Flow measurement challenges for carbon capture, utilisation and storage

Carbon Capture, Utilisation and Storage (CCUS) is a key element in the United Kingdom Government strategy for reducing carbon dioxide (CO2) emissions. The UK aims to capture and store 10 million tonnes of CO2 each year by 2030. At each stage in the CCUS infrastructure, accurate measurement of the CO2 flow rate is required, over a range of temperatures, pressures, flow rates and fluid phases, where the flow measurement must be validated through a credible traceability chain. The traceability chain provides the underpinning confidence required to verify meter performance, financial and fiscal transactions, and environmental compliance. The UK equivalent of the EU Emissions Trading System (EU ETS) specifies a maximum uncertainty value for CO2 flow measurement. Accordingly, the provision of accurate and traceable flow measurement of CO2 is a prerequisite for an operational CCUS scheme. However, there are currently no CO2 flow measurement facilities, nationally or internationally, providing traceable flow calibrations of gas phase, liquid/dense phase and supercritical phase CO2 that replicate real-world CCUS conditions. This lack of traceable CO2 gas and liquid flow measurement facilities and associated flow measurement standards is a significant barrier to the successful implementation of CCUS projects worldwide. This paper presents an overview of the traceability chain required for CO2 flow measurement in the UK and globally. Current challenges are described along with potential solutions and opportunities for the flow measurement community.