Technological method for separating methanol, acetonitrile and benzene tertiary mixture

Abstract

The invention relates to a technological method for separating a methanol, acetonitrile and benzene tertiary mixture. According to the method, a preliminary separating column is arranged, and methanol is introduced to change a distillation area of the mixture so that the distillation end point develops towards a methanol-benzene binary mixture, wherein the acetonitrile content of the mixture is nearly 0 when the mixture enters a difficult separating area, and thus methanol-benzene is extracted from a column top and methano-acetonitrile is extracted from a column bottom. By utilizing the method, a tertiary material system is decomposed into two binary material systems under the condition of not introducing a fourth material; the methanol-benzene mixture which is extracted from the column top can be decomposed so as to respectively obtain over 99.0% of the methanol and over 99.0% of benzene through pressure-swing distillation; and a methano-acetonitrile mixture which is extracted from the column bottom can be decomposed so as to respectively obtain over 99.0% of the methanol and over 99.0% of acetonitrile through pressure-swing distillation.

Description

technical field [0001] The invention relates to a method for separating a three-component mixture, in particular to a method for effectively separating methanol, acetonitrile and benzene mixture without adding an external solvent. Background technique [0002] Methanol, acetonitrile, and benzene are excellent organic solvents, and are raw materials for synthetic fuels, paints, medicines, pesticides, and various petrochemical products, and are widely used in many industries such as organic synthesis, plastics, resins, and medicine. When industrially producing a certain cephalosporin intermediate, the intermediate product needs to be treated with acetonitrile-benzene mixture, so part of the acetonitrile-benzene is mixed with the intermediate product, and methanol needs to be added for the next reaction. After the reaction, the waste liquid is separated into methanol , a mixture of acetonitrile and benzene. However, there is azeotropy between most solvents, which makes the sep...

AI Technical Summary

Problems solved by technology

However, there is azeotropy between most solvents, which makes the separation process difficult

In recent years, there have been many effective separation methods for binary azeotropic systems, but the separation of three-component systems is extremely difficult due to the more complicated relationship between components and forces.

The separation method of the binary azeotrope system can no longer fully meet the separation requirements of the ternary azeotrope system

Moreover, the three-component mixture will form a ternary azeotrope, making separation very difficult

So far, there are no related articles and patents on the method and process of the separation of the three-component system

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