Apparatus and method for calibrating a Coriolis mass flow meter for carbon dioxide at pressure and temperature conditions represented to CCS pipeline operations

Accurate metering of transported dense phase carbon dioxide (CO2) is imperative in carbon capture and storage (CCS) operations. Coriolis mass flow meters have been proposed for CCS operations metering due to their reliability and high accuracy. However, no studies have been reported to quantify the measurement uncertainty for Coriolis meters operating with high pressure liquefied CO2. Accordingly, an apparatus was designed, built and tested to calibrate an industrial scale Coriolis meter using CO2 in either high pressure liquid or supercritical phases. In this study, the standard uncertainty of the meter was evaluated within the temperature range 290-303 K and at pressures between 6.5 and 8.5 MPa, these being representative of CCS transport operating conditions. The apparatus and method developed was based on a gravimetric calibration in which the totalised mass recorded by the Coriolis mass meter was compared with the increase in weight of a collection cylinder mounted on a highly accurate weigh scale. A back pressure controller was used to maintain the system pressure above vapour pressure and ensure the CO2 remained in liquid phase. The average standard uncertainty of the Coriolis meter using liquid phase CO2 was calculated to be 0.11% which is in good agreement with the meter's technical specification provided by the equipment manufacturer. The uncertainty of measurement of CO2 under test conditions is hardly affected by temperature, pressure and flow rate conditions within the range investigated in this study.