Large-Scale Pipeline Release and Dispersion of CO2: Experiments and Simulation

Carbon capture and storage/sequestration (CCS) has emerged as a viable technique to mitigate climate change and ocean acidification, and to enhance oil recovery. An important part of the CCS chain is pipeline transport of dense-phase carbon dioxide (CO₂) from large point sources to suitable storage sites. Since CO₂ is an asphyxiating gas, deliberate or accidental releases from pipelines represent a serious hazard, and realistic consequence modelling of such scenarios is of paramount importance in loss prevention and process safety. This paper presents results from numerical simulations of an industrial-scale pipeline release and the subsequent dispersion of CO₂in the atmosphere. The experiment was part of the CO2PipeHaz [1] project in the European Union’s Seventh Framework Programme for Research and Technological Development (FP7).

The length of the experimental pipeline was 260 m, and the internal diameter 0.233 m. Pure CO₂ was discharged through a 0.05 m diameter orifice located 0.5 m above ground at the end section of the pipeline. The initial temperature was 20 ^oC and the initial pressure 53 bar. The measurements included wind speed, wind direction and temperature of the CO₂ plume. Comparison between experimental results and numerical simulations with the computational fluid dynamics (CFD) software FLACS [2] shows good agreement. The numerical study provides useful insight into the dispersion behaviour of the CO₂plume, and highlights the sensitivity towards the use of various pseudo-source models, turbulence models, and wind conditions. The paper represents a significant contribution to the understanding of hazards associated with pipeline transport of carbon dioxide.

References

1. CO2PipeHaz, Quantitative Failure Consequence Hazard Assessment for Next Generation CO2Pipelines: The Missing Link. CO2PipeHaz project website, http://www.co2pipehaz.eu/, accessed 25.09.14, (2009).
2. GexCon AS, FLACS v10.3 User’s Manual. http://www.flacs.com, accessed 25.09.14, (2014).