CN112174775B

CN112174775B - Method for decoloring high-chlorine-content organic mixture

Info

Publication number: CN112174775B
Application number: CN202011056361.XA
Authority: CN
Inventors: 赵炯烽; 王伟松; 徐一帆; 秦飞; 王胜利
Original assignee: Zhejiang Huangma Technology Co Ltd; Zhejiang Lvkean Chemical Co Ltd; Zhejiang Huangma Shangyi New Material Co Ltd; Zhejiang Huangma Surfactant Research Institute Co Ltd
Current assignee: Zhejiang Huangma Technology Co Ltd; Zhejiang Lvkean Chemical Co Ltd; Zhejiang Huangma Shangyi New Material Co Ltd; Zhejiang Huangma Surfactant Research Institute Co Ltd
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2023-03-17
Anticipated expiration: 2040-09-29
Also published as: CN112174775A

Abstract

The invention discloses a method for decoloring an organic mixture with high chlorine content, belonging to the technical field of fine organic chemical industry. The decoloring method takes black tower bottoms with high chlorine content generated in the rectification process of preparing 2-methyl allyl chloride by reacting isobutene with chlorine as a raw material, and comprises the following steps: A. neutralizing and separating the black high-chlorine content tower bottoms by alkali liquor in sequence to obtain an orange primary decolorized product; B. b, bleaching the primary decolorized product obtained in the step A by using hydrogen peroxide to obtain a yellow secondary decolorized product; C. drying the secondary decolorized product by a drying agent, and adsorbing and decolorizing by an adsorbent to obtain a yellowish decolorized finished product with high chlorine content. The method obtains the yellowish organic mixture with high chlorine content through the decoloring steps of alkali neutralization, hydrogen peroxide bleaching, adsorbent adsorption and the like, and has the advantages of remarkable decoloring effect, low decoloring process energy consumption, low cost and less pollution.

Description

Method for decoloring high-chlorine-content organic mixture

Technical Field

The invention relates to the technical field of fine organic chemical industry, in particular to a method for decoloring an organic mixture with high chlorine content.

Background

2-methyl allyl chloride is an important organic synthesis intermediate, is widely applied to the fields of medicines, pesticides, macromolecules and the like, and has huge market demand.

Currently, 2-methylallyl chloride is obtained mainly by chlorination of isobutylene with chlorine. In addition to the production of 2-methallyl chloride, a large amount of other chlorinated alkanes or chlorinated alkenes are formed in the chlorination reaction. To obtain high purity 2-methylallyl chloride, it is necessary to carry out a multi-column continuous distillation, as described in CN1288119, CN 108164388A. However, during the rectification process, a large amount of black high-boiling organic matter remains in the column bottom. The existing method for treating the organic matters is mainly delivered to an environmental protection company for incineration and landfill treatment. Since the black high boiling residue contains a large amount of chlorine element (about 50 wt%), a large amount of hydrogen chloride gas is generated in the incineration process, which seriously damages the incineration equipment and harms the environment. In view of the increasing environmental requirements, this method is no longer suitable for the treatment of such black high boilers.

The black high-boiling by-product of 2-methyl allyl chloride is mainly various chlorinated alkanes and a small amount of chlorinated alkenes, and the chlorinated alkanes and the chlorinated alkenes are often important solvents in chemical reactions. Therefore, if the black high boiling substance is decolorized to a lighter color, it is possible to reuse it, and waste is changed into valuable. Conventional decolorization methods are generally applicable to relatively light colored materials, and it is difficult to decolorize such black high boiling materials to a lighter color by a single process.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide the method for decoloring the organic mixture with high chlorine content, the yellowish organic mixture with high chlorine content is obtained by decoloring steps such as alkali liquor neutralization, hydrogen peroxide bleaching, adsorbent adsorption and the like, the decoloring effect is obvious, and the decoloring process has low energy consumption, low cost and less pollution.

