阅读说明：本技术 一种利用氯苯和硝化废酸生产亚硝酰硫酸的方法 (Method for producing nitrosyl sulfuric acid by using chlorobenzene and nitration waste acid ) 是由 唐永 俞氽叶 汪玲玲 李寒梅 戴胜进 唐智勇 陈晓栋 徐万福 冯彦博 于 2021-08-26 设计创作，主要内容包括：本发明涉及一种利用氯苯和硝化废酸生产亚硝酰硫酸的方法。其包括如下步骤：(1)硝化反应：将硫酸和硝酸配制成硝化混酸A,然后使所述硝化混酸A、萃取液和氯苯进入硝化反应器进行硝化反应,使得到的反应液进入油水分离器进行分离,得到硝基氯苯和硝化废酸；(2)多级萃取：使所述硝化废酸进入萃取装置进行多级萃取,得到所述萃取液和萃取废酸,所述萃取液用作步骤(1)的萃取液；(3)酰化反应：将所述萃取废酸与硫酸和硝酸配制成酰化混酸B,使所述酰化混酸B和二氧化硫进入酰化反应器进行酰化反应,得到亚硝酰硫酸。该方法能够提高硝化反应的收率、保证亚硝酰硫酸的质量、节省酰化反应的原料和解决硝化废酸在工业上难处理的问题。(The invention relates to a method for producing nitrosyl sulfuric acid by using chlorobenzene and nitration waste acid. Which comprises the following steps: (1) nitration reaction: preparing sulfuric acid and nitric acid into a nitrified mixed acid A, then enabling the nitrified mixed acid A, an extraction liquid and chlorobenzene to enter a nitrifying reactor for nitration reaction, and enabling an obtained reaction liquid to enter an oil-water separator for separation to obtain nitrochlorobenzene and nitrified waste acid; (2) multi-stage extraction: allowing the nitrified waste acid to enter an extraction device for multi-stage extraction to obtain the extraction liquid and the extracted waste acid, wherein the extraction liquid is used as the extraction liquid in the step (1); (3) acylation reaction: and preparing the extraction waste acid, sulfuric acid and nitric acid into acylation mixed acid B, and enabling the acylation mixed acid B and sulfur dioxide to enter an acylation reactor for acylation reaction to obtain nitrosyl sulfuric acid. The method can improve the yield of nitration reaction, ensure the quality of nitrosyl sulfuric acid, save raw materials for acylation reaction and solve the problem that the nitration waste acid is difficult to treat industrially.)

1. A method for producing nitrosyl sulfuric acid by using chlorobenzene and nitration waste acid is characterized by comprising the following steps:

(1) nitration reaction: preparing sulfuric acid and nitric acid into a nitrified mixed acid A, then enabling the nitrified mixed acid A, an extraction liquid and chlorobenzene to enter a nitrifying reactor for nitration reaction, and enabling an obtained reaction liquid to enter an oil-water separator for separation to obtain nitrochlorobenzene and nitrified waste acid;

(2) multi-stage extraction: allowing the nitrified waste acid to enter an extraction device for multi-stage extraction to obtain the extraction liquid and the extracted waste acid, wherein the extraction liquid is used as the extraction liquid in the step (1);

(3) acylation reaction: and preparing the extraction waste acid, sulfuric acid and nitric acid into acylation mixed acid B, and enabling the acylation mixed acid B and sulfur dioxide to enter an acylation reactor for acylation reaction to obtain nitrosyl sulfuric acid.

2. The process of claim 1, wherein the nitration reactor of step (1) and the acylation reactor of step (3) are each one of a tank reactor, a tower reactor, a tube reactor, a hypergravity reactor, a microchannel reactor.

3. The method according to claim 1 or 2, wherein in the step (1), the mass ratio of the sulfuric acid to the nitric acid is (1.7-5): 1; the mass ratio of the nitrated mixed acid A to the extract to the chlorobenzene is (1-7): 0.1-1.5): 1, and the nitration temperature is 30-95 ℃.

4. The method according to claim 1 or 2, wherein in step (1), the nitrochlorobenzene is mononitrochlorobenzene or dinitrochlorobenzene, and the nitration waste acid is nitration waste acid generated by synthesizing the mononitrochlorobenzene or the dinitrochlorobenzene.

5. The method according to claim 1 or 2, wherein in the step (1), the nitrified waste acid contains 30-93% of sulfuric acid, 0.5-6% of nitric acid, 1000-15000 ppm of dinitrochlorobenzene, 2000-10000 ppm of mononitrochlorobenzene and 500-3000 ppm of chlorobenzene based on the total mass of the nitrified waste acid.

