Low-carbon economic optimization of integrated energy system with calcium-based carbon capture coupled with hydrogen utilization at multiple time scales

Due to the expected requirements for carbon mitigation, the present work proposes an integrated energy system combining calcium-based carbon capture with hydrogen energy utilization and demonstrated its superiority with in-depth discussion. Moreover, a multi-timescale optimal dispatch model with the objective of minimizing operating costs is established to obtain the optimal operating strategy. Through day-ahead, intra-day, and real-time three-stage rolling optimization, it coordinates the dispatch of flexible resources including carbon capture devices, electrolyzers, hydrogen fuel cells, and methane reactors. The developed system in present work can significantly enhance energy supply flexibility by leveraging the thermochemical energy storage characteristics of calcium-based carbon capture and the multi-energy conversion advantages of hydrogen energy. It is found that the calcium-based carbon capture technology reduces energy loss and enhances thermal load regulation by absorbing renewable energy and recovering waste heat. Furthermore, hydrogen energy, through diversified utilization, can collaboratively regulate electricity and thermal energy supply, providing a rapid response to load fluctuations. Compared to the traditional energy systems during the day-ahead phase, the total operating costs and carbon emissions are reduced by 6.8 % and 7.2 %, respectively. At final, through the multi-timescale optimization, the coupled system significantly reduces the deviation between the unit output and the day-ahead schedule, owing to the efficient utilization and conversion of energy.