CN212450641U

CN212450641U - Nitric acid treatment device containing high-boiling point organic matter

Info

Publication number: CN212450641U
Application number: CN202021217847.2U
Authority: CN
Inventors: 王勤波; 孙美玲; 于萌萌; 张海波; 刘明; 任苗苗; 熊振华
Original assignee: Shandong Youdao Chemical Co ltd
Current assignee: Shandong Youdao Chemical Co ltd
Priority date: 2020-06-24
Filing date: 2020-06-24
Publication date: 2021-02-02
Anticipated expiration: 2030-06-24

Abstract

The utility model provides a nitric acid treatment device containing high boiling point organic matter. The boiling point of the high-boiling-point organic matter is more than or equal to 240 ℃, the device comprises a dilution system, a solid-liquid separation system, a preliminary distillation system and a rectification system, and the dilution system is used for diluting nitric acid containing the high-boiling-point organic matter by using water to obtain a diluted material; the solid-liquid separation system is used for carrying out solid-liquid separation on the diluent to obtain high-boiling-point organic matters and diluted nitric acid; the preliminary distillation system is used for preliminarily distilling the diluted nitric acid to concentrate the diluted nitric acid to obtain concentrated nitric acid; the rectification system is used for rectifying the concentrated nitric acid to obtain recovered nitric acid. Utilize the utility model provides a processing apparatus handles the nitric acid that contains high boiling point organic matter, can effectively reduce the high boiling point organic matter content in the recovery nitric acid.

Description

Nitric acid treatment device containing high-boiling point organic matter

Technical Field

The utility model relates to the technical field of chemical industry, particularly, relate to a processing apparatus of nitric acid that contains high boiling point organic matter.

Background

Nitration is an important unit reaction widely used in the production of chemical products such as dyes, medicines, pesticides, explosives and the like, wherein nitrate nitration is a common nitration method. A large amount of waste nitric acid saturated by organic matters is generated in the nitric acid nitration reaction process, and when the waste nitric acid is directly used as three wastes for neutralization treatment, the three wastes are generated in large quantity, the content of the organic matters in the generated waste salt is high, the treatment cost is high, the waste salt cannot be effectively utilized, the resource waste is caused, the wastes are increased, and the secondary environment pollution is caused.

In order to improve the utilization rate of nitric acid in the nitric acid nitration process and reduce the discharge of three wastes, another common treatment method is to concentrate dilute nitric acid by distillation and remove part of organic matters in the nitric acid containing high-boiling-point organic matters (the boiling point is usually higher than 240 ℃) generated by the nitric acid nitration, so as to realize the reutilization of the nitric acid. However, in the conventional distillation treatment, organic matters dissolved in the nitric acid are volatilized due to gas-liquid phase equilibrium or are carried into the recovered nitric acid by steam, so that the content of the organic matters in the recovered nitric acid is high. If the recovered nitric acid is recycled to the system, the high-boiling-point organic matters in the system can be enriched, and the production safety is not facilitated. If this recovered nitric acid is used for other purposes, new organic impurities may be introduced into the nitric acid for other purposes. This limits the range of application of the nitric acid recovered by conventional distillation operations, and has potential safety hazards and affects product quality. Therefore, the effective utilization of nitric acid is difficult to realize by the conventional process of distilling, concentrating and nitrifying the nitric acid.

For the recovery of nitric acid containing high boiling point organic matter, some patent documents have been reported. For example, chinese patent CN108128826A, publication date 2018, 6 month 8, name of utility model: a nitric acid-containing waste water treatment device and a treatment method, namely discloses a treatment method for treating the nitric acid waste liquid. The patent describes a technical scheme of nitrating m-methyl benzoic acid by taking m-methyl benzoic acid as a specific example, firstly 98% nitric acid and m-methyl benzoic acid are mixed and subjected to nitration reaction, a generated nitrated product is filtered to obtain nitrated mother liquor and a nitrated product with the concentration of about 94%, then the nitrated product is subjected to gradient washing by using fresh water, washing filtrate and the nitrated mother liquor are mixed to obtain 70% nitric acid waste liquor, then the 70% nitric acid waste liquor is subjected to distillation and concentration treatment, distillate is cooled by a condenser and then is collected and recycled, namely dilute waste nitric acid is treated in a distillation mode. According to the general knowledge of the person skilled in the art, three isomers exist in the nitration at the 2-, 4-and 6-positions. According to the scheme disclosed by the report on the environmental impact of the Antai Jiangtai methylbenzoic acid series project (http:// sthjj. huaibei. gov. cn/jsxmhjyxpjsp/pqgs/8606871.html), it can be known that the content of the 6-position nitration isomer, namely 2-nitro-5-methylbenzoic acid in the m-methylbenzoic acid nitration product is 20%, when the nitration mother liquor of the m-methylbenzoic acid is diluted to the nitric acid concentration of 70%, the 2-nitro-5-methylbenzoic acid is not separated out, the 3-methyl-4-nitrobenzoic acid is not completely separated out, and the content of organic matters in the waste nitric acid generated by solid-liquid separation can be up to 8%. Therefore, the nitric acid recovered by distillation in the embodiment disclosed in CN108128826A is bound to be mixed with more organic substances, and the higher content of organic substances in the nitric acid also brings great safety hazard to the distillation operation. Through the calculation of professional chemical process simulation software (AspenPlus), when only the gas-liquid phase equilibrium is considered, the content of organic matters in the recovered nitric acid after distillation treatment in the specific example disclosed in CN108128826A is up to more than 3000ppm, and furthermore, because water has a stripping effect on methyl nitrobenzoic acid, the amount of organic matters carried in the actually recovered nitric acid is higher than the calculated value of the chemical process simulation calculation software. If the recovered nitric acid is directly used as industrial nitric acid for other nitration reactions, the quality of nitration products can be seriously influenced, and the practical application range of the nitric acid recovered by the method in the industry is strictly limited.

For the above reasons, there is a need for a process for more effectively reducing the content of high boiling point organic substances in nitrifying wastewater, so as to improve the availability of recovered nitric acid obtained after the nitrifying wastewater is treated.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a processing apparatus of nitric acid that contains high boiling point organic matter to after solving among the prior art and handling nitrify waste water, retrieve the problem that high boiling point organic matter content is too high in the nitric acid, influences its utilizability.

In order to achieve the above object, according to an aspect of the present invention, there is provided an apparatus for treating nitric acid containing high-boiling organic substances, the boiling point of the high-boiling organic substances being equal to or greater than 240 ℃, wherein the apparatus comprises: the diluting system is provided with a diluting material outlet and is used for diluting nitric acid containing high-boiling point organic matters to obtain a diluting material; the solid-liquid separation system is provided with a diluent inlet, a liquid phase outlet and a solid phase outlet, the diluent inlet is connected with the diluent outlet, and the solid-liquid separation system is used for carrying out solid-liquid separation on the diluent to obtain high-boiling-point organic matters and diluted nitric acid; the preliminary distillation system is provided with a dilute nitric acid inlet, a light component outlet and a first heavy component outlet, the dilute nitric acid inlet is connected with the liquid phase outlet, and the preliminary distillation system is used for preliminarily distilling the dilute nitric acid to concentrate the dilute nitric acid to obtain concentrated nitric acid; and the rectification system is provided with a concentrated nitric acid inlet and a recovered nitric acid outlet and is used for rectifying the concentrated nitric acid to obtain recovered nitric acid.

Further, the preliminary distillation system comprises: the distillation tower is provided with a dilute nitric acid inlet, a light component outlet and a first heavy component outlet, the first heavy component outlet is a side gas phase outlet of the distillation tower, and the position of the first heavy component outlet is lower than that of the dilute nitric acid inlet; and the tower kettle heater is used for heating the dilute nitric acid entering the distillation tower.

Further, the preliminary distillation system also comprises a first overhead condenser, the first overhead condenser is provided with a first condenser inlet and a first condenser outlet, and the first condenser inlet is connected with the light component outlet; and the dilution system is also provided with a first liquid inlet, the solid-liquid separation system is also provided with a second liquid inlet, and the outlet of the first condenser is connected with the first liquid inlet and/or the second liquid inlet.

Further, the rectification system comprises: the rectifying tower is provided with a concentrated nitric acid inlet and a recovered nitric acid outlet, the second tower top condenser is provided with a second condenser inlet and a second condenser outlet, and the second condenser inlet is connected with the recovered nitric acid outlet.

Furthermore, a rectification heavy component outlet is also arranged at the bottom of the rectification tower, the primary distillation system is also provided with a rectification heavy component inlet, the position of the rectification heavy component inlet is lower than that of the first heavy component outlet, and the rectification heavy component outlet is connected with the rectification heavy component inlet and/or the dilution system.

Further, the solid-liquid separation system comprises: the first solid-liquid separation unit is provided with a diluent inlet, a liquid phase outlet and a solid phase outlet, and the first solid-liquid separation unit is a centrifugal machine or a filter.

Further, the solid-liquid separation system further comprises: the pulping kettle or the recrystallization kettle is connected with the solid phase outlet and is provided with a second liquid inlet; the second solid-liquid separation unit is connected with an outlet of the pulping kettle or the recrystallization kettle, and is also provided with a clear liquid outlet which is connected with the dilution system; the second solid-liquid separation unit is a centrifuge or a filter.