In order to solve the problems, the technical scheme adopted by the invention is as follows:

a decoloring method of an organic mixture with high chlorine content takes black tower bottoms with high chlorine content generated in the rectification process of preparing 2-methyl allyl chloride by reacting isobutene with chlorine as a raw material, and specifically comprises the following steps:

A. neutralizing and separating the black high-chlorine content tower bottoms by alkali liquor in sequence to obtain an orange primary decolorized product;

B. b, bleaching the primary decolorized product obtained in the step A by using hydrogen peroxide to obtain a yellow secondary decolorized product;

C. drying the secondary decolorized product by a drying agent, and adsorbing and decolorizing by an adsorbent to obtain a yellowish decolorized finished product with high chlorine content.

As a preferred embodiment of the present invention, the alkali solution in step A is potassium hydroxide or sodium hydroxide; the concentration of the alkali liquor is 20-40 wt%, the addition amount of the alkali liquor is 0.5-5 wt%, the neutralization temperature of the alkali liquor is 30-50 ℃, and the neutralization time is 10-60 min.

In a preferred embodiment of the present invention, the time for separating in step A is 20 to 60min.

In a preferred embodiment of the present invention, the concentration of the hydrogen peroxide in step B is 20 to 70wt%; the adding amount of the hydrogen peroxide is 0.1 to 2 weight percent. The bleaching temperature of the hydrogen peroxide is 40-80 ℃, and the bleaching time is 30-120 min.

In a preferred embodiment of the present invention, the drying agent in step C is anhydrous sodium sulfate, anhydrous calcium chloride, or anhydrous calcium chloride,

One of molecular sieves, the addition of desiccant is 5-30 wt%; the drying time is 30-60 min.

In a preferred embodiment of the present invention, the adsorbent in step C is one of activated carbon, sodium bentonite, activated clay, and silica gel decolorized sand.

Wherein the adding amount of the active carbon is 0.5 to 3 weight percent, the adsorption temperature is 70 to 90 ℃, and the adsorption time is 30 to 90min. The addition amount of the sodium bentonite is 5-10 wt%, the adsorption temperature is 70-90 ℃, and the adsorption time is 30-60 min. The adding amount of the activated clay is 5-10 wt%, the adsorption temperature is 70-90 ℃, and the adsorption time is 30-60 min. The addition amount of the silica gel decolorizing sand is 5-10 wt%, the adsorption temperature is 20-40 ℃, and the adsorption time is 30-60 min.

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

the decoloring method provided by the invention takes black high-boiling byproducts generated in the production of 2-methyl allyl chloride as raw materials, and obtains a yellowish organic mixture with high chlorine content through decoloring steps such as alkali neutralization, hydrogen peroxide bleaching, adsorbent adsorption and the like, so that the decoloring effect is remarkable, and the decoloring process has the advantages of low energy consumption, low cost and less pollution.

In particular, the present invention has the following outstanding advantages over the prior art:

(1) The decoloring effect is remarkable: the decoloring method provided by the invention realizes the decoloring of black high-boiling-point tower bottoms, and the chroma of the decolored product is reduced to be within 100 (the chroma determination method refers to the national standard GB/T3143 platinum-cobalt method);

(2) The method is environment-friendly: the decoloring method provided by the invention has the advantages of small pollution and low energy consumption, and greatly reduces the damage to the environment;

(3) Waste utilization: the yellowish mixed organic matter with high chlorine content can be used as an organic solvent, and the purpose of recycling waste is realized.

Drawings

FIG. 1 is a graph comparing the effect of the decolorized product of example 1 of the present invention with that of the sample before decolorization;

FIG. 2 is a graph comparing the effect of the decolorized product of comparative example 1 and comparative example 2 of the present invention with that of the sample before decolorization;

wherein, a is a sample before decolorization, b is a product after decolorization in example 1, c is a product after decolorization in comparative example 1, and d is a product after decolorization in comparative example 1.

