Performance of Coriolis flowmeters in CO2 pipelines with pre-combustion, post-combustion and oxyfuel gas mixtures in carbon capture and storage

- Fluids for pre-combustion, post-combustion and oxyfuel processes were investigated.
- The experiments were performed in the flow loop in start/stop operations.
- Steady state/transient operation scenarios were studied with different mixtures.
- The average uncertainty of a Coriolis meter in the gas phase was obtained.
- The measured uncertainties are in agreement with EU ETS requirements.

Fiscal metering or custody transfer of CO2 with impurities is an important challenge due to the unusual physical properties of CO2 compared to other transportable fluids by pipelines (e.g. natural gas, water and oil products). The presence of impurities affects the thermophysical properties of CO2-rich systems, particularly in the conditions likely to be experienced in the CO2 transportation by pipeline. This can challenge the precise measurement of flow rate as the performance of the flowmeters are significantly affected by thermophysical properties of the transported fluid. The European Union Emission Trading Scheme (EU ETS) requires an uncertainty level of ±1.5% or less by mass for fiscal metering of CO2 with impurities. In this paper, the performance of Coriolis mass flowmeter (OPTIMASS 6000-S08, from KROHNE) was investigated in presence of impurities using different gas mixtures representing pre-combustion, post-combustion and oxyfuel processes. Steady state and transient conditions were studied in the mass flow rig using a weighing scale in start/stop operation and the uncertainty of the tests was obtained by comparing the measured mass by robust weighing scale and the mass readout from the flowmeter. The results show that the uncertainties can be expected to be within the range of EU ETS requirements for an appropriately sized flow meter.