units do not constitute a limitation of this application, and their specific settings can be adjusted according to the quality requirements, process route, or safety specifications of the target product. This application also does not limit the specific effects produced by each unit, as long as it can achieve the post-processing functions required by the target product.

[0055] In one possible embodiment, the diameter of the reaction chamber in the dynamic tubular reactor can be 2-3 times that of the static tubular reactor to accommodate the large amount of solid precipitation in the later stages of the reaction and reduce clogging. Since the dynamic tubular reactor is the final stage of the tubular system's reaction zone, to further enhance mixing, increase reaction conversion, and reduce the risk of clogging, axial or radial turbine agitators (impellers) can be installed inside the tube for forced mixing. For example, a two-stage radial impeller agitator can be used at a speed of 300-600 rpm to create a near-piston flow pattern in the fluid. The agitator uses corrosion-resistant materials (such as PTFE or ceramic-coated blades) to prevent the oxidizing media from corroding the metal.

[0056] To more concretely illustrate the effects of the reaction apparatus described above, such as... Figure 1 As shown, a possible embodiment is given below. Specifically, the reaction solution is input into the feed inlet of the first sub-static tubular reactor R1 at a preset flow rate and undergoes partial reaction in sub-static tubular reactor R1. Subsequently, the reaction solution flows sequentially through sub-static tubular reactors R2-R4 to undergo partial reaction. In this process, the structure of sub-static tubular reactors R1-R4 can provide a stable and defined residence time, has better mass transfer performance, and enables the reaction solution to form a homogeneous mixture, avoiding side reactions (such as self-condensation or excessive decomposition) caused by excessively high local concentrations. At the same time, segmented temperature control and segmented feeding also make the reaction progress easier to control and reduce the risk of thermal runaway.

[0057] Subsequently, the reaction solution is transported from the outlet of the sub-static tubular reactor R4 to the inlet of the dynamic tubular reactor R0, where the reaction continues. The diameter of the reaction chamber in the dynamic tubular reactor R0 is 2-3 times that of the sub-static tubular reactor, thereby reducing the risk of clogging. Unlike the aforementioned sub-static tubular reactor, the dynamic tubular reactor R0 does not rely on completely laminar flow conditions. Instead, it enhances solid-liquid mixing and increases the local diffusion rate through active agitation. This is beneficial for systems with high solids content or continuously increasing viscosity to maintain fluidity and reactivity, thereby improving reaction conversion while reducing the risk of clogging and solvent consumption.

[0058] In this embodiment, the crude product generated by the reaction in the static tubular reactors R1-R4 and the dynamic tubular reactor R0 enters the post-processor F1 through the product outlet of the dynamic tubular reactor R0. Different post-processing units are selected according to different target product requirements to finally obtain the target product.

[0059] It should be understood that those skilled in the art can replace, adjust or change the above-mentioned equipment or parameters according to actual needs. The specific equipment types, models, sizes, operating conditions and parameter ranges referenced in any of the embodiments of this application are only used to provide a more detailed description of the technical solution of the reaction device of this application.

[0060] Secondly, this application provides a method for preparing 2,2-dinitropropanol, such as... Figure 2 As shown, it includes the following steps:

[0061] Step 1) Nitroethane (SM1) and alkaline solution (SM2) undergo a dehydrogenation reaction in the first sub-static tubular reactor R1 to obtain a dehydrogenation system;

[0062] Step 2) The dehydrogenation system is transported to the second sub-static tubular reactor R2, and formaldehyde aqueous solution (SM3) is introduced into the second sub-static tubular reactor R2, so that the dehydrogenation system and formaldehyde aqueous solution undergo hydroxymethylation reaction in the second sub-static tubular reactor R2 to generate hydroxymethylation intermediate system;

[0063] Step 3) The hydroxymethylation intermediate system is transported to the third sub-static tubular reactor R3, and sodium nitrite solution (SM4) is introduced into the third sub-static tubular reactor R3, so that the hydroxymethylation intermediate system and sodium nitrite solution undergo a nitrosation reaction in the third sub-static tubular reactor R3 to generate a nitrosation intermediate system.

