A systematic method is proposed to integrate reactor and extractive distillation, and identify the optimal solvent, solvent to feed ratio and extractive distillation sequence. The relation among reactor parameters, the reactor effluent and the feed of extractive distillation is deduced, and the energy consumption of distillation is evaluated based on the marginal minimum vapour rate. Based on this, the influence of the reactor’s operating parameters is analyzed, and the optimal extractive distillation sequence and the optimal reactor parameters are identified. Furthermore, the energy consumption is evaluated to target the optimal solvent to feed ratio. A case is studied to illustrate the application of the proposed method.