Detailed Description

The invention is described in further detail below with reference to the drawings and the detailed description.

A. neutralizing the black high-chlorine-content tower bottoms with alkali liquor and separating liquid in sequence to obtain an orange primary decolorized product;

Wherein the alkali liquor in the step A is potassium hydroxide or sodium hydroxide; the concentration of the alkali liquor is 20 to 40 weight percent, preferably 25 to 35 weight percent; the addition amount of the alkali liquor is 0.5-5 wt%, preferably 0.5-2 wt%; the temperature of the alkali liquor neutralization is 30-50 ℃, preferably 35-45 ℃, and the neutralization time is 10-60 min, preferably 25-40 min. The time for separating in the step A is 20-60 min, preferably 40-60 min.

The concentration of the hydrogen peroxide in the step B is 20 to 70 weight percent, preferably 50 to 70 weight percent; the adding amount of the hydrogen peroxide is 0.1 to 2 weight percent, preferably 0.3 to 1 weight percent. The temperature of hydrogen peroxide bleaching is 40-80 ℃, preferably 60-75 ℃, and the bleaching time is 30-120 min, preferably 40-60 min.

The drying agent in the step C is anhydrous sodium sulfate, anhydrous calcium chloride,

One kind of molecular sieve, the addition amount of the drying agent is 5-30 wt%, preferably 20-30 wt%; drying timeIs 30 to 60min, preferably 45 to 60min. And the adsorbent in the step C is one of activated carbon, sodium bentonite, activated clay and silica gel decolorized sand. Wherein the adding amount of the active carbon is 0.5 to 3 weight percent, preferably 1 to 2 weight percent, the adsorption temperature is 70 to 90 ℃, preferably 80 to 90 ℃, and the adsorption time is 30 to 90min, preferably 60 to 90min. The addition amount of the sodium bentonite is 5-10 wt%, preferably 6-8 wt%, the adsorption temperature is 70-90 ℃, preferably 75-85 ℃, and the adsorption time is 30-60 min, preferably 40-60 min. The adding amount of the activated clay is 5 to 10 weight percent, preferably 6 to 8 weight percent, the adsorption temperature is 70 to 90 ℃, preferably 75 to 85 ℃, and the adsorption time is 30 to 60min, preferably 40 to 60min. The addition amount of the silica gel decolorizing sand is 5-10 wt%, preferably 7-10 wt%, the adsorption temperature is 20-40 ℃, preferably 25-35 ℃, and the adsorption time is 30-60 min, preferably 40-60 min.

1. Influence of different decoloring conditions on product color in step A

Taking 1Kg of black tower bottoms with high chlorine content, adding different amounts of NaOH solutions with the mass fraction of 30%, and stirring for 60min at different temperatures. And (3) after stirring is finished and standing for 30min, separating liquid to obtain an orange primary decolorized product at the upper layer, and observing and recording the result, wherein the result is shown in table 1.

TABLE 1 Effect of different decolorizing conditions in step A on product color

As can be seen from Table 1, when the addition amount of the alkali solution is 0.5 to 5wt%, and the neutralization temperature of the alkali solution is 30 to 50 ℃, a dark red or orange red transparent liquid can be obtained, and the effect is best under the conditions of 0.5 to 2wt% and 35 to 45 ℃.

2. Influence of different decoloring conditions in the step B on the color and luster of the product

Taking 1Kg of black high-chlorine content tower bottom liquid, adding 40g of NaOH solution with the mass fraction of 25%, and stirring at 50 ℃ for 20min. And after stirring and standing for 30min, separating liquid to obtain an orange primary decolorized product at the upper layer. Adding different amounts of 50% hydrogen peroxide into the primary decolorized product, and stirring for 1h at different temperatures. And after bleaching, standing for 30min, and separating liquid to obtain a secondary decolorized product with yellow lower layer. Color was measured and the results are shown in Table 2.