[0064] Step 4) The nitrosation intermediate system is transferred to the fourth sub-static tubular reactor R4, and sodium persulfate aqueous solution (SM5) and potassium ferricyanide aqueous solution (SM6) are introduced into the fourth sub-static tubular reactor R4. This allows the nitrosation intermediate system, sodium persulfate aqueous solution, and potassium ferricyanide aqueous solution to undergo a partial oxidation reaction in the fourth sub-static tubular reactor R4, generating a partially oxidized intermediate system.

[0065] Step 5) The partially oxidized intermediate system is transported to the dynamic tubular reactor R0, and the partially oxidized intermediate system continues to undergo oxidation reaction to generate the 2,2-dinitropropanol system.

[0066] In the preparation method of this application, in step 1), as follows: Figure 2As shown, nitrobenzene and an alkaline solution are fed into the reaction feed inlet of the first sub-static tubular reactor R1 at a preset flow rate, and a dehydrogenation reaction takes place in the sub-static tubular reactor R1 to generate a dehydrogenation system. Specifically, under the action of a strong base, the α-hydrogen of the nitrobenzene molecule (i.e., the hydrogen adjacent to the nitro group) is easily deprotonated, generating a highly reactive nitrobenzene intermediate or the corresponding anionic form. This anion has good structural stability due to the negative charge resonance stabilization effect of the nitro group, thus serving as a key active intermediate for the subsequent hydroxymethylation reaction. Simultaneously, the structure of the sub-static tubular reactor R1 provides a stable and defined residence time, allowing the deprotonation process of nitrobenzene in the alkaline medium to be completed gradually along the flow path. Furthermore, the tubular structure has superior mass transfer performance, ensuring a homogeneous mixture between the alkaline solution and nitrobenzene, avoiding side reactions (such as self-condensation or excessive decomposition) caused by excessively high local alkali concentrations.

[0067] In step 2), as Figure 2 As shown, the dehydrogenation system is transported from the outlet of sub-static tubular reactor R1 to the second sub-static tubular reactor R2. In sub-static tubular reactor R2, it undergoes a hydroxymethylation reaction with an aqueous formaldehyde solution, generating a hydroxymethylation intermediate system. The core reaction is the hydroxymethylation reaction between the nitrobenzene anion and formaldehyde. Specifically, the nitrobenzene anion has high nucleophilicity; its α-position carbon atom can actively attack the carbonyl carbon in the formaldehyde molecule, thereby forming a new carbon-carbon bond and generating a β-hydroxynitro compound, i.e., the hydroxymethylation intermediate system. During this reaction, the carbonyl group of the formaldehyde molecule exhibits higher electronegativity in an alkaline environment, thus making it more susceptible to nucleophilic attack by the anion. Simultaneously, the resonance stabilizing effect of the nitro group on the α-carbon anion ensures that the anion remains sufficiently stable in sub-static tubular reactor R1, guaranteeing the efficient occurrence of its addition reaction with formaldehyde.

[0068] Meanwhile, the continuous flow structure of the sub-static tubular reactor R2 provides excellent mixing and heat transfer performance, enabling the dehydrogenation system entering R2 to mix rapidly with the formaldehyde aqueous solution in the initial stage of the reactor. This avoids side reactions of formaldehyde in localized high-alkalinity zones and also prevents the formation of low-reactivity substances such as methanediol, which are detrimental to addition reactions. The tube length and inner diameter of the sub-static tubular reactor R2 can be designed according to the residence time, allowing the hydroxymethylation reaction to proceed gradually in the flow.

[0069] In step 3), as Figure 2As shown, the hydroxymethylation intermediate system is transported from the outlet of sub-static tubular reactor R2 to the third sub-static tubular reactor R3, where it undergoes a nitrosation reaction with the sodium nitrite solution, generating a nitrosation intermediate system. Under continuous flow conditions, sodium nitrite can continuously contact the hydroxymethylation intermediate during the flow path, forming NO⁺ or similar electrophilic nitrosation intermediates in the local microenvironment. These electrophilic nitrosation intermediates can undergo electrophilic substitution or rearrangement reactions with the hydroxyl groups or adjacent active sites of the hydroxymethylation intermediate, forming stable nitrosation products. This process involves partial water separation, gradually transforming the system into more reactive nitroso intermediates, providing a key precursor for subsequent oxidation steps. Simultaneously, since nitrosation is a strongly exothermic reaction, the slender tubular structure of sub-static tubular reactor R3, combined with an external temperature control device, effectively eliminates the accumulation of reaction heat, preventing localized temperature rises that could lead to the decomposition of nitrite or the generation of undesirable byproducts such as nitric oxide and nitrogen dioxide. Furthermore, the continuous flow structure allows for precise control of the addition rate and instantaneous concentration of sodium nitrite, thereby reducing side reactions caused by excessive nitrosation, such as unnecessary secondary nitrosation or destruction of molecular structure.

