Method for resource utilization of high-oxazine-content chemical waste residue and application thereof

Abstract

The present application relates to waste resource utilization technical field, especially disclose a kind of high azepine content tar waste residue generated in the production of p-phenylenediamine rubber antioxidant key intermediate-RT peiser high-efficiency resource utilization method and its application in the field of environmental remediation.The resource utilization method stably derives and prepares nano-porous carbon with high nitrogen doping amount with high yield to high-efficiency stabilization of azepine waste residue.The present application is simple, efficient, green and environmentally friendly, with no additional pollutant emissions, and the required raw materials can be recycled without wasting resources.The porous carbon prepared has excellent performance in adsorbing and removing various nitrophenol pollutants in water, achieving the goal of "waste treatment".

Description

(I) TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical waste residue resource utilization, in particular to a high-efficiency resource utilization method and application of high-phenoxazine-content tar waste residue generated in the production of a key intermediate of rubber antioxidant of p-phenylenediamine, RT PESI. (II) BACKGROUND

[0002] RT PESI (4-aminodiphenylamine) is a key intermediate of rubber antioxidant of p-phenylenediamine, and is currently mainly produced by the nitrobenzene method. The production process mainly includes two steps of condensation reaction of nitrobenzene and aniline and hydrogenation reduction reaction of nitrodiphenylamine and nitrosodiphenylamine. In the condensation reaction process of nitrobenzene and aniline in the presence of an alkaline condensation catalyst, phenoxazine is inevitably produced, which is the main by-product in the production process of RT PESI, and the amount of phenoxazine generated accounts for about 2.5% of the total amount of RT PESI product.

[0003] The by-product phenoxazine is mainly collected from the phenoxazine tower in the product refining section in the production of RT PESI, and part of RT PESI and a small amount of azobenzene and tar impurities are also collected, forming high-phenoxazine-content waste residue. According to the by-product proportion of phenoxazine, about 300 tons of phenoxazine waste residue will be generated per million tons of RT PESI. At present, the waste residue is usually treated by incineration. Due to the large amount of waste residue generated and the high nitrogen content, incineration not only easily generates toxic and harmful gases to cause secondary pollution, but also indirectly causes a large amount of resource waste. At present, there are patents and related literatures reporting that distillation, melt crystallization, dissolution extraction, solvent recrystallization and other methods are used to separate and refine phenoxazine waste residue. However, due to the close melting and boiling point properties of phenoxazine and RT PESI and other substances, the above conventional separation methods have the disadvantages of high energy consumption, large solvent consumption, complex operation process, high treatment cost and the like, which makes it difficult for enterprises to accept and adopt. Although phenoxazine has certain demand in the medical synthesis industry and the like, the overall demand is small, and the above-mentioned industry has strict requirements on the quality of phenoxazine, and it is difficult to meet the requirements by using the method of purifying from waste residue. Therefore, it is of important practical application significance to develop a high-efficiency, low-cost and environmentally sustainable resource utilization method for high-phenoxazine-content waste residue and expand its application range. (III) SUMMARY

[0004] In order to make up for the shortcomings of the prior art, the present application provides a high-efficiency, low-cost and environmentally sustainable resource utilization method and application of high-phenoxazine-content tar waste residue generated in the production of RT PESI.

[0005] The present application is realized by the following technical solutions:

[0006] A method for resource utilization of RT-PISTAZIN waste residue with high content of phenazine, taking the RT-PISTAZIN production tar waste residue with high content of phenazine as the processing object, and the method comprises the following steps:

[0007] 1. The RT-PISTAZIN production tar waste residue with high content of phenazine is used as carbon source and nitrogen source, the waste residue, an additive A, a catalyst B, a template precursor C and a certain amount of a solvent D are added into a reactor, and the mixture is reacted under stirring for a certain time;

[0008] 2. The mixture obtained in step 1 is subjected to vacuum distillation in the reactor to remove the solvent, and the distilled solvent is collected by condensation and reused;

[0009] 3. The remaining material obtained in step 2 is transferred into a rotary furnace, and is carbonized under a specific atmosphere, and the product obtained after carbonization is subjected to simple grinding, ultrasonic washing with hydrochloric acid solution to remove the residual additive, and then is subjected to ultrasonic water washing and drying to obtain an in-situ nitrogen-doped porous carbon material;

[0010] 4. The washing liquid after acid washing and water washing in step 3 is collected, and a mixture of the catalyst B and the template precursor C is recovered by vacuum evaporation and dehydration, and is reused.

