Coupling process simulation and life cycle assessment for the eco-design of bio-based ethyl acetate microbial production

The study investigates the environmental performance of the production of ethyl acetate through the integration of simulation and life cycle assessment. A process model was developed to evaluate the influence of operating parameters, including glucose concentration, air flow rate, and agitation speed, on ethyl acetate production performance. Agitation and input airflow were adjusted according to oxygen demand and mass transfer requirements to maintain process performance, while glucose concentration was varied to represent changes in substrate availability. The simulation results were used to generate the life cycle inventory, and the environmental impacts were assessed using the EF 3.1 method. The study evaluates multiple operating scenarios, where the base case scenario (Scenario 1) represents the reference laboratory-scale operating conditions. Five impact categories emerge as the most significant contributors to the environmental impact of ethyl acetate production: Climate change, resource use fossils, resource use minerals and metals, photochemical ozone depletion, and water use. The results identified glucose production from maize starch as the main environmental hotspot due to agricultural activities, while energy-intensive steps such as agitation and condensation significantly contributed to the overall impact in the operation stage. Increasing concentration of glucose, while determining the agitation speed and airflow through calculations to prevent oxygen limitation, improved production performance by 61% while reducing environmental impact by 9% compared to scenario 1, highlighting the importance of process optimization. This study demonstrates that coupling process simulation with LCA provides a powerful approach for linking process design to environmental performance and supports the development of sustainable bioprocesses.