Compressed carbon dioxide (CO2) energy storage is considered a novel long-term and large-scale energy storage solution due to better thermal stability, non-flammability, higher safety level and higher energy density in engineering applications than air energy storage. This study proposes an integrated solution of energy storage and CO2 reduction highlighted by trans-critical compressed CO2 energy storage systems (CCES). The system is developed by combining liquified natural gas (LNG) cold energy utilization and cryogenic carbon capture unit. To demonstrate the applicability of the developed system, two cases of gaseous and liquid phase in low-pressure storage tanks are designed and analyzed in terms of energy, exergy and life cycle techno-economics. In addition, since the system includes the capture and utilization of CO2, a green emission incentive is introduced in the form of a social cost of carbon to go through the techno-economic analysis. It is indicated that the energy, exergy and emission reduction potential of the two cases can outperform the conventional CO2 energy storage system combined cooling, heating and power at a peak time of 12 h. Between them, Case 2 has the highest system electrical round-trip efficiency, system energy efficiency and exergy efficiency, which are 0.6849, 0.7225 and 0.5930, respectively. It is also shown that the integrated solution of energy storage and CO2 reduction in this study results in high social benefits under certain conditions.

中文翻译：

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储能和 CO2 减排的集成解决方案：将碳捕获与 LNG 冷能相结合的跨临界 CO2 储能系统


压缩二氧化碳 （CO2） 储能在工程应用中比空气储能具有更好的热稳定性、不易燃性、更高的安全等级和更高的能量密度，因此被认为是一种新颖的长期、大规模储能解决方案。本研究提出了一种以跨临界压缩 CO2 储能系统 （CCES） 为重点的储能和 CO2 减排综合解决方案。该系统是通过液化天然气 （LNG） 冷能利用和低温碳捕获装置相结合而开发的。为了证明所开发系统的适用性，设计了低压储罐中气相和液相的两个案例，并从能量、用能和生命周期技术经济学方面进行了分析。此外，由于该系统包括二氧化碳的捕获和利用，因此以碳的社会成本的形式引入了绿色排放激励措施，以通过技术经济分析。结果表明，两种情况的能量、耗能和减排潜力在 12 h 的峰值时间内均能优于传统的 CO2 制冷、加热和电联储系统。其中，情况 2 的系统电往返效率最高，系统能效和用能效率最高，分别为 0.6849、0.7225 和 0.5930。研究还表明，本研究中的储能和二氧化碳减排综合解决方案在某些条件下会产生很高的社会效益。