[0070] In step 4), as Figure 2 As shown, the nitrosation intermediate system is transported from the outlet of sub-static tubular reactor R3 to the inlet of sub-static tubular reactor R4. Simultaneously, aqueous solutions of sodium persulfate and potassium ferricyanide are introduced into sub-static tubular reactor R4, where partial oxidation reactions occur, generating a partially oxidized intermediate system. Sodium persulfate in solution can generate highly reactive oxidizing intermediates such as sulfate radicals and persulfate radicals. These radicals can selectively oxidize the nitrosation intermediates, causing directional electron stripping of their surface active sites. Meanwhile, potassium ferricyanide, as an auxiliary oxidant, can form a reversible redox pair in solution, regulating the oxidation intensity and stabilizing the radical concentration, preventing structural collapse or excessive byproduct formation caused by strong oxidation.

[0071] Meanwhile, the sub-static tubular reactor R4 provides a stable laminar flow state, allowing the oxidation process to proceed gradually and uniformly along the flow path. Thanks to its continuous flow design, sodium persulfate and potassium ferricyanide can be added at controlled flow rates through independent metering units, maintaining the oxidant concentration and local oxidation intensity within a precise range and avoiding the instantaneous over-oxidation phenomenon common in batch reactions.

[0072] In step 5), as Figure 2As shown, the partially oxidized intermediate system is transported from the outlet of the static tubular reactor R4 to the inlet of the dynamic tubular reactor R0, where the oxidation reaction continues to occur, generating the 2,2-dinitropropanol system. The core reaction involves the further deep oxidation of the partially oxidized intermediate system obtained in step 4) under continuous mixing and controlled oxidation conditions. Dynamic mixing conditions allow for sufficient contact between the oxidant and the solid-liquid phase, ensuring complete conversion of the nitrosation and hydroxymethyl structures to the target dinitro structure, while simultaneously increasing the solid content in the system. However, the stirring effect of the dynamic tubular reactor R0 prevents localized agglomeration and ensures the completion of the oxidation reaction, improving the overall conversion rate without requiring large amounts of solvent dilution to prevent clogging.

[0073] Meanwhile, the dynamic tubular reactor R0 incorporates internal stirring or agitation structures, such as turbines, propellers, or ribbon agitators, to induce quasi-continuous turbulent mixing within the reactor. Unlike the aforementioned sub-static tubular reactors R1, R2, R3, and R4, the dynamic tubular reactor R0 does not rely on fully laminar flow conditions. Instead, it enhances solid-liquid mixing and increases local diffusion rates through active agitation. This helps systems with high solids content or continuously increasing viscosity maintain fluidity and reactivity, improving reaction conversion while reducing the risk of clogging and solvent consumption.

[0074] This preparation method significantly improves heat transfer and safety performance by seamlessly connecting the five reaction steps under continuous flow conditions, avoiding the risk of thermal runaway, enhancing the flow stability of the solid-containing system, avoiding blockage and cycle failure, and reducing the multiple material transfers, container replacements and cold start time in traditional processes, thereby significantly improving the cumulative reaction efficiency and overall reaction efficiency.