Further, the dilution system is a tank, a tube, or a tower, or any combination thereof.

Further, the distillation tower is also provided with a second heavy component outlet, and the position of the second heavy component outlet is lower than that of the first heavy component outlet; the second heavy component outlet is connected with the dilution system; or the treatment device further comprises a heavy component treatment system, the heavy component treatment system comprises a heavy component diluting device and a heavy component solid-liquid separation device which are sequentially connected, a second heavy component outlet is connected with the heavy component diluting device, and a filtrate outlet of the heavy component solid-liquid separation device is connected with the preliminary distillation system.

The nitration reaction product is generally high-boiling-point organic matter which has certain solubility in the nitric acid aqueous solution, and the higher the nitric acid concentration is, the higher the solubility of the nitrated organic matter in the nitric acid waste liquid is. The utility model discloses a dilution system dilutes the nitric acid that contains high boiling point organic matter earlier, can reduce high boiling point organic matter as far as possible through reducing the nitric acid concentration and at the solubility wherein, consequently, through this dilution processing, can separate out partial high boiling point organic matter in the dilution material that obtains to can reduce the high boiling point organic matter content in the follow-up rectification after retrieving the nitric acid. And then, carrying out solid-liquid separation on the diluent by using a solid-liquid separation system, so that the high-boiling-point organic matter and the dilute nitric acid can be separated. The diluted nitric acid enters a primary distillation system, most of water in the diluted nitric acid can be removed, the concentration effect is achieved, the concentrated nitric acid then enters a rectification system for further purification, and the recovered nitric acid with low content of high-boiling-point organic matters (lower than 100ppm) can be obtained.

In a word, utilize the utility model provides a processing apparatus handles the nitric acid that contains high boiling point organic matter, can effectively reduce the high boiling point organic matter content in the recovery nitric acid.

Drawings

The accompanying drawings, which form a part of the present application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural view showing a nitric acid treatment apparatus for high boiling point organic substances according to an embodiment of the present invention.

Wherein the figures include the following reference numerals:

100. a dilution system; 200. a solid-liquid separation system; 300. a preliminary distillation system; 400. a rectification system.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

In the present invention, it should be noted that, unless explicitly specified or limited, the connection mode between the systems should be understood in a broad sense, for example, the connection mode may be a direct pipe connection, a pipe connection connected to a pipe valve, an indirect connection through an intermediate medium, a fixed connection, or a detachable connection. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The concentration of the nitric acid in the utility model refers to mass concentration, and the concentration of the nitric acid refers to the mass percentage of the nitric acid in the total mass of the nitric acid and the water. The azeotropic concentration of the nitric acid water in the utility model refers to the mass percentage of the nitric acid in the total mass of the nitric acid and the water when the nitric acid and the water reach the azeotropic state under the conditions of normal pressure, reduced pressure or pressurization, for example, the azeotropic concentration of the nitric acid and the water under the normal pressure is 68.4 percent. The utility model discloses an each part in the production system, for example distillation column, rectifying column, solid-liquid separation equipment etc. all can be purchased from the market and obtained, but can handle the whole processing system who contains high boiling organic matter nitric acid and can't purchase from the market and obtain, also not known by technical personnel in the field.

As described in the background section, the prior art treatment of nitrified wastewater has a high content of high boiling point organic substances in the recovered nitric acid, which seriously affects the availability thereof.

In order to solve the above problem, the present invention provides a device for treating nitric acid containing high-boiling point organic matter, the boiling point of the high-boiling point organic matter is greater than or equal to 240 ℃, as shown in fig. 1, the device comprises a dilution system 100, a solid-liquid separation system 200, a preliminary distillation system 300 and a rectification system 400, the dilution system 100 has a diluent outlet, and is used for diluting the nitric acid containing the high-boiling point organic matter with water to obtain a diluent; the solid-liquid separation system 200 is provided with a diluent inlet, a liquid phase outlet and a solid phase outlet, the diluent inlet is connected with the diluent outlet, and the solid-liquid separation system 200 is used for carrying out solid-liquid separation on the diluent to obtain high boiling point organic matters and diluted nitric acid; the preliminary distillation system 300 is provided with a dilute nitric acid inlet, a light component outlet and a first heavy component outlet, the dilute nitric acid inlet is connected with the liquid phase outlet, and the preliminary distillation system 300 is used for preliminarily distilling the dilute nitric acid to concentrate the dilute nitric acid to obtain concentrated nitric acid; rectification system 400 has concentrated nitric acid import and retrieves the nitric acid export, and rectification system 400 is used for carrying out the rectification to concentrated nitric acid in order to obtain retrieving nitric acid.

The nitration reaction product is generally high-boiling-point organic matter which has certain solubility in the nitric acid aqueous solution, and the higher the nitric acid concentration is, the higher the solubility of the nitrated organic matter in the nitric acid waste liquid is. The utility model discloses a dilution system 100 dilutes the nitric acid that contains high boiling point organic matter earlier, can reduce high boiling point organic matter as far as possible through reducing the nitric acid concentration and at the solubility wherein, consequently, through this dilution processing, can separate out partial high boiling point organic matter in the dilution material that obtains to can reduce the high boiling point organic matter content in the follow-up rectification after retrieving the nitric acid. Subsequently, the solid-liquid separation system 200 is used to separate the high boiling point organic matter from the dilute nitric acid. The diluted nitric acid enters the preliminary distillation system 300, most of water in the diluted nitric acid can be removed, the concentration effect is achieved, the concentrated nitric acid then enters the rectification system 400 for further purification, and the recovered nitric acid with low content of high-boiling-point organic matters (lower than 100ppm) can be obtained.

In a preferred embodiment, the preliminary distillation system 300 includes a distillation column having a dilute nitric acid inlet, a light component outlet, and a first heavy component outlet, the first heavy component outlet being a side vapor outlet of the distillation column, and the first heavy component outlet being located lower than the dilute nitric acid inlet; the tower kettle heater is used for heating the dilute nitric acid entering the distillation tower. What need be explained in particular is, the utility model discloses a preliminary distillation system 300 includes distillation column and tower cauldron heater, and the side line gaseous phase export of distillation column will concentrate nitric acid and adopt with the gaseous phase, and tower cauldron heater can be omitted to subsequent rectification system, has reduced a theoretical board of rectification column height in the rectification system in other words.

In a preferred embodiment, the distillation column is further provided with a second heavy fraction outlet, and the second heavy fraction outlet is located at a lower level than the first heavy fraction outlet; wherein the second heavies outlet is coupled to the dilution system 100; or the treatment device further comprises a heavy component treatment system, the heavy component treatment system comprises a heavy component diluting device and a heavy component solid-liquid separation device which are sequentially connected, a second heavy component outlet is connected with the heavy component diluting device, and a filtrate outlet of the heavy component solid-liquid separation device is connected with the preliminary distillation system 300.

In a preferred embodiment, the preliminary distillation system 300 further comprises a first overhead condenser having a first condenser inlet and a first condenser outlet, the first condenser inlet being connected to the light fraction outlet; the dilution system 100 further has a first liquid inlet, the solid-liquid separation system 200 further has a second liquid inlet, and the outlet of the first condenser is connected with the first liquid inlet and/or the second liquid inlet. Therefore, the water evaporated by the preliminary distillation system 300 can be effectively utilized, and the effect of resource recycling is achieved.

In this way, in the actual operation process, as shown in fig. 1, the nitric acid containing high-boiling point organic substances enters the dilution system 100 as nitric acid containing high-boiling point organic substances (stream 1) and fresh water (stream 2) to be diluted, the obtained diluted material (stream 3) enters the solid-liquid separation system 200, and solid-liquid separation treatment is performed to obtain solid-phase high-boiling point organic substances (stream 5) and diluted nitric acid (stream 4). Dilute nitric acid (stream 4) enters the preliminary distillation system 300 and after preliminary distillation, the distilled light fraction (stream 8), the side vapor heavy fraction (stream 12) exiting the first heavy fraction outlet and the distilled heavy fraction (stream 9) exiting the second heavy fraction outlet are obtained. The side gas phase heavy component (stream 12) is used as concentrated nitric acid and enters a rectification system 400 for rectification treatment, and recovered nitric acid (stream 10) is obtained. The distilled light components (stream 8) are returned to dilution system 100 and/or solid-liquid separation system 200. The distilled heavies (stream 9) are returned to the dilution system 100 for recycle treatment. Thus, zero discharge of waste water can be realized, and the method is more environment-friendly and safer. For the second heavy component outlet, the second heavy component outlet may not be directly connected to the dilution system 100, and the second heavy component outlet may be connected to a heavy component treatment system, the heavy component treatment system including a heavy component dilution device and a heavy component solid-liquid separation device connected in sequence, an inlet of the heavy component dilution device being connected to the second heavy component outlet; the filtrate outlet of the heavy component solid-liquid separation device is connected with the preliminary distillation system 300. The heavy component treatment system is adopted to dilute and separate solid and liquid of the second heavy component, and the obtained filtrate also contains nitric acid and organic matters, and the nitric acid and the organic matters are directly returned to the preliminary distillation system 300 to be distilled together with the diluted nitric acid so as to further recover the nitric acid and the organic matters in the filtrate. For example, the heavy component dilution device may be a dilution kettle, a static pipeline mixer, a tower mixer, or other conventional devices, and the heavy component solid-liquid separation device may be a filter, or a centrifuge, or other common solid-liquid separation devices.

