PRESSURE SENSITIVITY ANALYSIS OF AZEOTROPES IN SYNTHESIS OF DISTILLATION COLUMN SEQUENCES

摘要

A new algorithm for pressure sensitivity analysis of azeotropes has been developed. It applies bifurcation theory together with an arc lenght continuation. This allows not only to track the composition of azeotropes as they change with pressure but also to find new azeotropes that appear at a particular pressure within specified pressure range. The algorithm is very effectient and the computationaltime required for the azeotrope's preessure sensittivity analysis is in the order of finding all azeotropes at constant pressure using homotopy method. Appearance or disappearance of azeotropes as the pressure changes has immense effect on the topol9gy of the residue curve map for the separated mixture and on the feasibility of the distillation sequence. However,the mere change of composition produces changes on the distillation boundaries and opens up opportunities for novel designs. The analysis provides very useful information for design of azeotropic distitillation sequences and shows opportunities for pressure swing distillation. In the paper, a few illustrative examples of pressure sesitivity analysis of azeotropes and synthesis of distillationcolumn sequences for separation of multicomponent azeotropic mixtures are presented.