Patent ID: 7393976

Claim:
A method of purifying (meth)acrylic acid comprising: a. directing a (meth)acrylic acid stream containing at least (meth)acrylic acid and water and at least one aldehyde compound to a distillation system; b. adding at least one aldehyde treating compound capable of reacting with said at least one aldehyde compound to the (meth)acrylic acid stream, such that said at least one aldehyde compound reacts with said at least one aldehyde treating compound to produce a first product having a higher boiling point temperature than (meth)acrylic acid; c. adding at least one reactive drying agent to the distillation system, wherein said at least one reactive drying agent is capable of reacting with said water such that said at least one reactive drying agent reacts with said water to produce a second product having a higher boiling point temperature than (meth)acrylic acid, wherein said at least one reactive drying agent is selected from the group consisting of acetals, ketals, halogenated anhydrides, isocyanates, 1,3-phenylene diisocyanate, tetramethoxy-1,4cyclohexadiene, trifluoroacetic anhydride, and combinations thereof; and d. separating said first and said second products from said (meth)acrylic acid stream by distillation to produce a high purity (meth)acrylic acid stream comprising less than 1 wt % impurities, less than 5 ppm furfural, and not more than 0.2 wt % water based on the total weight of the (meth)acrylic acid product.