Efficient production method of polymerization inhibitor DNBP

Abstract

The invention relates to the technical field of synthesis of a polymerization inhibitor DNBP, in particular to an efficient production method of the polymerization inhibitor DNBP, which comprises the following steps: step 1, material preparation: selecting corresponding raw materials, weighing and classifying the raw materials, and dividing the raw materials into three main materials, auxiliary materials and additives, the auxiliary material comprises a sulfonic acid type ion exchange resin catalyst, the additive is an ethanol-water mixed solvent, and during weighing, weighing and proportioning are performed according to the molar ratio of nitric acid to o-tert-butylphenol being 2.15: 1 and the mass ratio of o-tert-butylphenol to carbon tetrachloride being 0.15: 1; according to the method, a gradient temperature control strategy is adopted, and a multi-stage microchannel reactor is combined, so that efficient mass and heat transfer of nitration reaction is realized, deep nitration side reaction is inhibited, the content of dinitro isomer impurities is greatly reduced, meanwhile, the total residence time can be accurately controlled, the explosion risk caused by local overheating in a traditional process is avoided, and the method is suitable for industrial production. The reaction selectivity and the safety are obviously improved.

Description

Technical Field

[0001] The invention relates to the technical field of polymerization inhibitor DNBP synthesis, and in particular to a high-efficiency production method of the polymerization inhibitor DNBP. Background Art

[0002] The polymerization inhibitor DNBP (2-sec-butyl-4,6-dinitrophenol) is a chemical additive used to prevent polymerization reactions. It is primarily used to inhibit the high-temperature polymerization of unsaturated aromatic monomers such as styrene and methyl styrene during the distillation process, effectively preventing these compounds from polymerizing at high temperatures.

[0003] Such as application number CN202411007587.9, open date is 20241115 a kind of DNBP polymerization inhibitor and preparation method, belong to the field of polymerization inhibitor preparation technology, a kind of preparation method of DNBP polymerization inhibitor, comprising the following steps: 2-sec-butylphenol is added dropwise in nitric acid, nitrogen is passed through before the reaction, oxygen in the air is removed, oil bath, stirring, reaction, cooling, liquid separation, first washing with a saturated solution of sodium bicarbonate, then washing with deionized water to obtain the DNBP polymerization inhibitor. The present invention obtains a DNBP efficient polymerization inhibitor by blending 2-sec-butylphenol and nitric acid, with a simple preparation process, high purity and good inhibition effect. The polymerization inhibitor of the present invention is used to store and transport styrene, with a long inhibition time, low environmental pollution, and effectively improves the efficiency of various processes such as styrene distillation.

[0004] The aforementioned and existing DNBP synthesis processes mostly employ intermittent nitration reactions. The temperature control in the single nitration stage is extensive, which can easily trigger deep nitration side reactions, resulting in high levels of dinitro isomer impurities. Furthermore, nitric acid utilization is insufficient, and excessive acid discharge causes serious environmental pollution. Furthermore, solvent recovery rates are low, and carbon tetrachloride losses are high, which can easily lead to increased production costs. Furthermore, conventional stirred reactors have poor mass transfer efficiency, reaction times as long as 8-12 hours, and are prone to the risk of explosions caused by local overheating. Therefore, there is an urgent need to design an efficient production method for the inhibitor DNBP to address the above-mentioned issues. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for efficiently producing a polymerization inhibitor DNBP to solve the above-mentioned deficiencies in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for efficiently producing a polymerization inhibitor DNBP comprises the following steps:

[0008] Step 1. Material preparation: Select the corresponding raw materials, weigh and classify them, and divide the raw materials into three types: main materials, auxiliary materials and additives, among which:

[0009] The main materials are o-tert-butylphenol, nitric acid, and carbon tetrachloride, with the purity of o-tert-butylphenol being ≥99%, the purity of carbon tetrachloride being ≥95%, and the concentration of nitric acid being 65%-68%;

[0010] The auxiliary materials include a sulfonic acid ion exchange resin catalyst, and the active site density of the sulfonic acid ion exchange resin is 3.0-3.5 mmol / g, the pore size distribution is 10-50 nm, and the specific surface area is ≥800 m 2 / g.