[0011] The more preferred technical scheme of the present application is:

[0012] In step 1, the additive A is dimethoxymethane, the catalyst B is anhydrous FeCl3, the template precursor C is anhydrous MgCl2, and the solvent D is dichloroethane; the reaction temperature is 70-100 DEG C, and the reaction time is 3-20 h.

[0013] In step 2, the vacuum distillation temperature is controlled to be 45-70 DEG C, and the vacuum distillation pressure is controlled to be 0.1 atm-0.3 atm.

[0014] In step 3, the specific atmosphere is a mixed atmosphere of nitrogen, argon or carbon dioxide and water vapor, the heating rate of the material in the rotary furnace is 2-10 DEG C / min, the highest operating temperature is 600-900 DEG C, and the maintaining time at the highest operating temperature is 0.5-3 h.

[0015] In step 4, a proper amount of dry HCl is introduced during the dehydration process, and the temperature is 150-350 DEG C.

[0016] The further preferred technical scheme is that the waste residue with a phenazine content higher than 80% is used as the carbon source, and the nitrogen-doped porous carbon obtained has a yield greater than 40% (based on the raw material tar waste residue) and a nitrogen content higher than 8%.

[0017] The in-situ high-nitrogen-doped porous carbon material prepared by the method is applied to continuous adsorption and removal of nitrophenol wastewater.

[0018] The phenazine waste residue has high carbon content and is rich in nitrogen elements, and is theoretically an excellent precursor for synthesizing heteroatom-doped carbon-based nanomaterials. However, phenazine has a special property different from other nitrogen-containing precursors, that is, sublimation occurs during the heating process, which leads to ineffective carbonization during pyrolysis when using phenazine as a carbon source, and the final product yield is extremely low. For raw materials with poor thermal stability, methods such as oxidation polymerization are usually used to pre-stabilize the raw materials, but after a large number of experimental verifications, it is found that such methods have poor treatment effect on phenazine residue and are difficult to realize the stabilization thereof. The present application creatively uses the Friedel-Crafts alkylation method to cross-link the waste residue with high phenazine content at low cost, which significantly improves the stability thereof. The mixed precursor after stabilization treatment is only subjected to simple evaporation recovery of the solvent and then directly subjected to pyrolysis carbonization, wherein the ferric chloride is a key Lewis acid catalyst in the stabilization treatment process, and then is directly mixed in the precursor as a catalyst for catalytic carbonization to further improve the yield of the carbonized product, and also plays a part of the role of a template precursor. In the presence of water vapor, the magnesium chloride template precursor and the carbon source act on the inside of the product to form a nanoscale oxide hard template, and after acid washing and dissolution, a rich pore structure is formed. During the pyrolysis carbonization process, the catalyst and the template not only improve the total yield of the carbonized product through catalytic carbonization deposition, but also play an important role in anchoring nitrogen-containing species to improve the in-situ nitrogen doping amount of the carbon material. The acid washing liquid can be recycled by evaporation crystallization and drying in a hydrogen chloride atmosphere, and no salt-containing wastewater is generated.

[0019] The waste residue-derived porous carbon prepared by the present application has an outstanding nitrogen doping amount, and as a chemical site on the surface of the carbon-based material, can effectively improve the hydrophilic performance and surface polarity thereof, significantly enhances the capture and anchoring effect on polar organic molecules through strong weak interactions such as electrostatic and hydrogen bonding, and is easy to analyze and regenerate, and is an ideal adsorption material for nitrophenol pollutants.

[0020] The present application solves the problem that phenazine as a raw material cannot be directly pyrolyzed and carbonized to obtain carbon materials with high yield, all raw materials used in the preparation process of the carbon materials involved are cheap and readily available industrial grade raw materials, the preparation process does not produce wastewater and residue, overcoming the secondary pollution problem of a large amount of salt-containing wastewater produced by acid washing in the traditional preparation process of activated carbon materials, and having outstanding economic and environmental properties. The carbon material derived from the waste residue exhibits excellent performance in adsorbing and removing nitrophenol pollutants in water, realizes the goal of "waste treatment with waste", and opens up a high-efficiency, low-cost, green and sustainable method for resource utilization of high-phenazine-content chemical waste residue and application in environmental protection. (V)DETAILED DESCRIPTION

[0021] The present application will be further described below with reference to the accompanying drawings.

