Effect of Impurities on Depressurization of CO2 Pipeline Transport

Abstract

The objective of the present study is to gain an understanding on the effect of impurities during the depressurization of CO2 pipeline transport. In this study, experimental apparatus was built to simulate the transient behavior of CO2 pipeline transportation. The transient blowdown test was conducted at the initial conditions of 85 bar and 20 &#9702 C. To study the effect of impurities, N2 was added from 2% to 8% on mass fraction basis. The blowdown of CO2 pipeline transport system was numerically simulated. The dynamic multiphase flow simulator OLGA was used to model the depressurization of CO2 pipeline system. Comparisons of experimental data and numerical simulation results were carried out. Initial severe pressure drops during few seconds were well estimated by numerical simulation for both pure and mixture cases. On the other hand, the numerical simulation did not provide reliable temperature drop predictions. As the amount of N2 impurity increases the numerical simulation results showed better pressure drop predictions. But there were some difference between experimental data and numerical simulation results in gradual pressure drops as the amount of N2 impurity decreases. In conclusion, it is required to improve the phase change model of numerical simulator.line transportation. The transient blowdown test was conducted at the initial conditions of 85 bar and 20 &#9702 C. To study the effect of impurities, N2 was added from 2% to 8% on mass fraction basis. The blowdown of CO2 pipeline transport system was numerically simulated. The dynamic multiphase flow simulator OLGA was used to model the depressurization of CO2 pipeline system. Comparisons of experimental data and numerical simulation results were carried out. Initial severe pressure drops during few seconds were well estimated by numerical simulation for both pure and mixture cases. On the other hand, the numerical simulation did not provide reliable temperature drop predictions. As the amount of N2 impurity increases the numerical simulation results showed better pressure drop predictions. But there were some difference between experimental data and numerical simulation results in gradual pressure drops as the amount of N2 impurity decreases. In conclusion, it is required to improve the phase change model of numerical simulator.