Modelling the PhAse BehaviouR of Impure CO₂ Streams for Carbon Capture and Storage (CCS) Applications (MARCO2S)

We are recruiting for EPSRC & TWI (The Welding Institute) funded studentship  starting 1 October 2026. 

The project

The successful large-scale deployment of carbon capture and storage (CCS) depends on the safe and efficient transport of large quantities of CO₂. In most CCS systems, captured CO₂ is not pure. It contains varying concentrations of impurities such as NO_x, SO_x, O₂, N₂, H₂S, CH₄, H₂, NH₃, and water. These impurities can significantly influence the phase behaviour of CO₂, affecting the pressure-volume-temperature (PVT) relationships that underpin the design and operation of CO₂ transport and storage infrastructure, including pipelines and ships.

This PhD project will investigate the PVT behaviour of impure CO₂ streams, including an evaluation of the applicability of existing thermodynamic models and equations of state (EOS), and the development of modified or improved versions for CCS applications, including their validation. Successful completion of the project will reduce related uncertainties in the design and operation of critical CCS infrastructure.

Department 

Brunel Engineering already has established expertise in the areas of geological CO₂ storage (Principal Supervisor: Dr Lee Hosking, Civil Engineering) and CO₂ capture (Co-Supervisor: Dr Salman Masoudi Soltani, Chemical Engineering). This project provides an opportunity to bridge these research activities and will facilitate a growing critical mass in whole system CCS research. There is a clear pathway to follow-on projects. For example, the proposed research aligns with the EPSRC’s “energy and decarbonisation” theme, and specifically the “carbon capture and storage” research area. Specifically, this relates to the EPSRC’s stated emphasis on innovation supporting the successful integration of CCS technologies into current energy systems and the secure long-term storage of CO₂.

Expected impacts of project

A range of thermodynamic models and equations of state (EOS) are currently used to predict the PVT relationships of CO₂ mixtures. However, these models often have limited accuracy in the presence of multiple impurities and can fail near critical and triple point conditions.

This PhD project will investigate the PVT behaviour of impure CO₂ streams by:

• Evaluating existing EOS models and their applicability to CO₂ with multiple impurities.
• Assessing their performance near phase boundaries and critical regions using available experimental datasets.
• Developing improved or modified EOS models that better capture phase behaviour close to the edges of phase envelopes.
• Validating the developed models against benchmark data and exploring their implications for CO₂ transport.

The research will integrate thermodynamics, fluid phase equilibria, and advanced modelling approaches to aid the development of more reliable CO₂ transport systems.

Funding

• Stipend: approx. £23,805 (incl. Inner London weighting)
• Fees: Full-time Home tuition fees covered
• Duration: 42 months (3.5 years)
• Limited studentships (max 30% of intake) are available for international applicants, including EU.