Industrial decarbonization is considered as one of the key objectives in the global effort to respond to climate change. According to estimates by the International Energy Agency (IEA) [1], the industrial sector, including the power industry, accounts for a major portion of overall CO2 emissions. In order to achieve a net-zero industry, energy supply with less use of fossil fuel-based facilities and replacing them with renewable energy sources should be actively implemented. However, without addressing the intermittent nature of renewable energy sources, a consistently reliable and robust supply of energy to the industrial site is not possible.
Therefore, the integration of renewable energy systems with existing industrial processes, subject to energy storage and main grid interconnection, should be investigated to improve operational reliability and enhance the energy resilience of the total site. Previous studies [2] were limited to accurately reflect the flexibility and/or constraints associated with renewable energy production, as the power demand of the utility systems was simply met with electricity import from external renewable sources.
In this contribution, a novel process design and optimization framework is proposed for industrial utility systems integrated with renewable energy sources. A multi-period approach is adopted to consider variable demand and non-constant availability in renewable energy supply. The model also explores energy integration at the microgrid level, which enables various scenarios for the industrial utility system, including the sales of surplus electricity or steam generated beyond the site demand. Moreover, carbon capture is considered in this work as a viable decarbonization measure, which can be strategically combined with renewable-based electrification.
The optimization model is constructed to evaluate the economic trade-offs of integrating carbon capture, renewable energy, and energy storage. With the proposed approach, design guidelines for the transition of a conventional steady-state utility system with renewable energy can be systematically obtained, which ensures economically-viable and sustainable energy management in process industries. In a case study of an industrial utility system, the novel integrated design approach developed in this study was shown to reduce overall energy costs by 6%, compared to the conventional approach of purchasing renewable electricity
Reference
[1] International Energy Agency, CO2 Emissions in 2022, IEA, Paris, 2023. https://www.iea.org/reports/co2-emissions-in-2022
[2] H. Park, J-K. Kim, and S.C. Yi. Optimization of site utility systems for renewable energy integration. Energy, 269, 126799, 2023. https://doi.org/10.1016/j.energy.2023.126799
