Abstract
A concept of hypothetical pinch plate which is distinguished from the real pinch point has been proposed to solve the minimum reflux problem of nonideal multicomponent distillation for the operation type. It is assumed that the hypothetical pinch plate takes at a place between the real pinch point and the feed plate in the section where the nondistributed component exists. Any nondistributed component does not exist in the real pinch point, but an allowable small amount of nondistributed component exists in the hypothetical pinch plate. The composition of distillate and bottoms has been calculated by using the component relative volatility evaluated from the liquid composition of the hypothetical pinch plate or the feed plate. Also the normalized θ''s method has been applied to converge the liquid composition of hypothetical pinch plate and the over-all component material balance.
