Can the Operating Leaves of a Distillation Column Really Be Expanded?

Residue curves and pinch point curves are used to determine the operation leaves and hence the feasible region for distillation columns operating at a specific distillate and bottoms composition for all possible constant reflux and reboil ratios. In this paper we will experimentally show that we can expand the operating leaves of the rectifying section beyond the pinch point curve by varying the reflux ratio within the distillation column, and we will also show theoretically that this method can be used to cross the simple distillation boundaries.