The thermally coupled distillation flowsheets for multicomponent separations are discussed on the basis of the intended individual splits. Then, the generation of the thermally coupled distillation flowsheets with a lower number of thermal couplings than the partially coupled scheme is presented. A formula is presented to calculate the number of feasible schemes with a lower number of thermal couplings. An integrated framework is formulated for parametric design and synthesis of the optimal thermally coupled distillation flowsheets for multicomponent separations. Based on the results of the calculations, significant insights have been made which are very helpful to the design and synthesis of the optimal thermally coupled distillation schemes for multicomponent separations. It has been found that a thermally coupled scheme with a lower number of thermal couplings could be more advantageous than one with thermal couplings introduced for all of its internal submixtures for a specific simple column configuration.