阅读说明：本技术 一种生产安赛蜜的废酸处理方法及系统 (Waste acid treatment method and system for producing acesulfame potassium ) 是由 刘芳 庆九 俞新南 朱小刚 于 2021-07-13 设计创作，主要内容包括：本发明提供了一种生产安赛蜜的废酸处理方法及系统,通过对安赛蜜生产过程中产生的废酸先进行预处理,脱除其中的二氯甲烷,预处理后的废酸进行高温裂解,制备SO-(3),用于安赛蜜生产工艺中环合反应的原料；副产硫酸进行它用如销售或生产使用。解决了废酸的处理,使得SO-(3)得到回用。本发明工艺简单,能耗低,降低成本,资源得到综合利用,符合国家的产业政策。(The invention provides a waste acid treatment method and a waste acid treatment system for acesulfame potassium production 3 The raw materials are used for cyclization reaction in the acesulfame potassium production process; the by-product sulfuric acid is used for sale or production. Solves the problem of treatment of waste acid to ensure SO 3 And recycling the waste water. The invention has simple process, low energy consumption, reduced cost, comprehensive utilization of resources and accordance with national industrial policies.)

1. A waste acid treatment method for producing acesulfame potassium comprises the following steps: (1) removing light from waste acid to be recovered to obtain condensed dichloromethane and pretreated waste acid; (2) mixing the pretreated waste acid obtained in the step (1) with liquid sulfur and air for reaction, and cracking the waste acid to obtain cracked gas; (3) converting the pyrolysis gas obtained in the step (2) to obtain SO₃A gas; (4) absorbing SO obtained in step (3)₃Gas to obtain fuming sulfuric acid; (5) distilling the fuming sulfuric acid obtained in the step (4) to obtain SO₃And concentrated sulfuric acid.

2. The method according to claim 1, characterized in that the spent acid to be recovered comes from the spent acid after extraction.

3. The method according to claim 2, wherein the extracted waste acid is obtained by extracting an acid layer obtained after acylation, cyclization and hydrolysis with dichloromethane, and raffinate is the waste acid.

4. The method according to claim 1, wherein the light removal means that dichloromethane in waste acid is removed according to the boiling point of dichloromethane.

5. The method of claim 1, further comprising any one or more of the following features: (1) the waste acid cracking means that sulfuric acid and triethylamine sulfate in the waste acid undergo a cracking reaction at a high temperature to generate SO₂A gas; (2) the conversion refers to SO in the cracking gas under the action of a catalyst₂And O₂Reaction takes place to form SO₃。

6. The method of claim 1, wherein the SO is absorbed in step (4) with concentrated sulfuric acid₃A gas.

7. A spent acid treatment system for producing acesulfame k, comprising:

the lightness removing device is used for removing lightness of waste acid to be recovered to obtain condensed dichloromethane and pretreated waste acid;

the cracking device is used for mixing the pretreated waste acid with liquid sulfur and air, and cracking the waste acid under a high-temperature condition to obtain cracked gas;

the conversion device is used for converting the pyrolysis gas to obtain SO₃A gas;

an absorption device for absorbing the SO₃Gas to obtain fuming sulfuric acid;

a distillation device for distilling the oleum to obtain SO₃And concentrated sulfuric acid;

the light ends removal unit is in fluid communication with a cracking unit, the cracking unit is in fluid communication with the conversion unit, the conversion unit is in fluid communication with the absorption unit, and the absorption unit is in fluid communication with the distillation unit.

8. The system of claim 7, wherein the spent acid to be recovered in the light off unit is from the spent acid after extraction.

9. The system of claim 7, further comprising an SO₃Recovery unit, said SO₃A recovery unit is in fluid communication with the distillation unit.

10. The system of claim 7, further comprising a concentrated sulfuric acid recovery unit in fluid communication with the distillation unit.

Technical Field

The invention relates to the field of chemical industry, in particular to a waste acid treatment method and a waste acid treatment system for acesulfame potassium production.

Background

Acesulfame is the common name of AK sugar (Acesulfame-K), and has the Chinese cultural name of 6-methyl-1,2, 3-oxathiazine-4 (3H) -ketone-2, 2-potassium dioxide and English chemical nameIs 6-Methyl-1,2,3-oxathiazin-4(3H) -one 2,2-dioxide lotus salt. Appearance properties: colorless crystals. Solubility: is easily dissolved in water, and the solubility is 270g/L at 20 ℃. CAS number: 55589-62-3. The molecular formula is as follows: c₄H₄O₄KNS. Molecular weight: 201.24. melting Point (. degree. C.): 229-232. Relative density (water ═ 1): 1.81. pH value: the pH value is 5.5-7.5. Acesulfame potassium has the advantages of safety, no toxicity, stable property, sweet taste, no bad aftertaste, proper price and the like, is one of the sweeteners with the best stability in the world at present, and is used as a sweetener in the aspects of food, medicine and the like.