6. The process according to claim 1 or 2, characterized in that chlorobenzene is used as extractant in step (2).

7. The method according to claim 1 or 2, wherein in the step (2), the extraction device comprises 2-5 stages of extraction columns and 2-5 stages of oil-water separators, preferably 3 stages of extraction columns and 3 stages of oil-water separators.

8. The method according to claim 1 or 2, wherein in the step (2), the nitrified waste acid sequentially enters a 1 st-stage extraction tower, a 1 st-stage oil-water separator, a 2 nd-stage extraction tower, a 2 nd-stage oil-water separator, a 3 rd-stage extraction tower and a 3 rd-stage oil-water separator to obtain extracted waste acid; chlorobenzene serving as an extracting agent sequentially enters a 3 rd-level extraction tower, a 3 rd-level oil-water separator, a 2 nd-level extraction tower, a 2 nd-level oil-water separator, a 1 st-level extraction tower and a 1 st-level oil-water separator to obtain an extraction liquid; the mass ratio of the nitrified waste acid to chlorobenzene serving as an extracting agent is (4-12) to 1.

9. The method according to claim 1 or 2, wherein the extraction waste acid in the step (2) contains 30-93% of sulfuric acid, 0.5-6% of nitric acid, 5-30 ppm of dinitrochlorobenzene, 1-10 ppm of mononitrochlorobenzene and 10-100 ppm of chlorobenzene based on the total mass of the extraction waste acid.

10. The method according to claim 1 or 2, wherein in the step (3), the mass ratio of the extraction waste acid, the sulfuric acid and the nitric acid in the acylated mixed acid B is (0.5-6): 0.3-5): 1, the mass ratio of the acylated mixed acid B and the sulfur dioxide is (2.5-8.0): 1, and the acylation reaction temperature is 45-65 ℃; the nitrosyl sulfuric acid is colorless, light yellow or light green liquid, the mass concentration is 27-42%, and the residual nitric acid value is lower than the mass content of 0.2%.

Technical Field

The invention belongs to the field of fine chemical production, and particularly relates to a method for producing nitrosyl sulfuric acid by using chlorobenzene and nitration waste acid.

Background

In the chlorobenzene nitration reaction, an excess of nitric acid is generally used in order to increase the conversion of chlorobenzene. And after the nitration reaction is finished, carrying out oil-water separation on the reaction liquid to obtain nitrochlorobenzene and nitrated waste acid, wherein excessive nitric acid remains in the nitrated waste acid. The nitrified waste acid contains high-concentration sulfuric acid and low-concentration nitric acid, and a concentration device is generally adopted in industry to increase the concentration of the sulfuric acid to more than 93%, and then the sulfuric acid is returned to a nitration system for nitration reaction. On one hand, the nitration waste acid has strong corrosivity, so that the core equipment of the concentration device is made of tantalum material, and the cost is high; on the other hand, the sulfuric acid concentration consumes a large amount of steam and electricity, and the energy consumption is huge.

Nitrosyl sulfuric acid is an important diazotization reaction raw material. Diazotization refers to the interaction between a diazo component and a diazotizing agent, the final reaction resulting in a diazonium salt, the former usually being an aromatic primary amine and the latter usually being nitrous acid. However, nitrous acid is easily decomposed, so the diazotization reaction process usually adopts an operation mode that sodium nitrite and hydrochloric acid (or sulfuric acid) react in a solution to generate nitrous acid, and nitrous acid immediately reacts with diazo components. However, the process generates salts in the diazotization and subsequent production processes, which not only increases the treatment cost, but also easily causes environmental pollution.

Compared with sodium nitrite, nitrosyl sulfuric acid is a diazotization raw material with higher activity, not only can be used in the conventional diazotization reaction process, but also can be used for diazotization reaction with some low-activity amino groups. In addition, nitrosyl sulfuric acid is used as a diazotization component, so that the material mobility is better, salt is not generated in the diazotization and subsequent treatment processes, and the resource treatment of dilute sulfuric acid in the subsequent procedures is facilitated.