In a preferred embodiment, the rectification system 400 includes a rectification column having an inlet for concentrated nitric acid and an outlet for recovered nitric acid (preferably, the rectification column has only rectification sections); and the second tower top condenser is provided with a second condenser inlet and a second condenser outlet, and the second condenser inlet is connected with the nitric acid recovery outlet. As before, the side line gas phase export of distillation column will concentrate nitric acid and adopt with the gas phase, and column bottom heater can be left out to subsequent rectifying system, has reduced a theoretical board of rectifying column height in the rectifying system in other words, consequently, the utility model provides a rectifying system 400, rectifying column can not contain the stripping section, only contain the rectifying section, and the light component export of rectifying column is the export of retrieving nitric acid (stream 10) promptly, has reduced the rectifying column height on the one hand, also is favorable to the make full use of energy consumption on the one hand. Of course, the above-described rectification operation can be carried out by using a rectification column having both a stripping section and a rectification section. More preferably, the outlet of the second condenser is respectively connected with a reflux pipeline and a product extraction pipeline, the top of the rectifying tower is also provided with a reflux port, the reflux port is connected with the reflux pipeline, and the product extraction pipeline is used for extracting the condensed recovered nitric acid.

In a preferred embodiment, as shown in fig. 1, the bottom of the rectification column is further provided with a rectification heavy component outlet, the preliminary distillation system 300 is further provided with a rectification heavy component inlet, the position of the rectification heavy component inlet is lower than that of the first heavy component outlet, and the rectification heavy component outlet is connected with the rectification heavy component inlet and/or the dilution system 100. Thus, the heavy fraction (stream 11) at the bottom of the rectifying tower can be returned to the preliminary distillation system 300 and/or the dilution system 100 for recycling treatment, so as to recover the high-boiling-point organic matters and a small amount of nitric acid carried therein as much as possible, thereby achieving the purpose of zero emission of waste residues.

The solid-liquid separation system 200 is used for separating solid high-boiling-point organic substances precipitated in the diluent, and the specific equipment used can be common solid-liquid separation equipment, such as: the solid-liquid separation system 200 includes: the first solid-liquid separation unit is provided with a diluent inlet, a liquid phase outlet and a solid phase outlet, and comprises a centrifuge or a filter and other conventional solid-liquid separation equipment. To further enhance the separation effect, in a preferred embodiment, the solid-liquid separation system 200 further comprises: the pulping kettle or the recrystallization kettle is connected with the solid phase outlet and is provided with a second liquid inlet; the second solid-liquid separation unit is connected with an outlet of the pulping kettle or the recrystallization kettle, and is also provided with a clear liquid outlet which is connected with the dilution system 100; the second solid-liquid separation unit comprises a conventional solid-liquid separation device such as a centrifuge or a filter. Thus, the solid high-boiling-point organic matters obtained after separation by the first solid-liquid separation unit can enter a pulping kettle or a recrystallization kettle, and are subjected to re-pulping, rinsing or recrystallization under the action of the partial or total distilled light components (stream 6), and the obtained slurry enters the second solid-liquid separation unit for solid-liquid separation again, so that the solid high-boiling-point organic matters can be more fully separated. The clear liquid (stream 7) obtained in the second solid-liquid separation process is returned to the dilution system 100 to participate in the dilution process.

The dilution system 100 can be configured in a variety of ways, and preferably the dilution system 100 is in the form of a tank, a tube, or a tower, or any combination thereof. Any combination herein may be in series or in parallel.

According to another aspect of the present invention, there is provided a method for treating nitric acid containing high-boiling point organic substances, wherein the boiling point of the high-boiling point organic substances is not less than 240 ℃, the method comprises the steps of: s1, diluting nitric acid containing high-boiling point organic matters by using water in a dilution system 100 to obtain a diluted material; s2, performing solid-liquid separation on the diluted material through the solid-liquid separation system 200 to obtain high-boiling-point organic matter and diluted nitric acid; s3, preliminarily distilling the diluted nitric acid in the preliminary distillation system 300 to concentrate the diluted nitric acid to obtain concentrated nitric acid; s4, rectifying the concentrated nitric acid by the rectifying system 400 to obtain the recovered nitric acid.

In a word, utilize the utility model provides a processing method to handle the nitric acid that contains high boiling point organic matter, can effectively reduce the high boiling point organic matter content in the recovery nitric acid. Meanwhile, the treatment method of the utility model also has the advantages of simple operation, high purity of the recovered nitric acid, environmental protection and safety.

The purpose of the dilution process is to reduce the solubility of the high-boiling-point organic matter in the high-boiling-point organic matter as much as possible, and in the actual operation process, on the basis of a large number of experiments, the mass concentration of the nitric acid in the diluent in the step S1 is preferably 20-50%. The mass concentration of the organic matter is controlled to be 20-50%, the problem that the heat load is greatly increased in the subsequent preliminary distillation process due to the fact that the dilution concentration is too low can be solved, meanwhile, the solubility of the high-boiling-point organic matter can be reduced to the greatest extent, the organic matter is separated out as much as possible in the dilution and solid-liquid separation processes, and therefore the height and reflux ratio of a rectifying tower in the subsequent rectification treatment process are reduced.

In a preferred embodiment, in step S3, the light fraction is obtained in the preliminary distillation process, and the processing method further comprises: the distilled light components are condensed and then returned to the dilution system 100 and/or the solid-liquid separation system 200 of step S2. Therefore, the water evaporated by the preliminary distillation system 300 can be effectively utilized, and the effect of resource recycling is achieved. More preferably, in step S3, the distillation column of the preliminary distillation system 300 further comprises a second heavy component outlet; the treatment method further comprises the following steps: the distillation heavy component discharged from the second heavy component outlet is returned to the dilution system 100, or enters the heavy component treatment system, is diluted again, is subjected to solid-liquid separation again, and is returned to the preliminary distillation system 300.

In the actual operation process, as shown in fig. 1, the nitric acid containing high-boiling-point organic matters enters a dilution system 100 as nitric acid containing high-boiling-point organic matters (stream 1) and fresh water (stream 2) for dilution, the obtained diluted material (stream 3) enters a solid-liquid separation system 200, and solid-liquid separation treatment is performed to obtain solid-phase high-boiling-point organic matters (stream 5) and diluted nitric acid (stream 4). Dilute nitric acid (stream 4) enters the preliminary distillation system 300 and after preliminary distillation, the distilled light fraction (stream 8), the side vapor heavy fraction (stream 12) exiting the first heavy fraction outlet and the distilled heavy fraction (stream 9) exiting the second heavy fraction outlet are obtained. The side gas phase heavy component (stream 12) is used as concentrated nitric acid and enters a rectification system 400 for rectification treatment, and recovered nitric acid (stream 10) is obtained. The distilled light components (stream 8) are returned to dilution system 100 and/or solid-liquid separation system 200. The distilled heavies (stream 9) are returned to the dilution system 100 for recycle treatment. Thus, zero discharge of waste water can be realized, and the method is more environment-friendly and safer.

More preferably, in step S4, a rectification heavy component is also obtained in the rectification process; the process further includes returning the rectified heavy components to the preliminary distillation system 300 and/or the dilution system 100. Thus, the heavy fraction (stream 11) at the bottom of the rectifying tower can be returned to the preliminary distillation system 300 and/or the dilution system 100 for recycling treatment, so as to recover the high-boiling-point organic matters and a small amount of nitric acid carried therein as much as possible, thereby achieving the purpose of zero emission of waste residues. In addition, because the content of high-boiling point organic matters in the rectified heavy component (stream 11) is low, the energy consumption for dilution operation by circulating the rectified heavy component back to the dilution system 100 is high, and therefore, the rectified heavy component is preferably returned to the preliminary distillation system 300 for preliminary distillation, so that the energy consumption can be saved, and the recovery rate of nitric acid can be improved.

As before, the side line gaseous phase export of distillation column will concentrate nitric acid and extract with the gaseous phase, and column bottom heater can be omitted to subsequent rectifying system, has reduced a theoretical board of rectifying column height in the rectifying system in other words, consequently, the utility model provides a rectifying system 400, rectifying column preferably do not contain the stripping section, only contain the rectifying section, and the light component export of rectifying column is the export of retrieving nitric acid (stream 10), has reduced the rectifying column height on the one hand, also is favorable to the make full use of energy consumption on the one hand. More preferably, the outlet of the second condenser is respectively connected with a reflux pipeline and a product extraction pipeline, the top of the rectifying tower is also provided with a reflux port, the reflux port is connected with the reflux pipeline, and the product extraction pipeline is used for extracting the condensed recovered nitric acid.

The purpose of the preliminary distillation is to concentrate the dilute nitric acid and remove most of the water from it. In a preferred embodiment, in step S3, the distilled light component obtained in the preliminary distillation process is an aqueous nitric acid solution having a nitric acid concentration of not higher than 5 wt%. In the primary distillation process, if the content of the nitric acid in the distilled light component (stream 8) is higher than 5%, the energy consumption of a primary distillation system can be reduced, but the treatment amount of the waste nitric acid in the whole nitric acid treatment process can be correspondingly increased; if the nitric acid content in the distilled light component (stream 8) is less than 5%, the energy consumption of the primary distillation system is high, but the treatment capacity of the waste nitric acid is not increased. Therefore, the content of nitric acid in the middle distillation light component is preferably controlled to be not higher than 5 percent.