A large amount of waste acid is generated in the production process of acesulfame potassium, and the waste acid mainly contains sulfuric acid, triethylamine, dichloromethane, a small amount of acesulfame potassium and organic matters. The general process is as follows: the generated waste acid reacts with calcium carbonate, and CaSO can be generated in the process of recycling triethylamine₄﹒2H₂O, washing with water and calcining at high temperature to obtain anhydrous CaSO₄. The process has high energy consumption and is easy to cause environmental pollution.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention aims to provide a waste acid treatment method and system for producing acesulfame potassium, which solves the problems of the prior art.

In order to achieve the above objects and other related objects, the present invention adopts the following technical solutions:

the invention provides a waste acid treatment method for producing acesulfame potassium, which comprises the following steps:

(1) removing light from waste acid to be recovered to obtain condensed dichloromethane and pretreated waste acid;

(2) mixing the pretreated waste acid obtained in the step (1) with liquid sulfur and air for reaction, and cracking the waste acid at high temperature to obtain cracked gas;

(3) converting the pyrolysis gas obtained in the step (2) to obtain SO₃A gas;

(4) absorbing SO obtained in step (3)₃Gas to obtain fuming sulfuric acid;

(5) for the hair obtained in the step (4)Distilling the fume sulfuric acid to obtain SO₃And concentrated sulfuric acid.

Preferably, in the step (1), the waste acid to be recovered is waste acid after extraction. The extracted waste acid refers to an acid layer obtained after acylation, cyclization and hydrolysis reactions is extracted by adopting dichloromethane, and raffinate is the waste acid. The waste acid after extraction contains sulfuric acid, triethylamine sulfate, ACH, water, acetic acid, acetone, dichloromethane and other components.

In the invention, the light component removal refers to removing dichloromethane in waste acid according to the boiling point of dichloromethane.

The cracking of the waste acid refers to that sulfuric acid and triethylamine sulfate in the waste acid undergo a cracking reaction at a high temperature to generate SO₂A gas.

The cracking gas mainly contains SO₂、O₂、SO₃And (3) components.

Preferably, in step (4), concentrated sulfuric acid is used for absorbing SO₃A gas.

Conversion refers to the SO in the cracked gas under the action of a catalyst₂And O₂Reaction takes place to form SO₃。

In a second aspect of the present invention, there is provided a waste acid treatment system for producing acesulfame potassium, comprising:

the lightness removing device is used for removing lightness of waste acid to be recovered to obtain condensed dichloromethane and pretreated waste acid;

the cracking device is used for mixing and reacting the pretreated waste acid with liquid sulfur and air, and cracking the waste acid under a high-temperature condition to obtain cracked gas;

the conversion device is used for converting the pyrolysis gas to obtain SO₃A gas;

an absorption device for absorbing the SO₃Gas to obtain fuming sulfuric acid;

a distillation device for distilling the oleum to obtain SO₃And concentrated sulfuric acid;

the light ends removal unit is in fluid communication with a cracking unit, the cracking unit is in fluid communication with the conversion unit, the conversion unit is in fluid communication with the absorption unit, and the absorption unit is in fluid communication with the distillation unit.

Preferably, the waste acid to be recovered in the light-off device is from the extracted waste acid. The extracted waste acid refers to an acid layer obtained after acylation, cyclization and hydrolysis reactions is extracted by adopting dichloromethane, and raffinate is the waste acid. The waste acid after extraction contains sulfuric acid, triethylamine sulfate, ACH, water, acetic acid, acetone, dichloromethane and other components.

Preferably, the system further comprises an SO₃Recovery unit, said SO₃A recovery unit is in fluid communication with the distillation unit.

Preferably, the system further comprises a concentrated sulfuric acid recovery unit in fluid communication with the distillation unit.

In the invention, the light component removal refers to removing dichloromethane in waste acid according to the boiling point of dichloromethane.

The cracking of the waste acid refers to that the sulfuric acid and triethylamine sulfate in the waste acid undergo a cracking reaction at a high temperature to generate SO₂A gas.

The cracking gas mainly contains SO₂、O₂、SO₃And (3) components.

Preferably, concentrated sulfuric acid is provided in the absorption device for absorbing SO₃A gas.

