Modeling of the effects of CO₂ leaks from pipelines and process facilities

When processing and transporting significant quantities of CO₂ there is a potential for leaks of CO₂ to plant or surroundings. CO₂ is denser than air and will replace air near the ground. Significant leaks may represent a significant hazard to people down wind, and even moderate sized leaks may fill pits and lowerlying areas with CO₂ and be dangerous to people.
FLACS is a world-leading CFD-tool for gas explosion modeling, including hydrocarbon gas dispersion in congested process areas. In recent years a significant effort is invested in hydrogen safety, and FLACS is now gradually becoming a preferred tool also for hydrogen. FLACS has a potential to become a leading CFD-tool for dispersion of flammable and hazardous materials, including dense gas dispersion of CO₂.In the proposed project some development tasks are planned that will improve the capabilities of FLACS in the area of dense gas dispersion.

• Good source terms describing leaking liquid CO₂, including the pool generation and spread, crystallization/evaporation and sublimation. This model will be based on the framework of a recently developed liquid pool spread model for LNG, and BP will provide recent experimental liquid CO₂ release results for validation/calibration of source models.

• Reduce momentum loss for dense gas dispersion on a sloping terrain (with a Cartesian grid). The slope of terrain and large objects not aligned to grid will be identified, and modifications to numerical schemes developed, for a smoother gas transport.

• Recent test data (release of liquid CO₂, and measurement of downwind concentrations) made available by BP will be simulated, and used for validation of the new models.

• In the last phase of the project, some consolidation of models will be done, and demonstration simulations will be carried out. The project may be important to strengthen FLACS-DISPERSION, and GexCon will likely hire a PhD candidate on dispersion (however not specific for this project only).