Resource utilization method of 2, 4-dichloroacetophenone wastewater

Abstract

The invention provides a resource utilization method of 2, 4-dichloroacetophenone wastewater, which is characterized in that aluminum salt in the 2, 4-dichloroacetophenone wastewater is creatively subjected to activated carbon decoloration and negative pressure dehydration and then is put into a reaction system, and fresh anhydrous aluminum trichloride is directly obtained through hydrogen chloride bubbling and toluene water carrying. According to the method, direct use of a large amount of anhydrous aluminum trichloride is avoided, acetyl chloride is added into a system and reacts with m-dichlorobenzene, after the reaction is finished, water and toluene carried water removed under negative pressure are taken out and then put into the system, oil-water layering is realized through hydrolysis, a product in an oil layer is obtained through oil-water layering, and is obtained through rectification; a water layer is continuously recycled and reused through the method, no aqueous alkali is used for neutralization in the whole process, the use amount of hydrogen chloride gas is small, catalyst components in wastewater are effectively recycled, no wastewater is generated, emission of three wastes is effectively reduced, internal circulation of aluminum salt and water is formed, and the cost is greatly saved.

Description

technical field [0001] The invention relates to the technical field of fine chemicals, and relates to a wastewater treatment technology for pesticide intermediates, in particular to a resource utilization method for 2,4-dichloroacetophenone wastewater. Background technique [0002] 2,4-Dichloroacetophenone is an important fine chemical intermediate, which is widely used in medicine, pesticides and other fields. Azole and itraconazole can also be synthesized into low-toxicity, broad-spectrum, systemic fungicides teconazole, metroconazole, etoconazole and propiconazole. [0003] The synthesis of traditional 2,4-dichloroacetophenone mostly uses m-dichlorobenzene as raw material, with acetyl chloride or acetic anhydride as acylating reagent, in Lewis acid AlCl 3 Under the catalysis of acetylation, 2,4-dichloroacetophenone is obtained. The acylation reaction ends, the AlCl as catalyst 3 Further complex with the generated 2,4-dichloroacetophenone. At this time, a large amount o...

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Problems solved by technology

[0004] Chinese patent CN109721480A uses AlCl 3 As a catalyst, acetic anhydride is used as an acylating agent to carry out an electrophilic substitution reaction with m-dichlorobenzene to prepare 2,4-dichloroacetophenone. After the reaction, add toluene and 10% hydrochloric acid to separate layers, and recover the product 2,4- Dichloroacetophenone, 95% yield, but no mention of how the water layer was handled

After the reaction, the 2,4-dichloroacetophenone product was obtained by hydrolysis, layer separation, oil layer washing, and distillation. The patent also did not mention how to treat the acidic wastewater containing aluminum trichloride

[0006] 2,4-Dichloroacetophenone wastewater contains about 1.5% to 4% of aluminum, 8% to 25% of chlorine, about 3% to 10% of acidity in terms of hydrochloric acid, light yellow in color, and about 6000 to 10000 COD , the usual treatment method is to neutralize it with alkaline solution, filter out aluminum hydroxide, and then treat the wastewater by oxidation, biochemical and other methods. The demand for aluminum hydroxide is small, and generally it needs to be reprocessed to realize the resource utilization of wastewater. The whole The wastewater treatment process is long, and the resource utilization effect is poor

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