TABLE 2 Effect of different decolorizing conditions in step B on the color and luster of the product

As can be seen from Table 2, the addition of hydrogen peroxide is 0.1 to 2wt%, and the bleaching temperature is 40 to 80 ℃, the chromaticity is reduced, and the effect is best at the conditions of 0.3 to 1wt% and 60 to 75 ℃.

3. Influence of different decoloring conditions in the step C on the color and luster of the product

Taking 1Kg of black high-chlorine content tower bottom liquid, adding 40g of NaOH solution with the mass fraction of 25%, and stirring at 50 ℃ for 20min. And after stirring and standing for 30min, separating liquid to obtain an orange primary decolorized product at the upper layer. Adding 20g of 50% hydrogen peroxide into the primary decolorized product, and stirring for 1h at 60 ℃. And after bleaching, standing for 30min, and separating liquid to obtain a secondary decolorized product with yellow lower layer. And (3) drying the secondary decolorized product by using anhydrous sodium sulfate, adding different amounts of activated carbon, stirring for 1 hour at different temperatures, filtering while hot to obtain a yellowish decolorized finished product, and detecting the color and luster, wherein the results are shown in table 3.

TABLE 3 Effect of different decolorizing conditions on color of the product in step C

As can be seen from Table 3, when the amount of the added activated carbon is 0.5 to 3wt% and the adsorption temperature is 70 to 90 ℃, the chromaticity is reduced, and the effects are best at 1 to 2wt% and 80 to 90 ℃. After the adding amount of the activated carbon exceeds 2.0wt%, the chroma reducing effect is not obviously changed, and the product entrainment amount is increased.

4. Influence of different decoloring conditions in the step C on the color and luster of the product

Taking 1Kg of black tower bottoms with high chlorine content, adding 25g of NaOH solution with the mass fraction of 40%, and stirring at 45 ℃ for 20min. And after stirring and standing for 30min, separating liquid to obtain an orange primary decolorized product at the upper layer. Adding 30g of 50% hydrogen peroxide in the primary decolorized product, and stirring for 1h at 60 ℃. And after bleaching, standing for 30min, and separating liquid to obtain a secondary decolorized product with yellow lower layer. By using

And (3) drying the secondary decolored product by using a molecular sieve, adding different amounts of sodium bentonite, stirring at different temperatures for 1h, filtering while hot to obtain a yellowish decolored finished product, and detecting the color and luster, wherein the results are shown in table 4.

TABLE 4 Effect of different decolorizing conditions in step C on product color

As is clear from Table 4, when the amount of sodium bentonite added is 5 to 10wt% and the adsorption temperature is 70 to 90 ℃ C, the color is reduced, and the effect is best at 6 to 8wt% and 75 to 85 ℃.

5. Influence of different decoloring conditions in the step C on the color and luster of the product

Taking 1Kg of black high-chlorine content tower bottom liquid, adding 25g of NaOH solution with the mass fraction of 40%, and stirring at 45 ℃ for 20min. And after stirring and standing for 30min, separating liquid to obtain an orange primary decolorized product at the upper layer. Adding 30g of 50% hydrogen peroxide into the primary decolorized product, and stirring for 1h at 60 ℃. And after bleaching, standing for 30min, and separating liquid to obtain a secondary decolorized product with yellow lower layer. By using

And (3) drying the secondary decolorized product by using a molecular sieve, adding activated clay with different amounts, stirring for 1 hour at different temperatures, filtering while hot to obtain a yellowish decolorized finished product, and detecting the color and luster, wherein the results are shown in table 5.

TABLE 5 Effect of different decolorizing conditions on the color of the product in step C

As is clear from Table 5, the effect is best when the amount of activated clay added is 5 to 10wt% and the adsorption temperature is 70 to 90 ℃ because the chromaticity is reduced and the effect is 6 to 9wt% and 75 to 85 ℃.

