Writing for designers and operators of separation units in the chemical, pharmaceutical, food, and related industries as well as software designers, F.B. Petlyuk presents a clear, multidimensional geometric representation of distillation theory valid for all types of distillation column types, splits, and mixtures. DistillDesigner software allows refinement and confirmation of the algorithms of optimal design. Methods of the general geometric theory of distillation, encoded in DistillDesigner, provide quick and reliable solutions to problems of flowsheet synthesis and to optimal design calculations.