Doctoral Candidate Tage Winther Maltby at the Department of Chemistry and Biomedical Science will hold a trial lecture and defend his doctoral thesis for the degree of Philosophiae Doctor (PhD). The degree is administered by the Faculty of Natural Sciences at the Norwegian University of Science and Technology (NTNU).
Thesis title
Incorporating Intermolecular Information in the Modeling of Solid–Fluid Equilibria
Trial lecture
Assigned topic: How Pure is Pure Enough for Carbon Dioxide Transportation and Storage?
Assessment Committee
The Faculty of Natural Sciences has appointed the following members to the assessment committee for the evaluation of the thesis:
First opponent: Professor Martin Trusler, Imperial College London, UK
Second opponent: Dr. Marco Campestrini, Mines Paris, PSL France
Chair of the committee: Dr. Marie-Laure Olivier, Department of Physics, NTNU
The committee has concluded that the thesis is worthy of public defense for the PhD degree.
Supervisors
Main supervisor: Professor Øivind Wilhelmsen, Department of Chemistry and Biomedical Science, NTNU
Co-supervisor: Associate Professor Anders Lervik, Department of Chemistry and Biomedical Science, NTNU
Co-supervisor: Adjunct Professor Morten Hammer, Department of Chemistry and Biomedical Science, NTNU
Time and venue
The PhD trial lecture and defence of the thesis are open to the public:
Trial lecture: 3 November 2026 at 10:15 – Disputasrommet, the Main Building, Gløshaugen, NTNU
Defence of the thesis: 3 November 2026 at 13:15 – Disputasrommet, the Main Building, Gløshaugen, NTNU
You may also follow the entire event, including the trial lecture and defence, online via Microsoft Teams:
https://events.teams.microsoft.com/event/b8f6e31f-c1d7-42b7-9638-78b1a5371da8@09a10672-822f-4467-a5ba-5bb375967c05
Thesis summary
The formation of solids in fluid mixtures can create challenges in industrial processes such as carbon capture and storage and hydrogen liquefaction, where dry ice and frozen impurities can obstruct pipes and equipment. Predicting the conditions under which solids form requires an accurate description of how temperature, pressure and mixture composition influence phase behaviour. This thesis develops and evaluates thermodynamic models for this purpose, with particular emphasis on systems containing carbon dioxide, argon and neon.
The work combines separate equations of state for the solid and fluid phases and incorporates information about interactions between atoms and molecules, including results from quantum chemistry. Extensive experimental data are used to assess and refine the models. The contributions include new reference equations of state for solid argon and neon, which reproduce most measured properties within experimental uncertainty and enable predictions of solid formation in mixtures. An extended fluid equation of state is also developed to accommodate more detailed descriptions of molecular interactions.
For the carbon dioxide mixtures investigated, the choice of fluid equation of state is found to influence predictions of solid formation more strongly than the choice between the two reference solid models tested. The thesis also examines how temperature, pressure and interactions between atoms affect transitions between different crystal structures. Together, these contributions demonstrate how molecular information can improve thermodynamic models and provide a foundation for more accurate predictions of phase behaviour in cryogenic systems.