BIGCCS - International CCS Research Centre

CO₂ Transport

Contact person

Svend Tollak Munkejord

Chief Scientist

CO₂ pipeline integrity

Overall objective:
To develop a coupled fluid-structure fracture propagation model to enable safe and cost-effective design and operation of CO₂ pipelines.

CO₂ Pipeline integrity and its importance for CCS

Most large-scale implementations of CCS will require CO₂ to be transported as dense phase in a pipeline. Parts of this CO₂ transportation will in some situations interfere and be visible from areas with public access. For public acceptance of CCS, it is therefore of great importance that such pipelines are considered not to pose a threat to public safety.

A particular challenge for pipeline transport of CO₂ in dense phase (compared to e.g. natural gas), is the risk of long running fractures in the pipeline. Due to the two-phase behaviour of CO₂ during decompression from dense phase — e.g. as a result of a rupture caused by third party impact — a high CO₂ saturation pressure might cause a fracture to propagate for a long distance unless the pipeline material has sufficient fracture resistance. Though there is a DNV recommended practice (RP-J202) on design and operation of CO₂ pipelines, there are today no established methods, standards or tools to assess and predict the behaviour of running fractures in CO2pipelines. It is the aim of Task 2.1 to provide a numerical tool and method that can be used to provide safe and cost-effective design and operation of CO₂ pipelines.

Contribution to the overall objectives of BIGCCS
The International Energy Agency’s two-degree scenario is one realistic way of limiting the global warming to 2 °C. In this scenario, CCS accounts for about 1/5 of the CO₂-emission reduction in 2050, corresponding to seven billion metric tonnes per year.

Fracture propagation control (FCP), that is, the estimation of risk of long running fractures, is of great importance in design and operation of high pressure pipelines. For natural gas and hydrogen pipelines, FCP is well handled by existing (empirical) methods. However, there is limited worldwide experience in design and operation of CO₂ pipelines. Mainly due to the two-phase behaviour of CO₂ during decompression from dense phase, today’s FPC methods yields non-conservative estimates of the required pipeline properties. An important element in reducing cost, while maintaining the highest safety, is to understand how long running fractures in the CO₂ pipelines can be avoided. This is what we aim for in BIGCCS Task 2.1.

Task 2.1 achievements thus far

A coupled fluid-structure fracture propagation-control model has been developed, and it has been verified using data from hydrogen and methane crack-arrest experiments.
The coupled fluid-structure model has been extended to account for CO₂ properties, including the formation of solid CO₂.
Five journal articles and three conference articles have been published
One PhD has been completed.

We aim to avoid running fractures in a cost-effective way by developing physics-based models.