[0022] Figure 1 SEM photo of PZR-PC-1 in Example 1;

[0023] Figure 2 XPS spectrum of PZR-PC-1 in Example 1;

[0024] Figure 3 N2 adsorption-desorption isotherm graph of PZR-PC-1 in Example 1.

[0025] Figure 4 Dynamic adsorption breakthrough curve of 4-nitrophenol solution for 5 times in Example 11.

[0026] Figure 5 Dynamic adsorption breakthrough curve of 2,4-dinitrophenol solution for 5 times in Example 12.

[0027] Figure 6 Dynamic adsorption breakthrough curve of 2,4,6-trinitrocatechol solution for 5 times in Example 12.

[0028] Figure 7 Dynamic adsorption evaluation device used in Examples 11, 12 and 13. (V)DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below, and the present application will be further described with reference to the embodiments.

[0030] Example 1:

[0031] A high-phenazine-content tar residue collected from the RT process production section of a certain rubber antioxidant production enterprise was taken as the treatment object, and the phenazine content in the tar residue was 88.5% by high performance liquid chromatography quantitative analysis.

[0032] Take 100 g of the above tar residue, 93.5 g of dimethoxymethane, 19.9 g of anhydrous FeCl3, 50 g of anhydrous MgCl2, and 80 g of dichloroethane into a 1000 mL reaction kettle, and heat to 80°C under nitrogen protection and stirring conditions for 12 h. After the reaction is completed, directly perform vacuum distillation through the distillation head equipped on the reaction kettle, and the distillated dichloroethane is fully condensed and recovered. After the removal of the solvent, the remaining material is transferred to a small rotary furnace, and carbonization is performed in a mixed atmosphere of continuously introduced nitrogen and water vapor, with a ratio of 4:1 (V:V), and heated to 800°C at a rate of 5°C / min and maintained for 1 h to obtain a carbonized product. After the carbonized product is simply ground, 207 g of 30% hydrochloric acid is added for ultrasonic treatment and sufficient washing to remove residual additives. After acid washing, filtration is performed, and the obtained product is added with 100 g of water for ultrasonic washing, and then filtration. The washing liquid after acid washing and water washing is collected. The obtained product after water washing is dried at 120°C under reduced pressure to obtain 47.4 g of a porous carbon material, which is marked as PZR-PC-1.

[0033] Example 2:

[0034] The combined and collected hydrochloric acid washing filtrate and water washing filtrate in Example 1 are subjected to vacuum evaporation crystallization, and dehydrated and dried at 200°C under the protection of an HC1 gas stream to recover a mixture of FeCl3 and MgCl2. The recovered mixed hydrochloride salt is mixed with 100 g of the same tar residue in Example 1, and 93.5 g of fresh dimethoxymethane is added, and the dichloroethane recovered by vacuum distillation in Example 1 is also added. The mixture is heated to 80°C under nitrogen protection and stirring conditions for 12 h. After the reaction is completed, the solvent is recovered by vacuum distillation, the mixture is carbonized, the hydrochloric acid is ultrasonically washed, the water is ultrasonically washed, and the drying treatment method is the same as in Example 1. 46.8 g of a porous carbon material is obtained, which is marked as PZR-PC-Re1.

[0035] The combined and collected hydrochloric acid washing filtrate and water washing liquid is recovered by the same treatment method as described above to obtain a mixed hydrochloride salt, and continuous repeated use is continued. The dichloroethane recovered by vacuum distillation is also continuously reused. All the porous carbon preparation process conditions are consistent with those in Example 1. A total of 5 batches of continuous recovery and use experiments are investigated, and the obtained porous carbon samples of the 2nd to 5th batches are marked as PZR-PC-Re2, PZR-PC-Re3, PZR-PC-Re4, and PZR-PC-Re5, respectively. During the continuous recovery and use experiment, no fresh anhydrous FeCl3, anhydrous MgCl2, or dichloroethane is added.

[0036] Porous carbon material characterization: The key structural properties of the porous carbon materials prepared in Examples 1 and 2 were analyzed using SEM, XPS, elemental analysis, and N2 low-temperature physical adsorption-desorption techniques.

