초록

Process is disclosed for treating the reaction product of propionic acid and formaldehyde to recover methacrylic acid from an aqueous effluent wherein said effluent contains methacrylic acid, unreacted formaldehyde, unreacted propionic acid, water and by-products.

대표청구항 ▼

A process of distilling a reaction product formed by the reaction between a saturated aliphatic monocarboxylic acid compound and a formaldehyde compound and comprising unreacted saturated aliphatic monocarboxylic acid compound, an alpha,beta-ethylenically unsaturated aliphatic monocarboxylic acid co

A process of distilling a reaction product formed by the reaction between a saturated aliphatic monocarboxylic acid compound and a formaldehyde compound and comprising unreacted saturated aliphatic monocarboxylic acid compound, an alpha,beta-ethylenically unsaturated aliphatic monocarboxylic acid compound of one more carbon atom than the starting saturated aliphatic monocarboxylic acid compound, water, unreacted formaldehyde compound and by-products, which comprises fractionally distilling said reaction product whereby a sidestream comprising unreacted saturated aliphatic monocarboxylic acid compound and unreacted formaldehyde compound is removed from the central part of a distillation column, said alpha,beta-ethylenically unsaturated aliphatic monocarboxylic acid and water being removed as bottoms and overhead respectively. A process of distilling a reaction product formed by the reaction between a saturated aliphatic monocarboxylic acid compound and a formaldehyde compound and comprising unreacted saturated aliphatic monocarboxylic acid compound, an alpha,beta-ethylenically unsaturated aliphatic monocarboxylic acid compound of one more carbon atom than the starting saturated aliphatic monocarboxylic acid compound, water, unreacted formaldehyde compound and by-products, which comprises fractionally distilling said reaction product together with a non-reactive compound which entrains water and breaks or prevents the formation of a water azeotrope of said saturated aliphatic monocarboxylic acid compound under conditions whereby (1) a major proportion of said ethylenically unsaturated monocarboxylic acid compound is in the bottom of a distillation column, (2) a major portion of the water, a portion of aid formaldehyde compound and a major portion of said compound capable of breaking or preventing the formation of said azeotrope are removed overhead and (3) a sidestream comprising unreacted saturated aliphatic monocarboxylic acid compound and unreacted formaldehyde compound is removed from the central part of said distillation column.