Patent Number: 6,252,110

Title: Methods for recovering acrylic acid

Abstract: A method for recovering acrylic acid from high boiling impurities containing acrylic acid dimer, acrylic acid and maleic acid at high efficiency with stability which includes the steps of (1) introducing said high boiling impurities containing acrylic acid dimer, acrylic acid and maleic acid into an acrylic acid recovery column, distilling acrylic acid from the column top and recovering the same, (2) introducing bottom liquid A from said acrylic acid recovery column into a pyrolyzing tank to decompose the acrylic acid dimer in the bottom liquid A, and (3) recirculating at least a part of bottom liquid B from said pyrolyzing tank into the acrylic acid recovery column.

Inventors: Uemura; Masahiro (Himeji, JP), Takeda; Takahiro (Himeji, JP), Ueoka; Masatoshi (Himeji, JP)

Assignee: Nippon Shokubai Co LTD

International Classification: B01D 3/14 (20060101); C07C 51/44 (20060101); C07C 51/487 (20060101); C07C 51/42 (20060101); C07C 057/02 ()

Expiration Date: 06/26/2018