Design and Optimization of Carbon Dioxide Storage Technology: Energy Efficiency and Economic Analysis

The storage technology of carbon dioxide is an important part of the carbon capture, utilization, and storage (CCUS) process. This study employed Aspen series software to simulate and analyze the CO2 storage unit of a CCUS project with an annual capacity of one million tons. Three CO2 storage processes were simulated and optimized, including the process of high-pressure liquid carbon dioxide storage (HPLCD), optimized liquid carbon dioxide storage (OLCD), and hydrate carbon dioxide storage (HCD), and specific power consumption (SPC), energy efficiency, annual total cost, net present value (NPV), and internal rate of return (IRR) were analyzed. The results showed that the SPC of HPLCD, OLCD, and HCD were 0.0958, 0.0895, and 0.0614 kWh/kg CO2, respectively. The corresponding energy efficiencies were 54.61, 77.26, and 60.02%. Among the three processes, the HCD process exhibited the lowest SPC. After optimizing the liquid storage process with the genetic algorithm, the energy consumption was reduced by 9.24% compared to that of HPLCD. Economic analysis revealed that the annual total cost of the HPLCD, OLCD, and HCD processes is 65.11 million RMB, 60.78 million RMB, and 43.95 million RMB, respectively. Sensitivity analysis based on NPV and IRR for the three processes indicated that the CO2 profit was the most sensitive factor, and the HCD process exhibited the highest NPV and IRR values. Compared to energy consumption and economic results, the HCD process was the optimal CO2 storage technology at this scale, offering the highest investment value.