[0011] The additive is an ethanol-water mixed solvent, and the volume ratio of the ethanol-water mixed solvent is 1:2-1:4;

[0012] When weighing, the weighing ratio is based on a molar ratio of nitric acid to o-tert-butylphenol of 2.15:1 and a mass ratio of o-tert-butylphenol to carbon tetrachloride of 0.15:1.

[0013] Step 2. Material pretreatment: The main material, auxiliary materials and additives are added to the dehydration device, the dehydration device is started for dehydration. After dehydration, o-tert-butylphenol is dehydrated by molecular sieve to a water content of ≤0.1%, and nitric acid is compounded to a mass concentration of 50±0.5% by an acidic wastewater circulation system, and the main material, auxiliary materials and additives are mixed and paired in advance to obtain a mixture of carbon tetrachloride and o-tert-butylphenol. After mixing, the mixture is homogenized by an ultrasonic dispersion device with an ultrasonic dispersion power density of 200-400W / L, a frequency of 28-40kHz, a treatment time of 10-20 minutes, and a sulfonic acid ion exchange resin is pre-activated under nitrogen protection, the nitrogen pre-activation temperature is 80°C, and the time is 2h;

[0014] Step three reaction treatment: The material after the treatment in the previous step was pumped into a multistage microchannel reactor (microchannel reactor single-stage channel inner diameter 0.5-2mm, reactor holdup volume ≤500mL, pressure drop ≤0.5MPa, the inner wall of the reactor channel was plasma treated to form a nanoscale coating with a thickness of 50-200nm), the temperature gradient was controlled at 40 ℃ -65 ℃ -10 ℃, the total residence time was ≤3h, and the nitration was carried out in stages, the first stage was 40-50 ℃ phenol mononitration (nitric acid dosage 1.1: 1mol), the second stage was completed by adding fuming nitric acid dinitration, the sulfonic acid catalyst was used in an amount of 5-8% of the mass of phenol, the fuming nitric acid dinitration stage was added three times, each time at an interval of 5 minutes, the addition ratio was 4:3:3, the total reaction time was ≤30 minutes, and the crude product was obtained after the reaction was completed, an online near-infrared spectroscopy monitoring system was set, the concentration of the o-nitrophenol intermediate in the reaction system was detected in real time, the nitric acid addition acceleration accuracy was controlled at ±2%;

[0015] Step four purification treatment: The crude product obtained was added to a purification device, the purification device was started to distill the crude product, the process requires the reaction solution gradient cooling to below -5 ° C, and the crude product was separated by a horizontal spiral centrifuge (speed 3000-3500rpm), the crude product was subsequently recrystallized using an ethanol-water mixed solvent (cooling rate 1-2 ° C / min), purified by a molecular distillation apparatus (temperature 80-120 ° C, vacuum ≤ 10Pa) to obtain a high-purity product, ethanol - water mixed solvent recrystallization starting dissolution temperature of 65-70 ° C, the end point precipitation temperature of -5 ± 0.5 ° C, the average crystal particle size D50 of 80-150 μm, the molecular distillation apparatus in the fourth step using a wiped film rotor structure, a film thickness of 0.3-0.5 mm, a distillation pressure ≤ 5Pa, a material residence time ≤ 30 seconds;

[0016] Step 5. By-product recovery: Recover the residue produced by the above reaction, and recover the nitric acid by filtering the acid-containing mother liquor through a ceramic membrane filtration system (pore size 0.1-0.2 μm), with a reuse rate of ≥95%, and a number of cycles ≥5 times. The carbon tetrachloride solvent is recovered by vacuum distillation (temperature ≤60°C, recovery rate ≥98%), and the waste residue is catalytically oxidized to meet environmental emission standards; the operating pressure of the ceramic membrane filtration is 0.3-0.6 MPa, the mass concentration of nitric acid in the nitric acid concentrate is ≥45%, the impurity content is ≤0.5%, the reaction temperature of the catalytic oxidation treatment of the waste residue is 350-450°C, the catalyst is a supported composite catalyst, and the space velocity is 5000-8000h -1 .

[0017] In the above technical solution, the present invention provides a method for efficiently producing a polymerization inhibitor DNBP, which has the following beneficial effects:

[0018] (1) The present invention adopts a gradient temperature control strategy and combines it with a multi-stage microchannel reactor to achieve efficient mass and heat transfer in the nitration reaction, inhibit deep nitration side reactions, greatly reduce the content of dinitro isomer impurities, and at the same time can accurately control the total residence time, avoiding the risk of explosion caused by local overheating in traditional processes, and significantly improving the reaction selectivity and safety.

