Composition Estimation of Reactive Distillation Systems and Its Implication to Feasibility

This work presents a new mathematical procedure for estimating the liquid still composition trajectory of batch reactive distillation systems. Simple information such as material balance and reaction equilibrium will be utilized to estimate liquid trajectory of simultaneous reaction and V-L separation. The trajectory information is essential to determining whether products are reachable when several distillation boundaries are present, initial feed compositions can vary, and the number of components exceeds our visualization capability. For a given feed to product flow ratio with constant feed charge and product compositions, the still pot composition trajectory is mathematically confined to the intersection between the reaction equilibrium manifolds and a “material balance plane” that is the union of stoichiometric lines and material balance rays connecting still and product compositions. Starting from this estimated still pot trajectory, we can evaluate the feasibility of various batch reactive distillation configurations by constructing the residue curves for non-extractive cases and the feasible region formed by upper and lower bounds of reflux ratios for extractive cases.