[0037] Table 1 Analysis results of specific surface area, pore structure and yield of porous carbon

[0038] Sample No. Specific surface area (m 2 / g) Total pore volume (cm 3 / g) Carbon yield (%) PZR-PC-1 1444.07 1.096 47.4 PZR-PC-Re1 1465.24 1.108 46.8 PZR-PC-Re2 1409.58 1.057 46.5 PZR-PC-Re3 1461.40 1.107 47.2 PZR-PC-Re4 1432.57 1.087 45.7 PZR-PC-Re5 1458.51 1.107 48.3

[0039] The analysis results in Table 1 show that the high phenazine content tar residue derived porous carbon PZR-PC-1 prepared using the synthesis strategy of the present application has excellent specific surface area and pore volume data. As can be seen from the XPS characterization results of PZR-PC-1, the carbon material has rich nitrogen and oxygen doped species, and the elemental analysis results show that the nitrogen content of the material is as high as 11.05%. The series of key physical and chemical structural properties of PZR-PC-1 lay a good foundation for the material as a carbon-based adsorbent to improve the adsorption capture and mass transfer performance of polar organic pollutants. In addition, the yield of PZR-PC-1 is as high as 48.1%, which proves that the synthesis strategy of the present application can effectively convert phenazine with easy sublimation characteristics into a solid carbon material. More notably, the specific surface area and pore volume of the porous carbon materials prepared in five batches in succession using only the recycled mixed hydrochloride salt without adding any fresh anhydrous FeCl3, anhydrous MgCl2, and solvent dichloroethane are basically consistent with those of PZR-PC-1, with no significant difference, and the yield of the prepared carbon material also remains basically stable, indicating that the synthesis strategy of the present application has good recyclable reusability and can effectively reduce the preparation cost of porous carbon materials.

[0040] Example 3:

[0041] Another batch of high phenazine content waste residue collected from the production section of rubber antioxidant production enterprise RT was used as the treatment object, and the phenazine content in this batch of waste residue was 80.2% as quantitatively analyzed by high performance liquid chromatography.

[0042] Take 100g of the above tar waste residue, 84.7g of dimethoxymethane, 18g of anhydrous FeCl3, 50g of anhydrous MgCl2, and 80g of dichloroethane into a 1000mL reaction kettle, and heat to 80℃ under nitrogen protection and stirring conditions for 12h. After the reaction is completed, the solvent is recovered by distillation under reduced pressure, the mixture is carbonized, the hydrochloric acid is washed by ultrasonic, the water is washed by ultrasonic, and the drying treatment method is the same as in Example 1. 48.2g of porous carbon material is obtained, marked as PZR-PC-2.

[0043] Porous carbon material characterization: The key structural properties of the porous carbon materials prepared in Examples 1 and 2 were analyzed using SEM, XPS, elemental analysis, and N2 low-temperature physical adsorption-desorption techniques.

[0044] The specific surface area and total pore volume of PZR-PC-2 were 1414.30 m 2 / g and 1.053 cm 3 / g, which had a high specific surface area and developed pore structure, similar to PZR-PC-1. The elemental analysis results showed that the nitrogen content of PZR-PC-2 was 10.26%, which, similar to PZR-PC-1, was also maintained at a high level. In addition, the yield of PZR-PC-2 was 48.2%, which remained at a high level.

[0045] Example 4:

[0046] The same batch of tar residues with high phenoxazine content as in Example 1 was used as the treatment object. The raw material ratio, pretreatment reaction conditions, solvent recovery by reduced pressure distillation after the reaction, carbonization temperature control and carbonization time of the mixture, hydrochloric acid ultrasonic washing, water ultrasonic washing, and drying treatment methods were the same as in Example 1, the only difference being that the mixed gas was changed to a mixed gas of carbon dioxide and water vapor during the carbonization process of the mixture, and the ratio of carbon dioxide and water vapor was 3:1 (V:V). Finally, 45.5 g of porous carbon material was prepared, labeled as PZR-PC-3.

[0047] Porous carbon material characterization: The key structural properties of the prepared PZR-PC-2 were analyzed using elemental analysis and N2 low-temperature physical adsorption and desorption techniques.

[0048] The specific surface area and total pore volume of PZR-PC-3 were 1534.73 m 2 / g and 1.142 cm 3 / g, which had a larger specific surface area and more developed pore structure than PZR-PC-1 and PZR-PC-2, which may be due to the use of carbon dioxide in the carbonization process playing an auxiliary activation role. The elemental analysis results showed that PZR-PC-3 also had a high nitrogen doping amount, with a nitrogen content of 9.87%. In addition, the yield of PZR-PC-3 remained at a high level, reaching 45.5%.

