阅读说明：本技术 一种醚菌酯生产过程中副产物氯化铵的回收方法 (Method for recovering byproduct ammonium chloride in kresoxim-methyl production process ) 是由 王光金 李冰洁 张思思 高欢 于连友 王祥传 于 2020-05-25 设计创作，主要内容包括：本发明涉及农药环保技术领域,涉及农用杀菌剂醚菌酯制备过程中副产物的资源化回收技术,特别涉及一种醚菌酯生产过程中副产物氯化铵的回收方法。采用甲苯或石油醚作为萃取溶剂,加水进行溶剂混合,以醚菌酯生产过程中的副产物氯化铵粗品为原料,升温后静置分层,水相经过滤除杂后所得滤液进行降温结晶,最后通过离心得到高纯度氯化铵。工艺流程简单、周期短,成本低,产物纯度高达99.6％、收率高,实现了醚菌酯工业化生产无固废排放,真正实现了清洁生产；同时萃取溶剂和氯化铵母液可循环利用,节约了用水。(The invention relates to the technical field of pesticide environmental protection, relates to a recycling technology of byproducts in the preparation process of agricultural bactericide kresoxim-methyl, and particularly relates to a recycling method of byproduct ammonium chloride in the production process of kresoxim-methyl. Toluene or petroleum ether is used as an extraction solvent, water is added for solvent mixing, a byproduct ammonium chloride crude product in the kresoxim-methyl production process is used as a raw material, the raw material is heated and then stands for layering, the water phase is filtered to remove impurities, the obtained filtrate is cooled and crystallized, and finally, high-purity ammonium chloride is obtained through centrifugation. The process flow is simple, the period is short, the cost is low, the product purity is as high as 99.6%, the yield is high, the industrial production of the kresoxim-methyl is realized, no solid waste is discharged, and the clean production is really realized; meanwhile, the extraction solvent and the ammonium chloride mother liquor can be recycled, and water is saved.)

1. A method for recovering a byproduct ammonium chloride in the kresoxim-methyl production process is characterized by comprising the following steps:

adding a byproduct chloride crude product in the kresoxim-methyl production process into a mixed system of an extraction solvent and water, reacting for 1-2h at 60-80 ℃, standing for layering, filtering a water phase to remove impurities, and cooling, crystallizing and centrifuging the obtained filtrate to obtain ammonium chloride;

collecting an organic phase, and recovering the kresoxim-methyl intermediate 2- (2-methylphenoxymethyl) phenyloxalate and the extraction solvent through simple distillation and separation, wherein the recovered extraction solvent can be continuously used.

2. The method for recovering the byproduct ammonium chloride in the kresoxim-methyl production process according to claim 1, wherein the extraction solvent is one or two of toluene or petroleum ether.

3. The method for recovering the byproduct ammonium chloride in the kresoxim-methyl production process according to claim 1, wherein the mass ratio of the extraction solvent to the water is 1: 3.5-4.

4. The method for recovering the byproduct ammonium chloride in the kresoxim-methyl production process according to claim 1, wherein the mass ratio of the crude ammonium chloride to water is 1: 1.5-2.

5. The method for recovering the byproduct ammonium chloride in the kresoxim-methyl production process according to claim 1, wherein the temperature reduction and crystallization temperature is 0-5 ℃.

6. The method for recovering the byproduct ammonium chloride in the kresoxim-methyl production process according to claim 1, wherein the simple distillation temperature is 95-100 ℃.

7. The method for recovering the byproduct ammonium chloride in the kresoxim-methyl production process according to claim 1, wherein the centrifuged ammonium chloride mother liquor can be continuously reused, and the mass ratio of the ammonium chloride crude product to the ammonium chloride mother liquor is 1: 6.0-6.3.

8. The method for recovering the byproduct ammonium chloride in the kresoxim-methyl production process according to claim 1, wherein the extraction solvent recovered by simple distillation can be continuously used, and the mass ratio of the recovered extraction solvent to water is 1: 3.5-4.

Technical Field

The invention relates to the technical field of pesticide environmental protection, relates to a recycling technology of byproducts in the preparation process of agricultural bactericide kresoxim-methyl, and particularly relates to a recycling method of byproduct ammonium chloride in the production process of kresoxim-methyl.

Background

Kresoxim-methyl is also called (E) -2-methoxyimino- [2- (o-methyl phenoxymethyl) phenyl ] methyl acetate, and is a novel bactericide with high efficiency and broad spectrum. The kresoxim-methyl generates more three wastes in the synthesis process, wherein the purity of a byproduct, namely ammonium chloride is low, the ammonium chloride can only be used as a solid waste product, the treatment cost is high, and the treatment has great difficulty. With the industrial development of the kresoxim-methyl product, the solid waste ammonium chloride discharged in the production process is increasing day by day, and serious pollution and potential serious influence are brought to the environment.

