Source terms calculation and atmospheric dispersion for a dynamic release from a CO 2 pipeline containing methane and water as impurities

A method for calculating the source terms including values of leak rate, phase fraction, final velocity, and temperature at the position where the leakage jet has expanded to atmospheric pressure from a CO 2 pipeline containing impurities (methane and water) is presented with regard to the time‐dependency of the source terms during the leakage. The thermodynamical properties for the mixture are calculated using the Soave‐Redlich‐Kwong equation of state with modified 1st order Huron‐Vidal mixing rule, which is adjustable in PVTsim. The results for the solubility of water in CO 2 have shown that this thermodynamic model provides accurate predictions for the mixture properties. The thermodynamic model has been used along with a robust transient two‐phase flow simulator, OLGA, to simulate the leak from the pipeline. Finally, the predicted time‐dependant source terms (Release Rate, Phase Fraction, Final Velocity, and Temperature in the downstream of the leak) were used as input into the dispersion model (UDM) in form of sequential segments.