The concentration of nitric acid in the distilled heavies (stream 9) is increased over the concentration of nitric acid in the dilute nitric acid (stream 4) by concentration in the preliminary distillation system 300, but not above its azeotropic composition. If the concentration of nitric acid in the distillation heavy ends (stream 9) is increased too little compared to the concentration of dilute nitric acid (stream 4), the final recovered nitric acid concentration is relatively low, and if higher concentrations of recovered nitric acid are to be obtained, the work load of the rectification system 4 will necessarily increase. In order to take both of the above factors into consideration, in a preferred embodiment, in the preliminary distillation process, the concentration of nitric acid in the distillation heavy component is increased by not less than 10% compared to the dilute nitric acid, and the concentration of nitric acid in the distillation heavy component is not higher than the azeotropic concentration of nitric acid and water.

The solid-liquid separation process is performed for separating solid high-boiling-point organic substances precipitated in the diluent by a conventional separation method, and for example, the step S2 preferably includes: carrying out first solid-liquid separation on the diluent to obtain high-boiling-point organic matters and diluted nitric acid; the first solid-liquid separation is centrifugal separation or filtration separation. The solid high-boiling point organic matters obtained in the solid-liquid separation process can be further refined to obtain high-purity organic product.

In order to further enhance the separation effect, in a preferred embodiment, the step S2 further includes: pulping or recrystallizing the high-boiling-point organic matter by using the returned condensed distillation light component to obtain slurry; carrying out secondary solid-liquid separation on the slurry to obtain clear liquid; the second solid-liquid separation is centrifugal separation or filtration separation; the clear liquid is returned to the dilution system 100. Thus, the solid high-boiling-point organic matter obtained after the first solid-liquid separation can be repulped, rinsed or recrystallized under the action of the partially or totally distilled light component (stream 6), and the obtained slurry is subjected to the second solid-liquid separation, so that the solid high-boiling-point organic matter can be more fully separated. The clear liquid (stream 7) obtained in the second solid-liquid separation process is returned to the dilution system 100 to participate in the dilution process.

In the actual operation process, the preliminary distillation process and the rectification process can be respectively operated under the conditions of normal pressure, reduced pressure and pressurization, preferably under the normal pressure, so that the operation is convenient, and the energy-saving effect can be achieved.

By utilizing the method for treating the organic matters with high boiling points provided by the utility model, the content of the organic matters with high boiling points in the obtained recovered nitric acid can reach not higher than 100 ppm. More preferably, the mass concentration of nitric acid in the recovered nitric acid is from 40% to the azeotropic concentration of nitric acid and water. The recovered nitric acid can meet the general requirements of the industry, has good availability and widens the utilization range.

In a preferred embodiment, the high boiling point organic compound comprises benzoic acid of formula (I) and derivatives thereof, and is subjected to nitration reaction to obtain a product of formula (II) and/or unreacted raw materials:

wherein, R is independently selected from H, methyl, carboxyl, nitryl, halogen or sulfonic group, n is 1 or 2, and m is 0 or 1.

Preferably, the benzoic acid and the derivatives thereof are one or more of benzoic acid, o-methylbenzoic acid, m-methylbenzoic acid, p-methylbenzoic acid, o-chlorobenzoic acid, m-chlorobenzoic acid, p-chlorobenzoic acid, phthalic acid, m-dibenzoic acid, p-dibenzoic acid, o-nitrobenzoic acid, m-nitrobenzoic acid, p-nitrobenzoic acid, m-sulfobenzoic acid, o-sulfobenzoic acid and p-sulfobenzoic acid.

In summary, compared with the prior art, the processing device and the method of the present invention have the following advantages:

1. the content of organic matters in the recovered nitric acid is low. The utility model firstly dilutes the waste nitric acid to a lower concentration (preferably 20% -50%), and then separates out most of high boiling point organic matters by means of solid-liquid separation, thereby achieving the effect of reducing the organic matter content in the nitric acid waste liquid in advance; and then, carrying out primary distillation and rectification operation on the obtained diluted nitric acid, thereby realizing concentration and recovery of the diluted nitric acid and greatly reducing the content of organic matters in the recovered nitric acid product, so that the content of high-boiling point organic matters in the recovered nitric acid is not higher than 100ppm, and the nitric acid can be directly used for other conventional purposes.

2. The operation is safe. The higher the content of organic substances, in particular nitro compounds, in the nitric acid during the distillation or rectification operation, the more dangerous the operation. In the technical document disclosed in chinese patent publication No. CN108128826A, when the nitric acid waste liquid is distilled, the content of organic matters containing nitro groups in the waste nitric acid is as high as 8%, and the danger of direct distillation treatment is high. The utility model discloses dilute nitric acid earlier and carry out the predistillation and rectification after most organic matters of lower concentration (preferred 20% ~ 50%) separation again, advance the preceding organic matter content of predistillation system and reduce by a wide margin than traditional direct distillation technology, this makes the security of follow-up predistillation system obtain obvious promotion.

3. The discharge of three wastes is less. The utility model provides a treatment device and a method, the distilled light component is diluted by circulating the distilled light component back to the dilution system, thereby avoiding the discharge of waste water and reducing the consumption of fresh water; the heavy distillation components obtained by the distillation system are recycled to the dilution system for dilution operation, so that the wastewater discharge is reduced, the recovery rate of nitric acid and organic matters is improved, and the waste of materials is avoided; in the extraction stage of the whole treatment device, only the solid-liquid separation system separates out organic matters and the top of the rectification system separates out and recovers nitric acid, thereby really realizing zero emission of waste water and waste residues;

the present application is described in further detail below with reference to specific examples, which should not be construed as limiting the scope of the invention as claimed.

The embodiment of the present invention is an operation under normal pressure, and the person in the art can obtain a similar result by pressurizing or depressurizing, based on the present invention, which is also within the scope of the present invention.

The ordinary distillation column and the rectifying column can be selected by the technical personnel in the field, and parameters such as the heating temperature of the tower kettle, the number of tower plates, the reflux ratio, the extraction rate and the like are flexibly adjusted according to the common knowledge of the technical personnel in the field so as to achieve the concentration proportion provided by the utility model, therefore, the utility model is not limited to the parameters.

Example 1:

the outlet of the dilution kettle with a stirring structure in the dilution system 100 is connected with the dilute material inlet of the centrifuge in the solid-liquid separation system 200, the dilute nitric acid outlet of the centrifuge in the solid-liquid separation system 200 is connected with the dilute liquid inlet of the distillation tower in the preliminary distillation system 300, the high boiling point organic matter outlet of the centrifuge in the solid-liquid separation system 200 is an organic matter extraction outlet, the condenser outlet of the distillation tower in the preliminary distillation system 300 is a light component outlet connected with the inlet of the dilution kettle in the dilution system 100, the first heavy component outlet (side gas phase outlet) of the distillation tower in the preliminary distillation system 300 is connected with the concentrated nitric acid inlet of the distillation tower in the rectification system 400, the second heavy component outlet of the distillation tower in the preliminary distillation system 300 is connected with the inlet of the dilution kettle in the dilution system 100, the top condenser outlet of the rectification tower in the rectification system 400 is a recovered nitric acid extraction outlet, the rectification heavy component outlet of the rectification tower in the rectification system 400 is connected with the heavy component inlet of the distillation tower The ports are connected.

After benzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high-boiling-point organic matters such as benzoic acid, 3-nitrobenzoic acid, 3, 5-dinitrobenzoic acid and the like.

Nitrated waste acid from a benzoic acid nitration process is used as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to ensure that the mass concentration of the nitric acid in the dilution system 100 is 32%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a centrifuge in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is detected to have the organic matter content of 17000ppm, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, and distillation light components (stream 8: nitric acid aqueous solution with the nitric acid content of 4%) are condensed by a tower top condenser and then circulated back to the dilution kettle in the dilution system 100 to be subjected to dilution operation, the distillation heavy component (stream 9: diluted nitric acid with the concentration of 66.5%) circulates back to the dilution kettle in the dilution system 100 for dilution operation, the side line gas phase heavy component (stream 12) of the distillation tower enters the rectification tower of the rectification system 400 for rectification, the rectification light component is condensed by the condenser to obtain the recovered nitric acid (stream 10) with the mass concentration of 65% and the organic matter content of 28ppm, and the rectification heavy component (stream 11) circulates back to the distillation tower of the primary distillation system 300 for primary distillation operation.

Example 2:

the outlet of the dilution kettle with a stirring structure in the dilution system 100 is connected with the dilute material inlet of the filter in the solid-liquid separation system 200, the dilute nitric acid outlet of the filter in the solid-liquid separation system 200 is connected with the dilute liquid inlet of the distillation tower in the preliminary distillation system 300, the high boiling point organic matter outlet of the filter in the solid-liquid separation system 200 is an organic matter extraction outlet, the condenser outlet of the distillation tower in the preliminary distillation system 300 is a light component outlet connected with the inlet of the dilution kettle in the dilution system 100, the first heavy component outlet (side gas phase outlet) of the distillation tower in the preliminary distillation system 300 is connected with the concentrated nitric acid inlet of the distillation tower in the rectification system 400, the second heavy component outlet of the distillation tower in the preliminary distillation system 300 is connected with the inlet of the dilution kettle in the dilution system 100, the top condenser outlet of the rectification tower in the rectification system 400 is a recovered nitric acid extraction outlet, the rectification heavy component outlet of the rectification tower in the rectification system 400 is connected with the heavy component inlet of the distillation tower in The inlet is connected to the inlet of the dilution tank in the dilution system 100.