[0019] (2) The present invention constructs a nitric acid-carbon tetrachloride closed-loop circulation system to achieve efficient resource utilization and clean production. Nitric acid in the acid-containing mother liquor is recovered through a ceramic membrane filtration system, and carbon tetrachloride is recovered by vacuum distillation. The discharge of waste acid is greatly reduced compared with the traditional process, significantly reducing solvent consumption and environmental pollution.

[0020] (3) The present invention achieves material homogenization through an ultrasonic dispersing device, and combines nitrogen to pre-activate the sulfonic acid ion exchange resin to improve the utilization rate of the catalyst active sites, and sets an online near-infrared spectroscopy monitoring system to regulate the nitric acid addition rate in real time, thereby improving the controllability of the reaction process and ensuring process stability and product consistency.

[0021] (4) The present invention develops a gradient coupling purification process to break through the performance bottleneck of the inhibitor. By adopting gradient cooling recrystallization and combining it with wiped film molecular distillation, the DNBP crystal particle size is made uniform and the purity is improved. The inhibitory performance reaches the application standard of styrene high-temperature distillation, and the storage stability is greatly extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0023] Figure 1 The present invention provides a schematic flow chart of an embodiment of a method for efficiently producing the polymerization inhibitor DNBP.

[0024] Figure 2 A schematic diagram of the reaction formula for the nitration stage of an embodiment of a method for efficiently producing the polymerization inhibitor DNBP according to the present invention.

[0025] Figure 3 A schematic diagram of the reaction formula for the dinitration stage provided in an embodiment of the present invention for an efficient production method of the polymerization inhibitor DNBP.

[0026] Figure 4 This is a schematic diagram of the overall reaction formula provided in an embodiment of a method for efficiently producing the polymerization inhibitor DNBP according to the present invention.

[0027] Figure 5 A schematic diagram summarizing the reaction process of an embodiment of a method for efficiently producing the polymerization inhibitor DNBP according to the present invention. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] like Figure 1-5 As shown, an embodiment of the present invention provides a method for efficiently producing a polymerization inhibitor DNBP, comprising the following steps:

[0030] Step 1. Material preparation: Select the corresponding raw materials, weigh and classify them, and divide the raw materials into three types: main materials, auxiliary materials and additives, among which:

[0031] The main materials are o-tert-butylphenol, nitric acid, and carbon tetrachloride, with the purity of o-tert-butylphenol being ≥99%, the purity of carbon tetrachloride being ≥95%, and the concentration of nitric acid being 65%-68%;

[0032] The auxiliary materials include a sulfonic acid ion exchange resin catalyst, and the active site density of the sulfonic acid ion exchange resin is 3.0-3.5 mmol / g, the pore size distribution is 10-50 nm, and the specific surface area is ≥800 m 2 / g.

[0033] The additive is an ethanol-water mixed solvent, and the volume ratio of the ethanol-water mixed solvent is 1:2-1:4;

[0034] When weighing, the weighing ratio is based on a molar ratio of nitric acid to o-tert-butylphenol of 2.15:1 and a mass ratio of o-tert-butylphenol to carbon tetrachloride of 0.15:1.

[0035] Step 2. Material pretreatment: The main material, auxiliary materials and additives are added to the dehydration device, the dehydration device is started for dehydration. After dehydration, o-tert-butylphenol is dehydrated by molecular sieve to a water content of ≤0.1%, and nitric acid is compounded to a mass concentration of 50±0.5% by an acidic wastewater circulation system, and the main material, auxiliary materials and additives are mixed and paired in advance to obtain a mixture of carbon tetrachloride and o-tert-butylphenol. After mixing, the mixture is homogenized by an ultrasonic dispersion device with an ultrasonic dispersion power density of 200-400W / L, a frequency of 28-40kHz, a treatment time of 10-20 minutes, and a sulfonic acid ion exchange resin is pre-activated under nitrogen protection, the nitrogen pre-activation temperature is 80°C, and the time is 2h;

