Feasible products in complex batch reactive distillation

Abstract

A new feasibility evaluation procedure for reactive mixtures is presented, where simple homogeneous reactive batch columns cannot produce pure products. Such columns are not feasible for producing pure products if no node products exist that are reachable by residue curves from the reaction equilibrium manifold. Three alternatives are presented. If an unstable node heterogenous azeotrope decants to an almost-pure product, and that azeotrope is always reachable from the reaction equilibrium manifold, then a batch reactive rectifier can produce pure products with a decanter. If a homogeneous entrainer allows extractive section profiles to connect the reaction equilibrium manifold to an entrainer-product binary edge, then a homogeneous batch reactive extractive distillation (BRED) column can produce a pure product. If these criteria are not met, then an entrainer that induces an unstable node heterogenous azeotrope between itself and one of the products should be used in a rectifier, a middle-vessel column, or a BRED column. (c) 2006 American Institute of Chemical Engineers.