Optimization of Electric Ethylene Production: Exploring the Role of Cracker Flexibility, Batteries, and Renewable Energy Integration

The electrification of naphtha cracking for ethylene production could reduce the associated CO₂ emissions but would require significantly larger electricity consumption. Within this context, the flexible operation of electric crackers opens opportunities for improved integration with the future electricity system. In this work, we developed a computationally efficient mixed-integer linear programming model to investigate flexibility in electric crackers, exploring the effect of operational parameters, such as operating envelope, ramping time, and start-up/shut-down time, on costs and emissions. We optimized three electric cracker systems: two with grid electricity consumption (with/without batteries) and one with electricity supply from dedicated renewable technologies. We find that the operating envelope of the cracker has the strongest impact on cost savings, enabling up to 5.5% reduction when using flexible electricity from the grid and 58% for systems with direct coupling to renewables. Moreover, the flexible operation of electric crackers relying on the electricity grid enhances the CO₂ emission savings, achieving a 90.4% emission reduction against 54.6% of the constant operation case. Finally, we find that for direct coupling with renewables, electric crackers need to be flexible to avoid suboptimal oversizing of renewable technologies and especially unrealistic battery capacities.