Chinese patent application publication No. CN105923615A discloses a process for recovering waste nitrified acid to prepare nitrosyl sulfuric acid, wherein the waste nitrified acid and an extraction agent are mixed uniformly in an extraction tower, an extract phase obtained by separation is rectified to recover a solvent, a raffinate phase obtained by separation is conveyed to a reaction tower, nitric acid and sulfur dioxide are added into the reaction tower, and the reaction is terminated when the color of a liquid turns blue after the reaction in the reaction tower, so that nitrosyl sulfuric acid is obtained. On the one hand, the extractant utilized in the patent application document needs to be rectified and recovered, and the extraction phase contains benzene ring nitro-compound, so that the process of rectifying and recovering the solvent has a great safety risk. On the other hand, nitric acid and sulfur dioxide are added into the raffinate phase, the color of the obtained nitrosyl sulfuric acid is blue, and the industrial nitrosyl sulfuric acid is colorless or yellowish and light green liquid as required by nitrosyl sulfuric acid industry standard HG/T4673-2014. This indicates that the extraction operation of the process provided by the patent application document is not thorough, which causes impurities to be brought into the raffinate phase, and influences the quality of nitrosyl sulfuric acid.

Disclosure of Invention

Problems to be solved by the invention

The invention aims to provide a method for producing nitrosyl sulfuric acid by using chlorobenzene and nitration waste acid, which can improve the yield of nitration reaction, ensure the quality of nitrosyl sulfuric acid, save raw materials for acylation reaction and solve the problem that the nitration waste acid is difficult to treat industrially.

Means for solving the problems

[1] The method for producing nitrosyl sulfuric acid by using chlorobenzene and nitration waste acid comprises the following steps:

(1) nitration reaction: preparing sulfuric acid and nitric acid into a nitrified mixed acid A, then enabling the nitrified mixed acid A, an extraction liquid and chlorobenzene to enter a nitrifying reactor for nitration reaction, and enabling an obtained reaction liquid to enter an oil-water separator for separation to obtain nitrochlorobenzene and nitrified waste acid;

(2) multi-stage extraction: allowing the nitrified waste acid to enter an extraction device for multi-stage extraction to obtain the extraction liquid and the extracted waste acid, wherein the extraction liquid is used as the extraction liquid in the step (1);

(3) acylation reaction: and preparing the extraction waste acid, sulfuric acid and nitric acid into acylation mixed acid B, and enabling the acylation mixed acid B and sulfur dioxide to enter an acylation reactor for acylation reaction to obtain nitrosyl sulfuric acid.

[2] The process according to [1], wherein the nitration reactor in the step (1) and the acylation reactor in the step (3) are each one of a tank reactor, a tower reactor, a tubular reactor, a hypergravity reactor and a microchannel reactor.

[3] The method according to the item [1] or [2], wherein in the step (1), the mass ratio of the sulfuric acid to the nitric acid is (1.7-5): 1; the mass ratio of the nitrated mixed acid A to the extract to the chlorobenzene is (1-7): 0.1-1.5): 1, and the nitration temperature is 30-95 ℃.

[4] The method according to [1] or [2], wherein in the step (1), the nitrochlorobenzene is mononitrochlorobenzene or dinitrochlorobenzene, and the nitration waste acid is nitration waste acid generated by synthesizing the mononitrochlorobenzene or the dinitrochlorobenzene.

[5] The method according to [1] or [2], wherein in the step (1), the nitrified waste acid contains 30-93% of sulfuric acid, 0.5-6% of nitric acid, 1000-15000 ppm of dinitrochlorobenzene, 2000-10000 ppm of mononitrochlorobenzene and 500-3000 ppm of chlorobenzene, based on the total mass of the nitrified waste acid.

[6] The process according to [1] or [2], wherein chlorobenzene is used as an extractant in the step (2).

[7] The method according to [1] or [2], wherein in the step (2), the extraction device comprises a 2-5-stage extraction tower and a 2-5-stage oil-water separator, preferably a 3-stage extraction tower and a 3-stage oil-water separator.

[8] The method according to the item [1] or the item [2], wherein in the step (2), the nitrified waste acid sequentially enters a 1 st-stage extraction tower, a 1 st-stage oil-water separator, a 2 nd-stage extraction tower, a 2 nd-stage oil-water separator, a 3 rd-stage extraction tower and a 3 rd-stage oil-water separator to obtain extracted waste acid; chlorobenzene serving as an extracting agent sequentially enters a 3 rd-level extraction tower, a 3 rd-level oil-water separator, a 2 nd-level extraction tower, a 2 nd-level oil-water separator, a 1 st-level extraction tower and a 1 st-level oil-water separator to obtain an extraction liquid; the mass ratio of the nitrified waste acid to chlorobenzene serving as an extracting agent is (4-12) to 1.

