Separative work of separating unit for asymmetric process

The value function for a symmetric process depends only on the concentration, and is independent of the separation factor of the separator. In the case of an asymmetric process, however, the value function depends not only on the concentration but also on the separation factor of the separator. The values of the net separative work provided by cascades (net separative work meaning the total value for the separators in all the stages of the cascade minus the mixing losses in the cascade)-even when operated under identical conditions (rate and concentration) of product, feed and waste-vary with this value function, which is applied to derive the net separative work of the cascade. In order to eliminate this inconsistency, a normalization factor η is in troduced to normalize the net separative Work of the cascade. And a method is proposed of utilizing this normalization factor to make comparisons of the separative work between separators possessing different separation factors. It is shown that the value of η deviates rapidly from unity with accentuating asymmetry of the separation process. It is concluded that normalization such as proposed above is indispensable for comparing the values of the separative work by separators. possessing a large degree of the separation process asymmetry. (author)