After the o-methylbenzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high-boiling-point organic matters such as o-methylbenzoic acid, 2-methyl-3-nitrobenzoic acid, 2-methyl-5-nitrobenzoic acid, 2-methyl-3, 5-dimethylbenzoic acid and the like.

Nitrifying waste acid from an o-methylbenzoic acid nitration process is used as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system, distillation light components (stream 8) from the primary distillation system 300 and distillation heavy components (stream 11) from a rectifying tower in a rectifying system 400 are mixed in a diluting kettle of a diluting system 100, fresh water (stream 2) is supplemented to enable the mass concentration of the nitric acid in the diluting system 100 to be 37%, dilute nitric acid (stream 3) discharged from the diluting system 100 enters a filter in a solid-liquid separation system 200 for solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is detected to have the organic matter content of 14000ppm, the dilute nitric acid (stream 4) enters a distilling tower of the primary distillation system 300 for rectification, and distillation light components (stream 8: aqueous nitric acid solution with the nitric acid content of 4%) are condensed by an overhead condenser and then circulated back to the diluting system for dilution Diluting in a diluting kettle in the system 100, circulating distillation heavy components (stream 9: diluted nitric acid with the concentration of 67%) back to the diluting kettle in the diluting system 100 for diluting, rectifying side-stream gas-phase heavy components (stream 12) of a distillation tower in a rectifying tower of a rectifying system 400, condensing the rectified light components through a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 66.2% and the organic matter content of 33ppm, dividing the rectified heavy components (stream 11) into two streams with the mass ratio of 1:1 through a dividing valve, circulating one stream back to the distillation tower of the primary distillation system 300 for primary distillation, and allowing the other stream to enter the diluting kettle in the diluting system 100 for diluting;

example 3:

the outlet of the static pipeline mixer with a mixing structure in the dilution system 100 is connected with the dilute material inlet of the centrifuge in the solid-liquid separation system 200, the dilute nitric acid outlet of the centrifuge in the solid-liquid separation system 200 is connected with the dilute liquid inlet of the distillation tower in the preliminary distillation system 300, the high boiling point organic matter outlet of the centrifuge in the solid-liquid separation system 200 is an organic matter extraction outlet, the condenser outlet of the distillation tower in the preliminary distillation system 300 is a light component outlet connected with the inlet of the static pipeline mixer in the dilution system 100, the first heavy component outlet (side gas phase outlet) of the distillation tower in the preliminary distillation system 300 is connected with the concentrated nitric acid inlet of the distillation tower in the rectification system 400, the second heavy component outlet of the distillation tower in the preliminary distillation system 300 is connected with the inlet of the static pipeline mixer in the dilution system 100, the condenser outlet at the top of the rectification tower in the rectification system 400 is a recovered nitric acid extraction outlet, the outlet of the rectification heavy component of the rectification column in the rectification system 400 is connected with the inlet of the static pipeline mixer in the dilution system 100.

After the m-toluic acid is nitrified by nitric acid, the generated waste nitric acid contains high boiling point organic matters such as m-toluic acid, 2-nitro-m-toluic acid, 3-methyl-4-nitrobenzoic acid, 2-nitro-3-methylbenzoic acid, 3-methyl-2, 4-dinitrobenzoic acid, 3-methyl-2, 6-dinitrobenzoic acid, 3-methyl-2, 4-dinitrobenzoic acid and the like.

Nitrified waste acid from a m-toluic acid nitration process is used as nitric acid (stream 1) containing high-boiling point organic matters, a distillation light component (stream 8) from a primary distillation system 300 and a distillation heavy component (stream 11) from a rectifying tower in a rectification system 400 are mixed in a static pipeline mixer of a dilution system 100, fresh water (stream 2) is supplemented to enable the mass concentration of the nitric acid in the dilution system 100 to be 40%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a centrifuge in a solid-liquid separation system 200 for solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is detected to be 17000ppm in organic matter content, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 for rectification, and the distillation light component (stream 8: a nitric acid aqueous solution with 4% of nitric acid) is condensed at the top of a tower and then circulated back to the static pipeline mixer in the dilution system 100 for dilution Releasing operation, circulating distillation heavy components (stream 9: diluted nitric acid with the concentration of 65.5%) back to a static pipeline mixer in the dilution system 100 for dilution operation, rectifying side-stream gas-phase heavy components (stream 12) of a distillation tower into a rectifying tower of a rectifying system 400, condensing rectified light components through a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 64.7% and the organic matter content of 31ppm, and feeding the rectified heavy components (stream 11) into the static pipeline mixer in the dilution system 100 for dilution operation;

example 4:

the outlet of the tower mixer with a mixing structure in the dilution system 100 is connected with the dilute material inlet of the centrifuge in the solid-liquid separation system 200, the dilute nitric acid outlet of the centrifuge in the solid-liquid separation system 200 is connected with the dilute liquid inlet of the distillation tower in the preliminary distillation system 300, the high boiling point organic matter outlet of the centrifuge in the solid-liquid separation system 200 is an organic matter extraction outlet, the condenser outlet of the distillation tower in the preliminary distillation system 300 is a light component outlet connected with the inlet of the tower mixer in the dilution system 100, the first heavy component outlet (side gas phase outlet) of the distillation tower in the preliminary distillation system 300 is connected with the concentrated nitric acid inlet of the distillation tower in the rectification system 400, the second heavy component outlet of the distillation tower in the preliminary distillation system 300 is connected with the inlet of the dilution kettle in the dilution system 100, the outlet of the condenser at the top of the rectification tower in the rectification system 400 is a recovered nitric acid extraction outlet, the heavy rectification component outlet of the rectification column in the rectification system 400 is connected to the heavy rectification component inlet of the distillation column in the preliminary distillation system 300.

After the p-toluic acid is nitrified by nitric acid, the generated waste nitric acid contains high-boiling-point organic matters such as p-toluic acid, 3-nitro-4-toluic acid, 4-methyl-3, 5-dinitrobenzoic acid and the like.

Nitrated waste acid from a methyl benzoic acid nitration process is used as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a tower mixer of a dilution system 100, fresh water (stream 2) is supplemented to ensure that the mass concentration of the nitric acid in the dilution system 100 is 32%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a centrifuge in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is detected to have the organic matter content of 20000ppm, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, and distillation light components (stream 8: nitric acid aqueous solution with the nitric acid content of 4%) are condensed by an overhead condenser and then circulated back to the tower mixer in the dilution system 100 to be subjected to dilution operation, circulating distillation heavy components (stream 9: diluted nitric acid with the concentration of 67.8%) back to a tower mixer in the dilution system 100 for dilution operation, feeding side-line gas-phase heavy components (stream 12) of a distillation tower into a rectifying tower of a rectifying system 400 for rectification, condensing the rectified light components through a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 67.2% and the organic matter content of 63ppm, and circulating the rectification heavy components (stream 11) back to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 5:

the outlet of the dynamic tubular mixer with a stirring structure in the dilution system 100 is connected with the dilute material inlet of the filter in the solid-liquid separation system 200, the dilute nitric acid outlet of the filter in the solid-liquid separation system 200 is connected with the dilute liquid inlet of the distillation tower in the preliminary distillation system 300, the high boiling point organic matter outlet of the filter in the solid-liquid separation system 200 is the organic matter extraction outlet, the condenser outlet of the distillation tower in the preliminary distillation system 300 is the light component outlet connected with the inlet of the dynamic tubular mixer in the dilution system 100, the first heavy component outlet (side gas phase outlet) of the distillation tower in the preliminary distillation system 300 is connected with the concentrated nitric acid inlet of the distillation tower in the rectification system 400, the second heavy component outlet of the distillation tower in the preliminary distillation system 300 is connected with the inlet of the dynamic tubular mixer in the dilution system 100, the condenser outlet at the top of the rectification tower in the rectification system 400 is the recovered nitric acid extraction outlet, the heavy rectification component outlet of the rectification column in the rectification system 400 is connected to the heavy rectification component inlet of the distillation column in the preliminary distillation system 300.

After the o-chlorobenzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high boiling point organic matters such as the o-chlorobenzoic acid, 2-chloro-3-nitrobenzoic acid, 2-chloro-5-nitrobenzoic acid, 2-chloro-3, 5-dimethylbenzoic acid and the like.