[9] The method according to [1] or [2], wherein the extraction waste acid in the step (2) contains 30-93% of sulfuric acid, 0.5-6% of nitric acid, 5-30 ppm of dinitrochlorobenzene, 1-10 ppm of mononitrochlorobenzene and 10-100 ppm of chlorobenzene, based on the total mass of the extraction waste acid.

[10] The method according to the item [1] or the item [2], wherein in the step (3), the mass ratio of the extraction waste acid, the sulfuric acid and the nitric acid in the acylation mixed acid B is (0.5-6): 0.3-5): 1, the mass ratio of the acylation mixed acid B and the sulfur dioxide is (2.5-8.0): 1, and the acylation reaction temperature is 45-65 ℃; the nitrosyl sulfuric acid is colorless, light yellow or light green liquid, the mass concentration is 27-42%, and the residual nitric acid value is lower than the mass content of 0.2%.

ADVANTAGEOUS EFFECTS OF INVENTION

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention uses chlorobenzene, which is a raw material for producing nitrochlorobenzene, as an extracting agent, so that the dinitrochlorobenzene, the mononitrochlorobenzene and the chlorobenzene residual liquid in the nitrified waste acid are extracted by the chlorobenzene to form an extract liquid, and the extract liquid is returned to the nitrifying procedure, thereby improving the yield of the nitration reaction.

(2) The method adopts a multi-stage extraction means to effectively control the content of dinitrochlorobenzene, mononitrochlorobenzene and chlorobenzene residual liquid in the nitrified waste acid and ensure the quality of nitrosyl sulfuric acid.

(3) The invention utilizes the sulfuric acid and the nitric acid in the extracted waste acid, and then supplements the sulfuric acid and the nitric acid, thereby preparing the acylation mixed acid for the synthesis of the nitrosyl sulfuric acid, and saving the raw materials of the acylation reaction.

(4) The invention utilizes chlorobenzene and nitrified waste acid to produce nitrosyl sulfuric acid, and solves the problem that the nitrified waste acid is difficult to treat industrially.

Drawings

FIG. 1 is a process flow diagram of the production method of the present invention.

Detailed Description

In the following detailed description, numerous specific details are set forth in order to provide a better understanding of the invention. It will be understood by those skilled in the art that the present invention may be practiced without some of these specific details. In other instances, methods, means, devices and steps which are well known to those skilled in the art have not been described in detail so as not to obscure the invention.

< terms and definitions >

In the present specification, the numerical range represented by "numerical value a to numerical value B" means a range including the end point numerical value A, B.

In the present specification, the numerical ranges indicated by "above" or "below" mean the numerical ranges including the numbers.

In the present specification, the meaning of "may" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

As used herein, the use of "optionally" or "optional" means that certain materials, components, performance steps, application conditions, and the like are used or not used.

In the present specification, the unit names used are all international standard unit names, and the "%" used means weight or mass% content, if not specifically stated.

Reference throughout this specification to "a preferred embodiment," "an embodiment," and so forth, means that a particular element (e.g., feature, structure, property, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments.

< method for producing nitrosyl sulfuric acid Using Chlorobenzene and nitrated waste acid of the present invention >

The process for producing nitrosyl sulfuric acid from chlorobenzene and nitrated waste acid according to the present invention is explained below with reference to fig. 1, it being understood that the person skilled in the art can clearly understand that the practice of the present invention is not limited to fig. 1. The materials and production units of the present invention are commercially available if not otherwise specified.

Step (1): nitration reaction

In the step (1), sulfuric acid and nitric acid are prepared into a nitrified mixed acid A, then the nitrified mixed acid A, an extract and chlorobenzene enter a nitrifying reactor for nitration reaction, and the obtained reaction liquid enters an oil-water separator for separation to obtain nitrochlorobenzene and nitrified waste acid.

Each step of the method is a continuous process, each step is operated simultaneously after the process is started, and when the step (1) is used for feeding, the step (2) of multi-stage extraction also starts to produce extraction liquid simultaneously. The extract is subjected to nitration reaction as a raw material having the same efficacy as chlorobenzene, and since chlorobenzene, which is the raw material for nitration reaction, is directly used as the extractant in step (2), the obtained extract is directly used in the reaction in step (1) with chlorobenzene.

The nitration reactor in the step (1) is one of a kettle reactor, a tower reactor, a tubular reactor, a hypergravity reactor and a microchannel reactor.

