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

Abstract

The electrification of naphtha cracking for ethylene production could reduce the associated CO 2 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 CO 2 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.

Thermal Electrification of Chemical Processes Using Renewable Energy: Economic and Decarbonization Impacts

“…We will focus here on the use of a different form of direct electrification, namely, the replacement of thermal energy from combustion, such as in a gas-fueled furnace, with some form of electrically generated heat (e.g., resistance heating, induction heating, and plasma heating). Examples of both direct and indirect electrification and their impact on a methanol process have been given by Chen et al, and Tiggeloven et al have explored options for the direct electrification of thermal cracking processes for ethylene production. We will consider an agile scenario whereby a system of chemical manufacturing processes is supported by a hybrid heating system, in which production can be fully electrified (all fossil-based combustion heating replaced with electrical heating), conventional (fully fossil-based combustion heating), or anywhere in between.…”