[0049] Example 5: Verification experiment

[0050] The reagent phenoxazine with a purity of 98% purchased from Shanghai Macklin Biochemical Technology Co., Ltd. was used as the treatment object.

[0051] A 1000 mL reactor was charged with 100 g of phenazine, 103.5 g of dimethoxymethane, 22 g of anhydrous FeCl3, 50 g of anhydrous MgCl2, and 80 g of dichloroethane. The mixture was heated to 80 °C under nitrogen protection and stirring for 12 h. After the reaction was completed, the solvent was recovered by distillation under reduced pressure, and the mixture was carbonized, washed with hydrochloric acid under ultrasonic, washed with water under ultrasonic, and dried by the same method as in Example 1. 44.4 g of a porous carbon material was obtained, labeled as PZ-PC.

[0052] Porous carbon material characterization: The key structural properties of the prepared PZ-PC were analyzed by elemental analysis and N2 low-temperature physical adsorption and desorption techniques.

[0053] The specific surface area and total pore volume of PZ-PC were 1456.24 m 2 / g and 1.102 cm 3 / g, respectively. Elemental analysis showed that the nitrogen content of PZ-PC was as high as 11.24%. It is worth noting that the yield of PZ-PC is 44.4%, which still maintains a high level, further verifying the applicability of the synthesis strategy of the present application to the preparation of high-phenazine-content raw material derived porous carbon with thermal sublimation properties.

[0054] Example 6 (Comparative Experiment 1):

[0055] The same batch of high-phenazine-content tar residue as in Example 1 was used as the treatment object.

[0056] 100 g of the tar residue was directly added to a rotary furnace for pyrolysis carbonization under a nitrogen atmosphere. The temperature was raised to 800 °C at a rate of 5 °C / min and maintained for 1 h. The amount of carbonized product in the furnace tube was very small. After removing the soluble impurities by hydrochloric acid and water washing, the carbon material was dried, and only 1.3 g of carbon material was obtained. In addition, after the carbonization was completed, a large amount of yellow solid crystals were found to be attached and accumulated in the pipeline at the outlet end of the furnace tube. The solid was analyzed by sampling and was phenazine.

[0057] The results of this comparative experiment show that when high-phenazine-content tar residue is directly pyrolyzed, the phenazine therein exhibits its thermal sublimation property and cannot be effectively deposited to form solid carbon material, resulting in a very small amount of carbon product. It is speculated that the small amount of carbonized product is formed by pyrolysis and carbonization of high-polymerization-degree impurities with high thermal stability in the tar residue. Therefore, only using conventional pyrolysis carbonization cannot efficiently derive high-phenazine-content tar residue into carbon material.

[0058] Example 7 (Comparative Experiment 2):

[0059] The reagent phenazine in Example 5 was used as the treatment object.

[0060] Take 100 g of reagent phenazine and directly add it into the rotary furnace. Use the same processing method as in Example 6 to directly pyrolyze and carbonize. After carbonization, there is basically no carbonized product in the furnace tube. A large amount of phenazine crystals adhere and accumulate in the pipeline at the outlet end of the furnace tube.

[0061] The above experiment again verifies the sublimation property of phenazine under heat. It is difficult to efficiently pyrolyze and carbonize phenazine into ideal carbon materials by conventional pyrolysis and carbonization methods.

[0062] Example 8 (Comparative Experiment 3):

[0063] The same batch of high-phenazine-content tar waste residue as in Example 1 is used as the processing object.

[0064] Take 100 g of the above tar waste residue, 93.5 g of dimethoxymethane, 19.9 g of anhydrous FeCl3, and 80 g of dichloroethane and add them into a 1000 mL reaction kettle. Under the conditions of nitrogen protection and stirring, heat to 80°C and continue to react for 12 h. After the reaction is completed, distill off the solvent, and the remaining mixture weighs about 205.3 g. Use sufficient water to thoroughly ultrasonically heat wash the mixture, then use sufficient anhydrous ethanol to thoroughly ultrasonically heat wash the mixture after filtration, remove the residual FeCl3 and soluble substances, and then dry under reduced pressure. The product is labeled PZR-P1 and weighs 106.2 g.

