For the industrial separation problem of acetonitrile/methanol/benzene involving three azeotropes, this article proposes two novel intensified configurations with chlorobenzene as solvent by extending the extractive dividing-wall column (EDWC) and side-stream extractive distillation column (SEDC) from single azeotropic to multiazeotropic mixtures and makes a comparison with a conventional extractive distillation (CED) configuration in aspects of economic and controllability. Steady-state designs are optimized via using the sequential iterations search based on minimum total annual cost (TAC). The results show that extended-EDWC and extended-SEDC compared to CED can reduce TAC by 6.32% and 14.39% and energy consumption by 4.26% and 20.59%, respectively. As far as controllability is concerned, all proposed control structures can hold products at high purities with acceptable deviations and short settle time after introducing feed flow and composition disturbances. Overall, apparent economic benefits and high energy efficiency provided by the extended-SEDC configuration can be achieved without a deterioration of control behavior for some multiazeotropic mixtures.