Chloromethane water-washing wastewater recycling method and device

Abstract

The invention relates to a chloromethane water-washing wastewater recycling method and device, and belongs to the technical field of wastewater treatment. The device comprises a scrubbing tank, a distillation tower arranged on one side of the scrubbing tank and a water storage tank arranged below the scrubbing tank. According to the invention, by arranging evaporation plates arranged in a Z shape in a distillation tower and arranging heat exchange sheets arranged on the evaporation plates, wastewater flows through the evaporation plates to form a water film with a uniform thickness so as to facilitate rapid heating of the wastewater, and methanol and methylal steam are rapidly discharged due to the fact that the water film is thin and large in surface area; bubbles collide and are dispersed into small bubbles by arranging a water inlet mesh grid formed by connecting pipelines distributed in a staggered mode in a scrubbing tank, so that the contact area of bubbles and water is increased; and the bubbles are dispersed by water pumped by the water inlet mesh grid, and methanol is fully dissolved in the water, so that the chloromethane cleaning quality and efficiency are improved, the methanol content in the finally treated wastewater is 6.4-7.2 mg / L, and the wastewater can be collected for direct secondary utilization.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a method and device for recycling methyl chloride washing wastewater. Background technique [0002] Methyl chloride prepared in the production of glyphosate contains methanol, which is treated with concentrated sulfuric acid in the subsequent process. Because concentrated sulfuric acid has strong oxidizing and dehydrating properties, methanol is dehydrated under the action of concentrated sulfuric acid to generate dimethyl ether, which is An important impurity in the finished product, therefore, the crude methyl chloride of preparation needs to carry out methanol removal treatment, in the prior art, often utilize the characteristic that methanol is soluble in water methanol is eluted, but existing scrubber is to methanol The elution efficiency is not high, and the methanol content in the wastewater eluted each time is not high, resulting in high wastewate...

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Problems solved by technology

[0002] Methyl chloride prepared in the production of glyphosate contains methanol, which is treated with concentrated sulfuric acid in the subsequent process. Because concentrated sulfuric acid has strong oxidizing and dehydrating properties, methanol is dehydrated under the action of concentrated sulfuric acid to generate dimethyl ether, which is An important impurity in the finished product, therefore, the crude methyl chloride of preparation needs to carry out methanol removal treatment, in the prior art, often utilize the characteristic that methanol is soluble in water methanol is eluted, but existing scrubber is to methanol The elution efficiency is not high, and the methanol content in the wastewater eluted each time is not high, resulting in high wastewater treatment and recovery costs. At the same time, the existing elution wastewater treatment methods mostly use heating tanks to directly heat and evaporate the wastewater, although Equipped with a stirring device for stirring and heat exchange, but the middle and edge parts of the heating tank are still heated unevenly, the methanol in the middle part is difficult to fully evaporate, and the overheating of the edge part leads to excessive evaporation of water, resulting in low purity of the final collected fractions and methanol content in the discharged wastewater High, requires multi-stage processing

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