阅读说明：本技术 全铵盐体系生产吐氏酸并副产硫酸铵或氯化铵的方法 (Method for producing tobias acid and by-producing ammonium sulfate or ammonium chloride by using full ammonium salt system ) 是由 王宝丰 李志堂 邓志光 于 2021-09-02 设计创作，主要内容包括：本发明公开了一种全铵盐体系生产吐氏酸并副产硫酸铵或氯化铵的方法。它是在吐氏酸生产全流程不使用含钠的碱,而用氨,并保持全铵盐体系。吐氏酸母液经萃取、氧化、蒸发、结晶,副产得到纯硫酸铵或氯化铵。在获取主产品吐氏酸的同时可联产硫酸铵和氯化铵两种副产品,实现了吐氏酸生产工艺废水中无机盐的资源化利用；采用蒸发浓缩制铵盐,全部吐氏酸母液废水都经蒸发处理,蒸出的冷凝水全部回用到吐氏酸生产的所有用水环节。如：吸收氯化氢,吸收二氧化硫,吸收氨,中和以及吐氏酸过滤后的洗涤等,形成了工艺水的闭路循环,是一种最接近实现吐氏酸生产无废水排放的改良新工艺。(The invention discloses a method for producing tobias acid and by-producing ammonium sulfate or ammonium chloride by using a full ammonium salt system. It uses ammonia instead of sodium-containing alkali in the whole process of Tu's acid production, and keeps a whole ammonium salt system. Extracting, oxidizing, evaporating and crystallizing the tobias acid mother liquor to obtain pure ammonium sulfate or ammonium chloride as a byproduct. The method can co-produce two byproducts of ammonium sulfate and ammonium chloride while obtaining the main product tobias acid, thereby realizing the resource utilization of inorganic salt in wastewater of the tobias acid production process; the ammonium salt is prepared by evaporation and concentration, all tobias acid mother liquor wastewater is evaporated, and the evaporated condensate water is all recycled to all water consumption links of tobias acid production. Such as: the closed cycle of the process water is formed by absorbing hydrogen chloride, sulfur dioxide, ammonia, neutralization, washing after the tobias acid is filtered, and the like, and the process is an improved new process which is closest to realizing no wastewater discharge in the tobias acid production.)

1. A method for producing tobias acid and by-producing ammonium sulfate or ammonium chloride by using a full ammonium salt system is characterized by comprising the following steps of: the whole process of the tobias acid production does not use sodium-containing alkali, a full ammonium salt system is kept, inorganic salt in the wastewater of the tobias acid mother liquor is only ammonium salt, and the mother liquor is subjected to extraction, oxidation, evaporation and crystallization to obtain pure ammonium sulfate or ammonium chloride as a byproduct; the sodium-containing alkali refers to sodium hydroxide and sodium carbonate; the full ammonium salt system refers to that all salts related to the three process stages of neutralization, ammoniation and acid precipitation in the production flow of the tobias acid are ammonium salts; including ammonium hydroxy tobramate, ammonium bisulfite, ammonium sulfite, ammonium tobramate, ammonium sulfate, or ammonium chloride.

2. The method for producing tobias acid and coproducing ammonium sulfate or ammonium chloride by using the whole ammonium salt system as claimed in claim 1, wherein when sulfuric acid is used in the acidification process, the inorganic salt in the tobias acid mother liquor wastewater is ammonium sulfate; the mother liquor is extracted, oxidized, evaporated and crystallized to obtain ammonium sulfate as a byproduct.

3. The method for producing tobias acid and coproducing ammonium sulfate or ammonium chloride by using the whole ammonium salt system as claimed in claim 1, wherein when hydrochloric acid is used in the acidification process, the inorganic salt in the wastewater of the tobias acid mother liquor is ammonium chloride; the mother liquor is extracted, oxidized, evaporated and crystallized, and ammonium chloride is obtained as a byproduct.

4. The application of the method for producing tobias acid and by-producing ammonium sulfate and ammonium chloride by using the full ammonium salt system as defined in claim 1 in the aspect of recycling inorganic salts in tobias acid mother liquor; the inorganic salt recycling means that the problems of high sodium salt and high ammonia nitrogen of the tobias acid are effectively avoided.

Technical Field

The invention belongs to the technical field of chemical intermediate production, and relates to a technical method for recycling waste pollutants in tobias acid production. More particularly to a method for producing ammonium sulfate or ammonium chloride as a byproduct from wastewater of tobias acid production.