Related publications

A fracture-propagation-control model for pipelines transporting CO₂-rich mixtures including a new method for material-model calibration
Nordhagen, H. O., Munkejord, S. T., Hammer, M., Gruben, G., Fourmeau, M. and Dumoulin, S. | Engineering Structures, In press | 2017
Fracture propagation control in CO₂ pipelines: Validation of a coupled fluid–structure model
Aursand, E., Dumoulin, S., Hammer, M., Lange, H. I., Morin, A., Munkejord, S. T. and Nordhagen, H. O. | Engineering Structures, vol. 123, pp. 192–212 | 2016
A two-fluid four-equation model with instantaneous thermodynamical equilibrium
Morin, A. and Flåtten, T. | ESAIM: M2AN, vol. 50, pp. 1167-1193 | 2016
CO₂ transport: Data and models – A review
S.T. Munkejord, M. Hammer, S.W Løvseth | Applied Energy, 169, pp. 499-523 | 2016
Two-phase nozzle flow and the subcharacteristic condition
G. Linga, P. Aursand, T. Flåtten | Journal of Mathematical Analysis and Applications 426, pp. 917–934 | 2015
CO₂ pipeline integrity: Comparison of a coupled fluid-structure model and uncoupled two-curve methods
Aursand, E., Dørum, C., Hammer, M., Morin, A., Munkejord, S. T. and Nordhagen, H. O. | Energy Procedia, vol. 51, pp. 382-391 | 2014
Main Properties Governing the Ductile Fracture Velocity in Pipelines: A Numerical Study Using an (Artificial Fluid)-Structure Interaction Model
H. Nordhagen, S. Dumoulin, and G. Gruben | Procedia Materials Science, vol. 3, pp. 1650-1655 | 2014
Method using a density-energy state function with a reference equation of state for fluid-dynamics simulation of vapor-liquid-solid carbon dioxide
Hammer, M., Ervik, Å. and Munkejord, S. T. | Industrial & Engineering Chemistry Research, vol. 52, no. 29, pp. 9965-9978 | 2013
CO₂ Pipeline Integrity: A Coupled Fluid-structure Model Using a Reference Equation of State for CO₂
Aursand, E. Aursand, P. Berstad, T. Dørum, C. Hammer, M. Munkejord, T. Nordhagen, O. | Energy Procedia, vol. 37, pp. 3113–3122 | 2013
Klimaløsning i rør Munkejord, S.T. Mølnvik, M. Dørum, C. | Dagens Næringsliv, 19 April | 2013
A Roe Scheme for a Compressible Six-Equation Two-Fluid Model
Morin, A. Flåtten, T. Munkejord, S.T. | International Journal for Numerical Methods in Fluids, vol. 72, no. 4, pp. 478-504 | 2012
Solution of the Span–Wagner equation of state using a density–energy state function for fluid-dynamic simulation of carbon dioxide
Giljarhus, K.E.T. Munkejord, S.T. Skaugen, G. | Industrial & Engineering Chemistry Research, vol. 51, no. 2, pp. 1006-1014 | 2012
Pipeline flow modelling with source terms due to leakage: The straw method
Morin, A., Kragset, S. and Munkejord, S. T. | Energy Procedia, vol. 23, pp. 226-235 | 2012
A new coupled fluid–structure modeling methodology for running ductile fracture
Nordhagen, H.O. Kragset, S. Berstad, T. Morin, A. Dørum, C. Munkejord, S.T. | Computers & Structures, vol. 94-95, pp. 13-21 | 2012
On solutions to equilibrium problems for systems of stiffened gases
Flåtten, T. Morin, A. Munkejord, S. T. | SIAM Journal on Applied Mathematics, vol. 71, no. 1, pp. 41-67 | 2011
PVTxy properties of CO₂ mixtures relevant for CO₂ capture, transport and storage: Review of available experimental data and theoretical models
Li, H. Jakobsen, J.P. Wilhelmsen, Ø. Yan, J. | | 2011
CO₂ pipeline integrity: A new evaluation methodology
Berstad, T. Dørum, C. Jakobsen, J. P. Kragset, S. Li, H. Lund, H. Morin, A. Munkejord, S. T. Mølnvik, M. J. Nordhagen, H. O. Østby, E. | Energy Procedia, vol. 4, pp. 3000-3007 | 2011
Wave propagation in multicomponent flow models
Flåtten, T. Morin, A. Munkejord, S. T. | SIAM Journal on Applied Mathematics, vol. 70, no. 8, pp. 2861-2882 | 2010

CO2Mix: CO₂ mixture properties

Overall objective:
To acquire accurate data for thermophysical properties of CO₂-rich mixtures at conditions relevant for CCS.

Contribution to one or more of the overall goals/objectives of BIGCCS

CO₂ captured in a CCS process will never be absolutely pure. Even small quantities of impurities can significantly affect the thermophysical properties of CO₂. Therefore, to be able to design capture processes, transport systems and injection schemes, we need high-quality data for the various impurities in the relevant range of concentrations, pressure and temperature. Presently, there are several white areas on the map, and we aim to fill some of them.

Task 2.2 achievements thus far

Accurate experimental setups have been constructed to measure the following properties of CO₂-rich mixtures
- Vapour-liquid equilibrium
- Density of gas and super-critical phases
- Speed-of-sound of gas and super-critical phases
All setups are currently conducting measurement campaigns
Two PhD candidates are being educated
Three conference articles have been published, and several presentations at scientific conferences held

Phase Equilibrium Cell for CO₂ Mixtures (SINTEF ER)

The phase equilibrium setup is using an analytical technique and allows for very precise control of pressure and temperature. The film clip above shows the magic moment of phase separation as the pressure of a CO₂-N2 mixture is reduced from supercritical to subcritical.

Density and Speed of Sound Measurements (Ruhr-Universität Bochum)
The speed of sound meter measures the echo time of short acoustic pulses. The density is found by measuring the buoyancy of a single sinker using a magnetic coupling technique developed at RUB. The two apparatuses are connected by the same manifold such that the two properties easily can be measured for the same mixtures.