Numerical simulation of impurity-containing supercritical CO2 pipeline transport in CCUS

CO₂ pipelines in CCUS frequently operate under unstable conditions due to transient factors, such as fluctuations in gas flow at the pipeline's starting and ending points. In this study, a one-dimensional transient flow model of CO₂ pipeline containing impurities is proposed, which is capable of coupling the hydraulic and thermal factors in the flow process to achieve the hydraulic calculation along the pipeline in the slow transient process. The engineering simulation software OLGA is used to test and verify the model, the result of which shows the model produces comparable calculation results with improved computational stability. The model is used to investigate the effects of the slow transient conditions and three capture methods on the pipeline, and the results show that: (1) the fluctuations in the outlet flow have different effects along the pipeline., (2) the existence of the gas distributing and gathering points has different effects on the upstream and downstream, (3) there is a big difference in the content and type of impurities under the different capture methods, which greatly affects the CO₂ pipeline operation under the slow transient conditions.