As an extension to our earlier work (1999a), this article presents a systematic approach for the synthesis of combined separation/reaction systems which involves a phenomena-based representation formulated within a superstructure optimization framework. A multifunctional, mass-/heat-transfer-based process module is utilized as the building block of process alternatives. Within this module, Gibbs-free-energy-based "driving-force" constraints are introduced to describe the physiochemical phenomena and to ensure feasibility of pure separation, reaction or combined separation/reaction (such as reactive distillation). A superstructure of these multipurpose modules is then systematically constructed to represent process alternatives, which are not explicitly pre-postulated, but investigated as mass and heat exchange network possibilities.