The synthesis of distillation processes has been the subject of research for more than 50 years. Typically, the synthesis problem starts from a set of preestablished connections between steams and unit operations resulting in distillation sequences, which can be included in superstructure representations. Finally, the superstructures are reformulated as mathematical programming problems. Nevertheless, in the last decades, novel approaches to process synthesis that depart from the concept of unit operation and are based on a phenomenological approach have been proposed. This work decomposes distillation structures into distillation modules, where a module is equivalent to a vapor-liquid equilibrium stage in which inlet and outlet material and heat flows connect modules. Also, a process synthesis and intensification (PS+I) framework is proposed for the synthesis of distillation structures separating ternary mixtures. A novel mathematical relaxation is proposed to cover any composition that is not explicitly included in the modules. In other words, if there is a feasible path of material and energy flows, there will be a solution for the synthesis problem. The proposed framework has the following steps: database generation of distillation modules, optimization, solution interpretation, validation, and post-optimization. The separation of the BTX ternary mixture was taken as a study case and several interpretation guidelines have been proposed to help users at the interpretation step.