Process for recovering butyl acrylate substantially free from acrylic acid

摘要

A process for producing continuously recovering n-butyl acrylate substantially free of acrylic acid from an esterification reaction mixture, comprising the steps of: a) feeding continuously to an esterification reactor acrylic acid and n-butanol in a molar ratio of acrylic acid to n-butanol of from 1 to 1.1 to 1 to 1.7, and an acid catalyst; b) reacting the acrylic acid and n-butanol to yield n-butyl acrylate in a conversion of at least 60% based on acrylic acid, and yielding the esterification reaction mixture comprising acrylic acid, n-butyl acrylate, n-butanol, water, heavy ends, and acid catalyst; c) distilling from the esterification reactor a vaporized mixture comprising acrylic acid, n-butyl acrylate, n-butanol, and water; d) condensing the vaporized mixture to provide a first condensate comprising an organic phase and an aqueous phase; e) returning from 0 to 30 percent of the organic phase to an entrainment separator surmounting the esterification reactor; and f) feeding from 70 to 100 percent of the organic phase and from 50 to 100 percent of the aqueous phase to an acrylic acid separation column; g) distilling from the acrylic acid separation column, at a pressure of from 35 to 800 mm Hg, in an aqueous mode and at an aqueous reflux ratio of 8.5:1 to 17:1, an overhead mixture comprising an azeotropic mixture of n-butanol, n-butyl acrylate and water; h) removing from the distillation column an acrylic acid-rich bottom stream; i) recycling the acrylic acid-rich bottom stream from the acrylic acid separation column to the esterification reactor; j) condensing the overhead mixture to provide a second condensate; k) separating the second condensate into a n-butyl acrylate-rich organic phase and a separated aqueous phase; and l) removing the n-butyl acrylate-rich organic phase substantially free of acrylic acid.