Method for extracting and separating methylal-methanol mixture by using continuous countercurrent rotating disk

Abstract

The invention discloses a method for extracting and separating a methylal-methanol mixture by using a continuous countercurrent rotating disk, which comprises the following steps: by using polyalcohol as an extractant, the methylal-methanol mixture and the extractant enter a rotating disk extraction column in a countercurrent form, the two liquid phases sufficiently contact each other in the rotating disk column to complete the extraction process, the extract phase stands and deposits in the column kettle, and the raffinate stands and is enriched on the column top; the column top raffinate is distilled in a methylal treating column, and then can be directly used as the methylal product; and the column kettle extract phase is distilled in a regenerating column to remove methanol, thereby obtaining the methanol product on the column top, and the column kettle extractant can be recycled. The method disclosed by the invention has the advantages of simple technical steps, stable product quality and lower energy consumption; and the raw material liquid can be continuously extracted, so as to obtain the methylal of which the content is higher than 99.8% in one step and also obtain the methanol of which the content is higher than 98%.

Description

technical field [0001] The invention relates to a chemical separation method, in particular to a continuous countercurrent liquid-liquid extraction separation method of a methylal-methanol mixture. Background technique [0002] Methylal has excellent physical and chemical properties, such as good solubility, low boiling point, and good compatibility with methanol, and can be widely used in cosmetics, medicines, household products, industrial automotive supplies, insecticides, leather polishes, cleaning Agents, rubber products, paints, inks and other products. At present, chloramphenicol by-product method and acid catalysis method are widely used to prepare methylal. Regardless of the acid catalysis method or the chloramphenicol by-product method, the product after the reaction is a mixture of methylal-methanol, and there is a subsequent separation problem. Due to the azeotropic phenomenon between methylal and methanol, the azeotrope point is 41.85°C, and the azeotrope cont...

AI Technical Summary

Problems solved by technology

Due to the azeotropic phenomenon between methylal and methanol, the azeotrope point is 41.85°C, and the azeotrope contains 91.8% methylal, so it is difficult to obtain high-purity methylal products by ordinary distillation

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