Alternative processes for production of anhydrous ethanol through salt extractive distillation with reconstitution of the separation agent

Two process flowsheets were proposed for the production of anhydrous ethanol from a diluted aqueous solution of ethanol via extractive distillation with potassium acetate. In the first process, the diluted ethanol is directly fed in a salt distillation column and the salt is recovered in an evaporation system and in a spray dryer. In the second one, the diluted ethanol is pre-concentrated in a pre-concentration column and subsequently submitted to the salt distillation. In this case, the salt is recovered only in a "spray" dryer. In both the processes, the salt is recovered as a solid and is recycled in the extractive column. The equipment used in the processes was modeled separately and rigorously. Afterwards, they were connected for the global simulation of the plants. The results showed that the process with pre-concentration of diluted ethanol is more feasible in terms of energy consumption than the process without pre-concentration.