Nitrated waste acid from an o-chlorobenzoic acid nitration process is taken as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a dynamic tubular mixer of a dilution system 100, fresh water (stream 2) is added to ensure that the mass concentration of the nitric acid in the dilution system 100 is 48%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a filter in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is detected to have the organic matter content of 18000ppm, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, and distillation light components (stream 8: nitric acid aqueous solution with the nitric acid content of 4%) are condensed by a tower top condenser and then circulated back to the dynamic tubular mixer in the dilution system 100 to be subjected to dilution operation, circulating the distillation heavy component (stream 9: diluted nitric acid with concentration of 68%) back to a dynamic tube mixer in the dilution system 100 for dilution operation, feeding the side-line gas-phase heavy component (stream 12) of the distillation tower into a rectifying tower of the rectifying system 400 for rectification, condensing the rectified light component through a condenser to obtain recovered nitric acid (stream 10) with mass concentration of 67.2% and organic matter content of 74ppm, and circulating the rectification heavy component (stream 11) back to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 6:

the outlet of the dilution kettle with a stirring structure in the dilution system 100 is connected with the dilute material inlet of the filter in the solid-liquid separation system 200, the dilute nitric acid outlet of the filter in the solid-liquid separation system 200 is connected with the dilute liquid inlet of the distillation tower in the preliminary distillation system 300, the high boiling point organic matter outlet of the filter in the solid-liquid separation system 200 is an organic matter extraction outlet, the outlet of the condenser of the distillation tower in the preliminary distillation system 300 is a light component outlet connected with the inlet of the dilution kettle in the dilution system 100, the first heavy component outlet (side gas phase outlet) of the distillation tower in the preliminary distillation system 300 is connected with the concentrated nitric acid inlet of the distillation tower in the rectification system 400, the second heavy component outlet of the distillation tower in the preliminary distillation system 300 is connected with the inlet of the dilution kettle in the dilution system 100, the outlet of the condenser at the top of the rectification tower in the rectification system 400 is a recovered nitric acid extraction outlet, the rectification heavy component outlet of the rectification tower in the rectification system 400 is connected with the heavy And the distillation light component outlet of the preliminary distillation system 300 is connected with the inlet of a pulping kettle in the solid-liquid separation system 200, the outlet of the pulping kettle is connected with the inlet of a centrifuge in the solid-liquid separation system 200, and the outlet of the centrifuge is connected with the inlet of a dilution kettle in the dilution system 100.

After the m-chlorobenzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high boiling point organic matters such as m-chlorobenzoic acid, 2-nitro-m-chlorobenzoic acid, 3-chloro-4-nitrobenzoic acid, 2-nitro-3-chlorobenzoic acid, 3-chloro-2, 4-dinitrobenzoic acid, 3-chloro-2, 6-dinitrobenzoic acid, 3-chloro-2, 4-dinitrobenzoic acid and the like.

Nitrifying waste acid from an m-chlorobenzoic acid nitration process is used as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system 300, distillation light components (stream 8) from the primary distillation system 300 and clear liquid (stream 7) from a solid-liquid separation system 200 to be mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to enable the mass concentration of the nitric acid in the dilution system 100 to be 48%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a solid-liquid separation system 200 filter for solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is detected to be 20000ppm in organic matter content, the dilute nitric acid (stream 4) enters a distillation tower in the primary distillation system 300 for rectification, and distillation light components (stream 8: nitric acid aqueous solution with 3.3% of nitric acid) are condensed at the top of the tower and then are divided into two flows through a splitter valve into two flows after The stream with the ratio of 1:1 is circulated back to a dilution kettle of the dilution system 100 for dilution operation, the other stream and high boiling point organic matters (stream 5) separated by the solid-liquid separation system 200 enter a pulping kettle in the solid-liquid separation system 200 for washing the high boiling point organic matters, the stream discharged after washing enters a centrifuge of the solid-liquid separation system 200 for solid-liquid separation, preliminarily refined high boiling point organic matter products are obtained through separation, and the obtained clear liquid (stream 7) is circulated back to the dilution kettle of the dilution system 100 for dilution operation. Circulating distillation heavy components (stream 9: diluted nitric acid with the concentration of 64.3%) of the distillation tower back to the dilution system 100 for dilution operation, allowing side-line gas-phase heavy components (stream 12) of the distillation tower to enter a rectifying tower in the rectifying system 400 for rectification, condensing the rectified light components through a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 62.9% and the organic matter content of 57ppm, and circulating the rectified heavy components (stream 11) back to the distillation tower of the primary distillation system 300 for primary distillation operation;

example 7:

the outlet of the dilution kettle with a stirring structure in the dilution system 100 is connected with the dilute material inlet of the filter in the solid-liquid separation system 200, the dilute nitric acid outlet of the filter in the solid-liquid separation system 200 is connected with the dilute liquid inlet of the distillation tower in the preliminary distillation system 300, the high boiling point organic matter outlet of the filter in the solid-liquid separation system 200 is an organic matter extraction outlet, the condenser outlet of the distillation tower in the preliminary distillation system 300 is a light component outlet connected with the inlet of the dilution kettle in the dilution system 100, the first heavy component outlet (side gas phase outlet) of the distillation tower in the preliminary distillation system 300 is connected with the concentrated nitric acid inlet of the distillation tower in the rectification system 400, the second heavy component outlet of the distillation tower in the preliminary distillation system 300 is connected with the inlet of the dilution kettle in the dilution system 100, the top condenser outlet of the rectification tower in the rectification system 400 is a recovered nitric acid extraction outlet, the rectification heavy component outlet of the rectification tower in the rectification system 400 is connected with the heavy component inlet of the distillation tower The ports are connected.

After the p-chlorobenzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high boiling point organic matters such as p-methylbenzoic acid, 3-nitro-4-chlorobenzoic acid, 4-chloro-3, 5-dinitrobenzoic acid and the like.

Nitrified waste acid from a p-chlorobenzoic acid nitration process is taken as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to ensure that the mass concentration of the nitric acid in the dilution system 100 is 37 percent, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a filter in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is subjected to organic matter content detection of 19000ppm, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, distillation light components (stream 8: nitric acid aqueous solution with the nitric acid content of 2.7 percent) are condensed by a tower top condenser and then are circulated back to the dilution kettle in the dilution system 100 to be subjected to dilution operation, circulating the distillation heavy component (stream 9: 62% diluted nitric acid) to a dilution kettle in the dilution system 100 for dilution operation, feeding the side-line gas-phase heavy component (stream 12) of the distillation tower into a rectifying tower of a rectifying system 400 for rectification, condensing the rectified light component by a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 60.5% and the organic matter content of 36ppm, and circulating the rectified heavy component (stream 11) to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 8:

the outlet of the dilution kettle with a stirring structure in the dilution system 100 is connected with the dilute material inlet of the filter in the solid-liquid separation system 200, the dilute nitric acid outlet of the filter in the solid-liquid separation system 200 is connected with the dilute liquid inlet of the distillation tower in the preliminary distillation system 300, the high boiling point organic matter outlet of the filter in the solid-liquid separation system 200 is an organic matter extraction outlet, the outlet of the tower top condenser of the distillation tower in the preliminary distillation system 300 is a light component outlet connected with the inlet of the pulping kettle in the solid-liquid separation system (1), the outlet of the pulping kettle is connected with the inlet of the centrifuge in the solid-liquid separation system 200, the outlet of the centrifuge is connected with the inlet of the dilution kettle in the dilution system 100, the first heavy component outlet (side-line gas phase outlet) of the distillation tower in the preliminary distillation system 300 is connected with the concentrated nitric acid inlet of the distillation tower in the rectification system 400, the second heavy component outlet of the distillation tower in the, the outlet of the tower top condenser of the rectifying tower in the rectifying system 400 is a recovered nitric acid outlet, and the rectifying heavy component outlet of the rectifying tower in the rectifying system 400 is connected with the rectifying heavy component inlet of the distilling tower in the preliminary distilling system 300;

after the phthalic acid is nitrified by nitric acid, the generated waste nitric acid contains high boiling point organic matters such as phthalic acid, 3-nitrophthalic acid, 4-nitrophthalic acid benzoic acid and the like.

Nitrifying waste acid from a phthalic acid nitration process is used as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and clear liquid (stream 7) from a solid-liquid separation system 200 are mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to enable the mass concentration of the nitric acid in the dilution system 100 to be 27%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a filter of the solid-liquid separation system 200 for solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is subjected to organic matter content detection to be 14000ppm, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 for rectification, and distillation light components (stream 8: nitric acid aqueous solution with the nitric acid content of 1.9%) are condensed by a tower top condenser and then enter the solid-liquid separation system with the high-boiling point organic matters (stream 5) separated by the solid-liquid separation system The high boiling point organic matter is beaten and washed by the beating kettle in 200, the stream discharged after washing enters a centrifuge of a solid-liquid separation system 200 for solid-liquid separation, a primarily refined high boiling point organic matter product is obtained by separation, and the obtained clear liquid (stream 7) is circulated back to the dilution system 100 for dilution operation. The distillation heavy component (stream 9: diluted nitric acid with the concentration of 56.3%) of the distillation tower circulates back to the dilution system 100 for dilution operation, the side line gas phase heavy component (stream 12) of the distillation tower enters the rectification tower of the rectification system 400 for rectification, the rectification light component is condensed by the condenser to obtain the recovered nitric acid (stream 10) with the mass concentration of 55% and the organic matter content of 17ppm, and the rectification heavy component (stream 11) circulates back to the distillation tower of the primary distillation system 300 for primary distillation operation.

