A SIMPLE SYNTHESIS METHOD BASED ON UTILITY BOUNDING FOR HEAT-INTEGRATED DISTILLATION SEQUENCES

A new method is presented which will enable engineers to select better heat-integrated distillation systems quickly and easily. The key to this method is making the assumption that Q DELTA T, the product of the condenser or reboiler duty and the temperature difference between the reboiler and condenser, is constant for a single distillation task over a wide range of pressures. Using this assumption and the principles of multieffect distillation, a lower bound on the utility use for single distillation tasks and for distillation sequences is readily calculated for designs involving simple two-product columns that may or may not be multieffected. This also describes methods which can be used to synthesize distillation systems which approach these bounds. An algorithm is also presented which develops the least cost distillation system for separating a multicomponent feed.