[0075] In one possible embodiment, the conversion rate of 2,2-dinitropropanol in the partially oxidized intermediate system generated in step 4) is controlled at 70-80%. Lower conversion rates may result in insufficient release of reaction heat, while higher conversion rates may lead to large amounts of solid precipitation and blockage. However, this conversion rate allows for low-cost control of reaction heat using a static tubular reactor, ensuring that only a small amount of inorganic salt begins to precipitate within the system. The solid particles are small and well-dispersed, preventing deposition or blockage on the tube walls. Subsequently, the obtained partially oxidized intermediate system flows continuously into the dynamic tubular reactor R0. Since most of the reaction heat has been released in the sub-static tubular reactors R1, R2, R3, and R4, the dynamic tubular reactor R0 can safely and efficiently handle the remaining deep oxidation process within a temperature range of 0-40°C. Simultaneously, the internal stirring mechanism handles the gradually increasing solid salts, further advancing the reaction to complete oxidation, ultimately generating the target 2,2-dinitropropanol system.

[0076] In one possible embodiment, the alkaline solution is selected from at least one of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, lithium hydroxide aqueous solution, sodium carbonate aqueous solution, or ammonia solution. Exemplarily, the alkaline solution can be a sodium hydroxide aqueous solution, wherein the sodium hydroxide:water mass ratio is (1:1)-(1:10), preferably (1:3)-(1:5). Potassium hydroxide and lithium hydroxide aqueous solutions are also applicable, and can achieve more precise adjustment of hydrogen removal capacity by controlling the different solubilities and salt-forming characteristics of the metal cations. When it is necessary to further reduce the risk of inorganic salt precipitation in the system, sodium carbonate aqueous solution or ammonia solution can be used as a weaker alkaline system to avoid the initial formation of excessive inorganic salts, while still meeting the requirement for the formation of carbanions from nitrobenzene.

[0077] In one possible embodiment, to ensure the sufficiency of the dehydrogenation reaction and the stability of the subsequent hydroxymethylation reaction, the molar ratio of alkaline solution to nitrobenzene is controlled at (1:1)–(1.5:1). The alkaline solution is added in parallel flow through a pre-mixer or directly from the inlet, creating a fully mixed alkaline environment within the first sub-static tubular reactor R1. Through the rational selection and control of the above-mentioned alkaline system, the conversion ratio of nitrobenzene anions in the dehydrogenation system can be stably maintained at 70–95%, thereby ensuring the stable progress of the entire continuous flow reaction chain.

[0078] In one possible embodiment, the formaldehyde aqueous solution used in step 2) can be an industrial formaldehyde solution with a mass fraction of 30-40% or a diluted solution thereof. Higher concentrations of formaldehyde can increase the reaction rate, while moderate dilution helps to reduce the exothermic intensity and reduce polymerization side reactions. Therefore, this embodiment ensures that the hydroxymethylation reaction proceeds stably and uniformly in the second static tubular reactor R2 by adjusting the formaldehyde solution concentration to achieve a balance between reaction kinetics and safety.

[0079] In one possible embodiment, the sodium nitrite solution used in step 3) comprises sodium nitrite, water, and an organic solvent, wherein the mass ratio of sodium nitrite:water:organic solvent can be (1:1:1) to (1:10:10), preferably (1:2:2) to (1:4:4). The concentration of the sodium nitrite solution ensures sufficient effective intermediates such as NO⁺ are rapidly provided to the hydroxymethylation intermediate under low-temperature conditions, while avoiding instantaneous local overheating or excessive salt precipitation due to excessive concentration. The organic solvent can be a lower alcohol, such as methanol or ethanol. The organic solvent can help dissolve some organic products, thereby preventing premature precipitation in the reaction system and affecting the homogeneity of the reaction. An appropriate ratio of mixed solvents can also help adjust the freezing point of the system, facilitating nitrosation at low temperatures (e.g., -20°C to 40°C) to suppress side reactions and improve product purity.

[0080] In one possible embodiment, the oxidant system used in step 4) consists of an aqueous solution of sodium persulfate and an aqueous solution of potassium ferricyanide. The mass ratio of sodium persulfate to water is (1:2) to (1:10), preferably (1:2) to (1:4). The mass ratio of potassium ferricyanide to water is (1:2) to (1:10), preferably (1:2) to (1:4). This oxidant system maintains sufficient oxidizing power to initiate a partial oxidation reaction while avoiding excessive oxidant leading to severe exothermic reactions or a large accumulation of free radicals. Furthermore, the conversion rate can be precisely controlled by adjusting the concentration and flow rate.

