Thermodynamic Assessment of the Reactive Distillation Process for Anhydrous Ethanol Production Via Ethylene Oxide Hydration

Objective: This study evaluates the technical feasibility of reactive distillation for the separation of the ethanol/water azeotrope, considering operational, thermodynamic, and economic aspects of the process based on the hydration reaction of ethylene oxide (EO) and the effects of consecutive reactions leading to the formation of diethylene glycol (DEG) and triethylene glycol (TEG). Theoretical Framework: The research is supported by process intensification principles, with emphasis on reactive and extractive distillation techniques. The thermodynamic analysis combines the First and Second Laws of Thermodynamics to assess process irreversibilities and their impact on overall efficiency. Method: Steady-state simulations were performed in Aspen Plus™, considering different reactive scenarios. Results were compared to a conventional extractive distillation configuration using thermodynamic and economic performance metrics. Results and Discussion: Consecutive reactions increased thermodynamic inefficiency; however, reactive distillation still exhibited superior performance in terms of specific energy consumption (SEC) and total annual cost (TAC). The competitive nature of parallel reactions directly influenced process efficiency. Research Implications: The findings underscore the importance of integrated approaches in selecting separation routes, considering not only energy-related criteria but also the impact of reactions inherently associated with real operating conditions. Originality/Value: This study presents an original approach by quantifying the impact of consecutive reactions on reactive distillation, expanding the understanding of its limitations and potential compared to conventional alternatives.