Thermodynamic performance and environmental analysis of advanced diversified energy systems based on CO₂ energy storage and deep utilization of methane

To address the power fluctuations associated with renewable energy, the development of a new generation of energy storage systems that are both highly efficient and multifunctional is crucial. This paper proposed a new composite energy system based on the idea of diversified energy system, namely advanced integrated CO₂ energy storage and carbon capture system based on deep utilization of methane (ESCCM). This system for the first time organically couples CO₂ energy storage, carbon capture, and hydrogen energy systems, and reveals the operating mechanism of the system by comprehensively analyzing the impact of different factors on the performance and emission reduction capability of the system. The research results indicate that: (a) For the development of the advanced integrated CO, energy storageand carbon capture system based on deep utilization ofmethane (ESCCM), a dual modeof qualitative-quantitative utilization of methane was adopted. (b)In the design processof the cryogenic carbon capture unit, the carbon capture capacity of the V-shapedpolygonal structure is significantly higher than that of the spherical structure. (c)Thesystem is also integrated with a high-temperature proton exchange membrane fuel cell(HT-PEMFC), achieving a round-trip efficiency of 64.39 %, an energy storageefficiency of 98.568 %, an energy utilization index of 1.0087, and an actual net poweroutput of 32.66 kW.