Large-Scale CO ₂ Disposal/Storage in Bedded Rock Salt Caverns of China: An Evaluation of Safety and Suitability

Abstract

As a major greenhouse gas, carbon dioxide (CO₂) causes climate warming and weather changes. Based on the CO₂ disposal/storage in salt caverns in this study, a new carbon cycle is proposed, which provides a new way for carbon capture and storage. The safety and suitability evaluation of CO₂ disposal/storage in bedded rock salt caverns in China was carried out. Long-term disposal (Time ≥ 1000 years), medium-term disposal (several hundred years), and short-term storage (0-30 years) were studied to meet permanent geological isolation of carbon and temporary carbon cycle. The results show that: 1) For long-term and medium-term disposal/storage, it is feasible to carry out permanent geological isolation at proper depth and operating pressure. 2) For short-term storage, the stability of CO₂ and CH₄ storage in bedded salt rock has a little difference by controlling the operating pressure constant withdrawal-injection cycle. But the stored CO₂ has much larger storage density and working density than the stored CH₄. 3) If dozens of such caverns can be used in a salt mine, the potential for disposal or storage is much considerable. Therefore, the utilization of CO₂ storage in salt caverns acts also as an attractive way of carbon neutralization and carbon cycle.

Keywords: rock salt, CCUS, salt cavern, stability evaluation, serviceability analysis, CO2 storage