Multi-scale source-sink matching and transportation route optimization for geologic CO₂ sequestration of industrial CO₂ stationary sources in Jiangsu Province

Objective CO₂ stationary sources tend to show a dispersed distribution, while carbon sinks are concentrated in specific sedimentary basins. The resulting significant source-sink mismatch in space restricts the large-scale applications of carbon capture, utilization, and storage (CCUS) technology. Therefore, reducing CCUS costs by investigating source-sink matching and optimizing CO₂ transportation routes under a multi-scale spatial framework is the key to the engineering applications of CCUS.

Methods Targeting representative industrial CO₂ stationary sources and carbon sinks in Jiangsu Province, this study established source-sink matching models on multiple scales covering hydrocarbon reservoirs, sags, and basins. Based on both the geographic information system (GIS)-based least-cost path planning method and an improved pipeline network optimization strategy, this study explored regional multi-scale source-sink matching.

Results and Conclusions  By the end of 2023, a total of 269 representative industrial CO₂ stationary sources were identified in Jiangsu Province, with total annual CO₂ emissions reaching 6.26 × 10⁸ t. Among these sources, different types exhibited different CO₂ emission scales and spatial distributions, with the thermal power sector yielding the highest proportion of CO₂ emissions. In Jiangsu Province, thermal power plants and steel mills are primarily distributed in the southern part of the Yangtze River Delta and cities along the Yangtze River. In contrast, cement plants are concentrated in the southern part of the province, while synthetic ammonia plants show a scattered distribution. Within the study area, deep saline aquifers and oil reservoirs in sags, such as B10, B11, and B6, exhibited great potential for geologic CO₂ sequestration, with the sequestration capacities estimated at about 58.7 × 10⁸ t and 7.28 × 10⁸ t, respectively. In combination with the regional demands for carbon emission reduction and the source-sink spatial distribution, this study developed source-sink matching models on multiple scales covering hydrocarbon reservoirs, sags, and basins. The calculation results of these models indicate that the theoretical pipeline lengths on the scales of hydrocarbon reservoirs, sags, and basins were determined at 238.9 km, 398 km, 3 873 km (the Subei Basin), and 4 100 km (the Subei-southern Yellow Sea Basin), respectively. After being optimized by integrating the GIS and the saving algorithm-based strategy, the pipeline lengths on the scales of hydrocarbon reservoirs, sags, and basins were calculated at 243.7 km, 426 km, 1 831 km (the Subei Basin), and 2 121 km (the Subei-southern Yellow Sea Basin), respectively. Such effort contributed to the formation of optimized CO₂ transportation routes matched better with the geographical setting and actual engineering implementation requirements while effectively reducing the construction costs of pipeline networks. The results of this study will provide a theoretical basis and methodological support for building low-cost, highly adaptable CCUS transportation routes in the eastern coastal areas of China.