Abstract
The transition to a Climate-Neutral economy requires a reduction of energy-related carbon dioxide emissions and Carbon dioxide capture and geological storage (CCS) is a key technology that will contribute to mitigating climate change. Hazards and risks related to processing, transport, and storage of CO2 are not new aspects, but peculiarities of CO2 safety scenarios can lead to risk underestimation and misperception. Solid-phase occurrence and heavy gas dispersion, multiphase releases, leakages from wells and storage sites, and the integrity of equipment subjected to internal corrosion and cryogenic temperatures, are typical scenarios involved in CCS chains. These are often mentioned in technical standards and regulations and require proper advanced assessment. In this work, the main hazards and risk scenarios in CCS operations with a special focus on atypical instances that are peculiar to the case of CO2 will be reviewed. Open issues concerning the modeling of consequences and specific risk-related topics are discussed.