Density of carbon dioxide with impurities by Coriolis flow meter, oscillation-type densitometer and equations of state

Transporting CO₂ from the capture plant to the storage site may encounter challenges in the flow metering due to the unusual physical properties of CO₂ – especially when containing impurities. Building on the authors’ previous work on the effect of impurities in CO₂ mixtures on the performance of Coriolis flow meters, in this work, the accuracy of the density measurements of CO₂ mixtures was investigated using a Coriolis meter and a high-pressure Anton Paar densitometer. The measured density data were then compared to the Peng-Robinson cubic equation of state with CO₂ volume correction (PR-CO₂) as well as to the multi-parameter GERG-2008 equation of state. The Average Absolute Relative Deviations (AARD) of the density predictions with PR-CO₂ and GERG EOSs from the measured densities with the Anton Paar densitometer are 1.2% and 1.0%, respectively. While the Coriolis meter density values were consistently lower than the actual value in the gas phase. A correlation was obtained to correct the measured densities in the gas phase by fitting the measured densities to the prediction values using PR-CO₂ and GERG EoSs at elevated pressures and temperatures. The AARD was reduced from 26.1% to 2.3% using PR-CO₂ and from 25.4% to 3.6% using GERG EoSs.