Iso-Amyl Acetate Synthesis by Catalytic Distillation

Abstract

With ever-growing environmental concerns, petrochemical and fine chemical industries face an omnipresent issue in recovering dilute acetic acid from its aqueous solutions. Catalytic distillation holds an ascendancy over conventional physical separation methods such as distillation and extraction. Distillation is associated with the high costs involved in vaporising the more volatile water that exists in high proportions and possesses a high latent heat of vaporisation. Extraction is limited in view of the distribution of the components in the reacting system. The implementation of catalytic distillation reduces capital and operating costs, and allows for a wider range of operating conditions. Catalytic distillation is receiving increasing attention and holds a huge potential for the recovery of acetic acid. Through the application of catalytic distillation via the reaction of acetic acid with iso-amyl alcohol, a useful ester in the form of iso-amyl acetate could be produced.In the present work towards further process development, the synthesis of iso-amyl acetate via reactive distillation is studied using Katamax® catalyst packing in the catalytic reactive section. The reactive distillation experiments were carried out at laboratory scale in a 50 mm diameter column with a catalytic packing section of 1 m and non-reactive packed enriching and stripping sections of about 1 m each. A cation exchange resin catalyst, Purolite® CT-175, was used. The experiments were conducted with the aim of achieving an optimum column configuration as well as process conditions for the synthesis of iso-amyl acetate in a reactive distillation column (RDC). Several variants of the RDC set-up e.g. total feed mole ratio, reflux ratio, location of feed points, reflux configuration and acid concentrations were explored for the recovery of dilute acetic acid and to achieve a high purity value added product, iso-amyl acetate.