Multi-objective optimisation of a carbon capture and sequestration supply chain under seismic risk constraints. A case study considering industrial emissions in Italy

Carbon capture and sequestration represents a key decarbonisation option, particularly for large-scale fossil-based industry sectors (e.g. cement, steel, and oil refineries). Carbon capture and sequestration networks have nonetheless raised concerns regarding the possibility of leakages, especially in high seismic-risk regions. In this study, a multi-objective mixed integer linear programming modelling framework is developed to minimise the cost and the seismic risk associated with the deployment of a carbon capture and sequestration infrastructure in Italy. The most significant industrial carbon dioxide sources (23 cement plants, 7 refineries, and 2 steel mills) are included in the model. The optimisation variables comprise capture technologies, transport options (onshore vs. offshore pipelines), and the choice of onshore and offshore deep saline aquifers for sequestration. Three carbon dioxide emission reduction targets (20 %, 50 %, 80 %) are considered to assess the optimal design configurations in terms of either cost or seismic risk. Results show that the seismic risk optimum determines an increase in total cost ranging between 10 % (for an 80 % reduction target) and 65 % (for a 20 % reduction target) with respect to the economic optimum. Considering only offshore sequestration leads to cost increase between 20 % and 30 % with respect to solutions accepting onshore sequestration, too. Conversely, cost-optimal infrastructures have a seismic risk that is between 1.5 and 18 times higher than that of the safest chains.