[0081] In step 1), the dehydrogenation reaction of nitrobenzene is a base-catalyzed proton transfer process, the rate of which increases significantly with increasing temperature, but is accompanied by an increased risk of side reactions. Therefore, in one possible embodiment, the temperature of the dehydrogenation reaction is controlled at 0-10°C to ensure the high selectivity of nitrobenzene anion formation.

[0082] In step 2), the hydroxymethylation reaction is a nucleophilic addition reaction, and its kinetic constant increases linearly with increasing temperature. Therefore, in one possible embodiment, the reaction temperature is set to 10-20°C, which can increase the hydroxymethylation reaction rate without triggering formaldehyde self-polymerization or excessive exothermic reaction, thereby ensuring the temperature stability within the second sub-static tubular reactor R2.

[0083] In step 3), the nitrosation reaction is a typical weakly exothermic charge transfer reaction, and sodium nitrite can stably generate reactive intermediates such as nitrosamine ions at low temperatures. Therefore, in one possible embodiment, the reaction temperature can be -25-30°C to suppress the rapid precipitation of by-salts and improve the nitrosation selectivity. Preferably, the reaction temperature can also be -20-20°C.

[0084] In step 4), the partial oxidation reaction is highly exothermic; an increase in temperature will lead to a sharp increase in the concentration of free radicals and trigger over-oxidation. Therefore, in one possible embodiment, the reaction temperature can be controlled between -25 and 30°C to ensure that the system still has a sufficient thermal buffer space after the addition of the highly reactive oxidant. Preferably, the reaction temperature can also be between -20 and 20°C.

[0085] In step 5), to accelerate the final oxidation process and reduce the system viscosity, allowing the high-solids-content system to maintain fluidity under stirring, the temperature of the dynamic tubular reactor R0 can be appropriately increased. For example, in one possible embodiment, the reaction temperature can be 0-40°C. Preferably, the reaction temperature can also be 15-35°C.

[0086] To further obtain target products that meet different needs, this preparation method may also include post-processing. Post-processing may include quenching, extraction, and concentration and drying.

[0087] In one possible embodiment, at the R0 outlet of the dynamic tubular reactor, the 2,2-dinitropropanol system is first quenched by adding precooling water or diluting acidic solution to rapidly reduce the system temperature to 0-10°C, thereby terminating the oxidation reaction and promoting the dissolution or redispersion of some inorganic salts.

[0088] In one possible embodiment, the quenched material is further extracted. Specifically, a solid-liquid mixture containing 2,2-dinitropropanol is introduced into the extraction unit, and ethyl acetate is added to the extraction unit simultaneously to ensure sufficient contact and mixing between the aqueous and organic phases. Since the 2,2-dinitropropanol molecule contains both nitro and hydroxyl groups, it has some solubility in the aqueous phase but a higher partition coefficient in moderately polar organic solvents. Therefore, during the two-phase contact process, 2,2-dinitropropanol migrates from the aqueous phase to the ethyl acetate phase, achieving extraction and separation.

[0089] After extraction, the aqueous phase and organic phase are separated by settling or phase separation equipment to obtain an organic phase enriched with 2,2-dinitropropanol. The advantage of using ethyl acetate as the extractant is its good solubility for 2,2-dinitropropanol, while its low miscibility with water facilitates rapid phase separation and reduces solvent loss. Furthermore, ethyl acetate has a moderate boiling point, allowing for solvent recovery through evaporation or vacuum concentration, reducing overall energy consumption. It should be noted that any solvent capable of recovering 2,2-dinitropropanol from the aqueous phase can be used; this invention does not limit the specific solvent used.

[0090] In one possible embodiment, the extracted organic phase is further concentrated and dried. Specifically, the organic phase is fed into a concentration apparatus, where the organic solvent is evaporated under heating and / or reduced pressure conditions, gradually reducing the volume of the organic phase and enriching the target product. By controlling the temperature and pressure during the concentration process, ethyl acetate or organic solvents with similar properties can be preferentially vaporized, while 2,2-dinitropropanol, due to its higher boiling point, remains in the concentrate, thereby achieving effective separation of the solvent and product.