In the step (1), the mass ratio of the sulfuric acid to the nitric acid is (1.7-5): 1, preferably (2.0-4.5): 1. If the mass ratio of the sulfuric acid to the nitric acid is too low, the water content in the nitration reaction process is increased, the nitration reaction activity is influenced, and after the mass of reaction raw materials is reduced, the reaction temperature rise of a system is increased, so that the nitration reaction risk is increased. If the mass ratio of sulfuric acid to nitric acid is too high, the loss of reaction raw materials is increased, and the amount of generated waste acid is too large.

The mass ratio of the nitrated mixed acid A, the extract and the chlorobenzene is (1-7): 0.1-1.5): 1, and preferably (2-6): 0.2-1.3): 1. If the amount of the nitrated mixed acid A is too small, the conversion rate of the nitration reaction is low, and the product quality is influenced; if the amount of the nitrated mixed acid A is too much, the consumption of the nitrated mixed acid A is increased, the nitrated residual value in the nitrated waste acid is higher, and the nitrated waste acid can directly react with chlorobenzene serving as an extracting agent in the step (2), so that the extraction effect of the step (2) is influenced.

The nitration reaction temperature is 30-95 ℃, and preferably 50-85 ℃.

In the step (1), the nitrochlorobenzene is mononitrochlorobenzene or dinitrochlorobenzene, and the nitration waste acid is nitration waste acid generated by synthesizing the mononitrochlorobenzene or the dinitrochlorobenzene.

In the step (1), the nitrified waste acid contains 30-93% of sulfuric acid, preferably 35-93% of sulfuric acid; 0.5-6% of nitric acid, preferably 1.0-2.0% of nitric acid; 1000-15000 ppm dinitrochlorobenzene, preferably 5000-12000 ppm dinitrochlorobenzene; 2000 to 10000ppm of mononitrochlorobenzene, preferably 4000 to 8000ppm of mononitrochlorobenzene and 500 to 3000ppm of chlorobenzene, preferably 500 to 1000ppm of chlorobenzene, based on the total mass of the nitrated waste acid.

If the content of the sulfuric acid is higher, the viscosity of the nitrified waste acid is higher, and the flowability is poorer, so that the extraction effect is influenced; if the content of the nitric acid is higher, the nitric acid can react with the extractant, and the consumption of the extractant is higher; if the content of dinitrochlorobenzene, mononitrochlorobenzene and chlorobenzene is high, the oil-water separation is not thorough, the subsequent extraction effect is influenced, and the consumption of the extractant is increased.

Step (2): multistage extraction

In the step (2), chlorobenzene is used as an extracting agent, the nitrified waste acid enters an extraction device for multi-stage extraction, so that the extraction liquid and the extraction waste acid are obtained, and the extraction liquid is used as the extraction liquid in the step (1). The extraction device comprises a 2-5-stage extraction tower and a 2-5-stage oil-water separator, and preferably a 3-stage extraction tower and a 3-stage oil-water separator.

The extraction device has the following operation flow: the nitrified waste acid sequentially enters a 1 st-stage extraction tower, a 1 st-stage oil-water separator, a 2 nd-stage extraction tower, a 2 nd-stage oil-water separator, a 3 rd-stage extraction tower and a 3 rd-stage oil-water separator to obtain extracted waste acid; chlorobenzene serving as an extracting agent sequentially enters a 3 rd-level extraction tower, a 3 rd-level oil-water separator, a 2 nd-level extraction tower, a 2 nd-level oil-water separator, a 1 st-level extraction tower and a 1 st-level oil-water separator to obtain an extraction liquid; the mass ratio of the nitrified waste acid to chlorobenzene serving as an extracting agent is (4-12) to 1.

If the dosage of chlorobenzene used as an extracting agent is too small, the extraction effect is reduced, the content of organic matters in the extracted waste acid is higher, the dosage of chlorobenzene used as the extracting agent is too much, the improvement of the extraction effect is limited, the extraction liquid amount is increased, and the raw materials are lost. Therefore, the mass ratio of the nitrified waste acid to chlorobenzene as an extracting agent is preferably (6-10): 1.

In the step (2), the extraction waste acid contains 30-93% of sulfuric acid, preferably 35-93% of sulfuric acid; 0.5-6% of nitric acid, preferably 1-2% of nitric acid; 5 to 30ppm dinitrochlorobenzene, preferably 8 to 10ppm dinitrochlorobenzene; 1 to 10ppm of mononitrochlorobenzene, preferably 3 to 5ppm of mononitrochlorobenzene and 10 to 100ppm of chlorobenzene, preferably 12 to 20ppm of chlorobenzene, based on the total mass of the extraction waste acid. Wherein, too high content of nitrochlorobenzene and chlorobenzene can affect the quality of subsequent products, and too low content needs to consume a large amount of extractant.

