Patent ID: 8748545
Filing Date: 2014-06-10
Classification: C07C,C08F

Abstract:
1. A process for manufacturing polymer grade acrylic acid using naturally renewable starting materials comprising at least the steps of: i) dehydrating glycerol to form acrolein; ii) oxidizing the acrolein to form acrylic acid; iii) extracting the acrylic acid by countercurrentwise absorption and forming an aqueous acrylic acid solution; iv) dehydrating the aqueous acrylic acid solution in the presence of at least one solvent to form an acrylic acid mixture, wherein the solvent is immiscible with water and capable of forming an azeotrope with water; v) removing one or more light compounds from the acrylic acid mixture by distillation; vi) removing one or more heavy impurities from the acrylic acid mixture by distillation to form a technical grade of acrylic acid; and vii) purifying by distilling the technical grade of acrylic acid and adding at least one amino compound which reacts with aldehydes in the technical grade acrylic acid to form polymer grade acrylic acid, wherein the polymer grade acrylic acid contains greater than 99% by weight of acrylic acid, less than 5 ppm protoanemonin, less than 10 ppm total aldehydes, less than 30 ppm maleic anhydride, less than 10 ppm nonphenolic polymerization inhibitors, and a content by weight of