Example 9:

After the isophthalic acid is nitrified by the nitric acid, the generated waste nitric acid contains high boiling point organic matters such as isophthalic acid, 5-nitroisophthalic acid and the like

Nitrated waste acid from a m-dibenzoic acid nitration process is used as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to ensure that the mass concentration of the nitric acid in the dilution system 100 is 31 percent, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a filter in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is detected to have the organic matter content of 17000ppm, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, and distillation light components (stream 8: nitric acid aqueous solution with the nitric acid content of 2.8%) are condensed by a tower top condenser and then circulated back to the dilution kettle in the dilution system 100 to be subjected to dilution operation, circulating the distillation heavy component (stream 9: 61.6% diluted nitric acid) to a dilution kettle in the dilution system 100 for dilution operation, feeding the side-line gas-phase heavy component (stream 12) of the distillation tower into a rectifying tower of the rectifying system 400 for rectification, condensing the rectified light component by a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 59.3% and the organic matter content of 23ppm, and circulating the rectification heavy component (stream 11) to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 10:

After terephthalic acid is nitrified by nitric acid, the generated waste nitric acid contains high-boiling-point organic matters such as terephthalic acid, 2-nitroterephthalic acid and the like

The method comprises the following steps of mixing nitration waste acid from a dibenzoic acid nitration process as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 in a dilution kettle of a dilution system 100, supplementing fresh water (stream 2) to enable the mass concentration of the nitric acid in the dilution system 100 to be 23%, enabling diluted nitric acid (stream 3) discharged from the dilution system 100 to enter a filter in a solid-liquid separation system 200 for solid-liquid separation, separating separated high-boiling point organic matters (stream 5), enabling the obtained diluted nitric acid (stream 4) to be 7000ppm through detection of the content of the organic matters, enabling the diluted nitric acid (stream 4) to enter a distillation tower of the primary distillation system 300 for rectification, enabling distillation light components (stream 8: nitric acid aqueous solution with the content of 0.9%) to be condensed by an overhead condenser and then circulated back to the dilution kettle in the dilution system 100 for dilution operation, circulating the distillation heavy component (stream 9: diluted nitric acid with the concentration of 49.1%) back to a dilution kettle in the dilution system 100 for dilution operation, feeding the side-line gas-phase heavy component (stream 12) of the distillation tower into a rectifying tower of the rectifying system 400 for rectification, condensing the rectified light component through a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 48% and the organic matter content of 16ppm, and circulating the rectified heavy component (stream 11) back to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 11:

After the o-nitrobenzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high boiling point organic matters such as the o-nitrobenzoic acid, the 2, 3-dinitrobenzoic acid, the 2, 4-dinitrobenzoic acid, the 2, 6-dinitrobenzoic acid, the 2, 5-dinitrobenzoic acid and the like.

Nitrated waste acid from an o-nitrobenzoic acid nitration process is taken as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to ensure that the mass concentration of the nitric acid in the dilution system 100 is 48%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a filter in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is subjected to organic matter content detection of 19000ppm, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, and distillation light components (stream 8: nitric acid aqueous solution with 4% of nitric acid content) are condensed by an overhead condenser and then circulated back to the dilution kettle in the dilution system 100 to be subjected to dilution operation, circulating the distillation heavy component (stream 9: 65.3% diluted nitric acid) to a dilution kettle in the dilution system 100 for dilution operation, feeding the side-line gas-phase heavy component (stream 12) of the distillation tower into a rectifying tower of the rectifying system 400 for rectification, condensing the rectified light component by a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 64.5% and the organic matter content of 57ppm, and circulating the rectification heavy component (stream 11) to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 12:

After the m-nitrobenzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high boiling point organic matters such as the m-nitrobenzoic acid, 3, 5-dinitrobenzoic acid and the like.

Nitrated waste acid from an o-nitrobenzoic acid nitration process is used as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to ensure that the mass concentration of the nitric acid in the dilution system 100 is 46%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a filter in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is subjected to detection that the content of the organic matters is 16000ppm, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, and distillation light components (stream 8: nitric acid aqueous solution with the content of 3.7%) are condensed by a tower top condenser and then circulated back to the dilution kettle in the dilution system 100 to be subjected to dilution operation, circulating the distillation heavy component (stream 9: diluted nitric acid with the concentration of 67%) back to a dilution kettle in the dilution system 100 for dilution operation, feeding the side-line gas-phase heavy component (stream 12) of the distillation tower into a rectifying tower of a rectifying system 400 for rectification, condensing the rectified light component through a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 65.6% and the organic matter content of 66ppm, and circulating the rectified heavy component (stream 11) back to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 13:

After the paranitrobenzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high-boiling-point organic matters such as paranitrobenzoic acid, 2, 4-dinitrobenzoic acid, 3, 4-dinitrobenzoic acid and the like.

Nitrated waste acid from a p-nitrobenzoic acid nitration process is taken as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to ensure that the mass concentration of the nitric acid in the dilution system 100 is 50%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a filter in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is detected to have the organic matter content of 20000ppm, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, and distillation light components (stream 8: a nitric acid aqueous solution with the nitric acid content of 5%) are condensed by a tower top condenser and then circulated back to the dilution kettle in the dilution system 100 to be subjected to dilution operation, circulating the distillation heavy component (stream 9: diluted nitric acid with the concentration of 68%) back to a dilution kettle in the dilution system 100 for dilution operation, feeding the side-line gas-phase heavy component (stream 12) of the distillation tower into a rectifying tower of a rectifying system 400 for rectification, condensing the rectified light component through a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 67.7% and the organic matter content of 89ppm, and circulating the rectified heavy component (stream 11) back to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 14:

After the m-sulfobenzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high-boiling-point organic matters such as m-sulfobenzoic acid, 3-sulfo-5-nitrobenzoic acid and the like.

Nitrified waste acid from a m-sulfobenzoic acid nitration process is used as nitric acid (stream 1) containing high-boiling-point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to enable the mass concentration of the nitric acid in the dilution system 100 to be 25%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a filter in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling-point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is subjected to detection to the organic matter content of 8000ppm, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, and distillation light components (stream 8: nitric acid aqueous solution with the nitric acid content of 1.2%) are condensed by an overhead condenser and then circulated back to the dilution kettle in the dilution system 100 to be subjected to dilution, circulating the distillation heavy component (stream 9: diluted nitric acid with the concentration of 48%) back to a dilution kettle in the dilution system 100 for dilution operation, feeding the side-line gas-phase heavy component (stream 12) of the distillation tower into a rectifying tower of a rectifying system 400 for rectification, condensing the rectified light component through a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 47.1% and the organic matter content of 9ppm, and circulating the rectified heavy component (stream 11) back to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 15:

After the o-sulfobenzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high-boiling-point organic matters such as o-sulfobenzoic acid, 2-sulfonic-3-nitrobenzoic acid, 2-sulfonic-4-nitrobenzoic acid and the like.

Nitrified waste acid from an o-sulfonic benzoic acid nitration process is used as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to enable the mass concentration of the nitric acid in the dilution system 100 to be 33%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a filter in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is detected to be 10000ppm in organic matter content, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, and distillation light components (stream 8: nitric acid aqueous solution with the nitric acid content of 1.4%) are condensed by an overhead condenser and then circulated back to the dilution kettle in the dilution system 100 to be subjected to dilution operation, circulating the distillation heavy component (stream 9: 62% diluted nitric acid) to a dilution kettle in the dilution system 100 for dilution operation, feeding the side-line gas-phase heavy component (stream 12) of the distillation tower into a rectifying tower of a rectifying system 400 for rectification, condensing the rectified light component by a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 60.9% and the organic matter content of 35ppm, and circulating the rectified heavy component (stream 11) to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 16:

After the p-sulfobenzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high-boiling-point organic matters such as p-sulfobenzoic acid, 4-sulfonic-3-nitrobenzoic acid, 4-sulfonic-2-nitrobenzoic acid and the like.

Nitrated waste acid from a p-sulfobenzoic acid nitration process is used as nitric acid (stream 1) containing high-boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 to be mixed in a dilution kettle of a dilution system 100, fresh water (stream 2) is supplemented to enable the mass concentration of the nitric acid in the dilution system 100 to be 20%, dilute nitric acid (stream 3) discharged from the dilution system 100 enters a filter in a solid-liquid separation system 200 to be subjected to solid-liquid separation, separated high-boiling point organic matters (stream 5) are separated, the obtained dilute nitric acid (stream 4) is tested to be 5000ppm in organic matter content, the dilute nitric acid (stream 4) enters a distillation tower of the primary distillation system 300 to be rectified, and distillation light components (stream 8: nitric acid aqueous solution with the nitric acid content of 0.5%) are condensed by an overhead condenser and then circulated back to the dilution kettle in the dilution system 100 to be subjected to dilution operation, circulating the distillation heavy component (stream 9: diluted nitric acid with the concentration of 42.3%) back to a dilution kettle in the dilution system 100 for dilution operation, feeding the side-line gas-phase heavy component (stream 12) of the distillation tower into a rectifying tower of the rectifying system 400 for rectification, condensing the rectified light component through a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 40% and the organic matter content of 2ppm, and circulating the rectified heavy component (stream 11) back to a distillation tower of the primary distillation system 300 for primary distillation operation;

example 17:

After m-methyl benzoic acid and p-methyl benzoic acid are nitrified by nitric acid, the generated waste nitric acid contains high-boiling-point organic matters such as m-methyl benzoic acid, p-nitrobenzoic acid, 2-nitro-m-methyl benzoic acid, 3-methyl-4-nitrobenzoic acid, 2-nitro-3-methyl benzoic acid, 3-methyl-2, 4-dinitrobenzoic acid, 3-methyl-2, 6-dinitrobenzoic acid, 3-methyl-2, 4-dinitrobenzoic acid, 3-nitro-4-methyl benzoic acid, 4-methyl-3, 5-dinitrobenzoic acid and the like.

