A CFD study of the effects of combined impurities, ground temperature, and topography upon the consequence distances and plume shapes generated by CO2 release from CCS pipeline failure

In the carbon capture and storage (CCS) infrastructure, the risk of a high-pressure buried pipeline rupture possibly leads to catastrophic accidents due to the release of tremendous amounts of carbon dioxide (CO2). Therefore, it is crucial to conduct an in-depth study on CO2 atmospheric dispersion when developing CO2 pipeline. In fact, the CO2 captured from diverse industrial processes may contain a variety of impurities. The combined effect of the toxicities of the multiple impurities increases the risk, which has usually been ignored by previous studies. In this paper, computational fluid dynamics (CFD) technology is applied to investigate the influence of hazardous chemicals on CO2 stream dispersion under different meteorological, complex terrain features, and ground temperature condition. In addition, the effect of combined toxic impurities on consequence distance was also investigated comprehensively. It was found that complex conditions affected the near-surface flow field, and obstacles enhanced the lateral dispersion of CO2. Compared to 288 K ground temperature, the plume area inside the 50,000 ppmv CO2 boundary decreased by 8.2%. The hazardous effects of combined toxic impurities became significant compared to a single toxic impurity. This study may furnish a viable assessment technique for the risks associated with CCS.