The vehicle impact on the backlayering layer, an experimental and numerical study

International audience CCS is seen as a possibility to mitigate the global warming effect. The practical implementation of this technique faces a few challenges like safety issues. It is wondered if a massive spill affecting the pipeline (may be the most vulnerable part of the CCS chain) would not lead to a disaster remembering what happened in Africa about 28 years ago (Eos,2009). In this paper, the experimental techniques used to investigate this specific problem are described and illustrated with some key results extracted from various projects. Innovative techniques were employed to control the mass flowrate, blowdown, near field and far field dispersion in the atmosphere. A 2 m3 spherical vessel able to store up to 1 t of CO2 at a pressure above 70 bar was used. Dense CO2 was allowed to spill out via a 2’’ pipe. The temperature, CO2 concentration and density field of the outside cloud were monitored using thermocouples and concentration probes via a novel data redaction technique. Among other results, it was in particular shown that when the mass flowrate is large enough, body forces become significant forcing the cloud to stay on the ground. This phenomenon may have played a role during the Nyos Lake accident, explaining perhaps the large number of victims.