[0036] Step three reaction treatment: The material after the treatment in the previous step was pumped into a multistage microchannel reactor (microchannel reactor single-stage channel inner diameter 0.5-2mm, the reactor holdup volume ≤500mL, pressure drop ≤0.5MPa, the reactor channel wall was plasma treated to form a nanoscale SiO2 coating with a thickness of 50-200nm), the temperature gradient was controlled at 40 ℃ -65 ℃ -10 ℃, the total residence time was ≤3h, and the nitration was carried out in stages, the first stage was 40-50 ℃ phenol mononitration (nitric acid dosage 1.1: 1mol), the second stage was added with fuming nitric acid to complete the dinitration, the sulfonic acid catalyst was used in an amount of 5-8% of the mass of phenol, the dinitration stage of fuming nitric acid was added three times, each time at an interval of 5 minutes, the addition ratio was 4:3:3, the total reaction time was ≤30 minutes, and the crude product was obtained after the reaction was completed, an online near-infrared spectroscopy monitoring system was set for real-time detection of the concentration of o-nitrophenol intermediates in the reaction system, and the nitric acid addition acceleration accuracy was controlled to ±2%;

[0037] Step four purification treatment: The crude product obtained was added to a purification device, the purification device was started to distill the crude product, the process requires the reaction solution gradient cooling to below -5 ° C, and the crude product was separated by a horizontal spiral centrifuge (speed 3000-3500rpm), the crude product was subsequently recrystallized using an ethanol-water mixed solvent (cooling rate 1-2 ° C / min), purified by a molecular distillation apparatus (temperature 80-120 ° C, vacuum ≤ 10Pa) to obtain a high-purity product, ethanol - water mixed solvent recrystallization starting dissolution temperature of 65-70 ° C, the end point precipitation temperature of -5 ± 0.5 ° C, the average crystal particle size D50 of 80-150 μm, step four molecular distillation apparatus using a wiped film rotor structure, a film thickness of 0.3-0.5 mm, a distillation pressure ≤ 5Pa, a material residence time ≤ 30 seconds;

[0038] Step 5. By-product recovery: Recover the residue produced by the above reaction, and recover the nitric acid by filtering the acid-containing mother liquor through a ceramic membrane filtration system (pore size 0.1-0.2 μm), with a reuse rate of ≥95%, a number of cycles ≥5 times, and recover the carbon tetrachloride solvent by vacuum distillation (temperature ≤60 ° C, recovery rate ≥98%), and then subject the waste residue to catalytic oxidation treatment to meet environmental emission standards; the operating pressure of the ceramic membrane filtration is 0.3-0.6 MPa, the mass concentration of nitric acid in the nitric acid concentrate is ≥45%, the impurity content is ≤0.5%, the reaction temperature of the catalytic oxidation treatment of the waste residue is 350-450 ° C, the catalyst is a supported V2O5-WO3 / TiO2 composite catalyst, and the space velocity is 5000-8000h -1 .

[0039] Example 1

[0040] Step 1: o-tert-butylphenol (purity 99.2%), nitric acid (concentration 67.5%), carbon tetrachloride (purity 95.5%), molar ratio of nitric acid:phenol = 2.15:1, mass ratio of phenol:carbon tetrachloride = 0.15:1.

[0041] Step 2: Ultrasonic dispersion power density 350 W / L (frequency 35 kHz, treatment 15 min), nitrogen pre-activation sulfonic acid resin (80° C., 2 h).

[0042] Step 3: In a microchannel reactor (inner diameter 1 mm, liquid holding volume 450 mL, pressure drop 0.4 MPa), nitration was carried out in stages (monitration 45°C, dinitration 65°C, residence time 2.5 h), fuming nitric acid was added in three doses (4:3:3), and the nitric acid addition rate was regulated by online near-infrared monitoring (accuracy ±1.8%).

[0043] Step 4: Gradient cooling recrystallization (starting at 70°C → ending at -5°C, cooling rate of 1.5°C / min), molecular distillation (scraped film rotor, film thickness 0.4 mm, temperature 100°C, vacuum degree 8 Pa, residence time 25 seconds).

[0044] Step 5: Ceramic membrane filtration (operating pressure 0.5 MPa), carbon tetrachloride recovery temperature 55°C.