[0091] Solvent vapors generated during the concentration process are introduced into a condensation recovery system, where they are cooled, condensed into liquid organic solvents, and collected. This method not only reduces the consumption of organic solvents but also allows the recovered solvents to be recycled back into the aforementioned extraction step, thereby reducing production costs and organic waste gas emissions. Through the above concentration process, the solvent content in the organic phase is significantly reduced, providing suitable feed conditions for the subsequent drying step.

[0092] The concentrated material is further fed into a drying device and dried under a vacuum or inert atmosphere to remove residual organic solvents. The drying temperature should not be too high, for example, below 40°C, to ensure the process safety of the energetic compounds. Since the solvent content has been significantly reduced in the preceding concentration step, the energy required for the drying process is significantly lower, helping to prevent the decomposition or performance degradation of 2,2-dinitropropanol under high-temperature conditions. Through the combined concentration and drying steps, organic solvents can be efficiently recovered while ensuring product quality, ultimately obtaining a compliant solid or high-purity product, suitable for continuous and large-scale production.

[0093] In one possible embodiment, after obtaining the concentrated and dried crude 2,2-dinitropropanol product, it is recrystallized for purification to further remove entrained organic and trace inorganic impurities, thereby improving product purity. Specifically, the crude 2,2-dinitropropanol product is added to a recrystallization solvent and heated to fully dissolve the 2,2-dinitropropanol, forming a homogeneous solution. The recrystallization solvent can be an ethyl acetate-petroleum ether mixture, or a toluene-n-hexane mixture, etc. The selected recrystallization solvent is one that can dissolve 2,2-dinitropropanol at high temperatures but whose solubility decreases significantly at low temperatures, thus providing favorable solubility differential conditions for subsequent crystallization.

[0094] After complete dissolution, the solution is slowly cooled, or the system temperature is gradually reduced under controlled cooling rate. As the temperature decreases, the solubility of 2,2-dinitropropanol in the solvent decreases, and it begins to precipitate from the solution and form crystals. Due to the selectivity of the crystal growth process for molecular structure, the target product preferentially enters the crystal lattice structure, while most impurities remain dissolved in the mother liquor, thereby achieving physical separation and purification. By controlling the cooling rate and the termination temperature, 2,2-dinitropropanol crystals with uniform particle size and stable morphology can be obtained, which is beneficial for subsequent solid-liquid separation operations.

[0095] After crystallization, the crystals are separated from the mother liquor by filtration or centrifugation. The separated crystals are then washed with a small amount of low-temperature recrystallization solvent to further remove impurities adsorbed on the crystal surface. The washed crystals are then dried to obtain a high-purity 2,2-dinitropropanol product. This recrystallization purification step utilizes the differences in solubility and crystallization behavior between the target product and impurities to significantly improve product purity without introducing complex chemical reactions. The operating conditions are mild and reproducible, making it suitable for laboratory purification and industrial-scale production.

[0096] It should be noted that the post-processing in the embodiments of this application may include any of the above operations, or may only use a combination of any of the above operations. The configuration and combination order of the above post-processing operations do not constitute a limitation of this application, and their specific settings can be adjusted according to the quality requirements, process route, or safety specifications of the target product. This application also does not limit the specific effects produced by each operation, as long as it can achieve the post-processing functions required by the target product.

[0097] In summary, this application constructs a continuous flow reactor by sequentially integrating multi-stage static tubular reactors and dynamic tubular reactors, and synergistically matches five progressively coupled chemical steps: dehydrogenation, hydroxymethylation, nitrosation, partial oxidation, and final oxidation. This achieves a high degree of synergy between the apparatus structure and the chemical method. The static tubular reactor provides controllable residence time, uniform mixing, and excellent heat transfer capabilities, allowing each stage of the reaction to proceed independently and directionally under optimal conditions. The dynamic tubular reactor, on the other hand, maintains stable material flow and uniform reaction even in high-solids stages, preventing localized deposition and reaction stagnation through continuous stirring. The synergy of the entire apparatus and method enables multi-step reactions to proceed sequentially in a continuous, uninterrupted flow system, effectively suppressing the accumulation and scale-up of potential side reactions in each step, improving intermediate stability and reaction selectivity, and achieving efficient, high-yield, and highly consistent continuous synthesis from raw materials to the target product. Meanwhile, the structural features of the device and the segmented control strategy of the method complement each other in terms of safety, heat transfer efficiency and intermediate conversion rate, giving the overall process advantages of continuity and controllability that are difficult to achieve with traditional processes, and providing a reliable technical path for the stable industrial production of 2,2-dinitropropanol.

