Comparing catalytic distillation to separate reaction and distillation for the production of diacetone alcohol

Diacetone alcohol (DAA) is produced via the aldol condensation of acetone. The reaction is severely equilibrium-limited and high conversions of acetone are only possible if the unconverted acetone is separated and recycled. The reaction, separation and recycle can either be done separately in a reactor-distillation column-recycle process (RDR) or simultaneously in a catalytic distillation (CD) column. This work compares the separate process to the simultaneous process. An anion exchange resin was used to catalyse the reaction. Under the studied reaction conditions DAA partially dehydrates to form mesityl oxide (MO) and water. The study showed that that the RDR process is the superior process in terms of DAA-MO selectivity, catalyst productivity and separation costs. The main disadvantage of the CD process is the severe catalyst-liquid mass transfer resistance of the CD column and the inability to control temperature independently from pressure.