[0045] index Example 1 DNBP yield 93.5％ Product purity (HPLC) 99.8％ Dinitro isomer impurity content 0.15％ Nitric acid recycling rate (5 cycles) 96.2％ Carbon tetrachloride recovery rate 98.7％ Waste residue discharge (kg / ton) 5.8 Styrene inhibition time (0.01% addition) 76h

[0046] Example 2

[0047] (Comparative group: no microchannel reactor was used)

[0048] Adjustment parameters:

[0049] Step 3: Use a traditional stirred tank reaction (volume 5 L, jacket temperature control) with a total residence time of 6 h.

[0050] index Example 2 DNBP yield 82.1％ Product purity (HPLC) 98.3％ Dinitro isomer impurity content 1.8％ Nitric acid recycling rate (5 cycles) 72.4％ Carbon tetrachloride recovery rate 94.5％ Waste residue discharge (kg / ton) 18.6 Styrene inhibition time 48h

[0051] Example 3

[0052] (Comparison group: no gradient coupling purification)

[0053] Adjustment parameters:

[0054] Step 4: Use only single recrystallization (dissolve at room temperature → suddenly cool to -10°C, without molecular distillation). Experimental data:

[0055] index Example 3 DNBP yield 88.6％ Product purity (HPLC) 97.5％ Dinitro isomer impurity content 0.9％ Nitric acid recycling rate (5 cycles) 93.8％ Carbon tetrachloride recovery rate 97.2％ Waste residue discharge (kg / ton) 7.2 Styrene inhibition time 63h

[0056] Example 4

[0057] (Comparative group: non-closed-loop recycling system)

[0058] Adjustment parameters:

[0059] Step 5: The acid-containing mother liquor is directly discharged without using ceramic membrane filtration and carbon tetrachloride vacuum distillation. Experimental data:

[0060] index Example 4 DNBP yield 90.2％ Product purity (HPLC) 99.1％ Dinitro isomer impurity content 0.3％ Nitric acid recovery rate — Carbon tetrachloride recovery rate — Waste residue discharge (kg / ton) 32.5 Styrene inhibition time 72h

[0061] Data analysis and conclusion of the optimal embodiment:

[0062] Yield and purity:

[0063] The yield of Example 1 (93.5%) was significantly higher than that of the other groups because the efficient mass transfer and precise temperature control of the microchannel reactor reduced side reactions; molecular distillation + gradient recrystallization achieved a purity of 99.8%, which was better than the direct crystallization of Example 3 (97.5%).

[0064] Impurity control:

[0065] The content of dinitro isomers in Example 1 is only 0.15%, which is much higher than that in the conventional process (1.8% in Example 2).

[0066] Resource recycling:

[0067] The nitric acid recovery rate of 96.2% and the carbon tetrachloride recovery rate of 98.7% (Example 1) verify the economic and environmental benefits of the closed-loop system;

[0068] In Example 4, the waste residue discharge increased by 4.6 times due to non-recycling.

[0069] Inhibition performance:

[0070] The inhibition time of Example 1 is 76 hours, which meets the highest standard of GB / T29593-2013 (≥72 hours);

[0071] The inhibition efficiency of Example 3 was reduced due to insufficient purity.

[0072] Conclusion: Example 1 achieves comprehensive optimization of yield, purity and environmental protection through the combination of staged nitration-microchannel enhancement-closed-loop purification technology, and is the optimal implementation plan.

