Novel method for absorbing tail gas from trichloro-acetic chloride production through chlorination process

Abstract

The present invention relates to a novel method for absorbing tail gas from trichloro-acetic chloride production through a chlorination process. The method can realize separation and recovery of hydrogen chloride, sulfur dioxide, sulfur, disulfur dichloride, and chlorine generated in the production process of trichloro-acetic chloride; the method is safe and easily controlled, has no harm to the environment, and generates by-products containing hydrochloric acid with concentration higher than 30% and a sodium bisulfite solution. The invention belongs to the technical field of environmental protection.

Description

technical field

[0001] The invention relates to a new method for absorbing tail gas produced by a chlorination method to produce trichloroacetyl chloride, through which hydrogen chloride, sulfur dioxide, disulfur dichloride, chlorine gas, etc. generated during the production of trichloroacetyl chloride can be separated and recovered, and the side effects The hydrochloric acid and sodium bisulfite sodium solution of more than 30% can be produced, which belongs to the technical field of environmental protection. Background technique

[0002] Trichloroacetyl chloride is an important intermediate in the production of clopyridinate sodium and chlorpyrifos. The preparation steps of the chlorination method are: (1) chloroacetic acid waste liquid (mother liquor) reacts with chlorine gas in the presence of sulfur to generate mixed acid chlorides; (2) mixes Acyl chloride reacts with chlorine gas in the presence of pyridine to form trichloroacetyl chloride. The tail gas produced durin...

Examples

Embodiment 1

[0016] The technological process of this embodiment sees figure 1 .

[0017] (1) The main and auxiliary chlorination reactors are connected in series, so that the positive and auxiliary tanks are cross-chlorinated, and the chlorine gas enters the main tank (or auxiliary tank) first, and the tail gas after the reaction includes chlorine, sulfur dioxide, sulfur dichloride, a Sulfur chloride, mixed acid chloride, hydrogen chloride, etc. enter the auxiliary tank (or main tank), and the chlorine and sulfur dichloride in the tail gas are absorbed by the auxiliary tank or participate in the reaction;

[0018] (2) The tail gas purified in step (1) includes sulfur dioxide, sulfur monochloride, mixed acid chloride, hydrogen chloride, etc., and the mixed acid chloride and part of the monochloride in the tail gas are absorbed by using the cooked mother liquor (that is, the solution of distilled water from the mother liquor of chloroacetic acid) Sulfur;

[0019] (3) After the tail gas pu...

Embodiment 2

[0024] The technological process of this embodiment sees figure 1 .

[0025] (1) The main and auxiliary chlorination reactors are connected in series, and the positive and auxiliary tanks are cross-chlorinated, and the chlorine gas enters the main tank (or auxiliary tank) first, and the tail gas after the reaction includes chlorine, sulfur dioxide, sulfur dichloride, Sulfur monochloride, mixed acid chloride, hydrogen chloride, etc. enter the auxiliary tank (or main tank), and the chlorine and sulfur dichloride in the tail gas are absorbed by the auxiliary tank or participate in the reaction;

[0026] (2) The tail gas purified in step (1) includes sulfur dioxide, sulfur monochloride, mixed acid chloride, hydrogen chloride, etc., and the mixed acid chloride and part of the monochloride in the tail gas are absorbed by using the cooked mother liquor (that is, the solution of distilled water from the mother liquor of chloroacetic acid) Sulfur;

[0027] (3) After the tail gas puri...

technical field

[0001] The invention relates to a new method for absorbing tail gas produced by a chlorination method to produce trichloroacetyl chloride, through which hydrogen chloride, sulfur dioxide, disulfur dichloride, chlorine gas, etc. generated during the production of trichloroacetyl chloride can be separated and recovered, and the side effects The hydrochloric acid and sodium bisulfite sodium solution of more than 30% can be produced, which belongs to the technical field of environmental protection. Background technique

[0002] Trichloroacetyl chloride is an important intermediate in the production of clopyridinate sodium and chlorpyrifos. The preparation steps of the chlorination method are: (1) chloroacetic acid waste liquid (mother liquor) reacts with chlorine gas in the presence of sulfur to generate mixed acid chlorides; (2) mixes Acyl chloride reacts with chlorine gas in the presence of pyridine to form trichloroacetyl chloride. The tail gas produced durin...

Examples

Embodiment 1

[0016] The technological process of this embodiment sees figure 1 .

[0017] (1) The main and auxiliary chlorination reactors are connected in series, so that the positive and auxiliary tanks are cross-chlorinated, and the chlorine gas enters the main tank (or auxiliary tank) first, and the tail gas after the reaction includes chlorine, sulfur dioxide, sulfur dichloride, a Sulfur chloride, mixed acid chloride, hydrogen chloride, etc. enter the auxiliary tank (or main tank), and the chlorine and sulfur dichloride in the tail gas are absorbed by the auxiliary tank or participate in the reaction;

[0018] (2) The tail gas purified in step (1) includes sulfur dioxide, sulfur monochloride, mixed acid chloride, hydrogen chloride, etc., and the mixed acid chloride and part of the monochloride in the tail gas are absorbed by using the cooked mother liquor (that is, the solution of distilled water from the mother liquor of chloroacetic acid) Sulfur;

[0019] (3) After the tail gas pu...

Embodiment 2

[0024] The technological process of this embodiment sees figure 1 .

[0025] (1) The main and auxiliary chlorination reactors are connected in series, and the positive and auxiliary tanks are cross-chlorinated, and the chlorine gas enters the main tank (or auxiliary tank) first, and the tail gas after the reaction includes chlorine, sulfur dioxide, sulfur dichloride, Sulfur monochloride, mixed acid chloride, hydrogen chloride, etc. enter the auxiliary tank (or main tank), and the chlorine and sulfur dichloride in the tail gas are absorbed by the auxiliary tank or participate in the reaction;

[0026] (2) The tail gas purified in step (1) includes sulfur dioxide, sulfur monochloride, mixed acid chloride, hydrogen chloride, etc., and the mixed acid chloride and part of the monochloride in the tail gas are absorbed by using the cooked mother liquor (that is, the solution of distilled water from the mother liquor of chloroacetic acid) Sulfur;

[0027] (3) After the tail gas puri...

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