Sustainability Comparison of Glycidol and Ethylene Oxide in Reactive-Extractive Distillation across Distinct Azeotropic Systems

One of the promising technologies to separate water-containing ternary azeotropic mixtures is reactive-extractive distillation (RED). Nevertheless, the choice of reactant and process configuration remains highly system-specific and is still poorly addressed in the literature. While ethylene oxide (EO) is widely used in RED applications, glycidol (GD) has only been reported for the separation of tetrahydrofuran (THF)/methanol (MeOH)/water systems. As a result, it is still unclear whether stronger relative-volatility enhancement or higher reaction enthalpy alone leads to better RED performance, or if other factors play a decisive role. To close this gap, this study presents the first cross-system evaluation of GD-based RED by benchmarking its economic and environmental performance against EO-based RED for two azeotropic mixtures: THF/ethanol (EtOH)/water and 1,4-dioxane (Dio)/EtOH/water. Both double-column RED (DCRED) and thermally coupled DCRED (TC-DCRED) configurations are examined. The processes are optimized using a multi-objective genetic algorithm, aiming to minimize total reboiler duty while maximizing total net revenue (TNR). Beyond the optimization objectives, the resulting optimal designs are further evaluated in terms of carbon dioxide (CO 2 ) emissions, reboiler duty, total annual cost (TAC), and TNR. The results show that GD-based RED delivers higher TNR (up to 67.4%) than EO-based RED. However, this higher profitability is accompanied by increased energy consumption (up to 287% in the RED column), CO 2 emissions (up to 160%), and TAC (up to 74.8%), revealing a clear trade-off between economic gains and sustainability. Only the GD-based TC-DCRED for the THF/EtOH/water system shows a slight TAC advantage over its EO-based counterpart, at just 1.84% lower TAC. Overall, the findings highlight that reactant and configuration choices in RED should be made on a system-specific basis using integrated economic and environmental criteria.