Background

The chemical name of tobias acid is: 2-amino-1-naphthalenesulfonic acid. At present, the production method of tobias acid generally comprises the steps of sulfonating 2-naphthol by chlorosulfonic acid to obtain 2-naphthol-1-sulfonic acid (hydroxyl tobias acid); then neutralizing by alkali (sodium hydroxide or sodium carbonate) to obtain 2-naphthol-1-sodium sulfonate (hydroxyl sodium tobramate), then introducing ammonia in the presence of acidic ammonium sulfite, and carrying out ammoniation reaction in a high-pressure kettle to convert into 2-amino-1-sodium naphthalenesulfonate (sodium tobramate); acidifying with sulfuric acid or hydrochloric acid, separating out crystal, and filtering to obtain tobias acid. A large amount of waste water can be discharged in the tobias acid filtration process, CODcr is up to 45000-50000mg/L, the waste water is dark in color and large in salt content, sodium salt and ammonium salt coexist, ammonia nitrogen content is 20000-30000 mg/L, and serious pollution is caused to the environment after the waste water is discharged. At present, the CODcr can be reduced to below 2000mg/L by adopting an extraction method to treat the wastewater, but the problem of coexistence of sodium salt and ammonium salt in raffinate still needs to be solved. US patent US4510100A uses a method of treating ammoniated completion liquor: the method comprises neutralizing hydroxy tobias acid with ammonia to obtain hydroxy tobias acid ammonium, and aminating to obtain tobias acid ammonium. Then, the ammonia of the ammonium salt in the ammoniated solution is replaced by 20 percent of sodium hydroxide for recycling. Meanwhile, ammonium tobias acid in ammoniated liquid is converted into sodium tobias acid, ammonium sulfite is converted into sodium sulfite, and then acid is removed to separate tobias acid; the current domestic process is a method for treating acid precipitation mother liquor: after organic matters are removed from the acid-out mother liquor by extraction, ammonia nitrogen in raffinate is removed by sodium hydroxide replacement and stripping, and the removed ammonia is absorbed by sulfuric acid to prepare ammonium sulfate. Although the ammonia nitrogen content of the tobias acid mother liquor is reduced by the two treatment methods, the two treatment methods have the following defects: adds a complex deamination process, increases the consumption of sodium hydroxide, and leads a large amount of inorganic sodium salt with low recycling value to be generated in the mother liquor, which is difficult to treat and discharge after reaching the standard.

Disclosure of Invention

The invention aims to solve the problems of coexistence of sodium salt and ammonium salt, high sodium salt content and high ammonia nitrogen content in the tobias acid mother liquor, and seeks a method for further recycling inorganic salt in the tobias acid mother liquor.

The technical scheme adopted by the invention is as follows:

a method for producing tobias acid and by-producing ammonium sulfate or ammonium chloride by using a full ammonium salt system is characterized by comprising the following steps of: the whole process of the tobias acid production does not use sodium-containing alkali, a full ammonium salt system is maintained, inorganic salt in the wastewater of the tobias acid mother liquor is only ammonium salt, and the mother liquor is subjected to extraction, oxidation, evaporation and crystallization to obtain pure ammonium sulfate or ammonium chloride as a byproduct.

The full ammonium salt system refers to that all salts related to the three process stages of neutralization, ammoniation and acidification in the tobias acid production process are ammonium salts, and comprises hydroxyl tobias acid ammonium, ammonium bisulfite, ammonium sulfite, tobias acid ammonium, ammonium sulfate or ammonium chloride.

Wherein when sulfuric acid is used in the acidification process, the inorganic salt in the tobias acid mother liquor wastewater is ammonium sulfate; the mother liquor is extracted, oxidized, evaporated and crystallized to obtain ammonium sulfate as a byproduct.

Wherein when hydrochloric acid is used in the acidification process, the inorganic salt in the waste water of the tobias acid mother liquor is ammonium chloride; the mother liquor is extracted, oxidized, evaporated and crystallized, and ammonium chloride is obtained as a byproduct.

The invention further discloses application of the method for producing tobias acid and by-producing ammonium sulfate or ammonium chloride by using the full ammonium salt system in the aspect of recycling inorganic salt in tobias acid mother liquor; the resource utilization of the inorganic salt refers to the acquisition of ammonium salt with higher economic value than sodium salt. The experimental results show that: the method can co-produce two byproducts of ammonium sulfate and ammonium chloride while obtaining the main product tobias acid; all the tobias acid mother liquor wastewater is evaporated, and condensed water can be recycled to all water consumption links of tobias acid production, so that closed cycle of process water is formed, and a new process is provided for finally realizing wastewater-free discharge of the tobias acid production process.

The invention is described in more detail below:

the tobias acid is produced by adopting a full ammonium salt system, namely, sodium-containing alkali is not used in the full flow of the tobias acid production. Firstly, when 2-naphthol sulfonation product hydroxyl tobias acid is neutralized, ammonia water is used for replacing sodium hydroxide and sodium carbonate which are commonly used in the traditional domestic process, and hydroxyl tobias acid ammonium salt is obtained instead of sodium salt. Secondly, the method of recovering ammonia by replacing it with sodium hydroxide, which is proposed in US4510100A, is not used after completion of ammoniation, and the ammoniated solution still maintains the state of an ammonium salt system consisting of ammonium sulfite, ammonium tobias acid and a small amount of unconverted ammonium salt of hydroxyl tobias acid. After ammonia discharge and pressure reduction of ammoniated liquid, sulfuric acid or hydrochloric acid is used for acidification to obtain tobias acid. Thus, all the salts involved in the neutralization, ammoniation and acidification process stages of the tobias acid production flow are ammonium salts. Including ammonium hydroxy tobramate, ammonium bisulfite, ammonium sulfite, ammonium tobramate, ammonium sulfate or ammonium chloride; the whole process flow keeps a full ammonium salt system, and finally, only ammonium salt is the inorganic salt in the product tobias acid mother liquor wastewater. Extracting, oxidizing, evaporating and crystallizing the tobias acid mother liquor to obtain pure ammonium sulfate or ammonium chloride as a byproduct.