[0065] Take another 100 g of tar waste residue, 93.5 g of dimethoxymethane, 19.9 g of anhydrous FeCl3, 50 g of anhydrous MgCl2, and 80 g of dichloroethane and add them into a 1000 mL reaction kettle. Under the conditions of nitrogen protection and stirring, heat to 80°C and continue to react for 12 h. After the reaction is completed, distill off the solvent, and then the remaining material is also first thoroughly ultrasonically heat washed with sufficient water, then thoroughly ultrasonically heat washed with sufficient anhydrous ethanol after filtration, remove the residual FeCl3, MgCl2, and soluble substances, and then dry under reduced pressure. The product is labeled PZR-P2 and weighs 108.4 g.

[0066] Take another 100 g of tar waste residue, 93.5 g of dimethoxymethane, and 80 g of dichloroethane and add them into a 1000 mL reaction kettle. Follow the same reaction and post-treatment method as above to obtain a final remaining material weighing 32.24 g.

[0067] From the comprehensive analysis of the results of the above three groups of experiments, it can be seen that anhydrous FeCl3 can effectively catalyze the cross-linking reaction of phenazine and dimethoxymethane in tar residue waste, so as to efficiently form stable cross-linked products; anhydrous MgCl2 may have an auxiliary catalytic effect on the cross-linking reaction of phenazine and dimethoxymethane, but the catalytic enhancement effect is limited; without the catalytic effect of anhydrous FeCl3, the tar residue waste and dimethoxymethane are difficult to effectively spontaneously perform cross-linking reaction, and most of the phenazine and soluble substances in the tar are washed away by ethanol during the heat washing of the mixture in the post-processing process, and the remaining mass is small.

[0068] Example 9 (Comparative Experiment 4):

[0069] Take 50 g of anhydrous MgCl2 and mix it uniformly with 106.2 g of PZR-P1 obtained in Example 8. The mixture is treated according to the same carbonization, acid washing and water washing method as in Example 1, and finally 17.9 g of carbon material is obtained after drying, which is marked as PZR-PC-S1.

[0070] Porous carbon material characterization: The key structural properties of the prepared PZR-PC-S1 are analyzed by element analysis and N2 low-temperature physical adsorption and desorption techniques.

[0071] Firstly, the yield of PZR-PC-S1 is only 17.9%, which is significantly lower than that of PZR-PC-1 in Example 1, indicating that although both use cross-linking stabilization treatment to obtain a relatively stable precursor, the yield is significantly reduced in the absence of FeCl3 during pyrolytic carbonization, verifying the important influence of FeCl3 on the yield of the final carbon product during pyrolytic carbonization. Secondly, the specific surface area and total pore volume of PZR-PC-S1 are 952.13 m 2 / g and 0.461 cm 3 / g, which are also significantly lower than those of PZR-PC-1 in Example 1, indicating that FeCl3 also contributes to the formation of specific surface area and pore structure of porous carbon material during pyrolytic carbonization; finally, the nitrogen content of PZR-PC-S1 is 7.53%, which is also significantly lower than that of PZR-PC-1 in Example 1, indicating that FeCl3 also has an important influence on the stabilization of nitrogen-containing species during pyrolytic carbonization.

[0072] Example 10 (Comparative Experiment 5):

[0073] The same batch of tar residue waste with high phenazine content as in Example 1 is also used as the treatment object.

[0074] Take 100 g of the above tar residue, 93.5 g of dimethoxymethane, 19.9 g of anhydrous FeCl3, and 80 g of dichloroethane into a 1000 mL reaction kettle, and heat to 80°C under nitrogen protection and stirring conditions for 12 h. After the reaction is completed, the solvent is distilled off, and the remaining mixture is directly treated according to the same carbonization, acid washing and water washing method as in Example 1. After drying, 40.2 g of carbon material is obtained, which is marked as PZR-PC-S2.

[0075] Porous carbon material characterization: The key structural properties of the prepared PZR-PC-S2 were analyzed by N2 low temperature physical adsorption and desorption technology.

[0076] The specific surface area and total pore volume of PZR-PC-S2 are 618.11 m 2 / g and 0.328 cm 3 / g, which is significantly lower than that of PZR-PC-1 in Example 1, indicating that high specific surface area and pore volume cannot be created in the absence of MgCl2, verifying the important influence of MgCl2 on the specific surface area and pore structure of the final carbon product during pyrolysis and carbonization. Secondly, the yield of PZR-PC-S2 is also reduced compared to PZR-PC-1 in Example 1, indicating that MgCl2 also has an auxiliary promoting effect on the yield of the final carbon product.

