REACTIVE DISTILLATION OF PYRIDINE MIXTURES WITH AN ORGANIC-ACID .2. PARAMETRIC SENSITIVITY AND OPTIMIZATION OF THE PROCESS

A process of separation of close-boiling mixture by reactive distillation, exemplified by 3-/4-picoline separation through complexation with trifluoroacetic acid, has been analyzed in detail by numerical simulation. In such a process, the separation selectivity is supplied by a reversible chemical reaction and a displacement agent is used to regenerate the isomers. Parameter sensitivity analysis has shown the fundamental role played by the displacement agent in the regeneration as well as in the separation when the two isomers have to be recovered with the same purity. Optimization has shown that the displacement agent should ideally have an affinity for the reactive agent intermediate between that of the isomers to be separated. This affinity is measured by the ratio of the relative volatility to the chemical selectivity.