CO2 Gas Dispersion of Onshore Pipeline for Complex Terrain & Environment Using CFD

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Demonstrates CFD as a tool for dense-gas dispersion in complex terrain, providing parametric insights for CCUS safety.

🏢実務担当者:Can use exclusion-zone estimates and terrain-dependent dispersion patterns for pipeline routing and emergency planning.

🏛政策担当者:Informs safety regulations and permitting for CO2 pipelines in hilly or forested areas.

Accidental releases of carbon dioxide (CO2) during transportation present a significant safety challenge for CCUS projects, particularly in complex terrain where dense-phase CO2 can behave unpredictably. Unlike typical atmospheric gases, CO2 can form cold, gravity-driven clouds that move downslope, pool in depressions, and create persistent high-concentration zones. Recent field incidents have shown that such behaviour cannot be reliably captured using conventional flat-terrain dispersion models, highlighting the need for terrain-resolving approaches capable of representing dense-gas physics and environmental coupling. This study applies Computational Fluid Dynamics (CFD) to evaluate CO2 dispersion using real hill geometries and a structured parametric framework. Four key variables—wind velocity, leak rate, ambient humidity, and vegetation presence—were systematically varied to quantify their combined effects on plume evolution. The effect of forest or vegetation on CO2 dispersion was represented through a porosity-based modelling approach to capture aerodynamic drag and turbulence enhancement. The CFD simulations resolve momentum-driven, buoyancy-driven, and terrain-driven dispersion regimes, allowing detailed assessment of plume confinement, slope-driven accumulation, and dilution processes. Results show that terrain morphology strongly governs CO2 dispersion. Valleys and depressions consistently trap CO2 due to density-driven flow, with the longest persistence occurring under low-wind conditions. Higher wind velocities enhance mixing but broaden the overall exclusion zone. Vegetation increases turbulence and entrainment, accelerating dilution in forested regions compared to open terrain. The findings demonstrate that simplified 2D or flat-terrain models cannot adequately capture slope flows, channelling effects, or pooling behaviour. This work establishes CFD as an effective tool for predicting hazardous CO2 accumulation zones in complex landscapes. The outcomes support improved risk assessment, emergency response planning, and CCUS infrastructure design—particularly pipeline routing and exclusion-zone determination. By clarifying how terrain, environmental conditions, and vegetation interact to control dense-gas behaviour, the study provides practical guidance for safer implementation of onshore CO2 transport systems. Key findings from present study includes:Terrain characteristics such as hill height and valley depth – strongly influence CO2 cloud formation, either restricting or channelling downslope flow.CO2 tends to accumulate in depressions, forming localized pockets especially under low-wind conditions.Low wind speed limits the plume spread while higher wind speed would produce wider exclusion zones.Vegetations or forest, represented by porosity model – increasing entrainment of CO2 due to drags, thus accelerating dilution.Hill features such as height and depression – affect CO2 dispersion behaviour by channelling or trapping CO2 cloud.CFD results provide exclusion-zones estimates, supporting CCUS safety strategies and emergency response planning.

• semanticscholar https://doi.org/10.4043/36580-msfirst seen 2026-05-06 00:11:23