Fiscal metering and thermodynamics (Task 8)

Accurate thermophysical properties are needed for optimized design and operation of virtually all processes involved in CCS. This task aims to provide improved experimental data and models on properties of CO2-rich fluids relevant for CCS, and facilitate fiscal metering of the same fluids.

This task aims to provide improved experimental data and models on properties of CO2-rich fluids relevant for CCS, and facilitate fiscal metering of the same fluids.

Thermophysical properties

Vast amounts of CO2-rich fluids will have to be captured, transported, and stored if the goals of global warming mitigation are to be reached. Read more on this from IEA. Hence in order to avoid large excess costs, design and operations of all CCS systems have to be optimized, which again requires accurate data and models on the fluids involved exists.

For instance, it must be known whether the fluid is liquid, gas, or both. Properties like density, thermal conductivity, and viscosity, on which flow resistance depends, are important as well. In this task, we will measure and model these properties to great accuracy, filling important knowledge gaps.

Benefits of improved thermophysical property knowledge:
Accurate thermophysical properties are needed for optimized design and operation of virtually all processes involved in CCS e.g.:

  • Deployment Case 1: Optimization of liquefaction and ship transport requires accurate knowledge of VLE , freeze out (VLSE), and heat transfer (viscosity and thermal conductivity) (For more information on liquefaction see Task 4)
  • Deployment Case 2: Accurate properties are needed for fiscal metering.

See the page for Deployment Cases.

Fiscal metering

Fiscal metering is measurement of flow rate for legal or commercial purposes. For CCS in Europe, the ETS directive provides some legal requirements for mass flow measurements that have to be fulfilled in order to avoid purchasing Emission Unit Allowances for the stored CO2. Commercial transactions may have other requirements. Conventional flow metering techniques are not necessarily applicable to CO2-rich fluids for various reasons, and demonstration and verification lack at industrial relevant scale. In Task 8, the aim is to evaluate, develop and benchmark relevant fiscal flow metering concepts, and close knowledge gaps through experiments and modelling.

Results 2018

Main Results

  • First benchmarking of fiscal metering technologies for CO2 and strategy for verification test plan
  • Measurement of VLE on the ternary system CO2-N2-CH4
  • Improved models of the minor components in CCS mixtures, as well as CO2-CO, CO2-Ar, and initiation of work to include reactive mixtures
  • Initiation of NCCS / CLIMIT KPN "Impact of CO2 impurities and additives in CCS" (ImpreCCS)

Impact and innovations

  • New TREND library to be released, including the new mixture models
  • Published measurements are available also for other groups developing property models
  • New innovative experimental setup for viscosity and density measurements
  • Preparation for fiscal metering verification underway
Viscosity setup to be used in ImpreCCS

Results 2017

"Fiscal metering and thermodynamics properties" has produced new experimental data fully characterizing the phase equilibrium on mixtures between carbon monoxide (CO) and CO2 as a function of pressure at four different temperatures.

CO is an important impurity from many CO2 sources and capture processes, and a better description of its impact is now possible.

The new data cover important knowledge gaps and are under publishing. Further, Task 8 has significantly improved the thermodynamic model description for many other types of mixtures.

A first assessment of potential technologies for fiscal metering of CO2-rich flows has been performed, and specifications for fiscal meters for CCS have been proposed.

A new CLIMIT competence building project was granted for measurement and modelling of viscosity, density, and thermal conductivity. The project will be a part of NCCS ahead and apply new property correlations in reservoir simulations.

Task leader