Page 83 - Chemical and process design handbook

Speight_Part II_A 11/7/01 3:16 PM Page 2.24

2.24 MANUFACTURE OF CHEMICALS
Steam
Air
Acrolein
Off-gas
Propylene

Salt Salt

Aqueous acrylic
acid

Reactor Reactor Absorber
FIGURE 1 Manufacture of acrolein and acrylic acid by oxidation of propylene.

tion refining steps separate water and acetaldehyde (CH CHO) from the
3
crude acrolein. In another distillation column, refined acrolein is recovered
as an azeotrope with water.
The principal side reactions produce acrylic acid, acetaldehyde, acetic
acid, carbon monoxide, and carbon dioxide, and a variety of other aldehydes
and acids are also formed in small amounts.