6. Influence of different decoloring conditions in the step C on the color and luster of the product

Taking 1Kg of black high-chlorine content tower bottom liquid, adding 25g of KOH solution with the mass fraction of 40%, and stirring at 45 ℃ for 20min. And after stirring and standing for 30min, separating liquid to obtain an orange primary decolorized product at the upper layer. Adding 10g of 50% hydrogen peroxide by mass into the primary decolorized product, and stirring for 1h at 65 ℃. And after bleaching, standing for 30min, and separating liquid to obtain a secondary decolorized product with yellow lower layer. After drying the secondary decolorized product with anhydrous calcium chloride, adding different amounts of silica gel decolorized sand, stirring at 30 ℃ for different times, and filtering to obtain a yellowish decolorized finished product, wherein the color and luster are detected, and the results are shown in table 6.

TABLE 6 Effect of different decolorizing conditions on color of the product in step C

As can be seen from Table 6, when the silica gel desanding sand is added in an amount of 5 to 10wt% and the stirring time is 30 to 60min, the chromaticity is reduced, and the effect is best under the conditions of 7 to 10wt% and 40 to 60min. When the amount of the decolorizing sand exceeds 10 percent, the effect of reducing the chromaticity is not obviously changed, and the entrainment of the raw materials is increased.

Example 1:

taking 1Kg of black tower bottoms with high chlorine content, adding 40g of NaOH solution with the mass fraction of 25%, and stirring at 50 ℃ for 20min. And after stirring and standing for 30min, separating liquid to obtain an orange primary decolorized product at the upper layer. Adding 20g of 50% hydrogen peroxide into the primary decolorized product, and stirring for 1h at 60 ℃. And after bleaching, standing for 30min, and separating liquid to obtain a secondary decolorized product with yellow lower layer. And (3) drying the secondary decolorized product by using anhydrous sodium sulfate, adding 1% of activated carbon, stirring for 1 hour at the temperature of 80 ℃, and filtering while hot to obtain a yellowish decolorized finished product.

The main components of the obtained yellowish decolorized finished product are shown in table 1, the color of the decolorized finished product is shown in fig. 1 (b), the color is 80-100 (the color measuring method refers to the national standard GB/T3143 platinum cobalt method), and the water content is less than 0.2%.

TABLE 7 yellowish decolorized Final product Main Components

As can be seen from FIG. 1, compared with the sample before decolorization, the decolorized product obtained in example 1 has greatly reduced chromaticity, so that the decolorization effect of the present invention is significant, and the decolorization process has the advantages of low energy consumption, low cost and less pollution.

Example 2:

taking 1Kg of black high-chlorine content tower bottom liquid, adding 25g of NaOH solution with the mass fraction of 40%, and stirring at 45 ℃ for 20min. And after stirring and standing for 30min, separating liquid to obtain an orange primary decolorized product at the upper layer. Adding 30g of 50 percent hydrogen peroxide by mass into the primary decolorized productStirring at 60 ℃ for 1h. And after bleaching, standing for 30min, and separating liquid to obtain a secondary decolorized product with yellow lower layer. By using

And drying the secondary decolorized product by using a molecular sieve, adding 5% of sodium bentonite, stirring for 1h at 80 ℃, and filtering while the solution is hot to obtain a yellowish decolorized finished product. The color of the finished product is 70-90, and the water content is less than 0.2%.

Example 3:

taking 1Kg of black tower bottoms with high chlorine content, adding 25g of KOH solution with the mass fraction of 40%, and stirring for 20min at 45 ℃. And after stirring and standing for 30min, separating liquid to obtain an orange primary decolorized product at the upper layer. Adding 10g of 50% hydrogen peroxide by mass into the primary decolorized product, and stirring for 1h at 65 ℃. And after bleaching, standing for 30min, and separating liquid to obtain a secondary decolorized product with yellow lower layer. And (3) drying the secondary decolored product by using anhydrous calcium chloride, adding 10% of silica gel decolored sand, stirring for 1 hour at the temperature of 30 ℃, and filtering to obtain a yellowish decolored finished product. The color of the finished product is 75-90, and the water content is less than 0.2%.