[0077] Example 11 (Comparative Experiment 6):

[0078] The same batch of high pyrazine content tar residue as in Example 1 is also used as the treatment object.

[0079] The raw material dosage, ratio and preparation method are according to the method of Example 1, the only difference is that pure nitrogen is used as the protection atmosphere during carbonization, and no water vapor is introduced. After drying, a total of 26.4 g of carbon material is obtained, which is marked as PZR-PC-S3.

[0080] Porous carbon material characterization: The key structural properties of the prepared PZR-PC-S3 were analyzed by N2 low temperature physical adsorption and desorption technology.

[0081] The specific surface area and total pore volume of PZR-PC-S3 are 395.87 m 2 / g and 0.231 cm 3 / g, which is significantly lower than that of PZR-PC-1 in Example 1. More notably, the yield of PZR-PC-S3 is also significantly reduced compared to PZR-PC-1 in Example 1. The direct reason for the above results is that the lack of water during carbonization cannot effectively convert metal chloride salts into nano metal oxides, which cannot play a catalytic carbonization and pore-forming role.

[0082] Example 12: Continuous adsorption removal of nitrophenol pollutants in water - dynamic regeneration evaluation experiment 1

[0083] Accurately weigh 0.1005 g of PZR-PC-1 prepared in Example 1, add a small amount of anhydrous ethanol to form a slurry, and use the wet filling method to fill it into a stainless steel column with a length of 50 mm and an inner diameter of 4.6 mm, and the two ends are plugged with clean quartz sand. A pre-prepared 4-nitrophenol standard aqueous solution with a concentration of 100 mg / L is continuously pumped into the stainless steel packed column using a laminar pump, and the flow rate is controlled at 3 mL / min. The concentration of 4-nitrophenol in the effluent is monitored in real time using a UV-visible spectrophotometer. The detection wavelength of 4-nitrophenol is selected as 317 nm. The continuous adsorption operation temperature is 25°C. After saturation, the carbon adsorbent in the packed column is dynamically desorbed and regenerated using anhydrous methanol. During the regeneration process, the packed column is placed in a water bath, and the temperature is kept at 60°C. The desorption flow rate is 1.5 mL / min. After the desorption and regeneration process is completed, dynamic adsorption evaluation is performed again. The dynamic adsorption-regeneration cycle is continuously repeated for a total of 5 times. The dynamic breakthrough curve is drawn.

[0084] The evaluation results show that PZR-PC-1 exhibits excellent dynamic adsorption capacity and regenerability in 5 continuous dynamic adsorption-regeneration cycles. After 5 continuous adsorption-regeneration cycles, the dynamic adsorption performance does not change significantly compared to the initial state, showing good potential for practical application.

[0085] Example 13: Continuous adsorption removal of nitrophenol pollutants in water - dynamic regeneration evaluation experiment 2

[0086] Accurately weigh 0.1008 g of PZR-PC-1 prepared in Example 1, add a small amount of anhydrous ethanol to form a slurry, and use the wet filling method to fill it into a stainless steel column with a length of 50 mm and an inner diameter of 4.6 mm, and the two ends are plugged with clean quartz sand. A pre-prepared 2,4-dinitrophenol standard aqueous solution with a concentration of 100 mg / L is continuously pumped into the stainless steel packed column using a laminar pump, and the flow rate is controlled at 3 mL / min. The concentration of 2,4-dinitrophenol in the effluent is monitored in real time using a UV-visible spectrophotometer. The detection wavelength of 2,4-dinitrophenol is selected as 358 nm. The continuous adsorption operation temperature is 25°C. After saturation, the carbon adsorbent in the packed column is dynamically desorbed and regenerated using anhydrous methanol. During the regeneration process, the packed column is placed in a water bath, and the temperature is kept at 60°C. The desorption flow rate is 1.5 mL / min. After the desorption and regeneration process is completed, dynamic adsorption evaluation is performed again. The dynamic adsorption-regeneration cycle is continuously repeated for a total of 5 times. The dynamic breakthrough curve is drawn.

