Toward Sustainable and Cost‐Effective CO2 Conversion Processes to Propylene Carbonate Based on Ionic Liquids

The use of ionic liquids (ILs) for CO2 capture and utilization into a valuable product is attracting interest even though literature evaluating their sustainability is scarce. A liquid–liquid extraction (LLE)‐based separation is recently proposed as an alternative to the high energy‐consuming distillation‐based reference approach to produce propylene carbonate (PC). In this work, the environmental impacts associated to the distillation‐based reference and two proposed LLE‐based approaches to produce PC are evaluated by means of process modeling and life cycle impact assessment tools. Simulations prove that tuning operating variables in terms of environmental benefits also improves the cost‐effectiveness of the process. In addition, sustainability of the processes is nearly not altered by the IL selection when an effective recovery is designed. The emissions associated to the proposed approaches vary between 0.12 and 0.22 kg CO2 equiv. per kgPC, while the operational costs range from 3 to 8 $ per tPC. The water‐mediated LLE‐based approach imposes the best environmental, capital expenditures, and operating expenses performance. In this work, process simulation and life cycle assessment tools are employed to evaluate the sustainability of three different CO2 conversion processes to propylene carbonate. It is found that improving the processes in terms of sustainability also improves the techno–economic evaluation outcomes. Overall, using water as the extracting agent provides the best results.