Comparative example 1:

taking 1Kg of black high-chlorine content tower bottoms, adding 20g of 50% hydrogen peroxide by mass, stirring at 65 ℃ for 2h, standing for 30min, separating to obtain a lower organic phase, and drying the organic phase with anhydrous calcium chloride to obtain a dark decolorized product, as shown in fig. 2 (c).

Comparative example 2:

taking 1Kg of black high-chlorine content tower bottom liquid, adding 20g of activated carbon, stirring at 80 ℃ for 2h, and filtering while hot to obtain a dark decolorized product, as shown in fig. 2 (d).

As can be seen from FIGS. 1 and 2, the chroma of the decolorized product obtained by the decolorization method of the present invention is reduced to less than 100. Compared with the prior art of comparative examples 1 and 2, the decolorization effect is significantly improved, and the decolorization process has the advantages of low energy consumption, low cost and little pollution

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.

Claims

1. A method for decoloring high-chlorine-content organic mixture is characterized by comprising the following steps: the method takes black tower bottoms with high chlorine content generated in the rectification process of preparing 2-methyl allyl chloride by reacting isobutene and chlorine as raw materials, and comprises the following steps:

A. neutralizing the black high-chlorine-content tower bottoms with alkali liquor and separating liquid in sequence to obtain an orange primary decolorized product; the alkali liquor is potassium hydroxide or sodium hydroxide;

B. b, bleaching the primary decolorized product obtained in the step A by hydrogen peroxide to obtain a yellow secondary decolorized product;

C. drying the secondary decolorized product by a drying agent, and adsorbing and decolorizing by an adsorbent to obtain a yellowish decolorized finished product with high chlorine content; the adsorbent is one of activated carbon, sodium bentonite, activated clay and silica gel decolorization sand.

2. The process for the decolorization of organic mixtures having a high chlorine content according to claim 1, characterized in that: the concentration of the alkali liquor in the step A is 20 to 40wt%.

3. The process for the decolorization of organic mixtures having a high chlorine content according to claim 2, characterized in that: in the step A, the addition amount of the alkali liquor is 0.5 to 5wt%, the neutralization temperature of the alkali liquor is 30 to 50 ℃, and the neutralization time is 10 to 60min.

4. The process for the decolorization of organic mixtures having a high chlorine content according to claim 1, characterized in that: and the time for liquid separation in the step A is 20 to 60min.

5. The process for the decolorization of organic mixtures having a high chlorine content according to claim 1, characterized in that: in the step B, the concentration of the hydrogen peroxide is 20 to 70wt%, and the adding amount of the hydrogen peroxide is 0.1 to 2wt%.

6. The process according to claim 5 for decoloring organic mixtures with high chlorine content, characterized in that: and B, bleaching with hydrogen peroxide at the temperature of 40-80 ℃ for 30-120min.

7. The process for the decolorization of organic mixtures having a high chlorine content according to claim 1, characterized in that: and C, the drying agent in the step C is one of anhydrous sodium sulfate, anhydrous calcium chloride and a 4A molecular sieve, the adding amount of the drying agent is 5-30 wt%, and the drying time is 30-60min.

8. The process for the decolorization of organic mixtures having a high chlorine content according to claim 1, characterized in that: the adding amount of the activated carbon is 0.5 to 3wt%, the adsorption temperature is 70 to 90 ℃, and the adsorption time is 30 to 90min; the addition amount of the sodium bentonite is 5-10wt%, the adsorption temperature is 70-90 ℃, and the adsorption time is 30-60min; the adding amount of the activated clay is 5-10wt%, the adsorption temperature is 70-90 ℃, and the adsorption time is 30-60min; the addition amount of the silica gel decolorization sand is 5 to 10wt%, the adsorption temperature is 20 to 40 ℃, and the adsorption time is 30 to 60min.