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.