[0087] From the evaluation of the experimental results, similar to the performance of PZR-PC-1, PZR-PC-2 showed excellent dynamic adsorption capacity and regenerability in 5 continuous dynamic adsorption-regeneration cycles. After 5 continuous adsorption-regeneration cycles, the dynamic adsorption performance did not change significantly compared to the initial state, and also showed good potential for practical application.

[0088] Example 14: Evaluation experiment 3 of continuous adsorption removal of nitrophenol pollutants in water-dynamic regeneration

[0089] Accurately weigh 0.1012 g of PZR-PC-1 prepared in Example 1, add a small amount of anhydrous ethanol to form a slurry, and use the wet filling method to fill it into a stainless steel column with a length of 50 mm and an inner diameter of 4.6 mm, and the two ends are plugged with clean quartz sand. A 2,4,6-trinitroresorcinol standard aqueous solution with a concentration of 100 mg / L is prepared in advance and pumped into the stainless steel packed column using a horizontal flow pump, and the flow rate is controlled at 3 mL / min. The concentration of 2,4,6-trinitroresorcinol in the effluent is monitored in real time using a UV-visible spectrophotometer. The detection wavelength of 2,4,6-trinitroresorcinol is 398 nm. The continuous adsorption operation temperature is 25°C. After saturation, anhydrous methanol is used to dynamically desorb and regenerate the carbon adsorbent in the packed column. The regeneration process is carried out in a water bath at a constant temperature of 60°C. The desorption flow rate is 1.5 mL / min. After desorption and regeneration, the dynamic adsorption evaluation is carried out again. The above dynamic adsorption-regeneration cycle is repeated for a total of 5 times. The dynamic breakthrough curve is drawn.

[0090] The evaluation experiment results show that PZR-PC-1 exhibits excellent dynamic adsorption capacity and regenerability in 5 continuous dynamic adsorption-regeneration cycles. After 5 continuous adsorption-regeneration cycles, the dynamic adsorption performance did not change significantly compared to the initial state, and showed good potential for practical application.

Claims

1. A method for resource utilization of high-oxazine-content chemical waste residue, characterized in that, The high content of phenazine tar waste produced in the production process of rubber antioxidant key intermediate RT-Perst is taken as the processing object, including the following steps: (1) The RT-Perst production tar waste with high phenazine content is used as carbon source and nitrogen source, the waste is added into the reactor with auxiliary agent A, catalyst B, template precursor C and a certain amount of solvent D under stirring, and then heated for a certain time; wherein, the auxiliary agent A is dimethoxymethane, the catalyst B is anhydrous FeCl3, the template precursor C is anhydrous MgCl2, and the solvent D is dichloroethane, the reaction temperature is 70-100℃, and the reaction time is 3-20h; (2) The mixture obtained in step (1) is subjected to vacuum distillation in the reactor to remove the solvent, and the distilled solvent is collected after condensation and reused, wherein the vacuum distillation temperature is controlled at 45-70℃, and the vacuum distillation pressure is controlled at 0.1atm-0.3atm; (3) The remaining material obtained in step (2) is transferred to a rotary furnace for carbonization under a specific atmosphere, and the product obtained after carbonization is subjected to simple grinding and then ultrasonic washing with hydrochloric acid solution to remove the residual auxiliary agent, and the acid-washed product is subjected to ultrasonic water washing and drying to obtain an in-situ nitrogen-doped porous carbon material, wherein the specific atmosphere is nitrogen, argon or a mixed atmosphere of carbon dioxide and water vapor, the heating rate of the material in the rotary furnace is 2-10℃ / min, the highest operating temperature is 600-900℃, and the highest operating temperature is maintained for 0.5-3h; (4) The washing liquid after acid washing and water washing in step (3) is collected, and the mixture of catalyst B and template precursor C is recovered by vacuum evaporation and drying, and then reused, wherein the drying and dehydration process is protected by introducing appropriate dry HCl, and the temperature is 150-350℃.

2. The method for resource utilization of high-oxazine-content chemical industrial waste residue according to claim 1, characterized in that: The method is suitable for waste with phenazine content of 50%-99%.

3. The application of the in-situ high-nitrogen-doped porous carbon material obtained by the resource utilization method of high-phenazine-content chemical waste in the continuous adsorption and removal of nitrophenol wastewater.

4. Use according to claim 3, characterized in that: The nitrophenol pollutants in wastewater are one or more of 4-nitrophenol, 2-nitrophenol, 2,4-dinitrophenol, trinitrophenol and trinitrophenol.

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