Abstract: The integration of carbon capture and storage(CCS) technology with power-to-gas(P2G) is a critical pathway for achieving low-carbon operation in integrated energy systems(IES). To address the challenges of insufficient renewable energy utilization and the limited regulation capability and suboptimal carbon reduction effects of traditional flue gas diversion CCS, this study proposes a low-carbon economic dispatch model for IES, coupling liquid-storage-based CCS with a dual-stage, multi-hydrogen-use P2G system. Firstly, a liquid storage tank and a multi-hydrogen-use structure comprising hydrogen fuel cells (HFC) and hydrogen-blended microturbines(MT) are introduced, forming the coupling structure and model of liquid-storage-based CCS and the dual-stage P2G system. Secondly, a chance-constrained algorithm is employed to manage the uncertainties in wind and solar power output. Finally, a low-carbon economic dispatch model for electricity-heat-gas-hydrogen-cooling IES, incorporating a tiered carbon trading mechanism, is proposed to quantitatively evaluate the operational performance of the integrated system. Results indicate integrating liquid-storage-based CCS with the dual-stage P2G system significantly reduces carbon emissions. Compared to a system without CCS and P2G, operating costs are reduced by 47.55%, and carbon emissions are reduced by 29.72%. Compared to an IES with flue gas diversion CCS and traditional P2G, operating costs decrease are reduced by 19.19%, and carbon emissions by 24.31%. Compared to an IES with liquid-storage-based CCS and traditional P2G, incorporating the dual-stage P2G reduces operating costs by 4.59% and carbon emissions by 13.69%, achieving diversified hydrogen utilization and full renewable energy consumption.

Key words: integrated electricity-heat-gas-hydrogen-cooling energy system, liquid storage-based carbon capture and storage, power-to-gas(P2G), multi-hydrogen utilization, chance constraint, stepped carbon trading