Acrylic acid cracking process

The bottoms from the foreruns column are fed to the product column where the glacial acrylic acid of commerce is taken overhead Bottoms from the product column are stripped to recover acrylic acid values and the high boilers are burned The principal losses of acrylic acid in this process are to the aqueous raf finate and to the aqueous layer from the dehydration column and to dimerization of acrylic acid to 3-acryloxypropionic acid If necessary, the product column bottoms stripper may include provision for a short-contact-time cracker to crack tliis dimer back to acrylic acid (60). 

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