Conversion refers to the SO in the cracked gas under the action of a catalyst₂And O₂Reaction takes place to form SO₃。

The waste acid treatment method and the waste acid treatment system for producing acesulfame potassium have the following beneficial effects:

the invention mainly aims at the problems that the waste acid treatment process in the current acesulfame potassium synthesis process is high in energy consumption, easy to cause environmental pollution and the like, and provides a waste acid treatment method and a waste acid treatment system. Waste acid generated in the production process of acesulfame potassium is pretreated to remove dichloromethane, and the pretreated waste acid is subjected to pyrolysis to prepare SO₃The raw materials are used for cyclization reaction in the acesulfame potassium production process; by-product sulfuric acid for its use, e.g. for sale or productionThe preparation is used. Solves the problem of treatment of waste acid to ensure SO₃And recycling the waste water. The process is simple, the energy consumption is low, the cost is reduced, the resources are comprehensively utilized, and the industrial policy of the state is met.

Drawings

FIG. 1: the invention provides a schematic diagram of a waste acid treatment system for producing acesulfame potassium.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be understood that the processing equipment or apparatus not specifically identified in the following examples is conventional in the art. Furthermore, it is to be understood that one or more method steps mentioned in the present invention does not exclude that other method steps may also be present before or after the combined steps or that other method steps may also be inserted between these explicitly mentioned steps, unless otherwise indicated; it is also to be understood that a combined connection between one or more devices/apparatus as referred to in the present application does not exclude that further devices/apparatus may be present before or after the combined device/apparatus or that further devices/apparatus may be interposed between two devices/apparatus explicitly referred to, unless otherwise indicated. Moreover, unless otherwise indicated, the numbering of the various method steps is merely a convenient tool for identifying the various method steps, and is not intended to limit the order in which the method steps are arranged or the scope of the invention in which the invention may be practiced, and changes or modifications in the relative relationship may be made without substantially changing the technical content.

A waste acid treatment system for acesulfame k production, as shown in fig. 1, comprising:

the lightness-removing device 1 is used for removing lightness of waste acid to be recovered to obtain condensed dichloromethane and pretreated waste acid;

the cracking device 2 is used for mixing and reacting the pretreated waste acid with liquid sulfur and air, and cracking the waste acid under a high-temperature condition to obtain cracked gas;

a conversion device 3 for converting the cracking gas to obtain SO₃A gas;

an absorption device 4 for absorbing the SO₃Gas to obtain fuming sulfuric acid;

a distillation device 5 for distilling the oleum to obtain SO₃And concentrated sulfuric acid;

the light component removal device 1 is in fluid communication with a cracking device 2, the cracking device 2 is in fluid communication with the conversion device 3, the conversion device 3 is in fluid communication with the absorption device 4, and the absorption device 4 is in fluid communication with the distillation device 5.

In a preferred embodiment, the waste acid to be recovered in the lightness-removing device 1 is derived from waste acid after extraction. The extracted waste acid refers to an acid layer obtained after acylation, cyclization and hydrolysis reactions is extracted by adopting dichloromethane, and raffinate is the waste acid. The waste acid after extraction contains sulfuric acid, triethylamine sulfate, ACH, water, acetic acid, acetone, dichloromethane and other components.

In a preferred embodiment, the system further comprises an SO₃Recovery unit, said SO₃The recovery means is in fluid communication with said distillation means 5.

In a preferred embodiment, the system further comprises a concentrated sulfuric acid recovery unit in fluid communication with the distillation unit 5.

The light component removal refers to removing the dichloromethane in the waste acid according to the boiling point of the dichloromethane.

The cracking of the waste acid refers to that the sulfuric acid and triethylamine sulfate in the waste acid undergo a cracking reaction at a high temperature to generate SO₂A gas.

The cracking gas mainly contains SO₂、O₂、SO₃And (3) components.

The conversion refers to SO in the cracking gas under the action of a catalyst₂And O₂Reaction takes place to form SO₃。

Concentrated sulfuric acid is provided in the absorption device 4 for absorbing SO₃A gas.