Mixing nitration waste acid from m-toluic acid and p-toluic acid nitration process as nitric acid (stream 1) containing high boiling point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from a primary distillation system 300 in a dilution kettle of a dilution system 100, supplementing fresh water (stream 2) to ensure that the mass concentration of the nitric acid in the dilution system 100 is 43%, feeding diluted nitric acid (stream 3) discharged from the dilution system 100 into a filter in a solid-liquid separation system 200 for solid-liquid separation, separating separated high boiling point organic matters (stream 5), detecting that the content of the organic matters in the obtained diluted nitric acid (stream 4) is 16000ppm, feeding the diluted nitric acid (stream 4) into a distillation tower of the primary distillation system 300 for rectification, condensing the distillation light components (8: nitric acid aqueous solution with the content of 4.5%) through a tower top condenser, then circulating the diluted nitric acid (stream 4: nitric acid aqueous solution) back to the dilution kettle in the dilution system 100 for dilution operation, the distillation heavy component (stream 9: diluted nitric acid with the concentration of 67.8%) is circulated back to the dilution kettle in the dilution system 100 for dilution operation, the side line gas phase heavy component (stream 12) of the distillation tower enters the rectification tower of the rectification system 400 for rectification, the rectification light component is condensed by the condenser to obtain the recovered nitric acid (stream 10) with the mass concentration of 67.4% and the organic matter content of 2ppm, and the rectification heavy component (stream 11) is circulated back to the distillation tower of the primary distillation system 300 for primary distillation operation.

Example 18:

the outlet of the dilution kettle with a stirring structure in the dilution system 100 is connected with the dilute material inlet of the filter in the solid-liquid separation system 200, the dilute nitric acid outlet of the filter in the solid-liquid separation system 200 is connected with the dilute liquid inlet of the distillation tower in the preliminary distillation system 300, the high boiling point organic matter outlet of the filter in the solid-liquid separation system 200 is an organic matter extraction outlet, the condenser outlet of the distillation tower in the preliminary distillation system 300 is a light component outlet connected with the inlet of the dilution kettle in the dilution system 100, the first heavy component outlet (side gas phase outlet) of the distillation tower in the preliminary distillation system 300 is connected with the concentrated nitric acid inlet of the distillation tower in the rectification system 400, the second heavy component outlet of the distillation tower in the preliminary distillation system 300 is sequentially connected with the dilution kettle and the filter and then connected with the dilute liquid inlet of the distillation tower in the preliminary distillation system 300, the condenser outlet at the top of the rectification tower in the rectification system 400 is, the heavy rectification component outlet of the rectification column in the rectification system 400 is connected to the heavy rectification component inlet of the distillation column in the preliminary distillation system 300.

After 3, 5-dimethyl benzoic acid is nitrified by nitric acid, the generated waste nitric acid contains high-boiling-point organic matters such as 3, 5-dimethyl benzoic acid, 4-nitro-3, 5-dimethyl benzoic acid and the like.

Mixing a waste nitric acid mixed solution generated in the oxidation process of 3-nitro-o-xylene, wherein the waste nitric acid is obtained by taking nitration waste nitric acid from a 3, 5-dimethyl benzoic acid nitration process and nitric acid as oxidants and taking the mixed solution as nitric acid (stream 1) containing high-boiling-point organic matters, distillation heavy components (stream 9) from a primary distillation system and distillation light components (stream 8) from the primary distillation system 300 in a dilution kettle of a dilution system 100, supplementing fresh water (stream 2) to enable the mass concentration of the nitric acid in the dilution system 100 to be 45%, feeding diluted nitric acid (stream 3) discharged from the dilution system 100 into a filter in a solid-liquid separation system 200 for solid-liquid separation, separating the separated high-boiling-point organic matters (stream 5), detecting the content of the obtained diluted nitric acid (stream 4) to be 16000ppm through detection, feeding the diluted nitric acid (stream 4) into a distillation tower of the primary distillation system 300 for rectification, condensing a distillation light component (stream 8: nitric acid aqueous solution with 4.7% of nitric acid content) through an overhead condenser, circulating the condensed distillation light component back to a dilution kettle in the dilution system 100 for dilution operation, mixing a filtrate obtained after dilution and filtration of distillation heavy components (stream 9: diluted nitric acid with 66.9% of concentration) sequentially entering the dilution kettle and a filter with diluted nitric acid (stream 4), then entering a distillation tower of the primary distillation system 300 for rectification, introducing a lateral line gas phase heavy component (stream 12) of the distillation tower into a rectification tower of the rectification system 400 for rectification, condensing the rectification light component through a condenser to obtain recovered nitric acid (stream 10) with the mass concentration of 66.2% and the organic matter content of 90ppm, and circulating a rectification heavy component (stream 11) back to the distillation tower of the primary distillation system 300 for primary distillation operation.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A processing apparatus of nitric acid containing high boiling point organic matter, the boiling point of the high boiling point organic matter is more than or equal to 240 ℃, characterized by comprising:

a dilution system (100) having a dilution outlet, the dilution system (100) being configured to dilute the nitric acid containing high boiling point organics to obtain a dilution;

the solid-liquid separation system (200) is provided with a diluent inlet, a liquid phase outlet and a solid phase outlet, the diluent inlet is connected with the diluent outlet, and the solid-liquid separation system (200) is used for carrying out solid-liquid separation on the diluent to obtain high-boiling-point organic matters and diluted nitric acid;

the preliminary distillation system (300) is provided with a dilute nitric acid inlet, a light component outlet and a first heavy component outlet, the dilute nitric acid inlet is connected with the liquid phase outlet, and the preliminary distillation system (300) is used for preliminarily distilling the dilute nitric acid to concentrate the dilute nitric acid to obtain concentrated nitric acid; and

a rectification system (400) having a concentrated nitric acid inlet and a recovered nitric acid outlet, the rectification system (400) being configured to rectify the concentrated nitric acid to obtain recovered nitric acid.

2. The apparatus for nitric acid treatment of high boiling point organic matter according to claim 1, wherein said preliminary distillation system (300) comprises:

a distillation column having the dilute nitric acid inlet, the light component outlet, and the first heavy component outlet, wherein the first heavy component outlet is a side vapor outlet of the distillation column, and the first heavy component outlet is located at a position lower than the dilute nitric acid inlet;

and the tower kettle heater is used for heating the dilute nitric acid entering the distillation tower.

3. The apparatus for nitric acid treatment of high boiling point organic compounds according to claim 2, wherein said preliminary distillation system (300) further comprises a first overhead condenser having a first condenser inlet and a first condenser outlet, said first condenser inlet being connected to said light fraction outlet; and the dilution system (100) is also provided with a first liquid inlet, the solid-liquid separation system (200) is also provided with a second liquid inlet, and the outlet of the first condenser is connected with the first liquid inlet and/or the second liquid inlet.

4. The apparatus for nitric acid treatment of high boiling point organic matter containing according to any of claims 1 to 3, wherein said rectification system (400) comprises:

a rectifying tower provided with the concentrated nitric acid inlet and the recovered nitric acid outlet,

and the second tower top condenser is provided with a second condenser inlet and a second condenser outlet, and the second condenser inlet is connected with the nitric acid recovery outlet.

5. The apparatus for treating nitric acid containing high-boiling point organic substances according to claim 4, wherein the bottom of the distillation column is further provided with a heavy fraction outlet, the preliminary distillation system (300) further comprises a heavy fraction inlet, the heavy fraction inlet is lower than the first heavy fraction outlet, and the heavy fraction outlet is connected to the heavy fraction inlet and/or the dilution system (100).

6. The apparatus for nitric acid treatment of high boiling point organic matter according to claim 3, wherein said solid-liquid separation system (200) comprises: a first solid-liquid separation unit having the diluent inlet, the liquid phase outlet, and the solid phase outlet, the first solid-liquid separation unit being a centrifuge or a filter.

7. The apparatus for nitric acid treatment of high boiling point organic matter according to claim 6, wherein said solid-liquid separation system (200) further comprises:

the pulping kettle or the recrystallization kettle is connected with the solid phase outlet and is provided with the second liquid inlet;

the second solid-liquid separation unit is connected with an outlet of the pulping kettle or the recrystallization kettle, and is also provided with a clear liquid outlet which is connected with the dilution system (100); the second solid-liquid separation unit is a centrifuge or a filter.

8. The apparatus for treating nitric acid containing high boiling point organic compounds according to any one of claims 1 to 3, wherein said dilution system (100) is of a tank type, a tube type or a tower type, or any combination thereof.

9. The apparatus for treating nitric acid containing high-boiling point organic substances according to claim 2, wherein said distillation column is further provided with a second heavy component outlet, and the position of said second heavy component outlet is lower than the position of said first heavy component outlet;

the second heavy component outlet is connected with the dilution system (100); alternatively, the first and second electrodes may be,

the treatment device further comprises a heavy component treatment system, the heavy component treatment system comprises a heavy component diluting device and a heavy component solid-liquid separation device which are sequentially connected, the second heavy component outlet is connected with the heavy component diluting device, and the filtrate outlet of the heavy component solid-liquid separation device is connected with the preliminary distillation system (300).