[0073] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A method for efficiently producing a polymerization inhibitor DNBP, characterized in that: The following steps are involved: Step 1. Material preparation: Select the corresponding raw materials, weigh and classify them, and divide the raw materials into three types: main materials, auxiliary materials and additives, among which: The main materials are o-tert-butylphenol, nitric acid, and carbon tetrachloride. The auxiliary materials include sulfonic acid type ion exchange resin catalyst, The additive is an ethanol-water mixed solvent. When weighing, the weight ratio is 2.15:1 based on the molar ratio of nitric acid to o-tert-butylphenol and the mass ratio of o-tert-butylphenol to carbon tetrachloride being 0.15:1; Step 2. Material pretreatment: The main material, auxiliary materials and additives are added to the dehydration device, and the dehydration device is started for dehydration. After dehydration, the o-tert-butylphenol is dehydrated by molecular sieve to a water content of ≤0.1%, and nitric acid is compounded to a mass concentration of 50±0.5% through an acidic wastewater circulation system, and the main material, auxiliary materials and additives are mixed and paired in advance to obtain a mixture of carbon tetrachloride and o-tert-butylphenol. After mixing, the mixture is homogenized by an ultrasonic dispersion device and pre-activated under nitrogen protection. sulfonic acid ion exchange resin; Step 3. Reaction treatment: The material after the treatment in the previous step is pumped into a multi-stage microchannel reactor, the temperature gradient is controlled at 40 ° C -65 ° C -10 ° C, the total residence time is ≤3h, and the nitration is carried out in stages. In the first stage, phenol is mononitrated at 40-50 ° C, and in the second stage, fuming nitric acid is added to complete the dinitration. The amount of sulfonic acid catalyst is 5-8% of the mass of phenol. After the reaction, a crude product is obtained; Step 4. Purification: The crude product is added to a purification device, and the purification device is started to perform distillation on the crude product. This process needs to be carried out when the reaction liquid is gradually cooled to below -5°C, and the crude product is separated by a horizontal spiral centrifuge. The crude product is subsequently recrystallized once using an ethanol-water mixed solvent and purified by a molecular distillation device to obtain a high-purity product; Step 5. By-product recovery: Recover the residue produced by the above reaction, recover nitric acid from the acid-containing mother liquor through a ceramic membrane filtration system, with the number of cycles ≥ 5 times, and recover the carbon tetrachloride solvent through vacuum distillation. Finally, the waste residue is treated by catalytic oxidation to meet environmental emission standards.

2. The method for efficiently producing a polymerization inhibitor DNBP according to claim 1, wherein: In the step 1: Main materials: o-tert-butylphenol purity ≥99%, carbon tetrachloride purity ≥95%, nitric acid concentration 65%-68%; Excipients: Sulfonic acid ion exchange resin with an active site density of 3.0-3.5 mmol / g, a pore size distribution of 10-50 nm, and a specific surface area of ​​≥800 m 2 / g; Additive: ethanol-water mixed solvent volume ratio 1:2-1:

4.

3. The method for efficiently producing a polymerization inhibitor DNBP according to claim 1, wherein: In the step 2: Ultrasonic dispersion: power density is 200-400W / L, frequency is 28-40kHz, and processing time is 10-20 minutes; Nitrogen preactivation: temperature 80°C, time 2h.

4. The method for efficiently producing a polymerization inhibitor DNBP according to claim 1, wherein: In the step three: The inner diameter of a single-stage channel of the microchannel reactor is 0.5-2 mm, the liquid holding volume of the reactor is ≤500 mL, the pressure drop is ≤0.5 MPa, and the inner wall of the reactor channel is treated with plasma to form a nano-scale SiO2 coating with a thickness of 50-200 nm.

5. The method for efficiently producing a polymerization inhibitor DNBP according to claim 1, characterized in that: In the step 3, the fuming nitric acid in the dinitration stage is added three times, with an interval of 5 minutes between each addition, the addition ratio is 4:3:3, and the total reaction time is ≤30 minutes.

6. The method for efficiently producing a polymerization inhibitor DNBP according to claim 1, characterized in that: In the step 3, an online near-infrared spectroscopy monitoring system is set to detect the concentration of the o-nitrophenol intermediate in the reaction system in real time and adjust the nitric acid addition speed with an accuracy of ±2%.

7. The method for efficiently producing a polymerization inhibitor DNBP according to claim 1, characterized in that: In the step 4, the recrystallization starting dissolution temperature of the ethanol-water mixed solvent is 65-70° C., the end precipitation temperature is -5±0.5° C., and the average crystal particle size D50 is 80-150 μm.

8. The method for efficiently producing a polymerization inhibitor DNBP according to claim 1, characterized in that: The molecular distillation apparatus in step 4 adopts a scraped film rotor structure, with a film thickness of 0.3-0.5 mm, a distillation pressure of ≤5 Pa, and a material residence time of ≤30 seconds.

9. The method for efficiently producing a polymerization inhibitor DNBP according to claim 1, characterized in that: In the step 5, the operating pressure of the ceramic membrane filtration is 0.3-0.6 MPa, the mass concentration of nitric acid in the nitric acid concentrate is ≥45%, and the impurity content is ≤0.5%.

10. The method for efficiently producing a polymerization inhibitor DNBP according to claim 1, characterized in that: In the step 5, the reaction temperature of the catalytic oxidation treatment of the waste residue is 350-450 ° C, the catalyst is a supported V2O5-WO3 / TiO2 composite catalyst, and the space velocity is 5000-8000h -1 .

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