How to select potential sites for geologic CO2 sequestration? A CCS screening workflow

Emission-intensive sectors (e.g., cement, steel, refractories) have a high demand for decarbonization technologies and Carbon Capture and Storage (CCS) is widely regarded as the most important contributor to rapid and large-scale CO₂ mitigation. While shared CCS networks serving multiple emitters are favoured for their economies and scalability, dedicated CCS projects targeting individual companies remain critical and currently constitute the majority of operational CCS sites worldwide. The ultimate success of such localized CCS projects is strongly constrained by the geological prerequisites in the vicinity of the emission source. This work presents a regional geological screening for CCS potential tailored to a refractory manufacturing plant in the Anhui Province, China. A workflow was developed integrating both geologic and logistic factors, enabling a first-order assessment of both storage feasibility and associated transport costs. The geological screening covers a wide range of technological readiness levels from early-stage laboratory research to mature industrial applications, including saline aquifers, reservoirs associated with oil and gas operations (e.g., depleted fields or enhanced oil recovery), coalbed formations (e.g., enhanced coal bed methane recovery), as well as in-situ mineralization in basaltic rocks. Based on an extensive review of the literature and available reports, ten sedimentary basins and five abandoned coalfields were identified as promising storage options. A GIS-based database was constructed to visualize and compare all storage scenarios. For each candidate site, the shortest CO₂ transport pathway was determined using network-based proximity analysis of existing truck and railway infrastructures. Two sedimentary basins and five coalfields are located within 50 km of the plant, and another two sedimentary basins lie within 100 km. Transportation costs were subsequently estimated using published unit costs for truck and rail transport (EUR/km). Key parameters (e.g., porosity and permeability) of the four closest sedimentary basins were compared with those of international CCS demonstration projects (e.g., Sleipner and Ordos). The results show that for localized, single-emitter CCS projects, geological thresholds such as minimum storage depth and source-sink distance are critical determinants of feasibility, whereas reservoir petrophysical thresholds appear largely project dependent. In particular, while successful CCS projects provide useful benchmarks for porosity and permeability, these parameters alone should not be used as exclusion criteria for CCS deployment in site-specific assessments.