[0098] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations thereof. These variations, uses, or adaptations follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and are not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A reaction apparatus, characterized in that, It includes a static tubular reactor and a dynamic tubular reactor. The static tubular reactor includes N sub-static tubular reactors connected end to end, where N≥2. The outlet of the Nth sub-static tubular reactor is connected to the inlet of the dynamic tubular reactor. The first sub-static tubular reactor includes a raw material inlet, and the dynamic tubular reactor includes a product outlet.

2. The reaction apparatus according to claim 1, characterized in that, N=4。 3. The reaction apparatus according to claim 1 or 2, characterized in that, It also includes a post-processor, wherein the reaction product outlet of the dynamic tubular reactor is connected to the inlet of the post-processor.

4. The reaction apparatus according to any one of claims 1-3, characterized in that, The diameter of the reaction chamber of the dynamic tubular reactor is 2-3 times that of the reaction chamber of the static tubular reactor.

5. A method for preparing 2,2-dinitropropanol, characterized in that, The preparation is carried out using the reaction apparatus according to any one of claims 1-4, and the preparation method includes the following steps: Step 1) Nitroethane and alkaline solution undergo a dehydrogenation reaction in the first sub-static tubular reactor to obtain a dehydrogenation system; Step 2) The dehydrogenation system is transported to the second sub-static tubular reactor, and formaldehyde aqueous solution is introduced into the second sub-static tubular reactor, so that the dehydrogenation system and the formaldehyde aqueous solution undergo a hydroxymethylation reaction in the second sub-static tubular reactor to generate a hydroxymethylation intermediate system; Step 3) The hydroxymethylation intermediate system is transported to the third sub-static tubular reactor, and sodium nitrite solution is introduced into the third sub-static tubular reactor, so that the hydroxymethylation intermediate system and the sodium nitrite solution undergo a nitrosation reaction in the third sub-static tubular reactor to generate a nitrosation intermediate system; Step 4) The nitrosation intermediate system is transported to the fourth sub-static tubular reactor, and sodium persulfate aqueous solution and potassium ferricyanide aqueous solution are introduced into the fourth sub-static tubular reactor, so that the nitrosation intermediate system, sodium persulfate aqueous solution and potassium ferricyanide aqueous solution undergo a partial oxidation reaction in the fourth sub-static tubular reactor to generate a partially oxidized intermediate system; Step 5) The partially oxidized intermediate system is transported to the dynamic tubular reactor, and the partially oxidized intermediate system continues to undergo oxidation reaction to generate 2,2-dinitropropanol system.

6. The method according to claim 5, characterized in that, The conversion rate of the partially oxidized intermediate system is 70-80%.

7. The method according to claim 5 or 6, characterized in that, The alkaline solution includes at least one of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, lithium hydroxide aqueous solution, sodium carbonate aqueous solution, and ammonia solution.

8. The method according to any one of claims 5-7, characterized in that: The formaldehyde aqueous solution comprises formaldehyde and water; The sodium nitrite solution comprises sodium nitrite, water and organic solvent, wherein the mass ratio of sodium nitrite:water:organic solvent is (1:1:1) to (1:10:10). The sodium persulfate aqueous solution comprises sodium persulfate and water, wherein the mass ratio of sodium persulfate to water is (1:2) to (1:10). The potassium ferricyanide aqueous solution comprises potassium ferricyanide and water, wherein the mass ratio of potassium ferricyanide to water is (1:2) to (1:10).

9. The method according to any one of claims 5-8, characterized in that: In the nitrosation reaction in step 3) and the oxidation reaction in step 4), the reaction temperature is -20 to 40°C; The reaction temperature in step 5) is 0-40℃.

10. The method according to any one of claims 5-9, characterized in that, Following step 5), the 2,2-dinitropropanol system is further subjected to post-treatment, which includes quenching, extraction, concentration and drying.

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