When sulfuric acid is used in the acidification process, the inorganic salt in the tobias acid mother liquor wastewater is ammonium sulfate; extracting, oxidizing, evaporating and crystallizing the mother liquor to obtain ammonium sulfate as a byproduct;

when hydrochloric acid is used in the acidification process, the inorganic salt in the waste water of the tobias acid mother liquor is ammonium chloride; the mother liquor is extracted, oxidized, evaporated and crystallized, and ammonium chloride is obtained as a byproduct.

Compared with the prior art, the method for producing tobias acid and by-producing ammonium sulfate or ammonium chloride by using the full ammonium salt system has the positive effects that:

(1) the whole process of the tobias acid production does not use sodium-containing alkali, and one material is less than that used in the prior art;

(2) the method can co-produce two byproducts of ammonium sulfate and ammonium chloride while obtaining the main product tobias acid;

(3) the existing sodium hydroxide replacement deamination process is avoided, and the equipment investment, operation maintenance, material consumption and energy consumption are reduced;

(4) when the ammonium salt is prepared, all the tobias acid mother liquor wastewater is finally evaporated. The condensed water can be reused in all water consumption links of tobias acid production. Such as: hydrogen chloride absorption, sulfur dioxide absorption, ammonia absorption, neutralization, and washing after tobias acid filtration. The closed cycle of the process water is formed, and the foundation is laid for finally realizing no wastewater discharge of the tobias acid production process.

Detailed Description

The invention is described below by means of specific embodiments. Unless otherwise specified, the technical means used in the present invention are well known to those skilled in the art. In addition, the embodiments should be considered illustrative, and not restrictive, of the scope of the invention, which is defined solely by the claims. It will be apparent to those skilled in the art that various changes or modifications in the components and amounts of the materials used in these embodiments can be made without departing from the spirit and scope of the invention.

Example 1

750kg of 2-naphthol were dispersed in 2.5 m³In o-nitroethylbenzene, sulfonation is carried out at low temperature by using 650 kg of chlorosulfonic acid, and sulfonated substances are neutralized to pH7.5 by using 5% recovered ammonia water. Separating reaction solvent o-nitroethylbenzene, evaporating and concentrating to obtain hydroxyl ammonium tobramate solution; then adding acidic ammonium sulfite and introducing ammonia for preparation, and transferring the mixture into a high-pressure kettle for ammoniation to obtain ammonium tobramate; ammoniated liquid is discharged with ammonia and is depressurized, tobias acid crystals are precipitated by acidification of 50% sulfuric acid, 1033kg of tobias acid is obtained by filtration and drying, and meanwhile, about 6.5 cubic meters of tobias acid mother liquor is generated. Mother liquor CODcr 46000mg/L, ammonia nitrogen content 42000mg/L and pH 1.61. The mother liquor is extracted by three stages, CODcr is reduced to 620mg/L, pH3.2. Adding 30% hydrogen peroxide in an amount of 5kg per cubic meter of raffinate, oxidizing at 50-55 deg.C until the solution fades from dark brown to light yellow, and adding ammonia waterNeutralizing to pH6.5, adding active carbon, filtering and decolorizing to obtain almost colorless ammonium sulfate solution. The solution is evaporated, crystallized and dried to finally obtain 1.26 tons of ammonium sulfate with white appearance, and the nitrogen content of the ammonium sulfate is 19.6 percent.

Example 2

The procedure of example 1 was otherwise the same, and 1035kg of tobias acid was obtained by filtration and drying while producing about 6.1 cubic meters of tobias acid mother liquor. Mother liquor CODcr 43000mg/L, ammonia nitrogen content 46000mg/L, pH1.58. The mother liquor is extracted by three stages, CODcr is reduced to 570mg/L, pH3.3. Adding 30% hydrogen peroxide in an amount of 5kg per cubic meter of raffinate, oxidizing at 50-55 deg.C until the solution fades from dark brown to light yellow, neutralizing with ammonia water to pH6.5, adding activated carbon, filtering and decolorizing to obtain nearly colorless ammonium chloride solution. The solution is evaporated, crystallized and dried to finally obtain 0.99 ton of ammonium chloride with white appearance, and the nitrogen content of the ammonium chloride is 24.7 percent.

It will be apparent to those skilled in the art that various changes and modifications can be made in the above embodiments without departing from the scope and spirit of the invention, and it is intended that all simple changes, equivalents and modifications made to the above embodiments in accordance with the technical spirit of the invention shall fall within the scope of the invention. And the invention is not limited to the embodiments of the examples given in the description.