A dynamic optimization layout model for CO2–flue gas co-storage considering interactions and geological heterogeneity

Carbon storage in saline aquifers represents a promising technology for carbon mitigation, yet traditional approaches are constrained by costly CO2 separation processes. We propose a novel negative-emission disposal method that integrates carbon dioxide storage with multi-pollutant flue gas treatment. Through a comprehensive modeling framework, we holistically consider geological heterogeneity, multi-component flue gas composition, and its interactions with saline aquifers to formulate a dynamic multi-stage optimization model, identifying economically optimal storage locations and pipeline networks under evolving carbon market and technological conditions. The methodological framework is validated using data from a carbon storage project in the Ordos Basin through numerical simulations. The results show that: (i) The proposed model solves the pipeline network construction problem for multi-stage CO2 storage and flue gas co-treatment in saline aquifers, accounting for flue gas–brine interactions; it identifies the storage locations, corresponding quantities, transportation pipeline topology, and pipe diameters at each stage. (ii) Compared with static single-stage model, the pipeline network obtained from multi-stage dynamic planning exhibits stronger connectivity and achieves 39.86% reduction in the total cost. (iii) Compared with conventional CO2 storage methods, CO2-flue gas co-storage reduces emission treatment costs by 86.65% through carbon capture substitution with pretreatment processes, leading to an overall cost reduction of 21.45%. (iv) Unlike traditional flue gas treatment methods, this approach delivers multiple advantages, including carbon reduction, synergistic pollutant treatment, and compressed flue gas energy storage and utilization. This study provides a new pathway for the resource utilization of saline aquifers and holds significant engineering application value for promoting flue gas reduction and underground energy storage.