Numerical Simulation Study of Salt Cavern CO 2 Storage in Power-to-Gas System

Weizheng Bai, Jun Lu, Jian Wang, Xinghui Fu, Yaping Fu, Yashuai Huang, Xiao Wang and Xilin Shi ()
Additional contact information
Weizheng Bai: State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China
Jun Lu: PipeChina Energy Storage Technology Co., Ltd., Shanghai 200122, China
Jian Wang: PipeChina Energy Storage Technology Co., Ltd., Shanghai 200122, China
Xinghui Fu: Jiangsu Suyan Jingshen Co., Ltd., Huai’an 223200, China
Yaping Fu: PipeChina Energy Storage Technology Co., Ltd., Shanghai 200122, China
Yashuai Huang: State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China
Xiao Wang: State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China
Xilin Shi: State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China

Energies, 2024, vol. 17, issue 22, 1-19

Abstract: China’s renewable energy sector is experiencing rapid growth, yet its inherent intermittency is creating significant challenges for balancing power supply and demand. Power-to-gas (PtG) technology, which converts surplus electricity into combustible gas, offers a promising solution. Salt caverns, due to their favorable geological properties, are among the best choices for large-scale underground energy storage in PtG systems. CO 2 leakage along the interlayer and salt rock–interlayer interfaces is a key constraint on the CO 2 tightness of subsurface salt caverns. This paper focuses on the critical issue of tightness within salt cavern CO 2 storage, particularly in the Jintan region. A coupled hydro-mechanics mathematical model is developed to investigate CO 2 transportation and leakage in bedded salt caverns, with key variables such as permeability range, pore pressure evolution, and permeability changes being analyzed. The results reveal that permeability plays a decisive role in determining the CO 2 transportation rate and leakage extent within the salt rock layer. Notably, the CO 2 transportation rate and influence range in the mudstone interlayer are significantly larger than those in the salt rock over the same period. However, with prolonged storage time, the CO 2 transportation rate and pressure increase in both salt rock and mudstone interlayer exhibit a decreasing trend, eventually stabilizing as the CO 2 pressure front reaches the boundary of the simulation domain. Furthermore, elevated operating pressure markedly expands the permeability range and results in higher cumulative leakage. For a specific salt cavern, the CO 2 leakage range can reach up to 142 m, and the leakage volume can reach 522.5 tonnes with the increase in operating pressure during 35 years of operation. Therefore, the setting of operational pressure should fully consider the influence of permeability and mechanical strength of the salt rock and mudstone interlayer. These findings provide valuable insights into optimizing the sealing performance of salt cavern CO 2 storage systems under varying conditions.

Keywords: renewable energy; salt cavern CO 2 storage; permeability; operation pressure; leakage assessment (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2024
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/17/22/5786/pdf (application/pdf)
https://www.mdpi.com/1996-1073/17/22/5786/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:17:y:2024:i:22:p:5786-:d:1524771

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().