Large-scale CO2 disposal/storage in bedded rock salt caverns of China: An evaluation of safety and suitability

Abstract

As a major greenhouse gas, carbon dioxide (CO 2 ) causes climate warming and weather changes. On the basis of CO 2 disposal/storage in salt caverns in this study, a new carbon cycle model is proposed, which provides a new way for carbon capture and storage. The safety and suitability evaluation of CO 2 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 CO 2 and CH 4 storage in bedded rock salt has a little difference by controlling the operating pressure constant withdrawal-injection cycle. However, the stored CO 2 has a much larger storage density and working density than the stored CH 4 . 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 CO 2 storage in salt caverns also acts as an attractive way of carbon neutralization and carbon cycle. • The stability of CO 2 disposal/storage in salt caverns in China is evaluated. • Based on CO 2 storage in salt caverns, a novel carbon cycle is put forward. • The storage capacity of a salt cavern for storage/disposal is huge. • The storage density of CO 2 can exceed 700 kg/m 3 . • The working density of CO 2 is much higher than that of CH 4 .