Example 1

10.2kg of extracted waste acid (the sulfuric acid content is 55%) enters a light component removal device 1 for light component removal, namely dichloromethane in the waste acid is removed according to the boiling point of dichloromethane, 0.2kg of condensed dichloromethane and 10.0kg of pretreated waste acid are generated, the condensed dichloromethane is recycled, and the pretreated waste acid enters a cracking device 2. 1.5kg of liquid sulfur, 38.3kg of air and 10kg of pretreated waste acid react in a cracking device 2, so that sulfuric acid and triethylamine sulfate in the waste acid are completely cracked at high temperature to generate cracked gas. The cracking gas enters a conversion device 3 to generate SO₃A gas. SO (SO)₃The gas enters the absorption device 4 and is absorbed by the concentrated sulfuric acid to generate fuming sulfuric acid. The fuming sulfuric acid enters a distillation device 5 to respectively obtain 4kgSO₃And 6.7kg 98% sulfuric acid, the SO₃The recovered sulfuric acid can be used as a raw material for the cyclization reaction in the production of acesulfame potassium, and the 98% sulfuric acid can be used as a byproduct, namely concentrated sulfuric acid for sale or production and use. Recovery of SO₃The quality meets the requirement of superior products.

TABLE 1

Example 2

25kg of extracted waste acid (the sulfuric acid content is 60%) enters a light component removal device 1 for light component removal, namely dichloromethane in the waste acid is removed according to the boiling point of dichloromethane, 0.6kg of condensed dichloromethane and 24.4kg of pretreated waste acid are generated, the condensed dichloromethane is recycled, and the pretreated waste acid enters a cracking device 2. 2.5kg of liquid sulfur, 65kg of air and 24.4kg of pretreated waste acid react in the cracking device 2, so that sulfuric acid and triethylamine sulfate in the waste acid are completely cracked at high temperature to generate cracked gas. The cracking gas enters a conversion device 3 to generate SO₃A gas. SO (SO)₃The gas enters an absorption device 4 and is absorbed by concentrated sulfuric acid to generate fuming sulfuric acid. The fuming sulfuric acid enters a distillation device 5 to respectively obtain 12.2kgSO₃And 11.3kg 98% sulfuric acid, the SO₃The recovered sulfuric acid can be used as a raw material for the cyclization reaction in the production of acesulfame potassium, and the 98% sulfuric acid can be used as a byproduct, namely concentrated sulfuric acid for sale or production and use. Recovery of SO₃The quality meets the requirement of superior products.

TABLE 2

Example 3

25kg of extracted waste acid (the sulfuric acid content is 65%) enters a light component removal device 1 for light component removal, namely dichloromethane in the waste acid is removed according to the boiling point of dichloromethane, 0.5kg of condensed dichloromethane and 27kg of pretreated waste acid are generated, the condensed dichloromethane is recycled, and the pretreated waste acid enters a cracking device 2. 2.5kg of liquid sulfur, 65kg of air and 26kg of pretreated waste acid react in the cracking device 2, so that the waste sulfuric acid is completely cracked at high temperature to generate cracking gas. The cracking gas enters a conversion device 3 to generate SO₃A gas. SO (SO)₃The gas enters the absorption device 4 and is absorbed by the concentrated sulfuric acid to generate fuming sulfuric acid. The fuming sulfuric acid enters a distillation device 5 to respectively obtain 10kgSO₃And 15.4kg 98% sulfuric acid, the SO₃The recovered sulfuric acid can be used as a raw material for the cyclization reaction in the production of acesulfame potassium, and the 98% sulfuric acid can be used as a byproduct, namely concentrated sulfuric acid for sale or production and use. Recovery of SO₃Meets the requirements of superior products.

TABLE 3

The waste acid generated in the production process of acesulfame potassium is pretreated to remove dichloromethane, and the pretreated waste acid is subjected to pyrolysis to prepare SO₃Can be used as a raw material for cyclization reaction in the production process of acesulfame potassium; the by-product sulfuric acid is used for sale or production. On the one hand solve the wasteTreatment with acids to make SO₃Recycling is obtained; on the other hand, the obtained sulfuric acid can be sold or recycled. Simple process, low energy consumption, low cost, comprehensive utilization of resources and accordance with national industrial policies. Specifically, compared with the conventional process, the treatment cost of waste acid generated in the production process of acesulfame potassium can be reduced by 15%.

In conclusion, the present invention effectively overcomes various disadvantages of the prior art and has high industrial utilization value.

The above examples are intended to illustrate the disclosed embodiments of the invention and are not to be construed as limiting the invention. In addition, various modifications of the methods and compositions set forth herein, as well as variations of the methods and compositions of the present invention, will be apparent to those skilled in the art without departing from the scope and spirit of the invention. While the invention has been specifically described in connection with various specific preferred embodiments thereof, it should be understood that the invention should not be unduly limited to such specific embodiments. Indeed, various modifications of the above-described embodiments which are obvious to those skilled in the art to which the invention pertains are intended to be covered by the scope of the present invention.