Accident analysis of CO₂ pipeline failures: Patterns, detection, and consequences

This study provides a comprehensive assessment of carbon dioxide (CO 2 ) pipeline safety in the United States by integrating accident data from the Pipeline and Hazardous Materials Safety Administration (PHMSA) with detailed pipeline infrastructure records. The analysis links each reported CO 2 pipeline accident (1991–2024) to its corresponding pipeline segment, enabling a pipeline-level reliability evaluation of the U.S. CO 2 transport system. The resulting geospatial dataset reveals relationships between infrastructure attributes (such as diameter, operating pressure, age, etc.), and failure components (including valves, girth welds, pipe seams, etc.). Across 121 reported accidents, approximately 19,700 metric tons of CO 2 were released, resulting in US$6.96 million in damages but no fatalities. On average, CO 2 pipelines release only 0.0025% of transported volume annually, significantly lower than natural gas pipelines (0.0077%). Leakage rates are highest within the first decade of operation, decrease over time, and rise again after 30–40 years, suggesting an age-dependent “bathtub” failure pattern. Automated detection systems identified fewer than 20% of CO 2 releases, while 13% of accidents were first reported by the public. The biggest opportunity for improvement in CO 2 pipeline transportation would be the development and implementation of better automated detection systems. Overall, we conclude that CO 2 pipelines have a low risk profile.