Electrification in the Petrochemical Industry: Can Flexibility Enable Low-Carbon Utility Systems?

Electrifying the utility supply of existing petrochemical processes is a potential measure for CO₂ emission reduction in the chemical industry. With an increasing share of variable renewable energy sources in the electricity grid, electricity price fluctuations will become more frequent. However, most existing petrochemical processes operate continuously and, therefore, require a constant supply of utilities. In this paper, we model an electrified utility system that includes different types of storage units to explore how a constant utility demand could be supplied under fluctuating electricity prices. To achieve this, we model a utility system that provides electricity and heat to an olefins plant in the Port of Rotterdam and use mathematical optimisation to capture optimal hourly operations of the plant under fluctuating prices. We find that the cost-optimal utility system consists of electric boilers, integrated thermal energy storage, and technologies for storing and using hydrogen produced on-site. With data for prices of the Dutch electricity grid in 2022, the electrified utility system results in higher costs than a fossil-based system. Increasing price fluctuation levels would lead to lower operational costs as the system's flexibility enables shifting the electricity consumption to the hours with the lowest electricity prices.