A method for preparing isopropyl bromide from oxadiazon etherification wastewater

Abstract

The invention discloses a method of preparing isopropyl bromide oxadiazon esterification wastewater having 10-30% by mass of potassium bromide. Potassium bromide 98.5% and above in content is preferably attained by neutralizing the wastewater, filtering and washing with water; filter mother liquor is distilled before concentration, gradient crystallization is carried out before filtering, and washing is performed with water to attain potassium bromide 95% and above in content; potassium bromide, isopropanol and concentrated sulfuric acid are subjected to distillation reaction to prepare isopropyl bromide; the yield is higher than 90%, and the purity is higher than 99%. The method herein helps solve the problem that high-salinity wastewater is difficulty to treat; mass balance and cyclic utilization of bromine are achieved via the series of treatments; production cost and wastewater treatment burden are greatly decreased; the method has great economic benefit and environmental benefit.

Description

technical field [0001] The invention belongs to the field of resource utilization and treatment of production wastewater, and mainly relates to a method for purifying the effective component potassium bromide from the etherified high-salt wastewater of oxadiazone and using it to prepare isopropyl bromide, a raw material required for the process. Background technique [0002] The raw material wastewater used in the present invention is produced by the etherification process of oxadiazone, the main reaction is 2,4-dichloro-5-nitrophenol and 2-bromopropane with DMF as the solvent, and weak alkaline salt potassium carbonate as the acid binding agent, generating 2,4-dichloro-5-isopropoxynitrobenzene, potassium bromide, potassium bicarbonate, water and carbon dioxide. The specific reaction principle is: [0003] [0004] K 2 CO 3 +HBr→KBr+KHCO 3 [0005] KHCO 3 +HBr→KBr+H 2 O+CO 2 [0006] It needs to consume 0.66t of isopropyl bromide to produce one ton of product, an...

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Problems solved by technology

[0008] At present, the main synthesis methods of this raw material are: ① hydrobromic acid synthesis method, the crude product produced by this method needs to go through steps such as washing, pickling, alkali washing, rectification, etc., the operation process is complicated, the reaction process is relatively slow, and produces a large amount of concentration High waste acid increases the difficulty of follow-up treatment; ②NaBr (potassium)-concentrated sulfuric acid synthesis method, which is similar to hydrobromic acid synthesis method, produces a large amount of waste acid that is difficult to handle; ③PBr 3 Synthetic method, this method reaction speed is fast, and reaction condition is mild, but phosphorus tribromide has bigger danger, does not meet the production requirement of safety and environmental protection; 4. Microwave synthesis method, this method has reaction speed faster, The three wastes are less generated and the products are easy to separate, but there is no industrial production precedent at present, and further research is needed to find a method suitable for industrial production

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