In this work, continuous extractive distillation processes were optimized using simulated annealing (SA). The processes were modeled in Aspen Plus and the simulated-annealing optimization algorithm was implemented in MATLAB. For the separation of acetone and methanol, the TAC of the process for each entrainer considered was lower than the initial condition taken from the literature. For the separation of n-hexane and ethyl acetate,we considered NMP, 2-methylpyridine, 3-methylpyridine, DMF, and pyrrole as possible entrainers. The results show that DMF offers the best performance and economic benefit. For the separation of n-hexane and tetrahydrofuran, the candidate entrainers were DMF, NMP, and 2-methylpyridine. DMF was again found to be the most suitable entrainer. The results show that the SA algorithm has the advantage of running automatically and has a high probability to obtain a design near the global optimum.