Azeotropic rectification device and method for separating propylene glycol monomethyl ether and water

Abstract

The invention discloses an azeotropic rectification device and method for separating propylene glycol monomethyl ether and water. The azeotropic rectification device and method are characterized in that cyclohexane is adopted as an entrainer; waste liquor containing propylene glycol monomethyl ether, water and cyclohexane is added to a rectification kettle once; a rectification column is directly connected with the rectification kettle; a kettle-type reboiler is arranged on the rectification kettle; the waste liquor is heated into steam through the kettle-type reboiler and then enters the rectification column; the material at the top of the column is condensed and then transferred into the a reflux ratio controller; if the material at the top of the column is an azeotrope of cyclohexane and water, the material is fed into a phase splitting tank for phase splitting, a water phase is extracted, and cyclohexane reflows; if the material at the top of the column is cyclohexane, recovered cyclohexane is obtained; if the material at the top of the column is a transition fraction of cyclohexane and propylene glycol monomethyl ether, the material is extracted into a transition fraction storage tank; if the material at the top of the column is propylene glycol monomethyl ether, a propylene glycol monomethyl ether product can be obtained; once materials in the kettle of the column are basically the heavy components of the waste liquor, the extracting at the top of the column is stopped, and the residual materials in the kettle are discharged from the bottom part of the rectification kettle. The device and method for separating propylene glycol monomethyl ether and water are efficient and environment-friendly.

Description

Technical field [0001] The invention belongs to a process method of a chemical separation process, and further relates to a device and a method for separating propylene glycol methyl ether and water by azeotropic batch distillation. Background technique [0002] Propylene glycol methyl ether (PM) is a glycol ether solvent. The toxicity of propylene glycol ether to the human body is lower than that of glycol ether products, and it is a low-toxic ether. Propylene glycol methyl ether has a faint ether taste, but no strong pungent odor, making it more widely used and safe. Because its molecular structure has both ether groups and hydroxyl groups, its solubility is very good, and it has suitable volatilization rate and reactivity characteristics, and it has been widely used. Propylene glycol methyl ether is mainly used as solvent, dispersant, diluent, fuel antifreeze, extractant, paint and cleaning agent. Used in coatings, inks, printing and dyeing, pesticides, cellulose, acrylate a...

AI Technical Summary

Problems solved by technology

[0006] Generally, the entrainer used to separate propylene glycol methyl ether and water is benzene, but benzene pollutes the environment very seriously, and it will also have a serious impact on the health of personnel operating the equipment

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