heat integration of the extractive distillation process for separation of ethanol and water azeotropic mixture

The extractive distillation process is carried out to separate the minimum boiling azeotropic mixture of water and ethanol including ethylene glycol as entrainer, consists of two distillation columns, one of which is the main column and the other is the column for recovering ethylene glycol. taking into account that the distillation columns consume a large amount of energy, a considerable part of the costs of this process is related to the consumption of hot and cold utility in the reboilers and condensers of the distillation columns. therefore, the optimization of energy is quite necessary during this process. the present study utilized a method for splitting feed for the purpose of heat integration of the process. in this method, the feed is divided into two sections, and its bottom section is preheated through a process stream. this method considerably reduced the thermal load of the reboiler. according to the results, in comparison to the conventional extractive distillation process, the process of extractive distillation using the method of splitting the feed reduces the consumption of hot and cold utility down to 32.52% and 33.14%, respectively.