Step (3): acylation reaction

And (3) preparing the extraction waste acid, sulfuric acid and nitric acid into acylation mixed acid B, and enabling the acylation mixed acid B and sulfur dioxide to enter an acylation reactor for acylation reaction to obtain nitrosyl sulfuric acid.

In the step (3), the mass ratio of the extraction waste acid, the sulfuric acid and the nitric acid in the acylated mixed acid B is (0.5-6): (0.3-5): 1, preferably (1.0-5): 0.4-4): 1, the mass ratio of the acylated mixed acid B to the sulfur dioxide is (2.5-8.0): 1, preferably (2.7-7.5): 1, and the acylation reaction temperature is 45-65 ℃; the nitrosyl sulfuric acid is colorless, light yellow or light green liquid, the mass concentration is 27-42%, and the residual value of nitric acid is lower than 0.2% by mass.

The content of nitric acid in the acylated mixed acid B is controlled in the acylation reaction, the content of nitric acid is directly related to the content of nitrosyl sulfuric acid, and the content of nitrosyl sulfuric acid is deviated due to over-high or over-low of nitric acid. In addition, if the sulfur dioxide input is too little, the nitric acid reaction is incomplete, the residual value of the nitric acid is too high, and if the input is excessive, the sulfur dioxide loss is caused, and the waste gas treatment cost is increased.

The acylation reactor in the step (3) is one of a kettle reactor, a tower reactor, a tubular reactor, a hypergravity reactor and a microchannel reactor.

The present invention is further illustrated by the following specific examples. The apparatus used in the present invention is a conventional apparatus unless otherwise specified, and each of the substances used is a commercially available product.

Example 1

(1) Preparing a nitrified mixed acid A from 98 mass% of sulfuric acid and 98 mass% of nitric acid according to the mass ratio of 1.8:1, then enabling the nitrified mixed acid A, an extraction liquid and chlorobenzene to enter a tubular reactor according to the mass ratio of 4.33:0.55:1, enabling the reaction temperature to be 75-85 ℃, continuously extracting a reaction liquid, and enabling the reaction liquid to enter an oil-water separator for continuous separation to obtain nitrochlorobenzene and nitrified waste acid. And (3) sampling, detecting and analyzing, wherein the nitrified waste acid contains 81.5% of sulfuric acid, 3.6% of nitric acid, 8000ppm of dinitrochlorobenzene, 4000ppm of mononitrochlorobenzene and 800ppm of chlorobenzene, based on the total mass of the nitrified waste acid.

(2) The nitrified waste acid and chlorobenzene serving as an extracting agent enter an extraction device according to the mass ratio of 6:1, and the extraction device consists of a 3-level extraction tower and a 3-level oil-water separator. The operation flow of the extraction device is as follows: the nitrified waste acid sequentially enters a 1 st-stage extraction tower, a 1 st-stage oil-water separator, a 2 nd-stage extraction tower, a 2 nd-stage oil-water separator, a 3 rd-stage extraction tower and a 3 rd-stage oil-water separator to obtain extracted waste acid; chlorobenzene serving as an extracting agent sequentially enters a 3 rd-level extraction tower, a 3 rd-level oil-water separator, a 2 nd-level extraction tower, a 2 nd-level oil-water separator, a 1 st-level extraction tower and a 1 st-level oil-water separator to obtain an extraction liquid. The extraction waste acid contains 82.4% sulfuric acid, 2.0% nitric acid, 10ppm dinitrochlorobenzene, 4ppm mononitrochlorobenzene and 15ppm chlorobenzene based on the total mass of the extraction waste acid.

(3) Preparing the extraction waste acid, 98 mass percent sulfuric acid and 98 mass percent nitric acid into acylation mixed acid B according to the mass ratio of 4.4:0.68:1, enabling the acylation mixed acid B and sulfur dioxide to enter a tubular reactor according to the mass ratio of 6:1, enabling the acylation reaction temperature to be 55-60 ℃, and continuously extracting nitrosyl sulfuric acid.

