Thermodynamic Modeling for CO2 Capture Systems

Process simulation of carbon capture processes requires the availability of thermodynamic models for CO2 capture systems. The focus of this PhD project is the experimental measurements and the thermodynamic modeling of solvent systems potentially used for CO2 capture. The solvent systems used for CO2 capture are usually aqueous solutions of alkanolamines, ammonia, amino acids, or carbonates. These are electrolyte systems. When carbon dioxide is dissolved in these aqueous systems there is an increase in ionic strength. The thermodynamic modeling of these systems can therefore only be done with electrolyte models.

In some solvent systems, a liquid-liquid split can occur at certain CO2 concentrations. One such system is the CO2 - diethylethanolamine (DEEA) - methylaminopropylamine (MAPA) - H2O system. The extended UNIQUAC model has previously been applied successfully to liquid-liquid equilibrium in aqueous electrolyte solutions with alcohols.

Experimentation regarding some of the properties (e.g. freezing point depression, heat of absorption and vapor-liquid equilibrium) of above chemicals is planned where the required data is not available in the literature.
In this work, the modeling of the above systems is planned to be carried out with the Extended UNIQUAC thermodynamic model for electrolyte systems.

Supervisor: Assoc. Prof. Kaj Thomsen:

Co-supervisor: Assoc. Prof. Nicolas von Solms,