Endeavoring towards greater sustainability has driven process industries to search for opportunities to decrease the production costs, energy consumption, equipment size, and environment impact as well to improve the raw material yields, remote control and process flexibility. Process intensification (PI), which is defined as a set of innovative principles applied to the design of process and equipment to satisfy all those concerns, has become the main trend for improving the process performance. PI is utilized widely in heat transfer, reaction, separation, and mixing, which results in plant compactness, cleanliness and energy efficiency. This paper reviews briefly some of the main intensified separation processes and improvement mechanisms. This study focused mainly on the PI of distillation processes, which are the most important separation methods. In addition to these technologies, the potential and reliability of reactive separation processes are addressed briefly, which would enable industry to achieve higher efficiencies and high capacities. The authors propose and evaluate the membrane-assisted reactive dividing wall column (MRDWC), which is an innovative configuration combining reactive distillation used to overcome chemical equilibrium, and a dividing wall column used to save energy, with a membrane used to overcome the azeotrope in azeotropic distillation systems. Recent developments in current research are summarized to highlight the importance as well as the effects, challenges and future prospects of PI.