(4) Diazotizing the prepared nitrosyl sulfuric acid and 2, 6-dichloro-4-nitroaniline at 0-5 ℃ to generate diazo liquid, dropwise adding the diazo liquid into the dispersed yellow-brown 30 esterification pulping liquid, carrying out coupling reaction at 0-10 ℃, heating, carrying out crystal transformation and filtering to obtain a dispersed orange 30 filter cake.

And through sampling, detecting and analyzing, the obtained nitrosyl sulfuric acid is light green, the mass concentration is 28.12%, and the residual nitric acid value is 0.11% by mass. Further detecting and analyzing organic matters in the nitrosyl sulfuric acid, wherein the nitrosyl sulfuric acid contains 21 mass ppm of dinitrochlorobenzene, the mononitrochlorobenzene is not detected, and the chlorobenzene is not detected because the mononitrochlorobenzene and the chlorobenzene are completely converted into the dinitrochlorobenzene by reacting with nitric acid. The content of nitrochlorobenzene in the synthesized dispersed orange 30 filter cake is less than 1ppm, and the filter cake environmental protection index is met.

Example 2

Compared with the embodiment 1, the difference is that in the step (3), the extraction waste acid, 98 mass% sulfuric acid and 98 mass% nitric acid are prepared into acylation mixed acid B according to the mass ratio of 2.57:0.4:1, the acylation mixed acid B and sulfur dioxide enter a tubular reactor according to the mass ratio of 4:1, the acylation reaction temperature is 55-60 ℃, and nitrosyl sulfuric acid is continuously extracted. The resulting nitrosylsulfuric acid was also used to prepare a dispersed orange 30 filter cake.

And through sampling, detecting and analyzing, the obtained nitrosyl sulfuric acid is light green, the mass concentration is 40.15%, and the residual nitric acid value is 0.09% by mass. Further detecting and analyzing organic matters in the nitrosyl sulfuric acid, wherein the nitrosyl sulfuric acid contains 27 mass ppm of dinitrochlorobenzene, the mononitrochlorobenzene is not detected, and the chlorobenzene is not detected because the mononitrochlorobenzene and the chlorobenzene are completely converted into the dinitrochlorobenzene by reacting with nitric acid. The content of nitrochlorobenzene in the synthesized dispersed orange 30 filter cake is less than 1ppm, and the filter cake environmental protection index is met.

Example 3

(1) Preparing 45 mass percent sulfuric acid and 98 mass percent nitric acid into nitrified mixed acid A according to the mass ratio of 3.5:1, then enabling the nitrified mixed acid A, the extraction liquid and chlorobenzene to enter a tubular reactor according to the mass ratio of 2.36:0.39:1, enabling the reaction temperature to be 35-45 ℃, continuously extracting reaction liquid, and enabling the reaction liquid to enter an oil-water separator for continuous separation to obtain nitrochlorobenzene and nitrified waste acid. And (3) sampling, detecting and analyzing, wherein the nitrified waste acid contains 40% of sulfuric acid, 2% of nitric acid, 9200ppm of dinitrochlorobenzene, 2070ppm of mononitrochlorobenzene and 850ppm of chlorobenzene, based on the total mass of the nitrified waste acid.

(2) The nitrified waste acid and chlorobenzene serving as an extracting agent enter an extraction device according to the mass ratio of 6:1, and the extraction device consists of a 3-level extraction tower and a 3-level oil-water separator. The operation flow of the extraction device is as follows: the nitrified waste acid sequentially enters a 1 st-stage extraction tower, a 1 st-stage oil-water separator, a 2 nd-stage extraction tower, a 2 nd-stage oil-water separator, a 3 rd-stage extraction tower and a 3 rd-stage oil-water separator to obtain extracted waste acid; chlorobenzene serving as an extracting agent sequentially enters a 3 rd-level extraction tower, a 3 rd-level oil-water separator, a 2 nd-level extraction tower, a 2 nd-level oil-water separator, a 1 st-level extraction tower and a 1 st-level oil-water separator to obtain an extraction liquid. And (3) sampling, detecting and analyzing, wherein the extracted waste acid contains 83% of sulfuric acid, 3% of nitric acid, 6ppm of dinitrochlorobenzene, 3ppm of mononitrochlorobenzene and 22ppm of chlorobenzene, based on the total mass of the extracted waste acid.

(3) Preparing the extraction waste acid, 45 mass percent sulfuric acid and 98 mass percent nitric acid into acylation mixed acid B according to the mass ratio of 1.2:4.0:1, enabling the acylation mixed acid B and sulfur dioxide to enter a tubular reactor according to the mass ratio of 6:1, enabling the acylation reaction temperature to be 55-60 ℃, and continuously extracting nitrosyl sulfuric acid.