At present, a plurality of mature processes and equipment are matched for treating ammonium chloride in wastewater and waste, but the mature complex processes and equipment can increase the production cost of kresoxim-methyl, and can greatly reduce the market competitiveness and economic benefit of enterprise products, so that the ammonium chloride recovery process which is easy to operate, low in cost and clean in production needs to be developed by combining the current production situation of kresoxim-methyl. Patent CN103408038A provides a treatment method for recovering ammonium chloride, which repeatedly utilizes sodium chloride to "force out" ammonium chloride, but this process introduces sodium ion impurities, which can reduce the purity of the recovered ammonium chloride and is not favorable for removing organic impurities. Patent CN108046291A discloses a method for recovering and recycling a byproduct ammonium chloride in the kresoxim-methyl production process, which comprises adsorption filtration, pH adjustment, adsorption filtration, primary recrystallization, secondary recrystallization, drying and the like, and adopts two-time activated carbon adsorption and two-time recrystallization technology, so that the operation is complex, and organic impurities are still remained.

Disclosure of Invention

Aiming at the problems of complex recovery operation, high cost, residual organic impurities and the like of the byproduct ammonium chloride in the kresoxim-methyl synthesis process in the prior art, the invention provides the recovery method of the byproduct ammonium chloride in the kresoxim-methyl production process, which has the advantages of simple operation, high purity, low cost, clean production and no solid waste discharge in the industrial production of the kresoxim-methyl.

The technical scheme of the invention is as follows: toluene or petroleum ether is used as an extraction solvent, processing water is subjected to solvent mixing, a by-product ammonium chloride crude product in the kresoxim-methyl production process is used as a raw material, the raw material is heated and then stands for layering, the filtrate obtained after filtration and impurity removal of a water phase is subjected to cooling crystallization, and finally high-purity ammonium chloride is obtained through centrifugation.

Wherein the crude ammonium chloride product mainly comprises inorganic salt ammonium chloride and an organic matter 2- (2-methylphenoxymethyl) phenyloxalic acid methyl ester, and the crude ammonium chloride product is obtained in the technical process of synthesizing the kresoxim-methyl intermediate 2- (2-methylphenoxymethyl) phenyloxalic acid methyl ester by taking 2- (2-methylphenoxymethyl) benzoyl nitrile as a raw material.

A method for recovering a byproduct ammonium chloride in the kresoxim-methyl production process comprises the following steps:

adding a byproduct chloride crude product in the kresoxim-methyl production process into a mixed system of an extraction solvent and water, reacting for 1-2h at 60-80 ℃, standing for layering, filtering a water phase to remove impurities, and cooling, crystallizing and centrifuging the obtained filtrate to obtain ammonium chloride;

collecting an organic phase, and recovering the kresoxim-methyl intermediate 2- (2-methylphenoxymethyl) phenyloxalate and the extraction solvent through simple distillation and separation, wherein the recovered extraction solvent can be continuously used.

Wherein the content of the first and second substances,

the extraction solvent is one or two of toluene or petroleum ether.

The mass ratio of the extraction solvent to the water is 1: 3.5-4. The extraction effect is better along with the increase of the dosage of the extraction solvent, and the proportion range is determined to not only achieve the extraction effect but also meet the production requirement by combining the reasons of production operability, solvent loss and the like.

The mass ratio of the ammonium chloride crude product to the water is 1: 1.5-2. The extraction solvent extracts the organic matter, the water dissolves the ammonium chloride, the ratio range is selected based on the ratio range of the extraction solvent and the water.

The temperature of the cooling crystallization is 0-5 ℃. The solubility of ammonium chloride in water is increased when the temperature is too high, which is not beneficial to recovery, and the production is difficult to realize when the temperature is too low.

The simple distillation temperature is 95-100 ℃. Toluene or petroleum ether is recovered, and if the temperature is too low, the recovery rate of the extraction solvent is low.

The ammonium chloride mother liquor after centrifugation can be continuously used, and the mass ratio of the ammonium chloride crude product to the ammonium chloride mother liquor is 1: 6.0-6.3. The proportion range is based on the proportion of the ammonium chloride crude product and water and the water content in the mother liquor.

The extraction solvent recovered by simple distillation can be continuously used, and the mass ratio of the recovered extraction solvent to water is 1: 3.5-4. Although the recovered extraction solvent contains a small amount of water, the extraction effect is not influenced by the proportion, and continuous application is realized.

The beneficial effect of the invention is that,

(1) the method has the advantages of short period, low cost, less solvent consumption, simplicity and easiness in control, the purity of the recovered ammonium chloride is as high as 99.6%, the yield is high, the industrial production of the kresoxim-methyl is realized, no solid waste is discharged, and the clean production is realized;

(2) the extraction solvent and the ammonium chloride mother liquor can be recycled, so that the industrial water is saved;

(3) the method solves the problem that the crude product of the ammonium chloride as a byproduct in the kresoxim-methyl production is difficult to treat, reduces the environmental pollution, changes waste into valuable, and improves the actual industrial production yield of the kresoxim-methyl product.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.