(4) Diazotizing the prepared nitrosyl sulfuric acid and 2, 6-dichloro-4-nitroaniline at 0-5 ℃ to generate diazo liquid, dropwise adding the diazo liquid into the dispersed yellow-brown 30 esterification pulping liquid, carrying out coupling reaction at 0-10 ℃, heating, carrying out crystal transformation and filtering to obtain a dispersed orange 30 filter cake.

The nitrosyl sulfuric acid obtained by sampling, detecting and analyzing is light yellow, the mass concentration is 28.06 percent, and the residual nitric acid value is 0.09 percent. Further detecting and analyzing organic matters in the nitrosyl sulfuric acid, wherein the nitrosyl sulfuric acid contains 24 mass ppm of dinitrochlorobenzene, the mononitrochlorobenzene is not detected, and the chlorobenzene is not detected because the mononitrochlorobenzene and the chlorobenzene are completely converted into the dinitrochlorobenzene by reacting with nitric acid. The content of nitrochlorobenzene in the synthesized dispersed orange 30 filter cake is less than 1ppm, and the filter cake environmental protection index is met.

Example 4

Compared with the embodiment 1, the difference is that in the step (3), the extraction waste acid, 98 mass% sulfuric acid and 98 mass% nitric acid are prepared into acylation mixed acid B according to the mass ratio of 0.68:2.35:1, the acylation mixed acid B and sulfur dioxide enter a tubular reactor according to the mass ratio of 4:1, the acylation reaction temperature is 55-60 ℃, and nitrosyl sulfuric acid is continuously extracted. The resulting nitrosylsulfuric acid was also used to prepare a dispersed orange 30 filter cake.

The nitrosyl sulfuric acid obtained by sampling, detecting and analyzing is light yellow, the mass concentration is 40.04%, and the residual nitric acid value is 0.13% by mass. Further detecting and analyzing organic matters in the nitrosyl sulfuric acid, wherein the nitrosyl sulfuric acid contains 24 mass ppm of dinitrochlorobenzene, the mononitrochlorobenzene is not detected, and the chlorobenzene is not detected because the mononitrochlorobenzene and the chlorobenzene are completely converted into the dinitrochlorobenzene by reacting with nitric acid. The content of nitrochlorobenzene in the synthesized dispersed orange 30 filter cake is less than 1ppm, and the filter cake environmental protection index is met.

Examples 1-4 show that the nitrified waste acid obtained by the method can be used for synthesizing nitrosyl sulfuric acid, the residual quantity of dinitrochlorobenzene in the product is not high, and the synthesized filter cake can meet the requirement of environmental protection indexes.

Comparative example

The steps (1) and (2) of example 1 were carried out, differing from example 1 in that in the above step (2), the extraction apparatus consisted of a stage 1 extraction column and a stage 1 oil-water separator. And (3) sampling, detecting and analyzing, wherein the waste extraction acid contains 83% of sulfuric acid, 3% of nitric acid, 155ppm of dinitrochlorobenzene, 27ppm of mononitrochlorobenzene and 213ppm of chlorobenzene, based on the total mass of the waste extraction acid.

Nitrosyl sulfuric acid and dispersed orange 30 cake were further synthesized according to the methods of steps (3), (4) of example 1. And through sampling, detecting and analyzing, the obtained nitrosyl sulfuric acid is light green, the mass concentration is 28.17%, and the residual nitric acid value is 0.10% by mass. Further detecting and analyzing organic matters in the nitrosyl sulfuric acid, wherein the nitrosyl sulfuric acid contains 371 mass ppm of dinitrochlorobenzene, and mononitrochlorobenzene is not detected, because the mononitrochlorobenzene and chlorobenzene are completely converted into the dinitrochlorobenzene by reacting with nitric acid. But the content of nitrochlorobenzene in the synthesized dispersed orange 30 filter cake is 32ppm, which cannot reach less than 1ppm of the environmental protection requirement.

The comparative example shows that if the stage numbers of the extraction tower and the oil-water separator are out of the range of the application, the residual amount of organic matters in the extracted waste acid is large, and the environmental protection index of the subsequent filter cake is influenced.

Industrial applicability

The method can effectively utilize chlorobenzene and nitrified waste acid to produce nitrosyl sulfuric acid, and the obtained nitrosyl sulfuric acid can be effectively used as a diazotization reaction raw material for preparing disperse dyes.